bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigations on the ability of clenbuterol hydrochloride to reduce clinical signs and inflammation associated with equine influenza A infection
Authors: KÄSTNER SABINE B. R. , HAINES DEBORAH M. , ARCHER JOY , TOWNSEND H. G. G.
Published: April 2010

Twenty‐four Quarter Horse and Quarter Horse‐cross yearlings were experimentally infected with influenza A virus (Influenza A/equine/Saskatoon/90 [H3N8]) by nebulisation. In a double blind controlled trial the horses were randomly assigned to 3 groups of 8 animals.Group 1received a placebo, (carrier syrup),Group 2the labelled dose andGroup 3twice the labelled dose of clenbuterol hydrochloride. All treatments were givenper osb.i.d. for 10 days and started on the day of infection. The horses were monitored for clinical signs of influenza infection for 14 days. Bronchoalveolar lavages were performed 4 days prior to, and 5 and 13 days after infection. Cell counts and concentrations of prostaglandin E2and prostaglandin F2αin the lavage fluid were determined. Blood samples for haematology and serology were taken 4 days before, on the day of infection, 5, 9 and 13 days after infection. All horses experienced a typical influenza infection with fever, coughing and secondary bacterial infections with mainlyActinobacillusspp. andStreptococcusspp. There was no statistically or clinically significant effect of treatment with clenbuterol hydrochloride on measured clinical or laboratory parameters within 14 days of infection.
New approaches to detect cortisol administration in the horse
Authors: POPOT M. A. , LACABARATZ E. , GARCIA P. , LAROUTE V. , BONNAIRE Y. , TOUTAIN P. L. , COWAN D. A.
Published: April 2010

The cortisol threshold concentration of 1.0 μg/ml in horse urine adopted by the International Federation of the racing Authorities in 1994 is specific. However, an increase in the sensitivity for the detection of cortisol administration would be helpful. Previous studies have shown that 20β‐dihydrocortisol concentration in urine would be a good indicator of cortisol administration. The purpose of the present work was to estimate the population parameters and the critical values of 20β‐dihydrocortisol and 20β‐dihydrocortisone concentration in urine compared with that of cortisol. Using the same probability (1.1 times 10−4) which was used for the establishment of the official cortisol threshold, the critical values of 5000 ng/ml for 20β‐dihydrocortisol and 350 ng/ml for 20β‐dihydrocortisone were obtained. Considering these 2 critical values for 20β‐dihydrocortisol and 20β‐dihydrocortisone, the time during which a horse could be declared positive is significantly increased.
Attenuation by phenylbutazone of the renal effects and excretion of frusemide in horses
Authors: DYKE T. M. , HINCHCLIFF K. W. , SAMS R. A.
Published: April 2010

The objectives of this study were to determine the effect of phenylbutazone premedication on the pharmacokinetics and urinary excretion of frusemide in horses; and on frusemide‐induced changes in urinary electrolyte excretion. Six Standardbred mares were used in a 3‐way crossover design.

The pharmacokinetics and renal effects of frusemide (1 mg/kg bwt i.v.) were studied with and without phenylbutazone premedication (8.8 mg/kg bwtper os24 h before, followed by 4.4 mg/kg bwt i.v. 30 min before frusemide administration). A control (saline) treatment was also studied.

Administration of frusemide without phenylbutazone led to diuresis, natriuresis, kaliuresis and chloruresis, and altered the ratio of sodium:chloride excretion from 0.4 to 1.0 in the first hour of diuresis. When frusemide and phenylbutazone were administered, sodium and chloride excretion in the first hour were significantly (P<0.05) reduced by 40 and 32%, respectively, when compared to frusemide administration without phenylbutazone. The fractional clearance of sodium and chloride was also significantly reduced. Potassium excretion, potassium fractional clearance and the ratio of sodium to chloride excretion were not affected by administration of phenylbutazone. During peak diuresis, phenylbutazone did not affect the efficiency of frusemide with respect to electrolye excretion.

The plasma disposition of frusemide was not affected by phenylbutazone. However, the renal excretion of frusemide decreased by approximately 25%. We conclude that the decreased urinary excretion of frusemide by phenylbutazone led to an attenuation of frusemide‐induced increases in urinary excretion of sodium and chloride. Since the efficiency of frusemide was not affected by phenylbutazone, we conclude that phenylbutazone attenuates the renal excretion of frusemide without inhibiting the intrarenal activity of frusemide in horses.
Histopathological findings in equine sinonasal disorders
Authors: TREMAINE W. H. , CLARKE C. J. , DIXON P. M.
Published: April 2010

Biopsies collected from 79 referred cases of equine sinonasal disease, including 27 horses with primary sinusitis, 10 with secondary dental sinusitis, 19 with sinus cysts, 11 with progressive ethmoid haematomata (PEH), 4 with false nostril epidermal inclusion cysts, 4 with sinonasal polyps, 3 with sinonasal mycosis and from 2 control animals were examined histologically. Observations were made on epithelial type and integrity, cellular inflammatory response, fibroplasia and presence of potential pathogens. Chronic inflammatory changes including mucosal thickening, ulceration and significant fibroplasia, were found in the sinus mucosa with most sinus disorders, similar to those found in human chronic sinusitis. Bacteria were variably present on sinusitis mucosae but their aetiological significance was unclear. The presence of apparently irreversible changes including fibroplasia in some of these sinusitis cases may explain their poor or delayed response to treatment. Sinus cysts had histological similarities to human mucocoeles. Progressive ethmoid haematomata showed recent and older haemorrhage, as did sinus cysts (and occasionally some chronic sinusitis sections), but support for a common aetiology between sinus cysts and PEH was absent.
Results of treatment of 145 fractures of the third metacarpal/metatarsal condyles in 135 horses (1986–1994)
Authors: ZEKAS LISA J. , BRAMLAGE L. R. , EMBERTSON R. M. , HANCE S. R.
Published: April 2010

The objectives of this study were to correlate condylar fracture characteristics and type of treatment with subsequent capacity for athletic ability, and to determine the characteristics of healing that affect prognosis after fracture fixation. Medical records, post operative radiographic studies and race records were examined for 135 horses sustaining 145 fractures. Sixty‐five percent of horses overall started in a race post injury (SPI) in a mean time of 9.7 months with a mean of 13.7 races post injury. Having raced pre‐injury did not confer an advantage to starting post injury, though nonstarters pre‐injury tended to take longer to return. For horses starting pre‐ and post injury, 66% improved or maintained their race class level after injury, whereas 64.2% decreased their race earnings post injury. Eighty‐five percent of the fractures received internal fixation, of which 70% were complete fractures. Eighty‐seven percent of horses with incomplete‐nondisplaced fractures treated conservatively raced post injury. The percent SPI for incomplete‐nondisplaced, complete‐nondisplaced and complete‐displaced fractures treated with internal fixation were 74%, 58%, and 60%, respectively. Males (72%) raced post injury more frequently than fillies (53%), and may represent a truer probability of SPI. Spiral fractures tended to take longer until their first start (mean 13.3 months). Fifty‐two percent of horses with articular fragments were able to race post injury. Horses were more likely to start if 2–4 month radiographic healing revealed no evidence of the fracture except the presence of lag screws. Based on this series of cases, the majority of horses, with proper treatment, were able to return to racing regardless of fracture characteristic. Prognosis appeared to be affected by the severity of the injury to the joint, the presence of articular comminution and the quality of surgical repair.
Ambient temperature and relative humidity influenced packed cell volume, total plasma protein and other variables in horses during an incremental submaximal field exercise test
Authors: HARGREAVES BELINDA J. , KRONFELD D. S. , NAYLOR J. R. J.
Published: April 2010

Thermoregulation may limit exercise performance under hot and humid conditions. This study compared heart rate (HR), respiratory rate (RR), rectal temperature (Tr), packed cell volume (PCV) and total plasma protein concentration (TPP) during a submaximal incremental field exercise test under high vs. low ambient temperature and relative humidity. Ten horses were tested 3 times in summer (July) and 3 times in autumn (September). Heart rate was measured continuously, the other variables at rest and immediately after 4 min at 3.5, 4.5 and 7.0 m/s, separated by 3 min rest intervals, and after 5 and 10 min recovery. Data for ail variables were significantly greater during exercise and recovery in the hot vs. cool conditions, respectively: after 4 min at 7.0 m/s, HR was 135 ± 1 and 123 ± 1/min (P<0.0001), Tr was 39.0 ± 0.06 and 38.0 ± 0.05°C (P<0.0001), RR was 99 ± 3 and 50 ± 3/min (P<0.0001), PCV was 48.8 ± 0.06 and 42.1 ± 0.3% (P<0.0001) and TPP was 7.7 ± 0.14 and 7.6 ± 0.12 g/l (P = 0.026). These data reflect the thermal burden during submaximal exercise under hot conditions in the field. The greater relative PCV increase in the heat probably conferred a thermoregulatory advantage and reflected a greater circulating red cell volume increase rather than a decrease of plasma volume. This study illustrates how differences in environmental conditions can affect assessment of exercise responses and how these factors must be considered in monitoring progress during fitness and acclimatisation regimes in the field.
Matrix metalloproteinase‐2 and −9 are activated in joint diseases
Authors: CLEGG P. D. , CARTER S. D.
Published: April 2010

A study was performed to identify the activation status of the gelatinase MMPs, MMP‐2 and −9, in both normal and diseased equine articular tissues. In addition, the production and activation status of equine MMP‐2 and −9 by equine articular cells and tissues in response to increasing IL‐1β concentrations was assessed. The study was performed to test the hypothesis that activation of MMPs is a fundamental step in the pathogenesis of joint diseases; and that this activation is mediated by the cytokine IL‐1.

Using purified equine MMP‐2 and −9, the molecular weights of the zymogen and activated form of equine MMP‐2 and −9 were identified by a combination of gelatin zymography and a gelatin degradation assay using aminophenylmercuric acetate as a chemical activator of the molecules. Normal equine articular tissues (cartilage and synovial membrane) maintained in short‐term tissue culture produced MMP‐2 zymogen alone, while similar tissues obtained from a variety of pathological conditions produce both zymogen and active MMP‐2, as well as MMP‐9 monomer and dimer. Activated MMP‐9 was an inconsistent finding. Normal equine synovial fibroblasts in monolayer culture produced zymogen MMP‐2 alone under basal conditions. A mild increase in active and zymogen MMP‐2 levels occurred with IL‐1β treatment. Equine synovial membrane explants demonstrated a dose‐dependent increase in active and zymogen MMP‐2 and MMP‐9 levels following IL‐1β treatment. Monolayer chondrocyte cell cultures demonstrated a dose‐dependent mild increase in active and zymogen MMP‐2 following IL‐1β treatment. Explant cartilage cultures demonstrated a dose‐dependent mild increase in zymogen MMP‐2 alone following IL‐1β treatment.

This study supports the hypothesis that activation of MMPs is occurring in joint disease, and thatin vitrostimulation of equine articular cells and tissues causes not only an increase in MMP production, but also an increase in amount of activated enzyme released. Further research is required to investigate the role of MMP activation in joint diseases, and to investigate the potential use of therapeutic agents, which inhibit MMP activation, in the treatment and prevention of joint diseases.
Horse vision and an explanation for the visual behaviour originally explained by the ‘ramp retina’
Authors: HARMAN ALISON M. , MOORE S. , HOSKINS R. , KELLER P.
Published: April 2010

Here we provide confirmation that the ‘ramp retina’ of the horse, once thought to result in head rotating visual behaviour, does not exist. We found a 9% variation in axial length of the eye between the streak region and the dorsal periphery. However, the difference was in the opposite direction to that proposed for the ‘ramp retina’. Furthermore, acuity in the narrow, intense visual streak in the inferior retina is 16.5 cycles per degree compared with 2.7 cycles per degree in the periphery. Therefore, it is improbable that the horse rotates its head to focus onto the peripheral retina. Rather, the horse rotates the nose up high to observe distant objects because binocular overlap is oriented down the nose, with a blind area directly in front of the forehead.
Age‐related changes to the molecular and cellular components of equine flexor tendons
Authors: BIRCH HELEN L. , BAILEY J. V. B. , BAILEY A. J. , GOODSHIP A. E.
Published: April 2010

Specific tendons show a high incidence of partial central core rupture which is preceded by degeneration. In the performance horse, the superficial digital flexor tendon (SDFT) is most often affected. We have described previously the molecular changes that are associated with degeneration in the central core region of the equine SDFT. The pathophysiological mechanism leading to change in synthetic activity of central zone cells in degenerated tendons is not known. In this study, we test the hypothesis that ageing results in matrix composition changes within the central zone of the SDFT. Extracellular matrix composition and cellularity were analysed in equine SDFTs collected from Thoroughbred horses and compared with a flexor tendon which rarely shows degenerative change and subsequent injury (deep digital flexor tendon, DDFT). Data were examined for age‐related changes to central and peripheral zone tissue of the SDFT and DDFT. Ageing in both tendons (SDFT and DDFT) resulted in a significant increase in collagen‐linked fluorescence and a decrease in cellularity in the DDFT but not the SDFT. The central zone tissue from the SDFT had a significantly higher proportion oftype IIIcollagen than the peripheral zone of the tendon. The highest level oftype IIIcollagen was found in the central zone tissue of the SDFT from the older group of horses and this may represent the early stages of a degenerative change. Collagen content did not differ between the 2 flexor tendons; however, there were differences in collagen type and organisation. The SDFT had a highertype IIIcollagen content, higher levels of the mature trifunctional collagen crosslink hydroxylysylpyridinoline, lower total chondroitin sulphate equivalent glycosaminoglycan content, smaller diameter collagen fibrils and a higher cellularity than the DDFT. In conclusion, differences in macromolecular composition exist between the flexor tendons and ageing contributes to a tendon specific change in composition.
Analysis of video‐recorded images to determine linear and angular dimensions in the growing horse
Authors: HUNT W. F. , THOMAS V. G. , STIEFEL W.
Published: April 2010

Studies of growth and conformation require statistical methods that are not applicable to subjective conformation standards used by breeders and trainers. A new system was developed to provide an objective approach for both science and industry, based on analysis of video images to measure aspects of conformation that were represented by angles or lengths. A studio crush was developed in which video images of horses of different sizes were taken after bone protuberances, located by palpation, were marked with white paper stickers. Screen pixel coordinates of calibration marks, bone markers and points on horse outlines were digitised from captured images and corrected for aspect ratio and ‘fish‐eye’ lens effects. Calculations from the corrected coordinates produced linear dimensions and angular dimensions useful for comparison of horses for conformation and experimental purposes. The precision achieved by the method in determining linear and angular dimensions was examined through systematically determining variance for isolated steps of the procedure. Angles of the front limbs viewed from in front were determined with a standard deviation of 2–5 degrees and effects of viewing angle were detectable statistically. The height of the rump and wither were determined with precision closely related to the limitations encountered in locating a point on a screen, which was greater for markers applied to the skin than for points at the edge of the image. Parameters determined from markers applied to the skin were, however, more variable (because their relation to bone position was affected by movement), but still provided a means by which a number of aspects of size and conformation can be determined objectively for many horses during growth. Sufficient precision was achieved to detect statistically relatively small effects on calculated parameters of camera height position.
Clinical, haematological and biochemical findings in foals with neonatal Equine herpesvirus‐1 infection compared with septic and premature foals
Authors: PERKINS GILLIAN , AINSWORTH DOROTHY M. , ERB H. N. , DEL PIERO F. , MILLER M. , WILKINS PAMELA A. , PALMER J. , FRAZER M.
Published: April 2010

A retrospective multicentre study comparing historical, clinical, haematological, acid‐base and biochemical findings of foals with Equine herpesvirus‐1 (EHV‐1) infection, septicaemia or prematurity was performed to determine if early diagnosis of EHV‐1 foals was possible. Fifty‐three foals were studied and were assigned to one of 2 groups: herpes positive (n = 14) or herpes negative (n = 39). The latter group included 20 septic, 11 premature, and 8 premature and septic foals. The presence of herpes antigen was confirmed by immunoperoxidase histochemical staining of tissues from necropsied foals. A nonparametric statistical analysis followed by a backwards elimination logistic regression was performed to establish a model at a P value of <0.05.

All herpes positive foals died, while 47% (9/19) of the septic foals survived. Based upon our analysis, herpes positive foals were more likely to have total white blood cell counts less than 3 times 109/l and to be icteric as compared to the septic and premature foals. Despite profound hepatic necrosis in the herpes positive foals, liver enzymes were not elevated and were not significantly different from the controls.
Radiological study to evaluate suspected scapulohumeral joint dysplasia in Shetland ponies
Authors: BOSWELL JANE C. , SCHRAMME M. C. , WILSON A. M. , MAY S. A.
Published: April 2010

A radiological study was performed to test the hypothesis that osteoarthritis of the scapulohumeral joint in Shetland ponies is secondary to shoulder dysplasia. Animals were selected into 3 groups:Group 1: Shetland ponies with a radiological and clinical diagnosis of scapulohumeral osteoarthritis (n = 8),*Group 2: Shetland ponies without forelimb lameness (n = 12);Group 3: Horses/ponies without a history or clinical signs of forelimb lameness (n = 22). Anatomical indices were measured from mediolateral radiographs of a scapulohumeral joint from each animal.

There was a significant difference in the mean radius of curvature of the glenoid cavity of the scapula (RCG) between the 3 groups (MANOVA test, P = 0.003). The mean RCG of bothGroup 1(P = 0.001) and Group 2 (P = 0.022) was significantly greater than that ofGroup 3.There was no significant effect of group on the radius of curvature of the humeral head or on the Conformity Index. There was a significant effect of group on the Glenoid Ratio (MANOVA test, P = 3 times 10‐6). The mean Glenoid Ratio was significantly lower in bothGroup 1(P = 2 times 106) and inGroup 2(P = 0.006) than inGroup 3.These results indicate that the glenoid cavity of the scapula is ‘flatter’ and ‘shallower’ in Shetland ponies which we postulate to be a primary dysplasia in this breed.
A survey of white line disease in Japanese racehorses
Authors: KUWANO A. , TANAKA K. , KAWABATA M. , OOI Y. , TAKAHASHl T. , YOSHIHARA T. , REILLY J. D.
Published: April 2010

A survey was carried out into white line disease in 1781 Thoroughbred racehorses kept in stables at the Japan Racing Association (JRA) Miho Training Center (MTC) September‐October 1996. The survey was conducted while horses were being shod by farriers. The horses that still exhibited damaged white lines after regular trimming were diagnosed as having white line disease. The factors recorded were age, sex, number of diseased horses, number of diseased hooves, number of lesions by region over the bearing border of the hoof and the classified length of such lesions. The percentage of total diseased horses was 11.5% (204 animals), with incidence increasing significantly with age (P<0.01). Occurrence was independent of sex (P>0.05) was more frequent in the fore‐ than in the hindhoof and developed more frequently at the toe than at any other region of the forehoof‐bearing border. Most lesions ranged from 20 to 30 mm in length.
Equine dental disease Part 2: a long‐term study of 400 cases: disorders of development and eruption and variations in position of the cheek teeth
Authors: DIXON P. M. , TREMAINE W. H. , PICKLES KIRSTIE , KUHNS LORNA , HAWE CARLYN , McCANN JACQUI , McGORUM B. C. , RAILTON D.I. , BRAMMER STEPHANIE
Published: April 2010

Of 400 referred horses with dental disorders, 349 cases suffered from primary disorders of their cheek teeth, ninety of these from disorders of development or eruption, or displacements. These included 20 cases with rostral maxillary and caudal mandibular cheek teeth overgrowths, 16 with diastemata, 15 with grossly enlarged mandibular ‘eruption cysts’, 4 with grossly enlarged maxillary cheek teeth ‘eruption cysts’, 10 cases with supernumerary cheek teeth and 23 cases with displaced cheek teeth. These displacements were believed to be developmental in 16 cases and acquired in the remaining 7 cases. Long‐term response to treatments, that included removal of overgrowths and extraction of teeth with deep secondary periodontal disease was excellent for most disorders except diastemata.
External skeletal fixation in the management of equine mandibular fractures: 16 cases (1988–1998)
Authors: BELSITO K. A. , FISCHER A. T.
Published: April 2010

Fifty‐three cases of equine mandibular fractures were managed surgically from 1988–1998, of which 16 (30%) were repaired by external skeletal fixation (ESF). Three surgical methods were utilised: transmandibular 4.76 or 6.35 mm Steinmann pins incorporated into fibreglass casting material or nonsterile dental acrylic (methyl methacrylate ‐ MMA) bars reinforced with steel; transmandibular 9.6 mm self‐tapping threaded pins ± 4.76 or 6.35 mm Steinmann pins incorporated into MMA bars reinforced with steel; and 4.5 mm or 5.5 mm ASIF cortical bone screws incorporated into MMA bars reinforced with steel or a ventral MMA splint. Fourteen horses were presented to the hospital for fixator removal at an average of 56.2 days. At removal, fractures were stable and occlusion of incisor and cheek teeth was considered adequate. Complications of the procedure occurred in 3 horses. Two horses with persistent drainage and ring sequestra from pin tracts required curettage 4 or 5 months after ESF removal. A third horse required replacement of the original fibreglass ESF with MMA bars to regain access to open, infected wounds. Another horse required removal of the second premolar at the time of fixator removal because the tooth root had been damaged in the original injury. ESF for the surgical management of mandibular fractures in horses has produced good results, with incisive and cheek tooth alignment reestablished in all horses. Horses that were managed via ESF had a rapid return to full feed and did not require any supplementation via nasogastric tube or oesophagostomy to maintain bodyweight or hydration status.
Assessment of the rate of solid‐phase gastric emptying in ponies by means of the13C‐octanoic acid breath test: a preliminary study
Authors: WYSE C. A. , MURPHY D. M. , PRESTON T. , MORRISON D. J. , LOVE S.
Published: April 2010

The aim of this study was to assess the feasibility of applying the13C‐octanoic acid breath test for assessment of gastric emptying in ponies by investigating the pattern of13C enrichment in breath following the administration of a test meal ±13C‐octanoic acid. After a 14 h fast, the ponies received either no meal(Test I)or a standardised test meal labelled with 0 mg(Test II), 125 mg(Test III), 250 mg(Test IV)or 500 mg(Test V)13C‐octanoic acid. For each test (I‐V), exhaled breath samples were collected in duplicate at 1 h and immediately before ingestion of the test meal and at frequent intervals thereafter for 12 h. Breath samples were analysed by continuous flow isotope ratio mass spectrometry. Three indices of breath13C‐enrichment were computed; half dose recovery time (t 1/2), gastric emptying coefficient (GEC) and time to peak breath13C‐enrichment t(max). ForTests IandII, the ratio of13CO2:12CO2remained stable for the duration of the sampling period. ForTests III, IVandV, an increase in the ratio of13CO2:12CO2was detected. The test was reproducible within individuals, and intersubject variation was low. Further validation studies of this noninvasive technique are justified.
Semitheoretical Model of an Evaporator to Reduce Design Cycle Time
Authors: Zietlow David , Spurgeon Dan A.
Published: April 2010

Original equipment manufacturers are looking for ways to reduce the product development cycle. A tool to reduce this time in the design of air conditioning systems is introduced in this paper. This is done by using a semitheoretical model of each of the components of a system. The semitheoretical model has the advantage of reducing the number of geometrical inputs that need to be specified when compared with a “theoretical” model. This paper focuses on the most complex of the components—the evaporator. A tube and fin evaporator was successfully modeled and validated. The model was tuned using supplier component data (Luvata, 2005, Heatcraft Evaporator—Version 3.07.05.122 B-DHLEX.EVP) for the evaporator. The tuned accuracy of heat transfer rate and pressure drop, both air- and refrigerant-side, was within 5% over the range of conditions representative of air conditioning applications.
A Study on Mechanical Damage of Tumor Microvasculature Induced by Alternate Cooling and Heating
Authors: Shen Yuanyuan , Zhang Aili , Xu Lisa X.
Published: April 2010

Tumor microvascular damage caused by the alternate cooling and heating treatment was found much more severe than that of cooling or heating alone from our previous experimental studies. The induced stresses on the vessel wall are expected to play an important role in vascular damage. Both thermal and mechanical stresses are involved due to the rapid changes in temperature and blood reperfusion during the treatment. To investigate the stress effect, theoretical modeling and numerical simulations have been performed in the present study. Thermal stresses on the tumor microvessel wall during the freezing process are analyzed using the elastic models through the coupled field method. To simulate mechanical stresses induced by blood reperfusion, the fluid and structural mechanics are coupled on the interface between the blood flow domain and the vessel wall. Numerical results show that the thermal stress on the vessel wall is negative in the tumor center, indicating the compression effect during the freezing process. The magnitude of the radial stress reaches 2.5×107 dyn/cm2. During the postheating process, the nonuniform stress distribution exists in the tortuous periphery vessel wall owing to the irregular structures, and higher stresses normally appear at the vessel bifurcations. Synergy of the thermal and mechanical stresses on the vessel wall play critical roles in damaging of the heterogeneous tumor vasculature during the alternate cooling and heating treatment. Results obtained in the present study are expected to help better understand the vascular injury process, and to develop a more effective thermal treatment protocol for tumor therapy.
Numerical Study of Natural Convective Heat Transfer in a Two-Dimensional Cavity With Centrally Located Partition Utilizing Nanofluids
Authors: Anilkumar S. H. , Kuzhiveli Biju T.
Published: April 2010

A two-dimensional single-phase natural convective heat transfer in a cavity with centrally located thin partition utilizing nanofluids has been numerically analyzed. The nanofluid used, which is composed of aluminum nanoparticles in suspension of Benzene, was provided at various solid volume fractions. The study is carried out numerically for a range of Rayleigh numbers, solid volume fractions, partition heights, and aspect ratios. Regions with the same velocity and temperature distributions are identified as a symmetry of sections. One-half of such a rectangular region is chosen as the computational domain, taking into account the symmetry about the thin partition. The governing equations are modeled by a stream function-vorticity formulation and are solved numerically by finite-difference schemes. Comparison with previously published numerical and experimental results showed excellent agreement. It is demonstrated that the partition height has a strong effect on both the heat transfer rate and the flow pattern. Results are presented in the form of streamlines and isotherm plots. The variation in the local Nusselt number along the thin partition provides valuable insight into the physical processes. A new correlation is proposed for the heat transfer studies in a wide range of thermal and geometric parameters.
Minimum Mass Polymer Seawater Heat Exchanger for LNG Applications
Authors: Luckow P. , Bar-Cohen A. , Rodgers P.
Published: April 2010

The present study explores the thermofluid characteristics of a corrosion-resistant, thermally enhanced polymer composite, seawater-methane heat exchanger module for use in the liquefaction of natural gas on offshore platforms. Several metrics, including the heat transfer rate, the mass-specific heat transfer rate, and the total coefficient of performance (COPT), are used to compare the thermal performance of polymer composites having a range of thermal conductivities with that of corrosion-resistant metals. For operating conditions considered typical of the natural gas liquefaction industry in the Persian Gulf, a 10 W/m K polymer composite is found to provide nearly identical heat transfer rate to that of a corrosion-resistant titanium heat exchanger, almost 50% higher mass-specific heat transfer than for titanium (at 200 W pumping power), and COPT values approximately twice that of a least-material titanium heat exchanger. The results contribute to establishing the viability of using polymer composites for gas-liquid heat exchanger applications involving seawater and other corrosive fluids.
Mechanism of ultrathin tunnel barrier failure due to mechanical-stress-induced nanosized hillocks and voids
Authors: Tyagi Pawan , Hinds Bruce J.
Published: April 2010

Understanding the failure mechanisms of ultrathin insulators is critical for reliably improving the device life of tunneling magnetoresistance devices, Josephson junctions, and novel molecular electrodes. The relaxation of mechanical stresses forms nanosized defects causing the failure of ultrathin ∼2-nm alumina (Al2O3) insulators. Wafer curvature, atomic-force microscopy, and transmission-electron microscopy show that stress relaxation dramatically changed the morphology of ultrathin insulators. Time evolution of compressive stresses formed the nanohillocks, resulting in metallic shorts between two metal electrodes. The time evolution of tensile-stress relaxation fractured the insulator film to produce nanosized voids. These defects adversely affected the tunnel-barrier life and the junctions failed without the application of breakdown voltage. Deleterious effects of the stresses were mitigated by optimizing the insulator-growth methodology with a two-step process. The present work emphasizes the need to complement electrical-breakdown tests with the study of mechanical stresses and corresponding morphological changes for the comprehensive understanding of a tunnel-barrier failure mechanism.
Small RNA Duplexes Function as Mobile Silencing Signals Between Plant Cells
Authors: Dunoyer Patrice , Schott Gregory , Himber Christophe , Meyer Denise , Takeda Atsushi , Carrington James C. , Voinnet Olivier
Published: April 2010

siRNA Movement in Plant Tissues

Long-distance movement of RNA interference (RNAi)–derived signals in plants plays an important role in development and in defense against viral attack. The nature of the signals that spread from cell to cell is not known, although evidence suggests that they are nucleic acids of some sort (see the Perspective by

Martienssen

).

Molnar
et al.

(p.
872
, published online 22 April) and

Dunoyer
et al.

(p.
912
, published online 22 April) now show that in
Arabidopsis
, both exogenous and endogenous small interfering RNAs (siRNAs), rather than their long double-stranded precursor RNAs, are the molecules that transfer information between plant cells. A viral protein that counters RNAi though sequestering siRNAs blocked spreading of a transgene RNAi silencing signal. Furthermore, siRNA-processing enzymes were required in the source, and not the recipient, cells for spreading, and bombardment of plants with double-stranded siRNAs directly showed siRNA spread between cells. Endogenous siRNAs also spread between tissues and were capable of directing DNA methylation of target sequences in distant tissues.
Small Silencing RNAs in Plants Are Mobile and Direct Epigenetic Modification in Recipient Cells
Authors: Molnar Attila , Melnyk Charles W. , Bassett Andrew , Hardcastle Thomas J. , Dunn Ruth , Baulcombe David C.
Published: April 2010

siRNA Movement in Plant Tissues

Long-distance movement of RNA interference (RNAi)–derived signals in plants plays an important role in development and in defense against viral attack. The nature of the signals that spread from cell to cell is not known, although evidence suggests that they are nucleic acids of some sort (see the Perspective by

Martienssen

).

Molnar
et al.

(p.
872
, published online 22 April) and

Dunoyer
et al.

(p.
912
, published online 22 April) now show that in
Arabidopsis
, both exogenous and endogenous small interfering RNAs (siRNAs), rather than their long double-stranded precursor RNAs, are the molecules that transfer information between plant cells. A viral protein that counters RNAi though sequestering siRNAs blocked spreading of a transgene RNAi silencing signal. Furthermore, siRNA-processing enzymes were required in the source, and not the recipient, cells for spreading, and bombardment of plants with double-stranded siRNAs directly showed siRNA spread between cells. Endogenous siRNAs also spread between tissues and were capable of directing DNA methylation of target sequences in distant tissues.
Clear cell sarcoma of tendons and aponeuroses, and osteoclast-rich tumour of the gastrointestinal tract with features resembling clear cell sarcoma of soft parts: a review and update
Authors: Kosemehmetoglu Kemal , Folpe Andrew L
Published: April 2010

Clear cell sarcoma (CCS) is a rare, distinctive soft tissue neoplasm, typically occurring in the distal extremities of young adult patients. Although CCS shows melanocytic differentiation, it is now clear that it is clinicopathologically and genetically distinct from conventional malignant melanoma. The ‘osteoclast-rich tumour of the gastrointestinal tract with features resembling clear cell sarcoma of soft parts’ is an extraordinarily rare gastrointestinal neoplasm that shares some features of CCS, but differs from it in other ways. The historical, histopathological, ultrastructural, immunohistochemical and genetic aspects of these two tumours are reviewed in this article.
The HLA system: immunobiology, HLA typing, antibody screening and crossmatching techniques
Authors: Howell W M , Carter V , Clark B
Published: April 2010

The Human Leukocyte Antigen (HLA) system plays a critical role in regulating the immune response. As a consequence of its role in immune regulation and exquisite polymorphism, the HLA system also constitutes an immunological barrier which must be avoided or otherwise overcome in clinical transplantation. This introductory review provides a brief summary of the immunobiology of the HLA system and methodology for HLA typing, antibody screening and patient-donor cross-matching. This constitutes a basis for consideration of the importance of these procedures in the system-specific reviews which follow.
Infundibular carcinoma of the skin: a distinct morphological and immunohistochemical entity
Authors: Haykal Siba , Al Habeeb Ayman S , Goldstein David P , Murray Christian A , Ghazarian Danny
Published: April 2010

This report describes a new entity which has been defined as infundibular carcinoma (IC) of the skin. This new entity must be distinguished from other basaloid carcinomas arising from the epidermis, the hair follicles or from sweat duct and glandular elements. Specific criteria have been used to define ICs. These include the macroscopic and the microscopic site of the tumour as well as its histomorphological and immunohistochemical patterns. A brief review of benign and malignant tumours of the pilar unit and the differential diagnosis of IC is also provided.
Some Toxic Constituents of Chlorination-Stage Effluents from Bleached Kraft Pulp Mills
Authors: McKague A. B.
Published: April 2010

Constituents responsible for the toxicity of a sample of bleached kraft chlorination-stage effluent to juvenile rainbow trout (Salmo gairdneri) were investigated. Tetrachlorocatechol, 3,4,5-trichlorocatechol, and 2,6-dichlorohydroquinone were identified and evidence was obtained for the presence of other chlorodihydroxybenzenes in toxic acidic fractions of the sample. Concentrations of 0.46 mg/L 3,4,5-trichloro- and 0.74 mg/L tetrachloro-catechol were estimated in the sample by analytical gas chromatography. Toxic materials in the nonacidic fraction were not identified although the nontoxic dichloromethyl methyl sulfone was isolated.Key words: chlorination-stage effluent, toxicity, pulp mill, chlorocatechols, chlorodihydroxybenzenes
The First Diets of Postemergent Brook Trout (Salvelinus fontinalis) and Atlantic Salmon (Salmo salar) Alevins in a Quebec River
Authors: Williams D. Dudley
Published: April 2010

In the Matamek River, Quebec, brook trout (Salvelinus fontinalis) and Atlantic salmon (Salmo salar) coexist. The trout alevins emerge from the redds in early June and the salmon ~1 mo later. The first diet of the trout consists primarily of small- to medium-sized invertebrates passing in the water column. Among the most common items are blackfly larvae and zooplankton derived from an upstream lake. The alevins also feed at the water surface and take considerable numbers of emerging adults of orthocladine chironomids. There appears to be diel variation in the importance of various dietary species. The salmon alevins hold station in faster water and tend to feed more from the substrate on medium- to large-sized invertebrates. Their first meals include large stonefly nymphs, chironomid pupae, and larval dytiscid beetles. The salmon also feed extensively on adult chironomids and caddisflies as they emerge at the water surface. All of these items are important in the diet of the older brook trout at this time. The concept of food availability is discussed.Key words: brook trout, Atlantic salmon, alevins, feeding behavior, invertebrates, drift
Temporal, Intra-population Differences in Energy Allocation and Use by American Shad (Alosa sapidissima) During the Spawning Migration
Authors: Glebe B. D. , Leggett W. C.
Published: April 2010

The intra-population tissue weight dynamics and bioenergetics of American shad (Alosa sapidissima) were studied during the freshwater migration in the Connecticut River. Emphasis was on the extent and significance of temporal differences in the magnitude and rate of depletion of stored body reserves. This was accomplished by the comparison of body reserves of shad sampled at various locations and times along the migratory route. Somatic weight loss and associated energy depletion was extreme (45–60%); up to 50 and 70% of available body protein and lipid, respectively, were used to fuel the migration. The extent of reserve depletion was sex- and size-specific. Small individuals and males suffered the greatest tissue depletion. High water temperatures accounted for the reduced energy efficiency of late migrant shad (average of 42 vs. 24 KJ∙kg−1∙km−1 expended by earlier migrants), and resulted in, greater depletion of total body reserves. More extensive depletion may contribute to the higher mortality reported among this component of the population. Gonad development was complete prior to entry into the river. This may spare somatic reserves during the freshwater fast and hence maximize survival. The pattern and extent of energy utilization in other anadromous fish species are discussed with reference to possible influence on demographic parameters, especially the repeat spawning habit.Key words: American shad, Alosa sapidissima; energetics, allocation, weight loss, temporal differences, Connecticut River, migration
Latitudinal Differences in Energy Allocation and Use During the Freshwater Migrations of American Shad (Alosa sapidissima) and Their Life History Consequences
Authors: Glebe B. D. , Leggett W. C.
Published: April 2010

We studied the relationships between tissue dynamics and bioenergetics of the anadromous American shad (Alosa sapidissima) homing to the St. Johns (Fla.), York (Va.), and Connecticut (Conn.) Rivers and the life history characteristics of these populations. Shad in the three populations studied differed in the degree of development of the gonads at river entry, in the absolute and relative energy allocation to reproductive products vs. migration, and in the extent of total energy depletion during the migration. St. Johns River fish consumed 70–80% of their total energy reserves to reach the spawning grounds and spawn. In this population all shad die following spawning. York River shad consumed ~30% and Connecticut River shad 40–60% of their energy reserves to migrate to the spawning grounds, spawn, and return to the sea. In these populations 25 and 35%, respectively, of the spawning adults survive to spawn again. The principal determinants of energy use were migration distance and river gradient. We rejected the hypothesis that the latitudinal cline in adult survival results from differences in energy use during migration. We concluded that interpopulation differences in energy allocation to migration vs. reproduction are a consequence, rather than a cause, of the different life history strategies exhibited by populations of shad over its Atlantic Coast range. A similar pattern is apparent in other anadromous species: obligate semelparous species use > 70% of their energy reserves to reach the spawning areas and spawn; iteroparous species allocate more energy to postreproductive reserves at the expense of reproductive products thereby ensuring a successful return migration to the sea. Freshwater swimming speeds also appear to differ in a consistent way between semelparous and iteroparous species. Semelparous species swim at close to maximum sustained speed thereby minimizing the duration of the migration. Iteroparous species swim at speeds yielding near optimum energy efficiency (J∙kg−1∙km−1) thereby minimizing the energy cost of migraiton.Key words: American shad, (Alosa sapidissima); migration, bioenergetics, life history tactics, latitudinal clines, swimming speeds, energy allocation, anadromy
Deep-water eelpouts, Zoarcidae, from Arctic Canada and Alaska
Authors: McAllister Don E. , Anderson M. Eric , Hunter J. G.
Published: April 2010

Lycodes sagittarius and Gymnelus retrodorsalis are reported from Canada for the first time; L. eudipleurostictus and L. squamiventer are reported from Alaska for the first time, extending their known ranges 2400 and 4000 km, respectively; the known range of L. rossi is extended over 1300 km eastward, L. seminudus 1900 km southwestward, and the known range of L. frigidus over 6500 km eastward. Descriptions and synonymies are presented. Keys to these and other species of Zoarcidae from Canada are provided.Key words: Zoarcidae, Arctic, Canada, Gymnelus, Lycodes, eelpouts, Alaska
Growth Patterns in Sand Lance, Ammodytes dubius, from the Grand Bank
Authors: Winters G. H.
Published: April 2010

Growth patterns in sand lance (Ammodytes dubius) from the Grand Bank were examined using back-calculated lengths from otolith measurements. Lee's phenomenon of apparent change in growth rate with age is clearly demonstrated as is the phenomenon of growth compensation. Lee's phenomenon is explained by discriminatory mortality of the faster-growing sand lance whereas growth compensation is attributed to the differing ages of maturity of the initial faster-growing and slower-growing fish. The significant reduction in the standard deviation and the increasing degree of left skewness in length frequencies of older sand lance is explained by a combination of Lee's phenomenon and growth compensation acting together throughout the growth history of individual sand lance.Key words: sand lance, growth, back-calculation. Grand Bank
ON IRREDUCIBLE FACTORS OF THE POLYNOMIAL f(x) - g(y)
Authors: ENGLER A. J. , KHANDUJA SUDESH K.
Published: April 2010

In this paper, all irreducible factors of bivariate polynomials of the form f(x) - g(y) over an arbitrary field are described. It also proves that the number of irreducible factors of f(x) - g(y) (counting multiplicities) does not exceed the greatest common divisor of the degrees of f(x) and g(y), yielding a well known result of Tverberg regarding the irreducibility of f(x) - g(y). It proves that if f(x) and g(y) are non-constant polynomials with coefficients in the field ℚ of rational numbers and deg f(x) is a prime number, then f(x) - g(y) is a product of at most two irreducible polynomials over ℚ. This contributes to a problem raised by Cassels which asks for the polynomials f, such that the polynomial [Formula: see text] is reducible.
CHEN–RUAN COHOMOLOGY OF SOME MODULI SPACES, II
Authors: BISWAS INDRANIL , PODDAR MAINAK
Published: April 2010

Let X be a compact connected Riemann surface of genus at least two. Let r be a prime number and ξ → X a holomorphic line bundle such that r is not a divisor of degree ξ. Let [Formula: see text] denote the moduli space of stable vector bundles over X of rank r and determinant ξ. By Γ we will denote the group of line bundles L over X such that L⊗r is trivial. This group Γ acts on [Formula: see text] by the rule (E, L) ↦ E ⊗ L. We compute the Chen–Ruan cohomology of the corresponding orbifold.