bluuebunny/crossref_metadata_2025 huggingface dataset:
Barriers and Facilitators in the Delivery of Environmental Risk Reduction by Public Health Nurses in the Home Setting
Authors: Tinker Elizabeth , Postma Julie , Butterfield Patricia
Published: November 2010

ABSTRACT
Objective: The goal of this study was to identify the factors that contributed to or detracted from the ability of public health nurses (PHNs) to deliver environmental risk reduction (ERR) in the home setting.

Design and Sample: Structured one‐to‐one interviews were conducted with 10 PHNs from 2 county health departments in the western United States that were delivering an ERR intervention in a randomized clinical trial.

Results: Barriers to incorporating ERR into PHN practice were: a change in the perceived mission of public health, nurses' lack of environmental health (EH) training, the absence of a strong relationship with EH, the multidimensional role of PHNs, presentation of nurse participation by management, incorporation of ERR visits into nursing schedules, and challenges engaging parents in EH. Facilitating factors included: training and support, opportunities for capacity building, belief that ERR is important, building a more visible face for PHN, and personal interest in EH and ERR.

Conclusions: Adapting PHN practice to include ERR strategies is feasible, but not without challenges. With adequate training, time, and institutional support, multiple challenges can be overcome. PHNs are well positioned to improve the health of families and communities by integrating ERR into their scope of practice.
The Henry Street Consortium Population‐Based Competencies for Educating Public Health Nursing Students
Authors: Schaffer Marjorie A. , Cross Sharon , Keller Linda O. , Nelson Pamela , Schoon Patricia M. , Henton Pat
Published: November 2010

ABSTRACT
The Henry Street Consortium, a collaboration of nurse educators from universities and colleges and public health nurses (PHNs) from government, school, and community agencies, developed 11 population‐based competencies for educating nursing students and the novice PHN. Although many organizations have developed competency lists for experts, the Consortium developed a set of competencies that clearly define expectations for the beginning PHN. The competencies are utilized by both education and practice. They guide nurse educators and PHNs in the creation of learning experiences that develop population‐based knowledge and skills for baccalaureate nursing students. Public health nursing leaders use the competencies to frame their expectations and orientations for nurses who are new to public health nursing. This paper explains the meaning of each of the 11 population‐based competencies and provides examples of student projects that demonstrate competency development. Strategies are suggested for nurse educators and PHNs to promote effective population‐based student projects in public health agencies.
Meta‐analysis of the randomized controlled trials of the hemostatic efficacy and capacity of pathogen‐reduced platelets
Authors: Vamvakas Eleftherios C.
Published: November 2010

BACKGROUND: A recent independently funded randomized controlled trial (RCT; Br J Haematol 2010;150:209‐17) questioned prevailing opinion concerning the hemostatic capacity of pathogen‐reduced platelets (PLTs). Meta‐analysis was used to calculate the effect of pathogen reduction (PR) of PLTs on hemostatic efficacy and capacity based on all available data and to investigate possible reasons for the variation in reported findings.

STUDY DESIGN AND METHODS: RCTs allocating patients to receive routine PLT transfusions with pathogen‐reduced or untreated PLTs and reporting on at least one of six hemostasis endpoints were eligible for analysis. Five RCTs of hemato‐oncology patients met eligibility criteria. Endpoints determined by similar criteria in all RCTs were integrated by fixed‐effects methods. Endpoints determined by different criteria were integrated by random‐effects methods.

RESULTS: Studies were statistically homogeneous in all analyses. Pathogen‐reduced PLTs were associated with a significant (p < 0.05) reduction in 1‐ and 24‐hour posttransfusion corrected count increments (summary mean difference, 3260; 95% confidence interval [CI], 2450‐4791; and summary mean difference, 3315; 95% CI, 2027‐4603) as well as a significant increase in all and in clinically significant bleeding complications (summary odds ratio [OR], 1.58; 95% CI, 1.11‐2.26; and summary OR, 1.54; 95% CI, 1.11‐2.13). The frequency of severe bleeding complications did not differ.

CONCLUSION: The results of the recent RCT are not inconsistent with those of the earlier studies. Introduction of PR technologies in their current stage of development would result in an increase in mild and moderate (albeit not severe) bleeding complications, which the transfusion‐medicine community must explicitly tolerate to reap the benefits from PR.
The Use of Health Service Areas for Measuring Provider Availability*
Authors: M. Makuc Diane , Haglund Bengt , Ingram Deborah D. , Kleinman Joel C. , Feldman Jacob J.
Published: November 2010

ABSTRACT: Measurement of the availability of health care providers in a geographic area is a useful component in assessing access to health care. One of the problems associated with the county provider‐to‐population ratio as a measure of availability is that patients frequently travel outside their counties of residence for health care, especially those residing in nonmetropolitan counties. Thus, in measuring the number of providers per capita, it is important that the geographic unit of analysis be a health service area. We have defined health care service areas for the coterminous United States, based on 1988 Medicare data on travel patterns between counties for routine hospital care. We used hierarchical cluster analysis to group counties into 802 service areas. More than one half of the service areas include only nonmetropolitan counties. The service areas vary substantially in the availability of health care resources as measured by physicians and hospital beds per 100,000 population. For almost all of the service areas, the majority of hospital stays by area residents occur within the service area. In contrast/for 39 percent of counties, the majority of hospital stays by county residents occur outside the county. Thus, the service areas area more appropriate georgraphic unit than the county for measuring the availability of health care.
Rural Populations and Rural Physicians: Estimates of Critical Mass Ratios, by Specialty*
Authors: Hicks Lanis L. , Glenn John K.
Published: November 2010

ABSTRACT: As physicians and other providers of health care services see their traditional markets erode, an increasingly important element of any provider location decision is the determination of a population base or “critical mass” that can professionally and financially support a given set of health care services. While the size of a local population is not the sole determinant of success, ultimately an adequate population base to support a given spectrum of services must be defined, and providers increasingly need tools for evaluating opportunities in the new economic market. This is especially true in rural areas. An earlier supply and demand model for estimating the critical mass of population needed to support a physician in any one of 25 specialties and subspecialties in urban and suburban areas is adapted to the rural market. The assumptions inherent in the earlier model are examined and the issue of “critical mass” is examined from a rural health care perspective in this paper.
Future Trends in Nursing Practice and Technology*
Authors: Fuszard Barbara
Published: November 2010

ABSTRACT: Rural hospitals will be affected by changes in nursing anticipated in the future. Welcome changes will be the maturity and life experiences new graduates will bring to the work setting, knowledge of computers, and a broadening database. New graduates will also know various methods of care delivery, including case management, and will be able to select the delivery system that best meets the needs of the patients and institution. They will be more autonomous and possess leadership and management skills. With their knowledge of community as well as institutional nursing, they will be able to draw upon the skills of both groups to bring the two areas of nursing into continuity of care for patients. A difficulty ahead for rural hospitals is recruitment of new graduates, the majority of whom will have established families and lives elsewhere. And the practice of developing their own employees for higher levels of nursing will be compounded by the doubling of time necessary to complete nursing programs in the future.
The 1990s and Beyond: Determining the Need for Community Health and Primary Care Nurses for Rural Populations*
Authors: Hanson Charlene M.
Published: November 2010

ABSTRACT: Increased numbers of primary care and advanced practice nurses with unique generalist skills will be required to meet the accelerating physiologic and sociocultural health care needs of rural populations. Several factors have been identified that will influence the demands and position of community‐based nurses in rural practice settings during the next decade. A back‐to‐basics type of health care offered out of a growing elderly population; technological breakthroughs that make it possible for more chronically ill patients to live at home; serious substance abuse and other adolescent problems; AIDS; and high infant morbidity and mortality statistics are only some of the concerns that will demand nursing intervention. These changes speak to the need for improved nursing coordination, stronger collegial relationships, and better communication between physicians and nurses. Health care is moving in new directions to offer more efficient and technologically sophisticated care. These changes enhance the need for clinically expert educators who teach and jointly practice in programs with a rural focus. Telecommunications, and heightened computer literacy, will play a major role both in nursing education and clinical practice. The goals of kindergarten through 12th grade health promotion and disease prevention strategies in school health will be the norm and will require better prepared, and positions for, school nurses. More midwives and public health nurses will be needed to care for the growing population of sexually active adolescents who are in need of family planning and prenatal care. Underinsured and indigent populations will continue to fall within the purview of midlevel practitioners, as will providing anesthesia services in small rural hospitals. The transition of some rural hospitals into expanded primary care units (e.g., EACHs and RPCHs), and new models of case management will greatly influence nursing demands. This paper will further identify critical areas of advanced practice nursing within community settings, including new relationships with other health care providers, and will introduce strategies upon which rural health policy recommendations for the 1990s can be addressed.
Geographic Distribution of Physician Manpower: the GMENAC Legacy*
Authors: Jacoby Itzhak
Published: November 2010

ABSTRACT: The Graduate Medical Education National Advisory Committee (GMENAC) projected the need for and supply of physicians and other providers, recommended time and access standards for health care services, and developed guidelines for the geographic distribution of physicians. Since this study, analysts have given scant attention to national problems of physician geographic distribution. The issue deserves additional scrutiny in light of the current continuing problems of underservice in rural areas. The emergence of geographic information systems offers a unique opportunity to acquire data on provider distribution and provide a framework for developing and testing redistribution policy.
Determination of Nurse Adequacy in Rural Areas*
Authors: Moses Evelyn B.
Published: November 2010

ABSTRACT: The examination of the adequacy of nursing resources requires an analysis of a variety of factors. Because registered nurses primarily provide their services as employees of organized health care delivery structures, the number, size and type of these structures in an area are key to the nursing resources required and the nurse supply.
Challenges of antibacterial discovery revisited
Authors: Gwynn Michael N. , Portnoy Alison , Rittenhouse Stephen F. , Payne David J.
Published: November 2010

The discovery of novel antibiotic classes has not kept pace with the growing threat of bacterial resistance. Antibiotic candidates that act at new targets or via distinct mechanisms have the greatest potential to overcome resistance; however, novel approaches are also associated with higher attrition and longer timelines. This uncertainty has contributed to the withdrawal from antibiotic programs by many pharmaceutical companies. Genomic approaches have not yielded satisfactory results, in part due to nascent knowledge about unprecedented molecular targets, the challenge of achieving antibacterial activity by lead optimization of enzyme inhibitors, and the limitations of compound screening libraries for antibacterial discovery. Enhanced diversity of compound screening banks, entry into new chemical space, and new screening technologies are currently being exploited to improve hit rates for antibacterial discovery. Antibacterial compound lead optimization faces hurdles associated with the high plasma exposures required for efficacy. Lead optimization would be enhanced by the identification of new antibiotic classes with improved tractability and by expanding the predictability of in vitro safety assays. Implementing multiple screening and target identification strategies is recommended for improving the likelihood of discovering new antibacterial compounds that address unmet needs.
Comparison of kinematic symmetry index calculations and the effects of straight and circular trotting
Authors: WALKER A. M. , WILSON A. M. , PFAU T.
Published: November 2010

Reasons for performing study: When assessing lameness in horses, left to right ratios of kinematic parameters are often used to quantify movement symmetry. Different methods of symmetry related measures have been proposed and inertial sensor data was used to evaluate the application of 3 methods of symmetry calculation during straight and circular trotting.

Objectives: To compare 3 sensor based methods of symmetry index calculation to assess; tuber coxae vs. sacrum motion, the effects of circular trotting and effect of using whole trials in place of individual stride calculations.

Methods: Inertial sensors were attached to the sacrum, left and right tuber coxae (LTC/RTC) of 21 non‐lame horses. Straight and circular trotting data were collected. Symmetry indices based on vertical movement were calculated for each stride using 3 previously published methods.

Results: Method 2 (Fourier analysis) had significantly higher ratio values than method 1 (displacement amplitude ratio; tuber coxae) and methods 1 (displacement amplitude ratio; sacrum) and 3 (difference between LTC/RTC displacement). The effect of circular trotting within methods was highly variable, but was not significantly different between methods. No significant differences were found between whole trial and individual stride calculations. Method 2 when compared to method 1 underestimates the asymmetry present in a non‐uniform way due to the use of squared amplitudes. Methods 2 and 3 become less accurate during circular trotting due to changes in amplitude timing.

Conclusions: On the same data substantial differences in symmetry indices are found when using different methods and locations. Further differences exist in accuracy when used on circular data. Interpretation and direct comparison of different symmetry indices should be approached with caution.
Cortisol and haematochemical variables of horses during a two day trekking event: effects of preliminary transport
Authors: MEDICA P. , GIACOPPO E. , FAZIO E. , AVENI F. , PELLIZZOTTO R. , FERLAZZO A.
Published: November 2010

Reasons for performing study:Trekking is a noncompetitive sport, involving maximal skeletal muscle effort. Exercise and transport may involve significant energy expenditure and give rise to substantial stress. Few studies have examined the combined effect of exercise and additional preliminary transport on adrenocortical and haematochemical responses in horses during trekking.

Objectives:To ascertain whether exercise and additional preliminary transport before trekking would affect the circulating cortisol levels and haematochemical variables of horses during a 2 day trekking event.

Materials and methods:Twenty‐nine healthy horses were used. Twenty‐four horses were transported over distances of 70 km the day before trekking and 5 horses were stabled at the starting place. Blood samples were taken from horses at 16.00 h the day before trekking; and at 08.30 h and 17.30 h before and after the first day of trekking; at 08.30 h and at 13.30 h before and after the second day of trekking. Serum cortisol and haematochemical variables were determined in duplicate by using commercial test kits. One‐way analysis of variance for repeated measures (RM‐ANOVA) was applied to determine whether trekking and transport had any effects.

Results:Trekking significantly (P<0.01) affected total protein, albumin, urea, aspartate aminotransferase (AST), alanine aminotransferase (ALT), PCV and cortisol changes in transported horses and only urea and PCV (P<0.01) changes in untransported horses. Untransported horses showed lower basal total protein (P<0.05) and albumin (P<0.01) concentrations, higher urea concentrations (P<0.001) at the second day and lower cortisol levels after the first and the second (P<0.05) day of trekking than transported horses.

Conclusion:These data show that the preliminary transport stress induced additional significant changes of cortisol and haematochemical patterns in horses after trekking.
Dehydration, electrolyte imbalances and renin‐angiotensin‐aldosterone‐vasopressin axis in successful and unsuccessful endurance horses
Authors: MUÑOZ A. , RIBER C. , TRIGO P. , CASTEJÓN‐RIBER C. , CASTEJÓN F. M.
Published: November 2010

Reason for performing study:Limited information exists concerning the defence of homeostasis during endurance competitions and the relationship with performance.

Objectives:This research analysed renin (REN), angiotensin II (ANG), aldosterone (ALD) and vasopressin (AVP) in horses covering different distances, assesses differences between successful and eliminated horses and evaluates correlations between hydration status, renal function, electrolytes, REN, ANG, ALD and AVP.

Methods:Packed cell volume (PCV), velocity and serum concentrations of REN, ANG, ALD, AVP, Na, K, Cl, Ca, Mg, P, creatine kinase, aspartate aminotransferase, lactate dehydrogenase, total proteins (TSP), albumin (ALB), serum ureic nitrogen (SUN), creatinine (CREAT) and lactate were analysed in both successful horses (SH) and in horses eliminated due to metabolic problems (MH). Two types of competition were studied: 91 km in one day (Competition A: 20 SH, 9 MH) and 166 km in 2 days, 83 km/day (Competition B: 10 SH and 5 MH).

Results:Research analysed renin was not affected by exercise, whereas ANG, ALD and AVP increased. In the SH group, resting ALD and AVP concentrations at the beginning of the second day ofCompetition Bwere higher than preride values. Vasopressin did not change during the second day ofCompetition B, whereas ALD progressively increased. Metabolic problems of both groups showed more evident dehydration (higher PCV, TSP, ALB, SUN and CREAT) and electrolyte alterations (more intense decreases of Na and Cl) than SH at the different sampling times. Metabolic problems presented higher ALD and AVP concentrations. Angiotensin II was higher at certain sampling times in the horses.

Conclusions:Endurance horses with dehydration and electrolyte disturbances showed a more intense activation of the REN‐ANG‐ALD‐AVP axis.

Potential relevance:The study of the response of the REN‐ANG‐ALD‐AVP axis during prolonged exercise in horses with different performance will aid to minimise the risk of metabolic diseases during competitions.
Endurance veterinarians detect physiologically compromised horses in a 160 km ride
Authors: BARNES A. , KINGSTON J. , BEETSON S. , KUIPER C.
Published: November 2010

Reasons for performing study:This study investigated the physiology of endurance horses competing in warm weather over technical terrain, a situation where horses may become metabolically compromised.

Hypotheses:There will be changes in physiological, haematological and biochemical variables as horses progress through the 160 km ride and horses detected clinically at the veterinary inspections as metabolically compromised will have significant differences in measured laboratory variables compared to horses that complete the ride successfully.

Methods:Forty‐eight horses competing in the Australian Tom Quilty 160 km endurance ride were monitored and weighed, and blood samples collected for analysis of electrolytes, packed cell volume (PCV), plasma protein and acid‐base variables, preride, mid‐ride, at the end of their ride and the following morning after a period of recovery. Statistical analysis was performed using multinomial logistic regression and repeated measures ANOVA.

Results:Of the 48 horses participating in the study, only 18 successfully completed the ride (SC), 16 were eliminated for lameness (VOL) and 10 for metabolic reasons (VOM); 4 were voluntarily withdrawn by the riders. A lighter preride bodyweight was predictive for VOM. PCV and total plasma protein increased mid‐ride in all groups compared to preride, with significantly greater increases in PCV for VOM compared to the other horses. Changes were detected in blood concentrations of sodium, chloride and calcium over time and between the groups, with lower mid‐ride sodium and chloride in VOM compared to SC and VOL.

Conclusions:VOM horses weighed less preride and were, on analysis of blood and physiological variables mid‐ride, more dehydrated with greater electrolyte depletion than the SC or VOL horses.
The effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine
Authors: SLEUTJENS J. , VOORHOUT G. , Van Der KOLK J. H. , WIJNBERG I. D. , BACK W.
Published: November 2010

Reasons for performing study: In dressage, the head and neck position has become an issue of concern as certain extreme positions may imply a welfare risk for the horse. In man, extension and flexion of the cervical spine cause a decrease and increase in intervertebral foramina dimensions, respectively. However, in horses, the influence of flexion and extension on foramina dimensions and its possible interference with peripheral nerve functioning remains unknown.

Objectives: To determine the effect of ex vivo flexion and extension on intervertebral foramina dimensions in the equine cervical spine.

Methods: Computed tomography was performed on 6 cadaver cervical spines from adult Warmblood horses subjected to euthanasia for reasons unrelated to cervical spine abnormalities, in a neutral position, in 20 and 40° extension, and in 20 and 40° flexion. Multiplanar reconstructions were made to obtain transverse images perpendicular to the long axis of each pair of intervertebral foramina from C2–T1. Intervertebral foramina dimensions were measured in the 5 positions.

Results: Compared to the neutral position, 40° extension caused a decrease in foramina dimensions at segments C4–C5, C5–C6, C6–C7 (P<0.001) and C7–T1 (P<0.002); 20° extension caused a decrease in foramina dimensions at segments C5–C6 (P<0.02), C6–C7 (P<0.001) and C7–T1 (P<0.01); 20° flexion caused an increase in foramen length at segment C6–C7 (P<0.01).

Conclusions: Ex vivo extension of the cervical spine causes a decrease in intervertebral foramina dimensions at segments C4–T1, similar to that found in man.

Potential relevance: In vivo extension of the cervical spine could possibly interfere with peripheral nerve functioning at segments C4–T1. This effect may be even more profound in patients with a reduced intervertebral foramina space, for example in the presence of facet joint arthrosis.
Effects of three warm‐up regimens of equal distance onV̇o2kinetics during supramaximal exercise in Thoroughbred horses
Authors: MUKAI K. , HIRAGA A. , TAKAHASHI T. , OHMURA H. , JONES J. H.
Published: November 2010

Reasons for performing study:Several studies have indicated that even low‐intensity warm‐up increases O2transport kinetics and that high‐intensity warm‐up may not be needed in horses. However, conventional warm‐up exercise for Thoroughbred races is more intense than those utilised in previous studies of equine warm‐up responses.

Objectives:To test the hypothesis that warm‐up exercise at different intensities alters the kinetics and total contribution of aerobic power to total metabolic power in subsequent supramaximal (sprint) exercise in Thoroughbred horses.

Methods:Nine well‐trained Thoroughbreds ran until fatigue at 115% of maximal oxygen consumption () 10 min after warming‐up under each of 3 protocols of equal running distance: 400 s at 30%(LoWU), 200 s at 60%(MoWU) and 120 s at 100%(HiWU). Variables measured during exercise were rates of O2and CO2consumption/production (,), respiratory exchange ratio (RER), heart rate, blood lactate concentration and accumulation rate and blood gas variables.

Results:was significantly higher in HiWU than in LoWU at the onset of the sprint exercise andHRwas significantly higher in HiWU than in LoWU throughout the sprint. Accumulation of blood lactate,RER,Paco2andin the first 60 s were significantly lower in HiWU than in LoWU and MoWU. There were no significant differences in stroke volume, run time or arterial‐mixed venous O2concentration.

Conclusions:These results suggest HiWU accelerateskinetics and reduces reliance on net anaerobic power compared with LoWU at the onset of the subsequent sprint.
Efficacy of single‐dose intravenous phenylbutazone and flunixin meglumine before, during and after exercise in an experimental reversible model of foot lameness in horses
Authors: FOREMAN J. H. , GRUBB T. L. , INOUE O. J. , BANNER S. E. , BALL K. T.
Published: November 2010

Reasons for performing study:Objective blinded efficacy data during exercise are lacking on the use of single‐dose i.v. nonsteroidal anti‐inflammatory drugs (NSAIDs) before, during and after exercise.

Hypothesis:Single i.v. doses of either phenylbutazone (PBZ) or flunixin meglumine (FM) would prove more efficacious than negative saline control (SAL) before, during and after exercise in a reversible model of foot lameness.

Methods:Six Quarter Horse mares had lameness induced by tightening a set screw against a heart bar shoe 1 h prior to treatment. Randomised blinded treatments included PBZ (4.4 mg/kg bwt i.v.), FM (1.1 mg/kg bwt i.v.), and SAL (1 ml/45 kg i.v.). Heart rate and lameness score (LS) were recorded at rest; every 20 min after lameness induction for 5 h and at the end of 2 min treadmill workloads of 2 and 4 m/s. Heart rate was also recorded from 0.5–60 min post exercise. Results were compared using RM ANOVA and Student‐Newman‐Keul's test (HR) and Wilcoxon signed rank test (%ΔLS) with significance set at P<0.05.

Results:Pre‐exercise mean HR was decreased for both NSAIDs compared to SAL from 1:20–4 h post treatment (P<0.05). Pre‐exercise mean %ΔLS was decreased for PBZ (1:20–4 h) and FM (1–4 h) compared to SAL (P<0.01). With exercise, there were no HR differences between treatments (P>0.05), but mean %ΔLS was decreased for both NSAIDs compared to SAL (P<0.01). Mean recovery HR was decreased for PBZ and FM from 1–60 min compared to SAL (P<0.05).

Conclusions:PBZ and FM demonstrated definitive clinical efficacy after single i.v. doses before, during and after exercise. Use of single i.v. doses during competition may mask lameness and may affect the ability of judges in determining the soundness of horses in competition.
Nutrition‐associated problems facing elite level three‐day eventing horses
Authors: LEAHY E. R. , BURK A. O. , GREENE E. A. , WILLIAMS C. A.
Published: November 2010

Reasons for performing study: The main goal of feeding elite 3‐day event horses is to deliver nutrients in optimal amounts to allow the horse to maximize its health and performance. However, improper nutritional management and/or physiological stressors related to intense training and competition may increase the risk of nutrition‐associated disorders in these horses. An understanding of the nutrition‐associated problems contributing to poor performance is critical to the health and welfare of the horse.

Objectives: To characterize the nutrition‐associated problems affecting top level 3‐day event horses during 2008.

Methods: Contact information for riders competing in the 2 highest levels of 3‐day eventing in 2008 was obtained from the United States Eventing Association. A survey containing 10 questions pertaining to participant demographics and nutrition‐associated problems experienced by their horses was mailed and e‐mailed to the 81 individuals fitting our criteria of living in USA and Canada. Data was collected in April and May 2009.

Results: Twenty‐nine of 81 riders completed the survey (35.8%). Respondents rode a total of 45 horses in top level 3‐day events in 2008. The top 5 nutrition‐associated problems that horses faced at a significantly higher level than the other problems (P<0.0001) were gastric ulcers (42.2%), joint problems (37.7%), decreased appetite (31.1%), weight loss (31.1%) and hyperexcitability (22.2%). There was no significant difference in frequency of problems between home and competition (P = 0.22).

Conclusions: Horses competing at a high level of 3‐day eventing in 2008 were at risk of reduced performance given the significant rate of gastric ulcers, decreased appetite and weight loss. Research addressing specific causes of and/or feeding management changes that would reduce the incidence of these problems in these horses is needed to ensure optimal health and performance.
Effects of short‐term training on thermoregulatory and sweat responses during exercise in hot conditions
Authors: McCUTCHEON L. J. , GEOR R. J.
Published: November 2010

Reasons for performing study:There is evidence that extensive training in cool conditions results in improvements to heat dissipation that contribute to successful acclimatisation. In horses, the effects of a less extensive training regimen have not been determined.

Objective:This study investigated whether 10 consecutive days of moderate intensity treadmill training in cool conditions would improve thermoregulatory and sweating responses of horses to exercise in the heat.

Methods:Six unfit Thoroughbred horses completed a standardised treadmill exercise test (SET) in hot, dry conditions (32–34°C, 45–55% RH) before (SET1) and after (SET2) 10 consecutive days of running at 55% VO2maxfor 60 min in cool conditions (19–21°C, 45–55% RH). Each SET consisted of a 5 min warm‐up and cool down at a walk, 40 min of trotting (50% VO2max), 7 min at 75% VO2maxand a 30 min standing recovery. Bodyweight was determined pre‐ and post SET. Heart rate, rectal, skin, pulmonary artery and muscle temperatures were measured throughout the SETs and sweating rate (SR) and sweat ion losses determined for each 5 min interval.

Results:Following training, mean VO2maxincreased by 8.9% (P<0.05). In SET2, PCV was lower during the last 30 min of exercise and end‐exercise rectal, muscle and pulmonary artery temperatures were decreased by 1.5 ± 0.2, 0.8 ± 0.1 and 1.0 ± 0.2°C, respectively (P<0.05). Peak SR and the pattern of sweat ion losses during exercise was unchanged post training whereas SR and sweat losses during recovery were decreased (P<0.05).

Conclusions:Similar SRs for a given core temperature during exercise but a more rapid decrease in recovery resulted in an overall reduction in sweat fluid losses with no change in sweat ion losses after training.

Relevance:The results provide insight into the extent to which short‐term training can improve the capacity of horses to exercise in hot conditions.
The effect of exercise regimens on racing performance in National Hunt racehorses
Authors: ELY E. R. , PRICE J. S. , SMITH R. K. , WOOD J. L. N. , VERHEYEN K. L. P.
Published: November 2010

Reasons for performing study: A previous study has identified exercise undertaken during training to be associated with racing performance in flat racehorses. However, no such studies have been conducted in National Hunt (NH) horses.

Aim: To determine whether exercise undertaken during training is associated with racing performance in NH racehorses.

Methods: Data were collected as part of a larger study investigating injury occurrence in NH racehorses. Race records and daily exercise data were obtained from NH racehorses at 14 training yards. Canter, gallop and race distances accumulated in the 30 days preceding a ‘case race’ were calculated. Associations between exercise‐, horse‐ and race‐level variables and the odds of winning, winning prize money, being pulled up and falling were identified using mixed effects logistic regression.

Results: Data from 4444 races run by 858 horses were included in analyses. Horses accumulating longer canter distances in the preceding 30 days were more likely to win or win prize money and less likely to be pulled‐up. Horses accumulating longer race distances in a 30 day period were more likely to win, whilst those accumulating longer gallop distances in a 30 day period were more likely to win prize money. Horses that had jump‐schooled in the preceding 30 days were more likely to fall during the race than those that had not. Trainer and horse were associated with racing performance after adjusting for exercise.

Conclusions: Results from this study suggest that NH race performance may be improved through modification of exercise regimens. After controlling for the abilities of individual trainers and horses and conditions of the case race, horses accumulating longer exercise distances in the 30 days preceding a race were more likely to be successful. However, horses that had jump‐schooled in the 30 days preceding a race were more likely to fall.
The relationship between massage to the equine caudal hindlimb muscles and hindlimb protraction
Authors: HILL C. , CROOK T.
Published: November 2010

Reasons for performing study: Massage is widely used in physiotherapy, but there has been little previous research examining its effectiveness in increasing equine soft tissue length.

Objectives: To determine the effect of massage on equine hindlimb protraction. We hypothesised that massage to the caudal muscles of the equine hindlimb, specifically the superficial gluteal, semitendinosus, biceps femoris and semimembranosus muscles, can increase passive and active hindlimb protraction.

Materials and methods: The study used a crossover design in which 8 horses were randomly assigned to 2 groups of 4, A and B. Group A received massage for 30 min, group B received sham treatment for 30 min. The procedure was repeated following a 7 day ‘washout’ period, when group A received the 30 min sham treatment and group B, 30 min of massage. Passive hindlimb protraction was measured before and after each intervention, using a modified version of the human ‘Sit and Reach test’ for general muscle flexibility. Active protraction was measured using 2 dimensional kinematic analysis of stride length. The data analysis used the Wilcoxon signed rank test at a significance of P<0.05.

Results: Massage to the caudal limb muscles significantly increased passive (P = 0.01) and active limb (P = 0.01) protraction.

Conclusions: This study indicates that massage can increase protraction of the equine hindlimb. Massage may, therefore, play a valuable role in the development of strategies used to improve a horse's locomotor function, e.g. during rehabilitation or optimum performance for competition.
Serum amyloid A level as a potential indicator of the status of endurance horses
Authors: CYWINSKA A. , GORECKA R. , SZARSKA E. , WITKOWSKI L. , DZIEKAN P. , SCHOLLENBERGER A.
Published: November 2010

Reasons for performing study: Changes in serum levels of acute phase proteins (APPs) reflect the acute phase reaction, a rapid and nonspecific response to any tissue damage. Serum amyloid A (SAA) is the main APP in horses, which increases in various diseases, surgical injuries and after long distance endurance rides; however, this nonspecific parameter has not been investigated as an indicator of subclinical disorders, which may result in elimination during endurance competitions.

Objectives: To evaluate the serum concentration of SAA as a potential indicator for the status of horses prepared for long distance endurance rides (120 and 160 km).

Materials and methods: Twenty Arabian horses were tested and 12 were eliminated during the ride and 8 completed the distances. Routine haematological and biochemical tests and measurement of serum concentrations of SAA were carried out before and after the competition. Results were compared using the Mann Whitney U test.

Results: Before the competition all haematological and biochemical parameters varied within reference ranges with no differences between the eliminated horses and the ones that successfully finished the competition. After the rides creatine phosphokinase activity and neutrophil: lymphocyte ratio reflecting exercise‐induced leukogram changes increased (P<0.05) in both groups. Before the competition, the concentration of SAA remained within reference ranges; however, it was significantly (P<0.05) lower in horses that successfully finished the competition than in eliminated ones (411.7 ± 144 ng/ml vs. 5809.5 ± 2242.7 ng/ml). After the ride SAA levels increased (P<0.05) and were similar in both groups (13 833.8 ± 1354.3 ng/ml and 12 831.2 ± 1317.6 ng/ml).

Conclusions: Serum SAA level was the only laboratory parameter that indicated most (66.6%) of the eliminated horses before entering the competition. None of the horses with SAA level higher than 1000 ng/ml completed the distance. Thus, it may be postulated that serum SAA concentration may indicate a poor status of a horse, resulting in elimination during a competition.
A preliminary model study of the equine back including activity of longissimus dorsi muscle
Authors: GROESEL M. , ZSOLDOS R. R. , KOTSCHWAR A. , GFOEHLER M. , PEHAM C.
Published: November 2010

Reasons for performing study: Identifying the underlying problem of equine back pain and diseases of the spine are significant problems in veterinary orthopaedics. A study to validate a preliminary biomechanical model of the equine back based on CT images including longissimus dorsi (LD) muscle is therefore important.

Objectives: Validation of the back model by comparing the shortening of LD muscles in the model with integrated EMG (IEMG) at stance during induced lateral flexion of the spine.

Methods: Longissimus dorsi muscle activity at stance has been used for validation. EMG electrodes were placed laterally at the level of T12, T16 and L3. Reflective markers have been attached on top of the spinous processes T5, T12, T16, L1 and the sacral bone (OS1, OS2) for motion tracking analysis. A virtual model of the equine's back (T1–S5) was built with inclusion of a simplified LD muscle by 2 separate contours left and right of the spine, starting at tuber coxae laterally and attaching to the spinous process T5 medially. Shortening of LD during induced lateral flexion caused by the kinematic data (input) was compared to the 3 EMG signals (T12, T16 and L3) on the active side via correlation.

Results: Pearson correlation coefficient between IEMG and shortening length of LD in the model was (mean ± s.d.) 0.95 ± 0.07 for the left side and 0.91 ± 0.07 for the right side of LD.

Conclusions: Activity of the LD muscles is mainly responsible for stabilisation of the vertebral column with isometric muscle contraction against dynamic forces in walk and trot. This validation requires muscle shortening in the back, like induced lateral flexion at stance. The length of the shortening muscle model and the IEMG show a linear relationship. These findings will help to model the LD for forward simulations, e.g. from force to motion.
The effect of sildenafil citrate administration on selected physiological parameters of exercising Thoroughbred horses
Authors: COLAHAN P. T. , JACKSON C. A. , RICE B. , SZABO N. , JONES J. H.
Published: November 2010

Reasons for performing study:Sildenafil, a phosphodiesterase‐5 inhibitor vasodilator, increases cGMP concentrations by inhibiting enzymatic degradation. Marketed to treat erectile dysfunction in men, it also reduces pulmonary arterial pressure (PAP). Because it reduces PAP, sildenafil may enhance performance and/or prevent exercise induced‐pulmonary haemorrhage (EIPH).

Objective:To determine if sildenafil citrate administration altered commonly measured indices of performance or reduced EIPH in exercised horses.

Methods:Thirteen athletically conditioned Thoroughbred horses (2 mares and 11 geldings, age 3–12 years) were administered sildenafil citrate or placebo in 2 crossover design exercise testing studies. In a step‐wise test to exhaustion, inspired/expired gas analysis, blood lactate, heart rate, runtime and bronchoalveolar lavage (BAL) cytology were measured. In a 13 m/s test to exhaustion, blood lactate, heart rate, runtime, BAL cytology and pulmonary arterial pressure were measured. Data were analysed with paired and unpairedttests, one‐way ANOVA and Tukey's pair‐wise multiple comparison and Friedman repeated measure analysis of variance on ranks.

Results:The administration of sildenafil did not alter mean inspired/expired gas measurements, plasma lactate concentrations or acute pulmonary haemorrhage in either exercise test or pulmonary arterial pressure measurement in the 13 m/s trial. Heart rates in both stress tests were significantly different at submaximal speeds and during the early recovery period. Run time was not affected by sildenafil administration in the step‐wise trial (P = 0.622) or in the 13 m/s trial (P = 0.059).

Conclusions:Sildenafil did not alleviate pulmonary haemorrhage or enhance performance‐related indices in these trials. Sildenafil administration altered cardiovascular adaptation to intense exercise as evidenced by altered heart rates at submaximal speeds and post exercise. The effect of these alterations on other performance perimeters was not evident.
The role of tendon stiffness in development of equine locomotion with age
Authors: ADDIS P. R. , LAWSON S. E. M.
Published: November 2010

Reasons for performing study:The flexor tendons support the metacarpophalangeal (MCP) and distal interphalangeal (DIP) joints during stance phase and since tendon stiffness and strain changes with age, it is likely that kinematics are also age‐dependent.

Hypothesis:Maximum MCP and DIP angles decrease in the young horse, plateau in the mature horse and increase towards senescence.

Methods:The distal limbs of 57 walking horses age 3–212 months were filmed and digitised with an automated tracking system. Maximum MCP and DIP angles during stance phase were used to calculate strain in the superficial and deep digital flexor tendons. Horses were divided into 3 age groups; young (3–35 months), mature (36–99 months) and older horses (100–212 months). Pearson's correlation coefficients were calculated to determine the relationship between age and kinematics.

Results:Tendon strain decreased in young horses, stayed constant in mature horses and increased in older horses. Joint angles showed significant negative correlation in young horses, with coefficients of −0.88 (MCP) and −0.81 (DIP). In mature horses, correlations were not significant (P = 0.2 for MCP; P = 0.5 for DIP). In older horses, angles showed significant positive correlation, with coefficients of 0.62 (MCP) and 0.48 (DIP).

Conclusions:Joint angles decreased in the young horse as tendon stiffness increases, remained constant in the mature horse where tendon stiffness is constant and increased in older horses as tendons weakens and stiffness decreases. Strain patterns were similar to those foundin vitro.

Potential relevance:Changing tendon stiffness appeared to influence the development and degeneration of gait. This has implications for studying musculoskeletal development, especially for identification of normal and pathological development.
Effects of flunixin on cardiorespiratory, plasma lactate and stride length responses to intense treadmill exercise in Standardbred trotters
Authors: KALLINGS P. , PERSSON S. G. B. , ESSÉN‐GUSTAVSSON B.
Published: November 2010

Reasons for performing study:Since nonsteroidal anti‐inflammatory drugs, such as flunixin, on account of their anti‐inflammatory and analgesic properties, are used in both racing and equestrian sport horses, the question has been raised as to whether these drugs affect the physiological responses to exercise and thus performance potential.

Objectives:The aims of this investigation were to study the effects of flunixin on cardiorespiratory, metabolic and locomotor parameters in horses during intense treadmill exercise.

Methods:Six Standardbred trotters underwent an incremental treadmill exercise test to fatigue, without drug and then after administration of flunixin meglumine (1.1 mg/kg bwt i.m.). Heart rate (HR), oxygen uptake and stride length were measured and venous blood samples drawn repeatedly during the test.

Results:Heart rates were found to be significantly higher at submaximal speeds, while the velocity causing a HR of 200 beats/min was significantly decreased after treatment with flunixin. Maximal HR and plasma lactate concentration 5 min after exercise were unchanged after medication. Flunixin caused higher plasma lactate concentrations at all speeds and the lactate threshold was decreased, compared with baseline values. Oxygen uptake levelled off at the highest velocities and did not change after flunixin treatment. Stride length was increased after treatment, although not at the highest velocities.

Conclusion:The increased HR and lactate responses to exercise after flunixin treatment indicate that it does influence physiological responses, but does not improve the performance potential of clinically healthy horses. However, the lengthened stride during submaximal exercise after medication could imply undetected subclinical lameness, masked in some of the horses, i.e. they have performed with a longer stride at the cost of a higher heart rate and an increased lactate concentration.
Triple-Choking Model for Ejector
Authors: Sargolzaei J. , Pirzadi Jahromi M. R. , Saljoughi E.
Published: November 2010

In this study, a 1D analysis has been presented for the prediction of ejector performance at critical mode operation. The new triple-choking model has been developed using the governing equations of the compressible fluids and thermodynamics properties based on the frictional adiabatic fluid study. A new approach has been introduced to consider the frictional effects on the mixing efficiencies by extending the 1D ejector theory. A very good agreement has been reported for the R141b and steam experimental data at critical mode operation. Furthermore, simulated results have been compared with some of the recent theoretical models. In addition, the influence of operation conditions on the ejector performance and the required cross-sectional area of the mixing chamber has been showed. Finally, the influence of the operation conditions (such as generator, condenser, and evaporator temperatures) and the size of ejector on the mixing efficiency have been studied.