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Insight problems are likely to trigger an initial, incorrect mental representation, which needs to be restructured in order to find the solution. Despite the widespread theoretical assumption that this restructuring process happens suddenly, leading to the typical "Aha!" experience, the evidence is inconclusive. Among the reasons for this lack of clarity is that many measures of insight rely solely on the solvers' subjective experience of the solution process. In our previous paper, we used matchstick arithmetic problems to demonstrate that it is possible to objectively trace problem-solving processes by combining eye movements with new analytical and statistical approaches. Specifically, we divided the problem-solving process into ten (relative) temporal phases to better capture possible small changes in problem representation. Here, we go a step further to demonstrate that classical statistical procedures, such as ANOVA, cannot capture sudden representational change processes, which are typical for insight problems. Only nonlinear statistical models, such as generalized additive (mixed) models (GAMs) and change points analysis, correctly identified the abrupt representational change. Additionally, we demonstrate that explicit hints reorient participants' focus in a qualitatively different manner, changing the dynamics of restructuring in insight problem solving. While insight problems may indeed require a sudden restructuring of the initial mental representation, more sophisticated analytical and statistical approaches are necessary to uncover their true nature. [ABSTRACT FROM AUTHOR]

Insight problems are likely to trigger an initial, inappropriate mental representation, which needs to be restructured in order to find the solution. Despite the widespread theoretical assumption that this restructuring process happens suddenly, which leads to the typical Aha! experience, the evidence is inconclusive. Among the reasons for this lack of clarity is a reluctance to measure solvers' subjective experience of the solution process. Here, we overcome previous methodological problems by measuring the dynamics of the solution process using eye movements in combination with the subjective Aha! experience. Our results demonstrate that in a problem that requires restructuring of the initial mental representation, paying progressively more attention to the crucial elements of the problem often preceded the finding of the solution. Most importantly, the sooner solvers started paying attention to the crucial elements, the less sudden and surprising the solution felt to them. The close link between the eye movement patterns and self-reported Aha! experience in the present study underlines the necessity of measuring both the cognitive and the affective components of insight to capture the essence of this phenomenon. [ABSTRACT FROM AUTHOR]

This study investigated how problem solvers get into and out of a state of impasse while solving difficult problems. 47 participants had to decipher the secret method behind 33 magic tricks while repeatedly giving feeling of warmth ratings. After the first viewing of each trick, participants were led into an impasse by presenting two implausible solutions, together with the information that those were incorrect. After another viewing, cues were given to guide out of the impasse. Warmth ratings were flat and non-increasing after the implausible solution manipulation, suggesting a state of impasse. Cues helped to overcome the impasse, with higher solution rates for pictorial (49%) than for verbal cues (39%) and both higher than a no cue condition (29%). Warmth ratings also reflected cue efficacy, with higher ratings after helpful cues. This study represents a first attempt at influencing the onset and offset of the state of impasse. [ABSTRACT FROM AUTHOR]

Two hallmarks of insightful problem solving are thought to be suddenness in the emergence of solution due to changes in problem representation, and the subjective Aha! experience. Although a number of studies have explored the Aha! experience, few studies have attempted to measure representational change. Following the lead of Durso et al. (Psychol Sci 5(2):94–97, 1994) and Cushen and Wiley (Conscious Cognit 21(3):1166–1175, 2012), in this study, participants made importance-to-solution ratings throughout their solution attempts as a way to assess representational change. Participants viewed a set of magic trick videos with the task of finding out how each trick worked, and rated six action verbs for each trick (including one that implied the correct solution) multiple times during solution. They were also asked to indicate the extent to which they experienced an Aha! moment. Patterns of ratings that showed a sudden change towards a correct solution led to stronger Aha! experiences than patterns that showed a more incremental change towards a correct solution, or a change towards incorrect solutions. The results show a connection between sudden changes in problem representations (leading to correct solutions) and the subjective appraisal of solutions as an Aha! experience. This offers the first empirical support for a close relationship between two theoretical constructs that have traditionally been assumed to be related to insightful problem solving. [ABSTRACT FROM AUTHOR]

Insight problems are difficult because the initially activated knowledge hinders successful solving. The crucial information needed for a solution is often so far removed that gaining access to it through restructuring leads to the subjective experience of "Aha!". Although this assumption is shared by most insight theories, there is little empirical evidence for the connection between the necessity of restructuring an incorrect problem representation and the Aha! experience. Here, we demonstrate a rare case where previous knowledge facilitates the solving of insight problems but reduces the accompanying Aha! experience. Chess players were more successful than non-chess players at solving the mutilated checkerboard insight problem, which requires retrieval of chess-related information about the color of the squares. Their success came at a price, since they reported a diminished Aha! experience compared to controls. Chess players' problem-solving ability was confined to that particular problem, since they struggled to a similar degree to non-chess players to solve another insight problem (the eight-coin problem), which does not require chess-related information for a solution. Here, chess players and non-chess players experienced the same degree of insight. [ABSTRACT FROM AUTHOR]

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The article presents the paper analyzing several misconceptions regarding nuclear fuel cycles that breed fissile uranium-233 from thorium. The paper concludes that Uranium-233 is an attractive material for making fission bombs and is a credible material for the use of subnational and national groups. It suggests that the denatured thorium-uranium cycles are not effective safeguards against subnational bomb-making and that other features of mixed thorium-uranium cycles are unattractive from a safeguards point of view. Thorium cycles cannot provide major savings in nuclear fuel resources even though they are known to have some potential technical advantages.

The subjective Aha! experience that problem solvers often report when they find a solution has been taken as a marker for insight. If Aha! is closely linked to insightful solution processes, then theoretically, an Aha! should only be experienced when the correct solution is found. However, little work has explored whether the Aha! experience can also accompany incorrect solutions ("false insights"). Similarly, although the Aha! experience is not a unitary construct, little work has explored the different dimensions that have been proposed as its constituents. To address these gaps in the literature, 70 participants were presented with a set of difficult problems (37 magic tricks), and rated each of their solutions for Aha! as well as with regard to Suddenness in the emergence of the solution, Certainty of being correct, Surprise, Pleasure, Relief, and Drive. Solution times were also used as predictors for the Aha! experience. This study reports three main findings: First, false insights exist. Second, the Aha! experience is multidimensional and consists of the key components Pleasure, Suddenness and Certainty. Third, although Aha! experiences for correct and incorrect solutions share these three common dimensions, they are also experienced differently with regard to magnitude and quality, with correct solutions emerging faster, leading to stronger Aha! experiences, and higher ratings of Pleasure, Suddenness, and Certainty. Solution correctness proffered a slightly different emotional coloring to the Aha! experience, with the additional perception of Relief for correct solutions, and Surprise for incorrect ones. These results cast some doubt on the assumption that the occurrence of an Aha! experience can serve as a definitive signal that a true insight has taken place. On the other hand, the quantitative and qualitative differences in the experience of correct and incorrect solutions demonstrate that the Aha! experience is not a mere epiphenomenon. Strong Aha! experiences are clearly, but not exclusively linked to correct solutions. [ABSTRACT FROM AUTHOR]

Reasons for performing study Ingestion of sycamore seeds ( Acer pseudoplatanus) is the likely source of hypoglycin A in atypical myopathy ( AM) but ingestion of seedlings in spring might also contribute to intoxication. Objectives To test for hypoglycin A in seeds and seedlings collected on pastures where AM cases were reported and compare its concentration in serum of affected and healthy horses. Study design Field investigation of clinical cases. Methods Whenever present, samaras (the winged nuts that each contain one seed) and/or seedlings were collected from pastures of 8 AM cases and 5 unaffected horses from different premises. Two AM cases were each co-grazing with an apparently healthy horse. Acylcarnitines and hypoglycin A were quantified in blood samples of all horses involved in the study. Results Hypoglycin A was detected in serum of AM (5.47 ± 1.60 μmol/l) but not in healthy controls pasturing where A. pseudoplatanus trees were not present. However, hypoglycin A was detected at high concentrations (7.98 μmol/l) in serum of a clinically healthy horse grazing a pasture with seedlings and samaras and also in the 2 healthy horses co-grazing with AM cases (0.43 ± 0.59 μmol/l). Hypoglycin A was detected in all samples of seeds and spring seedlings of A. pseudoplatanus. Conclusions Atypical myopathy can be associated with the ingestion of sycamore samaras and also ingestion of seedlings. Hypoglycin A can be detected in the blood of horses with no detectable clinical signs at pasture in which there is A. pseudoplatanus. Determination of hypoglycin A concentration in blood is useful for screening for exposure in suspected cases of AM. [ABSTRACT FROM AUTHOR]

Insightful problem solving is a vital part of human thinking, yet very difficult to grasp. Traditionally, insight has been investigated by using a set of established "insight tasks," assuming that insight has taken place if these problems are solved. Instead of assuming that insight takes place during every solution of the 9 Dot, 8 Coin, and Matchstick Arithmetic Problems, this study explored the likelihood that solutions evoked the "Aha! experience," which is often regarded as the defining characteristic of insight. It was predicted that the rates of selfreported Aha! experiences might vary based on the necessary degree of constraint relaxation. The main assumption was that the likelihood of experiencing an Aha! would decrease with increasing numbers of constraints that must be relaxed, because several steps are needed to achieve a representational change and solve the problem, and thus, the main feature of suddenness of a solution might be lacking. The results supported this prediction, and demonstrated that in many cases participants do solve these classical insight problems without any Aha! experience. These results show the importance of obtaining insight ratings from participants to determine whether any given problem is solved with insight or not. [ABSTRACT FROM AUTHOR]

Background Risk factors for cardiac diseases in horses have not been explored in a large population of animals. Objectives To describe risk factors for various cardiac diseases in a hospital-based population of horses. Animals Files of 3,434 horses admitted at the Internal Medicine Department of the Liege Equine Teaching Hospital between 1994 and 2011 were reviewed and of those, 284 were categorized as having moderate-to-severe cardiac disease. Methods Observational study. After calculating prevalence for each cardiac disease, we tested whether breed (chi-square test) or sex, age, body weight ( BW), and other cardiac diseases (logistic regressions) were risk factors ( p < .05 significant). Results Mitral regurgitation ( MR, 4.4%), atrial fibrillation ( AF, 2.3%), aortic regurgitation ( AR, 2.1%), and tricuspid regurgitation ( TR, 1.7%) were the most common cardiac abnormalities detected. Determinants were male sex and increasing age for AR ( OR = 2.03, CI = 1.07-4.94), racehorses breed and middle-age for TR ( OR = 4.36; CI = 1.10-17.24), and high BW for AF ( OR = 3.54; CI = 1.67-7.49). MR was the most common valvular disease associated with AF, clinically important ventricular arrhythmia, pulmonary regurgitation ( PR), and congestive heart failure ( CHF). TR was also associated with AF, PR, and CHF; AR was not associated with CHF. Conclusions and Clinical Importance Several previously suspected risk factors for a variety of equine cardiac diseases are statistically confirmed and other risk factors are highlighted in the studied hospital-based population. These observations should be taken into account in health and sport's monitoring of horses presenting predisposing factors. [ABSTRACT FROM AUTHOR]

The article cites a research study that identifies clinical variables that could be indicators for West Nile Fever (WNF) outbreaks in horses. It compares clinical findings of Belgian non-WNF neurological cases with those of French-confirmed WNF cases in horses. The frequency of WNF outbreaks is on the increase in mideastern and southern Europe.

Background Descriptions of acid-base disturbances in atypical myopathy ( AM) are limited. Objectives Describe and compare traditional and quantitative acid-base abnormalities and cardiovascular shock status in horses with AM at admission. Animals 34 horses with AM, 15 healthy controls. Methods Retrospective case-control study. Records were searched for shock variables (packed cell volume [ PCV], blood urea nitrogen [ BUN], heart and respiratory rate) and acid-base variables (venous blood gas analysis, electrolytes, total protein, lactate) on admission. Base excess ( BE) of free water ( BEfw), chloride ( BEcl), total protein ( BEtp), and unidentified anions ( BEua), anion gap ( AG), measured strong ion difference ( SIDm), and concentration of total nonvolatile weak acids ([Atot]) were calculated. Acid-base classifications, using simplified strong ion model and traditional approach, and shock grades were assigned. A 2-sample Wilcoxon rank-sum test and Bonferroni correction compared variables in AM cases versus control horses. Significance was P < .05/16 for acid-base and P < .05/5 for shock variables. Results Tachycardia, tachypnea, and normal to increased PCV and BUN were common in AM cases. Respiratory, metabolic acid-base alterations, or both were mainly caused by respiratory alkalosis, lactic acidosis, and SIDm alkalosis, alone or in combination. Evaluated variables (except pH, potassium concentration, total protein, and related calculations) were significantly different ( P < .001) between AM cases and control horses. The strong ion model provided a more accurate assessment than the traditional approach and identified mixed derangements. Conclusions and clinical importance Acid-base derangements should be evaluated in horses with AM and this preferably with the strong ion model. [ABSTRACT FROM AUTHOR]

Reasons for performing study: Appropriate management of atypical myopathy (AM) requires the establishment of an accurate diagnosis and prognosis. Furthermore, preventive measures to avoid AM need to be refined. Objectives: The aims of the study were as follows: 1) to improve the diagnosis of AM; 2) to identify prognostic predictors; and 3) to refine recommended preventive measures based on indicators of risk factors. Methods: An exploratory analysis of cases in Europe between 2006 and 2009 reported to the Atypical Myopathy Alert Group was conducted. Based on clinical data, reported cases were allocated into 2 groups: confirmed or highly probable AM (AM group; further divided into survivors and nonsurvivors); and cases with a low probability of having AM or with another final diagnosis (non-AM group). Using Welch's test and odds ratios corrected for multiple comparisons, the AM vs. non-AM groups were compared to identify indicators for diagnosis and risk factors, and survivors vs. nonsurvivors in the AM group were compared to identify prognostic factors. Sensitivity, specificity and positive and negative predictive values were calculated for specific clinical signs related to final diagnosis and outcome. Results: From 600 reported cases, 354 AM cases (survival rate of 26%) and 69 non-AM cases were identified, while there were insufficient data to categorise the remainder. Variables valuable for diagnosing AM compared with similar diseases were as follows: presence of dead leaves and wood and/or trees on pastures; sloping pastures; full-time pasture access; no food supplementation; normal body condition; pigmenturia; normothermia; and congested mucous membranes. Nonsurvival was associated with recumbency, sweating, anorexia, dyspnoea, tachypnoea and/or tachycardia. Survival was associated with remaining standing most of the time, normothermia, normal mucous membranes, defaecation and vitamin and antioxidant therapy. Conclusions and potential relevance: This study refines the list of risk factors for AM. Clinical signs valuable for diagnosis and prognosis have been identified, enabling clinicians to improve management of AM cases. [ABSTRACT FROM AUTHOR]

Reasons for performing study: Improved understanding of the epidemiology of atypical myopathy (AM) will help to define the environmental factors that permit or support the causal agent(s) to exert toxicity. Objectives: This European survey of AM aimed to describe spatiotemporal distribution, survival, clinical signs, circumstances in which AM develops and its different expressions between countries and over time. Methods: The spatiotemporal distribution, history and clinical features of AM cases reported to the Atypical Myopathy Alert Group from 2006 to 2009 were described. Comparisons of data from the most severely affected countries and from the large outbreaks were made with Fisher's exact and Welch's tests with Bonferroni correction. Results: Of 600 suspected cases, 354 met the diagnostic criteria for confirmed or highly probable AM. The largest outbreaks occurred during the autumns of 2006 and 2009 in Belgium, France and Germany. For the first time, donkeys, zebras and old horses were affected, and clinical signs such as gastrointestinal impaction, diarrhoea, penile prolapse, buccal ulceration and renal dysfunction were observed. Affected horses spent >6 h/day on pastures that almost always contained or were surrounded by trees. The latency period was estimated at up to 4 days. Overall survival rate was 26%. Although differences between countries in affected breeds, body condition, horse management and pasture characteristics were recognised, the common presenting clinical signs and mortality were similar between countries. Conclusions and potential relevance: This study describes new data on case details, history and clinical course of AM that is of preventive, diagnostic and therapeutic value. However, the true impact of the findings of this study on the development of or severity of AM should be tested with case-control studies. [ABSTRACT FROM AUTHOR]

Echocardiography has become a routine non-invasive cardiac diagnostic tool in most species. Accurate measurement of cardiac dimensions requires reference values, which are poorly documented in goats. The aim of the present study was to test the inter-day repeatability and to establish the reference values of two-dimensional (2D-) and time-motion (M-) mode echocardiographic variables in healthy adult Saanen goats. Six goats were investigated three times by the same observer at one-day interval using a standardised 2D- and M-mode echocardiographic protocol. The intra-observer inter-day repeatability was tested using analysis of variance, calculation of the coefficient of variation and confidence intervals. A single echocardiographic examination was performed in six other goats, and values obtained in the 12 goats were used to establish the 2D- and M-mode echocardiographic reference values in healthy adult female Saanen goats. Statistical analysis revealed a good inter-day repeatability of the echocardiographic cardiac measurements. Echocardiographic reference values obtained in healthy adult Saanen goats seemed slightly higher than those reported in healthy Swedish domestic goats and were similar to those reported in healthy adult sheep. [ABSTRACT FROM AUTHOR]

Summary Reasons for performing study: Limited information exists about the muscle mitochondrial respiratory function changes that occur in horses during an endurance season. Objectives: To determine effects of training and racing on muscle oxidative phosphorylation (OXPHOS) and electron transport system (ETS) capacities in horses with high resolution respirometry (HRR). Methods: Mitochondrial respiration was measured in microbiopsies taken from the triceps brachii ( tb) and gluteus medius ( gm) muscles in 8 endurance horses (7 purebred Arabians and 1 crossbred Arabian) before training (T0), after two 10 week training periods (T1, T2) and after 2 CEI** endurance races (R1, R2). Muscle OXPHOS capacity was determined using 2 titration protocols without (SUIT 1) or with pyruvate (SUIT 2) as substrate. Electrons enter at the level of Complex I, Complex II or both complexes simultaneously (Complexes I+II). Muscle ETS capacity was obtained by uncoupling Complexes I+II sustained respiration. Results: T1 improved OXPHOS and ETS capacities in the tb as demonstrated by the significant increase of oxygen fluxes vs. T0 (Complex I: +67%; ETS: +37%). Training improved only OXPHOS in the gm (Complex I: +34%). Among horses that completed the race, a significant decrease in OXPHOS (Complex I: ∼−35%) and ETS (−22%) capacities was found in the tb with SUIT 2 indicating a reduced aerobic glycolysis. Significant correlations between CK activities and changes in OXPHOS were found suggesting a relationship between exercise-induced muscle damage and depression of mitochondrial respiration. Conclusions: For the first time, OXPHOS and ETS capacities in equine muscle at different steps of an endurance season have been determined by HRR. Significant alterations in mitochondrial respiratory function in response to endurance training and endurance racing have been observed although these changes appeared to be muscle group specific. [ABSTRACT FROM AUTHOR]

Summary Reasons for performing study: It is unknown whether or not exercise-induced cardiac fatigue (EICF), as demonstrated in human athletes performing long duration exercise, occurs in endurance horses. Objective: To examine the effects of a long distance endurance race on left ventricular systolic function in horses. Methods: Echocardiography was performed before, and after, a 2 or 3 star international endurance race (106-132 km) in 11 horses. Systolic (s) and diastolic (d) interventricular and left ventricular free wall thickness (IVS and LVFW, respectively), left ventricular, left atrial and aortic internal diameter (LVID, LA and Ao, respectively), fractional shortening (FS) and ejection fraction (EF) were measured by echocardiography. Heart rate (HR), peak flow velocity (Vmax), flow velocity integral (FVI), ejection time (ET), pre-ejection period (PEP), velocity of circumferential fibre shortening (Vcf), stroke volume (SV) and cardiac output (CO) were measured from aortic Doppler wave recordings. Results: After the race, LVIDd, Ao, LA, EF, FS, FVI, SV, ET and ET indexed for HR were significantly lower and IVSd, LVFWd, HR, PEP, PEP/ET and Vcf significantly higher as compared with prerace values. Pre- to post exercise changes in those parameters were not significantly correlated with changes in HR or in LVIDd. Conclusions: Results suggest that EICF, with a decrease in left ventricular systolic function, could occur post exercise in horses performing long duration endurance races. However, a multanecus effect of altered preload and heart rate on the studied variables cannot be discounted. [ABSTRACT FROM AUTHOR]

Background: Reports of doxycycline-induced toxicity are limited despite common use of this antibiotic to treat infectious respiratory disorders in calves. Objective: To describe previously unreported kidney lesions and diagnostic test results in doxycycline-overdosed calves and to compare these results with other findings reported previously. Animals: Thirty-two calves that presented with adverse effects after receiving high doses of doxycycline as a treatment for mild respiratory disorders. Method: Retrospective review of medical records. Results: Clinical examination identified mainly lethargy, dyspnea, cough, tongue paresia or paralysis associated with dysphagia and sialorrhea, tachycardia, tachypnea, and signs of myopathy. Blood analysis indicated increases in creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and sorbitol dehydrogenase activities and increased serum creatinine and urea concentrations. ECG recordings and Doppler echocardiography examination identified ventricular premature beats and a decrease in left ventricular global and systolic function, respectively. Necropsy and histopathology disclosed necrosis of the myocardium, tongue, and some striated muscles, acute renal tubular necrosis, and fatty degeneration or congestion of the liver. Conclusions: Most of these findings corroborate previous observations made in doxycycline-overdosed calves, and further suggest myocardial and striated muscular toxicity as well as renal toxicity in doxycycline-overdosed calves. [ABSTRACT FROM AUTHOR]

Background: Endocarditis is a rare heart condition with variable clinical expressions in equids. Risk factors for this disease are incompletely understood. Objective: Describe risk factors for endocarditis in equids. Animals: One hundred and fifty-three equids admitted to Liège University, 9 diagnosed with endocarditis and 144 free from endocarditis but admitted to the hospital with a differential diagnosis including this disease. Methods: Retrospective case-control study. Results: Equids with endocarditis were significantly younger (mean age = 4.84 ± 5.74 years) than control equids (mean age = 10.8 ± 7.73 years) ( P= .01). No sex or breed predisposition was observed. Animals with hyperthermia (odds ratio [OR] = 24.4; confidence interval [CI] = 1.40–428), synovial distension (OR = 13.4; CI = 3.00–59.8), lameness (OR = 6.52; CI = 1.63–26.1), hyperglobulinemia (OR = 26.4; CI = 3.03–229), hypoalbuminemia (OR = 11.4; CI = 1.34–96.8), hyperfibrinogenemia (OR = 9.81; CI = 1.16–82.7), or leukocytosis (OR = 7.12; CI = 1.40–36.4) presented a significantly higher risk of having endocarditis than control horses. The presence of two of the clinical signs mentioned above significantly increased the probability of a diagnosis of endocarditis ( P≤ .05). Conclusions and Clinical Importance: Age is associated with equine endocarditis. The diagnostic value of certain clinical signs and abnormalities in blood parameters in this disease are described. [ABSTRACT FROM AUTHOR]

Bioavailability and pharmacological effects of tiludronate were compared when administered as an intravenous (i.v.) bolus at a dosage of 0.1 mg/kg body weight (b.w.) once daily for 10 consecutive days (group 1, n = 6) and as a single constant rate infusion (CRI) at a total dose of 1 mg/kg b.w. (group 2, n = 6) in healthy adult horses. Tiludronate and carboxy-terminal cross-linking telopeptide of type I collagen (CTX-1) were measured in plasma and urine. There was no statistically significant difference in area under the curve ( AUC) and clearance ( Cl) between the two groups. Bioavailability of the CRI was 103% (not significantly different) that of the 10 daily i.v. bolus doses. Cumulative urine tiludronate excretion could not be compared between groups because of poor sensitivity of the assay in urine. Plasma and urine CTX-1 levels were not different between groups throughout the study. However, interindividual variations were greater in group 1 than in group 2. A significant decrease in CTX-1 levels was observed in plasma after the first administration in group 1, but not in urine; while in group 2, a significant decrease in CTX-1 concentrations was observed after treatment in both plasma and urine. In conclusion, both dosage regimens of tiludronate produced similar plasma exposure and pharmacological effects in adult healthy horses. [ABSTRACT FROM AUTHOR]

Summary Reasons for performing study: Equine motor neuron disease (EMND) was diagnosed in 3 horses maintained on lush, grass-based pasture. This contrasted with North American studies which identified limited or no access to green herbage as an important risk factor for EMND. Hypothesis: Grazing horses that have an apparently adequate intake of pasture herbage to meet normal equine vitamin E requirements can develop EMND. Methods: Owners of 32 European horses diagnosed with EMND completed a questionnaire regarding intrinsic, managemental, nutritional and environmental factors that could potentially be risk factors for EMND, and also regarding clinical signs, treatments and case outcome. Plasma/serum vitamin E data for these horses were supplied by the veterinarians. No control population was studied. Results: Thirteen of 32 horses (termed the 'grazing' group) had part- or full-time access to grass-based pasture at the onset of EMND (median duration at pasture 12 h/day, range 3-24 h). Five of these horses were at pasture for at least 23.5 h/day at the onset of EMND, 2 of which were at pasture for at least 23.5 h/day throughout the year. Despite grazing, all these horses had a low vitamin E status. The remaining 19 horses resembled those cases reported from North America, in that they had no or limited access to pasture. Conclusions and potential relevance: A diagnosis of EMND should not be discounted on the basis that a horse has access, even full-time, to lush grass-based pasture. Inadequate vitamin E intake was probably not the sole cause of either the EMND or the low vitamin E status in the grazing horses; the latter was probably the result of abnormal bioavailability or excessive utilisation of vitamin E. [ABSTRACT FROM AUTHOR]

Bone responds to exercise with changes in bone (re-)modelling, which might be monitored non-invasively with biochemical bone markers. The aim of this study was to evaluate the influence of exercise on serum osteocalcin and serum carboxy-terminal cross-linked telopeptide of type I collagen generated by matrix metalloproteinases (CTX-MMP) concentration in young racehorses. Seventy-one 2 to 4-year-old Thoroughbreds were included in this prospective infield study. Blood sampling was performed six times (i.e. six sampling cycles) during a 9-month period. Serum samples were analysed with commercial osteocalcin and CTX-MMP radioimmunoassays. Two-year-old racehorses had higher serum osteocalcin and CTX-MMP values than 3-year-old horses. Gender and training amplitude did not significantly influence serum osteocalcin and CTX-MMP values. Two-year-old horses showed an increase in osteocalcin values between cycles 2 and 3 and an increase in serum CTX-MMP values between cycles 1 and 2. Serum osteocalcin and CTX-MMP concentrations decreased between cycles 4 and 5, and 5 and 6. Three-year-old horses showed an increase in serum osteocalcin levels between cycles 3 and 4 and an increase in serum CTX-MMP concentrations between cycles 1 and 2, and 3 and 4. Serum osteocalcin levels decreased between cycles 5 and 6, whereas serum CTX-MMP levels decreased between cycles 4 and 5, and 5 and 6. Two- and three-year-old horses showed a decreased osteocalcin/CTX-MMP ratio between cycles 1 and 2. Moreover, 2-year-old horses showed an increase in the osteocalcin/CTX-MMP ratio between cycles 2 and 3. Sore shin formation did not significantly influence serum osteocalcin and CTX-MMP values. Serum osteocalcin and CTX-MMP are promising bone markers for monitoring exercise induced changes in equine bone metabolism. [ABSTRACT FROM AUTHOR]

The purpose of this study was to validate an equine-specific osteocalcin (OC) radioimmunoassay (RIA) for use in donkeys and to establish age-related changes in serum OC concentrations in healthy donkeys. Serial dilutions of donkey serum showed parallelism with standard curves obtained with the equine-specific OC RIA. There was a tight linear regression between donkey serum OC values obtained with the equine specific OC RIA and a commercially available bovine-specific OC RIA. Serum OC levels of 27 healthy donkeys, analysed with the equine-specific OC RIA, showed a tight negative logarithmic regression with age. Least square means and standard error of serum OC values were 67 ± 10 μg/l in 0.6–4-year-old donkeys (group 1), 32 ± 9 μg/l in 5–9-year-old donkeys (group 2) and 15 ± 11 μg/l in >9-year-old donkeys (group 3). Serum OC values were significantly (p < 0.01) higher in group 1 than in groups 2 and 3. The equine-specific OC RIA may be a useful and practical tool to assess bone metabolism and skeletal diseases in donkeys. [ABSTRACT FROM AUTHOR]

The effects of an acute non-isocapnic hypoxia on ventilation and pulmonary mechanics were investigated in 6 healthy unsedated Holstein-Friesian (HF) calves and in 7 double-muscled calves of the Belgian White and Blue (BWB) breed known to develop more severe hypoxemia during exercise and respiratory diseases. Data were collected at 1 min intervals throughout the following protocol: breathing air (FIO2 = 21%), then breathing hypoxic gas mixture (FIO2 = 10%) for 5 min, and, finally, breathing air again for 5 min of recovery. Arterial blood was sampled at rest and at the 4th min of hypoxia for blood gas analysis. In HF and BWB calves, hypoxia induced a significant increase in tidal and minute volume, but did not change respiratory rate, dynamic lung compliance and total pulmonary resistance. However, with regard to their ventilation during normoxia at rest, BWB calves showed a comparatively greater rise in ventilation than HF calves during the first 4 min of hypoxia. On the contrary, by the 5th minute of hypoxia, ventilation of BWB calves declined to the normoxic level while HF calves largely sustained hyperventilation. This hypoxic ventilatory depression in BWB calves could be explained by the proportionately greater initial increase in ventilation. It was concluded that BWB calves supported this hypoxic challenge less easily than HF calves. [ABSTRACT FROM AUTHOR]

A Pasteurella haemolytica A1 broth was injected intratracheally in eight calves and measurements of pulmonary function values (PFV) were made once before and hourly post inoculation (p.i.). Changes in PFVs, included increased respiratory rate and minute ventilation (up to 158 % of baseline 2 h p.i.) and decreased tidal volume and lung dynamic compliance (up to 33 % of baseline 3 h p.i.). Total pulmonary resistance was not affected. At and after 3 h p.i. there was a progressive impairement of gas exchange, as judged from arterial O2 tension which decreased up to 65 % of baseline. In contrast, arterial CO2 tension was not affected. Pulmonary hypertension was observed during the 3 last h of the study and was attributable to an increased pulmonary vascular resistance. Severe neutropenia was observed at 3h p.i. and post-mortem histological findings were consistent with an acute fibrinohemorragic bronchopneumonia. In conclusion, P. haemolytica airway challenge unequivocally resulted in acute pneumonia, providing a reproducible pathophysiological model for investigations regarding new therapeutic strategies. [ABSTRACT FROM AUTHOR]

This study derives normal values for electro- and vectocardiographic parameters, as generated by the Holmes semi-orthogonal lead system, in healthy growing calves. Sixty-four electrocardiograms were recorded from healthy Friesian calves aged from one week to one year. Waveform and duration were analysed and compared in the X-, Y- and Z-leads. The modal P, QRS and T tridimensional vectors were graphically constructed and their magnitude and orientation were calculated. The duration of waves and intervals were similar to data previously reported in the bovine species. Differences from data reported in other species were attributed to heart rate. The duration of waves and QT and ST intervals significantly lengthened with the decrease in heart rate which occurred during growth. PR interval significantly lengthened with physical maturation, and this change was independent of the decrease in heart rate. The magnitude and the orientation of the spatial modal vectors were approximately similar to the few data previously reported in cattle and in other ungulates and were not affected by somatic growth. [ABSTRACT FROM AUTHOR]

For spatial vectocardiography to become applicable for cardiac investigation in cattle, it was necessary to develop a reliable standardized electrocardiographic lead system in this species. In this study, four tridimensional lead systems, initially developed in horses, were compared when applied in calves. Fifty seven electrocardiograms were collected. The between-subject variability of the magnitude and angles of the tridimensional P, QRS and T modal vectors obtained by use of each lead system was compared. Reproducibility of vectocardiographic measurements was analyzed by comparing results obtained in 10 calves within a one day interval. The Holmes semi-orthogonal lead system, giving the lowest between-subject variability and the highest between-day reproducibility, appeared to be the most reliable lead system in order to apply vectocardiography in the bovine species. [ABSTRACT FROM AUTHOR]

In order to facilitate lung auscultation, a transitory hyperpnea may be obtained by lobeline administration, use of a rebreathing bag or exercise. The effect of these three methods on the pulmonary function were studied and compared in 5 healthy ponies. Respiratory airflow and tidal volume were measured with a pneumotachograph Nr. 5 and pleural pressure with the esophageal balloon catheter technique. Pulmonary function values were measured before, during and after the hyperpnea induced by (i) lobeline, (ii) rebreathing and (iii) exercise. Lobeline administration induced an hyperpnea due to both an increase in tidal volume and respiratory rate; this increase in ventilation lasted for about 90s and was accompanied by a sharp rise in the respiratory peak airflows, especially the expiratory ones. The rebreathing method induced a less hyperpnea which lasted only 30s. Lastly the hyperpnea after a light treadmill exercise was the longer in duration and intermediate between the preceding methods in intensity. [ABSTRACT FROM AUTHOR]

The purpose of this study was to establish a standardized protocol in order to obtain accurate and reproducible cardiac output (CO) measurements by the thermodilution technique in the unsedated calf. In 5 healthy calves, the effect of various temperatures, volumes, rates, means and sites of injection of the thermal indicator were tested for their effect on accuracy and reproducibility of CO measurement by the thermodilution technique, the Fick method being used as the standard technique. Five milliliters of an iced 5% dextrose solution per 100 kg body weight constituted the correct amount of thermal indicator. Manual injection of the indicator bolus and/or injection of this bolus through the proximal lumen of a thermodilution Swan-Ganz catheter gave poor results of CO measurements by the thermodilution technique. On the other hand, results of CO measurements were highly reliable when the bolus injection was performed by an ECG-synchronized injection pump and/or through a right atrial catheter with a larger diameter and a shorter length than the classical Swan-Ganz catheter. It was concluded that an iced 5% solution of dextrose (5 ml/100 kg body weight) injectated through a right atrial catheter by an ECG-synchronized pump gives the most accurate and reproducible CO measurements by the thermodilution technique in unsedated calves. [ABSTRACT FROM AUTHOR]

Seven sport horses were investigated to compare physiological and pharmacological stresses on the plasma glucocorticosteroid levels. Venous blood was sampled and analysed for Cortisol concentrations before and after each type of stress. The physiological stress was induced by the completion of a cross-country and the pharmacological one, by an intravenous ACTH administration (200 μg) in the same horses, one week after the course. Both exercise and ACTH injection induced a highly significant Cortisol increase of 79±0. 10% and 160±0. 18%, respectively. The relative plasma Cortisol increases due to exercise on the one hand, and due to ACTH administration on the other hand, were correlated with a coefficient of 0. 82. It was concluded that the plasma Cortisol increase induced by a standardised pharmacological stress could be used in order to predict the exercise-induced stress response. [ABSTRACT FROM AUTHOR]

The aim of the present experiment was to investigate the hypothesis that there is a respiration-locomotion coupling in trotting equids. Therefore the respiratory airflow (V̇), the gastric pressure (Pga) and pleural pressure (Ppl) changes and the step frequency (SF) were simultaneously recorded in 5 trotting ponies (body weight: 255±15 kg; age: 3. 5±0. 4 years). Airflow was measured using a Fleisch pneumotachograph fixed on a face mask. Esophageal and gastric balloon catheters coupled to pressure transducers allowed the recording of Ppl and Pga. The exercise was performed on a treadmill and consisted of 1 min walking (1. 5m · s−1), 1 min slow trotting (3. 0m · s−1) (Trot 1) and 3 min fast trotting (3. 5m · s−1) (Trot 2). Data were continuously recorded before and during exercise. At walk and Trot 1, none of the ponies displayed a coupling between SF and the respiratory frequency (RF). In one pony, SF and RF were coupled at a constant ratio of 2:1 during Trot 2 while two other ponies displayed the same coupling only up to the second minute of Trot 2. In the two last ponies, a coupling occurred at the third minute of Trot 2. In all ponies, the peaks in Pga occurring during expiration occurred always simultaneously with the first and/or the second peak V̇, whether or not there was a relationship between SF and RF. On the other hand, when SF and RF were coupled, the first part of inspiration was always simultaneous to a decrease in Pga. It was concluded that in trotting ponies respiration and locomotion are not always independent and that the abdominal piston may act in synergy with the respiratory pump in some phases of the breathing cycle. Zusammenfassung Synchronisation von Lokomotion und Atmung bei trabenden Ponies Ziel der Untersuchung war es, die Hypothese einer Koppelung zwischen Atmung und Lokomotion bei trabenden Equiden zu prüfen. Bei 5 trabenden Ponies (Körpergewicht: 255±15 kg, Alter: 3,5±0,4 Jahre) wurde daher das Atemzeitvolumen (V̇), die Veränderungen des intragastralen Drucks (Pga) und des pleuralen Drucks (Ppl) sowie die Schnittfrequenz (SF) gleichzeitig registriert. Das Atemzeitvolumen wurde mit einem an einer Gesichtsmaske fixierten Pneumotochographen nach F leisch gemessen. Jeweils an einen Druckwandler angeschlossene Ösophagus- bzw. Magen-Ballon-katheter ermöglichten die Aufzeichnung des Ppl und des Pga. Die Bewegung der Tiere erfolgte auf einem Laufband und umfaßte einminütiges Gehen (1,5m · s−1), einminiitiges langsames Traben (3,0m · s−1) (Trab 1) und dreiminiitiges schnelles Traben (3,5m · s−1) (Trab 2). Die Daten wurden vor und während der Bewegung kontinuierlich registriert. Beim Gehen und beim Trab 1 ergab sich bei keinem der Ponies eine Koppelung zwischen SF und Respirationsfrequenz (RF). Während des Trabes 1 waren SF und RF bei einem Pony konstant im Verhältnis 2:1 gekoppelt, während zwei weitere Ponies diese Koppelung nur bis zur zweiten Minute des Trabes 2 aufwiesen. Bei den anderen zwei Ponies ergab sich eine entsprechende Koppelung in der dritten Minute des Trabes 2. Bei alien Ponies trat der während der Exspiration zu verzeichnende Peak des Pga unabhängig von der Beziehung zwischen SF und RF immer gleichzeitig mit dem ersten und/oder zweiten Peak von V̇ auf. Bei einer Koppelung von SF und RF fiel andererseits der erste Abschnitt der Inspiration immer mit einer Verringerung des Pga zusammen. Es wird geschlossen, daß beim trabenden Pony Atmung und Lokomotion nicht immer unabhängig voneinander sind und daß während einiger Phasen des Atmungszyklus die sich wie ein Kolben verhaltenden abdominalen Eingeweide synergistisch zur respiratorischen 'Pumpe' verhalten. [ABSTRACT FROM AUTHOR]

The variability of the post-exercise values (PEV) of blood lactate and of some other blood constituents were studied in 8 healthy and fit jumpers through 5 national competitions of equal difficulty. The effects of factors such as the individual, performance and competition on these PEV were analysed. Venous blood was sampled immediately after the 5 show-jumping contests and was analysed for packed cell volume (PCV), blood lactate, blood glucose (GLU), total plasma protein (TPP), bicarbonate (HCO3−), sodium (Na+), potassium (K+), chloride (Cl−), calcium (Ca2+), serum activities of lactate dehydrogenase (LDH), creatine phosphokinase (CPK), glutamic-oxalacetic transaminase (GOT) and gamma glutamyl transferase (γGT). PEV of these 13 blood parameters were analysed using a fixed linear model which included the effect of horse, score and competition and their respective interactions. The analysis of the influence of each of the 3 fixed variables showed that (1) there was no relationship between the PEV variations and the score; (2) there were significant (P < 0. 05) variations induced by the competition in Na+, Ca2+, TPP, LDH and GLU, and (3) there were significant interindividual variations as regards Ca2+, TPP, CPK, γGT and PCV with P < 0. 05, LDH with P < 0. 01 and blood lactate with P < 0. 001. This wide variability of PEV between individuals led us to conclude that the use of the PEV of some blood parameters in the medical follow-up of jumping horses in field conditions necessitates not only regular blood analyses immediately after standardized exercises, but also that the PEV relating to each horse should be compared to each other and not to mean values. [ABSTRACT FROM AUTHOR]

The mechanics of breathing was investigated in six healthy calves breathing either air or a mixture of 79% helium and 21% oxygen (He-O2). Intrapleural pressure (Ppl) was measured with an esophageal balloon catheter and transpulmonary pressure was obtained by subtracting the mouth pressure (Pm) from Ppl. Respiratory airflow (V) was measured using a Fleisch pneumotachograph N°3 and tidal volume (Vt) was electronically derived by integrating V with respect to time. Respiratory airflow, Vt, Ppl and Pm were simultaneously recorded while the calves breathed first air (1 min), secondly He-O2 (1 min) and finally air again (1 min). The pulmonary function values were calculated on the tracings and the He-O2 values were compared to the corresponding 'air' values. The ventilatory response to resistance unloading was characterized by a significant increase in minute volume exclusively due to an increase in respiratory frequency, while Vt remained unchanged. A decrease of 32% in the total pulmonary resistance (RL) and 16% in the work per litre of ventilation (Wrm/1) were observed when calves breathed He-O2. The effect of the He-O2 on RL and on Wrm/1 suggests that, in the bovine species, airflow turbulences in the upper part of the respiratory tract play a significant role in the total airways resistance. [ABSTRACT FROM AUTHOR]

Fifty-eight healthy horses were studied during five sporting events of various intensities and durations, namely show-jumping ( n=6), cross-country in a three-day event ( n=30), trotting races ( n=7), galloping reces ( n=7) and endurance rides ( n=8). Venous blood samples were collected at rest and immediately after exercise and analysed for plasma cortisol (CORT) and lactate (LA) levels. The experimental procedure was the same throughout the investigation so as to permit a reliable comparison between the five types of exercise. The type of event significantly affected both the resting ( p≤0.05) and the postexercise ( p≤0.01) plasma CORT. The degree of exercise-induced hypercortisolaemia was related to both the intensity and the duration of exercise for all five sporting events, but the endurance ride induced the most and show-jumping the least serious post-exercise CORT changes. LA production was much more closely related to the intensity of the exercise than was CORT. It is concluded that simultaneous measurements of plasma CORT and LA levels may be useful to discriminate between different types of exercise, adjust training programmes, and improve our comprehension of the physiology of sport horses at exercise. [ABSTRACT FROM AUTHOR]

The purpose of this study was (1) to evaluate the technical and methodological problems associated with invasive haemodynamic measurements in unsedated cattle; (2) to assess the reproducibility of such measurements both within and between days; and (3) to compare the values with those previously reported. Twenty-one healthy calves, aged from 5.5 to 12 months, were studied. The central venous, the right ventricular, the pulmonary arterial, the pulmonary capillary wedge and the systemic arterial pressures were obtained by means of fluid-filled catheters, and the cardiac output was measured by the thermodilution technique. The heart rate, the stroke volume, the pulmonary and systemic vascular resistances and the pulmonary and systemic ventricular workloads were calculated. An adverse reaction, consisting of severe pulmonary hypertension, tachycardia, tachypnoea and transient weakness, occurred in 7 calves during the catheterization procedures. Such a reaction might be due to a local reflex induced by stimulation of mechano-receptors by the catheter tip. It should be avoided by reducing the manipulation of the catheter as much as possible and by inflating the tip of the balloon when moving it forwards. A comparison of the vascular pressures with those previously reported was difficult because of methodological or technical limitations, such as, for instance, a lack of standardization of the baseline. The reproducibility of the haemodynamic measurements obtained was satisfactory, in contrast to previous studies performed in conscious animals. This was attributed to our animals being better trained to the experimental conditions and emphasizes the importance of reducing mental stress in obtaining reliable haemodynamic measurements in unsedated and potentially uncooperative animals. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the variability of the peak systolic (PAPs) and the end diastolic (PAPd) pulmonary arterial pressures induced by intrapleural pressure changes in cattle. The pleural pressure (Ppl), the electrocardiogram and the pulmonary arterial pressure (PAP) were simultaneously recorded in five healthy calves under three different conditions, i.e. normoxia (N), normoxia with an added airflow resistance (R) and hypoxia (H). PAPs, PAPd and their corresponding transmural pressures were measured and averaged over 10 successive regular cardiac cycles. The maximum Ppl changes (maxΔPpl) were measured on the same tracings. The variance and coefficients of variation were calculated for each set of vascular measurements. MaxΔPpl was significantly increased with regard to N values during R and H conditions. This increase in maxΔPpl induced a simultaneous rise in the variability of PAP measurements, while in each condition, this variability was greatly lowered by use of the corresponding transmural pressure. It was concluded that, in calves with high maxΔPpl, the influence of respiration on PAP becomes considerable. In such cases, the use of transmural pressures rather than luminal pressures can greatly reduce the variability of these pulmonary pressure measurements and therefore increase their sensitivity. [ABSTRACT FROM AUTHOR]

In order to better understand the bovine breathing pattern, tidal breathing flow-volume loops (TBFVL) were analyzed in 24 healthy cattle of different body weights (range: 37-660 kg) (Group A) and in 28 cattle suffering from the common respiratory diseases: verminous bronchitis (Group B); shipping fever (Group C); acute respiratory distress syndrome (Group D); respiratory syncytial virus pneumonia (Group E); organophosphate poisoning (Group F); and necrotic laryngitis (Group G). Respiratory airflow and tidal volume were measured with a breathing mask-Fleisch pneumotachograph assembly. TBFVL were traced from these values using a computerized method. All the loop indices proposed by Amis and Kurpershoek (1986a) were calculated from 5 representative breathing cycles for each of the 52 animals. The TBFVL shapes and indices were relatively constant in most healthy cattle and were not correlated with the body size. When compared to normal values, animals with moderate respiratory syndromes (Groups B and C) had a more flattened shape to their TBFVL. On the other hand, in most cattle with severe respiratory pathologies (Groups D, F and G) expiration tended to be biphasic with the peak expiratory flow (PEF) occurring significantly later than in healthy animals. Both PEF and peak inspiratory flow were increased in all the pathological conditions. The TBFVL indices were more frequently and more severely changed during expiration than during inspiration. [ABSTRACT FROM AUTHOR]

Sometimes, the solution to a difficult problem simply pops into mind. Such a moment of sudden comprehension is known as "insight". This fundamental cognitive process is crucial for problem solving, creativity and innovation, yet its true nature remains elusive, despite one century of psychological research. Typically, insight is investigated by using spatial puzzles or verbal riddles. Broadening the traditional approach, we propose to tackle this question by presenting magic tricks to participants and asking them to find out the secret method used by the magician. Combining this approach with cueing in an fMRI experiment, we were able to break down the insight process into two underlying components: cognitive conflict and restructuring. During cognitive conflict, problem solvers identify incongruent information that does not match their current mental representation. In a second step this information is restructured, thereby allowing them to correctly determine how the magic trick was done. We manipulated the occurrence of cognitive conflict by presenting two types of cues that lead participants to either maintain their perceptual belief (congruent cue) or to change their perceptual belief (incongruent cue) for the mechanism behind the magic trick. We found that partially overlapping but distinct networks of brain activity were recruited for cognitive conflict and restructuring. Posterior, predominantly visual brain activity during cognitive conflict reflected processes related to prediction error, attention to the relevant cue-specific sensory domain, and the default brain state. Restructuring on the other hand, showed a highly distributed pattern of brain activity in regions of the default mode, executive control networks, and salience networks. The angular gyrus and middle temporal gyrus were active in both cognitive conflict and restructuring, suggesting that these regions are important throughout the insight problem solving process. We believe this type of approach towards understanding insight will give lead to a better understanding of this complex process and the specific role that different brain regions play in creative thought. [ABSTRACT FROM AUTHOR]