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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]

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]

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]

Prior research indicates that solutions accompanied by an Aha! experience are remembered better than those missing this feeling of epiphany. The question for the present studies was whether this insight memory advantage for problem solutions is modulated by the affective component of insight (the strong feelings that typically accompany the Aha! experience), or by the cognitive component (the restructuring or representational change that occurs during insightful problem solving). In both studies, participants viewed a set of magic trick videos to generate solutions for how each trick was done, and memory for the generated solutions was tested after a week delay. They also indicated the extent to which they experienced an Aha! moment at solution along with other perceptions of their experience. In the second study, they additionally rated the relevance of five action verbs for each trick (including one that implied the correct solution) multiple times during solution as a measure of restructuring the problem representation. The explanation for the insight memory advantage that was best supported by the results is that it is the joint consequence of finding correct solutions, the subjective feeling that one has found a correct solution (certainty), and experiencing an emotional pleasurable reaction during the problem solving process that all contribute to better memory for the solution. However, it did not seem to rely on having reached the solution via a sudden restructuring process. [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]