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A recent epidemiological study identified various aspects of arena surfaces and arena surface maintenance that w ere related to risk of injury in horses and that arena maintenance is important in reducing injury risk. However, there has been little research into how properties of arena surfaces change with harrowing. This study aimed to compare the properties of different arena surface types pre- and postharrowing. The Orono Biomechanical Surface Tester fitted with accelerometers and a single- and a threeaxis load cell was used to test 11 arenas with two different surfaces types, sand with rubber (SR) and waxed-sand with fibre (WSF). Three drop tests were carried out at 10 standardised locations on each arena. Mixed models w ere created to assess the effect of surface type, pre- or post-harrowing, and drop number on the properties of the surface, including maximum horizontal deceleration, maximum vertical deceleration, maximum vertical load and maximum horizontal load. Post-harrowing, none of the parameters were altered significantly on SR. On WSF, maximum vertical deceleration and maximum vertical load significantly decreased post-harrowing. The differences in the effects of superficial harrowing on SR and WSF could be attributed to the different compositions and sizes of the surface material. The results suggest that different maintenance techniques may be more suitable for different surface types and that the effects of superficial harrowing are short-lived due to the rapid re-compaction of the surface with repeated drops on WSF. Further work is required to determine the effects of other maintenance techniques, and on other surface types. [ABSTRACT FROM AUTHOR]

Development of core muscle strength is important for training and during rehabilitation following injury. A Pessoa training aid (PTA) is a system of ropes and pulleys which is commonly used during equine training and rehabilitation, but there is limited information on its effectiveness. The objective of the study was to determine the effect of the PTA on the temporal, linear and angular kinematics of the working trot. Influence of testing order on effect of a PTA was assessed in four horses. Twelve riding horses were lunged at working trot on a 16 m diameter circle without (WO) and with a PTA (WP) that was set level with the shoulder. Objective measurements were carried out using high-speed motion capture (125 Hz) and inertial measurement units. Subjective video assessment was also under-taken. When a PTA was applied there was a significant reduction in speed, stride length, head angle (P< 0.0001 for all) and lumbosacral angle at maximal hindlimb retraction (P = 0.0028), but no effect on limb joint angles. The highest point of the horse was significantly different between conditions (WO, poll; WP, crest) (P = 0.0010). Dorsoventral displacement of the middle of the back (P<0.0001) and overall impression grade (P = 0.0002) were significantly greater WP compared with WO. These findings indicated that a PTA may be beneficial for general training and rehabilitation as a method of improving posture, stimulating core muscle activation and improving overall way of going, without increasing the loading of forelimb and hindlimb structures. Further work is warranted to understand the mechanism which induces these changes. [ABSTRACT FROM AUTHOR]

Demonstrates how computational methods can be applied to understanding perception through a process of reverse engineering. Physical characterization of the echo generation and reception process; Implementation and evaluation of the hypothesised perceptual mechanism aboard a mobile robot; Performance of the perceptual mechanism; Conclusion.

Breast cancer (BC) radiotherapy (RT) and resulting left ventricle (LV) exposure have been associated with subclinical LV dysfunction characterized by a global longitudinal strain (GLS) reduction > 10-15% that could arise 6 months after RT. The acute phase of radiation response consists of inflammatory process. Fibrinogen, an essential coagulation factor which has also important role in inflammatory response, may be useful to enhance prediction of the risk of subclinical LV dysfunction in BC patients treated with RT. To investigate the predictive value of pre-RT/post-RT plasma fibrinogen evolution in detecting patients with subclinical LV dysfunction defined as a GLS reduction > 10% six months after BC RT. The study consisted of BC patients treated with RT without chemotherapy. Speckle tracking echocardiography provided GLS before RT and 6 months postRT. Fibrinogen level was measured pre RT and at the end of RT and its evolution was defined by the ratio Post-RT-Pre-RT/Pre-RT (evoFIB). The prediction model was based on logistic regression including LV dose, evoFIB, and covariates. Area Under the Curve (AUC), sensitivity (Se), specificity (Spe) and misclassification error rate were considered in order to evaluate the predictive value of models. The study included 75 BC patients. The addition of FIB, to LV dose and covariates, in the prediction model, allowed enhancing the AUC from 0.80 to 0.85 with an OR per 10% evoFIB increase of = 1.60 (1.1–2.2). Se and Spe were increased from 67% to 75% and from 74% to 78% respectively. Information on evoFIB allowed decreasing misclassification error rate from 29% to 23%. Collecting information on fibrinogen level pre and post RT in BC patients treated with RT could help to enhance prediction of subclinical LV dysfunction. The inflammatory process associated with coagulation in the acute phase post-RT may also be involved in mechanism of cardiac dysfunction observed at later phase. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) radiotherapy (RT) and the resulting cardiac exposure is associated with early decrease of global longitudinal strain (GLS). Recent software allows multi-layer and segmental analysis of strain, which may be of interest to quantify and locate the impact of cardiac exposure on myocardial function and potentially increase the early detection of radiation-induced cardiotoxicity. To evaluate whether decrease in GLS after BC RT is layer-specific and if it varies according to the left ventricular regional level and the coronary arterial territories. LS was measured at baseline before radiotherapy and 6 months post-radiotherapy. The LS was obtained for each myocardial layer (endocardial, mid-myocardial, epicardial), left ventricular regional level (basal, mid, apical) and coronary artery territory (left anterior descending artery (LAD), circumflex artery, right coronary artery). The study included 64 left sided BC patients. Mean age was 58 ± 4 years, mean doses to the heart, the left ventricle and the LAD were respectively 3.0, 6.7 and 16.4 Gy. Despite unchanged LVEF between baseline and 6 months post-RT (61 ± 7% vs. 60 ± 9%, P = 0.07), decreased GLS was observed for the three layers (endocardial: −20.0 ± 3.2% to −18.8 ± 3.8%; mid-myocardial: −16.0 ± 2.7% to −15.0 ± 3.1%; epicardial: −12.3 ± 2.5% to −11.4 ± 2.8%, all P = 0.02), but only the endocardial layer GLS (GLS-endo) relative change was significant (−4.7%, P = 0.049). Indeed, the GLS-endo was significantly decreased for the most exposed parts of the left ventricle corresponding to the apical level (−26.3 ± 4.0% vs. −24.2 ± 7.1%, P = 0.03) and LAD territory (−22.8 ± 4.0% vs. −21.4 ± 4.8%, P = 0.03). Six months post-RT, GLS decreased predominantly in the endocardial layer of the most exposed part of the left ventricle. For precise evaluation of RT-induced cardiotoxicity and early left ventricular dysfunction, the endocardial layer-based GLS might be the most sensitive parameter. [ABSTRACT FROM AUTHOR]

Breast cancer radiotherapy (BC RT) can be associated with long-term, silent and lately detected cardiotoxicity. Longitudinal strain (LS), based on 2D speckle-tracking echocardiography (2DSTE) can early detect subclinical left ventricular dysfunction. Little is known on the association between RT-induced cardiac doses and LS changes. To analyze the relationship between cardiac doses and LS changes after BC RT. BACCARAT is a monocentric prospective cohort study that included BC patients treated with RT without chemotherapy. Global LS, in particular in the mid-layer of the myocardium (GLS-mid), was measured with 2DSTE before RT and 6 months after RT. We evaluated radiation doses to whole heart, left ventricle (LV), left anterior descending coronary artery (LAD). A subclinical event of cardiotoxicity "decreased GLS-mid ≥ 10%" was defined as a relative decrease ≥ 10%. We included 94 patients (18 right-sided BC, 76 left-sided BC) aged 59 ± 8 years. Mean doses to the heart, LV and LAD were respectively: 3.0 ± 1.3 Gy, 6.6 ± 3.2 Gy and 16.5 ± 7.5 Gy for the left-sided BC; 0.6 ± 0.5 Gy, 0.2 ± 0.2 Gy and 0.3 ± 0.5 Gy for the right-sided BC. Left-sided BC had a significant decrease in GLS-mid (%relative change = 9.0%, P = 0.02); the event "decreased GLS-mid ≥ 10%" was detected in 50% of left-sided BC and 38% in the right-sided group. We observed dose-response relationships with mean doses to the heart, the LV and the LAD in univariate analysis, that remained marginally significant in adjusted analysis for mean LV dose and indicating an increase of the event by 11% for each increase of 1 Gy in LV dose (OR = 1.11, 95%CI [0.98–1.26]). This is the first study to establish dose-response relationships between BC RT-induced cardiac doses and decreased LS 6 months after RT. With longer follow-up, it remains to be determined whether these dose-related changes are confirmed and if detection of this subclinical LV dysfunction is related to clinical outcome. [ABSTRACT FROM AUTHOR]