Variance In Length Research Articles

Protein aggregates thermodynamically order regardless of sequence.

Proteins can aggregate into disordered aggregates or ordered assemblies such as amyloid fibrils. These two distinct phases serve differing roles in function and disease. How protein sequence determines the preferred phase is unknown. Here we establish a statistical mechanical disorder-to-order transition condition for compact polymer aggregates, including proteins. The theory produces a simple universal equation determining the favored phase as a function of temperature, polymer length, and interaction energy variance. We show that the sequence-dependent energy variance is efficiently calculated using atomistic simulations, so that the theory has no adjustable parameters. The equation accurately predicts experimental length-dependent crystallization temperatures of synthetic polymers. The equation also predicts that all protein sequences that aggregate will also favor ordering. Consequently, energy must be expended to maintain the steady-state disordered phase if it is not kinetically metastable on physiological timescales. More broadly, the theory suggests that aggregates of organic polymers will generally tend to order on habitable planets.

Root PRR7 Improves the Accuracy of the Shoot Circadian Clock through Nutrient Transport.

The circadian clock allows plants to anticipate and adapt to periodic environmental changes. Organ- and tissue-specific properties of the circadian clock and shoot-to-root circadian signaling have been reported. While this long-distance signaling is thought to coordinate physiological functions across tissues, little is known about the feedback regulation of the root clock on the shoot clock in the hierarchical circadian network. Here, we show that the plant circadian clock conveys circadian information between shoots and roots through sucrose and K+. We also demonstrate that K+ transport from roots suppresses the variance of period length in shoots and then improves the accuracy of the shoot circadian clock. Sucrose measurements and qPCR showed that root sucrose accumulation was regulated by the circadian clock. Furthermore, root circadian clock genes, including PSEUDO-RESPONSE REGULATOR7 (PRR7), were regulated by sucrose, suggesting the involvement of sucrose from the shoot in the regulation of root clock gene expression. Therefore, we performed time-series measurements of xylem sap and micrografting experiments using prr7 mutants and showed that root PRR7 regulates K+ transport and suppresses variance of period length in the shoot. Our modeling analysis supports the idea that root-to-shoot signaling contributes to the precision of the shoot circadian clock. We performed micrografting experiments that illustrated how root PRR7 plays key roles in maintaining the accuracy of shoot circadian rhythms. We thus present a novel directional signaling pathway for circadian information from roots to shoots and propose that plants modulate physiological events in a timely manner through various timekeeping mechanisms.

Variability in sonographic anterior drawer test measurements of the ankle: Experienced versus beginner examiners

BackgroundThis study aimed to clarify the variability in the measurements of stress sonography of the ankle and determine the effects of examiner experience on the measurements. MethodsTwenty examiners (10 experienced and 10 beginners) were included in the study. Each examiner performed stress ultrasonography on a patient with a chronic anterior talofibular ligament injury and a patient with an intact ligament using the reverse anterior drawer method. Changes in ligament length before versus after stress were determined. The same 20 examiners performed ultrasonography on two other patients with an injured or intact ATFL using the anterior drawer method. The length change values and variance were compared between the groups using t-tests and F-tests. ResultsUsing the reverse anterior drawer method, the change in the anterior talofibular ligament length was 3.3 mm (range, 2.2–4.8 mm) in the experienced group and 2.7 mm (0.0–4.1 mm) in the beginner group for the ligament injured patient. The length changes for the patient with intact anterior talofibular ligament were 0.5 mm (0.1–0.9 mm) and 0.4 mm (−0.1–1.5 mm) in the experienced and beginner groups, respectively. There were no significant intergroup differences in measurement amount (P = 0.37) or variance (P = 0.72). Similarly, using the anterior drawer method, no significant differences between the groups were found in measurement amount or variance. ConclusionThe quantitative evaluation of stress sonography of the ankle was variable regardless of examiner experience or stress method, particularly in patients with an anterior talofibular ligament injury. The amount of variability appeared to be unacceptably large for clinical application. Our study results highlight the need for technical standardization.

Content-Rating Consistency of Online Product Review and Its Impact on Helpfulness: A Fine-Grained Level Sentiment Analysis

Aim/Purpose: The objective of this research is to investigate the effect of review consistency between textual content and rating on review helpfulness. A measure of review consistency is introduced to determine the degree to which the review sentiment of textual content conforms with the review rating score. A theoretical model grounded in signaling theory is adopted to explore how different variables (review sentiment, review rating, review length, and review rating variance) affect review consistency and the relationship between review consistency and review helpfulness. Background: Online reviews vary in their characteristics and hence their different quality features and degrees of helpfulness. High-quality online reviews offer consumers the ability to make informed purchase decisions and improve trust in e-commerce websites. The helpfulness of online reviews continues to be a focal research issue regardless of the independent or joint effects of different factors. This research posits that the consistency between review content and review rating is an important quality indicator affecting the helpfulness of online reviews. The review consistency of online reviews is another important requirement for maintaining the significance and perceived value of online reviews. Incidentally, this parameter is inadequately discussed in the literature. A possible reason is that review consistency is not a review feature that can be readily monitored on e-commerce websites. Methodology: More than 100,000 product reviews were collected from Amazon.com and preprocessed using natural language processing tools. Then, the quality reviews were identified, and relevant features were extracted for model training. Machine learning and sentiment analysis techniques were implemented, and each review was assigned a consistency score between 0 (not consistent) and 1 (fully consistent). Finally, signaling theory was employed, and the derived data were analyzed to determine the effect of review consistency on review helpfulness, the effect of several factors on review consistency, and their relationship with review helpfulness. Contribution: This research contributes to the literature by introducing a mathematical measure to determine the consistency between the textual content of online reviews and their associated ratings. Furthermore, a theoretical model grounded in signaling theory was developed to investigate the effect on review helpfulness. This work can considerably extend the body of knowledge on the helpfulness of online reviews, with notable implications for research and practice. Findings: Empirical results have shown that review consistency significantly affects the perceived helpfulness of online reviews. The study similarly finds that review rating is an important factor affecting review consistency; it also confirms a moderating effect of review sentiment, review rating, review length, and review rating variance on the relationship between review consistency and review helpfulness. Overall, the findings reveal the following: (1) online reviews with textual content that correctly explains the associated rating tend to be more helpful; (2) reviews with extreme ratings are more likely to be consistent with their textual content; and (3) comparatively, review consistency more strongly affects the helpfulness of reviews with short textual content, positive polarity textual content, and lower rating scores and variance. Recommendations for Practitioners: E-commerce systems should incorporate a review consistency measure to rank consumer reviews and provide customers with quick and accurate access to the most helpful reviews. Impact on Society: Incorporating a score of review consistency for online reviews can help consumers access the best reviews and make better purchase decisions, and e-commerce systems improve their business, ultimately leading to more effective e-commerce. Future Research: Additional research should be conducted to test the impact of review consistency on helpfulness in different datasets, product types, and different moderating variables.

Psychomotor slowing alters gait velocity, cadence, and stride length and indicates negative symptom severity in psychosis

Schizophrenia is a severe mental disorder, in which 50% of the patients present with motor abnormalities such as psychomotor slowing. Slow spontaneous gait has been reported in schizophrenia. However, comprehensive objective instrumental assessments of multiple gait conditions are missing. Finally, the specific gait patterns of subjects with psychomotor slowing are still unknown. Therefore, this study aimed to objectively assess multiple gait parameters at different walking conditions in patients with schizophrenia with and without psychomotor slowing. Also, we hypothesised gait impairments to correlate with expert ratings of hypokinetic movement disorders and negative symptoms. We collected gait data (GAITRite®) in 70 patients with psychomotor slowing (SRRS (Salpetriere retardation rating scale) ≥15), 22 non-psychomotor slowed patients (SRRS < 15), and 42 healthy controls. Participants performed four walking conditions (self-selected speed, maximum speed, head reclined, and eyes closed) and six gait parameters were extracted (velocity, cadence, stride length, functional ambulation profile (FAP), and variance of stride length and time). Patients with psychomotor slowing presented slower velocity, lower cadence, and shorter stride length in all walking conditions compared to healthy controls, with the non-slowed patients in an intermediate position (all F > 16.18, all p < 0.001). Secondly, slower velocity was associated with more severe hypokinetic movement disorders and negative symptoms. In conclusion, gait impairments exist in a spectrum with healthy controls on one end and patients with psychomotor slowing on the other end. Patients with psychomotor slowing are specifically impaired when an adaptation of gait patterns is required, contributing to the deleterious effects of sedentary behaviours.

The evolutionary dynamics that retain long neutral genomic sequences in face of indel deletion bias: a model and its application to human introns.

Insertions and deletions (indels) of short DNA segments are common evolutionary events. Numerous studies showed that deletions occur more often than insertions in both prokaryotes and eukaryotes. It raises the question why neutral sequences are not eradicated from the genome. We suggest that this is due to a phenomenon we term border-induced selection. Accordingly, a neutral sequence is bordered between conserved regions. Deletions occurring near the borders occasionally protrude to the conserved region and are thereby subject to strong purifying selection. Thus, for short neutral sequences, an insertion bias is expected. Here, we develop a set of increasingly complex models of indel dynamics that incorporate border-induced selection. Furthermore, we show that short conserved sequences within the neutrally evolving sequence help explain: (i) the presence of very long sequences; (ii) the high variance of sequence lengths; and (iii) the possible emergence of multimodality in sequence length distributions. Finally, we fitted our models to the human intron length distribution, as introns are thought to be mostly neutral and bordered by conserved exons. We show that when accounting for the occurrence of short conserved sequences within introns, we reproduce the main features, including the presence of long introns and the multimodality of intron distribution.

Small Scale CLTs for the Nodal Length of Monochromatic Waves

We consider Berry's random planar wave model (1977) for a positive Laplace eigenvalue $E>0$, both in the real and complex case, and prove limit theorems for the nodal statistics associated with a smooth compact domain, in the high-energy limit ($E\to \infty$). Our main result is that both the nodal length (real case) and the number of nodal intersections (complex case) verify a Central Limit Theorem, which is in sharp contrast with the non-Gaussian behaviour observed for real and complex arithmetic random waves on the flat $2$-torus, see Marinucci et al. (2016) and Dalmao et al. (2016). Our findings can be naturally reformulated in terms of the nodal statistics of a single random wave restricted to a compact domain diverging to the whole plane. As such, they can be fruitfully combined with the recent results by Canzani and Hanin (2016), in order to show that, at any point of isotropic scaling and for energy levels diverging sufficently fast, the nodal length of any Gaussian pullback monochromatic wave verifies a central limit theorem with the same scaling as Berry's model. As a remarkable byproduct of our analysis, we rigorously confirm the asymptotic behaviour for the variances of the nodal length and of the number of nodal intersections of isotropic random waves, as derived in Berry (2002).

Temperature and Humidity Regulate Sporulation of Corynespora cassiicola That Is Associated with Pathogenicity in Cucumber (Cucumis sativus L.).

Cucumber target leaf spot, caused by Corynespora cassiicola, is an emerging disease with a high incidence that causes severe damage to cucumbers on a global scale. Therefore, efforts need to be undertaken to limit the spread and infection of this pathogen, preferably by using environmentally friendly methods. In this study, the effects of temperature and moisture on the sporulation of C. cassiicola were investigated in vitro and in vivo. The novelty of our study refers to the observation of spore production and size as well as the revelation of a correlation between spore size and virulence. On potato dextrose agar (PDA) and cucumber-leaf extract agar (CEA), temperature played a critical role in spore production, which was strongly influenced by both temperature and moisture on detached leaves and cucumber seedlings. Maximum spore production was found at 30 °C on PDA and 25 °C on CEA, cucumber detached leaves and living plants. Lower spore productions were observed with a stepwise change of 5 °C. In addition, the largest spore production was found at 100% relative humidity (RH) in comparison to the other tested moisture. Moreover, moisture was found to be the most important factor affecting spore size, accounting for 83.09-84.86% of the total variance in length and 44.72-73.10% of the total variance in width. The longest-narrowest spores were formed at 100% RH, and the shortest-widest spores were formed at 75% RH. Furthermore, the result showed that larger spores of C. cassiicola were more virulent and small spores were avirulent. Our findings will contribute to the development of new strategies for the effective alleviation and control of cucumber target leaf spot.

Freezing of gait, gait initiation, and gait automaticity share a similar neural substrate in Parkinson's disease

Individuals with Parkinson’s disease (PD) and freezing of gait (FOG) have difficulty initiating and maintaining a healthy gait pattern; however, the relationship among FOG severity, gait initiation, and gait automaticity, in addition to the neural substrate of this relationship has not been investigated. This study investigated the association among FOG severity during turning (FOG-ratio), gait initiation (anticipatory postural adjustment [APA]), and gait automaticity (dual-task cost [DTC]), and the neural substrates of these associations. Thirty-four individuals with FOG of PD were assessed in the ON-medication state. FOG-ratio during a turning test, gait automaticity using DTC on stride length and gait speed, and APA during an event-related functional magnetic resonance imaging protocol to assess brain activity from the regions of interest (e.g., dorsolateral prefrontal cortex [DLPFC] and mesencephalic locomotor region [MLR]) were assessed in separated days. Results showed that FOG-ratio, APA amplitude, and DTC on stride length are negatively associated among them (P < 0.05). APA amplitude and DTC on stride length explained 59% of the FOG-ratio variance (P < 0.05). Although the activity of the right DLPFC and right MLR explained 55% of the FOG-ratio variance (P < 0.05) and 30% of the DTC on stride length variance (P ≤ 0.05), only the activity of the right MLR explained 23% of the APA amplitude (P < 0.05). FOG severity during turning, APA amplitude, and stride length automaticity are associated among them and share a similar locomotor substrate, as the MLR activity was a common brain region in explaining the variance of these variables.

Syntactic modulation of rhythm in Australian pied butcherbird song.

The acoustic structure of birdsong is spectrally and temporally complex. Temporal complexity is often investigated in a syntactic framework focusing on the statistical features of symbolic song sequences. Alternatively, temporal patterns can be investigated in a rhythmic framework that focuses on the relative timing between song elements. Here, we investigate the merits of combining both frameworks by integrating syntactic and rhythmic analyses of Australian pied butcherbird (Cracticus nigrogularis) songs, which exhibit organized syntax and diverse rhythms. We show that rhythms of the pied butcherbird song bouts in our sample are categorically organized and predictable by the song’s first-order sequential syntax. These song rhythms remain categorically distributed and strongly associated with the first-order sequential syntax even after controlling for variance in note length, suggesting that the silent intervals between notes induce a rhythmic structure on note sequences. We discuss the implication of syntactic–rhythmic relations as a relevant feature of song complexity with respect to signals such as human speech and music, and advocate for a broader conception of song complexity that takes into account syntax, rhythm, and their interaction with other acoustic and perceptual features.

Influence of Wood Pulp Properties on the Efficiency of Carboxymethylation

Wood pulp properties are important controlling parameters to produce cellulose derivatives because they could affect the chemical accessibility and reactivity. This study investigated the effect of wood pulp properties on the carboxymethylation of pulp cellulose using various cooking techniques and species-appropriates fractionations. The efficiency of carboxymethylation was improved with the increase in the alpha-cellulose of pulp because lignin and hemicellulose, which adversely affect derivatization, were removed. In the case of hardwood, the removal of the fines comprising vessel elements had a positive effect on the carboxymethylation. In the case of softwood, the narrow variance of fiber length and width by fractionation was positive in improving the efficiency of carboxymethylation. The highest carboxyl content was 2.02 mmole/g when 12 g of monochloroacetic acid is added. Therefore, it is important to control pulp fiber characteristics to achieve the desired quality of carboxymethyl cellulose.

The effect of sex, stature, and limb length on the preferred walk-to-run transition speed

BackgroundThe preferred walk-to-run transition speed (PTS) for healthy adults is approximately 2 m∙s-1, however, PTS is influenced by anthropometric factors. Yet despite known sex differences in anthropometrics, studies have reported no sex differences in PTS. Research questionDo stature and limb length affect PTS in the same way for both male and female healthy adults? MethodsThirty-seven (19 female) non-injured adults volunteered for this study. Participants completed a walk-to-run transition protocol, where the treadmill speed was increased from 1.2 m∙s-1 to 2.2 m∙s-1, in increments of 0.1 m∙s-1 every two minutes. An independent t-test compared PTS between sexes. Multiple regression analysis determined the effect of sex and stature and sex and limb length on PTS. ResultsFemale participants transitioned at a lower PTS than male participants (1.8 (0.2) m∙s-1 versus 1.9 (0.1) m∙s-1; p ≤ 0.026). Sex and stature explained 19% of the variance in PTS, while sex and limb length explained 21% of the variance. Including interactions increased the variance explained by 23% and 2% for sex and stature and sex and limb length, respectively. The significant interaction between sex and stature showed PTS was inversely proportional to stature for male participants but directly proportional for female participants. SignificanceThese findings suggest that the extent to which stature and limb length influence the preferred transition speed may differ between sexes.

Are external fixators as effective as volar plates in multi-fragmented radius distal intra-articular fractures (AO type C)?

This study aimed to compare the radiological and clinical results of VP and EF applications in multi-fragmented radius distal intra-articular fractures (AO type C) in our clinic. We retrospectively analysed 80 patients who underwent surgery for radius distal fracture (AO type C) between 2014 and 2020. Group 1 comprised patients who were treated with VP, and Group 2 comprised patients who were treated with EF. Radiological evaluation was performed by measuring radial inclination, radial length, volar tilt, intra-articular step-off and ulnar variance by two-way radiography. The clinical findings were evaluated using the Gartland and Werley scoring system, and complications were noted. There were no statistically significant differences between the two groups in terms of age, gender, side, fracture subtypes and follow-up time (p > 0.05). There were no statistically significant differences between the two groups in radiological parameters (based on cut-off values) (p > 0.05). The clinical evaluation did not reveal a statistically significant difference between the two groups (p = 0.613). EF is as successful as VP in providing radiological cut-off values. EF treatment can be used as an effective and safe alternative method for multi-fragmented radius distal intra-articular fractures.

Predicting Language in Children with ASD Using Spontaneous Language Samples and Standardized Measures.

This longitudinal study examined the degree to which standardized measures of language and natural language samples predicted later language usage in a heterogeneous sample of children with autism spectrum disorder (ASD), and how this relationship is impacted by ASD severity and interventions. Participants with a diagnosis of ASD (N = 54, 41 males) completed standardized assessments of language and social functioning; natural language samples were transcribed from play-based interactions. Findings indicated that standardized language measures, natural language measures, and ADOS severity were each unique predictors of later lexical use. Intervention types also appeared to impact later language; in particular, participation in mainstream inclusion accounted for significant amounts of variance in children's mean length of utterance at T3.

Functional and radiological outcome measures of surgically treated unstable distal radius fractures using a variable angle volar locking compression plate

Background: Various treatment modalities have been described to manage unstable distal end radius fractures. The use of variable angle volar locking compression plates is promoted for the management of these difficult fractures. Objectives: Objective was to evaluate the clinical and radiological outcomes in surgically treated unstable distal radius fractures with variable angle volar locking compression plates. Patients and Methods: We reviewed 23 out of 36 unstable distal end radius fractures that were surgically treated with variable angle volar locking compression plates at our institute. The mean age of these patients were 32.82 _ 11.81 years (range 19 to 62) and the mean follow-up duration was 11.04_2.47 months (range 6 to 15). All of them underwent open reduction and internal fixation with a variable angle volar locking compression plate. Radiological parameters measured were radial inclination, length, tilt, and ulnar variance. These were measured at six weeks and at the final follow up. The functional evaluation was by measuring the range of motion at the wrist and the grip strength. To assess the final outcome Gartland and Werley’s demerit scoring system was used.

Optimization of Non-Uniform Perforation Parameters for Multi-Cluster Fracturing

Stress shadowing affects the simultaneous propagation of fractures from multiple perforation clusters. Employing uniform perforation parameters for all clusters cause the unbalanced growth of fractures, which arouses the demand of optimizing non-uniform perforation parameters. An optimization workflow combining a fracture propagation model and the particle swarm optimization method (PSO) is proposed for multi-cluster fracturing in this study. The fracture model considers the coupling of rock deformation and fluid flow along the wellbore and fractures, and it is solved by using the Newton iteration method. The optimization is performed by taking the variance of multiple fracture lengths as fitness value function in the frame of the PSO method. Numerical results show that using the same spacings and perforation parameters for all clusters is detrimental to the balanced growth of multiple fractures. The variance of fracture lengths drops greatly through optimization of cluster spacings and perforation number/diameter. Properly increasing the spacing and perforation number/diameter for the middle clusters promotes the balanced growth of multiple fractures. This study provides an efficient optimization workflow for multi-cluster fracturing treatment in horizontal wells.

Addressing discourse differences in the writing of Russian engineering students and international researchers

Virtually all researchers understand the requirement of presenting their studies in peer-reviewed English-medium journals. Russian scientific writers understand this necessity too; however, evidence suggests that these particular researchers are under-performing relative to similar non-native English speakers. The considerable challenge Russians face centers on articulating their ideas in English in the way that meets the norms and expectations of their international discourse community. That is, their writing is characterized as wordy, cumbersome, too academese, and syntactically complex. These issues need to be addressed in the early stages of developing writing skills. In this study, we address discourse differences between the scientific writing of Russian engineering students and that of international experts. Using the computational linguistics tools Coh-Metrix and Gramulator, we compare a corpus of students’ manuscripts with a similar corpus of experts’ published papers. We focused on six conceptual categories: readability, writing quality, cohesion, syntax, word choice, and genre purity. The overall results suggest that student writing differs significantly for multiple characteristics of text and discourse. A discriminant analysis provided a model that successfully predicts group membership and helps identify the most important issues in Russian student writing. Measures such as noun phrase density, genre purity, word age of acquisition, and variance in sentence length were found to be significant positive predictors of Russian student writing, whereas lexical diversity, adversative/contrastive connectives, adverbial phrase density, and word concreteness were significant positive predictors of expert writing. Our analysis allowed us to provide guidance for instructors, materials designers, as well as for technological assessment tools.

Clinical outcomes of open-wedge corrective osteotomy using autogenous or allogenic bone grafts for malunited distal radius: A novel parameter for measuring the rate of bone union.

The aims of the study were (1) to compare outcomes in terms of malunited distal radius bone union in open-wedge corrective osteotomy using autogenous or allogenic bone and (2) to introduce a new parameter that quantifies the rate of the bone union. This retrospective study included 22 patients (14 males, 8 females) who underwent open-wedge corrective osteotomy with bone grafting for a malunited distal radius fracture between January 2006 and December 2018 were enrolled. The mean follow-up duration was 57.2 weeks (SD 46.1, range 12-206). All the patients were then divided into 1 of the 2 groups based on the graft material used: autog- enous bone graft group (n=10, 5 males and 5 females) and allogenic bone graft group (n=12, 9 males and 3 females). We introduced the "duration of union/correction gap ratio" to represent the healing potential of each graft materials. Radiologic parameters including initial correction gap, radial inclination, radial length, palmar tilt, and ulnar variance were also measured pre- and postoperatively. Functional outcomes were assessed by grip strength, range of motion, and the disability of the Arm, Shoulder, and Hand score. Of the 22 patients, 16 (72.7%) achieved complete union within 12 weeks, 3 (13.6%) in over 12 weeks, and the other 3 (13.6%) showed nonunion. Excluding the 3 nonunion cases, the mean union duration was 10.6 weeks, and the mean correction gap was 10 mm. The mean correction gap was wider in the autogenous bone graft group, and the mean union duration was longer in the allogenic bone graft group. Autogenous bone grafts had a significantly lower duration of bone union/correction gap ratio than allogenic bone grafts (0.76 vs. 1.61, P < 0.001). According to the correction method (simple open-wedge corrective osteotomy vs. open-wedge corrective oste- otomy OWCO), only duration of bone union/correction gap ratio reflected the actual difference between values. Despite autogenous bone graft donor site morbidities, in our study, autogenous bone showed better bone healing potential than allogenic bone. In terms of bone union, autogenous bone has the benefit of better union in larger gaps than allogenic bone. Surgeons can take advantage of the newly introduced "duration of bone union/correction gap ratio" to compare the bone healing potential by graft materials or surgical options. Level IV, Therapeutic Study.

Development of a modified cross-over hop test to reduce measurement errors in return-to-competition testing.

Hop tests play an important role in the rehabilitation process after injuries. A comparison of the jumping distances of both extremities allows for an evaluation of the injured limb. In the conventional cross-over hop test for distance, the jump width (medial vs. lateral) that the athlete has to cross during the jump is not standardised and therefore highly variable. This affects the absolute jump length in each jump series. Modifying the test may reduce the jump length variance between test series of an athlete as well as the test-dependent variations in the cross-over hop for distance. N = 47 athletes from the German and French national Judo youth teams were included in the study (age: 15.3 years ± 13-17). A modified version of the cross-over hop for distance was developed with a cross-over width of 50 cm and a fixed landing zone of 10 cm. The jump lengths of the conventional test and the modified test were documented. The change in jump length variations of the two sexes were compared. The mean value of the coefficient of variation decreased significantly from 4.09 % to 2.83 % (p < 0.01) due to the test modification. This resulted in an absolute improvement in accuracy of 1.26 % and a relative improvement of 30.8 %. A comparison of the limb symmetry index between the conventional and the modified cross-over hop for distance revealed no significant differences. The modified cross-over hop for distance showed a significantly lower variation in jump lengths compared with the conventional cross-over hop for distance. As a result, more accurate statements can be made regarding the patient's return-to-competition progress.

Determining Objective Parameters to Assess Gait Quality in Franches-Montagnes Horses for Ground Coverage and Over-Tracking - Part 1: At Walk

Ground coverage and over-tracking are two gait quality traits describing the forward movement of the front respectively the hind limbs in relation to stride length and over-tracking distance. To investigate the complex interplay of different movement patterns in ground coverage and over-tracking, limb and body kinematics of 24 Franches-Montagnes (FM) stallions were measured with 3D optical motion capture (OMC) on a treadmill during an incremental speed test at the walk (1.4–2.0 m/s). The significance and amount of explained variance of kinematic parameters on stride length and over-tracking distance were estimated using linear mixed-effect models, with speed and horse as random effects. Two separate models were tested: a full model with all parameters measurable by OMC, and a reduced model with a subset of parameters also measurable with inertial measurement units (IMUs). The kinematic parameters were correlated to the subjective scores from six breeding experts to interpret their external validity. The parameter for ground coverage at the walk, explaining most of the variance in stride length, were the maximal forelimb retraction angle (11%) measured with OMC, and the range of pelvis pitch (10%) if measuring with IMUs. The latter was also the most relevant for quantifying over-tracking, explaining 24% to 33% of the variance in the over-tracking distance. The scores from most breeding experts were significantly correlated (r ≥ |0.41|) with the fore- and hind limb protraction angles, which reflect the textual definition of ground coverage and over-tracking. Both gait quality traits can be objectively quantified using either OMC or IMUs.