Toe Length Research Articles

Effects of Body Indices and Shoeing on Hoof Morphometry among Sudanese Country-Bred Polo Horses in Nigeria

Several factors influence hoof size which largely determine the normal function of the equine limbs. The effects of shoeing and body indices on hoof morphometry among Sudanese country-bred polo horses in Nigeria were evaluated in the present study. Apparently healthy, shod/barefooted Sudanese country-bred mares without hoof abnormalities were randomly selected and included in the present study. As body indices, we measured the height at withers, heart-girth, body length, and body weight; as hoof parameters, we measured the toe length, solar length, hoof width, and dorsal and ventral hoof wall width on all limbs. Pearson correlation analysis and the independent sample T test were applied for data analysis. The mean height, body weight, heart girth and body length of the Sudanese country-bred horses were 1589.5 ± 56.0 mm, 430.8 ± 42.9 kg, 1758.8±65.31mm and 1649.4±50.03mm respectively which were not significantly different between the shod and barefooted. The dorsal hoof wall width and the hoof solar length and width between the shod and barefooted groups differed statistically significantly (p<0.05). In Sudanese country-bred mares, there was a strong positive correlation that was different significantly between the heart-girth, body length, and body weight. Hoof morphometry and body indices showed a strong positive correlation. The most important ratios relating to hoof size differences between horses with shoes and those without were the hoof index, length, and width to body measurement ratios. According to this study, Sudanese Country-bred horses' hoof morphometry is significantly impacted by shoeing and body indices.

Laboratory-scale study of mixed barriers in stratified layers with an inclined ocean aquifer boundary

The over-pumping of freshwater makes shoreline aquifers susceptible to seawater intrusion. Most studies on aquifer homogeneity that are used to form management guidelines focus on salinization sensitivity. However, under certain extraction conditions, the geographic structure can be quite diverse, with low-permeability obstacles and preferred flow routes that affect circulation and saline transport mechanisms. Here, we used a laboratory-scale glass box apparatus of dimension 100 × 50 × 10 cm3 to study intrusion in stratified layers under the influence of an inclined ocean-aquifer boundary with a mixed barrier as a remediation technique. The TL\\H ratio ranged from 0.2 to 12.84 for all stratification conditions and remediation installed. There was a 40–48 % decrease in the extent of toe length after installation. With a mixed barrier installed, the height of the intrusion was reduced, resulting in an increase in the TL\\H and a decrease in the potential for toe length. The intrusion was delayed by 86.67 % in parallel stratification and 28.22 % in perpendicular stratification after comparing the time frame for base case and the mixed barrier installed condition. A parabolic profile of intrusion was observed in the low-permeability layer, while a convex-outward profile was observed in the higher-permeability layers. Similar results are obtained after conducting the sensitivity analysis. The intrusion follows an increasing pattern of ratio with increasing interaction gap opening in parallel stratification, while for perpendicular stratification, with gap opening from 10 cm to 30 cm, there was a decreasing trend followed by an increasing trend, indicating an increase in magnitude with a similar pattern of intrusion. The results of this investigation shed light on the mixed barrier's suitability for use in realistically diverse coastal aquifers. Future research could explore the utilization of different combinations of new barriers, such as under-surface barriers, which work well for stratified layers, and already established barrier systems, to further improve the efficiency of mixed barriers.

U-T Flap for Distal Symes Toe Amputation. A New Flap Adapted to Diabetic Ulcers of the Pulp of the Lesser Toes

The surgical management of diabetic ulcers of the tip of the toes complicated with osteomyelitis of the distal phalanx usually consists of the excision of the bone and soft tissue using a distal Symes toe amputation. This surgery is usually conducted through 2 coronal flaps. When the ulcer is away from the nail or extends further on the plantar side of the pulp, wound closure could be difficult to achieve resulting in wound dehiscence. In addition, the remaining toe is often too short when compared with the neighboring digits. The objective of this surgical technique is to propose a new flap design that could be simple and easy to learn, mainly when dealing with small-to-moderate–sized wounds. The U-T flap is designed to reduce wound complications and yield better esthetics. We found the U-T flap to be a reproducible technique with better outcomes in terms of surgical wound healing and final toe length, after excision of distal infected toes. Level of Evidence: Diagnostic level 5—expert opinion. See Instructions for Authors for a complete description of levels of evidence.

Experimental and numerical investigation of the effect of air injection on seawater intrusion mitigation

Previous studies have proposed compressed air injection to mitigate seawater intrusion, as a substitute for a hydraulic barrier created using freshwater injection. However, the current understanding of this strategy is based almost entirely on numerical simulation, and therefore, there is a need to investigate the complex processes accompanying this method within a physical setting. This study used sand tank experiments to explore the influence of air injection on the behavior of saltwater within a coastal confined aquifer, extending previous experiments by accounting for freshwater-saltwater density differences. Numerical modeling of the experiments assisted in interpreting experimental observations and allowed for field-scale conditions to be assessed. Numerical models were well matched to experimental observations, which showed a 34 % reduction in saltwater volume and a retreat of the saltwater toe length from 59 cm to 40 cm following air injection. A hypothetical field-scale confined aquifer model indicated that the largest seaward shift in the seawater wedge toe is obtained when the air-injection well is above the initial seawater wedge toe. However, maximal reductions in the seawater volume within the aquifer were obtained from injecting air within the original wedge rather than landward of the toe. This study provides the first physical evidence (through laboratory experiments) that injecting compressed air can effectively mitigate seawater intrusion. We considered a period of one year for field-scale applications, which show that the extent of desaturation likely needs to be mitigated from prolonged application of the method. Initial guidance is developed for the selection of air-injection locations, at least under simplified conditions (e.g. homogeneous, uniform aquifer, etc.).

Tectonic controls on the morphometry of alluvial fans in an arid region, northeast Iran

ABSTRACT The morphology of alluvial fans provides valuable information about changes in tectonic, climate, base level, and drainage basin characteristics. This study aims to evaluate the relationship between active tectonics and morphometric characteristics of alluvial fans in the less studied southern region of the Joghatay mountain, northeast Iran. The study area includes 13 alluvial fans and their corresponding catchment basins in a region with semi-arid climate. Morphometric characteristics of alluvial fans and their corresponding drainage basin including fan area, fan slope, sweep angle, fan toe length, fan radius, basin area, basin slope, fan’s width-to-length ratio, asymmetry factor, and basin shape were measured. Our results revealed a negative relationship between the slope of alluvial fans and their corresponding basin area. The weak correlation between the drainage basin area and the fans area may be attributed to the lithology and active tectonics in the study area. The small sweep angle values of the studied alluvial fans can be attributed to the activity of thrust faults and presence of an uplifting anticline that resulted in formation of elongated alluvial fans in our study area. Analysis of the relationship between the morphometric characteristics of the fans and their corresponding basins indicated a negative correlation, which can be attributed to the sediment transport efficiency of the basins.

Experimental investigation to check the feasibility of an under-surface barrier for stratified layers to remediate seawater intrusion considering an inclined boundary

Passive seawater intrusion is recorded due to geological heterogeneity, such as stratification of aquifers. The purpose of this study is to check the performance of a new kind of barrier system for stratified layers with different permeabilities under the influence of an inclined ocean-aquifer interface. The value of permeability ranges from 0.165–0.457 cm/sec. A base case of homogenous aquifer was used to check the feasibility of the glass box model. Coarser material was employed to validate the results with literature by showing similar wedge formation with faster intrusion that reaches the boundary. Toe length to height ratio was in the range of 2.0 to 3.14. Longitudinal dispersion of 1 cm, transverse dispersion of 0.1 cm, and Péclet number of 1.5 were calculated, which falls under the range defined in literature. Results show that the under-surface barrier is much more successful in stopping intrusion when materials with monotonically increasing permeability are considered, as the toe length increases with increasing permeability. For perpendicular stratification, the use of conventional barrier is much less efficient as compared to an under-surface barrier as the toe length to height ratio decreases. Height of intrusion after using an under-surface barrier in different layers decreases subsequently as compared to without the barrier. Application of these results to real-life problems considering factors such as scaling, heterogeneity, applicability of boundary conditions, and temporal dynamics is suggested. Under-surface barriers have merits like ease of installation, fewer complications, etc. Results exhibit that the use of an under-surface barrier starting from the point where the equilibrium of water has reached and extending towards the impermeable strata is the most efficient approach to follow. Sensitivity analysis to check the behavior of saltwater intrusion under various height openings shows that the toe length is affected by the presence of material with higher permeability.

Bioinspired multilayer braided structure with controllable nonlinear mechanical properties for artificial ligaments

Inspired by “crimped” collagen fiber, which induce a low-level load region within the hierarchical structures of ligaments and tendons, this study introduces a braiding technology aiming at characterizing nonlinear mechanical behavior. Samples of the developed artificial ligament with a multilayer braided structure were fabricated and tested. Alterations in the number of braiding layers, wales, and courses significantly affect the mechanical properties of the artificial ligaments. Specifically, the toe length exhibited an increase of up to 104.58 %, while the linear stiffness exhibited variations concomitant with changes in these parameters. Additionally, a mathematical model to describe the relationship between the toe length and linear stiffness was developed based on the braiding parameters and material properties of the fibers. Alternative fibers were employed and tested to demonstrate a consistency with the mathematical model. The correlation coefficients were calculated as 0.9644 for the toe length and 0.9203 for the linear stiffness. Lastly, this study mimics the mechanical behavior of the human medial collateral ligament (MCL) by integrating the artificial ligament into a bio-fidelity knee model with a joint stiffness of 1.77 Nm/deg, resulting in a high degree of similarity with human knee in valgus-varus, further affirming the utility and applicability of this study.

Human foot form and function: variable and versatile, yet sufficiently related to predict function from form.

The human foot is a complex structure that plays an important role in our capacity for upright locomotion. Comparisons of our feet with those of our closest extinct and extant relatives have linked shape features (e.g. the longitudinal and transverse arches, heel size and toe length) to specific mechanical functions. However, foot shape varies widely across the human population, so it remains unclear if and how specific shape variants are related to locomotor mechanics. Here we constructed a statistical shape-function model (SFM) from 100 healthy participants to directly explore the relationship between the shape and function of our feet. We also examined if we could predict the joint motion and moments occurring within a person's foot during locomotion based purely on shape features. The SFM revealed that the longitudinal and transverse arches, relative foot proportions and toe shape along with their associated joint mechanics were most variable. However, each of these only accounted for small proportions of the overall variation in shape, deformation and joint mechanics, most likely owing to the high structural complexity of the foot. Nevertheless, a leave-one-out analysis showed that the SFM can accurately predict joint mechanics of a novel foot, based on its shape and deformation.

APPLICATION OF MULTIVARIATE STATISTICAL ANALYSIS IN CHARACTERISING THE PHENOTYPIC VARIABILITY OF LOCALLY ADAPTED MUSCOVY DUCKS (CAIRINA MOSCHATA) IN NIGERIA

While there are studies that describe the biometric traits and phenotypic variations in Muscovy ducks in Nigeria, there are limited studies that employ a multivariate approach to depict the phenotypic variability of Muscovy ducks in Nigeria. Therefore, this study aimed to explicate genetic variabilities within C. moschata using qualitative and biometric traits. This study used a multivariate statistical method to phenotypically characterise locally adapted Muscovy duck populations from seven ecogeographical locations in Ibadan, Nigeria. Four qualitative traits (eye colour, bill colour, bean colour and shank colour) and eleven biometric traits (head length, neck length, body length, wings length, shank length, toe length, thigh length, bill length, breast length, breast width and bodyweight) were evaluated in 201 ducks (109 males and 92 females). To study the possible effects of geographical locations on selected phenotypes, frequency distribution, univariate analysis, stepwise and canonical discriminant analyses and cluster analysis were performed. The association between body weight (BWT) and other biometric traits was assessed using the Pearson product-moment correlation coefficient. Male ducks (drakes) were generally more abundant than female ducks (hens). The most prevalent colour traits of locally adapted Muscovy ducks were brown eye colour (70.65 %), black bean colour (62.69 %), pinkish white bill colour (45.27 %) and grey shank colour (56.22 %). Overall, ecogeographical location did not significantly affect (p < 0.05) the measured biometric traits. However, across all locations, the sexual dimorphism was favourable in male ducks, with respect to biometric traits. Stepwise-canonical discriminant analysis revealed a substantial intermixing of biometric traits, especially in Molete, Oje, Adogba and Ajibode ducks. Similarly, the cluster analysis, although it separated the birds into different clusters, showed some level of admixture. The small Mahalanobis distance (0.61 − 3.88) suggested that, with respect to location, there was more morphological similarity than dissimilarity between ducks. The correlation analysis revealed that the body weight of ducks can be fairly estimated from other biometric traits due to their positive, statistically significant correlation. In general, the ducks from all seven ecogeographical locations were rather homogeneous than heterogeneous.

195 The Impact of Developmental Housing Type on Toe Growth and Wear in Sows

Abstract Swine housing systems are ever-changing to improve animal husbandry. Recently, gilts are being transitioned from gestation stalls to pens with resulting phenotypic effects being unclear. Toe growth and wear are often negated during structural analysis, with objective data of their trends being limited. Therefore, the objective of this study was to determine the impact of housing type on toe growth and wear during gestation of golts. York x Landrace gilts (n = 321) were used at the UNL ENREC swine farm. Gilts were randomly assigned to either pen (4 pigs/pen; 2.09 m2/pig) or stall (2.06 x 0.48 m) housing at 210 days of age. For analysis, gilts were lifted in a Feet First Chute (Zinpro) to permanently mark the lateral toes on the left front and back feet at ~1 cm from the coronary band. Toe length above and below the mark was measured with a digital caliper. Measurements took place before breeding (PRE), at day 30 (D30), day 57 (D57), and day 100 (D100) of gestation, and at weaning (WEAN). Estimated marginal means were calculated with regards for development group, housing type, and initial toe lengths. From PRE to D100, stall housed gilts had greater (P < 0.01) front growth (32.5 vs. 26.8 mm), similar front wear (-25.3 vs. -23.4 mm), greater (P < 0.01) back growth (39.1 vs. 34.3 mm), greater (P < 0.01) back wear (-32.3 vs. -28.1 mm), a greater (P < 0.01) total front length (41.6 vs. 39.6 mm), and a slightly longer total back length (45.5 vs. 45 mm). From D100 to WEAN, pen housed gilts had more (P < 0.05) back wear (-5.12 vs. -4.32 mm) and subsequently less (P < 0.01) total back growth (4.88 vs. 6.50 mm); with no other differences showing significance. These results suggest that housing can alter feet conformation with stall developed gilts having longer toes when entering farrowing.

Research on the toe structure design of FPSO module stools

The Nanhai Fenjin floating production storage and offloading (FPSO) vessel has been in service for 20 years, since 2002, and this paper describes a safety assessment for continued service until 2032. In particular, the influences of the toe shape and plate thickness of the module stools on the stress distribution and fatigue life in the toe region were investigated. Initially, four stools located on the port side and in the middle sections were evaluated. The stool with the highest stress levels was then selected for life extension and performance enhancement studies. The investigated factors include panel taper angles, toe shape, soft-toe length, and plate thickness variations; the effects of these factors on stress and fatigue life were determined. A thorough analysis of the stress concentration and weld fatigue in the toe region was performed. Results indicate that altering the toe shape can effectively enhance toe strength and fatigue performance, and extending the toe length within an appropriate range results in large improvements in stool performance. Other factors also exert varying degrees of influence on toe strength and fatigue performance. This study provides valuable insights for designing toes for various marine structures.

Verification of experimental saltwater intrusion interface in unconfined coastal aquifers using numerical and analytical solutions

Saltwater intrusion (SWI) is a widespread environmental problem that poses a threat to coastal aquifers. To address this issue, this research employs both numerical and experimental methods to study saltwater intrusion under the impact of sea level rise and varying freshwater boundary conditions in two homogeneous aquifers. The study compares transient numerical groundwater heads and salt concentrations to experimental results under receding-front and advancing front conditions. In the low permeability aquifer, the root mean square error is 0.33 cm and the R2 is greater than 0.9817. Similarly, in the high permeability aquifer, the root mean square error is 0.92 cm and the R2 is greater than 0.9335. The study also compares the results of ten experimental tests for steady-state saltwater intrusion wedge and toe length with seven different analytical solutions. The experimental results are then compared to these analytical solutions to find the most suitable equation. The Rumer and Harleman equation shows good agreement with experimental saltwater intrusion wedge, while the Anderson equation is a good fit for saltwater intrusion toe length. Overall, this research provides valuable insights into saltwater intrusion in coastal aquifers, and the findings can be used to inform policies and management strategies to mitigate the negative impacts of saltwater intrusion. The investigation shed light on how inland water head and Sea Level Rise (SLR) affect SWI behavior.

Immediate Effect of Hoof Trimming on Hoof and Thoracic Joint Angles in Mangalarga Mares.

It is important to understand the effects of hoof trimming on hoof and limb conformation to maximize its benefits on the health of the appendicular skeleton of horses, thus promoting improvements in athletic performance and sporting longevity with regard to athletic horses. There is little information on possible changes in the angulation of the thoracic limb joints after hoof trimming and correlations between the angulation of the thoracic limb joints with hoof measurements. To that purpose, nineteen Mangalarga mares received routine hoof trimming. Visual recordings (photographs) were taken before and after the procedure. Differences (p < 0.05) were found in hoof length, toe angle, heel angle, medial heel height, and metacarpophalangeal angle. Before trimming, correlations were found between frog length and scapulohumeral angle (SH) (r = -0.457; p = 0.049), and between toe length and shoulder-ground angle (SG) (r = -0.553; p = 0.049). A correlation was also seen between the distance from the frog to the lateral wall and the SH angle (r = 0.690; p = 0.001). After trimming, there was a correlation between humeroradial (HR) and SH joint angles (r = 0.669; p = 0.002), and the SG and SH angles (r = 0.488; p = 0.034). This study showed an immediate effect of trimming on the toe angle and heel angle and on the metacarpophalangeal joint angle, in addition to correlations between the hoof and proximal joint angles, following trimming, thus evidencing the relevance of trimming not only in hoof morphology, but also in the conformation of the appendicular skeleton of horses.

The effect of biological maturation on foot morphology, and their relation to postural stability performance in male footballers.

Biological maturity (BM) and foot morphology (FM) can independently alter neuromuscular loading on the ankle-foot complex, potentially causing stability deficits and injury predisposition. However, the influence of BM on FM, and how much both explain neuromuscular performance in postural stability (PS) tests, has been understudied. This study aimed to investigate the effect of BM on FM, and then discover to what extent both factors explain the variance in PS performance in adolescent footballers. Over one season, 399 three-dimensional foot scans were gathered from 72 footballers (U12-U15). PS was measured by center of pressure (COP) displacement in bilateral and unilateral stance. The Khamis and Roche equation determined maturity status (MS), while formulae from Mirwald and Khamis and Roche estimated timing of biological maturation (TBM). Principal component analysis determined nine principal components that explained the most variance in FM. An ANCOVA determined the effect of TBM on FM principal components, with covariates of age, height, weight, playing position, and foot preference. Step-wise linear regression determined the explanation of COP displacement by the above-mentioned predictors. There was significantly increased foot pronation during and after peak height velocity/puberty. MS and four foot principal components (foot arch and width, great toe width and length) were significant predictors in all PS tests (R2: 0.105-0.180). TBM had a significant effect on FM presentation, and should be a part of adolescent foot assessment. While they only explained a small amount of variance, determining MS and FM may identify those requiring additional PS attention.

Donor Foot Morbidity Following Nonvascularized Toe Phalanx Transfer Utilizing a New Reconstruction Technique.

Nonvascularized toe phalanx transfer is an accepted surgical option for short and hypoplastic digits in congenital hand abnormalities. However, one of the criticisms of this technique is the donor site morbidity. The purpose of this study was to evaluate donor foot morbidity after nonvascularized toe phalanx transfer using a new donor site reconstruction technique. We retrospectively reviewed 116 nonvascularized toe phalanx transfers in 69 children between 2001 and 2020 in whom the donor foot was reconstructed with a new technique using iliac osteochondral bone graft with periosteum. Feet treated with an isolated donor proximal phalanx of the fourth toe were selected and morbidity was assessed both subjectively and objectively at a minimum of 2 years after surgery. Motion, stability, and alignment of the metatarsophalangeal joint were clinically evaluated. The relative length of the fourth toe to the third toe was measured on a roentgenogram. The satisfaction of the parents for overall function and appearance was evaluated using a visual analog scale. Ninety-four operated feet in 65 patients, including 43 boys and 22 girls, were included. The right foot was evaluated in 52 patients and the left foot in 42 patients. The mean age at operation was 2 years and the mean follow-up period was 7.6 years. Motion at the metatarsophalangeal joint was good at 69% with an average extension of 45 degrees and flexion of 25 degrees. Stability and alignment were good at 95% and 84%, respectively. Only 4 toes had gross instability and 4 toes with poor alignment required revision surgery. Sixty-two toes (66%) maintained proportional length and 9 toes were graded as short. Parental satisfaction was high for appearance as well as function. This newly described technique of using iliac osteochondral bone graft with periosteum to reconstruct toe phalanx donors provided satisfactory results. The function and appearance of the donor foot after a nonvascularized toe phalanx transfer was well preserved. Level IV; therapeutic.

Seawater intrusion in fractured coastal aquifers influenced by tides: Laboratory and numerical investigations

Fractured aquifers are particularly vulnerable to seawater intrusion (SWI), but the mechanism of SWI in such aquifers remains largely unknown. This study aims to investigate the influence of tides on SWI in fractured aquifers through laboratory experiments and numerical models. Six fractured aquifers and one homogeneous aquifer were employed to conduct laboratory and numerical experiments to preliminary analyze the comprehensive effects of tides and fractures on salinity distributions, flow fields and submarine groundwater discharge (SGD). Sensitivity analyses were performed to further explore the impact of each fracture characteristic (i.e., horizontal position, vertical position, length and orientation) on SWI properties (i.e., saltwater wedge, mixing, saline volume) and concentration distribution under non-tidal and tidal conditions. The results indicate that tides can expand the variation range of most SWI properties in fractured aquifers and alter the influence patterns of fracture characteristics. Fractures tend to converge around freshwater, and their effect on SWI properties depends on their relative position to the saltwater. Toe length (TL) reached its maximum when the fractures had just separated from the saltwater wedge and were fully submerged in freshwater. Longer fractures promoted SWI and relieved the tides’ restriction on TL. Moreover, horizontal fractures can significantly amplify high-concentration (50%-90%) saltwater distribution, SGD and upper saline plume (USP) with the help of tides, while vertical fractures only had an impact on the mixing zone. These results have important implications for improving our understanding of comprehensive impact of tides and fractures on SWI in coastal subsurface environments.

Morphologic Changes in Postaxial Polydactyly of the Foot: A Standardized Quantitative Analysis Using the Watanabe-Fujita Classification.

Postaxial polydactyly of the foot is one of the most common congenital abnormalities. A wide forefoot, short toe, and lateral joint deviation are associated with aesthetic and functional outcomes. This study used the Watanabe-Fujita classification to characterize the preoperative and postoperative skeletal morphology of postaxial polydactyly of the foot. This retrospective study included 42 patients (51 feet) with postaxial polydactyly treated at age 1 year. Radiographs taken at ages 0 and 3 to 4 years were used for morphologic analysis. The length of the reconstructed toe, the distance between the fourth and fifth metatarsals, and joint deviation angles were measured. The length measures were standardized using the length of the third metatarsal. Morphologic characteristics were compared based on the Watanabe-Fujita classification at ages 0 and 3 to 4 years. Long-term outcomes were also evaluated in patients followed up for longer than 6 years. The fifth-ray proximal phalangeal subtype had the shortest toe length both at ages 0 and 3 to 4 years. Proximal phalangeal joint lateral deviation improved postoperatively in 78% of patients with the fifth-ray middle phalangeal subtype, regardless of reconstruction type. There was no significant change in proximal phalangeal joint deviation between ages 3 to 4 years and 7 years or older. A residual metatarsal was associated with lateral metatarsophalangeal joint deviation and a wide intermetatarsal distance, and required revision surgery. Morphologic changes of postaxial polydactyly of the foot were successfully characterized using the Watanabe-Fujita classification. This classification could be useful for planning surgical strategies and anticipating morphologic outcomes. Therapeutic, IV.

Ecomorphological adaptations of owl feet and talons

AbstractFeet and talons are the most specialized predatory attributes of raptor morphology. As such, the hindlimb morphology of owls should reflect their dietary specialization. Owls' diet varies widely between species with only a subset of owl species preying predominantly on small mammals. We hypothesize that different owl species have varied hindlimb morphology, adapted to their main prey types, and that only dietary specialists will be distinguishable based on talon morphology (e.g. toe length, talon curvature and thickness, etc.). We used a sample of 63 specimens from 15 owl species to obtain a variety of measurements of hindlimb morphology. We then used a discriminant function analysis to investigate the degree of variation between species and diet groups in terms of their morphological measurements. Our results indicate that talon morphology is linked to prey type in the owl species studied. Insect specialists and small mammal specialists were characterized by a low talon curvature, whereas generalists presented a pronounced talon curvature. Fish specialists presented particularly thick and robust talons, and insect specialists showed lower digit strength than other owl species. These findings could help determine the diet of other owl species, particularly endangered species for which data on diet is often scarce. This study will also be very useful in future studies of the ecology of sympatric species, resource partitioning between species, or between sexes of the same species, and more generally to the evolution of owls.

Geometric Morphometric Assessment of Toe Shape in Forest and Urban Lizards Following Hurricane Disturbances.

Evidence suggests that hurricanes can influence the evolution of organisms, with phenotypic traits involved in adhesion, such as the toepads of arboreal lizards, being particularly susceptible to natural selection imposed by hurricanes. To investigate this idea, we quantified trait variation before and after Hurricanes Irma and Maria (2017) in forest and urban populations of the Puerto Rican lizard Anolis cristatellus. We found that the hurricanes affected toe morphology differently between forest and urban sites. In particular, toepads of the forefeet were longer and narrower in forest, but wider in urban populations, compared to pre-hurricane measures. Toepads of the hind feet were larger in area following the hurricanes. Fore and rear toes increased in length following the hurricane. There were no changes in the number of lamellae scales or lamellae spacing, but lamellae 6-11 of the forefeet shifted proximally following the hurricane. We also measured clinging performance and toe shape. We found that toepad area and toe lengths were stronger predictors of adhesive forces than toepad shape. Our results highlight an interaction between urbanization and hurricanes, demonstrating the importance to consider how urban species will respond to extreme weather events. Additionally, our different results for fore and rear feet highlight the importance of evaluating both of these traits when measuring the morphological response to hurricanes in arboreal lizards.

Effect of age at training initiation on hoof morphology and lameness in juvenile American Quarter Horses.

Lameness, discipline, training intensity, environmental variability, and shoeing are all factors demonstrated to affect hoof loading and therefore act as adaptive stimuli to alter hoof morphology. To evaluate the effect of age at training initiation on hoof morphology and lameness incidence and determine if specific hoof morphology measurements correlate with lameness in juvenile American Quarter Horses. Prospective cohort study. American Quarter Horses (n=42; 29 two-year-olds, 13 three-year-olds) entering training were monitored for hoof morphology and lameness over 6 months (months 0, 2, 4, and 6). Hoof measurements (palmar/plantar angles, frog base width/length, toe length/angle, heel length/angle, heel and foot width, wall height/angle) from radiographs and photographs were recorded. Lameness was graded subjectively and objectively (Lameness locator®). Statistical analyses were performed with Fisher's exact test and repeated measures ANOVA with p < 0.05. 25/42 horses developed subclinical lameness (16/42 forelimb, 19/42 hindlimb), with 3-year-olds developing lameness more frequently compared to 2-year-olds overall (p=0.04; 84.6 vs. 48.3%) and in forelimbs (p=0.05; 61.5% vs. 27.6%); no difference was noted between 2- versus 3-year-olds in hindlimbs (p=0.2; 61.5% vs. 37.9%). In lame versus sound forelimbs, 3-year-olds had decreased foot width (p=0.03; 11.48 cm [CI 10.68-12.28] vs. 12.21 cm [CI 11.99-12.42]), decreased toe length (p=0.03; 6.02 cm [CI 5.69-6.36] vs. 6.45 cm [CI 6.32-6.58]), shorter lateral wall height (p=0.03; 4.64 cm [CI 4.31-4.96] vs. 5.11 cm [CI 5.03-5.2]), and shorter medial wall height (p=0.02; 4.58 cm [CI 4.06-5.10] vs. 5.15 cm [CI 4.99-5.30]). In lame versus sound hindlimbs, horses overall (p=0.05; 3.74, CI 3.53-3.96 vs. 3.55, CI 3.48-3.61) and 3-year-olds had longer heels p=0.01; 3.90 cm (CI 3.5-4.3) vs. 3.50 cm (CI 3.39-3.61). Small sample size, lack of control group not entering training. Three-year-old American Quarter Horses entering training were more likely to develop forelimb lameness than 2-year-olds. This subclinical lameness was associated with specific hoof morphology characteristics (decreased foot width, toe length, heel length, and lateral/medial wall height; greater toe angle).