Assessment of cannabidiol use in pets according to a national survey in the USA.

OBJECTIVES: Conduct an online questionnaire to understand the motivations and perceptions about cannabidiol use in companion animals in the USA. MATERIALS AND METHODS: Data from a USA population sample who owned a pet were gathered using an online questionnaire. Perception of cannabidiol efficacy was analysed for independence against explanatory variables using the Pearson chi-square test, followed by a binary logistic regression. RESULTS: A total of 1238 participants completed the survey; 356 had administered cannabidiol to their pet before. Dogs were the most prevalent pet, followed by cats (75.8 and 22.2%, respectively). Treats/chews and oils were the most common forms of cannabidiol (44.6 and 42.9%, respectively). The most prevalent condition for treating with cannabidiol was anxiety and stress (67.4%), followed by joint pain and inflammation (23%). Doses and frequency of cannabidiol used by many pet owners were inconsistent, and yet many participants perceived an improvement of their pets' condition with supplementation, with mild to no side effects. Most respondents had not given cannabidiol to their pets before due to uncertainty about its efficacy and safety. The frequency of cannabidiol administration and length of time administered were both significant for whether participants found it efficacious in treating a given condition, and this was more evident when supplementing cannabidiol for a longer time. CLINICAL SIGNIFICANCE: We found heterogeneity regarding cannabidiol dosage and dosing frequency. Cannabidiol was mostly perceived as safe and effective, but there is a need to conduct further research on cannabidiol long-term tolerability and therapeutic efficacy for treating various conditions.

Comparison of radiographic scoring systems for assessment of bone healing after tibial plateau leveling osteotomy in dogs.

Introduction: Accurate radiographic assessment of bone healing is vital in determining both clinical treatment and for assessing interventions aimed at the promotion of bone healing. Several scoring systems have been used to evaluate osteotomy changes following tibial plateau leveling osteotomy (TPLO). The goal of this study was to compare the ability of five radiographic scoring systems to identify changes in bone healing following TPLO over time (Aim I), and to evaluate the influence of limb positioning on TPLO osteotomy scoring (Aim II). Materials and methods: Phase I-A randomized, blinded, prospective study was conducted using similarly positioned postoperative TPLO radiographs from seven dogs taken immediately postoperatively, 6-weeks, and 8-weeks postoperatively. Ten reviewers assessed the radiographs, and five different scoring systems were tested for each set including three previously published ones, a Visual Analog Score (VAS), and a subjective 11-point scale. For each system, responses for 6-week postoperative were compared to 8-week postoperative. Scores were judged as correct (=showing an increase in score), incorrect (=decrease in score), or unchanged (=same score). Phase II-An international group of 39 reviewers was asked to score radiographs from three dogs, taken in different positions, using the VAS grading system. Scores were averaged and comparisons were made for each set. Results: Phase I-The VAS system identified the greatest number of sets correctly (76%), with the least unchanged scores (15%), and 9% incorrect scores. Phase II-All three patients had an increase in the average difference between VAS-scores for differently positioned radiographs compared to similarly positioned radiographs. The magnitude of change between different positions far exceeded the magnitude of comparison of the similarly positioned radiographs from the 6- and 8-week time point. Discussion/Conclusion: The VAS system appears to be the most appropriate of the tested systems to identify small changes in bone healing. In addition, the positioning of postoperative TPLO radiographs makes a substantial difference in the healing score that is assigned. Care must be undertaken when performing postoperative radiographs in both the clinical and research setting to ensure accurate assessment of bone healing.

Comparison of activity levels derived from two accelerometers in dogs with osteoarthritis: Implications for clinical trials.

Accelerometer measurements are frequently reported as total weekly activity counts (AC). Methods of utilizing activity parameters to allow differentiation of activity intensities (i.e., manually derived cut-points) have been described. While this information may provide valuable data for researchers, only few investigators have utilized these methods. This may, in part, be due to the challenge associated with data processing. Some devices, however, generate activity intensity data automatically. This study was conducted to evaluate a novel accelerometer that allows for remote download of data via Wi-Fi (Heyrex), to compare automatically generated parameters quantifying activity levels to previously established cut-points (Actical) and to describe the variability of accelerometer data in dogs with osteoarthritis. Twelve client-owned dogs with osteoarthritis were fitted with a collar with two accelerometers (Heyrex and Actical). Accelerometer data were recorded for 28 days. Pearson bivariate correlations and coefficient of variation (CV%) were calculated for accelerometer data. There was a strong correlation between the AC reported by Heyrex and Actical devices. Several automatically generated parameters showed strong correlations to previously validated cut-points and displayed lower CV% than weekly AC. The activity intensity derived from the Heyrex was associated with the lowest CV% of all parameters from both accelerometers. Automatically generated activity intensity parameters should be considered as potential outcome measures in clinical trials for dogs with osteoarthritis. This novel technology may allow for convenient acquisition of activity intensity data in companion animals. However, technical difficulties (e.g., lack of Wi-Fi connectivity) may pose challenges when using this novel device.

Hanbury-Brown and Twiss exchange and non-equilibrium-induced correlations in disordered, four-terminal graphene-ribbon conductor.

We have investigated current-current correlations in a cross-shaped conductor made of graphene. The mean free path of charge carriers is on the order of the ribbon width which leads to a hybrid conductor where there is diffusive transport in the device arms while the central connection region displays near ballistic transport. Our data on auto and cross correlations deviate from the predictions of Landauer-Büttiker theory, and agreement can be obtained only by taking into account contributions from non-thermal electron distributions at the inlets to the semiballistic center, in which the partition noise becomes strongly modified. The experimental results display distinct Hanbury - Brown and Twiss (HBT) exchange correlations, the strength of which is boosted by the non-equilibrium occupation-number fluctuations internal to this hybrid conductor. Our work demonstrates that variation in electron coherence along atomically-thin, two-dimensional conductors has significant implications on their noise and cross correlation properties.

Compact étendue-preserving light-mixing optics.

We present a compact freeform optic, called "Freeform Shell-Mixer", which, when placed on top of a multicolor light source (particularly, a multi-chip LED), turns it into a virtual source in which colors are uniformly mixed. The optic, compatible with injection molding, makes use of étendue-conserving Köhler integration to provide homogeneous mixing of light. Its minimal size (just 2x larger than the source) makes the concept compatible with many luminaries, as ray tracing models show. Simulations indicate that the Freeform Shell-Mixer can reach efficiencies above 95% and both the size of the virtual source and its emission pattern are very similar to the ones of the original source, so the correct performance of the luminaire is secured.

High energy focused shock wave therapy accelerates bone healing. A blinded, prospective, randomized canine clinical trial.

OBJECTIVES: To evaluate the influence of shock wave therapy (SWT) on radiographic evidence of bone healing after tibial plateau leveling osteotomy (TPLO). METHODS: Healthy dogs between two to nine years of age that underwent TPLO were randomly assigned to receive either electro-hydraulic SWT (1,000 shocks) or sham treatment (SHAM). Treatment or SHAM was administered to the osteotomy site immediately postoperatively and two weeks postoperatively. Three blinded radiologists evaluated orthogonal radiographs performed eight weeks postoperatively with both a 5-point and a 10-point bone healing scale. Linear regression analysis was used to compare median healing scores between groups. RESULTS: Forty-two dogs (50 stifles) were included in the statistical analysis. No major complications were observed and all osteotomies healed uneventfully. The median healing scores were significantly higher at eight weeks postoperatively for the SWT group compared to the SHAM group for the 10-point (p <0.0002) and 5-point scoring systems (p <0.0001). CLINICAL SIGNIFICANCE: Shock wave therapy applied immediately and two weeks postoperatively led to more advanced bone healing at the eight week time point in this study population. The results of this study support the use of electro-hydraulic SWT as a means of accelerating acute bone healing of canine osteotomies. Additional studies are needed to evaluate its use for acceleration of bone healing following fracture, or with delayed union.

Evaluation of the accuracy of a veterinary dynamometric wire tensioner.

OBJECTIVES: The purpose of this study was to determine the accuracy of a commonly used veterinary wire tensioner. METHODS: Wire tension was measured using a load cell after each of five tensioners were used to tension each of six wires to the 66, 84, and 118 mm ring settings in an adjustable custom testing fixture. Each tensioner then experienced simulated aging and testing was repeated. Percentage error was calculated for each ring size, before and after tensioner aging. Measured tension values were compared to manufacturer reported tension values for each ring size using a one-sample two-way t-test; p <0.05 was considered significant. RESULTS: Compared to the manufacturer reported values, measured wire tension values were significantly lower for 66 mm and 84 mm rings and significantly higher for 118 mm rings, before and after simulated aging. Mean wire tension values did not significantly differ between individual wire tensioners. CLINICAL SIGNIFICANCE: The tensioners tested achieved significantly different wire tension values than those reported by the manufacturer. This discrepancy could lead to under-tensioning and allowing excessive movement at a fracture site or over-tensioning, leading to wire breakage. We recommend tensioning wires at least to the recommended line on the device for 66 mm and 84 mm rings and at most to the recommended line for 118 mm rings. Further studies are needed to evaluate other veterinary wire tensioners and to develop a calibration method for these devices in practice.

Treatment of canine cranial cruciate ligament disease. A survey of ACVS Diplomates and primary care veterinarians.

OBJECTIVE: To describe veterinarians' treatment recommendations and decision-making factors for dogs with cranial cruciate ligament disease (CCLD). METHODS: An online survey of American College of Veterinary Surgeons (ACVS)-Diplomates (surgeon group) and primary care veterinarians (practitioner group) was performed. The survey included questions on treatment recommendations for common case scenarios (small or large breed dog with complete or partial CCLD), treatment decision factors, non-surgical treatment options, and actual treatment, if any, provided for a client-owned dog as well as one owned by their family or close friend. RESULTS: The response rate was 42% for the surgeon group (n = 305/723) and four percent for the practitioner group (n = 1145/ 27,771). Extracapsular stabilization (ES) was the most common treatment recommendation for CCLD in small (9.1 kg) breed dogs amongst surgeons and practitioners. Tibial plateau levelling osteotomy (TPLO) was the most common treatment recommendation for CCLD in large (27.2 kg) breed dogs amongst both groups. The two most important treatment decision factors were dog size (78% of practitioners, 69% of surgeons) and activity level (63% of practitioners, 52% of surgeons). The most common treatment provided for a dog of their own or close relation in the surgeon group was TPLO (64%) followed by ES (15%), whereas in the practitioner group it was ES (38%) followed by TPLO (30%). CLINICAL SIGNIFICANCE: Extracapsular stabilization and TPLO are the most commonly employed surgical procedures in the surveyed population; dog size and activity level (but not age) are the major factors influencing treatment decisions.

Accuracy of a radiographic stitching technique to measure tibial plateau angle in large and giant breed dogs.

OBJECTIVE: To determine if a novel radiographic stitching technique yields accurate tibial plateau angle (TPA) measurements in large and giant breed dogs. METHODS: Three medio-lateral digital radiographic projections (traditional TPLO, stifle-centred, tarsus-centred) were obtained from each of 17 pairs of pelvic limbs from skeletally mature large and giant breed dogs. Eight observers performed image stitching followed by TPA measurements on the stitched (sTPA) and traditional radiographs (tTPA). The TPA was also measured on photographs made of isolated anatomical tibial specimens (aTPA). Measurements were compared between observers and between image type using ANOVA and correlation coefficients. RESULTS: There was no statistically significant difference in TPA between observers for tTPA or sTPA radiographs (p >0.05); both sTPA and tTPA were highly correlated with aTPA and with each other (r = 0.88, 0.89, and 0.97 respectively). CLINICAL RELEVANCE: This novel digital stitching method provides an alternative technique for accurately measuring TPA utilizing a stifle-centred radiograph that may be useful when traditional TPLO radiographs are difficult to obtain. This may be particularly useful in large and giant breed dogs because collimation to include the entire tibial length can preclude proper centring of the radiographic beam over the stifle.

Fractional quantum Hall effect in suspended graphene probed with two-terminal measurements.

Recently, fractional quantization of two-terminal conductance was reported in suspended graphene. The quantization, which was clearly visible in fields as low as 2 T and persistent up to 20 K in 12 T, was attributed to the formation of an incompressible fractional quantum Hall state. Here, we argue that the failure of earlier experiments to detect the integer and fractional quantum Hall effect with a Hall-bar lead geometry is a consequence of the invasive character of voltage probes in mesoscopic samples, which are easily shorted out owing to the formation of hot spots near the edges of the sample. This conclusion is supported by a detailed comparison with a solvable transport model. We also consider, and rule out, an alternative interpretation of the quantization in terms of the formation of a p-n-p junction, which could result from contact doping or density inhomogeneity. Finally, we discuss the estimate of the quasi-particle gap of the quantum Hall state. The gap value, obtained from the transport data using a conformal mapping technique, is considerably larger than in GaAs-based two-dimensional electron systems, reflecting the stronger Coulomb interactions in graphene.

Modification of electronic properties of graphene with self-assembled monolayers.

Integration of organic and inorganic electronic materials is one of the emerging approaches to achieve novel material functionalities. Here, we demonstrate a stable self-assembled monolayer of an alkylsilane grown at the surface of graphite and graphene. Detailed characterization of the system using scanning probe microscopy, X-ray photoelectron spectroscopy, and transport measurements reveals the monolayer structure and its effect on the electronic properties of graphene. The monolayer induces a strong surface doping with a high density of mobile holes (n > 10(13) cm(-2)). The ability to tune electronic properties of graphene via stable molecular self-assembly, including selective doping of steps, edges, and other defects, may have important implications in future graphene electronics.