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Background Creatine kinase (CK) and aspartate aminotransferase (AST) activity can be increased with myositis associated with Toxoplasma and Neospora infection in dogs. Hypothesis/Objectives Serum activity of CK and AST can be used as a rapid screen for predicting positive serology in meningoencephalitis caused by Toxoplasma gondii or Neospora caninum in dogs compared to dogs with noninfectious meningoencephalitis. Animals Eighty dogs with meningoencephalitis based on magnetic resonance imaging and cerebrospinal fluid analysis. Methods Retrospective case‐control study. Serological cutoffs (≥1:800 immunofluorescence for Neospora and ≥1:400 IgG or ≥1:64 IgM or both for Toxoplasma) categorized dogs as infected (n = 21, all neosporosis) or noninfected (n = 59). Activities of CK and AST between infected and noninfected groups were compared using a Mann‐Whitney U test and receiver operating characteristic curve analysis. Results No dogs were diagnosed with toxoplasmosis. Serum CK and AST activities were significantly increased (P 99%. An AST cutoff of 57 U/L had 94.44% sensitivity and 85.71% specificity with an estimated negative predicative value of 99%. Conclusions and Clinical Importance High serum CK and AST activity can increase suspicion for neosporosis while awaiting serological tests for dogs with meningoencephalitis.

Background Implantable vagus nerve stimulation (VNS) devices can be used to treat epilepsy in dogs. Adverse effects and short-term complications associated with delivering suggested therapeutic electrical stimulation (>1.5 mA) are not well-described. Objectives To compare complications and adverse effects observed with standard and rapid protocols of current increase. Animals Sixteen client-owned dogs with idiopathic epilepsy. Methods Nonrandomized, nonblinded prospective cohort study. Surgical complications, stimulation-related adverse effects, modifications to stimulator settings, number of hospital visits, and time to reach 1.5 mA stimulation current without intolerable adverse effects were described in dogs receiving current increases every 1 to 3 weeks (slow ramping) and dogs receiving current increases every 8 to 12 hours (fast ramping). Results Self-resolving surgery site seromas formed in 6 dogs. No other surgical complications were observed. Fourteen dogs reached 1.5 mA. Coughing (11/14 dogs; 5 slow, 6 fast ramping) was the most common adverse effect. Intolerable coughing that limited current increases despite changing other stimulus parameters occurred in 6/7 of the fast-ramping group and in none of the slow-ramping group. Median time to 1.5 mA was 72 days (range, 28-98) in the slow-ramping group and 77 days (range, 3-152) in the fast-ramping group. Median number of clinic visits was 6 for the slow-ramping group (range, 5-6) and 3 for the fast-ramping group (range, 1-7). Conclusions and clinical importance Coughing is a common adverse effect of VNS in dogs and generally is well tolerated, particularly if current is increased slowly and other stimulation parameters are adapted for effect.

Monin–Obukhov similarity theory (MOST) provides important scaling laws for flow properties in the surface layer of the atmosphere and has contributed to most of our understanding of the near-surface turbulence. The prediction of near-surface vertical mixing in most operational ocean models is largely built upon this theory. However, the validity of MOST in the upper ocean is questionable due to the demonstrated importance of surface waves in the region. Here we examine the validity of MOST in the statically unstable oceanic surface layer, using data collected from two open ocean sites with different wave conditions. The observed vertical temperature gradients are found to be about half of those predicted by MOST. We hypothesize this is attributable to either the breaking of surface waves, or Langmuir turbulence generated by the wave–current interaction. Existing turbulence closure models for surface wave breaking and for Langmuir turbulence are simplified to test these two hypotheses. Although both models predict reduced temperature gradients, the simplified Langmuir turbulence model matches observations more closely, when appropriately tuned.

A survey of sound speed profiles obtained from archived mooring and glider observations over the continental shelf, slope, and further offshore along the U.S. Pacific Northwest coastline reveals a shallow subsurface duct that appears at depths below the mixed layer. Sound propagation simulations using parabolic equation techniques demonstrate that the presence of the duct has a strong impact on sound propagation at 3.5 kHz. The duct is more prevalent in summer to fall than in winter to spring and extends to at least 200 km offshore from the shelf break. The depth of the minimum sound speed of the duct decreases onshore from between 80 m and 100 m offshore of the continental slope to less than 60 m over the shelf. The duct is also more prevalent offshore of the shelf break than over the shelf. Two processes potentially contribute to the formation of the subsurface duct: (1) differential advection of water masses driven by large-scale circulation within the northern California Current Systemand (2) wintertime surface cooling and convective deepening of the surface mixed layer. Data analysis conducted in this study suggests that the former is likely the dominant mechanism. [Work supported by the Office of Naval Research.]

A joint Oceanography/Acoustics experiment was conducted 15 July–13 August, 2022 in Washington’s shallow coastal shelf waters to investigate mid-frequency sound intensity fluctuations and the oceanographic mechanisms driving them, including subsurface ducts, internal tides, and internal waves. Acoustic pulses centered at 3.5 kHz and 6 kHz were transmitted up-shelf from a stationary source and recorded by receivers on two moorings at 10 km and 20 km ranges, respectively. A ship-towed Shallow Water Integrated Mapping System (SWIMS) repeatedly sampled the ocean between the source and receiver moorings, providing sound speed measurements as a function of range, depth, and time. In addition, five oceanographic moorings strategically placed around the acoustic path took additional ocean data over time. The sound speed profiles feature a surface mixed layer underneath which a subsurface duct with local sound speed minima of 1–2 m/s is frequently present. Analysis shows that (1) when the sound source is inside the subsurface duct, transmission loss is reduced by 15 dB compared to when the source is outside and (2) the statistics of the acoustic intensity are consistent with strong scattering. [Work supported by the Office of Naval Research.]

We present an analysis of ocean surface dispersion characteristics, on 1–100-m scales, obtained by optically tracking a release of bamboo plates for 2 h in the northern Gulf of Mexico. Under sustained 5–6 m s−1 winds, energetic Langmuir cells are clearly delineated in the spatially dense plate observations. Within 10 min of release, the plates collect in windrows with 15-m spacing aligned with the wind. Windrow spacing grows, through windrow merger, to 40 m after 20 min and then expands at a slower rate to 50 m. The presence of Langmuir cells produces strong horizontal anisotropy and scale dependence in all surface dispersion statistics computed from the plate observations. Relative dispersion in the crosswind direction initially dominates but eventually saturates, while downwind dispersion exhibits continual growth consistent with contributions from both turbulent fluctuations and organized mean shear. Longitudinal velocity differences in the crosswind direction indicate mean convergence at scales below the Langmuir cell diameter and mean divergence at larger scales. Although the second-order structure function measured by contemporaneous GPS-tracked surface drifters drogued at ~0.5 m shows persistent r2/3 power law scaling down to 100–200-m separation scales, the second-order structure function for the very near surface plates observations has considerably higher energy and significantly shallower slope at scales below 100 m. This is consistent with contemporaneous data from undrogued surface drifters and previously published model results indicating shallowing spectra in the presence of direct wind-wave forcing mechanisms.

Six recent Langmuir turbulence parameterization schemes and five traditional schemes are implemented in a common single‐column modeling framework and consistently compared. These schemes are tested in scenarios versus matched large eddy simulations, across the globe with realistic forcing (JRA55‐do, WAVEWATCH‐III simulated waves) and initial conditions (Argo), and under realistic conditions as observed at ocean moorings. Traditional non‐Langmuir schemes systematically underpredict large eddy simulation vertical mixing under weak convective forcing, while Langmuir schemes vary in accuracy. Under global, realistic forcing Langmuir schemes produce 6% (−1% to 14% for 90% confidence) or 5.2 m (−0.2 m to 17.4 m for 90% confidence) deeper monthly mean mixed layer depths than their non‐Langmuir counterparts, with the greatest differences in extratropical regions, especially the Southern Ocean in austral summer. Discrepancies among Langmuir schemes are large (15% in mixed layer depth standard deviation over the mean): largest under wave‐driven turbulence with stabilizing buoyancy forcing, next largest under strongly wave‐driven conditions with weak buoyancy forcing, and agreeing during strong convective forcing. Non‐Langmuir schemes disagree with each other to a lesser extent, with a similar ordering. Langmuir discrepancies obscure a cross‐scheme estimate of the Langmuir effect magnitude under realistic forcing, highlighting limited understanding and numerical deficiencies. Maps of the regions and seasons where the greatest discrepancies occur are provided to guide further studies and observations.

The use of systemic glucocorticoids (GCs), as well as local injections, continues to be a controversial issue in the sport/anti-doping community. There is widespread and legitimate use of GCs for numerous health conditions, yet there are concerns about side effects and the possibility of enhanced athletic performance in limited settings. This is compounded by the uncertainty regarding the prevalence of GC use, mechanisms underlying physiological effects and complex pharmacokinetics of different formulations. While WADA continues to promote research in this complex area, some international sporting federations, major event organisers and professional sports leagues have introduced innovative rules such as needle policies, mandatory rest periods and precompetition guidelines to promote judicious use of GCs, focusing on athlete health and supervision of medical personnel. These complementary sport-specific rules are helping to ensure the appropriate use of GCs in athletes where overuse is a particular concern. Where systemic GCs are medically necessary, Therapeutic Use Exemptions (TUEs) may be granted after careful evaluation by TUE Committees based on specific and strict criteria. Continued vigilance and cooperation between physicians, scientists and anti-doping organisations is essential to ensure that GC use in sport respects not only principles of fairness and adherence to the rules but also promotes athlete health and well-being. The purpose of this narrative review is to summarise the use and management of GCs in sport illustrating several innovative programmes by sport leagues and federations.

An autonomous Lagrangian float equipped with a high-resolution acoustic Doppler current profiler observed the evolution of upper-ocean stratification and velocity in the Eastern Pacific Fresh Pool for over 100 days in August-November 2016. Although convective mixing homogenized the water column to 40 m depth almost every night, the combination of diurnal warming on clear days and rainfall on cloudy days routinely produced strong stratification in the upper 10 m. Whether due to thermal or freshwater effects, the initial strong stratification was mixed downward and incorporated in the bulk of the mixed layer within a few hours. Stratification cycling was associated with pronounced variability of ocean surface boundary layer turbulence and vertical shear of wind-driven (Ekman) currents. Decoupled from the bulk of the mixed layer by strong stratification, warm and fresh near-surface waters were rapidly accelerated by wind, producing the well-known "slippery layer" effect, and leading to a strong downwind near-surface distortion of the Ekman profile. A case study illustrates the ability of the new generation of Lagrangian floats to measure rapidly evolving temperature, salinity, and velocity, including turbulent and internal wave components. Quantitative interpretation of the results remains a challenge, which can be addressed with high-resolution numerical modeling, given sufficiently accurate air-sea fluxes.

Objectives: \ud A previous single-country pilot study indicated serum anti-GM2 and anti-GA1 anti-glycolipid antibodies as potential biomarkers for acute canine polyradiculoneuritis. This study aims to validate these findings in a large geographically heterogenous cohort.\ud \ud Materials and Methods: \ud Sera from 175 dogs clinically diagnosed with acute canine polyradiculoneuritis, 112 dogs with other peripheral nerve, cranial nerve or neuromuscular disorders and 226 neurologically normal dogs were screened for anti-glycolipid antibodies against 11 common glycolipid targets to determine the immunoglobulin G anti-glycolipid antibodies with the highest combined sensitivity and specificity for acute canine polyradiculoneuritis.\ud \ud Results: \ud Anti-GM2 anti-glycolipid antibodies reached the highest combined sensitivity and specificity (sensitivity: 65.1%, 95% confidence interval 57.6 to 72.2%; specificity: 90.2%, 95% confidence interval 83.1 to 95.0%), followed by anti-GalNAc-GD1a anti-glycolipid antibodies (sensitivity: 61.7%, 95% confidence interval 54.1 to 68.9%; specificity: 89.3%, 95% confidence interval 82.0 to 94.3%) and these anti-glycolipid antibodies were frequently present concomitantly. Anti-GA1 anti-glycolipid antibodies were detected in both acute canine polyradiculoneuritis and control animals. Both for anti-GM2 and anti-GalNAc-GD1a anti-glycolipid antibodies, sex was found a significantly associated factor with a female to male odds ratio of 2.55 (P=0.0096) and 3.00 (P=0.0198), respectively. Anti-GalNAc-GD1a anti-glycolipid antibodies were more commonly observed in dogs unable to walk (odds ratio 4.56; P=0.0076).\ud \ud Clinical Significance: \ud Anti-GM2 and anti-GalNAc-GD1a immunoglobulin G anti-glycolipid antibodies represent serum biomarkers for acute canine polyradiculoneuritis.

Acrucial region of the ocean surface boundary layer (OSBL) is the strongly-sheared and -stratified transition layer (TL) separating the mixed layer from the upper pycnocline, where a diverse range of waves and instabilities are possible. Previous work suggests that these different waves and instabilities will lead to different OSBL behaviours. Therefore, understanding which physical processes occur is key for modelling the TL. Here we present observations of the TL from a Lagrangian float deployed for 73 days near Ocean Weather Station Papa (50°N, 145°W) during Fall 2018. The float followed the vertical motion of the TL, continuously measuring profiles across it using an ADCP, temperature chain and salinity sensors. The temperature chain made depth/time images of TL structures with a resolution of 6cm and 3 seconds. These showed the frequent occurrence of very sharp interfaces, dominated by temperature jumps of O(1)°C over 6cm or less. Temperature inversions were typically small (≲ 10cm), frequent, and strongly-stratified; very few large overturns were observed. The corresponding velocity profiles varied over larger length scales than the temperature profiles. These structures are consistent with scouring behaviour rather than Kelvin-Helmholtz-type overturning. Their net effect, estimated via a Thorpe-scale analysis, suggests that these frequent small temperature inversions can account for the observed mixed layer deepening and entrainment flux. Corresponding estimates of dissipation, diffusivity, and heat fluxes also agree with previous TL studies, suggesting that the TL dynamics is dominated by these nearly continuous 10cm-scale mixing structures, rather than by less frequent larger overturns.

Surface waves modify upper ocean dynamics through Stokes drift related processes. Stokes drift estimated from a discrete wave spectrum is compared to Stokes drift approximations as a monochromatic profile based on bulk surface wave parameters, and to two additional superexponential functional forms. The impact of these different methods on ocean processes is examined in two test‐bed cases of a wave‐current coupled system: (1) a wind‐free shallow water inlet test case and (2) an idealized deep water hurricane case with high varying winds. In case (1), tidal currents and bathymetry can modify the waves and significantly affect Stokes drift computed from the wave spectrum. In case (2), rapid variation in atmospheric stress at high wind speed generates large departures from fully developed equilibrium seas. In both cases, large deviations in ocean current response are produced when the Stokes drift is approximated monochromatically from bulk wave parameters, rather than from integration over the wave spectra. Deep water simulations using the two superexponential approximations are in better agreement with those estimated from wave spectra than are those using the monochromatic, exponential profile based on bulk wave parameters. In order to represent the impact of Stokes drift at resolved scales, we recommend that for studies of nearshore processes and deep water events, like wave‐current interactions under storms, the Stokes drift should be calculated from full wave spectra. For long simulations of open ocean dynamics, methods using superexponential profiles to represent equilibrium wind seas might be sufficient, but appear to be marginally more computationally efficient.

Turbulent flow in surface layer, the top few meters in the ocean, tends to exhibit consistent and repeatable characteristics, and useful empirical laws can be formed to shed light on turbulence par...

Surface electrodes have been used in electromyography and nerve conduction studies in human and veterinary medicine, but comparisons have not been made between surface and needle electrode recordings in dogs. Our aim in this method comparison study was to determine whether surface electrodes captured larger compound motor action potentials (CMAP) than needle electrodes. Tibial nerve CMAP from 25 dogs with normal limb function was acquired using both surface and needle recording electrodes; the stimulus was elicited with monopolar concentric needles. Paired Wilcoxon signed rank test (if data was not normally distributed) or a paired two tailed t-test was used if data were normally distributed; significance was set at P0.05. Mean CMAP amplitude (P=0.009), area (P=0.045) and latency (P=0.02) recorded with needle electrodes were larger compared with surface recording. CMAP duration was not significantly longer when recorded with surface electrodes (P=0.898). Needle electrode recordings are suitable for canine studies, although surface electrodes could also be considered. Low CMAP amplitudes recorded with surface electrodes should be verified with needle electrodes.

Once decompressive surgery has been elected, the approach that maximizes the likelihood of gaining access to the herniated material for complete removal should be chosen. In most cases, a procedure that optimizes access to the ventrolateral aspect of the spinal cord will be advantageous but it is important to tailor the details of the surgical procedure to suit individual patients. Decompressive surgery for chronic (type II) herniations will frequently demand a ventral approach with partial corpectomy.

Objectives To determine if dogs with acute polyradiculoneuritis have lower serum 25-hydroxy vitamin D3 concentration compared to a control group of dogs with idiopathic epilepsy. Materials and Methods Retrospective case–control study of 21 dogs with acute canine polyradiculoneuritis and 21 control dogs with idiopathic epilepsy matched for year and season of presentation from a referral hospital population in the UK. Serum concentration of 25-hydroxy vitamin D3 was compared between groups using Student's t-test. Results Dogs with acute canine polyradiculoneuritis had significantly lower (P=0·033) serum 25-hydroxy vitamin D3 concentration (87·1?nmol/L ±55·4?nmol/L) compared to a control group with idiopathic epilepsy (113?nmol/L ±66·3?nmol/L). Clinical Significance The cause and clinical significance of the altered vitamin D status in dogs with acute polyradiculoneuritis are not clear and require further investigation. Our findings pave the way for improved understanding of acute canine polyradiculoneuritis and, potentially, improved clinical management, if a causal role for 25-hydroxy vitamin D3 is defined

Objectives To investigate whether the development of acute canine polyradiculoneuritis is associated with various putative risk factors. Materials and Methods Retrospective case–control study with conditional logistic regression analysis from a referral hospital population in the UK where controls were matched for year of presentation. Results Forty-three cases were identified with acute canine polyradiculoneuritis and 86 controls were selected. Jack Russell terriers and West Highland white terriers were found to have a significantly greater odds of developing acute canine polyradiculoneuritis compared to a mixed baseline group of dogs. The odds of developing acute canine polyradiculoneuritis were greater in the autumn and winter compared to spring. Vaccination, rural/urban habitation, sex, neuter status and age were not associated with development of acute canine polyradiculoneuritis in our population of dogs. Clinical Significance Breed and season were associated with development of acute canine polyradiculoneuritis. However, this is a small sample and so this observation needs confirmation in further studies and other factors may also be involved. Nevertheless, these findings may be important in further understanding the aetiopathogenesis of this condition.

Oceanic bubbles play an important role in the air-sea exchange of weakly soluble gases at moderate to high wind speeds. A Lagrangian bubble model embedded in a large eddy simulation model is developed to study bubbles and their influence on dissolved gases in the upper ocean. The transient evolution of mixed-layer dissolved oxygen and nitrogen gases at Ocean Station Papa (50oN, 145oW) during a winter storm are reproduced with the model. Among different physical processes, gas bubbles are the most important in elevating dissolved gas concentrations during the storm, while atmospheric pressure governs the variability of gas saturation anomaly (the relative departure of dissolved gas concentration from the saturation concentration). For the same wind speed, bubble-mediated gas fluxes are larger during rising wind with smaller wave age than during falling wind with larger wave age. Wave conditions are the primary cause for the bubble gas flux difference: When wind strengthens, waves are less-developed with respect to wind, resulting in more frequent large breaking waves. Bubble generation in large breaking waves is favorable for a large bubble-mediated gas flux. The wave age dependence is not included in any existing bubble-mediated gas flux parameterizations. This article is protected by copyright. All rights reserved.

Background Development of management strategies for lumbosacral stenosis in dogs is hampered by the lack of objective diagnostic criteria and outcome measures. Objective To explore the suitability of electrodiagnostic tests as ancillary diagnostic aids, inclusion criteria, or outcome measures. Sample population Sixty‐one client‐owned dogs with clinical signs of lumbosacral foraminal stenosis. Methods A blinded, cross‐sectional cohort study. Fifty‐one dogs exhibiting apparent lumbosacral pain or pelvic limb lameness with no detected orthopedic cause had blinded review of magnetic resonance imaging (MRI), allowing classification as affected with foraminal stenosis (25 dogs), unaffected (20 dogs), or another diagnosis (6 dogs). The presence of electromyographic changes and tibial neurography variables were compared between groups. Results Cord dorsum potential onset latency, F‐wave onset latency (both corrected for limb length), and F‐ratio were increased in dogs with lumbosacral foraminal stenosis versus those without, although there was overlap of the values between groups. The proportion of dogs with electromyographic changes was not significantly greater in MRI‐affected dogs. Conclusion Electrophysiological testing is a useful ancillary test, either to provide stricter inclusion criteria and outcome measures or to aid clinical decision‐making in equivocal cases.

Intracranial neoplasia is commonly diagnosed in dogs and can be treated by a variety of methods, but formal comparisons of treatment efficacy are currently unavailable. This review was undertaken to summarize the current state of knowledge regarding outcome after the treatment of intracranial masses in dogs, with the aim of defining optimal recommendations for owners. This review summarizes data from 794 cases in 22 previously published reports and follows PRISMA guidelines for systematic review. A Pubmed search was used to identify suitable articles. These then were analyzed for quality and interstudy variability of inclusion and exclusion criteria and the outcome data extracted for summary in graphs and tables. There was a high degree of heterogeneity among studies with respect to inclusion and exclusion criteria, definition of survival periods, and cases lost to follow-up making comparisons among modalities troublesome. There is a need for standardized design and reporting of outcomes of treatment for brain tumors in dogs. The available data do not support lomustine as an effective treatment, but also do not show a clear difference in outcome between radiotherapy and surgery for those cases in which the choice is available.

Extreme winds and complex wave fields drive upper-ocean turbulence in tropical cyclone conditions. Motivated by Lagrangian float observations of bulk vertical velocity variance (VVV) under Hurricane Gustav (2008), upper-ocean turbulence is investigated based on large-eddy simulation (LES) of the wave-averaged Navier–Stokes equations. To realistically capture wind- and wave-driven Langmuir turbulence (LT), the LES model imposes the Stokes drift vector from spectral wave simulations; both the LES and wave model are forced by the NOAA Hurricane Research Division (HRD) surface wind analysis product. Results strongly suggest that without LT effects simulated VVV underestimates the observed VVV. LT increases the VVV, indicating that it plays a significant role in upper-ocean turbulence dynamics. Consistent with observations, the LES predicts a suppression of VVV near the hurricane eye due to wind-wave misalignment. However, this decrease is weaker and of shorter duration than that observed, potentially due to large-scale horizontal advection not present in the LES. Both observations and simulations are consistent with a highly variable upper ocean turbulence field beneath tropical cyclone cores. Bulk VVV, a TKE budget analysis, and anisotropy coefficient (ratio of horizontal to vertical velocity variances) profiles all indicate that LT is suppressed to levels closer to that of shear turbulence (ST) due to misaligned wind and wave fields. VVV approximately scales with the directional surface layer Langmuir number. Such a scaling provides guidance for the development of an upper-ocean boundary layer parameterization that explicitly depends on sea state.

A prior second-moment closure (SMC) model of Langmuir turbulence in the upper ocean is modified by introduction of inhomogeneous pressure–strain rate and pressure–scalar gradient closures that are similar to the high Reynolds number, near-wall treatments for solid wall boundaries. This repairs several near-surface defects in the algebraic Reynolds stress model (ARSM) of the prior SMC by redirecting Craik–Leibovich (CL) vortex force production of turbulent kinetic energy out of the surface-normal vertical component and into a horizontal one, with an associated reduction in near-surface CL production of vertical momentum flux. A surface-proximity function introduces a new closure parameter that is tuned to previous results from large-eddy simulations (LES), and a numerical SMC model based on stability functions from the new ARSM produces improved comparisons with mean profiles of momentum and TKE components from steady-state LES results forced by aligned wind and waves. An examination of higher-order quasi-homogeneous closures and a numerical simulation of Langmuir turbulence away from the boundaries both show the near-surface inhomogeneous closure to be both necessary for consistency and preferable for simplicity.

Background: The mode of waveform generation and circuit characteristics differ between high-frequency oscillators. It is unknown if this influences performance. Objectives: To describe the relationships between set and delivered pressure amplitude (ΔP), and the interaction with frequency and endotracheal tube (ETT) diameter, in eight high-frequency oscillators. Methods: Oscillators were evaluated using a 70-ml test lung at 1.0 and 2.0 ml/cm H2O compliance, with mean airway pressures (PAW) of 10 and 20 cm H2O, frequencies of 5, 10 and 15 Hz, and an ETT diameter of 2.5 and 3.5 mm. At each permutation of PAW, frequency and ETT, the set ΔP was sequentially increased from 15 to 50 cm H2O, or from 20 to 100% maximum amplitude (10% increments) depending on the oscillator design. The ΔP at the ventilator (ΔPVENT), airway opening (ΔPAO) and within the test lung (ΔPTRACH), and tidal volume (VT) at the airway opening were determined at each set ΔP. Results: In two oscillators the relationships between set and delivered ΔP were non-linear, with a plateau in ΔP thresholds noted at all frequencies (Dräger Babylog 8000) or ≥10 Hz (Dräger VN500). In all other devices there was a linear relationship between ΔPVENT, ΔPAO and ΔPTRACH (all r2 >0.93), with differing attenuation of the pressure wave. Delivered VT at the different settings tested varied between devices, with some unable to deliver VT >3 ml at 15 Hz, and others generating VT >20 ml at 5 Hz and a 1:1 inspiratory-to-expiratory time ratio. Conclusions: Clinicians should be aware that modern high-frequency oscillators exhibit important differences in the delivered ΔP and VT.

To determine if dogs with acute polyradiculoneuritis have lower serum 25-hydroxy vitamin D3 concentration compared to a control group of dogs with idiopathic epilepsy.Retrospective case-control study of 21 dogs with acute canine polyradiculoneuritis and 21 control dogs with idiopathic epilepsy matched for year and season of presentation from a referral hospital population in the UK. Serum concentration of 25-hydroxy vitamin D3 was compared between groups using Student's t-test.Dogs with acute canine polyradiculoneuritis had significantly lower (P=0·033) serum 25-hydroxy vitamin D3 concentration (87·1 nmol/L ±55·4 nmol/L) compared to a control group with idiopathic epilepsy (113 nmol/L ±66·3 nmol/L).The cause and clinical significance of the altered vitamin D status in dogs with acute polyradiculoneuritis are not clear and require further investigation. Our findings pave the way for improved understanding of acute canine polyradiculoneuritis and, potentially, improved clinical management, if a causal role for 25-hydroxy vitamin D3 is defined.

The Arabian Sea circulation is forced by strong monsoonal winds and is characterized by vigorous seasonally reversing currents, extreme differences in sea surface salinity, localized substantial upwelling, and widespread submesoscale thermohaline structures. Its complicated sea surface temperature patterns are important for the onset and evolution of the Asian monsoon. This article describes a program that aims to elucidate the role of upper-ocean processes and atmospheric feedbacks in setting the sea surface temperature properties of the region. The wide range of spatial and temporal scales and the difficulty of accessing much of the region with ships due to piracy motivated a novel approach based on state-of-the-art autonomous ocean sensors and platforms. The extensive data set that is being collected, combined with numerical models and remote sensing data, confirms the role of planetary waves in the reversal of the Somali Current system. These data also document the fast response of the upper equatorial ocean to monsoon winds through changes in temperature and salinity and the connectivity of the surface currents across the northern Indian Ocean. New observations of thermohaline interleaving structures and mixing in setting the surface temperature properties of the northern Arabian Sea are also discussed.

Background: Limited information is available about prognostic factors for recovery after spinal cord injury (SCI) to the L4-S3 segments. Previous research suggests that L4-S3 SCI does not have a worse prognosis than T3-L3 SCI. Hypothesis/Objectives: To elucidate prognostic factors for regaining urinary continence and ambulation in dogs with L4-S3 SCI and compare prognosis to T3-L3 SCI. Animals/Methods: A retrospective study on 61 nonambulatory dogs with L4-S3 SCI, matched to dogs with T3-L3 SCI, compared 3 weeks after onset. Prognostic factors explored using logistic regression and used for matching: nonchondrodystrophic dogs >15 kg versus dogs that were chondrodystrophic or Results: Fewer L4-S3 dogs regained continence compared to T3-L3 dogs (64 vs 85%, P = .0033), but no difference existed for regaining ambulation (66 vs 75%, P = .1306). In L4-S3 SCI dogs, fewer dogs regained continence with loss of CPP (P < .001), LMN incontinence (P = .004), and noncompressive lesions (P = .006). Negative prognostic factors for regaining ambulation included absent CPP (P < .001) and large nonchondrodystrophic breed (P = .022). Conclusions and Clinical Importance: Dogs with L4-S3 SCI have a poorer short-term prognosis than do dogs with T3-L3 SCI. Dogs with L4-S3 SCI had a poor prognosis with loss of CPP, or noncompressive lesions combined with LMN incontinence. Small-breed or chondrodystrophic dogs with retained CPP, compressive lesions, and UMN incontinence had an excellent prognosis. These findings may help guide decision-making in L4-S3 SCI.

Background The importance of Chiari-like malformation (CM) in the generation of clinical signs or the formation of syringomyelia in dogs is incompletely understood, partly because the prevalence of various CM definitions in unaffected dogs is unknown. Hypothesis/Objectives The aims were: to estimate the prevalence of CM in dogs asymptomatic for CM or syringomyelia, according to 3 currently used definitions; and, to investigate the effect of brachycephaly and head position during magnetic resonance (MR) imaging on estimates of the prevalence of CM. Animals One ninety-nine client-owned dogs without apparent signs of CM or syringomyelia. Methods Blinded, retrospective analysis. Archived MR images were analyzed for evidence of cerebellar indentation and impaction into or herniation through the foramen magnum. Logistic regression analysis was used to investigate the relationship of CM diagnosis with head position and the cranial index (a measure of brachycephaly). Results In 185 non-Cavalier King Charles Spaniel (CKCS) dogs, indentation was identified in 44% (95% CI, 47–51%) and impaction in 22% (95% CI, 16–28%). No asymptomatic, non-CKCS dogs showed herniation. Regression analysis showed a significant increase in the odds of indentation and impaction in an extended head position and as the cranial index increased (became more brachycephalic). Conclusions and Clinical Importance The high prevalence of cerebellar indentation and impaction suggests that they may be normal anatomical variations and therefore unsuitable as definitions of CM. We suggest that future research into CM in dogs should define cases and controls more strictly so that overlap between normal and abnormal animals is minimized.

An association between degenerative changes in the lumbosacral region of the vertebral column and clinical signs of pain and pelvic limb dysfunction has long been recognized in dogs and has become known as degenerative lumbosacral stenosis syndrome. Over the past two decades, methods of imaging this condition have advanced greatly, but definitive criteria for a reliable diagnosis using physical examination, imaging and electrodiagnostics remain elusive. Available treatment options have changed little over more than 30 years but, more importantly, there is a lack of comparative studies and little progress has been made in providing evidence-based recommendations for the treatment of affected dogs. This review provides an overview of the changes in diagnosis, understanding and treatment of lumbosacral disease in dogs over the past 30 years. Approaches to address the unanswered questions regarding treatment choice are also proposed.

[1] Nearly all operational ocean models use air-sea fluxes and the ocean shear and stratification to estimate upper ocean boundary layer mixing rates. This approach implicitly parameterizes surface wave effects in terms of these inputs. Here we test this assumption using parallel experiments in a lake with small waves and in the open ocean with much bigger waves. Under the same wind stress and adjusting for buoyancy flux, we find the mixed layer average turbulent vertical kinetic energy in the open ocean typically twice that in the lake. The increase is consistent with models of Langmuir turbulence, in which the wave Stokes drift, and not wave breaking, is the dominant mechanism by which waves energize turbulence in the mixed layer. Applying these same theories globally, we find enhanced mixing and deeper mixed layers resulting from the inclusion of Langmuir turbulence in the boundary layer parameterization, especially in the Southern Ocean.

[1] Wave and wind measurements at Ocean Weather Station P (OWS-P, 50°N 145°W) are used to evaluate the equilibrium range of surface wave energy spectra. Observations are consistent with a local balance between wind input and breaking dissipation, as described by Philips (1985). The measurements include direct covariance wind stress estimates and wave breaking dissipation rate estimates during a 3 week research cruise to OWS-P. The analysis is extended to a wider range of conditions using observations of wave energy spectra and wind speed during a 2 year mooring deployment at OWS-P. At moderate wind speeds (5–15 m/s), mooring wave spectra are in agreement, within 5% uncertainty, with the forcing implied by standard drag laws and mooring wind measurements. At high wind speeds (>15 m/s), mooring wave spectra are biased low, by 13%, relative to the forcing implied by standard drag laws and mooring wind measurements. Deviations from equilibrium are associated with directionality and variations at the swell frequencies. A spectral wave hindcast accurately reproduces the mooring observations, and is used to examine the wind input.

Objectives To evaluate whether screening tests used to identify infectious and neoplastic triggers for immune-mediated haemolytic anaemia, in particular a complete blood count and differential, serum biochemistry profile, urine analysis (including culture), abdominal ultrasound and thoracic radiographs, can identify triggers for steroid-responsive meningitis-arteritis. Methods Retrospective descriptive review. Results Twenty-one steroid-responsive meningitis-arteritis cases were identified in which all screening tests had been performed. All cases had changes in complete blood count (including neutrophilia, monocytosis, lymphocytosis, eosinopenia or anaemia); 19 had changes in biochemistry (including hypoalbuminaemia, hyperglobulinaemia, increased alkaline phosphatase activity, hyperphosphataemia, increased total calcium concentration, hypercholesterolaemia, hyperkalaemia, increased urea concentration and increased alanine aminotransferase activity); two cases had an elevated urine protein to creatinine ratio but none had positive urine culture results; no cases had abnormalities on orthogonal radiographs of the thorax; four cases had abnormalities identified on abdominal ultrasound, which following cytological examination suggested inflammation in the absence of pathological organisms. Clinical Significance Screening tests used to identify infectious and neoplastic triggers in immune-mediated haemolytic anaemia did not isolate triggers for steroid-responsive meningitis-arteritis in the population of dogs under investigation.

Aim The aim of this study is to compare the high-frequency pressure amplitude (oscillatory change in pressure (ΔP)) and tidal volume (high-frequency tidal volume at the airway opening (VTHF)) delivered by the Drager VN500 (Dragerwerk Ag & Co., Lubeck, Germany) and the Sensormedics 3100 (SM3100; CareFusion, San Diego, CA, USA) through a range of oscillatory frequencies. Methods In this benchtop study, high-frequency oscillations were applied to an infant test lung at unrestricted set amplitudes. Pressure and flow were measured as a function of frequency, incremented by 1 Hz from 5 to 15 Hz. Measurements were repeated for a range of ventilator settings, and lung resistive and compliance states. Results The VN500, but not the SM3100, demonstrated an exponential decrease in airway opening ΔP as frequency increased. The difference between the SM3100- and VN500-delivered VTHF became greater with each frequency increment. At 15 Hz, VN500 VTHF was 49% of SM3100 VTHF. Conclusions The VN500 demonstrates a frequency-related reduction in ΔP not observed in the SM3100. Clinicians need to be aware of these differences in performance characteristics.