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An experimental investigation of hingeless flow control by vortex breakdown manipulation over a delta wing is described. Employed as a method of longitudinal control for slender-wing planforms, the performance of this active flow control technique was evaluated as a possible replacement to conventional moving or hinged control surfaces. Testing was conducted with a 60-deg delta-wing model incorporating pneumatic vortex control (PVC) actuators. These actuators delivered high-pressure jets of varying parameters on the upper surface of the model. The jets were used to alter the flowfield over the wing caused by leading-edge vortices. The natural location of vortex breakdown was shifted by three sets of PVC actuators strategically positioned on the model. This effect was intended to control the chordwise lift distribution over the wing by inducing both premature and delayed vortex breakdown, resulting in nose-up and nose-down pitch responses, respectively. A comparative analysis of this hingeless flow control concept was conducted in Texas A&M University's 3 x 4 ft low-speed wind tunnel and 2 x 3 ft water tunnel. Testing included force balance measurements, laser-fluorescene visualizations, surface flow visualizations, and schlieren shadowgraph visualizations. Visualization results show successful manipulation of the vortex breakdown locations over the delta-wing model. Force balance results also show that the aerodynamic characteristics of the delta wing were altered. Observations show changes primarily in pitching moment, with no detrimental changes in lift or drag.

Objective--To determine an optimal dose of carbon 13 (13C)-Iabeled aminopyrine for use in a 13C-aminopyrine demethylation blood test in healthy dogs. Animals--9 adult dogs. Procedures--Food was withheld from each dog for 12 Hours. A 2-mL baseline blood sample was obtained from each dog and placed into an evacuated tube containing sodium heparin. Carbon 13-labeled aminopyrine was administered IV at doses of 1, 2, 5, or 10 mg/kg. Additional blood samples (2 mL) were obtained and placed into evacuated tubes containing sodium heparin 30, 45, 60, and 75 minutes after 13C-aminopyrine administration. Hydrochloric acid was used to extract CO2 from blood samples. The extracted gas was analyzed by fractional mass spectrometry to determine the percentage dose of 13C administered as 13C-aminopyrine and recovered in extracted gas (PCD). Results--Gross evidence of clinical adverse effects was not detected in any dog after administration of 13C-aminopyrine. The mean coefficient of variation (CV) for PCD was significantly lower than the mean CV for the summation of PCD values up to a given sampling time (CUMPCD). Mean PCD values among the 4 doses for each sample time were not significantly different. Administration of 13C-aminopyrine at a dose of 2 mg/kg resulted in the lowest interindividual variability. Conclusions and Clinical Relevance--The PCD is superior to CUMPCD for the quantification of 13C-aminopyrine demethylation. Administration of 13C-aminopyrine at a dose of 2 mg/kg is appropriate for use in the 13C-aminopyrine demethylation blood test in healthy dogs. [ABSTRACT FROM AUTHOR]

Objective To determine the change in tibial plateau angle (TPA) during healing after tibial plateau leveling osteotomy (TPLO) performed for cranial cruciate ligament insufficiency in dogs and to examine factors that may be associated with the change. Study Design Retrospective study. Study Population One hundred and forty-nine canine stifles after TPLO procedure. Methods Records of dogs that had TPLO were reviewed. Patient age, weight, sex, breed, pre- and postoperative TPA, recheck TPA, time to recheck, type of implant used, and radiographic evidence of healing were analyzed. Results Mean time to recheck evaluation was 46 days (range, 28–65 days). Mean difference between immediate postoperative and recheck TPA measurements was 1.5° (range, −3 to 9°). Recheck TPA was a significantly greater (numerically higher) than immediate postoperative TPA ( P<.0001). There was no significant effect of patient weight, type of plate used, or healing status of the osteotomy at the time of recheck. No correlation between pre- or postoperative TPA angles and change in TPA angle was detected. Conclusions TPA changes during osteotomy healing after TPLO, but factors influencing this change were not identified. Clinical Relevance TPA may increase during healing after TPLO despite apparently adequate osteotomy fixation. The clinical relevance of this increase is unknown but is likely minimal. [ABSTRACT FROM AUTHOR]

Focuses on the pathology of impulsivity. Stages of impulse control behaviors; Role of impulsivity in controlling thoughts and behaviors; Reasons behind the controversies in defining and measuring impulsivity; Clinical perspective in defining impulsivity; Techniques used in measuring sub-dimensions of impulsivity.

Objective--To describe the kinetics of demethylation of [sup13]C-aminopyrine in healthy dogs for use in determining the most appropriate time for collection of blood samples for a [sup13]C-aminopyrine demethylation blood test for evaluation of hepatic function. Animals--9 healthy dogs. Procedures--A 2-mL baseline blood sample was collected into an evacuated heparinized tube, and [sup13]Caminopyrine was administered to each dog (2 mg/kg, IV). Additional 2-mL blood samples were collected 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 180, 240, 300, and 360 minutes after [sup13]C-aminopyrine administration. The CO[sub2] was extracted from blood samples by addition of a strong acid, and the percentage dose of [sup13]CO[sub2] (PCD) in the extracted gas was determined by fractional mass spectrometry. Results--No dogs had gross evidence of adverse effects, and all had an increase in PCD after IV administration of [sup13]C-aminopyrine. The PCD had the least variability among 5 variables used to evaluate hepatic demethylating capacity. Peak PCD was detected at 30 minutes in 1 dog, 45 minutes in 5 dogs, 60 minutes in 2 dogs, and 75 minutes in 1 dog. The mean PCD for the 9 dogs peaked at 45 minutes after [sup13]C-aminopyrine administration. Conclusions and Clinical Relevance--PCD appears to be the preferable variable for evaluation of hepatic demethylating capacity. Intravenous administration of [sup13]C-aminopyrine leads to a consistent increase in PCD. Mean PCD peaked 45 minutes after administration, suggesting that blood sample collection 45 minutes after [sup13]C-aminopyrine administration may be appropriate for use in estimating hepatic demethylating capacity. [ABSTRACT FROM AUTHOR]