Reliability and identification of aortic valve prolapse in the horse

Background The objectives were to determine and assess the reliability of criteria for identification of aortic valve prolapse (AVP) using echocardiography in the horse. Results Opinion of equine cardiologists indicated that a long-axis view of the aortic valve (AoV) was most commonly used for identification of AVP (46%; n=13). There was consensus that AVP could be mimicked by ultrasound probe malignment. This was confirmed in 7 healthy horses, where the appearance of AVP could be induced by malalignment. In a study of a further 8 healthy horses (5 with AVP) examined daily for 5 days, by two echocardiographers standardized imaging guidelines gave good to excellent agreement for the assessment of AVP (kappa>0.80) and good agreement between days and observers (kappa >0.6). The technique allowed for assessment of the degree of prolapse and measurement of the prolapse distance that provided excellent agreement between echocardiographers, days and observers (kappa/ICC>0.8). Assessments made using real-time zoomed images provided similar measurements to the standard views (ICC=0.9), with agreement for the identification of AVP (kappa>0.8). Short axis views of the AoV were used for identification of AVP by fewer respondents (23%), however provided less agreement for the identification of AVP (kappa>0.6) and only adequate agreement with observations made in long axis (kappa>0.5), with AVP being identified more often in short axis (92%) compared to long axis (76%). Orthogonal views were used by 31% of respondents to identify the presence of AVP, and 85% to identify cusp. Its identification on both views on 4 days was used to categorise horses as having AVP, providing a positive predictive value of 79% and negative predictive value of 18%. Only the non-coronary cusp (NCC) of the AoV was observed to prolapse in these studies. Prolapse of the NCC was confirmed during the optimisation study using four-dimensional echocardiography, which concurred with the findings of two-dimensional echocardiography. Conclusions This study has demonstrated reliable diagnostic criteria for the identification and assessment of AVP that can be used for longitudinal research studies to better define the prevalence and natural history of this condition

Lower critical field measurements in YBa2Cu3O(6+x) single crystals

The temperature dependence of the lower critical field in YBa2Cu3O(6+x) single crystals was determined by magnetization measurements with the applied field parallel and perpendicular to the c-axis. Results are compared with data from the literature and fitted to Ginzberg-Landau equations by assuming a linear dependence of the parameter kappa on temperature. A value of 7 plus or minus 2 kOe was estimated for the thermodynamic critical field at T = O by comparison of calculated H (sub c2) values with experimental data from the literature

Measurement of H(sub c1) in a single crystal of YBa2Cu3O7 with low pinning

The measurement of H(sub c1) in barium yttrium copper oxide (BYCO) is often ambiguous because the presence of large pinning forces makes it difficult to discern exactly where the first deviation from linearity occurs. In addition there are complications because demagnetizing factors are often not well known. By utilizing a single crystal of YBCO with a nearly cubic shape, the uncertainty in the demagnetizing factor was minimized. In addition, the crystal used exhibited a very small amount of pinning with H applied perpendicular to the c axis, and a sharp break in the initial magnetization vs. field curve could be observed over a wide range of temperature. This allowed a precise determination of H(sub c1). The measured values of H(sub c1) could be well described by the Abrikosov relation with a Ginzburg-Landau parameter which varied linearly with temperature

Evaluation of an enhanced cleaning and storage method for in-office disinfection of hydrogel contact lenses

Even though a trial contact lens has been cleaned prior to storage, there is little guarantee that the lens storage environment is sterile (except in the case of autoclaving the lens within the storage vial). The underside of the cap is often an overlooked potential source of contamination to the system. This study evaluated the effectivity of Bausch & Lomb ReNu Multi-Purpose Solution as an in-office storage solution using an enhanced cleaning method, as well as the utility of inverting the lens vial during the disinfecting period. The results show that inversion of the vial assists in assuring a more growth free environment, yet proper cleaning of the lens and the vial stopper is vital to obtain maximum effectiveness with this in-office contact lens storage system

Supporting Sophomore Success Through a New Learning Community Model

The creation of a Sophomore Learning Community (SLC) model can help address concerns about the “sophomore slump” and sophomore attrition. While managing the logistics of a sophomore LC can be difficult, with proper faculty, staff, and administrative support, positive results can be produced. This article outlines the need for Sophomore Learning Communities and describes the process one university used to pilot an SLC program

Failed Surgery for Patellar Tendinopathy in Athletes: Midterm Results of Further Surgical Management

Background:Tendon injuries are commonly seen in sports medicine practice. Many elite players involved in high-impact activities develop patellar tendinopathy (PT) symptoms. Of them, a small percentage will develop refractory PT and need to undergo surgery. In some of these patients, surgery does not resolve these symptoms.Purpose:To report the clinical results in a cohort of athletes who underwent further surgery after failure of primary surgery for PT.Study Design:Case series; Level of evidence, 4.Methods:A total of 22 athletes who had undergone revision surgery for failed surgical management of PT were enrolled in the present study. Symptom severity was assessed through the Victorian Institute of Sport Assessment Scale for Patellar Tendinopathy (VISA-P) upon admission and at the final follow-up. Time to return to training, time to return to competition, and complications were also recorded.Results:The mean age of the athletes was 25.4 years, and the mean symptom duration from the index intervention was 15.3 months. At a mean follow-up of 30.0 +/- 4.9 months, the VISA-P score improved 27.8 points (P < .0001). The patients returned to training within a mean of 9.2 months. Fifteen patients (68.2%) returned to competition within a mean of 11.6 months. Of these 15 patients, a further 2 had decreased their performance, and 2 more had abandoned sports participation by the final follow-up. The overall rate of complications was 18.2%. One patient (4.5%) had a further revision procedure.Conclusion:Revision surgery was feasible and effective in patients in whom PT symptoms persisted after previous surgery for PT, achieving a statistically significant and clinically relevant improvement of the VISA-P score as well as an acceptable rate of return to sport at a follow-up of 30 months

Do Option Markets Substitute for Stock Markets?

Using a sample of cash tender offers occurring between 1993 and 2002, we find evidence that the options market has become the preferred venue for traders attempting to profit on anticipated announcements. Options offer advantages relative to stocks. Traders gain leverage by trading in options and multiple options contracts on an individual stock. The results of our study indicate that a substitution effect does exist. Abnormal volume in the option market replaces abnormal volume in the stock market prior to cash tender offer announcements, and this abnormal option volume precedes abnormal stock volume for targets with or without traded options