The commercial adoption of GaN-on-Si light emitting diode (LED) chip technology is lagging behind incumbent sapphire substrates due to significantly longer growth time and poorer crystalline quality. ...To address these challenges, we report on the growth of high-quality crack-free InGaN/GaN LED structure on 150 mm Si (111) substrate using thin buffer layer technology. The total epilayer thickness is only 3.75μm, offering significant growth time savings and faster manufacturing process throughput. A SiNx interlayer is inserted in the buffer layer to promote lateral overgrowth and improve material quality, resulting in full width at half maximum (0002) and (10-12) of 380 and 390 arcsec, respectively. Reducing dislocation density and optimizing KOH roughening of the n-GaN layer is found to be critical toward improving device performance. The devices were processed as 1 × 1 mm 2 vertical thin film dies and mounted into a conventional 3535 package with silicone dome lens. The result is a light output power of 563 mW and an operating voltage of 3.05 V, corresponding to a wall-plug-efficiency of 52.7% when driven at 350 mA. These results attest the feasibility of thin buffer GaN-on-Si technology for solid state lighting applications.
This report describes the use of an implantable cardioverter-defibrillator (ICD) in a young German shepherd dog afflicted with inherited ventricular arrhythmias. Proper generator and lead placement ...was necessary for successful termination of ventricular fibrillation during device testing at the time of implantation. The risks of inappropriate therapy triggered by sinus tachycardia and oversensing of the T wave were controlled by extensive programming of the device. Following spontaneous resolution of the arrhythmia and due to the development of sepsis associated with the device, the ICD was successfully removed.
Infection with the intravascular parasite Dirofilaria immitis is an increasingly recognized problem in domestic dogs and cats. Heartworm infection is preventable; however, once an animal is infected, ...heartworm disease and potentially life-threatening complications can develop. An understanding of the heartworm life cycle and transmission season, the limitations of testing methods, and the clinical signs of heartworm disease is necessary to provide clients with appropriate information regarding prevention and treatment of heartworm infection in their pets.
A clinically normal 2-year-old Hispaniolan Amazon parrot (Amazona ventralis) was found to have periodic second-degree atrioventricular (AV) block with variable nodal conductions while anesthetized ...with isoflurane during a thermal-support research project. Arrhythmias were observed on 5 successive weekly electrocardiograms. A complete cardiac evaluation, including a diagnostic electrocardiogram, revealed intermittent bradyarrhythmias ranging from a 2:1 to a 7:1 second-degree AV block, with concurrent hypotensive episodes during the nodal blocks. Results of a complete blood cell count, plasma biochemical profile, blood gas analysis, and atropine-response test, as well as radiography and auscultation, revealed no obvious cause for the arrhythmias. Echocardiography demonstrated cardiac wall thickness, chamber size, and systolic function similar to other psittacine birds. On return to the colony, the parrot continued to be outwardly asymptomatic despite the dramatic conduction disturbances. Although cardiac arrhythmias, including second-degree AV block, have been widely reported in birds, the wide variation of nodal conductions, the intermittent nature, and an arrhythmia with a 7:1 second-degree AV block that spontaneously reverts to normal as seen in this case have not been well documented in parrots.
We describe the echocardiographic findings in a 4‐day‐old thoroughbred foal with an aortico‐pulmonary septal defect. The foal had labored breathing, cyanotic mucous membranes and a continuous grade ...5/6 heart murmur with point of maximal intensity over the base of the heart on the right side. Echocardiographically, there was a large communication between the aorta and the pulmonary artery just dorsal to the base of the heart. The cardiac anomaly seen during the echocardiographic exam was confirmed at necropsy where a large communication between the two great vessels was observed. These findings correlate with previous studies in humans, dogs, and cats. The possible failure in the embryologic development that led to this unusual cardiac anomaly is discussed.
The dose-limiting toxicity of doxorubicin is cardiotoxicosis. The authors of this report hypothesized that by using their institution's adopted guidelines (that involve prescreening echocardiography ...and electrocardiography), they would detect pre-existing cardiac abnormalities that preclude doxorubicin administration in <10% of dogs. Of 101 dogs, only 6 were excluded from doxorubicin administration based on electrocardiogram abnormalities, with a majority of those arrhythmias classified as ventricular premature contractions. One patient was excluded based on echocardiogram alone due to hypertrophic cardiomyopathy. The incidence of cardiotoxicity in treated dogs was 8% (8/101). Additional pretreatment and ongoing studies are indicated to identify risk factors for cardiotoxicity.
Several agents are available for the prevention of heartworm infection. Melarsomine is up to 96% efficacious (after two doses) as a heartworm adulticide in infected dogs. However, treatment of dogs ...infected with D. immitis can be expensive, and adulticide therapy in patients with moderate to severe heartworm disease can be associated with life-threatening complications. Patients with clinical signs associated with pneumonitis benefit from short-term therapy with antiinflammatory doses of corticosteroids before and after adulticide treatment. Strict cage rest for 4 to 6 weeks is mandatory after adulticide administration. Microfilaricide therapy is indicated for microfilaremic patients. The prognosis is good in patients with mild to moderate infection, fair to guarded in severe cases, and poor to grave (even with treatment) in patients with caval syndrome, severe pulmonary thromboembolism, or congestive heart failure.
Cardiovascular anomalies have been reported rarely in psittacine birds. This report describes 2 cockatoos, each presenting with a heart murmur, tachycardia, and a bounding pulse. Clinical signs ...associated with these patients included cyanosis of the cere and, in 1 bird, ascites. Echocardiographic evaluations of both birds suggested ventricular septal defects, which corresponded to radiographic evidence of an enlarged cardiac silhouette. Pathologic evaluation revealed a ventricular septal defect and persistent truncus arteriosus in an umbrella cockatoo (Cacatua alba), whereas a Moluccan cockatoo (Cacatua moluccensis) had a subvalvular septal defect and aortic hypoplasia. Congenital cardiovascular anomalies should be considered when young psittacine birds are presented with heart murmurs and signs of circulatory dysfunction.
Training for crisis decision makers poses a number of challenges that range from the necessity to foster creative decision making to the need of creating engaging and realistic scenarios in support ...of experiential learning. This article describes our effort to build an end-to-end intelligent system, called the Pandora-Box, that supports a trainer in populating a 4-5 hours training session with exercises for a class of decision makers to teach them how to achieve joint decisions under stress. The paper gives a comprehensive view of the current system and in particular focuses on how AI planning technology has been customized to serve this purpose. Aspects considered are: (a) the timeline-based representation that acts as the core component for creating training sessions and unifying different concepts of the Pandora domain; (b) the combination of planning and execution functionalities to maintain and dynamically adapt a “lesson plan” on the basis of both trainees-trainer interactions and individual behavioral features and performance; (c) the importance of keeping the trainer in the loop preserving his/her responsibility in creating content for the class but endowing him/her with a set of new functionalities.
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