This article is available online at http://www.jlr.org coronary artery disease ( 3,4 ). An imbalance between myocardial substrate uptake and fatty acid oxidative capacity of the heart is thought to induce lipotoxicity, namely, an accumulation of lipid byproducts that give rise to noxious intermediates in the cardiomyocytes. However, the exact mechanism for lipotoxicity is still not known. A consistent fi nding is that myocardial triglycerides are increased in hearts of obese or type 2 diabetic patients ( 5, 6 ), which is associated with impaired left-ventricular diastolic function ( 7 ).Genetically modifi ed rodent models have been used extensively to investigate the pathophysiology of "lipotoxic cardiomyopathy" ( 8 ). Increased lipid infl ux in the heart ( 9, 10 ), decreased mobilization of triacylglycerol reserves ( 11 ), or increased fatty acid metabolism (12)(13)(14) all are associated with metabolic alterations that mimic those of diabetes, including hypertrophy of the heart and contractile dysfunction. These animal studies have led to the identifi cation of the lipid molecules that are potential culprits for impaired cardiac function. Increased reliance of the heart on ␤ -oxidation of fatty acids leads to increased reactive oxygen species generation, which promotes lipid peroxidation and alters mitochondrial function ( 15,16 ). In addition, intracellular saturated acyl-CoA species, ceramide and diacylglycerol, are linked to changes in membrane composition, endoplasmic reticulum stress, altered lipid signaling, and ultimately, apoptosis ( 17,18 ). These lipid species may also impair insulin signaling through increased serine phosphorylation of the insulin receptor and insulin receptor substrate 1 and/or reduced serine phosphorylation of PKB/Akt ( 19,20 ).However, there is controversy over whether myocardial lipids contribute to contractile dysfunction and heart Abstract The "lipotoxic footprint" of cardiac maladaptation in diet-induced obesity is poorly defi ned. We investigated how manipulation of dietary lipid and carbohydrate infl uenced potential lipotoxic species in the failing heart. In Wistar rats, contractile dysfunction develops at 48 weeks on a high-fat/high-carbohydrate "Western" diet, but not on low-fat/high-carbohydrate or high-fat diets. Cardiac content of the lipotoxic candidates-diacylglycerol, ceramide, lipid peroxide, and long-chain acyl-CoA species-was measured at different time points by high-performance liquid chromatography and biochemical assays, as was lipogenic capacity in the heart and liver by qRT-PCR and radiometric assays. Changes in membranes fl uidity were also monitored using fl uorescence polarization. We report that Western feeding induced a 40% decrease in myocardial palmitoleoyl-CoA content and a similar decrease in the unsaturated-to-saturated fatty acid ratio. These changes were associated with impaired cardiac mitochondrial membrane fl uidity. At the same time, hepatic lipogenic capacity was increased in animals fed Western diet (+270% fatty acid elongase activity comp...

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Control applications involving multiple Unmanned Aerial Systems (UASs) will often require the operator to switch attention between UASs and their respective camera views. An automated aid that transitions between camera views is under evaluation. Instead of discretely switching from the camera view for one UAS to the camera view for another, a transition format is presented. With this format, the camera imagery seamlessly fades into a synthetic imagery correlate of the real video image and then uses a “fly-out, fly-in” metaphor over several seconds, finishing with a transition back from synthetic to real video imagery at the new camera viewpoint. The results from the present simulation evaluation provide support that an automated camera view transition aid can improve task performance and situation awareness. Moreover, the results show potential benefits of allowing an operator to decide where and when the fly-in segment starts.

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