Abstract-Increased reactive oxygen species (ROS) production is implicated in the pathophysiology of left ventricular (LV) hypertrophy and heart failure. However, the enzymatic sources of myocardial ROS production are unclear. We examined the expression and activity of phagocyte-type NADPH oxidase in LV myocardium in an experimental guinea pig model of progressive pressure-overload LV hypertrophy. Concomitant with the development of LV hypertrophy, NADPH-dependent O 2 Ϫ production in LV homogenates, measured by lucigenin (5 mol/L) chemiluminescence or cytochrome c reduction assays, significantly and progressively increased (by Ϸ40% at the stage of LV decompensation; PϽ0.05). O 2 Ϫ production was fully inhibited by diphenyleneiodonium (100 mol/L). Immunoblotting revealed a progressive increase in expression of the NADPH oxidase subunits p22 phox , gp91 phox , p67 phox , and p47 phox in the LV hypertrophy group, whereas immunolabeling studies indicated the presence of oxidase subunits in cardiomyocytes and endothelial cells. In parallel with the increase in O 2 Ϫ production, there was a significant increase in activation of extracellular signal-regulated kinase 1/2, extracellular signal-regulated kinase 5, c-Jun NH2-terminal kinase 1/2, and p38 mitogen-activated protein kinase. These data indicate that an NADPH oxidase expressed in cardiomyocytes is a major source of ROS generation in pressure overload LV hypertrophy and may contribute to pathophysiological changes such as the activation of redox-sensitive kinases and progression to heart failure. Key Words: hypertrophy Ⅲ free radicals Ⅲ heart failure Ⅲ myocardium Ⅲ reactive oxygen species A n increase in oxidative stress resulting from increased cardiac generation of reactive oxygen species (ROS) is implicated in the pathophysiology of pressure-overload left ventricular hypertrophy (LVH) and congestive heart failure, both experimentally and in clinical studies. 1-3 Increased ROS production is implicated in the development of cellular hypertrophy and remodeling, at least in part through activation of redox-sensitive protein kinases such as the mitogenactivated protein kinase (MAPK) superfamily. The transition from compensated pressure-overload LVH to heart failure is associated with increased oxidative stress, which may promote myocyte apoptosis and necrosis. Several key proteins involved in excitation-contraction coupling, such as sarcolemmal ion channels and exchangers and sarcoplasmic reticulum calcium release channels, can undergo redoxsensitive alterations in activity, which contributes to myocardial contractile dysfunction. ROS also has indirect effects resulting from increased inactivation of NO and consequent generation of peroxynitrite, eg, coronary vascular endothelial dysfunction and peroxynitrite-induced inhibition of myocardial respiration. 4 The sources of ROS generation that contribute to these effects in pressure-overload LVH and heart failure remain poorly defined. Potential sources include the mitochondrial electron transport chain, xanthine oxida...

The utilization of machine vision and its associated algorithms improves the efficiency, functionality, intelligence, and remote interactivity of harvesting robots in complex agricultural environments. Machine vision and its associated emerging technology promise huge potential in advanced agricultural applications. However, machine vision and its precise positioning still have many technical difficulties, making it difficult for most harvesting robots to achieve true commercial applications. This article reports the application and research progress of harvesting robots and vision technology in fruit picking. The potential applications of vision and quantitative methods of localization, target recognition, 3D reconstruction, and fault tolerance of complex agricultural environment are focused, and fault-tolerant technology designed for utilization with machine vision and robotic systems are also explored. The two main methods used in fruit recognition and localization are reviewed, including digital image processing technology and deep learning-based algorithms. The future challenges brought about by recognition and localization success rates are identified: target recognition in the presence of illumination changes and occlusion environments; target tracking in dynamic interference-laden environments, 3D target reconstruction, and fault tolerance of the vision system for agricultural robots. In the end, several open research problems specific to recognition and localization applications for fruit harvesting robots are mentioned, and the latest development and future development trends of machine vision are described.

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