Abstract-With an increasing incidence of obesity worldwide, rational strategies are needed to control adipogenesis.Growth of any tissue requires the formation of a functional and mature vasculature. To gain mechanistic insight into the link between active adipogenesis and angiogenesis, we developed a model to visualize noninvasively and in real time both angiogenesis and adipogenesis using intravital microscopy. Implanted murine preadipocytes induced vigorous angiogenesis and formed fat pads in a mouse dorsal skin-fold chamber. The newly formed vessels subsequently remodeled into a mature network consisting of arterioles, capillaries, and venules, whereas the preadipocytes differentiated into adipocytes as confirmed by increased aP2 expression. Inhibition of adipocyte differentiation by transfection of preadipocytes with a peroxisome proliferator-activated receptor ␥ dominant-negative construct not only abrogated fat tissue formation but also reduced angiogenesis. Surprisingly, inhibition of angiogenesis by vascular endothelial growth factor receptor-2 (VEGFR2) blocking antibody not only reduced angiogenesis and tissue growth but also inhibited preadipocyte differentiation. We found that part of this inhibition stems from the paracrine interaction between endothelial cells and preadipocytes and that VEGF-VEGFR2 signaling in endothelial cells, but not preadipocytes, mediates this process. These findings reveal a reciprocal regulation of adipogenesis and angiogenesis, and suggest that blockade of VEGF signaling can inhibit in vivo adipose tissue formation.

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We study a model in which perfectly informed experts offer advice to a decision maker whose actions affect the welfare of all. Experts are biased and thus may wish to pull the decision maker in different directions and to different degrees. When the decision maker consults only a single expert, the expert withholds substantial information from the decision maker. We ask whether this situation is improved by having the decision maker sequentially consult two experts. We first show that there is no perfect Bayesian equilibrium in which full revelation occurs. When both experts are biased in the same direction, it is never beneficial to consult both. In contrast, when experts are biased in opposite directions, it is always beneficial to consult both. Indeed, in this case full revelation may be induced in an extended debate by introducing the possibility of rebuttal. Downloaded from1. Our results in the case of like biases concern monotonic equilibria where the action taken is a monotonic function of the state. While nonmonotonic equilibria exist, we provide sufficient conditions for all equilibria to be monotonic.2. Our results in the case of opposing biases hold generally for all equilibria, not just monotonic equilibria. 749 A MODEL OF EXPERTISE Downloaded from 3. The case where both b 1 , b 2 Ͻ 0 is qualitatively no different from the case where both b 1 , b 2 Ͼ 0. 752 QUARTERLY JOURNAL OF ECONOMICS at California State University, Fresno on July 24, 2015 http://qje.oxfordjournals.org/ Downloaded from 7. Although our analysis in the like bias case is confined to monotonic equilibria, we know of no instance where admitting a nonmonotonic equilibrium reverses the welfare comparisons. 759 A MODEL OF EXPERTISE