Volume holographic interconnections with maximal capacity and minimal cross talk

Optical interconnections utilizing volume holography are described. Intrinsic cross-talk effects that limit the number of independent interconnections are identified and analyzed by applying coupled-wave analysis. Sampling grids for removing the first-order cross talk are presented, resulting in a system limited by second- and third-order cross talk only

Interspecies Knowledge Transfer for Facial Keypoint Detection

We present a method for localizing facial keypoints on animals by transferring knowledge gained from human faces. Instead of directly finetuning a network trained to detect keypoints on human faces to animal faces (which is sub-optimal since human and animal faces can look quite different), we propose to first adapt the animal images to the pre-trained human detection network by correcting for the differences in animal and human face shape. We first find the nearest human neighbors for each animal image using an unsupervised shape matching method. We use these matches to train a thin plate spline warping network to warp each animal face to look more human-like. The warping network is then jointly finetuned with a pre-trained human facial keypoint detection network using an animal dataset. We demonstrate state-of-the-art results on both horse and sheep facial keypoint detection, and significant improvement over simple finetuning, especially when training data is scarce. Additionally, we present a new dataset with 3717 images with horse face and facial keypoint annotations.Comment: CVPR 2017 Camera Read

Ranking influential spreaders is an ill-defined problem

Finding influential spreaders of information and disease in networks is an important theoretical problem, and one of considerable recent interest. It has been almost exclusively formulated as a node-ranking problem -- methods for identifying influential spreaders rank nodes according to how influential they are. In this work, we show that the ranking approach does not necessarily work: the set of most influential nodes depends on the number of nodes in the set. Therefore, the set of $n$ most important nodes to vaccinate does not need to have any node in common with the set of $n+1$ most important nodes. We propose a method for quantifying the extent and impact of this phenomenon, and show that it is common in both empirical and model networks

Cooperation of Gq, Gi, and G12/13 in Protein Kinase D Activation and Phosphorylation Induced by Lysophosphatidic Acid

To examine the contribution of different G-protein pathways to lysophosphatidic acid (LPA)-induced protein kinase D (PKD) activation, we tested the effect of LPA on PKD activity in murine embryonic cell lines deficient in Galpha q/11 (Galpha q/11 KO cells) or Galpha 12/13 (Galpha 12/13 KO cells) and used cells lacking rhodopsin kinase (RK cells) as a control. In RK and Galpha 12/13 KO cells, LPA induced PKD activation through a phospholipase C/protein kinase C pathway in a concentration-dependent fashion with maximal stimulation (6-fold for RK cells and 4-fold for Galpha 12/13 KO cells in autophosphorylation activity) achieved at 3 µM. In contrast, LPA did not induce any significant increase in PKD activity in Galpha q/11 KO cells. However, LPA induced a significantly increased PKD activity when Galpha q/11 KO cells were transfected with Galpha q. LPA-induced PKD activation was modestly attenuated by prior exposure of RK cells to pertussis toxin (PTx) but abolished by the combination treatments of PTx and Clostridium difficile toxin B. Surprisingly, PTx alone strikingly inhibited LPA-induced PKD activation in a concentration-dependent fashion in Galpha 12/13 KO cells. Similar results were obtained when activation loop phosphorylation at Ser-744 was determined using an antibody that detects the phosphorylated state of this residue. Our results indicate that Gq is necessary but not sufficient to mediate LPA-induced PKD activation. In addition to Gq, LPA requires additional G-protein pathways to elicit a maximal response with Gi playing a critical role in Galpha 12/13 KO cells. We conclude that LPA induces PKD activation through Gq, Gi, and G12 and propose that PKD activation is a point of convergence in the action of multiple G-protein pathways