Image-to-Image Translation with Conditional Adversarial Networks

We investigate conditional adversarial networks as a general-purpose solution to image-to-image translation problems. These networks not only learn the mapping from input image to output image, but also learn a loss function to train this mapping. This makes it possible to apply the same generic approach to problems that traditionally would require very different loss formulations. We demonstrate that this approach is effective at synthesizing photos from label maps, reconstructing objects from edge maps, and colorizing images, among other tasks. Indeed, since the release of the pix2pix software associated with this paper, a large number of internet users (many of them artists) have posted their own experiments with our system, further demonstrating its wide applicability and ease of adoption without the need for parameter tweaking. As a community, we no longer hand-engineer our mapping functions, and this work suggests we can achieve reasonable results without hand-engineering our loss functions either.Comment: Website: https://phillipi.github.io/pix2pix/, CVPR 201

The Unreasonable Effectiveness of Deep Features as a Perceptual Metric

While it is nearly effortless for humans to quickly assess the perceptual similarity between two images, the underlying processes are thought to be quite complex. Despite this, the most widely used perceptual metrics today, such as PSNR and SSIM, are simple, shallow functions, and fail to account for many nuances of human perception. Recently, the deep learning community has found that features of the VGG network trained on ImageNet classification has been remarkably useful as a training loss for image synthesis. But how perceptual are these so-called "perceptual losses"? What elements are critical for their success? To answer these questions, we introduce a new dataset of human perceptual similarity judgments. We systematically evaluate deep features across different architectures and tasks and compare them with classic metrics. We find that deep features outperform all previous metrics by large margins on our dataset. More surprisingly, this result is not restricted to ImageNet-trained VGG features, but holds across different deep architectures and levels of supervision (supervised, self-supervised, or even unsupervised). Our results suggest that perceptual similarity is an emergent property shared across deep visual representations.Comment: Accepted to CVPR 2018; Code and data available at https://www.github.com/richzhang/PerceptualSimilarit

Neutrino self-energy in a magnetized medium in arbitrary ξ\xi-gauge

We calculate the one-loop neutrino self-energy in a magnetized plasma to all orders in the magnetic field. The calculation is done in a general gauge. We obtain the dispersion relation and effective potential for neutrinos in a CP-symmetric plasma under various conditions, and show that, while the self-energy depends on the gauge parameter $\xi$, the dispersion relation and effective potential to leading order are independent of it.Comment: 13 pages, RevTeX, epsfig, axodra

STZ-diabetic rat heart maintains developed tension amplitude by increasing sarcomere length and crossbridge density

New Findings: What is the central question of this study? In the papillary muscle from type I diabetic rats, does diabetes-associated altered ventricular function result from changes of acto-myosin interactions and are these modifications attributable to a possible sarcomere rearrangement? What is the main finding and its importance? For the first time, we showed that type-I diabetes altered sarcomeric ultrastructure, as seen by transmission electron microscopy, consistent with physiological parameters. The diabetic condition induced slower timing parameters, which is compatible with a diastolic dysfunction. At the sarcomeric level, augmented β-myosin heavy chain content and increased sarcomere length and crossbridges' number preserve myocardial stroke and could concur to maintain the ejection fraction. Abstract: We investigated whether diabetes-associated altered ventricular function, in a type I diabetes animal model, results from a modification of acto-myosin interactions, through the in vitro recording of left papillary muscle mechanical parameters and examination of sarcomere morphology by transmission electron microscopy (TEM). Experiments were performed on streptozotocin-induced diabetic and age-matched control female Wistar rats. Mechanical isometric and isotonic indexes and timing parameters were determined. Using Huxley's equations, we calculated mechanics, kinetics and energetics of myosin crossbridges. Sarcomere length and A-band length were measured on TEM images. Type I and III collagen and β-myosin heavy chain (MHC) expression were determined by immunoblotting. No variation in resting and developed tension or maximum extent of shortening was evident between groups, but diabetic rats showed lower maximum shortening velocity and prolonged timing parameters. Compared to controls, diabetics also displayed a higher number of crossbridges with lower unitary force. Moreover, no change in type I and III collagen was associated to diabetes, but pathological rats showed a two-fold enhancement of β-MHC content and longer sarcomeres and A-band, detected by ultrastructural morphometry. Overall, these data address whether a preserved systolic function accompanied by an altered diastolic phase results from a recruitment of super-relaxed myosin heads or the phosphorylation of the regulatory light chain site in myosin. Although the early signs of diabetic cardiomyopathy were well expressed, the striking finding of our study was that, in diabetics, sarcomere modification may be a possible compensatory mechanism that preserves systolic function

Bose Einstein condensation on inhomogeneous amenable graphs

We investigate the Bose-Einstein Condensation on nonhomogeneous amenable networks for the model describing arrays of Josephson junctions. The resulting topological model, whose Hamiltonian is the pure hopping one given by the opposite of the adjacency operator, has also a mathematical interest in itself. We show that for the nonhomogeneous networks like the comb graphs, particles condensate in momentum and configuration space as well. In this case different properties of the network, of geometric and probabilistic nature, such as the volume growth, the shape of the ground state, and the transience, all play a role in the condensation phenomena. The situation is quite different for homogeneous networks where just one of these parameters, e.g. the volume growth, is enough to determine the appearance of the condensation.Comment: 43 pages, 12 figures, final versio

Toward a Global History of Inclusive Travel

This paper provides an overview of the development of inclusive travel and tourism, from its origins in the United States and Europe following World War I and II to its current status as an increasingly important and viable movement worldwide. The paper investigates the key roles played by disability organizations, disability rights legislation, technological change, international organizations and pioneers within the travel and tourism industry. Developments are described sector by sector for air travel, ground transport, the cruise lines and the hospitality industry. While the primary historical focus is the U.S., the paper also highlights advances taking place in Dubai, Egypt, India, Japan, South Africa, Thailand and other countries. It concludes with a case study by José Isola of the development of inclusive travel in Peru. Mr. Isola also describes disability conferences that took place in South America in 2004. It is hoped others will begin to investigate the development of inclusive travel in their own countries and regions and contribute to a truly global history

Are African stock markets efficient? Evidence from wavelet unit root test for random walk

In this paper, we used the recently developed frequency based wavelet unit root test alongside a number of time domain unit root tests to examine the validity or otherwise of the random walk hypothesis for seven African largest markets. Unlike previous studies that affirms the validity of the random walk behaviour for African markets, our results reveal that when frequency domain is factored into stock market behaviour framework, evidence abound to reject the null of unit root test for each of the African markets studied. This implies that African markets are inefficient, contributes to growth and provide good opportunities for arbitrage trading. The results have critical implications for investors, policy makers as well as the academic

Stock Market Volatility: Does our Fundamentals Matter?

This study used EGARCH estimation techniques to examine the impact of the systematic risk emanating from the macroeconomy on stock market volatility based on monthly data sourced from 1985 to 2013 on the Nigerian economy. Our results show that all the macroeconomic variables tested exerts on stock market pricing and that the stock market pricing is most influenced by exchange rate volatility. We thus recommend that policy makers on the one hand should pay close attention to the innovations in the macroeconomic variables when formulating macroeconomic or financial stability policy. On the other hand, market practitioners should calibrate volatility of macroeconomic variables in their portfolio decision making proces