Multi-Path Region-Based Convolutional Neural Network for Accurate Detection of Unconstrained "Hard Faces"

Large-scale variations still pose a challenge in unconstrained face detection. To the best of our knowledge, no current face detection algorithm can detect a face as large as 800 x 800 pixels while simultaneously detecting another one as small as 8 x 8 pixels within a single image with equally high accuracy. We propose a two-stage cascaded face detection framework, Multi-Path Region-based Convolutional Neural Network (MP-RCNN), that seamlessly combines a deep neural network with a classic learning strategy, to tackle this challenge. The first stage is a Multi-Path Region Proposal Network (MP-RPN) that proposes faces at three different scales. It simultaneously utilizes three parallel outputs of the convolutional feature maps to predict multi-scale candidate face regions. The "atrous" convolution trick (convolution with up-sampled filters) and a newly proposed sampling layer for "hard" examples are embedded in MP-RPN to further boost its performance. The second stage is a Boosted Forests classifier, which utilizes deep facial features pooled from inside the candidate face regions as well as deep contextual features pooled from a larger region surrounding the candidate face regions. This step is included to further remove hard negative samples. Experiments show that this approach achieves state-of-the-art face detection performance on the WIDER FACE dataset "hard" partition, outperforming the former best result by 9.6% for the Average Precision.Comment: 11 pages, 7 figures, to be presented at CRV 201

Loss of strength in Ni3Al at elevated temperatures

Stress decrease above the stress peak temperature (750 K) is studied in h123i single crystals of Ni3(Al, 3 at.% Hf ). Two thermally activated deformation mechanisms are evidenced on the basis of stress relaxation and strain rate change experiments. From 500 to 1070 K, the continuity of the activation volume/temperature curves reveals a single mechanism of activation enthalpy 3.8 eV/atom and volume 90 b3 at 810K with an athermal stress of 330 MPa. Over the very same temperature interval, impurity or solute diffusion towards dislocation cores is evidenced through serrated yielding, peculiar shapes of stress–strain curves while changing the rate of straining and stress relaxation experiments. This complicates the identification of the deformation mechanism, which is likely connected with cube glide. From 1070 to 1270 K, the high-temperature mechanism has an activation enthalpy and volume of 4.8 eV/atom and 20 b3, respectively, at 1250 K

Active contractility in actomyosin networks

Contractile forces are essential for many developmental processes involving cell shape change and tissue deformation. Recent experiments on reconstituted actomyosin networks, the major component of the contractile machinery, have shown that active contractility occurs above a threshold motor concentration and within a window of crosslink concentration. We present a microscopic dynamic model that incorporates two essential aspects of actomyosin self-organization: the asymmetric load response of individual actin filaments and the correlated motor-driven events mimicking myosin-induced filament sliding. Using computer simulations we examine how the concentration and susceptibility of motors contribute to their collective behavior and interplay with the network connectivity to regulate macroscopic contractility. Our model is shown to capture the formation and dynamics of contractile structures and agree with the observed dependence of active contractility on microscopic parameters including the contractility onset. Cooperative action of load-resisting motors in a force-percolating structure integrates local contraction/buckling events into a global contractile state via an active coarsening process, in contrast to the flow transition driven by uncorrelated kicks of susceptible motors.Comment: 15 pages, 4 main figures, 4 supplementary figure

Imitation in Large Games

In games with a large number of players where players may have overlapping objectives, the analysis of stable outcomes typically depends on player types. A special case is when a large part of the player population consists of imitation types: that of players who imitate choice of other (optimizing) types. Game theorists typically study the evolution of such games in dynamical systems with imitation rules. In the setting of games of infinite duration on finite graphs with preference orderings on outcomes for player types, we explore the possibility of imitation as a viable strategy. In our setup, the optimising players play bounded memory strategies and the imitators play according to specifications given by automata. We present algorithmic results on the eventual survival of types

NADPH oxidases regulate cell growth and migration in myeloid cells transformed by oncogenic tyrosine kinases

Transformation by tyrosine kinase oncogenes in myeloid malignancies, including BCR-ABL in chronic myeloid leukemia, FLT3ITD in acute myeloid leukemia (AML) or JAK2V617F in myeloproliferative neoplasms (MPN), is associated with increased growth and cytoskeletal abnormalities. Using targeted approaches against components of the superoxide-producing NADPH-oxidases, including NOX2, NOX4 and the common p22phox subunit of NOX1-4, myeloid cells were found to display reduced cell growth and spontaneous migration. Consistent with a role of NOX as regulators of membrane proximal signaling events in non-phagocytic cells, NOX2 and NOX4 were not involved in the excess production of intracellular reactive oxygen species and did not significantly increase oxygen consumption. All NOX family members are controlled in part through levels of the rate-limiting substrate NADPH, which was found to be significantly elevated in tyrosine kinase oncogene transformed cells. Also, reduced phosphorylation of the actin filament crosslinking protein MARCKS in response to suppression of p22phox hints at a novel effector of NOX signaling. MARCKS was also found to be required for increased migration. Overall, these data suggest a model whereby NOX links metabolic NADPH production to cellular events that directly contribute to transformation

Time Evolution of Entanglement of Electrons and Nuclei and Partial Traces in Ultrafast Photochemistry

peer reviewe

Density-Polarization Functional Theory of the response of a periodic insulating solid to an electric field.

The response of an infinite, periodic, insulating, solid to an infinitesimally small electric field is investigated in the framework of Density Functional Theory. We find that the applied perturbing potential is not a unique functional of the periodic density change~: it depends also on the change in the macroscopic {\em polarization}. Moreover, the dependence of the exchange-correlation energy on polarization induces an exchange-correlation electric field. These effects are exhibited for a model semiconductor. We also show that the scissor-operator technique is an approximate way of bypassing this polarization dependence.Comment: 11 pages, 1 Fig

Military spending and economic growth in China: a regime-switching analysis

This article has been made available through the Brunel Open Access Publishing Fund.This article investigates the impact of military spending changes on economic growth in China over the period 1953 to 2010. Using two-state Markov-switching specifications, the results suggest that the relationship between military spending changes and economic growth is state dependent. Specifically, the results show that military spending changes affect the economic growth negatively during a slower growth-higher variance state, while positively within a faster growth-lower variance one. It is also demonstrated that military spending changes contain information about the growth transition probabilities. As a policy tool, the results indicate that increases in military spending can be detrimental to growth during slower growth-higher growth volatility periods. © 2014 © 2014 The Author(s). Published by Taylor & Francis

A Model for the Elasticity of Compressed Emulsions

We present a new model to describe the unusual elastic properties of compressed emulsions. The response of a single droplet under compression is investigated numerically for different Wigner-Seitz cells. The response is softer than harmonic, and depends on the coordination number of the droplet. Using these results, we propose a new effective inter-droplet potential which is used to determine the elastic response of a monodisperse collection of disordered droplets as a function of volume fraction. Our results are in excellent agreement with recent experiments. This suggests that anharmonicity, together with disorder, are responsible for the quasi-linear increase of $G$ and $\Pi$ observed at $\varphi_c$.Comment: RevTeX with psfig-included figures and a galley macr