Lithographic engineering of anisotropies in (Ga,Mn)As

The focus of studies on ferromagnetic semiconductors is moving from material issues to device functionalities based on novel phenomena often associated with the anisotropy properties of these materials. This is driving a need for a method to locally control the anisotropy in order to allow the elaboration of devices. Here we present a method which provides patterning induced anisotropy which not only can be applied locally, but also dominates over the intrinsic material anisotropy at all temperatures

Physical Representation-based Predicate Optimization for a Visual Analytics Database

Querying the content of images, video, and other non-textual data sources requires expensive content extraction methods. Modern extraction techniques are based on deep convolutional neural networks (CNNs) and can classify objects within images with astounding accuracy. Unfortunately, these methods are slow: processing a single image can take about 10 milliseconds on modern GPU-based hardware. As massive video libraries become ubiquitous, running a content-based query over millions of video frames is prohibitive. One promising approach to reduce the runtime cost of queries of visual content is to use a hierarchical model, such as a cascade, where simple cases are handled by an inexpensive classifier. Prior work has sought to design cascades that optimize the computational cost of inference by, for example, using smaller CNNs. However, we observe that there are critical factors besides the inference time that dramatically impact the overall query time. Notably, by treating the physical representation of the input image as part of our query optimization---that is, by including image transforms, such as resolution scaling or color-depth reduction, within the cascade---we can optimize data handling costs and enable drastically more efficient classifier cascades. In this paper, we propose Tahoma, which generates and evaluates many potential classifier cascades that jointly optimize the CNN architecture and input data representation. Our experiments on a subset of ImageNet show that Tahoma's input transformations speed up cascades by up to 35 times. We also find up to a 98x speedup over the ResNet50 classifier with no loss in accuracy, and a 280x speedup if some accuracy is sacrificed.Comment: Camera-ready version of the paper submitted to ICDE 2019, In Proceedings of the 35th IEEE International Conference on Data Engineering (ICDE 2019

Improved Sequence-Based Speculation Techniques for Implementing Memory Consistency

This work presents BMW, a new design for speculative implementations of memory consistency models in shared-memory multiprocessors. BMW obtains the same performance as prior proposals, but achieves this performance while avoiding several undesirable attributes of prior proposals: non-scalable structures, per-word valid bits in the data cache, modifications to the cache coherence protocol, and global arbitration. BMW uses a read and write bit per cache block and a standard invalidation-based cache coherence protocol to perform conflict detection while speculating. While speculating, stores to block not in the cache are placed into a coalescing store buffer until those misses return. Stores are written speculatively to the primary cache, and non-speculative state is maintained by cleaning dirty blocks before being written speculatively. Speculative blocks are invalidated on abort and marked as non-speculative on commit. This organization allows for fast, local commits while avoiding a non-scalable store queue

Les stéréotypies des animaux élevés en captivité : étude bibliographique

et n’ayant aucun but particulier. Elles posent de nombreux problèmes éthiques notamment dans les zoos, car elles sont considérées comme reflétant le mal-être des animaux, ce qui rend l’opinion publique très sensible à ce genre de trouble comportemental. Il existe de nombreuses formes de stéréotypies, qui sont exprimées par un grand nombre d’espèce animales. Elles sont dues à une impossibilité de l’animal de réaliser un comportement donné, dans un environnement trop pauvre en stimuli et sont à l’origine de modifications neurologiques rendant ce comportement encore plus « figé ». Après avoir défini et présenté les stéréotypies, ainsi que leurs causes et les mécanismes associés, ce travail envisage les possibilités de traitement et de prévention, en particulier par la mise en place d’enrichissements, complétés si besoin de traitements médicaux

Dual Laser Beam Processing of Semiconducting Thin Films by Excited State Absorption

We present a unique dual laser beam processing approach based on excited state absorption by structuring 200 nm thin zinc oxide films sputtered on fused silica substrates. The combination of two pulsed nanosecond-laser beams with different photon energies—one below and one above the zinc oxide band gap energy—allows for a precise, efficient, and homogeneous ablation of the films without substrate damage. Based on structuring experiments in dependence on laser wavelength, pulse fluence, and pulse delay of both laser beams, a detailed concept of energy transfer and excitation processes during irradiation was developed. It provides a comprehensive understanding of the thermal and electronic processes during ablation. To quantify the efficiency improvements of the dual-beam process compared to single-beam ablation, a simple efficiency model was developed

Multipotency of skeletal muscle stem cells on their native substrate and the expression of Connexin 43 during adoption of adipogenic and osteogenic fate

Skeletal muscle contains a resident stem cell population called Satellite cells (SC) which have a huge capacity to regenerate damaged tissue. Transplantation of a single fiber consisting of less than ten cells is able to generate tens of thousands of myonuclei within a matter of a few weeks (Collins et al., 2005). SC take their name from their peripheral position relative to the muscle fiber (Mauro, 1961). They are located under the basal lamina, in direct contact with the sarcolemma of muscle fibers. In undamaged muscle, they are relatively metabolically inactive as indicated by their low cytoplasmic content and they exist in a quiescent state. However, they express certain markers including Pax7 that aid their identification (Zammit et al., 2006). Upon muscle damage, SC become activated by inducing a number of genes including MyoD that encodes a member of the Myogenic Determination Factor family (MRF) of transcriptions factors (Zammit et al., 2006). Activation of SC permits cell division as well as migration. Initially, SC migrate under the basal lamina but then take up a supra-basal position by remodeling their overlying extra-cellular matrix (Otto et al., 2011). Activated SC can either revert to their quiescent state by down-regulating MyoD while maintaining Pax7 or can commit to myogenic differentiation by shutting off Pax7 expression and inducing the expression o