Magnetomechanical performance of directionally solidified Fe-Ga alloys

Iron-gallium alloys can produce magnetostrictions of ~400 ppm and might serve as mechanically robust actuator/sensing materials. However, for polycrystalline Fe-Ga alloys, the magnetostrictive performance decreases with the increasing deviations from the ideal <100> texture. In this paper, three directionally solidified Fe-Ga alloys with gallium contents of 17, 18.4, and 19.5 at. % were characterized at ambient temperature. These specimens exhibit high d33 and magnetic permeability when subjected to applied magnetic fields, indicating their suitability for light weight actuator applications but not for high force applications due to their low saturation magnetostriction and hence low blocking force. All the alloys produce significant changes in magnetization, around 0.7Ms-0.8Ms when subjected to cyclic compressive stresses of 51 MPa, making them promising candidate materials for sensing and energy harvesting applications. However, eddy current effects may easily become a problem when such materials are subjected to a high frequency vibration or magnetic field due to their intrinsic high magnetic permeability

In Vitro Ability of a Novel Nanohydroxyapatite Oral Rinse to Occlude Dentine Tubules.

Objectives. The aim of the study was to investigate the ability of a novel nanohydroxyapatite (nHA) desensitizing oral rinse to occlude dentine tubules compared to selected commercially available desensitizing oral rinses. Methods. 25 caries-free extracted molars were sectioned into 1 mm thick dentine discs. The dentine discs (n = 25) were etched with 6% citric acid for 2 minutes and rinsed with distilled water, prior to a 30-second application of test and control oral rinses. Evaluation was by (1) Scanning Electron Microscopy (SEM) of the dentine surface and (2) fluid flow measurements through a dentine disc. Results. Most of the oral rinses failed to adequately cover the dentine surface apart from the nHa oral rinse. However the hydroxyapatite, 1.4% potassium oxalate, and arginine/PVM/MA copolymer oral rinses, appeared to be relatively more effective than the nHA test and negative control rinses (potassium nitrate) in relation to a reduction in fluid flow measurements. Conclusions. Although the novel nHA oral rinse demonstrated the ability to occlude the dentine tubules and reduce the fluid flow measurements, some of the other oral rinses appeared to demonstrate a statistically significant reduction in fluid flow through the dentine disc, in particular the arginine/PVM/MA copolymer oral rinse

Transplantation of the small intestine: the pathologist's perspective.

Small-bowel transplantation is now ready for clinical trials. The surgical techniques and methods for immunosuppression and monitoring bowel status have been developed in animal models over the past 30 years. Several attempts at small-bowel transplantation in humans have already been reported. In the course of future trials, pathologists will be involved in the monitoring of the posttransplant course by mucosal biopsies and functional studies, including maltose and xylose absorption tests. The morphology of rejection has been studied in canine and rat models. Activated lymphocytes and plasma cells infiltrate the lamina propria and invade crypt epithelium, causing "cryptitis." Villous blunting ensues, resulting eventually in necrosis. Graft survival without immunosuppression is about 10 days. Under Cyclosporine immunosuppression, a lymphoplasmacytic infiltrate has been noted around nerves and vessels in the submucosa. The overlying mucosa may be relatively normal. End-stage bowel is characterized by a contracted, scarred mass. Due to the large amount of lymphoid tissue in the allograft, graft-versus-host disease is a significant problem in small-bowel transplantation

Interpretable and Generalizable Person Re-Identification with Query-Adaptive Convolution and Temporal Lifting

For person re-identification, existing deep networks often focus on representation learning. However, without transfer learning, the learned model is fixed as is, which is not adaptable for handling various unseen scenarios. In this paper, beyond representation learning, we consider how to formulate person image matching directly in deep feature maps. We treat image matching as finding local correspondences in feature maps, and construct query-adaptive convolution kernels on the fly to achieve local matching. In this way, the matching process and results are interpretable, and this explicit matching is more generalizable than representation features to unseen scenarios, such as unknown misalignments, pose or viewpoint changes. To facilitate end-to-end training of this architecture, we further build a class memory module to cache feature maps of the most recent samples of each class, so as to compute image matching losses for metric learning. Through direct cross-dataset evaluation, the proposed Query-Adaptive Convolution (QAConv) method gains large improvements over popular learning methods (about 10%+ mAP), and achieves comparable results to many transfer learning methods. Besides, a model-free temporal cooccurrence based score weighting method called TLift is proposed, which improves the performance to a further extent, achieving state-of-the-art results in cross-dataset person re-identification. Code is available at https://github.com/ShengcaiLiao/QAConv.Comment: This is the ECCV 2020 version, including the appendi

Feature-Guided Black-Box Safety Testing of Deep Neural Networks

Despite the improved accuracy of deep neural networks, the discovery of adversarial examples has raised serious safety concerns. Most existing approaches for crafting adversarial examples necessitate some knowledge (architecture, parameters, etc.) of the network at hand. In this paper, we focus on image classifiers and propose a feature-guided black-box approach to test the safety of deep neural networks that requires no such knowledge. Our algorithm employs object detection techniques such as SIFT (Scale Invariant Feature Transform) to extract features from an image. These features are converted into a mutable saliency distribution, where high probability is assigned to pixels that affect the composition of the image with respect to the human visual system. We formulate the crafting of adversarial examples as a two-player turn-based stochastic game, where the first player's objective is to minimise the distance to an adversarial example by manipulating the features, and the second player can be cooperative, adversarial, or random. We show that, theoretically, the two-player game can con- verge to the optimal strategy, and that the optimal strategy represents a globally minimal adversarial image. For Lipschitz networks, we also identify conditions that provide safety guarantees that no adversarial examples exist. Using Monte Carlo tree search we gradually explore the game state space to search for adversarial examples. Our experiments show that, despite the black-box setting, manipulations guided by a perception-based saliency distribution are competitive with state-of-the-art methods that rely on white-box saliency matrices or sophisticated optimization procedures. Finally, we show how our method can be used to evaluate robustness of neural networks in safety-critical applications such as traffic sign recognition in self-driving cars.Comment: 35 pages, 5 tables, 23 figure

Experimental Investigation of Ultracapacitor Impedance Characteristics

© 2015 The Authors. Published by Elsevier Ltd. Ultracapacitors (UCs) are being increasingly studied and deployed as a short-term energy storage device in various energy systems including uninterruptible power supplies, electrified vehicles, renewable energy systems, and wireless communication. They exhibit excellent power density and energy efficiency. The dynamic behavior of a UC, however, strongly depends on its impedance characteristics. In this paper, the impedance characteristics of a commercial UC are experimentally investigated through the well-adopted Electrochemical Impedance Spectroscopy (EIS) technique. The implications of the UC operating conditions (i.e., state of charge (SOC) and temperature) to the impedance are systematically examined. The results show that the impedance is highly sensitive to temperature and SOC; and the temperature effect is more significant. The experimental design and multi-condition impedance analysis provides prudent insights into UC system integration, dimensioning, and energy management strategy synthesis in advanced energy systems

SPAD-Array Contention Signal and Noise Model Suitable for Multilevel Modulation Schemes with Signal Processing

The first signal model for a single photon avalanche diode (SPAD)-array communication receiver for multilevel modulation schemes is reported. This paper proposes a novel, generalised SPAD array signal and noise model for both digital and analogue, synchronous and asynchronous SPAD readout arrays, which includes the competition between the input photons, dark counts and after-pulsing counts. With this contention signal and noise model, multilevel signals including the signal variation after distortion or equalisation can be evaluated. Also, we report the first numerical investigation for SPAD-based, high data rate, free space, visible light communication using higher order pulse amplitude modulation (PAM) with matched filter, linear and non-linear Volterra post-equalization. Simulations have been carried out to analyze and compare the bit error rate (BER) performances under a variety of conditions. The model is verified by comparison with published experimental results.UK EPSRC via the TOWS project (EP/S016570/1

Photoreceptor spectral sensitivities of the Small White butterfly Pieris rapae crucivora interpreted with optical modeling

The compound eye of the Small White butterfly, Pieris rapae crucivora, has four classes of visual pigments, with peak absorption in the ultraviolet, violet, blue and green, but electrophysiological recordings yielded eight photoreceptors classes: an ultraviolet, violet, blue, double-peaked blue, green, blue-suppressed-green, pale-red and deep-red class. These photoreceptor classes were identified in three types of ommatidia, distinguishable by the different eye shine spectra and fluorescence; the latter only being present in the eyes of males. We present here two slightly different optical models that incorporate the various visual pigments, the light-filtering actions of the fluorescent, pale-red and deep-red screening pigment, located inside or adjacent to the rhabdom, and the reflectance spectrum of the tapetum that abuts the rhabdom proximally. The models serve to explain the photoreceptor spectral sensitivities as well as the eye shine

Dentine Tubule Occlusion by Novel Bioactive Glass-Based Toothpastes.

There are numerous over-the-counter (OTC) and professionally applied (in-office) products and techniques currently available for the treatment of dentine hypersensitivity (DH), but more recently, the use of bioactive glasses in toothpaste formulations have been advocated as a possible solution to managing DH. Aim. The aim of the present study, therefore, was to compare several bioactive glass formulations to investigate their effectiveness in an established in vitro model. Materials and Methods. A 45S5 glass was synthesized in the laboratory together with several other glass formulations: (1) a mixed glass (fluoride and chloride), (2) BioMinF, (3) a chloride glass, and (4) an amorphous chloride glass. The glass powders were formulated into five different toothpaste formulations. Dentine discs were sectioned from extracted human teeth and prepared for the investigation by removing the cutting debris (smear layer) following sectioning using a 6% citric acid solution for 2 minutes. Each disc was halved to provide test and control halves for comparison following the brushing of the five toothpaste formulations onto the test halves for each toothpaste group. Following the toothpaste application, the test discs were immersed in either artificial saliva or exposed to an acid challenge. Results. The dentine samples were analyzed using scanning electron microscopy (SEM), and observation of the SEM images indicated that there was good surface coverage following artificial saliva immersion. Furthermore, although the acid challenge removed the hydroxyapatite layer on the dentine surface for most of the samples, except for the amorphous chloride glass, there was evidence of tubular occlusion in the dentine tubules. Conclusions. The conclusions from the study would suggest that the inclusion of bioactive glass into a toothpaste formulation may be an effective approach to treat DH

TIFA, an inflammatory signaling adaptor, is tumor suppressive for liver cancer.

TIFA (TNF receptor associated factor (TRAF)-interacting protein with a Forkhead-associated (FHA) domain), also called T2BP, was first identified using a yeast two-hybrid screening. TIFA contains a FHA domain, which directly binds phosphothreonine and phosphoserine, and a consensus TRAF6-binding motif. TIFA-mediated oligomerization and poly-ubiquitinylation of TRAF6 mediates signaling downstream of the Tumor necrosis factor alpha receptor 1 (TNFaR-I) and interleukin-1/Toll-like receptor 4 (TLR4) pathways. Examining TIFA expression in hepatocellular carcinoma (HCC) tissues microarrays, we noted marked decreases TIFA reactivity in tumor versus control samples. In agreement, we found that HCC cell lines show reduced TIFA expression levels versus normal liver controls. Reconstituting TIFA expression in HCC cell lines promoted two independent apoptosis signaling pathways: the induction of p53 and cell cycle arrest, and the activation of caspase-8 and caspase-3. In contrast, the expression of a non-oligomerizing mutant of TIFA impacted cells minimally, and suppression of TIFA expression protected cells from apoptosis. Mice bearing TIFA overexpression hepatocellular xenografts develop smaller tumors versus TIFA mutant tumors; terminal deoxynucleotidyl transferase dUTP nick end labeling staining demonstrates increased cell apoptosis, and decreased proliferation, reflecting cell cycle arrest. Interestingly, p53 has a greater role in decreased proliferation than cell death, as it appeared dispensable for TIFA-induced cell killing. The findings demonstrate a novel suppressive role of TIFA in HCC progression via promotion of cell death independent of p53