Hybrid Radio-map for Noise Tolerant Wireless Indoor Localization

In wireless networks, radio-map based locating techniques are commonly used to cope the complex fading feature of radio signal, in which a radio-map is built by calibrating received signal strength (RSS) signatures at training locations in the offline phase. However, in severe hostile environments, such as in ship cabins where severe shadowing, blocking and multi-path fading effects are posed by ubiquitous metallic architecture, even radio-map cannot capture the dynamics of RSS. In this paper, we introduced multiple feature radio-map location method for severely noisy environments. We proposed to add low variance signature into radio map. Since the low variance signatures are generally expensive to obtain, we focus on the scenario when the low variance signatures are sparse. We studied efficient construction of multi-feature radio-map in offline phase, and proposed feasible region narrowing down and particle based algorithm for online tracking. Simulation results show the remarkably performance improvement in terms of positioning accuracy and robustness against RSS noises than the traditional radio-map method.Comment: 6 pages, 11th IEEE International Conference on Networking, Sensing and Control, April 7-9, 2014, Miami, FL, US

Blockage of bone marrow kinase in chromosome X enhances ABC294640-induced growth inhibition and apoptosis of colorectal cancer cells

Purpose: To investigate the role of bone marrow kinase in chromosome X (BMX) in colorectal cancer (CRC) cell resistance to ABC294640 treatment.Methods: HCT-116R, LS174T and WiDr cells were transfected with either BMX-specific siRNA or scrambled siRNA, and then BMX mRNA and protein expressions were detected by quantitative polymerase chain reaction (qPCR) and western blotting, respectively. The cells were treated with ABC294640 and cell viability evaluated using cell counting and colony formation assays. Apoptosis wasdetermined by detecting caspase 3/7 activity. To evaluate tumor growth of  HCT-116R cells, a xenograft model was utilized to measure tumor size.Results: Pharmacological inhibition of sphingosine kinase type 2 (SK2) with ABC294640 significantly decreased cell viability (p < 0.001) when compared with control group. SK2 inhibition also remarkably induced apoptosis in HCT-116 CRC cells in a dose-dependent manner (p < 0.01 and p < 0.001). However, no significant effects were observed in HCT-116R, LS174T, or WiDr cells following ABC294640 treatment. BMX mRNA and protein expression increased in ABC294640-resistant cell lines. In addition, silencing BMX expression with siRNA potentiated  ABC294640-induced inhibition of tumor growth in CRC cells in vitro and in vivo.Conclusion: ABC294640-induced BMX upregulation impedes the antitumor effect of ABC294640 in CRC cells. Therefore, these results may provide a novel therapeutic strategy for CRC using a combination of ABC294640 treatment and BMX blockade.Keywords: ABC294640, Apoptosis, Bone marrow kinase in chromosome X, Cell viability, Colorectal cance

A compact butterfly-style silicon photonic-electronic neural chip for hardware-efficient deep learning

The optical neural network (ONN) is a promising hardware platform for next-generation neurocomputing due to its high parallelism, low latency, and low energy consumption. Previous ONN architectures are mainly designed for general matrix multiplication (GEMM), leading to unnecessarily large area cost and high control complexity. Here, we move beyond classical GEMM-based ONNs and propose an optical subspace neural network (OSNN) architecture, which trades the universality of weight representation for lower optical component usage, area cost, and energy consumption. We devise a butterfly-style photonic-electronic neural chip to implement our OSNN with up to 7x fewer trainable optical components compared to GEMM-based ONNs. Additionally, a hardware-aware training framework is provided to minimize the required device programming precision, lessen the chip area, and boost the noise robustness. We experimentally demonstrate the utility of our neural chip in practical image recognition tasks, showing that a measured accuracy of 94.16% can be achieved in hand-written digit recognition tasks with 3-bit weight programming precision.Comment: 17 pages,5 figure

Point mutant mice with hypersensitive alpha 4 nicotinic receptors show dopaminergic deficits and increased anxiety

Knock-in mice were generated that harbored a leucine-to-serine mutation in the alpha4 nicotinic receptor near the gate in the channel pore. Mice with intact expression of this hypersensitive receptor display dominant neonatal lethality. These mice have a severe deficit of dopaminergic neurons in the substantia nigra, possibly because the hypersensitive receptors are continuously activated by normal extracellular choline concentrations. A strain that retains the neo selection cassette in an intron has reduced expression of the hypersensitive receptor and is viable and fertile. The viable mice display increased anxiety, poor motor learning, excessive ambulation that is eliminated by very low levels of nicotine, and a reduction of nigrostriatal dopaminergic function upon aging. These knock-in mice provide useful insights into the pathophysiology of sustained nicotinic receptor activation and may provide a model for Parkinson's disease

Functional studies oftwist during mouse embryogenesis

A fundamental task in developmental biology is to understand the molecular mechanisms governing early embryogenesis. The aim of this study was to understand the developmental role of a putative basic helix-loop-helix (b-HLH) transcription factor, twist, during mouse embryogenesis. twist was originally identified in Drosophila as one of the zygotic genes, including snail, that were required for dorsal-ventral patterning. In Drosophila embryogenesis, twist is expressed in the cells of the ventral midline destined to form mesoderm. In embryos lacking twist expression, their ventral cells fail to form a ventral furrow and subsequently no mesoderm is formed. During mouse embryogenesis, twist is expressed after initial mesoderm formation in both mesoderm and cranial neural crest cell derivatives. To study the role of twist in vivo, twist-null embryos were generated by gene targeting. Embryos homozygous for the twist mutation die at midgestation. The most prominent phenotype in the present study was a failure of the cranial neural tube to close (exencephaly). twist-null embryos also showed defects in head mesenchyme, branchial arches, somites, and limb buds. To understand whether twist functions cell-autonomously and to investigate how twist-null cells interact with wild-type cells in vivo, twist chimeras composed of both twist-null and wild-type cells marked by the expression of the lacZgene were generated. Chimeric analysis revealed a correlation between the incidence of exencephaly and the contribution of the underlying twist-null head mesenchyme, thus strongly suggesting that twist-expressing head mesenchyme is required for the closure of the cranial neural tube. These studies have identified twist as a critical regulator for the mesenchymal fate determination within the cranial neural crest lineage. Most strikingly, twist-null head mesenchyme cells were always segregated from wild-type cells, indicating that the twist mutation altered the adhesive specificity of these cells. Furthermore, these results also indicated that twist functions cell-autonomously in the head, arch, and limb mesenchyme but non-cell-autonomously in the somites. Taken together, these studies have established the essential role of twist during mouse embryogenesis

Wavelength-division-multiplexing (WDM)-based integrated electronic–photonic switching network (EPSN) for high-speed data processing and transportation

Integrated photonics offers attractive solutions for realizing combinational logic for high-performance computing. The integrated photonic chips can be further optimized using multiplexing techniques such as wavelength-division multiplexing (WDM). In this paper, we propose a WDM-based electronic–photonic switching network (EPSN) to realize the functions of the binary decoder and the multiplexer, which are fundamental elements in microprocessors for data transportation and processing. We experimentally demonstrate its practicality by implementing a 3–8 (three inputs, eight outputs) switching network operating at 20 Gb/s. Detailed performance analysis and performance enhancement techniques are also given in this paper

Efficient On-Chip Learning for Optical Neural Networks Through Power-Aware Sparse Zeroth-Order Optimization

Optical neural networks (ONNs) have demonstrated record-breaking potential in high-performance neuromorphic computing due to their ultra-high execution speed and low energy consumption. However, current learning protocols fail to provide scalable and efficient solutions to photonic circuit optimization in practical applications. In this work, we propose a novel on-chip learning framework to release the full potential of ONNs for power-efficient in situ training. Instead of deploying implementation-costly back-propagation, we directly optimize the device configurations with computation budgets and power constraints. We are the first to model the ONN on-chip learning as a resource-constrained stochastic noisy zeroth-order optimization problem, and propose a novel mixed-training strategy with two-level sparsity and power-aware dynamic pruning to offer a scalable on-chip training solution in practical ONN deployment. Compared with previous methods, we are the first to optimize over 2,500 optical components on chip. We can achieve much better optimization stability, 3.7x-7.6x higher efficiency, and save >90% power under practical device variations and thermal crosstalk

neurogenin1 Is Essential for the Determination of Neuronal Precursors for Proximal Cranial Sensory Ganglia

The NEUROGENINS (NGNs) are neural-specific basic helix–loop–helix (bHLH) transcription factors. Mouse embryos lacking ngn1 fail to generate the proximal subset of cranial sensory neurons. ngn1 is required for the activation of a cascade of downstream bHLH factors, including NeuroD, MATH3, and NSCL1. ngn1 is expressed by placodal ectodermal cells and acts prior to neuroblast delamination. Moreover, NGN1 positively regulates the Delta homolog DLL1 and can be negatively regulated by Notch signaling. Thus, ngn1 functions similarly to the proneural genes in Drosophila. However, the initial pattern of ngn1 expression appears to be Notch independent. Taken together with the fact that ectopic ngn1 expression can convert ectodermal cells to neurons in Xenopus ( Ma et al. 1996), these data and those of Fode et al. 1998) identify ngns as vertebrate neuronal determination genes, analogous to myoD and myf5 in myogenesis

Investigation on the water vapor oxidation of Super304H at 600 ℃

Steam oxidation is the main limited factor for the heat-resistant steel in fossil power plant. Disclosing the oxidation mechanism and kinetics could be helpful for the daily inspection to ensure the safety operation. To investigate the water vapor oxidation behavior of Super304H, the oxidation test was conducted at 600 ℃ for 25, 50, 100, 150 and 200 h in flowing steam. The structure and compositions of the oxide layers were investigated by line-scanning of scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). Surface morphology was observed after the oxidation test. The oxide phases were identified by XRD. The results showed that the oxide layer was duplex structure consisted of a Fe _3 O _4 - Fe _2 O _3 outer layer and an inner oxide layer which contained nickel oxide, Cr _2 O _3 , and FeCr _2 O _4 . As the oxidation time increased, the thickness of the total oxide layer and inner layer both increased. After 100 h oxidation, oxide layer exfoliation occurred and resulted in rapid growth of new oxide layer in the exfoliation region

Isolation and characterization of mammalian homologs of the Drosophila gene glial cells missing

The glial cells missing (gcm) gene in Drosophila encodes a transcription factor that determines the choice between glial and neuronal fates. We report here the isolation of two mammalian gcm homologs, Gcm1 and Gcm2, and the characterization of their expression patterns during embryonic development. Although Gcm2 is expressed in neural tissues at a low level, the major sites of expression for both of the mammalian genes are nonneural, suggesting that the functions of the mammalian homologs have diverged and diversified. However, when expressed ectopically, Gcm1 can substitute functionally for Drosophila gcm by transforming presumptive neurons into glia. Thus, certain biochemical properties, although not the specificity of the tissue in which the gene is expressed, have been conserved through the evolution of the Gcm gene family