Algebraic signal processing theory: 2-D spatial hexagonal lattice.

PubMed

Pünschel, Markus; Rötteler, Martin

2007-06-01

We develop the framework for signal processing on a spatial, or undirected, 2-D hexagonal lattice for both an infinite and a finite array of signal samples. This framework includes the proper notions of z-transform, boundary conditions, filtering or convolution, spectrum, frequency response, and Fourier transform. In the finite case, the Fourier transform is called discrete triangle transform. Like the hexagonal lattice, this transform is nonseparable. The derivation of the framework makes it a natural extension of the algebraic signal processing theory that we recently introduced. Namely, we construct the proper signal models, given by polynomial algebras, bottom-up from a suitable definition of hexagonal space shifts using a procedure provided by the algebraic theory. These signal models, in turn, then provide all the basic signal processing concepts. The framework developed in this paper is related to Mersereau's early work on hexagonal lattices in the same way as the discrete cosine and sine transforms are related to the discrete Fourier transform-a fact that will be made rigorous in this paper.

Image reconstruction: an overview for clinicians.

PubMed

Hansen, Michael S; Kellman, Peter

2015-03-01

Image reconstruction plays a critical role in the clinical use of magnetic resonance imaging (MRI). The MRI raw data is not acquired in image space and the role of the image reconstruction process is to transform the acquired raw data into images that can be interpreted clinically. This process involves multiple signal processing steps that each have an impact on the image quality. This review explains the basic terminology used for describing and quantifying image quality in terms of signal-to-noise ratio and point spread function. In this context, several commonly used image reconstruction components are discussed. The image reconstruction components covered include noise prewhitening for phased array data acquisition, interpolation needed to reconstruct square pixels, raw data filtering for reducing Gibbs ringing artifacts, Fourier transforms connecting the raw data with image space, and phased array coil combination. The treatment of phased array coils includes a general explanation of parallel imaging as a coil combination technique. The review is aimed at readers with no signal processing experience and should enable them to understand what role basic image reconstruction steps play in the formation of clinical images and how the resulting image quality is described. © 2014 Wiley Periodicals, Inc.

Process Instrumentation. Teacher Edition.

ERIC Educational Resources Information Center

Brown, A. O., III; Fowler, Malcolm

This module provides instructional materials that are designed to help teachers train students in job skills for entry-level jobs as instrumentation technicians. This text addresses the basics of troubleshooting control loops, and the transducers, transmitters, signal conditioners, control valves, and controllers that enable process systems to…

Physiological correlates of mental workload

NASA Technical Reports Server (NTRS)

Zacharias, G. L.

1980-01-01

A literature review was conducted to assess the basis of and techniques for physiological assessment of mental workload. The study findings reviewed had shortcomings involving one or more of the following basic problems: (1) physiologic arousal can be easily driven by nonworkload factors, confounding any proposed metric; (2) the profound absence of underlying physiologic models has promulgated a multiplicity of seemingly arbitrary signal processing techniques; (3) the unspecified multidimensional nature of physiological "state" has given rise to a broad spectrum of competing noncommensurate metrics; and (4) the lack of an adequate definition of workload compels physiologic correlations to suffer either from the vagueness of implicit workload measures or from the variance of explicit subjective assessments. Using specific studies as examples, two basic signal processing/data reduction techniques in current use, time and ensemble averaging are discussed.

Mathematical models utilized in the retrieval of displacement information encoded in fringe patterns

NASA Astrophysics Data System (ADS)

Sciammarella, Cesar A.; Lamberti, Luciano

2016-02-01

All the techniques that measure displacements, whether in the range of visible optics or any other form of field methods, require the presence of a carrier signal. A carrier signal is a wave form modulated (modified) by an input, deformation of the medium. A carrier is tagged to the medium under analysis and deforms with the medium. The wave form must be known both in the unmodulated and the modulated conditions. There are two basic mathematical models that can be utilized to decode the information contained in the carrier, phase modulation or frequency modulation, both are closely connected. Basic problems connected to the detection and recovery of displacement information that are common to all optical techniques will be analyzed in this paper, focusing on the general theory common to all the methods independently of the type of signal utilized. The aspects discussed are those that have practical impact in the process of data gathering and data processing.

Stereo optical guidance system for control of industrial robots

NASA Technical Reports Server (NTRS)

Powell, Bradley W. (Inventor); Rodgers, Mike H. (Inventor)

1992-01-01

A device for the generation of basic electrical signals which are supplied to a computerized processing complex for the operation of industrial robots. The system includes a stereo mirror arrangement for the projection of views from opposite sides of a visible indicia formed on a workpiece. The views are projected onto independent halves of the retina of a single camera. The camera retina is of the CCD (charge-coupled-device) type and is therefore capable of providing signals in response to the image projected thereupon. These signals are then processed for control of industrial robots or similar devices.

Riding the Waves: How Our Cells Send Signals | Center for Cancer Research

Cancer.gov

The ability of cells to perceive and respond to their environment is critical in order to maintain basic cellular functions such as development, tissue repair, and response to stress. This process happens through a complex system of communication, called cell signaling, which governs basic cellular activities and coordinates cell actions. Errors in cell signaling have been linked to numerous diseases, including cancer. NF-κB is a protein complex that plays a critical role in many cell signaling pathways by controlling gene activation. It is widely used by cells to regulate cell growth and survival and helps to protect the cell from conditions that would otherwise cause it to die. Many tumor cells have mutations in genes that cause NF-κB to become overactive. Blocking NF-κB could cause tumor cells to stop growing, die, or become more sensitive to therapeutics.

Enhancing the Bandwidth Utilization in the Millimeter Wave Band and to Modernize the Digital Signal Processing Laboratory at the California State University, Bakersfield

DTIC Science & Technology

2016-03-16

PIs at Boise State University. . . . 39 3.16 Phase noise measurement results via mm-wave test bed. . . . . . . . 40 iv Chapter 1 Foreword WIRELESS...enabling the PI to acquire various testing 1 and measurement equipment that can be used to enhance instructional, research, and outreach activities at...etc. Although the Digital Signal Processing and Communication Laboratory (DSPCL) at CSUB was equipped with basic testing and measurement equipment and

Anti-jamming Technology in Small Satellite Communication

NASA Astrophysics Data System (ADS)

Jia, Zixiang

2018-01-01

Small satellite communication has an increasingly important position among the wireless communications due to the advantages of low cost and high technology. However, in view of the case that its relay station stays outside the earth, its uplink may face interference from malicious signal frequently. Here this paper classified enumerates existing interferences, and proposes channel signals as main interference by comparison. Based on a basic digital communication process, then this paper discusses the possible anti - jamming techniques that commonly be realized at all stages in diverse processes, and comes to the conclusion that regarding the spread spectrum technology and antenna anti-jamming technology as fundamental direction of future development. This work provides possible thought for the design of new small satellite communication system with the coexistence of multi - technologies. This basic popular science can be consulted for people interested in small satellite communication.

Basic research on machinery fault diagnostics: Past, present, and future trends

NASA Astrophysics Data System (ADS)

Chen, Xuefeng; Wang, Shibin; Qiao, Baijie; Chen, Qiang

2018-06-01

Machinery fault diagnosis has progressed over the past decades with the evolution of machineries in terms of complexity and scale. High-value machineries require condition monitoring and fault diagnosis to guarantee their designed functions and performance throughout their lifetime. Research on machinery Fault diagnostics has grown rapidly in recent years. This paper attempts to summarize and review the recent R&D trends in the basic research field of machinery fault diagnosis in terms of four main aspects: Fault mechanism, sensor technique and signal acquisition, signal processing, and intelligent diagnostics. The review discusses the special contributions of Chinese scholars to machinery fault diagnostics. On the basis of the review of basic theory of machinery fault diagnosis and its practical applications in engineering, the paper concludes with a brief discussion on the future trends and challenges in machinery fault diagnosis.

New Modular Ultrasonic Signal Processing Building Blocks for Real-Time Data Acquisition and Post Processing

NASA Astrophysics Data System (ADS)

Weber, Walter H.; Mair, H. Douglas; Jansen, Dion

2003-03-01

A suite of basic signal processors has been developed. These basic building blocks can be cascaded together to form more complex processors without the need for programming. The data structures between each of the processors are handled automatically. This allows a processor built for one purpose to be applied to any type of data such as images, waveform arrays and single values. The processors are part of Winspect Data Acquisition software. The new processors are fast enough to work on A-scan signals live while scanning. Their primary use is to extract features, reduce noise or to calculate material properties. The cascaded processors work equally well on live A-scan displays, live gated data or as a post-processing engine on saved data. Researchers are able to call their own MATLAB or C-code from anywhere within the processor structure. A built-in formula node processor that uses a simple algebraic editor may make external user programs unnecessary. This paper also discusses the problems associated with ad hoc software development and how graphical programming languages can tie up researchers writing software rather than designing experiments.

Recurrent neural network approach to quantum signal: coherent state restoration for continuous-variable quantum key distribution

NASA Astrophysics Data System (ADS)

Lu, Weizhao; Huang, Chunhui; Hou, Kun; Shi, Liting; Zhao, Huihui; Li, Zhengmei; Qiu, Jianfeng

2018-05-01

In continuous-variable quantum key distribution (CV-QKD), weak signal carrying information transmits from Alice to Bob; during this process it is easily influenced by unknown noise which reduces signal-to-noise ratio, and strongly impacts reliability and stability of the communication. Recurrent quantum neural network (RQNN) is an artificial neural network model which can perform stochastic filtering without any prior knowledge of the signal and noise. In this paper, a modified RQNN algorithm with expectation maximization algorithm is proposed to process the signal in CV-QKD, which follows the basic rule of quantum mechanics. After RQNN, noise power decreases about 15 dBm, coherent signal recognition rate of RQNN is 96%, quantum bit error rate (QBER) drops to 4%, which is 6.9% lower than original QBER, and channel capacity is notably enlarged.

Platform for Post-Processing Waveform-Based NDE

NASA Technical Reports Server (NTRS)

Roth, Don J.

2010-01-01

Signal- and image-processing methods are commonly needed to extract information from the waves, improve resolution of, and highlight defects in an image. Since some similarity exists for all waveform-based nondestructive evaluation (NDE) methods, it would seem that a common software platform containing multiple signal- and image-processing techniques to process the waveforms and images makes sense where multiple techniques, scientists, engineers, and organizations are involved. NDE Wave & Image Processor Version 2.0 software provides a single, integrated signal- and image-processing and analysis environment for total NDE data processing and analysis. It brings some of the most useful algorithms developed for NDE over the past 20 years into a commercial-grade product. The software can import signal/spectroscopic data, image data, and image series data. This software offers the user hundreds of basic and advanced signal- and image-processing capabilities including esoteric 1D and 2D wavelet-based de-noising, de-trending, and filtering. Batch processing is included for signal- and image-processing capability so that an optimized sequence of processing operations can be applied to entire folders of signals, spectra, and images. Additionally, an extensive interactive model-based curve-fitting facility has been included to allow fitting of spectroscopy data such as from Raman spectroscopy. An extensive joint-time frequency module is included for analysis of non-stationary or transient data such as that from acoustic emission, vibration, or earthquake data.

Antagonistic Basic Helix-Loop-Helix/bZIP Transcription Factors Form Transcriptional Modules That Integrate Light and Reactive Oxygen Species Signaling in Arabidopsis[W

PubMed Central

Chen, Dongqin; Xu, Gang; Tang, Weijiang; Jing, Yanjun; Ji, Qiang; Fei, Zhangjun; Lin, Rongcheng

2013-01-01

The critical developmental switch from heterotrophic to autotrophic growth of plants involves light signaling transduction and the production of reactive oxygen species (ROS). ROS function as signaling molecules that regulate multiple developmental processes, including cell death. However, the relationship between light and ROS signaling remains unclear. Here, we identify transcriptional modules composed of the basic helix-loop-helix and bZIP transcription factors PHYTOCHROME-INTERACTING FACTOR1 (PIF1), PIF3, ELONGATED HYPOCOTYL5 (HY5), and HY5 HOMOLOGY (HYH) that bridge light and ROS signaling to regulate cell death and photooxidative response. We show that pif mutants release more singlet oxygen and exhibit more extensive cell death than the wild type during Arabidopsis thaliana deetiolation. Genome-wide expression profiling indicates that PIF1 represses numerous ROS and stress-related genes. Molecular and biochemical analyses reveal that PIF1/PIF3 and HY5/HYH physically interact and coordinately regulate the expression of five ROS-responsive genes by directly binding to their promoters. Furthermore, PIF1/PIF3 and HY5/HYH function antagonistically during the seedling greening process. In addition, phytochromes, cryptochromes, and CONSTITUTIVE PHOTOMORPHOGENIC1 act upstream to regulate ROS signaling. Together, this study reveals that the PIF1/PIF3-HY5/HYH transcriptional modules mediate crosstalk between light and ROS signaling and sheds light on a new mechanism by which plants adapt to the light environments. PMID:23645630

[Sociophysiology: basic processes of empathy].

PubMed

Haker, Helene; Schimansky, Jenny; Rössler, Wulf

2010-01-01

The aim of this review is to describe sociophysiological and social cognitive processes that underlie the complex phenomenon of human empathy. Automatic reflexive processes such as physiological contagion and action mirroring are mediated by the mirror neuron system. They are a basis for further processing of social signals and a physiological link between two individuals. This link comprises simultaneous activation of shared motor representations. Shared representations lead implicitly via individual associations in the limbic and vegetative system to a shared affective state. These processes are called sociophysiology. Further controlled- reflective, self-referential processing of those social signals leads to explicit, conscious representations of others' minds. Those higher-order processes are called social cognition. The interaction of physiological and cognitive social processes lets arise the phenomenon of human empathy.

Software algorithms for false alarm reduction in LWIR hyperspectral chemical agent detection

NASA Astrophysics Data System (ADS)

Manolakis, D.; Model, J.; Rossacci, M.; Zhang, D.; Ontiveros, E.; Pieper, M.; Seeley, J.; Weitz, D.

2008-04-01

The long-wave infrared (LWIR) hyperpectral sensing modality is one that is often used for the problem of detection and identification of chemical warfare agents (CWA) which apply to both military and civilian situations. The inherent nature and complexity of background clutter dictates a need for sophisticated and robust statistical models which are then used in the design of optimum signal processing algorithms that then provide the best exploitation of hyperspectral data to ultimately make decisions on the absence or presence of potentially harmful CWAs. This paper describes the basic elements of an automated signal processing pipeline developed at MIT Lincoln Laboratory. In addition to describing this signal processing architecture in detail, we briefly describe the key signal models that form the foundation of these algorithms as well as some spatial processing techniques used for false alarm mitigation. Finally, we apply this processing pipeline to real data measured by the Telops FIRST hyperspectral (FIRST) sensor to demonstrate its practical utility for the user community.

Smart Sensors: Why and when the origin was and why and where the future will be

NASA Astrophysics Data System (ADS)

Corsi, C.

2013-12-01

Smart Sensors is a technique developed in the 70's when the processing capabilities, based on readout integrated with signal processing, was still far from the complexity needed in advanced IR surveillance and warning systems, because of the enormous amount of noise/unwanted signals emitted by operating scenario especially in military applications. The Smart Sensors technology was kept restricted within a close military environment exploding in applications and performances in the 90's years thanks to the impressive improvements in the integrated signal read-out and processing achieved by CCD-CMOS technologies in FPA. In fact the rapid advances of "very large scale integration" (VLSI) processor technology and mosaic EO detector array technology allowed to develop new generations of Smart Sensors with much improved signal processing by integrating microcomputers and other VLSI signal processors. inside the sensor structure achieving some basic functions of living eyes (dynamic stare, non-uniformity compensation, spatial and temporal filtering). New and future technologies (Nanotechnology, Bio-Organic Electronics, Bio-Computing) are lightning a new generation of Smart Sensors extending the Smartness from the Space-Time Domain to Spectroscopic Functional Multi-Domain Signal Processing. History and future forecasting of Smart Sensors will be reported.

Signal processing for non-destructive testing of railway tracks

NASA Astrophysics Data System (ADS)

Heckel, Thomas; Casperson, Ralf; Rühe, Sven; Mook, Gerhard

2018-04-01

Increased speed, heavier loads, altered material and modern drive systems result in an increasing number of rail flaws. The appearance of these flaws also changes continually due to the rapid change in damage mechanisms of modern rolling stock. Hence, interpretation has become difficult when evaluating non-destructive rail testing results. Due to the changed interplay between detection methods and flaws, the recorded signals may result in unclassified types of rail flaws. Methods for automatic rail inspection (according to defect detection and classification) undergo continual development. Signal processing is a key technology to master the challenge of classification and maintain resolution and detection quality, independent of operation speed. The basic ideas of signal processing, based on the Glassy-Rail-Diagram for classification purposes, are presented herein. Examples for the detection of damages caused by rolling contact fatigue also are given, and synergetic effects of combined evaluation of diverse inspection methods are shown.

Towards the understanding of network information processing in biology

NASA Astrophysics Data System (ADS)

Singh, Vijay

Living organisms perform incredibly well in detecting a signal present in the environment. This information processing is achieved near optimally and quite reliably, even though the sources of signals are highly variable and complex. The work in the last few decades has given us a fair understanding of how individual signal processing units like neurons and cell receptors process signals, but the principles of collective information processing on biological networks are far from clear. Information processing in biological networks, like the brain, metabolic circuits, cellular-signaling circuits, etc., involves complex interactions among a large number of units (neurons, receptors). The combinatorially large number of states such a system can exist in makes it impossible to study these systems from the first principles, starting from the interactions between the basic units. The principles of collective information processing on such complex networks can be identified using coarse graining approaches. This could provide insights into the organization and function of complex biological networks. Here I study models of biological networks using continuum dynamics, renormalization, maximum likelihood estimation and information theory. Such coarse graining approaches identify features that are essential for certain processes performed by underlying biological networks. We find that long-range connections in the brain allow for global scale feature detection in a signal. These also suppress the noise and remove any gaps present in the signal. Hierarchical organization with long-range connections leads to large-scale connectivity at low synapse numbers. Time delays can be utilized to separate a mixture of signals with temporal scales. Our observations indicate that the rules in multivariate signal processing are quite different from traditional single unit signal processing.

Signal Prediction With Input Identification

NASA Technical Reports Server (NTRS)

Juang, Jer-Nan; Chen, Ya-Chin

1999-01-01

A novel coding technique is presented for signal prediction with applications including speech coding, system identification, and estimation of input excitation. The approach is based on the blind equalization method for speech signal processing in conjunction with the geometric subspace projection theory to formulate the basic prediction equation. The speech-coding problem is often divided into two parts, a linear prediction model and excitation input. The parameter coefficients of the linear predictor and the input excitation are solved simultaneously and recursively by a conventional recursive least-squares algorithm. The excitation input is computed by coding all possible outcomes into a binary codebook. The coefficients of the linear predictor and excitation, and the index of the codebook can then be used to represent the signal. In addition, a variable-frame concept is proposed to block the same excitation signal in sequence in order to reduce the storage size and increase the transmission rate. The results of this work can be easily extended to the problem of disturbance identification. The basic principles are outlined in this report and differences from other existing methods are discussed. Simulations are included to demonstrate the proposed method.

Excitatory signal flow and connectivity in a cortical column: focus on barrel cortex.

PubMed

Lübke, Joachim; Feldmeyer, Dirk

2007-07-01

A basic feature of the neocortex is its organization in functional, vertically oriented columns, recurring modules of signal processing and a system of transcolumnar long-range horizontal connections. These columns, together with their network of neurons, present in all sensory cortices, are the cellular substrate for sensory perception in the brain. Cortical columns contain thousands of neurons and span all cortical layers. They receive input from other cortical areas and subcortical brain regions and in turn their neurons provide output to various areas of the brain. The modular concept presumes that the neuronal network in a cortical column performs basic signal transformations, which are then integrated with the activity in other networks and more extended brain areas. To understand how sensory signals from the periphery are transformed into electrical activity in the neocortex it is essential to elucidate the spatial-temporal dynamics of cortical signal processing and the underlying neuronal 'microcircuits'. In the last decade the 'barrel' field in the rodent somatosensory cortex, which processes sensory information arriving from the mysticial vibrissae, has become a quite attractive model system because here the columnar structure is clearly visible. In the neocortex and in particular the barrel cortex, numerous neuronal connections within or between cortical layers have been studied both at the functional and structural level. Besides similarities, clear differences with respect to both physiology and morphology of synaptic transmission and connectivity were found. It is therefore necessary to investigate each neuronal connection individually, in order to develop a realistic model of neuronal connectivity and organization of a cortical column. This review attempts to summarize recent advances in the study of individual microcircuits and their functional relevance within the framework of a cortical column, with emphasis on excitatory signal flow.

Common computational properties found in natural sensory systems

NASA Astrophysics Data System (ADS)

Brooks, Geoffrey

2009-05-01

Throughout the animal kingdom there are many existing sensory systems with capabilities desired by the human designers of new sensory and computational systems. There are a few basic design principles constantly observed among these natural mechano-, chemo-, and photo-sensory systems, principles that have been proven by the test of time. Such principles include non-uniform sampling and processing, topological computing, contrast enhancement by localized signal inhibition, graded localized signal processing, spiked signal transmission, and coarse coding, which is the computational transformation of raw data using broadly overlapping filters. These principles are outlined here with references to natural biological sensory systems as well as successful biomimetic sensory systems exploiting these natural design concepts.

Broadband true time delay for microwave signal processing, using slow light based on stimulated Brillouin scattering in optical fibers.

PubMed

Chin, Sanghoon; Thévenaz, Luc; Sancho, Juan; Sales, Salvador; Capmany, José; Berger, Perrine; Bourderionnet, Jérôme; Dolfi, Daniel

2010-10-11

We experimentally demonstrate a novel technique to process broadband microwave signals, using all-optically tunable true time delay in optical fibers. The configuration to achieve true time delay basically consists of two main stages: photonic RF phase shifter and slow light, based on stimulated Brillouin scattering in fibers. Dispersion properties of fibers are controlled, separately at optical carrier frequency and in the vicinity of microwave signal bandwidth. This way time delay induced within the signal bandwidth can be manipulated to correctly act as true time delay with a proper phase compensation introduced to the optical carrier. We completely analyzed the generated true time delay as a promising solution to feed phased array antenna for radar systems and to develop dynamically reconfigurable microwave photonic filters.

Development of a battery status monitor

NASA Technical Reports Server (NTRS)

Zimmerman, R. I.

1974-01-01

A prototype battery status monitor system has been developed. The functions of the system are: (1) to provide the energy status of the battery, (2) to measure and transmit basic battery parameters, (3) to process these measurements required to determine abnormal functioning of the battery, and (4) to transmit warning signals of the abnormal condition along with a go/no go signal. The system was developed for use with the space shuttle.

A preferential design approach for energy-efficient and robust implantable neural signal processing hardware.

PubMed

Narasimhan, Seetharam; Chiel, Hillel J; Bhunia, Swarup

2009-01-01

For implantable neural interface applications, it is important to compress data and analyze spike patterns across multiple channels in real time. Such a computational task for online neural data processing requires an innovative circuit-architecture level design approach for low-power, robust and area-efficient hardware implementation. Conventional microprocessor or Digital Signal Processing (DSP) chips would dissipate too much power and are too large in size for an implantable system. In this paper, we propose a novel hardware design approach, referred to as "Preferential Design" that exploits the nature of the neural signal processing algorithm to achieve a low-voltage, robust and area-efficient implementation using nanoscale process technology. The basic idea is to isolate the critical components with respect to system performance and design them more conservatively compared to the noncritical ones. This allows aggressive voltage scaling for low power operation while ensuring robustness and area efficiency. We have applied the proposed approach to a neural signal processing algorithm using the Discrete Wavelet Transform (DWT) and observed significant improvement in power and robustness over conventional design.

Space-time dynamics of Stem Cell Niches: a unified approach for Plants.

PubMed

Pérez, Maria Del Carmen; López, Alejandro; Padilla, Pablo

2013-06-01

Many complex systems cannot be analyzed using traditional mathematical tools, due to their irreducible nature. This makes it necessary to develop models that can be implemented computationally to simulate their evolution. Examples of these models are cellular automata, evolutionary algorithms, complex networks, agent-based models, symbolic dynamics and dynamical systems techniques. We review some representative approaches to model the stem cell niche in Arabidopsis thaliana and the basic biological mechanisms that underlie its formation and maintenance. We propose a mathematical model based on cellular automata for describing the space-time dynamics of the stem cell niche in the root. By making minimal assumptions on the cell communication process documented in experiments, we classify the basic developmental features of the stem-cell niche, including the basic structural architecture, and suggest that they could be understood as the result of generic mechanisms given by short and long range signals. This could be a first step in understanding why different stem cell niches share similar topologies, not only in plants. Also the fact that this organization is a robust consequence of the way information is being processed by the cells and to some extent independent of the detailed features of the signaling mechanism.

Space-time dynamics of stem cell niches: a unified approach for plants.

PubMed

Pérez, Maria del Carmen; López, Alejandro; Padilla, Pablo

2013-04-02

Many complex systems cannot be analyzed using traditional mathematical tools, due to their irreducible nature. This makes it necessary to develop models that can be implemented computationally to simulate their evolution. Examples of these models are cellular automata, evolutionary algorithms, complex networks, agent-based models, symbolic dynamics and dynamical systems techniques. We review some representative approaches to model the stem cell niche in Arabidopsis thaliana and the basic biological mechanisms that underlie its formation and maintenance. We propose a mathematical model based on cellular automata for describing the space-time dynamics of the stem cell niche in the root. By making minimal assumptions on the cell communication process documented in experiments, we classify the basic developmental features of the stem-cell niche, including the basic structural architecture, and suggest that they could be understood as the result of generic mechanisms given by short and long range signals. This could be a first step in understanding why different stem cell niches share similar topologies, not only in plants. Also the fact that this organization is a robust consequence of the way information is being processed by the cells and to some extent independent of the detailed features of the signaling mechanism.

An optimal filter for short photoplethysmogram signals

PubMed Central

Liang, Yongbo; Elgendi, Mohamed; Chen, Zhencheng; Ward, Rabab

2018-01-01

A photoplethysmogram (PPG) contains a wealth of cardiovascular system information, and with the development of wearable technology, it has become the basic technique for evaluating cardiovascular health and detecting diseases. However, due to the varying environments in which wearable devices are used and, consequently, their varying susceptibility to noise interference, effective processing of PPG signals is challenging. Thus, the aim of this study was to determine the optimal filter and filter order to be used for PPG signal processing to make the systolic and diastolic waves more salient in the filtered PPG signal using the skewness quality index. Nine types of filters with 10 different orders were used to filter 219 (2.1s) short PPG signals. The signals were divided into three categories by PPG experts according to their noise levels: excellent, acceptable, or unfit. Results show that the Chebyshev II filter can improve the PPG signal quality more effectively than other types of filters and that the optimal order for the Chebyshev II filter is the 4th order. PMID:29714722

Analysis of the times involved in processing and communication in a lower limb simulation system controlled by SEMG

NASA Astrophysics Data System (ADS)

Profumieri, A.; Bonell, C.; Catalfamo, P.; Cherniz, A.

2016-04-01

Virtual reality has been proposed for different applications, including the evaluation of new control strategies and training protocols for upper limb prostheses and for the study of new rehabilitation programs. In this study, a lower limb simulation environment commanded by surface electromyography signals is evaluated. The time delays generated by the acquisition and processing stages for the signals that would command the knee joint, were measured and different acquisition windows were analysed. The subjective perception of the quality of simulation was also evaluated when extra delays were added to the process. The results showed that the acquisition window is responsible for the longest delay. Also, the basic implemented processes allowed for the acquisition of three signal channels for commanding the simulation. Finally, the communication between different applications is arguably efficient, although it depends on the amount of data to be sent.

The analysis of decimation and interpolation in the linear canonical transform domain.

PubMed

Xu, Shuiqing; Chai, Yi; Hu, Youqiang; Huang, Lei; Feng, Li

2016-01-01

Decimation and interpolation are the two basic building blocks in the multirate digital signal processing systems. As the linear canonical transform (LCT) has been shown to be a powerful tool for optics and signal processing, it is worthwhile and interesting to analyze the decimation and interpolation in the LCT domain. In this paper, the definition of equivalent filter in the LCT domain have been given at first. Then, by applying the definition, the direct implementation structure and polyphase networks for decimator and interpolator in the LCT domain have been proposed. Finally, the perfect reconstruction expressions for differential filters in the LCT domain have been presented as an application. The proposed theorems in this study are the bases for generalizations of the multirate signal processing in the LCT domain, which can advance the filter banks theorems in the LCT domain.

Signal processing methods for in-situ creep specimen monitoring

NASA Astrophysics Data System (ADS)

Guers, Manton J.; Tittmann, Bernhard R.

2018-04-01

Previous work investigated using guided waves for monitoring creep deformation during accelerated life testing. The basic objective was to relate observed changes in the time-of-flight to changes in the environmental temperature and specimen gage length. The work presented in this paper investigated several signal processing strategies for possible application in the in-situ monitoring system. Signal processing methods for both group velocity (wave-packet envelope) and phase velocity (peak tracking) time-of-flight were considered. Although the Analytic Envelope found via the Hilbert transform is commonly applied for group velocity measurements, erratic behavior in the indicated time-of-flight was observed when this technique was applied to the in-situ data. The peak tracking strategies tested had generally linear trends, and tracking local minima in the raw waveform ultimately showed the most consistent results.

Sensors, Volume 1, Fundamentals and General Aspects

NASA Astrophysics Data System (ADS)

Grandke, Thomas; Ko, Wen H.

1996-12-01

'Sensors' is the first self-contained series to deal with the whole area of sensors. It describes general aspects, technical and physical fundamentals, construction, function, applications and developments of the various types of sensors. This volume deals with the fundamentals and common principles of sensors and covers the wide areas of principles, technologies, signal processing, and applications. Contents include: Sensor Fundamentals, e.g. Sensor Parameters, Modeling, Design and Packaging; Basic Sensor Technologies, e.g. Thin and Thick Films, Integrated Magnetic Sensors, Optical Fibres and Intergrated Optics, Ceramics and Oxides; Sensor Interfaces, e.g. Signal Processing, Multisensor Signal Processing, Smart Sensors, Interface Systems; Sensor Applications, e.g. Automotive: On-board Sensors, Traffic Surveillance and Control, Home Appliances, Environmental Monitoring, etc. This volume is an indispensable reference work and text book for both specialits and newcomers, researchers and developers.

Processing of mammalian preprogastrin-releasing peptide.

PubMed

Reeve, J R; Cuttitta, F; Vigna, S R; Shively, J E; Walsh, J H

1988-01-01

The processing of preprogastrin-releasing peptide in mammalian tissues and in cultured cells takes place at discrete sites (Figure 6). Signal peptidase cleaves away the signal peptide from the amino terminus of gastrin-releasing peptide. An exopeptidase activity may remove dipeptides from the amino terminus. The amidation site (not shown in Fig. 6; see Fig. 2) has the same general sequence (Gly-Lys-Lys) seen for other amidated peptides. Cleavage after single basic residues yields gene-related products from Form I or II preproGRP. A unique non-basic cleavage yields a gene-related product from Form III preproGRP. The processing that occurs to form GRP, GRP, and GRP gene-related peptides is shown in Figure 7. ProGRP is cleaved by a series of enzymes to form GRP with an amidated carboxyl-terminal methionine (indicated by an asterisk in Fig. 7). GRP is cleaved to form the decapeptide GRP. The carboxyl-terminal flanking peptides of all three mRNA translation products are cleaved to form several gastrin-releasing peptide gene-related products. Knowledge of the processing of gastrin-releasing peptide and its gene-related products will allow synthesis of duplicates of the stored forms of these peptides, which can then be used for biological testing.

Diversity of Neuropeptide Cell-Cell Signaling Molecules Generated by Proteolytic Processing Revealed by Neuropeptidomics Mass Spectrometry

NASA Astrophysics Data System (ADS)

Hook, Vivian; Lietz, Christopher B.; Podvin, Sonia; Cajka, Tomas; Fiehn, Oliver

2018-05-01

Neuropeptides are short peptides in the range of 3-40 residues that are secreted for cell-cell communication in neuroendocrine systems. In the nervous system, neuropeptides comprise the largest group of neurotransmitters. In the endocrine system, neuropeptides function as peptide hormones to coordinate intercellular signaling among target physiological systems. The diversity of neuropeptide functions is defined by their distinct primary sequences, peptide lengths, proteolytic processing of pro-neuropeptide precursors, and covalent modifications. Global, untargeted neuropeptidomics mass spectrometry is advantageous for defining the structural features of the thousands to tens of thousands of neuropeptides present in biological systems. Defining neuropeptide structures is the basis for defining the proteolytic processing pathways that convert pro-neuropeptides into active peptides. Neuropeptidomics has revealed that processing of pro-neuropeptides occurs at paired basic residues sites, and at non-basic residue sites. Processing results in neuropeptides with known functions and generates novel peptides representing intervening peptide domains flanked by dibasic residue processing sites, identified by neuropeptidomics. While very short peptide products of 2-4 residues are predicted from pro-neuropeptide dibasic processing sites, such peptides have not been readily identified; therefore, it will be logical to utilize metabolomics to identify very short peptides with neuropeptidomics in future studies. Proteolytic processing is accompanied by covalent post-translational modifications (PTMs) of neuropeptides comprising C-terminal amidation, N-terminal pyroglutamate, disulfide bonds, phosphorylation, sulfation, acetylation, glycosylation, and others. Neuropeptidomics can define PTM features of neuropeptides. In summary, neuropeptidomics for untargeted, global analyses of neuropeptides is essential for elucidation of proteases that generate diverse neuropeptides for cell-cell signaling. [Figure not available: see fulltext.

Diversity of Neuropeptide Cell-Cell Signaling Molecules Generated by Proteolytic Processing Revealed by Neuropeptidomics Mass Spectrometry

NASA Astrophysics Data System (ADS)

Hook, Vivian; Lietz, Christopher B.; Podvin, Sonia; Cajka, Tomas; Fiehn, Oliver

2018-04-01

Neuropeptides are short peptides in the range of 3-40 residues that are secreted for cell-cell communication in neuroendocrine systems. In the nervous system, neuropeptides comprise the largest group of neurotransmitters. In the endocrine system, neuropeptides function as peptide hormones to coordinate intercellular signaling among target physiological systems. The diversity of neuropeptide functions is defined by their distinct primary sequences, peptide lengths, proteolytic processing of pro-neuropeptide precursors, and covalent modifications. Global, untargeted neuropeptidomics mass spectrometry is advantageous for defining the structural features of the thousands to tens of thousands of neuropeptides present in biological systems. Defining neuropeptide structures is the basis for defining the proteolytic processing pathways that convert pro-neuropeptides into active peptides. Neuropeptidomics has revealed that processing of pro-neuropeptides occurs at paired basic residues sites, and at non-basic residue sites. Processing results in neuropeptides with known functions and generates novel peptides representing intervening peptide domains flanked by dibasic residue processing sites, identified by neuropeptidomics. While very short peptide products of 2-4 residues are predicted from pro-neuropeptide dibasic processing sites, such peptides have not been readily identified; therefore, it will be logical to utilize metabolomics to identify very short peptides with neuropeptidomics in future studies. Proteolytic processing is accompanied by covalent post-translational modifications (PTMs) of neuropeptides comprising C-terminal amidation, N-terminal pyroglutamate, disulfide bonds, phosphorylation, sulfation, acetylation, glycosylation, and others. Neuropeptidomics can define PTM features of neuropeptides. In summary, neuropeptidomics for untargeted, global analyses of neuropeptides is essential for elucidation of proteases that generate diverse neuropeptides for cell-cell signaling. [Figure not available: see fulltext.

Quantitative analysis of phosphoinositide 3-kinase (PI3K) signaling using live-cell total internal reflection fluorescence (TIRF) microscopy.

PubMed

Johnson, Heath E; Haugh, Jason M

2013-12-02

This unit focuses on the use of total internal reflection fluorescence (TIRF) microscopy and image analysis methods to study the dynamics of signal transduction mediated by class I phosphoinositide 3-kinases (PI3Ks) in mammalian cells. The first four protocols cover live-cell imaging experiments, image acquisition parameters, and basic image processing and segmentation. These methods are generally applicable to live-cell TIRF experiments. The remaining protocols outline more advanced image analysis methods, which were developed in our laboratory for the purpose of characterizing the spatiotemporal dynamics of PI3K signaling. These methods may be extended to analyze other cellular processes monitored using fluorescent biosensors. Copyright © 2013 John Wiley & Sons, Inc.

Application of multirate digital filter banks to wideband all-digital phase-locked loops design

NASA Technical Reports Server (NTRS)

Sadr, Ramin; Shah, Biren; Hinedi, Sami

1993-01-01

A new class of architecture for all-digital phase-locked loops (DPLL's) is presented in this article. These architectures, referred to as parallel DPLL (PDPLL), employ multirate digital filter banks (DFB's) to track signals with a lower processing rate than the Nyquist rate, without reducing the input (Nyquist) bandwidth. The PDPLL basically trades complexity for hardware-processing speed by introducing parallel processing in the receiver. It is demonstrated here that the DPLL performance is identical to that of a PDPLL for both steady-state and transient behavior. A test signal with a time-varying Doppler characteristic is used to compare the performance of both the DPLL and the PDPLL.

Application of multirate digital filter banks to wideband all-digital phase-locked loops design

NASA Astrophysics Data System (ADS)

Sadr, Ramin; Shah, Biren; Hinedi, Sami

1993-06-01

A new class of architecture for all-digital phase-locked loops (DPLL's) is presented in this article. These architectures, referred to as parallel DPLL (PDPLL), employ multirate digital filter banks (DFB's) to track signals with a lower processing rate than the Nyquist rate, without reducing the input (Nyquist) bandwidth. The PDPLL basically trades complexity for hardware-processing speed by introducing parallel processing in the receiver. It is demonstrated here that the DPLL performance is identical to that of a PDPLL for both steady-state and transient behavior. A test signal with a time-varying Doppler characteristic is used to compare the performance of both the DPLL and the PDPLL.

Application of multirate digital filter banks to wideband all-digital phase-locked loops design

NASA Astrophysics Data System (ADS)

Sadr, R.; Shah, B.; Hinedi, S.

1992-11-01

A new class of architecture for all-digital phase-locked loops (DPLL's) is presented in this article. These architectures, referred to as parallel DPLL (PDPLL), employ multirate digital filter banks (DFB's) to track signals with a lower processing rate than the Nyquist rate, without reducing the input (Nyquist) bandwidth. The PDPLL basically trades complexity for hardware-processing speed by introducing parallel processing in the receiver. It is demonstrated here that the DPLL performance is identical to that of a PDPLL for both steady-state and transient behavior. A test signal with a time-varying Doppler characteristic is used to compare the performance of both the DPLL and the PDPLL.

Application of multirate digital filter banks to wideband all-digital phase-locked loops design

NASA Technical Reports Server (NTRS)

Sadr, R.; Shah, B.; Hinedi, S.

1992-01-01

A new class of architecture for all-digital phase-locked loops (DPLL's) is presented in this article. These architectures, referred to as parallel DPLL (PDPLL), employ multirate digital filter banks (DFB's) to track signals with a lower processing rate than the Nyquist rate, without reducing the input (Nyquist) bandwidth. The PDPLL basically trades complexity for hardware-processing speed by introducing parallel processing in the receiver. It is demonstrated here that the DPLL performance is identical to that of a PDPLL for both steady-state and transient behavior. A test signal with a time-varying Doppler characteristic is used to compare the performance of both the DPLL and the PDPLL.

Transient high frequency signal estimation: A model-based processing approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnes, F.L.

1985-03-22

By utilizing the superposition property of linear systems a method of estimating the incident signal from reflective nondispersive data is developed. One of the basic merits of this approach is that, the reflections were removed by direct application of a Weiner type estimation algorithm, after the appropriate input was synthesized. The structure of the nondispersive signal model is well documented, and thus its' credence is established. The model is stated and more effort is devoted to practical methods of estimating the model parameters. Though a general approach was developed for obtaining the reflection weights, a simpler approach was employed here,more » since a fairly good reflection model is available. The technique essentially consists of calculating ratios of the autocorrelation function at lag zero and that lag where the incident and first reflection coincide. We initially performed our processing procedure on a measurement of a single signal. Multiple application of the processing procedure was required when we applied the reflection removal technique on a measurement containing information from the interaction of two physical phenomena. All processing was performed using SIG, an interactive signal processing package. One of the many consequences of using SIG was that repetitive operations were, for the most part, automated. A custom menu was designed to perform the deconvolution process.« less

A simple and rapid chromatographic method to determine unauthorized basic colorants (rhodamine B, auramine O, and pararosaniline) in processed foods.

PubMed

Tatebe, Chiye; Zhong, Xining; Ohtsuki, Takashi; Kubota, Hiroki; Sato, Kyoko; Akiyama, Hiroshi

2014-09-01

A simple and rapid high-performance liquid chromatography (HPLC) method to determine basic colorants such as pararosaniline (PA), auramine O (AO), and rhodamine B (RB) in various processed foods was developed. Linearity of the calibration curves ranged from 0.05 to 50 μg/mL for PA and 0.05-100 μg/mL for AO and RB. The detection and quantification limits (LOD and LOQ) of the basic colorants, which were evaluated as signal-to-noise ratios of 3 for LOD and 10 for LOQ, ranged from 0.0125 to 0.05 and 0.025 to 0.125 μg/g, respectively. The recoveries and relative standard deviations of three basic colorants in six processed foods, namely, chili sauce, curry paste, gochujang (hot pepper paste), tandoori chicken (roasted chicken prepared with yogurt and spices), powder soup, and shrimp powder ranged from 70.2% to 102.8% and 0.8% to 8.0%, respectively. The intraday precision of the recovery test ranged from 1.7% to 4.5%, whereas the interday precision ranged from 3.7% to 7.7%. The reported method has been successfully applied to basic colorant determination in various processed foods such as fat-based food matrices (curry paste and tandoori chicken), chili products (gochujang and chili sauce), and protein-based products (shrimp powder and powder soup). Thin layer chromatography and liquid chromatography/mass spectrometry methods for the determination of basic colorants in processed foods were also developed for rapid analysis and identification, respectively. These methods are very useful for monitoring unauthorized basic colorants in inspection centers or quarantine laboratories in many countries.

Improving traffic signal management and operations : a basic service model.

DOT National Transportation Integrated Search

2009-12-01

This report provides a guide for achieving a basic service model for traffic signal management and : operations. The basic service model is based on simply stated and defensible operational objectives : that consider the staffing level, expertise and...

Dynamic pathway modeling of signal transduction networks: a domain-oriented approach.

PubMed

Conzelmann, Holger; Gilles, Ernst-Dieter

2008-01-01

Mathematical models of biological processes become more and more important in biology. The aim is a holistic understanding of how processes such as cellular communication, cell division, regulation, homeostasis, or adaptation work, how they are regulated, and how they react to perturbations. The great complexity of most of these processes necessitates the generation of mathematical models in order to address these questions. In this chapter we provide an introduction to basic principles of dynamic modeling and highlight both problems and chances of dynamic modeling in biology. The main focus will be on modeling of s transduction pathways, which requires the application of a special modeling approach. A common pattern, especially in eukaryotic signaling systems, is the formation of multi protein signaling complexes. Even for a small number of interacting proteins the number of distinguishable molecular species can be extremely high. This combinatorial complexity is due to the great number of distinct binding domains of many receptors and scaffold proteins involved in signal transduction. However, these problems can be overcome using a new domain-oriented modeling approach, which makes it possible to handle complex and branched signaling pathways.

Delayed Detection of Tonal Targets in Background Noise in Dyslexia

ERIC Educational Resources Information Center

Chait, Maria; Eden, Guinevere; Poeppel, David; Simon, Jonathan Z.; Hill, Deborah F.; Flowers, D. Lynn

2007-01-01

Individuals with developmental dyslexia are often impaired in their ability to process certain linguistic and even basic non-linguistic auditory signals. Recent investigations report conflicting findings regarding impaired low-level binaural detection mechanisms associated with dyslexia. Binaural impairment has been hypothesized to stem from a…

Signal and image processing for early detection of coronary artery diseases: A review

NASA Astrophysics Data System (ADS)

Mobssite, Youness; Samir, B. Belhaouari; Mohamad Hani, Ahmed Fadzil B.

2012-09-01

Today biomedical signals and image based detection are a basic step to diagnose heart diseases, in particular, coronary artery diseases. The goal of this work is to provide non-invasive early detection of Coronary Artery Diseases relying on analyzing images and ECG signals as a combined approach to extract features, further classify and quantify the severity of DCAD by using B-splines method. In an aim of creating a prototype of screening biomedical imaging for coronary arteries to help cardiologists to decide the kind of treatment needed to reduce or control the risk of heart attack.

Spaceborne SAR Imaging Algorithm for Coherence Optimized.

PubMed

Qiu, Zhiwei; Yue, Jianping; Wang, Xueqin; Yue, Shun

2016-01-01

This paper proposes SAR imaging algorithm with largest coherence based on the existing SAR imaging algorithm. The basic idea of SAR imaging algorithm in imaging processing is that output signal can have maximum signal-to-noise ratio (SNR) by using the optimal imaging parameters. Traditional imaging algorithm can acquire the best focusing effect, but would bring the decoherence phenomenon in subsequent interference process. Algorithm proposed in this paper is that SAR echo adopts consistent imaging parameters in focusing processing. Although the SNR of the output signal is reduced slightly, their coherence is ensured greatly, and finally the interferogram with high quality is obtained. In this paper, two scenes of Envisat ASAR data in Zhangbei are employed to conduct experiment for this algorithm. Compared with the interferogram from the traditional algorithm, the results show that this algorithm is more suitable for SAR interferometry (InSAR) research and application.

Spaceborne SAR Imaging Algorithm for Coherence Optimized

PubMed Central

Qiu, Zhiwei; Yue, Jianping; Wang, Xueqin; Yue, Shun

2016-01-01

This paper proposes SAR imaging algorithm with largest coherence based on the existing SAR imaging algorithm. The basic idea of SAR imaging algorithm in imaging processing is that output signal can have maximum signal-to-noise ratio (SNR) by using the optimal imaging parameters. Traditional imaging algorithm can acquire the best focusing effect, but would bring the decoherence phenomenon in subsequent interference process. Algorithm proposed in this paper is that SAR echo adopts consistent imaging parameters in focusing processing. Although the SNR of the output signal is reduced slightly, their coherence is ensured greatly, and finally the interferogram with high quality is obtained. In this paper, two scenes of Envisat ASAR data in Zhangbei are employed to conduct experiment for this algorithm. Compared with the interferogram from the traditional algorithm, the results show that this algorithm is more suitable for SAR interferometry (InSAR) research and application. PMID:26871446

Modeling of dielectric elastomer oscillators for soft biomimetic applications.

PubMed

Henke, E-F M; Wilson, Katherine E; Anderson, I A

2018-06-26

Biomimetic, entirely soft robots with animal-like behavior and integrated artificial nervous systems will open up totally new perspectives and applications. However, until now, most presented studies on soft robots were limited to only partly soft designs, since all solutions at least needed conventional, stiff electronics to sense, process signals and activate actuators. We present a novel approach for a set up and the experimental validation of an artificial pace maker that is able to drive basic robotic structures and act as artificial central pattern generator. The structure is based on multi-functional dielectric elastomers (DEs). DE actuators, DE switches and DE resistors are combined to create complex DE oscillators (DEOs). Supplied with only one external DC voltage, the DEO autonomously generates oscillating signals that can be used to clock a robotic structure, control the cyclic motion of artificial muscles in bionic robots or make a whole robotic structure move. We present the basic functionality, derive a mathematical model for predicting the generated signal waveform and verify the model experimentally.

On a Quantum Model of Brain Activities

NASA Astrophysics Data System (ADS)

Fichtner, K.-H.; Fichtner, L.; Freudenberg, W.; Ohya, M.

2010-01-01

One of the main activities of the brain is the recognition of signals. A first attempt to explain the process of recognition in terms of quantum statistics was given in [6]. Subsequently, details of the mathematical model were presented in a (still incomplete) series of papers (cf. [7, 2, 5, 10]). In the present note we want to give a general view of the principal ideas of this approach. We will introduce the basic spaces and justify the choice of spaces and operations. Further, we bring the model face to face with basic postulates any statistical model of the recognition process should fulfill. These postulates are in accordance with the opinion widely accepted in psychology and neurology.

Signal optimization in urban transport: A totally asymmetric simple exclusion process with traffic lights.

PubMed

Arita, Chikashi; Foulaadvand, M Ebrahim; Santen, Ludger

2017-03-01

We consider the exclusion process on a ring with time-dependent defective bonds at which the hopping rate periodically switches between zero and one. This system models main roads in city traffics, intersecting with perpendicular streets. We explore basic properties of the system, in particular dependence of the vehicular flow on the parameters of signalization as well as the system size and the car density. We investigate various types of the spatial distribution of the vehicular density, and show existence of a shock profile. We also measure waiting time behind traffic lights, and examine its relationship with the traffic flow.

Signal optimization in urban transport: A totally asymmetric simple exclusion process with traffic lights

NASA Astrophysics Data System (ADS)

Arita, Chikashi; Foulaadvand, M. Ebrahim; Santen, Ludger

2017-03-01

We consider the exclusion process on a ring with time-dependent defective bonds at which the hopping rate periodically switches between zero and one. This system models main roads in city traffics, intersecting with perpendicular streets. We explore basic properties of the system, in particular dependence of the vehicular flow on the parameters of signalization as well as the system size and the car density. We investigate various types of the spatial distribution of the vehicular density, and show existence of a shock profile. We also measure waiting time behind traffic lights, and examine its relationship with the traffic flow.

Internal curvature signal and noise in low- and high-level vision

PubMed Central

Grabowecky, Marcia; Kim, Yee Joon; Suzuki, Satoru

2011-01-01

How does internal processing contribute to visual pattern perception? By modeling visual search performance, we estimated internal signal and noise relevant to perception of curvature, a basic feature important for encoding of three-dimensional surfaces and objects. We used isolated, sparse, crowded, and face contexts to determine how internal curvature signal and noise depended on image crowding, lateral feature interactions, and level of pattern processing. Observers reported the curvature of a briefly flashed segment, which was presented alone (without lateral interaction) or among multiple straight segments (with lateral interaction). Each segment was presented with no context (engaging low-to-intermediate-level curvature processing), embedded within a face context as the mouth (engaging high-level face processing), or embedded within an inverted-scrambled-face context as a control for crowding. Using a simple, biologically plausible model of curvature perception, we estimated internal curvature signal and noise as the mean and standard deviation, respectively, of the Gaussian-distributed population activity of local curvature-tuned channels that best simulated behavioral curvature responses. Internal noise was increased by crowding but not by face context (irrespective of lateral interactions), suggesting prevention of noise accumulation in high-level pattern processing. In contrast, internal curvature signal was unaffected by crowding but modulated by lateral interactions. Lateral interactions (with straight segments) increased curvature signal when no contextual elements were added, but equivalent interactions reduced curvature signal when each segment was presented within a face. These opposing effects of lateral interactions are consistent with the phenomena of local-feature contrast in low-level processing and global-feature averaging in high-level processing. PMID:21209356

Two Dimensional Processing Of Speech And Ecg Signals Using The Wigner-Ville Distribution

NASA Astrophysics Data System (ADS)

Boashash, Boualem; Abeysekera, Saman S.

1986-12-01

The Wigner-Ville Distribution (WVD) has been shown to be a valuable tool for the analysis of non-stationary signals such as speech and Electrocardiogram (ECG) data. The one-dimensional real data are first transformed into a complex analytic signal using the Hilbert Transform and then a 2-dimensional image is formed using the Wigner-Ville Transform. For speech signals, a contour plot is determined and used as a basic feature. for a pattern recognition algorithm. This method is compared with the classical Short Time Fourier Transform (STFT) and is shown, to be able to recognize isolated words better in a noisy environment. The same method together with the concept of instantaneous frequency of the signal is applied to the analysis of ECG signals. This technique allows one to classify diseased heart-beat signals. Examples are shown.

SisPorto 4.0 - computer analysis following the 2015 FIGO Guidelines for intrapartum fetal monitoring.

PubMed

Ayres-de-Campos, Diogo; Rei, Mariana; Nunes, Inês; Sousa, Paulo; Bernardes, João

2017-01-01

SisPorto 4.0 is the most recent version of a program for the computer analysis of cardiotocographic (CTG) signals and ST events, which has been adapted to the 2015 International Federation of Gynaecology and Obstetrics (FIGO) guidelines for intrapartum foetal monitoring. This paper provides a detailed description of the analysis performed by the system, including the signal-processing algorithms involved in identification of basic CTG features and the resulting real-time alerts.

A minireview of E4BP4/NFIL3 in heart failure.

PubMed

Velmurugan, Bharath Kumar; Chang, Ruey-Lin; Marthandam Asokan, Shibu; Chang, Chih-Fen; Day, Cecilia-Hsuan; Lin, Yueh-Min; Lin, Yuan-Chuan; Kuo, Wei-Wen; Huang, Chih-Yang

2018-06-01

Heart failure (HF) remains a major cause of morbidity and mortality worldwide. The primary cause identified for HF is impaired left ventricular myocardial function, and clinical manifestations may lead to severe conditions like pulmonary congestion, splanchnic congestion, and peripheral edema. Development of new therapeutic strategies remains the need of the hour for controlling the problem of HF worldwide. Deeper insights into the molecular mechanisms involved in etiopathology of HF indicate the significant role of calcium signaling, autocrine signaling pathways, and insulin-like growth factor-1 signaling that regulates the physiologic functions of heart growth and development such as contraction, metabolism, hypertrophy, cytokine signaling, and apoptosis. In view of these facts, a transcription factor (TF) regulating the myriad of these signaling pathways may prove as a lead candidate for development of therapeutics. Adenovirus E4 promoter-binding protein (E4BP4), also known as nuclear-factor, interleukin 3 regulated (NFIL3), a type of basic leucine zipper TF, is known to regulate the signaling processes involved in the functioning of heart. The current review discusses about the expression, structure, and functional role of E4BP4 in signaling processes with emphasis on calcium signaling mechanisms, autocrine signaling, and insulin-like growth factor II receptor-mediated processes regulated by E4BP4 that may regulate the pathogenesis of HF. We propose that E4BP4, being the critical component for the regulation of the above signaling processes, may serve as a novel therapeutic target for HF, and scientific investigations are merited in this direction. © 2018 Wiley Periodicals, Inc.

Opioid Receptor Function Is Regulated by Post-endocytic Peptide Processing*

PubMed Central

Gupta, Achla; Gomes, Ivone; Wardman, Jonathan; Devi, Lakshmi A.

2014-01-01

Most neuroendocrine peptides are generated in the secretory compartment by proteolysis of the precursors at classical cleavage sites consisting of basic residues by well studied endopeptidases belonging to the subtilisin superfamily. In contrast, a subset of bioactive peptides is generated by processing at non-classical cleavage sites that do not contain basic residues. Neither the peptidases responsible for non-classical cleavages nor the compartment involved in such processing has been well established. Members of the endothelin-converting enzyme (ECE) family are considered good candidate enzymes because they exhibit functional properties that are consistent with such a role. In this study we have explored a role for ECE2 in endocytic processing of δ opioid peptides and its effect on modulating δ opioid receptor function by using selective inhibitors of ECE2 that we had identified previously by homology modeling and virtual screening of a library of small molecules. We found that agonist treatment led to intracellular co-localization of ECE2 with δ opioid receptors. Furthermore, selective inhibitors of ECE2 and reagents that increase the pH of the acidic compartment impaired receptor recycling by protecting the endocytosed peptide from degradation. This, in turn, led to a substantial decrease in surface receptor signaling. Finally, we showed that treatment of primary neurons with the ECE2 inhibitor during recycling led to increased intracellular co-localization of the receptors and ECE2, which in turn led to decreased receptor recycling and signaling by the surface receptors. Together, these results support a role for differential modulation of opioid receptor signaling by post-endocytic processing of peptide agonists by ECE2. PMID:24847082

Infrared Absorption Spectroscopy of Acetylene in the Lecture

ERIC Educational Resources Information Center

Briggs, Thomas E.; Sanders, Scott T.

2006-01-01

Lecture-based experimental methods that include topics ranging from basic signal processing to the proper use of thermocouples to advanced optical techniques such as laser-induced fluorescence are described. The data obtained from this demonstration could be provided to the students in digital form to obtain useful engineering results such as an…

Evolutionary dynamics of language systems

PubMed Central

Wu, Chieh-Hsi; Hua, Xia; Dunn, Michael; Levinson, Stephen C.; Gray, Russell D.

2017-01-01

Understanding how and why language subsystems differ in their evolutionary dynamics is a fundamental question for historical and comparative linguistics. One key dynamic is the rate of language change. While it is commonly thought that the rapid rate of change hampers the reconstruction of deep language relationships beyond 6,000–10,000 y, there are suggestions that grammatical structures might retain more signal over time than other subsystems, such as basic vocabulary. In this study, we use a Dirichlet process mixture model to infer the rates of change in lexical and grammatical data from 81 Austronesian languages. We show that, on average, most grammatical features actually change faster than items of basic vocabulary. The grammatical data show less schismogenesis, higher rates of homoplasy, and more bursts of contact-induced change than the basic vocabulary data. However, there is a core of grammatical and lexical features that are highly stable. These findings suggest that different subsystems of language have differing dynamics and that careful, nuanced models of language change will be needed to extract deeper signal from the noise of parallel evolution, areal readaptation, and contact. PMID:29073028

Preface: cardiac control pathways: signaling and transport phenomena.

PubMed

Sideman, Samuel

2008-03-01

Signaling is part of a complex system of communication that governs basic cellular functions and coordinates cellular activity. Transfer of ions and signaling molecules and their interactions with appropriate receptors, transmembrane transport, and the consequent intracellular interactions and functional cellular response represent a complex system of interwoven phenomena of transport, signaling, conformational changes, chemical activation, and/or genetic expression. The well-being of the cell thus depends on a harmonic orchestration of all these events and the existence of control mechanisms that assure the normal behavior of the various parameters involved and their orderly expression. The ability of cells to sustain life by perceiving and responding correctly to their microenvironment is the basis for development, tissue repair, and immunity, as well as normal tissue homeostasis. Natural deviations, or human-induced interference in the signaling pathways and/or inter- and intracellular transport and information transfer, are responsible for the generation, modulation, and control of diseases. The present overview aims to highlight some major topics of the highly complex cellular information transfer processes and their control mechanisms. Our goal is to contribute to the understanding of the normal and pathophysiological phenomena associated with cardiac functions so that more efficient therapeutic modalities can be developed. Our objective in this volume is to identify and enhance the study of some basic passive and active physical and chemical transport phenomena, physiological signaling pathways, and their biological consequences.

Software-defined microwave photonic filter with high reconfigurable resolution

PubMed Central

Wei, Wei; Yi, Lilin; Jaouën, Yves; Hu, Weisheng

2016-01-01

Microwave photonic filters (MPFs) are of great interest in radio frequency systems since they provide prominent flexibility on microwave signal processing. Although filter reconfigurability and tunability have been demonstrated repeatedly, it is still difficult to control the filter shape with very high precision. Thus the MPF application is basically limited to signal selection. Here we present a polarization-insensitive single-passband arbitrary-shaped MPF with ~GHz bandwidth based on stimulated Brillouin scattering (SBS) in optical fibre. For the first time the filter shape, bandwidth and central frequency can all be precisely defined by software with ~MHz resolution. The unprecedented multi-dimensional filter flexibility offers new possibilities to process microwave signals directly in optical domain with high precision thus enhancing the MPF functionality. Nanosecond pulse shaping by implementing precisely defined filters is demonstrated to prove the filter superiority and practicability. PMID:27759062

Software-defined microwave photonic filter with high reconfigurable resolution.

PubMed

Wei, Wei; Yi, Lilin; Jaouën, Yves; Hu, Weisheng

2016-10-19

Microwave photonic filters (MPFs) are of great interest in radio frequency systems since they provide prominent flexibility on microwave signal processing. Although filter reconfigurability and tunability have been demonstrated repeatedly, it is still difficult to control the filter shape with very high precision. Thus the MPF application is basically limited to signal selection. Here we present a polarization-insensitive single-passband arbitrary-shaped MPF with ~GHz bandwidth based on stimulated Brillouin scattering (SBS) in optical fibre. For the first time the filter shape, bandwidth and central frequency can all be precisely defined by software with ~MHz resolution. The unprecedented multi-dimensional filter flexibility offers new possibilities to process microwave signals directly in optical domain with high precision thus enhancing the MPF functionality. Nanosecond pulse shaping by implementing precisely defined filters is demonstrated to prove the filter superiority and practicability.

A high precision position sensor design and its signal processing algorithm for a maglev train.

PubMed

Xue, Song; Long, Zhiqiang; He, Ning; Chang, Wensen

2012-01-01

High precision positioning technology for a kind of high speed maglev train with an electromagnetic suspension (EMS) system is studied. At first, the basic structure and functions of the position sensor are introduced and some key techniques to enhance the positioning precision are designed. Then, in order to further improve the positioning signal quality and the fault-tolerant ability of the sensor, a new kind of discrete-time tracking differentiator (TD) is proposed based on nonlinear optimal control theory. This new TD has good filtering and differentiating performances and a small calculation load. It is suitable for real-time signal processing. The stability, convergence property and frequency characteristics of the TD are studied and analyzed thoroughly. The delay constant of the TD is figured out and an effective time delay compensation algorithm is proposed. Based on the TD technology, a filtering process is introduced in to improve the positioning signal waveform when the sensor is under bad working conditions, and a two-sensor switching algorithm is designed to eliminate the positioning errors caused by the joint gaps of the long stator. The effectiveness and stability of the sensor and its signal processing algorithms are proved by the experiments on a test train during a long-term test run.

A High Precision Position Sensor Design and Its Signal Processing Algorithm for a Maglev Train

PubMed Central

Xue, Song; Long, Zhiqiang; He, Ning; Chang, Wensen

2012-01-01

High precision positioning technology for a kind of high speed maglev train with an electromagnetic suspension (EMS) system is studied. At first, the basic structure and functions of the position sensor are introduced and some key techniques to enhance the positioning precision are designed. Then, in order to further improve the positioning signal quality and the fault-tolerant ability of the sensor, a new kind of discrete-time tracking differentiator (TD) is proposed based on nonlinear optimal control theory. This new TD has good filtering and differentiating performances and a small calculation load. It is suitable for real-time signal processing. The stability, convergence property and frequency characteristics of the TD are studied and analyzed thoroughly. The delay constant of the TD is figured out and an effective time delay compensation algorithm is proposed. Based on the TD technology, a filtering process is introduced in to improve the positioning signal waveform when the sensor is under bad working conditions, and a two-sensor switching algorithm is designed to eliminate the positioning errors caused by the joint gaps of the long stator. The effectiveness and stability of the sensor and its signal processing algorithms are proved by the experiments on a test train during a long-term test run. PMID:22778582

Separation and reconstruction of high pressure water-jet reflective sound signal based on ICA

NASA Astrophysics Data System (ADS)

Yang, Hongtao; Sun, Yuling; Li, Meng; Zhang, Dongsu; Wu, Tianfeng

2011-12-01

The impact of high pressure water-jet on the different materials target will produce different reflective mixed sound. In order to reconstruct the reflective sound signals distribution on the linear detecting line accurately and to separate the environment noise effectively, the mixed sound signals acquired by linear mike array were processed by ICA. The basic principle of ICA and algorithm of FASTICA were described in detail. The emulation experiment was designed. The environment noise signal was simulated by using band-limited white noise and the reflective sound signal was simulated by using pulse signal. The reflective sound signal attenuation produced by the different distance transmission was simulated by weighting the sound signal with different contingencies. The mixed sound signals acquired by linear mike array were synthesized by using the above simulated signals and were whitened and separated by ICA. The final results verified that the environment noise separation and the reconstruction of the detecting-line sound distribution can be realized effectively.

Aryl hydrocarbon receptor (AHR): "pioneer member" of the basic-helix/loop/helix per-Arnt-sim (bHLH/PAS) family of "sensors" of foreign and endogenous signals.

PubMed

Nebert, Daniel W

2017-07-01

The basic-helix/loop/helix per-Arnt-sim (bHLH/PAS) family comprises many transcription factors, found throughout all three kingdoms of life; bHLH/PAS members "sense" innumerable intracellular and extracellular "signals" - including endogenous compounds, foreign chemicals, gas molecules, redox potential, photons (light), gravity, heat, and osmotic pressure. These signals then initiate downstream signaling pathways involved in responding to that signal. The term "PAS", abbreviation for "per-Arnt-sim" was first coined in 1991. Although the mouse Arnt gene was not identified until 1991, evidence of its co-transcriptional binding partner, aryl hydrocarbon receptor (AHR), was first reported in 1974 as a "sensor" of foreign chemicals, up-regulating cytochrome P450 family 1 (CYP1) and other enzyme activities that usually metabolize the signaling chemical. Within a few years, AHR was proposed also to participate in inflammation. The mouse [Ah] locus was shown (1973-1989) to be relevant to chemical carcinogenesis, mutagenesis, toxicity and teratogenesis, the mouse Ahr gene was cloned in 1992, and the first Ahr(-/-) knockout mouse line was reported in 1995. After thousands of studies from the early 1970s to present day, we now realize that AHR participates in dozens of signaling pathways involved in critical-life processes, affecting virtually every organ and cell-type in the animal, including many invertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Deficient cortical face-sensitive N170 responses and basic visual processing in schizophrenia.

PubMed

Maher, S; Mashhoon, Y; Ekstrom, T; Lukas, S; Chen, Y

2016-01-01

Face detection, an ability to identify a visual stimulus as a face, is impaired in patients with schizophrenia. It is unclear whether impaired face processing in this psychiatric disorder results from face-specific domains or stems from more basic visual domains. In this study, we examined cortical face-sensitive N170 response in schizophrenia, taking into account deficient basic visual contrast processing. We equalized visual contrast signals among patients (n=20) and controls (n=20) and between face and tree images, based on their individual perceptual capacities (determined using psychophysical methods). We measured N170, a putative temporal marker of face processing, during face detection and tree detection. In controls, N170 amplitudes were significantly greater for faces than trees across all three visual contrast levels tested (perceptual threshold, two times perceptual threshold and 100%). In patients, however, N170 amplitudes did not differ between faces and trees, indicating diminished face selectivity (indexed by the differential responses to face vs. tree). These results indicate a lack of face-selectivity in temporal responses of brain machinery putatively responsible for face processing in schizophrenia. This neuroimaging finding suggests that face-specific processing is compromised in this psychiatric disorder. Copyright © 2015 Elsevier B.V. All rights reserved.

Synchronizing the tracking eye movements with the motion of a visual target: Basic neural processes.

PubMed

Goffart, Laurent; Bourrelly, Clara; Quinet, Julie

2017-01-01

In primates, the appearance of an object moving in the peripheral visual field elicits an interceptive saccade that brings the target image onto the foveae. This foveation is then maintained more or less efficiently by slow pursuit eye movements and subsequent catch-up saccades. Sometimes, the tracking is such that the gaze direction looks spatiotemporally locked onto the moving object. Such a spatial synchronism is quite spectacular when one considers that the target-related signals are transmitted to the motor neurons through multiple parallel channels connecting separate neural populations with different conduction speeds and delays. Because of the delays between the changes of retinal activity and the changes of extraocular muscle tension, the maintenance of the target image onto the fovea cannot be driven by the current retinal signals as they correspond to past positions of the target. Yet, the spatiotemporal coincidence observed during pursuit suggests that the oculomotor system is driven by a command estimating continuously the current location of the target, i.e., where it is here and now. This inference is also supported by experimental perturbation studies: when the trajectory of an interceptive saccade is experimentally perturbed, a correction saccade is produced in flight or after a short delay, and brings the gaze next to the location where unperturbed saccades would have landed at about the same time, in the absence of visual feedback. In this chapter, we explain how such correction can be supported by previous visual signals without assuming "predictive" signals encoding future target locations. We also describe the basic neural processes which gradually yield the synchronization of eye movements with the target motion. When the process fails, the gaze is driven by signals related to past locations of the target, not by estimates to its upcoming locations, and a catch-up is made to reinitiate the synchronization. © 2017 Elsevier B.V. All rights reserved.

Signs, Symbols and Signals. Book Five. Project Drive.

ERIC Educational Resources Information Center

Zook, Doris; And Others

This Project Drive booklet titled Signs, Symbols, and Signals is one of eight booklets designed for intermediate-level English-as-a-second-language students and low-level adult basic education/basic reading students. The goal of the booklet is to aid the student in developing the oral and sight vocabulary necessary for a basic driver training…

Third International Workshop on Ion Mobility Spectrometry

NASA Technical Reports Server (NTRS)

Cross, John H. (Editor)

1995-01-01

Basic research in ion mobility spectrometry has given rise to rapid advancement in hardware development and applications. The Third International Workshop on Ion Mobility Spectrometry (IMS) was held October 16-19, 1994, at Johnson Space Center to provide a forum for investigators to present the most recent results of both basic and applied IMS research. Presenters included manufacturers and various users, including military research organizations and drug enforcement agencies. Thirty papers were given in the following five sessions: Fundamental IMS Studies, Instrument Development, Hyphenated IMS Techniques, Applications, and Data Reduction and Signal Processing. Advances in hardware development, software development, and user applications are described.

Coordinated regulation of Arabidopsis microRNA biogenesis and red light signaling through Dicer-like 1 and phytochrome-interacting factor 4

PubMed Central

Sun, Zhenfei; Li, Min; Zhou, Ying; Guo, Tongtong; Liu, Yin; Zhang, Hui

2018-01-01

Light and microRNAs (miRNAs) are key external and internal signals for plant development, respectively. However, the relationship between the light signaling and miRNA biogenesis pathways remains unknown. Here we found that miRNA processer proteins DCL1 and HYL1 interact with a basic helix-loop-helix (bHLH) transcription factor, phytochrome-interacting factor 4 (PIF4), which mediates the destabilization of DCL1 during dark-to-red-light transition. PIF4 acts as a transcription factor for some miRNA genes and is necessary for the proper accumulation of miRNAs. DCL1, HYL1, and mature miRNAs play roles in the regulation of plant hypocotyl growth. These results uncovered a previously unknown crosstalk between miRNA biogenesis and red light signaling through the PIF4-dependent regulation of miRNA transcription and processing to affect red-light-directed plant photomorphogenesis. PMID:29522510

Full-field wrist pulse signal acquisition and analysis by 3D Digital Image Correlation

NASA Astrophysics Data System (ADS)

Xue, Yuan; Su, Yong; Zhang, Chi; Xu, Xiaohai; Gao, Zeren; Wu, Shangquan; Zhang, Qingchuan; Wu, Xiaoping

2017-11-01

Pulse diagnosis is an essential part in four basic diagnostic methods (inspection, listening, inquiring and palpation) in traditional Chinese medicine, which depends on longtime training and rich experience, so computerized pulse acquisition has been proposed and studied to ensure the objectivity. To imitate the process that doctors using three fingertips with different pressures to feel fluctuations in certain areas containing three acupoints, we established a five dimensional pulse signal acquisition system adopting a non-contacting optical metrology method, 3D digital image correlation, to record the full-field displacements of skin fluctuations under different pressures. The system realizes real-time full-field vibration mode observation with 10 FPS. The maximum sample frequency is 472 Hz for detailed post-processing. After acquisition, the signals are analyzed according to the amplitude, pressure, and pulse wave velocity. The proposed system provides a novel optical approach for digitalizing pulse diagnosis and massive pulse signal data acquisition for various types of patients.

Inertial processing of vestibulo-ocular signals

NASA Technical Reports Server (NTRS)

Hess, B. J.; Angelaki, D. E.

1999-01-01

New evidence for a central resolution of gravito-inertial signals has been recently obtained by analyzing the properties of the vestibulo-ocular reflex (VOR) in response to combined lateral translations and roll tilts of the head. It is found that the VOR generates robust compensatory horizontal eye movements independent of whether or not the interaural translatory acceleration component is canceled out by a gravitational acceleration component due to simultaneous roll-tilt. This response property of the VOR depends on functional semicircular canals, suggesting that the brain uses both otolith and semicircular canal signals to estimate head motion relative to inertial space. Vestibular information about dynamic head attitude relative to gravity is the basis for computing head (and body) angular velocity relative to inertial space. Available evidence suggests that the inertial vestibular system controls both head attitude and velocity with respect to a gravity-centered reference frame. The basic computational principles underlying the inertial processing of otolith and semicircular canal afferent signals are outlined.

[Study on the arc spectral information for welding quality diagnosis].

PubMed

Li, Zhi-Yong; Gu, Xiao-Yan; Li, Huan; Yang, Li-Jun

2009-03-01

Through collecting the spectral signals of TIG and MIG welding arc with spectrometer, the arc light radiations were analyzed based on the basic theory of plasma physics. The radiation of welding arc distributes over a broad range of frequency, from infrared to ultraviolet. The arc spectrum is composed of line spectra and continuous spectra. Due to the variation of metal density in the welding arc, there is great difference between the welding arc spectra of TIG and MIG in both their intensity and distribution. The MIG welding arc provides more line spectra of metal and the intensity of radiation is greater than TIG. The arc spectrum of TIG welding is stable during the welding process, disturbance factors that cause the spectral variations can be reflected by the spectral line related to the corresponding element entering the welding arc. The arc spectrum of MIG welding will fluctuate severely due to droplet transfer, which produces "noise" in the line spectrum aggregation zone. So for MIG welding, the spectral zone lacking spectral line is suitable for welding quality diagnosis. According to the characteristic of TIG and MIG, special spectral zones were selected for welding quality diagnosis. For TIG welding, the selected zone is in ultraviolet zone (230-300 nm). For MIG welding, the selected zone is in visible zone (570-590 nm). With the basic theory provided for welding quality diagnosis, the integral intensity of spectral signal in the selected zone of welding process with disturbing factor was studied to prove the theory. The results show that the welding quality and disturbance factors can be diagnosed with good signal to noise ratio in the selected spectral zone compared with signal in other spectral zone. The spectral signal can be used for real-time diagnosis of the welding quality.

Mutual information against correlations in binary communication channels.

PubMed

Pregowska, Agnieszka; Szczepanski, Janusz; Wajnryb, Eligiusz

2015-05-19

Explaining how the brain processing is so fast remains an open problem (van Hemmen JL, Sejnowski T., 2004). Thus, the analysis of neural transmission (Shannon CE, Weaver W., 1963) processes basically focuses on searching for effective encoding and decoding schemes. According to the Shannon fundamental theorem, mutual information plays a crucial role in characterizing the efficiency of communication channels. It is well known that this efficiency is determined by the channel capacity that is already the maximal mutual information between input and output signals. On the other hand, intuitively speaking, when input and output signals are more correlated, the transmission should be more efficient. A natural question arises about the relation between mutual information and correlation. We analyze the relation between these quantities using the binary representation of signals, which is the most common approach taken in studying neuronal processes of the brain. We present binary communication channels for which mutual information and correlation coefficients behave differently both quantitatively and qualitatively. Despite this difference in behavior, we show that the noncorrelation of binary signals implies their independence, in contrast to the case for general types of signals. Our research shows that the mutual information cannot be replaced by sheer correlations. Our results indicate that neuronal encoding has more complicated nature which cannot be captured by straightforward correlations between input and output signals once the mutual information takes into account the structure and patterns of the signals.

[Role of G-protein alpha sub-units in the morphogenic processes of filamentous Ascomycota fungi].

PubMed

García-Rico, Ramón O; Fierro, Francisco

The phylum Ascomycota comprises about 75% of all the fungal species described, and includes species of medical, phytosanitary, agricultural, and biotechnological importance. The ability to spread, explore, and colonise new substrates is a feature of critical importance for this group of organisms. In this regard, basic processes such as conidial germination, the extension of hyphae and sporulation, make up the backbone of development in most filamentous fungi. These processes require specialised morphogenic machinery, coordinated and regulated by mechanisms that are still being elucidated. In recent years, substantial progress has been made in understanding the role of the signalling pathway mediated by heterotrimericG proteins in basic biological processes of many filamentous fungi. This review focuses on the role of the alpha subunits of heterotrimericG proteins in the morphogenic processes of filamentous Ascomycota. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

Application of Higuchi's fractal dimension from basic to clinical neurophysiology: A review.

PubMed

Kesić, Srdjan; Spasić, Sladjana Z

2016-09-01

For more than 20 years, Higuchi's fractal dimension (HFD), as a nonlinear method, has occupied an important place in the analysis of biological signals. The use of HFD has evolved from EEG and single neuron activity analysis to the most recent application in automated assessments of different clinical conditions. Our objective is to provide an updated review of the HFD method applied in basic and clinical neurophysiological research. This article summarizes and critically reviews a broad literature and major findings concerning the applications of HFD for measuring the complexity of neuronal activity during different neurophysiological conditions. The source of information used in this review comes from the PubMed, Scopus, Google Scholar and IEEE Xplore Digital Library databases. The review process substantiated the significance, advantages and shortcomings of HFD application within all key areas of basic and clinical neurophysiology. Therefore, the paper discusses HFD application alone, combined with other linear or nonlinear measures, or as a part of automated methods for analyzing neurophysiological signals. The speed, accuracy and cost of applying the HFD method for research and medical diagnosis make it stand out from the widely used linear methods. However, only a combination of HFD with other nonlinear methods ensures reliable and accurate analysis of a wide range of neurophysiological signals. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A comparison of basic deinterlacing approaches for a computer assisted diagnosis approach of videoscope images

NASA Astrophysics Data System (ADS)

Kage, Andreas; Canto, Marcia; Gorospe, Emmanuel; Almario, Antonio; Münzenmayer, Christian

2010-03-01

In the near future, Computer Assisted Diagnosis (CAD) which is well known in the area of mammography might be used to support clinical experts in the diagnosis of images derived from imaging modalities such as endoscopy. In the recent past, a few first approaches for computer assisted endoscopy have been presented already. These systems use a video signal as an input that is provided by the endoscopes video processor. Despite the advent of high-definition systems most standard endoscopy systems today still provide only analog video signals. These signals consist of interlaced images that can not be used in a CAD approach without deinterlacing. Of course, there are many different deinterlacing approaches known today. But most of them are specializations of some basic approaches. In this paper we present four basic deinterlacing approaches. We have used a database of non-interlaced images which have been degraded by artificial interlacing and afterwards processed by these approaches. The database contains regions of interest (ROI) of clinical relevance for the diagnosis of abnormalities in the esophagus. We compared the classification rates on these ROIs on the original images and after the deinterlacing. The results show that the deinterlacing has an impact on the classification rates. The Bobbing approach and the Motion Compensation approach achieved the best classification results in most cases.

[Computers in biomedical research: I. Analysis of bioelectrical signals].

PubMed

Vivaldi, E A; Maldonado, P

2001-08-01

A personal computer equipped with an analog-to-digital conversion card is able to input, store and display signals of biomedical interest. These signals can additionally be submitted to ad-hoc software for analysis and diagnosis. Data acquisition is based on the sampling of a signal at a given rate and amplitude resolution. The automation of signal processing conveys syntactic aspects (data transduction, conditioning and reduction); and semantic aspects (feature extraction to describe and characterize the signal and diagnostic classification). The analytical approach that is at the basis of computer programming allows for the successful resolution of apparently complex tasks. Two basic principles involved are the definition of simple fundamental functions that are then iterated and the modular subdivision of tasks. These two principles are illustrated, respectively, by presenting the algorithm that detects relevant elements for the analysis of a polysomnogram, and the task flow in systems that automate electrocardiographic reports.

Two Anatomically and Computationally Distinct Learning Signals Predict Changes to Stimulus-Outcome Associations in Hippocampus.

PubMed

Boorman, Erie D; Rajendran, Vani G; O'Reilly, Jill X; Behrens, Tim E

2016-03-16

Complex cognitive processes require sophisticated local processing but also interactions between distant brain regions. It is therefore critical to be able to study distant interactions between local computations and the neural representations they act on. Here we report two anatomically and computationally distinct learning signals in lateral orbitofrontal cortex (lOFC) and the dopaminergic ventral midbrain (VM) that predict trial-by-trial changes to a basic internal model in hippocampus. To measure local computations during learning and their interaction with neural representations, we coupled computational fMRI with trial-by-trial fMRI suppression. We find that suppression in a medial temporal lobe network changes trial-by-trial in proportion to stimulus-outcome associations. During interleaved choice trials, we identify learning signals that relate to outcome type in lOFC and to reward value in VM. These intervening choice feedback signals predicted the subsequent change to hippocampal suppression, suggesting a convergence of signals that update the flexible representation of stimulus-outcome associations. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

A new method of hybrid frequency hopping signals selection and blind parameter estimation

NASA Astrophysics Data System (ADS)

Zeng, Xiaoyu; Jiao, Wencheng; Sun, Huixian

2018-04-01

Frequency hopping communication is widely used in military communications at home and abroad. In the case of single-channel reception, it is scarce to process multiple frequency hopping signals both effectively and simultaneously. A method of hybrid FH signals selection and blind parameter estimation is proposed. The method makes use of spectral transformation, spectral entropy calculation and PRI transformation basic theory to realize the sorting and parameter estimation of the components in the hybrid frequency hopping signal. The simulation results show that this method can correctly classify the frequency hopping component signal, and the estimated error of the frequency hopping period is about 5% and the estimated error of the frequency hopping frequency is less than 1% when the SNR is 10dB. However, the performance of this method deteriorates seriously at low SNR.

Low power sensor network for wireless condition monitoring

NASA Astrophysics Data System (ADS)

Richter, Ch.; Frankenstein, B.; Schubert, L.; Weihnacht, B.; Friedmann, H.; Ebert, C.

2009-03-01

For comprehensive fatigue tests and surveillance of large scale structures, a vibration monitoring system working in the Hz and sub Hz frequency range was realized and tested. The system is based on a wireless sensor network and focuses especially on the realization of a low power measurement, signal processing and communication. Regarding the development, we met the challenge of synchronizing the wireless connected sensor nodes with sufficient accuracy. The sensor nodes ware realized by compact, sensor near signal processing structures containing components for analog preprocessing of acoustic signals, their digitization, algorithms for data reduction and network communication. The core component is a digital micro controller which performs the basic algorithms necessary for the data acquisition synchronization and the filtering. As a first application, the system was installed in a rotor blade of a wind power turbine in order to monitor the Eigen modes over a longer period of time. Currently the sensor nodes are battery powered.

Ultrasonic inspection of carbon fiber reinforced plastic by means of sample-recognition methods

NASA Technical Reports Server (NTRS)

Bilgram, R.

1985-01-01

In the case of carbon fiber reinforced plastic (CFRP), it has not yet been possible to detect nonlocal defects and material degradation related to aging with the aid of nondestructive inspection method. An approach for overcoming difficulties regarding such an inspection involves an extension of the ultrasonic inspection procedure on the basis of a use of signal processing and sample recognition methods. The basic concept involved in this approach is related to the realization that the ultrasonic signal contains information regarding the medium which is not utilized in conventional ultrasonic inspection. However, the analytical study of the phyiscal processes involved is very complex. For this reason, an empirical approach is employed to make use of the information which has not been utilized before. This approach uses reference signals which can be obtained with material specimens of different quality. The implementation of these concepts for the supersonic inspection of CFRP laminates is discussed.

S-192 analysis: Conventional and special data processing techniques. [Michigan

NASA Technical Reports Server (NTRS)

Nalepka, R. F. (Principal Investigator); Morganstern, J.; Cicone, R.; Sarno, J.; Lambeck, P.; Malila, W.

1975-01-01

The author has identified the following significant results. Multispectral scanner data gathered over test sites in southeast Michigan were analyzed. This analysis showed the data to be somewhat deficient especially in terms of the limited signal range in most SDOs and also in regard to SDO-SDO misregistration. Further analysis showed that the scan line straightening algorithm increased the misregistration of the data. Data were processed using the conic format. The effects of such misregistration on classification accuracy was analyzed via simulation and found to be significant. Results of employing conventional as well as special, unresolved object, processing techniques were disappointing due, at least in part, to the limited signal range and noise content of the data. Application of a second class of special processing techniques, signature extension techniques, yielded better results. Two of the more basic signature extension techniques seemed to be useful in spite of the difficulties.

Process observation in fiber laser-based selective laser melting

NASA Astrophysics Data System (ADS)

Thombansen, Ulrich; Gatej, Alexander; Pereira, Milton

2015-01-01

The process observation in selective laser melting (SLM) focuses on observing the interaction point where the powder is processed. To provide process relevant information, signals have to be acquired that are resolved in both time and space. Especially in high-power SLM, where more than 1 kW of laser power is used, processing speeds of several meters per second are required for a high-quality processing results. Therefore, an implementation of a suitable process observation system has to acquire a large amount of spatially resolved data at low sampling speeds or it has to restrict the acquisition to a predefined area at a high sampling speed. In any case, it is vitally important to synchronously record the laser beam position and the acquired signal. This is a prerequisite that allows the recorded data become information. Today, most SLM systems employ f-theta lenses to focus the processing laser beam onto the powder bed. This report describes the drawbacks that result for process observation and suggests a variable retro-focus system which solves these issues. The beam quality of fiber lasers delivers the processing laser beam to the powder bed at relevant focus diameters, which is a key prerequisite for this solution to be viable. The optical train we present here couples the processing laser beam and the process observation coaxially, ensuring consistent alignment of interaction zone and observed area. With respect to signal processing, we have developed a solution that synchronously acquires signals from a pyrometer and the position of the laser beam by sampling the data with a field programmable gate array. The relevance of the acquired signals has been validated by the scanning of a sample filament. Experiments with grooved samples show a correlation between different powder thicknesses and the acquired signals at relevant processing parameters. This basic work takes a first step toward self-optimization of the manufacturing process in SLM. It enables the addition of cognitive functions to the manufacturing system to the extent that the system could track its own process. The results are based on analyzing and redesigning the optical train, in combination with a real-time signal acquisition system which provides a solution to certain technological barriers.

The basics of epithelial-mesenchymal transition.

PubMed

Kalluri, Raghu; Weinberg, Robert A

2009-06-01

The origins of the mesenchymal cells participating in tissue repair and pathological processes, notably tissue fibrosis, tumor invasiveness, and metastasis, are poorly understood. However, emerging evidence suggests that epithelial-mesenchymal transitions (EMTs) represent one important source of these cells. As we discuss here, processes similar to the EMTs associated with embryo implantation, embryogenesis, and organ development are appropriated and subverted by chronically inflamed tissues and neoplasias. The identification of the signaling pathways that lead to activation of EMT programs during these disease processes is providing new insights into the plasticity of cellular phenotypes and possible therapeutic interventions.

The high frequency characteristics of laser reflection and visible light during solid state disk laser welding

NASA Astrophysics Data System (ADS)

Gao, Xiangdong; You, Deyong; Katayama, Seiji

2015-07-01

Optical properties are related to weld quality during laser welding. Visible light radiation generated from optical-induced plasma and laser reflection is considered a key element reflecting weld quality. An in-depth analysis of the high-frequency component of optical signals is conducted. A combination of a photoelectric sensor and an optical filter helped to obtain visible light reflection and laser reflection in the welding process. Two groups of optical signals were sampled at a high sampling rate (250 kHz) using an oscilloscope. Frequencies in the ranges 1-10 kHz and 10-125 kHz were investigated respectively. Experimental results showed that there was an obvious correlation between the high-frequency signal and the laser power, while the high-frequency signal was not sensitive to changes in welding speed. In particular, when the defocus position was changed, only a high frequency of the visible light signal was observed, while the high frequency of the laser reflection signal remained unchanged. The basic correlation between optical features and welding status during the laser welding process is specified, which helps to provide a new research focus for investigating the stability of welding status.

Optical signal processing

NASA Astrophysics Data System (ADS)

Vanderlugt, A.

1993-07-01

A quasi-realtime adaptive processing system was used to correct the multipath distortion found in wideband digital radios. The measured power spectral density of the input signal was used to adaptively select one of eight equalization filters which reduce the residual distortion to less than 3.6 dB even for the most severe channel distortion. A related adaptive system was used for signal excision in which we removed narrowband interference from wideband signals with minimum signal distortion. An 8x8 acousto-optic switch in a multimode fiber-optic system was built. Insertion loss is approximately 2-4 dB, signal-to-crosstalk ratio is better than 25 dB, and the reconfiguration time is 880 nsec. Short pulses were detected by using the Fresnel transform. Pulses as short as the theoretical limit of 20 nanoseconds were detected for this system, and separated by as little as 60 nanoseconds or by as much as 17 nanoseconds. All possible acousto-optic scanning configurations were considered and classified into four basic types. A consistent set of design relationships for each of the scanning configurations was developed and presented in both tabular and graphic forms from which a preliminary design is obtained.

Multi-step EMG Classification Algorithm for Human-Computer Interaction

NASA Astrophysics Data System (ADS)

Ren, Peng; Barreto, Armando; Adjouadi, Malek

A three-electrode human-computer interaction system, based on digital processing of the Electromyogram (EMG) signal, is presented. This system can effectively help disabled individuals paralyzed from the neck down to interact with computers or communicate with people through computers using point-and-click graphic interfaces. The three electrodes are placed on the right frontalis, the left temporalis and the right temporalis muscles in the head, respectively. The signal processing algorithm used translates the EMG signals during five kinds of facial movements (left jaw clenching, right jaw clenching, eyebrows up, eyebrows down, simultaneous left & right jaw clenching) into five corresponding types of cursor movements (left, right, up, down and left-click), to provide basic mouse control. The classification strategy is based on three principles: the EMG energy of one channel is typically larger than the others during one specific muscle contraction; the spectral characteristics of the EMG signals produced by the frontalis and temporalis muscles during different movements are different; the EMG signals from adjacent channels typically have correlated energy profiles. The algorithm is evaluated on 20 pre-recorded EMG signal sets, using Matlab simulations. The results show that this method provides improvements and is more robust than other previous approaches.

Instrumentation & Data Acquisition System (D AS) Engineer

NASA Technical Reports Server (NTRS)

Jackson, Markus Deon

2015-01-01

The primary job of an Instrumentation and Data Acquisition System (DAS) Engineer is to properly measure physical phenomenon of hardware using appropriate instrumentation and DAS equipment designed to record data during a specified test of the hardware. A DAS system includes a CPU or processor, a data storage device such as a hard drive, a data communication bus such as Universal Serial Bus, software to control the DAS system processes like calibrations, recording of data and processing of data. It also includes signal conditioning amplifiers, and certain sensors for specified measurements. My internship responsibilities have included testing and adjusting Pacific Instruments Model 9355 signal conditioning amplifiers, writing and performing checkout procedures, writing and performing calibration procedures while learning the basics of instrumentation.

U.S. data processing for the IRAS project. [by Jet Propulsion Laboratory Scientific Data Analysis System

NASA Technical Reports Server (NTRS)

Duxbury, J. H.

1983-01-01

The JPL's Scientific Data Analysis System (SDAS), which will process IRAS data and produce a catalogue of perhaps a million infrared sources in the sky, as well as other information for astronomical records, is described. The purposes of SDAS are discussed, and the major SDAS processors are shown in block diagram. The catalogue processing is addressed, mentioning the basic processing steps which will be applied to raw detector data. Signal reconstruction and conversion to astrophysical units, source detection, source confirmation, data management, and survey data products are considered in detail.

Methylation of eukaryotic elongation factor 2 induced by basic fibroblast growth factor via mitogen-activated protein kinase.

PubMed

Jung, Gyung Ah; Shin, Bong Shik; Jang, Yeon Sue; Sohn, Jae Bum; Woo, Seon Rang; Kim, Jung Eun; Choi, Go; Lee, Kyung Mi; Min, Bon Hong; Lee, Kee Ho; Park, Gil Hong

2011-10-31

Protein arginine methylation is important for a variety of cellular processes including transcriptional regulation, mRNA splicing, DNA repair, nuclear/cytoplasmic shuttling and various signal transduction pathways. However, the role of arginine methylation in protein biosynthesis and the extracellular signals that control arginine methylation are not fully understood. Basic fibroblast growth factor (bFGF) has been identified as a potent stimulator of myofibroblast dedifferentiation into fibroblasts. We demonstrated that symmetric arginine dimethylation of eukaryotic elongation factor 2 (eEF2) is induced by bFGF without the change in the expression level of eEF2 in mouse embryo fibroblast NIH3T3 cells. The eEF2 methylation is preceded by ras-raf-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK1/2)- p21Cip/WAF1 activation, and suppressed by the mitogenactivated protein kinase (MAPK) inhibitor PD98059 and p21Cip/WAF1 short interfering RNA (siRNA). We determined that protein arginine methyltransferase 7 (PRMT7) is responsible for the methylation, and that PRMT5 acts as a coordinator. Collectively, we demonstrated that eEF2, a key factor involved in protein translational elongation is symmetrically arginine-methylated in a reversible manner, being regulated by bFGF through MAPK signaling pathway.

Methylation of eukaryotic elongation factor 2 induced by basic fibroblast growth factor via mitogen-activated protein kinase

PubMed Central

Jung, Gyung Ah; Shin, Bong Shik; Jang, Yeon Sue; Sohn, Jae Bum; Woo, Seon Rang; Kim, Jung Eun; Choi, Go; Lee, Kyung-Mi; Min, Bon Hong

2011-01-01

Protein arginine methylation is important for a variety of cellular processes including transcriptional regulation, mRNA splicing, DNA repair, nuclear/cytoplasmic shuttling and various signal transduction pathways. However, the role of arginine methylation in protein biosynthesis and the extracellular signals that control arginine methylation are not fully understood. Basic fibroblast growth factor (bFGF) has been identified as a potent stimulator of myofibroblast dedifferentiation into fibroblasts. We demonstrated that symmetric arginine dimethylation of eukaryotic elongation factor 2 (eEF2) is induced by bFGF without the change in the expression level of eEF2 in mouse embryo fibroblast NIH3T3 cells. The eEF2 methylation is preceded by ras-raf-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK1/2)-p21Cip/WAF1 activation, and suppressed by the mitogen-activated protein kinase (MAPK) inhibitor PD98059 and p21Cip/WAF1 short interfering RNA (siRNA). We determined that protein arginine methyltransferase 7 (PRMT7) is responsible for the methylation, and that PRMT5 acts as a coordinator. Collectively, we demonstrated that eEF2, a key factor involved in protein translational elongation is symmetrically arginine-methylated in a reversible manner, being regulated by bFGF through MAPK signaling pathway. PMID:21778808

Biophoton signal transmission and processing in the brain.

PubMed

Tang, Rendong; Dai, Jiapei

2014-10-05

The transmission and processing of neural information in the nervous system plays a key role in neural functions. It is well accepted that neural communication is mediated by bioelectricity and chemical molecules via the processes called bioelectrical and chemical transmission, respectively. Indeed, the traditional theories seem to give valuable explanations for the basic functions of the nervous system, but difficult to construct general accepted concepts or principles to provide reasonable explanations of higher brain functions and mental activities, such as perception, learning and memory, emotion and consciousness. Therefore, many unanswered questions and debates over the neural encoding and mechanisms of neuronal networks remain. Cell to cell communication by biophotons, also called ultra-weak photon emissions, has been demonstrated in several plants, bacteria and certain animal cells. Recently, both experimental evidence and theoretical speculation have suggested that biophotons may play a potential role in neural signal transmission and processing, contributing to the understanding of the high functions of nervous system. In this paper, we review the relevant experimental findings and discuss the possible underlying mechanisms of biophoton signal transmission and processing in the nervous system. Copyright © 2014 Elsevier B.V. All rights reserved.

Molecular Mechanisms of Neuroplasticity: An Expanding Universe.

PubMed

Gulyaeva, N V

2017-03-01

Biochemical processes in synapses and other neuronal compartments underlie neuroplasticity (functional and structural alterations in the brain enabling adaptation to the environment, learning, memory, as well as rehabilitation after brain injury). This basic molecular level of brain plasticity covers numerous specific proteins (enzymes, receptors, structural proteins, etc.) participating in many coordinated and interacting signal and metabolic processes, their modulation forming a molecular basis for brain plasticity. The articles in this issue are focused on different "hot points" in the research area of biochemical mechanisms supporting neuroplasticity.

Biosignals learning and synthesis using deep neural networks.

PubMed

Belo, David; Rodrigues, João; Vaz, João R; Pezarat-Correia, Pedro; Gamboa, Hugo

2017-09-25

Modeling physiological signals is a complex task both for understanding and synthesize biomedical signals. We propose a deep neural network model that learns and synthesizes biosignals, validated by the morphological equivalence of the original ones. This research could lead the creation of novel algorithms for signal reconstruction in heavily noisy data and source detection in biomedical engineering field. The present work explores the gated recurrent units (GRU) employed in the training of respiration (RESP), electromyograms (EMG) and electrocardiograms (ECG). Each signal is pre-processed, segmented and quantized in a specific number of classes, corresponding to the amplitude of each sample and fed to the model, which is composed by an embedded matrix, three GRU blocks and a softmax function. This network is trained by adjusting its internal parameters, acquiring the representation of the abstract notion of the next value based on the previous ones. The simulated signal was generated by forecasting a random value and re-feeding itself. The resulting generated signals are similar with the morphological expression of the originals. During the learning process, after a set of iterations, the model starts to grasp the basic morphological characteristics of the signal and later their cyclic characteristics. After training, these models' prediction are closer to the signals that trained them, specially the RESP and ECG. This synthesis mechanism has shown relevant results that inspire the use to characterize signals from other physiological sources.

Computer implemented empirical mode decomposition method, apparatus, and article of manufacture for two-dimensional signals

NASA Technical Reports Server (NTRS)

Huang, Norden E. (Inventor)

2001-01-01

A computer implemented method of processing two-dimensional physical signals includes five basic components and the associated presentation techniques of the results. The first component decomposes the two-dimensional signal into one-dimensional profiles. The second component is a computer implemented Empirical Mode Decomposition that extracts a collection of Intrinsic Mode Functions (IMF's) from each profile based on local extrema and/or curvature extrema. The decomposition is based on the direct extraction of the energy associated with various intrinsic time scales in the profiles. In the third component, the IMF's of each profile are then subjected to a Hilbert Transform. The fourth component collates the Hilbert transformed IMF's of the profiles to form a two-dimensional Hilbert Spectrum. A fifth component manipulates the IMF's by, for example, filtering the two-dimensional signal by reconstructing the two-dimensional signal from selected IMF(s).

Fiber Fabry-Perot interferometer sensor for measuring resonances of piezoelectric elements

NASA Astrophysics Data System (ADS)

da Silva, Ricardo E.; Oliveira, Roberson A.; Pohl, Alexandre A. P.

2011-05-01

The development of a fiber extrinsic Fabry-Perot interferometer for measuring vibration amplitude and resonances of piezoelectric elements is reported. The signal demodulation method based on the use of an optical spectrum analyzer allows the measurement of displacements and resonances with high resolution. The technique consists basically in monitoring changes in the intensity or the wavelength of a single interferometric fringe at a point of high sensitivity in the sensor response curve. For sensor calibration, three signal processing techniques were employed. Vibration amplitude measurement with 0.84 nm/V sensitivity and the characterization of the piezo resonance is demonstrated.

A survey of the state-of-the-art and focused research in range systems

NASA Technical Reports Server (NTRS)

Kung, Yao; Balakrishnan, A. V.

1988-01-01

In this one-year renewal of NASA Contract No. 2-304, basic research, development, and implementation in the areas of modern estimation algorithms and digital communication systems have been performed. In the first area, basic study on the conversion of general classes of practical signal processing algorithms into systolic array algorithms is considered, producing four publications. Also studied were the finite word length effects and convergence rates of lattice algorithms, producing two publications. In the second area of study, the use of efficient importance sampling simulation technique for the evaluation of digital communication system performances were studied, producing two publications.

Design study report. Volume 2: Electronic unit

NASA Technical Reports Server (NTRS)

1973-01-01

The recording system discussed is required to record and reproduce wideband data from either of the two primary Earth Resources Technology Satellite sensors: Return Beam Vidicon (RBV) camera or Multi-Spectral Scanner (MSS). The camera input is an analog signal with a bandwidth from dc to 3.5 MHz; this signal is accommodated through FM recording techniques which provide a recorder signal-to-noise ratio in excess of 39 db, black-to-white signal/rms noise, over the specified bandwidth. The MSS provides, as initial output, 26 narrowband channels. These channels are multiplexed prior to transmission, or recording, into a single 15 Megabit/second digital data stream. Within the recorder, the 15 Megabit/second NRZL signal is processed through the same FM electronics as the RBV signal, but the basic FM standards are modified to provide an internal, 10.5 MHz baseland response with signal-to-noise ratio of about 25 db. Following FM demodulation, however, the MSS signal is digitally re-shaped and re-clocked so that good bit stability and signal-to-noise exist at the recorder output.

47 CFR 76.611 - Cable television basic signal leakage performance criteria.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Cable television basic signal leakage performance criteria. 76.611 Section 76.611 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Technical Standards § 76.611 Cable...

High-resolution correlation

NASA Astrophysics Data System (ADS)

Nelson, D. J.

2007-09-01

In the basic correlation process a sequence of time-lag-indexed correlation coefficients are computed as the inner or dot product of segments of two signals. The time-lag(s) for which the magnitude of the correlation coefficient sequence is maximized is the estimated relative time delay of the two signals. For discrete sampled signals, the delay estimated in this manner is quantized with the same relative accuracy as the clock used in sampling the signals. In addition, the correlation coefficients are real if the input signals are real. There have been many methods proposed to estimate signal delay to more accuracy than the sample interval of the digitizer clock, with some success. These methods include interpolation of the correlation coefficients, estimation of the signal delay from the group delay function, and beam forming techniques, such as the MUSIC algorithm. For spectral estimation, techniques based on phase differentiation have been popular, but these techniques have apparently not been applied to the correlation problem . We propose a phase based delay estimation method (PBDEM) based on the phase of the correlation function that provides a significant improvement of the accuracy of time delay estimation. In the process, the standard correlation function is first calculated. A time lag error function is then calculated from the correlation phase and is used to interpolate the correlation function. The signal delay is shown to be accurately estimated as the zero crossing of the correlation phase near the index of the peak correlation magnitude. This process is nearly as fast as the conventional correlation function on which it is based. For real valued signals, a simple modification is provided, which results in the same correlation accuracy as is obtained for complex valued signals.

Plant Development, Auxin, and the Subsystem Incompleteness Theorem

PubMed Central

Niklas, Karl J.; Kutschera, Ulrich

2012-01-01

Plant morphogenesis (the process whereby form develops) requires signal cross-talking among all levels of organization to coordinate the operation of metabolic and genomic subsystems operating in a larger network of subsystems. Each subsystem can be rendered as a logic circuit supervising the operation of one or more signal-activated system. This approach simplifies complex morphogenetic phenomena and allows for their aggregation into diagrams of progressively larger networks. This technique is illustrated here by rendering two logic circuits and signal-activated subsystems, one for auxin (IAA) polar/lateral intercellular transport and another for IAA-mediated cell wall loosening. For each of these phenomena, a circuit/subsystem diagram highlights missing components (either in the logic circuit or in the subsystem it supervises) that must be identified experimentally if each of these basic plant phenomena is to be fully understood. We also illustrate the “subsystem incompleteness theorem,” which states that no subsystem is operationally self-sufficient. Indeed, a whole-organism perspective is required to understand even the most simple morphogenetic process, because, when isolated, every biological signal-activated subsystem is morphogenetically ineffective. PMID:22645582

Parametric adaptive filtering and data validation in the bar GW detector AURIGA

NASA Astrophysics Data System (ADS)

Ortolan, A.; Baggio, L.; Cerdonio, M.; Prodi, G. A.; Vedovato, G.; Vitale, S.

2002-04-01

We report on our experience gained in the signal processing of the resonant GW detector AURIGA. Signal amplitude and arrival time are estimated by means of a matched-adaptive Wiener filter. The detector noise, entering in the filter set-up, is modelled as a parametric ARMA process; to account for slow non-stationarity of the noise, the ARMA parameters are estimated on an hourly basis. A requirement of the set-up of an unbiased Wiener filter is the separation of time spans with 'almost Gaussian' noise from non-Gaussian and/or strongly non-stationary time spans. The separation algorithm consists basically of a variance estimate with the Chauvenet convergence method and a threshold on the Curtosis index. The subsequent validation of data is strictly connected with the separation procedure: in fact, by injecting a large number of artificial GW signals into the 'almost Gaussian' part of the AURIGA data stream, we have demonstrated that the effective probability distributions of the signal-to-noise ratio χ2 and the time of arrival are those that are expected.

A Comparison of Physiological Signal Analysis Techniques and Classifiers for Automatic Emotional Evaluation of Audiovisual Contents

PubMed Central

Colomer Granero, Adrián; Fuentes-Hurtado, Félix; Naranjo Ornedo, Valery; Guixeres Provinciale, Jaime; Ausín, Jose M.; Alcañiz Raya, Mariano

2016-01-01

This work focuses on finding the most discriminatory or representative features that allow to classify commercials according to negative, neutral and positive effectiveness based on the Ace Score index. For this purpose, an experiment involving forty-seven participants was carried out. In this experiment electroencephalography (EEG), electrocardiography (ECG), Galvanic Skin Response (GSR) and respiration data were acquired while subjects were watching a 30-min audiovisual content. This content was composed by a submarine documentary and nine commercials (one of them the ad under evaluation). After the signal pre-processing, four sets of features were extracted from the physiological signals using different state-of-the-art metrics. These features computed in time and frequency domains are the inputs to several basic and advanced classifiers. An average of 89.76% of the instances was correctly classified according to the Ace Score index. The best results were obtained by a classifier consisting of a combination between AdaBoost and Random Forest with automatic selection of features. The selected features were those extracted from GSR and HRV signals. These results are promising in the audiovisual content evaluation field by means of physiological signal processing. PMID:27471462

A Comparison of Physiological Signal Analysis Techniques and Classifiers for Automatic Emotional Evaluation of Audiovisual Contents.

PubMed

Colomer Granero, Adrián; Fuentes-Hurtado, Félix; Naranjo Ornedo, Valery; Guixeres Provinciale, Jaime; Ausín, Jose M; Alcañiz Raya, Mariano

2016-01-01

This work focuses on finding the most discriminatory or representative features that allow to classify commercials according to negative, neutral and positive effectiveness based on the Ace Score index. For this purpose, an experiment involving forty-seven participants was carried out. In this experiment electroencephalography (EEG), electrocardiography (ECG), Galvanic Skin Response (GSR) and respiration data were acquired while subjects were watching a 30-min audiovisual content. This content was composed by a submarine documentary and nine commercials (one of them the ad under evaluation). After the signal pre-processing, four sets of features were extracted from the physiological signals using different state-of-the-art metrics. These features computed in time and frequency domains are the inputs to several basic and advanced classifiers. An average of 89.76% of the instances was correctly classified according to the Ace Score index. The best results were obtained by a classifier consisting of a combination between AdaBoost and Random Forest with automatic selection of features. The selected features were those extracted from GSR and HRV signals. These results are promising in the audiovisual content evaluation field by means of physiological signal processing.

The brain in time: insights from neuromagnetic recordings.

PubMed

Hari, Riitta; Parkkonen, Lauri; Nangini, Cathy

2010-03-01

The millisecond time resolution of magnetoencephalography (MEG) is instrumental for investigating the brain basis of sensory processing, motor planning, cognition, and social interaction. We review the basic principles, recent progress, and future potential of MEG in noninvasive tracking of human brain activity. Cortical activation sequences from tens to hundreds of milliseconds can be followed during, e.g., perception, motor action, imitation, and language processing by recording both spontaneous and evoked brain signals. Moreover, tagging of sensory input can be used to reveal neuronal mechanisms of binaural interaction and perception of ambiguous images. The results support the emerging ideas of multiple, hierarchically organized temporal scales in human brain function. Instrumentation and data analysis methods are rapidly progressing, enabling attempts to decode the four-dimensional spatiotemporal signal patterns to reveal correlates of behavior and mental contents.

Ultrasensitive response motifs: basic amplifiers in molecular signalling networks

PubMed Central

Zhang, Qiang; Bhattacharya, Sudin; Andersen, Melvin E.

2013-01-01

Multi-component signal transduction pathways and gene regulatory circuits underpin integrated cellular responses to perturbations. A recurring set of network motifs serve as the basic building blocks of these molecular signalling networks. This review focuses on ultrasensitive response motifs (URMs) that amplify small percentage changes in the input signal into larger percentage changes in the output response. URMs generally possess a sigmoid input–output relationship that is steeper than the Michaelis–Menten type of response and is often approximated by the Hill function. Six types of URMs can be commonly found in intracellular molecular networks and each has a distinct kinetic mechanism for signal amplification. These URMs are: (i) positive cooperative binding, (ii) homo-multimerization, (iii) multistep signalling, (iv) molecular titration, (v) zero-order covalent modification cycle and (vi) positive feedback. Multiple URMs can be combined to generate highly switch-like responses. Serving as basic signal amplifiers, these URMs are essential for molecular circuits to produce complex nonlinear dynamics, including multistability, robust adaptation and oscillation. These dynamic properties are in turn responsible for higher-level cellular behaviours, such as cell fate determination, homeostasis and biological rhythm. PMID:23615029

49 CFR 236.923 - Task analysis and basic requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Standards for Processor-Based Signal and Train Control Systems § 236.923 Task analysis and basic requirements..., inspection, testing, and operating tasks that must be performed on a railroad's products. This includes the...

49 CFR 236.923 - Task analysis and basic requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Standards for Processor-Based Signal and Train Control Systems § 236.923 Task analysis and basic requirements..., inspection, testing, and operating tasks that must be performed on a railroad's products. This includes the...

49 CFR 236.923 - Task analysis and basic requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Standards for Processor-Based Signal and Train Control Systems § 236.923 Task analysis and basic requirements..., inspection, testing, and operating tasks that must be performed on a railroad's products. This includes the...

49 CFR 236.923 - Task analysis and basic requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Standards for Processor-Based Signal and Train Control Systems § 236.923 Task analysis and basic requirements..., inspection, testing, and operating tasks that must be performed on a railroad's products. This includes the...

UAV Data-Links: Tasks, Types, Technologies and Examples

DTIC Science & Technology

2000-04-01

Services Mercedes - Benz *Clapra Mercedes - Benz Al cmercial *Leasing *rinancial R ail Systams aftrs Services *smar * lpmoser F reightliner commerciali...highlighting the basic variants of data-links Blohm, MTU and others to form Daimler- Benz and their general advantages and disadvantages a Aerospace (now...bandwidth devices for the consumer market . antenna characteristics Generally speaking, the data-rate of a digital-link signal processing. using BPSK

Synthesizing a novel genetic sequential logic circuit: a push-on push-off switch

PubMed Central

Lou, Chunbo; Liu, Xili; Ni, Ming; Huang, Yiqi; Huang, Qiushi; Huang, Longwen; Jiang, Lingli; Lu, Dan; Wang, Mingcong; Liu, Chang; Chen, Daizhuo; Chen, Chongyi; Chen, Xiaoyue; Yang, Le; Ma, Haisu; Chen, Jianguo; Ouyang, Qi

2010-01-01

Design and synthesis of basic functional circuits are the fundamental tasks of synthetic biologists. Before it is possible to engineer higher-order genetic networks that can perform complex functions, a toolkit of basic devices must be developed. Among those devices, sequential logic circuits are expected to be the foundation of the genetic information-processing systems. In this study, we report the design and construction of a genetic sequential logic circuit in Escherichia coli. It can generate different outputs in response to the same input signal on the basis of its internal state, and ‘memorize' the output. The circuit is composed of two parts: (1) a bistable switch memory module and (2) a double-repressed promoter NOR gate module. The two modules were individually rationally designed, and they were coupled together by fine-tuning the interconnecting parts through directed evolution. After fine-tuning, the circuit could be repeatedly, alternatively triggered by the same input signal; it functions as a push-on push-off switch. PMID:20212522

Synthesizing a novel genetic sequential logic circuit: a push-on push-off switch.

PubMed

Lou, Chunbo; Liu, Xili; Ni, Ming; Huang, Yiqi; Huang, Qiushi; Huang, Longwen; Jiang, Lingli; Lu, Dan; Wang, Mingcong; Liu, Chang; Chen, Daizhuo; Chen, Chongyi; Chen, Xiaoyue; Yang, Le; Ma, Haisu; Chen, Jianguo; Ouyang, Qi

2010-01-01

Design and synthesis of basic functional circuits are the fundamental tasks of synthetic biologists. Before it is possible to engineer higher-order genetic networks that can perform complex functions, a toolkit of basic devices must be developed. Among those devices, sequential logic circuits are expected to be the foundation of the genetic information-processing systems. In this study, we report the design and construction of a genetic sequential logic circuit in Escherichia coli. It can generate different outputs in response to the same input signal on the basis of its internal state, and 'memorize' the output. The circuit is composed of two parts: (1) a bistable switch memory module and (2) a double-repressed promoter NOR gate module. The two modules were individually rationally designed, and they were coupled together by fine-tuning the interconnecting parts through directed evolution. After fine-tuning, the circuit could be repeatedly, alternatively triggered by the same input signal; it functions as a push-on push-off switch.

Central Auditory Processing of Temporal and Spectral-Variance Cues in Cochlear Implant Listeners

PubMed Central

Pham, Carol Q.; Bremen, Peter; Shen, Weidong; Yang, Shi-Ming; Middlebrooks, John C.; Zeng, Fan-Gang; Mc Laughlin, Myles

2015-01-01

Cochlear implant (CI) listeners have difficulty understanding speech in complex listening environments. This deficit is thought to be largely due to peripheral encoding problems arising from current spread, which results in wide peripheral filters. In normal hearing (NH) listeners, central processing contributes to segregation of speech from competing sounds. We tested the hypothesis that basic central processing abilities are retained in post-lingually deaf CI listeners, but processing is hampered by degraded input from the periphery. In eight CI listeners, we measured auditory nerve compound action potentials to characterize peripheral filters. Then, we measured psychophysical detection thresholds in the presence of multi-electrode maskers placed either inside (peripheral masking) or outside (central masking) the peripheral filter. This was intended to distinguish peripheral from central contributions to signal detection. Introduction of temporal asynchrony between the signal and masker improved signal detection in both peripheral and central masking conditions for all CI listeners. Randomly varying components of the masker created spectral-variance cues, which seemed to benefit only two out of eight CI listeners. Contrastingly, the spectral-variance cues improved signal detection in all five NH listeners who listened to our CI simulation. Together these results indicate that widened peripheral filters significantly hamper central processing of spectral-variance cues but not of temporal cues in post-lingually deaf CI listeners. As indicated by two CI listeners in our study, however, post-lingually deaf CI listeners may retain some central processing abilities similar to NH listeners. PMID:26176553

Nuclear Receptor Signaling Atlas: Opening Access to the Biology of Nuclear Receptor Signaling Pathways.

PubMed

Becnel, Lauren B; Darlington, Yolanda F; Ochsner, Scott A; Easton-Marks, Jeremy R; Watkins, Christopher M; McOwiti, Apollo; Kankanamge, Wasula H; Wise, Michael W; DeHart, Michael; Margolis, Ronald N; McKenna, Neil J

2015-01-01

Signaling pathways involving nuclear receptors (NRs), their ligands and coregulators, regulate tissue-specific transcriptomes in diverse processes, including development, metabolism, reproduction, the immune response and neuronal function, as well as in their associated pathologies. The Nuclear Receptor Signaling Atlas (NURSA) is a Consortium focused around a Hub website (www.nursa.org) that annotates and integrates diverse 'omics datasets originating from the published literature and NURSA-funded Data Source Projects (NDSPs). These datasets are then exposed to the scientific community on an Open Access basis through user-friendly data browsing and search interfaces. Here, we describe the redesign of the Hub, version 3.0, to deploy "Web 2.0" technologies and add richer, more diverse content. The Molecule Pages, which aggregate information relevant to NR signaling pathways from myriad external databases, have been enhanced to include resources for basic scientists, such as post-translational modification sites and targeting miRNAs, and for clinicians, such as clinical trials. A portal to NURSA's Open Access, PubMed-indexed journal Nuclear Receptor Signaling has been added to facilitate manuscript submissions. Datasets and information on reagents generated by NDSPs are available, as is information concerning periodic new NDSP funding solicitations. Finally, the new website integrates the Transcriptomine analysis tool, which allows for mining of millions of richly annotated public transcriptomic data points in the field, providing an environment for dataset re-use and citation, bench data validation and hypothesis generation. We anticipate that this new release of the NURSA database will have tangible, long term benefits for both basic and clinical research in this field.

Analysis of transcriptome in hickory (Carya cathayensis), and uncover the dynamics in the hormonal signaling pathway during graft process.

PubMed

Qiu, Lingling; Jiang, Bo; Fang, Jia; Shen, Yike; Fang, Zhongxiang; Rm, Saravana Kumar; Yi, Keke; Shen, Chenjia; Yan, Daoliang; Zheng, Bingsong

2016-11-17

Hickory (Carya cathayensis), a woody plant with high nutritional and economic value, is widely planted in China. Due to its long juvenile phase, grafting is a useful technique for large-scale cultivation of hickory. To reveal the molecular mechanism during the graft process, we sequenced the transcriptomes of graft union in hickory. In our study, six RNA-seq libraries yielded a total of 83,676,860 clean short reads comprising 4.19 Gb of sequence data. A large number of differentially expressed genes (DEGs) at three time points during the graft process were identified. In detail, 777 DEGs in the 7 d vs 0 d (day after grafting) comparison were classified into 11 enriched Gene Ontology (GO) categories, and 262 DEGs in the 14 d vs 0 d comparison were classified into 15 enriched GO categories. Furthermore, an overview of the PPI network was constructed by these DEGs. In addition, 20 genes related to the auxin-and cytokinin-signaling pathways were identified, and some were validated by qRT-PCR analysis. Our comprehensive analysis provides basic information on the candidate genes and hormone signaling pathways involved in the graft process in hickory and other woody plants.

Transient Modulations of Neural Responses to Heartbeats Covary with Bodily Self-Consciousness.

PubMed

Park, Hyeong-Dong; Bernasconi, Fosco; Bello-Ruiz, Javier; Pfeiffer, Christian; Salomon, Roy; Blanke, Olaf

2016-08-10

Recent research has investigated self-consciousness associated with the multisensory processing of bodily signals (e.g., somatosensory, visual, vestibular signals), a notion referred to as bodily self-consciousness, and these studies have shown that the manipulation of bodily inputs induces changes in bodily self-consciousness such as self-identification. Another line of research has highlighted the importance of signals from the inside of the body (e.g., visceral signals) and proposed that neural representations of internal bodily signals underlie self-consciousness, which to date has been based on philosophical inquiry, clinical case studies, and behavioral studies. Here, we investigated the relationship of bodily self-consciousness with the neural processing of internal bodily signals. By combining electrical neuroimaging, analysis of peripheral physiological signals, and virtual reality technology in humans, we show that transient modulations of neural responses to heartbeats in the posterior cingulate cortex covary with changes in bodily self-consciousness induced by the full-body illusion. Additional analyses excluded that measured basic cardiorespiratory parameters or interoceptive sensitivity traits could account for this finding. These neurophysiological data link experimentally the cortical mapping of the internal body to self-consciousness. What are the brain mechanisms of self-consciousness? Prominent views propose that the neural processing associated with signals from the internal organs (such as the heart and the lung) plays a critical role in self-consciousness. Although this hypothesis dates back to influential views in philosophy and psychology (e.g., William James), definitive experimental evidence supporting this idea is lacking despite its recent impact in neuroscience. In the present study, we show that posterior cingulate activities responding to heartbeat signals covary with changes in participants' conscious self-identification with a body that were manipulated experimentally using virtual reality technology. Our finding provides important neural evidence about the long-standing proposal that self-consciousness is linked to the cortical processing of internal bodily signals. Copyright © 2016 the authors 0270-6474/16/368453-08$15.00/0.

Experimental facility for the study of acoustic emission registered in the primary circuit components of WWER power units

NASA Astrophysics Data System (ADS)

Petrosyan, V. G.; Hovakimyan, T. H.; Yeghoyan, E. A.; Hovhannisyan, H. T.; Mayilyan, D. G.; Petrosyan, A. P.

2017-01-01

This paper is dedicated to the creation of a facility for the experimental study of a phenomenon of background acoustic emission (AE), which is detected in the main circulation loop (MCL) of WWER power units. The analysis of the operating principle and the design of a primary feed-and-blow down system (FB) deaerator of NPP as the most likely source of continuous acoustic emission is carried out. The experimental facility for the systematic study of a phenomenon of continuous AE is developed. A physical model of a thermal deaerator is designed and constructed. A thermal monitoring system is introduced. An automatic system providing acoustic signal registration in a low frequency (0.03-30 kHz) and high frequency (30-300 kHz) bands and study of its spectral characteristics is designed. Special software for recording and processing of digitized electrical sensor signals is developed. A separate and independent principle of study of the most probable processes responsible for the generation of acoustic emission signals in the deaerator is applied. Trial series of experiments and prechecks of acoustic signals in different modes of the deaerator model are conducted. Compliance of basic technological parameters with operating range of the real deaerator was provided. It is shown that the acoustic signal time-intensity curve has several typical regions. The pilot research showed an impact of various processes that come about during the operation of the deaerator physical model on the intensity of the AE signal. The experimental results suggest that the main sources of generation of the AE signals are the processes of steam condensation, turbulent flow of gas-vapor medium, and water boiling.

The Seismic Tool-Kit (STK): an open source software for seismology and signal processing.

NASA Astrophysics Data System (ADS)

Reymond, Dominique

2016-04-01

We present an open source software project (GNU public license), named STK: Seismic ToolKit, that is dedicated mainly for seismology and signal processing. The STK project that started in 2007, is hosted by SourceForge.net, and count more than 19 500 downloads at the date of writing. The STK project is composed of two main branches: First, a graphical interface dedicated to signal processing (in the SAC format (SAC_ASCII and SAC_BIN): where the signal can be plotted, zoomed, filtered, integrated, derivated, ... etc. (a large variety of IFR and FIR filter is proposed). The estimation of spectral density of the signal are performed via the Fourier transform, with visualization of the Power Spectral Density (PSD) in linear or log scale, and also the evolutive time-frequency representation (or sonagram). The 3-components signals can be also processed for estimating their polarization properties, either for a given window, or either for evolutive windows along the time. This polarization analysis is useful for extracting the polarized noises, differentiating P waves, Rayleigh waves, Love waves, ... etc. Secondly, a panel of Utilities-Program are proposed for working in a terminal mode, with basic programs for computing azimuth and distance in spherical geometry, inter/auto-correlation, spectral density, time-frequency for an entire directory of signals, focal planes, and main components axis, radiation pattern of P waves, Polarization analysis of different waves (including noize), under/over-sampling the signals, cubic-spline smoothing, and linear/non linear regression analysis of data set. A MINimum library of Linear AlGebra (MIN-LINAG) is also provided for computing the main matrix process like: QR/QL decomposition, Cholesky solve of linear system, finding eigen value/eigen vectors, QR-solve/Eigen-solve of linear equations systems ... etc. STK is developed in C/C++, mainly under Linux OS, and it has been also partially implemented under MS-Windows. Usefull links: http://sourceforge.net/projects/seismic-toolkit/ http://sourceforge.net/p/seismic-toolkit/wiki/browse_pages/

47 CFR 76.611 - Cable television basic signal leakage performance criteria.

Code of Federal Regulations, 2014 CFR

2014-10-01

... average power level of the strongest cable television carrier on the system. (c) In paragraph (a)(1) and... 47 Telecommunication 4 2014-10-01 2014-10-01 false Cable television basic signal leakage...) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Technical Standards § 76.611 Cable...

47 CFR 76.611 - Cable television basic signal leakage performance criteria.

Code of Federal Regulations, 2013 CFR

2013-10-01

... average power level of the strongest cable television carrier on the system. (c) In paragraph (a)(1) and... 47 Telecommunication 4 2013-10-01 2013-10-01 false Cable television basic signal leakage...) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Technical Standards § 76.611 Cable...

47 CFR 76.611 - Cable television basic signal leakage performance criteria.

Code of Federal Regulations, 2012 CFR

2012-10-01

... average power level of the strongest cable television carrier on the system. (c) In paragraph (a)(1) and... 47 Telecommunication 4 2012-10-01 2012-10-01 false Cable television basic signal leakage...) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Technical Standards § 76.611 Cable...

Music Tune Restoration Based on a Mother Wavelet Construction

NASA Astrophysics Data System (ADS)

Fadeev, A. S.; Konovalov, V. I.; Butakova, T. I.; Sobetsky, A. V.

2017-01-01

It is offered to use the mother wavelet function obtained from the local part of an analyzed music signal. Requirements for the constructed function are proposed and the implementation technique and its properties are described. The suggested approach allows construction of mother wavelet families with specified identifying properties. Consequently, this makes possible to identify the basic signal variations of complex music signals including local time-frequency characteristics of the basic one.

Practical remarks on the heart rate and saturation measurement methodology

NASA Astrophysics Data System (ADS)

Kowal, M.; Kubal, S.; Piotrowski, P.; Staniec, K.

2017-05-01

A surface reflection-based method for measuring heart rate and saturation has been introduced as one having a significant advantage over legacy methods in that it lends itself for use in special applications such as those where a person’s mobility is of prime importance (e.g. during a miner’s work) and excluding the use of traditional clips. Then, a complete ATmega1281-based microcontroller platform has been described for performing computational tasks of signal processing and wireless transmission. In the next section remarks have been provided regarding the basic signal processing rules beginning with raw voltage samples of converted optical signals, their acquisition, storage and smoothing. This chapter ends with practical remarks demonstrating an exponential dependence between the minimum measurable heart rate and the readout resolution at different sampling frequencies for different cases of averaging depth (in bits). The following section is devoted strictly to the heart rate and hemoglobin oxygenation (saturation) measurement with the use of the presented platform, referenced to measurements obtained with a stationary certified pulsoxymeter.

Digital seismo-acoustic signal processing aboard a wireless sensor platform

NASA Astrophysics Data System (ADS)

Marcillo, O.; Johnson, J. B.; Lorincz, K.; Werner-Allen, G.; Welsh, M.

2006-12-01

We are developing a low power, low-cost wireless sensor array to conduct real-time signal processing of earthquakes at active volcanoes. The sensor array, which integrates data from both seismic and acoustic sensors, is based on Moteiv TMote Sky wireless sensor nodes (www.moteiv.com). The nodes feature a Texas Instruments MSP430 microcontroller, 48 Kbytes of program memory, 10 Kbytes of static RAM, 1 Mbyte of external flash memory, and a 2.4-GHz Chipcon CC2420 IEEE 802.15.4 radio. The TMote Sky is programmed in TinyOS. Basic signal processing occurs on an array of three peripheral sensor nodes. These nodes are tied into a dedicated GPS receiver node, which is focused on time synchronization, and a central communications node, which handles data integration and additional processing. The sensor nodes incorporate dual 12-bit digitizers sampling a seismic sensor and a pressure transducer at 100 samples per second. The wireless capabilities of the system allow flexible array geometry, with a maximum aperture of 200m. We have already developed the digital signal processing routines on board the Moteiv Tmote sensor nodes. The developed routines accomplish Real-time Seismic-Amplitude Measurement (RSAM), Seismic Spectral- Amplitude Measurement (SSAM), and a user-configured Short Term Averaging / Long Term Averaging (STA LTA ratio), which is used to calculate first arrivals. The processed data from individual nodes are transmitted back to a central node, where additional processing may be performed. Such processing will include back azimuth determination and other wave field analyses. Future on-board signal processing will focus on event characterization utilizing pattern recognition and spectral characterization. The processed data is intended as low bandwidth information which can be transmitted periodically and at low cost through satellite telemetry to a web server. The processing is limited by the computational capabilities (RAM, ROM) of the nodes. Nevertheless, we envision this product to be a useful tool for assessing the state of unrest at remote volcanoes.

Time Reversal Mirrors and Cross Correlation Functions in Acoustic Wave Propagation

NASA Astrophysics Data System (ADS)

Fishman, Louis; Jonsson, B. Lars G.; de Hoop, Maarten V.

2009-03-01

In time reversal acoustics (TRA), a signal is recorded by an array of transducers, time reversed, and then retransmitted into the configuration. The retransmitted signal propagates back through the same medium and retrofocuses on the source that generated the signal. If the transducer array is a single, planar (flat) surface, then this configuration is referred to as a planar, one-sided, time reversal mirror (TRM). In signal processing, for example, in active-source seismic interferometry, the measurement of the wave field at two distinct receivers, generated by a common source, is considered. Cross correlating these two observations and integrating the result over the sources yield the cross correlation function (CCF). Adopting the TRM experiments as the basic starting point and identifying the kinematically correct correspondences, it is established that the associated CCF signal processing constructions follow in a specific, infinite recording time limit. This perspective also provides for a natural rationale for selecting the Green's function components in the TRM and CCF expressions. For a planar, one-sided, TRM experiment and the corresponding CCF signal processing construction, in a three-dimensional homogeneous medium, the exact expressions are explicitly calculated, and the connecting limiting relationship verified. Finally, the TRM and CCF results are understood in terms of the underlying, governing, two-way wave equation, its corresponding time reversal invariance (TRI) symmetry, and the absence of TRI symmetry in the associated one-way wave equations, highlighting the role played by the evanescent modal contributions.

Generating Control Commands From Gestures Sensed by EMG

NASA Technical Reports Server (NTRS)

Wheeler, Kevin R.; Jorgensen, Charles

2006-01-01

An effort is under way to develop noninvasive neuro-electric interfaces through which human operators could control systems as diverse as simple mechanical devices, computers, aircraft, and even spacecraft. The basic idea is to use electrodes on the surface of the skin to acquire electromyographic (EMG) signals associated with gestures, digitize and process the EMG signals to recognize the gestures, and generate digital commands to perform the actions signified by the gestures. In an experimental prototype of such an interface, the EMG signals associated with hand gestures are acquired by use of several pairs of electrodes mounted in sleeves on a subject s forearm (see figure). The EMG signals are sampled and digitized. The resulting time-series data are fed as input to pattern-recognition software that has been trained to distinguish gestures from a given gesture set. The software implements, among other things, hidden Markov models, which are used to recognize the gestures as they are being performed in real time. Thus far, two experiments have been performed on the prototype interface to demonstrate feasibility: an experiment in synthesizing the output of a joystick and an experiment in synthesizing the output of a computer or typewriter keyboard. In the joystick experiment, the EMG signals were processed into joystick commands for a realistic flight simulator for an airplane. The acting pilot reached out into the air, grabbed an imaginary joystick, and pretended to manipulate the joystick to achieve left and right banks and up and down pitches of the simulated airplane. In the keyboard experiment, the subject pretended to type on a numerical keypad, and the EMG signals were processed into keystrokes. The results of the experiments demonstrate the basic feasibility of this method while indicating the need for further research to reduce the incidence of errors (including confusion among gestures). Topics that must be addressed include the numbers and arrangements of electrodes needed to acquire sufficient data; refinements in the acquisition, filtering, and digitization of EMG signals; and methods of training the pattern- recognition software. The joystick and keyboard simulations were chosen for the initial experiments because they are familiar to many computer users. It is anticipated that, ultimately, interfaces would utilize EMG signals associated with movements more nearly natural than those associated with joysticks or keyboards. Future versions of the pattern-recognition software are planned to be capable of adapting to the preferences and day-today variations in EMG outputs of individual users; this capability for adaptation would also make it possible to select gestures that, to a given user, feel the most nearly natural for generating control signals for a given task (provided that there are enough properly positioned electrodes to acquire the EMG signals from the muscles involved in the gestures).

Generation of Long-time Complex Signals for Testing the Instruments for Detection of Voltage Quality Disturbances

NASA Astrophysics Data System (ADS)

Živanović, Dragan; Simić, Milan; Kokolanski, Zivko; Denić, Dragan; Dimcev, Vladimir

2018-04-01

Software supported procedure for generation of long-time complex test sentences, suitable for testing the instruments for detection of standard voltage quality (VQ) disturbances is presented in this paper. This solution for test signal generation includes significant improvements of computer-based signal generator presented and described in the previously published paper [1]. The generator is based on virtual instrumentation software for defining the basic signal parameters, data acquisition card NI 6343, and power amplifier for amplification of output voltage level to the nominal RMS voltage value of 230 V. Definition of basic signal parameters in LabVIEW application software is supported using Script files, which allows simple repetition of specific test signals and combination of more different test sequences in the complex composite test waveform. The basic advantage of this generator compared to the similar solutions for signal generation is the possibility for long-time test sequence generation according to predefined complex test scenarios, including various combinations of VQ disturbances defined in accordance with the European standard EN50160. Experimental verification of the presented signal generator capability is performed by testing the commercial power quality analyzer Fluke 435 Series II. In this paper are shown some characteristic complex test signals with various disturbances and logged data obtained from the tested power quality analyzer.

Instantaneous and Frequency-Warped Signal Processing Techniques for Auditory Source Separation.

NASA Astrophysics Data System (ADS)

Wang, Avery Li-Chun

This thesis summarizes several contributions to the areas of signal processing and auditory source separation. The philosophy of Frequency-Warped Signal Processing is introduced as a means for separating the AM and FM contributions to the bandwidth of a complex-valued, frequency-varying sinusoid p (n), transforming it into a signal with slowly-varying parameters. This transformation facilitates the removal of p (n) from an additive mixture while minimizing the amount of damage done to other signal components. The average winding rate of a complex-valued phasor is explored as an estimate of the instantaneous frequency. Theorems are provided showing the robustness of this measure. To implement frequency tracking, a Frequency-Locked Loop algorithm is introduced which uses the complex winding error to update its frequency estimate. The input signal is dynamically demodulated and filtered to extract the envelope. This envelope may then be remodulated to reconstruct the target partial, which may be subtracted from the original signal mixture to yield a new, quickly-adapting form of notch filtering. Enhancements to the basic tracker are made which, under certain conditions, attain the Cramer -Rao bound for the instantaneous frequency estimate. To improve tracking, the novel idea of Harmonic -Locked Loop tracking, using N harmonically constrained trackers, is introduced for tracking signals, such as voices and certain musical instruments. The estimated fundamental frequency is computed from a maximum-likelihood weighting of the N tracking estimates, making it highly robust. The result is that harmonic signals, such as voices, can be isolated from complex mixtures in the presence of other spectrally overlapping signals. Additionally, since phase information is preserved, the resynthesized harmonic signals may be removed from the original mixtures with relatively little damage to the residual signal. Finally, a new methodology is given for designing linear-phase FIR filters which require a small fraction of the computational power of conventional FIR implementations. This design strategy is based on truncated and stabilized IIR filters. These signal-processing methods have been applied to the problem of auditory source separation, resulting in voice separation from complex music that is significantly better than previous results at far lower computational cost.

Low Temperature Performance of High-Speed Neural Network Circuits

NASA Technical Reports Server (NTRS)

Duong, T.; Tran, M.; Daud, T.; Thakoor, A.

1995-01-01

Artificial neural networks, derived from their biological counterparts, offer a new and enabling computing paradigm specially suitable for such tasks as image and signal processing with feature classification/object recognition, global optimization, and adaptive control. When implemented in fully parallel electronic hardware, it offers orders of magnitude speed advantage. Basic building blocks of the new architecture are the processing elements called neurons implemented as nonlinear operational amplifiers with sigmoidal transfer function, interconnected through weighted connections called synapses implemented using circuitry for weight storage and multiply functions either in an analog, digital, or hybrid scheme.

Comparison of the impedance cardiogram with continuous wave radar using body-contact antennas.

PubMed

Buxi, Dilpreet; Dugar, Rahul; Redoute, Jean-Michel; Yuce, Mehmet Rasit

2017-07-01

This paper describes a continuous wave (CW) radar system with body-contact antennas and basic signal processing. The goal is to assess the signals' reproducibility across different subjects as well as a respiration cycle. Radar signals using body-contact antennas with a carrier frequency of 868 MHz are used to acquire the cardiac activity at the sternum. The radar I and Q channel signals are combined to form their magnitude. Signals are collected from six healthy males during paced breathing conditions. The electrocardiogram (ECG) and impedance cardiogram (ICG) signals are acquired simultaneously as reference. The chosen feature in the radar signal is the maximum of its second derivative, which is closest to the ICG B-point. The median and mean absolute errors in pre-ejection period (PEP) in milliseconds between the ICG's B-point and chosen feature in the radar signal range from -6-119.7 ms and 7.8-62.3 ms for all subjects. The results indicate that a reproducible radar signal is obtained from all six subjects. More work is needed on understanding the origin of the radar signals using ultrasound as a comparison.

Acoustic emission characteristics of a single cylinder diesel generator at various loads and with a failing injector

NASA Astrophysics Data System (ADS)

Dykas, Brian; Harris, James

2017-09-01

Acoustic emission sensing techniques have been applied in recent years to dynamic machinery with varying degrees of success in diagnosing various component faults and distinguishing between operating conditions. This work explores basic properties of acoustic emission signals measured on a small single cylinder diesel engine in a laboratory setting. As reported in other works in the open literature, the measured acoustic emission on the engine is mostly continuous mode and individual burst events are generally not readily identifiable. Therefore, the AE are processed into the local (instantaneous) root mean square (rms) value of the signal which is averaged over many cycles to obtain a mean rms AE in the crank angle domain. Crank-resolved spectral representation of the AE is also given but rigorous investigation of the AE spectral qualities is left to future study. Cycle-to-cycle statistical dispersion of the AE signal is considered to highlight highly variable engine processes. Engine speed was held constant but load conditions are varied to investigate AE signal sensitivity to operating condition. Furthermore, during the course of testing the fuel injector developed a fault and acoustic emission signals were captured and several signal attributes were successful in distinguishing this altered condition. The sampling and use of instantaneous rms acoustic emission signal demonstrated promise for non-intrusive and economical change detection of engine injection, combustion and valve events.

Methyl jasmonate as a vital substance in plants.

PubMed

Cheong, Jong-Joo; Choi, Yang Do

2003-07-01

The plant floral scent methyl jasmonate (MeJA) has been identified as a vital cellular regulator that mediates diverse developmental processes and defense responses against biotic and abiotic stresses. The pleiotropic effects of MeJA have raised numerous questions about its regulation for biogenesis and mode of action. Characterization of the gene encoding jasmonic acid carboxyl methyltransferase has provided basic information on the role(s) of this phytohormone in gene-activation control and systemic long-distance signaling. Recent approaches using functional genomics and bioinformatics have identified a whole set of MeJA-responsive genes, and provide insights into how plants use volatile signals to withstand diverse and variable environments.

Fate of nuclear material during subsequent steps of the kinetin-induced PCD in apical parts of Vicia faba ssp. minor seedling roots.

PubMed

Kaźmierczak, Andrzej; Soboska, Kamila

2018-07-01

In animals during apoptosis, the best examined type of programmed cell death (PCD), three main phases are distinguished: (i) specification (signaling), (ii) killing and (iii) execution one. It has bean postulated that plant PCD also involves three subsequent phases: (i) transmission of death signals to cells (signaling), (ii) initiation of killing processes and (iii) destruction of cells. One of the most important hallmarks of animal and plant PCD are those regarding nucleus, not thoroughly studied in plants so far. To study kinetin-induced PCD (Kin-PCD) in the context of nuclear material faith, 2-cm apical parts of Vicia faba ssp. minor seedling roots were used. Applied assays involving spectrophotometry, transmission electron microscopy, fluorescence and white light microscopy allowed to examine metabolic and cytomorphologic hallmarks such as changes in DNA content, ssDNA formation and activity of acidic and basic nucleases (DNases and RNases) as well as malformations and fragmentation of nucleoli and nuclei. The obtained results concerning the PCD hallmarks and influence of ZnSO 4 on Kin-PCD allowed us to confirmed presence of specification/signaling, killing and execution/degradation phases of the process and broaden the knowledge about processes affecting nuclei during PCD. Copyright © 2018 Elsevier Ltd. All rights reserved.

Nested effects models for learning signaling networks from perturbation data.

PubMed

Fröhlich, Holger; Tresch, Achim; Beissbarth, Tim

2009-04-01

Targeted gene perturbations have become a major tool to gain insight into complex cellular processes. In combination with the measurement of downstream effects via DNA microarrays, this approach can be used to gain insight into signaling pathways. Nested Effects Models were first introduced by Markowetz et al. as a probabilistic method to reverse engineer signaling cascades based on the nested structure of downstream perturbation effects. The basic framework was substantially extended later on by Fröhlich et al., Markowetz et al., and Tresch and Markowetz. In this paper, we present a review of the complete methodology with a detailed comparison of so far proposed algorithms on a qualitative and quantitative level. As an application, we present results on estimating the signaling network between 13 genes in the ER-alpha pathway of human MCF-7 breast cancer cells. Comparison with the literature shows a substantial overlap.

Medical telesensors

NASA Astrophysics Data System (ADS)

Ferrell, Trinidad L.; Crilly, P. B.; Smith, S. F.; Wintenberg, Alan L.; Britton, Charles L., Jr.; Morrison, Gilbert W.; Ericson, M. N.; Hedden, D.; Bouldin, Donald W.; Passian, A.; Downey, Todd R.; Wig, A. G.; Meriaudeau, Fabrice

1998-05-01

Medical telesensors are self-contained integrated circuits for measuring and transmitting vital signs over a distance of approximately 1-2 meters. The circuits are unhoused and contain a sensor, signal processing and modulation electronics, a spread-spectrum transmitter, an antenna and a thin-film battery. We report on a body-temperature telesensor, which is sufficiently small to be placed on a tympanic membrane in a child's ear. We also report on a pulse-oximeter telesensor and a micropack receiver/long- range transmitter unit, which receives form a telesensor array and analyzes and re-transmits the vital signs over a longer range. Signal analytics are presented for the pulse oximeter, which is currently in the form of a finger ring. A multichip module is presented as the basic signal-analysis component. The module contains a microprocessor, a field=programmable gate array, memory elements and other components necessary for determining trauma and reporting signals.

Improvement of range spatial resolution of medical ultrasound imaging by element-domain signal processing

NASA Astrophysics Data System (ADS)

Hasegawa, Hideyuki

2017-07-01

The range spatial resolution is an important factor determining the image quality in ultrasonic imaging. The range spatial resolution in ultrasonic imaging depends on the ultrasonic pulse length, which is determined by the mechanical response of the piezoelectric element in an ultrasonic probe. To improve the range spatial resolution without replacing the transducer element, in the present study, methods based on maximum likelihood (ML) estimation and multiple signal classification (MUSIC) were proposed. The proposed methods were applied to echo signals received by individual transducer elements in an ultrasonic probe. The basic experimental results showed that the axial half maximum of the echo from a string phantom was improved from 0.21 mm (conventional method) to 0.086 mm (ML) and 0.094 mm (MUSIC).

Endocannabinoid Signaling in Motivation, Reward, and Addiction: Influences on Mesocorticolimbic Dopamine Function.

PubMed

Sagheddu, Claudia; Muntoni, Anna Lisa; Pistis, Marco; Melis, Miriam

2015-01-01

Evidence suggests that the endocannabinoid system has been conserved in the animal kingdom for 500 million years, and this system influences many critical behavioral processes including associative learning, reward signaling, goal-directed behavior, motor skill learning, and action-habit transformation. Additionally, the neurotransmitter dopamine has long been recognized to play a critical role in the processing of natural rewards, as well as of motivation that regulates approach and avoidance behavior. This motivational role of dopamine neurons is also based upon the evidence provided by several studies investigating disorders of dopamine pathways such as drug addiction and Parkinson's disease. From an evolutionary point of view, individuals engage in behaviors aimed at maximizing and minimizing positive and aversive consequences, respectively. Accordingly, those with the greatest fitness have a better potential to survival. Hence, deviations from fitness can be viewed as a part of the evolutionary process by means of natural selection. Given the long evolutionary history of both the endocannabinoid and dopaminergic systems, it is plausible that they must serve as fundamental and basic modulators of physiological functions and needs. Notably, endocannabinoids regulate dopamine neuronal activity and its influence on behavioral output. The goal of this chapter is to examine the endocannabinoid influence on dopamine signaling specifically related to (i) those behavioral processes that allow us to successfully adapt to ever-changing environments (i.e., reward signaling and motivational processes) and (ii) derangements from behavioral flexibility that underpin drug addiction. © 2015 Elsevier Inc. All rights reserved.

Perceived Synchrony of Frog Multimodal Signal Components Is Influenced by Content and Order.

PubMed

Taylor, Ryan C; Page, Rachel A; Klein, Barrett A; Ryan, Michael J; Hunter, Kimberly L

2017-10-01

Multimodal signaling is common in communication systems. Depending on the species, individual signal components may be produced synchronously as a result of physiological constraint (fixed) or each component may be produced independently (fluid) in time. For animals that rely on fixed signals, a basic prediction is that asynchrony between the components should degrade the perception of signal salience, reducing receiver response. Male túngara frogs, Physalaemus pustulosus, produce a fixed multisensory courtship signal by vocalizing with two call components (whines and chucks) and inflating a vocal sac (visual component). Using a robotic frog, we tested female responses to variation in the temporal arrangement between acoustic and visual components. When the visual component lagged a complex call (whine + chuck), females largely rejected this asynchronous multisensory signal in favor of the complex call absent the visual cue. When the chuck component was removed from one call, but the robofrog inflation lagged the complex call, females responded strongly to the asynchronous multimodal signal. When the chuck component was removed from both calls, females reversed preference and responded positively to the asynchronous multisensory signal. When the visual component preceded the call, females responded as often to the multimodal signal as to the call alone. These data show that asynchrony of a normally fixed signal does reduce receiver responsiveness. The magnitude and overall response, however, depend on specific temporal interactions between the acoustic and visual components. The sensitivity of túngara frogs to lagging visual cues, but not leading ones, and the influence of acoustic signal content on the perception of visual asynchrony is similar to those reported in human psychophysics literature. Virtually all acoustically communicating animals must conduct auditory scene analyses and identify the source of signals. Our data suggest that some basic audiovisual neural integration processes may be at work in the vertebrate brain. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology 2017. This work is written by US Government employees and is in the public domain in the US.

PhysioNet: physiologic signals, time series and related open source software for basic, clinical, and applied research.

PubMed

Moody, George B; Mark, Roger G; Goldberger, Ary L

2011-01-01

PhysioNet provides free web access to over 50 collections of recorded physiologic signals and time series, and related open-source software, in support of basic, clinical, and applied research in medicine, physiology, public health, biomedical engineering and computing, and medical instrument design and evaluation. Its three components (PhysioBank, the archive of signals; PhysioToolkit, the software library; and PhysioNetWorks, the virtual laboratory for collaborative development of future PhysioBank data collections and PhysioToolkit software components) connect researchers and students who need physiologic signals and relevant software with researchers who have data and software to share. PhysioNet's annual open engineering challenges stimulate rapid progress on unsolved or poorly solved questions of basic or clinical interest, by focusing attention on achievable solutions that can be evaluated and compared objectively using freely available reference data.

Signal Construction-Based Dispersion Compensation of Lamb Waves Considering Signal Waveform and Amplitude Spectrum Preservation

PubMed Central

Cai, Jian; Yuan, Shenfang; Wang, Tongguang

2016-01-01

The results of Lamb wave identification for the aerospace structures could be easily affected by the nonlinear-dispersion characteristics. In this paper, dispersion compensation of Lamb waves is of particular concern. Compared with the similar research works on the traditional signal domain transform methods, this study is based on signal construction from the viewpoint of nonlinear wavenumber linearization. Two compensation methods of linearly-dispersive signal construction (LDSC) and non-dispersive signal construction (NDSC) are proposed. Furthermore, to improve the compensation effect, the influence of the signal construction process on the other crucial signal properties, including the signal waveform and amplitude spectrum, is considered during the investigation. The linear-dispersion and non-dispersion effects are firstly analyzed. Then, after the basic signal construction principle is explored, the numerical realization of LDSC and NDSC is discussed, in which the signal waveform and amplitude spectrum preservation is especially regarded. Subsequently, associated with the delay-and-sum algorithm, LDSC or NDSC is employed for high spatial resolution damage imaging, so that the adjacent multi-damage or quantitative imaging capacity of Lamb waves can be strengthened. To verify the proposed signal construction and damage imaging methods, the experimental and numerical validation is finally arranged on the aluminum plates. PMID:28772366

Signal Construction-Based Dispersion Compensation of Lamb Waves Considering Signal Waveform and Amplitude Spectrum Preservation.

PubMed

Cai, Jian; Yuan, Shenfang; Wang, Tongguang

2016-12-23

The results of Lamb wave identification for the aerospace structures could be easily affected by the nonlinear-dispersion characteristics. In this paper, dispersion compensation of Lamb waves is of particular concern. Compared with the similar research works on the traditional signal domain transform methods, this study is based on signal construction from the viewpoint of nonlinear wavenumber linearization. Two compensation methods of linearly-dispersive signal construction (LDSC) and non-dispersive signal construction (NDSC) are proposed. Furthermore, to improve the compensation effect, the influence of the signal construction process on the other crucial signal properties, including the signal waveform and amplitude spectrum, is considered during the investigation. The linear-dispersion and non-dispersion effects are firstly analyzed. Then, after the basic signal construction principle is explored, the numerical realization of LDSC and NDSC is discussed, in which the signal waveform and amplitude spectrum preservation is especially regarded. Subsequently, associated with the delay-and-sum algorithm, LDSC or NDSC is employed for high spatial resolution damage imaging, so that the adjacent multi-damage or quantitative imaging capacity of Lamb waves can be strengthened. To verify the proposed signal construction and damage imaging methods, the experimental and numerical validation is finally arranged on the aluminum plates.

Design of a signal conditioner for the Fermilab Magnet Test Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giannelli, Pietro

2012-01-01

This thesis describes the design of a remotely-programmable signal conditioner for the harmonic measurement of accelerator magnets. A 10-channel signal conditioning circuit featuring bucking capabilities was designed from scratch and implemented to the level of the printed circuit board layout. Other system components were chosen from those available on the market. Software design was started with the definition of routine procedures. This thesis is part of an upgrade project for replacing obsolescent automated test equipment belonging to the Fermilab Magnet Test Facility. The design started with a given set of requirements. Using a top-down approach, all the circuits were designedmore » and their expected performances were theoretically predicted and simulated. A limited prototyping phase followed. The printed circuit boards were laid out and routed using a CAD software and focusing the design on maximum electromagnetic interference immunity. An embedded board was selected for controlling and interfacing the signal conditioning circuitry with the instrumentation network. Basic low level routines for hardware access were defined. This work covered the entire design process of the signal conditioner, resulting in a project ready for manufacturing. The expected performances are in line with the requirements and, in the cases where this was not possible, approval of trade-offs was sought and received from the end users. Part I deals with the global structure of the signal conditioner and the subdivision in functional macro-blocks. Part II treats the hardware design phase in detail, covering the analog and digital circuits, the printed circuit layouts, the embedded controller and the power supply selection. Part III deals with the basic hardware-related routines to be implemented in the final software.« less

Nuclear Receptor Signaling Atlas: Opening Access to the Biology of Nuclear Receptor Signaling Pathways

PubMed Central

Becnel, Lauren B.; Darlington, Yolanda F.; Ochsner, Scott A.; Easton-Marks, Jeremy R.; Watkins, Christopher M.; McOwiti, Apollo; Kankanamge, Wasula H.; Wise, Michael W.; DeHart, Michael; Margolis, Ronald N.; McKenna, Neil J.

2015-01-01

Signaling pathways involving nuclear receptors (NRs), their ligands and coregulators, regulate tissue-specific transcriptomes in diverse processes, including development, metabolism, reproduction, the immune response and neuronal function, as well as in their associated pathologies. The Nuclear Receptor Signaling Atlas (NURSA) is a Consortium focused around a Hub website (www.nursa.org) that annotates and integrates diverse ‘omics datasets originating from the published literature and NURSA-funded Data Source Projects (NDSPs). These datasets are then exposed to the scientific community on an Open Access basis through user-friendly data browsing and search interfaces. Here, we describe the redesign of the Hub, version 3.0, to deploy “Web 2.0” technologies and add richer, more diverse content. The Molecule Pages, which aggregate information relevant to NR signaling pathways from myriad external databases, have been enhanced to include resources for basic scientists, such as post-translational modification sites and targeting miRNAs, and for clinicians, such as clinical trials. A portal to NURSA’s Open Access, PubMed-indexed journal Nuclear Receptor Signaling has been added to facilitate manuscript submissions. Datasets and information on reagents generated by NDSPs are available, as is information concerning periodic new NDSP funding solicitations. Finally, the new website integrates the Transcriptomine analysis tool, which allows for mining of millions of richly annotated public transcriptomic data points in the field, providing an environment for dataset re-use and citation, bench data validation and hypothesis generation. We anticipate that this new release of the NURSA database will have tangible, long term benefits for both basic and clinical research in this field. PMID:26325041

Signal functions for emergency obstetric care as an intervention for reducing maternal mortality: a survey of public and private health facilities in Lusaka District, Zambia.

PubMed

Tembo, Tannia; Chongwe, Gershom; Vwalika, Bellington; Sitali, Lungowe

2017-09-06

Zambia's maternal mortality ratio was estimated at 398/100,000 live births in 2014. Successful aversion of deaths is dependent on availability and usability of signal functions for emergency obstetric and neonatal care. Evidence of availability, usability and quality of signal functions in urban settings in Zambia is minimal as previous research has evaluated their distribution in rural settings. This survey evaluated the availability and usability of signal functions in private and public health facilities in Lusaka District of Zambia. A descriptive cross sectional study was conducted between November 2014 and February 2015 at 35 public and private health facilities. The Service Availability and Readiness Assessment tool was adapted and administered to overall in-charges, hospital administrators or maternity ward supervisors at health facilities providing maternal and newborn health services. The survey quantified infrastructure, human resources, equipment, essential drugs and supplies and used the UN process indicators to determine availability, accessibility and quality of signal functions. Data on deliveries and complications were collected from registers for periods between June 2013 and May 2014. Of the 35 (25.7% private and 74.2% public) health facilities assessed, only 22 (62.8%) were staffed 24 h a day, 7 days a week and had provided obstetric care 3 months prior to the survey. Pre-eclampsia/ eclampsia and obstructed labor accounted for most direct complications while postpartum hemorrhage was the leading cause of maternal deaths. Overall, 3 (8.6%) and 5 (14.3%) of the health facilities had provided Basic and Comprehensive EmONC services, respectively. All facilities obtained blood products from the only blood bank at a government referral hospital. The UN process indicators can be adequately used to monitor progress towards maternal mortality reduction. Lusaka district had an unmet need for BEmONC as health facilities fell below the minimum UN standard. Public health facilities with capacity to perform signal functions should be upgraded to Basic EmONC status. Efforts must focus on enhancing human resource capacity in EmONC and improving infrastructure and supply chain. Obstetric health needs and international trends must drive policy change.

The Seismic Tool-Kit (STK): An Open Source Software For Learning the Basis of Signal Processing and Seismology.

NASA Astrophysics Data System (ADS)

Reymond, D.

2016-12-01

We present an open source software project (GNU public license), named STK: Seismic Tool-Kit, that is dedicated mainly for learning signal processing and seismology. The STK project that started in 2007, is hosted by SourceForge.net, and count more than 20000 downloads at the date of writing.The STK project is composed of two main branches:First, a graphical interface dedicated to signal processing (in the SAC format (SAC_ASCII and SAC_BIN): where the signal can be plotted, zoomed, filtered, integrated, derivated, ... etc. (a large variety of IFR and FIR filter is proposed). The passage in the frequency domain via the Fourier transform is used to introduce the estimation of spectral density of the signal , with visualization of the Power Spectral Density (PSD) in linear or log scale, and also the evolutive time-frequency representation (or sonagram). The 3-components signals can be also processed for estimating their polarization properties, either for a given window, or either for evolutive windows along the time. This polarization analysis is useful for extracting the polarized noises, differentiating P waves, Rayleigh waves, Love waves, ... etc. Secondly, a panel of Utilities-Program are proposed for working in a terminal mode, with basic programs for computing azimuth and distance in spherical geometry, inter/auto-correlation, spectral density, time-frequency for an entire directory of signals, focal planes, and main components axis, radiation pattern of P waves, Polarization analysis of different waves (including noise), under/over-sampling the signals, cubic-spline smoothing, and linear/non linear regression analysis of data set. STK is developed in C/C++, mainly under Linux OS, and it has been also partially implemented under MS-Windows. STK has been used in some schools for viewing and plotting seismic records provided by IRIS, and it has been used as a practical support for teaching the basis of signal processing. Useful links:http://sourceforge.net/projects/seismic-toolkit/http://sourceforge.net/p/seismic-toolkit/wiki/browse_pages/

A Non-Invasive Multichannel Hybrid Fiber-Optic Sensor System for Vital Sign Monitoring

PubMed Central

Fajkus, Marcel; Nedoma, Jan; Martinek, Radek; Vasinek, Vladimir; Nazeran, Homer; Siska, Petr

2017-01-01

In this article, we briefly describe the design, construction, and functional verification of a hybrid multichannel fiber-optic sensor system for basic vital sign monitoring. This sensor uses a novel non-invasive measurement probe based on the fiber Bragg grating (FBG). The probe is composed of two FBGs encapsulated inside a polydimethylsiloxane polymer (PDMS). The PDMS is non-reactive to human skin and resistant to electromagnetic waves, UV absorption, and radiation. We emphasize the construction of the probe to be specifically used for basic vital sign monitoring such as body temperature, respiratory rate and heart rate. The proposed sensor system can continuously process incoming signals from up to 128 individuals. We first present the overall design of this novel multichannel sensor and then elaborate on how it has the potential to simplify vital sign monitoring and consequently improve the comfort level of patients in long-term health care facilities, hospitals and clinics. The reference ECG signal was acquired with the use of standard gel electrodes fixed to the monitored person’s chest using a real-time monitoring system for ECG signals with virtual instrumentation. The outcomes of these experiments have unambiguously proved the functionality of the sensor system and will be used to inform our future research in this fast developing and emerging field. PMID:28075341

Do not throw out the baby with the bath water: choosing an effective baseline for a functional localizer of speech processing.

PubMed

Stoppelman, Nadav; Harpaz, Tamar; Ben-Shachar, Michal

2013-05-01

Speech processing engages multiple cortical regions in the temporal, parietal, and frontal lobes. Isolating speech-sensitive cortex in individual participants is of major clinical and scientific importance. This task is complicated by the fact that responses to sensory and linguistic aspects of speech are tightly packed within the posterior superior temporal cortex. In functional magnetic resonance imaging (fMRI), various baseline conditions are typically used in order to isolate speech-specific from basic auditory responses. Using a short, continuous sampling paradigm, we show that reversed ("backward") speech, a commonly used auditory baseline for speech processing, removes much of the speech responses in frontal and temporal language regions of adult individuals. On the other hand, signal correlated noise (SCN) serves as an effective baseline for removing primary auditory responses while maintaining strong signals in the same language regions. We show that the response to reversed speech in left inferior frontal gyrus decays significantly faster than the response to speech, thus suggesting that this response reflects bottom-up activation of speech analysis followed up by top-down attenuation once the signal is classified as nonspeech. The results overall favor SCN as an auditory baseline for speech processing.

Users' manual for computer program for three-dimensional analysis of coupler-cavity traveling wave tubes

NASA Technical Reports Server (NTRS)

Omalley, T. A.

1984-01-01

The use of the coupled cavity traveling wave tube for space communications has led to an increased interest in improving the efficiency of the basic interaction process in these devices through velocity resynchronization and other methods. A flexible, three dimensional, axially symmetric, large signal computer program was developed for use on the IBM 370 time sharing system. A users' manual for this program is included.

Discrimination of acoustic communication signals by grasshoppers (Chorthippus biguttulus): temporal resolution, temporal integration, and the impact of intrinsic noise.

PubMed

Ronacher, Bernhard; Wohlgemuth, Sandra; Vogel, Astrid; Krahe, Rüdiger

2008-08-01

A characteristic feature of hearing systems is their ability to resolve both fast and subtle amplitude modulations of acoustic signals. This applies also to grasshoppers, which for mate identification rely mainly on the characteristic temporal patterns of their communication signals. Usually the signals arriving at a receiver are contaminated by various kinds of noise. In addition to extrinsic noise, intrinsic noise caused by stochastic processes within the nervous system contributes to making signal recognition a difficult task. The authors asked to what degree intrinsic noise affects temporal resolution and, particularly, the discrimination of similar acoustic signals. This study aims at exploring the neuronal basis for sexual selection, which depends on exploiting subtle differences between basically similar signals. Applying a metric, by which the similarities of spike trains can be assessed, the authors investigated how well the communication signals of different individuals of the same species could be discriminated and correctly classified based on the responses of auditory neurons. This spike train metric yields clues to the optimal temporal resolution with which spike trains should be evaluated. (c) 2008 APA, all rights reserved

Redox signaling: Potential arbitrator of autophagy and apoptosis in therapeutic response.

PubMed

Zhang, Lu; Wang, Kui; Lei, Yunlong; Li, Qifu; Nice, Edouard Collins; Huang, Canhua

2015-12-01

Redox signaling plays important roles in the regulation of cell death and survival in response to cancer therapy. Autophagy and apoptosis are discrete cellular processes mediated by distinct groups of regulatory and executioner molecules, and both are thought to be cellular responses to various stress conditions including oxidative stress, therefore controlling cell fate. Basic levels of reactive oxygen species (ROS) may function as signals to promote cell proliferation and survival, whereas increase of ROS can induce autophagy and apoptosis by damaging cellular components. Growing evidence in recent years argues for ROS that below detrimental levels acting as intracellular signal transducers that regulate autophagy and apoptosis. ROS-regulated autophagy and apoptosis can cross-talk with each other. However, how redox signaling determines different cell fates by regulating autophagy and apoptosis remains unclear. In this review, we will focus on understanding the delicate molecular mechanism by which autophagy and apoptosis are finely orchestrated by redox signaling and discuss how this understanding can be used to develop strategies for the treatment of cancer. Copyright © 2015 Elsevier Inc. All rights reserved.

Evolution of neuronal signalling: transmitters and receptors.

PubMed

Hoyle, Charles H V

2011-11-16

Evolution is a dynamic process during which the genome should not be regarded as a static entity. Molecular and morphological information yield insights into the evolution of species and their phylogenetic relationships, and molecular information in particular provides information into the evolution of signalling processes. Many signalling systems have their origin in primitive, even unicellular, organisms. Through time, and as organismal complexity increased, certain molecules were employed as intercellular signal molecules. In the autonomic nervous system the basic unit of chemical transmission is a ligand and its cognate receptor. The general mechanisms underlying evolution of signal molecules and their cognate receptors have their basis in the alteration of the genome. In the past this has occurred in large-scale events, represented by two or more doublings of the whole genome, or large segments of the genome, early in the deuterostome lineage, after the emergence of urochordates and cephalochordates, and before the emergence of vertebrates. These duplications were followed by extensive remodelling involving subsequent small-scale changes, ranging from point mutations to exon duplication. Concurrent with these processes was multiple gene loss so that the modern genome contains roughly the same number of genes as in early deuterostomes despite the large-scale genomic duplications. In this review, the principles that underlie evolution that have led to large and small families of autonomic neurotransmitters and their receptors are discussed, with emphasis on G protein-coupled receptors. Copyright © 2010 Elsevier B.V. All rights reserved.

Basic Radio Circuits and Vacuum Tube AM Troubleshooting; Radio and Television Service, Intermediate: 9785.03.

ERIC Educational Resources Information Center

Dade County Public Schools, Miami, FL.

The 135-hour quinmester course covers study of basic radio circuits as applied to vacuum tube radios in six blocks of instruction: orientation; AM receivers with tubes; no signal, audio failure; distortion; weak, noisy signals; and a post-test. Each block is subdivided into several units, and block objectives are outlined. Completion of AC…

Visual body perception in anorexia nervosa.

PubMed

Urgesi, Cosimo; Fornasari, Livia; Perini, Laura; Canalaz, Francesca; Cremaschi, Silvana; Faleschini, Laura; Balestrieri, Matteo; Fabbro, Franco; Aglioti, Salvatore Maria; Brambilla, Paolo

2012-05-01

Disturbance of body perception is a central aspect of anorexia nervosa (AN) and several neuroimaging studies have documented structural and functional alterations of occipito-temporal cortices involved in visual body processing. However, it is unclear whether these perceptual deficits involve more basic aspects of others' body perception. A consecutive sample of 15 adolescent patients with AN were compared with a group of 15 age- and gender-matched controls in delayed matching to sample tasks requiring the visual discrimination of the form or of the action of others' body. Patients showed better visual discrimination performance than controls in detail-based processing of body forms but not of body actions, which positively correlated with their increased tendency to convert a signal of punishment into a signal of reinforcement (higher persistence scores). The paradoxical advantage of patients with AN in detail-based body processing may be associated to their tendency to routinely explore body parts as a consequence of their obsessive worries about body appearance. Copyright © 2012 Wiley Periodicals, Inc.

Visual Functions of the Thalamus

PubMed Central

Usrey, W. Martin; Alitto, Henry J.

2017-01-01

The thalamus is the heavily interconnected partner of the neocortex. All areas of the neocortex receive afferent input from and send efferent projections to specific thalamic nuclei. Through these connections, the thalamus serves to provide the cortex with sensory input, and to facilitate interareal cortical communication and motor and cognitive functions. In the visual system, the lateral geniculate nucleus (LGN) of the dorsal thalamus is the gateway through which visual information reaches the cerebral cortex. Visual processing in the LGN includes spatial and temporal influences on visual signals that serve to adjust response gain, transform the temporal structure of retinal activity patterns, and increase the signal-to-noise ratio of the retinal signal while preserving its basic content. This review examines recent advances in our understanding of LGN function and circuit organization and places these findings in a historical context. PMID:28217740

Vibration and Noise in Magnetic Resonance Imaging of the Vocal Tract: Differences between Whole-Body and Open-Air Devices.

PubMed

Přibil, Jiří; Přibilová, Anna; Frollo, Ivan

2018-04-05

This article compares open-air and whole-body magnetic resonance imaging (MRI) equipment working with a weak magnetic field as regards the methods of its generation, spectral properties of mechanical vibration and acoustic noise produced by gradient coils during the scanning process, and the measured noise intensity. These devices are used for non-invasive MRI reconstruction of the human vocal tract during phonation with simultaneous speech recording. In this case, the vibration and noise have negative influence on quality of speech signal. Two basic measurement experiments were performed within the paper: mapping sound pressure levels in the MRI device vicinity and picking up vibration and noise signals in the MRI scanning area. Spectral characteristics of these signals are then analyzed statistically and compared visually and numerically.

Analysis of the mechanics and deformation characteristics of optical fiber acceleration sensor

NASA Astrophysics Data System (ADS)

Liu, Zong-kai; Bo, Yu-ming; Zhou, Ben-mou; Wang, Jun; Huang, Ya-dong

2016-10-01

The optical fiber sensor holds many advantages such as smaller volume, lighter weight, higher sensitivity, and stronger anti-interference ability, etc. It can be applied to oil exploration to improve the exploration efficiency, since the underground petroleum distribution can be obtained by detecting and analyzing the echo signals. In this paper, the cantilever beam optical fiber sensor was mainly investigated. Specifically, the finite element analysis method is applied to the numerical analysis of the changes and relations of the optical fiber rail slot elongation on the surface of the PC material fiber winding plate along with the changes of time and power under the action of sine force. The analysis results show that, when the upper and lower quality blocks are under the action of sine force, the cantilever beam optical fiber sensor structure can basically produce synchronized deformation along with the force. And the optical fiber elongation length basically has a linear relationship with the sine force within the time ranges of 0.2 0.4 and 0.6 0.8, which would be beneficial for the subsequent signal acquisition and data processing.

Measuring the RC time constant with Arduino

NASA Astrophysics Data System (ADS)

Pereira, N. S. A.

2016-11-01

In this work we use the Arduino UNO R3 open source hardware platform to assemble an experimental apparatus for the measurement of the time constant of an RC circuit. With adequate programming, the Arduino is used as a signal generator, a data acquisition system and a basic signal visualisation tool. Theoretical calculations are compared with direct observations from an analogue oscilloscope. Data processing and curve fitting is performed on a spreadsheet. The results obtained for the six RC test circuits are within the expected interval of values defined by the tolerance of the components. The hardware and software prove to be adequate to the proposed measurements and therefore adaptable to a laboratorial teaching and learning context.

AAPM/RSNA physics tutorial for residents. Topics in US: B-mode US: basic concepts and new technology.

PubMed

Hangiandreou, Nicholas J

2003-01-01

Ultrasonography (US) has been used in medical imaging for over half a century. Current US scanners are based largely on the same basic principles used in the initial devices for human imaging. Modern equipment uses a pulse-echo approach with a brightness-mode (B-mode) display. Fundamental aspects of the B-mode imaging process include basic ultrasound physics, interactions of ultrasound with tissue, ultrasound pulse formation, scanning the ultrasound beam, and echo detection and signal processing. Recent technical innovations that have been developed to improve the performance of modern US equipment include the following: tissue harmonic imaging, spatial compound imaging, extended field of view imaging, coded pulse excitation, electronic section focusing, three-dimensional and four-dimensional imaging, and the general trend toward equipment miniaturization. US is a relatively inexpensive, portable, safe, and real-time modality, all of which make it one of the most widely used imaging modalities in medicine. Although B-mode US is sometimes referred to as a mature technology, this modality continues to experience a significant evolution in capability with even more exciting developments on the horizon. Copyright RSNA, 2003

Schizophrenia - A disturbance of signal interaction between the entorhinal cortex and the dentate gyrus? The contribution of experimental dibenamine psychosis to the pathogenesis of schizophrenia: A hypothesis.

PubMed

Arnold, O H

1999-01-01

In addition to the existence of complex memory (similar to the implicit nondeclarative memory of Squire), the existence of a phylogenetically old apparatus of a memory of situations (SMA) is supposed, which is to some extent comparable with the declarative memory of Squire. During actual sensory information the SMA generates a general frame and forms a general 'mark', indicating whether a given information has its origin inside or outside the body, and whether it is new or known. The procedure of this marking process can be explained as the time-depending arrest of a copy of the actual original information-transporting signal 'shower'; this copy must last until the feedback from thalamocortical centers indicates the termination of the processing of the original signal showers. The arrest of the shower copies is the performance of neuronal networks of the entorhinal cortex (EC) and the gyrus dentatus (GD). The psychopathological and biochemical analyses of experimental dibenamine psychosis show a different effect of dibenamine on the noradrenaline (NA) receptors of the EC and GD, respectively: these effects are responsible for the repeated perception cycles of a single situation. N,N-Dibencylamine blocks the postsynaptic alpha(1)-receptors of the EC without influencing the beta-receptors of the GD. Thus the interaction between EC and GD is changed: instead of new scenes, perceptions that have just been experienced get repeated presence and the quality of familiarity. The prolonged arrest of shower copies simultaneously blocks the entrance of new signal showers from the EC to the GD. No information-transporting signal showers can come in as long as the arrest lasts. In case of a disturbance in NA-dependent actions within the EC and the GD, the duration of arrest of information-transporting signal showers is shortened. Thus the formal frame of experience receives the quality of novelty instead of familiarity, and in addition the qualities of uncertainty, vagueness, and alienity. These very changes in perception and experience represent the basic disturbance of schizophrenia. All the symptoms of schizophrenia may be explained by this basic disturbance. The analysis of biochemical aspects turns attention to the energetic situation of NA and N-methyl-D-aspartate systems. These considerations suggest a genetic background of the basic disturbance of schizophrenia: transmitter effects on membranes of neurons and possibly also on glial cells, and energy supply of these effects may be predetermined genetically. It may be assumed that the compensation of such membrane-dependent disturbances will be possible within wide areas of the neural network, except for the 'bottleneck' of the overlapping region of the iso- and allocortex.

Quantum-like model of processing of information in the brain based on classical electromagnetic field.

PubMed

Khrennikov, Andrei

2011-09-01

We propose a model of quantum-like (QL) processing of mental information. This model is based on quantum information theory. However, in contrast to models of "quantum physical brain" reducing mental activity (at least at the highest level) to quantum physical phenomena in the brain, our model matches well with the basic neuronal paradigm of the cognitive science. QL information processing is based (surprisingly) on classical electromagnetic signals induced by joint activity of neurons. This novel approach to quantum information is based on representation of quantum mechanics as a version of classical signal theory which was recently elaborated by the author. The brain uses the QL representation (QLR) for working with abstract concepts; concrete images are described by classical information theory. Two processes, classical and QL, are performed parallely. Moreover, information is actively transmitted from one representation to another. A QL concept given in our model by a density operator can generate a variety of concrete images given by temporal realizations of the corresponding (Gaussian) random signal. This signal has the covariance operator coinciding with the density operator encoding the abstract concept under consideration. The presence of various temporal scales in the brain plays the crucial role in creation of QLR in the brain. Moreover, in our model electromagnetic noise produced by neurons is a source of superstrong QL correlations between processes in different spatial domains in the brain; the binding problem is solved on the QL level, but with the aid of the classical background fluctuations. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Systems modelling methodology for the analysis of apoptosis signal transduction and cell death decisions.

PubMed

Rehm, Markus; Prehn, Jochen H M

2013-06-01

Systems biology and systems medicine, i.e. the application of systems biology in a clinical context, is becoming of increasing importance in biology, drug discovery and health care. Systems biology incorporates knowledge and methods that are applied in mathematics, physics and engineering, but may not be part of classical training in biology. We here provide an introduction to basic concepts and methods relevant to the construction and application of systems models for apoptosis research. We present the key methods relevant to the representation of biochemical processes in signal transduction models, with a particular reference to apoptotic processes. We demonstrate how such models enable a quantitative and temporal analysis of changes in molecular entities in response to an apoptosis-inducing stimulus, and provide information on cell survival and cell death decisions. We introduce methods for analyzing the spatial propagation of cell death signals, and discuss the concepts of sensitivity analyses that enable a prediction of network responses to disturbances of single or multiple parameters. Copyright © 2013 Elsevier Inc. All rights reserved.

Challenges and Recent Developments in Hearing Aids: Part I. Speech Understanding in Noise, Microphone Technologies and Noise Reduction Algorithms

PubMed Central

Chung, King

2004-01-01

This review discusses the challenges in hearing aid design and fitting and the recent developments in advanced signal processing technologies to meet these challenges. The first part of the review discusses the basic concepts and the building blocks of digital signal processing algorithms, namely, the signal detection and analysis unit, the decision rules, and the time constants involved in the execution of the decision. In addition, mechanisms and the differences in the implementation of various strategies used to reduce the negative effects of noise are discussed. These technologies include the microphone technologies that take advantage of the spatial differences between speech and noise and the noise reduction algorithms that take advantage of the spectral difference and temporal separation between speech and noise. The specific technologies discussed in this paper include first-order directional microphones, adaptive directional microphones, second-order directional microphones, microphone matching algorithms, array microphones, multichannel adaptive noise reduction algorithms, and synchrony detection noise reduction algorithms. Verification data for these technologies, if available, are also summarized. PMID:15678225

Basic Gravitational Reflexes in the Larval Frog

NASA Technical Reports Server (NTRS)

Cochran, Stephen L.

1996-01-01

This investigation was designed to determine how a primitive vertebrate, the bullfrog tadpole, is able to sense and process gravitational stimuli. Because of the phylogenetic similarities of the vestibular systems in all vertebrates, the understanding of the gravitational reflexes in this relatively simple vertebrate should elucidate a skeletal framework on a elementary level, upon which the more elaborate reflexes of higher vertebrates may be constructed. The purpose of this study was to understand how the nervous system of the larval amphibian processes gravitational information. This study involved predominantly electrophysiological investigations of the isolated, alert (forebrain removed) bullfrog tadpole head. The focus of these experiments is threefold: (1) to understand from whole extraocular nerve recordings the signals sent to the eye following static gravitational tilt of the head; (2) to localize neuronal centers responsible for generating these signals through reversible pharmacological ablation of these centers; and (3) to record intracellularly from neurons within these centers in order to determine the single neuron's role in the overall processing of the center. This study has provided information on the mechanisms by which a primitive vertebrate processes gravitational reflexes.

Cognitive measure on different profiles.

PubMed

Spindola, Marilda; Carra, Giovani; Balbinot, Alexandre; Zaro, Milton A

2010-01-01

Based on neurology and cognitive science many studies are developed to understand the human model mental, getting to know how human cognition works, especially about learning processes that involve complex contents and spatial-logical reasoning. Event Related Potential - ERP - is a basic and non-invasive method of electrophysiological investigation. It can be used to assess aspects of human cognitive processing by changing the rhythm of the frequency bands brain indicate that some type of processing or neuronal behavior. This paper focuses on ERP technique to help understand cognitive pathway in subjects from different areas of knowledge when they are exposed to an external visual stimulus. In the experiment we used 2D and 3D visual stimulus in the same picture. The signals were captured using 10 (ten) Electroencephalogram - EEG - channel system developed for this project and interfaced in a ADC (Analogical Digital System) board with LabVIEW system - National Instruments. That research was performed using project of experiments technique - DOE. The signal processing were done (math and statistical techniques) showing the relationship between cognitive pathway by groups and intergroups.

A core viral protein binds host nucleosomes to sequester immune danger signals

PubMed Central

Avgousti, Daphne C.; Herrmann, Christin; Kulej, Katarzyna; Pancholi, Neha J.; Sekulic, Nikolina; Petrescu, Joana; Molden, Rosalynn C.; Blumenthal, Daniel; Paris, Andrew J.; Reyes, Emigdio D.; Ostapchuk, Philomena; Hearing, Patrick; Seeholzer, Steven H.; Worthen, G. Scott; Black, Ben E.; Garcia, Benjamin A.; Weitzman, Matthew D.

2016-01-01

Viral proteins mimic host protein structure and function to redirect cellular processes and subvert innate defenses1. Small basic proteins compact and regulate both viral and cellular DNA genomes. Nucleosomes are the repeating units of cellular chromatin and play an important role in innate immune responses2. Viral encoded core basic proteins compact viral genomes but their impact on host chromatin structure and function remains unexplored. Adenoviruses encode a highly basic protein called protein VII that resembles cellular histones3. Although protein VII binds viral DNA and is incorporated with viral genomes into virus particles4,5, it is unknown whether protein VII impacts cellular chromatin. Our observation that protein VII alters cellular chromatin led us to hypothesize that this impacts antiviral responses during adenovirus infection. We found that protein VII forms complexes with nucleosomes and limits DNA accessibility. We identified post-translational modifications on protein VII that are responsible for chromatin localization. Furthermore, proteomic analysis demonstrated that protein VII is sufficient to alter protein composition of host chromatin. We found that protein VII is necessary and sufficient for retention in chromatin of members of the high-mobility group protein B family (HMGB1, HMGB2, and HMGB3). HMGB1 is actively released in response to inflammatory stimuli and functions as a danger signal to activate immune responses6,7. We showed that protein VII can directly bind HMGB1 in vitro and further demonstrated that protein VII expression in mouse lungs is sufficient to decrease inflammation-induced HMGB1 content and neutrophil recruitment in the bronchoalveolar lavage fluid. Together our in vitro and in vivo results show that protein VII sequesters HMGB1 and can prevent its release. This study uncovers a viral strategy in which nucleosome binding is exploited to control extracellular immune signaling. PMID:27362237

Cultural Transmission and Evolution of Melodic Structures in Multi-generational Signaling Games.

PubMed

Lumaca, Massimo; Baggio, Giosuè

2017-01-01

It has been proposed that languages evolve by adapting to the perceptual and cognitive constraints of the human brain, developing, in the course of cultural transmission, structural regularities that maximize or optimize learnability and ease of processing. To what extent would perceptual and cognitive constraints similarly affect the evolution of musical systems? We conducted an experiment on the cultural evolution of artificial melodic systems, using multi-generational signaling games as a laboratory model of cultural transmission. Signaling systems, using five-tone sequences as signals, and basic and compound emotions as meanings, were transmitted from senders to receivers along diffusion chains in which the receiver in each game became the sender in the next game. During transmission, structural regularities accumulated in the signaling systems, following principles of proximity, symmetry, and good continuation. Although the compositionality of signaling systems did not increase significantly across generations, we did observe a significant increase in similarity among signals from the same set. We suggest that our experiment tapped into the cognitive and perceptual constraints operative in the cultural evolution of musical systems, which may differ from the mechanisms at play in language evolution and change.

Classical analysis of time behavior of radiation fields associated with biophoton signals.

PubMed

Choi, Jeong Ryeol; Kim, Daeyeoul; Menouar, Salah; Sever, Ramazan; Abdalla, M Sebawe

2016-04-29

Propagation of photon signals in biological systems, such as neurons, accompanies the production of biophotons. The role of biophotons in a cell deserves special attention because it can be applied to diverse optical systems. This work has been aimed to investigate the time behavior of biophoton signals emitted from living systems in detail, by introducing a Hamiltonian that describes the process. The ratio of the energy loss during signal dissipation will also be investigated. To see the adiabatic properties of the biophoton signal, we introduced an adiabatic invariant of the system according to the method of its basic formulation. The energy of the released biophoton dissipates over time in a somewhat intricate way when t is small. However, after a sufficient long time, it dissipates in proportion (1+λ_0t)^2 to where λ_0 is a constant that is relevant to the degree of dissipation. We have confirmed that the energy of the biophoton signal oscillates in a particular way while it dissipates. This research clarifies the characteristics of radiation fields associated with biophotons on the basis of Hamiltonian dynamics which describes phenomenological aspects of biophotons signals.

A Simulation System Based on the Actor Paradigm

DTIC Science & Technology

1988-02-01

of the protocol. Shared memory communication requires the programmer to wait and signal semaphores explicitly to synchronize the communicating parties...wide range of possibilities within the same basic protocol. - The simplicity of the primitive operation set affords those creating new operations...more flexibility (Ada has a large and complicated primitive set). -3- II I I I B A I -I I I I I . 0 1 2 3 4 5 Time 0: Both processes A and B are

Users' manual for computer program for one-dimensional analysis of coupled-cavity traveling wave tubes

NASA Technical Reports Server (NTRS)

Omalley, T. A.; Connolly, D. J.

1977-01-01

The use of the coupled cavity traveling wave tube for space communications has led to an increased interest in improving the efficiency of the basic interaction process in these devices through velocity resynchronization and other methods. To analyze these methods, a flexible, large signal computer program for use on the IBM 360/67 time-sharing system has been developed. The present report is a users' manual for this program.

Theoretical foundations of spatially-variant mathematical morphology part ii: gray-level images.

PubMed

Bouaynaya, Nidhal; Schonfeld, Dan

2008-05-01

In this paper, we develop a spatially-variant (SV) mathematical morphology theory for gray-level signals and images in the Euclidean space. The proposed theory preserves the geometrical concept of the structuring function, which provides the foundation of classical morphology and is essential in signal and image processing applications. We define the basic SV gray-level morphological operators (i.e., SV gray-level erosion, dilation, opening, and closing) and investigate their properties. We demonstrate the ubiquity of SV gray-level morphological systems by deriving a kernel representation for a large class of systems, called V-systems, in terms of the basic SV graylevel morphological operators. A V-system is defined to be a gray-level operator, which is invariant under gray-level (vertical) translations. Particular attention is focused on the class of SV flat gray-level operators. The kernel representation for increasing V-systems is a generalization of Maragos' kernel representation for increasing and translation-invariant function-processing systems. A representation of V-systems in terms of their kernel elements is established for increasing and upper-semi-continuous V-systems. This representation unifies a large class of spatially-variant linear and non-linear systems under the same mathematical framework. Finally, simulation results show the potential power of the general theory of gray-level spatially-variant mathematical morphology in several image analysis and computer vision applications.

Face recognition increases during saccade preparation.

PubMed

Lin, Hai; Rizak, Joshua D; Ma, Yuan-ye; Yang, Shang-chuan; Chen, Lin; Hu, Xin-tian

2014-01-01

Face perception is integral to human perception system as it underlies social interactions. Saccadic eye movements are frequently made to bring interesting visual information, such as faces, onto the fovea for detailed processing. Just before eye movement onset, the processing of some basic features, such as the orientation, of an object improves at the saccade landing point. Interestingly, there is also evidence that indicates faces are processed in early visual processing stages similar to basic features. However, it is not known whether this early enhancement of processing includes face recognition. In this study, three experiments were performed to map the timing of face presentation to the beginning of the eye movement in order to evaluate pre-saccadic face recognition. Faces were found to be similarly processed as simple objects immediately prior to saccadic movements. Starting ∼ 120 ms before a saccade to a target face, independent of whether or not the face was surrounded by other faces, the face recognition gradually improved and the critical spacing of the crowding decreased as saccade onset was approaching. These results suggest that an upcoming saccade prepares the visual system for new information about faces at the saccade landing site and may reduce the background in a crowd to target the intended face. This indicates an important role of pre-saccadic eye movement signals in human face recognition.

Continuous tooth generation in mouse is induced by activated epithelial Wnt/β-catenin signaling

PubMed Central

Järvinen, Elina; Salazar-Ciudad, Isaac; Birchmeier, Walter; Taketo, Makoto M.; Jernvall, Jukka; Thesleff, Irma

2006-01-01

The single replacement from milk teeth to permanent teeth makes mammalian teeth different from teeth of most nonmammalian vertebrates and other epithelial organs such as hair and feathers, whose continuous replacement has been linked to Wnt signaling. Here we show that mouse tooth buds expressing stabilized β-catenin in epithelium give rise to dozens of teeth. The molar crowns, however, are typically simplified unicusped cones. We demonstrate that the supernumerary teeth develop by a renewal process where new signaling centers, the enamel knots, bud off from the existing dental epithelium. The basic aspects of the unlocked tooth renewal can be reproduced with a computer model on tooth development by increasing the intrinsic level of activator production, supporting the role of β-catenin pathway as an upstream activator of enamel knot formation. These results may implicate Wnt signaling in tooth renewal, a capacity that was all but lost when mammals evolved progressively more complicated tooth shapes. PMID:17121988

Fringe pattern information retrieval using wavelets

NASA Astrophysics Data System (ADS)

Sciammarella, Cesar A.; Patimo, Caterina; Manicone, Pasquale D.; Lamberti, Luciano

2005-08-01

Two-dimensional phase modulation is currently the basic model used in the interpretation of fringe patterns that contain displacement information, moire, holographic interferometry, speckle techniques. Another way to look to these two-dimensional signals is to consider them as frequency modulated signals. This alternative interpretation has practical implications similar to those that exist in radio engineering for handling frequency modulated signals. Utilizing this model it is possible to obtain frequency information by using the energy approach introduced by Ville in 1944. A natural complementary tool of this process is the wavelet methodology. The use of wavelet makes it possible to obtain the local values of the frequency in a one or two dimensional domain without the need of previous phase retrieval and differentiation. Furthermore from the properties of wavelets it is also possible to obtain at the same time the phase of the signal with the advantage of a better noise removal capabilities and the possibility of developing simpler algorithms for phase unwrapping due to the availability of the derivative of the phase.

Repressor logic modules assembled by rolling circle amplification platform to construct a set of logic gates

PubMed Central

Wei, Hua; Hu, Bo; Tang, Suming; Zhao, Guojie; Guan, Yifu

2016-01-01

Small molecule metabolites and their allosterically regulated repressors play an important role in many gene expression and metabolic disorder processes. These natural sensors, though valuable as good logic switches, have rarely been employed without transcription machinery in cells. Here, two pairs of repressors, which function in opposite ways, were cloned, purified and used to control DNA replication in rolling circle amplification (RCA) in vitro. By using metabolites and repressors as inputs, RCA signals as outputs, four basic logic modules were constructed successfully. To achieve various logic computations based on these basic modules, we designed series and parallel strategies of circular templates, which can further assemble these repressor modules in an RCA platform to realize twelve two-input Boolean logic gates and a three-input logic gate. The RCA-output and RCA-assembled platform was proved to be easy and flexible for complex logic processes and might have application potential in molecular computing and synthetic biology. PMID:27869177

Serotonin 2A Receptor Signaling Underlies LSD-induced Alteration of the Neural Response to Dynamic Changes in Music.

PubMed

Barrett, Frederick S; Preller, Katrin H; Herdener, Marcus; Janata, Petr; Vollenweider, Franz X

2017-09-28

Classic psychedelic drugs (serotonin 2A, or 5HT2A, receptor agonists) have notable effects on music listening. In the current report, blood oxygen level-dependent (BOLD) signal was collected during music listening in 25 healthy adults after administration of placebo, lysergic acid diethylamide (LSD), and LSD pretreated with the 5HT2A antagonist ketanserin, to investigate the role of 5HT2A receptor signaling in the neural response to the time-varying tonal structure of music. Tonality-tracking analysis of BOLD data revealed that 5HT2A receptor signaling alters the neural response to music in brain regions supporting basic and higher-level musical and auditory processing, and areas involved in memory, emotion, and self-referential processing. This suggests a critical role of 5HT2A receptor signaling in supporting the neural tracking of dynamic tonal structure in music, as well as in supporting the associated increases in emotionality, connectedness, and meaningfulness in response to music that are commonly observed after the administration of LSD and other psychedelics. Together, these findings inform the neuropsychopharmacology of music perception and cognition, meaningful music listening experiences, and altered perception of music during psychedelic experiences. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Signal replication in a DNA nanostructure

NASA Astrophysics Data System (ADS)

Mendoza, Oscar; Houmadi, Said; Aimé, Jean-Pierre; Elezgaray, Juan

2017-01-01

Logic circuits based on DNA strand displacement reaction are the basic building blocks of future nanorobotic systems. The circuits tethered to DNA origami platforms present several advantages over solution-phase versions where couplings are always diffusion-limited. Here we consider a possible implementation of one of the basic operations needed in the design of these circuits, namely, signal replication. We show that with an appropriate preparation of the initial state, signal replication performs in a reproducible way. We also show the existence of side effects concomitant to the high effective concentrations in tethered circuits, such as slow leaky reactions and cross-activation.

Real-Time and Secure Wireless Health Monitoring

PubMed Central

Dağtaş, S.; Pekhteryev, G.; Şahinoğlu, Z.; Çam, H.; Challa, N.

2008-01-01

We present a framework for a wireless health monitoring system using wireless networks such as ZigBee. Vital signals are collected and processed using a 3-tiered architecture. The first stage is the mobile device carried on the body that runs a number of wired and wireless probes. This device is also designed to perform some basic processing such as the heart rate and fatal failure detection. At the second stage, further processing is performed by a local server using the raw data transmitted by the mobile device continuously. The raw data is also stored at this server. The processed data as well as the analysis results are then transmitted to the service provider center for diagnostic reviews as well as storage. The main advantages of the proposed framework are (1) the ability to detect signals wirelessly within a body sensor network (BSN), (2) low-power and reliable data transmission through ZigBee network nodes, (3) secure transmission of medical data over BSN, (4) efficient channel allocation for medical data transmission over wireless networks, and (5) optimized analysis of data using an adaptive architecture that maximizes the utility of processing and computational capacity at each platform. PMID:18497866

Network complexity as a measure of information processing across resting-state networks: evidence from the Human Connectome Project

PubMed Central

McDonough, Ian M.; Nashiro, Kaoru

2014-01-01

An emerging field of research focused on fluctuations in brain signals has provided evidence that the complexity of those signals, as measured by entropy, conveys important information about network dynamics (e.g., local and distributed processing). While much research has focused on how neural complexity differs in populations with different age groups or clinical disorders, substantially less research has focused on the basic understanding of neural complexity in populations with young and healthy brain states. The present study used resting-state fMRI data from the Human Connectome Project (Van Essen et al., 2013) to test the extent that neural complexity in the BOLD signal, as measured by multiscale entropy (1) would differ from random noise, (2) would differ between four major resting-state networks previously associated with higher-order cognition, and (3) would be associated with the strength and extent of functional connectivity—a complementary method of estimating information processing. We found that complexity in the BOLD signal exhibited different patterns of complexity from white, pink, and red noise and that neural complexity was differentially expressed between resting-state networks, including the default mode, cingulo-opercular, left and right frontoparietal networks. Lastly, neural complexity across all networks was negatively associated with functional connectivity at fine scales, but was positively associated with functional connectivity at coarse scales. The present study is the first to characterize neural complexity in BOLD signals at a high temporal resolution and across different networks and might help clarify the inconsistencies between neural complexity and functional connectivity, thus informing the mechanisms underlying neural complexity. PMID:24959130

Energy-efficient neural information processing in individual neurons and neuronal networks.

PubMed

Yu, Lianchun; Yu, Yuguo

2017-11-01

Brains are composed of networks of an enormous number of neurons interconnected with synapses. Neural information is carried by the electrical signals within neurons and the chemical signals among neurons. Generating these electrical and chemical signals is metabolically expensive. The fundamental issue raised here is whether brains have evolved efficient ways of developing an energy-efficient neural code from the molecular level to the circuit level. Here, we summarize the factors and biophysical mechanisms that could contribute to the energy-efficient neural code for processing input signals. The factors range from ion channel kinetics, body temperature, axonal propagation of action potentials, low-probability release of synaptic neurotransmitters, optimal input and noise, the size of neurons and neuronal clusters, excitation/inhibition balance, coding strategy, cortical wiring, and the organization of functional connectivity. Both experimental and computational evidence suggests that neural systems may use these factors to maximize the efficiency of energy consumption in processing neural signals. Studies indicate that efficient energy utilization may be universal in neuronal systems as an evolutionary consequence of the pressure of limited energy. As a result, neuronal connections may be wired in a highly economical manner to lower energy costs and space. Individual neurons within a network may encode independent stimulus components to allow a minimal number of neurons to represent whole stimulus characteristics efficiently. This basic principle may fundamentally change our view of how billions of neurons organize themselves into complex circuits to operate and generate the most powerful intelligent cognition in nature. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Monoglyceride lipase as a drug target: At the crossroads of arachidonic acid metabolism and endocannabinoid signaling.

PubMed

Grabner, Gernot F; Zimmermann, Robert; Schicho, Rudolf; Taschler, Ulrike

2017-07-01

Monoglyerides (MGs) are short-lived, intermediary lipids deriving from the degradation of phospho- and neutral lipids, and monoglyceride lipase (MGL), also designated as monoacylglycerol lipase (MAGL), is the major enzyme catalyzing the hydrolysis of MGs into glycerol and fatty acids. This distinct function enables MGL to regulate a number of physiological and pathophysiological processes since both MGs and fatty acids can act as signaling lipids or precursors thereof. The most prominent MG species acting as signaling lipid is 2-arachidonoyl glycerol (2-AG) which is the most abundant endogenous agonist of cannabinoid receptors in the body. Importantly, recent observations demonstrate that 2-AG represents a quantitatively important source for arachidonic acid, the precursor of prostaglandins and other inflammatory mediators. Accordingly, MGL-mediated 2-AG degradation affects lipid signaling by cannabinoid receptor-dependent and independent mechanisms. Recent genetic and pharmacological studies gave important insights into MGL's role in (patho-)physiological processes, and the enzyme is now considered as a promising drug target for a number of disorders including cancer, neurodegenerative and inflammatory diseases. This review summarizes the basics of MG (2-AG) metabolism and provides an overview on the therapeutic potential of MGL. Copyright © 2017 Elsevier Inc. All rights reserved.

Field-quadrature and photon-number correlations produced by parametric processes.

PubMed

McKinstrie, C J; Karlsson, M; Tong, Z

2010-09-13

In a previous paper [Opt. Express 13, 4986 (2005)], formulas were derived for the field-quadrature and photon-number variances produced by multiple-mode parametric processes. In this paper, formulas are derived for the quadrature and number correlations. The number formulas are used to analyze the properties of basic devices, such as two-mode amplifiers, attenuators and frequency convertors, and composite systems made from these devices, such as cascaded parametric amplifiers and communication links. Amplifiers generate idlers that are correlated with the amplified signals, or correlate pre-existing pairs of modes, whereas attenuators decorrelate pre-existing modes. Both types of device modify the signal-to-noise ratios (SNRs) of the modes on which they act. Amplifiers decrease or increase the mode SNRs, depending on whether they are operated in phase-insensitive (PI) or phase-sensitive (PS) manners, respectively, whereas attenuators always decrease these SNRs. Two-mode PS links are sequences of transmission fibers (attenuators) followed by two-mode PS amplifiers. Not only do these PS links have noise figures that are 6-dB lower than those of the corresponding PI links, they also produce idlers that are (almost) completely correlated with the signals. By detecting the signals and idlers, one can eliminate the effects of electronic noise in the detectors.

Sodium signaling and astrocyte energy metabolism.

PubMed

Chatton, Jean-Yves; Magistretti, Pierre J; Barros, L Felipe

2016-10-01

The Na(+) gradient across the plasma membrane is constantly exploited by astrocytes as a secondary energy source to regulate the intracellular and extracellular milieu, and discard waste products. One of the most prominent roles of astrocytes in the brain is the Na(+) -dependent clearance of glutamate released by neurons during synaptic transmission. The intracellular Na(+) load collectively generated by these processes converges at the Na,K-ATPase pump, responsible for Na(+) extrusion from the cell, which is achieved at the expense of cellular ATP. These processes represent pivotal mechanisms enabling astrocytes to increase the local availability of metabolic substrates in response to neuronal activity. This review presents basic principles linking the intracellular handling of Na(+) following activity-related transmembrane fluxes in astrocytes and the energy metabolic pathways involved. We propose a role of Na(+) as an energy currency and as a mediator of metabolic signals in the context of neuron-glia interactions. We further discuss the possible impact of the astrocytic syncytium for the distribution and coordination of the metabolic response, and the compartmentation of these processes in cellular microdomains and subcellular organelles. Finally, we illustrate future avenues of investigation into signaling mechanisms aimed at bridging the gap between Na(+) and the metabolic machinery. GLIA 2016;64:1667-1676. © 2016 Wiley Periodicals, Inc.

Demodulator for binary-phase modulated signals having a variable clock rate

NASA Technical Reports Server (NTRS)

Wu, Ta Tzu (Inventor)

1976-01-01

Method and apparatus for demodulating binary-phase modulated signals recorded on a magnetic stripe on a card as the card is manually inserted into a card reader. Magnetic transitions are sensed as the card is read and the time interval between immediately preceeding basic transitions determines the duration of a data sampling pulse which detects the presence or absence of an intermediate transition pulse indicative of two respective logic states. The duration of the data sampling pulse is approximately 75 percent of the preceeding interval between basic transitions to permit tracking succeeding time differences in basic transition intervals of up to approximately 25 percent.

Root gravitropism: an experimental tool to investigate basic cellular and molecular processes underlying mechanosensing and signal transmission in plants

NASA Technical Reports Server (NTRS)

Boonsirichai, K.; Guan, C.; Chen, R.; Masson, P. H.

2002-01-01

The ability of plant organs to use gravity as a guide for growth, named gravitropism, has been recognized for over two centuries. This growth response to the environment contributes significantly to the upward growth of shoots and the downward growth of roots commonly observed throughout the plant kingdom. Root gravitropism has received a great deal of attention because there is a physical separation between the primary site for gravity sensing, located in the root cap, and the site of differential growth response, located in the elongation zones (EZs). Hence, this system allows identification and characterization of different phases of gravitropism, including gravity perception, signal transduction, signal transmission, and curvature response. Recent studies support some aspects of an old model for gravity sensing, which postulates that root-cap columellar amyloplasts constitute the susceptors for gravity perception. Such studies have also allowed the identification of several molecules that appear to function as second messengers in gravity signal transduction and of potential signal transducers. Auxin has been implicated as a probable component of the signal that carries the gravitropic information between the gravity-sensing cap and the gravity-responding EZs. This has allowed the identification and characterization of important molecular processes underlying auxin transport and response in plants. New molecular models can be elaborated to explain how the gravity signal transduction pathway might regulate the polarity of auxin transport in roots. Further studies are required to test these models, as well as to study the molecular mechanisms underlying a poorly characterized phase of gravitropism that is independent of an auxin gradient.

Organic membrane photonic integrated circuits (OMPICs).

PubMed

Amemiya, Tomohiro; Kanazawa, Toru; Hiratani, Takuo; Inoue, Daisuke; Gu, Zhichen; Yamasaki, Satoshi; Urakami, Tatsuhiro; Arai, Shigehisa

2017-08-07

We propose the concept of organic membrane photonic integrated circuits (OMPICs), which incorporate various functions needed for optical signal processing into a flexible organic membrane. We describe the structure of several devices used within the proposed OMPICs (e.g., transmission lines, I/O couplers, phase shifters, photodetectors, modulators), and theoretically investigate their characteristics. We then present a method of fabricating the photonic devices monolithically in an organic membrane and demonstrate the operation of transmission lines and I/O couplers, the most basic elements of OMPICs.

47 CFR 76.1803 - Signal leakage monitoring.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Signal leakage monitoring. 76.1803 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Reports and Filings § 76.1803 Signal leakage monitoring. MVPDs... of the method by which compliance with basic signal leakage criteria is achieved and the method of...

47 CFR 76.1803 - Signal leakage monitoring.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Signal leakage monitoring. 76.1803 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Reports and Filings § 76.1803 Signal leakage monitoring. MVPDs... of the method by which compliance with basic signal leakage criteria is achieved and the method of...

47 CFR 76.1803 - Signal leakage monitoring.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 4 2013-10-01 2013-10-01 false Signal leakage monitoring. 76.1803 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Reports and Filings § 76.1803 Signal leakage monitoring. MVPDs... of the method by which compliance with basic signal leakage criteria is achieved and the method of...

47 CFR 76.1803 - Signal leakage monitoring.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 4 2014-10-01 2014-10-01 false Signal leakage monitoring. 76.1803 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Reports and Filings § 76.1803 Signal leakage monitoring. MVPDs... of the method by which compliance with basic signal leakage criteria is achieved and the method of...

47 CFR 76.1803 - Signal leakage monitoring.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 4 2012-10-01 2012-10-01 false Signal leakage monitoring. 76.1803 Section 76... MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Reports and Filings § 76.1803 Signal leakage monitoring. MVPDs... of the method by which compliance with basic signal leakage criteria is achieved and the method of...

Redox signaling in skeletal muscle: role of aging and exercise.

PubMed

Ji, Li Li

2015-12-01

Skeletal muscle contraction is associated with the production of ROS due to altered O2 distribution and flux in the cell. Despite a highly efficient antioxidant defense, a small surplus of ROS, such as hydrogen peroxide and nitric oxide, may serve as signaling molecules to stimulate cellular adaptation to reach new homeostasis largely due to the activation of redox-sensitive signaling pathways. Recent research has highlighted the important role of NF-κB, MAPK, and peroxisome proliferator-activated receptor-γ coactivator-1α, along with other newly discovered signaling pathways, in some of the most vital biological functions, such as mitochondrial biogenesis, antioxidant defense, inflammation, protein turnover, apoptosis, and autophagy. There is evidence that the inability of the cell to maintain proper redox signaling underlies some basic mechanisms of biological aging, during which inflammatory and catabolic pathways eventually predominate. Physical exercise has been shown to activate various redox signaling pathways that control the adaptation and remodeling process. Although this stimulatory effect of exercise declines with aging, it is not completed abolished. Thus, aged people can still benefit from regular physical activity in the appropriate forms and at proper intensity to preserve muscle function. Copyright © 2015 The American Physiological Society.

Search for geo-neutrinos and rare nuclear processes with Borexino

NASA Astrophysics Data System (ADS)

Caminata, Alessio; Davini, Stefano; di Noto, Lea; Pallavicini, Marco; Testera, Gemma; Zavatarelli, Sandra

2018-03-01

Borexino was designed to measure solar neutrinos in the MeV or sub-MeV energy range. The unprecedented radiopurity of the detector has allowed the detection of geo-neutrinos and the determination of competitive limits on the rate of rare or forbidden processes. In this paper, we review the basic principle of neutrinos and antineutrinos detection in Borexino and we describe the results of the geo-neutrinos measurements and their implications. Then we summarize the search for Borexino events correlated with gamma ray bursts and for axion induced signals, and the limits achieved on Pauli forbidden transitions and on the electron charge conservation.

Signals and circuits in the purkinje neuron.

PubMed

Abrams, Zéev R; Zhang, Xiang

2011-01-01

Purkinje neurons (PN) in the cerebellum have over 100,000 inputs organized in an orthogonal geometry, and a single output channel. As the sole output of the cerebellar cortex layer, their complex firing pattern has been associated with motor control and learning. As such they have been extensively modeled and measured using tools ranging from electrophysiology and neuroanatomy, to dynamic systems and artificial intelligence methods. However, there is an alternative approach to analyze and describe the neuronal output of these cells using concepts from electrical engineering, particularly signal processing and digital/analog circuits. By viewing the PN as an unknown circuit to be reverse-engineered, we can use the tools that provide the foundations of today's integrated circuits and communication systems to analyze the Purkinje system at the circuit level. We use Fourier transforms to analyze and isolate the inherent frequency modes in the PN and define three unique frequency ranges associated with the cells' output. Comparing the PN to a signal generator that can be externally modulated adds an entire level of complexity to the functional role of these neurons both in terms of data analysis and information processing, relying on Fourier analysis methods in place of statistical ones. We also re-describe some of the recent literature in the field, using the nomenclature of signal processing. Furthermore, by comparing the experimental data of the past decade with basic electronic circuitry, we can resolve the outstanding controversy in the field, by recognizing that the PN can act as a multivibrator circuit.

Prosthetic EMG control enhancement through the application of man-machine principles

NASA Technical Reports Server (NTRS)

Simcox, W. A.

1977-01-01

An area in medicine that appears suitable to man-machine principles is rehabilitation research, particularly when the motor aspects of the body are involved. If one considers the limb, whether functional or not, as the machine, the brain as the controller and the neuromuscular system as the man-machine interface, the human body is reduced to a man-machine system that can benefit from the principles behind such systems. The area of rehabilitation that this paper deals with is that of an arm amputee and his prosthetic device. Reducing this area to its man-machine basics, the problem becomes one of attaining natural multiaxis prosthetic control using Electromyographic activity (EMG) as the means of communication between man and prothesis. In order to use EMG as the communication channel it must be amplified and processed to yield a high information signal suitable for control. The most common processing scheme employed is termed Mean Value Processing. This technique for extracting the useful EMG signal consists of a differential to single ended conversion to the surface activity followed by a rectification and smoothing.

Generalization of the Poincare sphere to process 2D displacement signals

NASA Astrophysics Data System (ADS)

Sciammarella, Cesar A.; Lamberti, Luciano

2017-06-01

Traditionally the multiple phase method has been considered as an essential tool for phase information recovery. The in-quadrature phase method that theoretically is an alternative pathway to achieve the same goal failed in actual applications. The authors in a previous paper dealing with 1D signals have shown that properly implemented the in-quadrature method yields phase values with the same accuracy than the multiple phase method. The present paper extends the methodology developed in 1D to 2D. This extension is not a straight forward process and requires the introduction of a number of additional concepts and developments. The concept of monogenic function provides the necessary tools required for the extension process. The monogenic function has a graphic representation through the Poincare sphere familiar in the field of Photoelasticity and through the developments introduced in this paper connected to the analysis of displacement fringe patterns. The paper is illustrated with examples of application that show that multiple phases method and the in-quadrature are two aspects of the same basic theoretical model.

Modifying Yeast Tolerance to Inhibitory Conditions of Ethanol Production Processes

PubMed Central

Caspeta, Luis; Castillo, Tania; Nielsen, Jens

2015-01-01

Saccharomyces cerevisiae strains having a broad range of substrate utilization, rapid substrate consumption, and conversion to ethanol, as well as good tolerance to inhibitory conditions are ideal for cost-competitive ethanol production from lignocellulose. A major drawback to directly design S. cerevisiae tolerance to inhibitory conditions of lignocellulosic ethanol production processes is the lack of knowledge about basic aspects of its cellular signaling network in response to stress. Here, we highlight the inhibitory conditions found in ethanol production processes, the targeted cellular functions, the key contributions of integrated -omics analysis to reveal cellular stress responses according to these inhibitors, and current status on design-based engineering of tolerant and efficient S. cerevisiae strains for ethanol production from lignocellulose. PMID:26618154

Synthetic signal sequences that enable efficient secretory protein production in the yeast Kluyveromyces marxianus.

PubMed

Yarimizu, Tohru; Nakamura, Mikiko; Hoshida, Hisashi; Akada, Rinji

2015-02-14

Targeting of cellular proteins to the extracellular environment is directed by a secretory signal sequence located at the N-terminus of a secretory protein. These signal sequences usually contain an N-terminal basic amino acid followed by a stretch containing hydrophobic residues, although no consensus signal sequence has been identified. In this study, simple modeling of signal sequences was attempted using Gaussia princeps secretory luciferase (GLuc) in the yeast Kluyveromyces marxianus, which allowed comprehensive recombinant gene construction to substitute synthetic signal sequences. Mutational analysis of the GLuc signal sequence revealed that the GLuc hydrophobic peptide length was lower limit for effective secretion and that the N-terminal basic residue was indispensable. Deletion of the 16th Glu caused enhanced levels of secreted protein, suggesting that this hydrophilic residue defined the boundary of a hydrophobic peptide stretch. Consequently, we redesigned this domain as a repeat of a single hydrophobic amino acid between the N-terminal Lys and C-terminal Glu. Stretches consisting of Phe, Leu, Ile, or Met were effective for secretion but the number of residues affected secretory activity. A stretch containing sixteen consecutive methionine residues (M16) showed the highest activity; the M16 sequence was therefore utilized for the secretory production of human leukemia inhibitory factor protein in yeast, resulting in enhanced secreted protein yield. We present a new concept for the provision of secretory signal sequence ability in the yeast K. marxianus, determined by the number of residues of a single hydrophobic residue located between N-terminal basic and C-terminal acidic amino acid boundaries.

Role of the FGF and MEK signaling pathway in the ascidian embryo.

PubMed

Kim, G J; Nishida, H

2001-10-01

In the ascidian embryo, a fibroblast growth factor (FGF)-like signal from presumptive endoderm blastomeres between the 32-cell and early 64-cell stages induces the formation of notochord and mesenchyme cells. However, it has not been known whether endogenous FGF signaling is involved in the process. Here it is shown that 64-cell embryos exhibit a marked increase in endogenous extracellular signal-regulated kinase (ERK/MAPK) activity. The increase in ERK activity was reduced by treatment with an FGF receptor 1 inhibitor, SU5402, and a MEK (ERK kinase/MAPKK) inhibitor, U0126. Both drugs blocked the formation of notochord and mesenchyme when embryos were treated at the 32-cell stage, but not at the 2- or 110-cell stages. The dominant-negative form of Ras also suppressed notochord and mesenchyme formation. Both inhibitors suppressed induction by exogenous basic FGF. These results suggest that the FGF signaling cascade is indeed necessary for the formation of notochord and mesenchyme cells during ascidian embryogenesis. It is also shown that FGF signaling is required for formation of the secondary notochord, secondary muscle and neural tissues, and at least ERK activity is necessary for the formation of trunk lateral cells and posterior endoderm. Therefore, FGF and MEK signaling are required for the formation of various tissues in the ascidian embryo.

Developing a reliable signal wire attachment method for rail.

DOT National Transportation Integrated Search

2014-11-01

The goal of this project was to develop a better attachment method for rail signal wires to improve the reliability of signaling : systems. EWI conducted basic research into the failure mode of current attachment methods and developed and tested a ne...

[How we smell and what it means to us: basic principles of the sense of smell].

PubMed

Manzini, I; Frasnelli, J; Croy, I

2014-12-01

The origins of the sense of smell lie in the perception of environmental molecules and go back to unicellular organisms such as bacteria. Odors transmit a multitude of information about the chemical composition of our environment. The sense of smell helps people and animals with orientation in space, warns of potential threats, influences the choice of sexual partners, regulates food intake and influences feelings and social behavior in general. The perception of odors begins in sensory neurons residing in the olfactory epithelium that express G protein-coupled receptors, the so-called olfactory receptors. The binding of odor molecules to olfactory receptors initiates a signal transduction cascade that converts olfactory stimuli into electrical signals. These signals are then transmitted to the olfactory bulb, the first relay center in the olfactory pathway, via the axons of the sensory neurons. The olfactory information is processed in the bulb and then transferred to higher olfactory centers via axons of mitral cells, the bulbar projection neurons. This review describes the mechanisms involved in peripheral detection of odorants, outlines the further processing of olfactory information in higher olfactory centers and finally gives an overview of the overall significance of the ability to smell.

Multichannel Phase and Power Detector

NASA Technical Reports Server (NTRS)

Li, Samuel; Lux, James; McMaster, Robert; Boas, Amy

2006-01-01

An electronic signal-processing system determines the phases of input signals arriving in multiple channels, relative to the phase of a reference signal with which the input signals are known to be coherent in both phase and frequency. The system also gives an estimate of the power levels of the input signals. A prototype of the system has four input channels that handle signals at a frequency of 9.5 MHz, but the basic principles of design and operation are extensible to other signal frequencies and greater numbers of channels. The prototype system consists mostly of three parts: An analog-to-digital-converter (ADC) board, which coherently digitizes the input signals in synchronism with the reference signal and performs some simple processing; A digital signal processor (DSP) in the form of a field-programmable gate array (FPGA) board, which performs most of the phase- and power-measurement computations on the digital samples generated by the ADC board; and A carrier board, which allows a personal computer to retrieve the phase and power data. The DSP contains four independent phase-only tracking loops, each of which tracks the phase of one of the preprocessed input signals relative to that of the reference signal (see figure). The phase values computed by these loops are averaged over intervals, the length of which is chosen to obtain output from the DSP at a desired rate. In addition, a simple sum of squares is computed for each channel as an estimate of the power of the signal in that channel. The relative phases and the power level estimates computed by the DSP could be used for diverse purposes in different settings. For example, if the input signals come from different elements of a phased-array antenna, the phases could be used as indications of the direction of arrival of a received signal and/or as feedback for electronic or mechanical beam steering. The power levels could be used as feedback for automatic gain control in preprocessing of incoming signals. For another example, the system could be used to measure the phases and power levels of outputs of multiple power amplifiers to enable adjustment of the amplifiers for optimal power combining.

Programmable rate modem utilizing digital signal processing techniques

NASA Technical Reports Server (NTRS)

Bunya, George K.; Wallace, Robert L.

1989-01-01

The engineering development study to follow was written to address the need for a Programmable Rate Digital Satellite Modem capable of supporting both burst and continuous transmission modes with either binary phase shift keying (BPSK) or quadrature phase shift keying (QPSK) modulation. The preferred implementation technique is an all digital one which utilizes as much digital signal processing (DSP) as possible. Here design tradeoffs in each portion of the modulator and demodulator subsystem are outlined, and viable circuit approaches which are easily repeatable, have low implementation losses and have low production costs are identified. The research involved for this study was divided into nine technical papers, each addressing a significant region of concern in a variable rate modem design. Trivial portions and basic support logic designs surrounding the nine major modem blocks were omitted. In brief, the nine topic areas were: (1) Transmit Data Filtering; (2) Transmit Clock Generation; (3) Carrier Synthesizer; (4) Receive AGC; (5) Receive Data Filtering; (6) RF Oscillator Phase Noise; (7) Receive Carrier Selectivity; (8) Carrier Recovery; and (9) Timing Recovery.

Design and evaluation of online arithmetic for signal processing applications on FPGAs

NASA Astrophysics Data System (ADS)

Galli, Reto; Tenca, Alexandre F.

2001-11-01

This paper shows the design and the evaluation of on-line arithmetic modules for the most common operators used in DSP applications, using FPGAs as the target technology. The designs are highly optimized for the target technology and the common range of precision in DSP. The results are based on experimental data collected using CAD tools. All designs are synthesized for the same type of devices (Xilinx XC4000) for comparison, avoiding rough estimates of the system performance, and generating a more reliable and detailed comparison of on-line signal processing solutions with other state of the art approaches, such as distributed arithmetic. We show that on-line designs have a hard stand for basic DSP applications that use only addition and multiplication. However, we also show that on-line designs are able to overtake other approaches as the applications become more sophisticated, e.g. when data dependencies exist, or when non constant multiplicands restrict the use of other approaches.

High resolution ultrasonic spectroscopy system for nondestructive evaluation

NASA Technical Reports Server (NTRS)

Chen, C. H.

1991-01-01

With increased demand for high resolution ultrasonic evaluation, computer based systems or work stations become essential. The ultrasonic spectroscopy method of nondestructive evaluation (NDE) was used to develop a high resolution ultrasonic inspection system supported by modern signal processing, pattern recognition, and neural network technologies. The basic system which was completed consists of a 386/20 MHz PC (IBM AT compatible), a pulser/receiver, a digital oscilloscope with serial and parallel communications to the computer, an immersion tank with motor control of X-Y axis movement, and the supporting software package, IUNDE, for interactive ultrasonic evaluation. Although the hardware components are commercially available, the software development is entirely original. By integrating signal processing, pattern recognition, maximum entropy spectral analysis, and artificial neural network functions into the system, many NDE tasks can be performed. The high resolution graphics capability provides visualization of complex NDE problems. The phase 3 efforts involve intensive marketing of the software package and collaborative work with industrial sectors.

Unique membrane properties and enhanced signal processing in human neocortical neurons.

PubMed

Eyal, Guy; Verhoog, Matthijs B; Testa-Silva, Guilherme; Deitcher, Yair; Lodder, Johannes C; Benavides-Piccione, Ruth; Morales, Juan; DeFelipe, Javier; de Kock, Christiaan Pj; Mansvelder, Huibert D; Segev, Idan

2016-10-06

The advanced cognitive capabilities of the human brain are often attributed to our recently evolved neocortex. However, it is not known whether the basic building blocks of the human neocortex, the pyramidal neurons, possess unique biophysical properties that might impact on cortical computations. Here we show that layer 2/3 pyramidal neurons from human temporal cortex (HL2/3 PCs) have a specific membrane capacitance ( C m ) of ~0.5 µF/cm 2 , half of the commonly accepted 'universal' value (~1 µF/cm 2 ) for biological membranes. This finding was predicted by fitting in vitro voltage transients to theoretical transients then validated by direct measurement of C m in nucleated patch experiments. Models of 3D reconstructed HL2/3 PCs demonstrated that such low C m value significantly enhances both synaptic charge-transfer from dendrites to soma and spike propagation along the axon. This is the first demonstration that human cortical neurons have distinctive membrane properties, suggesting important implications for signal processing in human neocortex.

Helicopter force-feel and stability augmentation system with parallel servo-actuator

NASA Technical Reports Server (NTRS)

Hoh, Roger H. (Inventor)

2006-01-01

A force-feel system is implemented by mechanically coupling a servo-actuator to and in parallel with a flight control system. The servo-actuator consists of an electric motor, a gearing device, and a clutch. A commanded cockpit-flight-controller position is achieved by pilot actuation of a trim-switch. The position of the cockpit-flight-controller is compared with the commanded position to form a first error which is processed by a shaping function to correlate the first error with a commanded force at the cockpit-flight-controller. The commanded force on the cockpit-flight-controller provides centering forces and improved control feel for the pilot. In an embodiment, the force-feel system is used as the basic element of stability augmentation system (SAS). The SAS provides a stabilization signal that is compared with the commanded position to form a second error signal. The first error is summed with the second error for processing by the shaping function.

Advances in thermographic signal reconstruction

NASA Astrophysics Data System (ADS)

Shepard, Steven M.; Frendberg Beemer, Maria

2015-05-01

Since its introduction in 2001, the Thermographic Signal Reconstruction (TSR) method has emerged as one of the most widely used methods for enhancement and analysis of thermographic sequences, with applications extending beyond industrial NDT into biomedical research, art restoration and botany. The basic TSR process, in which a noise reduced replica of each pixel time history is created, yields improvement over unprocessed image data that is sufficient for many applications. However, examination of the resulting logarithmic time derivatives of each TSR pixel replica provides significant insight into the physical mechanisms underlying the active thermography process. The deterministic and invariant properties of the derivatives have enabled the successful implementation of automated defect recognition and measurement systems. Unlike most approaches to analysis of thermography data, TSR does not depend on flawbackground contrast, so that it can also be applied to characterization and measurement of thermal properties of flaw-free samples. We present a summary of recent advances in TSR, a review of the underlying theory and examples of its implementation.

Statistical generation of training sets for measuring NO3(-), NH4(+) and major ions in natural waters using an ion selective electrode array.

PubMed

Mueller, Amy V; Hemond, Harold F

2016-05-18

Knowledge of ionic concentrations in natural waters is essential to understand watershed processes. Inorganic nitrogen, in the form of nitrate and ammonium ions, is a key nutrient as well as a participant in redox, acid-base, and photochemical processes of natural waters, leading to spatiotemporal patterns of ion concentrations at scales as small as meters or hours. Current options for measurement in situ are costly, relying primarily on instruments adapted from laboratory methods (e.g., colorimetric, UV absorption); free-standing and inexpensive ISE sensors for NO3(-) and NH4(+) could be attractive alternatives if interferences from other constituents were overcome. Multi-sensor arrays, coupled with appropriate non-linear signal processing, offer promise in this capacity but have not yet successfully achieved signal separation for NO3(-) and NH4(+)in situ at naturally occurring levels in unprocessed water samples. A novel signal processor, underpinned by an appropriate sensor array, is proposed that overcomes previous limitations by explicitly integrating basic chemical constraints (e.g., charge balance). This work further presents a rationalized process for the development of such in situ instrumentation for NO3(-) and NH4(+), including a statistical-modeling strategy for instrument design, training/calibration, and validation. Statistical analysis reveals that historical concentrations of major ionic constituents in natural waters across New England strongly covary and are multi-modal. This informs the design of a statistically appropriate training set, suggesting that the strong covariance of constituents across environmental samples can be exploited through appropriate signal processing mechanisms to further improve estimates of minor constituents. Two artificial neural network architectures, one expanded to incorporate knowledge of basic chemical constraints, were tested to process outputs of a multi-sensor array, trained using datasets of varying degrees of statistical representativeness to natural water samples. The accuracy of ANN results improves monotonically with the statistical representativeness of the training set (error decreases by ∼5×), while the expanded neural network architecture contributes a further factor of 2-3.5 decrease in error when trained with the most representative sample set. Results using the most statistically accurate set of training samples (which retain environmentally relevant ion concentrations but avoid the potential interference of humic acids) demonstrated accurate, unbiased quantification of nitrate and ammonium at natural environmental levels (±20% down to <10 μM), as well as the major ions Na(+), K(+), Ca(2+), Mg(2+), Cl(-), and SO4(2-), in unprocessed samples. These results show promise for the development of new in situ instrumentation for the support of scientific field work.

Artificial synapse network on inorganic proton conductor for neuromorphic systems.

PubMed

Zhu, Li Qiang; Wan, Chang Jin; Guo, Li Qiang; Shi, Yi; Wan, Qing

2014-01-01

The basic units in our brain are neurons, and each neuron has more than 1,000 synapse connections. Synapse is the basic structure for information transfer in an ever-changing manner, and short-term plasticity allows synapses to perform critical computational functions in neural circuits. Therefore, the major challenge for the hardware implementation of neuromorphic computation is to develop artificial synapse network. Here in-plane lateral-coupled oxide-based artificial synapse network coupled by proton neurotransmitters are self-assembled on glass substrates at room-temperature. A strong lateral modulation is observed due to the proton-related electrical-double-layer effect. Short-term plasticity behaviours, including paired-pulse facilitation, dynamic filtering and spatiotemporally correlated signal processing are mimicked. Such laterally coupled oxide-based protonic/electronic hybrid artificial synapse network proposed here is interesting for building future neuromorphic systems.

Otolith-Canal Convergence in Vestibular Nuclei Neurons

NASA Technical Reports Server (NTRS)

Dickman, J. David

1996-01-01

During manned spaceflight, acute vestibular disturbances often occur, leading to physical duress and a loss of performance. Vestibular adaptation to the weightless environment follows within two to three days yet the mechanisms responsible for the disturbance and subsequent adaptation are still unknown In order to understand vestibular system function in space and normal earth conditions the basic physiological mechanisms of vestibular information co coding must be determined. Information processing regarding head movement and head position with respect to gravity takes place in the vestibular nuclei neurons that receive signals From the semicircular canals and otolith organs in the vestibular labyrinth. These neurons must synthesize the information into a coded output signal that provides for the head and eye movement reflexes as well as the conscious perception of the body in three-dimensional space The current investigation will for the first time. determine how the vestibular nuclei neurons quantitatively synthesize afferent information from the different linear and angular acceleration receptors in the vestibular labyrinths into an integrated output signal. During the second year of funding, progress on the current project has been focused on the anatomical orientation of semicircular canals and the spatial orientation of the innervating afferent responses. This information is necessary in order to understand how vestibular nuclei neurons process the incoming afferent spatial signals particularly with the convergent otolith afferent signals that are also spatially distributed Since information from the vestibular nuclei is presented to different brain regions associated with differing reflexive and sensory functions it is important to understand the computational mechanisms used by vestibular neurons to produce the appropriate output signal.

Optical integrator for optical dark-soliton detection and pulse shaping.

PubMed

Ngo, Nam Quoc

2006-09-10

The design and analysis of an Nth-order optical integrator using the digital filter technique is presented. The optical integrator is synthesized using planar-waveguide technology. It is shown that a first-order optical integrator can be used as an optical dark-soliton detector by converting an optical dark-soliton pulse into an optical bell-shaped pulse for ease of detection. The optical integrators can generate an optical step function, staircase function, and paraboliclike functions from input optical Gaussian pulses. The optical integrators may be potentially used as basic building blocks of all-optical signal processing systems because the time integrals of signals may sometimes be required for further use or analysis. Furthermore, an optical integrator may be used for the shaping of optical pulses or in an optical feedback control system.

Multiscale mechanobiology: computational models for integrating molecules to multicellular systems

PubMed Central

Mak, Michael; Kim, Taeyoon

2015-01-01

Mechanical signals exist throughout the biological landscape. Across all scales, these signals, in the form of force, stiffness, and deformations, are generated and processed, resulting in an active mechanobiological circuit that controls many fundamental aspects of life, from protein unfolding and cytoskeletal remodeling to collective cell motions. The multiple scales and complex feedback involved present a challenge for fully understanding the nature of this circuit, particularly in development and disease in which it has been implicated. Computational models that accurately predict and are based on experimental data enable a means to integrate basic principles and explore fine details of mechanosensing and mechanotransduction in and across all levels of biological systems. Here we review recent advances in these models along with supporting and emerging experimental findings. PMID:26019013

Improving EMG based classification of basic hand movements using EMD.

PubMed

Sapsanis, Christos; Georgoulas, George; Tzes, Anthony; Lymberopoulos, Dimitrios

2013-01-01

This paper presents a pattern recognition approach for the identification of basic hand movements using surface electromyographic (EMG) data. The EMG signal is decomposed using Empirical Mode Decomposition (EMD) into Intrinsic Mode Functions (IMFs) and subsequently a feature extraction stage takes place. Various combinations of feature subsets are tested using a simple linear classifier for the detection task. Our results suggest that the use of EMD can increase the discrimination ability of the conventional feature sets extracted from the raw EMG signal.

Processing Functional Near Infrared Spectroscopy Signal with a Kalman Filter to Assess Working Memory during Simulated Flight.

PubMed

Durantin, Gautier; Scannella, Sébastien; Gateau, Thibault; Delorme, Arnaud; Dehais, Frédéric

2015-01-01

Working memory (WM) is a key executive function for operating aircraft, especially when pilots have to recall series of air traffic control instructions. There is a need to implement tools to monitor WM as its limitation may jeopardize flight safety. An innovative way to address this issue is to adopt a Neuroergonomics approach that merges knowledge and methods from Human Factors, System Engineering, and Neuroscience. A challenge of great importance for Neuroergonomics is to implement efficient brain imaging techniques to measure the brain at work and to design Brain Computer Interfaces (BCI). We used functional near infrared spectroscopy as it has been already successfully tested to measure WM capacity in complex environment with air traffic controllers (ATC), pilots, or unmanned vehicle operators. However, the extraction of relevant features from the raw signal in ecological environment is still a critical issue due to the complexity of implementing real-time signal processing techniques without a priori knowledge. We proposed to implement the Kalman filtering approach, a signal processing technique that is efficient when the dynamics of the signal can be modeled. We based our approach on the Boynton model of hemodynamic response. We conducted a first experiment with nine participants involving a basic WM task to estimate the noise covariances of the Kalman filter. We then conducted a more ecological experiment in our flight simulator with 18 pilots who interacted with ATC instructions (two levels of difficulty). The data was processed with the same Kalman filter settings implemented in the first experiment. This filter was benchmarked with a classical pass-band IIR filter and a Moving Average Convergence Divergence (MACD) filter. Statistical analysis revealed that the Kalman filter was the most efficient to separate the two levels of load, by increasing the observed effect size in prefrontal areas involved in WM. In addition, the use of a Kalman filter increased the performance of the classification of WM levels based on brain signal. The results suggest that Kalman filter is a suitable approach for real-time improvement of near infrared spectroscopy signal in ecological situations and the development of BCI.

Processing Functional Near Infrared Spectroscopy Signal with a Kalman Filter to Assess Working Memory during Simulated Flight

PubMed Central

Durantin, Gautier; Scannella, Sébastien; Gateau, Thibault; Delorme, Arnaud; Dehais, Frédéric

2016-01-01

Working memory (WM) is a key executive function for operating aircraft, especially when pilots have to recall series of air traffic control instructions. There is a need to implement tools to monitor WM as its limitation may jeopardize flight safety. An innovative way to address this issue is to adopt a Neuroergonomics approach that merges knowledge and methods from Human Factors, System Engineering, and Neuroscience. A challenge of great importance for Neuroergonomics is to implement efficient brain imaging techniques to measure the brain at work and to design Brain Computer Interfaces (BCI). We used functional near infrared spectroscopy as it has been already successfully tested to measure WM capacity in complex environment with air traffic controllers (ATC), pilots, or unmanned vehicle operators. However, the extraction of relevant features from the raw signal in ecological environment is still a critical issue due to the complexity of implementing real-time signal processing techniques without a priori knowledge. We proposed to implement the Kalman filtering approach, a signal processing technique that is efficient when the dynamics of the signal can be modeled. We based our approach on the Boynton model of hemodynamic response. We conducted a first experiment with nine participants involving a basic WM task to estimate the noise covariances of the Kalman filter. We then conducted a more ecological experiment in our flight simulator with 18 pilots who interacted with ATC instructions (two levels of difficulty). The data was processed with the same Kalman filter settings implemented in the first experiment. This filter was benchmarked with a classical pass-band IIR filter and a Moving Average Convergence Divergence (MACD) filter. Statistical analysis revealed that the Kalman filter was the most efficient to separate the two levels of load, by increasing the observed effect size in prefrontal areas involved in WM. In addition, the use of a Kalman filter increased the performance of the classification of WM levels based on brain signal. The results suggest that Kalman filter is a suitable approach for real-time improvement of near infrared spectroscopy signal in ecological situations and the development of BCI. PMID:26834607

Joint Carrier-Phase Synchronization and LDPC Decoding

NASA Technical Reports Server (NTRS)

Simon, Marvin; Valles, Esteban

2009-01-01

A method has been proposed to increase the degree of synchronization of a radio receiver with the phase of a suppressed carrier signal modulated with a binary- phase-shift-keying (BPSK) or quaternary- phase-shift-keying (QPSK) signal representing a low-density parity-check (LDPC) code. This method is an extended version of the method described in Using LDPC Code Constraints to Aid Recovery of Symbol Timing (NPO-43112), NASA Tech Briefs, Vol. 32, No. 10 (October 2008), page 54. Both methods and the receiver architectures in which they would be implemented belong to a class of timing- recovery methods and corresponding receiver architectures characterized as pilotless in that they do not require transmission and reception of pilot signals. The proposed method calls for the use of what is known in the art as soft decision feedback to remove the modulation from a replica of the incoming signal prior to feeding this replica to a phase-locked loop (PLL) or other carrier-tracking stage in the receiver. Soft decision feedback refers to suitably processed versions of intermediate results of iterative computations involved in the LDPC decoding process. Unlike a related prior method in which hard decision feedback (the final sequence of decoded symbols) is used to remove the modulation, the proposed method does not require estimation of the decoder error probability. In a basic digital implementation of the proposed method, the incoming signal (having carrier phase theta theta (sub c) plus noise would first be converted to inphase (I) and quadrature (Q) baseband signals by mixing it with I and Q signals at the carrier frequency [wc/(2 pi)] generated by a local oscillator. The resulting demodulated signals would be processed through one-symbol-period integrate and- dump filters, the outputs of which would be sampled and held, then multiplied by a soft-decision version of the baseband modulated signal. The resulting I and Q products consist of terms proportional to the cosine and sine of the carrier phase cc as well as correlated noise components. These products would be fed as inputs to a digital PLL that would include a number-controlled oscillator (NCO), which provides an estimate of the carrier phase, theta(sub c).

Telecommunications handbook for transportation professionals : the basics of telecommunications.

DOT National Transportation Integrated Search

2004-08-01

This handbook was created to provide individuals responsible for managing and implementing Traffic : Signal, and Freeway Management programs with an understand of the basic technologies of : telecommunications. The handbook provides a brief look at t...

Parallel heterogeneous architectures for efficient OMP compressive sensing reconstruction

NASA Astrophysics Data System (ADS)

Kulkarni, Amey; Stanislaus, Jerome L.; Mohsenin, Tinoosh

2014-05-01

Compressive Sensing (CS) is a novel scheme, in which a signal that is sparse in a known transform domain can be reconstructed using fewer samples. The signal reconstruction techniques are computationally intensive and have sluggish performance, which make them impractical for real-time processing applications . The paper presents novel architectures for Orthogonal Matching Pursuit algorithm, one of the popular CS reconstruction algorithms. We show the implementation results of proposed architectures on FPGA, ASIC and on a custom many-core platform. For FPGA and ASIC implementation, a novel thresholding method is used to reduce the processing time for the optimization problem by at least 25%. Whereas, for the custom many-core platform, efficient parallelization techniques are applied, to reconstruct signals with variant signal lengths of N and sparsity of m. The algorithm is divided into three kernels. Each kernel is parallelized to reduce execution time, whereas efficient reuse of the matrix operators allows us to reduce area. Matrix operations are efficiently paralellized by taking advantage of blocked algorithms. For demonstration purpose, all architectures reconstruct a 256-length signal with maximum sparsity of 8 using 64 measurements. Implementation on Xilinx Virtex-5 FPGA, requires 27.14 μs to reconstruct the signal using basic OMP. Whereas, with thresholding method it requires 18 μs. ASIC implementation reconstructs the signal in 13 μs. However, our custom many-core, operating at 1.18 GHz, takes 18.28 μs to complete. Our results show that compared to the previous published work of the same algorithm and matrix size, proposed architectures for FPGA and ASIC implementations perform 1.3x and 1.8x respectively faster. Also, the proposed many-core implementation performs 3000x faster than the CPU and 2000x faster than the GPU.

Satellite single-axis attitude determination based on Automatic Dependent Surveillance - Broadcast signals

NASA Astrophysics Data System (ADS)

Zhou, Kaixing; Sun, Xiucong; Huang, Hai; Wang, Xinsheng; Ren, Guangwei

2017-10-01

The space-based Automatic Dependent Surveillance - Broadcast (ADS-B) is a new technology for air traffic management. The satellite equipped with spaceborne ADS-B system receives the broadcast signals from aircraft and transfers the message to ground stations, so as to extend the coverage area of terrestrial-based ADS-B. In this work, a novel satellite single-axis attitude determination solution based on the ADS-B receiving system is proposed. This solution utilizes the signal-to-noise ratio (SNR) measurement of the broadcast signals from aircraft to determine the boresight orientation of the ADS-B receiving antenna fixed on the satellite. The basic principle of this solution is described. The feasibility study of this new attitude determination solution is implemented, including the link budget and the access analysis. On this basis, the nonlinear least squares estimation based on the Levenberg-Marquardt method is applied to estimate the single-axis orientation. A full digital simulation has been carried out to verify the effectiveness and performance of this solution. Finally, the corresponding results are processed and presented minutely.

Transient-Switch-Signal Suppressor

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr.

1995-01-01

Circuit delays transmission of switch-opening or switch-closing signal until after preset suppression time. Used to prevent transmission of undesired momentary switch signal. Basic mode of operation simple. Beginning of switch signal initiates timing sequence. If switch signal persists after preset suppression time, circuit transmits switch signal to external circuitry. If switch signal no longer present after suppression time, switch signal deemed transient, and circuit does not pass signal on to external circuitry, as though no transient switch signal. Suppression time preset at value large enough to allow for damping of underlying pressure wave or other mechanical transient.

Engineering self-contained DNA circuit for proximity recognition and localized signal amplification of target biomolecules

PubMed Central

Ang, Yan Shan; Yung, Lin-Yue Lanry

2014-01-01

Biomolecular interactions have important cellular implications, however, a simple method for the sensing of such proximal events is lacking in the current molecular toolbox. We designed a dynamic DNA circuit capable of recognizing targets in close proximity to initiate a pre-programmed signal transduction process resulting in localized signal amplification. The entire circuit was engineered to be self-contained, i.e. it can self-assemble onto individual target molecules autonomously and form localized signal with minimal cross-talk. α-thrombin was used as a model protein to evaluate the performance of the individual modules and the overall circuit for proximity interaction under physiologically relevant buffer condition. The circuit achieved good selectivity in presence of non-specific protein and interfering serum matrix and successfully detected for physiologically relevant α-thrombin concentration (50 nM–5 μM) in a single mixing step without any further washing. The formation of localized signal at the interaction site can be enhanced kinetically through the control of temperature and probe concentration. This work provides a basic general framework from which other circuit modules can be adapted for the sensing of other biomolecular or cellular interaction of interest. PMID:25056307

Quantitative prediction of perceptual decisions during near-threshold fear detection

NASA Astrophysics Data System (ADS)

Pessoa, Luiz; Padmala, Srikanth

2005-04-01

A fundamental goal of cognitive neuroscience is to explain how mental decisions originate from basic neural mechanisms. The goal of the present study was to investigate the neural correlates of perceptual decisions in the context of emotional perception. To probe this question, we investigated how fluctuations in functional MRI (fMRI) signals were correlated with behavioral choice during a near-threshold fear detection task. fMRI signals predicted behavioral choice independently of stimulus properties and task accuracy in a network of brain regions linked to emotional processing: posterior cingulate cortex, medial prefrontal cortex, right inferior frontal gyrus, and left insula. We quantified the link between fMRI signals and behavioral choice in a whole-brain analysis by determining choice probabilities by means of signal-detection theory methods. Our results demonstrate that voxel-wise fMRI signals can reliably predict behavioral choice in a quantitative fashion (choice probabilities ranged from 0.63 to 0.78) at levels comparable to neuronal data. We suggest that the conscious decision that a fearful face has been seen is represented across a network of interconnected brain regions that prepare the organism to appropriately handle emotionally challenging stimuli and that regulate the associated emotional response. decision making | emotion | functional MRI

Towards bioelectronic logic (Conference Presentation)

NASA Astrophysics Data System (ADS)

Meredith, Paul; Mostert, Bernard; Sheliakina, Margarita; Carrad, Damon J.; Micolich, Adam P.

2016-09-01

One of the critical tasks in realising a bioelectronic interface is the transduction of ion and electron signals at high fidelity, and with appropriate speed, bandwidth and signal-to-noise ratio [1]. This is a challenging task considering ions and electrons (or holes) have drastically different physics. For example, even the lightest ions (protons) have mobilities much smaller than electrons in the best semiconductors, effective masses are quite different, and at the most basic level, ions are `classical' entities and electrons `quantum mechanical'. These considerations dictate materials and device strategies for bioelectronic interfaces alongside practical aspects such as integration and biocompatibility [2]. In my talk I will detail these `differences in physics' that are pertinent to the ion-electron transduction challenge. From this analysis, I will summarise the basic categories of device architecture that are possibilities for transducing elements and give recent examples of their realisation. Ultimately, transducing elements need to be combined to create `bioelectronic logic' capable of signal processing at the interface level. In this regard, I will extend the discussion past the single element concept, and discuss our recent progress in delivering all-solids-state logic circuits based upon transducing interfaces. [1] "Ion bipolar junction transistors", K. Tybrandt, K.C. Larsson, A. Richter-Dahlfors and M. Berggren, Proc. Natl Acad. Sci., 107, 9929 (2010). [2] "Electronic and optoelectronic materials and devices inspired by nature", P Meredith, C.J. Bettinger, M. Irimia-Vladu, A.B. Mostert and P.E. Schwenn, Reports on Progress in Physics, 76, 034501 (2013).

Function of Matrix IGF-1 in Coupling Bone Resorption and Formation

PubMed Central

Crane, Janet L.; Cao, Xu

2013-01-01

Balancing bone resorption and formation is the quintessential component for the prevention of osteoporosis. Signals that determine the recruitment, replication, differentiation, function, and apoptosis of osteoblasts and osteoclasts direct bone remodeling and determine whether bone tissue is gained, lost, or balanced. Therefore understanding the signaling pathways involved in the coupling process will help develop further targets for osteoporosis therapy, by blocking bone resorption or enhancing bone formation in a space and time dependent manner. Insulin-like growth factor type 1 (IGF-1) has long been known to play a role in bone strength. It is one of the most abundant substances in the bone matrix, circulates systemically and is secreted locally, and has a direct relationship with bone mineral density. Recent data has helped further our understanding of the direct role of IGF-1 signaling in coupling bone remodeling which will be discussed in this review. The bone marrow microenvironment plays a critical role in the fate of MSCs and HSCs and thus how IGF-1 interacts with other factors in the microenvironment are equally important. While previous clinical trials with IGF-1 administration have been unsuccessful at enhancing bone formation, advances in basic science studies have provided insight into further mechanisms that should be considered for future trials. Additional basic science studies dissecting the regulation and the function of matrix IGF-1 in modeling and remodeling will continue to provide further insight for future directions for anabolic therapies for osteoporosis. PMID:24068256

Function of matrix IGF-1 in coupling bone resorption and formation.

PubMed

Crane, Janet L; Cao, Xu

2014-02-01

Balancing bone resorption and formation is the quintessential component for the prevention of osteoporosis. Signals that determine the recruitment, replication, differentiation, function, and apoptosis of osteoblasts and osteoclasts direct bone remodeling and determine whether bone tissue is gained, lost, or balanced. Therefore, understanding the signaling pathways involved in the coupling process will help develop further targets for osteoporosis therapy, by blocking bone resorption or enhancing bone formation in a space- and time-dependent manner. Insulin-like growth factor type 1 (IGF-1) has long been known to play a role in bone strength. It is one of the most abundant substances in the bone matrix, circulates systemically and is secreted locally, and has a direct relationship with bone mineral density. Recent data has helped further our understanding of the direct role of IGF-1 signaling in coupling bone remodeling which will be discussed in this review. The bone marrow microenvironment plays a critical role in the fate of mesenchymal stem cells and hematopoietic stem cells and thus how IGF-1 interacts with other factors in the microenvironment are equally important. While previous clinical trials with IGF-1 administration have been unsuccessful at enhancing bone formation, advances in basic science studies have provided insight into further mechanisms that should be considered for future trials. Additional basic science studies dissecting the regulation and the function of matrix IGF-1 in modeling and remodeling will continue to provide further insight for future directions for anabolic therapies for osteoporosis.

HIV-1 tat protein recruits CIS to the cytoplasmic tail of CD127 to induce receptor ubiquitination and proteasomal degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugden, Scott, E-mail: scott.sugden@ircm.qc.ca

HIV-1 Tat protein down regulates expression of the IL-7 receptor alpha-chain (CD127) from the surface of CD8 T cells resulting in impaired T cell proliferation and cytolytic capacity. We have previously shown that soluble Tat protein is taken up by CD8 T cells and interacts with the cytoplasmic tail of CD127 to induce receptor degradation. The N-terminal domain of Tat interacts with CD127 while the basic domain directs CD127 to the proteasome. We have also shown that upon IL-7 binding to its receptor, CD127 is phosphorylated resulting in CIS-mediated proteasomal degradation. Here, we show that Tat mimics this process bymore » recruiting CIS to CD127 in the absence of IL-7 and receptor phosphorylation, leading to CD127 ubiquitination and degradation. Tat therefore acts as an adapter to induce cellular responses under conditions where they may not otherwise occur. Thusly, Tat reduces IL-7 signaling and impairs CD8 T cell survival and function. -- Highlights: •Soluble HIV-1 Tat decreases CD127 expression on CD8 T cells, causing dysfunction. •Tat induces CD127 ubiquitination without activating IL-7 signaling. •Tat binds CD127 and recruits the E3 ubiquitin ligase CIS via its basic domain. •Tat hijacks a normal cellular mechanism to degrade CD127 without IL-7 signaling.« less

Cross-Approximate Entropy parallel computation on GPUs for biomedical signal analysis. Application to MEG recordings.

PubMed

Martínez-Zarzuela, Mario; Gómez, Carlos; Díaz-Pernas, Francisco Javier; Fernández, Alberto; Hornero, Roberto

2013-10-01

Cross-Approximate Entropy (Cross-ApEn) is a useful measure to quantify the statistical dissimilarity of two time series. In spite of the advantage of Cross-ApEn over its one-dimensional counterpart (Approximate Entropy), only a few studies have applied it to biomedical signals, mainly due to its high computational cost. In this paper, we propose a fast GPU-based implementation of the Cross-ApEn that makes feasible its use over a large amount of multidimensional data. The scheme followed is fully scalable, thus maximizes the use of the GPU despite of the number of neural signals being processed. The approach consists in processing many trials or epochs simultaneously, with independence of its origin. In the case of MEG data, these trials can proceed from different input channels or subjects. The proposed implementation achieves an average speedup greater than 250× against a CPU parallel version running on a processor containing six cores. A dataset of 30 subjects containing 148 MEG channels (49 epochs of 1024 samples per channel) can be analyzed using our development in about 30min. The same processing takes 5 days on six cores and 15 days when running on a single core. The speedup is much larger if compared to a basic sequential Matlab(®) implementation, that would need 58 days per subject. To our knowledge, this is the first contribution of Cross-ApEn measure computation using GPUs. This study demonstrates that this hardware is, to the day, the best option for the signal processing of biomedical data with Cross-ApEn. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Flexible Software Architecture for Visualization and Seismic Data Analysis

NASA Astrophysics Data System (ADS)

Petunin, S.; Pavlov, I.; Mogilenskikh, D.; Podzyuban, D.; Arkhipov, A.; Baturuin, N.; Lisin, A.; Smith, A.; Rivers, W.; Harben, P.

2007-12-01

Research in the field of seismology requires software and signal processing utilities for seismogram manipulation and analysis. Seismologists and data analysts often encounter a major problem in the use of any particular software application specific to seismic data analysis: the tuning of commands and windows to the specific waveforms and hot key combinations so as to fit their familiar informational environment. The ability to modify the user's interface independently from the developer requires an adaptive code structure. An adaptive code structure also allows for expansion of software capabilities such as new signal processing modules and implementation of more efficient algorithms. Our approach is to use a flexible "open" architecture for development of geophysical software. This report presents an integrated solution for organizing a logical software architecture based on the Unix version of the Geotool software implemented on the Microsoft NET 2.0 platform. Selection of this platform greatly expands the variety and number of computers that can implement the software, including laptops that can be utilized in field conditions. It also facilitates implementation of communication functions for seismic data requests from remote databases through the Internet. The main principle of the new architecture for Geotool is that scientists should be able to add new routines for digital waveform analysis via software plug-ins that utilize the basic Geotool display for GUI interaction. The use of plug-ins allows the efficient integration of diverse signal-processing software, including software still in preliminary development, into an organized platform without changing the fundamental structure of that platform itself. An analyst's use of Geotool is tracked via a metadata file so that future studies can reconstruct, and alter, the original signal processing operations. The work has been completed in the framework of a joint Russian- American project.

Fundamentals handbook of electrical and computer engineering. Volume 1 Circuits fields and electronics

NASA Astrophysics Data System (ADS)

Chang, S. S. L.

State of the art technology in circuits, fields, and electronics is discussed. The principles and applications of these technologies to industry, digital processing, microwave semiconductors, and computer-aided design are explained. Important concepts and methodologies in mathematics and physics are reviewed, and basic engineering sciences and associated design methods are dealt with, including: circuit theory and the design of magnetic circuits and active filter synthesis; digital signal processing, including FIR and IIR digital filter design; transmission lines, electromagnetic wave propagation and surface acoustic wave devices. Also considered are: electronics technologies, including power electronics, microwave semiconductors, GaAs devices, and magnetic bubble memories; digital circuits and logic design.

Neuropeptides and epitheliopeptides: structural and functional diversity in an ancestral metazoan Hydra.

PubMed

Takahashi, Toshio

2013-06-01

Peptides are known to play important developmental and physiological roles in signaling. The rich diversity of peptides, with functions as diverse as intercellular communication, neurotransmission and signaling that spatially and temporally controls axis formation and cell differentiation, hints at the wealth of information passed between interacting cells. Little is known about peptides that control developmental processes such as cell differentiation and pattern formation in metazoans. The cnidarian Hydra is one of the most basic metazoans and is a key model system for study of the peptides involved in these processes. We developed a novel peptidomic approach for the isolation and identification of functional peptide signaling molecules from Hydra (the Hydra Peptide Project). Over the course of this project, a wide variety of novel neuropeptides were identified. Most of these peptides act directly on muscle cells and their functions include induction of contraction and relaxation. Some peptides are involved in cell differentiation and morphogenesis. Moreover, epitheliopeptides that are produced by epithelial cells were originally identified in Hydra. Some of these epitheliopeptides exhibit morphogen-like activities, whereas others are involved in regulating neuron differentiation, possibly through neuron-epithelial cell interactions. We also describe below our high-throughput reverse-phase nano-flow LCMALDI- TOF-MS/MS approach, which has proved a powerful tool for the discovery of novel peptide signaling molecules in Hydra.

Cathepsin H Functions as an Aminopeptidase in Secretory Vesicles for Production of Enkephalin and Galanin Peptide Neurotransmitters

PubMed Central

Lu, W. Douglas; Funkelstein, Lydiane; Toneff, Thomas; Reinheckel, Thomas; Peters, Christoph; Hook, Vivian

2012-01-01

Peptide neurotransmitters function as key intercellular signaling molecules in the nervous system. These peptides are generated in secretory vesicles from proneuropeptides by proteolytic processing at dibasic residues, followed by removal of N- and/or C-terminal basic residues to form active peptides. Enkephalin biosynthesis from proenkephalin utilizes the cysteine protease cathepsin L and the subtilisin-like prohormone convertase 2 (PC2). Cathepsin L generates peptide intermediates with N-terminal basic residue extensions, which must be removed by an aminopeptidase. In this study, we identified cathepsin H as an aminopeptidase in secretory vesicles that produces (Met)enkephalin (ME) by sequential removal of basic residues from KR-ME and KK-ME, supported by in vivo knockout of the cathepsin H gene. Localization of cathepsin H in secretory vesicles was demonstrated by immunoelectron microscopy and confocal immunofluorescence microscopy. Purified human cathepsin H sequentially removes N-terminal basic residues to generate ME, with peptide products characterized by nano-LC-MS/MS tandem mass spectrometry. Cathepsin H shows highest activities for cleaving N-terminal basic residues (Arg and Lys) among amino acid fluorogenic substrates. Notably, knockout of the cathepsin H gene results in reduction of ME in mouse brain. Cathepsin H deficient mice also show a substantial decrease in galanin peptide neurotransmitter levels in brain. These results illustrate a role for cathepsin H as an aminopeptidase for enkephalin and galanin peptide neurotransmitter production. PMID:22582844

47 CFR 76.901 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND... basic tier, and any additional video programming signals a service added to the basic tier by the cable operator. (b) Cable programming service. Cable programming service includes any video programming provided...

A Signalling Device for Non-Oral Communicators.

ERIC Educational Resources Information Center

King, Thomas W.

1991-01-01

This article describes simple modifications to a basic 9-volt portable transistor radio to serve as a durable, inexpensive signalling device operable by a single external switch. The unit still functions as a radio, but can also help partially speaking students and users of communication aids to signal for help. (Author/PB)

Tri-state oriented parallel processing system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tenenbaum, J.; Wallach, Y.

1982-08-01

An alternating sequential/parallel system, the MOPPS was introduced a few years ago and is modified despite the fact that it solved satisfactorily a number of real-time problems. The new system, the TOPPS is described and compared to MOPPS and two applications are chosen to prove it to be superior. The advantage of having a third basic, the ring mode, is illustrated when solving sets of linear equations with band matrices. The advantage of having independent I/O for the slaves is illustrated for biomedical signal analysis. 11 references.

Phloem physics: mechanisms, constraints, and perspectives.

PubMed

Jensen, Kaare H

2018-04-13

Plants have evolved specialized vascular tissues for the distribution of energy, water, nutrients, and for communication. The phloem transports sugars from photosynthetic source regions (e.g. mature leaves) to sugar sinks (e.g. developing tissues such as buds, flowers, roots). Moreover, chemical signals such as hormones, RNAs and proteins also move in the phloem. Basic physical processes strongly limit phloem anatomy and function. This paper provides an overview of recent research and perspectives on phloem biomechanics and the physical constraints relevant to sugar transport in plants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Simulation of the GEM detector for BM@N experiment

NASA Astrophysics Data System (ADS)

Baranov, Dmitriy; Rogachevsky, Oleg

2017-03-01

The Gas Electron Multiplier (GEM) detector is one of the basic parts of the BM@N experiment included in the NICA project. The simulation model that takes into account features of signal generation process in an ionization GEM chamber is presented in this article. Proper parameters for the simulation were extracted from data retrieved with the help of Garfield++ (a toolkit for the detailed simulation of particle detectors). Due to this, we are able to generate clusters in layers of the micro-strip readout that correspond to clusters retrieved from a real physics experiment.

Adaptive identification and control of structural dynamics systems using recursive lattice filters

NASA Technical Reports Server (NTRS)

Sundararajan, N.; Montgomery, R. C.; Williams, J. P.

1985-01-01

A new approach for adaptive identification and control of structural dynamic systems by using least squares lattice filters thar are widely used in the signal processing area is presented. Testing procedures for interfacing the lattice filter identification methods and modal control method for stable closed loop adaptive control are presented. The methods are illustrated for a free-free beam and for a complex flexible grid, with the basic control objective being vibration suppression. The approach is validated by using both simulations and experimental facilities available at the Langley Research Center.

Self-organized Motion During Dictyostelium amoebae aggregation

NASA Astrophysics Data System (ADS)

Levine, Herbert

2004-03-01

After starvation, amoeba of the cellular slime mold Dictyostelium discoideum aggregate to form rudimentary multicellular organisms. The coordination of the individual motions of hundreds of thousands of individual cells is an important ingredient in the success of this process. This coordination is accomplished by chemical signaling during the early stages and by direct cell-cell interactions once the cells reach the nascent mound. This talk will review the basic nonequilibrium physics underlying the spatial patterns formed by these cooperative motions, including high-density incoming streams and spontaneously rotating mounds.

[Orienting reflex: "targeting reaction" and "searchlight of attention"].

PubMed

Sokolov, E N; Nezlina, N I; Polianskiĭ, V B; Evtikhin, D V

2001-01-01

The concept of orienting reflex based on the principle of vector coding of cognitive and executive processes is proposed. The orienting reflex to non-signal and signal stimuli is a set of orienting reactions: motor, autonomic, neuronal, and subjective emphasizing new and significant stimuli. Two basic mechanisms can be identified within the orienting reflex: a "targeting reaction" and a "searchlight of attention". In the visual system the first one consists in a foveation of a target stimulus. The foveation is performed with participation of premotor neurons excited by saccadic command neurons of the superior colliculi. The "searchlight of attention" is based on the resonance of gamma-oscillations in the reticular thalamus selectively enhancing responses of cortical neurons (involuntary attention). The novelty signal is generated in novelty neurons of the hippocampus, which are selectively tuned to a repeatedly presented standard stimulus. The selective tuning is caused by the depression of plastic synapses representing a "neuronal model" of the standard stimulus. A mismatch of the novel stimulus with the established neuronal model gives rise to a "novelty signal" enhancing the novel input. The novelty signal inhibits current conditioned reflexes (external inhibition) contributing to redirecting the behavior. By triggering the expression of early genes the novelty signal initiates the formation of the long-term memory connected with neoneurogenesis.

Systematic analysis of signaling pathways using an integrative environment.

PubMed

Visvanathan, Mahesh; Breit, Marc; Pfeifer, Bernhard; Baumgartner, Christian; Modre-Osprian, Robert; Tilg, Bernhard

2007-01-01

Understanding the biological processes of signaling pathways as a whole system requires an integrative software environment that has comprehensive capabilities. The environment should include tools for pathway design, visualization, simulation and a knowledge base concerning signaling pathways as one. In this paper we introduce a new integrative environment for the systematic analysis of signaling pathways. This system includes environments for pathway design, visualization, simulation and a knowledge base that combines biological and modeling information concerning signaling pathways that provides the basic understanding of the biological system, its structure and functioning. The system is designed with a client-server architecture. It contains a pathway designing environment and a simulation environment as upper layers with a relational knowledge base as the underlying layer. The TNFa-mediated NF-kB signal trans-duction pathway model was designed and tested using our integrative framework. It was also useful to define the structure of the knowledge base. Sensitivity analysis of this specific pathway was performed providing simulation data. Then the model was extended showing promising initial results. The proposed system offers a holistic view of pathways containing biological and modeling data. It will help us to perform biological interpretation of the simulation results and thus contribute to a better understanding of the biological system for drug identification.

Task and spatial frequency modulations of object processing: an EEG study.

PubMed

Craddock, Matt; Martinovic, Jasna; Müller, Matthias M

2013-01-01

Visual object processing may follow a coarse-to-fine sequence imposed by fast processing of low spatial frequencies (LSF) and slow processing of high spatial frequencies (HSF). Objects can be categorized at varying levels of specificity: the superordinate (e.g. animal), the basic (e.g. dog), or the subordinate (e.g. Border Collie). We tested whether superordinate and more specific categorization depend on different spatial frequency ranges, and whether any such dependencies might be revealed by or influence signals recorded using EEG. We used event-related potentials (ERPs) and time-frequency (TF) analysis to examine the time course of object processing while participants performed either a grammatical gender-classification task (which generally forces basic-level categorization) or a living/non-living judgement (superordinate categorization) on everyday, real-life objects. Objects were filtered to contain only HSF or LSF. We found a greater positivity and greater negativity for HSF than for LSF pictures in the P1 and N1 respectively, but no effects of task on either component. A later, fronto-central negativity (N350) was more negative in the gender-classification task than the superordinate categorization task, which may indicate that this component relates to semantic or syntactic processing. We found no significant effects of task or spatial frequency on evoked or total gamma band responses. Our results demonstrate early differences in processing of HSF and LSF content that were not modulated by categorization task, with later responses reflecting such higher-level cognitive factors.

A Feasibility Study of Computer Assisted Instruction in US Army Basic Electronics Training. Final Report.

ERIC Educational Resources Information Center

International Business Machines Corp., Gaithersburg, MD. Federal Systems Div.

A study of computer-assisted instruction (CAI) for US Army basic electronics training at the US Army Signal Center and School establishes the feasibility of CAI as a training technique. Three aspects of CAI are considered: effectiveness, efficiency, and applicability of CAI to basic electronics training. The study explores the effectiveness of the…

The AAPM/RSNA physics tutorial for residents. Basic physics of MR imaging: an introduction.

PubMed

Hendrick, R E

1994-07-01

This article provides an introduction to the basic physical principles of magnetic resonance (MR) imaging. Essential basic concepts such as nuclear magnetism, tissue magnetization, precession, excitation, and tissue relaxation properties are presented. Hydrogen spin density and tissue relaxation times T1, T2, and T2* are explained. The basic elements of a planar MR pulse sequence are described: section selection during tissue excitation, phase encoding, and frequency encoding during signal measurement.

General purpose graphic processing unit implementation of adaptive pulse compression algorithms

NASA Astrophysics Data System (ADS)

Cai, Jingxiao; Zhang, Yan

2017-07-01

This study introduces a practical approach to implement real-time signal processing algorithms for general surveillance radar based on NVIDIA graphical processing units (GPUs). The pulse compression algorithms are implemented using compute unified device architecture (CUDA) libraries such as CUDA basic linear algebra subroutines and CUDA fast Fourier transform library, which are adopted from open source libraries and optimized for the NVIDIA GPUs. For more advanced, adaptive processing algorithms such as adaptive pulse compression, customized kernel optimization is needed and investigated. A statistical optimization approach is developed for this purpose without needing much knowledge of the physical configurations of the kernels. It was found that the kernel optimization approach can significantly improve the performance. Benchmark performance is compared with the CPU performance in terms of processing accelerations. The proposed implementation framework can be used in various radar systems including ground-based phased array radar, airborne sense and avoid radar, and aerospace surveillance radar.

Percolation Model of Sensory Transmission and Loss of Consciousness Under General Anesthesia

NASA Astrophysics Data System (ADS)

Zhou, David W.; Mowrey, David D.; Tang, Pei; Xu, Yan

2015-09-01

Neurons communicate with each other dynamically; how such communications lead to consciousness remains unclear. Here, we present a theoretical model to understand the dynamic nature of sensory activity and information integration in a hierarchical network, in which edges are stochastically defined by a single parameter p representing the percolation probability of information transmission. We validate the model by comparing the transmitted and original signal distributions, and we show that a basic version of this model can reproduce key spectral features clinically observed in electroencephalographic recordings of transitions from conscious to unconscious brain activities during general anesthesia. As p decreases, a steep divergence of the transmitted signal from the original was observed, along with a loss of signal synchrony and a sharp increase in information entropy in a critical manner; this resembles the precipitous loss of consciousness during anesthesia. The model offers mechanistic insights into the emergence of information integration from a stochastic process, laying the foundation for understanding the origin of cognition.

Drosophila wing imaginal discs respond to mechanical injury via slow InsP3R-mediated intercellular calcium waves

NASA Astrophysics Data System (ADS)

Restrepo, Simon; Basler, Konrad

2016-08-01

Calcium signalling is a highly versatile cellular communication system that modulates basic functions such as cell contractility, essential steps of animal development such as fertilization and higher-order processes such as memory. We probed the function of calcium signalling in Drosophila wing imaginal discs through a combination of ex vivo and in vivo imaging and genetic analysis. Here we discover that wing discs display slow, long-range intercellular calcium waves (ICWs) when mechanically stressed in vivo or cultured ex vivo. These slow imaginal disc intercellular calcium waves (SIDICs) are mediated by the inositol-3-phosphate receptor, the endoplasmic reticulum (ER) calcium pump SERCA and the key gap junction component Inx2. The knockdown of genes required for SIDIC formation and propagation negatively affects wing disc recovery after mechanical injury. Our results reveal a role for ICWs in wing disc homoeostasis and highlight the utility of the wing disc as a model for calcium signalling studies.

Study of composition of espresso coffee prepared from various roast degrees of Coffea arabica L. coffee beans.

PubMed

Kučera, Lukáš; Papoušek, Roman; Kurka, Ondřej; Barták, Petr; Bednář, Petr

2016-05-15

Espresso coffee samples prepared at various roasting degrees defined according to its basic conventional classification (light, medium, medium-dark and dark roasted) were analyzed by ultra-performance liquid chromatography/tandem mass spectrometry. Obtained raw data were processed using multivariate statistical analysis (Principal Component Analysis, PCA) to evaluate chemical differences between each roasting degrees (untargeted part of study). All four roasting degrees were resolved in appropriate Score plot. Orthogonal Projections to Latent Structures provided signals of significant markers describing the differences among particular roasting degrees. Detailed interpretation of those signals by targeted LC/MS(2) analysis revealed four groups of compounds. The first two groups involve chlorogenic acids and related lactones. The signals of other two sets of markers were ascribed to some specific atractylosides and particular melanoidins. Ratios of contents of selected representatives of each group to the sum of all identified markers were proposed as definite parameters for determination of roasting degree of Brazilian coffee Arabica. Copyright © 2015 Elsevier Ltd. All rights reserved.

Basic Investigations of Dynamic Travel Time Estimation Model for Traffic Signals Control Using Information from Optical Beacons

NASA Astrophysics Data System (ADS)

Okutani, Iwao; Mitsui, Tatsuro; Nakada, Yusuke

In this paper put forward are neuron-type models, i.e., neural network model, wavelet neuron model and three layered wavelet neuron model(WV3), for estimating traveling time between signalized intersections in order to facilitate adaptive setting of traffic signal parameters such as green time and offset. Model validation tests using simulated data reveal that compared to other models, WV3 model works very fast in learning process and can produce more accurate estimates of travel time. Also, it is exhibited that up-link information obtainable from optical beacons, i.e., travel time observed during the former cycle time in this case, makes a crucial input variable to the models in that there isn't any substantial difference between the change of estimated and simulated travel time with the change of green time or offset when up-link information is employed as input while there appears big discrepancy between them when not employed.

Analysis of the damage threshold of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

NASA Astrophysics Data System (ADS)

Xi, Xiao-Wen; Chai, Chang-Chun; Liu, Yang; Yang, Yin-Tang; Fan, Qing-Yang; Shi, Chun-Lei

2016-08-01

An electromagnetic pulse (EMP)-induced damage model based on the internal damage mechanism of the GaAs pseudomorphic high electron mobility transistor (PHEMT) is established in this paper. With this model, the relationships among the damage power, damage energy, pulse width and signal amplitude are investigated. Simulation results show that the pulse width index from the damage power formula obtained here is higher than that from the empirical formula due to the hotspot transferring in the damage process of the device. It is observed that the damage energy is not a constant, which decreases with the signal amplitude increasing, and then changes little when the signal amplitude reaches up to a certain level. Project supported by the National Basic Research Program of China (Grant No. 2014CB339900) and the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology, China Academy of Engineering Physics (CAEP) (Grant No. 2015-0214.XY.K).

Signals from the Cosmos.

ERIC Educational Resources Information Center

Lichtman, Jeffrey M.

1991-01-01

Introduces the basics of radio astronomy and describes how to assemble several simple systems for receiving radio signals from the cosmos. Includes schematics, parts lists, working drawings, and contact information for radio astronomy suppliers. (11 references) (Author/JJK)

Feedback Activation of Basic Fibroblast Growth Factor Signaling via the Wnt/β-Catenin Pathway in Skin Fibroblasts

PubMed Central

Wang, Xu; Zhu, Yuting; Sun, Congcong; Wang, Tao; Shen, Yingjie; Cai, Wanhui; Sun, Jia; Chi, Lisha; Wang, Haijun; Song, Na; Niu, Chao; Shen, Jiayi; Cong, Weitao; Zhu, Zhongxin; Xuan, Yuanhu; Li, Xiaokun; Jin, Litai

2017-01-01

Skin wound healing is a complex process requiring the coordinated behavior of many cell types, especially in the proliferation and migration of fibroblasts. Basic fibroblast growth factor (bFGF) is a member of the FGF family that promotes fibroblast migration, but the underlying molecular mechanism remains elusive. The present RNA sequencing study showed that the expression levels of several canonical Wnt pathway genes, including Wnt2b, Wnt3, Wnt11, T-cell factor 7 (TCF7), and Frizzled 8 (FZD8) were modified by bFGF stimulation in fibroblasts. Enzyme-linked immunosorbent assay (ELISA) analysis also showed that Wnt pathway was activated under bFGF treatment. Furthermore, treatment of fibroblasts with lithium chloride or IWR-1, an inducer and inhibitor of the Wnt signaling pathway, respectively, promoted and inhibited cell migration. Also, levels of cytosolic glycogen synthase kinase 3 beta phosphorylated at serine9 (pGSK3β Ser9) and nuclear β-catenin were increased upon exposure to bFGF. Molecular and biochemical assays indicated that phosphoinositide 3-kinase (PI3K) signaling activated the GSK3β/β-catenin/Wnt signaling pathway via activation of c-Jun N-terminal kinase (JNK), suggesting that PI3K and JNK act at the upstream of β-catenin. In contrast, knock-down of β-catenin delayed fibroblast cell migration even under bFGF stimulation. RNA sequencing analysis of β-catenin knock-down fibroblasts demonstrated that β-catenin positively regulated the transcription of bFGF and FGF21. Moreover, FGF21 treatment activated AKT and JNK, and accelerated fibroblast migration to a similar extent as bFGF does. In addition, ELISA analysis demonstrated that both of bFGF and FGF21 were auto secretion factor and be regulated by Wnt pathway stimulators. Taken together, our analyses define a feedback regulatory loop between bFGF (FGF21) and Wnt signaling acting through β-catenin in skin fibroblasts. PMID:28217097

Evolutionary and Expression Analyses of the Apple Basic Leucine Zipper Transcription Factor Family

PubMed Central

Zhao, Jiao; Guo, Rongrong; Guo, Chunlei; Hou, Hongmin; Wang, Xiping; Gao, Hua

2016-01-01

Transcription factors (TFs) play essential roles in the regulatory networks controlling many developmental processes in plants. Members of the basic leucine (Leu) zipper (bZIP) TF family, which is unique to eukaryotes, are involved in regulating diverse processes, including flower and vascular development, seed maturation, stress signaling, and defense responses to pathogens. The bZIP proteins have a characteristic bZIP domain composed of a DNA-binding basic region and a Leu zipper dimerization region. In this study, we identified 112 apple (Malus domestica Borkh) bZIP TF-encoding genes, termed MdbZIP genes. Synteny analysis indicated that segmental and tandem duplication events, as well as whole genome duplication, have contributed to the expansion of the apple bZIP family. The family could be divided into 11 groups based on structural features of the encoded proteins, as well as on the phylogenetic relationship of the apple bZIP proteins to those of the model plant Arabidopsis thaliana (AtbZIP genes). Synteny analysis revealed that several paired MdbZIP genes and AtbZIP gene homologs were located in syntenic genomic regions. Furthermore, expression analyses of group A MdbZIP genes showed distinct expression levels in 10 different organs. Moreover, changes in these expression profiles in response to abiotic stress conditions and various hormone treatments identified MdbZIP genes that were responsive to high salinity and drought, as well as to different phytohormones. PMID:27066030

Evolutionary and Expression Analyses of the Apple Basic Leucine Zipper Transcription Factor Family.

PubMed

Zhao, Jiao; Guo, Rongrong; Guo, Chunlei; Hou, Hongmin; Wang, Xiping; Gao, Hua

2016-01-01

Transcription factors (TFs) play essential roles in the regulatory networks controlling many developmental processes in plants. Members of the basic leucine (Leu) zipper (bZIP) TF family, which is unique to eukaryotes, are involved in regulating diverse processes, including flower and vascular development, seed maturation, stress signaling, and defense responses to pathogens. The bZIP proteins have a characteristic bZIP domain composed of a DNA-binding basic region and a Leu zipper dimerization region. In this study, we identified 112 apple (Malus domestica Borkh) bZIP TF-encoding genes, termed MdbZIP genes. Synteny analysis indicated that segmental and tandem duplication events, as well as whole genome duplication, have contributed to the expansion of the apple bZIP family. The family could be divided into 11 groups based on structural features of the encoded proteins, as well as on the phylogenetic relationship of the apple bZIP proteins to those of the model plant Arabidopsis thaliana (AtbZIP genes). Synteny analysis revealed that several paired MdbZIP genes and AtbZIP gene homologs were located in syntenic genomic regions. Furthermore, expression analyses of group A MdbZIP genes showed distinct expression levels in 10 different organs. Moreover, changes in these expression profiles in response to abiotic stress conditions and various hormone treatments identified MdbZIP genes that were responsive to high salinity and drought, as well as to different phytohormones.

Tendon basic science: Development, repair, regeneration, and healing.

PubMed

Andarawis-Puri, Nelly; Flatow, Evan L; Soslowsky, Louis J

2015-06-01

Tendinopathy and tendon rupture are common and disabling musculoskeletal conditions. Despite the prevalence of these injuries, a limited number of investigators are conducting fundamental, basic science studies focused on understanding processes governing tendinopathies and tendon healing. Development of effective therapeutics is hindered by the lack of fundamental guiding data on the biology of tendon development, signal transduction, mechanotransduction, and basic mechanisms underlying tendon pathogenesis and healing. To propel much needed progress, the New Frontiers in Tendon Research Conference, co-sponsored by NIAMS/NIH, the Orthopaedic Research Society, and the Icahn School of Medicine at Mount Sinai, was held to promote exchange of ideas between tendon researchers and basic science experts from outside the tendon field. Discussed research areas that are underdeveloped and represent major hurdles to the progress of the field will be presented in this review. To address some of these outstanding questions, conference discussions and breakout sessions focused on six topic areas (Cell Biology and Mechanics, Functional Extracellular Matrix, Development, Mechano-biology, Scarless Healing, and Mechanisms of Injury and Repair), which are reviewed in this special issue and briefly presented in this review. Review articles in this special issue summarize the progress in the field and identify essential new research directions. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Surface acoustic waves voltage controlled directional coupler

NASA Astrophysics Data System (ADS)

Golan, G.; Griffel, G.; Yanilov, E.; Ruschin, S.; Seidman, A.; Croitoru, N.

1988-10-01

An important condition for the development of surface wave integrated-acoustic devices is the ability to guide and control the propagation of the acoustic energy. This can be implemented by deposition of metallic "loading" channels on an anisotropic piezoelectric substrate. Deposition of such two parallel channels causes an effective coupling of acoustic energy from one channel to the other. A basic requirement for this coupling effect is the existence of the two basic modes: a symmetrical and a nonsymmetrical one. A mode map that shows the number of sustained modes as a function of the device parameters (i.e., channel width; distance between channels; material velocity; and acoustical exciting frequency) is presented. This kind of map can help significantly in the design process of such a device. In this paper we devise an advanced acoustical "Y" coupler with the ability to control its effective coupling by an externally applied voltage, thereby causing modulation of the output intensities of the signals.

Photonics and terahertz tchnologies: part 1

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2011-10-01

This digest paper debates basic features of the terahertz band of frequencies. There are presented fundamental characteristics of the basic terahertz system consisting of a THz source, propagation media, transmission lines, THz signal processing, and detectors. Such a system finds research application, but also practical in two main areas: terahertz imaging - transmissive and reflective, and as a close range THz radar, but also as sensory systems mainly for molecular sensing. There were launched in this country a few THz research projects concerning the THz sources, detectors and their applications. Among these projects there is an infrastructural one called FOTEH, opened at the WUT. The details of this project are debated and the consequences of its realization in this country. The first part of the paper is an introduction debating THz band and comparing it with the photonics one. The second part presents the assumptions of the infrastructural FOTEH project on Photonics and Terahertz Technologies.

How to Achieve Fast Entrainment? The Timescale to Synchronization

PubMed Central

Granada, Adrián E.; Herzel, Hanspeter

2009-01-01

Entrainment, where oscillators synchronize to an external signal, is ubiquitous in nature. The transient time leading to entrainment plays a major role in many biological processes. Our goal is to unveil the specific dynamics that leads to fast entrainment. By studying a generic model, we characterize the transient time to entrainment and show how it is governed by two basic properties of an oscillator: the radial relaxation time and the phase velocity distribution around the limit cycle. Those two basic properties are inherent in every oscillator. This concept can be applied to many biological systems to predict the average transient time to entrainment or to infer properties of the underlying oscillator from the observed transients. We found that both a sinusoidal oscillator with fast radial relaxation and a spike-like oscillator with slow radial relaxation give rise to fast entrainment. As an example, we discuss the jet-lag experiments in the mammalian circadian pacemaker. PMID:19774087

The basics of thiols and cysteines in redox biology and chemistry.

PubMed

Poole, Leslie B

2015-03-01

Cysteine is one of the least abundant amino acids, yet it is frequently found as a highly conserved residue within functional (regulatory, catalytic, or binding) sites in proteins. It is the unique chemistry of the thiol or thiolate group of cysteine that imparts to functional sites their specialized properties (e.g., nucleophilicity, high-affinity metal binding, and/or ability to form disulfide bonds). Highlighted in this review are some of the basic biophysical and biochemical properties of cysteine groups and the equations that apply to them, particularly with respect to pKa and redox potential. Also summarized are the types of low-molecular-weight thiols present in high concentrations in most cells, as well as the ways in which modifications of cysteinyl residues can impart or regulate molecular functions important to cellular processes, including signal transduction. Copyright © 2014 Elsevier Inc. All rights reserved.

49 CFR 236.923 - Task analysis and basic requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... classroom, simulator, computer-based, hands-on, or other formally structured training and testing, except... for Processor-Based Signal and Train Control Systems § 236.923 Task analysis and basic requirements...) Based on a formal task analysis, identify the installation, maintenance, repair, modification...

49 CFR 236.1043 - Task analysis and basic requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Positive Train Control Systems § 236.1043 Task analysis and basic requirements. (a) Training structure and... installation, maintenance, repair, modification, inspection, testing, and operating tasks that must be...

49 CFR 236.1043 - Task analysis and basic requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Positive Train Control Systems § 236.1043 Task analysis and basic requirements. (a) Training structure and... installation, maintenance, repair, modification, inspection, testing, and operating tasks that must be...

49 CFR 236.1043 - Task analysis and basic requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Positive Train Control Systems § 236.1043 Task analysis and basic requirements. (a) Training structure and... installation, maintenance, repair, modification, inspection, testing, and operating tasks that must be...

49 CFR 236.1043 - Task analysis and basic requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Positive Train Control Systems § 236.1043 Task analysis and basic requirements. (a) Training structure and... installation, maintenance, repair, modification, inspection, testing, and operating tasks that must be...

49 CFR 236.1043 - Task analysis and basic requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Positive Train Control Systems § 236.1043 Task analysis and basic requirements. (a) Training structure and... installation, maintenance, repair, modification, inspection, testing, and operating tasks that must be...

Current trends in hardware and software for brain-computer interfaces (BCIs)

NASA Astrophysics Data System (ADS)

Brunner, P.; Bianchi, L.; Guger, C.; Cincotti, F.; Schalk, G.

2011-04-01

A brain-computer interface (BCI) provides a non-muscular communication channel to people with and without disabilities. BCI devices consist of hardware and software. BCI hardware records signals from the brain, either invasively or non-invasively, using a series of device components. BCI software then translates these signals into device output commands and provides feedback. One may categorize different types of BCI applications into the following four categories: basic research, clinical/translational research, consumer products, and emerging applications. These four categories use BCI hardware and software, but have different sets of requirements. For example, while basic research needs to explore a wide range of system configurations, and thus requires a wide range of hardware and software capabilities, applications in the other three categories may be designed for relatively narrow purposes and thus may only need a very limited subset of capabilities. This paper summarizes technical aspects for each of these four categories of BCI applications. The results indicate that BCI technology is in transition from isolated demonstrations to systematic research and commercial development. This process requires several multidisciplinary efforts, including the development of better integrated and more robust BCI hardware and software, the definition of standardized interfaces, and the development of certification, dissemination and reimbursement procedures.

Dissection of a nuclear localization signal.

PubMed

Hodel, M R; Corbett, A H; Hodel, A E

2001-01-12

The regulated process of protein import into the nucleus of a eukaryotic cell is mediated by specific nuclear localization signals (NLSs) that are recognized by protein import receptors. This study seeks to decipher the energetic details of NLS recognition by the receptor importin alpha through quantitative analysis of variant NLSs. The relative importance of each residue in two monopartite NLS sequences was determined using an alanine scanning approach. These measurements yield an energetic definition of a monopartite NLS sequence where a required lysine residue is followed by two other basic residues in the sequence K(K/R)X(K/R). In addition, the energetic contributions of the second basic cluster in a bipartite NLS ( approximately 3 kcal/mol) as well as the energy of inhibition of the importin alpha importin beta-binding domain ( approximately 3 kcal/mol) were also measured. These data allow the generation of an energetic scale of nuclear localization sequences based on a peptide's affinity for the importin alpha-importin beta complex. On this scale, a functional NLS has a binding constant of approximately 10 nm, whereas a nonfunctional NLS has a 100-fold weaker affinity of 1 microm. Further correlation between the current in vitro data and in vivo function will provide the foundation for a comprehensive quantitative model of protein import.

Harmonic analysis of electric locomotive and traction power system based on wavelet singular entropy

NASA Astrophysics Data System (ADS)

Dun, Xiaohong

2018-05-01

With the rapid development of high-speed railway and heavy-haul transport, the locomotive and traction power system has become the main harmonic source of China's power grid. In response to this phenomenon, the system's power quality issues need timely monitoring, assessment and governance. Wavelet singular entropy is an organic combination of wavelet transform, singular value decomposition and information entropy theory, which combines the unique advantages of the three in signal processing: the time-frequency local characteristics of wavelet transform, singular value decomposition explores the basic modal characteristics of data, and information entropy quantifies the feature data. Based on the theory of singular value decomposition, the wavelet coefficient matrix after wavelet transform is decomposed into a series of singular values that can reflect the basic characteristics of the original coefficient matrix. Then the statistical properties of information entropy are used to analyze the uncertainty of the singular value set, so as to give a definite measurement of the complexity of the original signal. It can be said that wavelet entropy has a good application prospect in fault detection, classification and protection. The mat lab simulation shows that the use of wavelet singular entropy on the locomotive and traction power system harmonic analysis is effective.

Electrophysiological measurement of human auditory function

NASA Technical Reports Server (NTRS)

Galambos, R.

1975-01-01

Knowledge of the human auditory evoked response is reviewed, including methods of determining this response, the way particular changes in the stimulus are coupled to specific changes in the response, and how the state of mind of the listener will influence the response. Important practical applications of this basic knowledge are discussed. Measurement of the brainstem evoked response, for instance, can state unequivocally how well the peripheral auditory apparatus functions. It might then be developed into a useful hearing test, especially for infants and preverbal or nonverbal children. Clinical applications of measuring the brain waves evoked 100 msec and later after the auditory stimulus are undetermined. These waves are clearly related to brain events associated with cognitive processing of acoustic signals, since their properties depend upon where the listener directs his attention and whether how long he expects the signal.

Optimization of an organic memristor as an adaptive memory element

NASA Astrophysics Data System (ADS)

Berzina, Tatiana; Smerieri, Anteo; Bernabò, Marco; Pucci, Andrea; Ruggeri, Giacomo; Erokhin, Victor; Fontana, M. P.

2009-06-01

The combination of memory and signal handling characteristics of a memristor makes it a promising candidate for adaptive bioinspired information processing systems. This poses stringent requirements on the basic device, such as stability and reproducibility over a large number of training/learning cycles, and a large anisotropy in the fundamental control material parameter, in our case the electrical conductivity. In this work we report results on the improved performance of electrochemically controlled polymeric memristors, where optimization of a conducting polymer (polyaniline) in the active channel and better environmental control of fabrication methods led to a large increase both in the absolute values of the conductivity in the partially oxydized state of polyaniline and of the on-off conductivity ratio. These improvements are crucial for the application of the organic memristor to adaptive complex signal handling networks.

Digital beacon receiver for ionospheric TEC measurement developed with GNU Radio

NASA Astrophysics Data System (ADS)

Yamamoto, M.

2008-11-01

A simple digital receiver named GNU Radio Beacon Receiver (GRBR) was developed for the satellite-ground beacon experiment to measure the ionospheric total electron content (TEC). The open-source software toolkit for the software defined radio, GNU Radio, is utilized to realize the basic function of the receiver and perform fast signal processing. The software is written in Python for a LINUX PC. The open-source hardware called Universal Software Radio Peripheral (USRP), which best matches the GNU Radio, is used as a front-end to acquire the satellite beacon signals of 150 and 400 MHz. The first experiment was successful as results from GRBR showed very good agreement to those from the co-located analog beacon receiver. Detailed design information and software codes are open at the URL http://www.rish.kyoto-u.ac.jp/digitalbeacon/.

Methods for Modeling Brassinosteroid-Mediated Signaling in Plant Development.

PubMed

Frigola, David; Caño-Delgado, Ana I; Ibañes, Marta

2017-01-01

Mathematical modeling of biological processes is a useful tool to draw conclusions that are contained in the data, but not directly reachable, as well as to make predictions and select the most efficient follow-up experiments. Here we outline a method to model systems of a few proteins that interact transcriptionally and/or posttranscriptionally, by representing the system as Ordinary Differential Equations and to study the model dynamics and stationary states. We exemplify this method by focusing on the regulation by the brassinosteroid (BR) signaling component BRASSINOSTEROID INSENSITIVE1 ETHYL METHYL SULFONATE SUPPRESSOR1 (BES1) of BRAVO, a quiescence-regulating transcription factor expressed in the quiescent cells of Arabidopsis thaliana roots. The method to extract the stationary states and the dynamics is provided as a Mathematica code and requires basic knowledge of the Mathematica software to be executed.

Dynamic facial expressions of emotion transmit an evolving hierarchy of signals over time.

PubMed

Jack, Rachael E; Garrod, Oliver G B; Schyns, Philippe G

2014-01-20

Designed by biological and social evolutionary pressures, facial expressions of emotion comprise specific facial movements to support a near-optimal system of signaling and decoding. Although highly dynamical, little is known about the form and function of facial expression temporal dynamics. Do facial expressions transmit diagnostic signals simultaneously to optimize categorization of the six classic emotions, or sequentially to support a more complex communication system of successive categorizations over time? Our data support the latter. Using a combination of perceptual expectation modeling, information theory, and Bayesian classifiers, we show that dynamic facial expressions of emotion transmit an evolving hierarchy of "biologically basic to socially specific" information over time. Early in the signaling dynamics, facial expressions systematically transmit few, biologically rooted face signals supporting the categorization of fewer elementary categories (e.g., approach/avoidance). Later transmissions comprise more complex signals that support categorization of a larger number of socially specific categories (i.e., the six classic emotions). Here, we show that dynamic facial expressions of emotion provide a sophisticated signaling system, questioning the widely accepted notion that emotion communication is comprised of six basic (i.e., psychologically irreducible) categories, and instead suggesting four. Copyright © 2014 Elsevier Ltd. All rights reserved.

Charactering lidar optical subsystem using four quadrants method

NASA Astrophysics Data System (ADS)

Tian, Xiaomin; Liu, Dong; Xu, Jiwei; Wang, Zhenzhu; Wang, Bangxin; Wu, Decheng; Zhong, Zhiqing; Xie, Chenbo; Wang, Yingjian

2018-02-01

Lidar is a kind of active optical remote sensing instruments , can be applied to sound atmosphere with a high spatial and temporal resolution. Many parameter of atmosphere can be get by using different inverse algorithm with lidar backscatter signal. The basic setup of a lidar consist of a transmitter and a receiver. To make sure the quality of lidar signal data, the lidar must be calibrated before being used to measure the atmospheric variables. It is really significant to character and analyze lidar optical subsystem because a well equiped lidar optical subsystem contributes to high quality lidar signal data. we pay close attention to telecover test to character and analyze lidar optical subsystem.The telecover test is called four quadrants method consisting in dividing the telescope aperture in four quarants. when a lidar is well configured with lidar optical subsystem, the normalized signal from four qudrants will agree with each other on some level. Testing our WARL-II lidar by four quadrants method ,we find the signals of the four basically consistent with each other both in near range and in far range. But in detail, the signals in near range have some slight distinctions resulting from overlap function, some signals distinctions are induced by atmospheric instability.

Brain Tissue Responses to Neural Implants Impact Signal Sensitivity and Intervention Strategies

PubMed Central

2015-01-01

Implantable biosensors are valuable scientific tools for basic neuroscience research and clinical applications. Neurotechnologies provide direct readouts of neurological signal and neurochemical processes. These tools are generally most valuable when performance capacities extend over months and years to facilitate the study of memory, plasticity, and behavior or to monitor patients’ conditions. These needs have generated a variety of device designs from microelectrodes for fast scan cyclic voltammetry (FSCV) and electrophysiology to microdialysis probes for sampling and detecting various neurochemicals. Regardless of the technology used, the breaching of the blood–brain barrier (BBB) to insert devices triggers a cascade of biochemical pathways resulting in complex molecular and cellular responses to implanted devices. Molecular and cellular changes in the microenvironment surrounding an implant include the introduction of mechanical strain, activation of glial cells, loss of perfusion, secondary metabolic injury, and neuronal degeneration. Changes to the tissue microenvironment surrounding the device can dramatically impact electrochemical and electrophysiological signal sensitivity and stability over time. This review summarizes the magnitude, variability, and time course of the dynamic molecular and cellular level neural tissue responses induced by state-of-the-art implantable devices. Studies show that insertion injuries and foreign body response can impact signal quality across all implanted central nervous system (CNS) sensors to varying degrees over both acute (seconds to minutes) and chronic periods (weeks to months). Understanding the underlying biological processes behind the brain tissue response to the devices at the cellular and molecular level leads to a variety of intervention strategies for improving signal sensitivity and longevity. PMID:25546652

Architecture for a 1-GHz Digital RADAR

NASA Technical Reports Server (NTRS)

Mallik, Udayan

2011-01-01

An architecture for a Direct RF-digitization Type Digital Mode RADAR was developed at GSFC in 2008. Two variations of a basic architecture were developed for use on RADAR imaging missions using aircraft and spacecraft. Both systems can operate with a pulse repetition rate up to 10 MHz with 8 received RF samples per pulse repetition interval, or at up to 19 kHz with 4K received RF samples per pulse repetition interval. The first design describes a computer architecture for a Continuous Mode RADAR transceiver with a real-time signal processing and display architecture. The architecture can operate at a high pulse repetition rate without interruption for an infinite amount of time. The second design describes a smaller and less costly burst mode RADAR that can transceive high pulse repetition rate RF signals without interruption for up to 37 seconds. The burst-mode RADAR was designed to operate on an off-line signal processing paradigm. The temporal distribution of RF samples acquired and reported to the RADAR processor remains uniform and free of distortion in both proposed architectures. The majority of the RADAR's electronics is implemented in digital CMOS (complementary metal oxide semiconductor), and analog circuits are restricted to signal amplification operations and analog to digital conversion. An implementation of the proposed systems will create a 1-GHz, Direct RF-digitization Type, L-Band Digital RADAR--the highest band achievable for Nyquist Rate, Direct RF-digitization Systems that do not implement an electronic IF downsample stage (after the receiver signal amplification stage), using commercially available off-the-shelf integrated circuits.

Body Morphology, Energy Stores, and Muscle Enzyme Activity Explain Cricket Acoustic Mate Attraction Signaling Variation

PubMed Central

Thomson, Ian R.; Darveau, Charles-A.; Bertram, Susan M.

2014-01-01

High mating success in animals is often dependent on males signalling attractively with high effort. Since males should be selected to maximize their reproductive success, female preferences for these traits should result in minimal signal variation persisting in the population. However, extensive signal variation persists. The genic capture hypothesis proposes genetic variation persists because fitness-conferring traits depend on an individual's basic processes, including underlying physiological, morphological, and biochemical traits, which are themselves genetically variable. To explore the traits underlying signal variation, we quantified among-male differences in signalling, morphology, energy stores, and the activities of key enzymes associated with signalling muscle metabolism in two species of crickets, Gryllus assimilis (chirper: <20 pulses/chirp) and G. texensis (triller: >20 pulses/chirp). Chirping G. assimilis primarily fuelled signalling with carbohydrate metabolism: smaller individuals and individuals with increased thoracic glycogen stores signalled for mates with greater effort; individuals with greater glycogen phosphorylase activity produced more attractive mating signals. Conversely, the more energetic trilling G. texensis fuelled signalling with both lipid and carbohydrate metabolism: individuals with increased β-hydroxyacyl-CoA dehydrogenase activity and increased thoracic free carbohydrate content signalled for mates with greater effort; individuals with higher thoracic and abdominal carbohydrate content and higher abdominal lipid stores produced more attractive signals. Our findings suggest variation in male reproductive success may be driven by hidden physiological trade-offs that affect the ability to uptake, retain, and use essential nutrients, although the results remain correlational in nature. Our findings indicate that a physiological perspective may help us to understand some of the causes of variation in behaviour. PMID:24608102

47 CFR 76.901 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... principal headend. (d) New Product Tier. A new product tier (“NPT”) is a cable programming service tier... CABLE TELEVISION SERVICE Cable Rate Regulation § 76.901 Definitions. (a) Basic service. The basic service tier shall, at a minimum, include all signals of domestic television broadcast stations provided...

47 CFR 76.901 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... principal headend. (d) New Product Tier. A new product tier (“NPT”) is a cable programming service tier... CABLE TELEVISION SERVICE Cable Rate Regulation § 76.901 Definitions. (a) Basic service. The basic service tier shall, at a minimum, include all signals of domestic television broadcast stations provided...

47 CFR 76.901 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... principal headend. (d) New Product Tier. A new product tier (“NPT”) is a cable programming service tier... CABLE TELEVISION SERVICE Cable Rate Regulation § 76.901 Definitions. (a) Basic service. The basic service tier shall, at a minimum, include all signals of domestic television broadcast stations provided...

Receiver design and performance characteristics

NASA Technical Reports Server (NTRS)

Simon, M. K.; Yuen, J. H.

1982-01-01

The basic design, principles of operation, and characteristics of deep space communications receivers are examined. In particular, the basic fundamentals of phase-locked loop and Costas loop receivers used for synchronization, tracking, and demodulation of phase-coherent signals in residual carrier and suppressed carrier systems are addressed.

Principles of Temporal Processing Across the Cortical Hierarchy.

PubMed

Himberger, Kevin D; Chien, Hsiang-Yun; Honey, Christopher J

2018-05-02

The world is richly structured on multiple spatiotemporal scales. In order to represent spatial structure, many machine-learning models repeat a set of basic operations at each layer of a hierarchical architecture. These iterated spatial operations - including pooling, normalization and pattern completion - enable these systems to recognize and predict spatial structure, while robust to changes in the spatial scale, contrast and noisiness of the input signal. Because our brains also process temporal information that is rich and occurs across multiple time scales, might the brain employ an analogous set of operations for temporal information processing? Here we define a candidate set of temporal operations, and we review evidence that they are implemented in the mammalian cerebral cortex in a hierarchical manner. We conclude that multiple consecutive stages of cortical processing can be understood to perform temporal pooling, temporal normalization and temporal pattern completion. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Basic characteristics and functions of traffic signal equipment.

DOT National Transportation Integrated Search

1977-01-01

A questionnaire survey was conducted to determine the types of traffic signal controls utilized by state and local agencies. The majority of the equipment was found to be supplied by three manufacturers; however, there are hundreds of different piece...

Guidelines for traffic signal energy back\\0x2010up systems : final report.

DOT National Transportation Integrated Search

2009-07-01

Power outages affect traffic signalized intersections, leading to potentially serious problems. Current practices of responding to power failures are very basic, ranging from do nothing to installing portable generators. The purpose of this res...

Power processor for a 30cm ion thruster

NASA Technical Reports Server (NTRS)

Biess, J. J.; Inouye, L. Y.

1974-01-01

A thermal vacuum power processor for the NASA Lewis 30cm Mercury Ion Engine was designed, fabricated and tested to determine compliance with electrical specifications. The power processor breadboard used the silicon controlled rectifier (SCR) series resonant inverter as the basic power stage to process all the power to an ion engine. The power processor includes a digital interface unit to process all input commands and internal telemetry signals so that operation is compatible with a central computer system. The breadboard was tested in a thermal vacuum environment. Integration tests were performed with the ion engine and demonstrate operational compatibility and reliable operation without any component failures. Electromagnetic interference data were also recorded on the design to provide information on the interaction with total spacecraft.

Quark contact interactions at the LHC

NASA Astrophysics Data System (ADS)

Bazzocchi, F.; De Sanctis, U.; Fabbrichesi, M.; Tonero, A.

2012-06-01

Quark contact interactions are an important signal of new physics. We introduce a model in which the presence of a symmetry protects these new interactions from giving large corrections in flavor changing processes at low energies. This minimal model provides the basic set of operators which must be considered to contribute to the high-energy processes. To discuss their experimental signature in jet pairs produced in proton-proton collisions, we simplify the number of possible operators down to two. We show (for a representative integrated luminosity of 200pb-1 at s=7TeV) how the presence of two operators significantly modifies the bound on the characteristic energy scale of the contact interactions, which is obtained by keeping a single operator.

An expanding universe of circadian networks in higher plants.

PubMed

Pruneda-Paz, Jose L; Kay, Steve A

2010-05-01

Extensive circadian clock networks regulate almost every biological process in plants. Clock-controlled physiological responses are coupled with daily oscillations in environmental conditions resulting in enhanced fitness and growth vigor. Identification of core clock components and their associated molecular interactions has established the basic network architecture of plant clocks, which consists of multiple interlocked feedback loops. A hierarchical structure of transcriptional feedback overlaid with regulated protein turnover sets the pace of the clock and ultimately drives all clock-controlled processes. Although originally described as linear entities, increasing evidence suggests that many signaling pathways can act as both inputs and outputs within the overall network. Future studies will determine the molecular mechanisms involved in these complex regulatory loops. 2010 Elsevier Ltd. All rights reserved.

Balancing: a basic process in end-of-life cancer care.

PubMed

Thulesius, Hans; Håkansson, Anders; Petersson, Kerstin

2003-12-01

In this grounded theory study, the authors interviewed caregivers and patients in end-of-life cancer care and found Balancing to be a fundamental process explaining the problem-solving strategies of most participants and offering a comprehensive perspective on both health care in general and end-of-life cancer care in particular. Balancing stages were Weighing--sensing needs and wishes signaled by patients, gauging them against caregiver resources in diagnosing and care planning; Shifting--breaking bad news, changing care places, and treatments; and Compensating--controlling symptoms, educating and team-working, prioritizing and "stretching" time, innovating care methods, improvising, and maintaining the homeostasis of hope. The Balancing outcome is characterized by Compromising, or "Walking a fine line," at best an optimized situation, at worst a deceit.

Testing Convergent Evolution in Auditory Processing Genes between Echolocating Mammals and the Aye-Aye, a Percussive-Foraging Primate

PubMed Central

Jerjos, Michael; Hohman, Baily; Lauterbur, M. Elise; Kistler, Logan

2017-01-01

Abstract Several taxonomically distinct mammalian groups—certain microbats and cetaceans (e.g., dolphins)—share both morphological adaptations related to echolocation behavior and strong signatures of convergent evolution at the amino acid level across seven genes related to auditory processing. Aye-ayes (Daubentonia madagascariensis) are nocturnal lemurs with a specialized auditory processing system. Aye-ayes tap rapidly along the surfaces of trees, listening to reverberations to identify the mines of wood-boring insect larvae; this behavior has been hypothesized to functionally mimic echolocation. Here we investigated whether there are signals of convergence in auditory processing genes between aye-ayes and known mammalian echolocators. We developed a computational pipeline (Basic Exon Assembly Tool) that produces consensus sequences for regions of interest from shotgun genomic sequencing data for nonmodel organisms without requiring de novo genome assembly. We reconstructed complete coding region sequences for the seven convergent echolocating bat–dolphin genes for aye-ayes and another lemur. We compared sequences from these two lemurs in a phylogenetic framework with those of bat and dolphin echolocators and appropriate nonecholocating outgroups. Our analysis reaffirms the existence of amino acid convergence at these loci among echolocating bats and dolphins; some methods also detected signals of convergence between echolocating bats and both mice and elephants. However, we observed no significant signal of amino acid convergence between aye-ayes and echolocating bats and dolphins, suggesting that aye-aye tap-foraging auditory adaptations represent distinct evolutionary innovations. These results are also consistent with a developing consensus that convergent behavioral ecology does not reliably predict convergent molecular evolution. PMID:28810710

Neural sensitivity to social deviance predicts attentive processing of peer-group judgment.

PubMed

Schnuerch, Robert; Trautmann-Lengsfeld, Sina Alexa; Bertram, Mario; Gibbons, Henning

2014-01-01

The detection of one's deviance from social norms is an essential mechanism of individual adjustment to group behavior and, thus, for the perpetuation of norms within groups. It has been suggested that error signals in mediofrontal cortex provide the neural basis of such deviance detection, which contributes to later adjustment to the norm. In the present study, we used event-related potentials (ERPs) to demonstrate that, across participants, the strength of mediofrontal brain correlates of the detection of deviance from a peer group's norms was negatively related to attentive processing of the same group's judgments in a later task. We propose that an individual's perception of social deviance might bias basic cognitive processing during further interaction with the group. Strongly perceiving disagreement with a group could cause an individual to avoid or inhibit this group's judgments.

The clinical relevance of neuroplasticity in corticostriatal networks during operant learning

PubMed Central

Andrzejewski, Matthew E.; McKee, Brenda L.; Baldwin, Anne E.; Burns, Lindsay; Hernandez, Pepe

2013-01-01

Dopamine and glutamate serve crucial functions in neural plasticity, learning and memory, and addiction. Contemporary theories contend that these two, widely-distributed neurotransmitter systems play an integrative role in motivational and associative information processing. Combined signaling of these systems, particularly through the dopamine (DA) D1 and glutamate (Glu) N-methyl-D-aspartate receptors (NMDAR), triggers critical intracellular signaling cascades that lead to changes in chromatin structure, gene expression, synaptic plasticity, and ultimately behavior. Addictive drugs also induce long-term neuroadaptations at the molecular and genomic levels causing structural changes that alter basic connectivity. Indeed, evidence that drugs of abuse engage D1- and NMDA-mediated neuronal cascades shared with normal reward learning provides one of the most important insights from contemporary studies on the neurobiology of addiction. Such drug-induced neuroadaptations likely contribute to abnormal information processing and behavior, resulting in the poor decision-making, loss of control, and compulsivity that characterize addiction. Such features are also common to many other neuropsychiatric disorders. Behavior problems, construed as difficulties associated with operant learning and behavior, present compelling challenges and unique opportunities for their treatment that require further study. The present review highlights the integrative work of Ann E. Kelley and colleagues, demonstrating a critical role not only for NMDAR, D1 receptors (D1R), and their associated signaling cascades, but also for other Glu receptors and protein synthesis in operant learning throughout a cortico-striatal-limbic network. Recent work has extended the impact of appetitive learning to epigenetic processes. A better understanding of these processes will likely assist in discovering therapeutics to engage neural plasticity-related processes and promote functional behavioral adaptations. PMID:23567518

Teaching computer interfacing with virtual instruments in an object-oriented language.

PubMed Central

Gulotta, M

1995-01-01

LabVIEW is a graphic object-oriented computer language developed to facilitate hardware/software communication. LabVIEW is a complete computer language that can be used like Basic, FORTRAN, or C. In LabVIEW one creates virtual instruments that aesthetically look like real instruments but are controlled by sophisticated computer programs. There are several levels of data acquisition VIs that make it easy to control data flow, and many signal processing and analysis algorithms come with the software as premade VIs. In the classroom, the similarity between virtual and real instruments helps students understand how information is passed between the computer and attached instruments. The software may be used in the absence of hardware so that students can work at home as well as in the classroom. This article demonstrates how LabVIEW can be used to control data flow between computers and instruments, points out important features for signal processing and analysis, and shows how virtual instruments may be used in place of physical instrumentation. Applications of LabVIEW to the teaching laboratory are also discussed, and a plausible course outline is given. PMID:8580361

Molecular and genetic characterization of osmosensing and signal transduction in the nematode Caenorhabditis elegans.

PubMed

Choe, Keith P; Strange, Kevin

2007-11-01

Osmotic homeostasis is a fundamental requirement for life. In general, the effector mechanisms that mediate cellular and extracellular osmoregulation in animals are reasonably well defined. However, at the molecular level, little is known about how animals detect osmotic and ionic perturbations and transduce them into regulatory responses. The nematode Caenorhabditis elegans provides numerous powerful experimental advantages for defining the genes and integrated gene networks that underlie basic biological processes. These advantages include a fully sequenced and well-annotated genome, forward and reverse genetic and molecular tractability, and a relatively simple anatomy. C. elegans normally inhabits soil environments where it is exposed to repeated osmotic stress. In the laboratory, nematodes readily acclimate to and recover from extremes of hypertonicity. We review recent progress in defining the molecular mechanisms that underlie osmosensing and associated signal transduction in C. elegans. Some of these mechanisms are now known to be highly conserved. Therefore, studies of osmosensing in nematodes have provided, and will undoubtedly continue to provide, new insights into similar processes in more complex organisms including mammals.

Yeast as a model for Ras signalling.

PubMed

Tisi, Renata; Belotti, Fiorella; Martegani, Enzo

2014-01-01

For centuries yeast species have been popular hosts for classical biotechnology processes, such as baking, brewing, and wine making, and more recently for recombinant proteins production, thanks to the advantages of unicellular organisms (i.e., ease of genetic manipulation and rapid growth) together with the ability to perform eukaryotic posttranslational modifications. Moreover, yeast cells have been used for few decades as a tool for identifying the genes and pathways involved in basic cellular processes such as the cell cycle, aging, and stress response. In the budding yeast S. cerevisiae the Ras/cAMP/PKA pathway is directly involved in the regulation of metabolism, cell growth, stress resistance, and proliferation in response to the availability of nutrients and in the adaptation to glucose, controlling cytosolic cAMP levels and consequently the cAMP-dependent protein kinase (PKA) activity. Moreover, Ras signalling has been identified in several pathogenic yeasts as a key controller for virulence, due to its involvement in yeast morphogenesis. Nowadays, yeasts are still useful for Ras-like proteins investigation, both as model organisms and as a test tube to study variants of heterologous Ras-like proteins.

Digital signal processing of the phonocardiogram: review of the most recent advancements.

PubMed

Durand, L G; Pibarot, P

1995-01-01

The objective of the present paper is to provide a detailed review of the most recent developments in instrumentation and signal processing of digital phonocardiography and heart auscultation. After a short introduction, the paper presents a brief history of heart auscultation and phonocardiography, which is followed by a summary of the basic theories and controversies regarding the genesis of the heart sounds. The application of spectral analysis and the potential of new time-frequency representations and cardiac acoustic mapping to resolve the controversies and better understand the genesis and transmission of heart sounds and murmurs within the heart-thorax acoustic system are reviewed. The most recent developments in the application of linear predictive coding, spectral analysis, time-frequency representation techniques, and pattern recognition for the detection and follow-up of native and prosthetic valve degeneration and dysfunction are also presented in detail. New areas of research and clinical applications and areas of potential future developments are then highlighted. The final section is a discussion about a multidegree of freedom theory on the origin of the heart sounds and murmurs, which is completed by the authors' conclusion.

Teaching computer interfacing with virtual instruments in an object-oriented language.

PubMed

Gulotta, M

1995-11-01

LabVIEW is a graphic object-oriented computer language developed to facilitate hardware/software communication. LabVIEW is a complete computer language that can be used like Basic, FORTRAN, or C. In LabVIEW one creates virtual instruments that aesthetically look like real instruments but are controlled by sophisticated computer programs. There are several levels of data acquisition VIs that make it easy to control data flow, and many signal processing and analysis algorithms come with the software as premade VIs. In the classroom, the similarity between virtual and real instruments helps students understand how information is passed between the computer and attached instruments. The software may be used in the absence of hardware so that students can work at home as well as in the classroom. This article demonstrates how LabVIEW can be used to control data flow between computers and instruments, points out important features for signal processing and analysis, and shows how virtual instruments may be used in place of physical instrumentation. Applications of LabVIEW to the teaching laboratory are also discussed, and a plausible course outline is given.

Integrated waveguide Bragg gratings for microwave photonics signal processing.

PubMed

Burla, Maurizio; Cortés, Luis Romero; Li, Ming; Wang, Xu; Chrostowski, Lukas; Azaña, José

2013-10-21

Integrated Microwave photonics (IMWP) signal processing using Photonic Integrated Circuits (PICs) has attracted a great deal of attention in recent years as an enabling technology for a number of functionalities not attainable by purely microwave solutions. In this context, integrated waveguide Bragg grating (WBG) devices constitute a particularly attractive approach thanks to their compactness and flexibility in producing arbitrarily defined amplitude and phase responses, by directly acting on coupling coefficient and perturbations of the grating profile. In this article, we review recent advances in the field of integrated WBGs applied to MWP, analyzing the advantages leveraged by an integrated realization. We provide a perspective on the exciting possibilities offered by the silicon photonics platform in the field of MWP, potentially enabling integration of highly-complex active and passive functionalities with high yield on a single chip, with a particular focus on the use of WBGs as basic building blocks for linear filtering operations. We demonstrate the versatility of WBG-based devices by proposing and experimentally demonstrating a novel, continuously-tunable, integrated true-time-delay (TTD) line based on a very simple dual phase-shifted WBG (DPS-WBG).

Effects of Sound Frequency on Audiovisual Integration: An Event-Related Potential Study.

PubMed

Yang, Weiping; Yang, Jingjing; Gao, Yulin; Tang, Xiaoyu; Ren, Yanna; Takahashi, Satoshi; Wu, Jinglong

2015-01-01

A combination of signals across modalities can facilitate sensory perception. The audiovisual facilitative effect strongly depends on the features of the stimulus. Here, we investigated how sound frequency, which is one of basic features of an auditory signal, modulates audiovisual integration. In this study, the task of the participant was to respond to a visual target stimulus by pressing a key while ignoring auditory stimuli, comprising of tones of different frequencies (0.5, 1, 2.5 and 5 kHz). A significant facilitation of reaction times was obtained following audiovisual stimulation, irrespective of whether the task-irrelevant sounds were low or high frequency. Using event-related potential (ERP), audiovisual integration was found over the occipital area for 0.5 kHz auditory stimuli from 190-210 ms, for 1 kHz stimuli from 170-200 ms, for 2.5 kHz stimuli from 140-200 ms, 5 kHz stimuli from 100-200 ms. These findings suggest that a higher frequency sound signal paired with visual stimuli might be early processed or integrated despite the auditory stimuli being task-irrelevant information. Furthermore, audiovisual integration in late latency (300-340 ms) ERPs with fronto-central topography was found for auditory stimuli of lower frequencies (0.5, 1 and 2.5 kHz). Our results confirmed that audiovisual integration is affected by the frequency of an auditory stimulus. Taken together, the neurophysiological results provide unique insight into how the brain processes a multisensory visual signal and auditory stimuli of different frequencies.

ROBUSTNESS OF SIGNALING GRADIENT IN DROSOPHILA WING IMAGINAL DISC

PubMed Central

Lei, Jinzhi; Wan, Frederic Y. M.; Lander, Arthur D.; Nie, Qing

2012-01-01

Quasi-stable gradients of signaling protein molecules (known as morphogens or ligands) bound to cell receptors are known to be responsible for differential cell signaling and gene expressions. From these follow different stable cell fates and visually patterned tissues in biological development. Recent studies have shown that the relevant basic biological processes yield gradients that are sensitive to small changes in system characteristics (such as expression level of morphogens or receptors) or environmental conditions (such as temperature changes). Additional biological activities must play an important role in the high level of robustness observed in embryonic patterning for example. It is natural to attribute observed robustness to various type of feedback control mechanisms. However, our own simulation studies have shown that feedback control is neither necessary nor sufficient for robustness of the morphogen decapentaplegic (Dpp) gradient in wing imaginal disc of Drosophilas. Furthermore, robustness can be achieved by substantial binding of the signaling morphogen Dpp with nonsignaling cell surface bound molecules (such as heparan sulfate proteoglygans) and degrading the resulting complexes at a sufficiently rapid rate. The present work provides a theoretical basis for the results of our numerical simulation studies. PMID:24098092

Disentangling neural representations of value and salience in the human brain

PubMed Central

Kahnt, Thorsten; Park, Soyoung Q; Haynes, John-Dylan; Tobler, Philippe N.

2014-01-01

A large body of evidence has implicated the posterior parietal and orbitofrontal cortex in the processing of value. However, value correlates perfectly with salience when appetitive stimuli are investigated in isolation. Accordingly, considerable uncertainty has remained about the precise nature of the previously identified signals. In particular, recent evidence suggests that neurons in the primate parietal cortex signal salience instead of value. To investigate neural signatures of value and salience, here we apply multivariate (pattern-based) analyses to human functional MRI data acquired during a noninstrumental outcome-prediction task involving appetitive and aversive outcomes. Reaction time data indicated additive and independent effects of value and salience. Critically, we show that multivoxel ensemble activity in the posterior parietal cortex encodes predicted value and salience in superior and inferior compartments, respectively. These findings reinforce the earlier reports of parietal value signals and reconcile them with the recent salience report. Moreover, we find that multivoxel patterns in the orbitofrontal cortex correlate with value. Importantly, the patterns coding for the predicted value of appetitive and aversive outcomes are similar, indicating a common neural scale for appetite and aversive values in the orbitofrontal cortex. Thus orbitofrontal activity patterns satisfy a basic requirement for a neural value signal. PMID:24639493

A diagnostic signal selection scheme for planetary gearbox vibration monitoring under non-stationary operational conditions

NASA Astrophysics Data System (ADS)

Feng, Ke; Wang, KeSheng; Zhang, Mian; Ni, Qing; Zuo, Ming J.

2017-03-01

The planetary gearbox, due to its unique mechanical structures, is an important rotating machine for transmission systems. Its engineering applications are often in non-stationary operational conditions, such as helicopters, wind energy systems, etc. The unique physical structures and working conditions make the vibrations measured from planetary gearboxes exhibit a complex time-varying modulation and therefore yield complicated spectral structures. As a result, traditional signal processing methods, such as Fourier analysis, and the selection of characteristic fault frequencies for diagnosis face serious challenges. To overcome this drawback, this paper proposes a signal selection scheme for fault-emphasized diagnostics based upon two order tracking techniques. The basic procedures for the proposed scheme are as follows. (1) Computed order tracking is applied to reveal the order contents and identify the order(s) of interest. (2) Vold-Kalman filter order tracking is used to extract the order(s) of interest—these filtered order(s) constitute the so-called selected vibrations. (3) Time domain statistic indicators are applied to the selected vibrations for faulty information-emphasized diagnostics. The proposed scheme is explained and demonstrated in a signal simulation model and experimental studies and the method proves to be effective for planetary gearbox fault diagnosis.

Cross-cultural recognition of basic emotions through nonverbal emotional vocalizations

PubMed Central

Sauter, Disa A.; Eisner, Frank; Ekman, Paul; Scott, Sophie K.

2010-01-01

Emotional signals are crucial for sharing important information, with conspecifics, for example, to warn humans of danger. Humans use a range of different cues to communicate to others how they feel, including facial, vocal, and gestural signals. We examined the recognition of nonverbal emotional vocalizations, such as screams and laughs, across two dramatically different cultural groups. Western participants were compared to individuals from remote, culturally isolated Namibian villages. Vocalizations communicating the so-called “basic emotions” (anger, disgust, fear, joy, sadness, and surprise) were bidirectionally recognized. In contrast, a set of additional emotions was only recognized within, but not across, cultural boundaries. Our findings indicate that a number of primarily negative emotions have vocalizations that can be recognized across cultures, while most positive emotions are communicated with culture-specific signals. PMID:20133790

Modeling the effects of Multi-path propagation and scintillation on GPS signals

NASA Astrophysics Data System (ADS)

Habash Krause, L.; Wilson, S. J.

2014-12-01

GPS signals traveling through the earth's ionosphere are affected by charged particles that often disrupt the signal and the information it carries due to "scintillation", which resembles an extra noise source on the signal. These signals are also affected by weather changes, tropospheric scattering, and absorption from objects due to multi-path propagation of the signal. These obstacles cause distortion within information and fading of the signal, which ultimately results in phase locking errors and noise in messages. In this work, we attempted to replicate the distortion that occurs in GPS signals using a signal processing simulation model. We wanted to be able to create and identify scintillated signals so we could better understand the environment that caused it to become scintillated. Then, under controlled conditions, we simulated the receiver's ability to suppress scintillation in a signal. We developed a code in MATLAB that was programmed to: 1. Create a carrier wave and then plant noise (four different frequencies) on the carrier wave, 2. Compute a Fourier transform on the four different frequencies to find the frequency content of a signal, 3. Use a filter and apply it to the Fourier transform of the four frequencies and then compute a Signal-to-noise ratio to evaluate the power (in Decibels) of the filtered signal, and 4.Plot each of these components into graphs. To test the code's validity, we used user input and data from an AM transmitter. We determined that the amplitude modulated signal or AM signal would be the best type of signal to test the accuracy of the MATLAB code due to its simplicity. This code is basic to give students the ability to change and use it to determine the environment and effects of noise on different AM signals and their carrier waves. Overall, we were able to manipulate a scenario of a noisy signal and interpret its behavior and change due to its noisy components: amplitude, frequency, and phase shift.

Performance verification and system integration tests of the pulse shape processor for the soft x-ray spectrometer onboard ASTRO-H

NASA Astrophysics Data System (ADS)

Takeda, Sawako; Tashiro, Makoto S.; Ishisaki, Yoshitaka; Tsujimoto, Masahiro; Seta, Hiromi; Shimoda, Yuya; Yamaguchi, Sunao; Uehara, Sho; Terada, Yukikatsu; Fujimoto, Ryuichi; Mitsuda, Kazuhisa

2014-07-01

The soft X-ray spectrometer (SXS) aboard ASTRO-H is equipped with dedicated digital signal processing units called pulse shape processors (PSPs). The X-ray microcalorimeter system SXS has 36 sensor pixels, which are operated at 50 mK to measure heat input of X-ray photons and realize an energy resolution of 7 eV FWHM in the range 0.3-12.0 keV. Front-end signal processing electronics are used to filter and amplify the electrical pulse output from the sensor and for analog-to-digital conversion. The digitized pulses from the 36 pixels are multiplexed and are sent to the PSP over low-voltage differential signaling lines. Each of two identical PSP units consists of an FPGA board, which assists the hardware logic, and two CPU boards, which assist the onboard software. The FPGA board triggers at every pixel event and stores the triggering information as a pulse waveform in the installed memory. The CPU boards read the event data to evaluate pulse heights by an optimal filtering algorithm. The evaluated X-ray photon data (including the pixel ID, energy, and arrival time information) are transferred to the satellite data recorder along with event quality information. The PSP units have been developed and tested with the engineering model (EM) and the flight model. Utilizing the EM PSP, we successfully verified the entire hardware system and the basic software design of the PSPs, including their communication capability and signal processing performance. In this paper, we show the key metrics of the EM test, such as accuracy and synchronicity of sampling clocks, event grading capability, and resultant energy resolution.

Epileptic seizure detection in EEG signal using machine learning techniques.

PubMed

Jaiswal, Abeg Kumar; Banka, Haider

2018-03-01

Epilepsy is a well-known nervous system disorder characterized by seizures. Electroencephalograms (EEGs), which capture brain neural activity, can detect epilepsy. Traditional methods for analyzing an EEG signal for epileptic seizure detection are time-consuming. Recently, several automated seizure detection frameworks using machine learning technique have been proposed to replace these traditional methods. The two basic steps involved in machine learning are feature extraction and classification. Feature extraction reduces the input pattern space by keeping informative features and the classifier assigns the appropriate class label. In this paper, we propose two effective approaches involving subpattern based PCA (SpPCA) and cross-subpattern correlation-based PCA (SubXPCA) with Support Vector Machine (SVM) for automated seizure detection in EEG signals. Feature extraction was performed using SpPCA and SubXPCA. Both techniques explore the subpattern correlation of EEG signals, which helps in decision-making process. SVM is used for classification of seizure and non-seizure EEG signals. The SVM was trained with radial basis kernel. All the experiments have been carried out on the benchmark epilepsy EEG dataset. The entire dataset consists of 500 EEG signals recorded under different scenarios. Seven different experimental cases for classification have been conducted. The classification accuracy was evaluated using tenfold cross validation. The classification results of the proposed approaches have been compared with the results of some of existing techniques proposed in the literature to establish the claim.

Prototype Scale Development of an Environmentally Benign Yellow Smoke Hand-Held Signal Formulation Based on Solvent Yellow 33

DTIC Science & Technology

2013-04-15

VAAR) was purchased from McGean. Hydrated basic magnesium carbonate was obtained from Pine Bluff Arsenal (Pine Bluff, AR) and was confirmed to be Mg5( CO3 ...a potential environmental exposure of approximately 29 g of the toxic yellow dyes throughout the life cycle of a single M194 signal! To mitigate this...consists of Solvent Yellow 33 as the smoke sublimating agent, hydrated basic magnesium carbonate (Mg5( CO3 )4(OH)2·4H2O) instead of sodium bicarbonate (NaHCO3

Signal Processing Design of Low Probability of Intercept Waveforms via Intersymbol Dither

DTIC Science & Technology

2008-03-01

filter output asynchronously. 3.3.1 Basic Receiver. This section considers the receiver shown in Fig- ure 3.4. Note that the matched filter output is...0 0.5 1 Q ua dr at ur e In−phase s1s2 s3 s4 Figure 4.3: 4-ary DPSK Constellation Table 4.1: 4-ary DPSK Gray code mapping Word Phase Shift, ∆θ 00 0 01...both the real and imaginary parts of each noise samples following an independent Gaussian distribution. The Marsaglia ziggurat algorithm in Matlabr is

Taste transductions in taste receptor cells: basic tastes and moreover.

PubMed

Iwata, Shusuke; Yoshida, Ryusuke; Ninomiya, Yuzo

2014-01-01

In the oral cavity, taste receptor cells dedicate to detecting chemical compounds in foodstuffs and transmitting their signals to gustatory nerve fibers. Heretofore, five taste qualities (sweet, umami, bitter, salty and sour) are generally accepted as basic tastes. Each of these may have a specific role in the detection of nutritious and poisonous substances; sweet for carbohydrate sources of calories, umami for protein and amino acid contents, bitter for harmful compounds, salty for minerals and sour for ripeness of fruits and spoiled foods. Recent studies have revealed molecular mechanisms for reception and transduction of these five basic tastes. Sweet, umami and bitter tastes are mediated by G-protein coupled receptors (GPCRs) and second-messenger signaling cascades. Salty and sour tastes are mediated by channel-type receptors. In addition to five basic tastes, taste receptor cells may have the ability to detect fat taste, which is elicited by fatty acids, and calcium taste, which is elicited by calcium. Taste compounds eliciting either fat taste or calcium taste may be detected by specific GPCRs expressed in taste receptor cells. This review will focus on transduction mechanisms and cellular characteristics responsible for each of basic tastes, fat taste and calcium taste.

Signal transduction mechanisms in plants: an overview

NASA Technical Reports Server (NTRS)

Clark, G. B.; Thompson, G. Jr; Roux, S. J.

2001-01-01

This article provides an overview on recent advances in some of the basic signalling mechanisms that participate in a wide variety of stimulus-response pathways. The mechanisms include calcium-based signalling, G-protein-mediated-signalling and signalling involving inositol phospholipids, with discussion on the role of protein kinases and phosphatases interspersed. As a further defining feature, the article highlights recent exciting findings on three extracellular components that have not been given coverage in previous reviews of signal transduction in plants, extracellular calmodulin, extracellular ATP, and integrin-like receptors, all of which affect plant growth and development.

Implementation of a Broadband Cable System on a University Campus.

ERIC Educational Resources Information Center

Rhoadarmer, Michael

1995-01-01

Discusses broadband communications; broadband coaxial cable and its utility in the media center; basic electronics of radio signals (radio frequency, radio band, bandwidth, MHz, skimming, decibels, sloped amplifiers); engineering basics (insertion loss, splitter, tap, and three beats); and factors to consider before designing a campus broadband…

Emergency obstetric and newborn care signal functions in public and private facilities in Bangladesh.

PubMed

Roy, Lumbini; Biswas, Taposh Kumar; Chowdhury, Mahbub Elahi

2017-01-01

Signal functions for emergency obstetric and newborn care (EmONC) are the major interventions for averting maternal and neonatal mortalities. Readiness of the facilities is essential to provide all the basic and comprehensive signal functions for EmONC to ensure emergency services from the designated facilities. The study assessed population coverage and availability of EmONC services in public and private facilities in Bangladesh. An assessment was conducted in all the public and private facilities providing obstetric care in to in-patients 24 districts. Data were collected on the performance of signal functions for EmONC from the study facilities in the last three months prior to the date of assessment. Trained data-collectors interviewed the facility managers and key service providers, along with review of records, using contextualized tools. Population coverage of signal functions was assessed by estimating the number of facilities providing the signal functions for EmONC compared to the United Nations requirements. Availability was assessed in terms of the proportion of facilities providing the services by type of facilities and by district. Caesarean section (CS) delivery and blood transfusion (BT) services (the two major components of comprehensive EmONC) were respectively available in 6.4 (0.9 public and 5.5 private) and 5.6 (1.3 public and 4.3 private) facilities per 500,000 population. The signal functions for basic EmONC, except two (parental anticonvulsants and assisted vaginal delivery), were available in a minimum of 5 facilities (public and private sectors combined) per 500,000 population. A major inter-district variation in the availability of signal functions was observed in each public- and private-sector facility. Among the various types of facilities, only the public medical college hospitals had all the signal functions. The situation was poor in other public facilities at the district and sub-district levels as well as in private facilities. In the public sector, CS delivery and BT services were available in the minimum required number of facilities. However, to ensure basic EmONC services, participation of the private sector is necessary. Public-private partnership should be promoted for nationwide coverage of signal functions for EmONC in Bangladesh.

Transit signal priority project, phase II : field and simulation evaluation results.

DOT National Transportation Integrated Search

2006-01-01

Transit Signal Priority (TSP) is recognized as an emerging technology that is capable of enhancing traditional transit services. Basic green-extension TSP was implemented on U.S. Route 1 in the Northern Virginia Area (or Washington, DC metropolitan a...

Operational and safety efficiency of traffic signal installations.

DOT National Transportation Integrated Search

2008-05-01

The basic principle of signalization is the provision of a safe and effective means for time and space allocation at an intersection for both vehicular and pedestrian needs. The safety community concurs on the fact that there is the potential for saf...

Wnt signaling and osteoporosis

PubMed Central

Manolagas, Stavros C.

2014-01-01

Major advances in understanding basic bone biology and the cellular and molecular mechanisms responsible for the development of osteoporosis, over the last 20 years, have dramatically altered the management of this disease. The purpose of this mini-review is to highlight the seminal role of Wnt signaling in bone homeostasis and disease and the emergence of novel osteoporosis therapies by targeting Wnt signaling with drugs. PMID:24815296

Denoising of chaotic signal using independent component analysis and empirical mode decomposition with circulate translating

NASA Astrophysics Data System (ADS)

Wen-Bo, Wang; Xiao-Dong, Zhang; Yuchan, Chang; Xiang-Li, Wang; Zhao, Wang; Xi, Chen; Lei, Zheng

2016-01-01

In this paper, a new method to reduce noises within chaotic signals based on ICA (independent component analysis) and EMD (empirical mode decomposition) is proposed. The basic idea is decomposing chaotic signals and constructing multidimensional input vectors, firstly, on the base of EMD and its translation invariance. Secondly, it makes the independent component analysis on the input vectors, which means that a self adapting denoising is carried out for the intrinsic mode functions (IMFs) of chaotic signals. Finally, all IMFs compose the new denoised chaotic signal. Experiments on the Lorenz chaotic signal composed of different Gaussian noises and the monthly observed chaotic sequence on sunspots were put into practice. The results proved that the method proposed in this paper is effective in denoising of chaotic signals. Moreover, it can correct the center point in the phase space effectively, which makes it approach the real track of the chaotic attractor. Project supported by the National Science and Technology, China (Grant No. 2012BAJ15B04), the National Natural Science Foundation of China (Grant Nos. 41071270 and 61473213), the Natural Science Foundation of Hubei Province, China (Grant No. 2015CFB424), the State Key Laboratory Foundation of Satellite Ocean Environment Dynamics, China (Grant No. SOED1405), the Hubei Provincial Key Laboratory Foundation of Metallurgical Industry Process System Science, China (Grant No. Z201303), and the Hubei Key Laboratory Foundation of Transportation Internet of Things, Wuhan University of Technology, China (Grant No.2015III015-B02).

Smad7 Protein Interacts with Receptor-regulated Smads (R-Smads) to Inhibit Transforming Growth Factor-β (TGF-β)/Smad Signaling.

PubMed

Yan, Xiaohua; Liao, Hongwei; Cheng, Minzhang; Shi, Xiaojing; Lin, Xia; Feng, Xin-Hua; Chen, Ye-Guang

2016-01-01

TGF-β is a pleiotropic cytokine that regulates a wide range of cellular actions and pathophysiological processes. TGF-β signaling is spatiotemporally fine-tuned. As a key negative regulator of TGF-β signaling, Smad7 exerts its inhibitory effects by blocking receptor activity, inducing receptor degradation or interfering with Smad-DNA binding. However, the functions and the molecular mechanisms underlying the actions of Smad7 in TGF-β signaling are still not fully understood. In this study we report a novel mechanism whereby Smad7 antagonizes TGF-β signaling at the Smad level. Smad7 oligomerized with R-Smad proteins upon TGF-β signaling and directly inhibited R-Smad activity, as assessed by Gal4-luciferase reporter assays. Mechanistically, Smad7 competes with Smad4 to associate with R-Smads and recruits the E3 ubiquitin ligase NEDD4L to activated R-Smads, leading to their polyubiquitination and proteasomal degradation. Similar to the R-Smad-Smad4 oligomerization, the interaction between R-Smads and Smad7 is mediated by their mad homology 2 (MH2) domains. A positive-charged basic region including the L3/β8 loop-strand module and adjacent amino acids in the MH2 domain of Smad7 is essential for the interaction. These results shed new light on the regulation of TGF-β signaling by Smad7. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Formation of the Embryonic Head in the Mouse: Attributes of a Gene Regulatory Network.

PubMed

Tam, Patrick P L; Fossat, Nicolas; Wilkie, Emilie; Loebel, David A F; Ip, Chi Kin; Ramialison, Mirana

2016-01-01

The embryonic head is the first major body part to be constructed during embryogenesis. The allocation and the assembly of the progenitor tissues, which start at gastrulation, are accompanied by the spatiotemporal activity of transcription factors and signaling pathways that drives lineage specification, germ layer formation, and cell/tissue movement. The morphogenesis, regionalization, and patterning of the brain and craniofacial structures rely on the function of LIM-domain, homeodomain, and basic helix-loop-helix transcription factors. These factors constitute the central nodes of a gene regulatory network (GRN) which encompasses and intersects with signaling pathways involved with head formation. It is predicted that the functional output of this "head GRN" impacts on cellular function and cell-cell interactions that are essential for lineage differentiation and tissue modeling, which are key processes underpinning the formation of the head. © 2016 Elsevier Inc. All rights reserved.

Using computers to overcome math-phobia in an introductory course in musical acoustics

NASA Astrophysics Data System (ADS)

Piacsek, Andrew A.

2002-11-01

In recent years, the desktop computer has acquired the signal processing and visualization capabilities once obtained only with expensive specialized equipment. With the appropriate A/D card and software, a PC can behave like an oscilloscope, a real-time signal analyzer, a function generator, and a synthesizer, with both audio and visual outputs. In addition, the computer can be used to visualize specific wave behavior, such as superposition and standing waves, refraction, dispersion, etc. These capabilities make the computer an invaluable tool to teach basic acoustic principles to students with very poor math skills. In this paper I describe my approach to teaching the introductory-level Physics of Musical Sound at Central Washington University, in which very few science students enroll. Emphasis is placed on how vizualization with computers can help students appreciate and apply quantitative methods for analyzing sound.

Studying Catabolism of Protein ADP-Ribosylation.

PubMed

Palazzo, Luca; James, Dominic I; Waddell, Ian D; Ahel, Ivan

2017-01-01

Protein ADP-ribosylation is a conserved posttranslational modification that regulates many major cellular functions, such as DNA repair, transcription, translation, signal transduction, stress response, cell division, aging, and cell death. Protein ADP-ribosyl transferases catalyze the transfer of an ADP-ribose (ADPr) group from the β-nicotinamide adenine dinucleotide (β-NAD + ) cofactor onto a specific target protein with the subsequent release of nicotinamide. ADP-ribosylation leads to changes in protein structure, function, stability, and localization, thus defining the appropriate cellular response. Signaling processes that are mediated by modifications need to be finely tuned and eventually silenced and one of the ways to achieve this is through the action of enzymes that remove (reverse) protein ADP-ribosylation in a timely fashion such as PARG, TARG1, MACROD1, and MACROD2. Here, we describe several basic methods used to study the enzymatic activity of de-ADP-ribosylating enzymes.

Regulation of Pituitary Stem Cells by Epithelial to Mesenchymal Transition Events and Signaling Pathways

PubMed Central

Cheung, Leonard Y. M.; Davis, Shannon W.; Brinkmeier, Michelle L.; Camper, Sally A.; Pérez-Millán, María Inés

2017-01-01

The anterior pituitary gland is comprised of specialized cell-types that produce and secrete polypeptide hormones in response to hypothalamic input and feedback from target organs. These specialized cells arise from stem cells that express SOX2 and the pituitary transcription factor PROP1, which is necessary to establish the stem cell pool and promote an epithelial to mesenchymal-like transition, releasing progenitors from the niche. The adult anterior pituitary responds to physiological challenge by mobilizing the SOX2-expressing progenitor pool and producing additional hormone-producing cells. Knowledge of the role of signaling pathways and extracellular matrix components in these processes may lead to improvements in the efficiency of differentiation of embryonic stem cells or induced pluripotent stem cells into hormone producing cells in vitro. Advances in our basic understanding of pituitary stem cell regulation and differentiation may lead to improved diagnosis and treatment for patients with hypopituitarism. PMID:27650955

Biliary wound healing, ductular reactions, and IL-6/gp130 signaling in the development of liver disease

PubMed Central

Demetris, A J; III, John G Lunz; Specht, Susan; Nozaki, Isao

2006-01-01

Basic and translational wound healing research in the biliary tree lag significantly behind similar studies on the skin and gastrointestinal tract. This is at least partly attributable to lack of easy access to the biliary tract for study. But clinical relevance, more interest in biliary epithelial cell (BEC) pathophysiology, and widespread availability of BEC cultures are factors reversing this trend. In the extra-hepatic biliary tree, ineffectual wound healing, scarring and stricture development are pressing issues. In the smallest intra-hepatic bile ducts either impaired BEC proliferation or an exuberant response can contribute to liver disease. Chronic inflammation and persistent wound healing reactions in large and small bile ducts often lead to liver cancer. General concepts of wound healing as they apply to the biliary tract, importance of cellular processes dependent on IL-6/gp130/STAT3 signaling pathways, unanswered questions, and future directions are discussed. PMID:16773708

Protein–protein interactions and selection: yeast-based approaches that exploit guanine nucleotide-binding protein signaling.

PubMed

Ishii, Jun; Fukuda, Nobuo; Tanaka, Tsutomu; Ogino, Chiaki; Kondo, Akihiko

2010-05-01

For elucidating protein–protein interactions, many methodologies have been developed during the past two decades. For investigation of interactions inside cells under physiological conditions, yeast is an attractive organism with which to quickly screen for hopeful candidates using versatile genetic technologies, and various types of approaches are now available.Among them, a variety of unique systems using the guanine nucleotide-binding protein (G-protein) signaling pathway in yeast have been established to investigate the interactions of proteins for biological study and pharmaceutical research. G-proteins involved in various cellular processes are mainly divided into two groups: small monomeric G-proteins,and heterotrimeric G-proteins. In this minireview, we summarize the basic principles and applications of yeast-based screening systems, using these two types of G-protein, which are typically used for elucidating biological protein interactions but are differentiated from traditional yeast two-hybrid systems.

Audio-Tactile Integration in Congenitally and Late Deaf Cochlear Implant Users

PubMed Central

Nava, Elena; Bottari, Davide; Villwock, Agnes; Fengler, Ineke; Büchner, Andreas; Lenarz, Thomas; Röder, Brigitte

2014-01-01

Several studies conducted in mammals and humans have shown that multisensory processing may be impaired following congenital sensory loss and in particular if no experience is achieved within specific early developmental time windows known as sensitive periods. In this study we investigated whether basic multisensory abilities are impaired in hearing-restored individuals with deafness acquired at different stages of development. To this aim, we tested congenitally and late deaf cochlear implant (CI) recipients, age-matched with two groups of hearing controls, on an audio-tactile redundancy paradigm, in which reaction times to unimodal and crossmodal redundant signals were measured. Our results showed that both congenitally and late deaf CI recipients were able to integrate audio-tactile stimuli, suggesting that congenital and acquired deafness does not prevent the development and recovery of basic multisensory processing. However, we found that congenitally deaf CI recipients had a lower multisensory gain compared to their matched controls, which may be explained by their faster responses to tactile stimuli. We discuss this finding in the context of reorganisation of the sensory systems following sensory loss and the possibility that these changes cannot be “rewired” through auditory reafferentation. PMID:24918766

Audio-tactile integration in congenitally and late deaf cochlear implant users.

PubMed

Nava, Elena; Bottari, Davide; Villwock, Agnes; Fengler, Ineke; Büchner, Andreas; Lenarz, Thomas; Röder, Brigitte

2014-01-01

Several studies conducted in mammals and humans have shown that multisensory processing may be impaired following congenital sensory loss and in particular if no experience is achieved within specific early developmental time windows known as sensitive periods. In this study we investigated whether basic multisensory abilities are impaired in hearing-restored individuals with deafness acquired at different stages of development. To this aim, we tested congenitally and late deaf cochlear implant (CI) recipients, age-matched with two groups of hearing controls, on an audio-tactile redundancy paradigm, in which reaction times to unimodal and crossmodal redundant signals were measured. Our results showed that both congenitally and late deaf CI recipients were able to integrate audio-tactile stimuli, suggesting that congenital and acquired deafness does not prevent the development and recovery of basic multisensory processing. However, we found that congenitally deaf CI recipients had a lower multisensory gain compared to their matched controls, which may be explained by their faster responses to tactile stimuli. We discuss this finding in the context of reorganisation of the sensory systems following sensory loss and the possibility that these changes cannot be "rewired" through auditory reafferentation.

25 CFR 15.11 - What are the basic steps of the probate process?

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false What are the basic steps of the probate process? 15.11 Section 15.11 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR PROBATE PROBATE OF INDIAN... are the basic steps of the probate process? The basic steps of the probate process are: (a) We learn...

Temporal Taylor's scaling of facial electromyography and electrodermal activity in the course of emotional stimulation

NASA Astrophysics Data System (ADS)

Chołoniewski, Jan; Chmiel, Anna; Sienkiewicz, Julian; Hołyst, Janusz A.; Küster, Dennis; Kappas, Arvid

2016-09-01

High frequency psychophysiological data create a challenge for quantitative modeling based on Big Data tools since they reflect the complexity of processes taking place in human body and its responses to external events. Here we present studies of fluctuations in facial electromyography (fEMG) and electrodermal activity (EDA) massive time series and changes of such signals in the course of emotional stimulation. Zygomaticus major (ZYG, "smiling" muscle) activity, corrugator supercilii (COR, "frowning"bmuscle) activity, and phasic skin conductance (PHSC, sweating) levels of 65 participants were recorded during experiments that involved exposure to emotional stimuli (i.e., IAPS images, reading and writing messages on an artificial online discussion board). Temporal Taylor's fluctuations scaling were found when signals for various participants and during various types of emotional events were compared. Values of scaling exponents were close to 1, suggesting an external origin of system dynamics and/or strong interactions between system's basic elements (e.g., muscle fibres). Our statistical analysis shows that the scaling exponents enable identification of high valence and arousal levels in ZYG and COR signals.

Tagged fast neutron beams En > 6 MeV

NASA Astrophysics Data System (ADS)

Favela, F.; Huerta, A.; Santa Rita, P.; Ramos, A. T.; de Lucio, O.; Andrade, E.; Acosta, L.; Ortiz, M. E.; Araujo, V.; Murillo, G.; Policroniades, R.; Varela, A.; Chávez, E.

2015-07-01

Controlled flux of neutrons are produced through the 14N(d,n)15O nuclear reaction. Deuteron beams (2-4 MeV) are delivered by the CN-Van de Graaff accelerator and directed with full intensity to our Nitrogen target at SUGAR (SUpersonic GAs jet taRget). Each neutron is electronically tagged by the detection of the associated15O. Its energy and direction are known and "beams" of fast monochromatic tagged neutrons (En> 6 MeV) are available for basic research and applied work. MONDE is a large area (158 × 63 cm2) plastic scintillating slab (5 cm thick), viewed by 16 PMTs from the sides. Fast neutrons (MeV) entering the detector will produce a recoiling proton that induces a light spark at the spot. Signals from the 16 detectors are processed to deduce the position of the spark. Time logic signals from both the 15O detector and MONDE are combined to deduce a time of flight (TOF) signal. Finally, the position information together with the TOF yields the full momentum vector of each detected neutron.

Depression and treatment response: dynamic interplay of signaling pathways and altered neural processes

PubMed Central

Duric, Vanja

2014-01-01

Since the 1960s, when the first tricyclic and monoamine oxidase inhibitor antidepressant drugs were introduced, most of the ensuing agents were designed to target similar brain pathways that elevate serotonin and/or norepinephrine signaling. Fifty years later, the main goal of the current depression research is to develop faster-acting, more effective therapeutic agents with fewer side effects, as currently available antidepressants are plagued by delayed therapeutic onset and low response rates. Clinical and basic science research studies have made significant progress towards deciphering the pathophysiological events within the brain involved in development, maintenance, and treatment of major depressive disorder. Imaging and postmortem brain studies in depressed human subjects, in combination with animal behavioral models of depression, have identified a number of different cellular events, intracellular signaling pathways, proteins, and target genes that are modulated by stress and are potentially vital mediators of antidepressant action. In this review, we focus on several neural mechanisms, primarily within the hippocampus and prefrontal cortex, which have recently been implicated in depression and treatment response. PMID:22585060

Unsolved mysteries of Rag GTPase signaling in yeast.

PubMed

Hatakeyama, Riko; De Virgilio, Claudio

2016-10-01

The target of rapamycin complex 1 (TORC1) plays a central role in controlling eukaryotic cell growth by fine-tuning anabolic and catabolic processes to the nutritional status of organisms and individual cells. Amino acids represent essential and primordial signals that modulate TORC1 activity through the conserved Rag family GTPases. These assemble, as part of larger lysosomal/vacuolar membrane-associated complexes, into heterodimeric sub-complexes, which typically comprise two paralogous Rag GTPases of opposite GTP-/GDP-loading status. The TORC1-stimulating/inhibiting states of these heterodimers are controlled by various guanine nucleotide exchange factor (GEF) and GTPase-activating protein (GAP) complexes, which are remarkably conserved in various eukaryotic model systems. Among the latter, the budding yeast Saccharomyces cerevisiae has been instrumental for the elucidation of basic aspects of Rag GTPase regulation and function. Here, we discuss the current state of the respective research, focusing on the major unsolved issues regarding the architecture, regulation, and function of the Rag GTPase containing complexes in yeast. Decoding these mysteries will undoubtedly further shape our understanding of the conserved and divergent principles of nutrient signaling in eukaryotes.

Unsolved mysteries of Rag GTPase signaling in yeast

PubMed Central

Hatakeyama, Riko; De Virgilio, Claudio

2016-01-01

ABSTRACT The target of rapamycin complex 1 (TORC1) plays a central role in controlling eukaryotic cell growth by fine-tuning anabolic and catabolic processes to the nutritional status of organisms and individual cells. Amino acids represent essential and primordial signals that modulate TORC1 activity through the conserved Rag family GTPases. These assemble, as part of larger lysosomal/vacuolar membrane-associated complexes, into heterodimeric sub-complexes, which typically comprise two paralogous Rag GTPases of opposite GTP-/GDP-loading status. The TORC1-stimulating/inhibiting states of these heterodimers are controlled by various guanine nucleotide exchange factor (GEF) and GTPase-activating protein (GAP) complexes, which are remarkably conserved in various eukaryotic model systems. Among the latter, the budding yeast Saccharomyces cerevisiae has been instrumental for the elucidation of basic aspects of Rag GTPase regulation and function. Here, we discuss the current state of the respective research, focusing on the major unsolved issues regarding the architecture, regulation, and function of the Rag GTPase containing complexes in yeast. Decoding these mysteries will undoubtedly further shape our understanding of the conserved and divergent principles of nutrient signaling in eukaryotes. PMID:27400376

Self-Organization of Stem Cell Colonies and of Early Mammalian Embryos: Recent Experiments Shed New Light on the Role of Autonomy vs. External Instructions in Basic Body Plan Development

PubMed Central

Denker, Hans-Werner

2016-01-01

“Organoids”, i.e., complex structures that can develop when pluripotent or multipotent stem cells are maintained in three-dimensional cultures, have become a new area of interest in stem cell research. Hopes have grown that when focussing experimentally on the mechanisms behind this type of in vitro morphogenesis, research aiming at tissue and organ replacements can be boosted. Processes leading to the formation of organoids in vitro are now often addressed as self-organization, a term referring to the formation of complex tissue architecture in groups of cells without depending on specific instruction provided by other cells or tissues. The present article focuses on recent reports using the term self-organization in the context of studies on embryogenesis, specifically addressing pattern formation processes in human blastocysts attaching in vitro, or in colonies of pluripotent stem cells (“gastruloids”). These morphogenetic processes are of particular interest because, during development in vivo, they lead to basic body plan formation and individuation. Since improved methodologies like those employed by the cited authors became available, early embryonic pattern formation/self-organization appears to evolve now as a research topic of its own. This review discusses concepts concerning the involved mechanisms, focussing on autonomy of basic body plan development vs. dependence on external signals, as possibly provided by implantation in the uterus, and it addresses biological differences between an early mammalian embryo, e.g., a morula, and a cluster of pluripotent stem cells. It is concluded that, apart from being of considerable biological interest, the described type of research needs to be contemplated carefully with regard to ethical implications when performed with human cells. PMID:27792143

Self-Organization of Stem Cell Colonies and of Early Mammalian Embryos: Recent Experiments Shed New Light on the Role of Autonomy vs. External Instructions in Basic Body Plan Development.

PubMed

Denker, Hans-Werner

2016-10-25

" Organoids ", i.e., complex structures that can develop when pluripotent or multipotent stem cells are maintained in three-dimensional cultures, have become a new area of interest in stem cell research. Hopes have grown that when focussing experimentally on the mechanisms behind this type of in vitro morphogenesis, research aiming at tissue and organ replacements can be boosted. Processes leading to the formation of organoids in vitro are now often addressed as self-organization , a term referring to the formation of complex tissue architecture in groups of cells without depending on specific instruction provided by other cells or tissues. The present article focuses on recent reports using the term self-organization in the context of studies on embryogenesis , specifically addressing pattern formation processes in human blastocysts attaching in vitro, or in colonies of pluripotent stem cells (" gastruloids "). These morphogenetic processes are of particular interest because, during development in vivo, they lead to basic body plan formation and individuation. Since improved methodologies like those employed by the cited authors became available, early embryonic pattern formation/self-organization appears to evolve now as a research topic of its own. This review discusses concepts concerning the involved mechanisms, focussing on autonomy of basic body plan development vs. dependence on external signals, as possibly provided by implantation in the uterus, and it addresses biological differences between an early mammalian embryo, e.g., a morula, and a cluster of pluripotent stem cells. It is concluded that, apart from being of considerable biological interest, the described type of research needs to be contemplated carefully with regard to ethical implications when performed with human cells.

Evidence for shared cognitive processing of pitch in music and language.

PubMed

Perrachione, Tyler K; Fedorenko, Evelina G; Vinke, Louis; Gibson, Edward; Dilley, Laura C

2013-01-01

Language and music epitomize the complex representational and computational capacities of the human mind. Strikingly similar in their structural and expressive features, a longstanding question is whether the perceptual and cognitive mechanisms underlying these abilities are shared or distinct--either from each other or from other mental processes. One prominent feature shared between language and music is signal encoding using pitch, conveying pragmatics and semantics in language and melody in music. We investigated how pitch processing is shared between language and music by measuring consistency in individual differences in pitch perception across language, music, and three control conditions intended to assess basic sensory and domain-general cognitive processes. Individuals' pitch perception abilities in language and music were most strongly related, even after accounting for performance in all control conditions. These results provide behavioral evidence, based on patterns of individual differences, that is consistent with the hypothesis that cognitive mechanisms for pitch processing may be shared between language and music.

Correlation analysis of respiratory signals by using parallel coordinate plots.

PubMed

Saatci, Esra

2018-01-01

The understanding of the bonds and the relationships between the respiratory signals, i.e. the airflow, the mouth pressure, the relative temperature and the relative humidity during breathing may provide the improvement on the measurement methods of respiratory mechanics and sensor designs or the exploration of the several possible applications in the analysis of respiratory disorders. Therefore, the main objective of this study was to propose a new combination of methods in order to determine the relationship between respiratory signals as a multidimensional data. In order to reveal the coupling between the processes two very different methods were used: the well-known statistical correlation analysis (i.e. Pearson's correlation and cross-correlation coefficient) and parallel coordinate plots (PCPs). Curve bundling with the number intersections for the correlation analysis, Least Mean Square Time Delay Estimator (LMS-TDE) for the point delay detection and visual metrics for the recognition of the visual structures were proposed and utilized in PCP. The number of intersections was increased when the correlation coefficient changed from high positive to high negative correlation between the respiratory signals, especially if whole breath was processed. LMS-TDE coefficients plotted in PCP indicated well-matched point delay results to the findings in the correlation analysis. Visual inspection of PCB by visual metrics showed range, dispersions, entropy comparisons and linear and sinusoidal-like relationships between the respiratory signals. It is demonstrated that the basic correlation analysis together with the parallel coordinate plots perceptually motivates the visual metrics in the display and thus can be considered as an aid to the user analysis by providing meaningful views of the data. Copyright © 2017 Elsevier B.V. All rights reserved.

Is the encoding of Reward Prediction Error reliable during development?

PubMed

Keren, Hanna; Chen, Gang; Benson, Brenda; Ernst, Monique; Leibenluft, Ellen; Fox, Nathan A; Pine, Daniel S; Stringaris, Argyris

2018-05-16

Reward Prediction Errors (RPEs), defined as the difference between the expected and received outcomes, are integral to reinforcement learning models and play an important role in development and psychopathology. In humans, RPE encoding can be estimated using fMRI recordings, however, a basic measurement property of RPE signals, their test-retest reliability across different time scales, remains an open question. In this paper, we examine the 3-month and 3-year reliability of RPE encoding in youth (mean age at baseline = 10.6 ± 0.3 years), a period of developmental transitions in reward processing. We show that RPE encoding is differentially distributed between the positive values being encoded predominantly in the striatum and negative RPEs primarily encoded in the insula. The encoding of negative RPE values is highly reliable in the right insula, across both the long and the short time intervals. Insula reliability for RPE encoding is the most robust finding, while other regions, such as the striatum, are less consistent. Striatal reliability appeared significant as well once covarying for factors, which were possibly confounding the signal to noise ratio. By contrast, task activation during feedback in the striatum is highly reliable across both time intervals. These results demonstrate the valence-dependent differential encoding of RPE signals between the insula and striatum, and the consistency of RPE signals or lack thereof, during childhood and into adolescence. Characterizing the regions where the RPE signal in BOLD fMRI is a reliable marker is key for estimating reward-processing alterations in longitudinal designs, such as developmental or treatment studies. Copyright © 2018 Elsevier Inc. All rights reserved.

HIDE & SEEK: End-to-end packages to simulate and process radio survey data

NASA Astrophysics Data System (ADS)

Akeret, J.; Seehars, S.; Chang, C.; Monstein, C.; Amara, A.; Refregier, A.

2017-01-01

As several large single-dish radio surveys begin operation within the coming decade, a wealth of radio data will become available and provide a new window to the Universe. In order to fully exploit the potential of these datasets, it is important to understand the systematic effects associated with the instrument and the analysis pipeline. A common approach to tackle this is to forward-model the entire system-from the hardware to the analysis of the data products. For this purpose, we introduce two newly developed, open-source Python packages: the HI Data Emulator (HIDE) and the Signal Extraction and Emission Kartographer (SEEK) for simulating and processing single-dish radio survey data. HIDE forward-models the process of collecting astronomical radio signals in a single-dish radio telescope instrument and outputs pixel-level time-ordered-data. SEEK processes the time-ordered-data, removes artifacts from Radio Frequency Interference (RFI), automatically applies flux calibration, and aims to recover the astronomical radio signal. The two packages can be used separately or together depending on the application. Their modular and flexible nature allows easy adaptation to other instruments and datasets. We describe the basic architecture of the two packages and examine in detail the noise and RFI modeling in HIDE, as well as the implementation of gain calibration and RFI mitigation in SEEK. We then apply HIDE &SEEK to forward-model a Galactic survey in the frequency range 990-1260 MHz based on data taken at the Bleien Observatory. For this survey, we expect to cover 70% of the full sky and achieve a median signal-to-noise ratio of approximately 5-6 in the cleanest channels including systematic uncertainties. However, we also point out the potential challenges of high RFI contamination and baseline removal when examining the early data from the Bleien Observatory. The fully documented HIDE &SEEK packages are available at http://hideseek.phys.ethz.ch/ and are published under the GPLv3 license on GitHub.

The Recombinant Inhibitor of DNA Binding Id2 Forms Multimeric Structures via the Helix-Loop-Helix Domain and the Nuclear Export Signal.

PubMed

Roschger, Cornelia; Schubert, Mario; Regl, Christof; Andosch, Ancuela; Marquez, Augusto; Berger, Thomas; Huber, Christian G; Lütz-Meindl, Ursula; Cabrele, Chiara

2018-04-07

The inhibitor of DNA binding and cell differentiation 2 (Id2) is a helix-loop-helix (HLH) protein that acts as negative dominant regulator of basic-HLH transcription factors during development and in cancer. The structural properties of Id2 have been investigated so far by using synthetic or recombinant fragments reproducing single domains (N-terminus, HLH, C-terminus): the HLH domain tends to dimerize into a four-helix bundle, whereas the flanking regions are flexible. In this work, the intact protein was expressed in E. coli , solubilized from inclusion bodies with urea, purified and dissolved in water at pH~4. Under these conditions, Id2 was obtained with both cysteine residues disulfide-bonded to β-mercaptoethanol that was present during the solubilization process. Moreover, it existed in a self-assembled state, in which the N-terminus remained highly flexible, while the HLH domain and, surprisingly, part of the C-terminus, which corresponds to the nuclear export signal (NES), both were involved in slowly tumbling, rigid structures. The protein oligomers also formed twisted fibrils that were several micrometers long and up to 80 nm thick. These results show that self-assembly decreases the backbone flexibility of those two protein regions (HLH and NES) that are important for interaction with basic-HLH transcription factors or for nucleocytoplasmic shuttling.

A straightforward graphical user interface for basic and advanced signal processing of thermographic infrared sequences

NASA Astrophysics Data System (ADS)

Klein, Matthieu T.; Ibarra-Castanedo, Clemente; Maldague, Xavier P.; Bendada, Abdelhakim

2008-03-01

IR-View, is a free and open source Matlab software that was released in 1998 at the Computer Vision and Systems Laboratory (CVSL) at Université Laval, Canada, as an answer to many common and recurrent needs in Infrared thermography. IR-View has proven to be a useful tool at CVSL for the past 10 years. The software by itself and/or its concept and functions may be of interest for other laboratories and companies working in research in the IR NDT field. This article describes the functions and processing techniques integrated to IR-View, freely downloadable under the GNU license at http://mivim.gel.ulaval.ca. Demonstration of IR-View functionalities will also be done during the DSS08 SPIE Defense and Security Symposium.

Emerging Role of Sensory Perception in Aging and Metabolism.

PubMed

Riera, Celine E; Dillin, Andrew

2016-05-01

Sensory perception comprises gustatory (taste) and olfactory (smell) modalities as well as somatosensory (pain, heat, and tactile mechanosensory) inputs, which are detected by a multitude of sensory receptors. These sensory receptors are contained in specialized ciliated neurons where they detect changes in environmental conditions and participate in behavioral decisions ranging from food choice to avoiding harmful conditions, thus insuring basic survival in metazoans. Recent genetic studies, however, indicate that sensory perception plays additional physiological functions, notably influencing energy homeostatic processes and longevity through neuronal circuits originating from sensory tissues. Here we review how these findings are redefining metabolic signaling and establish a prominent role of sensory neuroendocrine processes in controlling health span and lifespan, with a goal of translating this knowledge towards managing age-associated diseases. Copyright © 2016. Published by Elsevier Ltd.

Comparison of the results of refractometric measurements in the process of diffusion, obtained by means of the backgroundoriented schlieren method and the holographic interferometry method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kraiskii, A V; Mironova, T V

2015-08-31

The results of the study of interdiffusion of two liquids, obtained using the holographic recording scheme with a nonstationary reference wave with the frequency linearly varying in space and time are compared with the results of correlation processing of digital photographs, made with a random background screen. The spatio-temporal behaviour of the signal in four basic representations ('space – temporal frequency', 'space – time', 'spatial frequency – temporal frequency' and 'spatial frequency – time') is found in the holographic experiment and calculated (in the appropriate coordinates) based on the background-oriented schlieren method. Practical coincidence of the results of the correlationmore » analysis and the holographic double-exposure interferometry is demonstrated. (interferometry)« less

Advanced control of dissolved oxygen concentration in fed batch cultures during recombinant protein production.

PubMed

Kuprijanov, A; Gnoth, S; Simutis, R; Lübbert, A

2009-02-01

Design and experimental validation of advanced pO(2) controllers for fermentation processes operated in the fed-batch mode are described. In most situations, the presented controllers are able to keep the pO(2) in fermentations for recombinant protein productions exactly on the desired value. The controllers are based on the gain-scheduling approach to parameter-adaptive proportional-integral controllers. In order to cope with the most often appearing distortions, the basic gain-scheduling feedback controller was complemented with a feedforward control component. This feedforward/feedback controller significantly improved pO(2) control. By means of numerical simulations, the controller behavior was tested and its parameters were determined. Validation runs were performed with three Escherichia coli strains producing different recombinant proteins. It is finally shown that the new controller leads to significant improvements in the signal-to-noise ratio of other key process variables and, thus, to a higher process quality.

Network of Internet-Controlled HF Receivers for Ionospheric Researches

NASA Astrophysics Data System (ADS)

Koloskov, A. V.; Yampolski, Y. M.; Zalizovski, A. V.; Galushko, V. G.; Kascheev, A. S.; La Hoz, C.; Brekke, A.; Beley, V. S.; Rietveld, M. T.

2014-12-01

A network of HF receivers intended for multi-position monitoring of the ionosphere is described. At present, it includes nine observation sites located at high, middle and low latitudes in both hemispheres of the Earth. The basic element of the network is a small- size receiving and measuring units designed at the Institute of Radio Astronomy (IRA) of the National Academy of Sciences of Ukraine (NASU) on the basis of a personal computer equipped with commercial digital receiving modules. Software packages developed by the authors make it possible to remotely control the facilities via the Internet network. The received emissions are HF signals from special transmitters and broadcast radio stations. These are processed using Doppler and pulse selection algorithms. In the Internet-controlled mode, the observation results are transferred to the main server in real time to be automatically processed and visualized at the website of the IRA NASU’s Department of Radiophysics of Geospace. Several examples of using the observation results obtained with the HF receiver network for diagnostics of dynamic processes in the near-Earth plasma are presented. The advantages of the multiposition mode of observations are discussed. The possibility of upgrading the HF facilities to provide measuring angles of arrival of signals is considered.

Analysis of real-time vibration data

USGS Publications Warehouse

Safak, E.

2005-01-01

In recent years, a few structures have been instrumented to provide continuous vibration data in real time, recording not only large-amplitude motions generated by extreme loads, but also small-amplitude motions generated by ambient loads. The main objective in continuous recording is to track any changes in structural characteristics, and to detect damage after an extreme event, such as an earthquake or explosion. The Fourier-based spectral analysis methods have been the primary tool to analyze vibration data from structures. In general, such methods do not work well for real-time data, because real-time data are mainly composed of ambient vibrations with very low amplitudes and signal-to-noise ratios. The long duration, linearity, and the stationarity of ambient data, however, allow us to utilize statistical signal processing tools, which can compensate for the adverse effects of low amplitudes and high noise. The analysis of real-time data requires tools and techniques that can be applied in real-time; i.e., data are processed and analyzed while being acquired. This paper presents some of the basic tools and techniques for processing and analyzing real-time vibration data. The topics discussed include utilization of running time windows, tracking mean and mean-square values, filtering, system identification, and damage detection.

Event-related potential response to auditory social stimuli, parent-reported social communicative deficits and autism risk in school-aged children with congenital visual impairment.

PubMed

Bathelt, Joe; Dale, Naomi; de Haan, Michelle

2017-10-01

Communication with visual signals, like facial expression, is important in early social development, but the question if these signals are necessary for typical social development remains to be addressed. The potential impact on social development of being born with no or very low levels of vision is therefore of high theoretical and clinical interest. The current study investigated event-related potential responses to basic social stimuli in a rare group of school-aged children with congenital visual disorders of the anterior visual system (globe of the eye, retina, anterior optic nerve). Early-latency event-related potential responses showed no difference between the VI and control group, suggesting similar initial auditory processing. However, the mean amplitude over central and right frontal channels between 280 and 320ms was reduced in response to own-name stimuli, but not control stimuli, in children with VI suggesting differences in social processing. Children with VI also showed an increased rate of autistic-related behaviours, pragmatic language deficits, as well as peer relationship and emotional problems on standard parent questionnaires. These findings suggest that vision may be necessary for the typical development of social processing across modalities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Improving Drive Files for Vehicle Road Simulations

NASA Astrophysics Data System (ADS)

Cherng, John G.; Goktan, Ali; French, Mark; Gu, Yi; Jacob, Anil

2001-09-01

Shaker tables are commonly used in laboratories for automotive vehicle component testing to study durability and acoustics performance. An example is development testing of car seats. However, it is difficult to repeat the measured road data perfectly with the response of a shaker table as there are basic differences in dynamic characteristics between a flexible vehicle and substantially rigid shaker table. In addition, there are performance limits in the shaker table drive systems that can limit correlation. In practice, an optimal drive signal for the actuators is created iteratively. During each iteration, the error between the road data and the response data is minimised by an optimising algorithm which is generally a part of the feed back loop of the shake table controller. This study presents a systematic investigation to the errors in time and frequency domains as well as joint time-frequency domain and an evaluation of different digital signal processing techniques that have been used in previous work. In addition, we present an innovative approach that integrates the dynamic characteristics of car seats and the human body into the error-minimising iteration process. We found that the iteration process can be shortened and the error reduced by using a weighting function created by normalising the frequency response function of the car seat. Two road data test sets were used in the study.

Molecular inflammation: underpinnings of aging and age-related diseases.

PubMed

Chung, Hae Young; Cesari, Matteo; Anton, Stephen; Marzetti, Emanuele; Giovannini, Silvia; Seo, Arnold Young; Carter, Christy; Yu, Byung Pal; Leeuwenburgh, Christiaan

2009-01-01

Recent scientific studies have advanced the notion of chronic inflammation as a major risk factor underlying aging and age-related diseases. In this review, low-grade, unresolved, molecular inflammation is described as an underlying mechanism of aging and age-related diseases, which may serve as a bridge between normal aging and age-related pathological processes. Accumulated data strongly suggest that continuous (chronic) upregulation of pro-inflammatory mediators (e.g., TNF-alpha, IL-1beta, IL-6, COX-2, iNOS) are induced during the aging process due to an age-related redox imbalance that activates many pro-inflammatory signaling pathways, including the NF-kappaB signaling pathway. These pro-inflammatory molecular events are discussed in relation to their role as basic mechanisms underlying aging and age-related diseases. Further, the anti-inflammatory actions of aging-retarding caloric restriction and exercise are reviewed. Thus, the purpose of this review is to describe the molecular roles of age-related physiological functional declines and the accompanying chronic diseases associated with aging. This new view on the role of molecular inflammation as a mechanism of aging and age-related pathogenesis can provide insights into potential interventions that may affect the aging process and reduce age-related diseases, thereby promoting healthy longevity.

Molecular Inflammation: Underpinnings of Aging and Age-related Diseases

PubMed Central

Chung, Hae Young; Cesari, Matteo; Anton, Stephen; Marzetti, Emanuele; Giovannini, Silvia; Seo, Arnold Young; Carter, Christy; Yu, Byung Pal; Leeuwenburgh, Christiaan

2013-01-01

Recent scientific studies have advanced the notion of chronic inflammation as a major risk factor underlying aging and age-related diseases. In this review, low-grade, unresolved, molecular inflammation is described as an underlying mechanism of aging and age-related diseases, which may serve as a bridge between normal aging and age-related pathological processes. Accumulated data strongly suggest that continuous (chronic) up-regulation of pro-inflammatory mediators (e.g., TNF-α, IL-1β, 6, COX-2, iNOS) are induced during the aging process due to an age-related redox imbalance that activates many pro-inflammatory signaling pathways, including the NF-κB signaling pathway. These pro-inflammatory molecular events are discussed in relation to their role as basic mechanisms underlying aging and age-related diseases. Further, the anti-inflammatory actions of aging-retarding caloric restriction and exercise are reviewed. Thus, the purpose of this review is to describe the molecular roles of age-related physiological functional declines and the accompanying chronic diseases associated with aging. This new view on the role of molecular inflammation as a mechanism of aging and age-related pathogenesis can provide insights into potential interventions that may affect the aging process and reduce age-related diseases, thereby promoting healthy longevity. PMID:18692159

Portable laser speckle perfusion imaging system based on digital signal processor.

PubMed

Tang, Xuejun; Feng, Nengyun; Sun, Xiaoli; Li, Pengcheng; Luo, Qingming

2010-12-01

The ability to monitor blood flow in vivo is of major importance in clinical diagnosis and in basic researches of life science. As a noninvasive full-field technique without the need of scanning, laser speckle contrast imaging (LSCI) is widely used to study blood flow with high spatial and temporal resolution. Current LSCI systems are based on personal computers for image processing with large size, which potentially limit the widespread clinical utility. The need for portable laser speckle contrast imaging system that does not compromise processing efficiency is crucial in clinical diagnosis. However, the processing of laser speckle contrast images is time-consuming due to the heavy calculation for enormous high-resolution image data. To address this problem, a portable laser speckle perfusion imaging system based on digital signal processor (DSP) and the algorithm which is suitable for DSP is described. With highly integrated DSP and the algorithm, we have markedly reduced the size and weight of the system as well as its energy consumption while preserving the high processing speed. In vivo experiments demonstrate that our portable laser speckle perfusion imaging system can obtain blood flow images at 25 frames per second with the resolution of 640 × 480 pixels. The portable and lightweight features make it capable of being adapted to a wide variety of application areas such as research laboratory, operating room, ambulance, and even disaster site.

A Novel Approach for Adaptive Signal Processing

NASA Technical Reports Server (NTRS)

Chen, Ya-Chin; Juang, Jer-Nan

1998-01-01

Adaptive linear predictors have been used extensively in practice in a wide variety of forms. In the main, their theoretical development is based upon the assumption of stationarity of the signals involved, particularly with respect to the second order statistics. On this basis, the well-known normal equations can be formulated. If high- order statistical stationarity is assumed, then the equivalent normal equations involve high-order signal moments. In either case, the cross moments (second or higher) are needed. This renders the adaptive prediction procedure non-blind. A novel procedure for blind adaptive prediction has been proposed and considerable implementation has been made in our contributions in the past year. The approach is based upon a suitable interpretation of blind equalization methods that satisfy the constant modulus property and offers significant deviations from the standard prediction methods. These blind adaptive algorithms are derived by formulating Lagrange equivalents from mechanisms of constrained optimization. In this report, other new update algorithms are derived from the fundamental concepts of advanced system identification to carry out the proposed blind adaptive prediction. The results of the work can be extended to a number of control-related problems, such as disturbance identification. The basic principles are outlined in this report and differences from other existing methods are discussed. The applications implemented are speech processing, such as coding and synthesis. Simulations are included to verify the novel modelling method.

Ribosome Synthesis and MAPK Activity Modulate Ionizing Radiation-Induced Germ Cell Apoptosis in Caenorhabditis elegans

PubMed Central

Eberhard, Ralf; Stergiou, Lilli; Hofmann, E. Randal; Hofmann, Jen; Haenni, Simon; Teo, Youjin; Furger, André; Hengartner, Michael O.

2013-01-01

Synthesis of ribosomal RNA by RNA polymerase I (RNA pol I) is an elemental biological process and is key for cellular homeostasis. In a forward genetic screen in C. elegans designed to identify DNA damage-response factors, we isolated a point mutation of RNA pol I, rpoa-2(op259), that leads to altered rRNA synthesis and a concomitant resistance to ionizing radiation (IR)-induced germ cell apoptosis. This weak apoptotic IR response could be phenocopied when interfering with other factors of ribosome synthesis. Surprisingly, despite their resistance to DNA damage, rpoa-2(op259) mutants present a normal CEP-1/p53 response to IR and increased basal CEP-1 activity under normal growth conditions. In parallel, rpoa-2(op259) leads to reduced Ras/MAPK pathway activity, which is required for germ cell progression and physiological germ cell death. Ras/MAPK gain-of-function conditions could rescue the IR response defect in rpoa-2(op259), pointing to a function for Ras/MAPK in modulating DNA damage-induced apoptosis downstream of CEP-1. Our data demonstrate that a single point mutation in an RNA pol I subunit can interfere with multiple key signalling pathways. Ribosome synthesis and growth-factor signalling are perturbed in many cancer cells; such an interplay between basic cellular processes and signalling might be critical for how tumours evolve or respond to treatment. PMID:24278030

Testing Convergent Evolution in Auditory Processing Genes between Echolocating Mammals and the Aye-Aye, a Percussive-Foraging Primate.

PubMed

Bankoff, Richard J; Jerjos, Michael; Hohman, Baily; Lauterbur, M Elise; Kistler, Logan; Perry, George H

2017-07-01

Several taxonomically distinct mammalian groups-certain microbats and cetaceans (e.g., dolphins)-share both morphological adaptations related to echolocation behavior and strong signatures of convergent evolution at the amino acid level across seven genes related to auditory processing. Aye-ayes (Daubentonia madagascariensis) are nocturnal lemurs with a specialized auditory processing system. Aye-ayes tap rapidly along the surfaces of trees, listening to reverberations to identify the mines of wood-boring insect larvae; this behavior has been hypothesized to functionally mimic echolocation. Here we investigated whether there are signals of convergence in auditory processing genes between aye-ayes and known mammalian echolocators. We developed a computational pipeline (Basic Exon Assembly Tool) that produces consensus sequences for regions of interest from shotgun genomic sequencing data for nonmodel organisms without requiring de novo genome assembly. We reconstructed complete coding region sequences for the seven convergent echolocating bat-dolphin genes for aye-ayes and another lemur. We compared sequences from these two lemurs in a phylogenetic framework with those of bat and dolphin echolocators and appropriate nonecholocating outgroups. Our analysis reaffirms the existence of amino acid convergence at these loci among echolocating bats and dolphins; some methods also detected signals of convergence between echolocating bats and both mice and elephants. However, we observed no significant signal of amino acid convergence between aye-ayes and echolocating bats and dolphins, suggesting that aye-aye tap-foraging auditory adaptations represent distinct evolutionary innovations. These results are also consistent with a developing consensus that convergent behavioral ecology does not reliably predict convergent molecular evolution. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Time-Frequency Analysis of Chemosensory Event-Related Potentials to Characterize the Cortical Representation of Odors in Humans

PubMed Central

Huart, Caroline; Legrain, Valéry; Hummel, Thomas; Rombaux, Philippe; Mouraux, André

2012-01-01

Background The recording of olfactory and trigeminal chemosensory event-related potentials (ERPs) has been proposed as an objective and non-invasive technique to study the cortical processing of odors in humans. Until now, the responses have been characterized mainly using across-trial averaging in the time domain. Unfortunately, chemosensory ERPs, in particular, olfactory ERPs, exhibit a relatively low signal-to-noise ratio. Hence, although the technique is increasingly used in basic research as well as in clinical practice to evaluate people suffering from olfactory disorders, its current clinical relevance remains very limited. Here, we used a time-frequency analysis based on the wavelet transform to reveal EEG responses that are not strictly phase-locked to onset of the chemosensory stimulus. We hypothesized that this approach would significantly enhance the signal-to-noise ratio of the EEG responses to chemosensory stimulation because, as compared to conventional time-domain averaging, (1) it is less sensitive to temporal jitter and (2) it can reveal non phase-locked EEG responses such as event-related synchronization and desynchronization. Methodology/Principal Findings EEG responses to selective trigeminal and olfactory stimulation were recorded in 11 normosmic subjects. A Morlet wavelet was used to characterize the elicited responses in the time-frequency domain. We found that this approach markedly improved the signal-to-noise ratio of the obtained EEG responses, in particular, following olfactory stimulation. Furthermore, the approach allowed characterizing non phase-locked components that could not be identified using conventional time-domain averaging. Conclusion/Significance By providing a more robust and complete view of how odors are represented in the human brain, our approach could constitute the basis for a robust tool to study olfaction, both for basic research and clinicians. PMID:22427997

Multichannel audio monitor for detecting electrical signals.

PubMed

Friesen, W O; Stent, G S

1978-12-01

The multichannel audio monitor (MUCAM) permits the simultaneous auditory monitoring of concurrent trains of electrical signals generated by as many as eight different sources. The basic working principle of this device is the modulation of the amplitude of a given pure tone by the incoming signals of each input channel. The MUCAM thus converts a complex, multichannel, temporal signal sequence into a musical melody suitable for instant, subliminal pattern analysis by the human ear. Neurophysiological experiments requiring multi-electrode recordings have provided one useful application of the MUCAM.

Comparative Analysis on Nonlinear Models for Ron Gasoline Blending Using Neural Networks

NASA Astrophysics Data System (ADS)

Aguilera, R. Carreño; Yu, Wen; Rodríguez, J. C. Tovar; Mosqueda, M. Elena Acevedo; Ortiz, M. Patiño; Juarez, J. J. Medel; Bautista, D. Pacheco

The blending process always being a nonlinear process is difficult to modeling, since it may change significantly depending on the components and the process variables of each refinery. Different components can be blended depending on the existing stock, and the chemical characteristics of each component are changing dynamically, they all are blended until getting the expected specification in different properties required by the customer. One of the most relevant properties is the Octane, which is difficult to control in line (without the component storage). Since each refinery process is quite different, a generic gasoline blending model is not useful when a blending in line wants to be done in a specific process. A mathematical gasoline blending model is presented in this paper for a given process described in state space as a basic gasoline blending process description. The objective is to adjust the parameters allowing the blending gasoline model to describe a signal in its trajectory, representing in neural networks extreme learning machine method and also for nonlinear autoregressive-moving average (NARMA) in neural networks method, such that a comparative work be developed.

Effects of Sound Frequency on Audiovisual Integration: An Event-Related Potential Study

PubMed Central

Yang, Weiping; Yang, Jingjing; Gao, Yulin; Tang, Xiaoyu; Ren, Yanna; Takahashi, Satoshi; Wu, Jinglong

2015-01-01

A combination of signals across modalities can facilitate sensory perception. The audiovisual facilitative effect strongly depends on the features of the stimulus. Here, we investigated how sound frequency, which is one of basic features of an auditory signal, modulates audiovisual integration. In this study, the task of the participant was to respond to a visual target stimulus by pressing a key while ignoring auditory stimuli, comprising of tones of different frequencies (0.5, 1, 2.5 and 5 kHz). A significant facilitation of reaction times was obtained following audiovisual stimulation, irrespective of whether the task-irrelevant sounds were low or high frequency. Using event-related potential (ERP), audiovisual integration was found over the occipital area for 0.5 kHz auditory stimuli from 190–210 ms, for 1 kHz stimuli from 170–200 ms, for 2.5 kHz stimuli from 140–200 ms, 5 kHz stimuli from 100–200 ms. These findings suggest that a higher frequency sound signal paired with visual stimuli might be early processed or integrated despite the auditory stimuli being task-irrelevant information. Furthermore, audiovisual integration in late latency (300–340 ms) ERPs with fronto-central topography was found for auditory stimuli of lower frequencies (0.5, 1 and 2.5 kHz). Our results confirmed that audiovisual integration is affected by the frequency of an auditory stimulus. Taken together, the neurophysiological results provide unique insight into how the brain processes a multisensory visual signal and auditory stimuli of different frequencies. PMID:26384256

Using hyperentanglement to enhance resolution, signal-to-noise ratio, and measurement time

NASA Astrophysics Data System (ADS)

Smith, James F.

2017-03-01

A hyperentanglement-based atmospheric imaging/detection system involving only a signal and an ancilla photon will be considered for optical and infrared frequencies. Only the signal photon will propagate in the atmosphere and its loss will be classical. The ancilla photon will remain within the sensor experiencing low loss. Closed form expressions for the wave function, normalization, density operator, reduced density operator, symmetrized logarithmic derivative, quantum Fisher information, quantum Cramer-Rao lower bound, coincidence probabilities, probability of detection, probability of false alarm, probability of error after M measurements, signal-to-noise ratio, quantum Chernoff bound, time-on-target expressions related to probability of error, and resolution will be provided. The effect of noise in every mode will be included as well as loss. The system will provide the basic design for an imaging/detection system functioning at optical or infrared frequencies that offers better than classical angular and range resolution. Optimization for enhanced resolution will be included. The signal-to-noise ratio will be increased by a factor equal to the number of modes employed during the hyperentanglement process. Likewise, the measurement time can be reduced by the same factor. The hyperentanglement generator will typically make use of entanglement in polarization, energy-time, orbital angular momentum and so on. Mathematical results will be provided describing the system's performance as a function of loss mechanisms and noise.

Workbook, Basic Mathematics and Wastewater Processing Calculations.

ERIC Educational Resources Information Center

New York State Dept. of Environmental Conservation, Albany.

This workbook serves as a self-learning guide to basic mathematics and treatment plant calculations and also as a reference and source book for the mathematics of sewage treatment and processing. In addition to basic mathematics, the workbook discusses processing and process control, laboratory calculations and efficiency calculations necessary in…

Acoustic Behavior, Baseline Ecology and Habitat use of Pelagic Odontocete Species of Concern

DTIC Science & Technology

2013-09-30

signals of Hawaiian insular false killer whales (FKWs) and melon-headed whales (MHWs). 2) Determine baseline acoustic behavior, basic activities...of false killer whales and other species (funded to Cascadia Research Collective). This had the advantage of distributing tagging operational costs...location and (2) how the receiver’s head shapes that signal. A bottlenose dolphin (Tursiops truncatus), the signaler, and a false killer whale , the receiver

Localization of short-range acoustic and seismic wideband sources: Algorithms and experiments

NASA Astrophysics Data System (ADS)

Stafsudd, J. Z.; Asgari, S.; Hudson, R.; Yao, K.; Taciroglu, E.

2008-04-01

We consider the determination of the location (source localization) of a disturbance source which emits acoustic and/or seismic signals. We devise an enhanced approximate maximum-likelihood (AML) algorithm to process data collected at acoustic sensors (microphones) belonging to an array of, non-collocated but otherwise identical, sensors. The approximate maximum-likelihood algorithm exploits the time-delay-of-arrival of acoustic signals at different sensors, and yields the source location. For processing the seismic signals, we investigate two distinct algorithms, both of which process data collected at a single measurement station comprising a triaxial accelerometer, to determine direction-of-arrival. The direction-of-arrivals determined at each sensor station are then combined using a weighted least-squares approach for source localization. The first of the direction-of-arrival estimation algorithms is based on the spectral decomposition of the covariance matrix, while the second is based on surface wave analysis. Both of the seismic source localization algorithms have their roots in seismology; and covariance matrix analysis had been successfully employed in applications where the source and the sensors (array) are typically separated by planetary distances (i.e., hundreds to thousands of kilometers). Here, we focus on very-short distances (e.g., less than one hundred meters) instead, with an outlook to applications in multi-modal surveillance, including target detection, tracking, and zone intrusion. We demonstrate the utility of the aforementioned algorithms through a series of open-field tests wherein we successfully localize wideband acoustic and/or seismic sources. We also investigate a basic strategy for fusion of results yielded by acoustic and seismic arrays.

Fundamentals of image acquisition and processing in the digital era.

PubMed

Farman, A G

2003-01-01

To review the historic context for digital imaging in dentistry and to outline the fundamental issues related to digital imaging modalities. Digital dental X-ray images can be achieved by scanning analog film radiographs (secondary capture), with photostimulable phosphors, or using solid-state detectors (e.g. charge-coupled device and complementary metal oxide semiconductor). There are four characteristics that are basic to all digital image detectors; namely, size of active area, signal-to-noise ratio, contrast resolution and the spatial resolution. To perceive structure in a radiographic image, there needs to be sufficient difference between contrasting densities. This primarily depends on the differences in the attenuation of the X-ray beam by adjacent tissues. It is also depends on the signal received; therefore, contrast tends to increase with increased exposure. Given adequate signal and sufficient differences in radiodensity, contrast will be sufficient to differentiate between adjacent structures, irrespective of the recording modality and processing used. Where contrast is not sufficient, digital images can sometimes be post-processed to disclose details that would otherwise go undetected. For example, cephalogram isodensity mapping can improve soft tissue detail. It is concluded that it could be a further decade or two before three-dimensional digital imaging systems entirely replace two-dimensional analog films. Such systems need not only to produce prettier images, but also to provide a demonstrable evidence-based higher standard of care at a cost that is not economically prohibitive for the practitioner or society, and which allows efficient and effective workflow within the business of dental practice.

Influence of emotional states on inhibitory gating: Animals models to clinical neurophysiology

PubMed Central

Cromwell, Howard C.; Atchley, Rachel M.

2014-01-01

Integrating research efforts using a cross-domain approach could redefine traditional constructs used in behavioral and clinical neuroscience by demonstrating that behavior and mental processes arise not from functional isolation but from integration. Our research group has been examining the interface between cognitive and emotional processes by studying inhibitory gating. Inhibitory gating can be measured via changes in behavior or neural signal processing. Sensorimotor gating of the startle response is a well-used measure. To study how emotion and cognition interact during startle modulation in the animal model, we examined ultrasonic vocalization (USV) emissions during acoustic startle and prepulse inhibition. We found high rates of USV emission during the sensorimotor gating paradigm and revealed links between prepulse inhibition (PPI) and USV emission that could reflect emotional and cognitive influences. Measuring inhibitory gating as P50 event-related potential suppression has also revealed possible connections between emotional states and cognitive processes. We have examined the single unit responses during the traditional gating paradigm and found that acute and chronic stress can alter gating of neural signals in regions such as amygdala, striatum and medial prefrontal cortex. Our findings point to the need for more cross-domain research on how shifting states of emotion can impact basic mechanisms of information processing. Results could inform clinical work with the development of tools that depend upon cross-domain communication, and enable a better understanding and evaluation of psychological impairment. PMID:24861710

Warning Signals: Basic Criteria for Tracking At-Risk Infants and Toddlers.

ERIC Educational Resources Information Center

Blackman, James

Developed by a multidisciplinary group (convened by Project Zero to Three) of 17 experts in the identification and evaluation of high risk infants and young children, this manual presents basic criteria for tracking at risk infants and toddlers. The first section answers such questions about the criteria as the following: What is a tracking system…

Study of a novel electromagnetic liquid argon calorimeter — the TGT

NASA Astrophysics Data System (ADS)

Berger, C.; Braunschweig, W.; Geulig, E.; Schöntag, M.; Siedling, R.; Wlochal, M.; Putzer, A.; Wotschack, J.; Cheplakov, A.; Feshchenko, A.; Kazarinov, M.; Kukhtin, V.; Ladygin, E.; Obudovskij, V.; Geweniger, C.; Hanke, P.; Kluge, E.-E.; Krause, J.; Schmidt, M.; Stenzel, H.; Tittel, K.; Wunsch, M.; Zerwas, D.; Bruncko, D.; Jusko, A.; Kocper, B.; Lupták, M.; Aderholz, M.; Bán, J.; Brettel, H.; Dydak, F.; Fent, J.; Frey, H.; Huber, J.; Jakobs, K.; Kiesling, C.; Kiryunin, A. E.; Oberlack, H.; Ribarics, P.; Schacht, P.; Stiegler, U.; Bogolyubsky, M. Y.; Buyanov, O. V.; Chekulaev, S. V.; Kurchaninov, L. L.; Levitsky, M. S.; Maximov, V. V.; Minaenko, A. A.; Moiseev, A. M.; Semenov, P. A.; Tikhonov, V. V.; Straumann, U.

1995-02-01

The concept and the basic design of a fast, highly granular and compact electromagnetic liquid argon calorimeter are described. This novel calorimeter offers uniform energy response and constant energy resolution independent of the production angle of an impinging particle and of its impact position at the calorimeter. An example of a calorimeter with full rapidity coverage in an application in a collider detector is given. An important aspect of the concept is the electronics for fast signal processing matched to the short charge collection time. We report on the experience with the realization of a prototype calorimeter module and on its performance in a testbeam exposure.

Scientific bases of human-machine communication by voice.

PubMed Central

Schafer, R W

1995-01-01

The scientific bases for human-machine communication by voice are in the fields of psychology, linguistics, acoustics, signal processing, computer science, and integrated circuit technology. The purpose of this paper is to highlight the basic scientific and technological issues in human-machine communication by voice and to point out areas of future research opportunity. The discussion is organized around the following major issues in implementing human-machine voice communication systems: (i) hardware/software implementation of the system, (ii) speech synthesis for voice output, (iii) speech recognition and understanding for voice input, and (iv) usability factors related to how humans interact with machines. PMID:7479802

Design of two wheel self balancing car

NASA Astrophysics Data System (ADS)

He, Chun-hong; Ren, Bin

2018-02-01

This paper proposes a design scheme of the two-wheel self-balancing dolly, the integration of the gyroscope and accelerometer MPU6050 constitutes the car position detection device.System selects 32-bit MCU stmicroelectronics company as the control core, completed the processing of sensor signals, the realization of the filtering algorithm, motion control and human-computer interaction. Produced and debugging in the whole system is completed, the car can realize the independent balance under the condition of no intervention. The introduction of a suitable amount of interference, the car can adjust quickly to recover and steady state. Through remote control car bluetooth module complete forward, backward, turn left and other basic action..

Splitting nodes and linking channels: A method for assembling biocircuits from stochastic elementary units

NASA Astrophysics Data System (ADS)

Ferwerda, Cameron; Lipan, Ovidiu

2016-11-01

Akin to electric circuits, we construct biocircuits that are manipulated by cutting and assembling channels through which stochastic information flows. This diagrammatic manipulation allows us to create a method which constructs networks by joining building blocks selected so that (a) they cover only basic processes; (b) it is scalable to large networks; (c) the mean and variance-covariance from the Pauli master equation form a closed system; and (d) given the initial probability distribution, no special boundary conditions are necessary to solve the master equation. The method aims to help with both designing new synthetic signaling pathways and quantifying naturally existing regulatory networks.

Acoustic logic gates and Boolean operation based on self-collimating acoustic beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Ting; Xu, Jian-yi; Cheng, Ying, E-mail: chengying@nju.edu.cn

2015-03-16

The reveal of self-collimation effect in two-dimensional (2D) photonic or acoustic crystals has opened up possibilities for signal manipulation. In this paper, we have proposed acoustic logic gates based on the linear interference of self-collimated beams in 2D sonic crystals (SCs) with line-defects. The line defects on the diagonal of the 2D square SCs are actually functioning as a 3 dB splitter. By adjusting the phase difference between two input signals, the basic Boolean logic functions such as XOR, OR, AND, and NOT are achieved both theoretically and experimentally. Due to the non-diffracting property of self-collimation beams, more complex Boolean logicmore » and algorithms such as NAND, NOR, and XNOR can be realized by cascading the basic logic gates. The achievement of acoustic logic gates and Boolean operation provides a promising approach for acoustic signal computing and manipulations.« less

Acclimatization to long-term hypoxia: gene expression in ovine carotid arteries

PubMed Central

Goyal, Ravi

2014-01-01

Exposure to acute high-altitude hypoxia is associated with an increase in cerebral blood flow (CBF) as a consequence of low arterial O2 tension. However, in response to high altitude acclimatization, CBF returns to levels similar to those at sea level, and tissue blood flow is maintained by an increase in angiogenesis. Of consequence, dysregulation of the acclimatization responses and CBF can result in acute mountain sickness, acute cerebral and/or pulmonary edema. To elucidate the signal transduction pathways involved in successful acclimatization to high altitude, in ovine carotid arteries, we tested the hypothesis that high altitude-associated long-term hypoxia results in changes in gene expression of critical signaling pathways. We acclimatized nonpregnant adult sheep to 3,801 m altitude for ∼110 days and conducted oligonucleotide microarray experiments on carotid arteries. Of a total of 116 regulated genes, 58 genes were significantly upregulated and 58 genes were significantly downregulated (each >2-fold, P < 0.05). Major upregulated genes included suprabasin and myelin basic protein, whereas downregulated genes included BAG2. Several of these genes are known to activate the ERK canonical signal transduction pathway and the process of angiogenesis. We conclude that among other changes, the altered signal transduction molecules involved in high-altitude acclimatization are associated ERK activation and angiogenesis. PMID:25052263

Emergency obstetric and newborn care signal functions in public and private facilities in Bangladesh

PubMed Central

2017-01-01

Background Signal functions for emergency obstetric and newborn care (EmONC) are the major interventions for averting maternal and neonatal mortalities. Readiness of the facilities is essential to provide all the basic and comprehensive signal functions for EmONC to ensure emergency services from the designated facilities. The study assessed population coverage and availability of EmONC services in public and private facilities in Bangladesh. Methods An assessment was conducted in all the public and private facilities providing obstetric care in to in-patients 24 districts. Data were collected on the performance of signal functions for EmONC from the study facilities in the last three months prior to the date of assessment. Trained data-collectors interviewed the facility managers and key service providers, along with review of records, using contextualized tools. Population coverage of signal functions was assessed by estimating the number of facilities providing the signal functions for EmONC compared to the United Nations requirements. Availability was assessed in terms of the proportion of facilities providing the services by type of facilities and by district. Results Caesarean section (CS) delivery and blood transfusion (BT) services (the two major components of comprehensive EmONC) were respectively available in 6.4 (0.9 public and 5.5 private) and 5.6 (1.3 public and 4.3 private) facilities per 500,000 population. The signal functions for basic EmONC, except two (parental anticonvulsants and assisted vaginal delivery), were available in a minimum of 5 facilities (public and private sectors combined) per 500,000 population. A major inter-district variation in the availability of signal functions was observed in each public- and private-sector facility. Among the various types of facilities, only the public medical college hospitals had all the signal functions. The situation was poor in other public facilities at the district and sub-district levels as well as in private facilities. Conclusions In the public sector, CS delivery and BT services were available in the minimum required number of facilities. However, to ensure basic EmONC services, participation of the private sector is necessary. Public-private partnership should be promoted for nationwide coverage of signal functions for EmONC in Bangladesh. PMID:29091965

Resolving molecule-specific information in dynamic lipid membrane processes with multi-resonant infrared metasurfaces.

PubMed

Rodrigo, Daniel; Tittl, Andreas; Ait-Bouziad, Nadine; John-Herpin, Aurelian; Limaj, Odeta; Kelly, Christopher; Yoo, Daehan; Wittenberg, Nathan J; Oh, Sang-Hyun; Lashuel, Hilal A; Altug, Hatice

2018-06-04

A multitude of biological processes are enabled by complex interactions between lipid membranes and proteins. To understand such dynamic processes, it is crucial to differentiate the constituent biomolecular species and track their individual time evolution without invasive labels. Here, we present a label-free mid-infrared biosensor capable of distinguishing multiple analytes in heterogeneous biological samples with high sensitivity. Our technology leverages a multi-resonant metasurface to simultaneously enhance the different vibrational fingerprints of multiple biomolecules. By providing up to 1000-fold near-field intensity enhancement over both amide and methylene bands, our sensor resolves the interactions of lipid membranes with different polypeptides in real time. Significantly, we demonstrate that our label-free chemically specific sensor can analyze peptide-induced neurotransmitter cargo release from synaptic vesicle mimics. Our sensor opens up exciting possibilities for gaining new insights into biological processes such as signaling or transport in basic research as well as provides a valuable toolkit for bioanalytical and pharmaceutical applications.

Unreliable evoked responses in autism

PubMed Central

Dinstein, Ilan; Heeger, David J.; Lorenzi, Lauren; Minshew, Nancy J.; Malach, Rafael; Behrmann, Marlene

2012-01-01

Summary Autism has been described as a disorder of general neural processing, but the particular processing characteristics that might be abnormal in autism have mostly remained obscure. Here, we present evidence of one such characteristic: poor evoked response reliability. We compared cortical response amplitude and reliability (consistency across trials) in visual, auditory, and somatosensory cortices of high-functioning individuals with autism and controls. Mean response amplitudes were statistically indistinguishable across groups, yet trial-by-trial response reliability was significantly weaker in autism, yielding smaller signal-to-noise ratios in all sensory systems. Response reliability differences were evident only in evoked cortical responses and not in ongoing resting-state activity. These findings reveal that abnormally unreliable cortical responses, even to elementary non-social sensory stimuli, may represent a fundamental physiological alteration of neural processing in autism. The results motivate a critical expansion of autism research to determine whether (and how) basic neural processing properties such as reliability, plasticity, and adaptation/habituation are altered in autism. PMID:22998867

Landauer in the Age of Synthetic Biology: Energy Consumption and Information Processing in Biochemical Networks

NASA Astrophysics Data System (ADS)

Mehta, Pankaj; Lang, Alex H.; Schwab, David J.

2016-03-01

A central goal of synthetic biology is to design sophisticated synthetic cellular circuits that can perform complex computations and information processing tasks in response to specific inputs. The tremendous advances in our ability to understand and manipulate cellular information processing networks raises several fundamental physics questions: How do the molecular components of cellular circuits exploit energy consumption to improve information processing? Can one utilize ideas from thermodynamics to improve the design of synthetic cellular circuits and modules? Here, we summarize recent theoretical work addressing these questions. Energy consumption in cellular circuits serves five basic purposes: (1) increasing specificity, (2) manipulating dynamics, (3) reducing variability, (4) amplifying signal, and (5) erasing memory. We demonstrate these ideas using several simple examples and discuss the implications of these theoretical ideas for the emerging field of synthetic biology. We conclude by discussing how it may be possible to overcome these limitations using "post-translational" synthetic biology that exploits reversible protein modification.

Optical implementation of polarization-independent, bidirectional, nonblocking Clos network using polarization control technique in free space

NASA Astrophysics Data System (ADS)

Yang, Junbo; Yang, Jiankun; Li, Xiujian; Chang, Shengli; Su, Xianyu; Ping, Xu

2011-04-01

The clos network is one of the earliest multistage interconnection networks. Recently, it has been widely studied in parallel optical information processing systems, and there have been many efforts to develop this network. In this paper, a smart and compact Clos network, including Clos(2,3,2) and Clos(2,4,2), is proposed by using polarizing beam-splitters (PBS), phase spatial light modulators (PSLM), and mirrors. PBS features that are s-component (perpendicular to the incident plane) of the incident light beam is reflected, and the p-component (parallel to the incident plane) passes through it. According to switching logic, under control of external electrical signals, PSLM functions to control routing paths of the signal beams, i.e., the polarization of each optical signal is rotated or not rotated 90° by a programmable PSLM. This new type of configuration grants the features of less optical components, compact in structure, efficient in performance, and insensitive to polarization of signal beam. In addition, the straight, the exchange, and the broadcast functions of the basic switch element are implemented bidirectionally in free-space. Furthermore, the new optical experimental module of 2×3 and 2×4 optical switch is also presented by a cascading polarization-independent bidirectional 2×2 optical switch. Simultaneously, the routing state-table of 2×3 and 2×4 optical switch to perform all permutation output and nonblocking switch for the input signal beam, is achieved. Since the proposed optical setup consists of only optical polarization elements, it is compact in structure, and possesses a low energy loss, a high signal-to-ratio, and an available large number of optical channels. Finally, the discussions and the experimental results show that the Clos network proposed here should be helpful in the design of large-scale network matrix, and may be used in optical communication and optical information processing.

c-di-AMP: An Essential Molecule in the Signaling Pathways that Regulate the Viability and Virulence of Gram-Positive Bacteria

PubMed Central

Fahmi, Tazin; Port, Gary C.

2017-01-01

Signal transduction pathways enable organisms to monitor their external environment and adjust gene regulation to appropriately modify their cellular processes. Second messenger nucleotides including cyclic adenosine monophosphate (c-AMP), cyclic guanosine monophosphate (c-GMP), cyclic di-guanosine monophosphate (c-di-GMP), and cyclic di-adenosine monophosphate (c-di-AMP) play key roles in many signal transduction pathways used by prokaryotes and/or eukaryotes. Among the various second messenger nucleotides molecules, c-di-AMP was discovered recently and has since been shown to be involved in cell growth, survival, and regulation of virulence, primarily within Gram-positive bacteria. The cellular level of c-di-AMP is maintained by a family of c-di-AMP synthesizing enzymes, diadenylate cyclases (DACs), and degradation enzymes, phosphodiesterases (PDEs). Genetic manipulation of DACs and PDEs have demonstrated that alteration of c-di-AMP levels impacts both growth and virulence of microorganisms. Unlike other second messenger molecules, c-di-AMP is essential for growth in several bacterial species as many basic cellular functions are regulated by c-di-AMP including cell wall maintenance, potassium ion homeostasis, DNA damage repair, etc. c-di-AMP follows a typical second messenger signaling pathway, beginning with binding to receptor molecules to subsequent regulation of downstream cellular processes. While c-di-AMP binds to specific proteins that regulate pathways in bacterial cells, c-di-AMP also binds to regulatory RNA molecules that control potassium ion channel expression in Bacillus subtilis. c-di-AMP signaling also occurs in eukaryotes, as bacterially produced c-di-AMP stimulates host immune responses during infection through binding of innate immune surveillance proteins. Due to its existence in diverse microorganisms, its involvement in crucial cellular activities, and its stimulating activity in host immune responses, c-di-AMP signaling pathway has become an attractive antimicrobial drug target and therefore has been the focus of intensive study in several important pathogens. PMID:28783096

NaviSE: superenhancer navigator integrating epigenomics signal algebra.

PubMed

Ascensión, Alex M; Arrospide-Elgarresta, Mikel; Izeta, Ander; Araúzo-Bravo, Marcos J

2017-06-06

Superenhancers are crucial structural genomic elements determining cell fate, and they are also involved in the determination of several diseases, such as cancer or neurodegeneration. Although there are pipelines which use independent pieces of software to predict the presence of superenhancers from genome-wide chromatin marks or DNA-interaction protein binding sites, there is not yet an integrated software tool that processes automatically algebra combinations of raw data sequencing into a comprehensive final annotated report of predicted superenhancers. We have developed NaviSE, a user-friendly streamlined tool which performs a fully-automated parallel processing of genome-wide epigenomics data from sequencing files into a final report, built with a comprehensive set of annotated files that are navigated through a graphic user interface dynamically generated by NaviSE. NaviSE also implements an 'epigenomics signal algebra' that allows the combination of multiple activation and repression epigenomics signals. NaviSE provides an interactive chromosomal landscaping of the locations of superenhancers, which can be navigated to obtain annotated information about superenhancer signal profile, associated genes, gene ontology enrichment analysis, motifs of transcription factor binding sites enriched in superenhancers, graphs of the metrics evaluating the superenhancers quality, protein-protein interaction networks and enriched metabolic pathways among other features. We have parallelised the most time-consuming tasks achieving a reduction up to 30% for a 15 CPUs machine. We have optimized the default parameters of NaviSE to facilitate its use. NaviSE allows different entry levels of data processing, from sra-fastq files to bed files; and unifies the processing of multiple replicates. NaviSE outperforms the more time-consuming processes required in a non-integrated pipeline. Alongside its high performance, NaviSE is able to provide biological insights, predicting cell type specific markers, such as SOX2 and ZIC3 in embryonic stem cells, CDK5R1 and REST in neurons and CD86 and TLR2 in monocytes. NaviSE is a user-friendly streamlined solution for superenhancer analysis, annotation and navigation, requiring only basic computer and next generation sequencing knowledge. NaviSE binaries and documentation are available at: https://sourceforge.net/projects/navise-superenhancer/ .

Far-field DOA estimation and source localization for different scenarios in a distributed sensor network

NASA Astrophysics Data System (ADS)

Asgari, Shadnaz

Recent developments in the integrated circuits and wireless communications not only open up many possibilities but also introduce challenging issues for the collaborative processing of signals for source localization and beamforming in an energy-constrained distributed sensor network. In signal processing, various sensor array processing algorithms and concepts have been adopted, but must be further tailored to match the communication and computational constraints. Sometimes the constraints are such that none of the existing algorithms would be an efficient option for the defined problem and as the result; the necessity of developing a new algorithm becomes undeniable. In this dissertation, we present the theoretical and the practical issues of Direction-Of-Arrival (DOA) estimation and source localization using the Approximate-Maximum-Likelihood (AML) algorithm for different scenarios. We first investigate a robust algorithm design for coherent source DOA estimation in a limited reverberant environment. Then, we provide a least-square (LS) solution for source localization based on our newly proposed virtual array model. In another scenario, we consider the determination of the location of a disturbance source which emits both wideband acoustic and seismic signals. We devise an enhanced AML algorithm to process the data collected at the acoustic sensors. For processing the seismic signals, two distinct algorithms are investigated to determine the DOAs. Then, we consider a basic algorithm for fusion of the results yielded by the acoustic and seismic arrays. We also investigate the theoretical and practical issues of DOA estimation in a three-dimensional (3D) scenario. We show that the performance of the proposed 3D AML algorithm converges to the Cramer-Rao Bound. We use the concept of an isotropic array to reduce the complexity of the proposed algorithm by advocating a decoupled 3D version. We also explore a modified version of the decoupled 3D AML algorithm which can be used for DOA estimation with non-isotropic arrays. In this dissertation, for each scenario, efficient numerical implementations of the corresponding AML algorithm are derived and applied into a real-time sensor network testbed. Extensive simulations as well as experimental results are presented to verify the effectiveness of the proposed algorithms.

Retinoic acid signaling pathways in development and diseases.

PubMed

Das, Bhaskar C; Thapa, Pritam; Karki, Radha; Das, Sasmita; Mahapatra, Sweta; Liu, Ting-Chun; Torregroza, Ingrid; Wallace, Darren P; Kambhampati, Suman; Van Veldhuizen, Peter; Verma, Amit; Ray, Swapan K; Evans, Todd

2014-01-15

Retinoids comprise a group of compounds each composed of three basic parts: a trimethylated cyclohexene ring that is a bulky hydrophobic group, a conjugated tetraene side chain that functions as a linker unit, and a polar carbon-oxygen functional group. Biochemical conversion of carotenoid or other retinoids to retinoic acid (RA) is essential for normal regulation of a wide range of biological processes including development, differentiation, proliferation, and apoptosis. Retinoids regulate various physiological outputs by binding to nuclear receptors called retinoic acid receptors (RARs) and retinoid X receptors (RXRs), which themselves are DNA-binding transcriptional regulators. The functional response of RA and their receptors are modulated by a host of coactivators and corepressors. Retinoids are essential in the development and function of several organ systems; however, deregulated retinoid signaling can contribute to serious diseases. Several natural and synthetic retinoids are in clinical use or undergoing trials for treating specific diseases including cancer. In this review, we provide a broad overview on the importance of retinoids in development and various diseases, highlighting various retinoids in the drug discovery process, ranging all the way from retinoid chemistry to clinical uses and imaging. Copyright © 2013 Elsevier Ltd. All rights reserved.

Reservoir Computing Beyond Memory-Nonlinearity Trade-off.

PubMed

Inubushi, Masanobu; Yoshimura, Kazuyuki

2017-08-31

Reservoir computing is a brain-inspired machine learning framework that employs a signal-driven dynamical system, in particular harnessing common-signal-induced synchronization which is a widely observed nonlinear phenomenon. Basic understanding of a working principle in reservoir computing can be expected to shed light on how information is stored and processed in nonlinear dynamical systems, potentially leading to progress in a broad range of nonlinear sciences. As a first step toward this goal, from the viewpoint of nonlinear physics and information theory, we study the memory-nonlinearity trade-off uncovered by Dambre et al. (2012). Focusing on a variational equation, we clarify a dynamical mechanism behind the trade-off, which illustrates why nonlinear dynamics degrades memory stored in dynamical system in general. Moreover, based on the trade-off, we propose a mixture reservoir endowed with both linear and nonlinear dynamics and show that it improves the performance of information processing. Interestingly, for some tasks, significant improvements are observed by adding a few linear dynamics to the nonlinear dynamical system. By employing the echo state network model, the effect of the mixture reservoir is numerically verified for a simple function approximation task and for more complex tasks.

A three-level support method for smooth switching of the micro-grid operation model

NASA Astrophysics Data System (ADS)

Zong, Yuanyang; Gong, Dongliang; Zhang, Jianzhou; Liu, Bin; Wang, Yun

2018-01-01

Smooth switching of micro-grid between the grid-connected operation mode and off-grid operation mode is one of the key technologies to ensure it runs flexible and efficiently. The basic control strategy and the switching principle of micro-grid are analyzed in this paper. The reasons for the fluctuations of the voltage and the frequency in the switching process are analyzed from views of power balance and control strategy, and the operation mode switching strategy has been improved targeted. From the three aspects of controller’s current inner loop reference signal, voltage outer loop control strategy optimization and micro-grid energy balance management, a three-level security strategy for smooth switching of micro-grid operation mode is proposed. From the three aspects of controller’s current inner loop reference signal tracking, voltage outer loop control strategy optimization and micro-grid energy balance management, a three-level strategy for smooth switching of micro-grid operation mode is proposed. At last, it is proved by simulation that the proposed control strategy can make the switching process smooth and stable, the fluctuation problem of the voltage and frequency has been effectively improved.

Importance of Mediator complex in the regulation and integration of diverse signaling pathways in plants.

PubMed

Samanta, Subhasis; Thakur, Jitendra K

2015-01-01

Basic transcriptional machinery in eukaryotes is assisted by a number of cofactors, which either increase or decrease the rate of transcription. Mediator complex is one such cofactor, and recently has drawn a lot of interest because of its integrative power to converge different signaling pathways before channeling the transcription instructions to the RNA polymerase II machinery. Like yeast and metazoans, plants do possess the Mediator complex across the kingdom, and its isolation and subunit analyses have been reported from the model plant, Arabidopsis. Genetic, and molecular analyses have unraveled important regulatory roles of Mediator subunits at every stage of plant life cycle starting from flowering to embryo and organ development, to even size determination. It also contributes immensely to the survival of plants against different environmental vagaries by the timely activation of its resistance mechanisms. Here, we have provided an overview of plant Mediator complex starting from its discovery to regulation of stoichiometry of its subunits. We have also reviewed involvement of different Mediator subunits in different processes and pathways including defense response pathways evoked by diverse biotic cues. Wherever possible, attempts have been made to provide mechanistic insight of Mediator's involvement in these processes.

Importance of Mediator complex in the regulation and integration of diverse signaling pathways in plants

PubMed Central

Samanta, Subhasis; Thakur, Jitendra K.

2015-01-01

Basic transcriptional machinery in eukaryotes is assisted by a number of cofactors, which either increase or decrease the rate of transcription. Mediator complex is one such cofactor, and recently has drawn a lot of interest because of its integrative power to converge different signaling pathways before channeling the transcription instructions to the RNA polymerase II machinery. Like yeast and metazoans, plants do possess the Mediator complex across the kingdom, and its isolation and subunit analyses have been reported from the model plant, Arabidopsis. Genetic, and molecular analyses have unraveled important regulatory roles of Mediator subunits at every stage of plant life cycle starting from flowering to embryo and organ development, to even size determination. It also contributes immensely to the survival of plants against different environmental vagaries by the timely activation of its resistance mechanisms. Here, we have provided an overview of plant Mediator complex starting from its discovery to regulation of stoichiometry of its subunits. We have also reviewed involvement of different Mediator subunits in different processes and pathways including defense response pathways evoked by diverse biotic cues. Wherever possible, attempts have been made to provide mechanistic insight of Mediator's involvement in these processes. PMID:26442070

Photogate Timing with a Smartphone

ERIC Educational Resources Information Center

Forinash, Kyle; Wisman, Raymond F.

2015-01-01

In a previous article we demonstrated that a simple, passive external circuit incorporating a thermistor, connected to a mobile device through the headset jack, can be used to collect temperature data. The basic approach is to output a sine wave signal to the headset port, through the circuit, and input the resulting signal from the headset…

Children's Recognition of Disgust in Others

ERIC Educational Resources Information Center

Widen, Sherri C.; Russell, James A.

2013-01-01

Disgust has been theorized to be a basic emotion with a facial signal that is easily, universally, automatically, and perhaps innately recognized by observers from an early age. This article questions one key part of that theory: the hypothesis that children recognize disgust from its purported facial signal. Over the first 5 years, children…

Therapeutic Strategies in Fragile X Syndrome: Dysregulated mGluR Signaling and Beyond

PubMed Central

Gross, Christina; Berry-Kravis, Elizabeth M; Bassell, Gary J

2012-01-01

Fragile X syndrome (FXS) is an inherited neurodevelopmental disease caused by loss of function of the fragile X mental retardation protein (FMRP). In the absence of FMRP, signaling through group 1 metabotropic glutamate receptors is elevated and insensitive to stimulation, which may underlie many of the neurological and neuropsychiatric features of FXS. Treatment of FXS animal models with negative allosteric modulators of these receptors and preliminary clinical trials in human patients support the hypothesis that metabotropic glutamate receptor signaling is a valuable therapeutic target in FXS. However, recent research has also shown that FMRP may regulate diverse aspects of neuronal signaling downstream of several cell surface receptors, suggesting a possible new route to more direct disease-targeted therapies. Here, we summarize promising recent advances in basic research identifying and testing novel therapeutic strategies in FXS models, and evaluate their potential therapeutic benefits. We provide an overview of recent and ongoing clinical trials motivated by some of these findings, and discuss the challenges for both basic science and clinical applications in the continued development of effective disease mechanism-targeted therapies for FXS. PMID:21796106

Deficits in implicit attention to social signals in schizophrenia and high risk groups: behavioural evidence from a new illusion.

PubMed

van 't Wout, Mascha; van Rijn, Sophie; Jellema, Tjeerd; Kahn, René S; Aleman, André

2009-01-01

An increasing body of evidence suggests that the apparent social impairments observed in schizophrenia may arise from deficits in social cognitive processing capacities. The ability to process basic social cues, such as gaze direction and biological motion, effortlessly and implicitly is thought to be a prerequisite for establishing successful social interactions and for construing a sense of "social intuition." However, studies that address the ability to effortlessly process basic social cues in schizophrenia are lacking. Because social cognitive processing deficits may be part of the genetic vulnerability for schizophrenia, we also investigated two groups that have been shown to be at increased risk of developing schizophrenia-spectrum pathology: first-degree relatives of schizophrenia patients and men with Klinefelter syndrome (47,XXY). We compared 28 patients with schizophrenia, 29 siblings of patients with schizophrenia, and 29 individuals with Klinefelter syndrome with 46 matched healthy control subjects on a new paradigm. This paradigm measures one's susceptibility for a bias in distance estimation between two agents that is induced by the implicit processing of gaze direction and biological motion conveyed by these agents. Compared to control subjects, patients with schizophrenia, as well as siblings of patients and Klinefelter men, showed a lack of influence of social cues on their distance judgments. We suggest that the insensitivity for social cues is a cognitive aspect of schizophrenia that may be seen as an endophenotype as it appears to be present both in relatives who are at increased genetic risk and in a genetic disorder at risk for schizophrenia-spectrum psychopathology. These social cue-processing deficits could contribute, in part, to the difficulties in higher order social cognitive tasks and, hence, to decreased social competence that has been observed in these groups.

Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages.

PubMed

Wang, H; Chen, D; Yuan, G; Ma, X; Dai, X

2013-02-01

In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low values. When impurities were involved, the shape of BR curves showed that intense decomposition started earlier but morphological characteristics remained the same. In addition, compared to parameters such as pressure, the BR reflects reaction stages better and its change with pyrolysis process of PE/PP plastics with or without impurities was more intrinsically process correlated; therefore it can be adopted as a signal for pyrolysis process characterization, as well as offering guide to process improvement and reactor design. Copyright © 2012 Elsevier Ltd. All rights reserved.

Role of basic biological sciences in clinical orthodontics: a case series.

PubMed

Davidovitch, Ze'ev; Krishnan, Vinod

2009-02-01

Orthodontic therapy is based on interaction between mechanics and biology. Basic biologic research aims at developing a better understanding of the mechanism of transformation of mechanical energy into biologic reactions, and exposing the reasons for iatrogenic tissue damage in orthodontics. Previous research has shown that inflammation is a major part of the biologic response to orthodontic forces. In inflammation, signal molecules that originate in remote diseased organs can reach strained paradental tissues and exacerbate the inflammatory process, leading to tissue damage. Our case series includes 3 patients, each having had systemic diseases and malocclusion. One had diabetes mellitus, Hashimoto's thyroiditis, and depression. Concern about the possible effect of these conditions on the well-being of the teeth and their surrounding tissues compelled the orthodontist to choose not to treat this patient. The other 2 patients had allergies, and 1 also had bronchial asthma and bruises. Although these conditions are thought to be risk factors for root resorption, these patients received orthodontic treatment for 2 and 3.5 years, respectively. At the end of treatment, both had excessive root resorption of many teeth. In 1 patient, this damage led to the loss of most maxillary teeth. Basic research should continue to address questions related to the biologic mechanisms of tooth movement on tissue, cellular, and molecular levels. Moreover, this research should continue to identify risk factors that might jeopardize the longevity of treated teeth. Such basic research should promote the development of new tissue-friendly and patient-friendly therapeutic methods.

Simultaneous optical and electrical recording of a single ion-channel.

PubMed

Ide, Toru; Takeuchi, Yuko; Aoki, Takaaki; Yanagida, Toshio

2002-10-01

In recent years, the single-molecule imaging technique has proven to be a valuable tool in solving many basic problems in biophysics. The technique used to measure single-molecule functions was initially developed to study electrophysiological properties of channel proteins. However, the technology to visualize single channels at work has not received as much attention. In this study, we have for the first time, simultaneously measured the optical and electrical properties of single-channel proteins. The large conductance calcium-activated potassium channel (BK-channel) labeled with fluorescent dye molecules was incorporated into a planar bilayer membrane and the fluorescent image captured with a total internal reflection fluorescence microscope simultaneously with single-channel current recording. This innovative technology will greatly advance the study of channel proteins as well as signal transduction processes that involve ion permeation processes.

A rocket-borne pulse-height analyzer for energetic particle measurements

NASA Technical Reports Server (NTRS)

Leung, W.; Smith, L. G.; Voss, H. D.

1979-01-01

The pulse-height analyzer basically resembles a time-sharing multiplexing data-acquisition system which acquires analog data (from energetic particle spectrometers) and converts them into digital code. The PHA simultaneously acquires pulse-height information from the analog signals of the four input channels and sequentially multiplexes the digitized data to a microprocessor. The PHA together with the microprocessor form an on-board real-time data-manipulation system. The system processes data obtained during the rocket flight and reduces the amount of data to be sent back to the ground station. Consequently the data-reduction process for the rocket experiments is speeded up. By using a time-sharing technique, the throughput rate of the microprocessor is increased. Moreover, data from several particle spectrometers are manipulated to share one information channel; consequently, the TM capacity is increased.

An analog neural hardware implementation using charge-injection multipliers and neutron-specific gain control.

PubMed

Massengill, L W; Mundie, D B

1992-01-01

A neural network IC based on a dynamic charge injection is described. The hardware design is space and power efficient, and achieves massive parallelism of analog inner products via charge-based multipliers and spatially distributed summing buses. Basic synaptic cells are constructed of exponential pulse-decay modulation (EPDM) dynamic injection multipliers operating sequentially on propagating signal vectors and locally stored analog weights. Individually adjustable gain controls on each neutron reduce the effects of limited weight dynamic range. A hardware simulator/trainer has been developed which incorporates the physical (nonideal) characteristics of actual circuit components into the training process, thus absorbing nonlinearities and parametric deviations into the macroscopic performance of the network. Results show that charge-based techniques may achieve a high degree of neural density and throughput using standard CMOS processes.

Serotonergic and dopaminergic modulation of attentional processes.

PubMed

Boulougouris, Vasileios; Tsaltas, Eleftheria

2008-01-01

Disturbances in attentional processes are a common feature of several psychiatric disorders such as schizophrenia, attention deficit/hyperactivity disorder and Huntington's disease. The use of animal models has been useful in defining various candidate neural systems thus enabling us to translate basic laboratory science to the clinic and vice-versa. In this chapter, a comparative and integrated account is provided on the neuroanatomical and neurochemical modulation of basic behavioural operations such as selective attention, vigilance, set-shifting and executive control focusing on the comparative functions of the serotonin and dopamine systems in the cognitive control exerted by the prefrontal cortex. Specifically, we have reviewed evidence emerging from several behavioural paradigms in experimental animals and humans each of which centres on a different aspect of the attentional function. These paradigms offering both human and animal variants include the five-choice serial reaction time task (5CSRTT), attentional set-shifting and stop-signal reaction time task. In each case, the types of operation that are measured by the given paradigm and their neural correlates are defined. Then, the role of the ascending dopaminergic and serotonergic systems in the neurochemical modulation of its behavioural output are examined, and reference is made to clinical implications for neurological and neuropsychiatric disorders which exhibit deficits in these cognitive tests.

An Acetylation Switch Regulates SUMO-Dependent Protein Interaction Networks

PubMed Central

Ullmann, Rebecca; Chien, Christopher D.; Avantaggiati, Maria Laura; Muller, Stefan

2013-01-01

SUMMARY The attachment of the SUMO modifier to proteins controls cellular signaling pathways through noncovalent binding to SUMO-interaction motifs (SIMs). Canonical SIMs contain a core of hydrophobic residues that bind to a hydrophobic pocket on SUMO. Negatively charged residues of SIMs frequently contribute to binding by interacting with a basic surface on SUMO. Here we define acetylation within this basic interface as a central mechanism for the control of SUMO-mediated interactions. The acetyl-mediated neutralization of basic charges on SUMO prevents binding to SIMs in PML, Daxx, and PIAS family members but does not affect the interaction between RanBP2 and SUMO. Acetylation is controlled by HDACs and attenuates SUMO- and PIAS-mediated gene silencing. Moreover, it affects the assembly of PML nuclear bodies and restrains the recruitment of the corepressor Daxx to these structures. This acetyl-dependent switch thus expands the regulatory repertoire of SUMO signaling and determines the selectivity and dynamics of SUMO-SIM interactions. PMID:22578841

Progress in Acoustic Transmission of Power through Walls

NASA Technical Reports Server (NTRS)

Sherrit,Stewart; Coty, Benjamin; Bao, Xiaoqi; Bar-Cohen, Yoseph; Badescu, Mircea; Chang, Zensheu

2008-01-01

A document presents updated information on implementation of the wireless acoustic-electric feed-through (WAEF) concept, which was reported in Using Piezoelectric Devices To Transmit Power Through Walls (NPO-41157), NASA Tech Briefs, Vol. 32, No. 6 (June 2008), page 70. To recapitulate: In a basic WAEF setup, a transmitting piezoelectric transducer on one side of a wall is driven at resonance to excite ultrasonic vibrations in the wall. A receiving piezoelectric transducer on the opposite side of the wall converts the vibrations back to an ultrasonic AC electric signal, which is then detected and otherwise processed in a manner that depends on the modulation (if any) applied to the signal and whether the signal is used to transmit power, data, or both. The present document expands upon the previous information concerning underlying physical principles, advantages, and potential applications of WAEF. It discusses the design and construction of breadboard prototype piezoelectric transducers for WAEF. It goes on to present results of computational simulations of performance and results of laboratory tests of the prototypes. In one notable test, a 100-W light bulb was lit by WAEF to demonstrate the feasibility of powering a realistic load.

Encountering bird alarms in full-stare IRSTs

NASA Astrophysics Data System (ADS)

de Jong, Arie N.; Winkel, Hans; Kemp, Rob A. W.

2000-12-01

Birds are a potential source of frequent false alarms in Infrared Search and Track (IRST) systems. One reason is that the signals, generated by birds at short ranges (1-2 km) in IR sensors may be of the same magnitude as the signals generated by real targets (missiles) at long ranges (10-20 km). Another reason is that new generations of IRSTs have more sensitivity which brings more birds within the detection range. Furthermore military operations tend to be held more and more in coastal zones, where the frequency of occurrence of birds is greater than in the open ocean. Finally, the variety in type of birds and their flight characteristics and signature is larger. In the paper attention is spent on the IR signatures of birds in various backgrounds, including rapid variations in signature due to wing motions. Basically, these fluctuations and the flight pattern of a bird provide opportunities to encounter bird alarms in next generation IRSTs, using multiple Focal Plan Array cameras with high frame rates. One has to take into account in this process the difference between signal variations due to wing motions and scintillation for long range targets above the horizon.

Subarray-based FDA radar to counteract deceptive ECM signals

NASA Astrophysics Data System (ADS)

Abdalla, Ahmed; Wang, Wen-Qin; Yuan, Zhao; Mohamed, Suhad; Bin, Tang

2016-12-01

In recent years, the frequency diverse array (FDA) radar concept has attracted extensive attention, as it may benefit from a small frequency increment, compared to the carrier frequency across the array elements and thereby achieve an array factor that is a function of the angle, the time, and the range which is superior to the conventional phase array radar (PAR). However, limited effort on the subject of FDA in electronic countermeasure scenarios, especially in the presence of mainbeam deceptive jamming, has been published. Basic FDA is not desirable for anti-jamming applications, due to the range-angle coupling response of targets. In this paper, a novel method based on subarrayed FDA signal processing is proposed to counteract deceptive ECM signals. We divide the FDA array into multiple subarrays, each of which employs a distinct frequency increment. As a result, in the subarray-based FDA, the desired target can be distinguished at subarray level in joint range-angle-Doppler domain by utilizing the fact that the jammer generates false targets with the same ranges to each subarray without reparations. The performance assessment shows that the proposed solution is effective for deceptive ECM targets suppression. The effectiveness is verified by simulation results.

Graphene oxide based contacts as probes of biomedical signals

NASA Astrophysics Data System (ADS)

Hallfors, N. G.; Devarajan, A.; Farhat, I. A. H.; Abdurahman, A.; Liao, K.; Gater, D. L.; Elnaggar, M. I.; Isakovic, A. F.

We have developed a series of graphene oxide (GOx) on polymer contacts and have demonstrated these to be useful for collection of standard biomedically relevant signals, such as electrocardiogram (ECG). The process is wet solution-based and allows for control and tuning of the basic physical parameters of GOx, such as electrical and optical properties, simply by choosing the number of GOx layers. Our GOx characterization measurements show spectral (FTIR, XPS, IR absorbance) features most relevant to such performance, and point towards the likely explanations about the mechanisms for controlling the physical properties relevant for the contact performance. Structural (X-ray topography) and surface characterization (AFM, SEM) indicates to what degree these contacts can be considered homogeneous and therefore provide information on yield and repeatability. We compare the ECG signals recorded by standard commercial probes (Ag/AgCl) and GOx probes, displaying minor differences the solution to which may lead to a whole new way we perform ECG data collection, including wearable electronics and IoT friendly ECG monitoring. We acknowledge support from Mubadala-SRC AC4ES and from SRC 2011-KJ-2190. We thank J. B. Warren and G. L. Carr (BNL) for assistance.

G-protein-coupled receptors participate in cytokinesis

PubMed Central

Zhang, Xin; Bedigian, Anne V.; Wang, Wenchao; Eggert, Ulrike S.

2014-01-01

Cytokinesis, the last step during cell division, is a highly coordinated process that involves the relay of signals from both the outside and inside of the cell. We have a basic understanding of how cells regulate internal events, but how cells respond to extracellular cues is less explored. In a systematic RNAi screen of G-protein-coupled receptors (GPCRs) and their effectors, we found that some GPCRs are involved in cytokinesis. RNAi knockdown of these GPCRs caused increased binucleated cell formation, and live cell imaging showed that most formed midbodies but failed at the abscission stage. OR2A4 localized to cytokinetic structures in cells and its knockdown caused cytokinesis failure at an earlier stage, likely due to effects on the actin cytoskeleton. Identifying the downstream components that transmit GPCR signals during cytokinesis will be the next step and we show that GIPC1, an adaptor protein for GPCRs, may play a part. RNAi knockdown of GIPC1 significantly increased binucleated cell formation. Understanding the molecular details of GPCRs and their interaction proteins in cytokinesis regulation will give us important clues about GPCRs signaling as well as how cells communicate with their environment during division. PMID:22888021

Spatial distribution of emergency obstetric and newborn care services in Ghana: Using the evidence to plan interventions.

PubMed

Bosomprah, Samuel; Tatem, Andrew J; Dotse-Gborgbortsi, Winfred; Aboagye, Patrick; Matthews, Zoe

2016-01-01

To provide clear policy directions for gaps in the provision of signal function services and sub-regions requiring priority attention using data from the 2010 Ghana Emergency Obstetric and Newborn Care (EmONC) survey. Using 2010 survey data, the fraction of facilities with only one or two signal functions missing was calculated for each facility type and EmONC designation. Thematic maps were used to provide insight into inequities in service provision. Of 1159 maternity facilities, 89 provided all the necessary basic or comprehensive EmONC signal functions 3months prior to the 2010 survey. Only 21% of facility-based births were in fully functioning EmONC facilities, but an additional 30% occurred in facilities missing one or two basic signal functions-most often assisted vaginal delivery and removal of retained products. Tackling these missing signal functions would extend births taking place in fully functioning facilities to over 50%. Subnational analyses based on estimated total pregnancies in each district revealed a pattern of inequity in service provision across the country. Upgrading facilities missing only one or two signal functions will allow Ghana to meet international standards for availability of EmONC services. Reducing maternal deaths will require high national priority given to addressing inequities in the distribution of EmONC services. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

An optimized, universal hardware-based adaptive correlation receiver architecture

NASA Astrophysics Data System (ADS)

Zhu, Zaidi; Suarez, Hernan; Zhang, Yan; Wang, Shang

2014-05-01

The traditional radar RF transceivers, similar to communication transceivers, have the basic elements such as baseband waveform processing, IF/RF up-down conversion, transmitter power circuits, receiver front-ends, and antennas, which are shown in the upper half of Figure 1. For modern radars with diversified and sophisticated waveforms, we can frequently observe that the transceiver behaviors, especially nonlinear behaviors, are depending on the waveform amplitudes, frequency contents and instantaneous phases. Usually, it is a troublesome process to tune an RF transceiver to optimum when different waveforms are used. Another issue arises from the interference caused by the waveforms - for example, the range side-lobe (RSL) caused by the waveforms, once the signals pass through the entire transceiver chain, may be further increased due to distortions. This study is inspired by the two existing solutions from commercial communication industry, digital pre-distortion (DPD) and adaptive channel estimation and Interference Mitigation (AIM), while combining these technologies into a single chip or board that can be inserted into the existing transceiver system. This device is then named RF Transceiver Optimizer (RTO). The lower half of Figure 1 shows the basic element of RTO. With RTO, the digital baseband processing does not need to take into account the transceiver performance with diversified waveforms, such as the transmitter efficiency and chain distortion (and the intermodulation products caused by distortions). Neither does it need to concern the pulse compression (or correlation receiver) process and the related mitigation. The focus is simply the information about the ground truth carried by the main peak of correlation receiver outputs. RTO can be considered as an extension of the existing calibration process, while it has the benefits of automatic, adaptive and universal. Currently, the main techniques to implement the RTO are the digital pre- or -post distortions (DPD), and the main technique to implement the AIM is the Adaptive Pulse Compression (APC). The basic algorithms and experiments with DPD will be introduced which is also the focus of this paper. The discussion of AIM algorithms will be presented in other papers, while the initial implementation of AIM and correlation receiver in FPGA devices will also be introduced in this paper.

Efficient method for events detection in phonocardiographic signals

NASA Astrophysics Data System (ADS)

Martinez-Alajarin, Juan; Ruiz-Merino, Ramon

2005-06-01

The auscultation of the heart is still the first basic analysis tool used to evaluate the functional state of the heart, as well as the first indicator used to submit the patient to a cardiologist. In order to improve the diagnosis capabilities of auscultation, signal processing algorithms are currently being developed to assist the physician at primary care centers for adult and pediatric population. A basic task for the diagnosis from the phonocardiogram is to detect the events (main and additional sounds, murmurs and clicks) present in the cardiac cycle. This is usually made by applying a threshold and detecting the events that are bigger than the threshold. However, this method usually does not allow the detection of the main sounds when additional sounds and murmurs exist, or it may join several events into a unique one. In this paper we present a reliable method to detect the events present in the phonocardiogram, even in the presence of heart murmurs or additional sounds. The method detects relative maxima peaks in the amplitude envelope of the phonocardiogram, and computes a set of parameters associated with each event. Finally, a set of characteristics is extracted from each event to aid in the identification of the events. Besides, the morphology of the murmurs is also detected, which aids in the differentiation of different diseases that can occur in the same temporal localization. The algorithms have been applied to real normal heart sounds and murmurs, achieving satisfactory results.

Transient removal of proflavine inhibition of bovine beta-trypsin by the bovine basic pancreatic trypsin inhibitor (Kunitz). A case for "chronosteric effects".

PubMed

Antonini, E; Ascenzi, P; Bolognesi, M; Menegatti, E; Guarneri, M

1983-04-25

The formation of the bovine beta-trypsin-bovine basic pancreatic trypsin inhibitor (Kunitz) (BPTI) complex was monitored, making use of three different signals: proflavine displacement, optical density changes in the ultraviolet region, and the loss of the catalytic activity. The rates of the reactions indicated by the three different signals were similar at neutral pH, but diverged at low pH. At pH 3.50, proflavine displacement precedes the optical density changes in the ultraviolet and the loss of enzyme activity by several orders of magnitude in time (Antonini, E., Ascenzi, P., Menegatti, E., and Guarneri, M. (1983) Biopolymers 22, 363-375). These data indicated that the bovine beta-trypsin-BPTI complex formation is a multistage process and led to the prediction that, at pH 3.50, BPTI addition to the bovine beta-trypsin-proflavine complex would remove proflavine inhibition and the enzyme would recover transiently its catalytic activity before being irreversibly inhibited by completion of BPTI binding. The kinetic evidences, by completion of BPTI binding. The kinetic evidences, here shown, verified this prediction, indicating that during the bovine beta-trypsin-BPTI complex formation one transient intermediate occurs, which is not able to bind proflavine but may bind and hydrolyze the substrate. Thus, the observed peculiar catalytic behavior is in line with the proposed reaction mechanism for the bovine beta-trypsin-BPTI complex formation, which postulates a sequence of distinct polar and apolar interactions at the contact area.

Identification of basic/helix-loop-helix transcription factors reveals candidate genes involved in anthocyanin biosynthesis from the strawberry white-flesh mutant.

PubMed

Zhao, Fengli; Li, Gang; Hu, Panpan; Zhao, Xia; Li, Liangjie; Wei, Wei; Feng, Jiayue; Zhou, Houcheng

2018-02-09

As the second largest transcription factor family in plant, the basic helix-loop-helix (bHLH) transcription factor family, characterized by the conserved bHLH domain, plays a central regulatory role in many biological process. However, the bHLH transcription factor family of strawberry has not been systematically identified, especially for the anthocyanin biosynthesis. Here, we identified a total of 113 bHLH transcription factors and described their chromosomal distribution and bioinformatics for the diploid woodland strawberry Fragaria vesca. In addition, transcription profiles of 113 orthologous bHLH genes from various tissues were analyzed for the cultivar 'Benihoppe', its white-flesh mutant 'Xiaobai', and the 'Snow Princess' from their fruit development to the ripening, as well as those under either the ABA or Eth treatment. Both the RT-PCR and qRT-PCR results show that seven selected FabHLH genes (FabHLH17, FabHLH25, FabHLH27, FabHLH29, FabHLH40, FabHLH80, FabHLH98) are responsive to the fruit anthocyanin biosynthesis and hormone signaling according to transcript profiles where three color modes are observed for strawberry's fruit skin and flesh. Further, prediction for the protein interaction network reveals that four bHLHs (FabHLH25, FabHLH29, FabHLH80, FabHLH98) are involved in the fruit anthocyanin biosynthesis and hormone signaling transduction. These bioinformatics and expression profiles provide a good basis for a further investigation of strawberry bHLH genes.

Design criteria for noncoherent Gaussian channels with MFSK signaling and coding

NASA Technical Reports Server (NTRS)

Butman, S. A.; Levitt, B. K.; Bar-David, I.; Lyon, R. F.; Klass, M. J.

1976-01-01

This paper presents data and criteria to assess and guide the design of modems for coded noncoherent communication systems subject to practical system constraints of power, bandwidth, noise spectral density, coherence time, and number of orthogonal signals M. Three basic receiver types are analyzed for the noncoherent multifrequency-shift keying (MFSK) additive white Gaussian noise channel: hard decision, unquantized (optimum), and quantized (soft decision). Channel capacity and computational cutoff rate are computed for each type and presented as functions of the predetection signal-to-noise ratio and the number of orthogonal signals. This relates the channel constraints of power, bandwidth, coherence time, and noise power to the optimum choice of signal duration and signal number.

Fluorescent sensing with Fresnel microlenses for optofluidic systems

NASA Astrophysics Data System (ADS)

Siudzińska, Anna; Miszczuk, Andrzej; Marczak, Jacek; Komorowska, Katarzyna

2017-05-01

The concept of fluorescent sensing in a microchannel equipped with focusing light Fresnel lenses has been demonstrated. The concept employs a line or array of Fresnel lenses generating a line or array of focused light spots within a microfluidic channel, to increase the sensitivity of fluorescent signal detection in the system. We have presented efficient methods of master mold fabrication based on the lithography method and focused ion beam milling. The flexible microchannel was fabricated by an imprint process with new thiolene-epoxy resin with a good ability to replicate even submicron-size features. For final imprinted lenses, the measured background to peak signal level shows more than nine times the increase in brightness at the center of the focal spot for the green part of the spectrum (532 nm). The effectiveness of the microlenses in fluorescent-marked Escherichia coli bacteria was confirmed in a basic fluoroscope experiment, showing the increase of the sensitivity of the detection by the order of magnitude.

Neuroendocrine Regulation of Anxiety: Beyond the Hypothalamic-Pituitary-Adrenal Axis.

PubMed

Borrow, A P; Stranahan, A M; Suchecki, D; Yunes, R

2016-07-01

The central nervous system regulates and responds to endocrine signals, and this reciprocal relationship determines emotional processing and behavioural anxiety. Although the hypothalamic-pituitary-adrenal (HPA) axis remains the best-characterised system for this relationship, other steroid and peptide hormones are increasingly recognised for their effects on anxiety-like behaviour and reward. The present review examines recent developments related to the role of a number of different hormones in anxiety, including pregnane neurosteroids, gut peptides, neuropeptides and hormonal signals derived from fatty acids. Findings from both basic and clinical studies suggest that these alternative systems may complement or occlude stress-induced changes in anxiety and anxiety-like behaviour. By broadening the scope of mechanisms for depression and anxiety, it may be possible to develop novel strategies to attenuate stress-related psychiatric conditions. The targets for these potential therapies, as discussed in this review, encompass multiple circuits and systems, including those outside of the HPA axis. © 2016 British Society for Neuroendocrinology.

Investigation of a BeO-based optically stimulated luminescence dosemeter.

PubMed

Sommer, M; Henniger, J

2006-01-01

The optical sensitivity of BeO-based luminophors has been well-known for many years. The optical stimulation of BeO with blue light is most effective. Then the dosemeters emit luminescent light in the ultraviolet-range around 325 nm. Matched on these facts a simple optically stimulated luminescence (OSL) treatment has been developed. Intense blue light-emitting diodes are used for cw-stimulation. A Hamamatsu solar blind photomultiplier detects the OSL-light. Good separation of both spectral ranges by optical filters is very important. The dosemeter has a linear dose response between approximately 20 muGy and >10 Gy. It was suggested, that a modification of stimulation conditions would allow measurements down to 1 muGy. Fading, photon energy dependence and reproducibility of OSL-signal correspond well with requirements to clinical and personal dosemeters. In addition, basic questions of the OSL-process in BeO have been investigated. A relevant point of interest was the dependency of the OSL-signal on stimulation power.

Real-time phase correlation based integrated system for seizure detection

NASA Astrophysics Data System (ADS)

Romaine, James B.; Delgado-Restituto, Manuel; Leñero-Bardallo, Juan A.; Rodríguez-Vázquez, Ángel

2017-05-01

This paper reports a low area, low power, integer-based digital processor for the calculation of phase synchronization between two neural signals. The processor calculates the phase-frequency content of a signal by identifying the specific time periods associated with two consecutive minima. The simplicity of this phase-frequency content identifier allows for the digital processor to utilize only basic digital blocks, such as registers, counters, adders and subtractors, without incorporating any complex multiplication and or division algorithms. In fact, the processor, fabricated in a 0.18μm CMOS process, only occupies an area of 0.0625μm2 and consumes 12.5nW from a 1.2V supply voltage when operated at 128kHz. These low-area, low-power features make the proposed processor a valuable computing element in closed loop neural prosthesis for the treatment of neural diseases, such as epilepsy, or for extracting functional connectivity maps between different recording sites in the brain.

Tumor cell membrane-targeting pH-dependent electron donor-acceptor fluorescence systems with low background signals.

PubMed

Han, Liang; Liu, Mingming; Ye, Deyong; Zhang, Ning; Lim, Ed; Lu, Jing; Jiang, Chen

2014-03-01

Minimizing the background signal is crucial for developing tumor-imaging techniques with sufficient specificity and sensitivity. Here we use pH difference between healthy tissues and tumor and tumor targeting delivery to achieve this goal. We synthesize fluorophore-dopamine conjugate as pH-dependent electron donor-acceptor fluorescence system. Fluorophores are highly sensitive to electron-transfer processes, which can alter their optical properties. The intrinsic redox properties of dopamine are oxidation of hydroquinone to quinone at basic pH and reduction of quinone to hydroquinone at acidic pH. Quinone can accept electron then quench fluorescence. We design tumor cell membrane-targeting carrier for delivery. We demonstrate quenched fluorophore-quinone can be specially transferred to tumor extracellular environment and tumor-accumulated fluorophore can be activated by acidic pH. These tumor-targeting pH-dependent electron donor-acceptor fluorescence systems may offer new opportunity for developing tumor-imaging techniques. Copyright © 2014 Elsevier Ltd. All rights reserved.

Neuronal Representation of Social Information in the Medial Amygdala of Awake Behaving Mice.

PubMed

Li, Ying; Mathis, Alexander; Grewe, Benjamin F; Osterhout, Jessica A; Ahanonu, Biafra; Schnitzer, Mark J; Murthy, Venkatesh N; Dulac, Catherine

2017-11-16

The medial amygdala (MeA) plays a critical role in processing species- and sex-specific signals that trigger social and defensive behaviors. However, the principles by which this deep brain structure encodes social information is poorly understood. We used a miniature microscope to image the Ca 2+ dynamics of large neural ensembles in awake behaving mice and tracked the responses of MeA neurons over several months. These recordings revealed spatially intermingled subsets of MeA neurons with distinct temporal dynamics. The encoding of social information in the MeA differed between males and females and relied on information from both individual cells and neuronal populations. By performing long-term Ca 2+ imaging across different social contexts, we found that sexual experience triggers lasting and sex-specific changes in MeA activity, which, in males, involve signaling by oxytocin. These findings reveal basic principles underlying the brain's representation of social information and its modulation by intrinsic and extrinsic factors. Copyright © 2017 Elsevier Inc. All rights reserved.

Bruton's Tyrosine Kinase: An Emerging Key Player in Innate Immunity.

PubMed

Weber, Alexander N R; Bittner, Zsofia; Liu, Xiao; Dang, Truong-Minh; Radsak, Markus Philipp; Brunner, Cornelia

2017-01-01

Bruton's tyrosine kinase (BTK) was initially discovered as a critical mediator of B cell receptor signaling in the development and functioning of adaptive immunity. Growing evidence also suggests multiple roles for BTK in mononuclear cells of the innate immune system, especially in dendritic cells and macrophages. For example, BTK has been shown to function in Toll-like receptor-mediated recognition of infectious agents, cellular maturation and recruitment processes, and Fc receptor signaling. Most recently, BTK was additionally identified as a direct regulator of a key innate inflammatory machinery, the NLRP3 inflammasome. BTK has thus attracted interest not only for gaining a more thorough basic understanding of the human innate immune system but also as a target to therapeutically modulate innate immunity. We here review the latest developments on the role of BTK in mononuclear innate immune cells in mouse versus man, with specific emphasis on the sensing of infectious agents and the induction of inflammation. Therapeutic implications for modulating innate immunity and critical open questions are also discussed.

Extracellular vesicles at the cross-line between basic science and clinical needs.

PubMed

Sasso, Luana; Hosamuddin, Huma; Emanueli, Costanza

2017-01-01

MiRNAs are small noncoding RNAs vital for protein regulation and gene expression. Since their discovery in the early nineties, many of their intracellular roles have been characterized. However, it is only recently that EVs loaded with miRNAs and other molecular types have started to be appreciated for their substantial involvement in cell-to-cell communication and signaling in physiological and pathological processes. EVs cell-to-cell signaling functions are complex and largely unknown, which still hampers the direct use of endogenous engineered EVs as therapeutics. However, ad hoc engineered synthetic EVs could represent new therapeutics. The potential of EV-inspired delivery carriers has now attracted the interest of the pharmaceutical industry and has challenged drug delivery researchers with new questions. This review will focus on EVs and EV-inspired drug delivery carriers, on their potential and on the challenges involved in the use of EV-inspired drug delivery systems. © 2016 John Wiley & Sons Ltd.

Monitoring industrial pharmaceutical crystallization processes using acoustic emission in pure and impure media.

PubMed

Gherras, Nesrine; Serris, Eric; Fevotte, Gilles

2012-12-15

Acoustic emission (AE) which has been successfully applied for monitoring a rather wide variety of solids elaboration processes was almost never evaluated in the field of industrial pharmaceutical crystallization. Few papers reported that solution crystallization processes give rise to acoustic emission signals that could be related to the development of the basic crystallization phenomena. This study is intended to demonstrate new perspectives opened up by the possible use of acoustic emission (AE) as a non-intrusive and non destructive sensor for monitoring solution crystallization with a particular focus being put on the presence of impurities in real industrial processes. The wealth of acquired AE information is highlighted and it is suggested that such information could allow the design of innovative multipurpose sensing strategies. It is shown notably that AE provides a very early detection of nucleation events, much before the onset of the so-called "nucleation burst". It is also shown that AE brings new insight into the effect of impurities on both the development of the crystallization process and the quality of the crystallized product. Copyright © 2012 Elsevier B.V. All rights reserved.

Respiration in a changing environment.

PubMed

Perry, Steven F; Spinelli Oliveira, Elisabeth

2010-08-31

Multidisciplinary respiratory research highlighted in the present symposium uses existing and new models from all Kingdoms in both basic and applied research and bears upon molecular signaling processes that have been present from the beginning of life and have been maintained as an integral part of it. Many of these old mechanisms are still recognizable as ROS and oxygen-dependent pathways that probably were in place even before photosynthesis evolved. These processes are not only recognizable through relatively small molecules such as nucleotides and their derivatives. Also some DNA sequences such as the hypoxia response elements and pas gene family are ancient and have been co-opted in various functions. The products of pas genes, in addition to their function in regulating nuclear response to hypoxia as part of the hypoxia-inducible factor HIF, play key roles in development, phototransduction, and control of circadian rhythmicity. Also RuBisCO, an enzyme best known for incorporating CO(2) into organic substrates in plants also has an ancient oxygenase function, which plays a key role in regulating peroxide balance in cells. As life forms became more complex and aerobic metabolism became dominant in multicellular organisms, the signaling processes also took on new levels of complexity but many ancient elements remained. The way in which they are integrated into remodeling processes involved in tradeoffs between respiration and nutrition or in control of aging in complex organisms is an exciting field for future research. Copyright (c) 2010 Elsevier B.V. All rights reserved.

A general multiscroll Lorenz system family and its realization via digital signal processors.

PubMed

Yu, Simin; Lü, Jinhu; Tang, Wallace K S; Chen, Guanrong

2006-09-01

This paper proposes a general multiscroll Lorenz system family by introducing a novel parameterized nth-order polynomial transformation. Some basic dynamical behaviors of this general multiscroll Lorenz system family are then investigated, including bifurcations, maximum Lyapunov exponents, and parameters regions. Furthermore, the general multiscroll Lorenz attractors are physically verified by using digital signal processors.

Inquiry into Chemotherapy-Induced P53 Activation in Cancer Cells as a Model for Teaching Signal Transduction

ERIC Educational Resources Information Center

Srougi, Melissa C.; Carson, Susan

2013-01-01

Intracellular and extracellular communication is conducted through an intricate and interwoven network of signal transduction pathways. The mechanisms for how cells speak with one another are of significant biological importance to both basic and industrial scientists from a number of different disciplines. We have therefore developed and…

Target acquisition modeling over the exact optical path: extending the EOSTAR TDA with the TOD sensor performance model

NASA Astrophysics Data System (ADS)

Dijk, J.; Bijl, P.; Oppeneer, M.; ten Hove, R. J. M.; van Iersel, M.

2017-10-01

The Electro-Optical Signal Transmission and Ranging (EOSTAR) model is an image-based Tactical Decision Aid (TDA) for thermal imaging systems (MWIR/LWIR) developed for a sea environment with an extensive atmosphere model. The Triangle Orientation Discrimination (TOD) Target Acquisition model calculates the sensor and signal processing effects on a set of input triangle test pattern images, judges their orientation using humans or a Human Visual System (HVS) model and derives the system image quality and operational field performance from the correctness of the responses. Combination of the TOD model and EOSTAR, basically provides the possibility to model Target Acquisition (TA) performance over the exact path from scene to observer. In this method ship representative TOD test patterns are placed at the position of the real target, subsequently the combined effects of the environment (atmosphere, background, etc.), sensor and signal processing on the image are calculated using EOSTAR and finally the results are judged by humans. The thresholds are converted into Detection-Recognition-Identification (DRI) ranges of the real target. In experiments is shown that combination of the TOD model and the EOSTAR model is indeed possible. The resulting images look natural and provide insight in the possibilities of combining the two models. The TOD observation task can be done well by humans, and the measured TOD is consistent with analytical TOD predictions for the same camera that was modeled in the ECOMOS project.

Solar Process Heat Basics | NREL

Science.gov Websites

Process Heat Basics Solar Process Heat Basics Commercial and industrial buildings may use the same , black metal panel mounted on a south-facing wall to absorb the sun's heat. Air passes through the many nonresidential buildings. A typical system includes solar collectors that work along with a pump, heat exchanger

Analysis of Multipath Pixels in SAR Images

NASA Astrophysics Data System (ADS)

Zhao, J. W.; Wu, J. C.; Ding, X. L.; Zhang, L.; Hu, F. M.

2016-06-01

As the received radar signal is the sum of signal contributions overlaid in one single pixel regardless of the travel path, the multipath effect should be seriously tackled as the multiple bounce returns are added to direct scatter echoes which leads to ghost scatters. Most of the existing solution towards the multipath is to recover the signal propagation path. To facilitate the signal propagation simulation process, plenty of aspects such as sensor parameters, the geometry of the objects (shape, location, orientation, mutual position between adjacent buildings) and the physical parameters of the surface (roughness, correlation length, permittivity)which determine the strength of radar signal backscattered to the SAR sensor should be given in previous. However, it's not practical to obtain the highly detailed object model in unfamiliar area by field survey as it's a laborious work and time-consuming. In this paper, SAR imaging simulation based on RaySAR is conducted at first aiming at basic understanding of multipath effects and for further comparison. Besides of the pre-imaging simulation, the product of the after-imaging, which refers to radar images is also taken into consideration. Both Cosmo-SkyMed ascending and descending SAR images of Lupu Bridge in Shanghai are used for the experiment. As a result, the reflectivity map and signal distribution map of different bounce level are simulated and validated by 3D real model. The statistic indexes such as the phase stability, mean amplitude, amplitude dispersion, coherence and mean-sigma ratio in case of layover are analyzed with combination of the RaySAR output.

Nitric oxide and gene regulation in plants.

PubMed

Grün, S; Lindermayr, C; Sell, S; Durner, J

2006-01-01

There is increasing evidence that nitric oxide (NO), which was first identified as a unique diffusible molecular messenger in animals, plays an important role in diverse physiological processes in plants. Recent progress that has deepened our understanding of NO signalling functions in plants, with special emphasis on defence signalling, is discussed here. Several studies, based on plants with altered NO-levels, have recently provided genetic evidence for the importance of NO in gene induction. For a general overview of which gene expression levels are altered by NO, two studies, involving large-scale transcriptional analyses of Arabidopsis thaliana using custom-made or commercial DNA-microarrays, were performed. Furthermore, a comprehensive transcript profiling by cDNA-amplification fragment length polymorphism (AFLP) revealed a number of Arabidopsis thaliana genes that are involved in signal transduction, disease resistance and stress response, photosynthesis, cellular transport, and basic metabolism. In addition, NO affects the expression of numerous genes in other plant species such as tobacco or soybean. The NO-dependent intracellular signalling pathway(s) that lead to the activation or suppression of these genes have not yet been defined. Several lines of evidence point to an interrelationship between NO and salicylic acid (SA) in plant defence. Recent evidence suggests that NO also plays a role in the wounding/jasmonic acid (JA) signalling pathway. NO donors affect both wounding-induced H2O2 synthesis and wounding- or JA-induced expression of defence genes. One of the major challenges ahead is to determine how the correct specific response is evoked, despite shared use of the NO signal and, in some cases, its downstream second messengers.

Quantifying facial expression signal and intensity use during development.

PubMed

Rodger, Helen; Lao, Junpeng; Caldara, Roberto

2018-06-12

Behavioral studies investigating facial expression recognition during development have applied various methods to establish by which age emotional expressions can be recognized. Most commonly, these methods employ static images of expressions at their highest intensity (apex) or morphed expressions of different intensities, but they have not previously been compared. Our aim was to (a) quantify the intensity and signal use for recognition of six emotional expressions from early childhood to adulthood and (b) compare both measures and assess their functional relationship to better understand the use of different measures across development. Using a psychophysical approach, we isolated the quantity of signal necessary to recognize an emotional expression at full intensity and the quantity of expression intensity (using neutral expression image morphs of varying intensities) necessary for each observer to recognize the six basic emotions while maintaining performance at 75%. Both measures revealed that fear and happiness were the most difficult and easiest expressions to recognize across age groups, respectively, a pattern already stable during early childhood. The quantity of signal and intensity needed to recognize sad, angry, disgust, and surprise expressions decreased with age. Using a Bayesian update procedure, we then reconstructed the response profiles for both measures. This analysis revealed that intensity and signal processing are similar only during adulthood and, therefore, cannot be straightforwardly compared during development. Altogether, our findings offer novel methodological and theoretical insights and tools for the investigation of the developing affective system. Copyright © 2018 Elsevier Inc. All rights reserved.

LUNG INJURY, INFLAMMATION AND AKT SIGNALING FOLLOWING INHALATION OF PARTICULATE HEXAVALENT CHROMIUM

PubMed Central

Beaver, Laura M.; Stemmy, Erik J.; Constant, Stephanie L.; Schwartz, Arnold; Little, Laura G.; Gigley, Jason P.; Chun, Gina; Sugden, Kent D.; Ceryak, Susan M.; Patierno, Steven R.

2013-01-01

Certain particulate hexavalent chromium [Cr(VI)] compounds are human respiratory carcinogens that release genotoxic soluble chromate, and are associated with fibrosis, fibrosarcomas, adenocarcinomas and squamous cell carcinomas of the lung. We postulate that inflammatory processes and mediators may contribute to the etiology of Cr(VI) carcinogenesis, however the immediate (0–24 hours) pathologic injury and immune responses after exposure to particulate chromates have not been adequately investigated. Our aim was to determine the nature of the lung injury, inflammatory response, and survival signaling responses following intranasal exposure of BALB/c mice to particulate basic zinc chromate. Factors associated with lung injury, inflammation and survival signaling were measured in airway lavage fluid and in lung tissue. A single chromate exposure induced an acute immune response in the lung, characterized by a rapid and significant increase in IL-6 and GRO-α levels, an influx of neutrophils, and a decline in macrophages in lung airways. Histological examination of lung tissue in animals challenged with a single chromate exposure revealed an increase in bronchiolar cell apoptosis and mucosal injury. Furthermore, chromate exposure induced injury and inflammation that progressed to alveolar and interstitial pneumonitis. Finally, a single Cr(VI) challenge resulted in a rapid and persistent increase in the number of airways immunoreactive for phosphorylation of the survival signaling protein Akt, on serine 473. These data illustrate that chromate induces both survival signaling and an inflammatory response in the lung, which we postulate may contribute to early oncogenesis. PMID:19109987

Potential accuracy of methods of laser Doppler anemometry in the single-particle scattering mode

NASA Astrophysics Data System (ADS)

Sobolev, V. S.; Kashcheeva, G. A.

2017-05-01

Potential accuracy of methods of laser Doppler anemometry is determined for the singleparticle scattering mode where the only disturbing factor is shot noise generated by the optical signal itself. The problem is solved by means of computer simulations with the maximum likelihood method. The initial parameters of simulations are chosen to be the number of real or virtual interference fringes in the measurement volume of the anemometer, the signal discretization frequency, and some typical values of the signal/shot noise ratio. The parameters to be estimated are the Doppler frequency as the basic parameter carrying information about the process velocity, the signal amplitude containing information about the size and concentration of scattering particles, and the instant when the particles arrive at the center of the measurement volume of the anemometer, which is needed for reconstruction of the examined flow velocity as a function of time. The estimates obtained in this study show that shot noise produces a minor effect (0.004-0.04%) on the frequency determination accuracy in the entire range of chosen values of the initial parameters. For the signal amplitude and the instant when the particles arrive at the center of the measurement volume of the anemometer, the errors induced by shot noise are in the interval of 0.2-3.5%; if the number of interference fringes is sufficiently large (more than 20), the errors do not exceed 0.2% regardless of the shot noise level.

A novel signal acquisition platform of human cardiovascular information with noninvasive method

NASA Astrophysics Data System (ADS)

Chen, Longcong; Cai, Shaoxi; Li, Bo; Jiang, Qifeng; Ke, Ming; Zhao, Yi; Chen, Sijia; Zou, Misha

2017-05-01

Cardiovascular diseases (CVDs) are considered the major cause of death worldwide, so more researchers pay more and more attention to the development of a non-invasive method to obtain as much cardiovascular information (CVI) as possible for early screening and diagnosing. It is known that considerable brain information could be probed by a variety of stimuli (such as video, light, and sound). Therefore, it is quite possible that much more CVI could be extracted via giving the human body some special interrelated stimulus. Based on this hypothesis, we designed a novel signal platform to acquire more CVI with a special stimulus, which is to give a gradual decrease and a different settable constant pressure to six air belts placed on two-side brachia, wrists, and ankles, respectively. During the stimulating process, the platform is able to collect 24-channel dynamic signals related with CVI synchronously. Moreover, to improve the measurement accuracy of signal acquisition, a high precision reference chip and a software correction are adopted in this platform. Additionally, we have also shown some collection instances and analysis results in this paper for its reliability. The results suggest that our platform can not only be applied on study in a deep-going way of relationship between collected signals and CVDs but can also serve as the basic tool for developing a new noninvasive cardiovascular function detection instrument and system that can be used both at home and in the hospital.

Fiber optic interferometer as a security element

NASA Astrophysics Data System (ADS)

Nedoma, Jan; Zboril, Ondrej; Fajkus, Marcel; Cubik, Jakub; Zavodny, Petr; Novak, Martin; Bednarek, Lukas; Martinek, Radek; Vasinek, Vladimir

2016-04-01

Interferometric sensors can be categorized as highly sensitive and precise devices with series inconsiderable benefits from the possibility of using standard telecommunication fibers. They can be measured even small changes in the deformation of shapes in time, changes in temperature, pressure, voltage, vibration, electric field, etc. The basic idea, which is described in this article is the usage of the interferometer as a security and monitoring component, which offers a solution for securing of closed spaces, especially before unwanted entries. Its primary task is to detect intrusions - disrupting the integrity of the transparent window area due to vibration response. The base of the solution is a Mach-Zehnder interferometer, which consists of two arms in the power distribution ratio of 1:1, consisting of the SM optical fiber excited by a DFB laser. The interferometer is working on the wavelength of 1550 nm. The resulting signal is registered as a result of interference of optical beams from the reference and sensor arm. Realized measuring scheme was terminated optical receiver comprising PbSe detector. Below described experimental measurements have shown that implemented interferometer has a sufficient value of the signal to noise ratio (SNR) and is able to detect very weak signals in a wide frequency range from tens of Hz to kHz units. The signal was processed by applications developed for the amplitude-frequency spectrum. Evaluated was the maximum amplitude of the signal and compared to the noise. The results were verified by retesting the assembled prototype.

Establishment of spatial pattern.

PubMed

Slack, Jonathan

2014-01-01

An overview and perspective are presented of mechanisms for the development of spatial pattern in animal embryos. It is intended both for new entrants to developmental biology and for specialists in other fields, with only a basic knowledge of animal life cycles being required. The first event of pattern formation is normally the localization of a cytoplasmic determinant in the egg, either during oogenesis or post-fertilization. Following cleavage to a multicellular stage, some cells contain the determinant and others do not. The determinant confers a specific developmental pathway on the cells that contain it, often making them the source of the first extracellular signal, or inducing factor. Inducing factors often form concentration gradients to which cells respond by up or downregulating genes at various concentration thresholds. This enables an initial situation consisting of two cell states (with or without the determinant) to generate a multistate pattern. Multiple rounds of gradient signaling, interspersed with phases of morphogenetic movements, can generate a complex pattern using a small number of signals and responding genes. Development proceeds in a hierarchical manner, with broad body subdivisions being specified initially, and becoming successively subdivided to give individual organs and tissues composed of multiple cell types in a characteristic arrangement. Double gradient models can account for embryonic regulation, whereby a similarly proportioned body pattern is formed following removal of material. Processes that are involved at the later stages include the formation of repeating structures by the combination of an oscillator with a gradient, and the formation of tissues with one cell type scattered in a background of another through a process called lateral inhibition. This set of processes make up a 'developmental toolkit' which can be deployed in various sequences and combinations to generate a very wide variety of structures and cell types. © 2014 Wiley Periodicals, Inc.

Concept and realization of a fully configurable and programmable data-acquisition system for the neutron scattering instruments at SINQ

NASA Astrophysics Data System (ADS)

Greuter, U.; Buehler, C.; Rasmussen, P.; Emmenegger, M.; Maden, D.; Koennecke, M.; Schlumpf, N.

We present the basic concept and the realization of our fully configurable data-acquisition hardware for the neutron scattering instruments at SINQ. This system allows collection of the different data entities and event-related signals generated by the various detector units. It offers a variety of synchronization options, including a time-measuring mode for time-of-flight determinations. Based on configurable logic (FPGA, CPLD), event rates up to the MHz range can be processed and transmitted to a programmable online data-reduction system (Histogram Memory). It is implemented on a commercially available VME Power PC module running a real-time operating system (VxWorks).

Interoception in anxiety and depression

PubMed Central

Stein, Murray B.

2010-01-01

We review the literature on interoception as it relates to depression and anxiety, with a focus on belief, and alliesthesia. The connection between increased but noisy afferent interoceptive input, self-referential and belief-based states, and top-down modulation of poorly predictive signals is integrated into a neuroanatomical and processing model for depression and anxiety. The advantage of this conceptualization is the ability to specifically examine the interface between basic interoception, self-referential belief-based states, and enhanced top-down modulation to attenuate poor predictability. We conclude that depression and anxiety are not simply interoceptive disorders but are altered interoceptive states as a consequence of noisily amplified self-referential interoceptive predictive belief states. PMID:20490545

Content-based TV sports video retrieval using multimodal analysis

NASA Astrophysics Data System (ADS)

Yu, Yiqing; Liu, Huayong; Wang, Hongbin; Zhou, Dongru

2003-09-01

In this paper, we propose content-based video retrieval, which is a kind of retrieval by its semantical contents. Because video data is composed of multimodal information streams such as video, auditory and textual streams, we describe a strategy of using multimodal analysis for automatic parsing sports video. The paper first defines the basic structure of sports video database system, and then introduces a new approach that integrates visual stream analysis, speech recognition, speech signal processing and text extraction to realize video retrieval. The experimental results for TV sports video of football games indicate that the multimodal analysis is effective for video retrieval by quickly browsing tree-like video clips or inputting keywords within predefined domain.

Mechanics and Activation of Unconventional Myosins.

PubMed

Batters, Christopher; Veigel, Claudia

2016-08-01

Many types of cellular motility are based on the myosin family of motor proteins ranging from muscle contraction to exo- and endocytosis, cytokinesis, cell locomotion or signal transduction in hearing. At the center of this wide range of motile processes lies the adaptation of the myosins for each specific mechanical task and the ability to coordinate the timing of motor protein mobilization and targeting. In recent years, great progress has been made in developing single molecule technology to characterize the diverse mechanical properties of the unconventional myosins. Here, we discuss the basic mechanisms and mechanical adaptations of unconventional myosins, and emerging principles regulating motor mobilization and targeting. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A wide-range variable-frequency resonant tunneling diode oscillator using a variable resonator suitable for simple MEMS process

NASA Astrophysics Data System (ADS)

Yamashita, Takashi; Nakano, Daisuke; Mori, Masayuki; Maezawa, Koichi

2018-04-01

A resonant tunneling diode oscillator having a wide frequency variation range based on a novel MEMS resonator was proposed, which exploits the change in the signal propagation velocity on a coplanar waveguide according to a movable ground plane. First, we discussed the velocity modulation mechanism, and clarified the importance of the dielectric constant of the substrate. Then, a prototype device oscillating in a 10 to 20 GHz frequency range was fabricated to demonstrate the basic operation. A large and continuous increase in the oscillation frequency of about two times was achieved with this device. This is promising for various applications including THz spectroscopy.

Study on a novel laser target detection system based on software radio technique

NASA Astrophysics Data System (ADS)

Song, Song; Deng, Jia-hao; Wang, Xue-tian; Gao, Zhen; Sun, Ji; Sun, Zhi-hui

2008-12-01

This paper presents that software radio technique is applied to laser target detection system with the pseudo-random code modulation. Based on the theory of software radio, the basic framework of the system, hardware platform, and the implementation of the software system are detailed. Also, the block diagram of the system, DSP circuit, block diagram of the pseudo-random code generator, and soft flow diagram of signal processing are designed. Experimental results have shown that the application of software radio technique provides a novel method to realize the modularization, miniaturization and intelligence of the laser target detection system, and the upgrade and improvement of the system will become simpler, more convenient, and cheaper.

Unraveling Synaptic GCaMP Signals: Differential Excitability and Clearance Mechanisms Underlying Distinct Ca2+ Dynamics in Tonic and Phasic Excitatory, and Aminergic Modulatory Motor Terminals in Drosophila

PubMed Central

Xing, Xiaomin

2018-01-01

Abstract GCaMP is an optogenetic Ca2+ sensor widely used for monitoring neuronal activities but the precise physiological implications of GCaMP signals remain to be further delineated among functionally distinct synapses. The Drosophila neuromuscular junction (NMJ), a powerful genetic system for studying synaptic function and plasticity, consists of tonic and phasic glutamatergic and modulatory aminergic motor terminals of distinct properties. We report a first simultaneous imaging and electric recording study to directly contrast the frequency characteristics of GCaMP signals of the three synapses for physiological implications. Different GCaMP variants were applied in genetic and pharmacological perturbation experiments to examine the Ca2+ influx and clearance processes underlying the GCaMP signal. Distinct mutational and drug effects on GCaMP signals indicate differential roles of Na+ and K+ channels, encoded by genes including paralytic (para), Shaker (Sh), Shab, and ether-a-go-go (eag), in excitability control of different motor terminals. Moreover, the Ca2+ handling properties reflected by the characteristic frequency dependence of the synaptic GCaMP signals were determined to a large extent by differential capacity of mitochondria-powered Ca2+ clearance mechanisms. Simultaneous focal recordings of synaptic activities further revealed that GCaMPs were ineffective in tracking the rapid dynamics of Ca2+ influx that triggers transmitter release, especially during low-frequency activities, but more adequately reflected cytosolic residual Ca2+ accumulation, a major factor governing activity-dependent synaptic plasticity. These results highlight the vast range of GCaMP response patterns in functionally distinct synaptic types and provide relevant information for establishing basic guidelines for the physiological interpretations of presynaptic GCaMP signals from in situ imaging studies. PMID:29464198

Regulation of Yersina pestis Virulence by AI-2 Mediated Quorum Sensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Segelke, B; Hok, S; Lao, V

The proposed research was motivated by an interest in understanding Y. pestis virulence mechanisms and bacteria cell-cell communication. It is expected that a greater understanding of virulence mechanisms will ultimately lead to biothreat countermeasures and novel therapeutics. Y. pestis is the etiological agent of plague, the most devastating disease in human history. Y. pestis infection has a high mortality rate and a short incubation before mortality. There is no widely available and effective vaccine for Y. pestis and multi-drug resistant strains are emerging. Y. pestis is a recognized biothreat agent based on the wide distribution of the bacteria in researchmore » laboratories around the world and on the knowledge that methods exist to produce and aerosolize large amounts of bacteria. We hypothesized that cell-cell communication via signaling molecules, or quorum sensing, by Y. pestis is important for the regulation of virulence factor gene expression during host invasion, though a causative link had never been established. Quorum sensing is a mode of intercellular communication which enables orchestration of gene expression for many bacteria as a function of population density and available evidence suggests there may be a link between quorum sensing and regulation of Y. pesits virulence. Several pathogenic bacteria have been shown to regulate expression of virulence factor genes, including genes encoding type III secretion, via quorum sensing. The Y. pestis genome encodes several cell-cell signaling pathways and the interaction of at least three of these are thought to be involved in one or more modes of host invasion. Furthermore, Y. pestis gene expression array studies carried out at LLNL have established a correlation between expression of known virulence factors and genes involved in processing of the AI-2 quorum sensing signal. This was a basic research project that was intended to provide new insights into bacterial intercellular communication and how it is used to regulate virulence in Y. pestis. It is known that many bacteria use intercellular signaling molecules to orchestrate gene expression and cellular function. A fair amount is known about production and uptake of signaling molecules, but very little is known about how intercellular signaling regulates other pathways. Although several studies demonstrate that intercellular signaling plays a role in regulating virulence in other pathogens, the link between signaling and regulation of virulence has not been established. Very little work had been done directly with Y. pestis intercellular signaling apart from the work carried out at LLNL. The research we proposed was intended to both establish a causative link between AI-2 intercellular signaling and regulation of virulence in Y. pestis and elucidate the fate of the AI-2 signaling molecule after it is taken up and processed by Y. pestis. Elucidating the fate of AI-2 was expected to lead directly to the understanding of how AI-2 signal processing regulates other pathways as well as provide new insights in this direction.« less

Experimental Control of a Fast Chaotic Time-Delay Opto-Electronic Device

DTIC Science & Technology

2003-01-01

chaotic sources such as the erbium-doped Þber laser. The basic idea is to use the message as a driving signal for the chaotic system. The message...47 x 3.10 Block diagram of feedback loop. Light from the interferometer is con- verted into an electrical signal by the photodiode (PD). All...a time delay of τD. Finally, the electrical signal is converted back into light by the laser diode (LD). . . . . . . . . . . . . . . . . 48 3.11 Setup

Diffusion Tensor Imaging and Its Application to Traumatic Brain Injury: Basic Principles and Recent Advances

DTIC Science & Technology

2012-12-01

c) image, and unfolding arti- facts (d). (e), (f), (g). Susceptibility artifacts with geometric distortion before (e), (f) and after (g) correction...either using an electrostatic repul- sion scheme [45] or through various geometric polyhe- dral schemes [59]. 2.1.2.3. Signal-to-Noise (SNR) The...inhomogeneity (∆B), causes signal loss due to a shift of the maximal signal away from the theoretical echo time, leading to geometric distortion due to suscep

Basic Functional Capabilities for a Military Message Processing Service

DTIC Science & Technology

1974-09-01

AD-AiI1 166 BASIC FUNCTIONA’. CAPABILITIES FOR A MILITARY MESSAGE PROCESSING SERVICE Ronald Tugender, et al University of Southern California...Itte) S. TYPE OF REPORT & PERIOD COVERED BASIC FUNCTIONAL CAPABILITIES FOR A Research Report MILITARY MESSAGE PROCESSING SERVICE 6. PERFORMING ONG...WOROD (Conionwo m trevre aide If tneeoooy arm idmentify by egekA INber) automated message processing , command and control, writer-to-reader service

Learning Computers, Speaking English: Cooperative Activities for Learning English and Basic Word Processing.

ERIC Educational Resources Information Center

Quann, Steve; Satin, Diana

This textbook leads high-beginning and intermediate English-as-a-Second-Language (ESL) students through cooperative computer-based activities that combine language learning with training in basic computer skills and word processing. Each unit concentrates on a basic concept of word processing while also focusing on a grammar topic. Skills are…

Acclimatization to long-term hypoxia: gene expression in ovine carotid arteries.

PubMed

Goyal, Ravi; Longo, Lawrence D

2014-10-01

Exposure to acute high-altitude hypoxia is associated with an increase in cerebral blood flow (CBF) as a consequence of low arterial O2 tension. However, in response to high altitude acclimatization, CBF returns to levels similar to those at sea level, and tissue blood flow is maintained by an increase in angiogenesis. Of consequence, dysregulation of the acclimatization responses and CBF can result in acute mountain sickness, acute cerebral and/or pulmonary edema. To elucidate the signal transduction pathways involved in successful acclimatization to high altitude, in ovine carotid arteries, we tested the hypothesis that high altitude-associated long-term hypoxia results in changes in gene expression of critical signaling pathways. We acclimatized nonpregnant adult sheep to 3,801 m altitude for ∼110 days and conducted oligonucleotide microarray experiments on carotid arteries. Of a total of 116 regulated genes, 58 genes were significantly upregulated and 58 genes were significantly downregulated (each >2-fold, P < 0.05). Major upregulated genes included suprabasin and myelin basic protein, whereas downregulated genes included BAG2. Several of these genes are known to activate the ERK canonical signal transduction pathway and the process of angiogenesis. We conclude that among other changes, the altered signal transduction molecules involved in high-altitude acclimatization are associated ERK activation and angiogenesis. Copyright © 2014 the American Physiological Society.

Redox Regulation of Protein Kinases

PubMed Central

Truong, Thu H.; Carroll, Kate S.

2015-01-01

Protein kinases represent one of the largest families of genes found in eukaryotes. Kinases mediate distinct cellular processes ranging from proliferation, differentiation, survival, and apoptosis. Ligand-mediated activation of receptor kinases can lead to the production of endogenous H2O2 by membrane-bound NADPH oxidases. In turn, H2O2 can be utilized as a secondary messenger in signal transduction pathways. This review presents an overview of the molecular mechanisms involved in redox regulation of protein kinases and its effects on signaling cascades. In the first half, we will focus primarily on receptor tyrosine kinases (RTKs), whereas the latter will concentrate on downstream non-receptor kinases involved in relaying stimulant response. Select examples from the literature are used to highlight the functional role of H2O2 regarding kinase activity, as well as the components involved in H2O2 production and regulation during cellular signaling. In addition, studies demonstrating direct modulation of protein kinases by H2O2 through cysteine oxidation will be emphasized. Identification of these redox-sensitive residues may help uncover signaling mechanisms conserved within kinase subfamilies. In some cases, these residues can even be exploited as targets for the development of new therapeutics. Continued efforts in this field will further basic understanding of kinase redox regulation, and delineate the mechanisms involved in physiologic and pathological H2O2 responses. PMID:23639002

A new algorithm and system for the characterization of handwriting strokes with delta-lognormal parameters.

PubMed

Djioua, Moussa; Plamondon, Réjean

2009-11-01

In this paper, we present a new analytical method for estimating the parameters of Delta-Lognormal functions and characterizing handwriting strokes. According to the Kinematic Theory of rapid human movements, these parameters contain information on both the motor commands and the timing properties of a neuromuscular system. The new algorithm, called XZERO, exploits relationships between the zero crossings of the first and second time derivatives of a lognormal function and its four basic parameters. The methodology is described and then evaluated under various testing conditions. The new tool allows a greater variety of stroke patterns to be processed automatically. Furthermore, for the first time, the extraction accuracy is quantified empirically, taking advantage of the exponential relationships that link the dispersion of the extraction errors with its signal-to-noise ratio. A new extraction system which combines this algorithm with two other previously published methods is also described and evaluated. This system provides researchers involved in various domains of pattern analysis and artificial intelligence with new tools for the basic study of single strokes as primitives for understanding rapid human movements.

Photonics and terahertz technologies: part 2

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2011-10-01

This digest paper debates basic features of the terahertz band of frequencies and compares it to the classical photonics. There are presented fundamental characteristics of the basic terahertz system consisting of a THz source, propagation media, transmission lines, THz signal processing, and detectors. Such a system finds research application, but also practical in two main areas: terahertz imaging - transmission and reflective, and as a close range THz radar, but also as sensory systems mainly for molecular sensing. There were launched in this country a few THz research projects concerning the THz sources, detectors and their applications. Among these projects there is an infrastructural one called FOTEH, opened at the WUT. The details of this project are debated and the consequences of its realization in this country. The first part of the paper is an introduction debating THz band and comparing it with the photonics one. The second part presents the assumptions of the infrastructural FOTEH project on Photonics and Terahertz Technologies. The project is expected to have impact on the development of photonics and relate fields in Poland.

Fiber-Optical Sensors: Basics and Applications in Multiphase Reactors

PubMed Central

Li, Xiangyang; Yang, Chao; Yang, Shifang; Li, Guozheng

2012-01-01

This work presents a brief introduction on the basics of fiber-optical sensors and an overview focused on the applications to measurements in multiphase reactors. The most commonly principle utilized is laser back scattering, which is also the foundation for almost all current probes used in multiphase reactors. The fiber-optical probe techniques in two-phase reactors are more developed than those in three-phase reactors. There are many studies on the measurement of gas holdup using fiber-optical probes in three-phase fluidized beds, but negative interference of particles on probe function was less studied. The interactions between solids and probe tips were less studied because glass beads etc. were always used as the solid phase. The vision probes may be the most promising for simultaneous measurements of gas dispersion and solids suspension in three-phase reactors. Thus, the following techniques of the fiber-optical probes in multiphase reactors should be developed further: (1) online measuring techniques under nearly industrial operating conditions; (2) corresponding signal data processing techniques; (3) joint application with other measuring techniques.

Studies with spike initiators - Linearization by noise allows continuous signal modulation in neural networks

NASA Technical Reports Server (NTRS)

Yu, Xiaolong; Lewis, Edwin R.

1989-01-01

It is shown that noise can be an important element in the translation of neuronal generator potentials (summed inputs) to neuronal spike trains (outputs), creating or expanding a range of amplitudes over which the spike rate is proportional to the generator potential amplitude. Noise converts the basically nonlinear operation of a spike initiator into a nearly linear modulation process. This linearization effect of noise is examined in a simple intuitive model of a static threshold and in a more realistic computer simulation of spike initiator based on the Hodgkin-Huxley (HH) model. The results are qualitatively similar; in each case larger noise amplitude results in a larger range of nearly linear modulation. The computer simulation of the HH model with noise shows linear and nonlinear features that were earlier observed in spike data obtained from the VIIIth nerve of the bullfrog. This suggests that these features can be explained in terms of spike initiator properties, and it also suggests that the HH model may be useful for representing basic spike initiator properties in vertebrates.

The Muscle Sensor for on-site neuroscience lectures to pave the way for a better understanding of brain-machine-interface research.

PubMed

Koizumi, Amane; Nagata, Osamu; Togawa, Morio; Sazi, Toshiyuki

2014-01-01

Neuroscience is an expanding field of science to investigate enigmas of brain and human body function. However, the majority of the public have never had the chance to learn the basics of neuroscience and new knowledge from advanced neuroscience research through hands-on experience. Here, we report that we produced the Muscle Sensor, a simplified electromyography, to promote educational understanding in neuroscience. The Muscle Sensor can detect myoelectric potentials which are filtered and processed as 3-V pulse signals to shine a light bulb and emit beep sounds. With this educational tool, we delivered "On-Site Neuroscience Lectures" in Japanese junior-high schools to facilitate hands-on experience of neuroscientific electrophysiology and to connect their text-book knowledge to advanced neuroscience researches. On-site neuroscience lectures with the Muscle Sensor pave the way for a better understanding of the basics of neuroscience and the latest topics such as how brain-machine-interface technology could help patients with disabilities such as spinal cord injuries. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Efficient numerical modeling of the cornea, and applications

NASA Astrophysics Data System (ADS)

Gonzalez, L.; Navarro, Rafael M.; Hdez-Matamoros, J. L.

2004-10-01

Corneal topography has shown to be an essential tool in the ophthalmology clinic both in diagnosis and custom treatments (refractive surgery, keratoplastia), having also a strong potential in optometry. The post processing and analysis of corneal elevation, or local curvature data, is a necessary step to refine the data and also to extract relevant information for the clinician. In this context a parametric cornea model is proposed consisting of a surface described mathematically by two terms: one general ellipsoid corresponding to a regular base surface, expressed by a general quadric term located at an arbitrary position and free orientation in 3D space and a second term, described by a Zernike polynomial expansion, which accounts for irregularities and departures from the basic geometry. The model has been validated obtaining better adjustment of experimental data than other previous models. Among other potential applications, here we present the determination of the optical axis of the cornea by transforming the general quadric to its canonical form. This has permitted us to perform 3D registration of corneal topographical maps to improve the signal-to-noise ratio. Other basic and clinical applications are also explored.

[Application of adaptive canceling methods in temperature control in ultrasonic therapeutical treatment].

PubMed

Deng, Jun; Liu, Du-ren

2002-12-01

Objective. To improve the quality of ultrasonic therapeutical treatment by improving the accuracy of temperature control. Method. Adaptive canceling methods were used to reduce the noise of temperature signal gained, and enhance signal-to-noise ratio. Result. The test's result corresponds basically to the theoretical curve. Conclusion. Adaptive canceling methods can be applied to clinic treatment.

Improved sensitivity by post-column chemical environment modification of CE-ESI-MS using a flow-through microvial interface.

PubMed

Risley, Jessica May; Chen, David Da Yong

2017-06-01

Post-column chemical environment modification can affect detection sensitivity and signal appearance when capillary electrophoresis is coupled through electrospray ionization to mass spectrometry (CE-ESI-MS). In this study, changes in the signal intensity and peak shape of N-Acetylneuraminic acid (Neu5Ac) were examined when the modifier solution used in a flow-through microvial interface for CE-ESI-MS was prepared using an acidic or basic background electrolyte (BGE) composition. The use of a basic modifier resulted in improved detection compared to the results obtained when an acidic modifier was used in negative ion mode. Increased sensitivity and more symmetrical peak shape were obtained. Using an acidic modifier, the LOD of Neu5Ac was 47.7 nM, whereas for a basic modifier, the LOD of Neu5Ac was 5.20 nM. The calculated asymmetry factor at 100 nM of Neu5Ac ranged from 0.71 to 1.5 when an acidic modifier was used, while the factor ranged from 1.0 to 1.1 when a basic modifier was used. Properly chosen post-column chemical modification can have a significant effect on the performance of the CE-MS system. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modelling and simulating reaction-diffusion systems using coloured Petri nets.

PubMed

Liu, Fei; Blätke, Mary-Ann; Heiner, Monika; Yang, Ming

2014-10-01

Reaction-diffusion systems often play an important role in systems biology when developmental processes are involved. Traditional methods of modelling and simulating such systems require substantial prior knowledge of mathematics and/or simulation algorithms. Such skills may impose a challenge for biologists, when they are not equally well-trained in mathematics and computer science. Coloured Petri nets as a high-level and graphical language offer an attractive alternative, which is easily approachable. In this paper, we investigate a coloured Petri net framework integrating deterministic, stochastic and hybrid modelling formalisms and corresponding simulation algorithms for the modelling and simulation of reaction-diffusion processes that may be closely coupled with signalling pathways, metabolic reactions and/or gene expression. Such systems often manifest multiscaleness in time, space and/or concentration. We introduce our approach by means of some basic diffusion scenarios, and test it against an established case study, the Brusselator model. Copyright © 2014 Elsevier Ltd. All rights reserved.

Angiogenesis in Spontaneous Tumors and Implications for Comparative Tumor Biology

PubMed Central

Benazzi, C.; Al-Dissi, A.; Chau, C. H.; Figg, W. D.; Sarli, G.; de Oliveira, J. T.; Gärtner, F.

2014-01-01

Blood supply is essential for development and growth of tumors and angiogenesis is the fundamental process of new blood vessel formation from preexisting ones. Angiogenesis is a prognostic indicator for a variety of tumors, and it coincides with increased shedding of neoplastic cells into the circulation and metastasis. Several molecules such as cell surface receptors, growth factors, and enzymes are involved in this process. While antiangiogenic therapy for cancer has been proposed over 20 years ago, it has garnered much controversy in recent years within the scientific community. The complex relationships between the angiogenic signaling cascade and antiangiogenic substances have indicated the angiogenic pathway as a valid target for anticancer drug development and VEGF has become the primary antiangiogenic drug target. This review discusses the basic and clinical perspectives of angiogenesis highlighting the importance of comparative biology in understanding tumor angiogenesis and the integration of these model systems for future drug development. PMID:24563633

p38 Signaling and Receptor Recycling Events in a Microfluidic Endothelial Cell Adhesion Assay

PubMed Central

Vickers, Dwayne A. L.; Chory, Emma J.; Harless, Megan C.; Murthy, Shashi K.

2013-01-01

Adhesion-based microfluidic cell separation has proven to be very useful in applications ranging from cancer diagnostics to tissue engineering. This process involves functionalizing microchannel surfaces with a capture molecule. High specificity and purity capture can be achieved using this method. Despite these advances, little is known about the mechanisms that govern cell capture within these devices and their relationships to basic process parameters such as fluid shear stress and the presence of soluble factors. This work examines how the adhesion of human endothelial cells (ECs) is influenced by a soluble tetrapeptide, Arg-Glu-Asp-Val (REDV) and fluidic shear stress. The ability of these ECs to bind within microchannels coated with REDV is shown to be governed by shear- and soluble-factor mediated changes in p38 mitogen-activated protein kinase expression together with recycling of adhesion receptors from the endosome. PMID:23762436

Lipids, lysosomes, and autophagy

PubMed Central

2016-01-01

Lipids are essential components of a cell providing energy substrates for cellular processes, signaling intermediates, and building blocks for biological membranes. Lipids are constantly recycled and redistributed within a cell. Lysosomes play an important role in this recycling process that involves the recruitment of lipids to lysosomes via autophagy or endocytosis for their degradation by lysosomal hydrolases. The catabolites produced are redistributed to various cellular compartments to support basic cellular function. Several studies demonstrated a bidirectional relationship between lipids and lysosomes that regulate autophagy. While lysosomal degradation pathways regulate cellular lipid metabolism, lipids also regulate lysosome function and autophagy. In this review, we focus on this bidirectional relationship in the context of dietary lipids and provide an overview of recent evidence of how lipid-overload lipotoxicity, as observed in obesity and metabolic syndrome, impairs lysosomal function and autophagy that may eventually lead to cellular dysfunction or cell death. PMID:27330054

Hyperactivity in boys with attention deficit/hyperactivity disorder (ADHD): the association between deficient behavioral inhibition, attentional processes, and objectively measured activity.

PubMed

Alderson, R Matt; Rapport, Mark D; Kasper, Lisa J; Sarver, Dustin E; Kofler, Michael J

2012-01-01

Contemporary models of ADHD hypothesize that hyperactivity reflects a byproduct of inhibition deficits. The current study investigated the relationship between children's motor activity and behavioral inhibition by experimentally manipulating demands placed on the limited-resource inhibition system. Twenty-two boys (ADHD = 11, TD = 11) between the ages of 8 and 12 years completed a conventional stop-signal task, two choice-task variants (no-tone, ignore-tone), and control tasks while their motor activity was measured objectively by actigraphs placed on their nondominant wrist and ankles. All children exhibited significantly higher activity rates under all three experimental tasks relative to control conditions, and children with ADHD moved significantly more than typically developing children across conditions. No differences in activity level were observed between the inhibition and noninhibition experimental tasks for either group, indicating that activity level was primarily associated with basic attentional rather than behavioral inhibition processes.

Physiological principles of vestibular function on earth and in space

NASA Technical Reports Server (NTRS)

Minor, L. B.

1998-01-01

Physiological mechanisms underlying vestibular function have important implications for our ability to understand, predict, and modify balance processes during and after spaceflight. The microgravity environment of space provides many unique opportunities for studying the effects of changes in gravitoinertial force on structure and function of the vestibular system. Investigations of basic vestibular physiology and of changes in reflexes occurring as a consequence of exposure to microgravity have important implications for diagnosis and treatment of vestibular disorders in human beings. This report reviews physiological principles underlying control of vestibular processes on earth and in space. Information is presented from a functional perspective with emphasis on signals arising from labyrinthine receptors. Changes induced by microgravity in linear acceleration detected by the vestibulo-ocular reflexes. Alterations of the functional requirements for postural control in space are described. Areas of direct correlation between studies of vestibular reflexes in microgravity and vestibular disorders in human beings are discussed.

Review article: mitogen-activated protein kinases in chronic intestinal inflammation - targeting ancient pathways to treat modern diseases.

PubMed

Waetzig, G H; Schreiber, S

2003-07-01

Conventional treatment of chronic inflammatory disorders, including inflammatory bowel diseases, employs broad-range anti-inflammatory drugs. In order to reduce the side-effects and increase the efficacy of treatment, several strategies have been developed in the last decade to interfere with intercellular and intracellular inflammatory signalling processes. The highly conserved mitogen-activated protein kinase pathways regulate most cellular processes, particularly defence mechanisms such as stress reactions and inflammation. In this review, we provide an overview of the current knowledge of the specificity and interconnection of mitogen-activated protein kinase pathways, their functions in the gut immune system and published and ongoing studies on the role of mitogen-activated protein kinases in inflammatory bowel disease. The development of mitogen-activated protein kinase inhibitors and their use for the therapy of inflammatory disorders is a paradigm of the successful bridging of the gap between basic research and clinical practice.

Singular Spectrum Analysis for Astronomical Time Series: Constructing a Parsimonious Hypothesis Test

NASA Astrophysics Data System (ADS)

Greco, G.; Kondrashov, D.; Kobayashi, S.; Ghil, M.; Branchesi, M.; Guidorzi, C.; Stratta, G.; Ciszak, M.; Marino, F.; Ortolan, A.

We present a data-adaptive spectral method - Monte Carlo Singular Spectrum Analysis (MC-SSA) - and its modification to tackle astrophysical problems. Through numerical simulations we show the ability of the MC-SSA in dealing with 1/f β power-law noise affected by photon counting statistics. Such noise process is simulated by a first-order autoregressive, AR(1) process corrupted by intrinsic Poisson noise. In doing so, we statistically estimate a basic stochastic variation of the source and the corresponding fluctuations due to the quantum nature of light. In addition, MC-SSA test retains its effectiveness even when a significant percentage of the signal falls below a certain level of detection, e.g., caused by the instrument sensitivity. The parsimonious approach presented here may be broadly applied, from the search for extrasolar planets to the extraction of low-intensity coherent phenomena probably hidden in high energy transients.

Ultraweak photon emission in the brain.

PubMed

Salari, V; Valian, H; Bassereh, H; Bókkon, I; Barkhordari, A

2015-09-01

Besides the low-frequency electromagnetic body-processes measurable through the electroencephalography (EEG), electrocardiography (ECG), etc. there are processes that do not need external excitation, emitting light within or close to the visible spectra. Such ultraweak photon emission (UPE), also named biophoton emission, reflects the cellular (and body) oxidative status. Recently, a growing body of evidence shows that UPE may play an important role in the basic functioning of living cells. Moreover, interesting evidences are beginning to emerge that UPE may well play an important role in neuronal functions. In fact, biophotons are byproducts in cellular metabolism and produce false signals (e.g., retinal discrete dark noise) but on the other side neurons contain many light sensitive molecules that makes it hard to imagine how they might not be influenced by UPE, and thus UPE may carry informational contents. Here, we investigate UPE in the brain from different points of view such as experimental evidences, theoretical modeling, and physiological significance.

Digital plus analog output encoder

NASA Technical Reports Server (NTRS)

Hafle, R. S. (Inventor)

1976-01-01

The disclosed encoder is adapted to produce both digital and analog output signals corresponding to the angular position of a rotary shaft, or the position of any other movable member. The digital signals comprise a series of binary signals constituting a multidigit code word which defines the angular position of the shaft with a degree of resolution which depends upon the number of digits in the code word. The basic binary signals are produced by photocells actuated by a series of binary tracks on a code disc or member. The analog signals are in the form of a series of ramp signals which are related in length to the least significant bit of the digital code word. The analog signals are derived from sine and cosine tracks on the code disc.

Method for Improving EEG Based Emotion Recognition by Combining It with Synchronized Biometric and Eye Tracking Technologies in a Non-invasive and Low Cost Way

PubMed Central

López-Gil, Juan-Miguel; Virgili-Gomá, Jordi; Gil, Rosa; Guilera, Teresa; Batalla, Iolanda; Soler-González, Jorge; García, Roberto

2016-01-01

Technical advances, particularly the integration of wearable and embedded sensors, facilitate tracking of physiological responses in a less intrusive way. Currently, there are many devices that allow gathering biometric measurements from human beings, such as EEG Headsets or Health Bracelets. The massive data sets generated by tracking of EEG and physiology may be used, among other things, to infer knowledge about human moods and emotions. Apart from direct biometric signal measurement, eye tracking systems are nowadays capable of determining the point of gaze of the users when interacting in ICT environments, which provides an added value research on many different areas, such as psychology or marketing. We present a process in which devices for eye tracking, biometric, and EEG signal measurements are synchronously used for studying both basic and complex emotions. We selected the least intrusive devices for different signal data collection given the study requirements and cost constraints, so users would behave in the most natural way possible. On the one hand, we have been able to determine basic emotions participants were experiencing by means of valence and arousal. On the other hand, a complex emotion such as empathy has also been detected. To validate the usefulness of this approach, a study involving forty-four people has been carried out, where they were exposed to a series of affective stimuli while their EEG activity, biometric signals, and eye position were synchronously recorded to detect self-regulation. The hypothesis of the work was that people who self-regulated would show significantly different results when analyzing their EEG data. Participants were divided into two groups depending on whether Electro Dermal Activity (EDA) data indicated they self-regulated or not. The comparison of the results obtained using different machine learning algorithms for emotion recognition shows that using EEG activity alone as a predictor for self-regulation does not allow properly determining whether a person in self-regulation its emotions while watching affective stimuli. However, adequately combining different data sources in a synchronous way to detect emotions makes it possible to overcome the limitations of single detection methods. PMID:27594831

Method for Improving EEG Based Emotion Recognition by Combining It with Synchronized Biometric and Eye Tracking Technologies in a Non-invasive and Low Cost Way.

PubMed

López-Gil, Juan-Miguel; Virgili-Gomá, Jordi; Gil, Rosa; García, Roberto

2016-01-01

Technical advances, particularly the integration of wearable and embedded sensors, facilitate tracking of physiological responses in a less intrusive way. Currently, there are many devices that allow gathering biometric measurements from human beings, such as EEG Headsets or Health Bracelets. The massive data sets generated by tracking of EEG and physiology may be used, among other things, to infer knowledge about human moods and emotions. Apart from direct biometric signal measurement, eye tracking systems are nowadays capable of determining the point of gaze of the users when interacting in ICT environments, which provides an added value research on many different areas, such as psychology or marketing. We present a process in which devices for eye tracking, biometric, and EEG signal measurements are synchronously used for studying both basic and complex emotions. We selected the least intrusive devices for different signal data collection given the study requirements and cost constraints, so users would behave in the most natural way possible. On the one hand, we have been able to determine basic emotions participants were experiencing by means of valence and arousal. On the other hand, a complex emotion such as empathy has also been detected. To validate the usefulness of this approach, a study involving forty-four people has been carried out, where they were exposed to a series of affective stimuli while their EEG activity, biometric signals, and eye position were synchronously recorded to detect self-regulation. The hypothesis of the work was that people who self-regulated would show significantly different results when analyzing their EEG data. Participants were divided into two groups depending on whether Electro Dermal Activity (EDA) data indicated they self-regulated or not. The comparison of the results obtained using different machine learning algorithms for emotion recognition shows that using EEG activity alone as a predictor for self-regulation does not allow properly determining whether a person in self-regulation its emotions while watching affective stimuli. However, adequately combining different data sources in a synchronous way to detect emotions makes it possible to overcome the limitations of single detection methods.

Enhancement of the efficiency of the automatic control system to control the thermal load of steam boilers fired with fuels of several types

NASA Astrophysics Data System (ADS)

Ismatkhodzhaev, S. K.; Kuzishchin, V. F.

2017-05-01

An automatic control system to control the thermal load (ACS) in a drum-type boiler under random fluctuations in the blast-furnace and coke-oven gas consumption rates and to control action on the natural gas consumption is considered. The system provides for use of a compensator by the basic disturbance, the blast-furnace gas consumption rate. To enhance the performance of the system, it is proposed to use more accurate mathematical second-order delay models of the channels of the object under control in combination with calculation by frequency methods of the controller parameters as well as determination of the structure and parameters of the compensator considering the statistical characteristics of the disturbances and using simulation. The statistical characteristics of the random blast-furnace gas consumption signal based on experimental data are provided. The random signal is presented in the form of the low-frequency (LF) and high-frequency (HF) components. The models of the correlation functions and spectral densities are developed. The article presents the results of calculating the optimal settings of the control loop with the controlled variable in the form of the "heat" signal with the restricted frequency variation index using three variants of the control performance criteria, viz., the linear and quadratic integral indices under step disturbance and the control error variance under random disturbance by the blastfurnace gas consumption rate. It is recommended to select a compensator designed in the form of series connection of two parts, one of which corresponds to the operator inverse to the transfer function of the PI controller, i.e., in the form of a really differentiating element. This facilitates the realization of the second part of the compensator by the invariance condition similar to transmitting the compensating signal to the object input. The results of simulation under random disturbance by the blast-furnace gas consumption are reported. Recommendations are made on the structure and parameters of the shaping filters for modeling the LF and HF components of the random signal. The results of the research may find applications in the systems to control the thermal processes with compensation of basic disturbances, in particular, in boilers for combustion of accompanying gases.

Microwave signal processing with photorefractive dynamic holography

NASA Astrophysics Data System (ADS)

Fotheringham, Edeline B.

Have you ever found yourself listening to the music playing from the closest stereo rather than to the bromidic (uninspiring) person speaking to you? Your ears receive information from two sources but your brain listens to only one. What if your cell phone could distinguish among signals sharing the same bandwidth too? There would be no "full" channels to stop you from placing or receiving a call. This thesis presents a nonlinear optical circuit capable of distinguishing uncorrelated signals that have overlapping temporal bandwidths. This so called autotuning filter is the size of a U.S. quarter dollar and requires less than 3 mW of optical power to operate. It is basically an oscillator in which the losses are compensated with dynamic holographic gain. The combination of two photorefractive crystals in the resonator governs the filter's winner-take-all dynamics through signal-competition for gain. This physical circuit extracts what is mathematically referred to as the largest principal component of its spatio-temporal input space. The circuit's practicality is demonstrated by its incorporation in an RF-photonic system. An unknown mixture of unknown microwave signals, received by an antenna array, constitutes the input to the system. The output electronically returns one of the original microwave signals. The front-end of the system down converts the 10 GHz microwave signals and amplifies them before the signals phase modulate optical beams. The optical carrier is suppressed from these beams so that it may not be considered as a signal itself to the autotuning filter. The suppression is achieved with two-beam coupling in a single photorefractive crystal. The filter extracts the more intense of the signals present on the carrier-suppressed input beams. The detection of the extracted signal restores the microwave signal to an electronic form. The system, without the receiving antenna array, is packaged in a 13 x 18 x 6″ briefcase. Its power consumption equals that of a regular 50 W household light bulb. The system was shipped to different parts of the country for real-time demonstrations of signal separation thus also validating its claim to robustness.

47 CFR 69.119 - Basic service element expedited approval process.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Basic service element expedited approval process. 69.119 Section 69.119 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) ACCESS CHARGES Computation of Charges § 69.119 Basic service element...

Disintegration of Multisensory Signals from the Real Hand Reduces Default Limb Self-Attribution: An fMRI Study

PubMed Central

Guterstam, Arvid; Brozzoli, Claudio; Ehrsson, H. Henrik

2013-01-01

The perception of our limbs in space is built upon the integration of visual, tactile, and proprioceptive signals. Accumulating evidence suggests that these signals are combined in areas of premotor, parietal, and cerebellar cortices. However, it remains to be determined whether neuronal populations in these areas integrate hand signals according to basic temporal and spatial congruence principles of multisensory integration. Here, we developed a setup based on advanced 3D video technology that allowed us to manipulate the spatiotemporal relationships of visuotactile (VT) stimuli delivered on a healthy human participant's real hand during fMRI and investigate the ensuing neural and perceptual correlates. Our experiments revealed two novel findings. First, we found responses in premotor, parietal, and cerebellar regions that were dependent upon the spatial and temporal congruence of VT stimuli. This multisensory integration effect required a simultaneous match between the seen and felt postures of the hand, which suggests that congruent visuoproprioceptive signals from the upper limb are essential for successful VT integration. Second, we observed that multisensory conflicts significantly disrupted the default feeling of ownership of the seen real limb, as indexed by complementary subjective, psychophysiological, and BOLD measures. The degree to which self-attribution was impaired could be predicted from the attenuation of neural responses in key multisensory areas. These results elucidate the neural bases of the integration of multisensory hand signals according to basic spatiotemporal principles and demonstrate that the disintegration of these signals leads to “disownership” of the seen real hand. PMID:23946393

Analysis of a developmentally regulated nuclear localization signal in Xenopus

PubMed Central

1992-01-01

The 289 residue nuclear oncoprotein encoded by the adenovirus 5 Ela gene contains two peptide sequences that behave as nuclear localization signals (NLS). One signal, located at the carboxy terminus, is like many other known NLSs in that it consists of a short stretch of basic residues (KRPRP) and is constitutively active in cells. The second signal resides within an internal 45 residue region of E1a that contains few basic residues or sequences that resemble other known NLSs. Moreover, this internal signal functions in injected Xenopus oocytes, but not in transfected Xenopus A6 cells, suggesting that it could be regulated developmentally (Slavicek et al. 1989. J. Virol. 63:4047). In this study, we show that the activity of this signal is sensitive to ATP depletion in vivo, efficiently directs the import of a 50 kD fusion protein and can compete with the E1a carboxy-terminal NLS for nuclear import. In addition, we have delineated the precise amino acid residues that comprise the second E1a NLS, and have assessed its utilization during Xenopus embryogenesis. Using amino acid deletion and substitution analyses, we show that the signal consists of the sequence FV(X)7-20MXSLXYM(X)4MF. By expressing in Xenopus embryos a truncated E1a protein that contains only the second NLS and by monitoring its cytoplasmic/nuclear distribution during development with indirect immunofluorescence, we find that the second NLS is utilized up to the early neurula stage. In addition, there appears to be a hierarchy among the embryonic germ layers as to when the second NLS becomes nonfunctional. For this reason, we refer to this NLS as the developmentally regulated nuclear localization signal (drNLS). The implications of these findings for early development are discussed. PMID:1387407

Site-Specific Nitrosoproteomic Identification of Endogenously S-Nitrosylated Proteins in Arabidopsis1

PubMed Central

Hu, Jiliang; Huang, Xiahe; Chen, Lichao; Sun, Xuwu; Lu, Congming; Zhang, Lixin; Wang, Yingchun; Zuo, Jianru

2015-01-01

Nitric oxide (NO) regulates multiple developmental events and stress responses in plants. A major biologically active species of NO is S-nitrosoglutathione (GSNO), which is irreversibly degraded by GSNO reductase (GSNOR). The major physiological effect of NO is protein S-nitrosylation, a redox-based posttranslational modification mechanism by covalently linking an NO molecule to a cysteine thiol. However, little is known about the mechanisms of S-nitrosylation-regulated signaling, partly due to limited S-nitrosylated proteins being identified. In this study, we identified 1,195 endogenously S-nitrosylated peptides in 926 proteins from the Arabidopsis (Arabidopsis thaliana) by a site-specific nitrosoproteomic approach, which, to date, is the largest data set of S-nitrosylated proteins among all organisms. Consensus sequence analysis of these peptides identified several motifs that contain acidic, but not basic, amino acid residues flanking the S-nitrosylated cysteine residues. These S-nitrosylated proteins are involved in a wide range of biological processes and are significantly enriched in chlorophyll metabolism, photosynthesis, carbohydrate metabolism, and stress responses. Consistently, the gsnor1-3 mutant shows the decreased chlorophyll content and altered photosynthetic properties, suggesting that S-nitrosylation is an important regulatory mechanism in these processes. These results have provided valuable resources and new clues to the studies on S-nitrosylation-regulated signaling in plants. PMID:25699590

Hearing in three dimensions

NASA Astrophysics Data System (ADS)

Shinn-Cunningham, Barbara

2003-04-01

One of the key functions of hearing is to help us monitor and orient to events in our environment (including those outside the line of sight). The ability to compute the spatial location of a sound source is also important for detecting, identifying, and understanding the content of a sound source, especially in the presence of competing sources from other positions. Determining the spatial location of a sound source poses difficult computational challenges; however, we perform this complex task with proficiency, even in the presence of noise and reverberation. This tutorial will review the acoustic, psychoacoustic, and physiological processes underlying spatial auditory perception. First, the tutorial will examine how the many different features of the acoustic signals reaching a listener's ears provide cues for source direction and distance, both in anechoic and reverberant space. Then we will discuss psychophysical studies of three-dimensional sound localization in different environments and the basic neural mechanisms by which spatial auditory cues are extracted. Finally, ``virtual reality'' approaches for simulating sounds at different directions and distances under headphones will be reviewed. The tutorial will be structured to appeal to a diverse audience with interests in all fields of acoustics and will incorporate concepts from many areas, such as psychological and physiological acoustics, architectural acoustics, and signal processing.

System analysis identifies distinct and common functional networks governed by transcription factor ASCL1, in glioma and small cell lung cancer.

PubMed

Donakonda, Sainitin; Sinha, Swati; Dighe, Shrinivas Nivrutti; Rao, Manchanahalli R Satyanarayana

2017-07-25

ASCL1 is a basic Helix-Loop-Helix transcription factor (TF), which is involved in various cellular processes like neuronal development and signaling pathways. Transcriptome profiling has shown that ASCL1 overexpression plays an important role in the development of glioma and Small Cell Lung Carcinoma (SCLC), but distinct and common molecular mechanisms regulated by ASCL1 in these cancers are unknown. In order to understand how it drives the cellular functional network in these two tumors, we generated a gene expression profile in a glioma cell line (U87MG) to identify ASCL1 gene targets by an si RNA silencing approach and then compared this with a publicly available dataset of similarly silenced SCLC (NCI-H1618 cells). We constructed TF-TF and gene-gene interactions, as well as protein interaction networks of ASCL1 regulated genes in glioma and SCLC cells. Detailed network analysis uncovered various biological processes governed by ASCL1 target genes in these two tumor cell lines. We find that novel ASCL1 functions related to mitosis and signaling pathways influencing development and tumor growth are affected in both glioma and SCLC cells. In addition, we also observed ASCL1 governed functional networks that are distinct to glioma and SCLC.

Mechanoregulation of Wound Healing and Skin Homeostasis

PubMed Central

Rosińczuk, Joanna; Taradaj, Jakub; Dymarek, Robert; Sopel, Mirosław

2016-01-01

Basic and clinical studies on mechanobiology of cells and tissues point to the importance of mechanical forces in the process of skin regeneration and wound healing. These studies result in the development of new therapies that use mechanical force which supports effective healing. A better understanding of mechanobiology will make it possible to develop biomaterials with appropriate physical and chemical properties used to treat poorly healing wounds. In addition, it will make it possible to design devices precisely controlling wound mechanics and to individualize a therapy depending on the type, size, and anatomical location of the wound in specific patients, which will increase the clinical efficiency of the therapy. Linking mechanobiology with the science of biomaterials and nanotechnology will enable in the near future precise interference in abnormal cell signaling responsible for the proliferation, differentiation, cell death, and restoration of the biological balance. The objective of this study is to point to the importance of mechanobiology in regeneration of skin damage and wound healing. The study describes the influence of rigidity of extracellular matrix and special restrictions on cell physiology. The study also defines how and what mechanical changes influence tissue regeneration and wound healing. The influence of mechanical signals in the process of proliferation, differentiation, and skin regeneration is tagged in the study. PMID:27413744

49 CFR 212.211 - Apprentice signal and train control inspector.

Code of Federal Regulations, 2010 CFR

2010-10-01

... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STATE SAFETY PARTICIPATION REGULATIONS State... to use electrical test equipment in direct current and alternating current circuits; and (2) A basic...

Basic perceptual changes that alter meaning and neural correlates of recognition memory

PubMed Central

Gao, Chuanji; Hermiller, Molly S.; Voss, Joel L.; Guo, Chunyan

2015-01-01

It is difficult to pinpoint the border between perceptual and conceptual processing, despite their treatment as distinct entities in many studies of recognition memory. For instance, alteration of simple perceptual characteristics of a stimulus can radically change meaning, such as the color of bread changing from white to green. We sought to better understand the role of perceptual and conceptual processing in memory by identifying the effects of changing a basic perceptual feature (color) on behavioral and neural correlates of memory in circumstances when this change would be expected to either change the meaning of a stimulus or to have no effect on meaning (i.e., to influence conceptual processing or not). Abstract visual shapes (“squiggles”) were colorized during study and presented during test in either the same color or a different color. Those squiggles that subjects found to resemble meaningful objects supported behavioral measures of conceptual priming, whereas meaningless squiggles did not. Further, changing color from study to test had a selective effect on behavioral correlates of priming for meaningful squiggles, indicating that color change altered conceptual processing. During a recognition memory test, color change altered event-related brain potential (ERP) correlates of memory for meaningful squiggles but not for meaningless squiggles. Specifically, color change reduced the amplitude of frontally distributed N400 potentials (FN400), implying that these potentials indicated conceptual processing during recognition memory that was sensitive to color change. In contrast, color change had no effect on FN400 correlates of recognition for meaningless squiggles, which were overall smaller in amplitude than for meaningful squiggles (further indicating that these potentials signal conceptual processing during recognition). Thus, merely changing the color of abstract visual shapes can alter their meaning, changing behavioral and neural correlates of memory. These findings are relevant to understanding similarities and distinctions between perceptual and conceptual processing as well as the functional interpretation of neural correlates of recognition memory. PMID:25717298

Functional analysis of the C-terminal region of human adenovirus E1A reveals a misidentified nuclear localization signal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cohen, Michael J.; King, Cason R.; Dikeakos, Jimmy D.

The immortalizing function of the human adenovirus 5 E1A oncoprotein requires efficient localization to the nucleus. In 1987, a consensus monopartite nuclear localization sequence (NLS) was identified at the C-terminus of E1A. Since that time, various experiments have suggested that other regions of E1A influence nuclear import. In addition, a novel bipartite NLS was recently predicted at the C-terminal region of E1A in silico. In this study, we used immunofluorescence microscopy and co-immunoprecipitation analysis with importin-α to verify that full nuclear localization of E1A requires the well characterized NLS spanning residues 285–289, as well as a second basic patch situatedmore » between residues 258 and 263 ({sup 258}RVGGRRQAVECIEDLLNEPGQPLDLSCKRPRP{sup 289}). Thus, the originally described NLS located at the C-terminus of E1A is actually a bipartite signal, which had been misidentified in the existing literature as a monopartite signal, altering our understanding of one of the oldest documented NLSs. - Highlights: • Human adenovirus E1A is localized to the nucleus. • The C-terminus of E1A contains a bipartite nuclear localization signal (NLS). • This signal was previously misidentified to be a monopartite NLS. • Key basic amino acid residues within this sequence are highly conserved.« less

The RFET—a reconfigurable nanowire transistor and its application to novel electronic circuits and systems

NASA Astrophysics Data System (ADS)

Mikolajick, T.; Heinzig, A.; Trommer, J.; Baldauf, T.; Weber, W. M.

2017-04-01

With CMOS scaling reaching physical limits in the next decade, new approaches are required to enhance the functionality of electronic systems. Reconfigurability on the device level promises to realize more complex systems with a lower device count. In the last five years a number of interesting concepts have been proposed to realize such a device level reconfiguration. Among these the reconfigurable field effect transistor (RFET), a device that can be configured between an n-channel and p-channel behavior by applying an electrical signal, can be considered as an end-of-roadmap extension of current technology with only small modifications and even simplifications to the process flow. This article gives a review on the RFET basics and current status. In the first sections state-of-the-art of reconfigurable devices will be summarized and the RFET will be introduced together with related devices based on silicon nanowire technology. The device optimization with respect to device symmetry and performance will be discussed next. The potential of the RFET device technology will then be shown by discussing selected circuit implementations making use of the unique advantages of this device concept. The basic device concept was also extended towards applications in flexible devices and sensors, also extending the capabilities towards so-called More-than-Moore applications where new functionalities are implemented in CMOS-based processes. Finally, the prospects of RFET device technology will be discussed.

Basic visual perceptual processes in children with typical development and cerebral palsy: The processing of surface, length, orientation, and position.

PubMed

Schmetz, Emilie; Magis, David; Detraux, Jean-Jacques; Barisnikov, Koviljka; Rousselle, Laurence

2018-03-02

The present study aims to assess how the processing of basic visual perceptual (VP) components (length, surface, orientation, and position) develops in typically developing (TD) children (n = 215, 4-14 years old) and adults (n = 20, 20-25 years old), and in children with cerebral palsy (CP) (n = 86, 5-14 years old) using the first four subtests of the Battery for the Evaluation of Visual Perceptual and Spatial processing in children. Experiment 1 showed that these four basic VP processes follow distinct developmental trajectories in typical development. Experiment 2 revealed that children with CP present global and persistent deficits for the processing of basic VP components when compared with TD children matched on chronological age and nonverbal reasoning abilities.

A basic study on universal design of auditory signals in automobiles.

PubMed

Yamauchi, Katsuya; Choi, Jong-dae; Maiguma, Ryo; Takada, Masayuki; Iwamiya, Shin-ichiro

2004-11-01

In this paper, the impression of various kinds of auditory signals currently used in automobiles and a comprehensive evaluation were measured by a semantic differential method. The desirable acoustic characteristic was examined for each type of auditory signal. Sharp sounds with dominant high-frequency components were not suitable for auditory signals in automobiles. This trend is expedient for the aged whose auditory sensitivity in the high frequency region is lower. When intermittent sounds were used, a longer OFF time was suitable. Generally, "dull (not sharp)" and "calm" sounds were appropriate for auditory signals. Furthermore, the comparison between the frequency spectrum of interior noise in automobiles and that of suitable sounds for various auditory signals indicates that the suitable sounds are not easily masked. The suitable auditory signals for various purposes is a good solution from the viewpoint of universal design.

A review of hedgehog signaling in cranial bone development

PubMed Central

Pan, Angel; Chang, Le; Nguyen, Alan; James, Aaron W.

2013-01-01

During craniofacial development, the Hedgehog (HH) signaling pathway is essential for mesodermal tissue patterning and differentiation. The HH family consists of three protein ligands: Sonic Hedgehog (SHH), Indian Hedgehog (IHH), and Desert Hedgehog (DHH), of which two are expressed in the craniofacial complex (IHH and SHH). Dysregulations in HH signaling are well documented to result in a wide range of craniofacial abnormalities, including holoprosencephaly (HPE), hypotelorism, and cleft lip/palate. Furthermore, mutations in HH effectors, co-receptors, and ciliary proteins result in skeletal and craniofacial deformities. Cranial suture morphogenesis is a delicate developmental process that requires control of cell commitment, proliferation and differentiation. This review focuses on both what is known and what remains unknown regarding HH signaling in cranial suture morphogenesis and intramembranous ossification. As demonstrated from murine studies, expression of both SHH and IHH is critical to the formation and fusion of the cranial sutures and calvarial ossification. SHH expression has been observed in the cranial suture mesenchyme and its precise function is not fully defined, although some postulate SHH to delay cranial suture fusion. IHH expression is mainly found on the osteogenic fronts of the calvarial bones, and functions to induce cell proliferation and differentiation. Unfortunately, neonatal lethality of IHH deficient mice precludes a detailed examination of their postnatal calvarial phenotype. In summary, a number of basic questions are yet to be answered regarding domains of expression, developmental role, and functional overlap of HH morphogens in the calvaria. Nevertheless, SHH and IHH ligands are integral to cranial suture development and regulation of calvarial ossification. When HH signaling goes awry, the resultant suite of morphologic abnormalities highlights the important roles of HH signaling in cranial development. PMID:23565096

Hedgehog signaling contributes to basic fibroblast growth factor-regulated fibroblast migration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Zhong Xin; Sun, Cong Cong; Wenzhou People's Hospital, Wenzhou, Zhejiang

Fibroblast migration is a central process in skin wound healing, which requires the coordination of several types of growth factors. bFGF, a well-known fibroblast growth factor (FGF), is able to accelerate fibroblast migration; however, the underlying mechanism of bFGF regulation fibroblast migration remains unclear. Through the RNA-seq analysis, we had identified that the hedgehog (Hh) canonical pathway genes including Smoothened (Smo) and Gli1, were regulated by bFGF. Further analysis revealed that activation of the Hh pathway via up-regulation of Smo promoted fibroblast migration, invasion, and skin wound healing, but which significantly reduced by GANT61, a selective antagonist of Gli1/Gli2. Westernmore » blot analyses and siRNA transfection assays demonstrated that Smo acted upstream of phosphoinositide 3-kinase (PI3K)-c-Jun N-terminal kinase (JNK)-β-catenin to promote cell migration. Moreover, RNA-seq and qRT-PCR analyses revealed that Hh pathway genes including Smo and Gli1 were under control of β-catenin, suggesting that β-catenin turn feedback activates Hh signaling. Taken together, our analyses identified a new bFGF-regulating mechanism by which Hh signaling regulates human fibroblast migration, and the data presented here opens a new avenue for the wound healing therapy. - Highlights: • bFGF regulates Hedgehog (Hh) signaling in fibroblasts. • The Smo and Gli two master regulators of Hh signaling positively regulate fibroblast migration. • Smo facilitates β-catenin nuclear translocation via activation PI3K/JNK/GSK3β. • β-catenin positively regulates fibroblast cell migration and the expression of Hh signaling genes including Smo and Gli.« less

Ultralow-Power Digital Correlator for Microwave Polarimetry

NASA Technical Reports Server (NTRS)

Piepmeier, Jeffrey R.; Hass, K. Joseph

2004-01-01

A recently developed high-speed digital correlator is especially well suited for processing readings of a passive microwave polarimeter. This circuit computes the autocorrelations of, and the cross-correlations among, data in four digital input streams representing samples of in-phase (I) and quadrature (Q) components of two intermediate-frequency (IF) signals, denoted A and B, that are generated in heterodyne reception of two microwave signals. The IF signals arriving at the correlator input terminals have been digitized to three levels (-1,0,1) at a sampling rate up to 500 MHz. Two bits (representing sign and magnitude) are needed to represent the instantaneous datum in each input channel; hence, eight bits are needed to represent the four input signals during any given cycle of the sampling clock. The accumulation (integration) time for the correlation is programmable in increments of 2(exp 8) cycles of the sampling clock, up to a maximum of 2(exp 24) cycles. The basic functionality of the correlator is embodied in 16 correlation slices, each of which contains identical logic circuits and counters (see figure). The first stage of each correlation slice is a logic gate that computes one of the desired correlations (for example, the autocorrelation of the I component of A or the negative of the cross-correlation of the I component of A and the Q component of B). The sampling of the output of the logic gate output is controlled by the sampling-clock signal, and an 8-bit counter increments in every clock cycle when the logic gate generates output. The most significant bit of the 8-bit counter is sampled by a 16-bit counter with a clock signal at 2(exp 8) the frequency of the sampling clock. The 16-bit counter is incremented every time the 8-bit counter rolls over.

Global gene expression analysis of peripheral blood mononuclear cells in rhesus monkey infants with CA16 infection-induced HFMD.

PubMed

Song, Jie; Hu, Yajie; Hu, Yunguang; Wang, Jingjing; Zhang, Xiaolong; Wang, Lichun; Guo, Lei; Wang, Yancui; Ning, Ruotong; Liao, Yun; Zhang, Ying; Zheng, Huiwen; Shi, Haijing; He, Zhanlong; Li, Qihan; Liu, Longding

2016-03-02

Coxsackievirus A16 (CA16) is a dominant pathogen that results in hand, foot, and mouth disease and causes outbreaks worldwide, particularly in the Asia-Pacific region. However, the underlying molecular mechanisms remain unclear. Our previous study has demonstrated that the basic CA16 pathogenic process was successfully mimicked in rhesus monkey infant. The present study focused on the global gene expression changes in peripheral blood mononuclear cells of rhesus monkey infants with hand, foot, and mouth disease induced by CA16 infection at different time points. Genome-wide expression analysis was performed with Agilent whole-genome microarrays and established bioinformatics tools. Nine hundred and forty-eight significant differentially expressed genes that were associated with 5 gene ontology categories, including cell communication, cell cycle, immune system process, regulation of transcription and metabolic process were identified. Subsequently, the mapping of genes related to the immune system process by PANTHER pathway analysis revealed the predominance of inflammation mediated by chemokine and cytokine signaling pathways and the interleukin signaling pathway. Ultimately, co-expressed genes and their networks were analyzed. The results revealed the gene expression profile of the immune system in response to CA16 in rhesus monkey infants and suggested that such an immune response was generated as a result of the positive mobilization of the immune system. This initial microarray study will provide insights into the molecular mechanism of CA16 infection and will facilitate the identification of biomarkers for the evaluation of vaccines against this virus. Copyright © 2016 Elsevier B.V. All rights reserved.