The Activity of Thalamic Nucleus Reuniens Is Critical for Memory Retrieval, but Not Essential for the Early Phase of "Off-Line" Consolidation

ERIC Educational Resources Information Center

Mei, Hao; Logothetis, Nikos K.; Eschenko, Oxana

2018-01-01

Spatial navigation depends on the hippocampal function, but also requires bidirectional interactions between the hippocampus (HPC) and the prefrontal cortex (PFC). The cross-regional communication is typically regulated by critical nodes of a distributed brain network. The thalamic nucleus reuniens (RE) is reciprocally connected to both HPC and…

Bidirectional Coupling between Astrocytes and Neurons Mediates Learning and Dynamic Coordination in the Brain: A Multiple Modeling Approach

PubMed Central

Wade, John J.; McDaid, Liam J.; Harkin, Jim; Crunelli, Vincenzo; Kelso, J. A. Scott

2011-01-01

In recent years research suggests that astrocyte networks, in addition to nutrient and waste processing functions, regulate both structural and synaptic plasticity. To understand the biological mechanisms that underpin such plasticity requires the development of cell level models that capture the mutual interaction between astrocytes and neurons. This paper presents a detailed model of bidirectional signaling between astrocytes and neurons (the astrocyte-neuron model or AN model) which yields new insights into the computational role of astrocyte-neuronal coupling. From a set of modeling studies we demonstrate two significant findings. Firstly, that spatial signaling via astrocytes can relay a “learning signal” to remote synaptic sites. Results show that slow inward currents cause synchronized postsynaptic activity in remote neurons and subsequently allow Spike-Timing-Dependent Plasticity based learning to occur at the associated synapses. Secondly, that bidirectional communication between neurons and astrocytes underpins dynamic coordination between neuron clusters. Although our composite AN model is presently applied to simplified neural structures and limited to coordination between localized neurons, the principle (which embodies structural, functional and dynamic complexity), and the modeling strategy may be extended to coordination among remote neuron clusters. PMID:22242121

Robust bidirectional links for photonic quantum networks

PubMed Central

Xu, Jin-Shi; Yung, Man-Hong; Xu, Xiao-Ye; Tang, Jian-Shun; Li, Chuan-Feng; Guo, Guang-Can

2016-01-01

Optical fibers are widely used as one of the main tools for transmitting not only classical but also quantum information. We propose and report an experimental realization of a promising method for creating robust bidirectional quantum communication links through paired optical polarization-maintaining fibers. Many limitations of existing protocols can be avoided with the proposed method. In particular, the path and polarization degrees of freedom are combined to deterministically create a photonic decoherence-free subspace without the need for any ancillary photon. This method is input state–independent, robust against dephasing noise, postselection-free, and applicable bidirectionally. To rigorously quantify the amount of quantum information transferred, the optical fibers are analyzed with the tools developed in quantum communication theory. These results not only suggest a practical means for protecting quantum information sent through optical quantum networks but also potentially provide a new physical platform for enriching the structure of the quantum communication theory. PMID:26824069

Controller-Independent Bidirectional Direct Communication with Four-Qubit Cluster States

NASA Astrophysics Data System (ADS)

Cao, Yong; Zha, Xin-Wei; Wang, Shu-Kai

2018-03-01

We propose a feasible scheme for implementing bidirectional quantum direct communication protocol using four-qubit cluster states. In this scheme, the quantum channel between the sender Alice and the receiver Bob consists of an ordered sequence of cluster states which are prepared by Alice. After ensuring the security of quantum channel, according to the secret messages, the sender will perform the unitary operation and the receiver can obtain different secret messages in a deterministic way.

Long-distance multi-channel bidirectional chaos communication based on synchronized VCSELs subject to chaotic signal injection

NASA Astrophysics Data System (ADS)

Xie, Yi-Yuan; Li, Jia-Chao; He, Chao; Zhang, Zhen-Dong; Song, Ting-Ting; Xu, Chang-Jun; Wang, Gui-Jin

2016-10-01

A novel long-distance multi-channel bidirectional chaos communication system over multiple paths based on two synchronized 1550 nm vertical-cavity surface-emitting lasers (VCSELs) is proposed and studied theoretically. These two responding VCSELs (R-VCSELs) can output similar chaotic signals served as chaotic carrier in two linear polarization (LP) modes with identical signal injection from a driving VCSEL (D-VCSEL), which is subject to optical feedback and optical injection, simultaneously. Through the numerical simulations, high quality chaos synchronization between the two R-VCSELs can be obtained. Besides, the effects of varied qualities of chaos synchronization on communication performances in 20 km single mode fiber (SMF) channels are investigated by regulating different internal parameters mismatch after adopting chaos masking (CMS) technique. With the decrease of the maximum cross correlation coefficient (Max-C) between the two R-VCSELs, the bit error rate (BER) of decoded message increase. Meanwhile, the BER can still be less than 10-9 when the Max-C degrades to 0.982. Based on high quality synchronization, when the dispersion compensating fiber (DCF) links are introduced, 4n messages of 10 Gbit/s can transmit in 180 km SMF channels over n coupling paths, bidirectionally and simultaneously. Thorough tests are carried out with detailed analysis, demonstrating long-distance, multi-channel, bidirectional chaos communication based on VCSELs with chaotic signal injection.

Bidirectional fiber-wireless and fiber-VLLC transmission system based on an OEO-based BLS and a RSOA.

PubMed

Lu, Hai-Han; Li, Chung-Yi; Lu, Ting-Chien; Wu, Chang-Jen; Chu, Chien-An; Shiva, Ajay; Mochii, Takao

2016-02-01

A bidirectional fiber-wireless and fiber-visible-laser-light-communication (VLLC) transmission system based on an optoelectronic oscillator (OEO)-based broadband light source (BLS) and a reflective semiconductor optical amplifier (RSOA) is proposed and experimentally demonstrated. Through an in-depth observation of such bidirectional fiber-wireless and fiber-VLLC transmission systems, good bit error rate performances are obtained over a 40 km single-mode fiber and a 10 m RF/optical wireless transport. Such a bidirectional fiber-wireless and fiber-VLLC transmission system is an attractive option for providing broadband integrated services.

Bi-directional communication interface for microprocessor-to-system/370

NASA Technical Reports Server (NTRS)

Fischer, J. P.

1981-01-01

The design and operation of a bi-directional communication interface between a microcomputer and the IBM System/370 is documented. The hardware unit interconnects a modem to interface to the S/370, the microcomputer with an EIA I/O port, and a terminal for sending and receiving data from either the microcomputer or the S/370. Also described is the software necessary for the two-way interface. This interface is designed so that no modifications need to be made to the terminal, modem, or microcomputer.

Bad data packet capture device

DOEpatents

Chen, Dong; Gara, Alan; Heidelberger, Philip; Vranas, Pavlos

2010-04-20

An apparatus and method for capturing data packets for analysis on a network computing system includes a sending node and a receiving node connected by a bi-directional communication link. The sending node sends a data transmission to the receiving node on the bi-directional communication link, and the receiving node receives the data transmission and verifies the data transmission to determine valid data and invalid data and verify retransmissions of invalid data as corresponding valid data. A memory device communicates with the receiving node for storing the invalid data and the corresponding valid data. A computing node communicates with the memory device and receives and performs an analysis of the invalid data and the corresponding valid data received from the memory device.

The power of sound: miniaturized medical implants with ultrasonic links

NASA Astrophysics Data System (ADS)

Wang, Max L.; Chang, Ting Chia; Charthad, Jayant; Weber, Marcus J.; Arbabian, Amin

2017-05-01

Miniaturized wirelessly powered implants capable of operating and communicating deep in the body are necessary for the next-generation of diagnostics and therapeutics. A major challenge in developing these minimally invasive implants is the tradeoff between device size, functionality, and operating depth. Here, we review two different wireless powering methods, inductive and ultrasonic power transfer, examine how to analyze their power transfer efficiency, and evaluate their potential for powering implantable medical devices. In particular, we show how ultrasonic wireless power transfer can address these challenges due to its safety, low attenuation, and millimeter wavelengths in the body. Finally, we demonstrate two ultrasonically powered implants capable of active power harvesting and bidirectional communication for closed-loop operation while functioning through multiple centimeters of tissue.

Spherical transceivers for ultrafast optical wireless communications

NASA Astrophysics Data System (ADS)

Jin, Xian; Hristovski, Blago A.; Collier, Christopher M.; Geoffroy-Gagnon, Simon; Born, Brandon; Holzman, Jonathan F.

2016-02-01

Optical wireless communications (OWC) offers the potential for high-speed and mobile operation in indoor networks. Such OWC systems often employ a fixed transmitter grid and mobile transceivers, with the mobile transceivers carrying out bi-directional communication via active downlinks (ideally with high-speed signal detection) and passive uplinks (ideally with broad angular retroreflection and high-speed modulation). It can be challenging to integrate all of these bidirectional communication capabilities within the mobile transceivers, however, as there is a simultaneous desire for compact packaging. With this in mind, the work presented here introduces a new form of transceiver for bi-directional OWC systems. The transceiver incorporates radial photoconductive switches (for high-speed signal detection) and a spherical retro-modulator (for broad angular retroreflection and high-speed all-optical modulation). All-optical retromodulation are investigated by way of theoretical models and experimental testing, for spherical retro-modulators comprised of three glasses, N-BK7, N-LASF9, and S-LAH79, having differing levels of refraction and nonlinearity. It is found that the spherical retro-modulator comprised of S-LAH79, with a refractive index of n ≍ 2 and a Kerr nonlinear index of n2 ≍ (1.8 ± 0.1) × 10-15 cm2/W, yields both broad angular retroreflection (over a solid angle of 2π steradians) and ultrafast modulation (over a duration of 120 fs). Such transceivers can become important elements for all-optical implementations in future bi-directional OWC systems.

Asymmetric homotypic interactions of the atypical cadherin Flamingo mediate intercellular polarity signaling

PubMed Central

Chen, Wei-Shen; Antic, Dragana; Matis, Maja; Logan, Catriona Y.; Povelones, Michael; Anderson, Graham; Nusse, Roel; Axelrod, Jeffrey D.

2008-01-01

Acquisition of planar cell polarity (PCP) in epithelia involves intercellular communication, during which cells align their polarity with that of their neighbors. The transmembrane proteins Frizzled (Fz) and Van Gogh (Vang) are essential components of the intercellular communication mechanism, as loss of either strongly perturbs the polarity of neighboring cells. How Fz and Vang communicate polarity information between neighboring cells is poorly understood. The atypical cadherin, Flamingo (Fmi), is implicated in this process, yet whether Fmi acts permissively as a scaffold, or instructively as a signal is unclear. Here, we provide evidence that Fmi functions instructively to mediate Fz-Vang intercellular signal relay, recruiting Fz and Vang to opposite sides of cell boundaries. We propose that two functional forms of Fmi, one of which is induced by and physically interacts with Fz, form cadherin homodimers that signal bidirectionally and asymmetrically, instructing unequal responses in adjacent cell membranes to establish molecular asymmetry. PMID:18555784

Laser communications through the atmosphere

NASA Technical Reports Server (NTRS)

Shaik, Kamran; Churnside, J. H.

1988-01-01

Atmospheric properties affecting laser propagation with reference to optical communications are reviewed. Some of the optical space network configurations and various diversity techniques that may need to be utilized to develop robust bi-directional space-earth laser communication links are explored.

Agency as a Construct for Guiding the Establishment of Communication-Friendly Classrooms

ERIC Educational Resources Information Center

Alper, Rebecca M.; McGregor, Karla K.

2015-01-01

Educators face the challenge of creating classroom environments that are physically, socially, and didactically "communication friendly" for children with diverse communication needs and differences. In this article we propose that (1) communication and the development of agency are bi-directionally linked and, therefore, (2) the…

Programmable Pacemaker

NASA Technical Reports Server (NTRS)

1996-01-01

Released in 1995, the Trilogy cardiac pacemaker is the fourth generation of a unit developed in the 1970s by NASA, Johns Hopkins Applied Physics Laboratory and St. Jude Medical's Cardiac Rhythm Management Division (formerly known as Pacesetter Systems, Inc.). The new system incorporates the company's PDx diagnostic and programming software and a powerful microprocessor that allows more functions to be fully automatic and gives more detailed information on the patient's health and the performance of the pacing systems. The pacemaker incorporates bidirectional telemetry used for space communications for noninvasive communication with the implanted pacemaker, smaller implantable pulse generators from space microminiaturization, and longer-life batteries from technology for spacecraft electrical power systems.

Space station communications and tracking equipment management/control system

NASA Technical Reports Server (NTRS)

Kapell, M. H.; Seyl, J. W.

1982-01-01

Design details of a communications and tracking (C and T) local area network and the distribution system requirements for the prospective space station are described. The hardware will be constructed of LRUs, including those for baseband, RF, and antenna subsystems. It is noted that the C and T equipment must be routed throughout the station to accommodate growth of the station. Configurations of the C and T modules will therefore be dependent on the function of the space station module where they are located. A block diagram is provided of a sample C and T hardware distribution configuration. A topology and protocol will be needed to accommodate new terminals, wide bandwidths, bidirectional message transmission, and distributed functioning. Consideration will be given to collisions occurring in the data transmission channels.

Experimental demonstration of bidirectional up to 40 Gbit/s QPSK coherent free-space optical communication link over ∼1 km

NASA Astrophysics Data System (ADS)

Feng, Xianglian; Wu, Zhihang; Wang, Tianshu; Zhang, Peng; Li, Xiaoyan; Jiang, Huilin; Su, Yuwei; He, Hongwei; Wang, Xiaoyan; Gao, Shiming

2018-03-01

Advanced multi-level modulation formats have shown their great potential in high-speed and high-spectral-efficiency optical communications. Using quadrature phase-shift keying (QPSK) modulation format for free-space optical (FSO) communication, a bidirectional high-speed FSO transmission link with the bit rates of up to 40 Gbit/s over ∼1 km, between two buildings in the campus of Changchun University of Science and Technology, Changchun, China, is experimentally demonstrated cooperating by capture and tracking systems. The eye-diagrams and constellation diagrams of the transmitted QPSK signals are clearly observed. By comparing the bit error rate (BER) curves before and after transmission, one can find that the receiving powers are both less than -16.5 dBm for the forward and backward transmissions of the bidirectional 20, 30, and 40 Gbit/s FSO links, and their power penalties due to the phase fluctuation of the atmospheric channel are both less than 2.6 dB, at the BER of 3.8 ×10-3.

Collaborative and Bidirectional Feedback Between Students and Clinical Preceptors: Promoting Effective Communication Skills on Health Care Teams.

PubMed

Myers, Kara; Chou, Calvin L

2016-11-01

Current literature on feedback suggests that clinical preceptors lead feedback conversations that are primarily unidirectional, from preceptor to student. While this approach may promote clinical competency, it does not actively develop students' competency in facilitating feedback discussions and providing feedback across power differentials (ie, from student to preceptor). This latter competency warrants particular attention given its fundamental role in effective health care team communication and its related influence on patient safety. Reframing the feedback process as collaborative and bidirectional, where both preceptors and students provide and receive feedback, maximizes opportunities for role modeling and skills practice in the context of a supportive relationship, thereby enhancing team preparedness. We describe an initiative to introduce these fundamental skills of collaborative, bidirectional feedback in the nurse-midwifery education program at the University of California, San Francisco. © 2016 by the American College of Nurse-Midwives.

Enhanced correlation of received power-signal fluctuations in bidirectional optical links

NASA Astrophysics Data System (ADS)

Minet, Jean; Vorontsov, Mikhail A.; Polnau, Ernst; Dolfi, Daniel

2013-02-01

A study of the correlation between the power signals received at both ends of bidirectional free-space optical links is presented. By use of the quasi-optical approximation, we show that an ideal (theoretically 100%) power-signal correlation can be achieved in optical links with specially designed monostatic transceivers based on single-mode fiber collimators. The theoretical prediction of enhanced correlation is supported both by experiments conducted over a 7 km atmospheric path and wave optics numerical analysis of the corresponding bidirectional optical link. In the numerical simulations, we also compare correlation properties of received power signals for different atmospheric conditions and for optical links with monostatic and bistatic geometries based on single-mode fiber collimator and on power-in-the-bucket transceiver types. Applications of the observed phenomena for signal fading mitigation and turbulence-enhanced communication link security in free-space laser communication links are discussed.

Analysis and Improvement of Large Payload Bidirectional Quantum Secure Direct Communication Without Information Leakage

NASA Astrophysics Data System (ADS)

Liu, Zhi-Hao; Chen, Han-Wu

2018-02-01

As we know, the information leakage problem should be avoided in a secure quantum communication protocol. Unfortunately, it is found that this problem does exist in the large payload bidirectional quantum secure direct communication (BQSDC) protocol (Ye Int. J. Quantum. Inf. 11(5), 1350051 2013) which is based on entanglement swapping between any two Greenberger-Horne-Zeilinger (GHZ) states. To be specific, one half of the information interchanged in this protocol is leaked out unconsciously without any active attack from an eavesdropper. Afterward, this BQSDC protocol is revised to the one without information leakage. It is shown that the improved BQSDC protocol is secure against the general individual attack and has some obvious features compared with the original one.

The effects of gut microbiota on CNS function in humans

PubMed Central

Tillisch, Kirsten

2014-01-01

The role of the gastrointestinal microbiota in human brain development and function is an area of increasing interest and research. Preclinical models suggest a role for the microbiota in broad aspects of human health, including mood, cognition, and chronic pain. Early human studies suggest that altering the microbiota with beneficial bacteria, or probiotics, can lead to changes in brain function, as well as subjective reports of mood. As the mechanisms of bidirectional communication between the brain and microbiota are better understood, it is expected that these pathways will be harnessed to provide novel methods to enhance health and treat disease. PMID:24838095

Visceral Inflammation and Immune Activation Stress the Brain

PubMed Central

Holzer, Peter; Farzi, Aitak; Hassan, Ahmed M.; Zenz, Geraldine; Jačan, Angela; Reichmann, Florian

2017-01-01

Stress refers to a dynamic process in which the homeostasis of an organism is challenged, the outcome depending on the type, severity, and duration of stressors involved, the stress responses triggered, and the stress resilience of the organism. Importantly, the relationship between stress and the immune system is bidirectional, as not only stressors have an impact on immune function, but alterations in immune function themselves can elicit stress responses. Such bidirectional interactions have been prominently identified to occur in the gastrointestinal tract in which there is a close cross-talk between the gut microbiota and the local immune system, governed by the permeability of the intestinal mucosa. External stressors disturb the homeostasis between microbiota and gut, these disturbances being signaled to the brain via multiple communication pathways constituting the gut–brain axis, ultimately eliciting stress responses and perturbations of brain function. In view of these relationships, the present article sets out to highlight some of the interactions between peripheral immune activation, especially in the visceral system, and brain function, behavior, and stress coping. These issues are exemplified by the way through which the intestinal microbiota as well as microbe-associated molecular patterns including lipopolysaccharide communicate with the immune system and brain, and the mechanisms whereby overt inflammation in the GI tract impacts on emotional-affective behavior, pain sensitivity, and stress coping. The interactions between the peripheral immune system and the brain take place along the gut–brain axis, the major communication pathways of which comprise microbial metabolites, gut hormones, immune mediators, and sensory neurons. Through these signaling systems, several transmitter and neuropeptide systems within the brain are altered under conditions of peripheral immune stress, enabling adaptive processes related to stress coping and resilience to take place. These aspects of the impact of immune stress on molecular and behavioral processes in the brain have a bearing on several disturbances of mental health and highlight novel opportunities of therapeutic intervention. PMID:29213271

Optical Design of an Optical Communications Terminal

NASA Technical Reports Server (NTRS)

Biswas, Abhijit; Page, Norman; Hemmati, Hamid

2005-01-01

An optical communications terminal (OCT) is being developed to enable transmission of data at a rate as high as 2.5 Gb/s, from an aircraft or spacecraft to a ground station. In addition to transmitting high data rates, OCT will also be capable of bidirectional communications.

A nonlinear plasmonic waveguide based all-optical bidirectional switching

NASA Astrophysics Data System (ADS)

Bana, Xiaoqiang; Pang, Xingxing; Li, Xiaohui; Hu, Bin; Guo, Yixuan; Zheng, Hairong

2018-01-01

In this paper, an all-optical switching with a nanometer coupled ring resonator is demonstrated based on the nonlinear material. By adjusting the light intensity, we implement the resonance wavelength from 880 nm to 940 nm in the nonlinear material structure monocyclic. In the bidirectional switch structure, the center wavelength (i.e. 880 nm) is fixed. By changing the light intensity from I = 0 to I = 53 . 1 MW /cm2, the function of optical switching can be obtained. The results demonstrate that both the single-ring cavity and the T-shaped double-ring structure can realize the optical switching effect. This work takes advantage of the simple structure. The single-ring cavity plasmonic switches have many advantages, such as nanoscale size, low pumping light intensity, ultrafast response time (femtosecond level), etc. It is expected that the proposed all-optical integrated devices can be potentially applied in optical communication, signal processing, and signal sensing, etc.

Non-conventional protrusions: the diversity of cell interactions at short and long distance.

PubMed

Caviglia, Sara; Ober, Elke A

2018-06-08

Cells use different means to communicate within and between tissues and thereby coordinate their behaviours. Following the initial observations of enigmatic long filopodia unrelated to cell movement, it became clear that the roles of cellular protrusions are not restricted to sensing functions or motility and are much more diverse than previously appreciated. Advances in live-imaging and genetic tools revealed several types of non-conventional cell protrusions and their functions, ranging from tissue patterning, proliferation and differentiation control, tissue matching and cell spacing to more unexpected roles such as priming of cell adhesion as well as bidirectional coordination of tissue movements. Here, we will highlight exciting new insights into highly diverse cell behaviours elicited by protrusions and contact-dependent cell communication, essential for embryonic development across species. Copyright © 2018. Published by Elsevier Ltd.

Ultrafast all-optical technologies for bidirectional optical wireless communications.

PubMed

Jin, Xian; Hristovski, Blago A; Collier, Christopher M; Geoffroy-Gagnon, Simon; Born, Brandon; Holzman, Jonathan F

2015-04-01

In this Letter, a spherical retro-modulator architecture is introduced for operation as a bidirectional transceiver in passive optical wireless communication links. The architecture uses spherical retroreflection to enable retroreflection with broad directionality (2π steradians), and it uses all-optical beam interaction to enable modulation on ultrafast timescales (120 fs duration). The spherical retro-modulator is investigated from a theoretical standpoint and is fabricated for testing with three glasses, N-BK7, N-LASF9, and S-LAH79. It is found that the S-LAH79 structure provides the optimal refraction and nonlinearity for the desired retroreflection and modulation capabilities.

Controlled Bidirectional Quantum Secure Direct Communication

PubMed Central

Chou, Yao-Hsin; Lin, Yu-Ting; Zeng, Guo-Jyun; Lin, Fang-Jhu; Chen, Chi-Yuan

2014-01-01

We propose a novel protocol for controlled bidirectional quantum secure communication based on a nonlocal swap gate scheme. Our proposed protocol would be applied to a system in which a controller (supervisor/Charlie) controls the bidirectional communication with quantum information or secret messages between legitimate users (Alice and Bob). In this system, the legitimate users must obtain permission from the controller in order to exchange their respective quantum information or secret messages simultaneously; the controller is unable to obtain any quantum information or secret messages from the decoding process. Moreover, the presence of the controller also avoids the problem of one legitimate user receiving the quantum information or secret message before the other, and then refusing to help the other user decode the quantum information or secret message. Our proposed protocol is aimed at protecting against external and participant attacks on such a system, and the cost of transmitting quantum bits using our protocol is less than that achieved in other studies. Based on the nonlocal swap gate scheme, the legitimate users exchange their quantum information or secret messages without transmission in a public channel, thus protecting against eavesdroppers stealing the secret messages. PMID:25006596

The signaling role for chloride in the bidirectional communication between neurons and astrocytes.

PubMed

Wilson, Corinne S; Mongin, Alexander A

2018-01-09

It is well known that the electrical signaling in neuronal networks is modulated by chloride (Cl - ) fluxes via the inhibitory GABA A and glycine receptors. Here, we discuss the putative contribution of Cl - fluxes and intracellular Cl - to other forms of information transfer in the CNS, namely the bidirectional communication between neurons and astrocytes. The manuscript (i) summarizes the generic functions of Cl - in cellular physiology, (ii) recaps molecular identities and properties of Cl - transporters and channels in neurons and astrocytes, and (iii) analyzes emerging studies implicating Cl - in the modulation of neuroglial communication. The existing literature suggests that neurons can alter astrocytic Cl - levels in a number of ways; via (a) the release of neurotransmitters and activation of glial transporters that have intrinsic Cl - conductance, (b) the metabotropic receptor-driven changes in activity of the electroneutral cation-Cl - cotransporter NKCC1, and (c) the transient, activity-dependent changes in glial cell volume which open the volume-regulated Cl - /anion channel VRAC. Reciprocally, astrocytes are thought to alter neuronal [Cl - ] i through either (a) VRAC-mediated release of the inhibitory gliotransmitters, GABA and taurine, which open neuronal GABA A and glycine receptor/Cl - channels, or (b) the gliotransmitter-driven stimulation of NKCC1. The most important recent developments in this area are the identification of the molecular composition and functional heterogeneity of brain VRAC channels, and the discovery of a new cytosolic [Cl - ] sensor - the Wnk family protein kinases. With new work in the field, our understanding of the role of Cl - in information processing within the CNS is expected to be significantly updated. Copyright © 2018 Elsevier B.V. All rights reserved.

A small step in VLC systems - a big step in Li-Fi implementation

NASA Astrophysics Data System (ADS)

Rîurean, S. M.; Nagy, A. A.; Leba, M.; Ionica, A. C.

2018-01-01

Light is part of our sustainable environmental life so, using it would be the handiest and cheapest way for wireless communication. Since ever, light has been used to send messages in different ways and now, due to the high technological improvements, bits through light, at high speed on multiple paths, allow humans to communicate. Using the lighting system both for illumination and communication represents lately one of the worldwide main research issues with several implementations with real benefits. This paper presents a viable VLC system, that proves its sustainability for sending by light information not only few millimetres but meters away. This system has multiple potential applications in different areas where other communication systems are bottlenecked, too expensive, unavailable or even forbidden. Since a Li-Fi fully developed system requires bidirectional, multiple access communication, there are still some challenges towards a functional Li-Fi wireless network. Although important steps have been made, Li-Fi is still under experimental stage.

Preliminary results of BTDF calibration of transmissive solar diffusers for remote sensing

NASA Astrophysics Data System (ADS)

Georgiev, Georgi T.; Butler, James J.; Thome, Kurt; Cooksey, Catherine; Ding, Leibo

2016-09-01

Satellite instruments operating in the reflected solar wavelength region require accurate and precise determination of the optical properties of their diffusers used in pre-flight and post-flight calibrations. The majority of recent and current space instruments use reflective diffusers. As a result, numerous Bidirectional Reflectance Distribution Function (BRDF) calibration comparisons have been conducted between the National Institute of Standards and Technology (NIST) and other industry and university-based metrology laboratories. However, based on literature searches and communications with NIST and other laboratories, no Bidirectional Transmittance Distribution Function (BTDF) measurement comparisons have been conducted between National Measurement Laboratories (NMLs) and other metrology laboratories. On the other hand, there is a growing interest in the use of transmissive diffusers in the calibration of satellite, air-borne, and ground-based remote sensing instruments. Current remote sensing instruments employing transmissive diffusers include the Ozone Mapping and Profiler Suite instrument (OMPS) Limb instrument on the Suomi-National Polar-orbiting Partnership (S-NPP) platform,, the Geostationary Ocean Color Imager (GOCI) on the Korea Aerospace Research Institute's (KARI) Communication, Ocean, and Meteorological Satellite (COMS), the Ozone Monitoring Instrument (OMI) on NASA's Earth Observing System (EOS) Aura platform, the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument and the Geostationary Environmental Monitoring Spectrometer (GEMS).. This ensemble of instruments requires validated BTDF measurements of their onboard transmissive diffusers from the ultraviolet through the near infrared. This paper presents the preliminary results of a BTDF comparison between the NASA Diffuser Calibration Laboratory (DCL) and NIST on quartz and thin Spectralon samples.

Mechanical analysis of non-uniform bi-directional functionally graded intelligent micro-beams using modified couple stress theory

NASA Astrophysics Data System (ADS)

Bakhshi Khaniki, Hossein; Rajasekaran, Sundaramoorthy

2018-05-01

This study develops a comprehensive investigation on mechanical behavior of non-uniform bi-directional functionally graded beam sensors in the framework of modified couple stress theory. Material variation is modelled through both length and thickness directions using power-law, sigmoid and exponential functions. Moreover, beam is assumed with linear, exponential and parabolic cross-section variation through the length using power-law and sigmoid varying functions. Using these assumptions, a general model for microbeams is presented and formulated by employing Hamilton’s principle. Governing equations are solved using a mixed finite element method with Lagrangian interpolation technique, Gaussian quadrature method and Wilson’s Lagrangian multiplier method. It is shown that by using bi-directional functionally graded materials in nonuniform microbeams, mechanical behavior of such structures could be affected noticeably and scale parameter has a significant effect in changing the rigidity of nonuniform bi-directional functionally graded beams.

Bidirectional optical coupler for plastic optical fibers.

PubMed

Sugita, Tatsuya; Abe, Tomiya; Hirano, Kouki; Itoh, Yuzo

2005-05-20

We have developed a low-loss bidirectional optical coupler for high-speed optical communication with plastic optical fibers (POFs). The coupler, which is fabricated by an injection molding method that uses poly (methyl methacrylate), has an antisymmetric tapered shape. We show that the coupler has low insertion and branching losses. The tapered shape of the receiving branch reduces beam diameter and increases detection efficiency coupling to a photodetector, whose area is smaller than that of the plastic optical fiber. The possibility of more than 15-m bidirectional transmission with a signaling bit rate up to 500 Mbits/s for simplex step-index POFs is demonstrated.

Anti-Noise Bidirectional Quantum Steganography Protocol with Large Payload

NASA Astrophysics Data System (ADS)

Qu, Zhiguo; Chen, Siyi; Ji, Sai; Ma, Songya; Wang, Xiaojun

2018-06-01

An anti-noise bidirectional quantum steganography protocol with large payload protocol is proposed in this paper. In the new protocol, Alice and Bob enable to transmit classical information bits to each other while teleporting secret quantum states covertly. The new protocol introduces the bidirectional quantum remote state preparation into the bidirectional quantum secure communication, not only to expand secret information from classical bits to quantum state, but also extract the phase and amplitude values of secret quantum state for greatly enlarging the capacity of secret information. The new protocol can also achieve better imperceptibility, since the eavesdropper can hardly detect the hidden channel or even obtain effective secret quantum states. Comparing with the previous quantum steganography achievements, due to its unique bidirectional quantum steganography, the new protocol can obtain higher transmission efficiency and better availability. Furthermore, the new algorithm can effectively resist quantum noises through theoretical analysis. Finally, the performance analysis proves the conclusion that the new protocol not only has good imperceptibility, high security, but also large payload.

Anti-Noise Bidirectional Quantum Steganography Protocol with Large Payload

NASA Astrophysics Data System (ADS)

Qu, Zhiguo; Chen, Siyi; Ji, Sai; Ma, Songya; Wang, Xiaojun

2018-03-01

An anti-noise bidirectional quantum steganography protocol with large payload protocol is proposed in this paper. In the new protocol, Alice and Bob enable to transmit classical information bits to each other while teleporting secret quantum states covertly. The new protocol introduces the bidirectional quantum remote state preparation into the bidirectional quantum secure communication, not only to expand secret information from classical bits to quantum state, but also extract the phase and amplitude values of secret quantum state for greatly enlarging the capacity of secret information. The new protocol can also achieve better imperceptibility, since the eavesdropper can hardly detect the hidden channel or even obtain effective secret quantum states. Comparing with the previous quantum steganography achievements, due to its unique bidirectional quantum steganography, the new protocol can obtain higher transmission efficiency and better availability. Furthermore, the new algorithm can effectively resist quantum noises through theoretical analysis. Finally, the performance analysis proves the conclusion that the new protocol not only has good imperceptibility, high security, but also large payload.

Non-Verbal Communicative Signals Modulate Attention to Object Properties

PubMed Central

Marno, Hanna; Davelaar, Eddy J.; Csibra, Gergely

2015-01-01

We investigated whether the social context in which an object is experienced influences the encoding of its various properties. We hypothesized that when an object is observed in a communicative context, its intrinsic features (such as its shape) would be preferentially encoded at the expense of its extrinsic properties (such as its location). In the three experiments, participants were presented with brief movies, in which an actor either performed a non-communicative action towards one of five different meaningless objects, or communicatively pointed at one of them. A subsequent static image, in which either the location or the identity of an object changed, tested participants’ attention to these two kinds of information. Throughout the three experiments we found that communicative cues tended to facilitate identity change detection and to impede location change detection, while in the non-communicative contexts we did not find such a bidirectional effect of cueing. The results also revealed that the effect of the communicative context was due to the presence of ostensive-communicative signals before the object-directed action, and not to the pointing gesture per se. We propose that such an attentional bias forms an inherent part of human communication, and function to facilitate social learning by communication. PMID:24294871

Schemes for Hybrid Bidirectional Controlled Quantum Communication via Multi-qubit Entangled States

NASA Astrophysics Data System (ADS)

Ma, Peng-Cheng; Chen, Gui-Bin; Li, Xiao-Wei; Zhan, You-Bang

2018-02-01

We present two schemes for hybrid bidirectional controlled quantum communication (HBCQC) via six- and nine-qubit entangled states as the quantum channel, respectively. In these schemes, two distant parties, Alice and Bob are not only senders but also receivers, and Alice wants to teleport an unknown single-qubit state to Bob, at the same time, Bob wishes to help Alice remotely prepares an arbitrary single- and two- qubit state, respectively. It is shown that, only if the two senders and the controller collaborate with each other, the HBCQC can be completed successfully. We demonstrate, in our both schemes, the total success probability of the HBCQC can reach 1, that is, the schemes are deterministic.

Exploring bi-directional and SMS messaging for communications between Public Health Agencies and their stakeholders: a qualitative study.

PubMed

Revere, Debra; Calhoun, Rebecca; Baseman, Janet; Oberle, Mark

2015-07-08

Communication technologies that enable bi-directional/two-way communications and cell phone texting (SMS) between public health agencies and their stakeholders may improve public health surveillance, ensure targeted distribution of alerts to hard-to-reach populations, reduce mortality and morbidity in an emergency, and enable a crucial feedback loop between public health agencies and the communities they serve. Building on prior work regarding health care provider preferences for receiving one-way public health communications by email, fax or SMS, we conducted a formative, exploratory study to understand how a bi-directional system and the incorporation of SMS in that system might be used as a strategy to send and receive messages between public health agencies and community-based organizations which serve vulnerable populations, health care providers, and public health workers. Our research question: Under what conditions and/or situations might public health agencies utilize bi-directional and/or SMS messaging for disseminating time-sensitive public health information (alerts, advisories, updates, etc.) to their stakeholders? A mixed methods (qualitative and quantitative) study was conducted between April and July 2014. Data collection included a survey distributed to health care providers and semi-structured interviews with providers, community- and government-based organization leaders and directors, and public health agency internal workforce staff. Survey respondents and interviewees were asked about their exposure to public health messages, how these messages are received and how the information in these messages are handled, and in what situations (for example, a local vs. a national event, a pandemic or emergency vs. a health update) a bi-directional and/or SMS messaging system might improve communications between public health agencies and their stakeholder group. Interview and survey data were qualitatively analyzed. Thematic codes were quantitized into dichotomous variables of 0 or 1 on a per respondent basis to enumerate the presence or absence of each thematic code, enable quantitative analysis, and inform interpretation of findings. Five major themes emerged from synthesizing survey and interview results: 1) Regardless of situational context (emergency vs. non-urgent) and message recipient (stakeholder group), e-mail is a favored modality for receiving public health messages; 2) The decision to use bi-directional, SMS or multiple communication strategies is complex and public health agencies' need to manage messaging concerns/barriers and benefits for all parties; 3) Both public health agencies and their stakeholders share similar values/uses and concerns regarding two-way public health messaging and SMS; 4) Public health is highly trusted, thus thoughtful, effective messaging will ensure continuation of this goodwill; and 5) Information reciprocity between public health agencies and stakeholders who share their information is essential. Multiple communication strategies might be utilized but the choice of a specific strategy needs to balance message content (emergency vs. routine communications), delivery (one- vs. two-way), channel (SMS, email, etc.), and public health agency burden with stakeholder preferences and technical capabilities, all while mitigating the risk of message overload and disregard of important communications by recipients.

The impact of neurotechnology on rehabilitation.

PubMed

Berger, Theodore W; Gerhardt, Greg; Liker, Mark A; Soussou, Walid

2008-01-01

This paper present results of a multi-disciplinary project that is developing a microchip-based neural prosthesis for the hippocampus, a region of the brain responsible for the formation of long-term memories. Damage to the hippocampus is frequently associated with epilepsy, stroke, and dementia (Alzheimer's disease) and is considered to underlie the memory deficits related to these neurological conditions. The essential goals of the multi-laboratory effort include: (1) experimental study of neuron and neural network function--how does the hippocampus encode information? (2) formulation of biologically realistic models of neural system dynamics--can that encoding process be described mathematically to realize a predictive model of how the hippocampus responds to any event? (3) microchip implementation of neural system models--can the mathematical model be realized as a set of electronic circuits to achieve parallel processing, rapid computational speed, and miniaturization? and (4) creation of hybrid neuron-silicon interfaces-can structural and functional connections between electronic devices and neural tissue be achieved for long-term, bi-directional communication with the brain? By integrating solutions to these component problems, we are realizing a microchip-based model of hippocampal nonlinear dynamics that can perform the same function as part of the hippocampus. Through bi-directional communication with other neural tissue that normally provides the inputs and outputs to/from a damaged hippocampal area, the biomimetic model could serve as a neural prosthesis. A proof-of-concept will be presented in which the CA3 region of the hippocampal slice is surgically removed and is replaced by a microchip model of CA3 nonlinear dynamics--the "hybrid" hippocampal circuit displays normal physiological properties. How the work in brain slices is being extended to behaving animals also will be described.

Electronic control of gene expression and cell behaviour in Escherichia coli through redox signalling

NASA Astrophysics Data System (ADS)

Tschirhart, Tanya; Kim, Eunkyoung; McKay, Ryan; Ueda, Hana; Wu, Hsuan-Chen; Pottash, Alex Eli; Zargar, Amin; Negrete, Alejandro; Shiloach, Joseph; Payne, Gregory F.; Bentley, William E.

2017-01-01

The ability to interconvert information between electronic and ionic modalities has transformed our ability to record and actuate biological function. Synthetic biology offers the potential to expand communication `bandwidth' by using biomolecules and providing electrochemical access to redox-based cell signals and behaviours. While engineered cells have transmitted molecular information to electronic devices, the potential for bidirectional communication stands largely untapped. Here we present a simple electrogenetic device that uses redox biomolecules to carry electronic information to engineered bacterial cells in order to control transcription from a simple synthetic gene circuit. Electronic actuation of the native transcriptional regulator SoxR and transcription from the PsoxS promoter allows cell response that is quick, reversible and dependent on the amplitude and frequency of the imposed electronic signals. Further, induction of bacterial motility and population based cell-to-cell communication demonstrates the versatility of our approach and potential to drive intricate biological behaviours.

Family Functioning in Suicidal Inpatients With Intimate Partner Violence

PubMed Central

Heru, Alison M.; Stuart, Gregory L.; Recupero, Patricia Ryan

2007-01-01

Background: Intimate partner violence (IPV) is commonly bidirectional with both partners perpetrating and being victims of aggressive behaviors. In these couples, family dysfunction is reported across a broad range of family functions: communication, intimacy, problem solving, expression or control of anger, and designation of relationship roles. This study reports on the perceived family functioning of suicidal inpatients. Method: In this descriptive, cross-sectional study of adult suicidal inpatients, participants completed assessments of recent IPV and family functioning. Recruited patients were between 18 and 65 years of age and English fluent, had suicidal ideation, and were living with an intimate partner for at least the past 6 months. Intimate partner violence was assessed using the Conflict Tactics Scale-Revised, and family functioning was measured using the McMaster Family Assessment Device. The study was conducted from August 2004 through February 2005. Results: In 110 inpatients with suicidal ideation and IPV, family functioning was perceived as poor across many domains, although patients did report family strengths. Gender differences were not found in the overall prevalence of IPV, but when the sample was divided into good and poor family functioning, women with poorer family functioning reported more psychological abuse by a partner. For both genders, physical and psychological victimization was associated with poorer family functioning. Conclusion: Among psychiatric inpatients with suicidal ideation, IPV occurred in relationships characterized by general dysfunction. Poorer general family functioning was associated with the perception of victimization for both genders. The high prevalence of bidirectional IPV highlights the need for the development of couples treatment for this population of suicidal psychiatric inpatients. PMID:18185819

Bidirectional and Asymmetric Controlled Quantum Information Transmission via Five-qubit Brown State

NASA Astrophysics Data System (ADS)

Fang, Sheng-hui; Jiang, Min

2017-05-01

We put forward a new protocol of deterministic controlled bidirectional quantum information transmission, using a five-qubit Brown state. That is to say Alice wants to teleport an arbitrary single-qubit state to Bob and Bob wants to remotely prepare a known state for Alice via the control of the supervisor Charlie. In terms of physical implementations, only a CNOT gate, one Bell-state measurement and one qubit measurement are used in our protocol. Compared with previous study for solely bidirectional quantum teleportation and solely bidirectional remote state preparation schemes, our protocol is a kind of hybrid approach of information communication which makes the quantum channel multipurpose, i.e., no matter whether the transmitted state is known or unknown, the state information can be transmitted with each other via a five-qubit Brown state under the control of the third party as a supervisor.

The Bloomsburg University Goniometer (B.U.G.) Laboratory: An Integrated Laboratory for Measuring Bidirectional Reflectance Functions

NASA Technical Reports Server (NTRS)

Shepard, M. K.

2001-01-01

We have constructed a photometric goniometer for measuring the full bidirectional reflectance function of planetary analog materials. Additional information is contained in the original extended abstract.

Bidirectional communication between amygdala and fusiform gyrus during facial recognition.

PubMed

Herrington, John D; Taylor, James M; Grupe, Daniel W; Curby, Kim M; Schultz, Robert T

2011-06-15

Decades of research have documented the specialization of fusiform gyrus (FG) for facial information processes. Recent theories indicate that FG activity is shaped by input from amygdala, but effective connectivity from amygdala to FG remains undocumented. In this fMRI study, 39 participants completed a face recognition task. 11 participants underwent the same experiment approximately four months later. Robust face-selective activation of FG, amygdala, and lateral occipital cortex were observed. Dynamic causal modeling and Bayesian Model Selection (BMS) were used to test the intrinsic connections between these structures, and their modulation by face perception. BMS results strongly favored a dynamic causal model with bidirectional, face-modulated amygdala-FG connections. However, the right hemisphere connections diminished at time 2, with the face modulation parameter no longer surviving Bonferroni correction. These findings suggest that amygdala strongly influences FG function during face perception, and that this influence is shaped by experience and stimulus salience. Copyright © 2011 Elsevier Inc. All rights reserved.

Nonverbal communicative signals modulate attention to object properties.

PubMed

Marno, Hanna; Davelaar, Eddy J; Csibra, Gergely

2014-04-01

We investigated whether the social context in which an object is experienced influences the encoding of its various properties. We hypothesized that when an object is observed in a communicative context, its intrinsic features (such as its shape) would be preferentially encoded at the expense of its extrinsic properties (such as its location). In 3 experiments, participants were presented with brief movies, in which an actor either performed a noncommunicative action toward 1 of 5 different meaningless objects, or communicatively pointed at 1 of them. A subsequent static image, in which either the location or the identity of an object changed, tested participants' attention to these 2 kinds of information. Throughout the 3 experiments we found that communicative cues tended to facilitate identity change detection and to impede location change detection, whereas in the noncommunicative contexts we did not find such a bidirectional effect of cueing. The results also revealed that the effect of the communicative context was a result the presence of ostensive-communicative signals before the object-directed action, and not to the pointing gesture per se. We propose that such an attentional bias forms an inherent part of human communication, and function to facilitate social learning by communication.

Analyzing Hedges in Verbal Communication: An Adaptation-Based Approach

ERIC Educational Resources Information Center

Wang, Yuling

2010-01-01

Based on Adaptation Theory, the article analyzes the production process of hedges. The procedure consists of the continuous making of choices in linguistic forms and communicative strategies. These choices are made just for adaptation to the contextual correlates. Besides, the adaptation process is dynamic, intentional and bidirectional.

Bi-directional gap junction-mediated soma-germline communication is essential for spermatogenesis.

PubMed

Smendziuk, Christopher M; Messenberg, Anat; Vogl, A Wayne; Tanentzapf, Guy

2015-08-01

Soma-germline interactions play conserved essential roles in regulating cell proliferation, differentiation, patterning and homeostasis in the gonad. In the Drosophila testis, secreted signalling molecules of the JAK-STAT, Hedgehog, BMP and EGF pathways are used to mediate soma-germline communication. Here, we demonstrate that gap junctions may also mediate direct, bi-directional signalling between the soma and germ line. When gap junctions between the soma and germ line are disrupted, germline differentiation is blocked and germline stem cells are not maintained. In the soma, gap junctions are required to regulate proliferation and differentiation. Localization and RNAi-mediated knockdown studies reveal that gap junctions in the fly testis are heterotypic channels containing Zpg (Inx4) and Inx2 on the germ line and the soma side, respectively. Overall, our results show that bi-directional gap junction-mediated signalling is essential to coordinate the soma and germ line to ensure proper spermatogenesis in Drosophila. Moreover, we show that stem cell maintenance and differentiation in the testis are directed by gap junction-derived cues. © 2015. Published by The Company of Biologists Ltd.

Precision Time Protocol-Based Trilateration for Planetary Navigation

NASA Technical Reports Server (NTRS)

Murdock, Ron

2015-01-01

Progeny Systems Corporation has developed a high-fidelity, field-scalable, non-Global Positioning System (GPS) navigation system that offers precision localization over communications channels. The system is bidirectional, providing position information to both base and mobile units. It is the first-ever wireless use of the Institute of Electrical and Electronics Engineers (IEEE) Precision Time Protocol (PTP) in a bidirectional trilateration navigation system. The innovation provides a precise and reliable navigation capability to support traverse-path planning systems and other mapping applications, and it establishes a core infrastructure for long-term lunar and planetary occupation. Mature technologies are integrated to provide navigation capability and to support data and voice communications on the same network. On Earth, the innovation is particularly well suited for use in unmanned aerial vehicles (UAVs), as it offers a non-GPS precision navigation and location service for use in GPS-denied environments. Its bidirectional capability provides real-time location data to the UAV operator and to the UAV. This approach optimizes assisted GPS techniques and can be used to determine the presence of GPS degradation, spoofing, or jamming.

Bidirectional reflection functions from surface bump maps

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

Cabral, B.; Max, N.; Springmeyer, R.

1987-04-29

The Torrance-Sparrow model for calculating bidirectional reflection functions contains a geometrical attenuation factor to account for shadowing and occlusions in a hypothetical distribution of grooves on a rough surface. Using an efficient table-based method for determining the shadows and occlusions, we calculate the geometric attenuation factor for surfaces defined by a specific table of bump heights. Diffuse and glossy specular reflection of the environment can be handled in a unified manner by using an integral of the bidirectional reflection function times the environmental illumination, over the hemisphere of solid angle above a surface. We present a method of estimating themore » integral, by expanding the bidirectional reflection coefficient in spherical harmonics, and show how the coefficients in this expansion can be determined efficiently by reorganizing our geometric attenuation calculation.« less

Behavioural conditioning of immune functions: how the central nervous system controls peripheral immune responses by evoking associative learning processes.

PubMed

Riether, Carsten; Doenlen, Raphaël; Pacheco-López, Gustavo; Niemi, Maj-Britt; Engler, Andrea; Engler, Harald; Schedlowski, Manfred

2008-01-01

During the last 30 years of psychoneuroimmunology research the intense bi-directional communication between the central nervous system (CNS) and the immune system has been demonstrated in studies on the interaction between the nervous-endocrine-immune systems. One of the most intriguing examples of such interaction is the capability of the CNS to associate an immune status with specific environmental stimuli. In this review, we systematically summarize experimental evidence demonstrating the behavioural conditioning of peripheral immune functions. In particular, we focus on the mechanisms underlying the behavioural conditioning process and provide a theoretical framework that indicates the potential feasibility of behaviourally conditioned immune changes in clinical situations.

PRELIMINARY RESULTS OF BTDF CALIBRATION OF TRANSMISSIVE SOLAR DIFFUSERS FOR REMOTE SENSING.

PubMed

Georgiev, Georgi T; Butler, James J; Thome, Kurt; Cooksey, Catherine; Ding, Leibo

2016-01-01

Satellite instruments operating in the reflected solar wavelength region require accurate and precise determination of the optical properties of their diffusers used in pre-flight and post-flight calibrations. The majority of recent and current space instruments use reflective diffusers. As a result, numerous Bidirectional Reflectance Distribution Function (BRDF) calibration comparisons have been conducted between the National Institute of Standards and Technology (NIST) and other industry and university-based metrology laboratories. However, based on literature searches and communications with NIST and other laboratories, no Bidirectional Transmittance Distribution Function (BTDF) measurement comparisons have been conducted between National Measurement Laboratories (NMLs) and other metrology laboratories. On the other hand, there is a growing interest in the use of transmissive diffusers in the calibration of satellite, air-borne, and ground-based remote sensing instruments. Current remote sensing instruments employing transmissive diffusers include the Ozone Mapping and Profiler Suite instrument (OMPS) Limb instrument on the Suomi-National Polar-orbiting Partnership (S-NPP) platform,, the Geostationary Ocean Color Imager (GOCI) on the Korea Aerospace Research Institute's (KARI) Communication, Ocean, and Meteorological Satellite (COMS), the Ozone Monitoring Instrument (OMI) on NASA's Earth Observing System (EOS) Aura platform, the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument and the Geostationary Environmental Monitoring Spectrometer (GEMS).. This ensemble of instruments requires validated BTDF measurements of their on-board transmissive diffusers from the ultraviolet through the near infrared. This paper presents the preliminary results of a BTDF comparison between the NASA Diffuser Calibration Laboratory (DCL) and NIST on quartz and thin Spectralon samples.

Preliminary Results of BTDF Calibration of Transmissive Solar Diffusers for Remote Sensing

NASA Technical Reports Server (NTRS)

Georgiev, Georgi T.; Butler, James J.; Thome, Kurt; Cooksey, Catherine; Ding, Leibo

2016-01-01

Satellite instruments operating in the reflected solar wavelength region require accurate and precise determination of the optical properties of their diffusers used in pre-flight and post-flight calibrations. The majority of recent and current space instruments use reflective diffusers. As a result, numerous Bidirectional Reflectance Distribution Function (BRDF) calibration comparisons have been conducted between the National Institute of Standards and Technology (NIST) and other industry and university-based metrology laboratories. However, based on literature searches and communications with NIST and other laboratories, no Bidirectional Transmittance Distribution Function (BTDF) measurement comparisons have been conducted between National Measurement Laboratories (NMLs) and other metrology laboratories. On the other hand, there is a growing interest in the use of transmissive diffusers in the calibration of satellite, air-borne, and ground-based remote sensing instruments. Current remote sensing instruments employing transmissive diffusers include the Ozone Mapping and Profiler Suite instrument (OMPS) Limb instrument on the Suomi-National Polar-orbiting Partnership (S-NPP) platform,, the Geostationary Ocean Color Imager (GOCI) on the Korea Aerospace Research Institute's (KARI) Communication, Ocean, and Meteorological Satellite (COMS), the Ozone Monitoring Instrument (OMI) on NASA's Earth Observing System (EOS) Aura platform, the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument and the Geostationary Environmental Monitoring Spectrometer (GEMS).. This ensemble of instruments requires validated BTDF measurements of their on-board transmissive diffusers from the ultraviolet through the near infrared. This paper presents the preliminary results of a BTDF comparison between the NASA Diffuser Calibration Laboratory (DCL) and NIST on quartz and thin Spectralon samples.

PRELIMINARY RESULTS OF BTDF CALIBRATION OF TRANSMISSIVE SOLAR DIFFUSERS FOR REMOTE SENSING

PubMed Central

Georgiev, Georgi T.; Butler, James J.; Thome, Kurt; Cooksey, Catherine; Ding, Leibo

2016-01-01

Satellite instruments operating in the reflected solar wavelength region require accurate and precise determination of the optical properties of their diffusers used in pre-flight and post-flight calibrations. The majority of recent and current space instruments use reflective diffusers. As a result, numerous Bidirectional Reflectance Distribution Function (BRDF) calibration comparisons have been conducted between the National Institute of Standards and Technology (NIST) and other industry and university-based metrology laboratories. However, based on literature searches and communications with NIST and other laboratories, no Bidirectional Transmittance Distribution Function (BTDF) measurement comparisons have been conducted between National Measurement Laboratories (NMLs) and other metrology laboratories. On the other hand, there is a growing interest in the use of transmissive diffusers in the calibration of satellite, air-borne, and ground-based remote sensing instruments. Current remote sensing instruments employing transmissive diffusers include the Ozone Mapping and Profiler Suite instrument (OMPS) Limb instrument on the Suomi-National Polar-orbiting Partnership (S-NPP) platform,, the Geostationary Ocean Color Imager (GOCI) on the Korea Aerospace Research Institute’s (KARI) Communication, Ocean, and Meteorological Satellite (COMS), the Ozone Monitoring Instrument (OMI) on NASA’s Earth Observing System (EOS) Aura platform, the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument and the Geostationary Environmental Monitoring Spectrometer (GEMS).. This ensemble of instruments requires validated BTDF measurements of their on-board transmissive diffusers from the ultraviolet through the near infrared. This paper presents the preliminary results of a BTDF comparison between the NASA Diffuser Calibration Laboratory (DCL) and NIST on quartz and thin Spectralon samples. PMID:28003712

The interplay between neurons and glia in synapse development and plasticity.

PubMed

Stogsdill, Jeff A; Eroglu, Cagla

2017-02-01

In the brain, the formation of complex neuronal networks amenable to experience-dependent remodeling is complicated by the diversity of neurons and synapse types. The establishment of a functional brain depends not only on neurons, but also non-neuronal glial cells. Glia are in continuous bi-directional communication with neurons to direct the formation and refinement of synaptic connectivity. This article reviews important findings, which uncovered cellular and molecular aspects of the neuron-glia cross-talk that govern the formation and remodeling of synapses and circuits. In vivo evidence demonstrating the critical interplay between neurons and glia will be the major focus. Additional attention will be given to how aberrant communication between neurons and glia may contribute to neural pathologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bidirectional electric communication between the inferior occipital gyrus and the amygdala during face processing.

PubMed

Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Matsuda, Kazumi; Usui, Keiko; Usui, Naotaka; Inoue, Yushi; Toichi, Motomi

2017-09-01

Faces contain multifaceted information that is important for human communication. Neuroimaging studies have revealed face-specific activation in multiple brain regions, including the inferior occipital gyrus (IOG) and amygdala; it is often assumed that these regions constitute the neural network responsible for the processing of faces. However, it remains unknown whether and how these brain regions transmit information during face processing. This study investigated these questions by applying dynamic causal modeling of induced responses to human intracranial electroencephalography data recorded from the IOG and amygdala during the observation of faces, mosaics, and houses in upright and inverted orientations. Model comparisons assessing the experimental effects of upright faces versus upright houses and upright faces versus upright mosaics consistently indicated that the model having face-specific bidirectional modulatory effects between the IOG and amygdala was the most probable. The experimental effect between upright versus inverted faces also favored the model with bidirectional modulatory effects between the IOG and amygdala. The spectral profiles of modulatory effects revealed both same-frequency (e.g., gamma-gamma) and cross-frequency (e.g., theta-gamma) couplings. These results suggest that the IOG and amygdala communicate rapidly with each other using various types of oscillations for the efficient processing of faces. Hum Brain Mapp 38:4511-4524, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Bi-directionally protective communication between neurons and astrocytes under ischemia.

PubMed

Wu, Xiao-Mei; Qian, Christopher; Zhou, Yu-Fu; Yan, Yick-Chun; Luo, Qian-Qian; Yung, Wing-Ho; Zhang, Fa-Li; Jiang, Li-Rong; Qian, Zhong Ming; Ke, Ya

2017-10-01

The extensive existing knowledge on bi-directional communication between astrocytes and neurons led us to hypothesize that not only ischemia-preconditioned (IP) astrocytes can protect neurons but also IP neurons protect astrocytes from lethal ischemic injury. Here, we demonstrated for the first time that neurons have a significant role in protecting astrocytes from ischemic injury. The cultured medium from IP neurons (IPcNCM) induced a remarkable reduction in LDH and an increase in cell viability in ischemic astrocytes in vitro. Selective neuronal loss by kainic acid injection induced a significant increase in apoptotic astrocyte numbers in the brain of ischemic rats in vivo. Furthermore, TUNEL analysis, DNA ladder assay, and the measurements of ROS, GSH, pro- and anti-apoptotic factors, anti-oxidant enzymes and signal molecules in vitro and/or in vivo demonstrated that IP neurons protect astrocytes by an EPO-mediated inhibition of pro-apoptotic signals, activation of anti-apoptotic proteins via the P13K/ERK/STAT5 pathways and activation of anti-oxidant proteins via up-regulation of anti-oxidant enzymes. We demonstrated the existence of astro-protection by IP neurons under ischemia and proposed that the bi-directionally protective communications between cells might be a common activity in the brain or peripheral organs under most if not all pathological conditions. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

A reference standard for bidirectional reflection distribution function and bidirectional transmission distribution function measurement

NASA Technical Reports Server (NTRS)

Witherow, William K. (Inventor)

1988-01-01

A Lambertian reference standard for uniformly scattering a beam of light is constructed of a plate having a planar surface with a layer of glue disposed on the surface. An evenly packed layer of monodisperse spheres is set in the layer, and when the standard is used for bi-directional (BRDF) measurements, the spheres are coated with a layer of highly relective substance, such as gold or silver. When the standard is used for bi-directional transmittance distribution function (BTDF) measurements, the spheres are of a transparent material and are provided with a roughened surface, as by acid etching. In this case, the layer of glue is an optical cement, and the plate is of glass, with the spheres, the layer, and the plate all possessing a similar refractive index.

Bidirectional private key exchange using delay-coupled semiconductor lasers.

PubMed

Porte, Xavier; Soriano, Miguel C; Brunner, Daniel; Fischer, Ingo

2016-06-15

We experimentally demonstrate a key exchange cryptosystem based on the phenomenon of identical chaos synchronization. In our protocol, the private key is symmetrically generated by the two communicating partners. It is built up from the synchronized bits occurring between two current-modulated bidirectionally coupled semiconductor lasers with additional self-feedback. We analyze the security of the exchanged key and discuss the amplification of its privacy. We demonstrate private key generation rates up to 11  Mbit/s over a public channel.

Language Learning by Dint of Social Cognitive Advancement

ERIC Educational Resources Information Center

Mathew, Bincy; Raja, B. William Dharma

2015-01-01

Language is of vital importance to human beings. It is a means of communication and it has specific cognitive links. Advanced social cognition is necessary for children to acquire language, and sophisticated mind-reading abilities to assume word meanings and communicate pragmatically. Language can be defined as a bi-directional system that permits…

Generic Service Integration in Adaptive Learning Experiences Using IMS Learning Design

ERIC Educational Resources Information Center

de-la-Fuente-Valentin, Luis; Pardo, Abelardo; Kloos, Carlos Delgado

2011-01-01

IMS Learning Design is a specification to capture the orchestration taking place in a learning scenario. This paper presents an extension called Generic Service Integration. This paradigm allows a bidirectional communication between the course engine in charge of the orchestration and conventional Web 2.0 tools. This communication allows the…

Bi-directional exchange of membrane components occurs during co-culture of mesenchymal stem cells and nucleus pulposus cells.

PubMed

Strassburg, Sandra; Hodson, Nigel W; Hill, Patrick I; Richardson, Stephen M; Hoyland, Judith A

2012-01-01

Mesenchymal stem cell (MSC)-based therapies have been proposed as novel treatments for intervertebral disc (IVD) degeneration. We have previously demonstrated that when MSCs are co-cultured with nucleus pulposus (NP) cells with direct cell-cell contact, they differentiate along the NP lineage and simultaneously stimulate the degenerate NP cell population to regain a normal (non-degenerate) phenotype, an effect which requires cell-cell communication. However, the mechanisms by which NP cells and MSCs interact in this system are currently unclear. Thus, in this study we investigated a range of potential mechanisms for exchange of cellular components or information that may direct these changes, including cell fusion, gap-junctional communication and exchange of membrane components by direct transfer or via microvesicle formation. Flow cytometry of fluorescently labeled MSCs and NP cells revealed evidence of some cell fusion and formation of gapjunctions, although at the three timepoints studied these phenomena were detectable only in a small proportion of cells. While these mechanisms may play a role in cell-cell communication, the data suggests they are not the predominant mechanism of interaction. However, flow cytometry of fluorescently dual-labeled cells showed that extensive bi-directional transfer of membrane components is operational during direct co-culture of MSCs and NP cells. Furthermore, there was also evidence for secretion and internalization of membrane-bound microvesicles by both cell types. Thus, this study highlights bi-directional intercellular transfer of membrane components as a possible mechanism of cellular communication between MSC and NP cells.

Bidirectional plant canopy reflection models derived from the radiation transfer equation

NASA Technical Reports Server (NTRS)

Beeth, D. R.

1975-01-01

A collection of bidirectional canopy reflection models was obtained from the solution of the radiation transfer equation for a horizontally homogeneous canopy. A phase function is derived for a collection of bidirectionally reflecting and transmitting planar elements characterized geometrically by slope and azimuth density functions. Two approaches to solving the radiation transfer equation for the canopy are presented. One approach factors the radiation transfer equation into a solvable set of three first-order linear differential equations by assuming that the radiation field within the canopy can be initially approximated by three components: uniformly diffuse downwelling, uniformly diffuse upwelling, and attenuated specular. The solution to these equations, which can be iterated to any degree of accuracy, was used to obtain overall canopy reflection from the formal solution to the radiation transfer equation. A programable solution to canopy overall bidirectional reflection is given for this approach. The special example of Lambertian leaves with constant leaf bidirectional reflection and scattering functions is considered, and a programmable solution for this example is given. The other approach to solving the radiation transfer equation, a generalized Chandrasekhar technique, is presented in the appendix.

The Bi-Directional Prediction of Carbon Fiber Production Using a Combination of Improved Particle Swarm Optimization and Support Vector Machine.

PubMed

Xiao, Chuncai; Hao, Kuangrong; Ding, Yongsheng

2014-12-30

This paper creates a bi-directional prediction model to predict the performance of carbon fiber and the productive parameters based on a support vector machine (SVM) and improved particle swarm optimization (IPSO) algorithm (SVM-IPSO). In the SVM, it is crucial to select the parameters that have an important impact on the performance of prediction. The IPSO is proposed to optimize them, and then the SVM-IPSO model is applied to the bi-directional prediction of carbon fiber production. The predictive accuracy of SVM is mainly dependent on its parameters, and IPSO is thus exploited to seek the optimal parameters for SVM in order to improve its prediction capability. Inspired by a cell communication mechanism, we propose IPSO by incorporating information of the global best solution into the search strategy to improve exploitation, and we employ IPSO to establish the bi-directional prediction model: in the direction of the forward prediction, we consider productive parameters as input and property indexes as output; in the direction of the backward prediction, we consider property indexes as input and productive parameters as output, and in this case, the model becomes a scheme design for novel style carbon fibers. The results from a set of the experimental data show that the proposed model can outperform the radial basis function neural network (RNN), the basic particle swarm optimization (PSO) method and the hybrid approach of genetic algorithm and improved particle swarm optimization (GA-IPSO) method in most of the experiments. In other words, simulation results demonstrate the effectiveness and advantages of the SVM-IPSO model in dealing with the problem of forecasting.

TESAT laser communication terminal performance results on 5.6Gbit coherent inter satellite and satellite to ground links

NASA Astrophysics Data System (ADS)

Gregory, M.; Heine, F.; Kämpfner, H.; Meyer, R.; Fields, R.; Lunde, C.

2017-11-01

The increasing demand on high speed communication networks has stimulated the development of optical free space data transmission during the last years. TESAT has developed a laser communication terminal (LCT) that fulfills the need of a power efficient system whose capability has been successfully demonstrated at bidirectional space-to-space links and bidirectional space-to-ground links (SGLs) at a data rate of 5.625 GBit/s with a homodyne detection scheme and a BPSK modulation format. In comparison to a direct detection system, the homodyne detection scheme works as a bandpass filter. The transmission is immune to false light and even data transmission with the sun in the receiver field of view (FOV) is possible. Compared to common RF transmission which is implemented on spacecrafts for data transmission, optical transmission provides not only higher transmission rates (factor 10) but also shows excellent security features since the laser beams directivity making it immune to interception.

Submicron bidirectional all-optical plasmonic switches

PubMed Central

Chen, Jianjun; Li, Zhi; Zhang, Xiang; Xiao, Jinghua; Gong, Qihuang

2013-01-01

Ultra-small all-optical switches are of importance in highly integrated optical communication and computing networks. However, the weak nonlinear light-matter interactions in natural materials present an enormous challenge to realize efficiently switching for the ultra-short interaction lengths. Here, we experimentally demonstrate a submicron bidirectional all-optical plasmonic switch with an asymmetric T-shape single slit. Sharp asymmetric spectra as well as significant field enhancements (about 18 times that in the conventional slit case) occur in the symmetry-breaking structure. Consequently, both of the surface plasmon polaritons propagating in the opposite directions on the metal surface are all-optically controlled inversely at the same time with the on/off switching ratios of >6 dB for the device lateral dimension of <1 μm. Moreover, in such a submicron structure, the coupling of free-space light and the on-chip bidirectional switching are integrated together. This submicron bidirectional all-optical switch may find important applications in the highly integrated plasmonic circuits. PMID:23486232

An Augmented Lecture Feedback System to Support Learner and Teacher Communication

ERIC Educational Resources Information Center

Zarraonandia, Telmo; Aedo, Ignacio; Diaz, Paloma; Montero, Alvaro

2013-01-01

In this paper, it is advocated that the feedback loop between learners and teachers could be improved by making use of augmented reality (AR) techniques. The bidirectional communication between teacher and learners is sometimes hampered by students' fear of showing themselves up in front of their classmates. In order to overcome this problem, a…

Results of Kirari optical communication demonstration experiments with NICT optical ground station (KODEN) aiming for future classical and quantum communications in space

NASA Astrophysics Data System (ADS)

Toyoshima, Morio; Takenaka, Hideki; Shoji, Yozo; Takayama, Yoshihisa; Koyama, Yoshisada; Kunimori, Hiroo

2012-05-01

Bi-directional ground-to-satellite laser communication experiments were successfully performed between the optical ground station developed by the National Institute of Information and Communications Technology (NICT), located in Koganei City in suburban Tokyo, and a low earth orbit (LEO) satellite, the "Kirari" Optical Inter-orbit Communications Engineering Test Satellite (OICETS). The experiments were conducted in cooperation with the Japan Aerospace Exploration Agency (JAXA), and called the Kirari Optical communication Demonstration Experiments with the NICT optical ground station (or KODEN). The ground-to-OICETS laser communication experiment was the first in-orbit demonstration involving the LEO satellite. The laser communication experiment was conducted since March 2006. The polarization characteristics of an artificial laser source in space, such as Stokes parameters, and the degree of polarization were measured through space-to-ground atmospheric transmission paths, which results contribute to the link estimation for quantum key distribution via space and provide the potential for enhancements in quantum cryptography on a global scale in the future. The Phase-5 experiment, international laser communications experiments were also successfully conducted with four optical ground stations located in the United States, Spain, Germany, and Japan from April 2009 to September 2009. The purpose of the Phase-5 experiment was to establish OICETS-to-ground laser communication links from the different optical ground stations and the statistical analyses such as the normalized power, scintillation index, probability density function, auto-covariance function, and power spectral density were performed. Thus the applicability of the satellite laser communications was demonstrated, aiming not only for geostationary earth orbit-LEO links but also for ground-to-LEO optical links. This paper presents the results of the KODEN experiments and mainly introduces the common analyses among the different optical ground stations.

Modulation of Gut Microbiota-Brain Axis by Probiotics, Prebiotics, and Diet.

PubMed

Liu, Xiaofei; Cao, Shangqing; Zhang, Xuewu

2015-09-16

There exists a bidirectional communication system between the gastrointestinal tract and the brain. Increasing evidence shows that gut microbiota can play a critical role in this communication; thus, the concept of a gut microbiota and brain axis is emerging. Here, we review recent findings in the relationship between intestinal microbes and brain function, such as anxiety, depression, stress, autism, learning, and memory. We highlight the advances in modulating brain development and behavior by probiotics, prebiotics, and diet through the gut microbiota-brain axis. A variety of mechanisms including immune, neural, and metabolic pathways may be involved in modulation of the gut microbiota-brain axis. We also discuss some future challenges. A deeper understanding of the relationship between the gut bacteria and their hosts is implicated in developing microbial-based therapeutic strategies for brain disorders.

Spatial Distribution and Receptor Specificity of Zebrafish Kit System - Evidence for a Kit-Mediated Bi-Directional Communication System in the Preovulatory Ovarian Follicle

PubMed Central

Yao, Kai; Ge, Wei

2013-01-01

Consisting of Kit ligand and receptor Kit, the Kit system is involved in regulating many ovarian functions such as follicle activation, granulosa cell proliferation, and oocyte growth and maturation. In mammals, Kit ligand is derived from the granulosa cells and Kit receptor is expressed in the oocyte and theca cells. In the zebrafish, the Kit system contains two ligands (Kitlga and Kitlgb) and two receptors (Kita and Kitb). Interestingly, Kitlga and Kitb are localized in the somatic follicle cells, but Kitlgb and Kita are expressed in the oocyte. Using recombinant zebrafish Kitlga and Kitlgb, we demonstrated that Kitlga preferentially activated Kita whereas Kitlgb specifically activated Kitb by Western analysis for receptor phosphorylation. In support of this, Kitlgb triggered a stronger and longer MAPK phosphorylation in follicle cells than Kitlga, whereas Kitlga but not Kitlgb activated MAPK in the denuded oocytes, in agreement with the distribution of Kita and Kitb in the follicle and their specificity for Kitlga and Kitlgb. Further analysis of the interaction between Kit ligands and receptors by homology modeling showed that Kitlga-Kita and Kitlgb-Kitb both have more stable electrostatic interaction than Kitlgb-Kita or Kitlga-Kitb. A functional study of Kit involvement in final oocyte maturation showed that Kitlga and Kitlgb both suppressed the spontaneous maturation significantly; in contrast, Kitlgb but not Kitlga significantly promoted 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) -induced oocyte maturation. Our results provided strong evidence for a Kit-mediated bi-directional communication system in the zebrafish ovarian follicle, which could be part of the complex interplay between the oocyte and the follicle cells in the development of follicles. PMID:23409152

Chaos synchronization communication using extremely unsymmetrical bidirectional injections.

PubMed

Zhang, Wei Li; Pan, Wei; Luo, Bin; Zou, Xi Hua; Wang, Meng Yao; Zhou, Zhi

2008-02-01

Chaos synchronization and message transmission between two semiconductor lasers with extremely unsymmetrical bidirectional injections (EUBIs) are discussed. By using EUBIs, synchronization is realized through injection locking. Numerical results show that if the laser subjected to strong injection serves as the receiver, chaos pass filtering (CPF) of the system is similar to that of unidirectional coupled systems. Moreover, if the other laser serves as the receiver, a stronger CPF can be obtained. Finally, we demonstrate that messages can be extracted successfully from either of the two transmission directions of the system.

Crosstalk between cancer and the neuro-immune system.

PubMed

Kuol, Nyanbol; Stojanovska, Lily; Apostolopoulos, Vasso; Nurgali, Kulmira

2018-02-15

In the last decade, understanding of cancer initiation and progression has been given much attention with studies mainly focusing on genetic abnormalities. Importantly, cancer cells can influence their microenvironment and bi-directionally communicate with other systems such as the immune system. The nervous system plays a fundamental role in regulating immune responses to a range of disease states including cancer. Its dysfunction influences the progression of cancer. The role of the immune system in tumor progression is of relevance to the nervous system since they can bi-directionally communicate via neurotransmitters and neuropeptides, common receptors, and, cytokines. However, cross-talk between these cells is highly complex in nature, and numerous variations are possible according to the type of cancer involved. The neuro-immune interaction is essential in influencing cancer development and progression. Copyright © 2017 Elsevier B.V. All rights reserved.

Full-Duplex Bidirectional Secure Communications Under Perfect and Distributionally Ambiguous Eavesdropper's CSI

NASA Astrophysics Data System (ADS)

Li, Qiang; Zhang, Ying; Lin, Jingran; Wu, Sissi Xiaoxiao

2017-09-01

Consider a full-duplex (FD) bidirectional secure communication system, where two communication nodes, named Alice and Bob, simultaneously transmit and receive confidential information from each other, and an eavesdropper, named Eve, overhears the transmissions. Our goal is to maximize the sum secrecy rate (SSR) of the bidirectional transmissions by optimizing the transmit covariance matrices at Alice and Bob. To tackle this SSR maximization (SSRM) problem, we develop an alternating difference-of-concave (ADC) programming approach to alternately optimize the transmit covariance matrices at Alice and Bob. We show that the ADC iteration has a semi-closed-form beamforming solution, and is guaranteed to converge to a stationary solution of the SSRM problem. Besides the SSRM design, this paper also deals with a robust SSRM transmit design under a moment-based random channel state information (CSI) model, where only some roughly estimated first and second-order statistics of Eve's CSI are available, but the exact distribution or other high-order statistics is not known. This moment-based error model is new and different from the widely used bounded-sphere error model and the Gaussian random error model. Under the consider CSI error model, the robust SSRM is formulated as an outage probability-constrained SSRM problem. By leveraging the Lagrangian duality theory and DC programming, a tractable safe solution to the robust SSRM problem is derived. The effectiveness and the robustness of the proposed designs are demonstrated through simulations.

Neurotransmitter-Triggered Transfer of Exosomes Mediates Oligodendrocyte–Neuron Communication

PubMed Central

Kuo, Wen Ping; Amphornrat, Jesa; Thilemann, Sebastian; Saab, Aiman S.; Kirchhoff, Frank; Möbius, Wiebke; Goebbels, Sandra; Nave, Klaus-Armin; Schneider, Anja; Simons, Mikael; Klugmann, Matthias; Trotter, Jacqueline; Krämer-Albers, Eva-Maria

2013-01-01

Reciprocal interactions between neurons and oligodendrocytes are not only crucial for myelination, but also for long-term survival of axons. Degeneration of axons occurs in several human myelin diseases, however the molecular mechanisms of axon-glia communication maintaining axon integrity are poorly understood. Here, we describe the signal-mediated transfer of exosomes from oligodendrocytes to neurons. These endosome-derived vesicles are secreted by oligodendrocytes and carry specific protein and RNA cargo. We show that activity-dependent release of the neurotransmitter glutamate triggers oligodendroglial exosome secretion mediated by Ca2+ entry through oligodendroglial NMDA and AMPA receptors. In turn, neurons internalize the released exosomes by endocytosis. Injection of oligodendroglia-derived exosomes into the mouse brain results in functional retrieval of exosome cargo in neurons. Supply of cultured neurons with oligodendroglial exosomes improves neuronal viability under conditions of cell stress. These findings indicate that oligodendroglial exosomes participate in a novel mode of bidirectional neuron-glia communication contributing to neuronal integrity. PMID:23874151

Neurotransmitter-triggered transfer of exosomes mediates oligodendrocyte-neuron communication.

PubMed

Frühbeis, Carsten; Fröhlich, Dominik; Kuo, Wen Ping; Amphornrat, Jesa; Thilemann, Sebastian; Saab, Aiman S; Kirchhoff, Frank; Möbius, Wiebke; Goebbels, Sandra; Nave, Klaus-Armin; Schneider, Anja; Simons, Mikael; Klugmann, Matthias; Trotter, Jacqueline; Krämer-Albers, Eva-Maria

2013-07-01

Reciprocal interactions between neurons and oligodendrocytes are not only crucial for myelination, but also for long-term survival of axons. Degeneration of axons occurs in several human myelin diseases, however the molecular mechanisms of axon-glia communication maintaining axon integrity are poorly understood. Here, we describe the signal-mediated transfer of exosomes from oligodendrocytes to neurons. These endosome-derived vesicles are secreted by oligodendrocytes and carry specific protein and RNA cargo. We show that activity-dependent release of the neurotransmitter glutamate triggers oligodendroglial exosome secretion mediated by Ca²⁺ entry through oligodendroglial NMDA and AMPA receptors. In turn, neurons internalize the released exosomes by endocytosis. Injection of oligodendroglia-derived exosomes into the mouse brain results in functional retrieval of exosome cargo in neurons. Supply of cultured neurons with oligodendroglial exosomes improves neuronal viability under conditions of cell stress. These findings indicate that oligodendroglial exosomes participate in a novel mode of bidirectional neuron-glia communication contributing to neuronal integrity.

Interdyad differences in early mother-infant face-to-face communication: real-time dynamics and developmental pathways.

PubMed

Lavelli, Manuela; Fogel, Alan

2013-12-01

A microgenetic research design with a multiple case study method and a combination of quantitative and qualitative analyses was used to investigate interdyad differences in real-time dynamics and developmental change processes in mother-infant face-to-face communication over the first 3 months of life. Weekly observations of 24 mother-infant dyads with analyses performed dyad by dyad showed that most dyads go through 2 qualitatively different developmental phases of early face-to-face communication: After a phase of mutual attentiveness, mutual engagement begins in Weeks 7-8, with infant smiling and cooing bidirectionally linked with maternal mirroring. This gives rise to sequences of positive feedback that, by the 3rd month, dynamically stabilizes into innovative play routines. However, when there is a lack of bidirectional positive feedback between infant and maternal behaviors, and a lack of permeability of the early communicative patterns to incorporate innovations, the development of the mutual engagement phase is compromised. The findings contribute both to theories of relationship change processes and to clinical work with at-risk mother-infant interactions. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Initial Studies of the Bidirectional Reflectance Distribution Function of Multi-Walled Carbon Nanotube Structures for Stray Light Control Applications

NASA Technical Reports Server (NTRS)

Butler, J. J.; Tveekrem, J. L.; Quijada, M. A.; Getty, S. A.; Hagopian, J. G.; Georglev, G. T.

2010-01-01

The presentation examines the application of low reflectance surfaces in optical instruments, multi-walled carbon nanotubes (MWCNTs), research objects, MWCNT samples, measurement of 8 deg. directional/hemispherical reflectance, measurement of bidirectional reflectance distribution function (BRDF), and what is current the "blackest ever black".

Bi-Directional Communication: A Critical Component of HAT

NASA Technical Reports Server (NTRS)

Shively, Robert J.

2016-01-01

Known problems with automation include lack of mode awareness, automation brittleness, and risk of miscalibrated trust. Human-Autonomy Teaming (HAT) is essential for improving these problems. This presentation outlines critical components for Human-Autonomy Teaming.

Advanced Pacemaker

NASA Technical Reports Server (NTRS)

1990-01-01

Synchrony, developed by St. Jude Medical's Cardiac Rhythm Management Division (formerly known as Pacesetter Systems, Inc.) is an advanced state-of-the-art implantable pacemaker that closely matches the natural rhythm of the heart. The companion element of the Synchrony Pacemaker System is the Programmer Analyzer APS-II which allows a doctor to reprogram and fine tune the pacemaker to each user's special requirements without surgery. The two-way communications capability that allows the physician to instruct and query the pacemaker is accomplished by bidirectional telemetry. APS-II features 28 pacing functions and thousands of programming combinations to accommodate diverse lifestyles. Microprocessor unit also records and stores pertinent patient data up to a year.

Bidirectional fiber-wireless and fiber-IVLLC integrated system based on polarization-orthogonal modulation scheme.

PubMed

Lu, Hai-Han; Li, Chung-Yi; Chen, Hwan-Wei; Ho, Chun-Ming; Cheng, Ming-Te; Huang, Sheng-Jhe; Yang, Zih-Yi; Lin, Xin-Yao

2016-07-25

A bidirectional fiber-wireless and fiber-invisible laser light communication (IVLLC) integrated system that employs polarization-orthogonal modulation scheme for hybrid cable television (CATV)/microwave (MW)/millimeter-wave (MMW)/baseband (BB) signal transmission is proposed and demonstrated. To our knowledge, it is the first one that adopts a polarization-orthogonal modulation scheme in a bidirectional fiber-wireless and fiber-IVLLC integrated system with hybrid CATV/MW/MMW/BB signal. For downlink transmission, carrier-to-noise ratio (CNR), composite second-order (CSO), composite triple-beat (CTB), and bit error rate (BER) perform well over 40-km single-mode fiber (SMF) and 10-m RF/50-m optical wireless transport scenarios. For uplink transmission, good BER performance is obtained over 40-km SMF and 50-m optical wireless transport scenario. Such a bidirectional fiber-wireless and fiber-IVLLC integrated system for hybrid CATV/MW/MMW/BB signal transmission will be an attractive alternative for providing broadband integrated services, including CATV, Internet, and telecommunication services. It is shown to be a prominent one to present the advancements for the convergence of fiber backbone and RF/optical wireless feeder.

Bidirectional Associations between Sleep (Quality and Duration) and Psychosocial Functioning across the University Years

ERIC Educational Resources Information Center

Tavernier, Royette; Willoughby, Teena

2014-01-01

Despite extensive research on sleep and psychosocial functioning, an important gap within the literature is the lack of inquiry into the direction of effects between these 2 constructs. The purpose of the present 3-year longitudinal study was to examine bidirectional associations between sleep (quality and duration) and 3 indices of psychosocial…

Adrenergic Blockade Bi-directionally and Asymmetrically Alters Functional Brain-Heart Communication and Prolongs Electrical Activities of the Brain and Heart during Asphyxic Cardiac Arrest

PubMed Central

Tian, Fangyun; Liu, Tiecheng; Xu, Gang; Li, Duan; Ghazi, Talha; Shick, Trevor; Sajjad, Azeem; Wang, Michael M.; Farrehi, Peter; Borjigin, Jimo

2018-01-01

Sudden cardiac arrest is a leading cause of death in the United States. The neurophysiological mechanism underlying sudden death is not well understood. Previously we have shown that the brain is highly stimulated in dying animals and that asphyxia-induced death could be delayed by blocking the intact brain-heart neuronal connection. These studies suggest that the autonomic nervous system plays an important role in mediating sudden cardiac arrest. In this study, we tested the effectiveness of phentolamine and atenolol, individually or combined, in prolonging functionality of the vital organs in CO2-mediated asphyxic cardiac arrest model. Rats received either saline, phentolamine, atenolol, or phentolamine plus atenolol, 30 min before the onset of asphyxia. Electrocardiogram (ECG) and electroencephalogram (EEG) signals were simultaneously collected from each rat during the entire process and investigated for cardiac and brain functions using a battery of analytic tools. We found that adrenergic blockade significantly suppressed the initial decline of cardiac output, prolonged electrical activities of both brain and heart, asymmetrically altered functional connectivity within the brain, and altered, bi-directionally and asymmetrically, functional, and effective connectivity between the brain and heart. The protective effects of adrenergic blockers paralleled the suppression of brain and heart connectivity, especially in the right hemisphere associated with central regulation of sympathetic function. Collectively, our results demonstrate that blockade of brain-heart connection via alpha- and beta-adrenergic blockers significantly prolonged the detectable activities of both the heart and the brain in asphyxic rat. The beneficial effects of combined alpha and beta blockers may help extend the survival of cardiac arrest patients. PMID:29487541

Adrenergic Blockade Bi-directionally and Asymmetrically Alters Functional Brain-Heart Communication and Prolongs Electrical Activities of the Brain and Heart during Asphyxic Cardiac Arrest.

PubMed

Tian, Fangyun; Liu, Tiecheng; Xu, Gang; Li, Duan; Ghazi, Talha; Shick, Trevor; Sajjad, Azeem; Wang, Michael M; Farrehi, Peter; Borjigin, Jimo

2018-01-01

Sudden cardiac arrest is a leading cause of death in the United States. The neurophysiological mechanism underlying sudden death is not well understood. Previously we have shown that the brain is highly stimulated in dying animals and that asphyxia-induced death could be delayed by blocking the intact brain-heart neuronal connection. These studies suggest that the autonomic nervous system plays an important role in mediating sudden cardiac arrest. In this study, we tested the effectiveness of phentolamine and atenolol, individually or combined, in prolonging functionality of the vital organs in CO 2 -mediated asphyxic cardiac arrest model. Rats received either saline, phentolamine, atenolol, or phentolamine plus atenolol, 30 min before the onset of asphyxia. Electrocardiogram (ECG) and electroencephalogram (EEG) signals were simultaneously collected from each rat during the entire process and investigated for cardiac and brain functions using a battery of analytic tools. We found that adrenergic blockade significantly suppressed the initial decline of cardiac output, prolonged electrical activities of both brain and heart, asymmetrically altered functional connectivity within the brain, and altered, bi-directionally and asymmetrically, functional, and effective connectivity between the brain and heart. The protective effects of adrenergic blockers paralleled the suppression of brain and heart connectivity, especially in the right hemisphere associated with central regulation of sympathetic function. Collectively, our results demonstrate that blockade of brain-heart connection via alpha- and beta-adrenergic blockers significantly prolonged the detectable activities of both the heart and the brain in asphyxic rat. The beneficial effects of combined alpha and beta blockers may help extend the survival of cardiac arrest patients.

Neural circuitry and immunity

PubMed Central

Pavlov, Valentin A.; Tracey, Kevin J.

2015-01-01

Research during the last decade has significantly advanced our understanding of the molecular mechanisms at the interface between the nervous system and the immune system. Insight into bidirectional neuroimmune communication has characterized the nervous system as an important partner of the immune system in the regulation of inflammation. Neuronal pathways, including the vagus nerve-based inflammatory reflex are physiological regulators of immune function and inflammation. In parallel, neuronal function is altered in conditions characterized by immune dysregulation and inflammation. Here, we review these regulatory mechanisms and describe the neural circuitry modulating immunity. Understanding these mechanisms reveals possibilities to use targeted neuromodulation as a therapeutic approach for inflammatory and autoimmune disorders. These findings and current clinical exploration of neuromodulation in the treatment of inflammatory diseases defines the emerging field of Bioelectronic Medicine. PMID:26512000

Bidirectional Reflectance Round-Robin in Support of the Earth Observing System Program

NASA Technical Reports Server (NTRS)

Early, E.; Barnes, P.; Johnson, B.; Butler, J.; Bruegge, C.; Biggar, S.; Spyak, P.; Pavlov, M.

1999-01-01

Laboratory measurements of the bidirectional reflectance distribution function (BRDRF) of diffuse reflectors are required to support calibration in the Earth Observing System (EOS) program of the National Aeronautics and Space Administration.

Performance Requirements for Emergency Responder Interoperable and Compatible Electronic Safety Equipment

NASA Technical Reports Server (NTRS)

Greenberg, Paul S.

2012-01-01

Firefighters and other emergency response personnel are presented with an increasing array of technologies to improve their health and safety. This includes real-time bidirectional communication, navigation and positional information, data on physiological and metabolic functions, as well as data on their surrounding environment. The emerging challenge is to integrate these elements into a practical system, addressing such features as power, data transfer, and inter-element coordination and communication. In many respects, NASA has addressed these aspects in the context of Extra Vehicular Activity (EVA). The EVA environment shares many common attributes with that of emergency response scenarios. A similar situation exists in terms of the need for interoperability among the various system sub-elements. A brief overview is presented on the similarities and differences in these two applications, as well as the technical approach adopted by NASA in terms of system design philosophy.

Sex differences in the gut microbiome-brain axis across the lifespan.

PubMed

Jašarević, Eldin; Morrison, Kathleen E; Bale, Tracy L

2016-02-19

In recent years, the bidirectional communication between the gut microbiome and the brain has emerged as a factor that influences immunity, metabolism, neurodevelopment and behaviour. Cross-talk between the gut and brain begins early in life immediately following the transition from a sterile in utero environment to one that is exposed to a changing and complex microbial milieu over a lifetime. Once established, communication between the gut and brain integrates information from the autonomic and enteric nervous systems, neuroendocrine and neuroimmune signals, and peripheral immune and metabolic signals. Importantly, the composition and functional potential of the gut microbiome undergoes many transitions that parallel dynamic periods of brain development and maturation for which distinct sex differences have been identified. Here, we discuss the sexually dimorphic development, maturation and maintenance of the gut microbiome-brain axis, and the sex differences therein important in disease risk and resilience throughout the lifespan. © 2016 The Author(s).

Experiences with real-time teleconsultation in neuroradiology

NASA Astrophysics Data System (ADS)

Stahl, Johannes N.; Zhang, Jianguo; Zhou, Xiaoqiang; Lou, Shyhliang A.; Huang, H. K.

1999-07-01

Real-time teleconsultation can be a useful tool for the handling of neuroradiological emergency case in remote locations. Unlike with teleradiology, which describes a mere transmission of images for remote review. Teleconsultation allows physicians to interactively discuss images and findings by means of image transmission, bi-directional remote manipulation and audiovisual communication. This paper describes the communication model, implementation and clinical evaluation of such a Teleconsultation system.

Bidirectional reflectance function in coastal waters: modeling and validation

NASA Astrophysics Data System (ADS)

Gilerson, Alex; Hlaing, Soe; Harmel, Tristan; Tonizzo, Alberto; Arnone, Robert; Weidemann, Alan; Ahmed, Samir

2011-11-01

The current operational algorithm for the correction of bidirectional effects from the satellite ocean color data is optimized for typical oceanic waters. However, versions of bidirectional reflectance correction algorithms, specifically tuned for typical coastal waters and other case 2 conditions, are particularly needed to improve the overall quality of those data. In order to analyze the bidirectional reflectance distribution function (BRDF) of case 2 waters, a dataset of typical remote sensing reflectances was generated through radiative transfer simulations for a large range of viewing and illumination geometries. Based on this simulated dataset, a case 2 water focused remote sensing reflectance model is proposed to correct above-water and satellite water leaving radiance data for bidirectional effects. The proposed model is first validated with a one year time series of in situ above-water measurements acquired by collocated multi- and hyperspectral radiometers which have different viewing geometries installed at the Long Island Sound Coastal Observatory (LISCO). Match-ups and intercomparisons performed on these concurrent measurements show that the proposed algorithm outperforms the algorithm currently in use at all wavelengths.

Communication strategies and timeliness of response to life critical telemetry alarms.

PubMed

Bonzheim, Kimberly A; Gebara, Rani I; O'Hare, Bridget M; Ellis, R Darin; Brand, Monique A; Balar, Salil D; Stockman, Rita; Sciberras, Annette M; Haines, David E

2011-05-01

A centralized electrocardiogram telemetry monitoring system (TMS) facilitates early identification of critical arrhythmias and acute medical decompensation. Timely intervention can only be performed if abnormalities are communicated rapidly to the direct caregiver. The study objectives were to measure effectiveness of bi-directional voice communication badges versus one-way alphanumeric pagers for telemetry alarm response and communication loop closure. A sequential observational pilot study of nursing response to TMS alarms compared communication technologies on four nursing units in a 1,061 bed tertiary care hospital with 264 TMS channels of telemetry over a 2-year period. Subsequently, the communication technologies were compared in a randomized fashion on a 68-bed progressive cardiac care unit. Caregivers were blinded to the protocol. All alarm responses were recorded during two periods using either pagers or voice communication devices. Alarm response time and closure of the communication loop were analyzed in a blinded fashion. The direct communication functionality of the badge significantly shortened the time to first contact, time to completion, and rate of closure of the communication loop in both the pilot and study phases. Median time to first contact with the communication badge was 0.5  min, compared to 1.6  min with pager communication (p < 0.0003). Communication loop closure was achieved in 100% of clinical alarms using the badge versus 19% with the pager (p < 0.0001). Communication badge technology reduced alarm time to first contact and completion as well as facilitated communication loop closures. Immediate two-way communication significantly impacted practice, alarm management, and resulted in faster bedside care.

Controlled Bidirectional Hybrid of Remote State Preparation and Quantum Teleportation via Seven-Qubit Entangled State

NASA Astrophysics Data System (ADS)

Wu, Hao; Zha, Xin-Wei; Yang, Yu-Quan

2018-01-01

We propose a new protocol of implementing four-party controlled joint remote state preparation and meanwhile realizing controlled quantum teleportation via a seven-qubit entangled state. That is to say, Alice wants to teleport an arbitrary single-qubit state to Bob and Bob wants to remotely prepare a known state for Alice via the control of supervisors Fred and David. Compared with previous studies for the schemes of solely bidirectional quantum teleportation and remote state preparation, the new protocol is a kind of hybrid approach of information communication which makes the quantum channel multipurpose.

The ACR-NEMA Digital Imaging And Communications Standard: Evolution, Overview And Implementation Considerations

NASA Astrophysics Data System (ADS)

Alzner, Edgar; Murphy, Laura

1986-06-01

The growing digital nature of radiology images led to a recognition that compatibility of communication between imaging, display and data storage devices of different modalities and different manufacturers is necessary. The ACR-NEMA Digital Imaging and Communications Standard Committee was formed to develop a communications standard for radiological images. This standard includes the overall structure of a communication message and the protocols for bi-directional communication using end-to-end connections. The evolution and rationale of the ACR-NEMA Digital Imaging and Communication Standard are described. An overview is provided and sane practical implementation considerations are discussed. PACS will became reality only if the medical community accepts and implements the ACR-NEMA Standard.

Star-coupled Hindmarsh-Rose neural network with chemical synapses

NASA Astrophysics Data System (ADS)

Usha, K.; Subha, P. A.

We analyze the patterns like synchrony, desynchrony, and Drum head mode in a network of Hindmarsh-Rose (HR) neurons interacting via chemical synapse in unidirectional and bidirectional star topology. A two-coupled system has been studied for synchronization by varying the coupling strength and the parameter describing the activation and inactivation of the fast ion channel. The transverse Lyapunov exponent spectrum is plotted to observe the point of transition from desynchrony to synchrony. The synchronized, desynchronized, and drum head mode regions are observed when the neurons are connected in unidirectional and bidirectional coupling configurations. A detailed analysis about the time evolution of membrane potential corresponding to each region is presented. The annihilation of synchronized region and the expansion of drum head mode region in bidirectional coupling is discussed using parameter space. Our work provides finer insight into the existence and stability of Drum head mode and is useful for designing communication networks.

A Novel User Created Message Application Service Design for Bidirectional TPEG

NASA Astrophysics Data System (ADS)

Lee, Sang-Hee; Jo, Kang-Hyun

The T-DMB (Terrestrial-Digital Multimedia Broadcasting) is the national service, currently successful in use in Korea since 2008. Among other services, TPEG (Transport Protocol Experts Group) service has been spotlighted in the aspects of creating earnings. At present, TPEG service is not so popular as it fails to satisfy the user’s demands on various aspects. Thus, the variety of services including bidirectional service is necessary in stage of DMB2.0. In this paper, the limitations of existing TPEG-POI (Point of Interest) application service using the wireless communication network are indicated. To overcome such limitations, we propose a business model for TPEG-UCM (User Created Message) application service which uses individual bidirectional media. The experiment shown in this paper proves the usability and operability of the proposed method, suggesting that the implementation of the proposed method would be overcome a lack of variety and unidirectional of existing TPEG application.

Modulating the function of the immune system by thyroid hormones and thyrotropin.

PubMed

Jara, Evelyn L; Muñoz-Durango, Natalia; Llanos, Carolina; Fardella, Carlos; González, Pablo A; Bueno, Susan M; Kalergis, Alexis M; Riedel, Claudia A

2017-04-01

Accumulating evidence suggests a close bidirectional communication and regulation between the neuroendocrine and immune systems. Thyroid hormones (THs) can exert responses in various immune cells, e.g., monocytes, macrophages, natural killer cells, and lymphocytes, affecting several inflammation-related processes (such as, chemotaxis, phagocytosis, reactive oxygen species generation, and cytokines production). The interactions between the endocrine and immune systems have been shown to contribute to pathophysiological conditions, including sepsis, inflammation, autoimmune diseases and viral infections. Under these conditions, TH therapy could contribute to restoring normal physiological functions. Here we discuss the effects of THs and thyroid stimulating hormone (TSH) on the immune system and the contribution to inflammation and pathogen clearance, as well as the consequences of thyroid pathologies over the function of the immune system. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Open communication: Recommendations for enhancing communication among primary care and mental health providers, services, and systems.

PubMed

Wong, Shale L; Talmi, Ayelet

2015-06-01

Comments on the article "Please break the silence: Parents' views on communication between pediatric primary care and mental health providers" by Greene et al. (see record 2015-14521-001). The article highlights the need to improve communication between primary care and mental health care providers to better serve children and families. The report reaffirms that parents understand the value and necessity of collaborative care, as evidenced by the identification of gaps in consistency of bidirectional communication between providers in traditional and separate practice settings and the desire for improved care coordination. (c) 2015 APA, all rights reserved).

Implications for bidirectional signaling between afferent nerves and urothelial cells-ICI-RS 2014.

PubMed

Kanai, Anthony; Fry, Christopher; Ikeda, Youko; Kullmann, Florenta Aura; Parsons, Brian; Birder, Lori

2016-02-01

To present a synopsis of the presentations and discussions from Think Tank I, "Implications for afferent-urothelial bidirectional communication" of the 2014 International Consultation on Incontinence-Research Society (ICI-RS) meeting in Bristol, UK. The participants presented what is new, currently understood or still unknown on afferent-urothelial signaling mechanisms. New avenues of research and experimental methodologies that are or could be employed were presented and discussed. It is clear that afferent-urothelial interactions are integral to the regulation of normal bladder function and that its disruption can have detrimental consequences. The urothelium is capable of releasing numerous signaling factors that can affect sensory neurons innervating the suburothelium. However, the understanding of how factors released from urothelial cells and afferent nerve terminals regulate one another is incomplete. Utilization of techniques such as viruses that genetically encode Ca(2+) sensors, based on calmodulin and green fluorescent protein, has helped to address the cellular mechanisms involved. Additionally, the epithelial-neuronal interactions in the urethra may also play a significant role in lower urinary tract regulation and merit further investigation. The signaling capabilities of the urothelium and afferent nerves are well documented, yet how these signals are integrated to regulate bladder function is unclear. There is unquestionably a need for expanded methodologies to further our understanding of lower urinary tract sensory mechanisms and their contribution to various pathologies. © 2016 Wiley Periodicals, Inc.

High-speed laser communications in UAV scenarios

NASA Astrophysics Data System (ADS)

Griethe, Wolfgang; Gregory, Mark; Heine, Frank; Kämpfner, Hartmut

2011-05-01

Optical links, based on coherent homodyne detection and BPSK modulation with bidirectional data transmission of 5.6 Gbps over distances of about 5,000 km and BER of 10-8, have been sufficiently verified in space. The verification results show that this technology is suitable not only for space applications but also for applications in the troposphere. After a brief description of the Laser Communication Terminal (LCT) for space applications, the paper consequently discusses the future utilization of satellite-based optical data links for Beyond Line of Sight (BLOS) operations of High Altitude Long Endurance (HALE) Unmanned Aerial Vehicles (UAV). It is shown that the use of optical frequencies is the only logical consequence of an ever-increasing demand for bandwidth. In terms of Network Centric Warfare it is highly recommended that Unmanned Aircraft Systems (UAS) of the future should incorporate that technology which allows almost unlimited bandwidth. The advantages of optical communications especially for Intelligence, Surveillance and Reconnaissance (ISR) are underlined. Moreover, the preliminary design concept of an airborne laser communication terminal is described. Since optical bi-directional links have been tested between a LCT in space and a TESAT Optical Ground Station (OGS), preliminary analysis on tracking and BER performance and the impact of atmospheric disturbances on coherent links will be presented.

Designing the Electronic Classroom.

ERIC Educational Resources Information Center

Adams, Laural L.

In an increasingly technological environment, traditional teaching presentation methods such as the podium, overhead, and transparencies are no longer sufficient. This document serves as a guide to designing and planning an electronic classroom for "bidirectional" communication between teacher and student. Topics include: (1) determining…

Bidirectional reflectance distribution function measurements and analysis of retroreflective materials.

PubMed

Belcour, Laurent; Pacanowski, Romain; Delahaie, Marion; Laville-Geay, Aude; Eupherte, Laure

2014-12-01

We compare the performance of various analytical retroreflecting bidirectional reflectance distribution function (BRDF) models to assess how they reproduce accurately measured data of retroreflecting materials. We introduce a new parametrization, the back vector parametrization, to analyze retroreflecting data, and we show that this parametrization better preserves the isotropy of data. Furthermore, we update existing BRDF models to improve the representation of retroreflective data.

The Neuro-endocrinological Role of Microbial Glutamate and GABA Signaling

PubMed Central

Mazzoli, Roberto; Pessione, Enrica

2016-01-01

Gut microbiota provides the host with multiple functions (e.g., by contributing to food digestion, vitamin supplementation, and defense against pathogenic strains) and interacts with the host organism through both direct contact (e.g., through surface antigens) and soluble molecules, which are produced by the microbial metabolism. The existence of the so-called gut–brain axis of bi-directional communication between the gastrointestinal tract and the central nervous system (CNS) also supports a communication pathway between the gut microbiota and neural circuits of the host, including the CNS. An increasing body of evidence has shown that gut microbiota is able to modulate gut and brain functions, including the mood, cognitive functions, and behavior of humans. Nonetheless, given the extreme complexity of this communication network, its comprehension is still at its early stage. The present contribution will attempt to provide a state-of-the art description of the mechanisms by which gut microbiota can affect the gut–brain axis and the multiple cellular and molecular communication circuits (i.e., neural, immune, and humoral). In this context, special attention will be paid to the microbial strains that produce bioactive compounds and display ascertained or potential probiotic activity. Several neuroactive molecules (e.g., catecholamines, histamine, serotonin, and trace amines) will be considered, with special focus on Glu and GABA circuits, receptors, and signaling. From the basic science viewpoint, “microbial endocrinology” deals with those theories in which neurochemicals, produced by both multicellular organisms and prokaryotes (e.g., serotonin, GABA, glutamate), are considered as a common shared language that enables interkingdom communication. With regards to its application, research in this area opens the way toward the possibility of the future use of neuroactive molecule-producing probiotics as therapeutic agents for the treatment of neurogastroenteric and/or psychiatric disorders. PMID:27965654

The Neuro-endocrinological Role of Microbial Glutamate and GABA Signaling.

PubMed

Mazzoli, Roberto; Pessione, Enrica

2016-01-01

Gut microbiota provides the host with multiple functions (e.g., by contributing to food digestion, vitamin supplementation, and defense against pathogenic strains) and interacts with the host organism through both direct contact (e.g., through surface antigens) and soluble molecules, which are produced by the microbial metabolism. The existence of the so-called gut-brain axis of bi-directional communication between the gastrointestinal tract and the central nervous system (CNS) also supports a communication pathway between the gut microbiota and neural circuits of the host, including the CNS. An increasing body of evidence has shown that gut microbiota is able to modulate gut and brain functions, including the mood, cognitive functions, and behavior of humans. Nonetheless, given the extreme complexity of this communication network, its comprehension is still at its early stage. The present contribution will attempt to provide a state-of-the art description of the mechanisms by which gut microbiota can affect the gut-brain axis and the multiple cellular and molecular communication circuits (i.e., neural, immune, and humoral). In this context, special attention will be paid to the microbial strains that produce bioactive compounds and display ascertained or potential probiotic activity. Several neuroactive molecules (e.g., catecholamines, histamine, serotonin, and trace amines) will be considered, with special focus on Glu and GABA circuits, receptors, and signaling. From the basic science viewpoint, "microbial endocrinology" deals with those theories in which neurochemicals, produced by both multicellular organisms and prokaryotes (e.g., serotonin, GABA, glutamate), are considered as a common shared language that enables interkingdom communication. With regards to its application, research in this area opens the way toward the possibility of the future use of neuroactive molecule-producing probiotics as therapeutic agents for the treatment of neurogastroenteric and/or psychiatric disorders.

Wireless opto-electro neural interface for experiments with small freely behaving animals.

PubMed

Jia, Yaoyao; Khan, Wasif; Lee, Byunghun; Fan, Bin; Madi, Fatma; Weber, Arthur; Li, Wen; Ghovanloo, Maysam

2018-05-25

We have developed a wireless opto-electro interface (WOENI) device, which combines electrocorticogram (ECoG) recording and optical stimulation for bi-directional neuromodulation on small, freely behaving animals, such as rodents. The device is comprised of two components, a detachable headstage and an implantable polyimide-based substrate. The headstage establishes a Bluetooth Low Energy (BLE) bi-directional data communication with an external custom-designed USB dongle for receiving user commands and optogenetic stimulation patterns, and sending digitalized ECoG data. The functionality and stability of the device were evaluated in vivo on freely behaving rats. When the animal received optical stimulation on the primary visual cortex (V1) and visual stimulation via eyes, spontaneous changes in ECoG signals were recorded from both left and right V1 during 4 consecutive experiments with 7-day intervals over a time span of 21 days following device implantation. Immunostained tissue analyses showed results consistent with ECoG analyses, validating the efficacy of optical stimulation to upregulate the activity of cortical neurons expressing ChR2. The proposed WOENI device is potentially a versatile tool in the studies that involve long-term optogenetic neuromodulation. © 2018 IOP Publishing Ltd.

Angular radiation models for Earth-atmosphere system. Volume 1: Shortwave radiation

NASA Technical Reports Server (NTRS)

Suttles, J. T.; Green, R. N.; Minnis, P.; Smith, G. L.; Staylor, W. F.; Wielicki, B. A.; Walker, I. J.; Young, D. F.; Taylor, V. R.; Stowe, L. L.

1988-01-01

Presented are shortwave angular radiation models which are required for analysis of satellite measurements of Earth radiation, such as those fro the Earth Radiation Budget Experiment (ERBE). The models consist of both bidirectional and directional parameters. The bidirectional parameters are anisotropic function, standard deviation of mean radiance, and shortwave-longwave radiance correlation coefficient. The directional parameters are mean albedo as a function of Sun zenith angle and mean albedo normalized to overhead Sun. Derivation of these models from the Nimbus 7 ERB (Earth Radiation Budget) and Geostationary Operational Environmental Satellite (GOES) data sets is described. Tabulated values and computer-generated plots are included for the bidirectional and directional modes.

Performance Evaluation of IEEE 802.11ah Networks With High-Throughput Bidirectional Traffic.

PubMed

Šljivo, Amina; Kerkhove, Dwight; Tian, Le; Famaey, Jeroen; Munteanu, Adrian; Moerman, Ingrid; Hoebeke, Jeroen; De Poorter, Eli

2018-01-23

So far, existing sub-GHz wireless communication technologies focused on low-bandwidth, long-range communication with large numbers of constrained devices. Although these characteristics are fine for many Internet of Things (IoT) applications, more demanding application requirements could not be met and legacy Internet technologies such as Transmission Control Protocol/Internet Protocol (TCP/IP) could not be used. This has changed with the advent of the new IEEE 802.11ah Wi-Fi standard, which is much more suitable for reliable bidirectional communication and high-throughput applications over a wide area (up to 1 km). The standard offers great possibilities for network performance optimization through a number of physical- and link-layer configurable features. However, given that the optimal configuration parameters depend on traffic patterns, the standard does not dictate how to determine them. Such a large number of configuration options can lead to sub-optimal or even incorrect configurations. Therefore, we investigated how two key mechanisms, Restricted Access Window (RAW) grouping and Traffic Indication Map (TIM) segmentation, influence scalability, throughput, latency and energy efficiency in the presence of bidirectional TCP/IP traffic. We considered both high-throughput video streaming traffic and large-scale reliable sensing traffic and investigated TCP behavior in both scenarios when the link layer introduces long delays. This article presents the relations between attainable throughput per station and attainable number of stations, as well as the influence of RAW, TIM and TCP parameters on both. We found that up to 20 continuously streaming IP-cameras can be reliably connected via IEEE 802.11ah with a maximum average data rate of 160 kbps, whereas 10 IP-cameras can achieve average data rates of up to 255 kbps over 200 m. Up to 6960 stations transmitting every 60 s can be connected over 1 km with no lost packets. The presented results enable the fine tuning of RAW and TIM parameters for throughput-demanding reliable applications (i.e., video streaming, firmware updates) on one hand, and very dense low-throughput reliable networks with bidirectional traffic on the other hand.

Performance Evaluation of IEEE 802.11ah Networks With High-Throughput Bidirectional Traffic

PubMed Central

Kerkhove, Dwight; Tian, Le; Munteanu, Adrian; De Poorter, Eli

2018-01-01

So far, existing sub-GHz wireless communication technologies focused on low-bandwidth, long-range communication with large numbers of constrained devices. Although these characteristics are fine for many Internet of Things (IoT) applications, more demanding application requirements could not be met and legacy Internet technologies such as Transmission Control Protocol/Internet Protocol (TCP/IP) could not be used. This has changed with the advent of the new IEEE 802.11ah Wi-Fi standard, which is much more suitable for reliable bidirectional communication and high-throughput applications over a wide area (up to 1 km). The standard offers great possibilities for network performance optimization through a number of physical- and link-layer configurable features. However, given that the optimal configuration parameters depend on traffic patterns, the standard does not dictate how to determine them. Such a large number of configuration options can lead to sub-optimal or even incorrect configurations. Therefore, we investigated how two key mechanisms, Restricted Access Window (RAW) grouping and Traffic Indication Map (TIM) segmentation, influence scalability, throughput, latency and energy efficiency in the presence of bidirectional TCP/IP traffic. We considered both high-throughput video streaming traffic and large-scale reliable sensing traffic and investigated TCP behavior in both scenarios when the link layer introduces long delays. This article presents the relations between attainable throughput per station and attainable number of stations, as well as the influence of RAW, TIM and TCP parameters on both. We found that up to 20 continuously streaming IP-cameras can be reliably connected via IEEE 802.11ah with a maximum average data rate of 160 kbps, whereas 10 IP-cameras can achieve average data rates of up to 255 kbps over 200 m. Up to 6960 stations transmitting every 60 s can be connected over 1 km with no lost packets. The presented results enable the fine tuning of RAW and TIM parameters for throughput-demanding reliable applications (i.e., video streaming, firmware updates) on one hand, and very dense low-throughput reliable networks with bidirectional traffic on the other hand. PMID:29360798

Discovery deep space optical communications (DSOC) transceiver

NASA Astrophysics Data System (ADS)

Roberts, W. Thomas

2017-02-01

NASA's 22 cm diameter Deep Space Optical Communications (DSOC) Transceiver is designed to provide a bidirectional optical link between a spacecraft in the inner solar system and an Earth-based optical ground station. This design, optimized for operation across a wide range of illumination conditions, is focused on minimizing blinding from stray light, and providing reliable, accurate attitude information to point its narrow communication beam accurately to the future location of the ground terminal. Though our transceiver will transmit in the 1550 nm waveband and receive in the 1064 nm waveband, the system design relies heavily on reflective optical elements, extending flexibility to be modified for use at different wavebands. The design makes use of common path propagation among transmit, receive and pointing verification optical channels to maintain precise alignment among its components, and to naturally correct for element misalignment resulting from launch or thermal element perturbations. This paper presents the results of trade studies showing the evolution of the design, unique operational characteristics of the design, elements that help to maintain minimal stray light contamination, and preliminary results from development and initial testing of a functional aluminum test model.

Microbiota-gut-brain axis and the central nervous system.

PubMed

Zhu, Xiqun; Han, Yong; Du, Jing; Liu, Renzhong; Jin, Ketao; Yi, Wei

2017-08-08

The gut and brain form the gut-brain axis through bidirectional nervous, endocrine, and immune communications. Changes in one of the organs will affect the other organs. Disorders in the composition and quantity of gut microorganisms can affect both the enteric nervous system and the central nervous system (CNS), thereby indicating the existence of a microbiota-gut-brain axis. Due to the intricate interactions between the gut and the brain, gut symbiotic microorganisms are closely associated with various CNS diseases, such as Parkinson's disease, Alzheimer's disease, schizophrenia, and multiple sclerosis. In this paper, we will review the latest advances of studies on the correlation between gut microorganisms and CNS functions & diseases.

Aeronautical-Satellite-Assisted Process Being Developed for Information Exchange Through Network Technologies (Aero-SAPIENT)

NASA Technical Reports Server (NTRS)

Zernic, Michael J.

2001-01-01

Communications technologies are being developed to address safety issues during aviation travel. Some of these technologies enable the aircraft to be in constant bidirectional communications with necessary systems, people, and other aircraft that are not currently in place today. Networking technologies, wireless datalinks, and advanced avionics techniques are areas of particular importance that the NASA Glenn Research Center has contributed. Glenn, in conjunction with the NASA Ames Research Center, NASA Dryden Flight Research Center, and NASA Langley Research Center, is investigating methods and applications that would utilize these communications technologies. In mid-June 2000, the flight readiness of the network and communications technologies were demonstrated via a simulated aircraft. A van simulating an aircraft was equipped with advanced phased-array antennas (Advanced Communications/Air Traffic Management (AC/ATM) Advanced Air Transportation Technologies (AATT) project) that used commercial Ku-band satellite communications to connect Glenn, Dryden, and Ames in a combined system ground test. This test simulated air-ground bidirectional transport of real-time digital audio, text, and video data via a hybrid network configuration that demonstrated the flight readiness of the network and communications technologies. Specifically, a Controller Pilot Data Link Communications application was used with other applications to demonstrate a multiprotocol capability via Internet-protocol encapsulated ATN (Aeronautical Telecommunications Network) data packets. The significance of this combined ground test is its contribution to the Aero Information Technology Base Program Level I milestone (Software Technology investment area) of a real-time data link for the National Airspace System. The objective of this milestone was to address multiprotocol technology applicable for real-time data links between aircraft, a satellite, and the ground as well as the ability to distribute flight data with multilevel priorities among several sites.

MEMS tracking mirror system for a bidirectional free-space optical link.

PubMed

Jeon, Sungho; Toshiyoshi, Hiroshi

2017-08-20

We report on a bidirectional free-space optical system that is capable of automatic connection and tracking of an optical link between two nodes. A piezoelectric micro-electro-mechanical systems (MEMS) optical scanner is used to steer a laser beam of two wavelengths superposed to visually present a communication zone, to search for the position of the remote node by means of the retro-reflector optics, and to transmit the data between the nodes. A feedback system is developed to control the MEMS scanner to dynamically establish the optical link within a 10-ms transition time and to keep track of the moving node.

Glial response to polyglutamine-mediated stress

PubMed Central

Vig, Parminder J.S.; Shao, Qingmei; Lopez, Maripar E

2009-01-01

Neurodegenerative trinucleotide (CAG) repeat disorders are caused by the expansion of polyglutamine tracts within the disease proteins. Some of these proteins have an unknown function. How does expanded polyglutamine cause target neurons to degenerate, is not clear. Recent evidence suggests that intercellular miscommunication may contribute to polyglutamine pathogenesis in CAG repeat disorders. Polyglutamine induced degeneration of the target neuron can be mediated via glia-neuron interactions. Here we hypothesize during neurodegenerative process the failure of cell: cell interactions have more severe consequences than alterations in intracellular neuron biology. We further believe that bidirectional communication between neurons and glia are prerequisite for the normal development and function of either cell-type. Understanding intercellular signaling mechanisms such as glial trophic factors and their receptors, cell adhesion or other well-defined signaling molecules provide opportunities for developing potential therapies. PMID:20046986

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.

Bidirectional DC/DC Converter

NASA Astrophysics Data System (ADS)

Pedersen, F.

2008-09-01

The presented bidirectional DC/DC converter design concept is a further development of an already existing converter used for low battery voltage operation.For low battery voltage operation a high efficient low parts count DC/DC converter was developed, and used in a satellite for the battery charge and battery discharge function.The converter consists in a bidirectional, non regulating DC/DC converter connected to a discharge regulating Buck converter and a charge regulating Buck converter.The Bidirectional non regulating DC/DC converter performs with relatively high efficiency even at relatively high currents, which here means up to 35Amps.This performance was obtained through the use of power MOSFET's with on- resistances of only a few mille Ohms connected to a special transformer allowing paralleling several transistor stages on the low voltage side of the transformer. The design is patent protected. Synchronous rectification leads to high efficiency at the low battery voltages considered, which was in the range 2,7- 4,3 Volt DC.The converter performs with low switching losses as zero voltage zero current switching is implemented in all switching positions of the converter.Now, the drive power needed, to switch a relatively large number of low Ohm , hence high drive capacitance, power MOSFET's using conventional drive techniques would limit the overall conversion efficiency.Therefore a resonant drive consuming considerable less power than a conventional drive circuit was implemented in the converter.To the originally built and patent protected bidirectional non regulating DC/DC converter, is added the functionality of regulation.Hereby the need for additional converter stages in form of a Charge Buck regulator and a Discharge Buck regulator is eliminated.The bidirectional DC/DC converter can be used in connection with batteries, motors, etc, where the bidirectional feature, simple design and high performance may be useful.

Longitudinal Associations Between PTSD Symptoms and Dyadic Conflict Communication Following a Severe Motor Vehicle Accident.

PubMed

Fredman, Steffany J; Beck, J Gayle; Shnaider, Philippe; Le, Yunying; Pukay-Martin, Nicole D; Pentel, Kimberly Z; Monson, Candice M; Simon, Naomi M; Marques, Luana

2017-03-01

There are well-documented associations between posttraumatic stress disorder (PTSD) symptoms and intimate relationship impairments, including dysfunctional communication at times of relationship conflict. To date, the extant research on the associations between PTSD symptom severity and conflict communication has been cross-sectional and focused on military and veteran couples. No published work has evaluated the extent to which PTSD symptom severity and communication at times of relationship conflict influence each other over time or in civilian samples. The current study examined the prospective bidirectional associations between PTSD symptom severity and dyadic conflict communication in a sample of 114 severe motor vehicle accident (MVA) survivors in a committed intimate relationship at the time of the accident. PTSD symptom severity and dyadic conflict communication were assessed at 4 and 16weeks post-MVA, and prospective associations were examined using path analysis. Total PTSD symptom severity at 4weeks prospectively predicted greater dysfunctional communication at 16weeks post-MVA but not vice versa. Examination at the level of PTSD symptom clusters revealed that effortful avoidance at 4weeks prospectively predicted greater dysfunctional communication at 16weeks, whereas dysfunctional communication 4weeks after the MVA predicted more severe emotional numbing at 16weeks. Findings highlight the role of PTSD symptoms in contributing to dysfunctional communication and the importance of considering PTSD symptom clusters separately when investigating the dynamic interplay between PTSD symptoms and relationship functioning over time, particularly during the early posttrauma period. Clinical implications for the prevention of chronic PTSD and associated relationship problems are discussed. Copyright © 2016. Published by Elsevier Ltd.

Efficient parallel and out of core algorithms for constructing large bi-directed de Bruijn graphs.

PubMed

Kundeti, Vamsi K; Rajasekaran, Sanguthevar; Dinh, Hieu; Vaughn, Matthew; Thapar, Vishal

2010-11-15

Assembling genomic sequences from a set of overlapping reads is one of the most fundamental problems in computational biology. Algorithms addressing the assembly problem fall into two broad categories - based on the data structures which they employ. The first class uses an overlap/string graph and the second type uses a de Bruijn graph. However with the recent advances in short read sequencing technology, de Bruijn graph based algorithms seem to play a vital role in practice. Efficient algorithms for building these massive de Bruijn graphs are very essential in large sequencing projects based on short reads. In an earlier work, an O(n/p) time parallel algorithm has been given for this problem. Here n is the size of the input and p is the number of processors. This algorithm enumerates all possible bi-directed edges which can overlap with a node and ends up generating Θ(nΣ) messages (Σ being the size of the alphabet). In this paper we present a Θ(n/p) time parallel algorithm with a communication complexity that is equal to that of parallel sorting and is not sensitive to Σ. The generality of our algorithm makes it very easy to extend it even to the out-of-core model and in this case it has an optimal I/O complexity of Θ(nlog(n/B)Blog(M/B)) (M being the main memory size and B being the size of the disk block). We demonstrate the scalability of our parallel algorithm on a SGI/Altix computer. A comparison of our algorithm with the previous approaches reveals that our algorithm is faster--both asymptotically and practically. We demonstrate the scalability of our sequential out-of-core algorithm by comparing it with the algorithm used by VELVET to build the bi-directed de Bruijn graph. Our experiments reveal that our algorithm can build the graph with a constant amount of memory, which clearly outperforms VELVET. We also provide efficient algorithms for the bi-directed chain compaction problem. The bi-directed de Bruijn graph is a fundamental data structure for any sequence assembly program based on Eulerian approach. Our algorithms for constructing Bi-directed de Bruijn graphs are efficient in parallel and out of core settings. These algorithms can be used in building large scale bi-directed de Bruijn graphs. Furthermore, our algorithms do not employ any all-to-all communications in a parallel setting and perform better than the prior algorithms. Finally our out-of-core algorithm is extremely memory efficient and can replace the existing graph construction algorithm in VELVET.

Bidirectional Reflectance Function Measurement of Molecular Contaminant Scattering in the Vacuum Ultraviolet

NASA Technical Reports Server (NTRS)

Herren, Kenneth A.; Gregory, Don A.

2006-01-01

Bi-directional reflectance distribution function (BRDF) measurements of optical surfaces both before and after molecular contamination were done using UV, VUV and visible light. Molecular contamination of optical surfaces from outgassed material has been shown in many cases to proceed from acclimation centers, and to produce many roughly hemispherical "islands" of contamination on the surface. Vacuum Ultraviolet (VW) wavelengths are used here to measure angularly scattered light from optical surfaces.

Bidirectional Associations Between Externalizing Behavior Problems and Maladaptive Parenting Within Parent-Son Dyads Across Childhood

PubMed Central

Loeber, Rolf; Hinshaw, Stephen P.; Pardini, Dustin A.

2018-01-01

Coercive parent–child interaction models posit that an escalating cycle of negative, bidirectional interchanges influences the development of boys’ externalizing problems and caregivers’ maladaptive parenting over time. However, longitudinal studies examining this hypothesis have been unable to rule out the possibility that between-individual factors account for bidirectional associations between child externalizing problems and maladaptive parenting. Using a longitudinal sample of boys (N = 503) repeatedly assessed eight times across 6-month intervals in childhood (in a range between 6 and 13 years), the current study is the first to use novel within-individual change (fixed effects) models to examine whether parents tend to increase their use of maladaptive parenting strategies following an increase in their son’s externalizing problems, or vice versa. These bidirectional associations were examined using multiple facets of externalizing problems (i.e., interpersonal callousness, conduct and oppositional defiant problems, hyperactivity/impulsivity) and parenting behaviors (i.e., physical punishment, involvement, parent–child communication). Analyses failed to support the notion that when boys increase their typical level of problem behaviors, their parents show an increase in their typical level of maladaptive parenting across the subsequent 6 month period, and vice versa. Instead, across 6-month intervals, within parent-son dyads, changes in maladaptive parenting and child externalizing problems waxed and waned in concert. Fixed effects models to address the topic of bidirectional relations between parent and child behavior are severely underrepresented. We recommend that other researchers who have found significant bidirectional parent–child associations using rank-order change models reexamine their data to determine whether these findings hold when examining changes within parent–child dyads. PMID:26780209

Bidirectional Associations Between Externalizing Behavior Problems and Maladaptive Parenting Within Parent-Son Dyads Across Childhood.

PubMed

Besemer, Sytske; Loeber, Rolf; Hinshaw, Stephen P; Pardini, Dustin A

2016-10-01

Coercive parent-child interaction models posit that an escalating cycle of negative, bidirectional interchanges influences the development of boys' externalizing problems and caregivers' maladaptive parenting over time. However, longitudinal studies examining this hypothesis have been unable to rule out the possibility that between-individual factors account for bidirectional associations between child externalizing problems and maladaptive parenting. Using a longitudinal sample of boys (N = 503) repeatedly assessed eight times across 6-month intervals in childhood (in a range between 6 and 13 years), the current study is the first to use novel within-individual change (fixed effects) models to examine whether parents tend to increase their use of maladaptive parenting strategies following an increase in their son's externalizing problems, or vice versa. These bidirectional associations were examined using multiple facets of externalizing problems (i.e., interpersonal callousness, conduct and oppositional defiant problems, hyperactivity/impulsivity) and parenting behaviors (i.e., physical punishment, involvement, parent-child communication). Analyses failed to support the notion that when boys increase their typical level of problem behaviors, their parents show an increase in their typical level of maladaptive parenting across the subsequent 6 month period, and vice versa. Instead, across 6-month intervals, within parent-son dyads, changes in maladaptive parenting and child externalizing problems waxed and waned in concert. Fixed effects models to address the topic of bidirectional relations between parent and child behavior are severely underrepresented. We recommend that other researchers who have found significant bidirectional parent-child associations using rank-order change models reexamine their data to determine whether these findings hold when examining changes within parent-child dyads.

Does superior caval vein pressure impact head growth in Fontan circulation?

PubMed

Trachsel, Tina; Balmer, Christian; Wåhlander, Håkan; Weber, Roland; Dave, Hitendu; Poretti, Andrea; Kretschmar, Oliver; Cavigelli-Brunner, Anna

2016-10-01

Patients with bidirectional cavopulmonary anastomosis have unphysiologically high superior caval vein pressure as it equals pulmonary artery pressure. Elevated superior caval vein pressure may cause communicating hydrocephalus and macrocephaly. This study analysed whether there exists an association between head circumference and superior caval vein pressure in patients with single ventricle physiology. We carried out a retrospective analysis of infants undergoing Fontan completion at our institution from 2007 to 2013. Superior caval vein pressures were measured during routine catheterisation before bidirectional cavopulmonary anastomosis and Fontan completion as well as head circumference, adjusted to longitudinal age-dependent percentiles. We included 74 infants in our study. Median ages at bidirectional cavopulmonary anastomosis and Fontan were 4.8 (1.6-12) and 27.9 (7-40.6) months, respectively. Head circumference showed significant growth from bidirectional cavopulmonary anastomosis until Fontan completion (7th (0-100th) versus 20th (0-100th) percentile). There was no correlation between superior caval vein pressure and head circumference before Fontan (R2=0.001). Children with lower differences in superior caval vein pressures between pre-bidirectional cavopulmonary anastomosis and pre-Fontan catheterisations showed increased growth of head circumference (R2=0.19). Patients with moderately elevated superior caval vein pressure associated with single ventricle physiology did not have a tendency to develop macrocephaly. There is no correlation between superior caval vein pressure before Fontan and head circumference, but between bidirectional cavopulmonary anastomosis and Fontan head circumference increases significantly. This may be explained by catch-up growth of head circumference in patients with more favourable haemodynamics and concomitant venous pressures in the lower range. Further studies with focus on high superior caval vein pressures are needed to exclude or prove a correlation.

Bidirectional neural interface: Closed-loop feedback control for hybrid neural systems.

PubMed

Chou, Zane; Lim, Jeffrey; Brown, Sophie; Keller, Melissa; Bugbee, Joseph; Broccard, Frédéric D; Khraiche, Massoud L; Silva, Gabriel A; Cauwenberghs, Gert

2015-01-01

Closed-loop neural prostheses enable bidirectional communication between the biological and artificial components of a hybrid system. However, a major challenge in this field is the limited understanding of how these components, the two separate neural networks, interact with each other. In this paper, we propose an in vitro model of a closed-loop system that allows for easy experimental testing and modification of both biological and artificial network parameters. The interface closes the system loop in real time by stimulating each network based on recorded activity of the other network, within preset parameters. As a proof of concept we demonstrate that the bidirectional interface is able to establish and control network properties, such as synchrony, in a hybrid system of two neural networks more significantly more effectively than the same system without the interface or with unidirectional alternatives. This success holds promise for the application of closed-loop systems in neural prostheses, brain-machine interfaces, and drug testing.

Design principles of electrical synaptic plasticity.

PubMed

O'Brien, John

2017-09-08

Essentially all animals with nervous systems utilize electrical synapses as a core element of communication. Electrical synapses, formed by gap junctions between neurons, provide rapid, bidirectional communication that accomplishes tasks distinct from and complementary to chemical synapses. These include coordination of neuron activity, suppression of voltage noise, establishment of electrical pathways that define circuits, and modulation of high order network behavior. In keeping with the omnipresent demand to alter neural network function in order to respond to environmental cues and perform tasks, electrical synapses exhibit extensive plasticity. In some networks, this plasticity can have dramatic effects that completely remodel circuits or remove the influence of certain cell types from networks. Electrical synaptic plasticity occurs on three distinct time scales, ranging from milliseconds to days, with different mechanisms accounting for each. This essay highlights principles that dictate the properties of electrical coupling within networks and the plasticity of the electrical synapses, drawing examples extensively from retinal networks. Copyright © 2017 The Author. Published by Elsevier B.V. All rights reserved.

The UTCOMS: a wireless video capsule nanoendoscope

NASA Astrophysics Data System (ADS)

Lee, Mike M.; Lee, Eun-Mi; Cho, Byung Lok; Eshraghian, Kamran; Kim, Yun-Hyun

2006-02-01

This research shows a 1mW Low Power and real-time imaging Tx/Rx communication system via RF-delay smart Antenna using up to 10GHz UWB(Ultra WideBand) as a concept of Wireless Medical Telemetry Service (WMTS). This UTCOMS (COMmunication System for Nano-scale USLI designed Endoscope using UWB technology) results in less body loss(about 6~13dB) at high frequency, disposable and ingestible compact size of 5×10 mm2 and multifunction, bidirectional communications, independent subsystem control multichannel, and high sensitivity smart receiving antenna of three-dimensional image captured still and moving images.

Implantable neurotechnologies: bidirectional neural interfaces--applications and VLSI circuit implementations.

PubMed

Greenwald, Elliot; Masters, Matthew R; Thakor, Nitish V

2016-01-01

A bidirectional neural interface is a device that transfers information into and out of the nervous system. This class of devices has potential to improve treatment and therapy in several patient populations. Progress in very large-scale integration has advanced the design of complex integrated circuits. System-on-chip devices are capable of recording neural electrical activity and altering natural activity with electrical stimulation. Often, these devices include wireless powering and telemetry functions. This review presents the state of the art of bidirectional circuits as applied to neuroprosthetic, neurorepair, and neurotherapeutic systems.

Bidirectional Neural Interfaces

PubMed Central

Masters, Matthew R.; Thakor, Nitish V.

2016-01-01

A bidirectional neural interface is a device that transfers information into and out of the nervous system. This class of devices has potential to improve treatment and therapy in several patient populations. Progress in very-large-scale integration (VLSI) has advanced the design of complex integrated circuits. System-on-chip (SoC) devices are capable of recording neural electrical activity and altering natural activity with electrical stimulation. Often, these devices include wireless powering and telemetry functions. This review presents the state of the art of bidirectional circuits as applied to neuroprosthetic, neurorepair, and neurotherapeutic systems. PMID:26753776

Changes in Optical Properties of Spacecraft Materials Due to Combined Effects of Aging Factors in a Space Environment

DTIC Science & Technology

2013-07-01

display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 16-07-2013 2...Bidirectional scattering distribution function (BSDF) and Bidirectional reflectance distribution function ( BRDF ) measurements were conducted for the...radiation (visible, ultraviolet, vacuum ultraviolet and soft X-ray radiation) at an altitude of 400 km 4) BSDF/ BRDF measurements have been conducted for

Transforming Business Communication by Building on Forman's Translation Metaphor.

ERIC Educational Resources Information Center

Sherblom, John C.

1998-01-01

Responds to an article in this issue. Reconceptualizes translation as a bidirectional, dynamically negotiated process that occurs within and between communities of scholars and that transforms the language, the person of the translator, the communities involved, and the cultural expectations. Argues that conception of translation predicts a…

From in silico astrocyte cell models to neuron-astrocyte network models: A review.

PubMed

Oschmann, Franziska; Berry, Hugues; Obermayer, Klaus; Lenk, Kerstin

2018-01-01

The idea that astrocytes may be active partners in synaptic information processing has recently emerged from abundant experimental reports. Because of their spatial proximity to neurons and their bidirectional communication with them, astrocytes are now considered as an important third element of the synapse. Astrocytes integrate and process synaptic information and by doing so generate cytosolic calcium signals that are believed to reflect neuronal transmitter release. Moreover, they regulate neuronal information transmission by releasing gliotransmitters into the synaptic cleft affecting both pre- and postsynaptic receptors. Concurrent with the first experimental reports of the astrocytic impact on neural network dynamics, computational models describing astrocytic functions have been developed. In this review, we give an overview over the published computational models of astrocytic functions, from single-cell dynamics to the tripartite synapse level and network models of astrocytes and neurons. Copyright © 2017 Elsevier Inc. All rights reserved.

Oral manifestations of thyroid disorders and its management

PubMed Central

Chandna, Shalu; Bathla, Manish

2011-01-01

The thyroid is the major regulator of metabolism and affects all of the bodily functions. Thyroid dysfunction is the second most common glandular disorder of the endocrine system which may rear its head in any system in the body including the mouth. The oral cavity is adversely affected by either an excess or deficiency of these hormones. Before treating a patient who has thyroid disorder, the endocrinologist needs to be familiar with the oral manifestations of thyroid dysfunctions. The patient with a thyroid dysfunction, as well as the patient taking medications for it, requires proper risk management before considering dental treatment by the dentist. Thus, communication of dentist with endocrinologist must be bidirectional, to maintain patient's oral and thyroid health. PMID:21966646

Infrared Communications for Small Spacecraft: From a Wireless Bus to Cluster Concepts

NASA Technical Reports Server (NTRS)

Webb, Suzanne C.; Schneider, Wolfger; Darrin, M. Ann G.; Boone, Bradley G.; Luers, Philip J.; Day, John H. (Technical Monitor)

2001-01-01

Nanosatellites operating singly or in clusters are anticipated for future space science missions. To implement this new communications paradigm, we are approaching cluster communications by first developing an infrared (IR) intra-craft wireless bus capability, following initially the MIL-STD-1553B protocol. Benefits of an IR wireless bus are low mass, size, power, and cost, simplicity of implementation, ease of use, minimum EMI, and efficient and reliable data transfer. Our goals are to maximize the reliable link margin in order to afford greater flexibility in receiver placement, which will ease technology insertion. We have developed a concept demonstration using a high-speed visible-band silicon PIN photodiode and a high-efficiency visible LED operating at a data rate up to 4 Mb/sec. In designing an internal IR wireless bus, we have characterized various candidate materials, emitters, and geometries, assuming a single reflection. Thus, we have measured the bidirectional reflectance distribution function (BRDF) for five different materials characteristic of typical spacecraft structures, which range from nearly Lambertian to highly specular. We have fit our data to empirical BRDF functions and modeled the detected irradiance anywhere in the plane of incidence for a divergent (LED) emitter. We have also determined the angular limits on the link geometry to remain within the required bit error rate by determining the received signal-to-noise ratio (SNR) for minimum values of irradiance received at the detector.

Evolution of bidirectional sex change and gonochorism in fishes of the gobiid genera Trimma, Priolepis, and Trimmatom.

PubMed

Sunobe, Tomoki; Sado, Tetsuya; Hagiwara, Kiyoshi; Manabe, Hisaya; Suzuki, Toshiyuki; Kobayashi, Yasuhisa; Sakurai, Makoto; Dewa, Shin-Ichi; Matsuoka, Midori; Shinomiya, Akihiko; Fukuda, Kazuya; Miya, Masaki

2017-04-01

Size-advantage and low-density models have been used to explain how mating systems favor hermaphroditism or gonochorism. However, these models do not indicate historical transitions in sexuality. Here, we investigate the evolution of bidirectional sex change and gonochorism by phylogenetic analysis using the mitochondrial gene of the gobiids Trimma (31 species), Priolepis (eight species), and Trimmatom (two species). Trimma and Priolepis formed a clade within the sister group Trimmatom. Gonadal histology and rearing experiments revealed that Trimma marinae, Trimma nasa, and Trimmatom spp. were gonochoric, whereas all other Trimma and Priolepis spp. were bidirectional sex changers or inferred ones. A maximum-likelihood reconstruction analysis demonstrated that the common ancestor of the three genera was gonochoristic. Bidirectional sex change probably evolved from gonochorism in a common ancestor of Trimma and Priolepis. As the gonads of bidirectional sex changers simultaneously contain mature ovarian and immature testicular components or vice versa, individuals are always potentially capable of functioning as females or males, respectively. Monogamy under low-density conditions may have been the ecological condition for the evolution of bidirectional sex change in a common ancestor. As T. marinae and T. nasa are a monophyletic group, gonochorism should have evolved from bidirectional sex change in a common ancestor.

Evolution of bidirectional sex change and gonochorism in fishes of the gobiid genera Trimma, Priolepis, and Trimmatom

NASA Astrophysics Data System (ADS)

Sunobe, Tomoki; Sado, Tetsuya; Hagiwara, Kiyoshi; Manabe, Hisaya; Suzuki, Toshiyuki; Kobayashi, Yasuhisa; Sakurai, Makoto; Dewa, Shin-ichi; Matsuoka, Midori; Shinomiya, Akihiko; Fukuda, Kazuya; Miya, Masaki

2017-04-01

Size-advantage and low-density models have been used to explain how mating systems favor hermaphroditism or gonochorism. However, these models do not indicate historical transitions in sexuality. Here, we investigate the evolution of bidirectional sex change and gonochorism by phylogenetic analysis using the mitochondrial gene of the gobiids Trimma (31 species), Priolepis (eight species), and Trimmatom (two species). Trimma and Priolepis formed a clade within the sister group Trimmatom. Gonadal histology and rearing experiments revealed that Trimma marinae, Trimma nasa, and Trimmatom spp. were gonochoric, whereas all other Trimma and Priolepis spp. were bidirectional sex changers or inferred ones. A maximum-likelihood reconstruction analysis demonstrated that the common ancestor of the three genera was gonochoristic. Bidirectional sex change probably evolved from gonochorism in a common ancestor of Trimma and Priolepis. As the gonads of bidirectional sex changers simultaneously contain mature ovarian and immature testicular components or vice versa, individuals are always potentially capable of functioning as females or males, respectively. Monogamy under low-density conditions may have been the ecological condition for the evolution of bidirectional sex change in a common ancestor. As T. marinae and T. nasa are a monophyletic group, gonochorism should have evolved from bidirectional sex change in a common ancestor.

Bidirectional reflectance modeling of non-homogeneous plant canopies

NASA Technical Reports Server (NTRS)

Norman, John M.

1986-01-01

The objective of this research is to develop a 3-dimensional radiative transfer model for predicting the bidirectional reflectance distribution function (BRDF) for heterogeneous vegetation canopies. Leaf bidirectional reflectance and transmittance distribution functions were measured for corn and soybean leaves. The measurements clearly show that leaves are complex scatterers and considerable specular reflectance is possible. Because of the character of leaf reflectance, true leaf reflectance is larger than the nadir reflectances that are normally used to represent leaves. A 3-dimensional reflectance model, named BIGAR (Bidirectional General Array Model), was developed and compared with measurements from corn and soybean. The model is based on the concept that heterogeneous canopies can be described by a combination of many subcanopies, which contain all the foliage, and these subcanopy envelopes can be characterized by ellipsoids of various sizes and shapes. The model/measurement comparison results indicate that this relatively simple model captures the essential character of row crop BRDF's. Finally, two soil BDRF models were developed: one represents soil particles as rectangular blocks and the other represents soil particles as spheres. The sphere model was found to be superior.

NASA 60 GHz intersatellite communication link definition study. Baseline document

NASA Technical Reports Server (NTRS)

1986-01-01

The overall system and component concepts for a 60 GHz intersatellite communications link system (ICLS) are described. The ICLS was designed to augment the capabilities of the current Tracking and Data Relay Satellite System (TDRSS), providing a data rate capacity large enough to accommodate the expected rates for user satellites (USAT's) in the post-1995 timeframe. The use of 60 GHz for the anticipated successor to TDRSS, the Tracking and Data Acquisition System (TDAS), was selected because of current technology development that will enable multigigibit data rates. Additionally, the attenuation of the earth's atmosphere at 60 GHz means that there is virtually no possibility of terrestrially generated interference (intentional or accidental) or terrestrially based intercept. The ICLS includes the following functional areas: (1) the ICLS payload package on the GEO TDAS satellite that communicates simultaneously with up to five LEO USAT's; (2) the payload package on the USAT that communicates with the TDAS satellite; and (3) the crosslink payload package on the TDAS satellite that communicates with another TDAS satellite. Two methods of data relay on-board the TDAS spacecraft were addressed. One is a complete baseband system (demod and remod) with a bi-directional 2 Gbps data stream; the other is a channelized system wherein some of the channels are baseband and others are merely frequency translated before re-transmission. Descriptions of the TDAS antenna, transmitter, receiver, and mechanical designs are presented.

Measurement of the Spatial Distribution of the Spectral Response Variation in the Field of View of the ASD Spectrometer Input Optics

DTIC Science & Technology

2014-12-01

development. It will be used for the measurement of the spectro-polarimetric BRDF (Bidirectional Reflectance Distribution function). For practical reasons...goniomètre est en développement. Il sera utilisé pour les mesures de BRDF (fonction de distribution de réflectance bidirectionnelle) spectrales et...by the independent measurements of the spectral and Bidirectional Reflectance Distribution Function ( BRDF ). The BRDF is the measurement of the

Comparison of Unscented Kalman Filter and Unscented Schmidt Kalman Filter in Predicting Attitude and Associated Uncertainty of a Geosynchronous Satellite

DTIC Science & Technology

2014-09-01

the MLI coating, and similarly, the surface model as represented by the bidirectional reflectance distribution function ( BRDF ) will never be...surface model as represented by the bidirectional reflectance distribution function ( BRDF ) will never be identical to that found on actual space objects... BRDF model and how it compares to the Ashikhmin-Shirley BRDF [14] using similar nomenclature can be found in Ref. [15]. In this scenario, the state

Spectral and geometrical variation of the bidirectional reflectance distribution function of diffuse reflectance standards.

PubMed

Ferrero, Alejandro; Rabal, Ana María; Campos, Joaquín; Pons, Alicia; Hernanz, María Luisa

2012-12-20

A study on the variation of the spectral bidirectional reflectance distribution function (BRDF) of four diffuse reflectance standards (matte ceramic, BaSO(4), Spectralon, and white Russian opal glass) is accomplished through this work. Spectral BRDF measurements were carried out and, using principal components analysis, its spectral and geometrical variation respect to a reference geometry was assessed from the experimental data. Several descriptors were defined in order to compare the spectral BRDF variation of the four materials.

Bidirectional control of absence seizures by the basal ganglia: a computational evidence.

PubMed

Chen, Mingming; Guo, Daqing; Wang, Tiebin; Jing, Wei; Xia, Yang; Xu, Peng; Luo, Cheng; Valdes-Sosa, Pedro A; Yao, Dezhong

2014-03-01

Absence epilepsy is believed to be associated with the abnormal interactions between the cerebral cortex and thalamus. Besides the direct coupling, anatomical evidence indicates that the cerebral cortex and thalamus also communicate indirectly through an important intermediate bridge-basal ganglia. It has been thus postulated that the basal ganglia might play key roles in the modulation of absence seizures, but the relevant biophysical mechanisms are still not completely established. Using a biophysically based model, we demonstrate here that the typical absence seizure activities can be controlled and modulated by the direct GABAergic projections from the substantia nigra pars reticulata (SNr) to either the thalamic reticular nucleus (TRN) or the specific relay nuclei (SRN) of thalamus, through different biophysical mechanisms. Under certain conditions, these two types of seizure control are observed to coexist in the same network. More importantly, due to the competition between the inhibitory SNr-TRN and SNr-SRN pathways, we find that both decreasing and increasing the activation of SNr neurons from the normal level may considerably suppress the generation of spike-and-slow wave discharges in the coexistence region. Overall, these results highlight the bidirectional functional roles of basal ganglia in controlling and modulating absence seizures, and might provide novel insights into the therapeutic treatments of this brain disorder.

Bidirectional Control of Absence Seizures by the Basal Ganglia: A Computational Evidence

PubMed Central

Wang, Tiebin; Jing, Wei; Xia, Yang; Xu, Peng; Luo, Cheng; Valdes-Sosa, Pedro A.; Yao, Dezhong

2014-01-01

Absence epilepsy is believed to be associated with the abnormal interactions between the cerebral cortex and thalamus. Besides the direct coupling, anatomical evidence indicates that the cerebral cortex and thalamus also communicate indirectly through an important intermediate bridge–basal ganglia. It has been thus postulated that the basal ganglia might play key roles in the modulation of absence seizures, but the relevant biophysical mechanisms are still not completely established. Using a biophysically based model, we demonstrate here that the typical absence seizure activities can be controlled and modulated by the direct GABAergic projections from the substantia nigra pars reticulata (SNr) to either the thalamic reticular nucleus (TRN) or the specific relay nuclei (SRN) of thalamus, through different biophysical mechanisms. Under certain conditions, these two types of seizure control are observed to coexist in the same network. More importantly, due to the competition between the inhibitory SNr-TRN and SNr-SRN pathways, we find that both decreasing and increasing the activation of SNr neurons from the normal level may considerably suppress the generation of spike-and-slow wave discharges in the coexistence region. Overall, these results highlight the bidirectional functional roles of basal ganglia in controlling and modulating absence seizures, and might provide novel insights into the therapeutic treatments of this brain disorder. PMID:24626189

Detailed validation of the bidirectional effect in various Case I and Case II waters.

PubMed

Gleason, Arthur C R; Voss, Kenneth J; Gordon, Howard R; Twardowski, Michael; Sullivan, James; Trees, Charles; Weidemann, Alan; Berthon, Jean-François; Clark, Dennis; Lee, Zhong-Ping

2012-03-26

Simulated bidirectional reflectance distribution functions (BRDF) were compared with measurements made just beneath the water's surface. In Case I water, the set of simulations that varied the particle scattering phase function depending on chlorophyll concentration agreed more closely with the data than other models. In Case II water, however, the simulations using fixed phase functions agreed well with the data and were nearly indistinguishable from each other, on average. The results suggest that BRDF corrections in Case II water are feasible using single, average, particle scattering phase functions, but that the existing approach using variable particle scattering phase functions is still warranted in Case I water.

An Intergenic Region Shared by At4g35985 and At4g35987 in Arabidopsis thaliana Is a Tissue Specific and Stress Inducible Bidirectional Promoter Analyzed in Transgenic Arabidopsis and Tobacco Plants

PubMed Central

Banerjee, Joydeep; Sahoo, Dipak Kumar; Dey, Nrisingha; Houtz, Robert L.; Maiti, Indu Bhushan

2013-01-01

On chromosome 4 in the Arabidopsis genome, two neighboring genes (calmodulin methyl transferase At4g35987 and senescence associated gene At4g35985) are located in a head-to-head divergent orientation sharing a putative bidirectional promoter. This 1258 bp intergenic region contains a number of environmental stress responsive and tissue specific cis-regulatory elements. Transcript analysis of At4g35985 and At4g35987 genes by quantitative real time PCR showed tissue specific and stress inducible expression profiles. We tested the bidirectional promoter-function of the intergenic region shared by the divergent genes At4g35985 and At4g35987 using two reporter genes (GFP and GUS) in both orientations in transient tobacco protoplast and Agro-infiltration assays, as well as in stably transformed transgenic Arabidopsis and tobacco plants. In transient assays with GFP and GUS reporter genes the At4g35985 promoter (P85) showed stronger expression (about 3.5 fold) compared to the At4g35987 promoter (P87). The tissue specific as well as stress responsive functional nature of the bidirectional promoter was evaluated in independent transgenic Arabidopsis and tobacco lines. Expression of P85 activity was detected in the midrib of leaves, leaf trichomes, apical meristemic regions, throughout the root, lateral roots and flowers. The expression of P87 was observed in leaf-tip, hydathodes, apical meristem, root tips, emerging lateral root tips, root stele region and in floral tissues. The bidirectional promoter in both orientations shows differential up-regulation (2.5 to 3 fold) under salt stress. Use of such regulatory elements of bidirectional promoters showing spatial and stress inducible promoter-functions in heterologous system might be an important tool for plant biotechnology and gene stacking applications. PMID:24260266

Two cell circuits of oriented adult hippocampal neurons on self-assembled monolayers for use in the study of neuronal communication in a defined system.

PubMed

Edwards, Darin; Stancescu, Maria; Molnar, Peter; Hickman, James J

2013-08-21

In this study, we demonstrate the directed formation of small circuits of electrically active, synaptically connected neurons derived from the hippocampus of adult rats through the use of engineered chemically modified culture surfaces that orient the polarity of the neuronal processes. Although synaptogenesis, synaptic communication, synaptic plasticity, and brain disease pathophysiology can be studied using brain slice or dissociated embryonic neuronal culture systems, the complex elements found in neuronal synapses makes specific studies difficult in these random cultures. The study of synaptic transmission in mature adult neurons and factors affecting synaptic transmission are generally studied in organotypic cultures, in brain slices, or in vivo. However, engineered neuronal networks would allow these studies to be performed instead on simple functional neuronal circuits derived from adult brain tissue. Photolithographic patterned self-assembled monolayers (SAMs) were used to create the two-cell "bidirectional polarity" circuit patterns. This pattern consisted of a cell permissive SAM, N-1[3-(trimethoxysilyl)propyl] diethylenetriamine (DETA), and was composed of two 25 μm somal adhesion sites connected with 5 μm lines acting as surface cues for guided axonal and dendritic regeneration. Surrounding the DETA pattern was a background of a non-cell-permissive poly(ethylene glycol) (PEG) SAM. Adult hippocampal neurons were first cultured on coverslips coated with DETA monolayers and were later passaged onto the PEG-DETA bidirectional polarity patterns in serum-free medium. These neurons followed surface cues, attaching and regenerating only along the DETA substrate to form small engineered neuronal circuits. These circuits were stable for more than 21 days in vitro (DIV), during which synaptic connectivity was evaluated using basic electrophysiological methods.

REVIEW ARTICLE: Hither and yon: a review of bi-directional microtubule-based transport

NASA Astrophysics Data System (ADS)

Gross, Steven P.

2004-06-01

Active transport is critical for cellular organization and function, and impaired transport has been linked to diseases such as neuronal degeneration. Much long distance transport in cells uses opposite polarity molecular motors of the kinesin and dynein families to move cargos along microtubules. It is increasingly clear that many cargos are moved by both sets of motors, and frequently reverse course. This review compares this bi-directional transport to the more well studied uni-directional transport. It discusses some bi-directionally moving cargos, and critically evaluates three different physical models for how such transport might occur. It then considers the evidence for the number of active motors per cargo, and how the net or average direction of transport might be controlled. The likelihood of a complex linking the activities of kinesin and dynein is also discussed. The paper concludes by reviewing elements of apparent universality between different bi-directionally moving cargos and by briefly considering possible reasons for the existence of bi-directional transport.

Comparison of control structures for a bidirectional high-frequency dc-dc converter

NASA Astrophysics Data System (ADS)

Himmelstoss, Felix A.; Kolar, Johann W.; Zach, Franz C.

1989-08-01

A system for dc-dc power conversion based on a buck-boost converter topology is presented. It makes power flow in both directions possible. The possibility of bidirectional power flow is useful for certain applications, such as uninterruptable power supplies. Starting from a structural diagram the transfer function of the system is derived. The controller for the converter is then designed. It is made up of a simple voltage controller, a voltage controller with an inner loop current controller (cascade control) and with two kinds of state space control. The transfer functions of the different system parts are derived and dimensioning guidelines for the controller sections are presented. The closed loop behavior of the bidirectional converter for the different control structures is analyzed based on simulation using duty cycle averaging. Bodediagrams and step responses are shown.

Robust stability of bidirectional associative memory neural networks with time delays

NASA Astrophysics Data System (ADS)

Park, Ju H.

2006-01-01

Based on the Lyapunov Krasovskii functionals combined with linear matrix inequality approach, a novel stability criterion is proposed for asymptotic stability of bidirectional associative memory neural networks with time delays. A novel delay-dependent stability criterion is given in terms of linear matrix inequalities, which can be solved easily by various optimization algorithms.

A Retrospective Examination of the Similarity between Clinical Practice and Manualized Treatment for Childhood Anxiety Disorders

ERIC Educational Resources Information Center

Vande Voort, Jennifer L.; Svecova, Jana; Jacobson, Amy Brown; Whiteside, Stephen P.

2010-01-01

The objective of this study was to facilitate the bidirectional communication between researchers and clinicians about the treatment of childhood anxiety disorders, including obsessive-compulsive disorder. Forty-four children were assessed before and after cognitive behavioral treatment with the parent versions of the Spence Child Anxiety Scale…

ARINC 818 specification revisions enable new avionics architectures

NASA Astrophysics Data System (ADS)

Grunwald, Paul

2014-06-01

The ARINC 818 Avionics Digital Video Bus is the standard for cockpit video that has gained wide acceptance in both the commercial and military cockpits. The Boeing 787, A350XWB, A400M, KC-46A, and many other aircraft use it. The ARINC 818 specification, which was initially release in 2006, has recently undergone a major update to address new avionics architectures and capabilities. Over the seven years since its release, projects have gone beyond the specification due to the complexity of new architectures and desired capabilities, such as video switching, bi-directional communication, data-only paths, and camera and sensor control provisions. The ARINC 818 specification was revised in 2013, and ARINC 818-2 was approved in November 2013. The revisions to the ARINC 818-2 specification enable switching, stereo and 3-D provisions, color sequential implementations, regions of interest, bi-directional communication, higher link rates, data-only transmission, and synchronization signals. This paper discusses each of the new capabilities and the impact on avionics and display architectures, especially when integrating large area displays, stereoscopic displays, multiple displays, and systems that include a large number of sensors.

On the Study of Cognitive Bidirectional Relaying with Asymmetric Traffic Demands

NASA Astrophysics Data System (ADS)

Ji, Xiaodong

2015-05-01

In this paper, we consider a cognitive radio network scenario, where two primary users want to exchange information with each other and meanwhile, one secondary node wishes to send messages to a cognitive base station. To meet the target quality of service (QoS) of the primary users and raise the communication opportunity of the secondary nodes, a cognitive bidirectional relaying (BDR) scheme is examined. First, system outage probabilities of conventional direct transmission and BDR schemes are presented. Next, a new system parameter called operating region is defined and calculated, which indicates in which position a secondary node can be a cognitive relay to assist the primary users. Then, a cognitive BDR scheme is proposed, giving a transmission protocol along with a time-slot splitting algorithm between the primary and secondary transmissions. Information-theoretic metric of ergodic capacity is studied for the cognitive BDR scheme to evaluate its performance. Simulation results show that with the proposed scheme, the target QoS of the primary users can be guaranteed, while increasing the communication opportunity for the secondary nodes.

Study on bi-directional pedestrian movement using ant algorithms

NASA Astrophysics Data System (ADS)

Sibel, Gokce; Ozhan, Kayacan

2016-01-01

A cellular automata model is proposed to simulate bi-directional pedestrian flow. Pedestrian movement is investigated by using ant algorithms. Ants communicate with each other by dropping a chemical, called a pheromone, on the substrate while crawling forward. Similarly, it is considered that oppositely moving pedestrians drop ‘visual pheromones’ on their way and the visual pheromones might cause attractive or repulsive interactions. This pheromenon is introduced into modelling the pedestrians’ walking preference. In this way, the decision-making process of pedestrians will be based on ‘the instinct of following’. At some densities, the relationships of velocity-density and flux-density are analyzed for different evaporation rates of visual pheromones. Lane formation and phase transition are observed for certain evaporation rates of visual pheromones.

Exploring the human mesenchymal stem cell tubule communication network through electron microscopy.

PubMed

Valente, Sabrina; Rossi, Roberta; Resta, Leonardo; Pasquinelli, Gianandrea

2015-04-01

Cells use several mechanisms to transfer information to other cells. In this study, we describe micro/nanotubular connections and exosome-like tubule fragments in multipotent mesenchymal stem cells (MSCs) from human arteries. Scanning and transmission electron microscopy allowed characterization of sinusoidal microtubular projections (700 nm average size, 200 µm average length, with bulging mitochondria and actin microfilaments); short, uniform, variously shaped nanotubular projections (100 nm, bidirectional communication); and tubule fragments (50 nm). This is the first study demonstrating that MSCs from human arteries constitutively interact through an articulate and dynamic tubule network allowing long-range cell to cell communication.

Interface Provides Standard-Bus Communication

NASA Technical Reports Server (NTRS)

Culliton, William G.

1995-01-01

Microprocessor-controlled interface (IEEE-488/LVABI) incorporates service-request and direct-memory-access features. Is circuit card enabling digital communication between system called "laser auto-covariance buffer interface" (LVABI) and compatible personal computer via general-purpose interface bus (GPIB) conforming to Institute for Electrical and Electronics Engineers (IEEE) Standard 488. Interface serves as second interface enabling first interface to exploit advantages of GPIB, via utility software written specifically for GPIB. Advantages include compatibility with multitasking and support of communication among multiple computers. Basic concept also applied in designing interfaces for circuits other than LVABI for unidirectional or bidirectional handling of parallel data up to 16 bits wide.

On chaos synchronization and secure communication.

PubMed

Kinzel, W; Englert, A; Kanter, I

2010-01-28

Chaos synchronization, in particular isochronal synchronization of two chaotic trajectories to each other, may be used to build a means of secure communication over a public channel. In this paper, we give an overview of coupling schemes of Bernoulli units deduced from chaotic laser systems, different ways to transmit information by chaos synchronization and the advantage of bidirectional over unidirectional coupling with respect to secure communication. We present the protocol for using dynamical private commutative filters for tap-proof transmission of information that maps the task of a passive attacker to the class of non-deterministic polynomial time-complete problems. This journal is © 2010 The Royal Society

Method and apparatus for communicating computer data from one point to another over a communications medium

DOEpatents

Arneson, Michael R [Chippewa Falls, WI; Bowman, Terrance L [Sumner, WA; Cornett, Frank N [Chippewa Falls, WI; DeRyckere, John F [Eau Claire, WI; Hillert, Brian T [Chippewa Falls, WI; Jenkins, Philip N [Eau Claire, WI; Ma, Nan [Chippewa Falls, WI; Placek, Joseph M [Chippewa Falls, WI; Ruesch, Rodney [Eau Claire, WI; Thorson, Gregory M [Altoona, WI

2007-07-24

The present invention is directed toward a communications channel comprising a link level protocol, a driver, a receiver, and a canceller/equalizer. The link level protocol provides logic for DC-free signal encoding and recovery as well as supporting many features including CRC error detection and message resend to accommodate infrequent bit errors across the medium. The canceller/equalizer provides equalization for destabilized data signals and also provides simultaneous bi-directional data transfer. The receiver provides bit deskewing by removing synchronization error, or skewing, between data signals. The driver provides impedance controlling by monitoring the characteristics of the communications medium, like voltage or temperature, and providing a matching output impedance in the signal driver so that fewer distortions occur while the data travels across the communications medium.

The role of the bidirectional hydrogenase in cyanobacteria.

PubMed

Carrieri, Damian; Wawrousek, Karen; Eckert, Carrie; Yu, Jianping; Maness, Pin-Ching

2011-09-01

Cyanobacteria have tremendous potential to produce clean, renewable fuel in the form of hydrogen gas derived from solar energy and water. Of the two cyanobacterial enzymes capable of evolving hydrogen gas (nitrogenase and the bidirectional hydrogenase), the hox-encoded bidirectional Ni-Fe hydrogenase has a high theoretical potential. The physiological role of this hydrogenase is a highly debated topic and is poorly understood relative to that of the nitrogenase. Here the structure, assembly, and expression of this enzyme, as well as its probable roles in metabolism, are discussed and analyzed to gain perspective on its physiological role. It is concluded that the bidirectional hydrogenase in cyanobacteria primarily functions as a redox regulator for maintaining a proper oxidation/reduction state in the cell. Recommendations for future research to test this hypothesis are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Bidirectional Reflectance of Flat, Optically Thick Particulate Layers: An Efficient Radiative Transfer Solution and Applications to Snow and Soil Surfaces

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.; Dlugach, Janna M.; Yanovitsku, Edgard G.; Zakharova, Nadia T.

1999-01-01

We describe a simple and highly efficient and accurate radiative transfer technique for computing bidirectional reflectance of a macroscopically flat scattering layer composed of nonabsorbing or weakly absorbing, arbitrarily shaped, randomly oriented and randomly distributed particles. The layer is assumed to be homogeneous and optically semi-infinite, and the bidirectional reflection function (BRF) is found by a simple iterative solution of the Ambartsumian's nonlinear integral equation. As an exact Solution of the radiative transfer equation, the reflection function thus obtained fully obeys the fundamental physical laws of energy conservation and reciprocity. Since this technique bypasses the computation of the internal radiation field, it is by far the fastest numerical approach available and can be used as an ideal input for Monte Carlo procedures calculating BRFs of scattering layers with macroscopically rough surfaces. Although the effects of packing density and coherent backscattering are currently neglected, they can also be incorporated. The FORTRAN implementation of the technique is available on the World Wide Web at http://ww,,v.giss.nasa.gov/-crmim/brf.html and can be applied to a wide range of remote sensing, engineering, and biophysical problems. We also examine the potential effect of ice crystal shape on the bidirectional reflectance of flat snow surfaces and the applicability of the Henyey-Greenstein phase function and the 6-Eddington approximation in calculations for soil surfaces.

Simulating the Daylight Performance of Complex Fenestration Systems Using Bidirectional Scattering Distribution Functions within Radiance

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

Ward, Gregory; Mistrick, Ph.D., Richard; Lee, Eleanor

2011-01-21

We describe two methods which rely on bidirectional scattering distribution functions (BSDFs) to model the daylighting performance of complex fenestration systems (CFS), enabling greater flexibility and accuracy in evaluating arbitrary assemblies of glazing, shading, and other optically-complex coplanar window systems. Two tools within Radiance enable a) efficient annual performance evaluations of CFS, and b) accurate renderings of CFS despite the loss of spatial resolution associated with low-resolution BSDF datasets for inhomogeneous systems. Validation, accuracy, and limitations of the methods are discussed.

Comparison of the bidirectional reflectance distribution function of various surfaces

NASA Astrophysics Data System (ADS)

Fernandez, Rene; Seasholtz, Richard G.; Oberle, Lawrence G.; Kadambi, Jaikrishnan R.

1989-04-01

This paper describes the development and use of a system to measure the bidirectional reflectance distribution function (BRDF) of various surfaces. The BRDF measurements are to be used in the analysis and design of optical measurement systems such as laser anemometers. An Ar-ion laser (514 nm) was the light source. Preliminary results are presented for eight samples: two glossy black paints, two flat black paints, black glass, sand-blasted Al, unworked Al, and a white paint. A BaSO4 white reflectance standard was used as the reference sample throughout the tests.

Wavelength dependence of the bidirectional reflectance distribution function (BRDF) of beach sands.

PubMed

Doctor, Katarina Z; Bachmann, Charles M; Gray, Deric J; Montes, Marcos J; Fusina, Robert A

2015-11-01

The wavelength dependence of the dominant directional reflective properties of beach sands was demonstrated using principal component analysis and the related correlation matrix. In general, we found that the hyperspectral bidirectional reflectance distribution function (BRDF) of beach sands has weak wavelength dependence. Its BRDF varies slightly in three broad wavelength regions. The variations are more evident in surfaces of greater visual roughness than in smooth surfaces. The weak wavelength dependence of the BRDF of beach sand can be captured using three broad wavelength regions instead of hundreds of individual wavelengths.

Modelling the bidirectional reflectance distribution function (BRDF) of seawater polluted by an oil film.

PubMed

Otremba, Zbigniew; Piskozub, Jacek

2004-04-19

The Bi-directional Reflectance Distribution Function (BRDF) of both clean seawaters and those polluted with oil film was determined using the Monte Carlo radiative transfer technique in which the spectrum of complex refractive index of Romashkino crude oil and the optical properties of case II water for chosen wavelengths was considered. The BRDF values were recorded for 1836 solid angular sectors of throughout the upper hemisphere. The visibility of areas polluted with oil observed from various directions and for various wavelengths is discussed.

Convergence analysis of stochastic hybrid bidirectional associative memory neural networks with delays

NASA Astrophysics Data System (ADS)

Wan, Li; Zhou, Qinghua

2007-10-01

The stability property of stochastic hybrid bidirectional associate memory (BAM) neural networks with discrete delays is considered. Without assuming the symmetry of synaptic connection weights and the monotonicity and differentiability of activation functions, the delay-independent sufficient conditions to guarantee the exponential stability of the equilibrium solution for such networks are given by using the nonnegative semimartingale convergence theorem.

The Cognitive, Perceptual, and Neural Bases of Skilled Performance

DTIC Science & Technology

1988-09-01

shunting, masking field, bidirectional associative memory, Volterra - Lotka , Gilpin-Ayala, ani Eigen-Schuster models. The Cohen-Grossberg model thus...field, bidirectional associative memory, Volterra - Lotka , Gilpin-Ayala, and Eigen-Schuster models. A Liapunov functional method is described for...storage by neural networks: A general model and global Liapunov method. In E.L. Schwartz (Ed.), Computational neuroscience. Cambridge, MA: MIT Press

Retrieval of seasonal dynamics of forest understory reflectance from semiarid to boreal forests using MODIS BRDF data

NASA Astrophysics Data System (ADS)

Pisek, Jan; Chen, Jing M.; Kobayashi, Hideki; Rautiainen, Miina; Schaepman, Michael E.; Karnieli, Arnon; Sprinstin, Michael; Ryu, Youngryel; Nikopensius, Maris; Raabe, Kairi

2016-03-01

Spatial and temporal patterns of forest background (understory) reflectance are crucial for retrieving biophysical parameters of forest canopies (overstory) and subsequently for ecosystem modeling. In this communication, we retrieved seasonal courses of understory normalized difference vegetation index (NDVI) from multiangular Moderate Resolution Imaging Spectroradiometer bidirectional reflectance distribution function (MODIS BRDF)/albedo data. We compared satellite-based seasonal courses of understory NDVI to understory NDVI values measured in different types of forests distributed along a wide latitudinal gradient (65.12°N-31.35°N). Our results indicated that the retrieval method performs well particularly over open forests of different types. We also demonstrated the limitations of the method for closed canopies, where the understory signal retrieval is much attenuated.

Artificial astrocytes improve neural network performance.

PubMed

Porto-Pazos, Ana B; Veiguela, Noha; Mesejo, Pablo; Navarrete, Marta; Alvarellos, Alberto; Ibáñez, Oscar; Pazos, Alejandro; Araque, Alfonso

2011-04-19

Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN) and artificial neuron-glia networks (NGN) to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function.

Artificial Astrocytes Improve Neural Network Performance

PubMed Central

Porto-Pazos, Ana B.; Veiguela, Noha; Mesejo, Pablo; Navarrete, Marta; Alvarellos, Alberto; Ibáñez, Oscar; Pazos, Alejandro; Araque, Alfonso

2011-01-01

Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN) and artificial neuron-glia networks (NGN) to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function. PMID:21526157

Advances in Human-Computer Interaction: Graphics and Animation Components for Interface Design

NASA Astrophysics Data System (ADS)

Cipolla Ficarra, Francisco V.; Nicol, Emma; Cipolla-Ficarra, Miguel; Richardson, Lucy

We present an analysis of communicability methodology in graphics and animation components for interface design, called CAN (Communicability, Acceptability and Novelty). This methodology has been under development between 2005 and 2010, obtaining excellent results in cultural heritage, education and microcomputing contexts. In studies where there is a bi-directional interrelation between ergonomics, usability, user-centered design, software quality and the human-computer interaction. We also present the heuristic results about iconography and layout design in blogs and websites of the following countries: Spain, Italy, Portugal and France.

Engaging Parents of Eighth Grade Students in Parent-Teacher Bidirectional Communication

ERIC Educational Resources Information Center

Bennett-Conroy, Waveline

2012-01-01

This article describes the development and evaluation of a classroom-based, low-cost intervention to increase parents' involvement in their children's education. In Phase 1 of the study, 17 parents of 8th grade students in a low-income, high immigrant and minority school district were interviewed to conduct a qualitative assessment of factors…

The Pavlovian analysis of instrumental conditioning.

PubMed

Gormezano, I; Tait, R W

1976-01-01

An account was given of the development within the Russian literature of a uniprocess formulation of classical and instrumental conditioning, known as the bidirectional conditioning hypothesis. The hypothesis purports to offer a single set of Pavlovian principles to account for both paradigms, based upon a neural model which assumes that bidirectional (forward and backward) connections are formed in both calssical and instrumental conditioning situations. In instrumental conditioning, the bidirectional connections are hypothesized to be simply more complex than those in classical conditioning, and any differences in empirical functions are presumed to lie not in difference in mechanism, but in the strength of the forward and backward connections. Although bidirectional connections are assumed to develop in instrumental conditioning, the experimental investigation of the bidirectional conditioning hypothesis has been essentially restricted to the classical conditioning operations of pairing two CSs (sensory preconditioning training), a US followed by a CS (backward conditioning training) and two USs. However, the paradigm involving the pairing of two USs, because of theoretical and analytical considerations, is the one most commonly employed by Russian investigators. The results of an initial experiment involving the pairing of two USs, and reference to the results of a more extensive investigation, leads us to tentatively question the validity of the bidirectional conditioning account of instrumental conditioning.

Driver-receiver combined optical transceiver modules for bidirectional optical interconnection

NASA Astrophysics Data System (ADS)

Park, Hyo-Hoon; Kang, Sae-Kyoung; Kim, Do-Won; Nga, Nguyen T. H.; Hwang, Sung-Hwan; Lee, Tae-Woo

2008-02-01

We review a bidirectional optical link scheme for memory-interface applications. A driver-receiver combined optical transceiver (TRx) modules was demonstrated on an optical printed-circuit board (OPCB) platform. To select the bidirectional electric input/output signals, a driver-receiver combined TRx IC with a switching function was designed in 0.18-μm CMOS technology. The TRx IC was integrated with VCSEL/PD chips for optical link in the TRx module. The optical TRx module was assembled on a fiber-embedded OPCB, employing a 90°-bent fiber connector for 90° deflection of light beams between the TRx module and the OPCB. The TRx module and the 90° connector were passively assembled on the OPCB, using ferrule-type guide pins/ holes. Employing these constituent components, the bidirectional optical link between a pair of TRx modules has been successfully demonstrated up to 1.25 Gb/s on the OPCB.

A little more conversation – the influence of communicative context on syntactic priming in brain and behavior

PubMed Central

Schoot, Lotte; Menenti, Laura; Hagoort, Peter; Segaert, Katrien

2014-01-01

We report on an functional magnetic resonance imaging (fMRI) syntactic priming experiment in which we measure brain activity for participants who communicate with another participant outside the scanner. We investigated whether syntactic processing during overt language production and comprehension is influenced by having a (shared) goal to communicate. Although theory suggests this is true, the nature of this influence remains unclear. Two hypotheses are tested: (i) syntactic priming effects (fMRI and behavioral) are stronger for participants in the communicative context than for participants doing the same experiment in a non-communicative context, and (ii) syntactic priming magnitude (behavioral) is correlated with the syntactic priming magnitude of the speaker’s communicative partner. Results showed that across conditions, participants were faster to produce sentences with repeated syntax, relative to novel syntax. This behavioral result converged with the fMRI data: we found repetition suppression effects in the left insula extending into left inferior frontal gyrus (BA 47/45), left middle temporal gyrus (BA 21), left inferior parietal cortex (BA 40), left precentral gyrus (BA 6), bilateral precuneus (BA 7), bilateral supplementary motor cortex (BA 32/8), and right insula (BA 47). We did not find support for the first hypothesis: having a communicative intention does not increase the magnitude of syntactic priming effects (either in the brain or in behavior) per se. We did find support for the second hypothesis: if speaker A is strongly/weakly primed by speaker B, then speaker B is primed by speaker A to a similar extent. We conclude that syntactic processing is influenced by being in a communicative context, and that the nature of this influence is bi-directional: speakers are influenced by each other. PMID:24672499

Content-Addressable Memory Storage by Neural Networks: A General Model and Global Liapunov Method,

DTIC Science & Technology

1988-03-01

point ex- ists. Liapunov functions were also described for Volterra -Lotka systems whose off-diagonal terms are relatively small (Kilmer, 1972...field, bidirectional associative memory, Volterra -Lotka, Gilpin-Ayala, and Eigen- Schuster models. The Cohen-Grossberg model thus defines a general...masking field, bidirectional associative memory. Volterra -Lotka, Gilpin-Ayala. and Eigen-Schuster models. The Cohen-Grossberg model thus defines a

Psycho-Neuro-Endocrine-Immunology: A Psychobiological Concept.

PubMed

França, Katlein; Lotti, Torello M

2017-01-01

Psycho-Neuro-Endocrine-Immunology (P.N.E.I.) is a scientific field of study that investigates the link between bidirectional communications among the nervous system, the endocrine system, and the immune system and the correlations of this cross-talk with physical health. The P.N.E.I. innovative medical approach represents a paradigm shift from a strictly biomedical view of health and disease taken as hermetically sealed compartments to a more interdisciplinary one. The key element of P.N.E.I. approach is represented by the concept of bidirectional cross-talk between the psychoneuroendocrine and immune systems. The Low Dose Medicine is one of the most promising approaches able to allow the researchers to design innovative therapeutic strategies for the treatment of skin diseases based on the rebalance of the immune response.

Bidirectional microwave-mechanical-optical transducer in a dilution refrigerator

NASA Astrophysics Data System (ADS)

Burns, Peter S.; Higginbotham, Andrew P.; Peterson, Robert W.; Urmey, Maxwell D.; Kampel, Nir S.; Menke, Timothy; Cicak, Katarina; Simmonds, Raymond. W.; Regal, Cindy A.; Lehnert, Konrad W.

Transferring quantum states between microwave and optical networks would be a powerful resource for quantum communication and computation. Our approach is to simultaneously couple one mode of a micromechanical oscillator to a resonant microwave circuit and a high-finesse optical cavity. Building on previous work demonstrating bidirectional and efficient classical conversion at 4 K, a new microwave-to-optical transducer is operated at 0.1 K and preparations are underway to operate it in the quantum regime. To improve transfer efficiency, we characterize and implement wireless microwave access to the converter chip. Transfer efficiency of the device is measured, and loss in the LC circuit due to laser light is characterized. We acknowledge support from AFOSR MURI Grant FA9550-15-1-0015 and PFC National Science Foundation Grant 1125844.

Establishing the bidirectional relationship between depression and subclinical arteriosclerosis--rationale, design, and characteristics of the BiDirect Study.

PubMed

Teismann, Henning; Wersching, Heike; Nagel, Maren; Arolt, Volker; Heindel, Walter; Baune, Bernhard T; Wellmann, Jürgen; Hense, Hans-Werner; Berger, Klaus

2014-06-13

Depression and cardiovascular diseases due to arteriosclerosis are both frequent and impairing conditions. Depression and (subclinical) arteriosclerosis appear to be related in a bidirectional way, and it is plausible to assume a partly joint causal relationship. However, the biological mechanisms and the behavioral pathways that lead from depression to arteriosclerosis and vice versa remain to be exactly determined. This study protocol describes the rationale and design of the prospective BiDirect Study that aims at investigating the mutual relationship between depression and (subclinical) arteriosclerosis. BiDirect is scheduled to follow-up three distinct cohorts of individuals ((i) patients with acute depression (N = 999), (ii) patients after an acute cardiac event (N = 347), and (iii) reference subjects from the general population (N = 912)). Over the course of 12 years, four personal examinations are planned to be conducted. The core examination program, which will remain identical across follow-ups, comprises a personal interview (e.g. medical diagnoses, health care utilization, lifestyle and risk behavior), a battery of self-administered questionnaires (e.g. depressive symptoms, readiness to change health behavior, perceived health-related quality of life), sensory (e.g. olfaction, pain) and neuropsychological (e.g. memory, executive functions, emotional processing, manual dexterity) assessments, anthropometry, body impedance measurement, a clinical work-up regarding the vascular status (e.g. electrocardiogram, blood pressure, intima media thickness), the taking of blood samples (serum and plasma, DNA), and structural and functional resonance imaging of the brain (e.g. diffusion tensor imaging, resting-state, emotional faces processing). The present report includes BiDirect-Baseline, the first data collection wave. Due to its prospective character, the integration of three distinct cohorts, the long follow-up time window, the diligent diagnosis of depression taking depression subtypes into account, the consideration of relevant comorbidities and risk factors, the assessment of indicators of (subclinical) arteriosclerosis in different vascular territories, and the structural and functional brain imaging that is performed for a large number of participants, the BiDirect Study represents an innovative approach that combines population-based cohorts with sophisticated clinical work-up methods and that holds the potential to overcome many of the drawbacks characterizing earlier investigations.

Reflection and emission models for deserts derived from Nimbus-7 ERB scanner measurements

NASA Technical Reports Server (NTRS)

Staylor, W. F.; Suttles, J. T.

1986-01-01

Broadband shortwave and longwave radiance measurements obtained from the Nimbus-7 Earth Radiation Budget scanner were used to develop reflectance and emittance models for the Sahara-Arabian, Gibson, and Saudi Deserts. The models were established by fitting the satellite measurements to analytic functions. For the shortwave, the model function is based on an approximate solution to the radiative transfer equation. The bidirectional-reflectance function was obtained from a single-scattering approximation with a Rayleigh-like phase function. The directional-reflectance model followed from integration of the bidirectional model and is a function of the sum and product of cosine solar and viewing zenith angles, thus satisfying reciprocity between these angles. The emittance model was based on a simple power-law of cosine viewing zenith angle.

Full four-dimensional and reciprocal Mueller matrix bidirectional reflectance distribution function of sintered polytetrafluoroethylene.

PubMed

Germer, Thomas A

2017-11-20

We measured the Mueller matrix bidirectional reflectance distribution function (BRDF) of a sintered polytetrafluoroethylene (PTFE) sample over the scattering hemisphere for six incident angles (0°-75° in 15° steps) and for four wavelengths (351 nm, 532 nm, 633 nm, and 1064 nm). The data for each wavelength were fit to a phenomenological description for the Mueller matrix BRDF, which is an extension of the bidirectional surface scattering modes developed by Koenderink and van Doorn [J. Opt. Soc. Am. A.15, 2903 (1998)JOAOD60740-323210.1364/JOSAA.15.002903] for unpolarized BRDF. This description is designed to be complete, to obey the appropriate reciprocity conditions, and to provide a full description of the Mueller matrix BRDF as a function of incident and scattering directions for each wavelength. The description was further extended by linearizing the surface scattering mode coefficients with wavelength. This data set and its parameterization provides a comprehensive on-demand description of the reflectance properties for this commonly used diffuse reflectance reference material over a wide range of wavelengths.

Radio Links for the NASA ABTS

NASA Technical Reports Server (NTRS)

Jeutter, Dean C.

1996-01-01

The closed loop prototype has operational bi-directional wireless links. The Wideband PCM-FSK receiver has been designed and characterized. Now that both links function, communication performance can be addressed. For example, noise problems with the received outlink signal that caused the PC program to lockup were just recently revealed and minimized by software "enhancements" to the Windows based PC program. A similar problem with inlink communication was uncovered several days before this report: A noise spike or dropout (expected events in the animal Habitat) caused an interrupt to the implant microcontroller which halted outlink transmission. Recovery of outlink transmission did not reliably occur. The problem has been defined and implant software is being modified to better recognize noise from data by changing the timing associated with valid data packet identification and by better utilizing the error flags generated by the microcontroller's SCI circuits. Excellent inlink performance will also require improvements in the implant's receiver. The biggest performance improvement can be provided by antenna design for the Habitat. The quarter wavelength whip antennas used with the demo prototype inlink leave much to be desired.

GGPP-Mediated Protein Geranylgeranylation in Oocyte Is Essential for the Establishment of Oocyte-Granulosa Cell Communication and Primary-Secondary Follicle Transition in Mouse Ovary.

PubMed

Jiang, Chen; Diao, Fan; Sang, Yong-Juan; Xu, Na; Zhu, Rui-Lou; Wang, Xiu-Xing; Chen, Zhong; Tao, Wei-Wei; Yao, Bing; Sun, Hai-Xiang; Huang, Xing-Xu; Xue, Bin; Li, Chao-Jun

2017-01-01

Folliculogenesis is a progressive and highly regulated process, which is essential to provide ova for later reproductive life, requires the bidirectional communication between the oocyte and granulosa cells. This physical connection-mediated communication conveys not only the signals from the oocyte to granulosa cells that regulate their proliferation but also metabolites from the granulosa cells to the oocyte for biosynthesis. However, the underlying mechanism of establishing this communication is largely unknown. Here, we report that oocyte geranylgeranyl diphosphate (GGPP), a metabolic intermediate involved in protein geranylgeranylation, is required to establish the oocyte-granulosa cell communication. GGPP and geranylgeranyl diphosphate synthase (Ggpps) levels in oocytes increased during early follicular development. The selective depletion of GGPP in mouse oocytes impaired the proliferation of granulosa cells, primary-secondary follicle transition and female fertility. Mechanistically, GGPP depletion inhibited Rho GTPase geranylgeranylation and its GTPase activity, which was responsible for the accumulation of cell junction proteins in the oocyte cytoplasm and the failure to maintain physical connection between oocyte and granulosa cells. GGPP ablation also blocked Rab27a geranylgeranylation, which might account for the impaired secretion of oocyte materials such as Gdf9. Moreover, GGPP administration restored the defects in oocyte-granulosa cell contact, granulosa cell proliferation and primary-secondary follicle transition in Ggpps depletion mice. Our study provides the evidence that GGPP-mediated protein geranylgeranylation contributes to the establishment of oocyte-granulosa cell communication and then regulates the primary-secondary follicle transition, a key phase of folliculogenesis essential for female reproductive function.

A low-power bidirectional telemetry device with a near-field charging feature for a cardiac microstimulator.

PubMed

Shuenn-Yuh Lee; Chih-Jen Cheng; Ming-Chun Liang

2011-08-01

In this paper, wireless telemetry using the near-field coupling technique with round-wire coils for an implanted cardiac microstimulator is presented. The proposed system possesses an external powering amplifier and an internal bidirectional microstimulator. The energy of the microstimulator is provided by a rectifier that can efficiently charge a rechargeable device. A fully integrated regulator and a charge pump circuit are included to generate a stable, low-voltage, and high-potential supply voltage, respectively. A miniature digital processor includes a phase-shift-keying (PSK) demodulator to decode the transmission data and a self-protective system controller to operate the entire system. To acquire the cardiac signal, a low-voltage and low-power monitoring analog front end (MAFE) performs immediate threshold detection and data conversion. In addition, the pacing circuit, which consists of a pulse generator (PG) and its digital-to-analog (D/A) controller, is responsible for stimulating heart tissue. The chip was fabricated by Taiwan Semiconductor Manufacturing Company (TSMC) with 0.35-μm complementary metal-oxide semiconductor technology to perform the monitoring and pacing functions with inductively powered communication. Using a model with lead and heart tissue on measurement, a -5-V pulse at a stimulating frequency of 60 beats per minute (bpm) is delivered while only consuming 31.5 μW of power.

Multi-functional quantum router using hybrid opto-electromechanics

NASA Astrophysics Data System (ADS)

Ma, Peng-Cheng; Yan, Lei-Lei; Chen, Gui-Bin; Li, Xiao-Wei; Liu, Shu-Jing; Zhan, You-Bang

2018-03-01

Quantum routers engineered with multiple frequency bands play a key role in quantum networks. We propose an experimentally accessible scheme for a multi-functional quantum router, using photon-phonon conversion in a hybrid opto-electromechanical system. Our proposed device functions as a bidirectional, tunable multi-channel quantum router, and demonstrates the possibility to route single optical photons bidirectionally and simultaneously to three different output ports, by adjusting the microwave power. Further, the device also behaves as an interswitching unit for microwave and optical photons, yielding probabilistic routing of microwave (optical) signals to optical (microwave) outports. With respect to potential application, we verify the insignificant influence from vacuum and thermal noises in the performance of the router under cryogenic conditions.

Monitoring of physiological parameters from multiple patients using wireless sensor network.

PubMed

Yuce, Mehmet R; Ng, Peng Choong; Khan, Jamil Y

2008-10-01

This paper presents a wireless sensor network system that has the capability to monitor physiological parameters from multiple patient bodies. The system uses the Medical Implant Communication Service band between the sensor nodes and a remote central control unit (CCU) that behaves as a base station. The CCU communicates with another network standard (the internet or a mobile network) for a long distance data transfer. The proposed system offers mobility to patients and flexibility to medical staff to obtain patient's physiological data on demand basis via Internet. A prototype sensor network including hardware, firmware and software designs has been implemented and tested. The developed system has been optimized for power consumption by having the nodes sleep when there is no communication via a bidirectional communication.

Comparison of the bidirectional reflectance distribution function of various surfaces

NASA Technical Reports Server (NTRS)

Fernandez, Rene; Seasholtz, Richard G.; Oberle, Lawrence G.; Kadambi, Jaikrishnan R.

1988-01-01

Described is the development and use of a system to measure the Bidirectional Reflectance Distribution Function (BRDF) of various surfaces. The BRDF measurements are used in the analysis and design of optical measurement systems, such as laser anemometers. An argon ion laser (514 nm) is the light source. Preliminary results are presented for eight samples: two glossy black paints, two flat black paints, black glass, sand blasted aluminum, unworked aluminum, and a white paint. A BaSO4 white reflectance standard was used as the reference sample throughout the tests. The reflectance characteristics of these surfaces are compared.

Hybrid artificial bee colony algorithm for parameter optimization of five-parameter bidirectional reflectance distribution function model.

PubMed

Wang, Qianqian; Zhao, Jing; Gong, Yong; Hao, Qun; Peng, Zhong

2017-11-20

A hybrid artificial bee colony (ABC) algorithm inspired by the best-so-far solution and bacterial chemotaxis was introduced to optimize the parameters of the five-parameter bidirectional reflectance distribution function (BRDF) model. To verify the performance of the hybrid ABC algorithm, we measured BRDF of three kinds of samples and simulated the undetermined parameters of the five-parameter BRDF model using the hybrid ABC algorithm and the genetic algorithm, respectively. The experimental results demonstrate that the hybrid ABC algorithm outperforms the genetic algorithm in convergence speed, accuracy, and time efficiency under the same conditions.

Stability analysis for stochastic BAM nonlinear neural network with delays

NASA Astrophysics Data System (ADS)

Lv, Z. W.; Shu, H. S.; Wei, G. L.

2008-02-01

In this paper, stochastic bidirectional associative memory neural networks with constant or time-varying delays is considered. Based on a Lyapunov-Krasovskii functional and the stochastic stability analysis theory, we derive several sufficient conditions in order to guarantee the global asymptotically stable in the mean square. Our investigation shows that the stochastic bidirectional associative memory neural networks are globally asymptotically stable in the mean square if there are solutions to some linear matrix inequalities(LMIs). Hence, the global asymptotic stability of the stochastic bidirectional associative memory neural networks can be easily checked by the Matlab LMI toolbox. A numerical example is given to demonstrate the usefulness of the proposed global asymptotic stability criteria.

Lactobacillus plantarum attenuates anxiety-related behavior and protects against stress-induced dysbiosis in adult zebrafish.

PubMed

Davis, Daniel J; Doerr, Holly M; Grzelak, Agata K; Busi, Susheel B; Jasarevic, Eldin; Ericsson, Aaron C; Bryda, Elizabeth C

2016-09-19

The consumption of probiotics has become increasingly popular as a means to try to improve health and well-being. Not only are probiotics considered beneficial to digestive health, but increasing evidence suggests direct and indirect interactions between gut microbiota (GM) and the central nervous system (CNS). Here, adult zebrafish were supplemented with Lactobacillus plantarum to determine the effects of probiotic treatment on structural and functional changes of the GM, as well as host neurological and behavioral changes. L. plantarum administration altered the β-diversity of the GM while leaving the major core architecture intact. These minor structural changes were accompanied by significant enrichment of several predicted metabolic pathways. In addition to GM modifications, L. plantarum treatment also significantly reduced anxiety-related behavior and altered GABAergic and serotonergic signaling in the brain. Lastly, L. plantarum supplementation provided protection against stress-induced dysbiosis of the GM. These results underscore the influence commensal microbes have on physiological function in the host, and demonstrate bidirectional communication between the GM and the host.

The Microbiome in Mental Health: Potential Contribution of Gut Microbiota in Disease and Pharmacotherapy Management.

PubMed

Flowers, Stephanie A; Ellingrod, Vicki L

2015-10-01

The gut microbiome is composed of ~10(13) -10(14) microbial cells and viruses that exist in a symbiotic bidirectional communicative relationship with the host. Bacterial functions in the gut have an important role in healthy host metabolic function, and dysbiosis can contribute to the pathology of many medical conditions. Alterations in the relationship between gut microbiota and host have gained some attention in mental health because new evidence supports the association of gut bacteria to cognitive and emotional processes. Of interest, illnesses such as major depressive disorder are disproportionately prevalent in patients with gastrointestinal illnesses such as inflammatory bowel disease, which pathologically has been strongly linked to microbiome function. Not only is the microbiome associated with the disease itself, but it may also influence the effectiveness or adverse effects associated with pharmacologic agents used to treat these disorders. This field of study may also provide new insights on how dietary agents may help manage mental illness both directly as well as though their influence on the therapeutic and adverse effects of psychotropic agents. © 2015 Pharmacotherapy Publications, Inc.

Hypertonic Saline Resuscitation Restores Inflammatory Cytokine Balance in Post-Traumatic Hemorrhagic Shock Patients

DTIC Science & Technology

2004-08-01

immunocompetant cells experience bidirectional communication with hormones and cytokines [35,40]. Thus, despite compelling experimental findings, HSD has not...hypertonic saline with 6% dextran-70 (HSD) has been shown in experimental studies to reduce shock/resuscitation-induced inflammatory reactions and...alterations have been described in clinical and experimental investigations of post-traumatic hemorrhagic shock [13]. The initial immunological

An analysis of bi-directional use of frequencies for satellite communications

NASA Technical Reports Server (NTRS)

Whyte, W. A., Jr.; Miller, E. F.; Sullivan, T.; Miller, J. E.

1986-01-01

The bi-directional use of frequencies allocated for space communications has the potential to double the orbit/spectrum capacity available. The technical feasibility of reverse band use (RBU) at C-band (4 GHz uplinks and 6 GHz downlinks) is studied. The analysis identifies the constraints under which both forward and reverse band use satellite systems can share the same frequencies with terrestrial, line of sight transmission systems. The results of the analysis show that RBU satellite systems can be similarly sized to forward band use (FBU) satellite systems. In addition, the orbital separation requirements between RBU and FBU satellite systems are examined. The analysis shows that a carrier to interference ratio of 45 dB can be maintianed between RBU and FBU satellites separated by less than 0.5 deg., and that a carrier to interference ratio of 42 dB can be maintained in the antipodal case. Rain scatter propagation analysis shows that RBU and FBU Earth stations require separation distances fo less than 10 km at a rain rate of 13.5 mm/hr escalating to less than 100 km at a rain rate of 178 mm/hr for Earth station antennas in the 3 to 10 m range.

Central nervous system regulation of hepatic lipid and lipoprotein metabolism.

PubMed

Taher, Jennifer; Farr, Sarah; Adeli, Khosrow

2017-02-01

Hepatic lipid and lipoprotein metabolism is an important determinant of fasting dyslipidemia and the development of fatty liver disease. Although endocrine factors like insulin have known effects on hepatic lipid homeostasis, emerging evidence also supports a regulatory role for the central nervous system (CNS) and neuronal networks. This review summarizes evidence implicating a bidirectional liver-brain axis in maintaining metabolic lipid homeostasis, and discusses clinical implications in insulin-resistant states. The liver utilizes sympathetic and parasympathetic afferent and efferent fibers to communicate with key regulatory centers in the brain including the hypothalamus. Hypothalamic anorexigenic and orexigenic peptides signal to the liver via neuronal networks to modulate lipid content and VLDL production. In addition, peripheral hormones such as insulin, leptin, and glucagon-like-peptide-1 exert control over hepatic lipid by acting directly within the CNS or via peripheral nerves. Central regulation of lipid metabolism in other organs including white and brown adipose tissue may also contribute to hepatic lipid content indirectly via free fatty acid release and changes in lipoprotein clearance. The CNS communicates with the liver in a bidirectional manner to regulate hepatic lipid metabolism and lipoprotein production. Impairments in these pathways may contribute to dyslipidemia and hepatic steatosis in insulin-resistant states.

Bidirectional Text Messaging to Improve Adherence to Recommended Lipid Testing.

PubMed

Baldwin, Laura-Mae; Morrison, Caitlin; Griffin, Jonathan; Anderson, Nick; Edwards, Kelly; Green, Jeff; Waldren, Cleary; Reiter, William

2017-01-01

Synergies between technology and health care in the United States are accelerating, increasing opportunities to leverage these technologies to improve patient care. This study was a collaboration between an academic study team, a rural primary care clinic, and a local nonprofit informatics company developing tools to improve patient care through population management. Our team created a text messaging management tool, then developed methods for and tested the feasibility of bidirectional text messaging to remind eligible patients about the need for lipid testing. We measured patient response to the text messages, then interviewed 8 patients to explore their text messaging experience. Of the 129 patients the clinic was able to contact by phone, 29.4% had no cell phone or text-messaging capabilities. An additional 20% refused to participate. Two thirds of the 28 patients who participated in the text messaging intervention (67.9%) responded to at least 1 of the up to 3 messages. Seven of 8 interviewed patients had a positive text-messaging experience. Bidirectional text messaging is a feasible and largely acceptable form of communication for test reminders that has the potential to reach large numbers of patients in clinical care. © Copyright 2017 by the American Board of Family Medicine.

Modified polarized geometrical attenuation model for bidirectional reflection distribution function based on random surface microfacet theory.

PubMed

Liu, Hong; Zhu, Jingping; Wang, Kai

2015-08-24

The geometrical attenuation model given by Blinn was widely used in the geometrical optics bidirectional reflectance distribution function (BRDF) models. Blinn's geometrical attenuation model based on symmetrical V-groove assumption and ray scalar theory causes obvious inaccuracies in BRDF curves and negatives the effects of polarization. Aiming at these questions, a modified polarized geometrical attenuation model based on random surface microfacet theory is presented by combining of masking and shadowing effects and polarized effect. The p-polarized, s-polarized and unpolarized geometrical attenuation functions are given in their separate expressions and are validated with experimental data of two samples. It shows that the modified polarized geometrical attenuation function reaches better physical rationality, improves the precision of BRDF model, and widens the applications for different polarization.

Continuity and Change in, and Child Predictors of, Caregiver Reported Anxiety Symptoms in Young People with Autism Spectrum Disorder: A Follow-Up Study.

PubMed

Teh, Elizabeth J; Chan, Diana Mei-En; Tan, Germaine Ke Jia; Magiati, Iliana

2017-12-01

Little is known about continuity, change and predictors of anxiety in ASD. This follow-up study investigated changes in caregiver-reported anxiety in 54 non-referred youth with ASD after 10-19 months. Earlier child predictors of later anxiety were also examined. Anxiety scores were generally stable. Time 1 ASD repetitive behavior symptoms, but not social/communication symptoms, predicted Time 2 total anxiety scores, over and above child age, gender and adaptive functioning scores, but this predictive relationship was fully mitigated by Time 1 anxiety scores when these were included as a covariate in the regression model. Exploring bi-directionality between autism and anxiety symptomatology, Time 1 anxiety scores did not predict Time 2 ASD symptoms. Preliminary clinical implications and possible future directions are discussed.

Attuning: A Communication Process between People with Severe and Profound Intellectual Disability and Their Interaction Partners.

PubMed

Griffiths, Colin; Smith, Martine

2016-03-01

People with severe and profound intellectual disability typically demonstrate a limited ability to communicate effectively. Most of their communications are non-verbal, often idiosyncratic and ambiguous. This article aims to identify the process that regulates communications of this group of people with others and to describe the methodological approach that was used to achieve this. In this qualitative study, two dyads consisting of a person with severe or profound intellectual and multiple disability and a teacher or carer were filmed as they engaged in school-based activities. Two 1-hour videotapes were transcribed and analysed using grounded theory. Attuning was identified within the theory proposed here as a central process that calibrates and regulates communication. Attuning is conceptualized as a bidirectional, dyadic communication process. Understanding this process may support more effective communication between people with severe or profound intellectual and multiple disability and their interaction partners. © 2015 John Wiley & Sons Ltd.

Congestion and communication in confined ant traffic

NASA Astrophysics Data System (ADS)

Gravish, Nick; Gold, Gregory; Zangwill, Andrew; Goodisman, Michael A. D.; Goldman, Daniel I.

2014-03-01

Many social animals move and communicate within confined spaces. In subterranean fire ants Solenopsis invicta, mobility within crowded nest tunnels is important for resource and information transport. Within confined tunnels, communication and traffic flow are at odds: trafficking ants communicate through tactile interactions while stopped, yet ants that stop to communicate impose physical obstacles on the traffic. We monitor the bi-directional flow of fire ant workers in laboratory tunnels of varied diameter D. The persistence time of communicating ant aggregations, τ, increases approximately linearly with the number of participating ants, n. The sensitivity of traffic flow increases as D decreases and diverges at a minimum diameter, Dc. A cellular automata model incorporating minimal traffic features--excluded volume and communication duration--reproduces features of the experiment. From the model we identify a competition between information transfer and the need to maintain jam-free traffic flow. We show that by balancing information transfer and traffic flow demands, an optimum group strategy exists which maximizes information throughput. We acknowledge funding from NSF PoLS #0957659 and #PHY-1205878.

Bidirectional Relationship between Cognitive Function and Pneumonia

PubMed Central

Shah, Faraaz Ali; Pike, Francis; Alvarez, Karina; Angus, Derek; Newman, Anne B.; Lopez, Oscar; Tate, Judith; Kapur, Vishesh; Wilsdon, Anthony; Krishnan, Jerry A.; Hansel, Nadia; Au, David; Avdalovic, Mark; Fan, Vincent S.; Barr, R. Graham

2013-01-01

Rationale: Relationships between chronic health conditions and acute infections remain poorly understood. Preclinical studies suggest crosstalk between nervous and immune systems. Objectives: To determine bidirectional relationships between cognition and pneumonia. Methods: We conducted longitudinal analyses of a population-based cohort over 10 years. We determined whether changes in cognition increase risk of pneumonia hospitalization by trajectory analyses and joint modeling. We then determined whether pneumonia hospitalization increased risk of subsequent dementia using a Cox model with pneumonia as a time-varying covariate. Measurements and Main Results: Of the 5,888 participants, 639 (10.9%) were hospitalized with pneumonia at least once. Most participants had normal cognition before pneumonia. Three cognition trajectories were identified: no, minimal, and severe rapid decline. A greater proportion of participants hospitalized with pneumonia were on trajectories of minimal or severe decline before occurrence of pneumonia compared with those never hospitalized with pneumonia (proportion with no, minimal, and severe decline were 67.1%, 22.8%, and 10.0% vs. 76.0%, 19.3%, and 4.6% for participants with and without pneumonia, respectively; P < 0.001). Small subclinical changes in cognition increased risk of pneumonia, even in those with normal cognition and physical function before pneumonia (β = −0.02; P < 0.001). Participants with pneumonia were subsequently at an increased risk of dementia (hazard ratio, 2.24 [95% confidence interval, 1.62–3.11]; P = 0.01). Associations were independent of demographics, health behaviors, other chronic conditions, and physical function. Bidirectional relationship did not vary based on severity of disease, and similar associations were noted for those with severe sepsis and other infections. Conclusions: A bidirectional relationship exists between pneumonia and cognition and may explain how a single episode of infection in well-appearing older individuals accelerates decline in chronic health conditions and loss of functional independence. PMID:23848267

Overview and Status of the Laser Communication Relay Demonstration

NASA Technical Reports Server (NTRS)

Luzhanskiy, E.; Edwards, B.; Israel, D.; Cornwell, D.; Staren, J.; Cummings, N.; Roberts, T.; Patschke, R.

2016-01-01

NASA is presently developing first all optical high data rate satellite relay system, LCRD. To be flown on commercial geosynchronous satellite, it will communicate at DPSK and PPM modulation formats up to 1.244 Gbps. LCRD flight payload is being developed by NASA's Goddard Space Flight Center. The two ground stations, one on Table Mountain in CA, developed by NASA's Jet Propulsion Laboratory and another on Hawaiian island will enable bi-directional relay operation and ground sites diversity experiments. In this paper we will report on the current state of LCRD system development, planned operational scenarios and expected system performance.

Chip-to-Chip Half Duplex Spiking Data Communication over Power Supply Rails

NASA Astrophysics Data System (ADS)

Hashida, Takushi; Nagata, Makoto

Chip-to-chip serial data communication is superposed on power supply over common Vdd/Vss connections through chip, package, and board traces. A power line transceiver demonstrates half duplex spiking communication at more than 100Mbps. A pair of transceivers consumes 1.35mA from 3.3V, at 130Mbps. On-chip power line LC low pass filter attenuates pseudo-differential communication spikes by 30dB, purifying power supply current for internal circuits. Bi-directional spiking communication was successfully examined in a 90-nm CMOS prototype setup of on-chip waveform capturing. A micro controller forwards clock pulses to and receives data streams from a comparator based waveform capturer formed on a different chip, through a single pair of power and ground traces. The bit error rate is small enough not to degrade waveform acquisition capability, maintaining the spurious free dynamic range of higher than 50dB.

EPPRD: An Efficient Privacy-Preserving Power Requirement and Distribution Aggregation Scheme for a Smart Grid.

PubMed

Zhang, Lei; Zhang, Jing

2017-08-07

A Smart Grid (SG) facilitates bidirectional demand-response communication between individual users and power providers with high computation and communication performance but also brings about the risk of leaking users' private information. Therefore, improving the individual power requirement and distribution efficiency to ensure communication reliability while preserving user privacy is a new challenge for SG. Based on this issue, we propose an efficient and privacy-preserving power requirement and distribution aggregation scheme (EPPRD) based on a hierarchical communication architecture. In the proposed scheme, an efficient encryption and authentication mechanism is proposed for better fit to each individual demand-response situation. Through extensive analysis and experiment, we demonstrate how the EPPRD resists various security threats and preserves user privacy while satisfying the individual requirement in a semi-honest model; it involves less communication overhead and computation time than the existing competing schemes.

A wireless medical monitoring over a heterogeneous sensor network.

PubMed

Yuce, Mehmet R; Ng, Peng Choong; Lee, Chin K; Khan, Jamil Y; Liu, Wentai

2007-01-01

This paper presents a heterogeneous sensor network system that has the capability to monitor physiological parameters from multiple patient bodies by means of different communication standards. The system uses the recently opened medical band called MICS (Medical Implant Communication Service) between the sensor nodes and a remote central control unit (CCU) that behaves as a base station. The CCU communicates with another network standard (the internet or a mobile network) for a long distance data transfer. The proposed system offers mobility to patients and flexibility to medical staff to obtain patient's physiological data on demand basis via Internet. A prototype sensor network including hardware, firmware and software designs has been implemented and tested by incorporating temperature and pulse rate sensors on nodes. The developed system has been optimized for power consumption by having the nodes sleep when there is no communication via a bidirectional communication.

EPPRD: An Efficient Privacy-Preserving Power Requirement and Distribution Aggregation Scheme for a Smart Grid

PubMed Central

Zhang, Lei; Zhang, Jing

2017-01-01

A Smart Grid (SG) facilitates bidirectional demand-response communication between individual users and power providers with high computation and communication performance but also brings about the risk of leaking users’ private information. Therefore, improving the individual power requirement and distribution efficiency to ensure communication reliability while preserving user privacy is a new challenge for SG. Based on this issue, we propose an efficient and privacy-preserving power requirement and distribution aggregation scheme (EPPRD) based on a hierarchical communication architecture. In the proposed scheme, an efficient encryption and authentication mechanism is proposed for better fit to each individual demand-response situation. Through extensive analysis and experiment, we demonstrate how the EPPRD resists various security threats and preserves user privacy while satisfying the individual requirement in a semi-honest model; it involves less communication overhead and computation time than the existing competing schemes. PMID:28783122

Global exponential stability of bidirectional associative memory neural networks with distributed delays

NASA Astrophysics Data System (ADS)

Song, Qiankun; Cao, Jinde

2007-05-01

A bidirectional associative memory neural network model with distributed delays is considered. By constructing a new Lyapunov functional, employing the homeomorphism theory, M-matrix theory and the inequality (a[greater-or-equal, slanted]0,bk[greater-or-equal, slanted]0,qk>0 with , and r>1), a sufficient condition is obtained to ensure the existence, uniqueness and global exponential stability of the equilibrium point for the model. Moreover, the exponential converging velocity index is estimated, which depends on the delay kernel functions and the system parameters. The results generalize and improve the earlier publications, and remove the usual assumption that the activation functions are bounded . Two numerical examples are given to show the effectiveness of the obtained results.

Bidirectional automatic release of reserve for low voltage network made with low capacity PLCs

NASA Astrophysics Data System (ADS)

Popa, I.; Popa, G. N.; Diniş, C. M.; Deaconu, S. I.

2018-01-01

The article presents the design of a bidirectional automatic release of reserve made on two types low capacity programmable logic controllers: PS-3 from Klöckner-Moeller and Zelio from Schneider. It analyses the electronic timing circuits that can be used for making the bidirectional automatic release of reserve: time-on delay circuit and time-off delay circuit (two types). In the paper are present the sequences code for timing performed on the PS-3 PLC, the logical functions for the bidirectional automatic release of reserve, the classical control electrical diagram (with contacts, relays, and time relays), the electronic control diagram (with logical gates and timing circuits), the code (in IL language) made for the PS-3 PLC, and the code (in FBD language) made for Zelio PLC. A comparative analysis will be carried out on the use of the two types of PLC and will be present the advantages of using PLCs.

The intestinal microbiome, probiotics and prebiotics in neurogastroenterology

PubMed Central

Saulnier, Delphine M.; Ringel, Yehuda; Heyman, Melvin B.; Foster, Jane A.; Bercik, Premysl; Shulman, Robert J.; Versalovic, James; Verdu, Elena F.; Dinan, Ted G.; Hecht, Gail; Guarner, Francisco

2013-01-01

The brain-gut axis allows bidirectional communication between the central nervous system (CNS) and the enteric nervous system (ENS), linking emotional and cognitive centers of the brain with peripheral intestinal functions. Recent experimental work suggests that the gut microbiota have an impact on the brain-gut axis. A group of experts convened by the International Scientific Association for Probiotics and Prebiotics (ISAPP) discussed the role of gut bacteria on brain functions and the implications for probiotic and prebiotic science. The experts reviewed and discussed current available data on the role of gut microbiota on epithelial cell function, gastrointestinal motility, visceral sensitivity, perception and behavior. Data, mostly gathered from animal studies, suggest interactions of gut microbiota not only with the enteric nervous system but also with the central nervous system via neural, neuroendocrine, neuroimmune and humoral links. Microbial colonization impacts mammalian brain development in early life and subsequent adult behavior. These findings provide novel insights for improved understanding of the potential role of gut microbial communities on psychological disorders, most particularly in the field of psychological comorbidities associated with functional bowel disorders like irritable bowel syndrome (IBS) and should present new opportunity for interventions with pro- and prebiotics. PMID:23202796

Gap junction-mediated calcium waves define communication networks among murine postnatal neural progenitor cells.

PubMed

Lacar, Benjamin; Young, Stephanie Z; Platel, Jean-Claude; Bordey, Angélique

2011-12-01

In the postnatal neurogenic niche, two populations of astrocyte-like cells (B cells) persist, one acting as neural progenitor cells (NPCs, B1 cells) and one forming a structural boundary between the neurogenic niche and the striatum (B2 cells, niche astrocytes). Despite being viewed as two distinct entities, we found that B1 and B2 cells express the gap junction protein connexin 43 and display functional coupling involving 50-60 cells. Using neonatal electroporation to label slowly cycling radial glia-derived B1 cells, which send a basal process onto blood vessels, we further confirmed dye coupling between NPCs. To assess the functionality of the coupling, we used calcium imaging in a preparation preserving the three-dimensional architecture of the subventricular zone. Intercellular calcium waves were observed among B cells. These waves travelled bidirectionally between B1 and B2 cells and propagated on blood vessels. Inter-B-cell calcium waves were absent in the presence of a gap junction blocker but persisted with purinergic receptor blockers. These findings show that privileged microdomains of communication networks exist among NPCs and niche astrocytes. Such functional coupling between these two cell types suggests that niche astrocytes do not merely have a structural role, but may play an active role in shaping the behavior of NPCs. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Promoting Healthy Workplaces by Building Cultures of Health and Applying Strategic Communications.

PubMed

Kent, Karen; Goetzel, Ron Z; Roemer, Enid C; Prasad, Aishwarya; Freundlich, Naomi

2016-02-01

The aim of the study was to identify key success elements of employer-sponsored health promotion (wellness) programs. We conducted an updated literature review, held discussions with subject matter experts, and visited nine companies with exemplary programs to examine current best and promising practices in workplace health promotion programs. Best practices include establishing a culture of health and using strategic communications. Key elements that contribute to a culture of health are leadership commitment, social and physical environmental support, and employee involvement. Strategic communications are designed to educate, motivate, market offerings, and build trust. They are tailored and targeted, multichanneled, bidirectional, with optimum timing, frequency, and placement. Increased efforts are needed to disseminate lessons learned from employers who have built cultures of health and excellent communications strategies and apply these insights more broadly in workplace settings.

Effective emissivities of isothermal blackbody cavities calculated by the Monte Carlo method using the three-component bidirectional reflectance distribution function model.

PubMed

Prokhorov, Alexander

2012-05-01

This paper proposes a three-component bidirectional reflectance distribution function (3C BRDF) model consisting of diffuse, quasi-specular, and glossy components for calculation of effective emissivities of blackbody cavities and then investigates the properties of the new reflection model. The particle swarm optimization method is applied for fitting a 3C BRDF model to measured BRDFs. The model is incorporated into the Monte Carlo ray-tracing algorithm for isothermal cavities. Finally, the paper compares the results obtained using the 3C model and the conventional specular-diffuse model of reflection.

Upgrade of goniospectrophtometer GEFE for near-field scattering and fluorescence radiance measurements

NASA Astrophysics Data System (ADS)

Bernad, Berta; Ferrero, Alejandro; Pons, Alicia; Hernanz, M. L.; Campos, Joaquín.

2015-03-01

The goniospectrophotometer GEFE, designed and developed at IO-CSIC (Instituto de Optica, Agencia Estatal Consejo Superior de Investigaciones Cientificas), was conceived to measure the spectral Bidirectional Reflectance Distribution Function (BRDF) at any pair of irradiation and detection directions. Although the potential of this instrument has largely been proved, it still required to be upgraded to deal with some important scattering features for the assessment of the appearance. Since it was not provided with a detector with spatial resolution, it simply could not measure spectrophotometric quantities to characterize texture through the Bidirectional Texture Function (BTF) or translucency through the more complex Bidirectional Scattering-Surface Reflectance Distribution Function (BSSRDF). Another requirement in the GEFE upgrading was to provide it with the capability of measuring fluorescence at different geometries, since some of the new pigments used in industry are fluorescent, which can have a non-negligible impact in the color of the product. Then, spectral resolution at irradiation and detection had to be available in GEFE. This paper describes the upgrading of the goniospectrophotometer GEFE, and its new capabilities through the presentation of sparkle and goniofluorescence measurements. In addition, the potential of the instrument to evaluate translucency by the measurement of the BSSRDF is briefly discussed.

Multi-scale Material Appearance

NASA Astrophysics Data System (ADS)

Wu, Hongzhi

Modeling and rendering the appearance of materials is important for a diverse range of applications of computer graphics - from automobile design to movies and cultural heritage. The appearance of materials varies considerably at different scales, posing significant challenges due to the sheer complexity of the data, as well the need to maintain inter-scale consistency constraints. This thesis presents a series of studies around the modeling, rendering and editing of multi-scale material appearance. To efficiently render material appearance at multiple scales, we develop an object-space precomputed adaptive sampling method, which precomputes a hierarchy of view-independent points that preserve multi-level appearance. To support bi-scale material appearance design, we propose a novel reflectance filtering algorithm, which rapidly computes the large-scale appearance from small-scale details, by exploiting the low-rank structures of Bidirectional Visible Normal Distribution Functions and pre-rotated Bidirectional Reflectance Distribution Functions in the matrix formulation of the rendering algorithm. This approach can guide the physical realization of appearance, as well as the modeling of real-world materials using very sparse measurements. Finally, we present a bi-scale-inspired high-quality general representation for material appearance described by Bidirectional Texture Functions. Our representation is at once compact, easily editable, and amenable to efficient rendering.

Changes in reflectance anisotropy of wheat crop during different phenophases

NASA Astrophysics Data System (ADS)

Lunagaria, Manoj M.; Patel, Haridas R.

2017-04-01

The canopy structure of wheat changes significantly with growth stages and leads to changes in reflectance anisotropy. Bidirectional reflectance distribution function characterises the reflectance anisotropy of the targets, which can be approximated. Spectrodirectional reflectance measurements on wheat crop were acquired using a field goniometer system. The bidirectional reflectance spectra were acquired at 54 view angles to cover the hemispheric span up to 60° view zenith. The observations were made during early growth stages till maturity of the crop. The anisotropy was not constant for all wavelengths and anisotropic factors clearly revealed spectral dependence, which was more pronounced in near principal plane. In near infrared, wheat canopy expressed less reflectance anisotropy because of higher multiple scattering. The broad hotspot signature was noticeable in reflectance of canopy whenever view and solar angles were close. Distinct changes in bidirectional reflectance distribution function were observed during booting to flowering stages as the canopy achieves more uniformity, height and head emergence. The function clearly reveals bowl shape during heading to early milking growth stages of the crop. Late growth stages show less prominent gap and shadow effects. Anisotropy index revealed that wheat exhibits changes in reflectance anisotropy with phenological development and with spectral bands.

Host gene-microbiome interactions: molecular mechanisms in inflammatory bowel disease.

PubMed

Chu, Hiutung

2017-07-24

Recent studies have identified links between host genetic variants and microbial recognition of the microbiome. Defects in host-microbiome interactions in individuals harboring inflammatory bowel disease risk alleles may result in imbalances of the microbial community, impaired pathogen clearance, and failure to sense beneficial commensal microbes. These findings highlight the importance of maintaining bi-directional communication at the mucosal interface during intestinal homeostasis.

Technological evaluation of gesture and speech interfaces for enabling dismounted soldier-robot dialogue

NASA Astrophysics Data System (ADS)

Kattoju, Ravi Kiran; Barber, Daniel J.; Abich, Julian; Harris, Jonathan

2016-05-01

With increasing necessity for intuitive Soldier-robot communication in military operations and advancements in interactive technologies, autonomous robots have transitioned from assistance tools to functional and operational teammates able to service an array of military operations. Despite improvements in gesture and speech recognition technologies, their effectiveness in supporting Soldier-robot communication is still uncertain. The purpose of the present study was to evaluate the performance of gesture and speech interface technologies to facilitate Soldier-robot communication during a spatial-navigation task with an autonomous robot. Gesture and speech semantically based spatial-navigation commands leveraged existing lexicons for visual and verbal communication from the U.S Army field manual for visual signaling and a previously established Squad Level Vocabulary (SLV). Speech commands were recorded by a Lapel microphone and Microsoft Kinect, and classified by commercial off-the-shelf automatic speech recognition (ASR) software. Visual signals were captured and classified using a custom wireless gesture glove and software. Participants in the experiment commanded a robot to complete a simulated ISR mission in a scaled down urban scenario by delivering a sequence of gesture and speech commands, both individually and simultaneously, to the robot. Performance and reliability of gesture and speech hardware interfaces and recognition tools were analyzed and reported. Analysis of experimental results demonstrated the employed gesture technology has significant potential for enabling bidirectional Soldier-robot team dialogue based on the high classification accuracy and minimal training required to perform gesture commands.

Global asymptotic stability of hybrid bidirectional associative memory neural networks with time delays

NASA Astrophysics Data System (ADS)

Arik, Sabri

2006-02-01

This Letter presents a sufficient condition for the existence, uniqueness and global asymptotic stability of the equilibrium point for bidirectional associative memory (BAM) neural networks with distributed time delays. The results impose constraint conditions on the network parameters of neural system independently of the delay parameter, and they are applicable to all bounded continuous non-monotonic neuron activation functions. The results are also compared with the previous results derived in the literature.

Laser Pulse Bidirectional Reflectance from CALIPSO Mission

NASA Technical Reports Server (NTRS)

Lu, Xiaomei; Hu, Yongxiang; Yang, Yuekui; Liu, Zhaoyan; Vaughan, Mark; Lucker, Patricia; Trepte, Charles

2017-01-01

In this Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) study, we present a simple way of determining laser pulse bidirectional reflectance over snow/ice surface using the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) 532 nanometer polarization channels' measurements. The saturated laser pulse returns from snow and ice surfaces are recovered based on surface tail information. The method overview and initial assessment of the method performance will be presented. The retrieved snow surface bidirectional reflectance is compared with reflectance from both CALIOP cloud cover regions and Moderate Resolution Imaging Spectroradiometer (Earth Observing System (EOS)) (MODIS) Bi-directional Reflectance Distribution Function (BRDF) / Albedo model parameters. The comparisons show that the snow surface bidirectional reflectance over Antarctica for saturation region are generally reliable with a mean value of about 0.90 plus or minus 0.10, while the mean surface reflectance from cloud cover region is about 0.84 plus or minus 0.13 and the calculated MODIS reflectance at 555 nanometers from the BRDF / Albedo model with near nadir illumination and viewing angles is about 0.96 plus or minus 0.04. The comparisons here demonstrate that the snow surface reflectance underneath the cloud with cloud optical depth of about 1 is significantly lower than that for a clear sky condition.

A geometrical optics polarimetric bidirectional reflectance distribution function for dielectric and metallic surfaces.

PubMed

Hyde, M W; Schmidt, J D; Havrilla, M J

2009-11-23

A polarimetric bidirectional reflectance distribution function (pBRDF), based on geometrical optics, is presented. The pBRDF incorporates a visibility (shadowing/masking) function and a Lambertian (diffuse) component which distinguishes it from other geometrical optics pBRDFs in literature. It is shown that these additions keep the pBRDF bounded (and thus a more realistic physical model) as the angle of incidence or observation approaches grazing and better able to model the behavior of light scattered from rough, reflective surfaces. In this paper, the theoretical development of the pBRDF is shown and discussed. Simulation results of a rough, perfect reflecting surface obtained using an exact, electromagnetic solution and experimental Mueller matrix results of two, rough metallic samples are presented to validate the pBRDF.

Bidirectional Reflectance Modeling of Non-homogeneous Plant Canopies

NASA Technical Reports Server (NTRS)

Norman, J. M.

1984-01-01

Efforts to develop a three dimensional model to predict canopy, bidirectional reflectance for heterogenous plant stands using incident radiation and canopy structural descriptions as inputs are described. Utility programs were developed to cope with the complex output from the 3 dimensional model. In addition an attempt was made to define leaf and soil properties, which are appropriate to the mode, by measuring leaf and soil bidirectional reflectance distribution functions; since almost no data exist on these distributions. In the process it was realized that most models probably are using the wrong leaf spectral properties, and that off-nadir reflectance measurements are difficult to make because of non-Lambertian properties of reference surfaces. Also, in the visible wavebands, rough soil may not be distinguishable from canopies when viewed from above.

WEB - A Wireless Experiment Box for the Dextre Pointing Package ELC Payload

NASA Technical Reports Server (NTRS)

Bleier, Leor Z.; Marrero-Fontanez, Victor J.; Sparacino, Pietro A.; Moreau, Michael C.; Mitchell, Jason William

2012-01-01

The Wireless Experiment Box (WEB) was proposed to work with the International Space Station (ISS) External Wireless Communication (EWC) system to support high-definition video from the Dextre Pointing Package (DPP). DPP/WEB was a NASA GSFC proposed ExPRESS Logistics Carrier (ELC) payload designed to flight test an integrated suite of Autonomous Rendezvous and Docking (AR&D) technologies to enable a wide spectrum of future missions across NASA and other US Government agencies. The ISS EWC uses COTS Wireless Access Points (WAPs) to provide high-rate bi-directional communications to ISS. In this paper, we discuss WEB s packaging, operation, antenna development, and performance testing.

A reusable anatomically segmented digital mannequin for public health communication.

PubMed

Fujieda, Kaori; Okubo, Kosaku

2016-01-01

The ongoing development of world wide web technologies has facilitated a change in health communication, which has now become bi-directional and encompasses people with diverse backgrounds. To enable an even greater role for medical illustrations, a data set, BodyParts3D, has been generated and its data set can be used by anyone to create and exchange customised three-dimensional (3D) anatomical images. BP3D comprises more than 3000 3D object files created by segmenting a digital mannequin in accordance with anatomical naming conventions. This paper describes the methodologies and features used to generate an anatomically correct male mannequin.

Web: A Wireless Experiment Box for the Dextre Pointing Package ELC Payload

NASA Technical Reports Server (NTRS)

Bleier, Leor Z.; Marrero-Fontanez, Victor J.; Sparacino, Pietro A.; Moreau, Michael C.; Mitchell, Jason W.

2012-01-01

The Wireless Experiment Box (WEB) was proposed to work with the International Space Station (ISS) External Wireless Communication (EWC) system to support high-definition video from the Dextre Pointing Package (DPP). DPP/WEB was a NASA GSFC proposed ExPRESS Logistics Carrier (ELC) payload designed to flight test an integrated suite of Autonomous Rendezvous and Docking (AR&D) technologies to enable a wide spectrum of future missions across NASA and other US Government agencies. The ISS EWC uses COTS Wireless Access Points (WAPs) to provide high-rate bi-directional communications to ISS. In this paper, we discuss WEB s packaging, operation, antenna development, and performance testing.

Analysis of link performance for the FOENEX laser communications system

NASA Astrophysics Data System (ADS)

Juarez, Juan C.; Young, David W.; Venkat, Radha A.; Brown, David M.; Brown, Andrea M.; Oberc, Rachel L.; Sluz, Joseph E.; Pike, H. Alan; Stotts, Larry B.

2012-06-01

A series of experiments were conducted to validate the performance of the free-space optical communications (FSOC) subsystem under DARPA's FOENEX program. Over six days, bidirectional links at ranges of 10 and 17 km were characterized during different periods of the day to evaluate link performance. This paper will present the test configuration, evaluate performance of the FSOC subsystem against a variety of characterization approaches, and discuss the impact of the results, particularly with regards to the optical terminals. Finally, this paper will summarize the impact of turbulence conditions on the FSOC subsystem and present methods for estimating performance under different link distances and turbulence conditions.

Dialogue enabling speech-to-text user assistive agent system for hearing-impaired person.

PubMed

Lee, Seongjae; Kang, Sunmee; Han, David K; Ko, Hanseok

2016-06-01

A novel approach for assisting bidirectional communication between people of normal hearing and hearing-impaired is presented. While the existing hearing-impaired assistive devices such as hearing aids and cochlear implants are vulnerable in extreme noise conditions or post-surgery side effects, the proposed concept is an alternative approach wherein spoken dialogue is achieved by means of employing a robust speech recognition technique which takes into consideration of noisy environmental factors without any attachment into human body. The proposed system is a portable device with an acoustic beamformer for directional noise reduction and capable of performing speech-to-text transcription function, which adopts a keyword spotting method. It is also equipped with an optimized user interface for hearing-impaired people, rendering intuitive and natural device usage with diverse domain contexts. The relevant experimental results confirm that the proposed interface design is feasible for realizing an effective and efficient intelligent agent for hearing-impaired.

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

Bennett, C. V.; Mendez, A. J.

This was a collaborative effort between Lawrence Livermore National Security, LLC (formerly The Regents of the University of California)/Lawrence Livermore National Laboratory (LLNL) and Mendez R & D Associates (MRDA) to develop and demonstrate a reconfigurable and cost effective design for optical code division multiplexing (O-CDM) with high spectral efficiency and throughput, as applied to the field of distributed computing, including multiple accessing (sharing of communication resources) and bidirectional data distribution in fiber-to-the-premise (FTTx) networks.

A Summary of the Naval Postgraduate School Research Program.

DTIC Science & Technology

1982-05-01

and testing of PCM modu- lation formats, design and test of an underwater video line using a diver’s handheld camera and bi-directional interconnection...to design and develop advanced control schemes which successfully optimize the tor- pedo steering performance for Project Courageous. cummary: Work...investigating the feasibility and design of fiber optic communications in underwater torpedo ranges. Summary: An underwater fiber optic video uplink was

Contingency Management with Human Autonomy Teaming

NASA Technical Reports Server (NTRS)

Shively, Robert J.; Lachter, Joel B.

2018-01-01

Automation is playing an increasingly important role in many operations. It is often cheaper faster and more precise than human operators. However, automation is not perfect. There are many situations in which a human operator must step in. We refer to these instances as contingencies and the act of stepping in contingency management. Here we propose coupling Human Autonomy Teaming (HAT) with contingency management. We describe two aspects to HAT, bi-directional communication, and working agreements (or plays). Bi-directional communication like Crew Resource Management in traditional aviation, allows all parties to contribute to a decision. Working agreements specify roles and responsibilities. Importantly working agreements allow for the possibility of roles and responsibilities changing depending on environmental factors (e.g., situations the automation was not designed for, workload, risk, or trust). This allows for the automation to "automatically" become more autonomous as it becomes more trusted and/or it is updated to deal with a more complete set of possible situations. We present a concrete example using a prototype contingency management station one might find in a future airline operations center. Automation proposes reroutes for aircraft that encounter bad weather or are forced to divert for environmental or systems reasons. If specific conditions are met, these recommendations may be autonomously datalinked to the affected aircraft.

Global robust stability of bidirectional associative memory neural networks with multiple time delays.

PubMed

Senan, Sibel; Arik, Sabri

2007-10-01

This correspondence presents a sufficient condition for the existence, uniqueness, and global robust asymptotic stability of the equilibrium point for bidirectional associative memory neural networks with discrete time delays. The results impose constraint conditions on the network parameters of the neural system independently of the delay parameter, and they are applicable to all bounded continuous nonmonotonic neuron activation functions. Some numerical examples are given to compare our results with the previous robust stability results derived in the literature.

Periodic bidirectional associative memory neural networks with distributed delays

NASA Astrophysics Data System (ADS)

Chen, Anping; Huang, Lihong; Liu, Zhigang; Cao, Jinde

2006-05-01

Some sufficient conditions are obtained for the existence and global exponential stability of a periodic solution to the general bidirectional associative memory (BAM) neural networks with distributed delays by using the continuation theorem of Mawhin's coincidence degree theory and the Lyapunov functional method and the Young's inequality technique. These results are helpful for designing a globally exponentially stable and periodic oscillatory BAM neural network, and the conditions can be easily verified and be applied in practice. An example is also given to illustrate our results.

APC: A New Code for Atmospheric Polarization Computations

NASA Technical Reports Server (NTRS)

Korkin, Sergey V.; Lyapustin, Alexei I.; Rozanov, Vladimir V.

2014-01-01

A new polarized radiative transfer code Atmospheric Polarization Computations (APC) is described. The code is based on separation of the diffuse light field into anisotropic and smooth (regular) parts. The anisotropic part is computed analytically. The smooth regular part is computed numerically using the discrete ordinates method. Vertical stratification of the atmosphere, common types of bidirectional surface reflection and scattering by spherical particles or spheroids are included. A particular consideration is given to computation of the bidirectional polarization distribution function (BPDF) of the waved ocean surface.

Model of bidirectional reflectance distribution function for metallic materials

NASA Astrophysics Data System (ADS)

Wang, Kai; Zhu, Jing-Ping; Liu, Hong; Hou, Xun

2016-09-01

Based on the three-component assumption that the reflection is divided into specular reflection, directional diffuse reflection, and ideal diffuse reflection, a bidirectional reflectance distribution function (BRDF) model of metallic materials is presented. Compared with the two-component assumption that the reflection is composed of specular reflection and diffuse reflection, the three-component assumption divides the diffuse reflection into directional diffuse and ideal diffuse reflection. This model effectively resolves the problem that constant diffuse reflection leads to considerable error for metallic materials. Simulation and measurement results validate that this three-component BRDF model can improve the modeling accuracy significantly and describe the reflection properties in the hemisphere space precisely for the metallic materials.

Far-infrared /FIR/ optical black bidirectional reflectance distribution function /BRDF/

NASA Technical Reports Server (NTRS)

Smith, S. M.

1981-01-01

A nonspecular reflectometer and its operation at far-infrared wavelengths are described. Large differences in nonspecular reflectance were found to exist between different optically black coatings. Normal incidence bidirectional reflectance distribution function /BRDF) measurements at wavelengths between 12 and 316 microns of three black coatings show that their mean BRDFs increase with wavelength. The specularity of two of these coatings also showed a strong wavelength dependence, while the specularity of one coating seemed independent of wavelength. The BRDF of one coating depended on the angle of incidence at 12 and 38 microns, but not at 316 microns. Beyond 200 microns, it was found necessary to correct the measurements for the beam spread of the instrument.

Bidirectional Associations Between Newlyweds' Marital Satisfaction and Marital Problems over Time.

PubMed

Lavner, Justin A; Karney, Benjamin R; Williamson, Hannah C; Bradbury, Thomas N

2017-12-01

Prevailing views of marital functioning generally adopt the view that marital problems predict decreases in marital satisfaction, but alternative theoretical perspectives raise the possibility that lowered satisfaction can also predict increases in problems. The current study sought to integrate and compare these perspectives by examining the bidirectional cross-lagged associations between newlyweds' reports of their marital satisfaction and marital problems over the first 4 years of marriage. Using annual assessments from 483 heterosexual newlywed couples, we find evidence for problem-to-satisfaction linkages as well as satisfaction-to-problem linkages. Satisfaction was a stronger predictor of marital problems early in marriage but not as time passed; by Year 4 only problem-to-satisfaction linkages remained significant. These findings are consistent with the idea that couples with more problems go on to report lower levels of satisfaction and couples with lower levels of satisfaction go on to report more marital problems. This dynamic interplay between global judgments about relationship satisfaction and ongoing specific relationship difficulties highlights the value of examining bidirectional effects to better understand marital functioning over time. © 2016 Family Process Institute.

A Day in the Life of the Laser Communications Relay Demonstration Project

NASA Technical Reports Server (NTRS)

Edwards, Bernard; Israel, David; Caroglanian, Armen; Spero, James; Roberts, Tom; Moores, John

2016-01-01

This paper provides an overview of the planned concept of operations for the Laser Communications Relay Demonstration Project (LCRD), a joint project among NASA's Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory, California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL). LCRD will provide at least two years of bi-directional optical communications at user data rates of up to 1.244 Gbps in an operational environment. The project lays the groundwork for establishing communications architecture and protocols, and developing the communications hardware and support infrastructure, concluding in a demonstration of optical communications' potential to meet NASA's growing need for higher data rates for future science and exploration missions. A pair of flight optical communications terminals will reside on a single commercial communications satellite in geostationary orbit; the two ground optical communications terminals will be located in Southern California and Hawaii. This paper summarizes the current LCRD architecture and key systems for the demonstration, focusing on what it will take to operate an optical communications relay that can support space-to-space, space-to-air, and space-to-ground optical links.

A Day in the Life of the Laser Communications Relay Demonstration (LCRD) Project.

NASA Technical Reports Server (NTRS)

Israel, David; Caroglanian, Armen; Edwards, Bernard; Spero, James; Roberts, Tom; Moores, John

2016-01-01

This presentation provides an overview of the planned concept of operations for the Laser Communications Relay Demonstration Project (LCRD), a joint project among NASA's Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory, California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MITLL). LCRD will provide at least two years of bi-directional optical communications at user data rates of up to 1.244 Gbps in an operational environment. The project lays the ground work for establishing communications architecture and protocols, and developing the communications hardware and support infrastructure, concluding in a demonstration of optical communications potential to meet NASAs growing need for higher data rates for future science and exploration missions. A pair of flight optical communications terminals will reside on a single commercial communications satellite in geostationary orbit; the two ground optical communications terminals will be located in Southern California and Hawaii. This paper summarizes the current LCRD architecture and key systems for the demonstration, focusing on what it will take to operate an optical communications relay that can support space-to-space, space-to-air, and space-to-ground optical links.

Neural interface methods and apparatus to provide artificial sensory capabilities to a subject

DOEpatents

Buerger, Stephen P.; Olsson, III, Roy H.; Wojciechowski, Kenneth E.; Novick, David K.; Kholwadwala, Deepesh K.

2017-01-24

Embodiments of neural interfaces according to the present invention comprise sensor modules for sensing environmental attributes beyond the natural sensory capability of a subject, and communicating the attributes wirelessly to an external (ex-vivo) portable module attached to the subject. The ex-vivo module encodes and communicates the attributes via a transcutaneous inductively coupled link to an internal (in-vivo) module implanted within the subject. The in-vivo module converts the attribute information into electrical neural stimuli that are delivered to a peripheral nerve bundle within the subject, via an implanted electrode. Methods and apparatus according to the invention incorporate implantable batteries to power the in-vivo module allowing for transcutaneous bidirectional communication of low voltage (e.g. on the order of 5 volts) encoded signals as stimuli commands and neural responses, in a robust, low-error rate, communication channel with minimal effects to the subjects' skin.

A bidirectional relationship between physical activity and executive function in older adults

PubMed Central

Daly, Michael; McMinn, David; Allan, Julia L.

2015-01-01

Physically active lifestyles contribute to better executive function. However, it is unclear whether high levels of executive function lead people to be more active. This study uses a large sample and multi-wave data to identify whether a reciprocal association exists between physical activity and executive function. Participants were 4555 older adults tracked across four waves of the English Longitudinal Study of Aging. In each wave executive function was assessed using a verbal fluency test and a letter cancelation task and participants reported their physical activity levels. Fixed effects regressions showed that changes in executive function corresponded with changes in physical activity. In longitudinal multilevel models low levels of physical activity led to subsequent declines in executive function. Importantly, poor executive function predicted reductions in physical activity over time. This association was found to be over 50% larger in magnitude than the contribution of physical activity to changes in executive function. This is the first study to identify evidence for a robust bidirectional link between executive function and physical activity in a large sample of older adults tracked over time. PMID:25628552

Bidirectional fiber-IVLLC and fiber-wireless convergence system with two orthogonally polarized optical sidebands.

PubMed

Lu, Hai-Han; Wu, Hsiao-Wen; Li, Chung-Yi; Ho, Chun-Ming; Yang, Zih-Yi; Cheng, Ming-Te; Lu, Chang-Kai

2017-05-01

A bidirectional fiber-invisible laser light communication (IVLLC) and fiber-wireless convergence system with two orthogonally polarized optical sidebands for hybrid cable television (CATV)/millimeter-wave (MMW)/baseband (BB) signal transmission is proposed and experimentally demonstrated. Two optical sidebands generated by a 60-GHz MMW signal are orthogonally polarized and separated into different polarizations. These orthogonally polarized optical sidebands are delivered over a 40-km single-mode fiber (SMF) transport to effectually reduce the fiber dispersion induced by a 40-km SMF transmission and the distortion caused by the parallel polarized optical sidebands. To the best of our knowledge, this work is the first to adopt two orthogonally polarized optical sidebands in a bidirectional fiber-IVLLC and fiber-wireless convergence system to reduce fiber dispersion and distortion effectually. Good carrier-to-noise ratio, composite second order, composite triple beat, and bit error rate (BER) are achieved for downlink transmission at a 40-km SMF operation and a 100-m free-space optical (FSO) link/3-m RF wireless transmission. For up-link transmission, good BER performance is acquired over a 40-km SMF transport and a 100-m FSO link. The approach presented in this work signifies the advancements in the convergence of SMF-based backbone and optical/RF wireless-based feeder.

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

The microbiome: stress, health and disease.

PubMed

Moloney, Rachel D; Desbonnet, Lieve; Clarke, Gerard; Dinan, Timothy G; Cryan, John F

2014-02-01

Bacterial colonisation of the gut plays a major role in postnatal development and maturation of key systems that have the capacity to influence central nervous system (CNS) programming and signaling, including the immune and endocrine systems. Individually, these systems have been implicated in the neuropathology of many CNS disorders and collectively they form an important bidirectional pathway of communication between the microbiota and the brain in health and disease. Regulation of the microbiome-brain-gut axis is essential for maintaining homeostasis, including that of the CNS. Moreover, there is now expanding evidence for the view that commensal organisms within the gut play a role in early programming and later responsivity of the stress system. Research has focused on how the microbiota communicates with the CNS and thereby influences brain function. The routes of this communication are not fully elucidated but include neural, humoral, immune and metabolic pathways. This view is underpinned by studies in germ-free animals and in animals exposed to pathogenic bacterial infections, probiotic agents or antibiotics which indicate a role for the gut microbiota in the regulation of mood, cognition, pain and obesity. Thus, the concept of a microbiome-brain-gut axis is emerging which suggests that modulation of the gut microflora may be a tractable strategy for developing novel therapeutics for complex stress-related CNS disorders where there is a huge unmet medical need.

Detailed validation of the bidirectional effect in various Case 1 waters for application to ocean color imagery

NASA Astrophysics Data System (ADS)

Voss, K. J.; Morel, A.; Antoine, D.

2007-09-01

The radiance viewed from the ocean depends on the illumination and viewing geometry along with the water properties, and this variation is called the bidirectional effect. This bidirectional effect depends on the inherent optical properties of the water, including the volume scattering function, and is important when comparing data from different satellite sensors. The current model of f/Q, which contains the bidirectional effect, by Morel et al. (2002) depends on modeled, not measured, water parameters, thus must be carefully validated. In this paper we combined upwelling radiance distribution data from several cruises, in varied water types and with a wide range of solar zenith angles. We compared modeled and measured Lview/Lnadir and found that the average difference between the model and data was less than 0.01, while the RMS difference between the model and data was on the order of 0.02-0.03. This is well within the statistical noise of the data, which was on the order of 0.04-0.05, due to environmental noise sources such as wave focusing.

Renewable energy sources, the internet of things and the third industrial revolution: Smart grid and contemporary information and communication technologies

NASA Astrophysics Data System (ADS)

Kitsios, Aristidis; Bousakas, Konstantinos; Salame, Takla; Bogno, Bachirou; Papageorgas, Panagiotis; Vokas, Georgios A.; Mauffay, Fabrice; Petit, Pierre; Aillerie, Michel; Charles, Jean-Pierre

2017-02-01

In this paper, the energy efficiency of a contemporary Smart Grid that is based on Distributed Renewable Energy Sources (DRES) is examined under the scope of the communication systems utilized between the energy loads and the energy sources. What is evident is that the Internet of Things (IoT) technologies that are based on the existing Web infrastructure can be heavily introduced in this direction especially when combined with long range low bandwidth networking technologies, power line communication technologies and optimization methodologies for renewable energy generation. The renewable energy generation optimization will be based on devices embedded in the PV panels and the wind power generators, which will rely on bidirectional communications with local gateways and remote control stations for achieving energy efficiency. Smart meters and DRES combined with IoT communications will be the enabling technologies for the ultimate fusion of Internet technology and renewable energy generation realizing the Energy Internet.

Anxiety, Depression, and the Microbiome: A Role for Gut Peptides.

PubMed

Lach, Gilliard; Schellekens, Harriet; Dinan, Timothy G; Cryan, John F

2018-01-01

The complex bidirectional communication between the gut and the brain is finely orchestrated by different systems, including the endocrine, immune, autonomic, and enteric nervous systems. Moreover, increasing evidence supports the role of the microbiome and microbiota-derived molecules in regulating such interactions; however, the mechanisms underpinning such effects are only beginning to be resolved. Microbiota-gut peptide interactions are poised to be of great significance in the regulation of gut-brain signaling. Given the emerging role of the gut-brain axis in a variety of brain disorders, such as anxiety and depression, it is important to understand the contribution of bidirectional interactions between peptide hormones released from the gut and intestinal bacteria in the context of this axis. Indeed, the gastrointestinal tract is the largest endocrine organ in mammals, secreting dozens of different signaling molecules, including peptides. Gut peptides in the systemic circulation can bind cognate receptors on immune cells and vagus nerve terminals thereby enabling indirect gut-brain communication. Gut peptide concentrations are not only modulated by enteric microbiota signals, but also vary according to the composition of the intestinal microbiota. In this review, we will discuss the gut microbiota as a regulator of anxiety and depression, and explore the role of gut-derived peptides as signaling molecules in microbiome-gut-brain communication. Here, we summarize the potential interactions of the microbiota with gut hormones and endocrine peptides, including neuropeptide Y, peptide YY, pancreatic polypeptide, cholecystokinin, glucagon-like peptide, corticotropin-releasing factor, oxytocin, and ghrelin in microbiome-to-brain signaling. Together, gut peptides are important regulators of microbiota-gut-brain signaling in health and stress-related psychiatric illnesses.

A Brain-Machine Interface Instructed by Direct Intracortical Microstimulation

PubMed Central

O'Doherty, Joseph E.; Lebedev, Mikhail A.; Hanson, Timothy L.; Fitzsimmons, Nathan A.; Nicolelis, Miguel A. L.

2009-01-01

Brain–machine interfaces (BMIs) establish direct communication between the brain and artificial actuators. As such, they hold considerable promise for restoring mobility and communication in patients suffering from severe body paralysis. To achieve this end, future BMIs must also provide a means for delivering sensory signals from the actuators back to the brain. Prosthetic sensation is needed so that neuroprostheses can be better perceived and controlled. Here we show that a direct intracortical input can be added to a BMI to instruct rhesus monkeys in choosing the direction of reaching movements generated by the BMI. Somatosensory instructions were provided to two monkeys operating the BMI using either: (a) vibrotactile stimulation of the monkey's hands or (b) multi-channel intracortical microstimulation (ICMS) delivered to the primary somatosensory cortex (S1) in one monkey and posterior parietal cortex (PP) in the other. Stimulus delivery was contingent on the position of the computer cursor: the monkey placed it in the center of the screen to receive machine–brain recursive input. After 2 weeks of training, the same level of proficiency in utilizing somatosensory information was achieved with ICMS of S1 as with the stimulus delivered to the hand skin. ICMS of PP was not effective. These results indicate that direct, bi-directional communication between the brain and neuroprosthetic devices can be achieved through the combination of chronic multi-electrode recording and microstimulation of S1. We propose that in the future, bidirectional BMIs incorporating ICMS may become an effective paradigm for sensorizing neuroprosthetic devices. PMID:19750199

Neuroimmune Interface in the Comorbidity between Alcohol Use Disorder and Major Depression

PubMed Central

Neupane, Sudan Prasad

2016-01-01

Bidirectional communication links operate between the brain and the body. Afferent immune-to-brain signals are capable of inducing changes in mood and behavior. Chronic heavy alcohol drinking, typical of alcohol use disorder (AUD), is one such factor that provokes an immune response in the periphery that, by means of circulatory cytokines and other neuroimmune mediators, ultimately causes alterations in the brain function. Alcohol can also directly impact the immune functions of microglia, the resident immune cells of the central nervous system (CNS). Several lines of research have established the contribution of specific inflammatory mediators in the development and progression of depressive illness. Much of the available evidence in this field stems from cross-sectional data on the immune interactions between isolated AUD and major depression (MD). Given their heterogeneity as disease entities with overlapping symptoms and shared neuroimmune correlates, it is no surprise that systemic and CNS inflammation could be a critical determinant of the frequent comorbidity between AUD and MD. This review presents a summary and analysis of the extant literature on neuroimmune interface in the AUD–MD comorbidity. PMID:28082989

Bidirectional relationship between time preference and adolescent smoking and alcohol use: Evidence from longitudinal data.

PubMed

Do, Young Kyung; Shin, Eunhae

2017-07-01

Scholarly interest in time preference as a potential predictor of risky health behaviors in adolescents has increased in recent years. However, most of the existing literature is limited due to the exclusive reliance on cross-sectional data, precluding the possibility of establishing the direction of causality. Using longitudinal data from the Korea Youth Panel Survey (2003-7), which followed up a nationally representative sample of 3449 adolescents aged 14years for five years, this study examines a bidirectional relationship between time preference and smoking and drinking behaviors among adolescents. We used discrete time hazard models of smoking and drinking initiation as a function of time preference measured at the baseline and fixed-effects ordered logit model of time preference, respectively. Our measure of time preference was derived from the survey question on a hypothetical choice between immediate enjoyment today and likely higher scores on an exam tomorrow. The overall results provide evidence on the bidirectional relationship; that is, higher time discounting (i.e., greater relative preference for present utility over future utility) results in an increased risk of engaging in smoking and drinking, and conversely, adopting such behaviors leads to a higher discount rate. The bidirectional relationship may function as a mechanism for adolescents to engage in increased smoking and drinking or additional negative health behaviors via gateway effects, strengthening the case for preventing the initiation of risky health behaviors among adolescents. Copyright © 2017 Elsevier Ltd. All rights reserved.

Principal Components Analysis on the spectral Bidirectional Reflectance Distribution Function of ceramic colour standards.

PubMed

Ferrero, A; Campos, J; Rabal, A M; Pons, A; Hernanz, M L; Corróns, A

2011-09-26

The Bidirectional Reflectance Distribution Function (BRDF) is essential to characterize an object's reflectance properties. This function depends both on the various illumination-observation geometries as well as on the wavelength. As a result, the comprehensive interpretation of the data becomes rather complex. In this work we assess the use of the multivariable analysis technique of Principal Components Analysis (PCA) applied to the experimental BRDF data of a ceramic colour standard. It will be shown that the result may be linked to the various reflection processes occurring on the surface, assuming that the incoming spectral distribution is affected by each one of these processes in a specific manner. Moreover, this procedure facilitates the task of interpolating a series of BRDF measurements obtained for a particular sample. © 2011 Optical Society of America

Printable Silicon Nanomembranes for Solar-Powered, Bi-Directional Phased-Array-Antenna Communication System on Flexible Substrates

DTIC Science & Technology

2013-04-01

Identification (RFID), Large Area Flexible Displays, Electronic Paper, Bio - Sensors , Large Area Conformal and Flexible Antennas, Smart and Interactive Textiles...Lepeshkin, R. W. Boyd, C. Chase, and J. E. Fajardo, “An environmental sensor based on an integrated optical whispering gallery mode disk resonator ...Ubiquitous Sensor Networks (USN), Vehicle Clickers Readers, Real Time Locating Systems, Lighting, Photovoltaics etc. FA9550-11-C-0014 STTR Phase II

Using a logical information model-driven design process in healthcare.

PubMed

Cheong, Yu Chye; Bird, Linda; Tun, Nwe Ni; Brooks, Colleen

2011-01-01

A hybrid standards-based approach has been adopted in Singapore to develop a Logical Information Model (LIM) for healthcare information exchange. The Singapore LIM uses a combination of international standards, including ISO13606-1 (a reference model for electronic health record communication), ISO21090 (healthcare datatypes), SNOMED CT (healthcare terminology) and HL7 v2 (healthcare messaging). This logic-based design approach also incorporates mechanisms for achieving bi-directional semantic interoperability.

Affective communication in rodents: ultrasonic vocalizations as a tool for research on emotion and motivation.

PubMed

Wöhr, Markus; Schwarting, Rainer K W

2013-10-01

Mice and rats emit and perceive calls in the ultrasonic range, i.e., above the human hearing threshold of about 20 kHz: so-called ultrasonic vocalizations (USV). Juvenile and adult rats emit 22-kHz USV in aversive situations, such as predator exposure and fighting or during drug withdrawal, whereas 50-kHz USV occur in appetitive situations, such as rough-and-tumble play and mating or in response to drugs of abuse, e.g., amphetamine. Aversive 22-kHz USV and appetitive 50-kHz USV serve distinct communicative functions. Whereas 22-kHz USV induce freezing behavior in the receiver, 50-kHz USV lead to social approach behavior. These opposite behavioral responses are paralleled by distinct patterns of brain activation. Freezing behavior in response to 22-kHz USV is paralleled by increased neuronal activity in brain areas regulating fear and anxiety, such as the amygdala and periaqueductal gray, whereas social approach behavior elicited by 50-kHz USV is accompanied by reduced activity levels in the amygdala but enhanced activity in the nucleus accumbens, a brain area implicated in reward processing. These opposing behavioral responses, together with distinct patterns of brain activation, particularly the bidirectional tonic activation or deactivation of the amygdala elicited by 22-kHz and 50-kHz USV, respectively, concur with a wealth of behavioral and neuroimaging studies in humans involving emotionally salient stimuli, such as fearful and happy facial expressions. Affective ultrasonic communication therefore offers a translational tool for studying the neurobiology underlying socio-affective communication. This is particularly relevant for rodent models of neurodevelopmental disorders characterized by social and communication deficits, such as autism and schizophrenia.

A Bidirectional Brain-Machine Interface Featuring a Neuromorphic Hardware Decoder.

PubMed

Boi, Fabio; Moraitis, Timoleon; De Feo, Vito; Diotalevi, Francesco; Bartolozzi, Chiara; Indiveri, Giacomo; Vato, Alessandro

2016-01-01

Bidirectional brain-machine interfaces (BMIs) establish a two-way direct communication link between the brain and the external world. A decoder translates recorded neural activity into motor commands and an encoder delivers sensory information collected from the environment directly to the brain creating a closed-loop system. These two modules are typically integrated in bulky external devices. However, the clinical support of patients with severe motor and sensory deficits requires compact, low-power, and fully implantable systems that can decode neural signals to control external devices. As a first step toward this goal, we developed a modular bidirectional BMI setup that uses a compact neuromorphic processor as a decoder. On this chip we implemented a network of spiking neurons built using its ultra-low-power mixed-signal analog/digital circuits. On-chip on-line spike-timing-dependent plasticity synapse circuits enabled the network to learn to decode neural signals recorded from the brain into motor outputs controlling the movements of an external device. The modularity of the BMI allowed us to tune the individual components of the setup without modifying the whole system. In this paper, we present the features of this modular BMI and describe how we configured the network of spiking neuron circuits to implement the decoder and to coordinate it with the encoder in an experimental BMI paradigm that connects bidirectionally the brain of an anesthetized rat with an external object. We show that the chip learned the decoding task correctly, allowing the interfaced brain to control the object's trajectories robustly. Based on our demonstration, we propose that neuromorphic technology is mature enough for the development of BMI modules that are sufficiently low-power and compact, while being highly computationally powerful and adaptive.

A Bidirectional Brain-Machine Interface Featuring a Neuromorphic Hardware Decoder

PubMed Central

Boi, Fabio; Moraitis, Timoleon; De Feo, Vito; Diotalevi, Francesco; Bartolozzi, Chiara; Indiveri, Giacomo; Vato, Alessandro

2016-01-01

Bidirectional brain-machine interfaces (BMIs) establish a two-way direct communication link between the brain and the external world. A decoder translates recorded neural activity into motor commands and an encoder delivers sensory information collected from the environment directly to the brain creating a closed-loop system. These two modules are typically integrated in bulky external devices. However, the clinical support of patients with severe motor and sensory deficits requires compact, low-power, and fully implantable systems that can decode neural signals to control external devices. As a first step toward this goal, we developed a modular bidirectional BMI setup that uses a compact neuromorphic processor as a decoder. On this chip we implemented a network of spiking neurons built using its ultra-low-power mixed-signal analog/digital circuits. On-chip on-line spike-timing-dependent plasticity synapse circuits enabled the network to learn to decode neural signals recorded from the brain into motor outputs controlling the movements of an external device. The modularity of the BMI allowed us to tune the individual components of the setup without modifying the whole system. In this paper, we present the features of this modular BMI and describe how we configured the network of spiking neuron circuits to implement the decoder and to coordinate it with the encoder in an experimental BMI paradigm that connects bidirectionally the brain of an anesthetized rat with an external object. We show that the chip learned the decoding task correctly, allowing the interfaced brain to control the object's trajectories robustly. Based on our demonstration, we propose that neuromorphic technology is mature enough for the development of BMI modules that are sufficiently low-power and compact, while being highly computationally powerful and adaptive. PMID:28018162

From gut dysbiosis to altered brain function and mental illness: mechanisms and pathways

PubMed Central

Rogers, G B; Keating, D J; Young, R L; Wong, M-L; Licinio, J; Wesselingh, S

2016-01-01

The human body hosts an enormous abundance and diversity of microbes, which perform a range of essential and beneficial functions. Our appreciation of the importance of these microbial communities to many aspects of human physiology has grown dramatically in recent years. We know, for example, that animals raised in a germ-free environment exhibit substantially altered immune and metabolic function, while the disruption of commensal microbiota in humans is associated with the development of a growing number of diseases. Evidence is now emerging that, through interactions with the gut–brain axis, the bidirectional communication system between the central nervous system and the gastrointestinal tract, the gut microbiome can also influence neural development, cognition and behaviour, with recent evidence that changes in behaviour alter gut microbiota composition, while modifications of the microbiome can induce depressive-like behaviours. Although an association between enteropathy and certain psychiatric conditions has long been recognized, it now appears that gut microbes represent direct mediators of psychopathology. Here, we examine roles of gut microbiome in shaping brain development and neurological function, and the mechanisms by which it can contribute to mental illness. Further, we discuss how the insight provided by this new and exciting field of research can inform care and provide a basis for the design of novel, microbiota-targeted, therapies. PMID:27090305

Mechanisms Underlying the Essential Role of Mitochondrial Membrane Lipids in Yeast Chronological Aging

PubMed Central

Medkour, Younes; Dakik, Paméla; McAuley, Mélissa; Mohammad, Karamat; Mitrofanova, Darya

2017-01-01

The functional state of mitochondria is vital to cellular and organismal aging in eukaryotes across phyla. Studies in the yeast Saccharomyces cerevisiae have provided evidence that age-related changes in some aspects of mitochondrial functionality can create certain molecular signals. These signals can then define the rate of cellular aging by altering unidirectional and bidirectional communications between mitochondria and other organelles. Several aspects of mitochondrial functionality are known to impact the replicative and/or chronological modes of yeast aging. They include mitochondrial electron transport, membrane potential, reactive oxygen species, and protein synthesis and proteostasis, as well as mitochondrial synthesis of iron-sulfur clusters, amino acids, and NADPH. Our recent findings have revealed that the composition of mitochondrial membrane lipids is one of the key aspects of mitochondrial functionality affecting yeast chronological aging. We demonstrated that exogenously added lithocholic bile acid can delay chronological aging in yeast because it elicits specific changes in mitochondrial membrane lipids. These changes allow mitochondria to operate as signaling platforms that delay yeast chronological aging by orchestrating an institution and maintenance of a distinct cellular pattern. In this review, we discuss molecular and cellular mechanisms underlying the essential role of mitochondrial membrane lipids in yeast chronological aging. PMID:28593023

Retrieval of background surface reflectance with BRD components from pre-running BRDF

NASA Astrophysics Data System (ADS)

Choi, Sungwon; Lee, Kyeong-Sang; Jin, Donghyun; Lee, Darae; Han, Kyung-Soo

2016-10-01

Many countries try to launch satellite to observe the Earth surface. As important of surface remote sensing is increased, the reflectance of surface is a core parameter of the ground climate. But observing the reflectance of surface by satellite have weakness such as temporal resolution and being affected by view or solar angles. The bidirectional effects of the surface reflectance may make many noises to the time series. These noises can lead to make errors when determining surface reflectance. To correct bidirectional error of surface reflectance, using correction model for normalized the sensor data is necessary. A Bidirectional Reflectance Distribution Function (BRDF) is making accuracy higher method to correct scattering (Isotropic scattering, Geometric scattering, Volumetric scattering). To correct bidirectional error of surface reflectance, BRDF was used in this study. To correct bidirectional error of surface reflectance, we apply Bidirectional Reflectance Distribution Function (BRDF) to retrieve surface reflectance. And we apply 2 steps for retrieving Background Surface Reflectance (BSR). The first step is retrieving Bidirectional Reflectance Distribution (BRD) coefficients. Before retrieving BSR, we did pre-running BRDF to retrieve BRD coefficients to correct scatterings (Isotropic scattering, Geometric scattering, Volumetric scattering). In pre-running BRDF, we apply BRDF with observed surface reflectance of SPOT/VEGETATION (VGT-S1) and angular data to get BRD coefficients for calculating scattering. After that, we apply BRDF again in the opposite direction with BRD coefficients and angular data to retrieve BSR as a second step. As a result, BSR has very similar reflectance to one of VGT-S1. And reflectance in BSR is shown adequate. The highest reflectance of BSR is not over 0.4μm in blue channel, 0.45μm in red channel, 0.55μm in NIR channel. And for validation we compare reflectance of clear sky pixel from SPOT/VGT status map data. As a result of comparing BSR with VGT-S1, bias is from 0.0116 to 0.0158 and RMSE is from 0.0459 to 0.0545. They are very reasonable results, so we confirm that BSR is similar to VGT-S1. And weakness of this study is missing pixel in BSR which are observed less time to retrieve BRD components. If missing pixels are filled, BSR is better to retrieve surface products with more accuracy. And we think that after filling the missing pixel and being more accurate, it can be useful data to retrieve surface product which made by surface reflectance like cloud masking and retrieving aerosol.

Experimental investigation of the deformable mirror with bidirectional thermal actuators.

PubMed

Huang, Lei; Ma, Xingkun; Gong, Mali; Bian, Qi

2015-06-29

A deformable mirror with actuators of thermoelectric coolers (TECs) is introduced in this paper. Due to the bidirectional thermal actuation property of the TEC, both upward and downward surface control is available for the DM. The response functions of the actuators are investigated. A close-loop wavefront control experiment is performed too, where the defocus and the astigmatism were corrected. The results reveal that there is a promising prospect for the novel design to be used in corrections of static aberrations, such as in the Inertial Confinement Fusion (ICF).

Performance analysis and comparison of a minimum interconnections direct storage model with traditional neural bidirectional memories.

PubMed

Bhatti, A Aziz

2009-12-01

This study proposes an efficient and improved model of a direct storage bidirectional memory, improved bidirectional associative memory (IBAM), and emphasises the use of nanotechnology for efficient implementation of such large-scale neural network structures at a considerable lower cost reduced complexity, and less area required for implementation. This memory model directly stores the X and Y associated sets of M bipolar binary vectors in the form of (MxN(x)) and (MxN(y)) memory matrices, requires O(N) or about 30% of interconnections with weight strength ranging between +/-1, and is computationally very efficient as compared to sequential, intraconnected and other bidirectional associative memory (BAM) models of outer-product type that require O(N(2)) complex interconnections with weight strength ranging between +/-M. It is shown that it is functionally equivalent to and possesses all attributes of a BAM of outer-product type, and yet it is simple and robust in structure, very large scale integration (VLSI), optical and nanotechnology realisable, modular and expandable neural network bidirectional associative memory model in which the addition or deletion of a pair of vectors does not require changes in the strength of interconnections of the entire memory matrix. The analysis of retrieval process, signal-to-noise ratio, storage capacity and stability of the proposed model as well as of the traditional BAM has been carried out. Constraints on and characteristics of unipolar and bipolar binaries for improved storage and retrieval are discussed. The simulation results show that it has log(e) N times higher storage capacity, superior performance, faster convergence and retrieval time, when compared to traditional sequential and intraconnected bidirectional memories.

Assessment of a Bidirectional Reflectance Distribution Correction of Above-Water and Satellite Water-Leaving Radiance in Coastal Waters

NASA Technical Reports Server (NTRS)

Hlaing, Soe; Gilerson, Alexander; Harmal, Tristan; Tonizzo, Alberto; Weidemann, Alan; Arnone, Robert; Ahmed, Samir

2012-01-01

Water-leaving radiances, retrieved from in situ or satellite measurements, need to be corrected for the bidirectional properties of the measured light in order to standardize the data and make them comparable with each other. The current operational algorithm for the correction of bidirectional effects from the satellite ocean color data is optimized for typical oceanic waters. However, versions of bidirectional reflectance correction algorithms specifically tuned for typical coastal waters and other case 2 conditions are particularly needed to improve the overall quality of those data. In order to analyze the bidirectional reflectance distribution function (BRDF) of case 2 waters, a dataset of typical remote sensing reflectances was generated through radiative transfer simulations for a large range of viewing and illumination geometries. Based on this simulated dataset, a case 2 water focused remote sensing reflectance model is proposed to correct above-water and satellite water-leaving radiance data for bidirectional effects. The proposed model is first validated with a one year time series of in situ above-water measurements acquired by collocated multispectral and hyperspectral radiometers, which have different viewing geometries installed at the Long Island Sound Coastal Observatory (LISCO). Match-ups and intercomparisons performed on these concurrent measurements show that the proposed algorithm outperforms the algorithm currently in use at all wavelengths, with average improvement of 2.4% over the spectral range. LISCO's time series data have also been used to evaluate improvements in match-up comparisons of Moderate Resolution Imaging Spectroradiometer satellite data when the proposed BRDF correction is used in lieu of the current algorithm. It is shown that the discrepancies between coincident in-situ sea-based and satellite data decreased by 3.15% with the use of the proposed algorithm.

[Differences of bi-directional regulative effects between acu-moxibustion and Chinese materia medica interventions].

PubMed

Cao, Xin; Yu, Zhi; Xu, Bin

2012-10-01

Bi-directional regulation is referred to a balancing effect of both acu-moxibustion and Chinese materia medica interventions when the human body is experiencing a hyperactivity or hypoactivity due to abnormal intrinsic or external factors. In the present paper, the authors analyze their identical and different characteristics from: 1) definition; 2) characters of regulative effects of acu-moxibustion therapy: A) differentiation of meridian and zangfu-organs being the basis of treatment, B) four factors (acupoint-location, body's functional state, acupoint-formula and needle-manipulation techniques) dependant, C) entirety regulation, and D) centrotaxis modulation; 3) characters of Chinese materia medica intervention: including a) correspondence between the drug property and the syndrome being the basis of the regulative effect, b) multi-factors [components (antagonist and agonist), combination, dosages and processing quality of Chinese materia medica, and functional state of the human body] dependant, c) entirety regulation, and d) both centrotaxis and deviation adjustment. In one word, the bi-directional regulation effect is one of the basic characteristics of both acu-moxibustion and Chinese materia medica in clinical practice, but their basis and modes for inducing effects are different.

A lab-in-a-droplet bioassay strategy for centrifugal microfluidics with density difference pumping, power to disc and bidirectional flow control.

PubMed

Wang, Guanghui; Ho, Ho-Pui; Chen, Qiulan; Yang, Alice Kar-Lai; Kwok, Ho-Chin; Wu, Shu-Yuen; Kong, Siu-Kai; Kwan, Yiu-Wa; Zhang, Xuping

2013-09-21

In this paper, we present a lab-in-a-droplet bioassay strategy for a centrifugal microfluidics or lab-on-a-disc (LOAD) platform with three important advancements including density difference pumping, power to disc and bidirectional flow control. First, with the water based bioassay droplets trapped in a micro-channel filled with mineral oil, centrifugal force due to the density difference between the water and oil phases actuates droplet movement while the oil based medium remains stationary. Second, electricity is coupled to the rotating disc through a split-core transformer, thus enabling on-chip real-time heating in selected areas as desired and wireless programmable functionality. Third, an inertial mechanical structure is proposed to achieve bidirectional flow control within the spinning disc. The droplets can move back and forth between two heaters upon changing the rotational speed. Our platform is an essential and versatile solution for bioassays such as those involving DNA amplification, where localized temperature cycling is required. Finally, without the loss of generality, we demonstrate the functionality of our platform by performing real-time polymerase chain reaction (RT-PCR) in a linear microchannel made with PTFE (Teflon) micro-tubing.

Bidirectional measurements of surface reflectance for view angle corrections of oblique imagery

NASA Technical Reports Server (NTRS)

Jackson, R. D.; Teillet, P. M.; Slater, P. N.; Fedosejevs, G.; Jasinski, Michael F.

1990-01-01

An apparatus for acquiring bidirectional reflectance-factor data was constructed and used over four surface types. Data sets were obtained over a headed wheat canopy, bare soil having several different roughness conditions, playa (dry lake bed), and gypsum sand. Results are presented in terms of relative bidirectional reflectance factors (BRFs) as a function of view angle at a number of solar zenith angles, nadir BRFs as a function of solar zenith angles, and, for wheat, vegetation indices as related to view and solar zenith angles. The wheat canopy exhibited the largest BRF changes with view angle. BRFs for the red and the NIR bands measured over wheat did not have the same relationship with view angle. NIR/Red ratios calculated from nadir BRFs changed by nearly a factor of 2 when the solar zenith angle changed from 20 to 50 degs. BRF versus view angle relationships were similar for soils having smooth and intermediate rough surfaces but were considerably different for the roughest surface. Nadir BRF versus solar-zenith angle relationships were distinctly different for the three soil roughness levels. Of the various surfaces, BRFs for gypsum sand changed the least with view angle (10 percent at 30 degs).

Finite-Time Stability for Fractional-Order Bidirectional Associative Memory Neural Networks with Time Delays

NASA Astrophysics Data System (ADS)

Xu, Chang-Jin; Li, Pei-Luan; Pang, Yi-Cheng

2017-02-01

This paper is concerned with fractional-order bidirectional associative memory (BAM) neural networks with time delays. Applying Laplace transform, the generalized Gronwall inequality and estimates of Mittag-Leffler functions, some sufficient conditions which ensure the finite-time stability of fractional-order bidirectional associative memory neural networks with time delays are obtained. Two examples with their simulations are given to illustrate the theoretical findings. Our results are new and complement previously known results. Supported by National Natural Science Foundation of China under Grant Nos.~61673008, 11261010, 11101126, Project of High-Level Innovative Talents of Guizhou Province ([2016]5651), Natural Science and Technology Foundation of Guizhou Province (J[2015]2025 and J[2015]2026), 125 Special Major Science and Technology of Department of Education of Guizhou Province ([2012]011) and Natural Science Foundation of the Education Department of Guizhou Province (KY[2015]482)

Bi-directional ROADM with one pair of NxN cyclic-AWGs for over N wavelength channels configuration

NASA Astrophysics Data System (ADS)

Tsai, Cheng-Mu

2018-01-01

This paper presents a bidirectional optical add-drop multiplexer (BROADM) with permitting white spectral channels input in bidirectional configuration. The filter routing rule of array waveguide grating (AWG) is applied for the wavelength channels (WCs) that need to be added and dropped by using the corresponding tunable fiber Bragg gratings (FBGs). The other WCs pass through output by tuning FBG filter spectra away from the WCs. The bandwidth between two adjacent WCs of each pair of ports in AWG is wider than one channel spacing so that the filter spectra of FBG is tuned to free spectral range (FSR) region to realize the wavelength routing function without interfering other WCs. The WCs can be flexibly handled by installing the corresponding tunable FBG. Therefore, the proposed BROADM is more flexible and has higher transmission capacity in the optical network.

Excellent selector performance in engineered Ag/ZrO2:Ag/Pt structure for high-density bipolar RRAM applications

NASA Astrophysics Data System (ADS)

Wang, Chao; Song, Bing; Zeng, Zhongming

2017-12-01

A high-performance selector with bidirectional threshold switching (TS) characteristics of Ag/ZrO2/Pt structure was prepared by incorporating metallic Ag into the ZrO2 matrix. The bidirectional TS device exhibited excellent switching uniformity, forming-free behavior, ultra-low off current of <1 nA and adjustable selectivity (from 102 to 107). The experiment results confirmed that metallic Ag clusters were penetrated into the ZrO2 matrix during the annealing process, which would function as an effective active source responsible for the bidirectional TS. The volatile behavior could be explained by the self-dissolution of unstable filaments caused by minimization of the interfacial energy and thermal effect. Furthermore, a bipolar-type one selector-one resistor (1S-1R) memory device was successfully fabricated and exhibited significant suppression of the undesired sneak current, indicating the great potential as selector in a cross-point array.

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

Regulating Cortical Oscillations in an Inhibition-Stabilized Network.

PubMed

Jadi, Monika P; Sejnowski, Terrence J

2014-04-21

Understanding the anatomical and functional architecture of the brain is essential for designing neurally inspired intelligent systems. Theoretical and empirical studies suggest a role for narrowband oscillations in shaping the functional architecture of the brain through their role in coding and communication of information. Such oscillations are ubiquitous signals in the electrical activity recorded from the brain. In the cortex, oscillations detected in the gamma range (30-80 Hz) are modulated by behavioral states and sensory features in complex ways. How is this regulation achieved? Although several underlying principles for the genesis of these oscillations have been proposed, a unifying account for their regulation has remained elusive. In a network of excitatory and inhibitory neurons operating in an inhibition-stabilized regime, we show that strongly superlinear responses of inhibitory neurons facilitate bidirectional regulation of oscillation frequency and power. In such a network, the balance of drives to the excitatory and inhibitory populations determines how the power and frequency of oscillations are modulated. The model accounts for the puzzling increase in their frequency with the salience of visual stimuli, and a decrease with their size. Oscillations in our model grow stronger as the mean firing level is reduced, accounting for the size dependence of visually evoked gamma rhythms, and suggesting a role for oscillations in improving the signal-to-noise ratio (SNR) of signals in the brain. Empirically testing such predictions is still challenging, and implementing the proposed coding and communication strategies in neuromorphic systems could assist in our understanding of the biological system.

Functional Characterization of a Bidirectional Plant Promoter from Cotton Leaf Curl Burewala Virus Using an Agrobacterium-Mediated Transient Assay

PubMed Central

Ashraf, Muhammad Aleem; Shahid, Ahmad Ali; Rao, Abdul Qayyum; Bajwa, Kamran Shehzad; Husnain, Tayyab

2014-01-01

The C1 promoter expressing the AC1 gene, and V1 promoter expressing the AV1 gene are located in opposite orientations in the large intergenic region of the Cotton leaf curl Burewala virus (CLCuBuV) genome. Agro-infiltration was used to transiently express putative promoter constructs in Nicotiana tabacum and Gossypium hirsutum leaves, which was monitored by a GUS reporter gene, and revealed that the bidirectional promoter of CLCuBuV transcriptionally regulates both the AC1 and AV1 genes. The CLCuBuV C1 gene promoter showed a strong, consistent transient expression of the reporter gene (GUS) in N. tabacum and G. hirsutum leaves and exhibited GUS activity two- to three-fold higher than the CaMV 35S promoter. The CLCuBuV bidirectional genepromoter is a nearly constitutive promoter that contains basic conserved elements. Many cis-regulatory elements (CREs) were also analyzed within the bidirectional plant promoters of CLCuBuV and closely related geminiviruses, which may be helpful in understanding the transcriptional regulation of both the virus and host plant. PMID:24424501

Myths on Bi-direction Communication of Web 2.0 Based Social Networks: Is Social Network Truly Interactive?

DTIC Science & Technology

2011-03-10

more and more social interactions are happening on the on-line. Especially recent uptake of the social network sites (SNSs), such as Facebook (http...results give overviews on social interactions on a popular social network site . As each twitter account has different characteristics based on...the public and individuals post their private stories on their blogs and share their interests using social network sites . On the other hand, people

Calf pump activity influencing venous hemodynamics in the lower extremity.

PubMed

Recek, Cestmir

2013-03-01

Calf muscle pump is the motive force enhancing return of venous blood from the lower extremity to the heart. It causes displacement of venous blood in both vertical and horizontal directions, generates ambulatory pressure gradient between thigh and lower leg veins, and bidirectional streaming within calf perforators. Ambulatory pressure gradient triggers venous reflux in incompetent veins, which induces ambulatory venous hypertension in the lower leg and foot. Bidirectional flow in calf perforators enables quick pressure equalization between deep and superficial veins of the lower leg; the outward (into the superficial veins) oriented component of the bidirectional flow taking place during calf muscle contraction is no pathological reflux but a physiological centripetal flow streaming via great saphenous vein into the femoral vein. Calf perforators are communicating channels between both systems making them conjoined vessels; they are not involved in the generation of pathological hemodynamic situations, nor do they cause ambulatory venous hypertension. The real cause why recurrences develop has not as yet been cleared. Pressure gradient arising during calf pump activity between the femoral vein and the saphenous remnant after abolition of saphenous reflux triggers biophysical and biochemical events, which might induce recurrence. Thus, abolition of saphenous reflux removes the hemodynamic disturbance, but at the same time it generates precondition for reflux recurrence and for the comeback of the previous pathological situation; this chain of events has been called hemodynamic paradox.

Bidirectional communication between the Aryl hydrocarbon Receptor (AhR) and the microbiome tunes host metabolism.

PubMed

Korecka, Agata; Dona, Anthony; Lahiri, Shawon; Tett, Adrian James; Al-Asmakh, Maha; Braniste, Viorica; D'Arienzo, Rossana; Abbaspour, Afrouz; Reichardt, Nicole; Fujii-Kuriyama, Yoshiaki; Rafter, Joseph; Narbad, Arjan; Holmes, Elaine; Nicholson, Jeremy; Arulampalam, Velmurugesan; Pettersson, Sven

2016-01-01

The ligand-induced transcription factor, aryl hydrocarbon receptor (AhR) is known for its capacity to tune adaptive immunity and xenobiotic metabolism-biological properties subject to regulation by the indigenous microbiome. The objective of this study was to probe the postulated microbiome-AhR crosstalk and whether such an axis could influence metabolic homeostasis of the host. Utilising a systems-biology approach combining in-depth 1 H-NMR-based metabonomics (plasma, liver and skeletal muscle) with microbiome profiling (small intestine, colon and faeces) of AhR knockout (AhR -/- ) and wild-type (AhR +/+ ) mice, we assessed AhR function in host metabolism. Microbiome metabolites such as short-chain fatty acids were found to regulate AhR and its target genes in liver and intestine. The AhR signalling pathway, in turn, was able to influence microbiome composition in the small intestine as evident from microbiota profiling of the AhR +/+ and AhR -/- mice fed with diet enriched with a specific AhR ligand or diet depleted of any known AhR ligands. The AhR -/- mice also displayed increased levels of corticosterol and alanine in serum. In addition, activation of gluconeogenic genes in the AhR -/- mice was indicative of on-going metabolic stress. Reduced levels of ketone bodies and reduced expression of genes involved in fatty acid metabolism in the liver further underscored this observation. Interestingly, exposing AhR -/- mice to a high-fat diet showed resilience to glucose intolerance. Our data suggest the existence of a bidirectional AhR-microbiome axis, which influences host metabolic pathways.

Extended bidirectional reflectance distribution function for polarized light scattering from subsurface defects under a smooth surface.

PubMed

Shen, Jian; Deng, Degang; Kong, Weijin; Liu, Shijie; Shen, Zicai; Wei, Chaoyang; He, Hongbo; Shao, Jianda; Fan, Zhengxiu

2006-11-01

By introducing the scattering probability of a subsurface defect (SSD) and statistical distribution functions of SSD radius, refractive index, and position, we derive an extended bidirectional reflectance distribution function (BRDF) from the Jones scattering matrix. This function is applicable to the calculation for comparison with measurement of polarized light-scattering resulting from a SSD. A numerical calculation of the extended BRDF for the case of p-polarized incident light was performed by means of the Monte Carlo method. Our numerical results indicate that the extended BRDF strongly depends on the light incidence angle, the light scattering angle, and the out-of-plane azimuth angle. We observe a 180 degrees symmetry with respect to the azimuth angle. We further investigate the influence of the SSD density, the substrate refractive index, and the statistical distributions of the SSD radius and refractive index on the extended BRDF. For transparent substrates, we also find the dependence of the extended BRDF on the SSD positions.

DNA cleavage site selection by Type III restriction enzymes provides evidence for head-on protein collisions following 1D bidirectional motion

PubMed Central

Schwarz, Friedrich W.; van Aelst, Kara; Tóth, Júlia; Seidel, Ralf; Szczelkun, Mark D.

2011-01-01

DNA cleavage by the Type III Restriction–Modification enzymes requires communication in 1D between two distant indirectly-repeated recognitions sites, yet results in non-specific dsDNA cleavage close to only one of the two sites. To test a recently proposed ATP-triggered DNA sliding model, we addressed why one site is selected over another during cleavage. We examined the relative cleavage of a pair of identical sites on DNA substrates with different distances to a free or protein blocked end, and on a DNA substrate using different relative concentrations of protein. Under these conditions a bias can be induced in the cleavage of one site over the other. Monte-Carlo simulations based on the sliding model reproduce the experimentally observed behaviour. This suggests that cleavage site selection simply reflects the dynamics of the preceding stochastic enzyme events that are consistent with bidirectional motion in 1D and DNA cleavage following head-on protein collision. PMID:21724613

Massively parallel processor computer

NASA Technical Reports Server (NTRS)

Fung, L. W. (Inventor)

1983-01-01

An apparatus for processing multidimensional data with strong spatial characteristics, such as raw image data, characterized by a large number of parallel data streams in an ordered array is described. It comprises a large number (e.g., 16,384 in a 128 x 128 array) of parallel processing elements operating simultaneously and independently on single bit slices of a corresponding array of incoming data streams under control of a single set of instructions. Each of the processing elements comprises a bidirectional data bus in communication with a register for storing single bit slices together with a random access memory unit and associated circuitry, including a binary counter/shift register device, for performing logical and arithmetical computations on the bit slices, and an I/O unit for interfacing the bidirectional data bus with the data stream source. The massively parallel processor architecture enables very high speed processing of large amounts of ordered parallel data, including spatial translation by shifting or sliding of bits vertically or horizontally to neighboring processing elements.

The Dichotomous Effect of Chronic Stress on Obesity.

PubMed

Razzoli, Maria; Bartolomucci, Alessandro

2016-07-01

Obesity and metabolic diseases are linked to chronic stress and low socioeconomic status. The mechanistic link between stress and obesity has not been clarified, partly due to the inherent complexity exemplified by the bidirectional effect of stress on eating and body weight. Recent studies focusing on adaptive thermogenesis and brown adipose tissue (BAT) function support a dichotomous relation to explain the impact of stress on obesity: stress promotes obesity in the presence of hyperphagia and unchanged BAT function; stress results in weight loss and/or obesity resistance in the presence of hypophagia, or when hyperphagia is associated with BAT recruitment and enhanced thermogenesis. Mechanistically dissecting the bidirectional effects of stress on metabolic outcomes might open new avenues for innovative pharmacotherapies for the treatment of obesity-associated diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

The dichotomous effect of chronic stress on obesity

PubMed Central

Razzoli, Maria; Bartolomucci, Alessandro

2016-01-01

Obesity and metabolic diseases are linked to chronic stress and low socio-economic status. The mechanistic link between stress and obesity has not been clarified, partly due to the inherent complexity exemplified by the bidirectional effect of stress on eating and body weight. Recent studies focusing on adaptive-thermogenesis and brown adipose tissue (BAT) function support a dichotomous relationship to explain the impact of stress on obesity: stress promotes obesity in the presence of hyperphagia and unchanged BAT function; stress results in weight-loss/obesity-resistance in the presence of hypophagia, or when hyperphagia is associated with BAT recruitment and enhanced thermogenesis. Mechanistically dissecting the bidirectional effects of stress on metabolic outcomes might open new avenues for innovative pharmacotherapies for the treatment of obesity-associated diseases. PMID:27162125

NMR-based metabonomic analysis of normal rat urine and faeces in response to (±)-venlafaxine treatment.

PubMed

Serrano-Contreras, José I; García-Pérez, Isabel; Meléndez-Camargo, María E; Zepeda-Vallejo, Luis G

2016-05-10

(±)-Venlafaxine, a bicyclic antidepressant of the serotonin-norepinephrine reuptake inhibitor (SNRI) class, is prescribed for the treatment of depression and anxiety disorders. As is the case with other antidepressants, its precise mechanisms of action are still unknown. Pharmacometabonomic approaches allow for the detection of diverse metabolites, unlike classic methods for analysing drug interaction based on single metabolites and linear pathways. This provides a global view of the state of homeostasis during treatment and an insight into the mechanisms of action of a drug. Accordingly, the final outcome of treatment is characterised by the network of reactome pathways derived from the on-target and off-target effects of the drug. Regarding antidepressants, the drug network may be located in the gut-microbiome-brain-liver-kidney-immune-cardiovascular system axis (GMBLKICA), implying that neurotransmitters participate as signalling molecules in bidirectional communication. If their bioavailability is increased, this communication and the state of homeostasis may be disrupted. With a pharmacometabonomic approach using NMR in combination with different chemometric methods, a determination was made of subtle changes in the metabolic profile (metabotype) of urine and faeces in normal Wistar rats following a single administration of pharmacological doses of (±)-venlafaxine hydrochloride. Based on the drug-response metabotypes observed, (±)-venlafaxine had effects on gut microbial co-metabolites and osmolytes. Hence, it can be hypothesized that bidirectional communication in the multiorgan axis was perturbed by this drug, and very likely by its active metabolite, (±)-desvenlafaxine. This disrupted signalling could be related not only to therapeutic and adverse effects, but also to the lag period in treatment response. Copyright © 2016 Elsevier B.V. All rights reserved.

Developing a Bidirectional Academic–Community Partnership with an Appalachian-American Community for Environmental Health Research and Risk Communication

PubMed Central

Beidler, Caroline; Wittberg, Richard; Meloncon, Lisa; Parin, Megan; Kopras, Elizabeth J.; Succop, Paul; Dietrich, Kim N.

2011-01-01

Background: Marietta, Ohio, is an Appalachian-American community whose residents have long struggled with understanding their exposure to airborne manganese (Mn). Although community engagement in research is strongly endorsed by the National Institutes of Health and the National Institute of Environmental Health Sciences in particular, little has been documented demonstrating how an academic–community partnership that implements the community-based participatory research (CBPR) principles can be created and mobilized for research. Objectives: We created a bidirectional, academic–community partnership with an Appalachian-American community to a) identify the community’s thoughts and perceptions about local air quality, its effect on health, and the perception of risk communication sources and b) jointly develop and conduct environmental health research. Methods: We formed a community advisory board (CAB), jointly conducted pilot research studies, and used the results to develop a community-driven research agenda. Results: Persons in the community were “very concerned” to “concerned” about local air quality (91%) and perceived the air quality to have a direct impact on their health and on their children’s health (93% and 94%, respectively). The CAB identified the primary research question: “Does Mn affect the cognition and behavior of children?” Although the community members perceived research scientists as the most trusted and knowledgeable regarding risks from industrial emissions, they received very little risk information from research scientists. Conclusions: Engaging a community in environmental health research from its onset enhanced the quality and relevance of the research investigation. The CBPR principles were a useful framework in building a strong academic–community partnership. Because of the current disconnect between communities and research scientists, academic researchers should consider working collaboratively with community-based risk communication sources. PMID:21680278

AAH Cage Out-Link and In-Link Antenna Characterization

NASA Technical Reports Server (NTRS)

Jeutter, Dean C.

1998-01-01

This final report encapsulates the accomplishments of the third year of work on an Advanced Biotelemetry System (ABTS). Overall MU/ABTS project objectives are to provide a biotelemetry system that can collect data from and send commands to an implanted biotransceiver. This system will provide for studies of rodent development in space. The system must be capable of operating in a metal animal cage environment. An important goal is the development of a small, "smart", micropower, -channel data output and single channel command implantable biotransceiver with eight input capabilities with the flexibility for easy customization for a variety of physiologic investigations. The NASA Ames/Marquette University Joint Research work has been devoted to the system design of such a new state of the art biotelemetry system, having multiple physiologic inputs, and bi-directional data transfer capabilities. This work has provided a successful prototype system that connects, by two-way radio links, an addressable biotelemetry system that provides communication between an animal biotelemeter prototype and a personal computer. The operational features of the prototype system are listed below: Two-Way PCM Communication with Implanted Biotelemeter Microcontroller Based Biotelemeter Out-Link: Wideband FSK (60 kbaud) In-Link: OOK (2.4 kbaud) Septum Antenna Arrays (In/Out-Links) Personal Computer Data Interface The important requirement of this third year's work, to demonstrate two-way communication with transmit and receive antennas inside the metal animal cage, has been successfully accomplished. The advances discussed in this report demonstrate that the AAH cage antenna system can provide Out-link and In-link capability for the ABTS bi-directional telemetry system, and can serve as a benchmark for project status.

Dyadic Dynamics in Young Couples Reporting Dating Violence: An Actor-Partner Interdependence Model.

PubMed

Paradis, Alison; Hébert, Martine; Fernet, Mylène

2017-01-01

This study uses a combination of observational methods and dyadic data analysis to understand how boyfriends' and girlfriends' perpetration of dating violence (DV) may shape their own and their partners' problem-solving communication behaviors. A sample of 39 young heterosexual couples aged between 15 and 20 years (mean age = 17.8 years) completed a set of questionnaires and were observed during a 45-min dyadic interaction, which was coded using the Interactional Dimension Coding System (IDCS). Results suggest that neither boyfriends' nor girlfriends' own perpetration of DV was related to their display of positive and negative communication behaviors. However, estimates revealed significant partner effects, suggesting that negative communication behaviors displayed by girls and boys and positive communication behavior displayed by girls were associated to their partner's DV but not to their own. Such results confirm the need to shift our focus from an individual perspective to examining dyadic influences and processes involved in the couple system and the bidirectionality of violent relationships. © The Author(s) 2015.

Dyadic Dynamics in Young Couples Reporting Dating Violence: An Actor-Partner interdependence model

PubMed Central

Paradis, Alison; Hébert, Martine; Fernet, Mylène

2016-01-01

This study uses a combination of observational methods and dyadic data analysis to understand how boyfriends’ and girlfriends’ perpetration of dating violence may shape their own and their partners’ problem-solving communication behaviors. A sample of 39 young heterosexual couples aged between 15 and 20 years (mean age 17.8 years) completed a set of questionnaires and were observed during a 45 minute dyadic interaction, which was coded using the Interactional Dimension Coding System (IDCS). Results suggest that, neither boyfriends nor girlfriends own perpetration of dating violence was related to their display of positive and negative communication behaviors. However, estimates revealed significant partner effects, suggesting that negative communication behaviors displayed by girls and boys and positive communication behavior displayed by girls were associated to their partner’s dating violence but not to their own. Such results confirm the need to shift our focus from an individual perspective to examining dyadic influences and processes involved in the couple system and the bi-directionality of violent relationships. PMID:25969443

Attitudes, Patterns of Recommendation, and Communication of Pediatric Providers About Complementary and Alternative Medicine in a Large Metropolitan Children’s Hospital

PubMed Central

Kundu, Anjana; Tassone, Rosalie F.; Jimenez, Nathalia; Seidel, Kristy; Valentine, Jessica K.; Pagel, Paul S.

2014-01-01

The authors conducted an Email survey of their medical staff to explore the attitudes, patterns of recommendation, and communication of pediatric providers about complementary and alternative medicine (CAM) in a large metropolitan children’s hospital. Two thirds of the respondents reported awareness about their patients’ CAM therapy use (65%) and recommended CAM therapy to their patients (67%). Providers who reported personal use of CAM (71%) were more likely to recommend CAM to their patients compared with those who do not (76% vs 45%; P < .05). One half of pediatric providers reported occasional consultation with their patient’s CAM provider, but bidirectional communication was rare (4%). Specific changes in care based on a CAM provider’s recommendations were also unusual (4%). Despite the positive attitudes about and willingness to recommend CAM by pediatric providers, communication between these clinicians and CAM providers may be less than ideal. PMID:21127080

Experimental multiplexing of quantum key distribution with classical optical communication

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

Wang, Liu-Jun; Chen, Luo-Kan; Ju, Lei

2015-02-23

We demonstrate the realization of quantum key distribution (QKD) when combined with classical optical communication, and synchronous signals within a single optical fiber. In the experiment, the classical communication sources use Fabry-Pérot (FP) lasers, which are implemented extensively in optical access networks. To perform QKD, multistage band-stop filtering techniques are developed, and a wavelength-division multiplexing scheme is designed for the multi-longitudinal-mode FP lasers. We have managed to maintain sufficient isolation among the quantum channel, the synchronous channel and the classical channels to guarantee good QKD performance. Finally, the quantum bit error rate remains below a level of 2% across themore » entire practical application range. The proposed multiplexing scheme can ensure low classical light loss, and enables QKD over fiber lengths of up to 45 km simultaneously when the fibers are populated with bidirectional FP laser communications. Our demonstration paves the way for application of QKD to current optical access networks, where FP lasers are widely used by the end users.« less

“Optical communication with brain cells by means of an implanted duplex micro-device with optogenetics and Ca2+ fluoroimaging”

PubMed Central

Kobayashi, Takuma; Haruta, Makito; Sasagawa, Kiyotaka; Matsumata, Miho; Eizumi, Kawori; Kitsumoto, Chikara; Motoyama, Mayumi; Maezawa, Yasuyo; Ohta, Yasumi; Noda, Toshihiko; Tokuda, Takashi; Ishikawa, Yasuyuki; Ohta, Jun

2016-01-01

To better understand the brain function based on neural activity, a minimally invasive analysis technology in a freely moving animal is necessary. Such technology would provide new knowledge in neuroscience and contribute to regenerative medical techniques and prosthetics care. An application that combines optogenetics for voluntarily stimulating nerves, imaging to visualize neural activity, and a wearable micro-instrument for implantation into the brain could meet the abovementioned demand. To this end, a micro-device that can be applied to the brain less invasively and a system for controlling the device has been newly developed in this study. Since the novel implantable device has dual LEDs and a CMOS image sensor, photostimulation and fluorescence imaging can be performed simultaneously. The device enables bidirectional communication with the brain by means of light. In the present study, the device was evaluated in an in vitro experiment using a new on-chip 3D neuroculture with an extracellular matrix gel and an in vivo experiment involving regenerative medical transplantation and gene delivery to the brain by using both photosensitive channel and fluorescent Ca2+ indicator. The device succeeded in activating cells locally by selective photostimulation, and the physiological Ca2+ dynamics of neural cells were visualized simultaneously by fluorescence imaging. PMID:26878910

“Optical communication with brain cells by means of an implanted duplex micro-device with optogenetics and Ca2+ fluoroimaging”

NASA Astrophysics Data System (ADS)

Kobayashi, Takuma; Haruta, Makito; Sasagawa, Kiyotaka; Matsumata, Miho; Eizumi, Kawori; Kitsumoto, Chikara; Motoyama, Mayumi; Maezawa, Yasuyo; Ohta, Yasumi; Noda, Toshihiko; Tokuda, Takashi; Ishikawa, Yasuyuki; Ohta, Jun

2016-02-01

To better understand the brain function based on neural activity, a minimally invasive analysis technology in a freely moving animal is necessary. Such technology would provide new knowledge in neuroscience and contribute to regenerative medical techniques and prosthetics care. An application that combines optogenetics for voluntarily stimulating nerves, imaging to visualize neural activity, and a wearable micro-instrument for implantation into the brain could meet the abovementioned demand. To this end, a micro-device that can be applied to the brain less invasively and a system for controlling the device has been newly developed in this study. Since the novel implantable device has dual LEDs and a CMOS image sensor, photostimulation and fluorescence imaging can be performed simultaneously. The device enables bidirectional communication with the brain by means of light. In the present study, the device was evaluated in an in vitro experiment using a new on-chip 3D neuroculture with an extracellular matrix gel and an in vivo experiment involving regenerative medical transplantation and gene delivery to the brain by using both photosensitive channel and fluorescent Ca2+ indicator. The device succeeded in activating cells locally by selective photostimulation, and the physiological Ca2+ dynamics of neural cells were visualized simultaneously by fluorescence imaging.

Apps for immunization: Leveraging mobile devices to place the individual at the center of care.

PubMed

Wilson, Kumanan; Atkinson, Katherine M; Westeinde, Jacqueline

2015-01-01

Mobile technology and applications (apps) have disrupted several industries including healthcare. The advantage of apps, being personally focused and permitting bidirectional communication, make them well suited to address many immunization challenges. As of April 25, 2015 searching the Android app store with the words 'immunize app' and 'immunization app' in Canada yielded 225 apps. On the Apple App Store a similar search produced 98 results. These include apps that provide immunization related information, permit vaccine tracking both for individuals and for animals, assist with the creation of customized schedules and identification of vaccine clinics and serve as sources of education. The diverse functionality of mobile apps creates the potential for transformation of immunization practice both at a personal level and a system level. For individuals, mobile apps offer the opportunity for better record keeping, assistance with the logistics of vaccination, and novel ways of communicating with and receiving information from public health officials. For the system, mobile apps offer the potential to improve the quality of information residing in immunization information systems and program evaluation, facilitate harmonization of immunization information between individuals, health care providers and public health as well as reduce vaccine hesitancy. As mobile technology continues to rapidly evolve there will emerge new ways in which apps can enhance immunization practice.

Developing a General Framework for Human Autonomy Teaming

NASA Technical Reports Server (NTRS)

Lachter, Joel; Brandt, Summer; Shively, Jay

2017-01-01

Automation has entered nearly every aspect of our lives, but it often remains hard to understand. Why is this? Automation is often brittle, requiring constant human oversight to assure it operates as intended. This oversight has become harder as automation has become more complicated. To resolve this problem, Human-Autonomy Teaming (HAT) has been proposed. HAT looks to make automation act as more of a teammate, by having it communicate with human operators in a more human, goal-directed, manner which provides transparency into the reasoning behind automated recommendations and actions. This, in turn, permits more trust in the automation when it is appropriate, and less when it is not, allowing a more targeted supervision of automated functions. This paper proposes a framework for HAT, incorporating two key tenets: bi-directional communication, and operator directed authority. We have successfully applied these tenets to integrating the autonomous constrained flight planner (an aide for planning diverts) into a dispatch station. We propose the development of general design patterns that may allow these results to be generalized to domains such as photography and automotive navigation. While these domains are very different, we find application of our HAT tenets provides a number of opportunities for improving interaction between human operators and automation.

Electromagnetic assessment of embedded micro antenna for a novel sphincter in the human body.

PubMed

Zan, Peng; Liu, Jinding; Ai, Yutao; Jiang, Enyu

2013-05-01

This paper presents a wireless, miniaturized, bi-directional telemetric artificial anal sphincter system that can be used for controlling patients' anal incontinence. The artificial anal sphincter system is mainly composed of an executive mechanism, a wireless power supply system and a wireless communication system. The wireless communication system consists of an internal RF transceiver, an internal RF antenna, a data transmission pathway, an external RF antenna and an external RF control transceiver. A micro NMHA (Normal Mode Helical Antenna) has been used for the transceiver of the internal wireless communication system and a quarter wave-length whip antenna of 7.75 cm has been used for the external wireless communication system. The RF carrier frequency of wireless communication is located in a license-free 433.1 MHz ISM (Industry, Science, and Medical) band. The radiation characteristics and SAR (Specific Absorption Rate) are evaluated using the finite difference time-domain method and 3D human body model. Results show that the SAR values of the antenna satisfy the ICNIRP (International Commission on Nonionizing Radiation Protection) limitations.

Global asymptotic stability analysis of bidirectional associative memory neural networks with time delays.

PubMed

Arik, Sabri

2005-05-01

This paper presents a sufficient condition for the existence, uniqueness and global asymptotic stability of the equilibrium point for bidirectional associative memory (BAM) neural networks with distributed time delays. The results impose constraint conditions on the network parameters of neural system independently of the delay parameter, and they are applicable to all continuous nonmonotonic neuron activation functions. It is shown that in some special cases of the results, the stability criteria can be easily checked. Some examples are also given to compare the results with the previous results derived in the literature.

Preliminary Results from a Model-Driven Architecture Methodology for Development of an Event-Driven Space Communications Service Concept

NASA Technical Reports Server (NTRS)

Roberts, Christopher J.; Morgenstern, Robert M.; Israel, David J.; Borky, John M.; Bradley, Thomas H.

2017-01-01

NASA's next generation space communications network will involve dynamic and autonomous services analogous to services provided by current terrestrial wireless networks. This architecture concept, known as the Space Mobile Network (SMN), is enabled by several technologies now in development. A pillar of the SMN architecture is the establishment and utilization of a continuous bidirectional control plane space link channel and a new User Initiated Service (UIS) protocol to enable more dynamic and autonomous mission operations concepts, reduced user space communications planning burden, and more efficient and effective provider network resource utilization. This paper provides preliminary results from the application of model driven architecture methodology to develop UIS. Such an approach is necessary to ensure systematic investigation of several open questions concerning the efficiency, robustness, interoperability, scalability and security of the control plane space link and UIS protocol.

From synapse to nucleus and back again--communication over distance within neurons.

PubMed

Fainzilber, Mike; Budnik, Vivian; Segal, Rosalind A; Kreutz, Michael R

2011-11-09

How do neurons integrate intracellular communication from synapse to nucleus and back? Here we briefly summarize aspects of this topic covered by a symposium at Neuroscience 2011. A rich repertoire of signaling mechanisms link both dendritic terminals and axon tips with neuronal soma and nucleus, using motor-dependent transport machineries to traverse the long intracellular distances along neuronal processes. Activation mechanisms at terminals include localized translation of dendritic or axonal RNA, proteolytic cleavage of receptors or second messengers, and differential phosphorylation of signaling moieties. Signaling complexes may be transported in endosomes, or as non-endosomal complexes associated with importins and dynein. Anterograde transport of RNA granules from the soma to neuronal processes, coupled with retrograde transport of proteins translated locally at terminals or within processes, may fuel ongoing bidirectional communication between soma and synapse to modulate synaptic plasticity as well as neuronal growth and survival decisions.

Bidirectional communication between sensory neurons and osteoblasts in an in vitro coculture system.

PubMed

Kodama, Daisuke; Hirai, Takao; Kondo, Hisataka; Hamamura, Kazunori; Togari, Akifumi

2017-02-01

Recent studies have revealed that the sensory nervous system is involved in bone metabolism. However, the mechanism of communication between neurons and osteoblasts is yet to be elucidated. In this study, we investigated the signaling pathways between sensory neurons of the dorsal root ganglion (DRG) and the osteoblast-like MC3T3-E1 cells using an in vitro coculture system. Our findings indicate that signal transduction from DRG-derived neurons to MC3T3-E1 cells is suppressed by antagonists of the AMPA receptor and the NK 1 receptor. Conversely, signal transduction from MC3T3-E1 cells to DRG-derived neurons is suppressed by a P2X 7 receptor antagonist. Our results suggest that these cells communicate with each other by exocytosis of glutamate, substance P in the efferent signal, and ATP in the afferent signal. © 2017 Federation of European Biochemical Societies.

CMOS serial link for fully duplexed data communication

NASA Astrophysics Data System (ADS)

Lee, Kyeongho; Kim, Sungjoon; Ahn, Gijung; Jeong, Deog-Kyoon

1995-04-01

This paper describes a CMOS serial link allowing fully duplexed 500 Mbaud serial data communication. The CMOS serial link is a robust and low-cost solution to high data rate requirements. A central charge pump PLL for generating multiphase clocks for oversampling is shared by several serial link channels. Fully duplexed serial data communication is realized in the bidirectional bridge by separating incoming data from the mixed signal on the cable end. The digital PLL accomplishes process-independent data recovery by using a low-ratio oversampling, a majority voting, and a parallel data recovery scheme. Mostly, digital approach could extend its bandwidth further with scaled CMOS technology. A single channel serial link and a charge pump PLL are integrated in a test chip using 1.2 micron CMOS process technology. The test chip confirms upto 500 Mbaud unidirectional mode operation and 320 Mbaud fully duplexed mode operation with pseudo random data patterns.

Branch and bound algorithm for accurate estimation of analytical isotropic bidirectional reflectance distribution function models.

PubMed

Yu, Chanki; Lee, Sang Wook

2016-05-20

We present a reliable and accurate global optimization framework for estimating parameters of isotropic analytical bidirectional reflectance distribution function (BRDF) models. This approach is based on a branch and bound strategy with linear programming and interval analysis. Conventional local optimization is often very inefficient for BRDF estimation since its fitting quality is highly dependent on initial guesses due to the nonlinearity of analytical BRDF models. The algorithm presented in this paper employs L₁-norm error minimization to estimate BRDF parameters in a globally optimal way and interval arithmetic to derive our feasibility problem and lower bounding function. Our method is developed for the Cook-Torrance model but with several normal distribution functions such as the Beckmann, Berry, and GGX functions. Experiments have been carried out to validate the presented method using 100 isotropic materials from the MERL BRDF database, and our experimental results demonstrate that the L₁-norm minimization provides a more accurate and reliable solution than the L₂-norm minimization.

3D visualization of optical ray aberration and its broadcasting to smartphones by ray aberration generator

NASA Astrophysics Data System (ADS)

Hellman, Brandon; Bosset, Erica; Ender, Luke; Jafari, Naveed; McCann, Phillip; Nguyen, Chris; Summitt, Chris; Wang, Sunglin; Takashima, Yuzuru

2017-11-01

The ray formalism is critical to understanding light propagation, yet current pedagogy relies on inadequate 2D representations. We present a system in which real light rays are visualized through an optical system by using a collimated laser bundle of light and a fog chamber. Implementation for remote and immersive access is enabled by leveraging a commercially available 3D viewer and gesture-based remote controlling of the tool via bi-directional communication over the Internet.

Widely tunable Tm-doped mode-locked all-fiber laser

PubMed Central

Yan, Zhiyu; Sun, Biao; Li, Xiaohui; Luo, Jiaqi; Shum, Perry Ping; Yu, Xia; Zhang, Ying; Wang, Qi Jie

2016-01-01

We demonstrated a widely tunable Tm-doped mode-locked all-fiber laser, with the widest tunable range of 136 nm, from 1842 to 1978 nm. Nonlinear polarization evolution (NPE) technique is employed to enable mode-locking and the wavelength-tunable operation. The widely tunable range attributes to the NPE-induced transmission modulation and bidirectional pumping mechanism. Such kind of tunable mode-locked laser can find various applications in optical communications, spectroscopy, time-resolved measurement, and among others. PMID:27263655

Design and implementation of a telecommunication interface for the TAATM/TCV real-time experiment

NASA Technical Reports Server (NTRS)

Nolan, J. D.

1981-01-01

The traffic situation display experiment of the terminal configured vehicle (TCV) research program requires a bidirectional data communications tie line between an computer complex. The tie line is used in a real time environment on the CYBER 175 computer by the terminal area air traffic model (TAATM) simulation program. Aircraft position data are processed by TAATM with the resultant output sent to the facility for the generation of air traffic situation displays which are transmitted to a research aircraft.

Incorporating ecogeomorphic feedbacks to better understand resiliency in streams: A review and directions forward

NASA Astrophysics Data System (ADS)

Atkinson, Carla L.; Allen, Daniel C.; Davis, Lisa; Nickerson, Zachary L.

2018-03-01

Decades of interdisciplinary research show river form and function depends on interactions between the living and nonliving world, but a dominant paradigm underlying ecogeomorphic work consists of a top-down, unidirectional approach with abiotic forces driving biotic systems. Stream form and location within the stream network does dictate the habitat and resources available for organisms and overall community structure. Yet this traditional hierarchal framework on its own is inadequate in communicating information regarding the influence of biological systems on fluvial geomorphology that lead to changes in channel morphology, sediment cycling, and system-scale functions (e.g., sediment yield, biogeochemical nutrient cycling). Substantial evidence that organisms influence fluvial geomorphology exists, specifically the ability of aquatic vegetation and lotic animals to modify flow velocities and sediment deposition and transport - thus challenging the traditional hierarchal framework. Researchers recognize the need for ecogeomorphic frameworks that conceptualize feedbacks between organisms, sediment transport, and geomorphic structure. Furthermore, vital ecosystem processes, such as biogeochemical nutrient cycling represent the conversations that are occurring between geomorphological and biological systems. Here we review and synthesize selected case studies highlighting the role organisms play in moderating geomorphic processes and likely interact with these processes to have an impact on an essential ecosystem process, biogeochemical nutrient recycling. We explore whether biophysical interactions can provide information essential to improving predictions of system-scale river functions, specifically sediment transport and biogeochemical cycling, and discuss tools used to study these interactions. We suggest that current conceptual frameworks should acknowledge that hydrologic, geomorphologic, and ecologic processes operate on different temporal scales, generating bidirectional feedback loops over space and time. Hydro- and geomorphologic processes, operating episodically during bankfull conditions, influence ecological processes (e.g., biogeochemical cycling) occurring over longer time periods during base-flow conditions. This ecological activity generates the antecedent conditions that influence the hydro- and geomorphologic processes occurring during the next high flow event, creating a bidirectional feedback. This feedback should enhance the resiliency of fluvial landforms and ecosystem processes, allowing physical and biological processes to pull and push against each other over time.

The role of sleep in regulating structural plasticity and synaptic strength: Implications for memory and cognitive function.

PubMed

Raven, Frank; Van der Zee, Eddy A; Meerlo, Peter; Havekes, Robbert

2018-06-01

Dendritic spines are the major sites of synaptic transmission in the central nervous system. Alterations in the strength of synaptic connections directly affect the neuronal communication, which is crucial for brain function as well as the processing and storage of information. Sleep and sleep loss bidirectionally alter structural plasticity, by affecting spine numbers and morphology, which ultimately can affect the functional output of the brain in terms of alertness, cognition, and mood. Experimental data from studies in rodents suggest that sleep deprivation may impact structural plasticity in different ways. One of the current views, referred to as the synaptic homeostasis hypothesis, suggests that wake promotes synaptic potentiation whereas sleep facilitates synaptic downscaling. On the other hand, several studies have now shown that sleep deprivation can reduce spine density and attenuate synaptic efficacy in the hippocampus. These data are the basis for the view that sleep promotes hippocampal structural plasticity critical for memory formation. Altogether, the impact of sleep and sleep loss may vary between regions of the brain. A better understanding of the role that sleep plays in regulating structural plasticity may ultimately lead to novel therapeutic approaches for brain disorders that are accompanied by sleep disturbances and sleep loss. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Satellite glial cells in sensory ganglia: its role in pain].

PubMed

Costa, Filipa Alexandra Leite; Moreira Neto, Fani Lourença

2015-01-01

Satellite glial cells in sensory ganglia are a recent subject of research in the field of pain and a possible therapeutic target in the future. Therefore, the aim of this study was to summarize some of the important physiological and morphological characteristics of these cells and gather the most relevant scientific evidence about its possible role in the development of chronic pain. In the sensory ganglia, each neuronal body is surrounded by satellite glial cells forming distinct functional units. This close relationship enables bidirectional communication via a paracrine signaling between those two cell types. There is a growing body of evidence that glial satellite cells undergo structural and biochemical changes after nerve injury, which influence neuronal excitability and consequently the development and/or maintenance of pain in different animal models of chronic pain. Satellite glial cells are important in the establishment of physiological pain, in addition to being a potential target for the development of new pain treatments. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Human-Machine Interface for the Control of Multi-Function Systems Based on Electrocutaneous Menu: Application to Multi-Grasp Prosthetic Hands

PubMed Central

Gonzalez-Vargas, Jose; Dosen, Strahinja; Amsuess, Sebastian; Yu, Wenwei; Farina, Dario

2015-01-01

Modern assistive devices are very sophisticated systems with multiple degrees of freedom. However, an effective and user-friendly control of these systems is still an open problem since conventional human-machine interfaces (HMI) cannot easily accommodate the system’s complexity. In HMIs, the user is responsible for generating unique patterns of command signals directly triggering the device functions. This approach can be difficult to implement when there are many functions (necessitating many command patterns) and/or the user has a considerable impairment (limited number of available signal sources). In this study, we propose a novel concept for a general-purpose HMI where the controller and the user communicate bidirectionally to select the desired function. The system first presents possible choices to the user via electro-tactile stimulation; the user then acknowledges the desired choice by generating a single command signal. Therefore, the proposed approach simplifies the user communication interface (one signal to generate), decoding (one signal to recognize), and allows selecting from a number of options. To demonstrate the new concept the method was used in one particular application, namely, to implement the control of all the relevant functions in a state of the art commercial prosthetic hand without using any myoelectric channels. We performed experiments in healthy subjects and with one amputee to test the feasibility of the novel approach. The results showed that the performance of the novel HMI concept was comparable or, for some outcome measures, better than the classic myoelectric interfaces. The presented approach has a general applicability and the obtained results point out that it could be used to operate various assistive systems (e.g., prosthesis vs. wheelchair), or it could be integrated into other control schemes (e.g., myoelectric control, brain-machine interfaces) in order to improve the usability of existing low-bandwidth HMIs. PMID:26069961

Human-Machine Interface for the Control of Multi-Function Systems Based on Electrocutaneous Menu: Application to Multi-Grasp Prosthetic Hands.

PubMed

Gonzalez-Vargas, Jose; Dosen, Strahinja; Amsuess, Sebastian; Yu, Wenwei; Farina, Dario

2015-01-01

Modern assistive devices are very sophisticated systems with multiple degrees of freedom. However, an effective and user-friendly control of these systems is still an open problem since conventional human-machine interfaces (HMI) cannot easily accommodate the system's complexity. In HMIs, the user is responsible for generating unique patterns of command signals directly triggering the device functions. This approach can be difficult to implement when there are many functions (necessitating many command patterns) and/or the user has a considerable impairment (limited number of available signal sources). In this study, we propose a novel concept for a general-purpose HMI where the controller and the user communicate bidirectionally to select the desired function. The system first presents possible choices to the user via electro-tactile stimulation; the user then acknowledges the desired choice by generating a single command signal. Therefore, the proposed approach simplifies the user communication interface (one signal to generate), decoding (one signal to recognize), and allows selecting from a number of options. To demonstrate the new concept the method was used in one particular application, namely, to implement the control of all the relevant functions in a state of the art commercial prosthetic hand without using any myoelectric channels. We performed experiments in healthy subjects and with one amputee to test the feasibility of the novel approach. The results showed that the performance of the novel HMI concept was comparable or, for some outcome measures, better than the classic myoelectric interfaces. The presented approach has a general applicability and the obtained results point out that it could be used to operate various assistive systems (e.g., prosthesis vs. wheelchair), or it could be integrated into other control schemes (e.g., myoelectric control, brain-machine interfaces) in order to improve the usability of existing low-bandwidth HMIs.

Validation of MODIS-derived bidirectional reflectivity retrieval algorithm in mid-infrared channel with field measurements.

PubMed

Tang, Bo-Hui; Wu, Hua-; Li, Zhao-Liang; Nerry, Françoise

2012-07-30

This work addressed the validation of the MODIS-derived bidirectional reflectivity retrieval algorithm in mid-infrared (MIR) channel, proposed by Tang and Li [Int. J. Remote Sens. 29, 4907 (2008)], with ground-measured data, which were collected from a field campaign that took place in June 2004 at the ONERA (Office National d'Etudes et de Recherches Aérospatiales) center of Fauga-Mauzac, on the PIRRENE (Programme Interdisciplinaire de Recherche sur la Radiométrie en Environnement Extérieur) experiment site [Opt. Express 15, 12464 (2007)]. The leaving-surface spectral radiances measured by a BOMEM (MR250 Series) Fourier transform interferometer were used to calculate the ground brightness temperatures with the combination of the inversion of the Planck function and the spectral response functions of MODIS channels 22 and 23, and then to estimate the ground brightness temperature without the contribution of the solar direct beam and the bidirectional reflectivity by using Tang and Li's proposed algorithm. On the other hand, the simultaneously measured atmospheric profiles were used to obtain the atmospheric parameters and then to calculate the ground brightness temperature without the contribution of the solar direct beam, based on the atmospheric radiative transfer equation in the MIR region. Comparison of those two kinds of brightness temperature obtained by two different methods indicated that the Root Mean Square Error (RMSE) between the brightness temperatures estimated respectively using Tang and Li's algorithm and the atmospheric radiative transfer equation is 1.94 K. In addition, comparison of the hemispherical-directional reflectances derived by Tang and Li's algorithm with those obtained from the field measurements showed that the RMSE is 0.011, which indicates that Tang and Li's algorithm is feasible to retrieve the bidirectional reflectivity in MIR channel from MODIS data.

Protein remote homology detection based on bidirectional long short-term memory.

PubMed

Li, Shumin; Chen, Junjie; Liu, Bin

2017-10-10

Protein remote homology detection plays a vital role in studies of protein structures and functions. Almost all of the traditional machine leaning methods require fixed length features to represent the protein sequences. However, it is never an easy task to extract the discriminative features with limited knowledge of proteins. On the other hand, deep learning technique has demonstrated its advantage in automatically learning representations. It is worthwhile to explore the applications of deep learning techniques to the protein remote homology detection. In this study, we employ the Bidirectional Long Short-Term Memory (BLSTM) to learn effective features from pseudo proteins, also propose a predictor called ProDec-BLSTM: it includes input layer, bidirectional LSTM, time distributed dense layer and output layer. This neural network can automatically extract the discriminative features by using bidirectional LSTM and the time distributed dense layer. Experimental results on a widely-used benchmark dataset show that ProDec-BLSTM outperforms other related methods in terms of both the mean ROC and mean ROC50 scores. This promising result shows that ProDec-BLSTM is a useful tool for protein remote homology detection. Furthermore, the hidden patterns learnt by ProDec-BLSTM can be interpreted and visualized, and therefore, additional useful information can be obtained.

Visual and tactile interfaces for bi-directional human robot communication

NASA Astrophysics Data System (ADS)

Barber, Daniel; Lackey, Stephanie; Reinerman-Jones, Lauren; Hudson, Irwin

2013-05-01

Seamless integration of unmanned and systems and Soldiers in the operational environment requires robust communication capabilities. Multi-Modal Communication (MMC) facilitates achieving this goal due to redundancy and levels of communication superior to single mode interaction using auditory, visual, and tactile modalities. Visual signaling using arm and hand gestures is a natural method of communication between people. Visual signals standardized within the U.S. Army Field Manual and in use by Soldiers provide a foundation for developing gestures for human to robot communication. Emerging technologies using Inertial Measurement Units (IMU) enable classification of arm and hand gestures for communication with a robot without the requirement of line-of-sight needed by computer vision techniques. These devices improve the robustness of interpreting gestures in noisy environments and are capable of classifying signals relevant to operational tasks. Closing the communication loop between Soldiers and robots necessitates them having the ability to return equivalent messages. Existing visual signals from robots to humans typically require highly anthropomorphic features not present on military vehicles. Tactile displays tap into an unused modality for robot to human communication. Typically used for hands-free navigation and cueing, existing tactile display technologies are used to deliver equivalent visual signals from the U.S. Army Field Manual. This paper describes ongoing research to collaboratively develop tactile communication methods with Soldiers, measure classification accuracy of visual signal interfaces, and provides an integration example including two robotic platforms.

[Novel bidirectional promoter from human genome].

PubMed

Orekhova, A S; Sverdlova, P S; Spirin, P V; Leonova, O G; Popenko, V I; Prasolov, V S; Rubtsov, P M

2011-01-01

In human and other mammalian genomes a number of closely linked gene pairs transcribed in opposite directions are found. According to bioinformatic analysis up to 10% of human genes are arranged in this way. In present work the fragment of human genome was cloned that separates genes localized at 2p13.1 and oriented "head-to-head", coding for hypothetical proteins with unknown functions--CCDC (Coiled Coil Domain Containing) 142 and TTC (TetraTricopeptide repeat Containing) 31. Intergenic CCDC142-TTC31 region overlaps with CpG-island and contains a number of potential binding sites for transcription factors. This fragment functions as bidirectional promoter in the system ofluciferase reporter gene expression upon transfection of human embryonic kidney (HEK293) cells. The vectors containing genes of two fluorescent proteins--green (EGFP) and red (DsRed2) in opposite orientations separated by the fragment of CCDC142-TTC31 intergenic region were constructed. In HEK293 cells transfected with these vectors simultaneous expression of two fluorescent proteins is observed. Truncated versions of intergenic region were obtained and their promoter activity measured. Minimal promoter fragment contains elements Inr, BRE, DPE characteristic for TATA-less promoters. Thus, from the human genome the novel bidirectional promoter was cloned that can be used for simultaneous constitutive expression of two genes in human cells.

Bidirectional reflectance distribution function of the Infrared Astronomical Satellite solar-shield material

NASA Technical Reports Server (NTRS)

Hubbs, J. E.; Nofziger, M. J.; Bartell, F. O.; Wolfe, W. L.; Brooks, L. D.

1982-01-01

The Infrared Astronomical Satellite (IRAS) telescope has an outer shield on it which is used to reduce the amount of thermal radiation that enters the telescope. The shield forms the first part of the baffle structure which reduces the photon incidence on the focal plane. It was, therefore, necessary to model this structure for scattering, and a required input for such modeling is the scattering characteristic of this surface. Attention is given to the measurement of the bidirectional reflectance distribution function (BRDF), the reflected radiance divided by the incident irradiance at 10.6 micrometers, 118 micrometers, and at several angles of incidence. Visual observation of the gold sample shows that there are striations which line up in a single direction. The data were, therefore, taken with the sample oriented in each of two directions.

Reflection of solar radiation by a cylindrical cloud

NASA Technical Reports Server (NTRS)

Smith, G. L.

1989-01-01

Potential applications of an analytic method for computing the solar radiation reflected by a cylindrical cloud are discussed, including studies of radiative transfer within finite clouds and evaluations of these effects on other clouds and on remote sensing problems involving finite clouds. The pattern of reflected sunlight from a cylindrical cloud as seen at a large distance has been considered and described by the bidirectional function method for finite cloud analysis, as previously studied theoretically for plane-parallel atmospheres by McKee and Cox (1974); Schmetz and Raschke (1981); and Stuhlmann et al. (1985). However, the lack of three-dimensional radiative transfer solutions for anisotropic scattering media have hampered theoretical investigations of bidirectional functions for finite clouds. The present approach permits expression of the directional variation of the radiation field as a spherical harmonic series to any desired degree and order.

Experimental analysis of bidirectional reflectance distribution function cross section conversion term in direction cosine space.

PubMed

Butler, Samuel D; Nauyoks, Stephen E; Marciniak, Michael A

2015-06-01

Of the many classes of bidirectional reflectance distribution function (BRDF) models, two popular classes of models are the microfacet model and the linear systems diffraction model. The microfacet model has the benefit of speed and simplicity, as it uses geometric optics approximations, while linear systems theory uses a diffraction approach to compute the BRDF, at the expense of greater computational complexity. In this Letter, nongrazing BRDF measurements of rough and polished surface-reflecting materials at multiple incident angles are scaled by the microfacet cross section conversion term, but in the linear systems direction cosine space, resulting in great alignment of BRDF data at various incident angles in this space. This results in a predictive BRDF model for surface-reflecting materials at nongrazing angles, while avoiding some of the computational complexities in the linear systems diffraction model.

Bidirectional reflectance distribution function of Spectralon white reflectance standard illuminated by incoherent unpolarized and plane-polarized light.

PubMed

Bhandari, Anak; Hamre, Børge; Frette, Øvynd; Zhao, Lu; Stamnes, Jakob J; Kildemo, Morten

2011-06-01

A Lambert surface would appear equally bright from all observation directions regardless of the illumination direction. However, the reflection from a randomly scattering object generally has directional variation, which can be described in terms of the bidirectional reflectance distribution function (BRDF). We measured the BRDF of a Spectralon white reflectance standard for incoherent illumination at 405 and 680 nm with unpolarized and plane-polarized light from different directions of incidence. Our measurements show deviations of the BRDF for the Spectralon white reflectance standard from that of a Lambertian reflector that depend both on the angle of incidence and the polarization states of the incident light and detected light. The non-Lambertian reflection characteristics were found to increase more toward the direction of specular reflection as the angle of incidence gets larger.

Bidirectional reflectance distribution function of diffuse extreme ultraviolet scatterers and extreme ultraviolet baffle materials.

PubMed

Newell, M P; Keski-Kuha, R A

1997-08-01

Bidirectional reflectance distribution function (BRDF) measurements of a number of diffuse extreme ultraviolet (EUV) scatterers and EUV baffle materials have been performed with the Goddard EUV scatterometer. BRDF data are presented for white Spectralon SRS-99 at 121.6 nm; the data exhibit a non-Lambertian nature and a total hemispherical reflectance lower than 0.15. Data are also presented for an evaporated Cu black sample, a black Spectralon SRS-02 sample, and a Martin Optical Black sample at wavelengths of 58.4 and 121.6 nm and for angles of incidence of 15 degrees and 45 degrees. Overall Martin Optical Black exhibited the lowest BRDF characteristic, with a total hemispherical reflectance of the order of 0.01 and measured BRDF values as low as 2 x 10(-3) sr(-1).

[Physiopathology of overactive bladder syndrome].

PubMed

Sacco, Emilio

2012-01-01

The pathophysiology of OAB is complex, multifactorial and still largely unknown. Several pathophysiological mechanisms have been highlighted that may play a different role in different patient groups. There are now experimental evidences that support both the myogenic and neurogenic hypothesis, but in recent years the "integrative" hypothesis has been gaining more and more acceptance, where a disruption in the multiple interactions between different cell types (neurons, urothelium, interstitial cells, myocytes) and network functions represent a central element of lower urinary tract dysfunctions. Of utmost importance, a disorder in the urothelial sensory function and in the urothelial/suburothelial non-neural cholinergic system, favored by age and comorbidities, appears to be crucial for the development of the OAB. Neuroplastic and detrusor changes in OAB are broadly similar to those observed in bladders exposed to outlet obstruction, neuropathies, inflammation or aging, and may be driven by a common urothelial dysfunction. Several signaling substances and their receptors were found to be involved in central pathways of bidirectional communication between the different cell types in the bladder, and were shown to be modified in several animal models of OAB as well as in human models, indicating new potential therapeutic targets.

The Place of Stress and Emotions in the Irritable Bowel Syndrome.

PubMed

Pellissier, S; Bonaz, B

2017-01-01

Our emotional state can have many consequences on our somatic health and well-being. Negative emotions such as anxiety play a major role in gut functioning due to the bidirectional communications between gut and brain, namely, the brain-gut axis. The irritable bowel syndrome (IBS), characterized by an unusual visceral hypersensitivity, is the most common disorder encountered by gastroenterologists. Among the main symptoms, the presence of current or recurrent abdominal pain or discomfort associated with bloating and altered bowel habits characterizes this syndrome that could strongly alter the quality of life. This chapter will present the physiopathology of IBS and explain how stress influences gastrointestinal functions (permeability, motility, microbiota, sensitivity, secretion) and how it could be predominantly involved in IBS. This chapter will also describe the role of the autonomic nervous system and the hypothalamic-pituitary axis through vagal tone and cortisol homeostasis. An analysis is made about how emotions and feelings are involved in the disruption of homeostasis, and we will see to what extent the balance between vagal tone and cortisol may reflect dysfunctions of the brain-gut homeostasis. Finally, the interest of therapeutic treatments focused on stress reduction and vagal tone enforcement is discussed. © 2017 Elsevier Inc. All rights reserved.

Gut-Brain Axis and Behavior.

PubMed

Martin, Clair R; Mayer, Emeran A

2017-01-01

In the last 5 years, interest in the interactions among the gut microbiome, brain, and behavior has exploded. Preclinical evidence supports a role of the gut microbiome in behavioral responses associated with pain, emotion, social interactions, and food intake. Limited, but growing, clinical evidence comes primarily from associations of gut microbial composition and function to behavioral and clinical features and brain structure and function. Converging evidence suggests that the brain and the gut microbiota are in bidirectional communication. Observed dysbiotic states in depression, chronic stress, and autism may reflect altered brain signaling to the gut, while altered gut microbial signaling to the brain may play a role in reinforcing brain alterations. On the other hand, primary dysbiotic states due to Western diets may signal to the brain, altering ingestive behavior. While studies performed in patients with depression and rodent models generated by fecal microbial transfer from such patients suggest causation, evidence for an influence of acute gut microbial alterations on human behavioral and clinical parameters is lacking. Only recently has an open-label microbial transfer therapy in children with autism tentatively validated the gut microbiota as a therapeutic target. The translational potential of preclinical findings remains unclear without further clinical investigation. © 2017 Nestec Ltd., Vevey/S. Karger AG, Basel.

Mitochondria: more than just a powerhouse.

PubMed

McBride, Heidi M; Neuspiel, Margaret; Wasiak, Sylwia

2006-07-25

Pioneering biochemical studies have long forged the concept that the mitochondria are the 'energy powerhouse of the cell'. These studies, combined with the unique evolutionary origin of the mitochondria, led the way to decades of research focusing on the organelle as an essential, yet independent, functional component of the cell. Recently, however, our conceptual view of this isolated organelle has been profoundly altered with the discovery that mitochondria function within an integrated reticulum that is continually remodeled by both fusion and fission events. The identification of a number of proteins that regulate these activities is beginning to provide mechanistic details of mitochondrial membrane remodeling. However, the broader question remains regarding the underlying purpose of mitochondrial dynamics and the translation of these morphological transitions into altered functional output. One hypothesis has been that mitochondrial respiration and metabolism may be spatially and temporally regulated by the architecture and positioning of the organelle. Recent evidence supports and expands this idea by demonstrating that mitochondria are an integral part of multiple cell signaling cascades. Interestingly, proteins such as GTPases, kinases and phosphatases are involved in bi-directional communication between the mitochondrial reticulum and the rest of the cell. These proteins link mitochondrial function and dynamics to the regulation of metabolism, cell-cycle control, development, antiviral responses and cell death. In this review we will highlight the emerging evidence that provides molecular definition to mitochondria as a central platform in the execution of diverse cellular events.

Bidirectional optical switch based on electrowetting

NASA Astrophysics Data System (ADS)

Liu, Chao; Li, Lei; Wang, Qiong-Hua

2013-05-01

In this paper, we demonstrate a bidirectional optical switch based on electrowetting. Four rectangular polymethyl methacrylate substrates are stacked to form the device and three ITO electrodes are fabricated on the bottom substrate. A black liquid droplet is placed on the middle of the ITO electrode and surrounded by silicone oil. When we apply a voltage to one ITO electrode, the droplet stretches and moves in one direction and a light beam is covered by the stretched droplet, while the droplet yields a space to let the original blocked light pass through. Due to the shift of the droplet, our device functions as a bidirectional optical switch. Our experiment shows that the device can obtain a wide optical attenuation from ˜1 dB to 30 dB and the transmission loss is ˜0.67 dB. The response time of the device is ˜177 ms. The proposed optical switch has potential applications in variable optical attenuators, electronic displays, and light shutters.

Nonlinear image registration with bidirectional metric and reciprocal regularization

PubMed Central

Ying, Shihui; Li, Dan; Xiao, Bin; Peng, Yaxin; Du, Shaoyi; Xu, Meifeng

2017-01-01

Nonlinear registration is an important technique to align two different images and widely applied in medical image analysis. In this paper, we develop a novel nonlinear registration framework based on the diffeomorphic demons, where a reciprocal regularizer is introduced to assume that the deformation between two images is an exact diffeomorphism. In detail, first, we adopt a bidirectional metric to improve the symmetry of the energy functional, whose variables are two reciprocal deformations. Secondly, we slack these two deformations into two independent variables and introduce a reciprocal regularizer to assure the deformations being the exact diffeomorphism. Then, we utilize an alternating iterative strategy to decouple the model into two minimizing subproblems, where a new closed form for the approximate velocity of deformation is calculated. Finally, we compare our proposed algorithm on two data sets of real brain MR images with two relative and conventional methods. The results validate that our proposed method improves accuracy and robustness of registration, as well as the gained bidirectional deformations are actually reciprocal. PMID:28231342

Far-ultraviolet Bidirectional Photometry of Apollo Soil 10084: New Results from The Southwest Ultraviolet Reflectance Chamber (SwURC).

NASA Astrophysics Data System (ADS)

Raut, U.

2017-12-01

We report new measurements of the far-ultraviolet (115-180 nm) bidirectional reflectance of Apollo soil 10084 in the Southwest Ultraviolet Reflectance Chamber (SwURC). We find the bidirectional reflectance distribution function (BRDF) to be featureless in this wavelength region, though with a small blue slope. The angular distribution of the BRDF at Ly-α and 160 nm shows that this mature mare soil, containing nanophase Fe and enriched in Ti, anisotropically scatters light in the forward direction. The phase angle dependence of the BRDF is fitted with Hapke's photometric model with an additional diffuse-directional term. Future plans include measurements of mare and highland soils of differing maturity index (Is/FeO), water ice frost and lunar soil-ice aggregates. Such measurements will help constrain the abundance and distribution of the water ice on the illuminated lunar surface and dark permanently shadowed regions of the moon, as reported by LRO-LAMP.

The Role of PTSD in Bi-directional Intimate Partner Violence in Military and Veteran Populations: A Research Review.

PubMed

Misca, Gabriela; Forgey, Mary Ann

2017-01-01

Evidence supporting the higher prevalence of PTSD linked to combat-related trauma in military personnel and veteran populations is well-established. Consequently, much research has explored the effects that combat related trauma and the subsequent PTSD may have on different aspects of relationship functioning and adjustment. In particular, PTSD in military and veterans has been linked with perpetrating intimate partner violence (IPV). New research and theoretical perspectives suggest that in order to respond effectively to IPV, a more accurate understanding of the direction of the violence experienced within each relationship is critical. In both civilian and military populations, research that has examined the direction of IPV's, bi-directional violence have been found to be highly prevalent. Evidence is also emerging as to how these bi-directional violence differ in relation to severity, motivation, physical and psychological consequences and risk factors. Of particular importance within military IPV research is the need to deepen understanding about the role of PTSD in bi-directional IPV not only as a risk factor for perpetration but also as a vulnerability risk factor for victimization, as findings from recent research suggest. This paper provides a timely, critical review of emergent literature to disentangle what is known about bi-directional IPV patterns in military and veteran populations and the roles that military or veterans' PTSD may play within these patterns. Although, this review aimed to identify global research on the topic, the majority of research meeting the inclusion criteria was from US, with only one study identified from outside, from Canada. Strengths and limitations in the extant research are identified. Directions for future research are proposed with a particular focus on the kinds of instruments and designs needed to better capture the complex interplay of PTSD and bi-directional IPV in military populations and further the development of effective interventions.

Robust state estimation for uncertain fuzzy bidirectional associative memory networks with time-varying delays

NASA Astrophysics Data System (ADS)

Vadivel, P.; Sakthivel, R.; Mathiyalagan, K.; Arunkumar, A.

2013-09-01

This paper addresses the issue of robust state estimation for a class of fuzzy bidirectional associative memory (BAM) neural networks with time-varying delays and parameter uncertainties. By constructing the Lyapunov-Krasovskii functional, which contains the triple-integral term and using the free-weighting matrix technique, a set of sufficient conditions are derived in terms of linear matrix inequalities (LMIs) to estimate the neuron states through available output measurements such that the dynamics of the estimation error system is robustly asymptotically stable. In particular, we consider a generalized activation function in which the traditional assumptions on the boundedness, monotony and differentiability of the activation functions are removed. More precisely, the design of the state estimator for such BAM neural networks can be obtained by solving some LMIs, which are dependent on the size of the time derivative of the time-varying delays. Finally, a numerical example with simulation result is given to illustrate the obtained theoretical results.

Dynamic data driven bidirectional reflectance distribution function measurement system

NASA Astrophysics Data System (ADS)

Nauyoks, Stephen E.; Freda, Sam; Marciniak, Michael A.

2014-09-01

The bidirectional reflectance distribution function (BRDF) is a fitted distribution function that defines the scatter of light off of a surface. The BRDF is dependent on the directions of both the incident and scattered light. Because of the vastness of the measurement space of all possible incident and reflected directions, the calculation of BRDF is usually performed using a minimal amount of measured data. This may lead to poor fits and uncertainty in certain regions of incidence or reflection. A dynamic data driven application system (DDDAS) is a concept that uses an algorithm on collected data to influence the collection space of future data acquisition. The authors propose a DDD-BRDF algorithm that fits BRDF data as it is being acquired and uses on-the-fly fittings of various BRDF models to adjust the potential measurement space. In doing so, it is hoped to find the best model to fit a surface and the best global fit of the BRDF with a minimum amount of collection space.

Coherence solution for bidirectional reflectance distributions of surfaces with wavelength-scale statistics.

PubMed

Hoover, Brian G; Gamiz, Victor L

2006-02-01

The scalar bidirectional reflectance distribution function (BRDF) due to a perfectly conducting surface with roughness and autocorrelation width comparable with the illumination wavelength is derived from coherence theory on the assumption of a random reflective phase screen and an expansion valid for large effective roughness. A general quadratic expansion of the two-dimensional isotropic surface autocorrelation function near the origin yields representative Cauchy and Gaussian BRDF solutions and an intermediate general solution as the sum of an incoherent component and a nonspecular coherent component proportional to an integral of the plasma dispersion function in the complex plane. Plots illustrate agreement of the derived general solution with original bistatic BRDF data due to a machined aluminum surface, and comparisons are drawn with previously published data in the examination of variations with incident angle, roughness, illumination wavelength, and autocorrelation coefficients in the bistatic and monostatic geometries. The general quadratic autocorrelation expansion provides a BRDF solution that smoothly interpolates between the well-known results of the linear and parabolic approximations.

Optical properties (bidirectional reflectance distribution function) of shot fabric.

PubMed

Lu, R; Koenderink, J J; Kappers, A M

2000-11-01

To study the optical properties of materials, one needs a complete set of the angular distribution functions of surface scattering from the materials. Here we present a convenient method for collecting a large set of bidirectional reflectance distribution function (BRDF) samples in the hemispherical scattering space. Material samples are wrapped around a right-circular cylinder and irradiated by a parallel light source, and the scattered radiance is collected by a digital camera. We tilted the cylinder around its center to collect the BRDF samples outside the plane of incidence. This method can be used with materials that have isotropic and anisotropic scattering properties. We demonstrate this method in a detailed investigation of shot fabrics. The warps and the fillings of shot fabrics are dyed different colors so that the fabric appears to change color at different viewing angles. These color-changing characteristics are found to be related to the physical and geometrical structure of shot fabric. Our study reveals that the color-changing property of shot fabrics is due mainly to an occlusion effect.

Dynamic Bidirectional Reflectance Distribution Functions: Measurement and Representation

DTIC Science & Technology

2008-02-01

be included in the harmonic fits. Other sets of orthogonal functions such as Zernike polynomials have also been used to characterize BRDF and could...reflectance spectra of 3D objects,” Proc. SPIE 4663, 370–378 2001. 13J. R. Shell II, C. Salvagio, and J. R. Schott, “A novel BRDF measurement technique

Obstructive sleep apnea and neurodegenerative diseases: A bidirectional relation

PubMed Central

Bahia, Christianne Martins Corrêa da Silva; Pereira, João Santos

2015-01-01

Sleep disorders are common during the clinical course of the main neurodegenerative diseases. Among these disorders, obstructive sleep apnea has been extensively studied in the last decade and recent knowledge regarding its relationship with the neurodegenerative process points a bidirectional relationship. Neurodegenerative diseases can lead to functional changes in the respiratory system that facilitate the emergence of apnea. On the other hand, obstructive sleep apnea itself can lead to acceleration of neuronal death due to intermittent hypoxia. Considering that obstructive sleep apnea is a potentially treatable condition, its early identification and intervention could have a positive impact on the management of patients with neurodegenerative diseases. PMID:29213936

Bidirectional peripheral nerve interface and applications.

PubMed

Thakor, Nitish V; Qihong Wang; Greenwald, Elliot

2016-08-01

Peripheral nerves, due to their small size and complex innervation to organs and complex physiology, pose particularly significant challenges towards interfacing electrodes and electronics to enable neuromodulation. Here, we present a review of the technology for building such interface, including recording and stimulating electrodes and low power electronics, as well as powering. Of particular advantage to building a miniature implanted device is a "bidirectional" system that both senses from the nerves or surrogate organs and stimulates the nerves to affect the organ function. This review and presentation will cover a range of electrodes, electronics, wireless power and data schemes and system integration, and will end with some examples and applications.

Bidirectional communication between the Aryl hydrocarbon Receptor (AhR) and the microbiome tunes host metabolism

PubMed Central

Korecka, Agata; Dona, Anthony; Lahiri, Shawon; Tett, Adrian James; Al-Asmakh, Maha; Braniste, Viorica; D’Arienzo, Rossana; Abbaspour, Afrouz; Reichardt, Nicole; Fujii-Kuriyama, Yoshiaki; Rafter, Joseph; Narbad, Arjan; Holmes, Elaine; Nicholson, Jeremy; Arulampalam, Velmurugesan; Pettersson, Sven

2016-01-01

The ligand-induced transcription factor, aryl hydrocarbon receptor (AhR) is known for its capacity to tune adaptive immunity and xenobiotic metabolism—biological properties subject to regulation by the indigenous microbiome. The objective of this study was to probe the postulated microbiome-AhR crosstalk and whether such an axis could influence metabolic homeostasis of the host. Utilising a systems-biology approach combining in-depth 1H-NMR-based metabonomics (plasma, liver and skeletal muscle) with microbiome profiling (small intestine, colon and faeces) of AhR knockout (AhR−/−) and wild-type (AhR+/+) mice, we assessed AhR function in host metabolism. Microbiome metabolites such as short-chain fatty acids were found to regulate AhR and its target genes in liver and intestine. The AhR signalling pathway, in turn, was able to influence microbiome composition in the small intestine as evident from microbiota profiling of the AhR+/+ and AhR−/− mice fed with diet enriched with a specific AhR ligand or diet depleted of any known AhR ligands. The AhR−/− mice also displayed increased levels of corticosterol and alanine in serum. In addition, activation of gluconeogenic genes in the AhR−/− mice was indicative of on-going metabolic stress. Reduced levels of ketone bodies and reduced expression of genes involved in fatty acid metabolism in the liver further underscored this observation. Interestingly, exposing AhR−/− mice to a high-fat diet showed resilience to glucose intolerance. Our data suggest the existence of a bidirectional AhR-microbiome axis, which influences host metabolic pathways. PMID:28721249

A miniature bidirectional telemetry system for in vivo gastric slow wave recordings.

PubMed

Farajidavar, Aydin; O'Grady, Gregory; Rao, Smitha M N; Cheng, Leo K; Abell, Thomas; Chiao, J-C

2012-06-01

Stomach contractions are initiated and coordinated by an underlying electrical activity (slow waves), and electrical dysrhythmias accompany motility diseases. Electrical recordings taken directly from the stomach provide the most valuable data, but face technical constraints. Serosal or mucosal electrodes have cables that traverse the abdominal wall, or a natural orifice, causing discomfort and possible infection, and restricting mobility. These problems motivated the development of a wireless system. The bidirectional telemetric system constitutes a front-end transponder, a back-end receiver and a graphical userinter face. The front-end module conditions the analogue signals, then digitizes and loads the data into a radio for transmission. Data receipt at the backend is acknowledged via a transceiver function. The system was validated in a bench-top study, then validated in vivo using serosal electrodes connected simultaneously to a commercial wired system. The front-end module was 35 × 35 × 27 mm3 and weighed 20 g. Bench-top tests demonstrated reliable communication within a distance range of 30 m, power consumption of 13.5 mW, and 124 h operation when utilizing a 560 mAh, 3 V battery. In vivo,slow wave frequencies were recorded identically with the wireless and wired reference systems (2.4 cycles min−1), automated activation time detection was modestly better for the wireless system (5% versus 14% FP rate), and signal amplitudes were modestly higher via the wireless system (462 versus 3 86μV; p<0.001). This telemetric system for slow wave acquisition is reliable,power efficient, readily portable and potentially implantable. The device will enable chronic monitoring and evaluation of slow wave patterns in animals and patients.0967-3334/

A miniature bidirectional telemetry system for in-vivo gastric slow wave recordings

PubMed Central

Farajidavar, Aydin; O’Grady, Gregory; Rao, Smitha M.N.; Cheng, Leo K; Abell, Thomas; Chiao, J.-C.

2012-01-01

Stomach contractions are initiated and coordinated by an underlying electrical activity (slow waves), and electrical dysrhythmias accompany motility diseases. Electrical recordings taken directly from the stomach provide the most valuable data, but face technical constraints. Serosal or mucosal electrodes have cables that traverse the abdominal wall, or a natural orifice, causing discomfort and possible infection, and restricting mobility. These problems motivated the development of a wireless system. The bidirectional telemetric system constitutes a front-end transponder, a back-end receiver and a graphical user interface. The front-end module conditions the analog signals, then digitizes and loads the data into a radio for transmission. Data receipt at the back-end is acknowledged via a transceiver function. The system was validated in a bench-top study, then validated in-vivo using serosal electrodes connected simultaneously to a commercial wired system. The front-end module was 35×35×27 mm3 and weighed 20 g. Bench-top tests demonstrated reliable communication within a distance range of 30 m, power consumption of 13.5 mW, and 124-hour operation when utilizing a 560-mAh, 3-V battery. In-vivo, slow wave frequencies were recorded identically with the wireless and wired reference systems (2.4 cycles/min), automated activation time detection was modestly better for the wireless system (5% vs 14% false positive rate), and signal amplitudes were modestly higher via the wireless system (462 vs 386 μV; p<0.001). This telemetric system for slow wave acquisition is reliable, power efficient, readily portable and potentially implantable. The device will enable chronic monitoring and evaluation of slow wave patterns in animals and patients. PMID:22635054

Laser pulse bidirectional reflectance from CALIPSO mission

NASA Astrophysics Data System (ADS)

Lu, Xiaomei; Hu, Yongxiang; Yang, Yuekui; Vaughan, Mark; Liu, Zhaoyan; Rodier, Sharon; Hunt, William; Powell, Kathy; Lucker, Patricia; Trepte, Charles

2018-06-01

This paper presents an innovative retrieval method that translates the CALIOP land surface laser pulse returns into the surface bidirectional reflectance. To better analyze the surface returns, the CALIOP receiver impulse response and the downlinked samples' distribution at 30 m vertical resolution are discussed. The saturated laser pulse magnitudes from snow and ice surfaces are recovered based on information extracted from the tail end of the surface signal. The retrieved snow surface bidirectional reflectance is compared with reflectance from both CALIOP cloud-covered regions and MODIS BRDF-albedo model parameters. In addition to the surface bidirectional reflectance, the column top-of-atmosphere bidirectional reflectances are calculated from the CALIOP lidar background data and compared with the bidirectional reflectances derived from WFC radiance measurements. The retrieved CALIOP surface bidirectional reflectance and column top-of-atmosphere bidirectional reflectance results provide unique information to complement existing MODIS standard data products and are expected to have valuable applications for modelers.

Bidirectional Pressure-Regulator System

NASA Technical Reports Server (NTRS)

Burke, Kenneth; Miller, John R.

2008-01-01

A bidirectional pressure-regulator system has been devised for use in a regenerative fuel cell system. The bidirectional pressure-regulator acts as a back-pressure regulator as gas flows through the bidirectional pressure-regulator in one direction. Later, the flow of gas goes through the regulator in the opposite direction and the bidirectional pressure-regulator operates as a pressure- reducing pressure regulator. In the regenerative fuel cell system, there are two such bidirectional regulators, one for the hydrogen gas and another for the oxygen gas. The flow of gases goes from the regenerative fuel cell system to the gas storage tanks when energy is being stored, and reverses direction, flowing from the storage tanks to the regenerative fuel cell system when the stored energy is being withdrawn from the regenerative fuel cell system. Having a single bidirectional regulator replaces two unidirectional regulators, plumbing, and multiple valves needed to reverse the flow direction. The term "bidirectional" refers to both the bidirectional nature of the gas flows and capability of each pressure regulator to control the pressure on either its upstream or downstream side, regardless of the direction of flow.

An Image Based Bidirectional Reflectivity Distribution Function Experiment

DTIC Science & Technology

2008-03-01

mirror grade Zerodur . It has an aluminum reflective surface and is coated with a protective layer. The key design consideration is the location of...11 4.2. Off Axis Parabolic Mirror ...12 4.4. Turning Mirrors

Daily alcohol use and romantic relationship functioning: evidence of bidirectional, gender-, and context-specific effects.

PubMed

Levitt, Ash; Cooper, M Lynne

2010-12-01

Whether beneficial or harmful, cause or effect, the nature of associations between drinking and close relationship processes remains unclear. The present study examined these issues by using daily reports of alcohol use and relationship functioning from 69 heterosexual couples over 3 weeks. Multilevel modeling indicated that alcohol had both positive and negative effects on relationship processes and that effects were more positive for women, and when small amounts were consumed, partners drank together, or they consumed similar amounts. Interestingly, however, positive effects on intimacy and partner behaviors were not mediated by sexual contact. In the reverse direction, women were found to drink more than men in response to relationship difficulties and feeling disconnected from their partner (i.e., low intimacy). Overall findings indicate that associations between drinking and relationship processes are complex and bidirectional and that they may be more important for women than men.

Executive function predicts artificial language learning

PubMed Central

Kapa, Leah L.; Colombo, John

2017-01-01

Previous research suggests executive function (EF) advantages among bilinguals compared to monolingual peers, and these advantages are generally attributed to experience controlling two linguistic systems. However, the possibility that the relationship between bilingualism and EF might be bidirectional has not been widely considered; while experience with two languages might improve EF, better EF skills might also facilitate language learning. In the current studies, we tested whether adults’ and preschool children’s EF abilities predicted success in learning a novel artificial language. After controlling for working memory and English receptive vocabulary, adults’ artificial language performance was predicted by their inhibitory control ability (Study 1) and children’s performance was predicted by their attentional monitoring and shifting ability (Study 2). These findings provide preliminary evidence suggesting that EF processes may be employed during initial stages of language learning, particularly vocabulary acquisition, and support the possibility of a bidirectional relationship between EF and language acquisition. PMID:29129958

Bidirectional Elastic Image Registration Using B-Spline Affine Transformation

PubMed Central

Gu, Suicheng; Meng, Xin; Sciurba, Frank C.; Wang, Chen; Kaminski, Naftali; Pu, Jiantao

2014-01-01

A registration scheme termed as B-spline affine transformation (BSAT) is presented in this study to elastically align two images. We define an affine transformation instead of the traditional translation at each control point. Mathematically, BSAT is a generalized form of the affine transformation and the traditional B-Spline transformation (BST). In order to improve the performance of the iterative closest point (ICP) method in registering two homologous shapes but with large deformation, a bi-directional instead of the traditional unidirectional objective / cost function is proposed. In implementation, the objective function is formulated as a sparse linear equation problem, and a sub-division strategy is used to achieve a reasonable efficiency in registration. The performance of the developed scheme was assessed using both two-dimensional (2D) synthesized dataset and three-dimensional (3D) volumetric computed tomography (CT) data. Our experiments showed that the proposed B-spline affine model could obtain reasonable registration accuracy. PMID:24530210

Application of the three-component bidirectional reflectance distribution function model to Monte Carlo calculation of spectral effective emissivities of nonisothermal blackbody cavities.

PubMed

Prokhorov, Alexander; Prokhorova, Nina I

2012-11-20

We applied the bidirectional reflectance distribution function (BRDF) model consisting of diffuse, quasi-specular, and glossy components to the Monte Carlo modeling of spectral effective emissivities for nonisothermal cavities. A method for extension of a monochromatic three-component (3C) BRDF model to a continuous spectral range is proposed. The initial data for this method are the BRDFs measured in the plane of incidence at a single wavelength and several incidence angles and directional-hemispherical reflectance measured at one incidence angle within a finite spectral range. We proposed the Monte Carlo algorithm for calculation of spectral effective emissivities for nonisothermal cavities whose internal surface is described by the wavelength-dependent 3C BRDF model. The results obtained for a cylindroconical nonisothermal cavity are discussed and compared with results obtained using the conventional specular-diffuse model.

Bidirectional reflectance distribution function based surface modeling of non-Lambertian using intensity data of light detection and ranging.

PubMed

Li, Xiaolu; Liang, Yu; Xu, Lijun

2014-09-01

To provide a credible model for light detection and ranging (LiDAR) target classification, the focus of this study is on the relationship between intensity data of LiDAR and the bidirectional reflectance distribution function (BRDF). An integration method based on the built-in-lab coaxial laser detection system was advanced. A kind of intermediary BRDF model advanced by Schlick was introduced into the integration method, considering diffuse and specular backscattering characteristics of the surface. A group of measurement campaigns were carried out to investigate the influence of the incident angle and detection range on the measured intensity data. Two extracted parameters r and S(λ) are influenced by different surface features, which illustrate the surface features of the distribution and magnitude of reflected energy, respectively. The combination of two parameters can be used to describe the surface characteristics for target classification in a more plausible way.

Bidirectional reflectance distribution function effects in ladar-based reflection tomography.

PubMed

Jin, Xuemin; Levine, Robert Y

2009-07-20

Light reflection from a surface is described by the bidirectional reflectance distribution function (BRDF). In this paper, BRDF effects in reflection tomography are studied using modeled range-resolved reflection from well-characterized geometrical surfaces. It is demonstrated that BRDF effects can cause a darkening at the interior boundary of the reconstructed surface analogous to the well-known beam hardening artifact in x-ray transmission computed tomography (CT). This artifact arises from reduced reflection at glancing incidence angles to the surface. It is shown that a purely Lambertian surface without shadowed components is perfectly reconstructed from range-resolved measurements. This result is relevant to newly fabricated carbon nanotube materials. Shadowing is shown to cause crossed streak artifacts similar to limited-angle effects in CT reconstruction. In tomographic reconstruction, these effects can overwhelm highly diffuse components in proximity to specularly reflecting elements. Diffuse components can be recovered by specialized processing, such as reducing glints via thresholded measurements.

Directional statistics-based reflectance model for isotropic bidirectional reflectance distribution functions.

PubMed

Nishino, Ko; Lombardi, Stephen

2011-01-01

We introduce a novel parametric bidirectional reflectance distribution function (BRDF) model that can accurately encode a wide variety of real-world isotropic BRDFs with a small number of parameters. The key observation we make is that a BRDF may be viewed as a statistical distribution on a unit hemisphere. We derive a novel directional statistics distribution, which we refer to as the hemispherical exponential power distribution, and model real-world isotropic BRDFs as mixtures of it. We derive a canonical probabilistic method for estimating the parameters, including the number of components, of this novel directional statistics BRDF model. We show that the model captures the full spectrum of real-world isotropic BRDFs with high accuracy, but a small footprint. We also demonstrate the advantages of the novel BRDF model by showing its use for reflection component separation and for exploring the space of isotropic BRDFs.

Streetlight Control System Based on Wireless Communication over DALI Protocol

PubMed Central

Bellido-Outeiriño, Francisco José; Quiles-Latorre, Francisco Javier; Moreno-Moreno, Carlos Diego; Flores-Arias, José María; Moreno-García, Isabel; Ortiz-López, Manuel

2016-01-01

Public lighting represents a large part of the energy consumption of towns and cities. Efficient management of public lighting can entail significant energy savings. This work presents a smart system for managing public lighting networks based on wireless communication and the DALI protocol. Wireless communication entails significant economic savings, as there is no need to install new wiring and visual impacts and damage to the facades of historical buildings in city centers are avoided. The DALI protocol uses bidirectional communication with the ballast, which allows its status to be controlled and monitored at all times. The novelty of this work is that it tackles all aspects related to the management of public lighting: a standard protocol, DALI, was selected to control the ballast, a wireless node based on the IEEE 802.15.4 standard with a DALI interface was designed, a network layer that considers the topology of the lighting network has been developed, and lastly, some user-friendly applications for the control and maintenance of the system by the technical crews of the different towns and cities have been developed. PMID:27128923

Parlaying digital imaging and communications in medicine and open architecture to our advantage: the new Department of Defense picture archiving and communications system.

PubMed

Cawthon, M A

1999-05-01

The Department of Defense (DoD) undertook a major systems specification, acquisition, and implementation project of multivendor picture archiving and communications system (PACS) and teleradiology systems during 1997 with deployment of the first systems in 1998. These systems differ from their DoD predecessor system in being multivendor in origin, specifying adherence to the developing Digital Imaging and Communications in Medicine (DICOM) 3.0 standard and all of its service classes, emphasizing open architecture, using personal computer (PC) and web-based image viewing access, having radiologic telepresence over large geographic areas as a primary focus of implementation, and requiring bidirectional interfacing with the DoD hospital information system (HIS). The benefits and advantages to the military health-care system accrue through the enabling of a seamless implementation of a virtual radiology operational environment throughout this vast healthcare organization providing efficient general and subspecialty radiologic interpretive and consultative services for our medical beneficiaries to any healthcare provider, anywhere and at any time of the night or day.

The Bi-directional Relationship between Source Characteristics and Message Content

PubMed Central

Collins, Peter J.; Hahn, Ulrike; von Gerber, Ylva; Olsson, Erik J.

2018-01-01

Much of what we believe we know, we know through the testimony of others (Coady, 1992). While there has been long-standing evidence that people are sensitive to the characteristics of the sources of testimony, for example in the context of persuasion, researchers have only recently begun to explore the wider implications of source reliability considerations for the nature of our beliefs. Likewise, much remains to be established concerning what factors influence source reliability. In this paper, we examine, both theoretically and empirically, the implications of using message content as a cue to source reliability. We present a set of experiments examining the relationship between source information and message content in people's responses to simple communications. The results show that people spontaneously revise their beliefs in the reliability of the source on the basis of the expectedness of a source's claim and, conversely, adjust message impact by perceived reliability; hence source reliability and message content have a bi-directional relationship. The implications are discussed for a variety of psychological, philosophical and political issues such as belief polarization and dual-route models of persuasion. PMID:29441029

Expanded DEMATEL for Determining Cause and Effect Group in Bidirectional Relations

PubMed Central

Falatoonitoosi, Elham; Ahmed, Shamsuddin; Sorooshian, Shahryar

2014-01-01

Decision-Making Trial and Evaluation Laboratory (DEMATEL) methodology has been proposed to solve complex and intertwined problem groups in many situations such as developing the capabilities, complex group decision making, security problems, marketing approaches, global managers, and control systems. DEMATEL is able to realize casual relationships by dividing important issues into cause and effect group as well as making it possible to visualize the casual relationships of subcriteria and systems in the course of casual diagram that it may demonstrate communication network or a little control relationships between individuals. Despite of its ability to visualize cause and effect inside a network, the original DEMATEL has not been able to find the cause and effect group between different networks. Therefore, the aim of this study is proposing the expanded DEMATEL to cover this deficiency by new formulations to determine cause and effect factors between separate networks that have bidirectional direct impact on each other. At the end, the feasibility of new extra formulations is validated by case study in three numerical examples of green supply chain networks for an automotive company. PMID:24693224

Expanded DEMATEL for determining cause and effect group in bidirectional relations.

PubMed

Falatoonitoosi, Elham; Ahmed, Shamsuddin; Sorooshian, Shahryar

2014-01-01

Decision-Making Trial and Evaluation Laboratory (DEMATEL) methodology has been proposed to solve complex and intertwined problem groups in many situations such as developing the capabilities, complex group decision making, security problems, marketing approaches, global managers, and control systems. DEMATEL is able to realize casual relationships by dividing important issues into cause and effect group as well as making it possible to visualize the casual relationships of subcriteria and systems in the course of casual diagram that it may demonstrate communication network or a little control relationships between individuals. Despite of its ability to visualize cause and effect inside a network, the original DEMATEL has not been able to find the cause and effect group between different networks. Therefore, the aim of this study is proposing the expanded DEMATEL to cover this deficiency by new formulations to determine cause and effect factors between separate networks that have bidirectional direct impact on each other. At the end, the feasibility of new extra formulations is validated by case study in three numerical examples of green supply chain networks for an automotive company.

Longitudinal Associations between Depressive Problems, Academic Performance, and Social Functioning in Adolescent Boys and Girls

ERIC Educational Resources Information Center

Verboom, Charlotte E.; Sijtsema, Jelle J.; Verhulst, Frank C.; Penninx, Brenda W. J. H.; Ormel, Johan

2014-01-01

Depressive problems and academic performance, social well-being, and social problems in adolescents are strongly associated. However, longitudinal and bidirectional relations between the two remain unclear, as well as the role of gender. Consequently, this study focuses on the relation between depressive problems and three types of functioning in…

Examining the Relations between Executive Function, Math, and Literacy during the Transition to Kindergarten: A Multi-Analytic Approach

ERIC Educational Resources Information Center

Schmitt, Sara A.; Geldhof, G. John; Purpura, David J.; Duncan, Robert; McClelland, Megan M.

2017-01-01

The present study explored the bidirectional and longitudinal associations between executive function (EF) and early academic skills (math and literacy) across 4 waves of measurement during the transition from preschool to kindergarten using 2 complementary analytical approaches: cross-lagged panel modeling and latent growth curve modeling (LCGM).…

Apps for immunization: Leveraging mobile devices to place the individual at the center of care

PubMed Central

Wilson, Kumanan; Atkinson, Katherine M; Westeinde, Jacqueline

2015-01-01

Mobile technology and applications (apps) have disrupted several industries including healthcare. The advantage of apps, being personally focused and permitting bidirectional communication, make them well suited to address many immunization challenges. As of April 25, 2015 searching the Android app store with the words ‘immunize app’ and ‘immunization app’ in Canada yielded 225 apps. On the Apple App Store a similar search produced 98 results. These include apps that provide immunization related information, permit vaccine tracking both for individuals and for animals, assist with the creation of customized schedules and identification of vaccine clinics and serve as sources of education. The diverse functionality of mobile apps creates the potential for transformation of immunization practice both at a personal level and a system level. For individuals, mobile apps offer the opportunity for better record keeping, assistance with the logistics of vaccination, and novel ways of communicating with and receiving information from public health officials. For the system, mobile apps offer the potential to improve the quality of information residing in immunization information systems and program evaluation, facilitate harmonization of immunization information between individuals, health care providers and public health as well as reduce vaccine hesitancy. As mobile technology continues to rapidly evolve there will emerge new ways in which apps can enhance immunization practice. PMID:26110351

The Relation Between Contempt, Anger, and Intimate Partner Violence: A Dyadic Approach.

PubMed

Sommer, Johannah; Iyican, Susan; Babcock, Julia

2016-08-01

Intimate partner violence (IPV) is a persistent problem in our society, and there is strong evidence for the existence of bidirectional violence in heterosexual romantic relationships. Couples' research has long focused on conflict and distressed communication patterns as a source of relationship distress and eventual dissolution. In addition to relationship dissatisfaction, dysfunctional communication also appears to be associated with elevated risk of IPV. In fact, one study found that communication difficulties were one of the most frequently self-reported motivations for committing partner violence in a sample of both males and females arrested for IPV. The current study sought to explore the association between the expression of distressed communication (contempt and anger) during a laboratory conflict discussion and reports of IPV perpetration using a dyadic data analysis method, the Actor Partner Interdependence Model, in a large ethnically diverse sample of heterosexual couples. We found that negative communication in the form of contempt was not only associated with one's own physical assault perpetration, but it was also associated with physical assault perpetration of the other partner. In contrast, anger was only associated with one's own physical assault perpetration. Therefore, our results highlight the potential efficacy of treatments for IPV that target negative communication patterns and affect.

Protocol for buffer space negotiation

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

Nessett, D.

There are at least two ways to manage the buffer memory of a communications node. On etechnique veiws the buffer as a single resource that is to be reserved and released as a unit for a particular communication transaction. A more common approach treats the node's buffer space as a collection of resources (e.g., bytes, words, packet slots) capable of being allocated among multiple concurrent conversations. To achieve buffer space multiplexing, some sort of negotiation for buffer space must take place between source and sink nodes before a transaction can commence. Results are presented which indicate that, for an applicationmore » involving a CSMA broadcast network, buffer space multiplexing offers better performance than buffer reservation. To achieve this improvement, a simple protocol is presented that features flow-control information traveling both from source to sink as well as from sink to source. It is argued that this bidirectionality allows the sink to allocate buffer space among its active communication paths more effectively. 13 figures.« less

Directed Communication between Nucleus Accumbens and Neocortex in Humans Is Differentially Supported by Synchronization in the Theta and Alpha Band.

PubMed

Horschig, Jörn M; Smolders, Ruud; Bonnefond, Mathilde; Schoffelen, Jan-Mathijs; van den Munckhof, Pepijn; Schuurman, P Richard; Cools, Roshan; Denys, Damiaan; Jensen, Ole

2015-01-01

Here, we report evidence for oscillatory bi-directional interactions between the nucleus accumbens and the neocortex in humans. Six patients performed a demanding covert visual attention task while we simultaneously recorded brain activity from deep-brain electrodes implanted in the nucleus accumbens and the surface electroencephalogram (EEG). Both theta and alpha oscillations were strongly coherent with the frontal and parietal EEG during the task. Theta-band coherence increased during processing of the visual stimuli. Granger causality analysis revealed that the nucleus accumbens was communicating with the neocortex primarily in the theta-band, while the cortex was communicating the nucleus accumbens in the alpha-band. These data are consistent with a model, in which theta- and alpha-band oscillations serve dissociable roles: Prior to stimulus processing, the cortex might suppress ongoing processing in the nucleus accumbens by modulating alpha-band activity. Subsequently, upon stimulus presentation, theta oscillations might facilitate the active exchange of stimulus information from the nucleus accumbens to the cortex.

Implementation of Smart Metering based on Internet of Things

NASA Astrophysics Data System (ADS)

Kaur, Milanpreet; Mathew, Lini, Dr.; Alokdeep; Kumar, Ajay

2018-03-01

From the aspect of saving energy, there is a continuous modification in communication technology and information in order to satisfy all customers demand. Today customers are demanding for accurate energy measurement, timely data and for good customer services. The best solution is smart grid system with various communication technologies which can be cost effective and electrical section to have a bidirectional communication in which information about electrical energy consumption is shared between consumers as well as by utility for remote checking. This paper describes the monitoring of energy consumption with Arduino Uno board and Ethernet using IoT (Internet of Things) concept. This proposed design eliminates human inclusion in the conservation of electricity. The consumer can receive the information about consumption of energy by using IP address on their devices. The web client code is uploaded for checking the client information such as location, content, connection, and disconnection to the web server. This proposed system gives reliable and accurate information regarding electrical energy management system (EMS) through Internet of things (IoT).

Stability in Cohen Grossberg-type bidirectional associative memory neural networks with time-varying delays

NASA Astrophysics Data System (ADS)

Cao, Jinde; Song, Qiankun

2006-07-01

In this paper, the exponential stability problem is investigated for a class of Cohen-Grossberg-type bidirectional associative memory neural networks with time-varying delays. By using the analysis method, inequality technique and the properties of an M-matrix, several novel sufficient conditions ensuring the existence, uniqueness and global exponential stability of the equilibrium point are derived. Moreover, the exponential convergence rate is estimated. The obtained results are less restrictive than those given in the earlier literature, and the boundedness and differentiability of the activation functions and differentiability of the time-varying delays are removed. Two examples with their simulations are given to show the effectiveness of the obtained results.

Periodic oscillation of higher-order bidirectional associative memory neural networks with periodic coefficients and delays

NASA Astrophysics Data System (ADS)

Ren, Fengli; Cao, Jinde

2007-03-01

In this paper, several sufficient conditions are obtained ensuring existence, global attractivity and global asymptotic stability of the periodic solution for the higher-order bidirectional associative memory neural networks with periodic coefficients and delays by using the continuation theorem of Mawhin's coincidence degree theory, the Lyapunov functional and the non-singular M-matrix. Two examples are exploited to illustrate the effectiveness of the proposed criteria. These results are more effective than the ones in the literature for some neural networks, and can be applied to the design of globally attractive or globally asymptotically stable networks and thus have important significance in both theory and applications.

Bidirectional cross metathesis and ring-closing metathesis/ring opening of a C 2-symmetric building block: a strategy for the synthesis of decanolide natural products.

PubMed

Schmidt, Bernd; Kunz, Oliver

2013-01-01

Starting from the conveniently available ex-chiral pool building block (R,R)-hexa-1,5-diene-3,4-diol, the ten-membered ring lactones stagonolide E and curvulide A were synthesized using a bidirectional olefin-metathesis functionalization of the terminal double bonds. Key steps are (i) a site-selective cross metathesis, (ii) a highly diastereoselective extended tethered RCM to furnish a (Z,E)-configured dienyl carboxylic acid and (iii) a Ru-lipase-catalyzed dynamic kinetic resolution to establish the desired configuration at C9. Ring closure was accomplished by macrolactonization. Curvulide A was synthesized from stagonolide E through Sharpless epoxidation.

A Bidirectional Brain-Machine Interface Algorithm That Approximates Arbitrary Force-Fields

PubMed Central

Semprini, Marianna; Mussa-Ivaldi, Ferdinando A.; Panzeri, Stefano

2014-01-01

We examine bidirectional brain-machine interfaces that control external devices in a closed loop by decoding motor cortical activity to command the device and by encoding the state of the device by delivering electrical stimuli to sensory areas. Although it is possible to design this artificial sensory-motor interaction while maintaining two independent channels of communication, here we propose a rule that closes the loop between flows of sensory and motor information in a way that approximates a desired dynamical policy expressed as a field of forces acting upon the controlled external device. We previously developed a first implementation of this approach based on linear decoding of neural activity recorded from the motor cortex into a set of forces (a force field) applied to a point mass, and on encoding of position of the point mass into patterns of electrical stimuli delivered to somatosensory areas. However, this previous algorithm had the limitation that it only worked in situations when the position-to-force map to be implemented is invertible. Here we overcome this limitation by developing a new non-linear form of the bidirectional interface that can approximate a virtually unlimited family of continuous fields. The new algorithm bases both the encoding of position information and the decoding of motor cortical activity on an explicit map between spike trains and the state space of the device computed with Multi-Dimensional-Scaling. We present a detailed computational analysis of the performance of the interface and a validation of its robustness by using synthetic neural responses in a simulated sensory-motor loop. PMID:24626393

All oxide semiconductor-based bidirectional vertical p-n-p selectors for 3D stackable crossbar-array electronics

PubMed Central

Bae, Yoon Cheol; Lee, Ah Rahm; Baek, Gwang Ho; Chung, Je Bock; Kim, Tae Yoon; Park, Jea Gun; Hong, Jin Pyo

2015-01-01

Three-dimensional (3D) stackable memory devices including nano-scaled crossbar array are central for the realization of high-density non-volatile memory electronics. However, an essential sneak path issue affecting device performance in crossbar array remains a bottleneck and a grand challenge. Therefore, a suitable bidirectional selector as a two-way switch is required to facilitate a major breakthrough in the 3D crossbar array memory devices. Here, we show the excellent selectivity of all oxide p-/n-type semiconductor-based p-n-p open-based bipolar junction transistors as selectors in crossbar memory array. We report that bidirectional nonlinear characteristics of oxide p-n-p junctions can be highly enhanced by manipulating p-/n-type oxide semiconductor characteristics. We also propose an associated Zener tunneling mechanism that explains the unique features of our p-n-p selector. Our experimental findings are further extended to confirm the profound functionality of oxide p-n-p selectors integrated with several bipolar resistive switching memory elements working as storage nodes. PMID:26289565

[Crop geometry identification based on inversion of semiempirical BRDF models].

PubMed

Huang, Wen-jiang; Wang, Jin-di; Mu, Xi-han; Wang, Ji-hua; Liu, Liang-yun; Liu, Qiang; Niu, Zheng

2007-10-01

Investigations have been made on identification of erective and horizontal varieties by bidirectional canopy reflected spectrum and semi-empirical bidirectional reflectance distribution function (BRDF) models. The qualitative effect of leaf area index (LAI) and average leaf angle (ALA) on crop canopy reflected spectrum was studied. The structure parameter sensitive index (SPEI) based on the weight for the volumetric kernel (fvol), the weight for the geometric kernel (fgeo), and the weight for constant corresponding to isotropic reflectance (fiso), was defined in the present study for crop geometry identification. However, the weights associated with the kernels of semi-empirical BRDF model do not have a direct relationship with measurable biophysical parameters. Therefore, efforts have focused on trying to find the relation between these semi-empirical BRDF kernel weights and various vegetation structures. SPEI was proved to be more sensitive to identify crop geometry structures than structural scattering index (SSI) and normalized difference f-index (NDFI), SPEI could be used to distinguish erective and horizontal geometry varieties. So, it is feasible to identify horizontal and erective varieties of wheat by bidirectional canopy reflected spectrum.

AAH Cage Out-Link and In-Link Antenna Characterization

NASA Technical Reports Server (NTRS)

Jeutter, Dean C.

1998-01-01

This final report encapsulates the accomplishments of the third year of work on an Advanced Biotelemetry System (ABTS). Overall MU/ABTS project objectives are to provide a biotelemetry system that can collect data from and send commands to an implanted biotransceiver. This system will provide for studies of rodent development in space. The system must be capable of operating in a metal animal cage environment. An important goal is the development of a small, "smart", micropower, implantable biotransceiver with eight-channel data output and single channel command input capabilities with the flexibility for easy customization for a variety of physiologic investigations. The NASA Ames/Marquette University Joint Research work has been devoted to the system design of such a new state of the art biotelemetry system, having multiple physiologic inputs, and bi-directional data transfer capabilities. This work has provided a successful prototype system that connects, by two-way radio links, an addressable biotelemetry system that provides communication between an animal biotelemeter prototype and a personal computer. The operational features of the prototype system are: (1) two-way PCM communication with implanted biotelemeter; (2) microcontroller based biotelemeter; (3) out-link: wideband FSK (60 kBaud); (4) in-link: OOK (2.4 kbaud); (5) septum antenna arrays (In/Out-Links); and (6) personal computer data interface. The important requirement of this third year's work, to demonstrate two-way communication with transmit and receive antennas inside the metal animal cage, has been successfully accomplished. The advances discussed in this report demonstrate that the AAH cage antenna system can provide Out-link and In-link capability for the ABTS bi-directional telemetry system, and can serve as a benchmark for project status. Additions and enhancements to the most recent (April 1997) prototype cage and antenna have been implemented. The implementation, testing, and documentation was accomplished at the Biotelemetry Laboratory at Marquette University with Out-Link (slot) antenna design assistance was provided.

Assessment of a bidirectional reflectance distribution correction of above-water and satellite water-leaving radiance in coastal waters.

PubMed

Hlaing, Soe; Gilerson, Alexander; Harmel, Tristan; Tonizzo, Alberto; Weidemann, Alan; Arnone, Robert; Ahmed, Samir

2012-01-10

Water-leaving radiances, retrieved from in situ or satellite measurements, need to be corrected for the bidirectional properties of the measured light in order to standardize the data and make them comparable with each other. The current operational algorithm for the correction of bidirectional effects from the satellite ocean color data is optimized for typical oceanic waters. However, versions of bidirectional reflectance correction algorithms specifically tuned for typical coastal waters and other case 2 conditions are particularly needed to improve the overall quality of those data. In order to analyze the bidirectional reflectance distribution function (BRDF) of case 2 waters, a dataset of typical remote sensing reflectances was generated through radiative transfer simulations for a large range of viewing and illumination geometries. Based on this simulated dataset, a case 2 water focused remote sensing reflectance model is proposed to correct above-water and satellite water-leaving radiance data for bidirectional effects. The proposed model is first validated with a one year time series of in situ above-water measurements acquired by collocated multispectral and hyperspectral radiometers, which have different viewing geometries installed at the Long Island Sound Coastal Observatory (LISCO). Match-ups and intercomparisons performed on these concurrent measurements show that the proposed algorithm outperforms the algorithm currently in use at all wavelengths, with average improvement of 2.4% over the spectral range. LISCO's time series data have also been used to evaluate improvements in match-up comparisons of Moderate Resolution Imaging Spectroradiometer satellite data when the proposed BRDF correction is used in lieu of the current algorithm. It is shown that the discrepancies between coincident in-situ sea-based and satellite data decreased by 3.15% with the use of the proposed algorithm. This confirms the advantages of the proposed model over the current one, demonstrating the need for a specific case 2 water BRDF correction algorithm as well as the feasibility of enhancing performance of current and future satellite ocean color remote sensing missions for monitoring of typical coastal waters. © 2012 Optical Society of America

[Current approaches to evaluating the anatomic and functional status of the cornea].

PubMed

Avetisov, S E; Borodina, N V; Kobzova, M V; Musaeva, G M

2010-01-01

The review provides data on current methods for evaluating the anatomic and functional status of the cornea (light refraction, light transmission, and biomechanical properties, in particular). It analyzes the main advantages and disadvantages of basic (biomicroscopy, endothelial microscopy, ophthalmometry, topography, and pachymetry) and special (confocal microscopy, optical coherence tomography, ultrasound biomicroscopy, aberrometry, bidirectional corneal applanation, and keratoesthesiometry) studies.

An optical approach to proximity-operations communications for Space Station Freedom

NASA Technical Reports Server (NTRS)

Marshalek, Robert G.

1991-01-01

An optical communications system is described that supports bi-directional interconnections between Space Station Freedom (SSF) and a host of attached and co-orbiting platforms. These proximity-operations (Prox-Ops) platforms are categorized by their maximum distance from SSF, with several remaining inside 1-km range and several extending out to 37-km and 2000-km ranges in the initial and growth phases, respectively. Two distinct Prox-Ops optical terminals are described. A 1-cm-aperture system is used on the short-range platforms to reduce payload mass, and a 10-cm-aperture system is used on the long-range platforms and on SSF to support the optical link budgets. The system supports up to four simultaneous user links, by assigning wavelengths to the various platforms and by using separate SSF terminals for each link.

Estimation of optical properties of aerosols and bidirectional reflectance from PARASOL/POLDER data over land

NASA Astrophysics Data System (ADS)

Kusaka, Takashi; Miyazaki, Go

2014-10-01

When monitoring target areas covered with vegetation from a satellite, it is very useful to estimate the vegetation index using the surface anisotropic reflectance, which is dependent on both solar and viewing geometries, from satellite data. In this study, the algorithm for estimating optical properties of atmospheric aerosols such as the optical thickness (τ), the refractive index (Nr), the mixing ratio of small particles in the bimodal log-normal distribution function (C) and the bidirectional reflectance (R) from only the radiance and polarization at the 865nm channel received by the PARASOL/POLDER is described. Parameters of the bimodal log-normal distribution function: mean radius, r1, standard deviation, σ1, of fine aerosols, and r2, σ2 of coarse aerosols were fixed, and these values were estimated from monthly averaged size distribution at AERONET sites managed by NASA near the target area. Moreover, it is assumed that the contribution of the surface reflectance with directional anisotropy to the polarized radiance received by the satellite is small because it is shown from our ground-based polarization measurements of light ray reflected by the grassland that degrees of polarization of the reflected light by the grassland are very low values at the 865nm channel. First aerosol properties were estimated from only the polarized radiance and then the bidirectional reflectance given by the Ross-Li BRDF model was estimated from only the total radiance at target areas in PARASOL/POLDER data over the Japanese islands taken on April 28, 2012 and April 25, 2010. The estimated optical thickness of aerosols was checked with those given in AERONET sites and the estimated parameters of BRDF were compared with those of vegetation measured from the radio-controlled helicopter. Consequently, it is shown that the algorithm described in the present study provides reasonable values for aerosol properties and surface bidirectional reflectance.

Operant Variability and Voluntary Action

ERIC Educational Resources Information Center

Neuringer, Allen; Jensen, Greg

2010-01-01

A behavior-based theory identified 2 characteristics of voluntary acts. The first, extensively explored in operant-conditioning experiments, is that voluntary responses produce the reinforcers that control them. This bidirectional relationship--in which reinforcer depends on response and response on reinforcer--demonstrates the functional nature…

Amino acid residues 489-503 of dihydropyridine receptor (DHPR) β1a subunit are critical for structural communication between the skeletal muscle DHPR complex and type 1 ryanodine receptor.

PubMed

Eltit, Jose M; Franzini-Armstrong, Clara; Perez, Claudio F

2014-12-26

The β1a subunit is a cytoplasmic component of the dihydropyridine receptor (DHPR) complex that plays an essential role in skeletal muscle excitation-contraction (EC) coupling. Here we investigate the role of the C-terminal end of this auxiliary subunit in the functional and structural communication between the DHPR and the Ca(2+) release channel (RyR1). Progressive truncation of the β1a C terminus showed that deletion of amino acid residues Gln(489) to Trp(503) resulted in a loss of depolarization-induced Ca(2+) release, a severe reduction of L-type Ca(2+) currents, and a lack of tetrad formation as evaluated by freeze-fracture analysis. However, deletion of this domain did not affect expression/targeting or density (Qmax) of the DHPR-α1S subunit to the plasma membrane. Within this motif, triple alanine substitution of residues Leu(496), Leu(500), and Trp(503), which are thought to mediate direct β1a-RyR1 interactions, weakened EC coupling but did not replicate the truncated phenotype. Therefore, these data demonstrate that an amino acid segment encompassing sequence (489)QVQVLTSLRRNLSFW(503) of β1a contains critical determinant(s) for the physical link of DHPR and RyR1, further confirming a direct correspondence between DHPR positioning and DHPR/RyR functional interactions. In addition, our data strongly suggest that the motif Leu(496)-Leu(500)-Trp(503) within the β1a C-terminal tail plays a nonessential role in the bidirectional DHPR/RyR1 signaling that supports skeletal-type EC coupling. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Leptin in the interplay of inflammation, metabolism and immune system disorders.

PubMed

Abella, Vanessa; Scotece, Morena; Conde, Javier; Pino, Jesús; Gonzalez-Gay, Miguel Angel; Gómez-Reino, Juan J; Mera, Antonio; Lago, Francisca; Gómez, Rodolfo; Gualillo, Oreste

2017-02-01

Leptin is one of the most relevant factors secreted by adipose tissue and the forerunner of a class of molecules collectively called adipokines. Initially discovered in 1994, its crucial role as a central regulator in energy homeostasis has been largely described during the past 20 years. Once secreted into the circulation, leptin reaches the central and peripheral nervous systems and acts by binding and activating the long form of leptin receptor (LEPR), regulating appetite and food intake, bone mass, basal metabolism, reproductive function and insulin secretion, among other processes. Research on the regulation of different adipose tissues has provided important insights into the intricate network that links nutrition, metabolism and immune homeostasis. The neuroendocrine and immune systems communicate bi-directionally through common ligands and receptors during stress responses and inflammation, and control cellular immune responses in several pathological situations including immune-inflammatory rheumatic diseases. This Review discusses the latest findings regarding the role of leptin in the immune system and metabolism, with particular emphasis on its effect on autoimmune and/or inflammatory rheumatic diseases, such as rheumatoid arthritis and osteoarthritis.

Nicotine Uses Neuron-Glia Communication to Enhance Hippocampal Synaptic Transmission and Long-term Memory

PubMed Central

López-Hidalgo, Mónica; Salgado-Puga, Karla; Alvarado-Martínez, Reynaldo; Medina, Andrea Cristina; Prado-Alcalá, Roberto A.; García-Colunga, Jesús

2012-01-01

Nicotine enhances synaptic transmission and facilitates long-term memory. Now it is known that bi-directional glia-neuron interactions play important roles in the physiology of the brain. However, the involvement of glial cells in the effects of nicotine has not been considered until now. In particular, the gliotransmitter D-serine, an endogenous co-agonist of NMDA receptors, enables different types of synaptic plasticity and memory in the hippocampus. Here, we report that hippocampal long-term synaptic plasticity induced by nicotine was annulled by an enzyme that degrades endogenous D-serine, or by an NMDA receptor antagonist that acts at the D-serine binding site. Accordingly, both effects of nicotine: the enhancement of synaptic transmission and facilitation of long-term memory were eliminated by impairing glial cells with fluoroacetate, and were restored with exogenous D-serine. Together, these results show that glial D-serine is essential for the long-term effects of nicotine on synaptic plasticity and memory, and they highlight the roles of glial cells as key participants in brain functions. PMID:23185511

Next-generation probes, particles, and proteins for neural interfacing

PubMed Central

Rivnay, Jonathan; Wang, Huiliang; Fenno, Lief; Deisseroth, Karl; Malliaras, George G.

2017-01-01

Bidirectional interfacing with the nervous system enables neuroscience research, diagnosis, and therapy. This two-way communication allows us to monitor the state of the brain and its composite networks and cells as well as to influence them to treat disease or repair/restore sensory or motor function. To provide the most stable and effective interface, the tools of the trade must bridge the soft, ion-rich, and evolving nature of neural tissue with the largely rigid, static realm of microelectronics and medical instruments that allow for readout, analysis, and/or control. In this Review, we describe how the understanding of neural signaling and material-tissue interactions has fueled the expansion of the available tool set. New probe architectures and materials, nanoparticles, dyes, and designer genetically encoded proteins push the limits of recording and stimulation lifetime, localization, and specificity, blurring the boundary between living tissue and engineered tools. Understanding these approaches, their modality, and the role of cross-disciplinary development will support new neurotherapies and prostheses and provide neuroscientists and neurologists with unprecedented access to the brain. PMID:28630894

The measurement and evaluation of bidirectional reflectance characteristics of Dunhuang radiometric calibration test site

NASA Astrophysics Data System (ADS)

Zhao, Chun-yan; Li, Xin; Wei, Wei; Zheng, Xiao-bing

2016-10-01

With the progress of quantitative remote sensing, the acquisition of surface BRDF becomes more and more important. In order to improve the accuracy of the surface BRDF measurements, a VNIR-SWIR Bidirectional Reflectance Automatic Measurement System, which was developed by Hefei Institutes of Physical Science (HIPS), is introduced that allows in situ measurements of hyperspectral bidirectional reflectance data. Hyperspectral bidirectional reflectance distribution function data sets taken with the BRDF automatic measurement system nominally cover the spectral range between 390 and 2390 nm in 971 bands. In July 2007, September 2008, June 2011, we acquired a series of the BRDF data covered Dunhuang radiometric calibration test site in terms of the BRDF measurement system. We have not obtained such comprehensive and accurate data as they are, since 1990s when the site was built up. These data are applied to calibration for FY-2 and other satellites sensors. Field BRDF data of a Dunhuang site surface reveal a strong spectral variability. An anisotropy factor (ANIF), defined as the ratio between the directional reflectance and nadir reflectance over the hemisphere, is introduced as a surrogate measurement for the extent of spectral BRDF effects. The ANIF data show a very high correlation with the solar zenith angle due to multiple scattering effects over a desert site. Since surface geometry, multiple scattering, and BRDF effects are related, these findings may help to derive BRDF model parameters from the in-situ BRDF measurement remotely sensed hyperspectral data sets.

Bidirectional Retroviral Integration Site PCR Methodology and Quantitative Data Analysis Workflow.

PubMed

Suryawanshi, Gajendra W; Xu, Song; Xie, Yiming; Chou, Tom; Kim, Namshin; Chen, Irvin S Y; Kim, Sanggu

2017-06-14

Integration Site (IS) assays are a critical component of the study of retroviral integration sites and their biological significance. In recent retroviral gene therapy studies, IS assays, in combination with next-generation sequencing, have been used as a cell-tracking tool to characterize clonal stem cell populations sharing the same IS. For the accurate comparison of repopulating stem cell clones within and across different samples, the detection sensitivity, data reproducibility, and high-throughput capacity of the assay are among the most important assay qualities. This work provides a detailed protocol and data analysis workflow for bidirectional IS analysis. The bidirectional assay can simultaneously sequence both upstream and downstream vector-host junctions. Compared to conventional unidirectional IS sequencing approaches, the bidirectional approach significantly improves IS detection rates and the characterization of integration events at both ends of the target DNA. The data analysis pipeline described here accurately identifies and enumerates identical IS sequences through multiple steps of comparison that map IS sequences onto the reference genome and determine sequencing errors. Using an optimized assay procedure, we have recently published the detailed repopulation patterns of thousands of Hematopoietic Stem Cell (HSC) clones following transplant in rhesus macaques, demonstrating for the first time the precise time point of HSC repopulation and the functional heterogeneity of HSCs in the primate system. The following protocol describes the step-by-step experimental procedure and data analysis workflow that accurately identifies and quantifies identical IS sequences.

Mittag-Leffler synchronization of delayed fractional-order bidirectional associative memory neural networks with discontinuous activations: state feedback control and impulsive control schemes.

PubMed

Ding, Xiaoshuai; Cao, Jinde; Zhao, Xuan; Alsaadi, Fuad E

2017-08-01

This paper is concerned with the drive-response synchronization for a class of fractional-order bidirectional associative memory neural networks with time delays, as well as in the presence of discontinuous activation functions. The global existence of solution under the framework of Filippov for such networks is firstly obtained based on the fixed-point theorem for condensing map. Then the state feedback and impulsive controllers are, respectively, designed to ensure the Mittag-Leffler synchronization of these neural networks and two new synchronization criteria are obtained, which are expressed in terms of a fractional comparison principle and Razumikhin techniques. Numerical simulations are presented to validate the proposed methodologies.

Bi-periodicity evoked by periodic external inputs in delayed Cohen-Grossberg-type bidirectional associative memory networks

NASA Astrophysics Data System (ADS)

Cao, Jinde; Wang, Yanyan

2010-05-01

In this paper, the bi-periodicity issue is discussed for Cohen-Grossberg-type (CG-type) bidirectional associative memory (BAM) neural networks (NNs) with time-varying delays and standard activation functions. It is shown that the model considered in this paper has two periodic orbits located in saturation regions and they are locally exponentially stable. Meanwhile, some conditions are derived to ensure that, in any designated region, the model has a locally exponentially stable or globally exponentially attractive periodic orbit located in it. As a special case of bi-periodicity, some results are also presented for the system with constant external inputs. Finally, four examples are given to illustrate the effectiveness of the obtained results.

Robust stability for stochastic bidirectional associative memory neural networks with time delays

NASA Astrophysics Data System (ADS)

Shu, H. S.; Lv, Z. W.; Wei, G. L.

2008-02-01

In this paper, the asymptotic stability is considered for a class of uncertain stochastic bidirectional associative memory neural networks with time delays and parameter uncertainties. The delays are time-invariant and the uncertainties are norm-bounded that enter into all network parameters. The aim of this paper is to establish easily verifiable conditions under which the delayed neural network is robustly asymptotically stable in the mean square for all admissible parameter uncertainties. By employing a Lyapunov-Krasovskii functional and conducting the stochastic analysis, a linear matrix inequality matrix inequality (LMI) approach is developed to derive the stability criteria. The proposed criteria can be easily checked by the Matlab LMI toolbox. A numerical example is given to demonstrate the usefulness of the proposed criteria.

Bisphenol A alters oocyte maturation by prematurely closing gap junctions in the cumulus cell-oocyte complex.

PubMed

Acuña-Hernández, Deyanira Guadalupe; Arreola-Mendoza, Laura; Santacruz-Márquez, Ramsés; García-Zepeda, Sihomara Patricia; Parra-Forero, Lyda Yuliana; Olivares-Reyes, Jesús Alberto; Hernández-Ochoa, Isabel

2018-04-01

In ovarian follicles, cumulus cells communicate with the oocyte through gap junction intercellular communication (GJIC), to nurture the oocyte and control its meiosis arrest and division. Bisphenol A (BPA) is a monomer found in polycarbonate-made containers that can induce functional alterations, including impaired oocyte meiotic division and reduced molecule transfer in GJIC. However, how BPA alters oocyte meiotic division is unclear. We investigated whether BPA effects on oocyte meiotic division were correlated with reduced transfer in GJIC. Cumulus cell-oocyte complexes (COCs) isolated from mouse preovulatory follicles were cultured with 0, 0.22, 2.2, 22, 220, and 2200 nM BPA for 2 h. An additional 16-h incubation with epidermal growth factor (EGF) was performed to promote the occurrence of meiotic resumption and progression to metaphase II. Without EGF stimulus, BPA treatment increased the percentage of oocytes undergoing meiotic resumption, decreased GJIC in the COCs, and did not modify GJIC gene (Cx43 and Cx37) and protein (CX43) expression. Following EGF stimulus, BPA increased the percentage of oocytes that remained at the anaphase and telophase stages, and decreased the percentage of oocytes reaching the metaphase II stage. Concomitantly, BPA reduced the expansion of cumulus cells. Carbenoxolone (a GJIC inhibitor) and 6-diazo-5-oxo-l-norleucine (a cumulus cell-expansion inhibitor) exerted effects on meiotic division similar to those exerted by BPA. These data suggest that BPA accelerates meiotic progression, leading to impaired prophase I-to-metaphase II transition, and that this adverse effect is correlated with reduced bidirectional communication in the COC. Copyright © 2018 Elsevier Inc. All rights reserved.

Multichannel signal enhancement

DOEpatents

Lewis, Paul S.

1990-01-01

A mixed adaptive filter is formulated for the signal processing problem where desired a priori signal information is not available. The formulation generates a least squares problem which enables the filter output to be calculated directly from an input data matrix. In one embodiment, a folded processor array enables bidirectional data flow to solve the recursive problem by back substitution without global communications. In another embodiment, a balanced processor array solves the recursive problem by forward elimination through the array. In a particular application to magnetoencephalography, the mixed adaptive filter enables an evoked response to an auditory stimulus to be identified from only a single trial.

Lambda network having 2.sup.m-1 nodes in each of m stages with each node coupled to four other nodes for bidirectional routing of data packets between nodes

DOEpatents

Napolitano, Jr., Leonard M.

1995-01-01

The Lambda network is a single stage, packet-switched interprocessor communication network for a distributed memory, parallel processor computer. Its design arises from the desired network characteristics of minimizing mean and maximum packet transfer time, local routing, expandability, deadlock avoidance, and fault tolerance. The network is based on fixed degree nodes and has mean and maximum packet transfer distances where n is the number of processors. The routing method is detailed, as are methods for expandability, deadlock avoidance, and fault tolerance.

Human guidance of mobile robots in complex 3D environments using smart glasses

NASA Astrophysics Data System (ADS)

Kopinsky, Ryan; Sharma, Aneesh; Gupta, Nikhil; Ordonez, Camilo; Collins, Emmanuel; Barber, Daniel

2016-05-01

In order for humans to safely work alongside robots in the field, the human-robot (HR) interface, which enables bi-directional communication between human and robot, should be able to quickly and concisely express the robot's intentions and needs. While the robot operates mostly in autonomous mode, the human should be able to intervene to effectively guide the robot in complex, risky and/or highly uncertain scenarios. Using smart glasses such as Google Glass∗, we seek to develop an HR interface that aids in reducing interaction time and distractions during interaction with the robot.

A logical approach to semantic interoperability in healthcare.

PubMed

Bird, Linda; Brooks, Colleen; Cheong, Yu Chye; Tun, Nwe Ni

2011-01-01

Singapore is in the process of rolling out a number of national e-health initiatives, including the National Electronic Health Record (NEHR). A critical enabler in the journey towards semantic interoperability is a Logical Information Model (LIM) that harmonises the semantics of the information structure with the terminology. The Singapore LIM uses a combination of international standards, including ISO 13606-1 (a reference model for electronic health record communication), ISO 21090 (healthcare datatypes), and SNOMED CT (healthcare terminology). The LIM is accompanied by a logical design approach, used to generate interoperability artifacts, and incorporates mechanisms for achieving unidirectional and bidirectional semantic interoperability.

Brain gut microbiome interactions and functional bowel disorders

USDA-ARS?s Scientific Manuscript database

Alterations in the bidirectional interactions between the intestine and the nervous system have important roles in the pathogenesis of irritable bowel syndrome (IBS). A body of largely preclinical evidence suggests that the gut microbiota can modulate these interactions. A small and poorly defined r...

BI-DIRECTIONAL REFLECTANCE DISTRIBUTION FUNCTION (BRDF) OF SMOOTH CORDGRASS (SPARTINA ALTERNIFLORA). (R826944)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Robust stability of interval bidirectional associative memory neural network with time delays.

PubMed

Liao, Xiaofeng; Wong, Kwok-wo

2004-04-01

In this paper, the conventional bidirectional associative memory (BAM) neural network with signal transmission delay is intervalized in order to study the bounded effect of deviations in network parameters and external perturbations. The resultant model is referred to as a novel interval dynamic BAM (IDBAM) model. By combining a number of different Lyapunov functionals with the Razumikhin technique, some sufficient conditions for the existence of unique equilibrium and robust stability are derived. These results are fairly general and can be verified easily. To go further, we extend our investigation to the time-varying delay case. Some robust stability criteria for BAM with perturbations of time-varying delays are derived. Besides, our approach for the analysis allows us to consider several different types of activation functions, including piecewise linear sigmoids with bounded activations as well as the usual C1-smooth sigmoids. We believe that the results obtained have leading significance in the design and application of BAM neural networks.

A Single Pair of Serotonergic Neurons Counteracts Serotonergic Inhibition of Ethanol Attraction in Drosophila

PubMed Central

Kaiser, Andrea; Gräber, Nikolas; Schläger, Laura; Ritze, Yvonne; Scholz, Henrike

2016-01-01

Attraction to ethanol is common in both flies and humans, but the neuromodulatory mechanisms underlying this innate attraction are not well understood. Here, we dissect the function of the key regulator of serotonin signaling—the serotonin transporter–in innate olfactory attraction to ethanol in Drosophila melanogaster. We generated a mutated version of the serotonin transporter that prolongs serotonin signaling in the synaptic cleft and is targeted via the Gal4 system to different sets of serotonergic neurons. We identified four serotonergic neurons that inhibit the olfactory attraction to ethanol and two additional neurons that counteract this inhibition by strengthening olfactory information. Our results reveal that compensation can occur on the circuit level and that serotonin has a bidirectional function in modulating the innate attraction to ethanol. Given the evolutionarily conserved nature of the serotonin transporter and serotonin, the bidirectional serotonergic mechanisms delineate a basic principle for how random behavior is switched into targeted approach behavior. PMID:27936023

A Single Pair of Serotonergic Neurons Counteracts Serotonergic Inhibition of Ethanol Attraction in Drosophila.

PubMed

Xu, Li; He, Jianzheng; Kaiser, Andrea; Gräber, Nikolas; Schläger, Laura; Ritze, Yvonne; Scholz, Henrike

2016-01-01

Attraction to ethanol is common in both flies and humans, but the neuromodulatory mechanisms underlying this innate attraction are not well understood. Here, we dissect the function of the key regulator of serotonin signaling-the serotonin transporter-in innate olfactory attraction to ethanol in Drosophila melanogaster. We generated a mutated version of the serotonin transporter that prolongs serotonin signaling in the synaptic cleft and is targeted via the Gal4 system to different sets of serotonergic neurons. We identified four serotonergic neurons that inhibit the olfactory attraction to ethanol and two additional neurons that counteract this inhibition by strengthening olfactory information. Our results reveal that compensation can occur on the circuit level and that serotonin has a bidirectional function in modulating the innate attraction to ethanol. Given the evolutionarily conserved nature of the serotonin transporter and serotonin, the bidirectional serotonergic mechanisms delineate a basic principle for how random behavior is switched into targeted approach behavior.

Bidirectional reflectance distribution function /BRDF/ measurements of stray light suppression coatings for the Space Telescope /ST/

NASA Technical Reports Server (NTRS)

Griner, D. B.

1979-01-01

The paper considers the bidirectional reflectance distribution function (BRDF) of black coatings used on stray light suppression systems for the Space Telescope (ST). The ST stray light suppression requirement is to reduce earth, moon, and sun light in the focal plane to a level equivalent to one 23 Mv star per square arcsecond, an attenuation of 14 orders of magnitude. It is impractical to verify the performance of a proposed baffle system design by full scale tests because of the large size of the ST, so that a computer analysis is used to select the design. Accurate computer analysis requires a knowledge of the diffuse scatter at all angles from the surface of the coatings, for all angles of incident light. During the early phases of the ST program a BRDF scanner was built at the Marshall Space Flight Center to study the scatter from black materials; the measurement system is described and the results of measurements on samples proposed for use on the ST are presented.

Measuring spatially varying, multispectral, ultraviolet bidirectional reflectance distribution function with an imaging spectrometer

NASA Astrophysics Data System (ADS)

Li, Hongsong; Lyu, Hang; Liao, Ningfang; Wu, Wenmin

2016-12-01

The bidirectional reflectance distribution function (BRDF) data in the ultraviolet (UV) band are valuable for many applications including cultural heritage, material analysis, surface characterization, and trace detection. We present a BRDF measurement instrument working in the near- and middle-UV spectral range. The instrument includes a collimated UV light source, a rotation stage, a UV imaging spectrometer, and a control computer. The data captured by the proposed instrument describe spatial, spectral, and angular variations of the light scattering from a sample surface. Such a multidimensional dataset of an example sample is captured by the proposed instrument and analyzed by a k-mean clustering algorithm to separate surface regions with same material but different surface roughnesses. The clustering results show that the angular dimension of the dataset can be exploited for surface roughness characterization. The two clustered BRDFs are fitted to a theoretical BRDF model. The fitting results show good agreement between the measurement data and the theoretical model.

Dual-Stack Single-Radio Communication Architecture for UAV Acting As a Mobile Node to Collect Data in WSNs

PubMed Central

Sayyed, Ali; Medeiros de Araújo, Gustavo; Bodanese, João Paulo; Buss Becker, Leandro

2015-01-01

The use of mobile nodes to collect data in a Wireless Sensor Network (WSN) has gained special attention over the last years. Some researchers explore the use of Unmanned Aerial Vehicles (UAVs) as mobile node for such data-collection purposes. Analyzing these works, it is apparent that mobile nodes used in such scenarios are typically equipped with at least two different radio interfaces. The present work presents a Dual-Stack Single-Radio Communication Architecture (DSSRCA), which allows a UAV to communicate in a bidirectional manner with a WSN and a Sink node. The proposed architecture was specifically designed to support different network QoS requirements, such as best-effort and more reliable communications, attending both UAV-to-WSN and UAV-to-Sink communications needs. DSSRCA was implemented and tested on a real UAV, as detailed in this paper. This paper also includes a simulation analysis that addresses bandwidth consumption in an environmental monitoring application scenario. It includes an analysis of the data gathering rate that can be achieved considering different UAV flight speeds. Obtained results show the viability of using a single radio transmitter for collecting data from the WSN and forwarding such data to the Sink node. PMID:26389911

Dual-Stack Single-Radio Communication Architecture for UAV Acting As a Mobile Node to Collect Data in WSNs.

PubMed

Sayyed, Ali; de Araújo, Gustavo Medeiros; Bodanese, João Paulo; Becker, Leandro Buss

2015-09-16

The use of mobile nodes to collect data in a Wireless Sensor Network (WSN) has gained special attention over the last years. Some researchers explore the use of Unmanned Aerial Vehicles (UAVs) as mobile node for such data-collection purposes. Analyzing these works, it is apparent that mobile nodes used in such scenarios are typically equipped with at least two different radio interfaces. The present work presents a Dual-Stack Single-Radio Communication Architecture (DSSRCA), which allows a UAV to communicate in a bidirectional manner with a WSN and a Sink node. The proposed architecture was specifically designed to support different network QoS requirements, such as best-effort and more reliable communications, attending both UAV-to-WSN and UAV-to-Sink communications needs. DSSRCA was implemented and tested on a real UAV, as detailed in this paper. This paper also includes a simulation analysis that addresses bandwidth consumption in an environmental monitoring application scenario. It includes an analysis of the data gathering rate that can be achieved considering different UAV flight speeds. Obtained results show the viability of using a single radio transmitter for collecting data from the WSN and forwarding such data to the Sink node.

Spatial and Functional Aspects of ER-Golgi Rabs and Tethers

PubMed Central

Saraste, Jaakko

2016-01-01

Two conserved Rab GTPases, Rab1 and Rab2, play important roles in biosynthetic-secretory trafficking between the endoplasmic reticulum (ER) and the Golgi apparatus in mammalian cells. Both are expressed as two isoforms that regulate anterograde transport via the intermediate compartment (IC) to the Golgi, but are also required for transport in the retrograde direction. Moreover, Rab1 has been implicated in the formation of autophagosomes. Rab1 and Rab2 have numerous effectors or partners that function in membrane tethering, but also have other roles. These include the coiled-coil proteins p115, GM130, giantin, golgin-84, and GMAP-210, as well as the multisubunit COG (conserved oligomeric Golgi) and TRAPP (transport protein particle) tethering complexes. TRAPP also acts as the GTP exchange factor (GEF) in the activation of Rab1. According to the traditional view of the IC elements as motile, transient structures, the functions of the Rabs could take place at the two ends of the ER-Golgi itinerary, i.e., at ER exit sites (ERES) and/or cis-Golgi. However, there is considerable evidence for their specific association with the IC, including its recently identified pericentrosomal domain (pcIC), where many of the effectors turn out to be present, thus being able to exert their functions at the pre-Golgi level. The IC localization of these proteins is of particular interest based on the imaging of Rab1 dynamics, indicating that the IC is a stable organelle that bidirectionally communicates with the ER and Golgi, and is functionally linked to the endosomal system via the pcIC. PMID:27148530

Generalized model of a bidirectional DC-DC converter

NASA Astrophysics Data System (ADS)

Hinov, Nikolay; Arnaudov, Dimitar; Penev, Dimitar

2017-12-01

The following paperwork presents models of bidirectional converters. A classic bidirectional converter and a new bidirectional circuit based on a ZCS resonant converter are investigated and compared. The developed models of these converters allow comparison between their characteristics showing their advantages and disadvantages. The models allow precise models of energy storage elements to be implemented as well, which is useful for examination of energy storage systems.

The role of parental alcohol-specific communication in early adolescents' alcohol use.

PubMed

Van Der Vorst, Haske; Burk, William J; Engels, Rutger C M E

2010-10-01

Many alcohol prevention programs advocate conversations about alcohol between parents and children because verbal communication is the most direct way for parents to express their thoughts, rules, and concerns about alcohol to their children, so called alcohol-specific communication. Nevertheless, research on the effects of alcohol-specific communication has produced inconsistent findings. This study examined the bidirectional links between frequency of alcohol-specific communication and early adolescents' alcohol use, and the moderating effects on these links of gender and experience with alcohol. The longitudinal sample consisted of 428 Dutch early adolescents who were followed over 3 years. Results of structural equation models indicated that more frequent alcohol-specific communication at time two predicted more adolescent alcohol use at time three. Follow-up multiple-group analyses clearly show that prospective links between alcohol-specific communication and adolescent alcohol use were limited to adolescent males reporting the highest levels of drinking. For this group of drinking males, alcohol use predicted less parent-child communication, and more frequency of alcohol-specific communication predicted an increase in drinking. Alcohol-specific communication and adolescent alcohol use were not prospectively linked for males reporting lower levels of alcohol use or for adolescent females. These findings highlight the need for future research that examines both quantitative and qualitative aspects of how parents communicate with their adolescent children about alcohol. Advocation of specific parent-child communication skills meant to reduce youth alcohol use may be somewhat premature until additional studies refine our understanding of how specific parenting strategies are linked to different patterns of adolescent alcohol use. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Beginning science teachers' strategies for communicating with families

NASA Astrophysics Data System (ADS)

Bloom, Nena E.

Science learning occurs in both formal and informal spaces. Families are critical for developing student learning and interest in science because they provide important sources of knowledge, support and motivation. Bidirectional communication between teachers and families can be used to build relationships between homes and schools, leverage family knowledge of and support for learners, and create successful environments for science learning that will support both teaching and student learning. To identify the communication strategies of beginning science teachers, who are still developing their teaching practices, a multiple case study was conducted with seven first year secondary science teachers. The methods these teachers used to communicate with families, the information that was communicated and shared, and factors that shaped these teachers' continued development of communication strategies were examined. Demographic data, interview data, observations and documentation of communication through logs and artifacts were collected for this study. Results indicated that the methods teachers had access to and used for communication impacted the frequency and efficacy of their communication. Teachers and families communicated about a number of important topics, but some topics that could improve learning experiences and science futures for their students were rarely discussed, such as advancement in science, student learning in science and family knowledge. Findings showed that these early career teachers were continuing to learn about their communities and to develop their communication strategies with families. Teachers' familiarity with their school community, opportunities to practice strategies during preservice preparation and student teaching, their teaching environment, school policies, and learning from families and students in their school culture continued to shape and influence their views and communication strategies. Findings and implications for teacher preparation programs, teachers, schools and organizations are discussed.

Frequency-agile wireless sensor networks

NASA Astrophysics Data System (ADS)

Arms, Steven W.; Townsend, Christopher P.; Churchill, David L.; Hamel, Michael J.; Galbreath, Jacob H.; Mundell, Steven W.

2004-07-01

Our goal was to demonstrate a wireless communications system capable of simultaneous, high speed data communications from a variety of sensors. We have previously reported on the design and application of 2 KHz data logging transceiver nodes, however, only one node may stream data at a time, since all nodes on the network use the same communications frequency. To overcome these limitations, second generation data logging transceivers were developed with software programmable radio frequency (RF) communications. Each node contains on-board memory (2 Mbytes), sensor excitation, instrumentation amplifiers with programmable gains & offsets, multiplexer, 16 bit A/D converter, microcontroller, and frequency agile, bi-directional, frequency shift keyed (FSK) RF serial data link. These systems are capable of continuous data transmission from 26 distinct nodes (902-928 MHz band, 75 kbaud). The system was demonstrated in a compelling structural monitoring application. The National Parks Service requested a means for continual monitoring and recording of sensor data from the Liberty Bell during a move to a new location (Philadelphia, October 2003). Three distinct, frequency agile, wireless sensing nodes were used to detect visible crack shear/opening micromotions, triaxial accelerations, and hairline crack tip strains. The wireless sensors proved to be useful in protecting the Liberty Bell.

The LHRH-astroglial network of signals as a model to study neuroimmune interactions: assessment of messenger systems and transduction mechanisms at cellular and molecular levels.

PubMed

Marchetti, B

1996-01-01

Neurons and astrocytes have a close anatomic and functional relationship that plays a crucial role during development and in the adult brain. Astrocytes in the central nervous system (CNS) express receptors for a variety of growth factors (GFs), neurotransmitters and/or neuromodulators; in turn, neuronal cells can respond to astrocyte-derived GFs and control astrocyte function via a common set of signaling molecules and intracellular transducing pathways. There is also increasing evidence that soluble factors from lymphoid/mononuclear cells are able to modulate the growth and function of cells found in the CNS, specifically macroglial and microglial cells. Furthermore, glial cells can secrete immunoregulatory molecules that influence immune cells as well as the glial cells themselves. As neuronal and immune cells share common signaling systems, the potential exists for bidirectional communication not only between lymphoid and glial cells, but also between neuronal cells and immune and glial cells. In the present work, interactions of luteinizing-hormone-releasing hormone (LHRH) and the astroglial cell are proposed as a prototype for the study of neuroimmune communication within the CNS in the light of (1) the commonality of signal molecules (hormones, neurotransmitters and cytokines) and transduction mechanisms shared by glia LHRH neurons and lymphoid cells; (2) the central role of glia in the developmental organization and pattern of LHRH neuronal migration during embryogenesis, and (3) the strong modulatory role played by sex steroids in mechanisms involved in synaptic and interneuronal organization, as well as in the sexual dimorphisms of neuroendocrine-immune functions. During their maturation and differentiation in vitro, astroglial cells release factors able to accelerate markedly the LHRH neuronal phenotypic differentiation as well as the acquisition of mature LHRH secretory potential, with a potency depending on both the 'age' and the specific brain localization of the astroglia, as well as the degree of LHRH neuronal differentiation in vitro. Regional differences in astroglial sensitivity to estrogens were also measured. Different experimental paradigms such as coculture and mixed-culture models between the immortalized LHRH (GT1-1) neuronal cell line and astroglial cells in primary culture, disclosed the presence of a bidirectional flow of informational molecules regulating both proliferative and secretory capacities of each cell type. The importance of adhesive mechanisms in such cross-talk is underscored by the complete abolition of GT1-1 LHRH production and cell proliferation following the counteraction of neuronal-neuronal/neuronal-glial interactions through addition of neural-cell adhesion molecule antiserum. Other information came from pharmacological experiments manipulating the astroglia-derived cytokines and/or nitric oxide, which revealed cross-talk between the neuronal and astroglial compartments. From the bulk of this information, it seems likely that interactions between astroglia and LHRH neurons play a major role in the integration of the multiplicity of brain signals converging on the LHRH neurons that govern reproduction. Another important facet of neuronal-glial interactions is that concerning neuron-guided migration, and unraveling astroglial/LHRH-neuronal networks might then constitute an additional effort in the comprehension of defective LHRH-neuronal migration in Kallman's syndrome.

[Supervised administration of Alzheimer's patients using information communication technology].

PubMed

Noda, Yasuha; Sakata, Yoshifumi; Kubota, Masakazu; Uemura, Kengo; Kihara, Takeshi; Kimura, Toru; Ino, Masashi; Tsuji, Teruyuki; Hayashi, Michiyuki; Kinoshita, Ayae

2014-12-01

Drug adherence is central to the treatment of dementia, which might reduce compliance due to memory loss, particularly among home-based patients with dementia. In order to improve drug adherence, we suggest the efficient and effective supervised administration by use of information communication technology(ICT). ICT makes face-to-face real-time communication possible, and it also enables picture sharing. Therefore, it might be useful to apply ICT to controlling and supervising medication for patients with dementia to improve drug adherence. Accordingly, we enrolled patients who were supposed to take a newly prescribed anti-dementia patch containing the choline esterase inhibitor rivastigmine(Rivastach®)and investigated the effect of ICT-based intervention for drug adherence, emotional change, and cognitive change, utilizing Skype, a free communication software program. Scheduled Skype interventions increased drug adherence ratio, levels of subjective satisfaction, and instrumental activities of daily living(IADL). Furthermore, we can provide patients and their caregivers with a feeling of safety through regular bidirectional communication, as patients can easily consult medical staff regarding the adverse effects of newly prescribed drugs. Instead of frequent visits to their primary physicians, ICT-based communications can be used as a substitute for supervision of medication, given the availability of the telecommunication system. By directly connecting the medical institution to the home, we expect that this ICT-based system will expand into the geriatric care field, including the care of elderly individuals living alone.

Manager Perspectives on Communication and Public ...

EPA Pesticide Factsheets

We argue that public engagement is crucial to achieving lasting ecological success in aquatic restoration efforts, and that the most effective public engagement mechanisms are what we term iterative mechanisms. Here we look to a particular social-ecological system – the restoration community in Rhode Island, U.S.A. and the rivers, wetlands, marshes, and estuaries, and their related species, that they work to protect – to better understand land managers’ perspectives on public engagement in restoration processes. Adopting an inductive approach to critical discourse analysis of interviews with 27 local, state, and federal restoration managers and the forms of public interaction they described, we identify three distinct models of public engagement in natural resources management employed by managers: unidirectional; bidirectional; and iterative. While unidirectional and bidirectional mechanisms can help managers achieve short-term ecological successes, we suggest that adopting an iterative approach can improve the quality of stakeholder and learning interactions and, subsequently, foster lasting ecological successes. We argue that managers can design deliberately for public engagement mechanisms that are best suited to projects in particular social-ecological systems in order to create restoration projects that achieve ecological, learning, and stakeholder successes. We attempt to synthesize the lessons learned from efforts at public engagement in restoratio

An update on ABO incompatible hematopoietic progenitor cell transplantation.

PubMed

Staley, Elizabeth M; Schwartz, Joseph; Pham, Huy P

2016-06-01

Hematopoietic progenitor cell (HPC) transplantation has long been established as the optimal treatment for many hematologic malignancies. In the setting of allogenic HLA matched HPC transplantation, greater than 50% of unrelated donors and 30% of related donors demonstrate some degree of ABO incompatibility (ABOi), which is classified in one of three ways: major, minor, or bidirectional. Major ABOi refers to the presence of recipient isoagglutinins against the donor's A and/or B antigen. Minor ABOi occurs when the HPC product contains the isoagglutinins targeting the recipient's A and/or B antigen. Bidirectional refers to the presence of both major and minor ABOi. Major adverse events associated with ABOi HPC transplantation includes acute and delayed hemolysis, pure red cell aplasia, and delayed engraftment. ABOi HPC transplantation poses a unique challenge to the clinical transplantation unit, the HPC processing lab, and the transfusion medicine service. Therefore, it is essential that these services actively communicate with one another to ensure patient safety. This review will attempt to globally address the challenges related to ABOi HPC transplantation, with an increased focus on aspects related to the laboratory and transfusion medicine services. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ground-to-Ground Optical Communications Demonstration

NASA Technical Reports Server (NTRS)

Biswas, A.; Lee, S.

2000-01-01

A bidirectional horizontal-path optical link was demonstrated between Strawberry Peak (SP), Lake Arrowhead, California, and the JPL Table Mountain Facility (TMF), Wrightwood, California, during June and November of 1998. The 0.6-m telescope at TMF was used to broadcast a 4-beam 780-nm beacon to SP. The JPL-patented Optical Communications Demonstrator (OCD) at SP received the beacon, performed ne tracking to compensate for the atmosphere-induced beacon motion and retransmitted a 844-nm communications laser beam modulated at 40 to 500 Mb/s back to TMF. Characteristics of the horizontal-path atmospheric channel as well as performance of the optical communications link were evaluated. The normalized variance of the irradiance fluctuations or scintillation index delta2/I at either end was determined. At TMF where a single 844-nm beam was received by a 0.6-m aperture, the measured delta2/I covered a wide range from 0.07 to 1.08. A single 780-nm beam delta2/I measured at SP using a 0.09-m aperture yielded values ranging from 0.66 to 1.03, while a combination of four beams reduced the scintillation index due to incoherent averaging to 0.22 to 0.40. This reduction reduced the dynamic range of the fluctuations from 17 to 21 dB to 13 to 14 dB as compared with the OCD tracking sensor dynamic range of 10 dB. Predictions of these values also were made based on existing theories and are compared. Generally speaking, the theoretical bounds were reasonable. Discussions on the probability density function (PDF) of the intensity fluctuations are presented and compared with the measurements made. The lognormal PDF was found to agree for the weak scintillation regime as expected. The present measurements support evidence presented by earlier measurements made using the same horizontal path, which suggests that the aperture averaging effect is better than theoretically predicted.

Analysis of Snow Bidirectional Reflectance from ARCTAS Spring-2008 Campaign

NASA Technical Reports Server (NTRS)

Lyapustin, A.; Gatebe, C. K.; Redemann, J.; Kahn, R.; Brandt, R.; Russell, P.; King, M. D.; Pedersen, C. A.; Gerland, S.; Poudyal, R.;

Radiative Transfer Photometric Analysis of Surface Materials at the Mars Exploration Rover Landing Sites

NASA Astrophysics Data System (ADS)

Seelos, F. P.; Arvidson, R. E.; Guinness, E. A.; Wolff, M. J.

2004-12-01

The Mars Exploration Rover (MER) Panoramic Camera (Pancam) observation strategy included the acquisition of multispectral data sets specifically designed to support the photometric analysis of Martian surface materials (J. R. Johnson, this conference). We report on the numerical inversion of observed Pancam radiance-on-sensor data to determine the best-fit surface bidirectional reflectance parameters as defined by Hapke theory. The model bidirectional reflectance parameters for the Martian surface provide constraints on physical and material properties and allow for the direct comparison of Pancam and orbital data sets. The parameter optimization procedure consists of a spatial multigridding strategy driving a Levenberg-Marquardt nonlinear least squares optimization engine. The forward radiance models and partial derivatives (via finite-difference approximation) are calculated using an implementation of the DIScrete Ordinate Radiative Transfer (DISORT) algorithm with the four-parameter Hapke bidirectional reflectance function and the two-parameter Henyey-Greenstein phase function defining the lower boundary. The DISORT implementation includes a plane-parallel model of the Martian atmosphere derived from a combination of Thermal Emission Spectrometer (TES), Pancam, and Mini-TES atmospheric data acquired near in time to the surface observations. This model accounts for bidirectional illumination from the attenuated solar beam and hemispherical-directional skylight illumination. The initial investigation was limited to treating the materials surrounding the rover as a single surface type, consistent with the spatial resolution of orbital observations. For more detailed analyses the observation geometry can be calculated from the correlation of Pancam stereo pairs (J. M. Soderblom et al., this conference). With improved geometric control, the radiance inversion can be applied to constituent surface material classes such as ripple and dune forms in addition to the soils on the Meridiani plain. Under the assumption of a Henyey-Greenstein phase function, initial results for the Opportunity site suggest a single scattering albedo on the order of 0.25 and a Henyey-Greenstein forward fraction approaching unity at an effective wavelength of 753 nm. As an extension of the photometric modeling, the radiance inversion also provides a means of calculating surface reflectance independent of the radiometric calibration target. This method for determining observed reflectance will provide an additional constraint on the dust deposition model for the calibration target.

Bidirectional Transfer between Metaphorical Related Domains in Implicit Learning of Form-Meaning Connections

PubMed Central

Yang, Zhiliang; Dienes, Zoltan

2013-01-01

People can implicitly learn a connection between linguistic forms and meanings, for example between specific determiners (e.g. this, that…) and the type of nouns to which they apply. Li et al (2013) recently found that transfer of form-meaning connections from a concrete domain (height) to an abstract domain (power) was achieved in a metaphor-consistent way without awareness, showing that unconscious knowledge can be abstract and flexibly deployed. The current study aims to determine whether people transfer knowledge of form-meaning connections not only from a concrete domain to an abstract one, but also vice versa, consistent with metaphor representation being bi-directional. With a similar paradigm as used by Li et al, participants learnt form- meaning connections of different domains (concrete vs. abstract) and then were tested on two kinds of generalizations (same and different domain generalization). As predicted, transfer of form-meaning connections occurred bidirectionally when structural knowledge was unconscious. Moreover, the present study also revealed that more transfer occurred between metaphorically related domains when judgment knowledge was conscious (intuition) rather than unconscious (guess). Conscious and unconscious judgment knowledge may have different functional properties. PMID:23844159

Bidirectional regulation of adenosine-to-inosine (A-to-I) RNA editing by DEAH box helicase 9 (DHX9) in cancer.

PubMed

Hong, HuiQi; An, Omer; Chan, Tim H M; Ng, Vanessa H E; Kwok, Hui Si; Lin, Jaymie S; Qi, Lihua; Han, Jian; Tay, Daryl J T; Tang, Sze Jing; Yang, Henry; Song, Yangyang; Bellido Molias, Fernando; Tenen, Daniel G; Chen, Leilei

2018-05-18

Adenosine-to-inosine (A-to-I) RNA editing entails the enzymatic deamination of adenosines to inosines by adenosine deaminases acting on RNA (ADARs). Dysregulated A-to-I editing has been implicated in various diseases, including cancers. However, the precise factors governing the A-to-I editing and their physiopathological implications remain as a long-standing question. Herein, we unravel that DEAH box helicase 9 (DHX9), at least partially dependent of its helicase activity, functions as a bidirectional regulator of A-to-I editing in cancer cells. Intriguingly, the ADAR substrate specificity determines the opposing effects of DHX9 on editing as DHX9 silencing preferentially represses editing of ADAR1-specific substrates, whereas augments ADAR2-specific substrate editing. Analysis of 11 cancer types from The Cancer Genome Atlas (TCGA) reveals a striking overexpression of DHX9 in tumors. Further, tumorigenicity studies demonstrate a helicase-dependent oncogenic role of DHX9 in cancer development. In sum, DHX9 constitutes a bidirectional regulatory mode in A-to-I editing, which is in part responsible for the dysregulated editome profile in cancer.

A Statistical Theory of Bidirectionality

NASA Technical Reports Server (NTRS)

DeLoach, Richard; Ulbrich, Norbert

2013-01-01

Original concepts related to the quantification and assessment of bidirectionality in strain-gage balances were introduced by Ulbrich in 2012. These concepts are extended here in three ways: 1) the metric originally proposed by Ulbrich is normalized, 2) a categorical variable is introduced in the regression analysis to account for load polarity, and 3) the uncertainty in both normalized and non-normalized bidirectionality metrics is quantified. These extensions are applied to four representative balances to assess the bidirectionality characteristics of each. The paper is tutorial in nature, featuring reviews of certain elements of regression and formal inference. Principal findings are that bidirectionality appears to be a common characteristic of most balance outputs and that unless it is taken into account, it is likely to consume the entire error budget of a typical balance calibration experiment. Data volume and correlation among calibration loads are shown to have a significant impact on the precision with which bidirectionality metrics can be assessed.

Bidirectional Frontoparietal Oscillatory Systems Support Working Memory.

PubMed

Johnson, Elizabeth L; Dewar, Callum D; Solbakk, Anne-Kristin; Endestad, Tor; Meling, Torstein R; Knight, Robert T

2017-06-19

The ability to represent and select information in working memory provides the neurobiological infrastructure for human cognition. For 80 years, dominant views of working memory have focused on the key role of prefrontal cortex (PFC) [1-8]. However, more recent work has implicated posterior cortical regions [9-12], suggesting that PFC engagement during working memory is dependent on the degree of executive demand. We provide evidence from neurological patients with discrete PFC damage that challenges the dominant models attributing working memory to PFC-dependent systems. We show that neural oscillations, which provide a mechanism for PFC to communicate with posterior cortical regions [13], independently subserve communications both to and from PFC-uncovering parallel oscillatory mechanisms for working memory. Fourteen PFC patients and 20 healthy, age-matched controls performed a working memory task where they encoded, maintained, and actively processed information about pairs of common shapes. In controls, the electroencephalogram (EEG) exhibited oscillatory activity in the low-theta range over PFC and directional connectivity from PFC to parieto-occipital regions commensurate with executive processing demands. Concurrent alpha-beta oscillations were observed over parieto-occipital regions, with directional connectivity from parieto-occipital regions to PFC, regardless of processing demands. Accuracy, PFC low-theta activity, and PFC → parieto-occipital connectivity were attenuated in patients, revealing a PFC-independent, alpha-beta system. The PFC patients still demonstrated task proficiency, which indicates that the posterior alpha-beta system provides sufficient resources for working memory. Taken together, our findings reveal neurologically dissociable PFC and parieto-occipital systems and suggest that parallel, bidirectional oscillatory systems form the basis of working memory. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Surface Material Characterization from Non-resolved Multi-band Optical Observations

DTIC Science & Technology

2012-09-01

functions ( BRDFs ) — then a forward model of the spectral signature of the entire body could be constructed by summing contributions from all reflecting...buffering). 3.3.2 Material Bi-directional Reflectance Distribution Functions ( BRDFs ) Notably, the satellite wire-frame and attitude models together...environments and/or created numerical BRDF models . For instance, BRDFs for several spacecraft materials — such as solar array panels, milled aluminum

Enzymatic Synthesis of GDP-α-l-fucofuranose by MtdL and Hyg20.

PubMed

Qin, Xiangjing; Xie, Yunchang; Huang, Hongbo; Chen, Qi; Ma, Junying; Li, Qinglian; Ju, Jianhua

2018-02-16

Two mutases, MtdL and Hyg20, are reported. Both are able to functionally drive the biosynthesis of GDP-α-l-fucofuranose. Both enzymes catalyze similar functions, catalytically enabling the bidirectional reaction between GDP-β-l-fucopyranose and GDP-α-l-fucofuranose using only divalent cations as cofactors. This realization is but one of a number of important insights into fucofuranose biosynthesis presented herein.

Development of Laser Beam Transmission Strategies for Future Ground-to-Space Optical Communications

NASA Technical Reports Server (NTRS)

Wilson, Keith E.; Kovalik, Joseph M.; Biswas, Abhijit; Roberts, William T.

2007-01-01

Optical communications is a key technology to meet the bandwidth expansion required in the global information grid. High bandwidth bi-directional links between sub-orbital platforms and ground and space terminals can provide a seamless interconnectivity for rapid return of critical data to analysts. The JPL Optical Communications Telescope Laboratory (OCTL) is located in Wrightwood California at an altitude of 2.2.km. This 200 sq-m facility houses a state-of- the-art 1-m telescope and is used to develop operational strategies for ground-to-space laser beam propagation that include safe beam transmission through navigable air space, adaptive optics correction and multi-beam scintillation mitigation, and line of sight optical attenuation monitoring. JPL has received authorization from international satellite owners to transmit laser beams to more than twenty retro-reflecting satellites. This paper presents recent progress in the development of these operational strategies tested by narrow laser beam transmissions from the OCTL to retro-reflecting satellites. We present experimental results and compare our measurements with predicted performance for a variety of atmospheric conditions.

Generation and characterisation of a parkin-Pacrg knockout mouse line and a Pacrg knockout mouse line.

PubMed

Stephenson, Sarah E M; Aumann, Timothy D; Taylor, Juliet M; Riseley, Jessica R; Li, Ruili; Mann, Jeffrey R; Tomas, Doris; Lockhart, Paul J

2018-05-14

Mutations in PARK2 (parkin) can result in Parkinson's disease (PD). Parkin shares a bidirectional promoter with parkin coregulated gene (PACRG) and the transcriptional start sites are separated by only ~200 bp. Bidirectionally regulated genes have been shown to function in common biological pathways. Mice lacking parkin have largely failed to recapitulate the dopaminergic neuronal loss and movement impairments seen in individuals with parkin-mediated PD. We aimed to investigate the function of PACRG and test the hypothesis that parkin and PACRG function in a common pathway by generating and characterizing two novel knockout mouse lines harbouring loss of both parkin and Pacrg or Pacrg alone. Successful modification of the targeted allele was confirmed at the genomic, transcriptional and steady state protein levels for both genes. At 18-20 months of age, there were no significant differences in the behaviour of parental and mutant lines when assessed by openfield, rotarod and balance beam. Subsequent neuropathological examination suggested there was no gross abnormality of the dopaminergic system in the substantia nigra and no significant difference in the number of dopaminergic neurons in either knockout model compared to wildtype mice.

Effects of self-coupling and asymmetric output on metastable dynamical transient firing patterns in arrays of neurons with bidirectional inhibitory coupling.

PubMed

Horikawa, Yo

2016-04-01

Metastable dynamical transient patterns in arrays of bidirectionally coupled neurons with self-coupling and asymmetric output were studied. First, an array of asymmetric sigmoidal neurons with symmetric inhibitory bidirectional coupling and self-coupling was considered and the bifurcations of its steady solutions were shown. Metastable dynamical transient spatially nonuniform states existed in the presence of a pair of spatially symmetric stable solutions as well as unstable spatially nonuniform solutions in a restricted range of the output gain of a neuron. The duration of the transients increased exponentially with the number of neurons up to the maximum number at which the spatially nonuniform steady solutions were stabilized. The range of the output gain for which they existed reduced as asymmetry in a sigmoidal output function of a neuron increased, while the existence range expanded as the strength of inhibitory self-coupling increased. Next, arrays of spiking neuron models with slow synaptic inhibitory bidirectional coupling and self-coupling were considered with computer simulation. In an array of Class 1 Hindmarsh-Rose type models, in which each neuron showed a graded firing rate, metastable dynamical transient firing patterns were observed in the presence of inhibitory self-coupling. This agreed with the condition for the existence of metastable dynamical transients in an array of sigmoidal neurons. In an array of Class 2 Bonhoeffer-van der Pol models, in which each neuron had a clear threshold between firing and resting, long-lasting transient firing patterns with bursting and irregular motion were observed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dynamical implications of bi-directional resource exchange within a meta-ecosystem.

PubMed

Messan, Marisabel Rodriguez; Kopp, Darin; Allen, Daniel C; Kang, Yun

2018-05-05

The exchange of resources across ecosystem boundaries can have large impacts on ecosystem structures and functions at local and regional scales. In this article, we develop a simple model to investigate dynamical implications of bi-directional resource exchanges between two local ecosystems in a meta-ecosystem framework. In our model, we assume that (1) Each local ecosystem acts as both a resource donor and recipient, such that one ecosystem donating resources to another results in a cost to the donating system and a benefit to the recipient; and (2) The costs and benefits of the bi-directional resource exchange between two ecosystems are correlated in a nonlinear fashion. Our model could apply to the resource interactions between terrestrial and aquatic ecosystems that are supported by the literature. Our theoretical results show that bi-directional resource exchange between two ecosystems can indeed generate complicated dynamical outcomes, including the coupled ecosystems having amensalistic, antagonistic, competitive, or mutualistic interactions, with multiple alternative stable states depending on the relative costs and benefits. In addition, if the relative cost for resource exchange for an ecosystem is decreased or the relative benefit for resource exchange for an ecosystem is increased, the production of that ecosystem would increase; however, depending on the local environment, the production of the other ecosystem may increase or decrease. We expect that our work, by evaluating the potential outcomes of resource exchange theoretically, can facilitate empirical evaluations and advance the understanding of spatial ecosystem ecology where resource exchanges occur in varied ecosystems through a complicated network. Copyright © 2018 Elsevier Inc. All rights reserved.

Molecular and functional characterization of multiple aquaporin water channel proteins from the western tarnished plant bug, Lygus hesperus

USDA-ARS?s Scientific Manuscript database

Aquaporins (AQPs) are integral membrane channel proteins that facilitate the bidirectional transfer of water or other small solutes across biological membranes involved in numerous essential physiological processes. In arthropods, AQPs belong to several subfamilies, which contribute to osmoregulatio...

A Study of Bi-Directional Reflectance Distribution Functions and Their Effect on Infrared Signature Models

DTIC Science & Technology

2007-03-01

66 3.5.1 Specular Reflection Assumption . . . . . . . . . . . . . . . . . . . 70 3.5.2 Radiosity ...69 3.31. Radiosity Algorithm Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 3.32. POV...3.5.2 Radiosity . The first algorithm implemented to attempt to hemispher- ically integrate the irradiance contribution was classical radiosity as

E-Assessment Data Compatibility Resolution Methodology with Bidirectional Data Transformation

ERIC Educational Resources Information Center

Malik, Kaleem Razzaq; Ahmad, Tauqir

2017-01-01

Electronic Assessment (E-Assessment) also known as computer aided assessment for the purposes involving diagnostic, formative or summative examining using data analysis. Digital assessments come commonly from social, academic, and adaptive learning in machine readable forms to deliver the machine scoring function. To achieve real-time and smart…

The Learning Hippocampus: Education and Experience-Dependent Plasticity

ERIC Educational Resources Information Center

Wenger, Elisabeth; Lövdén, Martin

2016-01-01

The hippocampal formation of the brain plays a crucial role in declarative learning and memory while at the same time being particularly susceptible to environmental influences. Education requires a well-functioning hippocampus, but may also influence the development of this brain structure. Understanding these bidirectional influences may have…

Evaluation of the VIIRS BRDF, Albedo and NBAR products suite and an assessment of continuity with the long term MODIS record

USDA-ARS?s Scientific Manuscript database

Bidirectional Reflectance Distribution Function (BRDF) model parameters, Albedo quantities, and Nadir BRDF Adjusted Reflectance (NBAR) products derived from the Visible Infrared Imaging Radiometer Suite (VIIRS), on the Suomi-NPP (National Polar-orbiting Partnership) satellite are evaluated through c...

BIDIRECTIONAL DISTRIBUTION FUNCTION (BRDF) CHARACTERISTICS OF SMOOTH CORDGRASS (SPARTINA ALTERNIFLORA) OBTAINED USING A SANDMEIER FIELD GONIOMETER. (R826944)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Monitoring NEON terrestrial sites phenology with daily MODIS BRDF/albedo product and landsat data

USDA-ARS?s Scientific Manuscript database

The MODerate resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF) and albedo products (MCD43) have already been in production for more than a decade. The standard product makes use of a linear “kernel-driven” RossThick-LiSparse Reciprocal (RTLSR) BRDF m...

Bidirectional negative differential thermal resistance in three-segment Frenkel-Kontorova lattices.

PubMed

Ou, Ya-Li; Lu, Shi-Cai; Hu, Cai-Tian; Ai, Bao-Quan

2016-12-14

By coupling three nonlinear 1D lattice segments, we demonstrate a thermal insulator model, where the system acts like an insulator for large temperature bias and a conductor for very small temperature bias. We numerically investigate the parameter range of the thermal insulator and find that the nonlinear response (the role of on-site potential), the weakly coupling interaction between each segment, and the small system size collectively contribute to the appearance of bidirectional negative differential thermal resistance (BNDTR). The corresponding exhibition of BNDTR can be explained in terms of effective phonon-band shifts. Our results can provide a new perspective for understanding the microscopic mechanism of negative differential thermal resistance and also would be conducive to further developments in designing and fabricating thermal devices and functional materials.

Enhanced robustness of evolving open systems by the bidirectionality of interactions between elements.

PubMed

Ogushi, Fumiko; Kertész, János; Kaski, Kimmo; Shimada, Takashi

2017-08-01

Living organisms, ecosystems, and social systems are examples of complex systems in which robustness against inclusion of new elements is an essential feature. A recently proposed simple model has revealed a general mechanism by which such systems can become robust against inclusion of elements with totally random interactions when the elements have a moderate number of links. The interaction is, however, in many systems often intrinsically bidirectional like for mutual symbiosis and competition in ecology. This study reports the strong reinforcement effect of the bidirectionality of the interactions on the robustness of evolving systems. We show that the system with purely bidirectional interactions can grow with twofold average degree, in comparison with the purely unidirectional system. This drastic shift of the transition point comes from the reinforcement of each node, not from a change in structure of the emergent system. For systems with partially bidirectional interactions we find that the regime of the growing phase gets expanded. In the dense interaction regime, there exists an optimum proportion of bidirectional interactions for the growth rate at around 1/3. In the sparsely connected systems, small but finite fraction of bidirectional links can change the system's behaviour from non-growing to growing.

Fail-safe bidirectional valve driver

NASA Technical Reports Server (NTRS)

Fujimoto, H.

1974-01-01

Cross-coupled diodes are added to commonly used bidirectional valve driver circuit to protect circuit and power supply. Circuit may be used in systems requiring fail-safe bidirectional valve operation, particularly in chemical- and petroleum-processing control systems and computer-controlled hydraulic or pneumatic systems.

[Participation of GDNF, LIMK1 signal pathways and heat shock proteins in processes of Drosophila learning and memory formation].

PubMed

Nikitina, E A; Medvedeva, A V; Dolgaia, Iu F; Korochkin, L I; Pavlova, G V; Savvateeva-Popova, E V

2012-01-01

Molecular mechanisms of the synapse and dendrite maintenance and their disturbance in psychiatric and neurodegenerative diseases (ND) are intensively studied in searching for target genes of therapeutic actions. It is suggested that glia, alongside with well-studied pre- and postsynaptic neurons, is the third, poorly studied partner in synaptic transmission (the tripartite synapse) that is involved in the positive feedback between the first two partners. This bidirectional coupling between presynaptic neurons and their postsynaptic targets involve neurotrophins (NTF), such as glial cell-derived neurotrophic factor (GDNF) that is produced LIM kinase 1 (LIMK1, the key enzyme of actin remodeling). The cytoplasmic domain of neuregulins interacts with LIMK1. Since neurons and axons that do not receive a sufficient NTF amount are at risk of degeneration and synapse elimination, GDNF seems to be the best studied factor of the ND therapy. The delivery of GDNF stem cells to the neurodegeneration locus is very efficient. There has been proposed a new approach based on use of Drosophila heat shock (hs) promoter. This promoter responds to the mammalian body temperature as to the shock factor resulting in the constant expression of the GDNF gene. The Drosophila models allow studying any given component of the bidirectional communication between pre- and postsynaptic neurons in development of the main diagnostic ND symptom, such as defective memory resulted from synaptic atrophy. In the present study we used the Drosophila stocks imitating different disturbances of the nervous system: Canton-S (wild type), GDNF (transgenic flies that carry human glial-cell-line derived nerve factor (GDNF) gene under hs promoter), l(1)ts403 with dusturbance of HSPs mRNA extranuclear transport, a defect of intracellular stress report, and agn(ts3) mutation in LIMK1 gene. We have revealed functional connections at the behavioral level (learning/memory) depending on the GDNF and LIMK1 brain expression and HSPs transduction that might provide targets for complex approaches for the ND treatment.

An Asymptotically-Optimal Sampling-Based Algorithm for Bi-directional Motion Planning

PubMed Central

Starek, Joseph A.; Gomez, Javier V.; Schmerling, Edward; Janson, Lucas; Moreno, Luis; Pavone, Marco

2015-01-01

Bi-directional search is a widely used strategy to increase the success and convergence rates of sampling-based motion planning algorithms. Yet, few results are available that merge both bi-directional search and asymptotic optimality into existing optimal planners, such as PRM*, RRT*, and FMT*. The objective of this paper is to fill this gap. Specifically, this paper presents a bi-directional, sampling-based, asymptotically-optimal algorithm named Bi-directional FMT* (BFMT*) that extends the Fast Marching Tree (FMT*) algorithm to bidirectional search while preserving its key properties, chiefly lazy search and asymptotic optimality through convergence in probability. BFMT* performs a two-source, lazy dynamic programming recursion over a set of randomly-drawn samples, correspondingly generating two search trees: one in cost-to-come space from the initial configuration and another in cost-to-go space from the goal configuration. Numerical experiments illustrate the advantages of BFMT* over its unidirectional counterpart, as well as a number of other state-of-the-art planners. PMID:27004130

Bidirectional Associations between Parenting Practices and Conduct Problems in Boys from Childhood to Adolescence: The Moderating Effect of Age and African-American Ethnicity

PubMed Central

Fite, Paula J.; Burke, Jeffrey D.

2010-01-01

This study examined the bidirectional relationship between parent and teacher reported conduct problems in youth and parenting practices using a longitudinal sample of boys assessed from 6 to 16 years of age. Analyses tested whether these bidirectional associations changed across development and whether the nature of these associations varied across African-American and Caucasian families. Overall, the results supported a bidirectional relationship between conduct problems and all parenting practices examined from childhood to adolescence. The influence of conduct problems on changes in parenting behaviors was as strong as the influence of parenting behaviors on changes in conduct problems across development. Changes in the bidirectional relationship across development were found in some, but not all, models. While corporal punishment was more strongly related to changes in teacher-reported conduct problems for African-American boys compared to Caucasian boys, more similarities than differences were found between the ethnic groups in terms of the bidirectional associations examined. PMID:17899362

Lambda network having 2{sup m{minus}1} nodes in each of m stages with each node coupled to four other nodes for bidirectional routing of data packets between nodes

DOEpatents

Napolitano, L.M. Jr.

1995-11-28

The Lambda network is a single stage, packet-switched interprocessor communication network for a distributed memory, parallel processor computer. Its design arises from the desired network characteristics of minimizing mean and maximum packet transfer time, local routing, expandability, deadlock avoidance, and fault tolerance. The network is based on fixed degree nodes and has mean and maximum packet transfer distances where n is the number of processors. The routing method is detailed, as are methods for expandability, deadlock avoidance, and fault tolerance. 14 figs.

Neuronal somatic ATP release triggers neuron–satellite glial cell communication in dorsal root ganglia

PubMed Central

Zhang, X.; Chen, Y.; Wang, C.; Huang, L.-Y. M.

2007-01-01

It has been generally assumed that the cell body (soma) of a neuron, which contains the nucleus, is mainly responsible for synthesis of macromolecules and has a limited role in cell-to-cell communication. Using sniffer patch recordings, we show here that electrical stimulation of dorsal root ganglion (DRG) neurons elicits robust vesicular ATP release from their somata. The rate of release events increases with the frequency of nerve stimulation; external Ca2+ entry is required for the release. FM1–43 photoconversion analysis further reveals that small clear vesicles participate in exocytosis. In addition, the released ATP activates P2X7 receptors in satellite cells that enwrap each DRG neuron and triggers the communication between neuronal somata and glial cells. Blocking L-type Ca2+ channels completely eliminates the neuron–glia communication. We further show that activation of P2X7 receptors can lead to the release of tumor necrosis factor-α (TNFα) from satellite cells. TNFα in turn potentiates the P2X3 receptor-mediated responses and increases the excitability of DRG neurons. This study provides strong evidence that somata of DRG neurons actively release transmitters and play a crucial role in bidirectional communication between neurons and surrounding satellite glial cells. These results also suggest that, contrary to the conventional view, neuronal somata have a significant role in cell–cell signaling. PMID:17525149

Basic study of a transcutaneous information transmission system using intra-body communication.

PubMed

Okamoto, Eiji; Sato, Yusuke; Seino, Kazuyuki; Kiyono, Takashi; Kato, Yoshikuni; Mitamura, Yoshinori

2010-07-01

The transcutaneous communication system (TCS) is one of the key technologies for monitoring and controling artificial hearts and other artificial organs in the body. In this study, we have developed a new TCS that uses the human body as a conductive medium. Having no energy conversion from electric currents into electromagnetic waves and light provides energy-saving data transmission with a simple electrical circuit. Each unit of the TCS mainly consists of two electrodes, an amplitude shift keying (ASK) modulator and an ASK demodulator (carrier frequency: 4 and 10 MHz). A resonant frequency of an L-C tank circuit including the capacitance component of the body is tuned into each carrier frequency in order to apply the data current effectively into the body. Performance of the TCS was evaluated by a communication test on the surface of a human body. The TCS was able to transmit 3,315 bytes of data bi-directionally at a transmission rate of 115 kbps from a left wrist to a right forearm, to an abdomen and to a left calf without communication error. The power consumption of each TCS unit was 125 mW with an ASK modulated current of 7 mA (RMS). While further study is required to secure its safety, the TCS promises to be a next-generation transcutaneous communication device.

Gut Microbiota-brain Axis

PubMed Central

Wang, Hong-Xing; Wang, Yu-Ping

2016-01-01

Objective: To systematically review the updated information about the gut microbiota-brain axis. Data Sources: All articles about gut microbiota-brain axis published up to July 18, 2016, were identified through a literature search on PubMed, ScienceDirect, and Web of Science, with the keywords of “gut microbiota”, “gut-brain axis”, and “neuroscience”. Study Selection: All relevant articles on gut microbiota and gut-brain axis were included and carefully reviewed, with no limitation of study design. Results: It is well-recognized that gut microbiota affects the brain's physiological, behavioral, and cognitive functions although its precise mechanism has not yet been fully understood. Gut microbiota-brain axis may include gut microbiota and their metabolic products, enteric nervous system, sympathetic and parasympathetic branches within the autonomic nervous system, neural-immune system, neuroendocrine system, and central nervous system. Moreover, there may be five communication routes between gut microbiota and brain, including the gut-brain's neural network, neuroendocrine-hypothalamic-pituitary-adrenal axis, gut immune system, some neurotransmitters and neural regulators synthesized by gut bacteria, and barrier paths including intestinal mucosal barrier and blood-brain barrier. The microbiome is used to define the composition and functional characteristics of gut microbiota, and metagenomics is an appropriate technique to characterize gut microbiota. Conclusions: Gut microbiota-brain axis refers to a bidirectional information network between the gut microbiota and the brain, which may provide a new way to protect the brain in the near future. PMID:27647198

Tact Training versus Bidirectional Intraverbal Training in Teaching a Foreign Language

ERIC Educational Resources Information Center

Dounavi, Katerina

2014-01-01

The current study involved an evaluation of the emergence of untrained verbal relations as a function of 3 different foreign-language teaching strategies. Two Spanish-speaking adults received foreign-language (English) tact training and native-to-foreign and foreign-to-native intraverbal training. Tact training and native-to-foreign intraverbal…

New Methodology for Measuring Semantic Functional Similarity Based on Bidirectional Integration

ERIC Educational Resources Information Center

Jeong, Jong Cheol

2013-01-01

1.2 billion users in Facebook, 17 million articles in Wikipedia, and 190 million tweets per day have demanded significant increase of information processing through Internet in recent years. Similarly life sciences and bioinformatics also have faced issues of processing Big data due to the explosion of publicly available genomic information…

Ultraviolet and visible BRDF data on spacecraft thermal control and optical baffle materials

NASA Technical Reports Server (NTRS)

Viehmann, W.; Predmore, R. E.

1987-01-01

Bidirectional scattering functions of numerous optical baffle materials and of spacecraft thermal control coatings and surfaces are presented. Measurements were made at 254 nm and at 633 nm. The coatings and surfaces include high-reflectance white paints, low-reflectance optical blacks, thermal control blankets, and various conversion coatings on aluminum.

Value Transmissions between Parents and Children: Gender and Developmental Phase as Transmission Belts

ERIC Educational Resources Information Center

Roest, Annette M. C.; Dubas, Judith Semon; Gerris, Jan R. M.

2010-01-01

This study applied the gender role model of socialization theory, the developmental aging theory, and the topic salience perspective to the investigation of parent-child value transmissions. Specifically, we examined whether the bi-directionality and selectivity of value transmissions differed as a function of parents' and children's gender and…

Kindergarten Social Withdrawal and Reading Achievement: A Cross-Lagged Path Model for At-Risk Learners

ERIC Educational Resources Information Center

Hall, Cristin M.; Welsh, Janet A.; Bierman, Karen L.; Nix, Robert

2016-01-01

The association between social withdrawal, school adjustment, and academic functioning in preschool and school entry is well-established. Children who experience social withdrawal in primary grades are at risk for decreased academic performance. The bidirectional relationships among early literacy and social withdrawal in primary grades have not…

Synthesis and Analysis of Custom Bi-directional Reflectivity Distribution Functions in DIRSIG

NASA Astrophysics Data System (ADS)

Dank, J.; Allen, D.

2016-09-01

The bi-directional reflectivity distribution (BRDF) function is a fundamental optical property of materials, characterizing important properties of light scattered by a surface. For accurate radiance calculations using synthetic targets and numerical simulations such as the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model, fidelity of the target BRDFs is critical. While fits to measured BRDF data can be used in DIRSIG, obtaining high-quality data over a large spectral continuum can be time-consuming and expensive, requiring significant investment in illumination sources, sensors, and other specialized hardware. As a consequence, numerous parametric BRDF models are available to approximate actual behavior; but these all have shortcomings. Further, DIRSIG doesn't allow direct visualization of BRDFs, making it difficult for the user to understand the numerical impact of various models. Here, we discuss the innovative use of "mixture maps" to synthesize custom BRDFs as linear combinations of parametric models and measured data. We also show how DIRSIG's interactive mode can be used to visualize and analyze both available parametric models currently used in DIRSIG and custom BRDFs developed using our methods.

Decorating surfaces with bidirectional texture functions.

PubMed

Zhou, Kun; Du, Peng; Wang, Lifeng; Matsushita, Yasuyuki; Shi, Jiaoying; Guo, Baining; Shum, Heung-Yeung

2005-01-01

We present a system for decorating arbitrary surfaces with bidirectional texture functions (BTF). Our system generates BTFs in two steps. First, we automatically synthesize a BTF over the target surface from a given BTF sample. Then, we let the user interactively paint BTF patches onto the surface such that the painted patches seamlessly integrate with the background patterns. Our system is based on a patch-based texture synthesis approach known as quilting. We present a graphcut algorithm for BTF synthesis on surfaces and the algorithm works well for a wide variety of BTF samples, including those which present problems for existing algorithms. We also describe a graphcut texture painting algorithm for creating new surface imperfections (e.g., dirt, cracks, scratches) from existing imperfections found in input BTF samples. Using these algorithms, we can decorate surfaces with real-world textures that have spatially-variant reflectance, fine-scale geometry details, and surfaces imperfections. A particularly attractive feature of BTF painting is that it allows us to capture imperfections of real materials and paint them onto geometry models. We demonstrate the effectiveness of our system with examples.

Spectral bidirectional reflectance distribution function measurements on well-defined textured surfaces: direct observation of shadowing, masking, inter-reflection, and transparency effects.

PubMed

Wilen, Larry; Dasgupta, Bivash R

2011-11-01

We present results for the bidirectional reflectance distribution function (BRDF) for samples of uniform rectangular and triangular grooves constructed from polydimethylsilicone replicas. The measurements are performed with the detector in the plane of incidence, but with varying groove orientations with respect to that plane. The samples are opaque in some cases and semitransparent in others. By measuring the BRDF for colored samples over a wide spectral range, we explicitly probe the effect of sample albedo, which is important for inter-reflections. For the opaque samples, we compare the results with exact theoretical results either taken from the literature (for the triangular geometry) or worked out here (for the rectangular geometry). For both geometries, we also extend the theoretical results to finite length grooves. There is generally very good agreement between theory and the experiment. Shadowing, masking, and inter-reflection are clearly observed, as well as effects that may be due to polarization and asperity scattering. For semitransparent samples, we observe the effect of increasing transparency on the BRDF.

Sequential fitting-and-separating reflectance components for analytical bidirectional reflectance distribution function estimation.

PubMed

Lee, Yu; Yu, Chanki; Lee, Sang Wook

2018-01-10

We present a sequential fitting-and-separating algorithm for surface reflectance components that separates individual dominant reflectance components and simultaneously estimates the corresponding bidirectional reflectance distribution function (BRDF) parameters from the separated reflectance values. We tackle the estimation of a Lafortune BRDF model, which combines a nonLambertian diffuse reflection and multiple specular reflectance components with a different specular lobe. Our proposed method infers the appropriate number of BRDF lobes and their parameters by separating and estimating each of the reflectance components using an interval analysis-based branch-and-bound method in conjunction with iterative K-ordered scale estimation. The focus of this paper is the estimation of the Lafortune BRDF model. Nevertheless, our proposed method can be applied to other analytical BRDF models such as the Cook-Torrance and Ward models. Experiments were carried out to validate the proposed method using isotropic materials from the Mitsubishi Electric Research Laboratories-Massachusetts Institute of Technology (MERL-MIT) BRDF database, and the results show that our method is superior to a conventional minimization algorithm.

Global evaluation of ammonia bidirectional exchange and livestock diurnal variation schemes

EPA Science Inventory

Bidirectional air–surface exchange of ammonia (NH3) has been neglected in many air quality models. In this study, we implement the bidirectional exchange of NH3 in the GEOS-Chem global chemical transport model. We also introduce an updated diurnal variability scheme for NH3...

Development of the Optical Communications Telescope Laboratory: A Laser Communications Relay Demonstration Ground Station

NASA Technical Reports Server (NTRS)

Wilson, K. E.; Antsos, D.; Roberts, L. C. Jr.,; Piazzolla, S.; Clare, L. P.; Croonquist, A. P.

2012-01-01

The Laser Communications Relay Demonstration (LCRD) project will demonstrate high bandwidth space to ground bi-directional optical communications links between a geosynchronous satellite and two LCRD optical ground stations located in the southwestern United States. The project plans to operate for two years with a possible extension to five. Objectives of the demonstration include the development of operational strategies to prototype optical link and relay services for the next generation tracking and data relay satellites. Key technologies to be demonstrated include adaptive optics to correct for clear air turbulence-induced wave front aberrations on the downlink, and advanced networking concepts for assured and automated data delivery. Expanded link availability will be demonstrated by supporting operations at small sun-Earth-probe angles. Planned optical modulation formats support future concepts of near-Earth satellite user services to a maximum of 1.244 Gb/s differential phase shift keying modulation and pulse position modulations formats for deep space links at data rates up to 311 Mb/s. Atmospheric monitoring instruments that will characterize the optical channel during the link include a sun photometer to measure atmospheric transmittance, a solar scintillometer, and a cloud camera to measure the line of sight cloud cover. This paper describes the planned development of the JPL optical ground station.

Detection of Bi-Directionality in Strain-Gage Balance Calibration Data

NASA Technical Reports Server (NTRS)

Ulbrich, Norbert

2012-01-01

An indicator variable was developed for both visualization and detection of bi-directionality in wind tunnel strain-gage balance calibration data. First, the calculation of the indicator variable is explained in detail. Then, a criterion is discussed that may be used to decide which gage outputs of a balance have bi- directional behavior. The result of this analysis could be used, for example, to justify the selection of certain absolute value or other even function terms in the regression model of gage outputs whenever the Iterative Method is chosen for the balance calibration data analysis. Calibration data of NASA s MK40 Task balance is analyzed to illustrate both the calculation of the indicator variable and the application of the proposed criterion. Finally, bi directionality characteristics of typical multi piece, hybrid, single piece, and semispan balances are determined and discussed.

Floral ontogeny in legume genera Petalostylis, Labichea, and Dialium (Caesalpinioideae: Cassieae), a series in floral reduction.

PubMed

Tucker, S

1998-02-01

Floral ontogeny of taxa of two subtribes (Labicheinae, Dialiinae) of caesalpinioid tribe Cassieae, characterized by reduced number of floral organs, was compared. All three taxa studied are distichous; Petalostylis labicheoides flowers are solitary in leaf axils, Labichea lanceolata has few-flowered racemes, and Dialium guineense has numerous-flowered cymes. The first sepal primordium in each is initiated abaxially and nonmedianly. Order of organogenesis in Petalostylis is: five sepals bidirectionally, five petals and carpel simultaneously, then five stamens bidirectionally, starting abaxially. The order in Labichea is: five sepals helically (one lagging in time), five petals unidirectionally starting abaxially, the carpel and petals concurrently, then two stamens successively, starting laterally. Order in Dialium is: five sepals bidirectionally, the single petal adaxially, and lastly the carpel and two stamens concurrently. Specializations include (1) reduction of the five sepals to four by fusion in Petalostylis and Labichea; (2) reduction of petal number to one in Dialium; (3) reduction of stamen number to two in Labichea and Dialium, and reduction of functional stamens to three in Petalostylis; and (4) an elaborate, late-developing style in Petalostylis. Floral asymmetry, another specialization, characterizes Labichea, expressed by dissimilar stamens, while the other genera have zygomorphic flowers. Floral ontogenies are compared with other taxa of Cassieae.

The Bidirectional Relationship between Sleep and Immunity against Infections

PubMed Central

Ibarra-Coronado, Elizabeth G.; Pantaleón-Martínez, Ana Ma.; Velazquéz-Moctezuma, Javier; Prospéro-García, Oscar; Méndez-Díaz, Mónica; Pérez-Tapia, Mayra; Pavón, Lenin; Morales-Montor, Jorge

2015-01-01

Sleep is considered an important modulator of the immune response. Thus, a lack of sleep can weaken immunity, increasing organism susceptibility to infection. For instance, shorter sleep durations are associated with a rise in suffering from the common cold. The function of sleep in altering immune responses must be determined to understand how sleep deprivation increases the susceptibility to viral, bacterial, and parasitic infections. There are several explanations for greater susceptibility to infections after reduced sleep, such as impaired mitogenic proliferation of lymphocytes, decreased HLA-DR expression, the upregulation of CD14+, and variations in CD4+ and CD8+ T lymphocytes, which have been observed during partial sleep deprivation. Also, steroid hormones, in addition to regulating sexual behavior, influence sleep. Thus, we hypothesize that sleep and the immune-endocrine system have a bidirectional relationship in governing various physiological processes, including immunity to infections. This review discusses the evidence on the bidirectional effects of the immune response against viral, bacterial, and parasitic infections on sleep patterns and how the lack of sleep affects the immune response against such agents. Because sleep is essential in the maintenance of homeostasis, these situations must be adapted to elicit changes in sleep patterns and other physiological parameters during the immune response to infections to which the organism is continuously exposed. PMID:26417606

The Bidirectional Relationship between Sleep and Immunity against Infections.

PubMed

Ibarra-Coronado, Elizabeth G; Pantaleón-Martínez, Ana Ma; Velazquéz-Moctezuma, Javier; Prospéro-García, Oscar; Méndez-Díaz, Mónica; Pérez-Tapia, Mayra; Pavón, Lenin; Morales-Montor, Jorge

2015-01-01

Sleep is considered an important modulator of the immune response. Thus, a lack of sleep can weaken immunity, increasing organism susceptibility to infection. For instance, shorter sleep durations are associated with a rise in suffering from the common cold. The function of sleep in altering immune responses must be determined to understand how sleep deprivation increases the susceptibility to viral, bacterial, and parasitic infections. There are several explanations for greater susceptibility to infections after reduced sleep, such as impaired mitogenic proliferation of lymphocytes, decreased HLA-DR expression, the upregulation of CD14+, and variations in CD4+ and CD8+ T lymphocytes, which have been observed during partial sleep deprivation. Also, steroid hormones, in addition to regulating sexual behavior, influence sleep. Thus, we hypothesize that sleep and the immune-endocrine system have a bidirectional relationship in governing various physiological processes, including immunity to infections. This review discusses the evidence on the bidirectional effects of the immune response against viral, bacterial, and parasitic infections on sleep patterns and how the lack of sleep affects the immune response against such agents. Because sleep is essential in the maintenance of homeostasis, these situations must be adapted to elicit changes in sleep patterns and other physiological parameters during the immune response to infections to which the organism is continuously exposed.

[Modeling polarimetric BRDF of leaves surfaces].

PubMed

Xie, Dong-Hui; Wang, Pei-Juan; Zhu, Qi-Jiang; Zhou, Hong-Min

2010-12-01

The purpose of the present paper is to model a physical polarimetric bidirectional reflectance distribution function (pBRDF), which can character not only the non-Lambertian but also the polarized features in order that the pBRDF can be applied to analyze the relationship between the degree of polarization and the physiological and biochemical parameters of leaves quantitatively later. Firstly, the bidirectional polarized reflectance distributions from several leaves surfaces were measured by the polarized goniometer developed by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences. The samples of leaves include two pieces of zea mays L. leaves (young leaf and mature leaf) and a piece of E. palcherrima wild leaf. Non-Lambertian characteristics of directional reflectance from the surfaces of these three leaves are obvious. A Cook-Torrance model was modified by coupling the polarized Fresnel equations to simulate the bidirectional polarized reflectance properties of leaves surfaces. The three parameters in the modified pBRDF model, such as diffuse reflectivity, refractive index and roughness of leaf surface were inversed with genetic algorithm (GA). It was found that the pBRDF model can fit with the measured data well. In addition, these parameters in the model are related with both the physiological and biochemical properties and the polarized characteristics of leaves, therefore it is possible to build the relationships between them later.

Intercomparison of two BRDF models in the estimation of the directional emissivity in MIR channel from MSG1-SEVIRI data.

PubMed

Jiang, Geng-Ming; Li, Zhao-Liang

2008-11-10

This work intercompared two Bi-directional Reflectance Distribution Function (BRDF) models, the modified Minnaert's model and the RossThick-LiSparse-R model, in the estimation of the directional emissivity in Middle Infra-Red (MIR) channel from the data acquired by the Spinning Enhanced Visible and Infra-Red Imager (SEVIRI) onboard the first Meteosat Second Generation (MSG1). The bi-directional reflectances in SEVIRI channel 4 (3.9 microm) were estimated from the combined MIR and Thermal Infra-Red (TIR) data and then were used to estimate the directional emissivity in this channel with aid of the BRDF models. The results show that: (1) Both models can relatively well describe the non-Lambertian reflective behavior of land surfaces in SEVIRI channel 4; (2) The RossThick-LiSparse-R model is better than the modified Minnaert's model in modeling the bi-directional reflectances, and the directional emissivities modeled by the modified Minnaert's model are always lower than the ones obtained by the RossThick-LiSparse-R model with averaged emissivity differences of approximately 0.01 and approximately 0.04 over the vegetated and bare areas, respectively. The use of the RossThick-LiSparse-R model in the estimation of the directional emissivity in MIR channel is recommended.

On Multiple AER Handshaking Channels Over High-Speed Bit-Serial Bidirectional LVDS Links With Flow-Control and Clock-Correction on Commercial FPGAs for Scalable Neuromorphic Systems.

PubMed

Yousefzadeh, Amirreza; Jablonski, Miroslaw; Iakymchuk, Taras; Linares-Barranco, Alejandro; Rosado, Alfredo; Plana, Luis A; Temple, Steve; Serrano-Gotarredona, Teresa; Furber, Steve B; Linares-Barranco, Bernabe

2017-10-01

Address event representation (AER) is a widely employed asynchronous technique for interchanging "neural spikes" between different hardware elements in neuromorphic systems. Each neuron or cell in a chip or a system is assigned an address (or ID), which is typically communicated through a high-speed digital bus, thus time-multiplexing a high number of neural connections. Conventional AER links use parallel physical wires together with a pair of handshaking signals (request and acknowledge). In this paper, we present a fully serial implementation using bidirectional SATA connectors with a pair of low-voltage differential signaling (LVDS) wires for each direction. The proposed implementation can multiplex a number of conventional parallel AER links for each physical LVDS connection. It uses flow control, clock correction, and byte alignment techniques to transmit 32-bit address events reliably over multiplexed serial connections. The setup has been tested using commercial Spartan6 FPGAs attaining a maximum event transmission speed of 75 Meps (Mega events per second) for 32-bit events at a line rate of 3.0 Gbps. Full HDL codes (vhdl/verilog) and example demonstration codes for the SpiNNaker platform will be made available.

Multicasting mesh AER: a scalable assembly approach for reconfigurable neuromorphic structured AER systems. Application to ConvNets.

PubMed

Zamarreno-Ramos, C; Linares-Barranco, A; Serrano-Gotarredona, T; Linares-Barranco, B

2013-02-01

This paper presents a modular, scalable approach to assembling hierarchically structured neuromorphic Address Event Representation (AER) systems. The method consists of arranging modules in a 2D mesh, each communicating bidirectionally with all four neighbors. Address events include a module label. Each module includes an AER router which decides how to route address events. Two routing approaches have been proposed, analyzed and tested, using either destination or source module labels. Our analyses reveal that depending on traffic conditions and network topologies either one or the other approach may result in better performance. Experimental results are given after testing the approach using high-end Virtex-6 FPGAs. The approach is proposed for both single and multiple FPGAs, in which case a special bidirectional parallel-serial AER link with flow control is exploited, using the FPGA Rocket-I/O interfaces. Extensive test results are provided exploiting convolution modules of 64 × 64 pixels with kernels with sizes up to 11 × 11, which process real sensory data from a Dynamic Vision Sensor (DVS) retina. One single Virtex-6 FPGA can hold up to 64 of these convolution modules, which is equivalent to a neural network with 262 × 10(3) neurons and almost 32 million synapses.

Design of a network for concurrent message passing systems

NASA Astrophysics Data System (ADS)

Song, Paul Y.

1988-08-01

We describe the design of the network design frame (NDF), a self-timed routing chip for a message-passing concurrent computer. The NDF uses a partitioned data path, low-voltage output drivers, and a distributed token-passing arbiter to provide a bandwidth of 450 Mbits/sec into the network. Wormhole routing and bidirectional virtual channels are used to provide low latency communications, less than 2us latency to deliver a 216 bit message across the diameter of a 1K node mess-connected machine. To support concurrent software systems, the NDF provides two logical networks, one for user messages and one for system messages. The two networks share the same set of physical wires. To facilitate the development of network nodes, the NDF is a design frame. The NDF circuitry is integrated into the pad frame of a chip leaving the center of the chip uncommitted. We define an analytic framework in which to study the effects of network size, network buffering capacity, bidirectional channels, and traffic on this class of networks. The response of the network to various combinations of these parameters are obtained through extensive simulation of the network model. Through simulation, we are able to observe the macro behavior of the network as opposed to the micro behavior of the NDF routing controller.

Feeding the microbiota-gut-brain axis: diet, microbiome, and neuropsychiatry.

PubMed

Sandhu, Kiran V; Sherwin, Eoin; Schellekens, Harriët; Stanton, Catherine; Dinan, Timothy G; Cryan, John F

2017-01-01

The microbial population residing within the human gut represents one of the most densely populated microbial niche in the human body with growing evidence showing it playing a key role in the regulation of behavior and brain function. The bidirectional communication between the gut microbiota and the brain, the microbiota-gut-brain axis, occurs through various pathways including the vagus nerve, the immune system, neuroendocrine pathways, and bacteria-derived metabolites. This axis has been shown to influence neurotransmission and the behavior that are often associated with neuropsychiatric conditions. Therefore, research targeting the modulation of this gut microbiota as a novel therapy for the treatment of various neuropsychiatric conditions is gaining interest. Numerous factors have been highlighted to influence gut microbiota composition, including genetics, health status, mode of birth, and environment. However, it is diet composition and nutritional status that has repeatedly been shown to be one of the most critical modifiable factors regulating the gut microbiota at different time points across the lifespan and under various health conditions. Thus the microbiota is poised to play a key role in nutritional interventions for maintaining brain health. Copyright © 2016 Elsevier Inc. All rights reserved.

Radiomicrobiomics: Advancing Along the Gut-brain Axis Through Big Data Analysis.

PubMed

De Santis, Silvia; Moratal, David; Canals, Santiago

2017-12-10

The gut-brain axis communicates the brain with the gut microbiota, a bidirectional conduit that has received increasing attention in recent years thanks to its emerging role in brain development and function. Alterations in microbiota composition have been associated to neurological and psychiatric disorders, and several studies suggest that the immune system plays a fundamental role in the gut-brain interaction. Recent advances in brain imaging and in microbiome sequencing have generated a large amount of information, yet the data from both these sources need to be combined efficiently to extract biological meaning, and any diagnostic and/or prognostic benefit from these tools. In addition, the causal nature of the gut-brain interaction remains to be fully established, and preclinical findings translated to humans. In this "Perspective" article, we discuss recent efforts to combine data on the gut microbiota with the features that can be obtained from the conversion of brain images into mineable data. The subsequent analysis of these data for diagnostic and prognostic purposes is an approach we call radiomicrobiomics and it holds tremendous potential to enhance our understanding of this fascinating connection. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Can the big five factors of personality predict lymphocyte counts?

PubMed

Ožura, Ana; Ihan, Alojz; Musek, Janek

2012-03-01

Psychological stress is known to affect the immune system. The Limbic Hypothalamic Pituitary Adrenal (LHPA) axis has been identified as the principal path of the bidirectional communication between the immune system and the central nervous system with significant psychological activators. Personality traits acted as moderators of the relationship between life conflicts and psychological distress. This study focuses on the relationship between the Big Five factors of personality and immune regulation as indicated by Lymphocyte counts. Our study included 32 professional soldiers from the Slovenian Army that completed the Big Five questionnaire (Goldberg IPIP-300). We also assessed their white blood cell counts with a detailed lymphocyte analysis using flow cytometry. The correlations between personality variables and immune system parameters were calculated. Furthermore, regression analyses were performed using personality variables as predictors and immune parameters as criteria. The results demonstrated that the model using the Big Five factors as predictors of Lymphocyte counts is significant in predicting the variance in NK and B cell counts. Agreeableness showed the strongest predictive function. The results offer support for the theoretical models that stressed the essential links between personality and immune regulation. Further studies with larger samples examining the Big five factors and immune system parameters are needed.

Discrete-time BAM neural networks with variable delays

NASA Astrophysics Data System (ADS)

Liu, Xin-Ge; Tang, Mei-Lan; Martin, Ralph; Liu, Xin-Bi

2007-07-01

This Letter deals with the global exponential stability of discrete-time bidirectional associative memory (BAM) neural networks with variable delays. Using a Lyapunov functional, and linear matrix inequality techniques (LMI), we derive a new delay-dependent exponential stability criterion for BAM neural networks with variable delays. As this criterion has no extra constraints on the variable delay functions, it can be applied to quite general BAM neural networks with a broad range of time delay functions. It is also easy to use in practice. An example is provided to illustrate the theoretical development.

Properties of dust and clouds in the Mars atmosphere: Analysis of Viking IRTM emission phase function sequences

NASA Technical Reports Server (NTRS)

Clancy, R. T.; Lee, S. W.

1991-01-01

An analysis of emission-phase-function (EPF) observations from the Viking Orbiter Infrared Thermal Mapper (IRTM) yields a wide variety of results regarding dust and cloud scattering in the Mars atmosphere and atmospheric-corrected albedos for the surface of Mars. A multiple scattering radiative transfer model incorporating a bidirectional phase function for the surface and atmospheric scattering by dust and clouds is used to derive surface albedos and dust and ice optical properties and optical depths for these various conditions on Mars.

A Comparative Study of the Bidirectional Reflectance Distribution Function of Several Surfaces as a Mid-wave Infrared Diffuse Reflectance Standard

DTIC Science & Technology

2009-03-01

it for the symbology used in this document before reading this chapter. 2.1 BRDF Development In this section, the BRDF will first be briefly be...geometric occlusion term, which was de- picted in Figure 6. This term in the Cook-Torrance model describes the shadowing and masking effects, and is...where the min() function selects the least of the arguments. The first term in the minimum function is where no occlusion of any kind is occurring

Thinking, Walking, Talking: Integratory Motor and Cognitive Brain Function

PubMed Central

Leisman, Gerry; Moustafa, Ahmed A.; Shafir, Tal

2016-01-01

In this article, we argue that motor and cognitive processes are functionally related and most likely share a similar evolutionary history. This is supported by clinical and neural data showing that some brain regions integrate both motor and cognitive functions. In addition, we also argue that cognitive processes coincide with complex motor output. Further, we also review data that support the converse notion that motor processes can contribute to cognitive function, as found by many rehabilitation and aerobic exercise training programs. Support is provided for motor and cognitive processes possessing dynamic bidirectional influences on each other. PMID:27252937

Bidirectional Longitudinal Relations between Father-Child Relationships and Chinese Children's Social Competence during Early Childhood

ERIC Educational Resources Information Center

Zhang, Xiao

2013-01-01

Using a two-year and three-wave cross-lagged design with a sample of 118 Chinese preschoolers, the present study examined bidirectional longitudinal relations between father-child relationships and children's social competence. The results of structural equation modeling showed bidirectional effects between father-child conflict and social…

Numerical Modelling of a Bidirectional Long Ring Raman Fiber Laser Dynamics

NASA Astrophysics Data System (ADS)

Sukhanov, S. V.; Melnikov, L. A.; Mazhirina, Yu A.

2017-11-01

The numerical model for the simulation of the dynamics of a bidirectional long ring Raman fiber laser is proposed. The model is based on the transport equations and Courant-Isaacson-Rees method. Different regimes of a bidirectional long ring Raman fiber laser and long time-domain realizations are investigated.

Analytical investigation of bidirectional ductile diaphragms in multi-span bridges

NASA Astrophysics Data System (ADS)

Wei, Xiaone; Bruneau, Michel

2018-04-01

In the AASHTO Guide Specifications for Seismic Bridge Design Provisions, ductile diaphragms are identified as Permissible Earthquake-Resisting Elements (EREs), designed to help resist seismic loads applied in the transverse direction of bridges. When adding longitudinal ductile diaphragms, a bidirectional ductile diaphragm system is created that can address seismic excitations acting along both the bridge's longitudinal and transverse axes. This paper investigates bidirectional ductile diaphragms with Buckling Restrained Braces (BRBs) in straight multi-span bridge with simply supported floating spans. The flexibility of the substructures in the transverse and longitudinal direction of the bridge is considered. Design procedures for the bidirectional ductile diaphragms are first proposed. An analytical model of the example bridge with bidirectional ductile diaphragms, designed based on the proposed methodology, is then built in SAP2000. Pushover and nonlinear time history analyses are performed on the bridge model, and corresponding results are presented. The effect of changing the longitudinal stiffness of the bidirectional ductile diaphragms in the end spans connecting to the abutment is also investigated, in order to better understand the impact on the bridge's dynamic performance.

Talk to the virtual hands: self-animated avatars improve communication in head-mounted display virtual environments.

PubMed

Dodds, Trevor J; Mohler, Betty J; Bülthoff, Heinrich H

2011-01-01

When we talk to one another face-to-face, body gestures accompany our speech. Motion tracking technology enables us to include body gestures in avatar-mediated communication, by mapping one's movements onto one's own 3D avatar in real time, so the avatar is self-animated. We conducted two experiments to investigate (a) whether head-mounted display virtual reality is useful for researching the influence of body gestures in communication; and (b) whether body gestures are used to help in communicating the meaning of a word. Participants worked in pairs and played a communication game, where one person had to describe the meanings of words to the other. In experiment 1, participants used significantly more hand gestures and successfully described significantly more words when nonverbal communication was available to both participants (i.e. both describing and guessing avatars were self-animated, compared with both avatars in a static neutral pose). Participants 'passed' (gave up describing) significantly more words when they were talking to a static avatar (no nonverbal feedback available). In experiment 2, participants' performance was significantly worse when they were talking to an avatar with a prerecorded listening animation, compared with an avatar animated by their partners' real movements. In both experiments participants used significantly more hand gestures when they played the game in the real world. Taken together, the studies show how (a) virtual reality can be used to systematically study the influence of body gestures; (b) it is important that nonverbal communication is bidirectional (real nonverbal feedback in addition to nonverbal communication from the describing participant); and (c) there are differences in the amount of body gestures that participants use with and without the head-mounted display, and we discuss possible explanations for this and ideas for future investigation.

Regulation of tRNA Bidirectional Nuclear-Cytoplasmic Trafficking in Saccharomyces cerevisiae

PubMed Central

Murthi, Athulaprabha; Shaheen, Hussam H.; Huang, Hsiao-Yun; Preston, Melanie A.; Lai, Tsung-Po; Phizicky, Eric M.

2010-01-01

tRNAs in yeast and vertebrate cells move bidirectionally and reversibly between the nucleus and the cytoplasm. We investigated roles of members of the β-importin family in tRNA subcellular dynamics. Retrograde import of tRNA into the nucleus is dependent, directly or indirectly, upon Mtr10. tRNA nuclear export utilizes at least two members of the β-importin family. The β-importins involved in nuclear export have shared and exclusive functions. Los1 functions in both the tRNA primary export and the tRNA reexport processes. Msn5 is unable to export tRNAs in the primary round of export if the tRNAs are encoded by intron-containing genes, and for these tRNAs Msn5 functions primarily in their reexport to the cytoplasm. The data support a model in which tRNA retrograde import to the nucleus is a constitutive process; in contrast, reexport of the imported tRNAs back to the cytoplasm is regulated by the availability of nutrients to cells and by tRNA aminoacylation in the nucleus. Finally, we implicate Tef1, the yeast orthologue of translation elongation factor eEF1A, in the tRNA reexport process and show that its subcellular distribution between the nucleus and cytoplasm is dependent upon Mtr10 and Msn5. PMID:20032305

Regulation of tRNA bidirectional nuclear-cytoplasmic trafficking in Saccharomyces cerevisiae.

PubMed

Murthi, Athulaprabha; Shaheen, Hussam H; Huang, Hsiao-Yun; Preston, Melanie A; Lai, Tsung-Po; Phizicky, Eric M; Hopper, Anita K

2010-02-15

tRNAs in yeast and vertebrate cells move bidirectionally and reversibly between the nucleus and the cytoplasm. We investigated roles of members of the beta-importin family in tRNA subcellular dynamics. Retrograde import of tRNA into the nucleus is dependent, directly or indirectly, upon Mtr10. tRNA nuclear export utilizes at least two members of the beta-importin family. The beta-importins involved in nuclear export have shared and exclusive functions. Los1 functions in both the tRNA primary export and the tRNA reexport processes. Msn5 is unable to export tRNAs in the primary round of export if the tRNAs are encoded by intron-containing genes, and for these tRNAs Msn5 functions primarily in their reexport to the cytoplasm. The data support a model in which tRNA retrograde import to the nucleus is a constitutive process; in contrast, reexport of the imported tRNAs back to the cytoplasm is regulated by the availability of nutrients to cells and by tRNA aminoacylation in the nucleus. Finally, we implicate Tef1, the yeast orthologue of translation elongation factor eEF1A, in the tRNA reexport process and show that its subcellular distribution between the nucleus and cytoplasm is dependent upon Mtr10 and Msn5.

Key diffusion mechanisms involved in regulating bidirectional water permeation across E. coli outer membrane lectin

PubMed Central

Sachdeva, Shivangi; Kolimi, Narendar; Nair, Sanjana Anilkumar; Rathinavelan, Thenmalarchelvi

2016-01-01

Capsular polysaccharides (CPSs) are major bacterial virulent determinants that facilitate host immune evasion. E. coli group1 K30CPS is noncovalently attached to bacterial surface by Wzi, a lectin. Intriguingly, structure based phylogenetic analysis indicates that Wzi falls into porin superfamily. Molecular dynamics (MD) simulations further shed light on dual role of Wzi as it also functions as a bidirectional passive water specific porin. Such a functional role of Wzi was not realized earlier, due to the occluded pore. While five water specific entry points distributed across extracellular & periplasmic faces regulate the water diffusion involving different mechanisms, a luminal hydrophobic plug governs water permeation across the channel. Coincidently, MD observed open state structure of “YQF” triad is seen in sugar-binding site of sodium-galactose cotransporters, implicating its involvement in K30CPS surface anchorage. Importance of Loop 5 (L5) in membrane insertion is yet another highlight. Change in water diffusion pattern of periplasmic substitution mutants suggests Wzi’s role in osmoregulation by aiding in K30CPS hydration, corroborating earlier functional studies. Water molecules located inside β-barrel of Wzi crystal structure further strengthens the role of Wzi in osmoregulation. Thus, interrupting water diffusion or L5 insertion may reduce bacterial virulence. PMID:27320406

Bi-Directional Theta Modulation between the Septo-Hippocampal System and the Mammillary Area in Free-Moving Rats

PubMed Central

Ruan, Ming; Young, Calvin K.; McNaughton, Neil

2017-01-01

Hippocampal (HPC) theta oscillations have long been linked to various functions of the brain. Many cortical and subcortical areas that also exhibit theta oscillations have been linked to functional circuits with the hippocampus on the basis of coupled activities at theta frequencies. We examine, in freely moving rats, the characteristics of diencephalic theta local field potentials (LFPs) recorded in the supramammillary/mammillary (SuM/MM) areas that are bi-directionally connected to the HPC through the septal complex. Using partial directed coherence (PDC), we find support for previous suggestions that SuM modulates HPC theta at higher frequencies. We find weak separation of SuM and MM by dominant theta frequency recorded locally. Contrary to oscillatory cell activities under anesthesia where SuM is insensitive, but MM is sensitive to medial septal (MS) inactivation, theta LFPs persisted and became indistinguishable after MS-inactivation. However, MS-inactivation attenuated SuM/MM theta power, while increasing the frequency of SuM/MM theta. MS-inactivation also reduced root mean squared power in both HPC and SuM/MM equally, but reduced theta power differentially in the time domain. We provide converging evidence that SuM is preferentially involved in coding HPC theta at higher frequencies, and that the MS-HPC circuit normally imposes a frequency-limiting modulation over the SuM/MM area as suggested by cell-based recordings in anesthetized animals. In addition, we provide evidence that the postulated SuM-MS-HPC-MM circuit is under complex bi-directional control, rather than SuM and MM having roles as unidirectional relays in the network. PMID:28955209

Initiation and Continuation of Best Friends and Adolescents' Alcohol Consumption: Do Self-Esteem and Self-Control Function as Moderators?

ERIC Educational Resources Information Center

Larsen, Helle; Overbeek, Geertjan; Vermulst, Ad A.; Granic, Isabela; Engels, Rutger C. M. E.

2010-01-01

In this three-wave longitudinal survey, we investigated bi-directional longitudinal associations between best friends and adolescents' alcohol consumption. Additionally, since the relation between best friends and adolescents' drinking may be stronger if adolescents have not consumed alcohol yet, we examined this relation not only with regard to…

Using Multi-Angle WorldView-2 Imagery to Determine Ocean Depth Near Oahu, Hawaii

DTIC Science & Technology

2012-09-01

Reflection geometry used in the definition of BRDF (From McConnon [2010...Visible/InfraRed Imaging Spectrometer BRDF : Bidirectional Reflectance Distribution Function DHMs: Digital Height Maps DNs: Digital Numbers EM...navigation and fisheries management, and are also helpful for improving models of ocean circulation, air-sea interaction, weather forecasting, and

Assessment of Refueling Hose Visibility

DTIC Science & Technology

2012-10-01

shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number...10 7 Basic Model of Contrast Loss through Aircraft Windscreen Due To Haze ..................... 10 8...known as a bidirectional (azimuth and elevation) reflectance distribution function or BRDF . This is extremely time-consuming and impractical. In

An empirical study on the utility of BRDF model parameters and topographic parameters for mapping vegetation in a semi-arid region with MISR imagery

USDA-ARS?s Scientific Manuscript database

Multi-angle remote sensing has been proved useful for mapping vegetation community types in desert regions. Based on Multi-angle Imaging Spectro-Radiometer (MISR) multi-angular images, this study compares roles played by Bidirectional Reflectance Distribution Function (BRDF) model parameters with th...

Realizing IoT service's policy privacy over publish/subscribe-based middleware.

PubMed

Duan, Li; Zhang, Yang; Chen, Shiping; Wang, Shiyao; Cheng, Bo; Chen, Junliang

2016-01-01

The publish/subscribe paradigm makes IoT service collaborations more scalable and flexible, due to the space, time and control decoupling of event producers and consumers. Thus, the paradigm can be used to establish large-scale IoT service communication infrastructures such as Supervisory Control and Data Acquisition systems. However, preserving IoT service's policy privacy is difficult in this paradigm, because a classical publisher has little control of its own event after being published; and a subscriber has to accept all the events from the subscribed event type with no choice. Few existing publish/subscribe middleware have built-in mechanisms to address the above issues. In this paper, we present a novel access control framework, which is capable of preserving IoT service's policy privacy. In particular, we adopt the publish/subscribe paradigm as the IoT service communication infrastructure to facilitate the protection of IoT services policy privacy. The key idea in our policy-privacy solution is using a two-layer cooperating method to match bi-directional privacy control requirements: (a) data layer for protecting IoT events; and (b) application layer for preserving the privacy of service policy. Furthermore, the anonymous-set-based principle is adopted to realize the functionalities of the framework, including policy embedding and policy encoding as well as policy matching. Our security analysis shows that the policy privacy framework is Chosen-Plaintext Attack secure. We extend the open source Apache ActiveMQ broker by building into a policy-based authorization mechanism to enforce the privacy policy. The performance evaluation results indicate that our approach is scalable with reasonable overheads.

1×2 demultiplexer for a light waveguide communications system based on a holographic grating

NASA Astrophysics Data System (ADS)

Ren, Xuechang; Zhang, Xiangsu; Wang, Canhui; Liu, Shou

2009-05-01

2-channel multiplexer/demultiplexer (Muxer/Demuxer) is a key component for bidirectional data traffics applied for optical communication. Up to date various types of Muxer/Demuxer have been proposed and demonstrated. A grating coupler diffracts light into substrates or waveguides, along which light beam propagates by total internal reflection. In addition, one can exploit the dispersive and filtering characteristics of gratings, for dropping or separating one or several wavelengths from one another. When a laser beam containing two wavelengths is striking the surface of the grating with an incident angle within certain range, four diffracted beams will be generated. If two diffracted beams, corresponding to different wavelengths, meet the condition of total internal reflection, they will propagate inside the glass substrate (performs as a waveguide). While the third one cannot meet total reflection condition, and the last one should become the evanescent wave. Therefore it can separate two signals and couple signals to different waveguides. These functions are suited for WDM application and directional couplers. For convenience sake, the visible lights at 458nm and 633nm were used as the incident laser beams. To give a simple sample for 1×2 demultiplexing system, a holographic grating was recorded, with the period around 441nm which was chose discretionally within the certain range. The primary experimental results indicate that the two-wavelength signal can be separated and coupled into the respective waveguide as long as the grating is recorded and operated complying with the certain condition. The average insertion loss and crosstalk of the device were presented in this paper.

Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve

PubMed Central

Bravo, Javier A.; Forsythe, Paul; Chew, Marianne V.; Escaravage, Emily; Savignac, Hélène M.; Dinan, Timothy G.; Bienenstock, John; Cryan, John F.

2011-01-01

There is increasing, but largely indirect, evidence pointing to an effect of commensal gut microbiota on the central nervous system (CNS). However, it is unknown whether lactic acid bacteria such as Lactobacillus rhamnosus could have a direct effect on neurotransmitter receptors in the CNS in normal, healthy animals. GABA is the main CNS inhibitory neurotransmitter and is significantly involved in regulating many physiological and psychological processes. Alterations in central GABA receptor expression are implicated in the pathogenesis of anxiety and depression, which are highly comorbid with functional bowel disorders. In this work, we show that chronic treatment with L. rhamnosus (JB-1) induced region-dependent alterations in GABAB1b mRNA in the brain with increases in cortical regions (cingulate and prelimbic) and concomitant reductions in expression in the hippocampus, amygdala, and locus coeruleus, in comparison with control-fed mice. In addition, L. rhamnosus (JB-1) reduced GABAAα2 mRNA expression in the prefrontal cortex and amygdala, but increased GABAAα2 in the hippocampus. Importantly, L. rhamnosus (JB-1) reduced stress-induced corticosterone and anxiety- and depression-related behavior. Moreover, the neurochemical and behavioral effects were not found in vagotomized mice, identifying the vagus as a major modulatory constitutive communication pathway between the bacteria exposed to the gut and the brain. Together, these findings highlight the important role of bacteria in the bidirectional communication of the gut–brain axis and suggest that certain organisms may prove to be useful therapeutic adjuncts in stress-related disorders such as anxiety and depression. PMID:21876150

Social networks help to infer causality in the tumor microenvironment.

PubMed

Crespo, Isaac; Doucey, Marie-Agnès; Xenarios, Ioannis

2016-03-15

Networks have become a popular way to conceptualize a system of interacting elements, such as electronic circuits, social communication, metabolism or gene regulation. Network inference, analysis, and modeling techniques have been developed in different areas of science and technology, such as computer science, mathematics, physics, and biology, with an active interdisciplinary exchange of concepts and approaches. However, some concepts seem to belong to a specific field without a clear transferability to other domains. At the same time, it is increasingly recognized that within some biological systems--such as the tumor microenvironment--where different types of resident and infiltrating cells interact to carry out their functions, the complexity of the system demands a theoretical framework, such as statistical inference, graph analysis and dynamical models, in order to asses and study the information derived from high-throughput experimental technologies. In this article we propose to adopt and adapt the concepts of influence and investment from the world of social network analysis to biological problems, and in particular to apply this approach to infer causality in the tumor microenvironment. We showed that constructing a bidirectional network of influence between cell and cell communication molecules allowed us to determine the direction of inferred regulations at the expression level and correctly recapitulate cause-effect relationships described in literature. This work constitutes an example of a transfer of knowledge and concepts from the world of social network analysis to biomedical research, in particular to infer network causality in biological networks. This causality elucidation is essential to model the homeostatic response of biological systems to internal and external factors, such as environmental conditions, pathogens or treatments.

Central nervous system regulation of intestinal lipid and lipoprotein metabolism.

PubMed

Farr, Sarah; Taher, Jennifer; Adeli, Khosrow

2016-02-01

In response to nutrient availability, the small intestine and brain closely communicate to modulate energy homeostasis and metabolism. The gut-brain axis involves complex nutrient sensing mechanisms and an integration of neuronal and hormonal signaling. This review summarizes recent evidence implicating the gut-brain axis in regulating lipoprotein metabolism, with potential implications for the dyslipidemia of insulin resistant states. The intestine and brain possess distinct mechanisms for sensing lipid availability, which triggers subsequent regulation of feeding, glucose homeostasis, and adipose tissue metabolism. More recently, central receptors, neuropeptides, and gut hormones that communicate with the brain have been shown to modulate hepatic and intestinal lipoprotein metabolism via parasympathetic and sympathetic signaling. Gut-derived glucagon-like peptides appear to be particularly important in modulating the intestinal secretion of chylomicron particles via a novel brain-gut axis. Dysregulation of these pathways may contribute to postprandial diabetic dyslipidemia. Emerging evidence implicates the central and enteric nervous systems in controlling many aspects of lipid and lipoprotein metabolism. Bidirectional communication between the gut and brain involving neuronal pathways and gut peptides is critical for regulating feeding and metabolism, and forms a neuroendocrine circuit to modulate dietary fat absorption and intestinal production of atherogenic chylomicron particles.

Vagus-brain communication in atherosclerosis-related inflammation: a neuroimmunomodulation perspective of CAD.

PubMed

Gidron, Yori; Kupper, Nina; Kwaijtaal, Martijn; Winter, Jobst; Denollet, Johan

2007-12-01

The current understanding of the pathophysiology of atherosclerosis leading to coronary artery disease (CAD) emphasizes the role of inflammatory mediators. Given the bidirectional communication between the immune and central nervous systems, an important question is whether the brain can be "informed" about and modulate CAD-related inflammation. A candidate communicator and modulator is the vagus nerve. Until now, the vagus nerve has received attention in cardiology mainly due to its role in the parasympathetic cardiovascular response. However, the vagus nerve can also "inform" the brain about peripheral inflammation since its paraganglia have receptors for interleukin-1. Furthermore, its efferent branch has a local anti-inflammatory effect. These effects have not been considered in research on the vagus nerve in CAD or in vagus nerve stimulation trials in CAD. In addition, various behavioural interventions, including relaxation, may influence CAD prognosis by affecting vagal activity. Based on this converging evidence, we propose a neuroimmunomodulation approach to atherogenesis. In this model, the vagus nerve "informs" the brain about CAD-related cytokines; in turn, activation of the vagus (via vagus nerve stimulation, vagomimetic drugs or relaxation) induces an anti-inflammatory response that can slow down the chronic process of atherogenesis.

Surface roughness effects on bidirectional reflectance

NASA Technical Reports Server (NTRS)

Smith, T. F.; Hering, R. G.

1972-01-01

An experimental study of surface roughness effects on bidirectional reflectance of metallic surfaces is presented. A facility capable of irradiating a sample from normal to grazing incidence and recording plane of incidence bidirectional reflectance measurements was developed. Samples consisting of glass, aluminum alloy, and stainless steel materials were selected for examination. Samples were roughened using standard grinding techniques and coated with a radiatively opaque layer of pure aluminum. Mechanical surface roughness parameters, rms heights and rms slopes, evaluated from digitized surface profile measurements are less than 1.0 micrometers and 0.28, respectively. Rough surface specular, bidirectional, and directional reflectance measurements for selected values of polar angle of incidence and wavelength of incident energy within the spectral range of 1 to 14 micrometers are reported. The Beckmann bidirectional reflectance model is compared with reflectance measurements to establish its usefulness in describing the magnitude and spatial distribution of energy reflected from rough surfaces.

Youth sport parenting styles and practices.

PubMed

Holt, Nicholas L; Tamminen, Katherine A; Black, Danielle E; Mandigo, James L; Fox, Kenneth R

2009-02-01

The purpose of this study was to examine parenting styles and associated parenting practices in youth sport. Following a season-long period of fieldwork, primary data were collected via interviews with 56 parents and supplemented by interviews with 34 of their female children. Data analysis was guided by Grolnick's (2003) theory of parenting styles. Analyses produced five findings: (1) Autonomy-supportive parents provided appropriate structure for their children and allowed them to be involved in decision making. These parents were also able to read their children's mood and reported open bidirectional communication. (2) Controlling parents did not support their children's autonomy, were not sensitive to their children's mood, and tended to report more closed modes of communication. (3) In some families, there were inconsistencies between the styles employed by the mother and father. (4) Some parenting practices varied across different situations. (5) Children had some reciprocal influences on their parents' behaviors. These findings reveal information about the multiple social interactions associated with youth sport parenting.

Study of wavelength division multiplexing as a means of increasing the number of channels in multimode fiber optic communication links

NASA Technical Reports Server (NTRS)

Bates, Harry

1990-01-01

A number of optical communication lines are now in use at the Kennedy Space Center (KSC) for the transmission of voice, computer data, and video signals. Presently, all of these channels utilize a single carrier wavelength centered near 1300 nm. The theoretical bandwidth of the fiber far exceeds the utilized capacity. Yet, practical considerations limit the usable bandwidth. The fibers have the capability of transmitting a multiplicity of signals simultaneously in each of two separate bands (1300 and 1550 nm). Thus, in principle, the number of transmission channels can be increased without installing new cable if some means of wavelength division multiplexing (WDM) can be utilized. The main goal of these experiments was to demonstrate that a factor of 2 increase in bandwidth utilization can share the same fiber in both a unidirectional configuration and a bidirectional mode of operation. Both signal and multimode fiber are installed at KSC. The great majority is multimode; therefore, this effort concentrated on multimode systems.

Design and Implementation of a MAC Protocol for Timely and Reliable Delivery of Command and Data in Dynamic Wireless Sensor Networks

PubMed Central

Oh, Hoon; Van Vinh, Phan

2013-01-01

This paper proposes and implements a new TDMA-based MAC protocol for providing timely and reliable delivery of data and command for monitoring and control networks. In this kind of network, sensor nodes are required to sense data from the monitoring environment periodically and then send the data to a sink. The sink determines whether the environment is safe or not by analyzing the acquired data. Sometimes, a command or control message is sent from the sink to a particular node or a group of nodes to execute the services or request further interested data. The proposed MAC protocol enables bidirectional communication, controls active and sleep modes of a sensor node to conserve energy, and addresses the problem of load unbalancing between the nodes near a sink and the other nodes. It can improve reliability of communication significantly while extending network lifetime. These claims are supported by the experimental results. PMID:24084116

Design and implementation of a MAC protocol for timely and reliable delivery of command and data in dynamic wireless sensor networks.

PubMed

Oh, Hoon; Van Vinh, Phan

2013-09-30

This paper proposes and implements a new TDMA-based MAC protocol for providing timely and reliable delivery of data and command for monitoring and control networks. In this kind of network, sensor nodes are required to sense data from the monitoring environment periodically and then send the data to a sink. The sink determines whether the environment is safe or not by analyzing the acquired data. Sometimes, a command or control message is sent from the sink to a particular node or a group of nodes to execute the services or request further interested data. The proposed MAC protocol enables bidirectional communication, controls active and sleep modes of a sensor node to conserve energy, and addresses the problem of load unbalancing between the nodes near a sink and the other nodes. It can improve reliability of communication significantly while extending network lifetime. These claims are supported by the experimental results.

Cryo-scatter measurements of beryllium

NASA Astrophysics Data System (ADS)

Lippey, Barret; Krone-Schmidt, Wilfried

1991-12-01

Bi-directional Reflection Distribution Function measurements were performed as a function of cryogenic temperature for various substrates. Substrates investigated include HIPed and sputtered beryllium produced from different powders and by various manufacturing and polishing processes. In some samples investigated, the BRDF at 10.6 microns increased by a factor of 2 to 5 during cooling from 300 to 30 Kelvin. On repeated temperature cycling the change in BRDF appeared to be totally elastic. The cryo-scatter effect does not occur for all types of beryllium.

Reconstructing networks from dynamics with correlated noise

NASA Astrophysics Data System (ADS)

Tam, H. C.; Ching, Emily S. C.; Lai, Pik-Yin

2018-07-01

Reconstructing the structure of complex networks from measurements of the nodes is a challenge in many branches of science. External influences are always present and act as a noise to the networks of interest. In this paper, we present a method for reconstructing networks from measured dynamics of the nodes subjected to correlated noise that cannot be approximated by a white noise. This method can reconstruct the links of both bidirectional and directed networks, the correlation time and strength of the noise, and also the relative coupling strength of the links when the coupling functions have certain properties. Our method is built upon theoretical relations between network structure and measurable quantities from the dynamics that we have derived for systems that have fixed point dynamics in the noise-free limit. Using these theoretical results, we can further explain the shortcomings of two common practices of inferring links for bidirectional networks using the Pearson correlation coefficient and the partial correlation coefficient.

Novel RF Interrogation of a Fiber Bragg Grating Sensor Using Bidirectional Modulation of a Mach-Zehnder Electro-Optical Modulator

PubMed Central

Choi, Sang-Jin; Mao, Wankai; Pan, Jae-Kyung

2013-01-01

We propose and experimentally demonstrate the novel radio-frequency (RF) interrogation of a fiber Bragg grating (FBG) sensor using bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). Based on the microwave photonic technique and active detection, the transfer function of the proposed system was obtained, and the time delay was calculated from the change in the free spectral range (FSR) at different wavelengths over the optimal measuring range. The results show that the time delay and the wavelength variation have a good linear relationship, with a gradient of 9.31 ps/nm. An actual measurement taken with a sensing FBG for temperature variation shows the relationship with a gradient of 0.93 ps/10 °C. The developed system could be used for FBG temperature or strain sensing and other multiplexed sensor applications. PMID:23820744

Feel like you belong: on the bidirectional link between emotional fit and group identification in task groups

PubMed Central

Delvaux, Ellen; Meeussen, Loes; Mesquita, Batja

2015-01-01

Three studies investigated the association between members’ group identification and the emotional fit with their group. In the first study, a cross-sectional study in a large organization, we replicated earlier research by showing that group identification and emotional fit are positively associated, using a broader range of emotions and using profile correlations to measure group members’ emotional fit. In addition, in two longitudinal studies, where groups of students were followed at several time points during their collaboration on a project, we tested the directionality of the relationship between group identification and emotional fit. The results showed a bidirectional, positive link between group identification and emotional fit, such that group identification and emotional fit either mutually reinforce or mutually dampen each other over time. We discuss how these findings increase insights in group functioning and how they may be used to change group processes for better or worse. PMID:26300806

Calculating the bidirectional reflectance of natural vegetation covers using Boolean models and geometric optics

NASA Technical Reports Server (NTRS)

Strahler, Alan H.; Li, Xiao-Wen; Jupp, David L. B.

1991-01-01

The bidirectional radiance or reflectance of a forest or woodland can be modeled using principles of geometric optics and Boolean models for random sets in a three dimensional space. This model may be defined at two levels, the scene includes four components; sunlight and shadowed canopy, and sunlit and shadowed background. The reflectance of the scene is modeled as the sum of the reflectances of the individual components as weighted by their areal proportions in the field of view. At the leaf level, the canopy envelope is an assemblage of leaves, and thus the reflectance is a function of the areal proportions of sunlit and shadowed leaf, and sunlit and shadowed background. Because the proportions of scene components are dependent upon the directions of irradiance and exitance, the model accounts for the hotspot that is well known in leaf and tree canopies.

Numerical modelling of chirality-induced bi-directional swimming of artificial flagella

PubMed Central

Namdeo, S.; Khaderi, S. N.; Onck, P. R.

2014-01-01

Biomimetic micro-swimmers can be used for various medical applications, such as targeted drug delivery and micro-object (e.g. biological cells) manipulation, in lab-on-a-chip devices. Bacteria swim using a bundle of flagella (flexible hair-like structures) that form a rotating cork-screw of chiral shape. To mimic bacterial swimming, we employ a computational approach to design a bacterial (chirality-induced) swimmer whose chiral shape and rotational velocity can be controlled by an external magnetic field. In our model, we numerically solve the coupled governing equations that describe the system dynamics (i.e. solid mechanics, fluid dynamics and magnetostatics). We explore the swimming response as a function of the characteristic dimensionless parameters and put special emphasis on controlling the swimming direction. Our results provide fundamental physical insight on the chirality-induced propulsion, and it provides guidelines for the design of magnetic bi-directional micro-swimmers. PMID:24511253

Cholinergic manipulations bidirectionally regulate object memory destabilization

PubMed Central

Stiver, Mikaela L.; Jacklin, Derek L.; Mitchnick, Krista A.; Vicic, Nevena; Carlin, Justine; O'Hara, Matthew

2015-01-01

Consolidated memories can become destabilized and open to modification upon retrieval. Destabilization is most reliably prompted when novel information is present during memory reactivation. We hypothesized that the neurotransmitter acetylcholine (ACh) plays an important role in novelty-induced memory destabilization because of its established involvement in new learning. Accordingly, we investigated the effects of cholinergic manipulations in rats using an object recognition paradigm that requires reactivation novelty to destabilize object memories. The muscarinic receptor antagonist scopolamine, systemically or infused directly into the perirhinal cortex, blocked this novelty-induced memory destabilization. Conversely, systemic oxotremorine or carbachol, muscarinic receptor agonists, administered systemically or intraperirhinally, respectively, mimicked the destabilizing effect of novel information during reactivation. These bidirectional effects suggest a crucial influence of ACh on memory destabilization and the updating functions of reconsolidation. This is a hitherto unappreciated mnemonic role for ACh with implications for its potential involvement in cognitive flexibility and the dynamic process of long-term memory storage. PMID:25776038

A Review of 25 Years of Research in Bidirectionality in Parent-Child Relationships: An Examination of Methodological Approaches

ERIC Educational Resources Information Center

Paschall, Katherine W.; Mastergeorge, Ann M.

2016-01-01

The concept of bidirectionality represents a process of mutual influence between parent and child, whereby each influences the other as well as the dyadic relationship. Despite the widespread acceptance of bidirectional models of influence, there is still a lack of integration of such models in current research designs. Research on…

Framewise phoneme classification with bidirectional LSTM and other neural network architectures.

PubMed

Graves, Alex; Schmidhuber, Jürgen

2005-01-01

In this paper, we present bidirectional Long Short Term Memory (LSTM) networks, and a modified, full gradient version of the LSTM learning algorithm. We evaluate Bidirectional LSTM (BLSTM) and several other network architectures on the benchmark task of framewise phoneme classification, using the TIMIT database. Our main findings are that bidirectional networks outperform unidirectional ones, and Long Short Term Memory (LSTM) is much faster and also more accurate than both standard Recurrent Neural Nets (RNNs) and time-windowed Multilayer Perceptrons (MLPs). Our results support the view that contextual information is crucial to speech processing, and suggest that BLSTM is an effective architecture with which to exploit it.

Estimation of shortwave hemispherical reflectance (albedo) from bidirectionally reflected radiance data

NASA Technical Reports Server (NTRS)

Starks, Patrick J.; Norman, John M.; Blad, Blaine L.; Walter-Shea, Elizabeth A.; Walthall, Charles L.

1991-01-01

An equation for estimating albedo from bidirectional reflectance data is proposed. The estimates of albedo are found to be greater than values obtained with simultaneous pyranometer measurements. Particular attention is given to potential sources of systematic errors including extrapolation of bidirectional reflectance data out to a view zenith angle of 90 deg, the use of inappropriate weighting coefficients in the numerator of the albedo equation, surface shadowing caused by the A-frame instrumentation used to measure the incoming and outgoing radiation fluxes, errors in estimates of the denominator of the proposed albedo equation, and a 'hot spot' contribution in bidirectional data measured by a modular multiband radiometer.

Design of PI Controlled Non Isolated Bidirectional DC to DC Converter for Electric Vehicle Application

NASA Astrophysics Data System (ADS)

Geetha, A.; Subramani, C.; Thamizh Thentral, T. M.; Krithika, V.; Usha, S.

2018-04-01

Non isolated Bidirectional DC-DC Converter (NIBDDC) is a good interface between DC source and inverter Fed induction motor drive. This paper deals with comparison between open loop and PI controlled Bidirectional DC to DC Converter Inverter System (BDDCIS). The modelling and control of BDDC is becomes an important issue. Open loop BDDCIS and closed loop PI controlled BDDCIS are designed, modelled and simulated using Matlab- simulink and their results are presented. The investigations indicate superior performance of PI controlled BDDCIS. The proposed BDDCIS has advantages like bidirectional power transfer ability, reduced hardware count and improved dynamic response.

Couple therapy for depression.

PubMed

Whisman, Mark A; Beach, Steven R H

2012-05-01

Relationship problems and depression often influence one another in a bidirectional, recursive fashion. Results from several clinical trials have demonstrated that couple therapy is effective in improving depression and reducing relationship problems. In this article, we describe an approach to working with depression in partnered individuals who are also unhappy in their relationship. This cognitive-behavior approach strives to (a) eliminate major stressors and reestablish positive activities in the relationship, (b) improve communication and problem solving in the relationship, and (c) solidify gains made in therapy and prevent relapse. The typical course of therapy is described and demonstrated in a case illustration. Couple therapy is a promising treatment for depressed individuals in distressed relationships. © 2012 Wiley Periodicals, Inc.

Wireless technologies for robotic endoscope in gastrointestinal tract.

PubMed

Gao, P; Yan, G; Wang, Z; Liu, H

2012-07-01

This paper introduces wireless technologies for use with robotic endoscopes in the gastrointestinal tract. The technologies include wireless power transmission (WPT), wireless remote control (WRC), and wireless image transmission (WIT). WPT, based on the electromagnetic coupling principle, powers active locomotion actuators and other peripherals in large air gaps. WRC, based on real-time bidirectional communication, has a multikernel frame in vivo to realize real-time multitasking. WIT provides a continuous dynamic image with a revolution of 320 × 240 pixel at 30 fps for in vitro diagnosis. To test these wireless technologies, three robotic endoscope prototypes were fabricated and equipped with the customized modules. The experimental results show that the wireless technologies have value for clinical applications.

Towards benchmarking citizen observatories: Features and functioning of online amateur weather networks.

PubMed

Gharesifard, Mohammad; Wehn, Uta; van der Zaag, Pieter

2017-05-15

Crowd-sourced environmental observations are increasingly being considered as having the potential to enhance the spatial and temporal resolution of current data streams from terrestrial and areal sensors. The rapid diffusion of ICTs during the past decades has facilitated the process of data collection and sharing by the general public and has resulted in the formation of various online environmental citizen observatory networks. Online amateur weather networks are a particular example of such ICT-mediated observatories that are rooted in one of the oldest and most widely practiced citizen science activities, namely amateur weather observation. The objective of this paper is to introduce a conceptual framework that enables a systematic review of the features and functioning of these expanding networks. This is done by considering distinct dimensions, namely the geographic scope and types of participants, the network's establishment mechanism, revenue stream(s), existing communication paradigm, efforts required by data sharers, support offered by platform providers, and issues such as data accessibility, availability and quality. An in-depth understanding of these dimensions helps to analyze various dynamics such as interactions between different stakeholders, motivations to run the networks, and their sustainability. This framework is then utilized to perform a critical review of six existing online amateur weather networks based on publicly available data. The main findings of this analysis suggest that: (1) there are several key stakeholders such as emergency services and local authorities that are not (yet) engaged in these networks; (2) the revenue stream(s) of online amateur weather networks is one of the least discussed but arguably most important dimensions that is crucial for the sustainability of these networks; and (3) all of the networks included in this study have one or more explicit modes of bi-directional communication, however, this is limited to feedback mechanisms that are mainly designed to educate the data sharers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improving doctor-patient communication in the outpatient setting using a facilitation tool: a preliminary study.

PubMed

Neeman, Naama; Isaac, Thomas; Leveille, Suzanne; Dimonda, Clementina; Shin, Jacob Y; Aronson, Mark D; Freedman, Steven D

2012-08-01

Patients often do not fully understand medical information discussed during office visits. This can result in lack of adherence to recommended treatment plans and poorer health outcomes. We developed and implemented a program utilizing an encounter form, which provides structure to the medical interaction and facilitates bidirectional communication and informed decision-making. We conducted a prospective quality improvement intervention at a large tertiary-care academic medical center utilizing the encounter form and studied the effect on patient satisfaction, understanding and confidence in communicating with physicians. The intervention included 108 patients seen by seven physicians in five sub-specialties. Ninety-eight percent of patients were extremely satisfied (77%) or somewhat satisfied (21%) with the program. Ninety-six percent of patients reported being involved in decisions about their care and treatments as well as high levels of understanding of medical information that was discussed during visit. Sixty-nine percent of patients reported that they shared the encounter form with their families and friends. Patients' self-confidence in communicating with their doctors increased from a score of 8.1 to 8.7 post-intervention (P-value = 0.0018). When comparing pre- and post-intervention experiences, only 38% of patients felt that their problems and questions were adequately addressed by other physicians' pre-intervention, compared with 94% post-intervention. We introduced a program to enhance physician-patient communication and found that patients were highly satisfied, more informed and more actively involved in their care. This approach may be an easily generalizable approach to improving physician-patient communication at outpatient visits.