WorldWideScience

Sample records for twin mirror systems

  1. Minimal Mirror Twin Higgs

    CERN Document Server

    Barbieri, Riccardo; Harigaya, Keisuke

    2016-01-01

    In a Mirror Twin World with a maximally symmetric Higgs sector the little hierarchy of the Standard Model can be significantly mitigated, perhaps displacing the cutoff scale above the LHC reach. We show that consistency with observations requires that the Z2 parity exchanging the Standard Model with its mirror be broken in the Yukawa couplings. A minimal such effective field theory, with this sole Z2 breaking, can generate the Z2 breaking in the Higgs sector necessary for the Twin Higgs mechanism, and has constrained and correlated signals in invisible Higgs decays, direct Dark Matter Detection and Dark Radiation, all within reach of foreseen experiments. For dark matter, both mirror neutrons and a variety of self-interacting mirror atoms are considered. Neutrino mass signals and the effects of a possible additional Z2 breaking from the vacuum expectation values of B-L breaking fields are also discussed.

  2. Cosmological Signals of a Mirror Twin Higgs

    CERN Document Server

    Craig, Nathaniel; Trott, Timothy

    2016-01-01

    We investigate the cosmology of the minimal model of neutral naturalness, the mirror Twin Higgs. The softly-broken mirror symmetry relating the Standard Model to its twin counterpart leads to significant dark radiation in tension with BBN and CMB observations. We quantify this tension and illustrate how it can be mitigated in several simple scenarios that alter the relative energy densities of the two sectors while respecting the softly-broken mirror symmetry. In particular, we consider both the out-of-equilibrium decay of a new scalar as well as reheating in a toy model of twinned inflation, Twinflation. In both cases the dilution of energy density in the twin sector does not merely reconcile the existence of a mirror Twin Higgs with cosmological constraints, but predicts contributions to cosmological observables that may be probed in current and future CMB experiments. This raises the prospect of discovering evidence of neutral naturalness through cosmology rather than colliders.

  3. A twin-mirrored galvanometer laser light sheet generator

    Science.gov (United States)

    Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

    1988-01-01

    A galvanometer mirror-based laser light sheet system has been developed for use in the Basic Aerodynamics Research Tunnel at NASA Langley. This system generates and positions single or multiple light sheets over aeronautical research models being tested in the low speed tunnel. This report describes a twin mirrored galvanometer laser light sheet generator and shows typical light sheet arrangements in use. With this system, illumination of smoke entrained in the flow over a delta wing model reveals the vortical flow produced by the separation of the flow at the leading edge of the model. The light sheet system has proven to be very adaptable and easy to use in sizing and positioning light sheets in wind tunnel applications.

  4. Cosmology in Mirror Twin Higgs and Neutrino Masses

    CERN Document Server

    Chacko, Zackaria; Fox, Patrick J; Harnik, Roni

    2016-01-01

    We explore a simple solution to the cosmological challenges of the original Mirror Twin Higgs (MTH) model that leads to interesting implications for experiment. We consider theories in which both the standard model and mirror neutrinos acquire masses through the familiar seesaw mechanism, but with a low right-handed neutrino mass scale of order a few GeV. In these $\

  5. Mirror systems

    Energy Technology Data Exchange (ETDEWEB)

    Howells, M.R.

    1985-12-01

    The physics of VUV and x-ray reflection is reviewed. The main functions of mirrors in synchrotron beamlines are stated briefly and include deflection, filtration, power absorption, formation of a real image of the source, focusing, and collimation. Methods of fabrication of optical surfaces are described. Types of imperfections are discussed, including, aberrations, surface figure inaccuracy, roughness, and degradation due to use. Calculation of the photon beam thermal load, including computer modelling, is considered. 50 refs., 7 figs. (LEW)

  6. Mirror-image trigger thumb in dichorionic identical twins.

    Science.gov (United States)

    Wang, Eric D; Xu, Xiaoti; Dagum, Alexander B

    2012-06-01

    The congenital vs acquired etiology of pediatric trigger thumb is the subject of considerable debate. Existing case reports of bilateral presentation in identical twins and first-degree familial association support the congenital hypothesis. However, prospective studies have yet to report a neonate presenting with this anomaly at birth. This article describes the first known set of dichorionic, monozygotic identical twins with unilateral trigger thumbs, affecting contralateral (mirror-image) hands and with asynchronous age at presentation (11 months and 18 months, respectively).Pediatric trigger thumb is caused by a mismatch between the flexor pollicis longus tendon and its A1 synovial pulley. Four sets of twins have been previously reported in the literature with trigger thumb. Of these, 3 sets were monozygotic twins who had bilaterally affected thumbs. Together with the absence of trauma, a congenital etiology was suggested. The fact that pediatric trigger thumb is generally seen several months after birth was felt to be due to infants holding their thumbs clutched in their palms until 6 months. However, no confirmed cases of trigger thumb have been diagnosed at birth in several large prospective studies of newborns.In the current case, the asynchronous presentation of unilateral trigger thumbs in identical twins does not support a solely congenital cause. Furthermore, the mirror-image presentation contradicts current embryological understanding of the temporal course of twinning and the determination of laterality. Thus, a multifactorial etiology is supported with both a genetic and acquired component affecting the development of this condition. Copyright 2012, SLACK Incorporated.

  7. Dramatically different dizygotic twins: will we include them in Research? Twin research reviews: congenital anomalies, mirror-image effects in conjoined twins, older mothers of twins; Twin statistics: 'Massachusetts, land of twins'; Tribute: Dr Victor A. McKusick.

    Science.gov (United States)

    Segal, Nancy L

    2008-10-01

    The increased frequency of interracial marriage is a likely source of unusual-looking dizygotic (DZ) twins. Some members of DZ twin pairs born to mixed-race couples inherit very different physical features from their parents. This raises several questions, such as: Will researchers wish to include such twins in their ongoing studies? Next, new twin research concerned with congenital anomalies, mirror-image effects in conjoined twins and older mothers of twins will be reviewed. New statistics on twinning rates in Massachusetts will also be summarized, followed by a tribute to the late medical geneticist Dr. Victor A. McKusick.

  8. Twin mirrors for laser interferometric gravitational-wave detectors.

    Science.gov (United States)

    Sassolas, Benoît; Benoît, Quentin; Flaminio, Raffaele; Forest, Danièle; Franc, Janyce; Galimberti, Massimo; Lacoudre, Aline; Michel, Christophe; Montorio, Jean-Luc; Morgado, Nazario; Pinard, Laurent

    2011-05-01

    Gravitational-wave detectors such as Virgo and the laser interferometric gravitational-wave observatory (LIGO) use a long-baseline Michelson interferometer with Fabry-Perot cavities in the arms to search for gravitational waves. The symmetry between the two Fabry-Perot cavities is crucial to reduce the interferometer's sensitivity to the laser amplitude and frequency noise. To this purpose, the transmittance of the mirrors in both cavities should be as close as possible. This paper describes the realization and the characterization of the first twin large low-loss mirrors with transmissions differing by less than 0.01%.

  9. TwinFocus CPV system

    Science.gov (United States)

    Nardello, Marco; Centro, Sandro

    2017-09-01

    TwinFocus® is a CPV solution that adopts quasi-parabolic, off axis mirrors, to obtain a concentration of 760× on 3J solar cells (Azur space technology) with 44% efficiency. The adoption of this optical solution allows for a cheap, lightweight and space efficient system. In particular, the addition of a secondary optics to the mirror, grants an efficient use of space, with very low thicknesses and a compact modular design. Materials are recyclable and allow for reduction of weights to a minimum level. The product is realized through the cooperation of leading edge industries active in automotive lighting and plastic materials molding. The produced prototypes provide up to 27.6% efficiency according to tests operated on the field with non-optimal spectral conditions.

  10. Twin-Mirrored-Galvanometer Laser-Light-Sheet Generator

    Science.gov (United States)

    Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

    1991-01-01

    Multiple, rotating laser-light sheets generated to illuminate flows in wind tunnels. Designed and developed to provide flexibility and adaptability to wide range of applications. Design includes capability to control size and location of laser-light sheet in real time, to generate horizontal or vertical sheets, to sweep sheet repeatedly through volume, to generate multiple sheets with controllable separation, and to rotate single or multiple laser-light sheets. Includes electronic equipment and laser mounted on adjustable-height platform. Twin-mirrored galvanometer unit supported by tripod to reduce vibration. Other possible applications include use in construction industry to align beams of building. Artistic or display applications also possible.

  11. Mirror imaging of impacted and supernumerary teeth in dizygotic twins: A case report.

    Science.gov (United States)

    Cassetta, Michele; Altieri, Federica; Giordano, Alessandra

    2015-02-01

    Mesiodens is the most common type of supernumerary tooth found in the premaxilla. It might be discovered by the clinical examination by chance on a radiograph or as the cause of an unerupted maxillary central incisor. The genetic transmission of supernumerary and impacted teeth is poorly understood. Mirror imaging in twins has been reported frequently in relation to several unilateral dental anomalies including mesiodens. This phenomenon is the appearance of an asymmetrical feature or anomaly occurring on the right side of one twin but on the left side of the other twin. The event of mesiodens mirror imaging in monozygotic twins has been described in literature. This is the first reported case of mesiodens mirror images in dizygotic twins. The de-scribed mesiodens caused the eruption failure of maxillary permanent incisors. The super-numerary teeth were removed to facilitate the spontaneous eruption of the impacted perma-nent maxillary incisors. Studies related to supernumerary teeth can be useful to clinicians in the early diagnosis of this anomaly. Clinical and radiographic examinations provide a correct therapeutic approach. Key words:Supernumerary teeth, twins, dental development.

  12. Space Mirror Alignment System

    Science.gov (United States)

    Jau, Bruno M.; McKinney, Colin; Smythe, Robert F.; Palmer, Dean L.

    2011-01-01

    An optical alignment mirror mechanism (AMM) has been developed with angular positioning accuracy of +/-0.2 arcsec. This requires the mirror s linear positioning actuators to have positioning resolutions of +/-112 nm to enable the mirror to meet the angular tip/tilt accuracy requirement. Demonstrated capabilities are 0.1 arc-sec angular mirror positioning accuracy, which translates into linear positioning resolutions at the actuator of 50 nm. The mechanism consists of a structure with sets of cross-directional flexures that enable the mirror s tip and tilt motion, a mirror with its kinematic mount, and two linear actuators. An actuator comprises a brushless DC motor, a linear ball screw, and a piezoelectric brake that holds the mirror s position while the unit is unpowered. An interferometric linear position sensor senses the actuator s position. The AMMs were developed for an Astrometric Beam Combiner (ABC) optical bench, which is part of an interferometer development. Custom electronics were also developed to accommodate the presence of multiple AMMs within the ABC and provide a compact, all-in-one solution to power and control the AMMs.

  13. Mirror syndrome after fetoscopic laser therapy for twin-twin transfusion syndrome due to transient donor hydrops that resolved before delivery. A case report.

    Science.gov (United States)

    Chang, Yao-Lung; Chao, An-Shine; Chang, Shuenn-Dyh; Wang, Chao-Nin

    2014-01-01

    Mirror syndrome is a rare complication of twin-twin transfusion syndrome (TTTS). Its clinical picture includes massive edema, oliguria, and hemodilution in the context of fetal hydrops. The occurrence of mirror syndrome after fetoscopic laser therapy for TTTS has been well documented, but resolution of mirror syndrome before delivery has not been reported in the literature. A 33-year-old woman was referred to our institution at 23(6)/7 weeks' gestation for TTTS, which had been treated with amnioreduction twice: at 21 and 22 gestational weeks, respectively. Mirror syndrome was diagnosed after fetoscopic laser therapy for TTTS at 24 weeks' gestation due to maternal manifestations of pulmonary edema, skin edema, anemia, low blood protein concentration and proteinuria accompanied by donor hydrops. The maternal respiratory symptoms then gradually abated in mirror syndrome after fetoscopic laser therapy in twin-twin transfusion due to donor hydrops doesn't necessarily predict a poor perinatal outcome.

  14. TwinMux Testing System

    CERN Document Server

    Wong, Wei Wen; CERN. Geneva. PH Department

    2015-01-01

    During the CERN summer school program, I joined the CMS Muon Drift Tube (DT) group, and mainly worked on two projects, which, both of them, are related to the electronics of a new data concentrator called the “TwinMux”. My first task within the TwinMux project was to build an integrated software test station in order to run several tests on the functionality of the TwinMux hardware. Essentially, I had to integrate existing testing scripts, adding several new ones, into a single user-friendly testing platform which can perform quick, convenient and automated hardware testing. Later, I was also involved in the design of the local technical triggering of the DT. Such system relies on some firmware functionality built in the TwinMux and controlled by software. I had attempted two different approaches to design the communication topology of all the 12 TwinMux cards in order to send a user-defined logical operation to the read-out electronics. The final goal of this system is to drive local trigger signal for...

  15. [The ontogeny of the mirror neuron system].

    Science.gov (United States)

    Myowa-Yamakoshi, Masako

    2014-06-01

    Abstract Humans utilize the mirror neuron system to understand and predict others' actions. However, the ontogeny of the mirror neuron system remains unknown. Whether mirror neuron function is an innate trait or whether mirror neurons acquire their sensorimotor matching properties ontogenetically remains to be clarified. In this paper, I review the ontogenetic theory of the mirror neuron system. I then discuss the functioning of the mirror neuron system in the context of social cognitive abilities, which are unique to humans. Recently, some researchers argue that it is too early to interpret the function of mirror neurons as an understanding of the underlying psychological states of others. They imply that such functioning would require inferential cognitive processes that are known to involve areas outside the mirror neuron system. Filling in this missing link may be the key to elucidating the unique ability of humans to understand others' actions.

  16. The mirror neuron system : New frontiers

    NARCIS (Netherlands)

    Keysers, Christian; Fadiga, Luciano

    2008-01-01

    Since the discovery of mirror neurons, much effort has been invested into Studying their location and properties in the human brain. Here we review these original findings and introduce the Main topics of this special issue of Social Neuroscience. What does the mirror system code? How is the mirror

  17. Steps toward increasing Q in mirror systems

    Energy Technology Data Exchange (ETDEWEB)

    Post, R.F.

    1979-08-20

    Experiments such as the 2XIIB experiment at Livermore have established the ability of mirror systems to confine high temperature, high density plasmas at central beta values exceeding unity. Given these results the next tasks for the mirror approach are to explore means for increasing the energy gain factor Q and to scale up the plasma volume, both of these requirements deriving from economic constraints. This report discusses means for increasng Q, including recent improvements in the tandem mirror concept and design studies of the field-reversed mirror in the context of upcoming and proposed scaled-up mirror experiments.

  18. Advanced Mirror Material System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Peregrine will bring together recent laboratory developments and mature the technology so that complete mirror and telescope assemblies can be reliably and robustly...

  19. Segmented mirror control system hardware for CELT

    Science.gov (United States)

    Mast, Terry S.; Nelson, Jerry E.

    2000-07-01

    The primary mirror of the proposed California Extremely Large Telescope is a 30-meter diameter mosaic of hexagonal segments. The primary mirror active control will be achieved using four systems: sensors, actuators, processor, and alignment camera. We describe here the basic requirements of sensors and actuators, sketch a sensor design, and indicate interesting actuator alternatives.

  20. The TWINS Science Data System after the launch of TWINS 1

    Science.gov (United States)

    Goldstein, J.; Valek, P.; Skoug, R.; Delapp, D.; Redfern, J.; Carruth, B.; McComas, D.

    2007-05-01

    The Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) 1 satellite is in orbit and science data are expected to commence in the near future. TWINS-1 comprises half of the TWINS stereoscopic neutral atom imaging system that will advance our knowledge of the Earth's ring current. To support the expected data return, we have developed a Science Data System (SDS) for the TWINS mission. The TWINS SDS is an IDL- and Java- driven data interface that operates primarily via a web browser, and has as its spine an SQL-queryable database. Through this interface, TWINS science data will be provided to the TWINS team, the space science community, and the public. In this paper we present the current and future capabilities of the TWINS SDS, as well as how the SDS fits into virtual observatory infrastructure.

  1. Mirror neurons and mirror systems in monkeys and humans.

    Science.gov (United States)

    Fabbri-Destro, Maddalena; Rizzolatti, Giacomo

    2008-06-01

    Mirror neurons are a distinct class of neurons that transform specific sensory information into a motor format. Mirror neurons have been originally discovered in the premotor and parietal cortex of the monkey. Subsequent neurophysiological (TMS, EEG, MEG) and brain imaging studies have shown that a mirror mechanism is also present in humans. According to its anatomical locations, mirror mechanism plays a role in action and intention understanding, imitation, speech, and emotion feeling.

  2. Tandem Mirror Reactor Systems Code (Version I)

    Energy Technology Data Exchange (ETDEWEB)

    Reid, R.L.; Finn, P.A.; Gohar, M.Y.; Barrett, R.J.; Gorker, G.E.; Spampinaton, P.T.; Bulmer, R.H.; Dorn, D.W.; Perkins, L.J.; Ghose, S.

    1985-09-01

    A computer code was developed to model a Tandem Mirror Reactor. Ths is the first Tandem Mirror Reactor model to couple, in detail, the highly linked physics, magnetics, and neutronic analysis into a single code. This report describes the code architecture, provides a summary description of the modules comprising the code, and includes an example execution of the Tandem Mirror Reactor Systems Code. Results from this code for two sensitivity studies are also included. These studies are: (1) to determine the impact of center cell plasma radius, length, and ion temperature on reactor cost and performance at constant fusion power; and (2) to determine the impact of reactor power level on cost.

  3. Knowledge data base system for twins study.

    Science.gov (United States)

    Reina, S; Miozza, F

    1994-01-01

    The medical research on twins, carried out at the Gregor Mendel Institute for Medical Genetics and Twin Study in Rome over the past four decades, has resulted in a vast collection of clinical paper records. A challenge was presented by the need for a more secure method of storage to preserve this enormously valuable historical and scientific patrimony and to render its contents more easily accessible for research purposes. We met the challenge by planning and developing the computerization of this material. New concepts, currently being explored in biomedical informatics, were applied to build a Knowledge Data Base System, using a fourth-generation language (SQL). This architecturally innovative computer system enables its users to manipulate data supplied, rather than just simply storing it. Based on heuristic relational criteria between variables and parameters, the system is employed to solve problems of sibling design analysis typically arising from twins' records, but is also equipped to meet future data base requirements. Another feature of the system is its users' ability to pull off data in the form of regular automated reports, which are distributed through a Local Area Network (LAN). Through a Bulletin Board System (BBS) and modem, any scientist (outside as well as within the Institute) is thus able to access data and exchange scientific information.

  4. Long Focal Length Large Mirror Fabrication System

    Science.gov (United States)

    Bennett, H. E.

    2003-01-01

    The goals of this ambitious program are (1) to develop systems to make large superpolished optical mirrors, (2) to develop low scatter polishing techniques using centrifugal elutriation, (3) to develop a means of measuring scatter at any point on the mirror, (4) to polish a Hindle sphere to measure the optical figure of a one meter diameter convex mandrel, and (5) to fabricate low scatter, large adaptive optic graphite filled, cyanate ester replica transfer mirrors using these mandrels. Deliverables are a 30 cm diameter superpolished composite AO mirror. We fabricated a 1/3rd meter superpolished zerodur flat mandrel and with the support of our major subcontractor, Composite Mirror Applications Inc (CMA) we have demonstrated a 30 cm lightweight cyanate ester mirror with an rms microroughness between 0.6 and 0.8 nm and 8 faceplate influence function of 5 cm. The influence function was chosen to be comparable to the atmospheric correlation coefficient r(sub 0) which is about 5 cm at sea level. There was no print-thru of the graphite fibers in the cyanate ester surface (the bane of many previous efforts to use cyanate ester mirrors). Our subcontractor has devised a means for developing a 30-50 nm thick layer of graphite free pure ester resin on the surface of the mirrors. This graphite fiber filled material has a thermal expansion coefficient in the 10(exp -8) centimeter per Kelvin range (the same range of expansion coefficient as Zerodur and ULE glasses) and does not take up water and swell, so it is a nearly ideal mirror material in these areas. Unfortunately for these 0.8mm thick faceplates, the number of plies is not enough to result in isometric coverage. Isolated figure irregularities can appear, making it necessary to go to thicker faceplates. The influence function will then only approximate the length of r(sub 0), at higher altitudes or longer wavelengths. The influence function goes as the cube of the thickness, so we are now making a faceplate optimized for

  5. Mirroring

    DEFF Research Database (Denmark)

    Wegener, Gregers

    2016-01-01

    and metaphorical value of mirroring for creativity theory across two different research fields — neuroscience and learning. We engage in a mutual (possibly creative) exploration of mirroring from ‘mirror neurons’ to mirroring in social learning theory. One of the most fascinating aspects of mirroring......Most definitions of creativity emphasise originality. The creative product is recognised as distinct from other products and the creative person as someone who stands out from the crowd. What tend to be overlooked are acts of mirroring as a crucial element of the creative process. The human ability...... to empathise and socialise is partly due to another, more fundamental ability to duplicate the stance of the other (see also Chapter 13). Through mirroring, we attune to other people and thus create resonance and preparedness for mutual creative exploration. In this chapter, we investigate the object...

  6. Four-mirror extreme ultraviolet (EUV) lithography projection system

    Science.gov (United States)

    Cohen, Simon J; Jeong, Hwan J; Shafer, David R

    2000-01-01

    The invention is directed to a four-mirror catoptric projection system for extreme ultraviolet (EUV) lithography to transfer a pattern from a reflective reticle to a wafer substrate. In order along the light path followed by light from the reticle to the wafer substrate, the system includes a dominantly hyperbolic convex mirror, a dominantly elliptical concave mirror, spherical convex mirror, and spherical concave mirror. The reticle and wafer substrate are positioned along the system's optical axis on opposite sides of the mirrors. The hyperbolic and elliptical mirrors are positioned on the same side of the system's optical axis as the reticle, and are relatively large in diameter as they are positioned on the high magnification side of the system. The hyperbolic and elliptical mirrors are relatively far off the optical axis and hence they have significant aspherical components in their curvatures. The convex spherical mirror is positioned on the optical axis, and has a substantially or perfectly spherical shape. The spherical concave mirror is positioned substantially on the opposite side of the optical axis from the hyperbolic and elliptical mirrors. Because it is positioned off-axis to a degree, the spherical concave mirror has some asphericity to counter aberrations. The spherical concave mirror forms a relatively large, uniform field on the wafer substrate. The mirrors can be tilted or decentered slightly to achieve further increase in the field size.

  7. Active Beam Shaping System and Method Using Sequential Deformable Mirrors

    Science.gov (United States)

    Norman, Colin A. (Inventor); Pueyo, Laurent A. (Inventor)

    2015-01-01

    An active optical beam shaping system includes a first deformable mirror arranged to at least partially intercept an entrance beam of light and to provide a first reflected beam of light, a second deformable mirror arranged to at least partially intercept the first reflected beam of light from the first deformable mirror and to provide a second reflected beam of light, and a signal processing and control system configured to communicate with the first and second deformable mirrors. The first deformable mirror, the second deformable mirror and the signal processing and control system together provide a large amplitude light modulation range to provide an actively shaped optical beam.

  8. The Mirror Neuron System: A Fresh View

    Science.gov (United States)

    Casile, Antonino; Caggiano, Vittorio; Ferrari, Pier Francesco

    2013-01-01

    Mirror neurons are a class of visuomotor neurons in the monkey premotor and parietal cortices that discharge during the execution and observation of goal-directed motor acts. They are deemed to be at the basis of primates’ social abilities. In this review, the authors provide a fresh view about two still open questions about mirror neurons. The first question is their possible functional role. By reviewing recent neurophysiological data, the authors suggest that mirror neurons might represent a flexible system that encodes observed actions in terms of several behaviorally relevant features. The second question concerns the possible developmental mechanisms responsible for their initial emergence. To provide a possible answer to question, the authors review two different aspects of sensorimotor development: facial and hand movements, respectively. The authors suggest that possibly two different “mirror” systems might underlie the development of action understanding and imitative abilities in the two cases. More specifically, a possibly prewired system already present at birth but shaped by the social environment might underlie the early development of facial imitative abilities. On the contrary, an experience-dependent system might subserve perception-action couplings in the case of hand movements. The development of this latter system might be critically dependent on the observation of own movements. PMID:21467305

  9. Culture systems: embryo culture and monozygotic twinning.

    Science.gov (United States)

    Sparks, Amy E

    2012-01-01

    The incidence of monozygotic twinning in pregnancies achieved with assisted reproductive technologies (ART) is significantly higher than spontaneously conceived pregnancies. The factors associated with ART that predispose the embryos to splitting are not well-characterized. Assisted hatching and extended embryo culture are two ART laboratory methods that have been risk factors for monozygotic twinning. The methods and strategies that may be employed to avoid monozygotic twinning are discussed in this chapter.

  10. Human mirror neuron system and its plasticity

    Institute of Scientific and Technical Information of China (English)

    Wei Chen; Tifei Yuan; Yin Wang; Jun Ding

    2008-01-01

    The mirror neuron system (MNS) was first discovered in non-human primates; these neurons fire when a monkey performs an action or observes another monkey (or even some people) performing that same action. Recent findings have suggested that neural rehabilitation might be achieved through the activation of the MNS in patients after stroke. We propose two major mechanisms (one involving adult neurogenesis and another involving brain-derived neurotrophic factor) that may underlie the activation, modulation and expe-rience-dependent plasticity in the MNS, for further study on promoting central nerve functional reconstruc-tion and rehabilitation of patients with central nervous system injury.

  11. Integration of Mirror Design with Suspension System using NASA's New Mirror Modeling Software

    Science.gov (United States)

    Arnold,William R., Sr.; Bevan, Ryan M.; Stahl, Philip

    2013-01-01

    Advances in mirror fabrication are making very large space based telescopes possible. In many applications, only monolithic mirrors can meet the performance requirements. The existing and near-term planned heavy launch vehicles place a premium on lowest possible mass, and then available payload shroud sizes limit near term designs to 4 meter class mirrors. Practical 8 meter class and beyond designs could encourage planners to include larger shrouds, if it can be proven that such mirrors can be manufactured. These two factors, lower mass and larger mirrors, present the classic optimization problem. There is a practical upper limit to how large of a mirror can be supported by a purely kinematic mount system handling both operational and launch loads. This paper shows how the suspension system and mirror blank need to be designed simultaneously. We will also explore the concepts of auxiliary support systems which act only during launch and disengage on orbit. We will define required characteristics of these systems and show how they can substantially reduce the mirror mass.

  12. Charge density wave order in 1D mirror twin boundaries of single-layer MoSe2

    Science.gov (United States)

    Barja, Sara; Wickenburg, Sebastian; Liu, Zhen-Fei; Zhang, Yi; Ryu, Hyejin; Ugeda, Miguel M.; Hussain, Zahid; Shen, Zhi-Xun; Mo, Sung-Kwan; Wong, Ed; Salmeron, Miquel B.; Wang, Feng; Crommie, Michael F.; Ogletree, D. Frank; Neaton, Jeffrey B.; Weber-Bargioni, Alexander

    2016-08-01

    We provide direct evidence for the existence of isolated, one-dimensional charge density waves at mirror twin boundaries (MTBs) of single-layer semiconducting MoSe2. Such MTBs have been previously observed by transmission electron microscopy and have been predicted to be metallic in MoSe2 and MoS2. Our low-temperature scanning tunnelling microscopy/spectroscopy measurements revealed a substantial bandgap of 100 meV opening at the Fermi energy in the otherwise metallic one-dimensional structures. We found a periodic modulation in the density of states along the MTB, with a wavelength of approximately three lattice constants. In addition to mapping the energy-dependent density of states, we determined the atomic structure and bonding of the MTB through simultaneous high-resolution non-contact atomic force microscopy. Density functional theory calculations based on the observed structure reproduced both the gap opening and the spatially resolved density of states.

  13. Speckle reduction in laser picoprojector by combining optical phase matrix with twin green lasers and oscillating MEMS mirror for coherence suppression

    Science.gov (United States)

    Lee, Jae-Yong; Kim, Tae-Ha; Yim, BooBin; Bu, Jong-Uk; Kim, Young-Joo

    2016-08-01

    The combined speckle reduction method is proposed and designed for laser picoprojectors taking small size, high optical power, and good image preservation into account. An optical phase matrix, twin green lasers, and an oscillating MEMS scanning mirror are used to suppress the speckle by reducing spatial and temporal coherences. The optical phase matrix is designed using a 5 µm pixel pitch based on Matlab simulation results and fabricated by imprinting. The twin green lasers with a modulation configuration and an oscillating MEMS scanning mirror are also applied taking the resolution of the display image and the scanning frequency of the MEMS scanning mirror into account. From the experimental results, it is confirmed that the speckle contrast is reduced by 47.47% by the optical phase matrix, 27.93% by the twin green lasers, and 18.89% by the oscillating MEMS scanning mirror. Finally, the combined speckle contrast results in a speckle reduction efficiency of 53.80% with a relatively small optical power loss of 18.21%.

  14. System Estimates Radius of Curvature of a Segmented Mirror

    Science.gov (United States)

    Rakoczy, John

    2008-01-01

    A system that estimates the global radius of curvature (GRoC) of a segmented telescope mirror has been developed for use as one of the subsystems of a larger system that exerts precise control over the displacements of the mirror segments. This GRoC-estimating system, when integrated into the overall control system along with a mirror-segment- actuation subsystem and edge sensors (sensors that measure displacements at selected points on the edges of the segments), makes it possible to control the GROC mirror-deformation mode, to which mode contemporary edge sensors are insufficiently sensitive. This system thus makes it possible to control the GRoC of the mirror with sufficient precision to obtain the best possible image quality and/or to impose a required wavefront correction on incoming or outgoing light. In its mathematical aspect, the system utilizes all the information available from the edge-sensor subsystem in a unique manner that yields estimates of all the states of the segmented mirror. The system does this by exploiting a special set of mirror boundary conditions and mirror influence functions in such a way as to sense displacements in degrees of freedom that would otherwise be unobservable by means of an edge-sensor subsystem, all without need to augment the edge-sensor system with additional metrological hardware. Moreover, the accuracy of the estimates increases with the number of mirror segments.

  15. Mirror system based therapy for autism spectrum disorders

    Institute of Scientific and Technical Information of China (English)

    Wei CHEN; Jing ZHANG; Jun DING

    2008-01-01

    This paper reviews the present theories and empirical research of autisms' cognitive research and mir-ror systems and introduces a new hypothesis about the causes of autism spectrum disorders (ASD): autistic mir-ror neuron dysfunction hypothesis. ASD subjects show obvious lack of the activation of the mirror system during the task of observation or emotional cognition. It is sig-nificant to investigate the mirror system for revealing the causes of autism and it is also helpful for developing new ways to diagnose or treat this disorder.

  16. Language comprehension warps the mirror neuron system.

    Science.gov (United States)

    Zarr, Noah; Ferguson, Ryan; Glenberg, Arthur M

    2013-01-01

    Is the mirror neuron system (MNS) used in language understanding? According to embodied accounts of language comprehension, understanding sentences describing actions makes use of neural mechanisms of action control, including the MNS. Consequently, repeatedly comprehending sentences describing similar actions should induce adaptation of the MNS thereby warping its use in other cognitive processes such as action recognition and prediction. To test this prediction, participants read blocks of multiple sentences where each sentence in the block described transfer of objects in a direction away or toward the reader. Following each block, adaptation was measured by having participants predict the end-point of videotaped actions. The adapting sentences disrupted prediction of actions in the same direction, but (a) only for videos of biological motion, and (b) only when the effector implied by the language (e.g., the hand) matched the videos. These findings are signatures of the MNS.

  17. The Mirror Neuron System and Action Recognition

    Science.gov (United States)

    Buccino, Giovanni; Binkofski, Ferdinand; Riggio, Lucia

    2004-01-01

    Mirror neurons, first described in the rostral part of monkey ventral premotor cortex (area F5), discharge both when the animal performs a goal-directed hand action and when it observes another individual performing the same or a similar action. More recently, in the same area mirror neurons responding to the observation of mouth actions have been…

  18. The Mirror Neuron System and Action Recognition

    Science.gov (United States)

    Buccino, Giovanni; Binkofski, Ferdinand; Riggio, Lucia

    2004-01-01

    Mirror neurons, first described in the rostral part of monkey ventral premotor cortex (area F5), discharge both when the animal performs a goal-directed hand action and when it observes another individual performing the same or a similar action. More recently, in the same area mirror neurons responding to the observation of mouth actions have been…

  19. Robotic Mirror Therapy System for Functional Recovery of Hemiplegic Arms.

    Science.gov (United States)

    Beom, Jaewon; Koh, Sukgyu; Nam, Hyung Seok; Kim, Wonshik; Kim, Yoonjae; Seo, Han Gil; Oh, Byung-Mo; Chung, Sun Gun; Kim, Sungwan

    2016-08-15

    Mirror therapy has been performed as effective occupational therapy in a clinical setting for functional recovery of a hemiplegic arm after stroke. It is conducted by eliciting an illusion through use of a mirror as if the hemiplegic arm is moving in real-time while moving the healthy arm. It can facilitate brain neuroplasticity through activation of the sensorimotor cortex. However, conventional mirror therapy has a critical limitation in that the hemiplegic arm is not actually moving. Thus, we developed a real-time 2-axis mirror robot system as a simple add-on module for conventional mirror therapy using a closed feedback mechanism, which enables real-time movement of the hemiplegic arm. We used 3 Attitude and Heading Reference System sensors, 2 brushless DC motors for elbow and wrist joints, and exoskeletal frames. In a feasibility study on 6 healthy subjects, robotic mirror therapy was safe and feasible. We further selected tasks useful for activities of daily living training through feedback from rehabilitation doctors. A chronic stroke patient showed improvement in the Fugl-Meyer assessment scale and elbow flexor spasticity after a 2-week application of the mirror robot system. Robotic mirror therapy may enhance proprioceptive input to the sensory cortex, which is considered to be important in neuroplasticity and functional recovery of hemiplegic arms. The mirror robot system presented herein can be easily developed and utilized effectively to advance occupational therapy.

  20. Closed-loop adaptive optical system with a liquid mirror.

    Science.gov (United States)

    Vdovin, Gleb

    2009-02-15

    A deformable mirror based on internal reflection from an electrostatically deformable liquid-air interface is proposed and investigated. A differential equation describing the static behavior of such a mirror is analyzed and solved numerically. Stable closed-loop operation of an adaptive optical system with a liquid deformable mirror is demonstrated, including forming and the correction of low-order aberrations described by Zernike polynomials and the real-time correction of dynamically changing aberrations.

  1. Adaptive optics ophthalmologic systems using dual deformable mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Jones, S; Olivier, S; Chen, D; Sadda, S; Joeres, S; Zawadzki, R; Werner, J S; Miller, D

    2007-02-01

    Adaptive Optics (AO) have been increasingly combined with a variety of ophthalmic instruments over the last decade to provide cellular-level, in-vivo images of the eye. The use of MEMS deformable mirrors in these instruments has recently been demonstrated to reduce system size and cost while improving performance. However, currently available MEMS mirrors lack the required range of motion for correcting large ocular aberrations, such as defocus and astigmatism. In order to address this problem, we have developed an AO system architecture that uses two deformable mirrors, in a woofer/tweeter arrangement, with a bimorph mirror as the woofer and a MEMS mirror as the tweeter. This setup provides several advantages, including extended aberration correction range, due to the large stroke of the bimorph mirror, high order aberration correction using the MEMS mirror, and additionally, the ability to ''focus'' through the retina. This AO system architecture is currently being used in four instruments, including an Optical Coherence Tomography (OCT) system and a retinal flood-illuminated imaging system at the UC Davis Medical Center, a Scanning Laser Ophthalmoscope (SLO) at the Doheny Eye Institute, and an OCT system at Indiana University. The design, operation and evaluation of this type of AO system architecture will be presented.

  2. [Mirror neuron system dysfunction in schizophrenia and its clinical implication].

    Science.gov (United States)

    Kato, Motoichiro; Kato, Yutaka

    2014-06-01

    Since the discovery of mirror neuron system, several neurophysiological and neuroimaging studies showed that the mirror neuron system might have a role in understanding other people's actions and intentions with automatic simulation of their actions. Moreover, some studies suggested that mirror neurons have a broader role in social cognition including understanding others' emotions and empathy. It has not been proved, however, whether the mirror neuron system is necessarily involved in empathy processes. In the domain of social cognition deficits, it is important to investigate the involvement of mirror neuron system dysfunction in psychosis such as schizophrenia. Using magnetoencephalography, we examined whether antipsychotic-free schizophrenia patients displayed mirror neuron system dysfunction during observation of biological motion (jaw movement). Compared with normal controls, the patients with schizophrenia had fewer components of both the waveform and equivalent current dipole, suggesting aberrant brain activity resulting from dysfunction of the right inferior parietal cortex. They also lacked the changes of alpha band and gamma band oscillation seen in normal controls, and had weaker phase locking factors and gamma-synchronization predominantly in right parietal cortex. This finding demonstrated that untreated patients with schizophrenia exhibited aberrant mirror neuron system function based on the right inferior parietal cortex, which is characterized by dysfunction of gamma-synchronization.

  3. Calibration of a catadioptric omnidirectional vision system with conic mirror

    Science.gov (United States)

    Marcato Junior, J.; Tommaselli, A. M. G.; Moraes, M. V. A.

    2016-03-01

    Omnidirectional vision systems that enable 360° imaging have been widely used in several research areas, including close-range photogrammetry, which allows the accurate 3D measurement of objects. To achieve accurate results in Photogrammetric applications, it is necessary to model and calibrate these systems. The major contribution of this paper relates to the rigorous geometric modeling and calibration of a catadioptric, omnidirectional vision system that is composed of a wide-angle lens camera and a conic mirror. The indirect orientation of the omnidirectional images can also be estimated using this rigorous mathematical model. When calibrating the system, which is composed of a wide-angle camera and a conic mirror, misalignment of the conical mirror axis with respect to the camera's optical axis is a critical problem that must be considered in mathematical models. The interior calibration technique developed in this paper encompasses the following steps: wide-angle camera calibration; conic mirror modeling; and estimation of the transformation parameters between the camera and conic mirror reference systems. The main advantage of the developed technique is that it does not require accurate physical alignment between the camera and conic mirror axis. The exterior orientation is based on the properties of the conic mirror reflection. Experiments were conducted with images collected from a calibration field, and the results verified that the catadioptric omnidirectional system allows for the generation of ground coordinates with high geometric quality, provided that rigorous photogrammetric processes are applied.

  4. Smart co-phasing system for segmented mirror telescopes

    Science.gov (United States)

    Simar, Juan F.; Stockman, Yvan; Surdej, Jean

    2016-07-01

    Space observations of fainter and more distant astronomical objects constantly require telescope primary mirrors with a larger size. The diameter of monolithic primary mirrors is limited to 10 m because of manufacturing and logistics limitations. For space telescopes, monolithic primary mirrors are limited to less than 5 m due to fairing capacity. Segmented primary mirrors thus constitute an alternative solution to deal with the steadily increase of the primary mirror size. The optical path difference between the individual segments must be close to zero (few nm) in order to be diffraction limited over the full telescope aperture. In this paper a new system that may co-phase 7 segments at once with the light of a star and without artificial one is proposed. First the measuring methods and feedback system is explained, then the breadboard setup is presented and the results are analyzed and discussed, finally a comparison with Keck telescope is performed. This system can be adapted in order to be used in the co-phasing system of future segmented mirrors, its dynamic range starts from several hundred of microns till some tenths of nanometers

  5. Twin Cities care system assessment: process, findings, and recommendations.

    Science.gov (United States)

    Othieno, Joan

    2007-08-01

    The Twin Cities Care system lacks services that are most needed in the later stages of HIV disease. Services in highest demand included housing, transportation, and translation; available translations services are generally limited to Somali, Oromo, and Amharic, the languages most widely spoken by the three largest African immigrant and refugee groups in the Twin Cities. The care system is not well-integrated, and most of the work of moving clients within the system is done by case managers and care advocates. The main technical competencies identified by providers as lacking are understanding mental health from the perspective of African-born people living with HIV/AIDS (PLWH) and addressing sexual issues, especially with women. African providers with foreign certifications not recognized in the United States are not able to use their professional skills. African clients are not well-informed about HIV, and African women are more likely than men to seek and stay in care.

  6. Concordance of autoimmune disease in a nationwide Danish systemic lupus erythematosus twin cohort

    DEFF Research Database (Denmark)

    Ulff-Møller, Constance Jensina; Svendsen, Anders Jørgen; Viemose, Louise Nørgaard

    2017-01-01

    OBJECTIVE: To determine the concordance of systemic lupus erythematosus (SLE) and co-aggregating autoimmune diseases among Danish twins. METHODS: SLE-affected twins were ascertained by record linkage between the National Patient Register (NPR) and the Danish Twin Registry (DTR). Registered SLE co...

  7. The mirror-neuron system: a Bayesian perspective

    DEFF Research Database (Denmark)

    Kilner, James; Friston, Karl; Frith, Christopher

    2007-01-01

    Is it possible to understand the intentions of other peopleby simply observing their movements? Many neuroscientists believe that this ability depends on the brain’s mirror-neuron system, which provides a direct link between action and observation. Precisely how intentions can be inferred through...... movement-observation, however, has provoked much debate. One problem in inferring the cause of an observed action, is that the problem is ill-posed because identical movements can be made when performing different actions with different goals. Here we suggest that this problem is solved by the mirror-neuron...... identifies a precise role for the mirror-neuron system in our ability to infer intentions from observed movement and outlines possible computational mechanisms....

  8. The Kinetic Stabilizer: A Route to Simpler Tandem Mirror Systems?

    Energy Technology Data Exchange (ETDEWEB)

    Post, R

    2001-05-30

    This paper discusses a new approach to an MHD stabilizing technique for magnetic fusion systems of the axisymmetric ''open-ended'' variety. The concept is adaptable to tandem-mirror systems and would result in a major simplification of such systems, accompanied by a substantial improvement in their confinement characteristics, The paper first discusses the present impetus to find a simpler and less expensive route to fusion than that offered by the mainline approach, the tokamak. The history of magnetic fusion research shows that closed and open systems exhibit very different confinement characteristics. Closed systems, such as the tokamak, the stellarator, or the reversed-field pinch have cross-field transport that is dominated by plasma turbulence. By contrast, there are examples of open-systems where turbulence, if present at all, was at such low levels that the transport agreed with ''classical'' predictions. The clearest examples are ones in which the field geometry was axiymmetric. However axisymmetric mirror systems are subject to MHD instability. Thus in the years following the famous Ioffe experiment, most open systems have employed asymmetric magnetic fields, with attendant problems of complexity and enhanced cross-field transport. This paper proposes a new means of stabilizing axisymmetric mirror-based systems. The idea, called the ''Kinetic Stabilizer'' has roots in experiments performed with the axisymmetric Gas Dynamic Trap at Novosibirsk. In these experiments, performed in a high collisionality plasma regime, it was shown that the presence of the effluent plasma in the positive-curvature expanding-field region outside the mirrors was effective in stabilizing a high-beta (30 percent) confined plasma against MHD modes. In the plasmas of tandem-mirror systems the density of the effluent plasma is too low to employ this method of stabilization. The Kinetic Stabilizer solves this problem by using

  9. The simplest possible design for a KB microfocus mirror system?

    Energy Technology Data Exchange (ETDEWEB)

    Collins, S. P., E-mail: steve.collins@diamond.ac.uk; Scott, S. M.; Hawkins, D. M.; Fabrizi, F.; Moser, B.; Nisbet, G.; Sutter, J. P. [Diamond Light Source, Harwell Science & Innovation Campus, Didcot, OX11 0DE (United Kingdom); Harwin, R. C. [Diamond Light Source, Harwell Science & Innovation Campus, Didcot, OX11 0DE (United Kingdom); Department of Physics, Cavendish Laboratory, JJ Thomson Avenue, Cambridge, CB3 0HE (United Kingdom); Harwin, W. S. [School of Systems Engineering, University of Reading, Whiteknights, Reading, Berkshire, RG6 6AH (United Kingdom)

    2016-07-27

    We report a design for a Kirkpatrick-Baez (KB) microfocussing mirror system. The main components are described, with emphasis on a ‘tripod’ manipulator, where we outline the required coordinate transformation calculations. The merit of this device lies in its simplicity of design, minimal degrees of freedom, and speed and ease of setup on a beamline. Test results and an example of the mirrors in use on Diamond Beamline I16, showing a high-resolution polar domain map of KTiOPO{sub 4} with a spot size of 1.25 µm × 1.5 µm, are presented.

  10. Extending the mirror neuron system model, II: what did I just do? A new role for mirror neurons.

    Science.gov (United States)

    Bonaiuto, James; Arbib, Michael A

    2010-04-01

    A mirror system is active both when an animal executes a class of actions (self-actions) and when it sees another execute an action of that class. Much attention has been given to the possible roles of mirror systems in responding to the actions of others but there has been little attention paid to their role in self-actions. In the companion article (Bonaiuto et al. Biol Cybern 96:9-38, 2007) we presented MNS2, an extension of the Mirror Neuron System model of the monkey mirror system trained to recognize the external appearance of its own actions as a basis for recognizing the actions of other animals when they perform similar actions. Here we further extend the study of the mirror system by introducing the novel hypotheses that a mirror system may additionally help in monitoring the success of a self-action and may also be activated by recognition of one's own apparent actions as well as efference copy from one's intended actions. The framework for this computational demonstration is a model of action sequencing, called augmented competitive queuing, in which action choice is based on the desirability of executable actions. We show how this "what did I just do?" function of mirror neurons can contribute to the learning of both executability and desirability which in certain cases supports rapid reorganization of motor programs in the face of disruptions.

  11. Optical systems for synchrotron radiation. Lecture 2. Mirror systems

    Energy Technology Data Exchange (ETDEWEB)

    Howells, M.R.

    1986-02-01

    The process of reflection of VUV and x-radiation is summarized. The functions of mirrors in synchrotron beamlines are described, which include deflection, filtration, power absorption, formation of a real image, focusing, and collimation. Fabrication of optical surfaces for synchrotron radiation beamlines are described, and include polishing of a near spherical surface as well as bending a cylindrical surface to toroidal shape. The imperfections present in mirrors, aberrations and surface figure inaccuracy, are discussed. Calculation of the thermal load of a mirror in a synchrotron radiation beam and the cooling of the mirror are covered briefly. 50 refs., 7 figs. (LEW)

  12. On Empathy: The Mirror Neuron System and Art Education

    Science.gov (United States)

    Jeffers, Carol S.

    2009-01-01

    This paper re/considers empathy and its implications for learning in the art classroom, particularly in light of relevant neuroscientific investigations of the mirror neuron system recently discovered in the human brain. These investigations reinterpret the meaning of perception, resonance, and connection, and point to the fundamental importance…

  13. The Mirror Neuron System: Grasping Others' Actions from Birth?

    Science.gov (United States)

    Lepage, Jean-Francois; Theoret, Hugo

    2007-01-01

    In the adult human brain, the presence of a system matching the observation and the execution of actions is well established. This mechanism is thought to rely primarily on the contribution of so-called "mirror neurons", cells that are active when a specific gesture is executed as well as when it is seen or heard. Despite the wealth of evidence…

  14. Acting together in and beyond the mirror neuron system

    NARCIS (Netherlands)

    Kokal, Idil; Gazzola, Valeria; Keysers, Christian

    2009-01-01

    Moving a set dinner table often takes two people, and doing so without spilling the glasses requires the close coordination of the two agents' actions. It has been argued that the mirror neuron system may be the key neural locus of such coordination. Instead, here we show that such coordination recr

  15. Mirror Fusion Test Facility: Superconducting magnet system cost analysis

    Energy Technology Data Exchange (ETDEWEB)

    1977-07-01

    At the request of Victor Karpenko, Project manager for LLL`s Mirror Fusion Test Facility, EG&G has prepared this independent cost analysis for the proposed MFTF Superconducting Magnet System. The analysis has attempted to show sufficient detail to provide adequate definition for a basis of estimating costs.

  16. The Mirror Neuron System: Grasping Others' Actions from Birth?

    Science.gov (United States)

    Lepage, Jean-Francois; Theoret, Hugo

    2007-01-01

    In the adult human brain, the presence of a system matching the observation and the execution of actions is well established. This mechanism is thought to rely primarily on the contribution of so-called "mirror neurons", cells that are active when a specific gesture is executed as well as when it is seen or heard. Despite the wealth of evidence…

  17. Empathy and the somatotopic auditory mirror system in humans

    NARCIS (Netherlands)

    Gazzola, Valeria; Aziz-Zadeh, Lisa; Keysers, Christian

    2006-01-01

    How do we understand the actions of other individuals if we can only hear them? Auditory mirror neurons respond both while monkeys perform hand or mouth actions and while they listen to sounds of similar actions [1, 2]. This system might be critical for auditory action understanding and language

  18. Linear decentralized systems with special structure. [for twin lift helicopters

    Science.gov (United States)

    Martin, C. F.

    1982-01-01

    Certain fundamental structures associated with linear systems having internal symmetries are outlined. It is shown that the theory of finite-dimensional algebras and their representations are closely related to such systems. It is also demonstrated that certain problems in the decentralized control of symmetric systems are equivalent to long-standing problems of linear systems theory. Even though the structure imposed arose in considering the problems of twin-lift helicopters, any large system composed of several identical intercoupled control systems can be modeled by a linear system that satisfies the constraints imposed. Internal symmetry can be exploited to yield new system-theoretic invariants and a better understanding of the way in which the underlying structure affects overall system performance.

  19. Transfiguration of extracting mirror in synchrotron radiation system at SSRF

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The first extracting mirror is very important for synchrotron radiation monitor (SRM). The SRM system of SSRF (Shanghai Synchrotron Radiation Facility) should extract the visible light with low optical distortion. The analysis of SR power spectrum and heat transfiguration based on Matlab is introduced in this paper, which will be used in calibration. One beryllium mirror with water-cooling is used to transmit X-ray and reflect visible light to satisfy the measurement request. The existing system suffers from a dynamic problem in some beam physics study. The system includes optics, image acquisition and interferometers. One of the instruments is a digital camera providing the image of the beam transverse profile. The hardware configuration will be summarized. The synchrotron radiation measurement system has been in operation in SSRF for more than one year.

  20. Design and Optimization of Thermophotovoltaic System Cavity with Mirrors

    Directory of Open Access Journals (Sweden)

    Tian Zhou

    2016-09-01

    Full Text Available Thermophotovoltaic (TPV systems can convert radiant energy into electrical power. Here we explore the design of the TPV system cavity, which houses the emitter and the photovoltaic (PV cells. Mirrors are utilized in the cavity to modify the spatial and spectral distribution within. After discussing the basic concentric tubular design, two novel cavity configurations are put forward and parametrically studied. The investigated variables include the shape, number, and placement of the mirrors. The optimization objectives are the optimized efficiency and the extended range of application of the TPV system. Through numerical simulations, the relationship between the design parameters and the objectives are revealed. The results show that careful design of the cavity configuration can markedly enhance the performance of the TPV system.

  1. Are mirror neurons the basis of speech perception? Evidence from five cases with damage to the purported human mirror system.

    Science.gov (United States)

    Rogalsky, Corianne; Love, Tracy; Driscoll, David; Anderson, Steven W; Hickok, Gregory

    2011-01-01

    The discovery of mirror neurons in macaque has led to a resurrection of motor theories of speech perception. Although the majority of lesion and functional imaging studies have associated perception with the temporal lobes, it has also been proposed that the 'human mirror system', which prominently includes Broca's area, is the neurophysiological substrate of speech perception. Although numerous studies have demonstrated a tight link between sensory and motor speech processes, few have directly assessed the critical prediction of mirror neuron theories of speech perception, namely that damage to the human mirror system should cause severe deficits in speech perception. The present study measured speech perception abilities of patients with lesions involving motor regions in the left posterior frontal lobe and/or inferior parietal lobule (i.e., the proposed human 'mirror system'). Performance was at or near ceiling in patients with fronto-parietal lesions. It is only when the lesion encroaches on auditory regions in the temporal lobe that perceptual deficits are evident. This suggests that 'mirror system' damage does not disrupt speech perception, but rather that auditory systems are the primary substrate for speech perception.

  2. Evaluating mirror alignment systems using the optical sensing matrix

    Energy Technology Data Exchange (ETDEWEB)

    Mantovani, M [Universita di Siena, INFN Pisa (Italy); Freise, A [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)], E-mail: mantovan@ego-gw.it

    2008-07-15

    The most sensitive gravitational-wave detectors today are based on large-scale laser interferometers whose optics are suspended from pendulums to decouple the instrument from seismic motion. Complex control systems are required to set and maintain the microscopic position of each mirror at a precisely defined value. Such control systems use the interferometer signals as input signals, and ideally it is designed such that the degrees of freedom (mirror positions) are well decoupled in the interferometer signals. However, this is not always feasible, in particular the mirror alignment control signals in interferometric gravitational wave detectors often show strong couplings between the different degrees of freedom. In this paper we will describe a simple and powerful method to quantify in advance the performances of an alignment control system by analyzing the optical matrix of the proposed read-out system. We will motivate the method using a Fabry-Perot cavity as an example, and we will further present results for the Virgo alignment system where this method was used to characterize and improve the alignment sensing scheme.

  3. Mirror Mapping of Laser Interferometer Measurement System on Ultra-precise Movement Stage

    Institute of Scientific and Technical Information of China (English)

    Zhou Yunfei; Yu Baocheng

    2006-01-01

    The accuracy and repeatability of the laser interferometer measurement system (LIMS) are often limited by the mirror surface error that comes from the mirror surface shape and distortion. This paper describes a new method to calibrate mirror map on ultraprecise movement stage (UPMS) with nanopositioning and to make a real-time compensation for the mirror surface error by using mirror map data tables with the software algorithm. Based on the mirror map test model, the factors affecting mirror map are analyzed through geometric method on the UPMS with six digrees of freedom. Data processing methods including spline interpolation and spline offsets are used to process the raw sampling data to build mirror map tables. The linear interpolation as compensation method to make a real-time correction on the stage mirror unflatness is adopted and the correction formulas are illuminated. In this way, the measurement accuracy of the system is obviously improved from 40 nm to 5 nm.

  4. Field Experience with 3-Sun Mirror Module Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fraas, Dr. Lewis [JX Crystals, Inc.; Avery, James E. [JX Crystals, Inc.; Huang, H, [JX Crystals, Inc.; Minkin, Leonid M [ORNL; Fraas, J. X. [JX Crystals, Inc.; Maxey, L Curt [ORNL; Gehl, Anthony C [ORNL

    2008-01-01

    JX Crystals 3-sun PV mirror modules have now been operating in four separate systems in the field for up to 2 years. Two post-mounted 2-axis tracking arrays of 12 modules each were installed at the Shanghai Flower Park in April of 2006. Then 672 modules were installed in a 100 kW array on N-S horizontal beam trackers at the Shanghai Flower Port in November of 2006. Finally, sets of 4 modules were installed on azimuth-tracking carousels on buildings at the Oak Ridge National Lab and at the U. of Nevada in Las Vegas in late 2007. All of these modules in each of these systems are still operating at their initial power ratings. No degradation in performance has been observed. The benefit of these 3-sun PV mirror modules is that they use 1/3 of the silicon single-crystal cell material in comparison to traditional planar modules. Since aluminum mirrors are much cheaper than high-purity single-crystal silicon-cells, these modules and systems should be much lower in cost when manufactured in high volume.

  5. The W. M. Keck Telescope segmented primary mirror active control system

    Energy Technology Data Exchange (ETDEWEB)

    Jared, R.C.; Arthur, A.A.; Andreae, S.; Biocca, A.; Cohen, R.W.; Fuertes, J.M.; Franck, J.; Gabor, G.; Llacer, J.; Mast, T.; Meng, J.; Merrick, T.; Minor, R.; Nelson, J.; Orayani, M.; Salz, P.; Schaefer, B.; Witebsky, C.

    1989-07-01

    The ten meter diameter primary mirror of the W. M. Keck Telescope is a mosaic of thirty-six hexagonal mirrors. An active control system stabilizes the primary mirror. The active control system uses 168 measurements of the relative positions of adjacent mirror segments and 3 measurements of the primary mirror position in the telescope structure to control the 108 degrees of freedom needed to stabilize the figure and position of the primary mirror. The components of the active control system are relative position sensors, electronics, computers, actuators that position the mirrors, and software. The software algorithms control the primary mirror, perform star image stacking, emulate the segments, store and fit calibration data, and locate hardware defects. We give an overview of the active control system, its functional requirements and test measurements. 12 refs.

  6. CFD Simulation of Twin Vertical Axis Tidal Turbines System

    Directory of Open Access Journals (Sweden)

    Syed Shah Khalid

    2013-01-01

    Full Text Available As concerns about rising fossil-fuel prices, energy security and climate-change increase, renewable energy can play a vital role in producing local, clean and inexhaustible energy to supply world rising demand for electricity. In this study, hydrodynamic analysis of vertical axis tidal turbine operating side-by-side is numerically analyzed. Two-dimensional numerical modeling of the unsteady flow through the blades of the turbine is performed using ANSYS CFX, hereafter CFX; this is based on a Reynolds-Averaged Navier-Stokes (RANS model. The purpose is to find an optimal distance between the turbines where interaction effect is minimal and constructive, where the turbines operate more efficiently than stand alone turbine. A transient simulation is done on Vertical Axis Tidal Turbine (VATT using the Shear Stress Transport Turbulence (SST model. Main hydrodynamic parameters like torque T, coefficients of performance CP and coefficient of torque CT are investigated. The gap spacing between the turbines has an important role in performance improvement and also in vortex shedding suppression for the flows around two counters rotating systems. The simulation results are validated with Ye and Calisal data. The results of this study prove that the total power output of a twin-turbine system with an optimal layout can be about 24% higher than two times that of a stand-alone turbine. We conclude that the optimally configured counter-rotating twin turbines should be a side-by-side arrangement.

  7. The hydrothermal system in central Twin Falls County, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, R.E.; Young, H.W.

    1989-01-01

    This report describes the results of a study to define the areal extent and thickness of the hydrothermal reservoir in Twin Falls County and to propose a generalized conceptual model of the system. Specific objectives of the study, done in cooperation with the Idaho Department of Water Resources, were to evaluate the existing resource as to its volume, temperature, pressure, and water chemistry, and to determine the effects of present development on the resource. The study was limited to Twin Falls County. Some geologic, geochemical, and hydrologic data for the hydrothermal system were available from earlier studies. However, information about the subsurface at depths greater than 1000 feet was sparse. One well for which data were available was drilled to 2525 feet; several others were drilled to depths between 1200 and 2200 feet. Direct-current electrical resistivity soundings conducted during the summer of 1985 as part of the study provided valuable information about the subsurface at depths less than about 6000 feet. Interpretation of computer-generated subsurface profiles constructed from the soundings provided the basis for determining the thickness of the Idavada Volcanics over much of the study area. 42 refs., 9 figs., 3 tabs.

  8. Tank waste information network system II (TWINS2) year 2000 compliance assurance plan

    Energy Technology Data Exchange (ETDEWEB)

    Adams, M.R.

    1998-04-16

    The scope of this plan includes the Tank Waste Information Network System II (TWINS2) that contains the following major components: Tank Characterization Database (TCD), Tank Vapor Database (TVD), Data Source Access (DSA), automated Tank Characterization Report, Best-Basis Inventory Model (BBIM), and Tracker (corrective action tracking) function. The automated Tank Characterization Report application currently in development also will reside on-the TWINS system as will the BBIM. Critical inputs to TWINS occur from the following databases: Labcore and SACS. Output does not occur from TWINS to these two databases.

  9. Stimulated Brillouin scattering mirror system, high power laser and laser peening method and system using same

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2007-04-24

    A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

  10. Deformation twinning in monazite

    Energy Technology Data Exchange (ETDEWEB)

    Hay, R.S.; Marshall, D.B

    2003-10-20

    Polycrystalline monazite (LaPO{sub 4}) was deformed at room temperature by a spherical indenter. Deformation twins were identified by TEM in 70 grains. Five twin planes were found: (100) was by far the most common; (001) and (120) were less common; (122-bar)was rare, and kinks in (120) twins were identified as irrational '(483)' twin planes. The twinning modes on these planes were inferred from the expression of twinning shear at free surfaces, predictions of classical deformation twinning theory, and various considerations of twin morphology and crystal structure. Atomic shuffle calculations that allow formation of either a glide plane or a mirror plane at the twin interface were used to analyze twin modes. The inferred twin modes all have small atomic shuffles. For (001) twins, the smallest shuffles were obtained with a glide plane at the interface, with displacement vector R=((1)/(2))[010]. The results do not uniquely define a twin mode on (100), leaving open the possibility of more than one mode operating on this plane. Factors that may determine the operative deformation twinning modes are discussed. Crystal structure considerations suggest that the relative abundance of twinning modes may correlate with low shear modulus on the twin plane in the direction of twinning shear, and with a possible low-energy interface structure consisting of a layer of xenotime of one half-unit-cell thickness that could form at (100) and (001) twins. The three most common twins have low strains to low {sigma} coincidence site lattices (CSLs)

  11. Mirror neuron system based therapy for emotional disorders.

    Science.gov (United States)

    Yuan, Ti-Fei; Hoff, Robert

    2008-11-01

    Mirror neuron system (MNS) represents one of the most important discoveries in the area of neuropsychology of past decades. More than 500 papers have been published in this area (PubMed), and the major functions of MNS include action understanding, imitation, empathy, all of which are critical for an individual to be social. Recent studies suggested that MNS can modulate emotion states possibly through the empathy mechanism. Here we propose that MNS-based therapies provide a non-invasive approach in treatments to emotional disorders that were observed in autism patients, post-stroke patients with depression as well as other mood dysregulation conditions.

  12. Toward high-dynamic active mirrors for LGS refocusing systems

    Science.gov (United States)

    Hugot, Emmanuel; Madec, Fabrice; Vives, Sébastien; Ferrari, Marc; Le Mignant, David; Cuby, Jean Gabriel

    2010-07-01

    In the frame of the E-ELT-EAGLE instrument phase A studies, we designed a convex VCM able to compensate for the focus variation on the Laser Guide Star (LGS) wavefront sensor, due to the elevation of the telescope and the fixed sodium layer altitude. We present an original optical design including this active convex mirror, providing a large sag variation on a spherical surface with a 120mm clear aperture, with an optical quality better than lambda/5 RMS up to 820μm of sag and better than lambda/4 RMS up to 1000μm of sag. Finite element analysis (FEA) allowed an optimisation of the mirror's variable thickness distribution to compensate for geometrical and material non linearity. Preliminary study of the pre-stressing has also been performed by FEA, showing that a permanent deformation remains after removal of the loads. Results and comparison with the FEA are presented in the article of F.Madec et al (AS10-7736-119, this conference), with an emphasis on the system approach.

  13. Minimization of the Ohmic Loss of Grooved Polarizer Mirrors in High-Power ECRH Systems

    Science.gov (United States)

    Wagner, D.; Leuterer, F.; Kasparek, W.; Stober, J.

    2016-10-01

    A set of two corrugated polarizer mirrors is typically used in high-power electron cyclotron resonance heating (ECRH) systems to provide the required polarization of the ECRH output beam. The ohmic losses of these mirrors can significantly exceed the losses of plane mirrors depending on the polarization of the incident beam with respect to the orientation of the grooves. Since polarizer mirrors incorporated into miter bends of a corrugated waveguide line are limited in size, active water cooling can become critical in high-power cw systems like the one for ITER. The ohmic loss of polarizer mirrors has been investigated experimentally at high power. A strategy to minimize the losses for given mirror geometries has been found.

  14. Minimization of the Ohmic Loss of Grooved Polarizer Mirrors in High-Power ECRH Systems

    Science.gov (United States)

    Wagner, D.; Leuterer, F.; Kasparek, W.; Stober, J.

    2017-02-01

    A set of two corrugated polarizer mirrors is typically used in high-power electron cyclotron resonance heating (ECRH) systems to provide the required polarization of the ECRH output beam. The ohmic losses of these mirrors can significantly exceed the losses of plane mirrors depending on the polarization of the incident beam with respect to the orientation of the grooves. Since polarizer mirrors incorporated into miter bends of a corrugated waveguide line are limited in size, active water cooling can become critical in high-power cw systems like the one for ITER. The ohmic loss of polarizer mirrors has been investigated experimentally at high power. A strategy to minimize the losses for given mirror geometries has been found.

  15. Entangling movable mirrors in a double cavity system

    DEFF Research Database (Denmark)

    Pinard, Michel; Dantan, Aurelien Romain; Vitali, David

    2005-01-01

    We propose a double-cavity set-up capable of generating a stationary entangled state of two movable mirrors at cryogenic temperatures. The scheme is based on the optimal transfer of squeezing of input optical fields to mechanical vibrational modes of the mirrors, realized by the radiation pressure...

  16. The mirror neuron system in post-stroke rehabilitation

    Science.gov (United States)

    2013-01-01

    Different treatments for stroke patients have been proposed; among them the mirror therapy and motion imagery lead to functional recovery by providing a cortical reorganization. Up today the basic concepts of the current literature on mirror neurons and the major findings regarding the use of mirror therapy and motor imagery as potential tools to promote reorganization and functional recovery in post-stroke patients. Bibliographic research was conducted based on publications over the past thirteen years written in English in the databases Scielo, Pubmed/MEDLINE, ISI Web of Knowledge. The studies showed how the interaction among vision, proprioception and motor commands promotes the recruitment of mirror neurons, thus providing cortical reorganization and functional recovery of post-stroke patients. We conclude that the experimental advances on Mirror Neurons will bring new rational therapeutic approaches to post-stroke rehabilitation. PMID:24134862

  17. Mirror neuron system based therapy for aphasia rehabilitation.

    Science.gov (United States)

    Chen, Wenli; Ye, Qian; Ji, Xiangtong; Zhang, Sicong; Yang, Xi; Zhou, Qiumin; Cong, Fang; Chen, Wei; Zhang, Xin; Zhang, Bing; Xia, Yang; Yuan, Ti-Fei; Shan, Chunlei

    2015-01-01

    To investigate the effect of hand action observation training, i.e., mirror neuron system (MNS) based training, on language function of aphasic patients after stroke. In addition, to reveal the tentative mechanism underlying this effect. Six aphasic patients after stroke, meeting the criteria, undergo 3 weeks' training protocol (30 min per day, 6 days per week). Among them, four patients accepted an ABA training design, i.e., they implemented Protocol A (hand action observation combined with repetition) in the first and third weeks and carried out Protocol B (static object observation combined with repetition) in the second week. Conversely, for the other two patients, BAB training design was adopted, i.e., patients took Protocol B in the first and third weeks and accepted Protocol A in the second week. Picture naming test, western aphasia battery (WAB) and Token Test were applied to evaluate the changes of language function before and after each week's training. Furthermore, two subjects (one aphasic patient and one healthy volunteer) attended a functional MRI (fMRI) experiment, by which we tried to reveal the mechanism underlying possible language function changes after training. Compared with static object observation and repetition training (Protocol B), hand action observation and repetition training (Protocol A) effectively improved most aspects of the language function in all six patients, as demonstrated in the picture naming test, subtests of oral language and aphasia quotient (AQ) of WAB. In addition, the fMRI experiment showed that Protocol A induced more activations in the MNS of one patient and one healthy control when compared to Protocol B. The mirror neuron based therapy may facilitate the language recovery for aphasic patients and this, to some extent, provides a novel direction of rehabilitation for aphasia patients.

  18. Off-axis mirror based optical system design for circularization, collimation, and expansion of elliptical laser beams

    Science.gov (United States)

    Serkan, Mert; Kirkici, Hulya; Cetinkaya, Hakan

    2007-08-01

    In this paper, we present two optical system design methods for beam circularization, collimation, and expansion of semiconductor laser output beam for possible application in LIDAR systems. Two different optical mirror systems are investigated: an off-axis hyperbolic/parabolic mirror system and an off-axis parabolic mirror system. Equations specific to these mirror systems are derived and computer package programs such as ZEMAX and MATLAB are used to simulate the optical designs. The beam reshaping results are presented.

  19. Wireless Control of Vehicle Mirror System Using Head Movement and PIC Microcontroller

    Directory of Open Access Journals (Sweden)

    Nidal F. Shilbayeh

    2005-01-01

    Full Text Available A PIC controlled IR system for the control car mirror system movement is designed and implemented. The designed and built system allows the side view mirrors to be adjusted based on the driver head movement. The infrared based head tracking system maps a predetermined coordinates for head movements and results in a triangularly computable geometry which is fed to the PIC based controlling system. This will cause the vehicle mirror movement via carefully selected miniature motors. The system takes blind spots and their angles into consideration

  20. Wavefront alignment research of segmented mirror synthetic aperture optical (SAO) system

    Science.gov (United States)

    Deng, Jian; An, Xiaoqiang; Tian, Hao

    2010-05-01

    Wavefront control technology and imaging experiment are introduced for a segmented mirror SAO system with deformable sub-mirrors. This system is a RC style with 300mm aperture, 4.5 F#, +/-0.4°FOV, 0.45~0.75μm wave band, and diffraction-limit design MTF. The primary mirror is composed by three sub-mirrors, with parabolic shape, and each deformable sub-mirror has 19 actuators to control and keep the surface shape, and 5 actuators to align sub-mirrors location in 5 degree of freedom. Interferometer is used to feed back and control exit wavefront error, and base on measurement and finite element analysis, location and quanitity of actuators are optimized, making the surface shape and misadjustment errors interact and compensate each other, and the synthetic system exit pupil wavefront error is controlled. The integrated exit pupil wavefront errors are gotten by ZYGO interferometer, and central FOV is 0.077λRMS, and edge FOV is 0.093λRMS. At the end, an imaging experiment is executed, and good results are obtained, which proves, the deformable sub-mirrors have the ability to meliorate alignment and the latter can retroact the former, and this relationship iterate make system exit pupil wavefront error convergence and improve segmented mirror SAO system imaging ability.

  1. LLNL Tandem Mirror Experiment (TMX) upgrade vacuum system

    Energy Technology Data Exchange (ETDEWEB)

    Pickles, W.L.; Chargin, A.K.; Drake, R.P.

    1981-09-15

    TMX Upgrade is a large, tandem, magnetic-mirror fusion experiment with stringent requirements on base pressure (10/sup -8/ torr), low H reflux from the first walls, and peak gas pressure (5 x 10/sup -7/ torr) due to neutral beam gas during plasma operation. The 225 m/sup 3/ vacuum vessel is initially evacuated by turbopumps. Cryopumps provide a continuous sink for gases other than helium, deuterium, and hydrogen. The neutral beam system introduces up to 480 l/s of H or D. The hydrogen isotopes are pumped at very high speed by titanium sublimed onto two cylindrical radially separated stainless steel quilted liners with a total surface area of 540 m/sup 2/. These surfaces (when cooled to about 80/sup 0/K) provide a pumping speed of 6 x 10/sup 7/ l/s for hydrogen. The titanium getter system is programmable and is used for heating as well as gettering. The inner plasma liner can be operated at elevated temperatures to enhance migration of gases away from the surfaces close to the plasma. Glow discharge cleaning is part of the pumpdown procedure. The design features are discussed in conjunction with the operating procedures developed to manage the dynamic vacuum conditions.

  2. Compact Low-Power Driver for Deformable Mirror Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Boston Micromachines Corporation (BMC), a leading developer of unique, high-resolution micromachined deformable mirrors (DMs), will develop a compact, low-power,...

  3. Nonresonance adiabatic photon confinement in spherical mirror system. Experimental study

    CERN Document Server

    Popov, S S; Burdakov, A V; Ushkova, M U

    2015-01-01

    New nonresonance approach of photon accumulation in two spherical mirrors has been experimentally demonstrated. In this work, we have received a high accumulation coefficient and shown good effectiveness of this technique for creating photo neutralizer of negative ion beams. This efficiency in such concept is generally determined by reflectance mirrors and is practically not dependent of input emission quality and does not require high precision adjusting the optical elements.

  4. Development of Slewing Mirror Telescope Optical System for the UFFO-pathfinder

    DEFF Research Database (Denmark)

    Jeong, S.; Nam, J.W.; Ahn, K.-B.

    2013-01-01

    The Slewing Mirror Telescope (SMT) is the UV/optical telescope of UFFO-pathfinder. The SMT optical system is a Ritchey-Chrétien (RC) telescope of 100 mm diameter pointed by means of a gimbal-mounted flat mirror in front of the telescope. The RC telescope has a 17 × 17arcmin2 in Field of View and ...

  5. Heat exchange and hydraulic resistance of compact laser mirror cooling systems

    Science.gov (United States)

    Shanin, Yu. I.; Shanin, O. I.

    2013-07-01

    The hydraulic resistance of cooling systems for laser mirrors and the heat exchange in them have been investigated experimentally. The data obtained have been generalized for several cooling systems with different porous elements.

  6. Mirror fusion propulsion system: A performance comparison with alternate propulsion systems for the manned Mars Mission

    Science.gov (United States)

    Schulze, Norman R.; Carpenter, Scott A.; Deveny, Marc E.; Oconnell, T.

    1993-06-01

    The performance characteristics of several propulsion technologies applied to piloted Mars missions are compared. The characteristics that are compared are Initial Mass in Low Earth Orbit (IMLEO), mission flexibility, and flight times. The propulsion systems being compared are both demonstrated and envisioned: Chemical (or Cryogenic), Nuclear Thermal Rocket (NTR) solid core, NTR gas core, Nuclear Electric Propulsion (NEP), and a mirror fusion space propulsion system. The proposed magnetic mirror fusion reactor, known as the Mirror Fusion Propulsion System (MFPS), is described. The description is an overview of a design study that was conducted to convert a mirror reactor experiment at Lawrence Livermore National Lab (LLNL) into a viable space propulsion system. Design principles geared towards minimizing mass and maximizing power available for thrust are identified and applied to the LLNL reactor design, resulting in the MFPS. The MFPS' design evolution, reactor and fuel choices, and system configuration are described. Results of the performance comparison shows that the MFPS minimizes flight time to 60 to 90 days for flights to Mars while allowing continuous return-home capability while at Mars. Total MFPS IMLEO including propellant and payloads is kept to about 1,000 metric tons.

  7. Mirror fusion propulsion system - A performance comparison with alternate propulsion systems for the manned Mars mission

    Science.gov (United States)

    Deveny, M.; Carpenter, S.; O'Connell, T.; Schulze, N.

    1993-06-01

    The performance characteristics of several propulsion technologies applied to piloted Mars missions are compared. The characteristics that are compared are Initial Mass in Low Earth Orbit (IMLEO), mission flexibility, and flight times. The propulsion systems being compared are both demonstrated and envisioned: Chemical (or Cryogenic), Nuclear Thermal Rocket (NTR) solid core, NTR gas core, Nuclear Electric Propulsion (NEP), and a mirror fusion space propulsion system. The proposed magnetic mirror fusion reactor, known as the Mirror Fusion Propulsion System (MFPS), is described. The description is an overview of a design study that was conducted to convert a mirror reactor experiment at Lawrence Livermore National Lab (LLNL) into a viable space propulsion system. Design principles geared towards minimizing mass and maximizing power available for thrust are identified and applied to the LLNL reactor design, resulting in the MFPS. The MFPS' design evolution, reactor and fuel choices, and system configuration are described. Results of the performance comparison shows that the MFPS minimizes flight time to 60 to 90 days for flights to Mars while allowing continuous return-home capability while at Mars. Total MFPS IMLEO including propellant and payloads is kept to about 1,000 metric tons.

  8. Scalar clouds in charged stringy black hole-mirror system

    Science.gov (United States)

    Li, Ran; Zhao, Junkun; Wu, Xinghua; Zhang, Yanming

    2015-04-01

    It was reported that massive scalar fields can form bound states around Kerr black holes (Herdeiro and Radu, Phys. Rev. Lett. 112:221101, 2014). These bound states are called scalar clouds; they have a real frequency , where is the azimuthal index and is the horizon angular velocity of Kerr black hole. In this paper, we study scalar clouds in a spherically symmetric background, i.e. charged stringy black holes, with the mirror-like boundary condition. These bound states satisfy the superradiant critical frequency condition for a charged scalar field, where is the charge of the scalar field, and is the horizon's electrostatic potential. We show that, for the specific set of black hole and scalar field parameters, the clouds are only possible for specific mirror locations . It is shown that analytical results of the mirror location for the clouds perfectly coincide with numerical results in the regime. We also show that the scalar clouds are also possible when the mirror locations are close to the horizon. Finally, we provide an analytical calculation of the specific mirror locations for the scalar clouds in the regime.

  9. Scalar clouds in charged stringy black hole-mirror system

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ran; Zhao, Junkun; Wu, Xinghua; Zhang, Yanming [Henan Normal University, Department of Physics, Xinxiang (China)

    2015-04-15

    It was reported that massive scalar fields can form bound states around Kerr black holes (Herdeiro and Radu, Phys. Rev. Lett. 112:221101, 2014). These bound states are called scalar clouds; they have a real frequency ω = mΩ{sub H}, where m is the azimuthal index and Ω{sub H} is the horizon angular velocity of Kerr black hole. In this paper, we study scalar clouds in a spherically symmetric background, i.e. charged stringy black holes, with the mirror-like boundary condition. These bound states satisfy the superradiant critical frequency condition ω = qΦ{sub H} for a charged scalar field, where q is the charge of the scalar field, and Φ{sub H} is the horizon's electrostatic potential. We show that, for the specific set of black hole and scalar field parameters, the clouds are only possible for specific mirror locations r{sub m}. It is shown that analytical results of the mirror location r{sub m} for the clouds perfectly coincide with numerical results in the qQ << 1 regime. We also show that the scalar clouds are also possible when the mirror locations are close to the horizon. Finally, we provide an analytical calculation of the specific mirror locations rm for the scalar clouds in the qQ >> 1 regime. (orig.)

  10. Method for pulse control in a laser including a stimulated brillouin scattering mirror system

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2007-10-23

    A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

  11. Delayed mirror visual feedback presented using a novel mirror therapy system enhances cortical activation in healthy adults.

    Science.gov (United States)

    Lee, Hsin-Min; Li, Ping-Chia; Fan, Shih-Chen

    2015-07-11

    Mirror visual feedback (MVF) generated in mirror therapy (MT) with a physical mirror promotes the recovery of hemiparetic limbs in patients with stroke, but is limited in that it cannot provide an asymmetric mode for bimanual coordination training. Here, we developed a novel MT system that can manipulate the MVF to resolve this issue. The aims of this pilot study were to examine the feasibility of delayed MVF on MT and to establish its effects on cortical activation in order to understand how it can be used for clinical applications in the future. Three conditions (no MVF, MVF, and 2-s delayed MVF) presented via our digital MT system were evaluated for their time-course effects on cortical activity by event-related desynchronization (ERD) of mu rhythm electroencephalography (EEG) during button presses in 18 healthy adults. Phasic ERD areas, defined as the areas of the relative ERD curve that were below the reference level and within -2-0 s (P0), 0-2 s (P1), and 2-4 s (P2) of the button press, were used. The overall (P0 to P2) and phasic ERD areas were higher when MVF was provided compared to when MVF was not provided for all EEG channels (C3, Cz, and C4). Phasic ERD areas in the P2 phase only increased during the delayed-MVF condition. Significant enhancement of cortical activation in the mirror neuron system and an increase in attention to the unseen limb may play major roles in the response to MVF during MT. In comparison to the no MVF condition, the higher phasic ERD areas that were observed during the P1 phase in the delayed-MVF condition indicate that the image of the still hand may have enhanced the cortical activation that occurred in response to the button press. This study is the first to achieve delayed MVF for upper-limb MT. Our approach confirms previous findings regarding the effects of MVF on cortical activation and contributes additional evidence supporting the use of this method in the future for upper-limb motor training in patients with stroke.

  12. Study on Hardware-in-loop Simulation of Twin-screw Extruder Experiment System

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>In order to facilitate the teaching of industrial processes and experiments on the twin-screw extruder control debugging,and be closer to the actual testing,to reduce the debugging costs and the risk of debugging process,the paper designs a hardware-in-loop simulation of twin-screw extruder experiment system which is closer to scene,low cost and high safety.The system through the establishment of twin-screw extruder’s mathematical model on computer to simulate the realistic system and there is hardware practicality in the computer simulation loop.The hardware based on C8051F020 can operate in the simulation loop in real time.In computer software design, we desigh man-machine interface that is intuitive and easy to operate,can reflect twin-screw extruder main operation information vividly.Finally,twin-screw extruder’s 3 heater temperature mathematical model and PID incremental control algorithm are presented.

  13. Actively Cooled Silicon Lightweight Mirrors for Far Infrared and Submillimeter Optical Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA Space Science Enterprise has 2 themes requiring large, lightweight cryogenic mirrors: Astronomical Search for Origins and Planetary Systems (ASO) and the...

  14. Improving the Performance of Three-Mirror Imaging Systems with Freeform Optics

    Science.gov (United States)

    Howard, Joseph M.; Wolbach, Steven

    2013-01-01

    The image quality improvement for three-mirror systems by Freeform Optics is surveyed over various f-number and field specifications. Starting with the Korsch solution, we increase the surface shape degrees of freedom and record the improvements.

  15. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2016-01-01

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  16. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2017-01-01

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  17. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2017-01-31

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  18. Freeform mirror for illumination system of color-sequential LCOS pico projector

    Science.gov (United States)

    Peng, Wei-Jei; Chen, Chun-Chieh; Huang, Chien-Yao; Hsu, Wei-Yao

    2014-09-01

    An efficient and uniform illumination system with a freeform mirror for a color-sequential LCOS pico projector based on LED is proposed in this paper. The novel homogenizer is composed of a micro lens array and a freeform mirror. A freeform mirror with XY polynomial profile is adopted for the reshaping of light pattern, the correction of keystone distortion and the folding mirror for the reduction of volume. Typically, the design of micro lens array, the aspect ratio of the lenslet is corresponding with that of the panel. However, the crosstalk phenomenon occurs due to each lenslet with different collecting angle in horizontal and vertical direction, especially when the aspect ratio of the panel in our study is 16:9. The crosstalk phenomenon not only reduces efficiency but also generates stray light on the panel. Therefore, we use a micro lens array with square lenslet to eliminate it. Subsequently, the square light pattern on the panel needs to be reshaped to fit the aspect ratio of the panel. A cylindrical mirror with a fixed power is used to compress the light pattern first. However, for the requirement of different focal distances from the cylindrical mirror to the panel on entire surface, it generates severe keystone distortion. A freeform mirror with progressive power variation is employed for the correction of keystone distortion with high overfilled efficiency and the reshaping of the light pattern fitting the ratio of the panel. In the results of optical simulation, JBMA uniformity on the panel is 98 % and the coupling efficiency from LED to the plane of the panel is 85 %. Furthermore, the alignment tolerance of the freeform mirror has also been discussed. Finally, the freeform mirror is fabricated by ultra-precision diamond milling process. The form accuracy and surface roughness of the freeform mirror are less than 0.5 um and 5 nm, respectively.

  19. Experiential effects on mirror systems and social learning: implications for social intelligence.

    Science.gov (United States)

    Reader, Simon M

    2014-04-01

    Investigations of biases and experiential effects on social learning, social information use, and mirror systems can usefully inform one another. Unconstrained learning is predicted to shape mirror systems when the optimal response to an observed act varies, but constraints may emerge when immediate error-free responses are required and evolutionary or developmental history reliably predicts the optimal response. Given the power of associative learning, such constraints may be rare.

  20. Aging Trajectories in Different Body Systems Share Common Environmental Etiology : The Healthy Aging Twin Study (HATS)

    NARCIS (Netherlands)

    Moayyeri, Alireza; Hart, Deborah J.; Snieder, Harold; Hammond, Christopher J.; Spector, Timothy D.; Steves, Claire J.

    Little is known about the extent to which aging trajectories of different body systems share common sources of variance. We here present a large twin study investigating the trajectories of change in five systems: cardiovascular, respiratory, skeletal, morphometric, and metabolic. Longitudinal

  1. Characterising x-ray mirror deformations with a phase measuring deflectometry system

    Science.gov (United States)

    Breunig, E.; Friedrich, P.; Proserpio, L.; Winter, A.

    2014-07-01

    MPE is developing modular x-ray mirrors for the next generation of high-energy astronomy missions. The mirror segments are based on thermally formed (a.k.a. slumped) glass sheets, with a typical thickness of 400µm. One of the major challenges is the alignment and integration of the mirror segments and the associated metrology. The optical performance of the mirror can be significantly compromised by adhesive shrinkage, gravity sag or residual stresses influenced by the properties of the mirror mounting and the integration procedure. In parallel with classic coordinate measurement techniques we utilize a deflectometry based metrology system to characterization shape errors of the mirror surfaces. A typical deflectometry setup uses a TFT display to project a sinusoidal pattern onto a specular test surface (SUT) and a camera that observes the reflected image. This reflected image contains slope information of the SUT in the form of distortions of the original displayed pattern. A phase shifting technique can be used to recover this slope information with only very few exposures and reasonable computational effort. The deflectometry system enables us to characterize bonding interfaces of slumped glass mirrors, as well as influence of temporary mounting points, handling and thermal distortions. It is also well suited to measure transient effects.

  2. Design of dual-curvature mirror for linear medium concentration photovoltaic systems

    Science.gov (United States)

    Lance, Tamir; Ackler, Harold; Finot, Marc

    2012-01-01

    The impact of mirror shape on energy production in Skyline Solar's reflective trough medium concentration photovoltaic system is reviewed using a combination of commercial and proprietary modeling tools. For linear concentrators, an important parameter for efficiency optimization is the uniformity of the flux line on the photovoltaic cells. A significant source of nonuniformity is the discontinuity of reflected light due to the gap between mirrors along the length of the trough. Standard concentrating solar power trough mirrors have a typical length of 1.5 m with a gap between mirrors of 10 to 20 mm. To reduce nonuniformity of the flux line due to this mirror to mirror gap, Skyline Solar developed a dual curvature mirror that stretches the flux line along the trough axis. Extensive modeling and experiments have been conducted to analyze the impact of this design. The methodology of optimization is presented for the X14 Skyline system architecture, and benefits of up to 3% of energy can be realized at locations with latitude below 30 deg.

  3. NASA's OCA Mirroring System: An Application of Multiagent Systems in Mission Control

    Science.gov (United States)

    Sierhuis, Maarten; Clancey, William J.; vanHoof, Ron J. J.; Seah, Chin H.; Scott, Michael S.; Nado, Robert A.; Blumenberg, Susan F.; Shafto, Michael G.; Anderson, Brian L.; Bruins, Anthony C.; hide

    2009-01-01

    Orbital Communications Adaptor (OCA) Flight Controllers, in NASA's International Space Station Mission Control Center, use different computer systems to uplink, downlink, mirror, archive, and deliver files to and from the International Space Station (ISS) in real time. The OCA Mirroring System (OCAMS) is a multiagent software system (MAS) that is operational in NASA's Mission Control Center. This paper presents OCAMS and its workings in an operational setting where flight controllers rely on the system 24x7. We also discuss the return on investment, based on a simulation baseline, six months of 24x7 operations at NASA Johnson Space Center in Houston, Texas, and a projection of future capabilities. This paper ends with a discussion of the value of MAS and future planned functionality and capabilities.

  4. NASA's OCA Mirroring System: An Application of Multiagent Systems in Mission Control

    Science.gov (United States)

    Sierhuis, Maarten; Clancey, William J.; vanHoof, Ron J. J.; Seah, Chin H.; Scott, Michael S.; Nado, Robert A.; Blumenberg, Susan F.; Shafto, Michael G.; Anderson, Brian L.; Bruins, Anthony C.; Buckley, Chris B.; Diegelman, Thomas E.; Hall, Timothy A.; Hood, Deborah; Reynolds, Fisher F.; Toschlog, Jason R.; Tucker, Tyson

    2009-01-01

    Orbital Communications Adaptor (OCA) Flight Controllers, in NASA's International Space Station Mission Control Center, use different computer systems to uplink, downlink, mirror, archive, and deliver files to and from the International Space Station (ISS) in real time. The OCA Mirroring System (OCAMS) is a multiagent software system (MAS) that is operational in NASA's Mission Control Center. This paper presents OCAMS and its workings in an operational setting where flight controllers rely on the system 24x7. We also discuss the return on investment, based on a simulation baseline, six months of 24x7 operations at NASA Johnson Space Center in Houston, Texas, and a projection of future capabilities. This paper ends with a discussion of the value of MAS and future planned functionality and capabilities.

  5. VLT DSM, the control system of the largest deformable secondary mirror ever manufactured

    Science.gov (United States)

    Manetti, Mauro; Morandini, Marco; Mantegazza, Paolo; Biasi, Roberto; Andrighettoni, Mario; Gallieni, Daniele

    2014-07-01

    A proven technology for the shape control of large secondary deformable mirrors employs a magnetically levitated contactless solution and relies on voice-coil actuators co-located to capacitive position sensors. The present work focuses on the description of the latest upgrade of this technology, as applied to the Very Large Telescope Deformable Secondary Mirror, the largest continuous facesheet adaptive mirror ever manufactured. The controller is based on a completely decentralized high frequency feedback coupled to a lower frequency improved feedforward. The system enhancements and performances are verified through electromechanical tests.

  6. Scalar clouds in charged stringy black hole-mirror system

    CERN Document Server

    Li, Ran; Wu, Xinghua; Zhang, Yanming

    2015-01-01

    It is reported that massive scalar fields can form bound states around Kerr black holes [C. Herdeiro, and E. Radu, Phys. Rev. Lett. 112, 221101 (2014)]. These bound states are called scalar clouds, which have a real frequency $\\omega=m\\Omega_H$, where $m$ is the azimuthal index and $\\Omega_H$ is the horizon angular velocity of Kerr black hole. In this paper, we study scalar clouds in a spherically symmetric background, i.e. charged stringy black holes, with the mirror-like boundary condition. These bound states satisfy the superradiant critical frequency condition $\\omega=q\\Phi_H$ for the charged scalar field, where $q$ is the charge of scalar field, and $\\Phi_H$ is the horizon electrostatic potential. We show that, for the specific set of black hole and scalar field parameters, the clouds are only possible for the specific mirror locations $r_m$. It is shown that the analytical results of mirror location $r_m$ for the clouds are perfectly coincide with the numerical results. In addition, we show that the sca...

  7. A human mirror neuron system for language: Perspectives from signed languages of the deaf.

    Science.gov (United States)

    Knapp, Heather Patterson; Corina, David P

    2010-01-01

    Language is proposed to have developed atop the human analog of the macaque mirror neuron system for action perception and production [Arbib M.A. 2005. From monkey-like action recognition to human language: An evolutionary framework for neurolinguistics (with commentaries and author's response). Behavioral and Brain Sciences, 28, 105-167; Arbib M.A. (2008). From grasp to language: Embodied concepts and the challenge of abstraction. Journal de Physiologie Paris 102, 4-20]. Signed languages of the deaf are fully-expressive, natural human languages that are perceived visually and produced manually. We suggest that if a unitary mirror neuron system mediates the observation and production of both language and non-linguistic action, three prediction can be made: (1) damage to the human mirror neuron system should non-selectively disrupt both sign language and non-linguistic action processing; (2) within the domain of sign language, a given mirror neuron locus should mediate both perception and production; and (3) the action-based tuning curves of individual mirror neurons should support the highly circumscribed set of motions that form the "vocabulary of action" for signed languages. In this review we evaluate data from the sign language and mirror neuron literatures and find that these predictions are only partially upheld.

  8. Importance of tip sensing for active control system of 30-m RIT primary mirror

    Institute of Scientific and Technical Information of China (English)

    Yichun Dai; Zhong Liu; Zhenyu Jin

    2009-01-01

    The active control of 30-m ring interferometric telescope(RIT)needs edge sensing and tip sensing when its primary mirror is composed by trapezoid-shaped segments,and the imaging performance of the RIT is determined by the accuracy of these two detecting approaches.Considering the detecting accuracy available in current segmented telescope active control systems,the effect of these detecting approaches on the surface error of the RIT primary mirror is calculated from the point of error propagation.The corresponding effect on imaging performance(modulation transfer functions(MTFs)and point spread functions(PSFs)at several typical wavelengths)of the RIT primary mirror is also simulated.The results show that tip sensing is very important for increasing the active control quality of the RIT primary mirror under the present techniques.

  9. The mirror neuron system and the strange case of Broca's area.

    Science.gov (United States)

    Cerri, Gabriella; Cabinio, Monia; Blasi, Valeria; Borroni, Paola; Iadanza, Antonella; Fava, Enrica; Fornia, Luca; Ferpozzi, Valentina; Riva, Marco; Casarotti, Alessandra; Martinelli Boneschi, Filippo; Falini, Andrea; Bello, Lorenzo

    2015-03-01

    Mirror neurons, originally described in the monkey premotor area F5, are embedded in a frontoparietal network for action execution and observation. A similar Mirror Neuron System (MNS) exists in humans, including precentral gyrus, inferior parietal lobule, and superior temporal sulcus. Controversial is the inclusion of Broca's area, as homologous to F5, a relevant issue in light of the mirror hypothesis of language evolution, which postulates a key role of Broca's area in action/speech perception/production. We assess "mirror" properties of this area by combining neuroimaging and intraoperative neurophysiological techniques. Our results show that Broca's area is minimally involved in action observation and has no motor output on hand or phonoarticulatory muscles, challenging its inclusion in the MNS. The presence of these functions in premotor BA6 makes this area the likely homologue of F5 suggesting that the MNS may be involved in the representation of articulatory rather than semantic components of speech. © 2014 Wiley Periodicals, Inc.

  10. Circadian system heritability as assessed by wrist temperature: a twin study.

    Science.gov (United States)

    Lopez-Minguez, Jesus; Ordoñana, Juan R; Sánchez-Romera, Juan F; Madrid, Juan A; Garaulet, Marta

    2015-02-01

    Previous research shows that wrist temperature (WT) is a good marker to assess the circadian system health in different circumstances. However, no studies have been performed in order to know the genetic component of this circadian marker. For this purpose, the aim was to determine, using classical twin models, the relative genetic and environmental influences on WT. The study was performed in 53 pairs of female twins (28 monozygotic (MZ) and 25 dizygotic (DZ)), with a body mass index 25.9 ± 3.78 and mean age 52 ± 6 years. The sample was selected from the Murcia Twin Register. Circadian patterns were studied by analyzing WT during one week every 10 min "Circadianware®". Genetic influences to WT variability were estimated by comparing correlations of MZ and DZ twin pairs and fitting genetic structural equation models to measured variables. MZ twins showed higher intra-pair correlations than DZ twins for most of the parameters. Genetic factors were responsible for between 46% and 70% of variance (broad sense heritability) in parameters such as mean temperature, mesor, acrophase, Rayleigh test, percentage of rhythmicity and five hours of maximum temperature. The pattern of correlations and the genetic models point to moderate to high heritability for most of the WT parameters, suggesting a relevant genetic influence. The presence of these genetic factors points to endogenicity as the main cause of the coincidence of the WT rhythms. However, some WT parameters are still dependent on environment to a relevant extent and, hence, more amenable to change through external interventions.

  11. Mapping the flow of information within the putative mirror neuron system during gesture observation

    NARCIS (Netherlands)

    Schippers, Marleen B.; Keysers, Christian

    2011-01-01

    The putative mirror neuron system may either function as a strict feed-forward system or as a dynamic control system. A strict feed-forward system would predict that action observation leads to a predominantly temporal -> parietal -> premotor flow of information in which a visual representation is t

  12. Modeling and Control of Magnetic Fluid Deformable Mirrors for Adaptive Optics Systems

    CERN Document Server

    Wu, Zhizheng; Ben Amara, Foued

    2013-01-01

    Modeling and Control of Magnetic Fluid Deformable Mirrors for Adaptive Optics Systems presents a novel design of wavefront correctors based on magnetic fluid deformable mirrors (MFDM) as well as corresponding control algorithms. The presented wavefront correctors are characterized by their linear, dynamic response. Various mirror surface shape control algorithms are presented along with experimental evaluations of the performance of the resulting adaptive optics systems. Adaptive optics (AO) systems are used in various fields of application to enhance the performance of optical systems, such as imaging, laser, free space optical communication systems, etc. This book is intended for undergraduate and graduate students, professors, engineers, scientists and researchers working on the design of adaptive optics systems and their various emerging fields of application. Zhizheng Wu is an associate professor at Shanghai University, China. Azhar Iqbal is a research associate at the University of Toronto, Canada. Foue...

  13. Does dysfunction of the mirror neuron system contribute to symptoms in amyotrophic lateral sclerosis?

    Science.gov (United States)

    Eisen, Andrew; Lemon, Roger; Kiernan, Matthew C; Hornberger, Michael; Turner, Martin R

    2015-07-01

    There is growing evidence that mirror neurons, initially discovered over two decades ago in the monkey, are present in the human brain. In the monkey, mirror neurons characteristically fire not only when it is performing an action, such as grasping an object, but also when observing a similar action performed by another agent (human or monkey). In this review we discuss the origin, cortical distribution and possible functions of mirror neurons as a background to exploring their potential relevance in amyotrophic lateral sclerosis (ALS). We have recently proposed that ALS (and the related condition of frontotemporal dementia) may be viewed as a failure of interlinked functional complexes having their origins in key evolutionary adaptations. This can include loss of the direct projections from the corticospinal tract, and this is at least part of the explanation for impaired motor control in ALS. Since, in the monkey, corticospinal neurons also show mirror properties, ALS in humans might also affect the mirror neuron system. We speculate that a defective mirror neuron system might contribute to other ALS deficits affecting motor imagery, gesture, language and empathy. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  14. A low-cost mirror mount control system for optics setups

    Science.gov (United States)

    Gopalakrishnan, Maithreyi; Gühr, Markus

    2015-02-01

    We describe a flexible, simple to build, low-cost, and computer-controlled optical mirror actuator system, developed for undergraduate research laboratories. Geared motors for hobby robotics are controlled by an Arduino microcontroller in combination with an H bridge to finely position mirror mount actuators. We present a graphical user interface based on the Python script language. The price of the fully controlled actuator system is only a small fraction of the price of a commercial system. It can be quickly implemented due to the use of open-hardware electronics. We discuss the performance of the system and give an outlook for future expansions and use in advanced optical setups.

  15. The Twin Arginine Translocation System Is Essential for Aerobic Growth and Full Virulence of Burkholderia thailandensis

    OpenAIRE

    Wagley, Sariqa; Hemsley, Claudia; Thomas, Rachael; Madeleine G Moule; Vanaporn, Muthita; Andreae, Clio; Robinson, Matthew; Goldman, Stan; Brendan W. Wren; Butler, Clive S.; Richard W Titball

    2014-01-01

    The twin arginine translocation (Tat) system in bacteria is responsible for transporting folded proteins across the cytoplasmic membrane, and in some bacteria, Tat-exported substrates have been linked to virulence. We report here that the Tat machinery is present in Burkholderia pseudomallei, B. mallei, and B. thailandensis, and we show that the system is essential for aerobic but not anaerobic growth. Switching off of the Tat system in B. thailandensis grown anaerobically resulted in filamen...

  16. No evidence for mirror system dysfunction in schizophrenia from a multimodal TMS/EEG study.

    Science.gov (United States)

    Andrews, Sophie C; Enticott, Peter G; Hoy, Kate E; Thomson, Richard H; Fitzgerald, Paul B

    2015-08-30

    Dysfunctional mirror neuron systems have been proposed to contribute to the social cognitive deficits observed in schizophrenia. A few studies have explored mirror systems in schizophrenia using various techniques such as TMS (levels of motor resonance) or EEG (levels of mu suppression), with mixed results. This study aimed to use a novel multimodal approach (i.e. concurrent TMS and EEG) to further investigate mirror systems and social cognition in schizophrenia. Nineteen individuals with schizophrenia or schizoaffective disorder and 19 healthy controls participated. Single-pulse TMS was applied to M1 during the observation of hand movements designed to elicit mirror system activity. Single EEG electrodes (C3, CZ, C4) recorded brain activity. Participants also completed facial affect recognition and theory of mind tasks. The schizophrenia group showed significant deficits in facial affect recognition and higher level theory of mind compared to healthy controls. A significant positive relationship was revealed between mu suppression and motor resonance for the overall sample, indicating concurrent validity of these measures. Levels of mu suppression and motor resonance were not significantly different between groups. These findings indicate that in stable outpatients with schizophrenia, mirror system functioning is intact, and therefore their social cognitive difficulties may be caused by alternative pathophysiology. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Reflecting on the mirror neuron system in autism: a systematic review of current theories.

    Science.gov (United States)

    Hamilton, Antonia F de C

    2013-01-01

    There is much interest in the claim that dysfunction of the mirror neuron system in individuals with autism spectrum condition causes difficulties in social interaction and communication. This paper systematically reviews all published studies using neuroscience methods (EEG/MEG/TMS/eyetracking/EMG/fMRI) to examine the integrity of the mirror system in autism. 25 suitable papers are reviewed. The review shows that current data are very mixed and that studies using weakly localised measures of the integrity of the mirror system are hard to interpret. The only well localised measure of mirror system function is fMRI. In fMRI studies, those using emotional stimuli have reported group differences, but studies using non-emotional hand action stimuli do not. Overall, there is little evidence for a global dysfunction of the mirror system in autism. Current data can be better understood under an alternative model in which social top-down response modulation is abnormal in autism. The implications of this model and future research directions are discussed.

  18. Controlling the Focal Length and the Spot Size in Flying Optics by Dual-deformable-mirror-systems

    Institute of Scientific and Technical Information of China (English)

    ZHAO Quanzhong; CHENG Zhaogu; GAO Haijun; CHAI Xiongliang; LUO Hongxin

    2002-01-01

    The models of several dual-deformable-mirror-systems,which can control focal the length and the spot size in flying optics,were introduced and their operating principle and adjusting characteristics were analyzed.The simulation results indicate that dual-deformable-mirror-systems can control the focal length and the spot size.This research is a good guidance to engineering application of dual-deformable-mirror-systems.

  19. Changes in the pattern of DNA methylation associate with twin discordance in systemic lupus erythematosus

    Science.gov (United States)

    Javierre, Biola M.; Fernandez, Agustin F.; Richter, Julia; Al-Shahrour, Fatima; Martin-Subero, J. Ignacio; Rodriguez-Ubreva, Javier; Berdasco, Maria; Fraga, Mario F.; O'Hanlon, Terrance P.; Rider, Lisa G.; Jacinto, Filipe V.; Lopez-Longo, F. Javier; Dopazo, Joaquin; Forn, Marta; Peinado, Miguel A.; Carreño, Luis; Sawalha, Amr H.; Harley, John B.; Siebert, Reiner; Esteller, Manel; Miller, Frederick W.; Ballestar, Esteban

    2010-01-01

    Monozygotic (MZ) twins are partially concordant for most complex diseases, including autoimmune disorders. Whereas phenotypic concordance can be used to study heritability, discordance suggests the role of non-genetic factors. In autoimmune diseases, environmentally driven epigenetic changes are thought to contribute to their etiology. Here we report the first high-throughput and candidate sequence analyses of DNA methylation to investigate discordance for autoimmune disease in twins. We used a cohort of MZ twins discordant for three diseases whose clinical signs often overlap: systemic lupus erythematosus (SLE), rheumatoid arthritis, and dermatomyositis. Only MZ twins discordant for SLE featured widespread changes in the DNA methylation status of a significant number of genes. Gene ontology analysis revealed enrichment in categories associated with immune function. Individual analysis confirmed the existence of DNA methylation and expression changes in genes relevant to SLE pathogenesis. These changes occurred in parallel with a global decrease in the 5-methylcytosine content that was concomitantly accompanied with changes in DNA methylation and expression levels of ribosomal RNA genes, although no changes in repetitive sequences were found. Our findings not only identify potentially relevant DNA methylation markers for the clinical characterization of SLE patients but also support the notion that epigenetic changes may be critical in the clinical manifestations of autoimmune disease. PMID:20028698

  20. Modeling of microelectromechanical systems deformable mirror diffraction grating

    Science.gov (United States)

    Sirbu, Dan; Pluzhnik, Eugene; Belikov, Ruslan

    2016-07-01

    Model-based wavefront control methods such as electric field conjugation require accurate optical propagation models to create high-contrast regions in the focal plane using deformable mirrors (DMs). Recently, it has been shown that it is possible to exceed the controllable outer-working angle imposed by the Nyquist limit based on the number of actuators by utilizing a diffraction grating. The print-through pattern on MEMS-based DMs formed during the fabrication process creates both an amplitude and a phase diffraction grating that can be used to enable Super-Nyquist wavefront control. Using interferometric measurements of a DM-actuator, we develop a DM-diffraction grating model. We compare the total energy enclosed in the first diffraction order due to the phase, amplitude, and combined phase-amplitude gratings with laboratory measurements.

  1. A novel mirror diversity receiver for indoor MIMO visible light communication systems

    KAUST Repository

    Park, Kihong

    2016-12-24

    In this paper, we propose and study a non-imaging receiver design reducing the correlation of channel matrix for indoor multiple-input multiple-output (MIMO) visible light communication (VLC) systems. Contrary to previous works, our proposed mirror diversity receiver (MDR) not only blocks the reception of light on one specific direction but also improves the channel gain on the other direction by receiving the light reflected by a mirror deployed between the photodetectors. We analyze the channel capacity and optimal height of mirror in terms of maximum channel capacity for a 2 × 2 MIMO-VLC system in a 2-dimensional geometric model. We prove that this constructive and destructive effects in channel matrix resulting from our proposed MDR are more beneficial to obtain well-conditioned channel matrix which is suitable for implementing spatial-multiplexing MIMO-VLC systems in order to support high data rate.

  2. Endoscopic swept-source optical coherence tomography based on a two-axis microelectromechanical system mirror

    Science.gov (United States)

    Wang, Donglin; Fu, Linlai; Wang, Xin; Gong, Zhongjian; Samuelson, Sean; Duan, Can; Jia, Hongzhi; Ma, Jun Shan; Xie, Huikai

    2013-08-01

    A microelectromechanical system (MEMS) mirror based endoscopic swept-source optical coherence tomography (SS-OCT) system that can perform three-dimensional (3-D) imaging at high speed is reported. The key component enabling 3-D endoscopic imaging is a two-axis MEMS scanning mirror which has a 0.8×0.8 mm2 mirror plate and a 1.6×1.4 mm2 device footprint. The diameter of the endoscopic probe is only 3.5 mm. The imaging rate of the SS-OCT system is 50 frames/s. OCT images of both human suspicious oral leukoplakia tissue and normal buccal mucosa were taken in vivo and compared. The OCT imaging result agrees well with the histopathological analysis.

  3. Aging Trajectories in Different Body Systems Share Common Environmental Etiology: The Healthy Aging Twin Study (HATS).

    Science.gov (United States)

    Moayyeri, Alireza; Hart, Deborah J; Snieder, Harold; Hammond, Christopher J; Spector, Timothy D; Steves, Claire J

    2016-02-01

    Little is known about the extent to which aging trajectories of different body systems share common sources of variance. We here present a large twin study investigating the trajectories of change in five systems: cardiovascular, respiratory, skeletal, morphometric, and metabolic. Longitudinal clinical data were collected on 3,508 female twins in the TwinsUK registry (complete pairs:740 monozygotic (MZ), 986 dizygotic (DZ), mean age at entry 48.9 ± 10.4, range 18-75 years; mean follow-up 10.2 ± 2.8 years, range 4-17.8 years). Panel data on multiple age-related variables were used to estimate biological ages for each individual at each time point, in linear mixed effects models. A weighted average approach was used to combine variables within predefined body system groups. Aging trajectories for each system in each individual were then constructed using linear modeling. Multivariate structural equation modeling of these aging trajectories showed low genetic effects (heritability), ranging from 2% in metabolic aging to 22% in cardiovascular aging. However, we found a significant effect of shared environmental factors on the variations in aging trajectories in cardiovascular (54%), skeletal (34%), morphometric (53%), and metabolic systems (53%). The remainder was due to environmental factors unique to each individual plus error. Multivariate Cholesky decomposition showed that among aging trajectories for various body systems there were significant and substantial correlations between the unique environmental latent factors as well as shared environmental factors. However, there was no evidence for a single common factor for aging. This study, the first of its kind in aging, suggests that diverse organ systems share non-genetic sources of variance for aging trajectories. Confirmatory studies are needed using population-based twin cohorts and alternative methods of handling missing data.

  4. The anthropomorphic brain : The mirror neuron system responds to human and robotic actions

    NARCIS (Netherlands)

    Gazzola, V.; Rizzolatti, G.; Wicker, B.; Keysers, C.

    2007-01-01

    In humans and monkeys the mirror neuron system transforms seen actions into our inner representation of these actions. Here we asked if this system responds also if we see an industrial robot perform similar actions. We localised the motor areas involved in the execution of hand actions, presented t

  5. Conjoined Twins

    Science.gov (United States)

    ... sites of conjoined twins. Abdomen. Omphalopagus (om-fuh-LOP-uh-gus) twins are joined near the bellybutton. ... brain tissue. Head and chest. Cephalopagus (sef-uh-LOP-uh-gus) twins are joined at the face ...

  6. Viability study of porous silicon photonic mirrors as secondary reflectors for solar concentration systems

    Energy Technology Data Exchange (ETDEWEB)

    de la Mora, M.B.; Jaramillo, O.A.; Nava, R.; Tagueena-Martinez, J. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, A. P. 34, 62580 Temixco, Morelos (Mexico); del Rio, J.A. [Centro Morelense de Innovacion y Transferencia Tecnologica, CCyTEM Camino Temixco a Emiliano Zapata, Km 0.3, Colonia Emiliano Zapata, 62760 Morelos (Mexico)

    2009-08-15

    In this paper we report the viability of using porous silicon photonic mirrors (PSPM) as secondary reflectors in solar concentration systems. The PSPM were fabricated with nanostructured porous silicon to reflect light from the visible range to the near infrared region (500-2500 nm), although this range could be tuned for specific wavelength applications. Our PSPM are multilayers of two alternated refractive indexes (1.5 and 2.0), where the condition of a quarter wavelength in the optical path was imposed. The PSPM were exposed to high radiation in a solar concentrator equipment. As a result, we observed a significant degradation of the mirrors at an approximated temperature of 900 C. In order to analyze the origin of the degradation of PSPM, we model the samples with a non-linear optical approach and study the effect of a temperature increase. Those theoretical and experimental studies allow us to conclude that the main phenomenon involved in the breakdown of the photonic mirrors is of thermal origin, produced by heterogeneous expansion of each layer. Our next step was to introduce a cooling system into the solar concentrator to keep the mirrors at approximately 70 C, with very good results. As a conclusion we propose the use of PSPM as selective secondary mirrors in solar concentration devices using temperature control to avoid thermal degradation. (author)

  7. Optimization of an Angle-Aided Mirror Diversity Receiver for Indoor MIMO-VLC Systems

    KAUST Repository

    Park, Kihong

    2017-02-07

    In this paper, we investigate the channel correlation problem which affects the performance of indoor multiple-input multiple-output (MIMO) visible light communication (VLC) systems. More specifically, in order to reduce the high correlation of channel matrix in MIMO-VLC intensity channel, we propose a non-imaging receiver called angle-aided mirror diversity receiver (AMDR) which utilizes not only a mirror placement but also a variation of orientation angle for the photodetector (PD) plane. Deploying a mirror helps reducing the correlation by blocking the reception of the light in one specific direction and by receiving additional light reflected in the mirror in another direction, while orienting the angle of PD plane into specific direction enables the directional reception of light. Applying a zero-forcing decorrelator at the receiver, we analyze the bit error rate (BER) performance for a 2×2 multiplexing MIMO-VLC system using a 2-dimensional geometric model. In particular, we formulate a min-max BER problem and find the optimal height of mirror and elevation angle of PD plane. Some selected numerical results validate our proposed optimal solution to our min-max BER problem and show that the BER performance of our proposed AMDR outperforms that of the previous non-imaging receivers.

  8. Neural mirroring and social interaction: Motor system involvement during action observation relates to early peer cooperation.

    Science.gov (United States)

    Endedijk, H M; Meyer, M; Bekkering, H; Cillessen, A H N; Hunnius, S

    2017-04-01

    Whether we hand over objects to someone, play a team sport, or make music together, social interaction often involves interpersonal action coordination, both during instances of cooperation and entrainment. Neural mirroring is thought to play a crucial role in processing other's actions and is therefore considered important for social interaction. Still, to date, it is unknown whether interindividual differences in neural mirroring play a role in interpersonal coordination during different instances of social interaction. A relation between neural mirroring and interpersonal coordination has particularly relevant implications for early childhood, since successful early interaction with peers is predictive of a more favorable social development. We examined the relation between neural mirroring and children's interpersonal coordination during peer interaction using EEG and longitudinal behavioral data. Results showed that 4-year-old children with higher levels of motor system involvement during action observation (as indicated by lower beta-power) were more successful in early peer cooperation. This is the first evidence for a relation between motor system involvement during action observation and interpersonal coordination during other instances of social interaction. The findings suggest that interindividual differences in neural mirroring are related to interpersonal coordination and thus successful social interaction. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Control Law Design for Twin Rotor MIMO System with Nonlinear Control Strategy

    Directory of Open Access Journals (Sweden)

    M. Ilyas

    2016-01-01

    Full Text Available Modeling of complex air vehicles is a challenging task due to high nonlinear behavior and significant coupling effect between rotors. Twin rotor multi-input multioutput system (TRMS is a laboratory setup designed for control experiments, which resembles a helicopter with unstable, nonlinear, and coupled dynamics. This paper focuses on the design and analysis of sliding mode control (SMC and backstepping controller for pitch and yaw angle control of main and tail rotor of the TRMS under parametric uncertainty. The proposed control strategy with SMC and backstepping achieves all mentioned limitations of TRMS. Result analysis of SMC and backstepping control schemes elucidates that backstepping provides efficient behavior with the parametric uncertainty for twin rotor system. Chattering and oscillating behaviors of SMC are removed with the backstepping control scheme considering the pitch and yaw angle for TRMS.

  10. Twin-truss system design for antarctic krill trawl processing ship

    Directory of Open Access Journals (Sweden)

    ZHOU Chungkai

    2017-05-01

    Full Text Available Aiming to improve the fishing efficiency of antarctic krill processing ships by averting the potential crushing of krill in the trawl to meet quality requirements, a twin-truss system design is proposed which has higher efficiency compared with the traditional system installed in ships. To simulate this design, an analysis of forces acting on the twin-truss structure is conducted under tethered and operating conditions using the structure model method, and an appropriate distance between trawl winch and truss structure, as well as the range for limiting the distance of the horizontal locating cable and truss structure, are obtained. It can also prevent the truss structure from breaking down, enabling the efficiency of trawling and horizontal locating cables during fishing operations. The simulation shows that the new twin-truss system design can improve the efficiency of trawl processing ships, whilst maintain the safety of the truss structure. This design can provide an optimal solution for the truss systems of national antarctic krill processing ships.

  11. Active optics: variable curvature mirrors for ELT laser guide star refocusing systems

    Science.gov (United States)

    Challita, Zalpha; Hugot, Emmanuel; Madec, Fabrice; Ferrari, Marc; Le Mignant, David; Vivès, Sébastien; Cuby, Jean-Gabriel

    2011-10-01

    The future generation of Extremely Large Telescopes will require a complex combination of technologies for adaptive optics (AO) systems assisted by laser guide stars (LGS). In this context, the distance from the LGS spot to the telescope pupil ranges from about 80 to 200 km, depending on the Sodium layer altitude and the elevation of the telescope. This variation leads to a defocusing effect on the LGS wave-front sensor which needs to be compensated. We propose an active mirror able to compensate for this variation, based on an original optical design including this active optics component. This LGS Variable Curvature Mirror (LGS-VCM) is a 120 mm spherical active mirror able to achieve 820 μm deflection sag with an optical quality better than 150 nm RMS, allowing the radius of curvature variation from F/12 to F/2. Based on elasticity theory, the deformation of the metallic mirror is provided by an air pressure applied on a thin meniscus with a variable thickness distribution. In this article, we detail the analytical development leading to the specific geometry of the active component, the results of finite element analysis and the expected performances in terms of surface error versus the range of refocalisation. Three prototypes have been manufactured to compare the real behavior of the mirror and the simulations data. Results obtained on the prototypes are detailed, showing that the deformation of the VCM is very close to the simulation, and leads to a realistic active concept.

  12. Sensorimotor cortex as a critical component of an 'extended' mirror neuron system: Does it solve the development, correspondence, and control problems in mirroring?

    Directory of Open Access Journals (Sweden)

    Pineda Jaime A

    2008-10-01

    Full Text Available Abstract A core assumption of how humans understand and infer the intentions and beliefs of others is the existence of a functional self-other distinction. At least two neural systems have been proposed to manage such a critical distinction. One system, part of the classic motor system, is specialized for the preparation and execution of motor actions that are self realized and voluntary, while the other appears primarily involved in capturing and understanding the actions of non-self or others. The latter system, of which the mirror neuron system is part, is the canonical action 'resonance' system in the brain that has evolved to share many of the same circuits involved in motor control. Mirroring or 'shared circuit systems' are assumed to be involved in resonating, imitating, and/or simulating the actions of others. A number of researchers have proposed that shared representations of motor actions may form a foundational cornerstone for higher order social processes, such as motor learning, action understanding, imitation, perspective taking, understanding facial emotions, and empathy. However, mirroring systems that evolve from the classic motor system present at least three problems: a development, a correspondence, and a control problem. Developmentally, the question is how does a mirroring system arise? How do humans acquire the ability to simulate through mapping observed onto executed actions? Are mirror neurons innate and therefore genetically programmed? To what extent is learning necessary? In terms of the correspondence problem, the question is how does the observer agent know what the observed agent's resonance activation pattern is? How does the matching of motor activation patterns occur? Finally, in terms of the control problem, the issue is how to efficiently control a mirroring system when it is turned on automatically through observation? Or, as others have stated the problem more succinctly: "Why don't we imitate all the time

  13. Two-axis polydimethylsiloxane-based electromagnetic microelectromechanical system scanning mirror for optical coherence tomography

    Science.gov (United States)

    Kim, Sehui; Lee, Changho; Kim, Jin Young; Kim, Jeehyun; Lim, Geunbae; Kim, Chulhong

    2016-10-01

    Compact size and fast imaging abilities are key requirements for the clinical implementation of an optical coherence tomography (OCT) system. Among the various small-sized technology, a microelectromechanical system (MEMS) scanning mirror is widely used in a miniaturized OCT system. However, the complexities of conventional MEMS fabrication processes and relatively high costs have restricted fast clinical translation and commercialization of the OCT systems. To resolve these problems, we developed a two-axis polydimethylsiloxane (PDMS)-based MEMS (2A-PDMS-MEMS) scanning mirror through simple processes with low costs. It had a small size of 15×15×15 mm3, was fast, and had a wide scanning range at a low voltage. The AC/DC responses were measured to evaluate the performance of the 2A-PDMS-MEMS scanning mirror. The maximum scanning angles were measured as ±16.6 deg and ±11.6 deg along the X and Y axes, respectively, and the corresponding field of view was 29.8 mm×20.5 mm with an optical focal length of 50 mm. The resonance frequencies were 82 and 57 Hz along the X and Y axes, respectively. Finally, in vivo B-scan and volumetric OCT images of human fingertips and palms were successfully acquired using the developed SD-OCT system based on the 2A-PDMS-MEMS scanning mirror.

  14. Superradiant instability of the charged scalar field in stringy black hole mirror system

    CERN Document Server

    Li, Ran

    2014-01-01

    It has been shown that the mass of the scalar field in the charged stringy black hole is never able to generate a potential well outside the event horizon to trap the superradiant modes. This is to say that the charged stringy black hole is stable against the massive charged scalar perturbation. In this paper we will study the superradiant instability of the massless scalar field in the background of charged stringy black hole due to a mirror-like boundary condition. The analytical expression of the unstable superradiant modes is derived by using the asymptotic matching method. It is also pointed out that the black hole mirror system becomes extremely unstable for a large charge $q$ of scalar field and the small mirror radius $r_m$.

  15. Implementation of the readout system in the UFFO Slewing Mirror Telescope

    CERN Document Server

    Kim, J E; Jung, A; Ahn, K -B; Choi, H S; Choi, Y J; Grossan, B; Hermann, I; Jeong, S; Kim, S -W; Kim, Y W; Lee, J; Linder, E V; Min, K W; Na, G W; Nam, J W; Nam, K H; Panayuk, M I; Park, I H; Smoot, G F; Suh, Y D; Svelitov, S; Vedenken, N; Yashin, I; Zhao, M H

    2011-01-01

    The Ultra-Fast Flash Observatory (UFFO) is a new space-based experiment to observe Gamma-Ray Bursts (GRBs). GRBs are the most luminous electromagnetic events in the universe and occur randomly in any direction. Therefore the UFFO consists of two telescopes; UFFO Burst Alert & Trigger Telescope (UBAT) to detect GRBs using a wide field-of-view (FOV), and a Slewing Mirror Telescope (SMT) to observe UV/optical events rapidly within the narrow, targeted FOV. The SMT is a Ritchey-Chretien telescope that uses a motorized mirror system and an Intensified Charge-Coupled Device (ICCD). When the GRB is triggered by the UBAT, the SMT receives the position information and rapidly tilts the mirror to the target. The ICCD start to take the data within a second after GRB is triggered. Here we give the details about the SMT readout electronics that deliver the data.

  16. Superradiant instability of charged scalar field in stringy black hole mirror system

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ran; Zhao, Junkun [Henan Normal University, Department of Physics, Xinxiang (China)

    2014-09-15

    It has been shown that the mass of a charged scalar field in the background of a charged stringy black hole is never able to generate a potential well outside the event horizon to trap the superradiant modes. This is to say that the charged stringy black hole is stable against massive charged scalar perturbations. In this paper we will study the superradiant instability of the massless scalar field in the background of charged stringy black hole due to a mirror-like boundary condition. The analytical expression of the frequencies of unstable superradiant modes is derived by using the asymptotic matching method. It is also pointed out that the black hole mirror system becomes extremely unstable for a large charge q of the scalar field and a small mirror radius r{sub m}. (orig.)

  17. The Role of Nature and Nurture for Individual Differences in Primary Emotional Systems: Evidence from a Twin Study.

    Directory of Open Access Journals (Sweden)

    Christian Montag

    Full Text Available The present study investigated for the first time the relative importance of genetics and environment on individual differences in primary emotionality as measured with the Affective Neuroscience Personality Scales (ANPS by means of a twin-sibling study design. In N = 795 participants (n = 303 monozygotic twins, n = 172 dizygotic twins and n = 267 non-twin full siblings, moderate to strong influences of genetics on individual differences in these emotional systems are observed. Lowest heritability estimates are presented for the SEEKING system (33% and highest for the PLAY system (69%. Further, multivariate genetic modeling was applied to the data showing that associations among the six ANPS scales were influences by both, a genetic as well as an environmental overlap between them. In sum, the study underlines the usefulness of the ANPS for biologically oriented personality psychology research.

  18. A Human Mirror Neuron System for Language: Perspectives from Signed Languages of the Deaf

    Science.gov (United States)

    Knapp, Heather Patterson; Corina, David P.

    2010-01-01

    Language is proposed to have developed atop the human analog of the macaque mirror neuron system for action perception and production [Arbib M.A. 2005. From monkey-like action recognition to human language: An evolutionary framework for neurolinguistics (with commentaries and author's response). "Behavioral and Brain Sciences, 28", 105-167; Arbib…

  19. The Mirror Neuron System and Observational Learning: Implications for the Effectiveness of Dynamic Visualizations

    Science.gov (United States)

    van Gog, Tamara; Paas, Fred; Marcus, Nadine; Ayres, Paul; Sweller, John

    2009-01-01

    Learning by observing and imitating others has long been recognized as constituting a powerful learning strategy for humans. Recent findings from neuroscience research, more specifically on the mirror neuron system, begin to provide insight into the neural bases of learning by observation and imitation. These findings are discussed here, along…

  20. A Human Mirror Neuron System for Language: Perspectives from Signed Languages of the Deaf

    Science.gov (United States)

    Knapp, Heather Patterson; Corina, David P.

    2010-01-01

    Language is proposed to have developed atop the human analog of the macaque mirror neuron system for action perception and production [Arbib M.A. 2005. From monkey-like action recognition to human language: An evolutionary framework for neurolinguistics (with commentaries and author's response). "Behavioral and Brain Sciences, 28", 105-167; Arbib…

  1. The Mirror Neuron System and Observational Learning: Implications for the Effectiveness of Dynamic Visualizations

    Science.gov (United States)

    van Gog, Tamara; Paas, Fred; Marcus, Nadine; Ayres, Paul; Sweller, John

    2009-01-01

    Learning by observing and imitating others has long been recognized as constituting a powerful learning strategy for humans. Recent findings from neuroscience research, more specifically on the mirror neuron system, begin to provide insight into the neural bases of learning by observation and imitation. These findings are discussed here, along…

  2. Speech-Associated Gestures, Broca's Area, and the Human Mirror System

    Science.gov (United States)

    Skipper, Jeremy I.; Goldin-Meadow, Susan; Nusbaum, Howard C.; Small, Steven L.

    2007-01-01

    Speech-associated gestures are hand and arm movements that not only convey semantic information to listeners but are themselves actions. Broca's area has been assumed to play an important role both in semantic retrieval or selection (as part of a language comprehension system) and in action recognition (as part of a "mirror" or…

  3. Two-axis Beam Steering Mirror Control system for Precision Pointing and Tracking Applications

    Energy Technology Data Exchange (ETDEWEB)

    Ulander, Klaus [California Polytechnic State Univ. (CalPoly), San Luis Obispo, CA (United States)

    2006-01-01

    Precision pointing and tracking of laser beams is critical in numerous military and industrial applications. This is particularly true for systems requiring atmospheric beam propagation. Such systems are plagued by environmental influences which cause the optical signal to break up and wander. Example applications include laser communications, precision targeting, active imaging, chemical remote sensing, and laser vibrometry. The goal of this project is to build a beam steering system using a two-axis mirror to maintain precise pointing control. Ultimately, position control to 0.08% accuracy (40 {micro}rad) with a bandwidth of 200 Hz is desired. The work described encompasses evaluation of the instrumentation system and the subsequent design and implementation of an analog electronic controller for a two-axis mirror used to steer the beam. The controller operates over a wide temperature range, through multiple mirror resonances, and is independent of specific mirrors. The design was built and successfully fielded in a Lawrence Livermore National Laboratory free-space optics experiment. All measurements and performance parameters are derived from measurements made on actual hardware that was built and field tested. In some cases, specific design details have been omitted that involve proprietary information pertaining to Lawrence Livermore National Laboratory patent positions and claims. These omissions in no way impact the general validity of the work or concepts presented in this thesis.

  4. Experimental Investigation of A Twin Shaft Micro Gas-Turbine System

    Science.gov (United States)

    Sadig, Hussain; Sulaiman, Shaharin Anwar; Ibrahim, Idris

    2013-06-01

    Due to the fast depletion of fossil fuels and its negative impact on the environment, more attention has been concentrated to find new resources, policies and technologies, which meet the global needs with regard to fuel sustainability and emissions. In this paper, as a step to study the effect of burning low calorific value fuels on gas-turbine performance; a 50 kW slightly pressurized non-premixed tubular combustor along with turbocharger based twin shaft micro gas-turbine was designed and fabricated. A series of tests were conducted to characterize the system using LPG fuel. The tests include the analysis of the temperature profile, pressure and combustor efficiency as well as air fuel ratio and speed of the second turbine. The tests showed a stable operation with acceptable efficiency, air fuel ratio, and temperature gradient for the single and twin shaft turbines.

  5. Integrated optofluidic-microfluidic twin channels: toward diverse application of lab-on-a-chip systems.

    Science.gov (United States)

    Lv, Chao; Xia, Hong; Guan, Wei; Sun, Yun-Lu; Tian, Zhen-Nan; Jiang, Tong; Wang, Ying-Shuai; Zhang, Yong-Lai; Chen, Qi-Dai; Ariga, Katsuhiko; Yu, Yu-De; Sun, Hong-Bo

    2016-01-29

    Optofluidics, which integrates microfluidics and micro-optical components, is crucial for optical sensing, fluorescence analysis, and cell detection. However, the realization of an integrated system from optofluidic manipulation and a microfluidic channel is often hampered by the lack of a universal substrate for achieving monolithic integration. In this study, we report on an integrated optofluidic-microfluidic twin channels chip fabricated by one-time exposure photolithography, in which the twin microchannels on both surfaces of the substrate were exactly aligned in the vertical direction. The twin microchannels can be controlled independently, meaning that fluids could flow through both microchannels simultaneously without interfering with each other. As representative examples, a tunable hydrogel microlens was integrated into the optofluidic channel by femtosecond laser direct writing, which responds to the salt solution concentration and could be used to detect the microstructure at different depths. The integration of such optofluidic and microfluidic channels provides an opportunity to apply optofluidic detection practically and may lead to great promise for the integration and miniaturization of Lab-on-a-Chip systems.

  6. Integrated optofluidic-microfluidic twin channels: toward diverse application of lab-on-a-chip systems

    Science.gov (United States)

    Lv, Chao; Xia, Hong; Guan, Wei; Sun, Yun-Lu; Tian, Zhen-Nan; Jiang, Tong; Wang, Ying-Shuai; Zhang, Yong-Lai; Chen, Qi-Dai; Ariga, Katsuhiko; Yu, Yu-De; Sun, Hong-Bo

    2016-01-01

    Optofluidics, which integrates microfluidics and micro-optical components, is crucial for optical sensing, fluorescence analysis, and cell detection. However, the realization of an integrated system from optofluidic manipulation and a microfluidic channel is often hampered by the lack of a universal substrate for achieving monolithic integration. In this study, we report on an integrated optofluidic-microfluidic twin channels chip fabricated by one-time exposure photolithography, in which the twin microchannels on both surfaces of the substrate were exactly aligned in the vertical direction. The twin microchannels can be controlled independently, meaning that fluids could flow through both microchannels simultaneously without interfering with each other. As representative examples, a tunable hydrogel microlens was integrated into the optofluidic channel by femtosecond laser direct writing, which responds to the salt solution concentration and could be used to detect the microstructure at different depths. The integration of such optofluidic and microfluidic channels provides an opportunity to apply optofluidic detection practically and may lead to great promise for the integration and miniaturization of Lab-on-a-Chip systems.

  7. MWCNTs/SiO2 Composite System: Carrier Transmission, Twin-Percolation and Dielectric Properties

    Institute of Scientific and Technical Information of China (English)

    CAO Wen-Qiang; LU Ming-Ming; WEN Bo; CHEN Yuan-Lu; LI Hong-Bo; YUAN Jie; CAO Mao-Sheng

    2011-01-01

    We synthesize composite systems of multi-wall carbon nanotubes (MWCNTs)/SiO2 by using the sol-gel method.The dielectric properties of the systems with different-concentration MWCNTs are studied.In our MWCNTs/SiO2 inorganic systems,the twin-percolation phenomenon exists when the concentrations of MWCNTs are 5-10% and 15-20%.The permittivity and conductivity have jumping changes.The twin-percolation phenomenon is attributed to the special transfer mechanism of MWCNTs in the system,determined by hopping and migrating electrons.Variations of dielectric properties and conductance of the M WCNTs/SiO2 systems are conformed to the percolation theory.The special percolation phenomenon and electric properties of MWCNTs/SiO2 can help us comprehend the conductivity mechanism of the MWCNTs/SiO2 systems effectively,and promote the development of a high performance function composite system.In recent years,one-dimensional (1D) nanomaterials,and especially 1D carbon nanomaterials,have attracted extensive interests due to their unique properties in various fields,such as physics,[1-4] chemistry,[5-8] and materials.[9,10] Carbon nanotubes (CNTs)[11-14] with unique one-dimensional nanostructures are widely used in field emission devices,hydrogen storage and microwave absorption,making them a good candidate for practical applications.%We synthesize composite systems of multi-wall carbon nanotubes (MWCNTs)/SiO2 by using the sol-gel method. The dielectric properties of the systems with different-concentration MWCNTs are studied. In our MWCNTs/SiO2 inorganic systems, the twin-percolation phenomenon exists when the concentrations of MWCNTs are 5-10% and 15 20%. The permittivity and conductivity have jumping changes. The twin-percolation phenomenon is attributed to the special transfer mechanism of MWCNTs in the system, determined by hopping and migrating electrons. Variations of dielectric properties and conductance of the MWCNTs/SiO2 systems are conformed to the percolation theory

  8. In situ surface monitoring system for synchrotron mirrors under high heat load.

    Science.gov (United States)

    Mui, P H; Srajer, G; Mills, D M

    1997-08-01

    A portable electro-optical system capable of real-time measurements of surface slope distortions down to 0.5 murad is described; the system is limited primarily by its short-term stability. The system employs an angle measurement technique that, in combination with the least-squares signal extraction method, reduces system fluctuations. In addition, a multireflection technique is used to enhance the detectable resolution. Although designed for use with mirrors for synchrotron radiation sources, this system has the flexibility to be applied to other optical components. The prototype system has been tested on a sample mirror piece, and preliminary results are presented. A brief discussion about the extension of this metrology unit to adaptive optics is also given.

  9. Do you mean me? Communicative intentions recruit the mirror and the mentalizing system.

    Science.gov (United States)

    Ciaramidaro, Angela; Becchio, Cristina; Colle, Livia; Bara, Bruno G; Walter, Henrik

    2014-07-01

    Being able to comprehend communicative intentions and to recognize whether such intentions are directed toward us or not is extremely important in social interaction. Two brain systems, the mentalizing and the mirror neuron system, have been proposed to underlie intention recognition. However, little is still known about how the systems cooperate within the process of communicative intention understanding and to what degree they respond to self-directed and other-directed stimuli. To investigate the role of the mentalizing and the mirror neuron system, we used functional magnetic resonance imaging with four types of action sequence: communicative and private intentions as well as other-directed and self-directed intentions. Categorical and functional connectivity analyses showed that both systems contribute to the encoding of communicative intentions and that both systems are significantly stronger activated and more strongly coupled in self-directed communicative actions.

  10. What do mirror neurons mirror?

    NARCIS (Netherlands)

    Uithol, S.; Rooij, I.J.E.I. van; Bekkering, H.; Haselager, W.F.G.

    2011-01-01

    Single cell recordings in monkeys provide strong evidence for an important role of the motor system in action understanding. This evidence is backed up by data from studies of the (human) mirror neuron system using neuroimaging or TMS techniques, and behavioral experiments. Although the data acquire

  11. What do mirror neurons mirror?

    NARCIS (Netherlands)

    Uithol, S.; Rooij, I.J.E.I. van; Bekkering, H.; Haselager, W.F.G.

    2011-01-01

    Single cell recordings in monkeys provide strong evidence for an important role of the motor system in action understanding. This evidence is backed up by data from studies of the (human) mirror neuron system using neuroimaging or TMS techniques, and behavioral experiments. Although the data

  12. ACARDIAC TWIN

    OpenAIRE

    Vinayachandran; Jyothi,; Bindu; Umadevi

    2014-01-01

    Acardiac twin is a very rare complication occurring in monozygotic twins in which one fetus develops normally (pump twin) and the other (recipient twin) demonstrate cardiac non development and othe r anomalies. This may represent an extreme form of TTTS, also referred to as TRAP sequence. 1,2,

  13. Compressive Strength Properties of Natural Gas Hydrate Pellet by Continuous Extrusion from a Twin-Roll System

    OpenAIRE

    Yun-Hoo Lee; Bong-Hwan Koh; Heung Soo Kim; Myung Ho Song

    2013-01-01

    This study investigates the compressive strength of natural gas hydrate (NGH) pellet strip extruded from die holes of a twin-roll press for continuous pelletizing (TPCP). The lab-scale TPCP was newly developed, where NGH powder was continuously fed and extruded into strip-type pellet between twin rolls. The system was specifically designed for future expansion towards mass production of solid form NGH. It is shown that the compressive strength of NGH pellet strip heavily depends on parameters...

  14. Is the human mirror neuron system plastic? Evidence from a transcranial magnetic stimulation study.

    Science.gov (United States)

    Mehta, Urvakhsh Meherwan; Waghmare, Avinash V; Thirthalli, Jagadisha; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

    2015-10-01

    Virtual lesions in the mirror neuron network using inhibitory low-frequency (1Hz) transcranial magnetic stimulation (TMS) have been employed to understand its spatio-functional properties. However, no studies have examined the influence of neuro-enhancement by using excitatory high-frequency (20Hz) repetitive transcranial magnetic stimulation (HF-rTMS) on these networks. We used three forms of TMS stimulation (HF-rTMS, single and paired pulse) to investigate whether the mirror neuron system facilitates the motor system during goal-directed action observation relative to inanimate motion (motor resonance), a marker of putative mirror neuron activity. 31 healthy individuals were randomized to receive single-sessions of true or sham HF-rTMS delivered to the left inferior frontal gyrus - a component of the human mirror system. Motor resonance was assessed before and after HF-rTMS using three TMS cortical reactivity paradigms: (a) 120% of resting motor threshold (RMT), (b) stimulus intensity set to evoke motor evoked potential of 1-millivolt amplitude (SI1mV) and (c) a short latency paired pulse paradigm. Two-way RMANOVA showed a significant group (true versus sham) X occasion (pre- and post-HF-rTMS motor resonance) interaction effect for SI1mV [F(df)=6.26 (1, 29), p=0.018] and 120% RMT stimuli [F(df)=7.01 (1, 29), p=0.013] indicating greater enhancement of motor resonance in the true HF-rTMS group than the sham-group. This suggests that HF-rTMS could adaptively modulate properties of the mirror neuron system. This neuro-enhancement effect is a preliminary step that can open translational avenues for novel brain stimulation therapeutics targeting social-cognition deficits in schizophrenia and autism. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. The aberration characteristics in a misaligned three-mirror anastigmatic (TMA) system

    Science.gov (United States)

    Wang, Bin; Wu, Fan; Ye, Yutang

    2016-09-01

    To realize the efficient alignment of the TMA system, the aberrations in a misaligned TMA system had been analyzed theoretically in this paper. Firstly, based on the nodal aberration theory (NAT), the aberration types and characteristics in the misaligned TMA system had been concluded; Secondly, a simulation validation had been carried out to testify the analysis results, the simulation results validates the aberration characteristics; Finally, the alignment procedures were determined according to the aberration characteristics: adjust the axial spacing of the mirrors in terms of Z9 in the center field of TMA system first; and then, adjust the decenters and tilts of the mirrors in terms of Z5 - Z8 in the edge field of TMA system. This method is helpful for the alignment of the TMA telescope.

  16. Fetal cardiac activity analysis during twin pregnancy using a multi-channel SQUID system

    Science.gov (United States)

    Costa Monteiro, E.; Schleussner, E.; Kausch, S.; Grimm, B.; Schneider, A.; Hall Barbosa, C.; Haueisen, J.

    2001-05-01

    The use of SQUID magnetometers for non-invasive in utero assessment of cardiac electrical disturbances has already been shown to be a valuable clinical tool. In this way, its applicability also for the complicated case of twin pregnancy, in which the proximity of the cardiac magnetic source of each fetus can hamper the individual analysis of cardiac electrical activity, is of clinical interest. In this paper, we present fetal magnetocardiography performed on a mother pregnant of twins with 26 weeks gestational age, measured inside a magnetically shielded room, by using two identical 31-channel low- Tc SQUID magnetometer systems. Each sensor array has been positioned over one of the fetuses, according to its heart position previously assessed with the aid of ultrasound measurements. The raw data is initially averaged in time and, afterwards, analyzed by means of time plots and isofield maps. The time recordings allow the study of the morphology of each fetus’ cardiac signal and the cardiac time intervals. The resultant equivalent dipole obtained from the isofield maps indicates the position and orientation of each fetus heart. The results agree with the ultrasound analysis performed immediately before the measurements and used to obtain the approximate location of the fetuses’ hearts. Since a distinct analysis of the cardiac electrical activity of each fetus could be achieved, the results indicate the potential of the fetal magnetocardiography in the individual antenatal diagnosis of each one of the fetuses of a twin pregnancy.

  17. Design, Modeling and Implementation of Pic Based Wireless Control System to Eliminate Blind Spots in Vehicle Side Mirrors

    Directory of Open Access Journals (Sweden)

    Mahmoud Z. Iskandarani

    2008-01-01

    Full Text Available A PIC controlled IR system for the control of vehicle side mirror system movements for the purpose of revealing blind spots is designed and implemented. The designed and built system allows the side view mirrors to be adjusted based on the driver head movement. The infrared-based head tracking system maps a predetermined coordinates for head movements and results in a triangularly computable geometry, which is fed to the PIC, based controlling system. This will cause the vehicle mirror movement via carefully selected miniature motors.

  18. Characterization and closed-loop performance of a liquid mirror adaptive optical system.

    Science.gov (United States)

    ten Have, Eric S; Vdovin, Gleb

    2012-04-20

    A deformable mirror based on the principle of total internal reflection of light from an electrostatically deformed liquid-air interface was realized and used to perform closed-loop adaptive optical (AO) correction on a collimated laser beam aberrated by a rotating phase disk. Equations describing the resonant and oscillatory behavior of the liquid system were obtained and applied to the system under consideration. Characterization of the mirror included open- and closed-loop frequency responses, determination of rise times, the damping times of the liquid, and the influence of liquid surface motion in the absence of external optical aberrations. The performance of the AO system was determined for static and dynamic aberrations for various sets of system parameters. The predictions of the general expressions were compared to the results of the experimental realization and were found to be in good agreement.

  19. A low-cost mirror mount control system for optics setups

    CERN Document Server

    Gopalakrishnan, Maithreyi

    2013-01-01

    We describe a flexible, simple to build, low-cost, and computer-controlled optical mirror actuator system we developed for undergraduate research laboratories. Geared motors for hobby robotics are controlled by an Arduino microcontroller board in combination with an H bridge to finely position the mirror mount actuators. We present a graphical user interface based on the free Python script language. The price of the fully controlled actuator system is thus only a small fraction of the price of any commercial system; however, it is quickly implementable due to the use of open hardware electronics. We show the performance of the system and give an outlook for future expansions and use in advanced optical setups.

  20. The cortical mirror system reflects the cortical motor system. Comment on "Grasping synergies: A motor-control approach to the mirror neuron mechanism" by A. D'Ausilio et al.

    Science.gov (United States)

    Naish, Katherine R.; Holmes, Nicholas P.

    2015-03-01

    Mirror neurons - cells that are active during both the execution and observation of actions - have been implicated in a wide range of functions. It was originally suggested that these interesting cells play a role in the ability to understand the actions of others [2]. While there are strong arguments against the mirror system being the only mechanism underlying our ability to interpret others' actions (e.g., [4]), it may well play a contributory role. One important constraint on the role that the mirror system could play in action understanding is the extent to which the observed action and the mirror representation match each other. To use the mirror analogy: how closely does the reflection resemble the subject standing in front of it?

  1. Mirror fusion test facility magnet system. Final design report

    Energy Technology Data Exchange (ETDEWEB)

    Henning, C.D.; Hodges, A.J.; VanSant, J.H.; Dalder, E.N.; Hinkle, R.E.; Horvath, J.A.; Scanlan, R.M.; Shimer, D.W.; Baldi, R.W.; Tatro, R.E.

    1980-09-03

    Information is given on each of the following topics: (1) magnet description, (2) superconducting manufacture, (3) mechanical behavior of conductor winding, (4) coil winding, (5) thermal analysis, (6) cryogenic system, (7) power supply system, (8) structural analysis, (9) structural finite element analysis refinement, (10) structural case fault analysis, and (11) structural metallurgy. (MOW)

  2. A microwave tomography system using a tunable mirror for beam steering

    Energy Technology Data Exchange (ETDEWEB)

    Tayebi, A. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Non-Destructive Evaluation Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Department of Physic (United States); Tang, J. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Paladhi, P. Roy; Udpa, L.; Udpa, S. [Department of Electrical and Computer Engineering, College of Engineering, Michigan State University, East Lansing, MI 48824 (United States); Non-Destructive Evaluation Laboratory, Michigan State University, East Lansing, MI 48824 (United States)

    2014-02-18

    Microwave tomography is a fast-growing technique in the fields of NDE and medical industry. This paper presents a new microwave tomography system which reduces the complexities of conventional microwave imaging systems by utilizing a reconfigurable mirror, a tunable reflectarray antenna. In order to build a tunable reflectarray with beam steering capabilities, the unit cell characteristics should dynamically alter. Modelling and experimental results of a single unit cell are presented in this work.

  3. Transport of ultracold neutrons through a mirror system with surface roughness as a velocity filter

    CERN Document Server

    Chizhova, L A; Jenke, T; Cronenberg, G; Geltenbort, P; Abele, H; Burgdörfer, J

    2012-01-01

    We perform classical Monte Carlo simulations of ultracold neutron transport through an absorbing-reflecting mirror system in the Earth's gravitational field. We show that the underlying mixed phase space of regular skipping motion and random motion due to disorder scattering can be exploited to realize a velocity filter for ultracold neutrons. The range of velocities selected is controlled by geometric parameters of the wave guide. Possible applications include investigations of transport and scattering dynamics in confined systems.

  4. SOFTWARE-CONTROLLED SYSTEM OF ULTRA-PRECISION MACHINING AXISYMMETRIC ASPHERIC MIRROR

    Institute of Scientific and Technical Information of China (English)

    GUO Yinbiao; WEI Lizhen

    2006-01-01

    In order to improve machining accuracy and efficiency, a software-controlled system of ultra-precision machining for axisymmetric aspheric mirror, using techniques of error compensation,remote transmission and modularization, is designed based on industrial PC, Windows 2000 work platform and Visual Basic 6.0. By experiments, this system realizes functions of ultra-precision machining, machining error compensation, remote data transmission and automatic data transformation among first machining, compensation machining and accuracy measurement. The actual application shows that error compensation improves machining accuracy, remote transmission improves machining efficiency while modularization avoids repeated work and improves design efficiency. Therefore, the system has met ultra-precision machining need for aspheric mirror.

  5. Grating exchange system of independent mirror supported by floating rotary stage

    Science.gov (United States)

    Zhang, Jianhuan; Tao, Jin; Liu, Yan; Nan, Yan

    2015-10-01

    The performance of The Grating Exchange System can satisfy the Thirty Meter Telescope - TMT for astronomical observation WFOS index requirements and satisfy the requirement of accuracy in the grating exchange. It is used to install in the MOBIE and a key device of MOBIE. The Wide Field Optical Spectrograph (WFOS) is one of the three first-light observing capabilities selected by the TMT Science Advisory Committee. The Multi-Object Broadband Imaging Echellette (MOBIE) instrument design concept has been developed to address the WFOS requirements as described in the TMT Science-Based Requirements Document (SRD). The Grating Exchange System uses a new type of separate movement way of three grating devices and a mirror device. Three grating devices with a mirror are able to achieve independence movement. This kind of grating exchange system can effectively solve the problem that the volume of the grating change system is too large and that the installed space of MOBIE instruments is too limit. This system adopts the good stability, high precision of rotary stage - a kind of using air bearing (Air bearing is famous for its ultra-high precision, and can meet the optical accuracy requirement) and rotation positioning feedback gauge turntable to support grating device. And with a kind of device which can carry greater weight bracket fixed on the MOBIE instrument, with two sets of servo motor control rotary stage and the mirror device respectively. And we use the control program to realize the need of exercising of the grating device and the mirror device. Using the stress strain analysis software--SolidWorks for stress and strain analysis of this structure. And then checking the structure of the rationality and feasibility. And prove that this system can realize the positioning precision under different working conditions can meet the requirements of imaging optical grating diffraction efficiency and error by the calculation and optical performance analysis.

  6. Caycedo's Sophrology and Lozanov's Suggestology: Mirror Images of a System.

    Science.gov (United States)

    Bancroft, W. Jane

    In the 1960's, two medical doctors, Georgi Lozanov and Alfonso Caycedo, discovered independently that certain yogic techniques of physical and mental relaxation could be used to produce not only analgesia but also improved memory and concentration. Systems originally used in medicine and psycho-therapy were applied to education, in particular to…

  7. Design and Implementation of Microcontroller Based SelfSwitching Control and Protection System for Twin Pumps

    Directory of Open Access Journals (Sweden)

    Hrudaynath Yelgudkar

    2016-07-01

    Full Text Available This paper apprises reader with a unique, modular and comprehensive control system designed using embedded systems approach (microcontroller based, primarily for efficient use of twin (two or couple of pumps working simultaneously in a given environment while constantly monitoring critical parameters such as current, voltage, temperature, water level in reservoir etc. for protection purposes. Though this control system is developed for pumps, it can be seamlessly adapted for controlling similar loads. We have developed the system using ATMmega-32 microcontroller of AVR family. The critical parameters were monitored using ADC port (analogto-digital-converter port of the microcontroller. Motivation behind developing this system was to replace classical „dedicated integrated circuit‟ based control system with more intelligent, compact, programmable and upgradable system besides lowering its cost aspects, using „embedded systems‟.

  8. View-Invariant Visuomotor Processing in Computational Mirror Neuron System for Humanoid.

    Science.gov (United States)

    Dawood, Farhan; Loo, Chu Kiong

    2016-01-01

    Mirror neurons are visuo-motor neurons found in primates and thought to be significant for imitation learning. The proposition that mirror neurons result from associative learning while the neonate observes his own actions has received noteworthy empirical support. Self-exploration is regarded as a procedure by which infants become perceptually observant to their own body and engage in a perceptual communication with themselves. We assume that crude sense of self is the prerequisite for social interaction. However, the contribution of mirror neurons in encoding the perspective from which the motor acts of others are seen have not been addressed in relation to humanoid robots. In this paper we present a computational model for development of mirror neuron system for humanoid based on the hypothesis that infants acquire MNS by sensorimotor associative learning through self-exploration capable of sustaining early imitation skills. The purpose of our proposed model is to take into account the view-dependency of neurons as a probable outcome of the associative connectivity between motor and visual information. In our experiment, a humanoid robot stands in front of a mirror (represented through self-image using camera) in order to obtain the associative relationship between his own motor generated actions and his own visual body-image. In the learning process the network first forms mapping from each motor representation onto visual representation from the self-exploratory perspective. Afterwards, the representation of the motor commands is learned to be associated with all possible visual perspectives. The complete architecture was evaluated by simulation experiments performed on DARwIn-OP humanoid robot.

  9. View-Invariant Visuomotor Processing in Computational Mirror Neuron System for Humanoid.

    Directory of Open Access Journals (Sweden)

    Farhan Dawood

    Full Text Available Mirror neurons are visuo-motor neurons found in primates and thought to be significant for imitation learning. The proposition that mirror neurons result from associative learning while the neonate observes his own actions has received noteworthy empirical support. Self-exploration is regarded as a procedure by which infants become perceptually observant to their own body and engage in a perceptual communication with themselves. We assume that crude sense of self is the prerequisite for social interaction. However, the contribution of mirror neurons in encoding the perspective from which the motor acts of others are seen have not been addressed in relation to humanoid robots. In this paper we present a computational model for development of mirror neuron system for humanoid based on the hypothesis that infants acquire MNS by sensorimotor associative learning through self-exploration capable of sustaining early imitation skills. The purpose of our proposed model is to take into account the view-dependency of neurons as a probable outcome of the associative connectivity between motor and visual information. In our experiment, a humanoid robot stands in front of a mirror (represented through self-image using camera in order to obtain the associative relationship between his own motor generated actions and his own visual body-image. In the learning process the network first forms mapping from each motor representation onto visual representation from the self-exploratory perspective. Afterwards, the representation of the motor commands is learned to be associated with all possible visual perspectives. The complete architecture was evaluated by simulation experiments performed on DARwIn-OP humanoid robot.

  10. Influence of the contaminant size on the thermal damage of optical mirrors used in high energy laser system

    Science.gov (United States)

    Han, Kai; Song, Rui; Xu, Xiaojun; Liu, Zejin

    2016-09-01

    The laser induced damage is a troublesome issue in the application of optical mirrors, which is related to the robustness of the whole laser system. There are two types of mechanisms about the damage of optical mirrors: thermal effect and field effect, which are responsible for the high energy continuous wave (cw) laser induced damage and the high power pulsed laser induced damage, respectively. Under the irradiation of high energy laser, the contaminant on the mirror surface absorbs the laser energy and converts the laser energy to heat. With the heat accumulating, the optical mirror is likely to fuse and even be totally destroyed. The temperature of the contaminant was measured when it was irradiated by a cw high energy laser with power intensity 3.3kW/cm2. It is found that the contaminant achieves thermal equilibrium in a few seconds and then the temperature stays at 1700K. A physical model was established to describe the process of the thermal equilibrium. The influence of the contaminant size on the thermal damage of the optical mirror was studied theoretically. The results show that the contaminant size plays an important role in the thermal damage of the optical mirror. Only when the contaminant size is smaller than a critical size ( 10μm), the contaminant may reach thermal equilibrium and the optical mirror works well in the high energy laser system. If the contaminant size is quite large (mirror will damage under the irradiation of high energy laser.

  11. Improvement in QEPAS system based on miniaturized collimator and flat mirror

    Science.gov (United States)

    Wang, Fupeng; Chang, Jun; Wang, Qiang; Liu, Yuanyuan; Liu, Zhaojun; Qin, Zengguang; Zhu, Cunguang

    2016-12-01

    An improved QEPAS (quartz enhanced photo-acoustic spectroscopy) system based on an optical structure comprising miniaturized collimator and flat mirror is proposed. The beam diameter of the miniaturized collimator is designed less than 0.2 mm in a 20 mm working distance. Experiments are set up to compare the beam quality and photo-acoustic performance of three optical structures (this one, fiber lead mode and conventional focus mode). By virtue of the micro-resonator tubes and flat mirror, the new proposed structure achieves a SNR of 260 for a 3000 ppmv water vapor sample, which is much better than 183 for the fiber lead mode and 193 for the conventional focus mode respectively. This test is achieved by using the same self-designed circuit with the same parameters. The proposed optical structure is simpler and easier for optical alignment, and provides an alternative way in improving and simplifying the QEPAS system for industrial applications.

  12. Robust entanglement between a movable mirror and atomic ensemble and entanglement transfer in coupled optomechanical system

    Science.gov (United States)

    Bai, Cheng-Hua; Wang, Dong-Yang; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

    2016-09-01

    We propose a scheme for the creation of robust entanglement between a movable mirror and atomic ensemble at the macroscopic level in coupled optomechanical system. We numerically simulate the degree of entanglement of the bipartite macroscopic entanglement and show that it depends on the coupling strength between the cavities and is robust with respect to the certain environment temperature. Inspiringly and surprisingly, according to the reported relation between the mechanical damping rate and the mechanical frequency of the movable mirror, the numerical simulation result shows that such bipartite macroscopic entanglement persists for environment temperature up to 170 K, which breaks the liquid nitrogen cooling and liquid helium cooling and largely lowers down the experiment cost. We also investigate the entanglement transfer based on this coupled system. The scheme can be used for the realization of quantum memories for continuous variable quantum information processing and quantum-limited displacement measurements.

  13. Robust entanglement between a movable mirror and atomic ensemble and entanglement transfer in coupled optomechanical system.

    Science.gov (United States)

    Bai, Cheng-Hua; Wang, Dong-Yang; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

    2016-09-14

    We propose a scheme for the creation of robust entanglement between a movable mirror and atomic ensemble at the macroscopic level in coupled optomechanical system. We numerically simulate the degree of entanglement of the bipartite macroscopic entanglement and show that it depends on the coupling strength between the cavities and is robust with respect to the certain environment temperature. Inspiringly and surprisingly, according to the reported relation between the mechanical damping rate and the mechanical frequency of the movable mirror, the numerical simulation result shows that such bipartite macroscopic entanglement persists for environment temperature up to 170 K, which breaks the liquid nitrogen cooling and liquid helium cooling and largely lowers down the experiment cost. We also investigate the entanglement transfer based on this coupled system. The scheme can be used for the realization of quantum memories for continuous variable quantum information processing and quantum-limited displacement measurements.

  14. Focus control system for stretched-membrane mirror module

    Science.gov (United States)

    Butler, Barry L.; Beninga, Kelly J.

    1991-01-01

    A focus control system dynamically sets and controls the focal length of a reflective membrane supported between a perimeter frame. A rear membrane is also supported between the perimeter frame rearward and spaced apart from a back side of the reflective membrane. The space between the membranes defines a plenum space into which a mass of gas at a first pressure is inserted. The pressure differential between the first pressure and an external pressure, such as the atmospheric pressure, causes the reflective membrane to assume a first curvature relative to a reference plane associated with the perimeter frame. This curvature defines the focal length of the reflective membrane. The focal length is dynamically controlled by changing the volume of the plenum space, thereby changing the first pressure. The system can be used to change or maintain the pressure differential and hence the front membrane curvature. The plenum volume is changed by pushing or pulling on a central section of the rear membrane using a suitable actuator. Sensing means continuously sense the location of the reflective membrane relative to the reference plane. This sensed position is compared to a reference position, and a resulting error signal, comprising the difference between the sensed position and reference position, drives the actuator in a direction to minimize the difference. A vent value compensates for temperature changes or leaks in the closed volume by allowing the pressure differential to be adjusted as required to center the working range of the actuator about the desired focal length.

  15. Robust Adaptive Fuzzy Output Tracking Control for a Class of Twin-Roll Strip Casting Systems

    Directory of Open Access Journals (Sweden)

    Yu-Jun Zhang

    2017-01-01

    Full Text Available This paper is concerned with the adaptive fuzzy control problem for a class of twin-roll strip casting systems. By using fuzzy logic systems (FLSs to approximate the compounded nonlinear functions, a novel robust output tracking controller with adaptation laws is designed based on the high gain observer. First, the nonlinear dynamic equations for the roll gap and the molten steel level are constructed, respectively. Then, the mean value theorem is employed to transform the nonaffine nonlinear systems to the corresponding affine nonlinear systems. Moreover, it is also proved that all the closed-loop signals are bounded and the systems output tracking errors can converge to the desired neighborhoods of the origin via the Lyapunov stability analysis. Finally, simulation results, based on semiexperimental system dynamic model and parameters, are worked out to show the effectiveness of the proposed adaptive fuzzy design method.

  16. Modeling of a Micro-Electronic Mechanical Systems (MEMS) Deformable Mirror for Simulation and Characterization

    Science.gov (United States)

    2016-09-01

    25  B.  MODEL USER APPLICABILITY ........................................................29  V.  CONCLUSION AND FUTURE WORK...this research, as it is the most complex mirror type. This device is composed of two mechanical systems: an array of actuations and a non- linear ...3.5) Equation (3.5) can be adapted into an algebraic expression in order to solve for the plate

  17. Autism and the mirror neuron system: insights from learning and teaching

    OpenAIRE

    2014-01-01

    Individuals with autism have difficulties in social learning domains which typically involve mirror neuron system (MNS) activation. However, the precise role of the MNS in the development of autism and its relevance to treatment remain unclear. In this paper, we argue that three distinct aspects of social learning are critical for advancing knowledge in this area: (i) the mechanisms that allow for the implicit mapping of and learning from others' behaviour, (ii) the motivation to attend to an...

  18. Communicative hand gestures and object-directed hand movements activated the mirror neuron system

    OpenAIRE

    Montgomery, Kimberly J.; Isenberg, Nancy; Haxby, James V.

    2007-01-01

    Humans produce hand movements to manipulate objects, but also make hand movements to convey socially relevant information to one another. The mirror neuron system (MNS) is activated during the observation and execution of actions. Previous neuroimaging experiments have identified the inferior parietal lobule (IPL) and frontal operculum as parts of the human MNS. Although experiments have suggested that object-directed hand movements drive the MNS, it is not clear whether communicative hand ge...

  19. Design of a multipurpose mirror system for LCLS-2 photon transport studies (Conference Presentation)

    Science.gov (United States)

    Morton, Daniel S.; Cocco, Daniele; Kelez, Nicholas M.; Srinivasan, Venkat N.; Stefan, Peter M.; Zhang, Lin

    2016-09-01

    LCLS-2 is a high repetition rate (up to 1 MHz) superconducting FEL and the soft x-ray branch will operate from 0.2 to 1.3 keV. Over this energy range, there is a large variation in beam divergence and therefore, a large variation in the beam footprint on the optics. This poses a significant problem as it creates thermal gradients across the tangential axis of the mirror, which, in turn, creates non-cylindrical deformations that cannot be corrected using a single actuator mechanical bender. To minimize power loss and preserve the wave front, the optics requires sub-nanometer RMS height errors and sub-microradian slope errors. One of the key components of the beam transport in the SXR beamline is the bendable focusing mirror system, operated in a Kirkpatrick-Baez Configuration. For the first time in the Synchrotron or FEL world, the large bending needed to focus the beam will be coupled with a cooling system on the same mirror assembly, since the majority of the FEL power is delivered through every optic leading up to the sample. To test such a concept, we have developed a mirror bender system to be used as a multipurpose optic. The system has been very accurately modeled in FEA. This, along with very good repeatability of the bending mechanism, makes it ideal for use as a metrology tool for calibrating instruments as well as to test the novel cooling/bending concept. The bender design and the tests carried out on it will be presented.

  20. Automatic method for synchronizing workpiece frames in twin-robot nondestructive testing system

    Science.gov (United States)

    Lu, Zongxing; Xu, Chunguang; Pan, Qinxue; Meng, Fanwu; Li, Xinliang

    2015-07-01

    The workpiece frames relative to each robot base frame should be known in advance for the proper operation of twin-robot nondestructive testing system. However, when two robots are separated from the workpieces, the twin robots cannot reach the same point to complete the process of workpiece frame positioning. Thus, a new method is proposed to solve the problem of coincidence between workpiece frames. Transformation between two robot base frames is initiated by measuring the coordinate values of three non-collinear calibration points. The relationship between the workpiece frame and that of the slave robot base frame is then determined according to the known transformation of two robot base frames, as well as the relationship between the workpiece frame and that of the master robot base frame. Only one robot is required to actually measure the coordinate values of the calibration points on the workpiece. This requirement is beneficial when one of the robots cannot reach and measure the calibration points. The coordinate values of the calibration points are derived by driving the robot hand to the points and recording the values of top center point(TCP) coordinates. The translation and rotation matrices relate either the two robot base frames or the workpiece and master robot. The coordinated are solved using the measured values of the calibration points according to the Cartesian transformation principle. An optimal method is developed based on exponential mapping of Lie algebra to ensure that the rotation matrix is orthogonal. Experimental results show that this method involves fewer steps, offers significant advantages in terms of operation and time-saving. A method used to synchronize workpiece frames in twin-robot system automatically is presented.

  1. Automatic Method for Synchronizing Workpiece Frames in Twin-robot Nondestructive Testing System

    Institute of Scientific and Technical Information of China (English)

    LU Zongxing; XU Chunguang; PAN Qinxue; MENG Fanwu; LI Xinliang

    2015-01-01

    The workpiece frames relative to each robot base frame should be known in advance for the proper operation of twin-robot nondestructive testing system. However, when two robots are separated from the workpieces, the twin robots cannot reach the same point to complete the process of workpiece frame positioning. Thus, a new method is proposed to solve the problem of coincidence between workpiece frames. Transformation between two robot base frames is initiated by measuring the coordinate values of three non-collinear calibration points. The relationship between the workpiece frame and that of the slave robot base frame is then determined according to the known transformation of two robot base frames, as well as the relationship between the workpiece frame and that of the master robot base frame. Only one robot is required to actually measure the coordinate values of the calibration points on the workpiece. This requirement is beneficial when one of the robots cannot reach and measure the calibration points. The coordinate values of the calibration points are derived by driving the robot hand to the points and recording the values of top center point(TCP) coordinates. The translation and rotation matrices relate either the two robot base frames or the workpiece and master robot. The coordinated are solved using the measured values of the calibration points according to the Cartesian transformation principle. An optimal method is developed based on exponential mapping of Lie algebra to ensure that the rotation matrix is orthogonal. Experimental results show that this method involves fewer steps, offers significant advantages in terms of operation and time-saving. A method used to synchronize workpiece frames in twin-robot system automatically is presented.

  2. Measuring Change in Health-System Pharmacy Over 50 Years: "Reflecting" on the Mirror, Part II.

    Science.gov (United States)

    Weber, Robert J; Stevenson, James G; White, Sara J

    2014-01-01

    The Director's Forum guides pharmacy leaders in establishing patient-centered services in hospitals and health systems. 2013 marked the 50th anniversary of the publication of the Mirror to Hospital Pharmacy, which was a comprehensive study of hospital pharmacy services in the United States. This iconic textbook was co-authored by Donald Francke, Clifton J. Latiolais, Gloria N. Francke, and Norman Ho. The Mirror's results profiled hospital pharmacy of the 1950s; these results established goals for the profession in 6 paradigms: (1) professional philosophy and ethics; (2) scientific and technical expansion of health-system pharmacy; (3) development of administrative and managerial acumen; (4) increased practice competence; (5) wage and salary commensurate with professional responsibilities; and (6) health-system pharmacy as a vehicle for advancing the profession as a whole. This article critically reviews our progress on the last of 3 goals. An understanding of the profession's progress on these goals since the seminal work of the Mirror provides directors of pharmacy a platform from which to develop strategies to enhance patient-centered pharmacy services.

  3. Measuring change in health-system pharmacy over 50 years: "reflecting" on the mirror, part I.

    Science.gov (United States)

    Weber, Robert J; Stevenson, James; Ng, Christine; White, Sara

    2013-12-01

    The Director's Forum guides pharmacy leaders in establishing patient-centered services in hospitals and health systems. August 2013 marked the 50th anniversary of the publication of the Mirror to Hospital Pharmacy, which was a comprehensive study of hospital pharmacy services in the United States. This iconic textbook was co-authored by Donald Francke, Clifton J. Latiolais, Gloria N. Francke, and Norman Ho. The Mirror profiled hospital pharmacy of the 1950s and established goals for the profession in 6 paradigms: (1) professional philosophy and ethics, (2) scientific and technical expansion of health-system pharmacy, (3) development of administrative and managerial acumen, (4) increased practice competence, (5) wage and salary compensation commensurate with professional responsibilities, and (6) health-system pharmacy as a vehicle for advancing the profession as a whole. This article critically reviews the profession's progress on the first 3 goals; an article in the January 2014 issue of Hospital Pharmacy will review the final 3 goals. An understanding of the profession's progress on these goals since the seminal work of the Mirror provides directors of pharmacy a platform from which to develop strategies to enhance patient-centered pharmacy services.

  4. Twin births

    DEFF Research Database (Denmark)

    Hoffmann, Elise; Oldenburg, Anna; Rode, Line;

    2012-01-01

    To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery.......To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery....

  5. Simulation study of mechanical properties of bulk metallic glass systems: martensitic inclusions and twinned precipitates

    Science.gov (United States)

    Zaheri, A.; Abdeljawad, F.; Haataja, M.

    2014-12-01

    Monolithic bulk metallic glasses (BMGs) exhibit a unique combination of mechanical properties, such as high strength and large elasticity limits, but the lack of ductility is considered the main Achilles' heel of BMG systems. To increase the competitiveness of BMGs vis-à-vis conventional structural materials, the problem of catastrophic failure via intense plastic strain localization (‘shear banding’) has to be addressed. Recent experimental observations suggest that the addition of structural heterogeneities, in the form of crystalline particles, to BMG systems hinders the catastrophic propagation of shear bands and leads to enhanced ductility. These structural heterogeneities can be introduced by either forming BMG composites, where second-phase crystalline particles accommodate applied loads via martensitic transformation mechanisms, or developing glassy alloys that precipitate crystalline particles under deformation, a process by which further deformation can be sustained by twinning mechanisms in the crystalline phase. In this work, we present a non-linear continuum model capable of capturing the structural heterogeneity in the glassy phase and accounting for intrinsic work hardening via martensitic transformations in second-phase reinforcements in BMG composites and deformation twinning in precipitated crystalline particles. Simulation results reveal that in addition to intrinsic work hardening in the crystalline phase, particle size greatly affects the overall mechanical behavior of these BMG systems. The precipitation of crystalline particles in monolithic BMGs yields two-phase microstructures that promote more homogeneous deformation, delay the propagation of incipient shear bands, and ultimately result in improved ductility characteristics.

  6. The panels for primary and secondary mirror reflectors and the Active Surface System for the new Sardinia Radio Telescope

    Science.gov (United States)

    Zacchiroli, G.; Fiocchi, F.; Maccaferri, G.; Morsiani, M.; Orfei, A.; Pernechele, C.; Pisanu, T.; Roda, J.; Vargiu, G.

    In this paper we will describe the panels for the primary and secondary mirror reflectors and the active surface system that will be provided on the Sardinia Radio Telescope. The panels for the primary and secondary mirror have been designed to allow an operating frequency up to 100 GHz. The active surface system will be used to overcome the effect of gravity deformation on the antenna gain and to re-shape the primary mirror in a parabolic form, in order to avoid large phase error contribution on the gain for the highest frequencies placed in the primary focus.

  7. Granule size distributions after twin-screw granulation - Do not forget the feeding systems.

    Science.gov (United States)

    Meier, R; Thommes, M; Rasenack, N; Moll, K-P; Krumme, M; Kleinebudde, P

    2016-09-01

    The aim of this study was to investigate the influence of qualitatively different powder feeder performances on resulting granule size distributions after twin-screw granulation of a highly drug loaded, hydrophobic mixture and a mannitol powder. It was shown that powder feeder related problems usually cannot be identified by trusting in the values given by the feeder. Therefore, a newly developed model for the evaluation of the performance of powder feeders was introduced and it was tried to connect this model to residence time distributions in twin-screw granulation processes. The influence of feeder performances on resulting granule size distributions varied, depending on the applied screw configuration and the used powder. Regarding the hydrophobic and highly drug loaded formulation, which was granulated at an L/S-ratio of 0.5, a pure conveying screw and a medium kneading configuration, consisting of 60° kneading blocks were negatively influenced by poor feeder settings. For optimal settings more narrow distributions could be obtained. For an extensive kneading configuration good and poor settings resulted in mono-modal granule size distributions but were differing in the overall size. Mannitol, a model substance for a liquid sensitive formulation was granulated at an L/S-ratio of 0.075. It was even more important to maintain optimal feeding as mannitol was highly affected by poor feeder performances. Even an extensive kneading configuration could not level the errors in powder feeder performance, resulting in qualitatively different granule size distributions. The results of this study demonstrate the importance of detailed knowledge about applied feeding systems to gain optimal performance in twin-screw granulation.

  8. Superradiant Instability of D-Dimensional Reissner—Nordström Black Hole Mirror System

    Science.gov (United States)

    Li, Ran; Zhao, Jun-Kun; Zhang, Yan-Ming

    2015-05-01

    We analytically study the superradiant instability of charged massless scalar field in the background of D-dimensional Reissner-Nordström (RN) black hole caused by mirror-like boundary condition. By using the asymptotic matching method to solve the Klein-Gordon equation that governs the dynamics of scalar field, we have derived the expressions of complex parts of boxed quasinormal frequencies, and shown they are positive in the regime of superradiance. This indicates the charged scalar field is unstable in D-dimensional Reissner-Nordström (RN) black hole surrounded by mirror. However, the numerical work to calculate the boxed quasinormal frequencies in this system is still required in the future. Supported by the National Natural Science Foundation of China under Grant No. 11205048

  9. Superradiant instability of D-dimensional Reissner-Nordstr\\"{o}m black hole mirror system

    CERN Document Server

    Li, Ran

    2014-01-01

    We analytically study the superradiant instability of a charged massless scalar field in the background of D-dimensional Reissner-Nordstr\\"{o}m (RN) black hole caused by the mirror's boundary condition. By using the asymptotic matching method to solve the Klein-Gordon equation that govern the dynamics of the scalar field, we have derived the expressions of the complex parts of the boxed quasinormal frequencies, and shown they are positive in the regime of superradiance. This indicates the charged scalar field is unstable in D-dimensional Reissner-Nordstr\\"{o}m (RN) black hole surrounded by mirror. The numerical work to calculate the boxed quasinormal frequencies in this system is still required in the future.

  10. Alignment System for Full-Shell Replicated X-Ray Mirrors

    Science.gov (United States)

    Gubarev, Mikhail; Arnold, William; Ramsey, Brian

    2009-01-01

    We are developing grazing-incidence x-ray optics for high-energy astrophysical applications using the electroformnickel replication process. For space-based applications these optics must be light-weight yet stable, which dictates the use of very-thin-walled full-shell mirrors. Such shells have been fabricated with resolution as good as 11 arcsec for hard x-rays, and technology enhancements under development at MSFC are aimed at producing mirrors with resolution better than 10 arcsec. The challenge, however, is to preserve this resolution during mounting and assembly. We present here a status report on a mounting and alignment system currently under development at Marshall Space Flight Center designed to meet this challenge.

  11. Relationship between activity in human primary motor cortex during action observation and the mirror neuron system.

    Directory of Open Access Journals (Sweden)

    James M Kilner

    Full Text Available The attenuation of the beta cortical oscillations during action observation has been interpreted as evidence of a mirror neuron system (MNS in humans. Here we investigated the modulation of beta cortical oscillations with the viewpoint of an observed action. We asked subjects to observe videos of an actor making a variety of arm movements. We show that when subjects were observing arm movements there was a significant modulation of beta oscillations overlying left and right sensorimotor cortices. This pattern of attenuation was driven by the side of the screen on which the observed movement occurred and not by the hand that was observed moving. These results are discussed in terms of the firing patterns of mirror neurons in F5 which have been reported to have similar properties.

  12. Development of a Twin-Screw D-2 Extruder for the ITER Pellet Injection System

    Energy Technology Data Exchange (ETDEWEB)

    Meitner, Steven J [ORNL; Baylor, Larry R [ORNL; Carbajo, Juan J [ORNL; Combs, Stephen Kirk [ORNL; Fehling, Dan T [ORNL; Foust, Charles R [ORNL; McFee, Marshall T [ORNL; McGill, James M [ORNL; Rasmussen, David A [ORNL; Sitterson, R G [ORNL; Sparks, Dennis O [ORNL; Qualls, A L [ORNL

    2009-07-01

    A twin-screw extruder for the ITER pellet injection system is under development at the Oak Ridge National Laboratory. The extruder will provide a stream of solid hydrogen isotopes to a secondary section, where pellets are cut and accelerated with single-stage gas gun into the plasma. A one-fifth ITER scale prototype extruder has been built to produce a continuous solid deuterium extrusion. Deuterium gas is precooled and liquefied before being introduced into the extruder. The precooler consists of a copper vessel containing liquid nitrogen surrounded by a deuterium gas filled copper coil. The liquefier is comprised of a copper cylinder connected to a Cryomech AL330 cryocooler, which is surrounded by a copper coil that the precooled deuterium flows through. The lower extruder barrel is connected to a Cryomech GB-37 cryocooler to solidify the deuterium (at approximate to 15 K) before it is forced through the extruder nozzle. A viewport located below the extruder nozzle provides a direct view of the extrusion. A camera is used to document the extrusion quality and duration. A data acquisition system records the extruder temperatures, torque, and speed, upstream, and downstream pressures. This paper will describe the prototype twin-screw extruder and initial extrusion results.

  13. Six movements measurement system employed for GAIA secondary mirror positioning system vacuum tests at cryogenic temperatures

    Science.gov (United States)

    Ramos Zapata, Gonzalo; Sánchez Rodríguez, Antonio; Garranzo García-Ibarrola, Daniel; Belenguer Dávila, Tomás

    2008-07-01

    In this work, the optical measurement system employed to evaluate the performance of a 6 degrees of freedom (dof) positioning mechanism under cryogenic conditions is explored. The mechanism, the flight model of three translations and three rotations positioning mechanism, was developed by the Spanish company SENER (for ASTRIUM) to fulfil the high performance requirements from ESA technology preparatory program for the positioning of a secondary mirror within the GAIA Astrometric Mission. Its performance has been evaluated under vacuum and temperature controlled conditions (up to a 10-6mbar and 100K) at the facilities of the Space Instrumentation Laboratory (LINES) of the Aerospace Technical Nacional Institute of Spain (INTA). After the description of the 'alignment tool' developed to compare a fixed reference with the optical signal corresponding to the movement under evaluation, the optical system that allows measuring the displacements and the rotations in the three space directions is reported on. Two similar bread-boards were defined and mounted for the measurements purpose, one containing two distancemeters, in order to measure the displacements through the corresponding axis, and an autocollimator in order to obtain the rotations on the plane whose normal vector is the axis mentioned before, and other one containing one distancemeter and one autocollimator. Both distancemeter and autocollimator measurements have been combined in order to extract the information about the accuracy of the mechanism movements as well as their repeatability under adverse environmental conditions.

  14. Fuzzy Controller Design Using Evolutionary Techniques for Twin Rotor MIMO System: A Comparative Study

    Directory of Open Access Journals (Sweden)

    H. A. Hashim

    2015-01-01

    Full Text Available This paper presents a comparative study of fuzzy controller design for the twin rotor multi-input multioutput (MIMO system (TRMS considering most promising evolutionary techniques. These are gravitational search algorithm (GSA, particle swarm optimization (PSO, artificial bee colony (ABC, and differential evolution (DE. In this study, the gains of four fuzzy proportional derivative (PD controllers for TRMS have been optimized using the considered techniques. The optimization techniques are developed to identify the optimal control parameters for system stability enhancement, to cancel high nonlinearities in the model, to reduce the coupling effect, and to drive TRMS pitch and yaw angles into the desired tracking trajectory efficiently and accurately. The most effective technique in terms of system response due to different disturbances has been investigated. In this work, it is observed that GSA is the most effective technique in terms of solution quality and convergence speed.

  15. Optimization design about gimbal structure of high-precision autonomous celestial navigation tracking mirror system

    Science.gov (United States)

    Huang, Wei; Yang, Xiao-xu; Han, Jun-feng; Wei, Yu; Zhang, Jing; Xie, Mei-lin; Yue, Peng

    2016-01-01

    High precision tracking platform of celestial navigation with control mirror servo structure form, to solve the disadvantages of big volume and rotational inertia, slow response speed, and so on. It improved the stability and tracking accuracy of platform. Due to optical sensor and mirror are installed on the middle-gimbal, stiffness and resonant frequency requirement for high. Based on the application of finite element modality analysis theory, doing Research on dynamic characteristics of the middle-gimbal, and ANSYS was used for the finite element dynamic emulator analysis. According to the result of the computer to find out the weak links of the structure, and Put forward improvement suggestions and reanalysis. The lowest resonant frequency of optimization middle-gimbal avoid the bandwidth of the platform servo mechanism, and much higher than the disturbance frequency of carrier aircraft, and reduces mechanical resonance of the framework. Reaching provides a theoretical basis for the whole machine structure optimization design of high-precision of autonomous Celestial navigation tracking mirror system.

  16. Toward a functional account of the human mirror system. Comment on "Grasping synergies: A motor-control approach to the mirror neuron mechanism" by A. D'Ausilio et al.

    Science.gov (United States)

    Enticott, Peter G.

    2015-03-01

    It has been more than 20 years since the first reports of macaque "mirror neurons" appeared in the literature [1], and a large number of studies have since established an analogous system in the human brain [2]. Despite a raft of studies using various methodological approaches, we appear to be moving further away from any form of consensus, particularly concerning what this mirror system actually "mirrors" (e.g., low-level motor representation, goal or intention coding), and the functional significance (if any) of this mechanism [3]. The conceptual issues discussed by D'Ausilio et al. [4] are indeed critical to the advancement of this field; interestingly, they suggest that examining kinematic vs. goal coding aspects of the mirror system might be redundant, and propose instead a new approach that examines the recruitment of motor synergies within the context of the mirror system.

  17. A spectrum of shadowed mirroring.

    Science.gov (United States)

    Wanamaker, Melissa C

    2012-04-01

    The central focus of this paper is to explore and extend Kohut's theory of maternal mirroring and to place it within the current context of psychoanalytic thinking. Kohut believed a child must experience "positive" mirroring from his or her mother in infancy and beyond to ensure development of a healthy self. Kohut alludes, however, to a possible situation in which the mother's face, metaphorically a mirror, can appear "faceless" to her child. From this I have inferred the concept of what I shall call "shadowed mirroring." Clinical and literary examples show that distorted, "shadowed" mirroring appears on a spectrum, with passive mirroring at one end and hostile (either verbal or nonverbal) mirroring on the other; some individuals experience both. I then consider how "shadowed mirroring," especially hostile mirroring, can be understood within the twin contexts of the overall mother-child relationship and present-day Intersubjective/Relational thinking that is both bidirectional and co-constructed. Shadowed mirroring can lead to severe personality dysfunction along the borderline-narcissistic range, as well as to difficulties in the areas of identity formation, failure of self-cohesiveness, and the blunting of certain humane qualities like empathy.

  18. A facile reporter system for the experimental identification of twin-arginine translocation (Tat) signal peptides from all kingdoms of life

    NARCIS (Netherlands)

    Widdick, David A.; Eijlander, Robyn T.; van Dijl, Jan Maarten; Kuipers, Oscar P.; Palmer, Tracy

    2008-01-01

    We have developed a reporter protein system for the experimental verification of twin-arginine signal peptides. This reporter system is based on the Streptomyces coelicolor agarase protein, which is secreted into the growth medium by the twin-arginine translocation (Tat) pathway and whose extracellu

  19. Mapping the flow of information within the putative mirror neuron system during gesture observation.

    Science.gov (United States)

    Schippers, Marleen B; Keysers, Christian

    2011-07-01

    The putative mirror neuron system may either function as a strict feed-forward system or as a dynamic control system. A strict feed-forward system would predict that action observation leads to a predominantly temporal→parietal→premotor flow of information in which a visual representation is transformed into motor-programs which contribute to action understanding. Instead, a dynamic feedback control system would predict that the reverse direction of information flow predominates because of a combination of inhibitory forward and excitatory inverse models. Here we test which of these conflicting predictions best matches the information flow within the putative mirror neuron system (pMNS) and between the pMNS and the rest of the brain during the observation of comparatively long naturalistic stretches of communicative gestures. We used Granger causality to test the dominant direction of influence. Our results fit the predictions of the dynamic feedback control system: we found predominantly an information flow within the pMNS from premotor to parietal and middle temporal cortices. This is more pronounced during an active guessing task than while passively reviewing the same gestures. In particular, the ventral premotor cortex sends significantly more information to other pMNS areas than it receives during active guessing than during passive observation.

  20. High-precision system identification method for a deformable mirror in wavefront control.

    Science.gov (United States)

    Huang, Lei; Ma, Xingkun; Bian, Qi; Li, Tenghao; Zhou, Chenlu; Gong, Mali

    2015-05-10

    Based on a mathematic model, the relation between the accuracy of the influence matrix and the performance of the wavefront correction is established. Based on the least squares method, a two-step system identification is proposed to improve the accuracy of the influence matrix, where the measurement noise can be suppressed and the nonlinearity of the deformable mirror can be compensated. The validity of the two-step system identification method is tested in the experiment, where improvements in wavefront correction precision as well as closed-loop control efficiency were observed.

  1. Water Cooled Mirror Design

    Energy Technology Data Exchange (ETDEWEB)

    Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Holloway, Michael Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pulliam, Elias Noel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-30

    This design is intended to replace the current mirror setup being used for the NorthStar Moly 99 project in order to monitor the target coupon. The existing setup has limited movement for camera alignment and is difficult to align properly. This proposed conceptual design for a water cooled mirror will allow for greater thermal transfer between the mirror and the water block. It will also improve positioning of the mirror by using flexible vacuum hosing and a ball head joint capable of a wide range of motion. Incorporating this design into the target monitoring system will provide more efficient cooling of the mirror which will improve the amount of diffraction caused by the heating of the mirror. The process of aligning the mirror for accurate position will be greatly improved by increasing the range of motion by offering six degrees of freedom.

  2. Application of MEMS Accelerometers and Gyroscopes in Fast Steering Mirror Control Systems.

    Science.gov (United States)

    Tian, Jing; Yang, Wenshu; Peng, Zhenming; Tang, Tao; Li, Zhijun

    2016-03-25

    In a charge-coupled device (CCD)-based fast steering mirror (FSM) tracking control system, high control bandwidth is the most effective way to enhance the closed-loop performance. However, the control system usually suffers a great deal from mechanical resonances and time delays induced by the low sampling rate of CCDs. To meet the requirements of high precision and load restriction, fiber-optic gyroscopes (FOGs) are usually used in traditional FSM tracking control systems. In recent years, the MEMS accelerometer and gyroscope are becoming smaller and lighter and their performance have improved gradually, so that they can be used in a fast steering mirror (FSM) to realize the stabilization of the line-of-sight (LOS) of the control system. Therefore, a tentative approach to implement a CCD-based FSM tracking control system, which uses MEMS accelerometers and gyroscopes as feedback components and contains an acceleration loop, a velocity loop and a position loop, is proposed. The disturbance suppression of the proposed method is the product of the error attenuation of the acceleration loop, the velocity loop and the position loop. Extensive experimental results show that the MEMS accelerometers and gyroscopes can act the similar role as the FOG with lower cost for stabilizing the LOS of the FSM tracking control system.

  3. Using geometric algebra to understand pattern rotations in multiple mirror optical systems

    Energy Technology Data Exchange (ETDEWEB)

    Hanlon, J.; Ziock, H.

    1997-05-01

    Geometric Algebra (GA) is a new formulation of Clifford Algebra that includes vector analysis without notation changes. Most applications of Ga have been in theoretical physics, but GA is also a very good analysis tool for engineering. As an example, the authors use GA to study pattern rotation in optical systems with multiple mirror reflections. The common ways to analyze pattern rotations are to use rotation matrices or optical ray trace codes, but these are often inconvenient. The authors use GA to develop a simple expression for pattern rotation that is useful for designing or tolerancing pattern rotations in a multiple mirror optical system by inspection. Pattern rotation is used in many optical engineering systems, but it is not normally covered in optical system engineering texts. Pattern rotation is important in optical systems such as: (1) the 192 beam National ignition Facility (NIF), which uses square laser beams in close packed arrays to cut costs; (2) visual optical systems, which use pattern rotation to present the image to the observer in the appropriate orientation, and (3) the UR90 unstable ring resonator, which uses pattern rotation to fill a rectangular laser gain region and provide a filled-in laser output beam.

  4. Application of MEMS Accelerometers and Gyroscopes in Fast Steering Mirror Control Systems

    Directory of Open Access Journals (Sweden)

    Jing Tian

    2016-03-01

    Full Text Available In a charge-coupled device (CCD-based fast steering mirror (FSM tracking control system, high control bandwidth is the most effective way to enhance the closed-loop performance. However, the control system usually suffers a great deal from mechanical resonances and time delays induced by the low sampling rate of CCDs. To meet the requirements of high precision and load restriction, fiber-optic gyroscopes (FOGs are usually used in traditional FSM tracking control systems. In recent years, the MEMS accelerometer and gyroscope are becoming smaller and lighter and their performance have improved gradually, so that they can be used in a fast steering mirror (FSM to realize the stabilization of the line-of-sight (LOS of the control system. Therefore, a tentative approach to implement a CCD-based FSM tracking control system, which uses MEMS accelerometers and gyroscopes as feedback components and contains an acceleration loop, a velocity loop and a position loop, is proposed. The disturbance suppression of the proposed method is the product of the error attenuation of the acceleration loop, the velocity loop and the position loop. Extensive experimental results show that the MEMS accelerometers and gyroscopes can act the similar role as the FOG with lower cost for stabilizing the LOS of the FSM tracking control system.

  5. Wall-crossing structures in Donaldson-Thomas invariants, integrable systems and Mirror Symmetry

    CERN Document Server

    Kontsevich, Maxim

    2013-01-01

    We introduce the notion of Wall-Crossing Structure and discuss it in several examples including complex integrable systems, Donaldson-Thomas invariants and Mirror Symmetry. For a big class of non-compact Calabi-Yau 3-folds we construct complex integrable systems of Hitchin type with the base given by the moduli space of deformations of those 3-folds. Then Donaldson-Thomas invariants of the Fukaya category of such a Calabi-Yau 3-fold can be (conjecturally) described in two more ways: in terms of the attractor flow on the base of the corresponding complex integrable system and in terms of the skeleton of the mirror dual to the total space of the integrable system. The paper also contains a discussion of some material related to the main subject, e.g. Betti model of Hitchin systems with irregular singularities, WKB asymptotics of connections depending on a small parameter, attractor points in the moduli space of complex structures of a compact Calabi-Yau 3-fold, relation to cluster varieties, etc.

  6. Applications of small computers for systems control on the Tandem Mirror Experiment-Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Bork, R.G.; Kane, R.J.; Moore, T.L.

    1983-11-29

    Desktop computers operating into a CAMAC-based interface are used to control and monitor the operation of the various subsystems on the Tandem Mirror Experiment-Upgrade (TMX-U) at Lawrence Livermore National Laboratory (LLNL). These systems include: shot sequencer/master timing, neutral beam control (four consoles), magnet power system control, ion-cyclotron resonant heating (ICRH) control, thermocouple monitoring, getter system control, gas fueling system control, and electron-cyclotron resonant heating (ECRH) monitoring. Two additional computers are used to control the TMX-U neutral beam test stand and provide computer-aided repair/test and development of CAMAC modules. These machines are usually programmed in BASIC, but some codes have been interpreted into assembly language to increase speed. Details of the computer interfaces and system complexity are described as well as the evolution of the systems to their present states.

  7. Experience with wavefront sensor and deformable mirror interfaces for wide-field adaptive optics systems

    CERN Document Server

    Basden, A G; Bharmal, N A; Bitenc, U; Brangier, M; Buey, T; Butterley, T; Cano, D; Chemla, F; Clark, P; Cohen, M; Conan, J -M; de Cos, F J; Dickson, C; Dipper, N A; Dunlop, C N; Feautrier, P; Fusco, T; Gach, J L; Gendron, E; Geng, D; Goodsell, S J; Gratadour, D; Greenaway, A H; Guesalaga, A; Guzman, C D; Henry, D; Holck, D; Hubert, Z; Huet, J M; Kellerer, A; Kulcsar, C; Laporte, P; Roux, B Le; Looker, N; Longmore, A J; Marteaud, M; Martin, O; Meimon, S; Morel, C; Morris, T J; Myers, R M; Osborn, J; Perret, D; Petit, C; Raynaud, H; Reeves, A P; Rousset, G; Lasheras, F Sanchez; Rodriguez, M Sanchez; Santos, J D; Sevin, A; Sivo, G; Stadler, E; Stobie, B; Talbot, G; Todd, S; Vidal, F; Younger, E J

    2016-01-01

    Recent advances in adaptive optics (AO) have led to the implementation of wide field-of-view AO systems. A number of wide-field AO systems are also planned for the forthcoming Extremely Large Telescopes. Such systems have multiple wavefront sensors of different types, and usually multiple deformable mirrors (DMs). Here, we report on our experience integrating cameras and DMs with the real-time control systems of two wide-field AO systems. These are CANARY, which has been operating on-sky since 2010, and DRAGON, which is a laboratory adaptive optics real-time demonstrator instrument. We detail the issues and difficulties that arose, along with the solutions we developed. We also provide recommendations for consideration when developing future wide-field AO systems.

  8. Experience with wavefront sensor and deformable mirror interfaces for wide-field adaptive optics systems

    Science.gov (United States)

    Basden, A. G.; Atkinson, D.; Bharmal, N. A.; Bitenc, U.; Brangier, M.; Buey, T.; Butterley, T.; Cano, D.; Chemla, F.; Clark, P.; Cohen, M.; Conan, J.-M.; de Cos, F. J.; Dickson, C.; Dipper, N. A.; Dunlop, C. N.; Feautrier, P.; Fusco, T.; Gach, J. L.; Gendron, E.; Geng, D.; Goodsell, S. J.; Gratadour, D.; Greenaway, A. H.; Guesalaga, A.; Guzman, C. D.; Henry, D.; Holck, D.; Hubert, Z.; Huet, J. M.; Kellerer, A.; Kulcsar, C.; Laporte, P.; Le Roux, B.; Looker, N.; Longmore, A. J.; Marteaud, M.; Martin, O.; Meimon, S.; Morel, C.; Morris, T. J.; Myers, R. M.; Osborn, J.; Perret, D.; Petit, C.; Raynaud, H.; Reeves, A. P.; Rousset, G.; Sanchez Lasheras, F.; Sanchez Rodriguez, M.; Santos, J. D.; Sevin, A.; Sivo, G.; Stadler, E.; Stobie, B.; Talbot, G.; Todd, S.; Vidal, F.; Younger, E. J.

    2016-06-01

    Recent advances in adaptive optics (AO) have led to the implementation of wide field-of-view AO systems. A number of wide-field AO systems are also planned for the forthcoming Extremely Large Telescopes. Such systems have multiple wavefront sensors of different types, and usually multiple deformable mirrors (DMs). Here, we report on our experience integrating cameras and DMs with the real-time control systems of two wide-field AO systems. These are CANARY, which has been operating on-sky since 2010, and DRAGON, which is a laboratory AO real-time demonstrator instrument. We detail the issues and difficulties that arose, along with the solutions we developed. We also provide recommendations for consideration when developing future wide-field AO systems.

  9. The "mirror-neuron system" in MS: A 3 tesla fMRI study.

    Science.gov (United States)

    Rocca, M A; Tortorella, P; Ceccarelli, A; Falini, A; Tango, D; Scotti, G; Comi, G; Filippi, M

    2008-01-22

    The mirror neuron system (MNS) is an observation-execution matching system activated, in humans, during action observation, motor learning, and imitation of action. We used functional MRI (fMRI) to investigate the properties of the MNS in patients with multiple sclerosis (MS). Using a 3 tesla scanner, we acquired fMRI in 16 right-handed patients with relapsing-remitting MS and 14 controls. Two motor tasks were studied. The first consisted of repetitive flexion-extension of the last four fingers of the right hand (simple task) alternated to epochs of rest; the second (MNS task) consisted of observation of a movie showing the hand of another subject while performing the same task. During the simple task, compared to controls, patients with MS had more significant activations of the contralateral primary sensorimotor cortex and supplementary motor area. During the MNS task, both groups showed the activation of several visual areas, the infraparietal sulcus, and the inferior frontal gyrus (IFG), bilaterally. The IFG and the visual areas were significantly more active in patients than controls. The between-group interaction analysis showed that in patients with MS, part of the regions of the MNS were more active also during the simple task. This study suggests increased activation of the mirror neuron system in patients with multiple sclerosis (MS) with a normal level of function and widespread CNS damage. The potentialities of this system in facilitating clinical recovery in patients with MS and other neurologic conditions should be investigated.

  10. Development of achromatic full-field x-ray microscopy with compact imaging mirror system

    Science.gov (United States)

    Matsuyama, S.; Emi, Y.; Kino, H.; Sano, Y.; Kohmura, Y.; Tamasaku, K.; Yabashi, M.; Ishikawa, T.; Yamauchi, K.

    2013-09-01

    Compact advanced Kirkpatrick-Baez optics are used to construct a microscope that is easy to align and robust against vibrations and thermal drifts. The entire length of the imaging mirror system is 286 mm, which is 34% shorter than the previous model. A spatial resolution test is performed in which magnified bright-field images of a pattern are taken with an X-ray camera at an energy of 10 keV at the BL29XUL beamline of SPring-8. A line-and-space pattern having a 50- nm width could be resolved, although the image contrast is low.

  11. Numerical simulation of debris-removal trajectories on the transport mirrors in high-power laser systems

    Institute of Scientific and Technical Information of China (English)

    Yangshuai Li; Jianqiang Zhu; Xiangyang Pang; Hua Tao; Xiang Jiao; Yongzhong Wu

    2015-01-01

    In high-power laser systems(HPLSs), understanding debris-removal trajectories is important in eliminating debris from the surfaces of transport mirrors online and keeping other optical components free from contamination. NS equations, the RNG k–ε model and the discrete phase model of the Euler–Lagrange method are used to conduct numerical simulations on the trajectories of contaminant particles of different sizes and types on the mirror surface using Fluent commercial software. A useful device is fabricated based on the simulation results. This device can capture and collect debris from the mirror surface online. Consequently, the effect of debris contamination on other optical components is avoided,cleaning time is shortened, and ultimately, the cleanliness of the mirrors in HPLSs is ensured.

  12. Fabrication and integration of microprism mirrors for high-speed three-dimensional measurement in inertial microfluidic system

    Science.gov (United States)

    Koh, Joonyoung; Kim, Jihye; Shin, Jung H.; Lee, Wonhee

    2014-09-01

    Inertial microfluidics utilizes fluid inertia from high flow velocity to manipulate particles and fluids in 3D. Acquiring a 3D information of particle positions and complex flow patterns within microfluidic devices requires 3D imaging techniques such as confocal microscopy, which are often expensive and slow. Here, we report on a prism-mirror-embedded microfluidic device that allows simultaneous imaging of the top and side view of the microchannel for a high-speed, low-cost 3D imaging. The microprism mirrors are fabricated and integrated into a microfluidic system using conventional microfabrication techniques including wet etch and soft lithography. This inexpensive high quality prism mirror provides a highly reflective, smooth mirror surface with precise 45° reflection angle, enabling 3D measurement of inertial migration of microparticles in a rectangular channel at speeds in excess of 10 000 frame/s.

  13. Combinational-deformable-mirror adaptive optics system for compensation of high-order modes of wavefront

    Institute of Scientific and Technical Information of China (English)

    Huafeng Yang; Guilin Liu; Changhui Rao; Yudong Zhang; Wenhan Jiang

    2007-01-01

    A new kind of adaptive optics (AO) system, in which several low spatial frequency deformable mirrors(DMs) with optical conjugation relationship are combined to correct high-order aberrations, is proposed.The phase compensation principle and the control method of the combinational AO system are introduced.The numerical simulations for the AO system with two 60-element DMs are presented. The results indicate that the combinational DM in the AO system can correct different aberrations effectively as one single DM with more actuators, and there is no change of control method. This technique can be applied to a large telescope AO system to improve the spatial compensation capability for wavefront by using current DM.

  14. The application of frequency characteristics test in fast control mirror system

    Science.gov (United States)

    Gan, Xun; Jang, Yu; Wang, Zong You; Mao, Yao

    2015-10-01

    The control bandwidth of the FSM affects directly on the performance of the tracking system based on the compound axis servo structure. The FSM's control system's accuracy affects the bandwidth and the tracking precision of the system directly. Obtaining the accurate transfer function of the control object is the basis of designing frequency characteristics based control system. Measurement of high precision transfer function is needed to compensate the influence of the mechanical resonance. The mechanical resonance of fast control mirror is mainly of high frequency. In this case, the measured signal's SNR is low so that the measurement accuracy of the frequency characteristic is reduced accordingly. One way to get frequency characteristics is to input sweeping sine drive signal to the system, measure the output of system, and then calculate the frequency characteristics by Fourier Transformation. However, the measuring result of the FSM system that has a low SNR in high frequency is not precise enough as in a system with a high SNR. To solve the problem mentioned above, this article presents a method to calculate frequency characteristics of an FSM system. This method uses the least squares to fit the fast mirror output overall waveform and the input source can be sine, white noise, multimode signal or chirp signal. A digital compensator based on this method is introduced to experimentally verify the efficiency of the method. Experiment results show that fitting the system's output curve in high frequency can effectively eliminate influence of quantization noise, gauss measurement noise and harmonic interference on the measurement accuracy and thus enhance the measuring signal's SNR. It is proved that by using this method a more accurate frequency characteristics of the FSM can be obtained.

  15. Dissociating object directed and non-object directed action in the human mirror system; implications for theories of motor simulation.

    Directory of Open Access Journals (Sweden)

    Zarinah K Agnew

    Full Text Available Mirror neurons are single cells found in macaque premotor and parietal cortices that are active during action execution and observation. In non-human primates, mirror neurons have only been found in relation to object-directed movements or communicative gestures, as non-object directed actions of the upper limb are not well characterized in non-human primates. Mirror neurons provide important evidence for motor simulation theories of cognition, sometimes referred to as the direct matching hypothesis, which propose that observed actions are mapped onto associated motor schemata in a direct and automatic manner. This study, for the first time, directly compares mirror responses, defined as the overlap between action execution and observation, during object directed and meaningless non-object directed actions. We present functional MRI data that demonstrate a clear dissociation between object directed and non-object directed actions within the human mirror system. A premotor and parietal network was preferentially active during object directed actions, whether observed or executed. Moreover, we report spatially correlated activity across multiple voxels for observation and execution of an object directed action. In contrast to predictions made by motor simulation theory, no similar activity was observed for non-object directed actions. These data demonstrate that object directed and meaningless non-object directed actions are subserved by different neuronal networks and that the human mirror response is significantly greater for object directed actions. These data have important implications for understanding the human mirror system and for simulation theories of motor cognition. Subsequent theories of motor simulation must account for these differences, possibly by acknowledging the role of experience in modulating the mirror response.

  16. A one-dimensional ion beam figuring system for x-ray mirror fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Idir, Mourad; Huang, Lei; Bouet, Nathalie; Kaznatcheev, Konstantine; Vescovi, Matthew; Lauer, Ken; Conley, Ray; Rennie, Kent; Kahn, Jim; Nethery, Richard; Zhou, Lin

    2015-10-01

    We report on the development of a one-dimensional Ion Beam Figuring (IBF) system for x-ray mirror polishing. Ion beam figuring provides a highly deterministic method for the final precision figuring of optical components with advantages over conventional methods. The system is based on a state of the art sputtering deposition system outfitted with a gridded radio frequency inductive coupled plasma ion beam source equipped with ion optics and dedicated slit developed specifically for this application. The production of an IBF system able to produce an elongated removal function rather than circular is presented in this paper, where we describe in detail the technical aspect and present the first obtained results. (C) 2015 AIP Publishing LLC.

  17. SALT segmented primary mirror: commissioning capacitive edge sensing system and performance comparison with inductive sensor

    Science.gov (United States)

    Buous, Sebastien; Menzies, John; Gajjar, Hitesh

    2008-07-01

    The SAMS (Segment Alignment Measurement System) is a capacitance-based edge sensing solution for the active alignment of the 10m SALT segmented primary mirror. Commissioning and calibrating the system has been an ongoing task in an attempt to counteract the unfavourable response of the sensors to high humidity conditions and high dust levels. Several solutions were implemented and tested including real-time feedback systems and the application of corrective functions. In parallel with the continuing efforts to improve the performance of the capacitive sensors, we have also been testing a prototype inductive sensor developed by Fogale Nanotech that is of a very similar flexible plate construction. In this paper we present the results obtained and performance gains achieved thus far with the capacitive edge-sensing system as well as a performance comparison of the Fogale inductive sensor to the capacitive edge sensor.

  18. A one-dimensional ion beam figuring system for x-ray mirror fabrication.

    Science.gov (United States)

    Idir, Mourad; Huang, Lei; Bouet, Nathalie; Kaznatcheev, Konstantine; Vescovi, Matthew; Lauer, Ken; Conley, Ray; Rennie, Kent; Kahn, Jim; Nethery, Richard; Zhou, Lin

    2015-10-01

    We report on the development of a one-dimensional Ion Beam Figuring (IBF) system for x-ray mirror polishing. Ion beam figuring provides a highly deterministic method for the final precision figuring of optical components with advantages over conventional methods. The system is based on a state of the art sputtering deposition system outfitted with a gridded radio frequency inductive coupled plasma ion beam source equipped with ion optics and dedicated slit developed specifically for this application. The production of an IBF system able to produce an elongated removal function rather than circular is presented in this paper, where we describe in detail the technical aspect and present the first obtained results.

  19. A USPL functional system with articulated mirror arm for in-vivo applications in dentistry

    Science.gov (United States)

    Schelle, Florian; Meister, Jörg; Dehn, Claudia; Oehme, Bernd; Bourauel, Christoph; Frentzen, Mathias

    Ultra-short pulsed laser (USPL) systems for dental application have overcome many of their initial disadvantages. However, a problem that has not yet been addressed and solved is the beam delivery into the oral cavity. The functional system that is introduced in this study includes an articulated mirror arm, a scanning system as well as a handpiece, allowing for freehand preparations with ultra-short laser pulses. As laser source an Nd:YVO4 laser is employed, emitting pulses with a duration of tp cavity preparation are being demonstrated on mammoth ivory. This study indicates that freehand preparation employing an USPL system is possible but challenging, and accompanied by a variety of side-effects. The ablation rate with fixed handpiece is about 10 mm3/min. Factors like defocussing and blinding affect treatment efficiency. Laser sources with higher average output powers might be needed in order to reach sufficient preparation speeds.

  20. A one-dimensional ion beam figuring system for x-ray mirror fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Idir, Mourad, E-mail: midir@bnl.gov; Huang, Lei; Bouet, Nathalie; Kaznatcheev, Konstantine; Vescovi, Matthew; Lauer, Ken [NSLS-II, Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973 (United States); Conley, Ray [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Rennie, Kent; Kahn, Jim; Nethery, Richard [Kaufman & Robinson, Inc., 1330 Blue Spruce Drive, Fort Collins, Colorado 80524 (United States); Zhou, Lin [College of Mechatronics and Automation, National University of Defense Technology, 109 Deya Road, Changsha, Hunan 410073 (China); Hu’nan Key Laboratory of Ultra-precision Machining Technology, Changsha, Hunan 410073 (China)

    2015-10-15

    We report on the development of a one-dimensional Ion Beam Figuring (IBF) system for x-ray mirror polishing. Ion beam figuring provides a highly deterministic method for the final precision figuring of optical components with advantages over conventional methods. The system is based on a state of the art sputtering deposition system outfitted with a gridded radio frequency inductive coupled plasma ion beam source equipped with ion optics and dedicated slit developed specifically for this application. The production of an IBF system able to produce an elongated removal function rather than circular is presented in this paper, where we describe in detail the technical aspect and present the first obtained results.

  1. Manufacturing of Lightweight Mirror

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Fabrication of the lightweight mirror is one of the key techniques for many large optical systems. CAD,CAM and CNC technologies are adopted in designing and manufacturing such mirrors in CIOMP. Better working efficiency and higher lightweight grade have been achieved. The results show that mirrors up to 70% weight reduction and 0.02λ(rms.) surface accuracy or better can be obtained.

  2. Fiber faceplate modulation readout in Bi-material micro-cantilever mirror array imaging system

    Science.gov (United States)

    Hui, Mei; Xia, Zhengzheng; Liu, Ming; Dong, Liquan; Liu, Xiaohua; Zhao, Yuejin

    2016-05-01

    Fiber faceplate modulation was applied to read out the precise actuation of silicon-based, surface micro-fabricated cantilever mirrors array in optical imaging system. The faceplate was made by ordered bundles consisting of as many as ten thousands fibers. The transmission loss of an individual fiber in the bundles was 0.35dB/cm and the cross talk between neighboring fibers in the faceplate was about 15%. Micro-cantilever mirrors array (Focal-Plane Array (FPA)) which composed of two-level bi-material pixels, absorb incident infrared flux and result in a temperature increase. The temperature distribution of incident flux transformed to the deformation distribution in FPA which has a very big difference in coefficients of thermal expansion. FPA plays the roles of target sensing and has the characteristics of high detection sensitivity. Instead of general filter such as knife edge or pinhole, fiber faceplate modulate the beam reflected by the units of FPA. An optical readout signal brings a visible spectrum into pattern recognition system, yielding a visible image on monitor. Thermal images at room temperature have been obtained. The proposed method permits optical axis compact and image noise suppression.

  3. Holographic twin Higgs model.

    Science.gov (United States)

    Geller, Michael; Telem, Ofri

    2015-05-15

    We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at m_{KK}, naturally allowing for m_{KK} beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider.

  4. Twin Jet

    Science.gov (United States)

    Henderson, Brenda; Bozak, Rick

    2010-01-01

    Many subsonic and supersonic vehicles in the current fleet have multiple engines mounted near one another. Some future vehicle concepts may use innovative propulsion systems such as distributed propulsion which will result in multiple jets mounted in close proximity. Engine configurations with multiple jets have the ability to exploit jet-by-jet shielding which may significantly reduce noise. Jet-by-jet shielding is the ability of one jet to shield noise that is emitted by another jet. The sensitivity of jet-by-jet shielding to jet spacing and simulated flight stream Mach number are not well understood. The current experiment investigates the impact of jet spacing, jet operating condition, and flight stream Mach number on the noise radiated from subsonic and supersonic twin jets.

  5. Design and construction of a cost-efficient Arduino-based mirror galvanometer system for scanning optical microscopy

    Science.gov (United States)

    Hsu, Jen-Feng; Dhingra, Shonali; D'Urso, Brian

    2017-01-01

    Mirror galvanometer systems (galvos) are commonly employed in research and commercial applications in areas involving laser imaging, laser machining, laser-light shows, and others. Here, we present a robust, moderate-speed, and cost-efficient home-built galvo system. The mechanical part of this design consists of one mirror, which is tilted around two axes with multiple surface transducers. We demonstrate the ability of this galvo by scanning the mirror using a computer, via a custom driver circuit. The performance of the galvo, including scan range, noise, linearity, and scan speed, is characterized. As an application, we show that this galvo system can be used in a confocal scanning microscopy system.

  6. Handbook of camera monitor systems the automotive mirror-replacement technology based on ISO 16505

    CERN Document Server

    2016-01-01

    This handbook offers a comprehensive overview of Camera Monitor Systems (CMS), ranging from the ISO 16505-based development aspects to practical realization concepts. It offers readers a wide-ranging discussion of the science and technology of CMS as well as the human-interface factors of such systems. In addition, it serves as a single reference source with contributions from leading international CMS professionals and academic researchers. In combination with the latest version of UN Regulation No. 46, the normative framework of ISO 16505 permits CMS to replace mandatory rearview mirrors in series production vehicles. The handbook includes scientific and technical background information to further readers’ understanding of both of these regulatory and normative texts. It is a key reference in the field of automotive CMS for system designers, members of standardization and regulation committees, engineers, students and researchers.

  7. Twin pregnancy

    DEFF Research Database (Denmark)

    Sperling, Lene; Tabor, A

    2001-01-01

    Determination of chorionicity is one of the most important issues in the management of twin pregnancy. Modern ultrasound equipment has made it possible to accurately assess placentation already in the first trimester with the lambda sign. With regard to prenatal diagnosis, it is important to know...... for clinicians caring for twin pregnancies....

  8. Einstein's Mirror

    Science.gov (United States)

    Gjurchinovski, Aleksandar; Skeparovski, Aleksandar

    2008-01-01

    Reflection of light from a plane mirror in uniform rectilinear motion is a century-old problem, intimately related to the foundations of special relativity. The problem was first investigated by Einstein in his famous 1905 paper by using the Lorentz transformations to switch from the mirror's rest frame to the frame where the mirror moves at a…

  9. A hybrid intelligent controller for a twin rotor MIMO system and its hardware implementation.

    Science.gov (United States)

    Juang, Jih-Gau; Liu, Wen-Kai; Lin, Ren-Wei

    2011-10-01

    This paper presents a fuzzy PID control scheme with a real-valued genetic algorithm (RGA) to a setpoint control problem. The objective of this paper is to control a twin rotor MIMO system (TRMS) to move quickly and accurately to the desired attitudes, both the pitch angle and the azimuth angle in a cross-coupled condition. A fuzzy compensator is applied to the PID controller. The proposed control structure includes four PID controllers with independent inputs in 2-DOF. In order to reduce total error and control energy, all parameters of the controller are obtained by a RGA with the system performance index as a fitness function. The system performance index utilized the integral of time multiplied by the square error criterion (ITSE) to build a suitable fitness function in the RGA. A new method for RGA to solve more than 10 parameters in the control scheme is investigated. For real-time control, Xilinx Spartan II SP200 FPGA (Field Programmable Gate Array) is employed to construct a hardware-in-the-loop system through writing VHDL on this FPGA.

  10. Exploring associations between gaze patterns and putative human mirror neuron system activity

    Directory of Open Access Journals (Sweden)

    Peter Hugh Donaldson

    2015-07-01

    Full Text Available The human mirror neuron system (MNS is hypothesised to be crucial to social cognition. Given that key MNS-input regions such as the superior temporal sulcus are involved in biological motion processing, and mirror neuron activity in monkeys has been shown to vary with visual attention, aberrant MNS function may be partly attributable to atypical visual input. To examine the relationship between gaze pattern and interpersonal motor resonance (IMR; an index of putative MNS activity, healthy right-handed participants aged 18-40 (n = 26 viewed videos of transitive grasping actions or static hands, whilst the left primary motor cortex received transcranial magnetic stimulation (TMS. Motor-evoked potentials (MEPs recorded in contralateral hand muscles were used to determine IMR. Participants also underwent eyetracking analysis to assess gaze patterns whilst viewing the same videos. No relationship was observed between predictive gaze (PG and IMR. However, IMR was positively associated with fixation counts in areas of biological motion in the videos, and negatively associated with object areas. These findings are discussed with reference to visual influences on the MNS, and the possibility that MNS atypicalities might be influenced by visual processes such as aberrant gaze pattern.

  11. Time domain analysis of superradiant instability for the charged stringy black hole–mirror system

    Directory of Open Access Journals (Sweden)

    Ran Li

    2015-11-01

    Full Text Available It has been proved that the charged stringy black holes are stable under the perturbations of massive charged scalar fields. However, superradiant instability can be generated by adding the mirror-like boundary condition to the composed system of charged stringy black hole and scalar field. The unstable boxed quasinormal modes have been calculated by using both analytical and numerical methods. In this paper, we further provide a time domain analysis by performing a long time evolution of charged scalar field configuration in the background of the charged stringy black hole with the mirror-like boundary condition imposed. We have used the ingoing Eddington–Finkelstein coordinates to derive the evolution equation, and adopted Pseudo-spectral method and the forth-order Runge–Kutta method to evolve the scalar field with the initial Gaussian wave packet. It is shown by our numerical scheme that Fourier transforming the evolution data coincides well with the unstable modes computed from frequency domain analysis. The existence of the rapid growth mode makes the charged stringy black hole a good test ground to study the nonlinear development of superradiant instability.

  12. Time domain analysis of superradiant instability for the charged stringy black hole-mirror system

    Science.gov (United States)

    Li, Ran; Tian, Yu; Zhang, Hongbao; Zhao, Junkun

    2015-11-01

    It has been proved that the charged stringy black holes are stable under the perturbations of massive charged scalar fields. However, superradiant instability can be generated by adding the mirror-like boundary condition to the composed system of charged stringy black hole and scalar field. The unstable boxed quasinormal modes have been calculated by using both analytical and numerical methods. In this paper, we further provide a time domain analysis by performing a long time evolution of charged scalar field configuration in the background of the charged stringy black hole with the mirror-like boundary condition imposed. We have used the ingoing Eddington-Finkelstein coordinates to derive the evolution equation, and adopted Pseudo-spectral method and the forth-order Runge-Kutta method to evolve the scalar field with the initial Gaussian wave packet. It is shown by our numerical scheme that Fourier transforming the evolution data coincides well with the unstable modes computed from frequency domain analysis. The existence of the rapid growth mode makes the charged stringy black hole a good test ground to study the nonlinear development of superradiant instability.

  13. Time domain analysis of superradiant instability for the charged stringy black hole-mirror system

    CERN Document Server

    Li, Ran; Zhang, Hongbao; Zhao, Junkun

    2015-01-01

    It has been proved that the charged stringy black holes are stable under the perturbations of massive charged scalar fields. However, superradiant instability can be generated by adding the mirror-like boundary condition to the composed system of charged stringy black hole and scalar field. The unstable boxed quasinormal modes have been calculated by using both analytical and numerical method. In this paper, we further provide a time domain analysis by performing a long time evolution of charged scalar field configuration in the background of the charged stringy black hole with the mirror-like boundary condition imposed. We have used the ingoing Eddington-Finkelstein coordinates to derive the evolution equation, and adopted Pseudo-spectral method and the forth-order Runge-Kutta method to evolve the scalar field with the initial Gaussian wave packet. It is shown by our numerical scheme that Fourier transforming the evolution data coincides well with the unstable modes computed from frequency domain analysis. T...

  14. Time domain analysis of superradiant instability for the charged stringy black hole–mirror system

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ran, E-mail: 021149@htu.cn [Department of Physics, Henan Normal University, Xinxiang 453007 (China); Tian, Yu, E-mail: ytian@ucas.ac.cn [School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhang, Hongbao, E-mail: hzhang@vub.ac.be [Department of Physics, Beijing Normal University, Beijing 100875 (China); Theoretische Natuurkunde, Vrije Universiteit Brussel, and The International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Zhao, Junkun, E-mail: zhaojkun1991@163.com [Department of Physics, Henan Normal University, Xinxiang 453007 (China)

    2015-11-12

    It has been proved that the charged stringy black holes are stable under the perturbations of massive charged scalar fields. However, superradiant instability can be generated by adding the mirror-like boundary condition to the composed system of charged stringy black hole and scalar field. The unstable boxed quasinormal modes have been calculated by using both analytical and numerical methods. In this paper, we further provide a time domain analysis by performing a long time evolution of charged scalar field configuration in the background of the charged stringy black hole with the mirror-like boundary condition imposed. We have used the ingoing Eddington–Finkelstein coordinates to derive the evolution equation, and adopted Pseudo-spectral method and the forth-order Runge–Kutta method to evolve the scalar field with the initial Gaussian wave packet. It is shown by our numerical scheme that Fourier transforming the evolution data coincides well with the unstable modes computed from frequency domain analysis. The existence of the rapid growth mode makes the charged stringy black hole a good test ground to study the nonlinear development of superradiant instability.

  15. Electroencephalogram evidence for the activation of human mirror neuron system during the observation of intransitive shadow and line drawing actions

    Institute of Scientific and Technical Information of China (English)

    Huaping Zhu; Yaoru Sun; Fang Wang

    2013-01-01

    Previous studies have demonstrated that hand shadows may activate the motor cortex associated with the mirror neuron system in human brain. However, there is no evidence of activity of the human mirror neuron system during the observation of intransitive movements by shadows and line drawings of hands. This study examined the suppression of electroencephalography mu waves hand actions, hand shadow actions and actions made by line drawings of hands. The results showed significant desynchronization of the mu rhythm ("mu suppression") across the sensorimotor cortex (recorded at C3, Cz and C4), the frontal cortex (recorded at F3, Fz and F4) and the central and right posterior parietal cortex (recorded at Pz and P4) under all three conditions. Our experimental findings suggest that the observation of "impoverished hand actions", such as intransitive movements of shadows and line drawings of hands, is able to activate widespread cortical areas related to the putative human mirror neuron system.

  16. Superradiant (in)stability of $D$-dimensional Reissner-Nordstr\\"{o}m-anti-de Sitter black hole mirror system

    CERN Document Server

    Huang, Yang; Li, Xin-Zhou

    2016-01-01

    Gaining insight into the behavior of a perturbed black hole surrounded by a reflecting mirror in asymptotically anti-de Sitter space-time is of great interest for current fundamental and practical research. In this work, a detailed analysis for superradiant stability of the system composed by a $D$-dimensional Reissner-Nordstr\\"{o}m-anti-de Sitter (RN-AdS) black hole and a reflecting mirror under charged scalar perturbations are presented in the linear regime. It is found that the stability of the system is heavily affected by the mirror radius as well as the mass of the scalar perturbation, AdS radius and the dimension of space-time. In a higher dimensional space-time, the degree of instability of the superradiant modes will be severely weakened. Nevertheless, the degree of instability can be magnified significantly by choosing a suitable value of the mirror radius. Remarkably, when the mirror radius is smaller than a threshold value the system becomes stable. We also find that massive charged scalar fields ...

  17. A microprocessor-based position control system for a telescope secondary mirror

    Science.gov (United States)

    Lorell, K. R.; Barrows, W. F.; Clappier, R. R.; Lee, G. K.

    1983-01-01

    The pointing requirements for the Shuttle IR Telescope Facility (SIRTF), which consists of an 0.85-m cryogenically cooled IR telescope, call for an image stability of 0.25 arcsec. Attention is presently given to a microprocessor-based position control system developed for the control of the SIRTF secondary mirror, employing a special control law (to minimize energy dissipation), a precision capacitive position sensor, and a specially designed power amplifier/actuator combination. The microprocessor generates the command angular position and rate waveforms in order to maintain a 90 percent dwell time/10 percent transition time ratio independently of chop frequency or amplitude. Performance and test results of a prototype system designed for use with a demonstration model of the SIRTF focal plane fine guidance sensor are presented.

  18. Why is your spouse so predictable? Connecting mirror neuron system and self-expansion model of love.

    Science.gov (United States)

    Ortigue, Stephanie; Bianchi-Demicheli, Francesco

    2008-12-01

    The simulation theory assumes we understand actions and intentions of others through a direct matching process. This matching process activates a complex brain network involving the mirror neuron system (MNS), which is self-related and active when one does something or observes someone else acting. Because social psychology admits that mutual intention's understanding grows in close relationship as love grows, we hypothesize that mirror mechanisms take place in love relationships. The similarities between the mirror matching process and the mutual intention's understanding that occurs when two persons are in love suggest that exposure to love might affect functional and neural mechanisms, thus facilitating the understanding of the beloved's intentions. Congruent with our hypothesis, our preliminary results from 38 subjects strongly suggest a significant facilitation effect of love on understanding the intentions of the beloved (as opposed to control stimuli). Based on these phenomenological, and neurofunctional findings we suggest that the mirror mechanisms are involved in the facilitation effects of love for understanding intentions, and might further be extended to any types of love (e.g., passionate love, maternal love). Love experiences are important not only to the beloved himself, but also to any societal, cultural, and institutional patterns that relate to love. Yet, concerning its subjective character, love experiences are difficult to access. The modern procedures and techniques of socio-cognitive neuroscience make it possible to understand love and self-related experiences not only by the analysis of subjective self-reported questionnaires, but also by approaching the automatic (non-conscious) mirror experiences of love in healthy subjects, and neurological patients with a brain damage within the mirror neuron system. Although the psychology of love is now well admitted, the systematic study of the automatic facilitation effect of love through mirror

  19. Twin arginine translocation system in secretory expression of recombinant human growth hormone

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Bagherinejad

    2016-01-01

    Full Text Available Recombinant protein production in E. coli has several advantages over other expression systems. Misfolding, inclusion body formation, and lack of eukaryotic post translational modification are the most disadvantages of this system. Exporting of correctly folded proteins to the outside of reductive cytoplasmic environment through twin-arginine system could help to pass these limiting steps. Two signal sequences, TorA and SufI are used at N-terminal of human growth hormone (hGH bearing DsbA gene sequence at C-terminal to enhance folding. The synthetic cassettes including the signal sequence, hGH and DsbA were transformed into E. coli BL21 (DE3 to study the effect of signal sequence and DsbA chaperone on translocation and folding of the protein. The results confirmed using signal sequence at N-terminal of targeted protein and coexpression with DsbA could transport proteins to the periplasmic space and culture media compared to control groups. Although there is no protein band of somatropin in SDS-Page of culture media samples when using SufI as signaling sequence, the study demonstrated TorA signal sequence could transport the target protein to the culture media. However, there was a considerable amount of hGH in periplasmic space when using SufI compared to control.

  20. Simulation study of an automatic trim system for reducing the control forces on a light twin after an engine failure

    Science.gov (United States)

    Stewart, E. C.; Brown, P. W.

    1985-01-01

    An automatic trim system for reducing the control forces after an engine failure on a light twin has been investigated on the Langley General Aviation Simulator. The system schedules open-loop trim tab deflections as a function of differential propeller slipstream dynamic pressure and freestream dynamic pressure. The system is described and the airplane-system static and dynamic characteristics are documented. Three NASA research pilots evaluated the effectiveness of the system for takeoff and landing maneuvers. A variety of off-nominal system characteristics were studied. The system was judged to be generally beneficial, providing a 2 to 3 point improvement in pilot rating for the tasks used in the evaluations.

  1. Simulation study of an automatic trim system for reducing the control forces on a light twin after an engine failure

    Science.gov (United States)

    Stewart, E. C.; Brown, P. W.

    1985-01-01

    An automatic trim system for reducing the control forces after an engine failure on a light twin has been investigated on the Langley General Aviation Simulator. The system schedules open-loop trim tab deflections as a function of differential propeller slipstream dynamic pressure and freestream dynamic pressure. The system is described and the airplane-system static and dynamic characteristics are documented. Three NASA research pilots evaluated the effectiveness of the system for takeoff and landing maneuvers. A variety of off-nominal system characteristics were studied. The system was judged to be generally beneficial, providing a 2 to 3 point improvement in pilot rating for the tasks used in the evaluations.

  2. Chiral mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Plum, Eric, E-mail: erp@orc.soton.ac.uk [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Zheludev, Nikolay I., E-mail: niz@orc.soton.ac.uk [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637378 (Singapore)

    2015-06-01

    Mirrors are used in telescopes, microscopes, photo cameras, lasers, satellite dishes, and everywhere else, where redirection of electromagnetic radiation is required making them arguably the most important optical component. While conventional isotropic mirrors will reflect linear polarizations without change, the handedness of circularly polarized waves is reversed upon reflection. Here, we demonstrate a type of mirror reflecting one circular polarization without changing its handedness, while absorbing the other. The polarization-preserving mirror consists of a planar metasurface with a subwavelength pattern that cannot be superimposed with its mirror image without being lifted out of its plane, and a conventional mirror spaced by a fraction of the wavelength from the metasurface. Such mirrors enable circularly polarized lasers and Fabry-Pérot cavities with enhanced tunability, gyroscopic applications, polarization-sensitive detectors of electromagnetic waves, and can be used to enhance spectroscopies of chiral media.

  3. Motor-Auditory-Visual Integration: The Role of the Human Mirror Neuron System in Communication and Communication Disorders

    Science.gov (United States)

    Le Bel, Ronald M.; Pineda, Jaime A.; Sharma, Anu

    2009-01-01

    The mirror neuron system (MNS) is a trimodal system composed of neuronal populations that respond to motor, visual, and auditory stimulation, such as when an action is performed, observed, heard or read about. In humans, the MNS has been identified using neuroimaging techniques (such as fMRI and mu suppression in the EEG). It reflects an…

  4. Motor-Auditory-Visual Integration: The Role of the Human Mirror Neuron System in Communication and Communication Disorders

    Science.gov (United States)

    Le Bel, Ronald M.; Pineda, Jaime A.; Sharma, Anu

    2009-01-01

    The mirror neuron system (MNS) is a trimodal system composed of neuronal populations that respond to motor, visual, and auditory stimulation, such as when an action is performed, observed, heard or read about. In humans, the MNS has been identified using neuroimaging techniques (such as fMRI and mu suppression in the EEG). It reflects an…

  5. Gene Expression Profiles from Disease Discordant Twins Suggest Shared Antiviral Pathways and Viral Exposures among Multiple Systemic Autoimmune Diseases.

    Science.gov (United States)

    Gan, Lu; O'Hanlon, Terrance P; Lai, Zhennan; Fannin, Rick; Weller, Melodie L; Rider, Lisa G; Chiorini, John A; Miller, Frederick W

    2015-01-01

    Viral agents are of interest as possible autoimmune triggers due to prior reported associations and widely studied molecular mechanisms of antiviral immune responses in autoimmunity. Here we examined new viral candidates for the initiation and/or promotion of systemic autoimmune diseases (SAID), as well as possible related signaling pathways shared in the pathogenesis of those disorders. RNA isolated from peripheral blood samples from 33 twins discordant for SAID and 33 matched, unrelated healthy controls was analyzed using a custom viral-human gene microarray. Paired comparisons were made among three study groups-probands with SAID, their unaffected twins, and matched, unrelated healthy controls-using statistical and molecular pathway analyses. Probands and unaffected twins differed significantly in the expression of 537 human genes, and 107 of those were associated with viral infections. These 537 differentially expressed human genes participate in overlapping networks of several canonical, biologic pathways relating to antiviral responses and inflammation. Moreover, certain viral genes were expressed at higher levels in probands compared to either unaffected twins or unrelated, healthy controls. Interestingly, viral gene expression levels in unaffected twins appeared intermediate between those of probands and the matched, unrelated healthy controls. Of the viruses with overexpressed viral genes, herpes simplex virus-2 (HSV-2) was the only human viral pathogen identified using four distinct oligonucleotide probes corresponding to three HSV-2 genes associated with different stages of viral infection. Although the effects from immunosuppressive therapy on viral gene expression remain unclear, this exploratory study suggests a new approach to evaluate shared viral agents and antiviral immune responses that may be involved in the development of SAID.

  6. Comparison of organic rankine cycle systems under varying conditions using turbine and twin-screw expanders

    OpenAIRE

    Read, M. G.; Smith, I K; Stosic, N.; Kovacevic, A.

    2016-01-01

    A multi-variable optimization program has been developed to investigate the performance of Organic Rankine Cycles (ORCs) for low temperature heat recovery applications using both turbine and twin-screw expanders when account is taken of performance variation due to changes in ambient conditions. The cycle simulation contains thermodynamic models of both types of expander. In the case of the twin-screw machine, the methods used to match the operation of the expander to the requirements of the ...

  7. Precise digital control system of a moving mirror's reciprocating move at even speed

    Institute of Scientific and Technical Information of China (English)

    Xiuming DOU; Qiang GUO

    2008-01-01

    The moving mirror's speed evenness and distance at even speed determine the spectrogram auality and resolution of the Fourier transform spectrometer(FTS).To ireprove the performance of FTS.a precise control system isdesigned to realize the moving mirror(MM)'s reciprocating move at even speed.A laser reference measurement interferometer with phase-shifting through polarization is introduced.which makes the position measurement resolution reach the half wavelength of the laser.At the moment MM changes direction.the configuration of the interference signal is complicated,which induces the measurement count error using a common direction judgment method.In this paper,an improved direction iudgment method is proposed based on the analysis of the interfering signal while MM changes direction,and the cortesponding logical circuits are designed in Field Programmable Gate Array(FPGAl.The MM is driven by a moving coil direct current(DC)linear motor,and the mathematical model is described.According to the analysis of the system characteristics and requirement.a fuzzy-PID control strategy is proposed.The fuzzy.PID control algorithm and its digital realization are studied.In order to reduce the computing quantity.the PID parameters for different inputs are calculated in advance by computer and stored in memory as tables.so the main work of the fuzzy-PID digital control algorithm is the simple look-up of the table.which makes the computing quantity very small and easy to realize in a Digital Signal Processing(DSP)chip.The control system is realized,and the experiment results show that the moving nlirror's speed reaches evenness within 0.ls almost without overshoot after changing direction.

  8. An Emotion Detection System Based on Multi Least Squares Twin Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Divya Tomar

    2014-01-01

    Full Text Available Posttraumatic stress disorder (PTSD, bipolar manic disorder (BMD, obsessive compulsive disorder (OCD, depression, and suicide are some major problems existing in civilian and military life. The change in emotion is responsible for such type of diseases. So, it is essential to develop a robust and reliable emotion detection system which is suitable for real world applications. Apart from healthcare, importance of automatically recognizing emotions from human speech has grown with the increasing role of spoken language interfaces in human-computer interaction applications. Detection of emotion in speech can be applied in a variety of situations to allocate limited human resources to clients with the highest levels of distress or need, such as in automated call centers or in a nursing home. In this paper, we used a novel multi least squares twin support vector machine classifier in order to detect seven different emotions such as anger, happiness, sadness, anxiety, disgust, panic, and neutral emotions. The experimental result indicates better performance of the proposed technique over other existing approaches. The result suggests that the proposed emotion detection system may be used for screening of mental status.

  9. Application of time reversal mirror technique in microwave-induced thermo-acoustic tomography system

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Microwave-induced thermo-acoustic tomography (MITAT) is a promising technique with great potential in biomedical imaging. It has both the high contrast of the microwave imaging and the high resolution of the ultrasound imaging. In this paper, the proportional relationship between the absorbed microwave energy distribution and the induced ultrasound source distribution is derived. Further, the time reversal mirror (TRM) technique based on the pseudo-spectral time domain (PSTD) method is applied to MITAT system. The simulation results show that high contrast and resolution can be achieved by the TRM technique based on PSTD method even for the received signals with very low signal-to-noise ratio (SNR) and the model parameter with random fluctuation.

  10. Optimization with numerical simulations of the conjugate altitudes of deformable mirrors in an MCAO system

    CERN Document Server

    Femenia, B

    2003-01-01

    This article reports on the results of simulations conducted to assess the performance of a modal Multi-Conjugate Adaptive Optics (MCAO) system on a 10m telescope with one Deformable Mirror (DM) conjugated to the telescope pupil and a second DM conjugated at a certain altitude above the pupil. The main goal of these simulations is to study the dependence of MCAO performance upon the altitude of the high-altitude conjugated DM and thereby determine its optimal conjugation. The performance is also studied with respect to the geometry of the Guide Star constellation when using constellations of Natural Guide Stars (NGS), which are rare, or constellations of Laser Guide Stars (LGS) which would allow large sky coverage.

  11. Electronic film with embedded micro-mirrors for solar energy concentrator systems

    Science.gov (United States)

    Rabinowitz, Mario; Davidson, Mark

    2004-01-01

    A novel electronic film solar energy concentrator with embedded micro-mirrors that track the sun is described. The potential viability of this new concept is presented. Due to miniaturization, the amount of material needed for the optical system is minimal. Because it is light-weight and flexible, it can easily be attached to the land or existing structures. This presents an economic advantage over conventional concentrators which require the construction of a separate structure to support them, and motors to orient them to intercept and properly reflect sunlight. Such separate structures must be able to survive gusts, windstorms, earthquakes, etc. This concentrator utilizes the ground or existing edifices which are already capable of withstanding such vicissitudes of nature.

  12. A Novel Mirror-Aided Non-imaging Receiver for Indoor 2x2 MIMO Visible Light Communication Systems

    KAUST Repository

    Park, Kihong

    2017-06-07

    Indoor visible light communication (VLC) systems are now possible because of advances in light emitting diode and laser diode technologies. These lighting technologies provide the foundation for multiple-input multiple-output (MIMO) data transmission through visible light. However, the channel matrix can be strongly correlated in indoor MIMO-VLC systems, preventing parallel data streams from being decoded. Here, in $2\\\\times 2$ MIMO-VLC systems, we describe a mirror diversity receiver (MDR) design that reduces the channel correlation by both blocking the reception of light from one specific direction and improving the channel gain from light from another direction by utilizing a double-sided mirror deployed between the receiver\\'s photodetectors. We report on the channel capacity of the MDR system and the optimal height of its mirrors in terms of maximum channel capacity. We also derived analytic results on the effect of rotation on MDR\\'s performance. Based on numerical and experimental results, we show that the double-sided mirror has both constructive and destructive effects on the channel matrix. Our design can be used with previously described non-imaging systems to improve the performance of indoor VLC systems.

  13. The Escherichia coli TatABC system and a Bacillus subtilis TatAC-type system recognise three distinct targeting determinants in twin-arginine signal peptides

    NARCIS (Netherlands)

    Mendel, Sharon; McCarthy, Andrew; Barnett, James P.; Eijlander, Robyn T.; Nenninger, Anja; Kuipers, Oscar P.; Robinson, Colin

    2008-01-01

    The Tat system transports folded proteins across bacterial and thylakoid membranes. In Gram-negative organisms, it is encoded by tatABC genes and the system recognizes substrates bearing signal peptides with a conserved twin-arginine motif. Most Gram-positive organisms lack a tatB gene, indicating m

  14. Conception and design of a control and monitoring system for the mirror alignment of the CBM RICH detector

    Science.gov (United States)

    Bendarouach, J.

    2016-08-01

    The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-proton and Ion Research (FAIR) complex will investigate the phase diagram of strongly interacting matter at high baryon density and moderate temperatures created in A+A collisions. For the SIS100 accelerator, the foreseen beam energy will range up to 11 AGeV for the heaviest nuclei. One of the key detector components required for the CBM physics program is the Ring Imaging CHerenkov (RICH) detector, which is developed for efficient and clean electron identification and pion suppression. An important aspect to guarantee a stable operation of the RICH detector is the alignment of the mirrors. A qualitative alignment control procedure for the mirror system has been implemented in the CBM RICH prototype detector and tested under real conditions at the CERN PS/T9 beamline. Collected data and results of image processing are reviewed and discussed. In parallel a quantitative method using recorded data has also been employed to compute mirror displacements of the RICH mirrors. Results based on simulated events and the limits of the method are presented and discussed as well. If mirror misalignment is detected, it can be subsequently included and rectified by correction routines. A first correction routine is presented and a comparison between misaligned, corrected and ideal geometries is shown.

  15. The design of an active support control system for a thin 1.2m primary mirror

    Science.gov (United States)

    Liu, Rong; Li, Xiaojin; Liu, Haitao; Wang, Hongqiao

    2014-09-01

    Active support system is a low-frequency wavefront error correction system, which is often used to correct the mirror deformation resulting from gravity, temperature, wind load, manufacture, installation and other factors. In addition, the active support technology can improve the efficiency of grinding and polishing by adjusting the surface shape in the process of manufacturing large mirrors. This article describes the design of an active support control system for a thin 1.2m primary mirror. The support system consists of 37 axial pneumatic actuators. And in order to change the shape of thin primary mirror we need to precisely control the 37 pneumatic actuators. These 37 pneumatic actuators are divided into six regions. Each region is designed with a control circuit board to realize force closed-loop control for the pneumatic actuators, and all control panels are connected to the PC by CAN bus. The control panels have to support: receive commands from the host PC; control the actuators; periodically return result of control. The whole control system is composed by hardware and control algorithm and communication program.

  16. First-principles Calculations of Twin-boundary and Stacking-fault Energies in Magnesium

    Science.gov (United States)

    2010-01-01

    The interfacial energies of twin boundaries and stacking faults in metal magnesium have been calculated using first-principles supercell approach...Four types of twin boundaries and two types of stacking faults are investigated, namely, those due to the mirror reflection, the mirror glide and the

  17. Role of the Mirror-Neuron System in Cross-Education

    NARCIS (Netherlands)

    Zult, Tjerk; Howatson, Glyn; Kadar, Endre E.; Farthing, Jonathan P.; Hortobagyi, Tibor

    The present review proposes the untested hypothesis that cross-education performed with a mirror increases the transfer of motor function to the resting limb compared with standard cross-education interventions without a mirror. The hypothesis is based on neuroanatomical evidence suggesting an

  18. Optical Correction Of Space-Based Telescopes Using A Deformable Mirror System

    Science.gov (United States)

    2016-12-01

    Experimental work first studied a severely degraded one-meter carbon fiber reinforced polymer mirror to establish a baseline. Simulations were...telescope. Experimental work first studied a severely degraded one-meter carbon fiber reinforced polymer mirror to establish a baseline. Simulations... INTRODUCTION ..................................................................................................1  A.  PURPOSE

  19. Stability and repeatability of a continuous twin screw granulation and drying system.

    Science.gov (United States)

    Vercruysse, J; Delaet, U; Van Assche, I; Cappuyns, P; Arata, F; Caporicci, G; De Beer, T; Remon, J P; Vervaet, C

    2013-11-01

    The aim of this study was to investigate the process transfer of a commercially available product from the current batch fluid bed granulation and drying production method to an innovative continuously operating "from powder to tablet" production line using twin screw granulation as an intermediate granulation step. By monitoring process outcomes (torque, water temperature at the granulator jacket inlet, differential pressure over the dryer filters, and temperature mill screen) and granule and tablet quality in function of process time, the stability and repeatability during long production runs were determined. Three consecutive 5h "from powder to tablet" production runs were performed using the ConsiGma™-25 system (GEA Pharma Systems, Collette™, Wommelgem, Belgium). A premix of two active ingredients, powdered cellulose, maize starch, pregelatinized starch, and sodium starch glycolate was granulated with distilled water. After drying and milling (1000 μm and 800 rpm), granules were in-line blended with magnesium stearate and directly compressed using a Modul™ P tablet press (tablet weight: 430 mg, main compression force: 12 kN). Granule (loss on drying, particle size distribution, friability, flow) and tablet (weight uniformity, hardness, thickness, friability, content uniformity, disintegration time, and dissolution) quality was evaluated in function of process time. For each of the logged process outcomes, a stabilization period was needed to reach steady-state conditions. Slightly deviating particle size distribution and friability results for milled granules were observed during start-up due to initial layering of the mill screen. However, no deviating tablet quality was detected in function of process time. For multiple hours, granule and tablet quality was constant in function of process time. Furthermore, process data trends were highly repeatable. Consequently, the ConsiGma™-25 system can be considered as a stable and repeatable system for the

  20. Dysfunction of the Human Mirror Neuron System in Ideomotor Apraxia: Evidence from Mu Suppression.

    Science.gov (United States)

    Frenkel-Toledo, Silvi; Liebermann, Dario G; Bentin, Shlomo; Soroker, Nachum

    2016-06-01

    Stroke patients with ideomotor apraxia (IMA) have difficulties controlling voluntary motor actions, as clearly seen when asked to imitate simple gestures performed by the examiner. Despite extensive research, the neurophysiological mechanisms underlying failure to imitate gestures in IMA remain controversial. The aim of the current study was to explore the relationship between imitation failure in IMA and mirror neuron system (MNS) functioning. Mirror neurons were found to play a crucial role in movement imitation and in imitation-based motor learning. Their recruitment during movement observation and execution is signaled in EEG recordings by suppression of the lower (8-10 Hz) mu range. We examined the modulation of EEG in this range in stroke patients with left (n = 21) and right (n = 15) hemisphere damage during observation of video clips showing different manual movements. IMA severity was assessed by the DeRenzi standardized diagnostic test. Results showed that failure to imitate observed manual movements correlated with diminished mu suppression in patients with damage to the right inferior parietal lobule and in patients with damage to the right inferior frontal gyrus pars opercularis-areas where major components of the human MNS are assumed to reside. Voxel-based lesion symptom mapping revealed a significant impact on imitation capacity for the left inferior and superior parietal lobules and the left post central gyrus. Both left and right hemisphere damages were associated with imitation failure typical of IMA, yet a clear demonstration of relationship to the MNS was obtained only in the right hemisphere damage group. Suppression of the 8-10 Hz range was stronger in central compared with occipital sites, pointing to a dominant implication of mu rather than alpha rhythms. However, the suppression correlated with De Renzi's apraxia test scores not only in central but also in occipital sites, suggesting a multifactorial mechanism for IMA, with a possible

  1. Multichannel analog-to-digital converters based on current mirrors for the optical systems

    Science.gov (United States)

    Krasilenko, Vladimir G.; Nikolskyy, A. I.; Nikolska, M. A.; Lobodzinska, R. F.

    2011-12-01

    The paper considers results of designing and modeling analogue-digital converters (ADC) based on current mirrors for the optical systems and neural networks with parallel inputs-outputs. Such ADC, named us multichannel analog-todigital converters based on current mirrors (M ADC CM). Compared with usual converters, for example, reading, a bitby- bit equilibration, and so forth, have a number of advantages: high speed and reliability, simplicity, small power consumption, the big degree of integration in linear and matrix structures. The considered aspects of designing of M_ADC CM in binary codes. Base digit cells (ABC) of such M_ADC CM, series-pipelined are connected in structures, consist from 20-30 CMOS the transistors, one photodiode, have low (1,5-3,5) supply voltage, work in current modes with the maximum values of currents (10-40)μA. Therefore such new principles of realization high-speed low-discharge M_ADC CM have allowed, as have shown modeling experiments, to reach time of transformation less than 20-30 nS at 5-6 bits of a binary code and the general power 1-5 mW. The quantity easily cascadable ABC depends on wordlength ADC, and makes n, and provides quantity of levels of quantization equal N=2n. Such simple enough on structure M ADC CM, having low power consumption CMOS-technologies has made 40 MHz, and can be increased 10 times) and accuracy (Δquantization 156,25nA for I max10μA) characteristics is show. The range can be transformed optical signals, taking into account sensitivity of modern photodetectors makes 20-200 μW in such ADC. M_ADC CM open new prospects for realization linear and matrix (with picture operands) micro photoelectronic structures which are necessary for neural networks, digital optoelectronic processors, neurofuzzy controllers, and so forth.

  2. Use of a continuous twin screw granulation and drying system during formulation development and process optimization.

    Science.gov (United States)

    Vercruysse, J; Peeters, E; Fonteyne, M; Cappuyns, P; Delaet, U; Van Assche, I; De Beer, T; Remon, J P; Vervaet, C

    2015-01-01

    Since small scale is key for successful introduction of continuous techniques in the pharmaceutical industry to allow its use during formulation development and process optimization, it is essential to determine whether the product quality is similar when small quantities of materials are processed compared to the continuous processing of larger quantities. Therefore, the aim of this study was to investigate whether material processed in a single cell of the six-segmented fluid bed dryer of the ConsiGma™-25 system (a continuous twin screw granulation and drying system introduced by GEA Pharma Systems, Collette™, Wommelgem, Belgium) is predictive of granule and tablet quality during full-scale manufacturing when all drying cells are filled. Furthermore, the performance of the ConsiGma™-1 system (a mobile laboratory unit) was evaluated and compared to the ConsiGma™-25 system. A premix of two active ingredients, powdered cellulose, maize starch, pregelatinized starch and sodium starch glycolate was granulated with distilled water. After drying and milling (1000 μm, 800 rpm), granules were blended with magnesium stearate and compressed using a Modul™ P tablet press (tablet weight: 430 mg, main compression force: 12 kN). Single cell experiments using the ConsiGma™-25 system and ConsiGma™-1 system were performed in triplicate. Additionally, a 1h continuous run using the ConsiGma™-25 system was executed. Process outcomes (torque, barrel wall temperature, product temperature during drying) and granule (residual moisture content, particle size distribution, bulk and tapped density, hausner ratio, friability) as well as tablet (hardness, friability, disintegration time and dissolution) quality attributes were evaluated. By performing a 1h continuous run, it was detected that a stabilization period was needed for torque and barrel wall temperature due to initial layering of the screws and the screw chamber walls with material. Consequently, slightly deviating

  3. Spina bifida occulta and monozygotic twins.

    Science.gov (United States)

    Spacca, Barbara; Buxton, Neil

    2008-10-01

    Central nervous system maldevelopment can have different presentations in twins. We report on a case of different presentations of spina bifida occulta in monozygotic twins. The first twin presented at birth with a lipomyelomeningocele; a tethered cord was diagnosed in the second twin at 2 years of age. Neural tube defects (NTDs) are a group of common congenital malformations of the brain and spine generated during neurulation. The genetic basis of this process is still not well known. Whenever an NTD is diagnosed in one of a pair of twins, the other twin should also be evaluated for NTDs.

  4. Imitation and Action Understanding in Autistic Spectrum Disorders: How Valid Is the Hypothesis of a Deficit in the Mirror Neuron System?

    Science.gov (United States)

    Hamilton, Antonia F. de C.; Brindley, Rachel M.; Frith, Uta

    2007-01-01

    The motor mirror neuron system supports imitation and goal understanding in typical adults. Recently, it has been proposed that a deficit in this mirror neuron system might contribute to poor imitation performance in children with autistic spectrum disorders (ASD) and might be a cause of poor social abilities in these children. We aimed to test…

  5. Imitation and Action Understanding in Autistic Spectrum Disorders: How Valid Is the Hypothesis of a Deficit in the Mirror Neuron System?

    Science.gov (United States)

    Hamilton, Antonia F. de C.; Brindley, Rachel M.; Frith, Uta

    2007-01-01

    The motor mirror neuron system supports imitation and goal understanding in typical adults. Recently, it has been proposed that a deficit in this mirror neuron system might contribute to poor imitation performance in children with autistic spectrum disorders (ASD) and might be a cause of poor social abilities in these children. We aimed to test…

  6. Object visibility alters the relative contribution of ventral visual stream and mirror neuron system to goal anticipation during action observation

    NARCIS (Netherlands)

    Thioux, Marc; Keysers, Christian

    2015-01-01

    We used fMRI to study the effect of hiding the target of a grasping action on the cerebral activity of an observer whose task was to anticipate the size of the object being grasped. Activity in the putative mirror neuron system (pMNS) was higher when the target was concealed from the view of the

  7. Compressive Strength Properties of Natural Gas Hydrate Pellet by Continuous Extrusion from a Twin-Roll System

    Directory of Open Access Journals (Sweden)

    Yun-Hoo Lee

    2013-01-01

    Full Text Available This study investigates the compressive strength of natural gas hydrate (NGH pellet strip extruded from die holes of a twin-roll press for continuous pelletizing (TPCP. The lab-scale TPCP was newly developed, where NGH powder was continuously fed and extruded into strip-type pellet between twin rolls. The system was specifically designed for future expansion towards mass production of solid form NGH. It is shown that the compressive strength of NGH pellet strip heavily depends on parameters in the extrusion process, such as feeding pressure, pressure ratio, and rotational speed. The mechanism of TPCP, along with the compressive strength and density of pellets, is discussed in terms of its feasibility for producing NGH pellets in the future.

  8. MEMS scanner mirror based system for retina scanning and in eye projection

    Science.gov (United States)

    Woittennek, Franziska; Knobbe, Jens; Pügner, Tino; Dallmann, Hans-Georg; Schelinski, Uwe; Grüger, Heinrich

    2015-02-01

    Many applications could benefit from miniaturized systems to scan blood vessels behind the retina in the human eye, so called "retina scanning". This reaches from access control to sophisticated security applications and medical devices. High volume systems for consumer applications require low cost and a user friendly operation. For example this includes no need for removal of glasses and self-adjustment, in turn guidance of focus and point of attraction by simultaneous projection for the user. A new system has been designed based on the well-known resonantly driven 2-d scanner mirror of Fraunhofer IPMS. A combined NIR and VIS laser system illuminates the eye through an eye piece designed for an operating distance allowing the use of glasses and granting sufficient field of view. This usability feature was considered to be more important than highest miniaturization. The modulated VIS laser facilitates the projection of an image directly onto the retina. The backscattered light from the continuous NIR laser contains the information of the blood vessels and is detected by a highly sensitive photo diode. A demonstrational setup has been realized including readout and driving electronics. The laser power was adjusted to an eye-secure level. Additional security features were integrated. Test measurements revealed promising results. In a first demonstration application the detection of biometric pattern of the blood vessels was evaluated for issues authentication in.

  9. Corticospinal mirror neurons.

    Science.gov (United States)

    Kraskov, A; Philipp, R; Waldert, S; Vigneswaran, G; Quallo, M M; Lemon, R N

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons' discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited 'classical' mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation ('suppression mirror-neurons'). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others.

  10. Design and implementation of a beam-waveguide mirror control system for vernier pointing of the DSS-13 antenna

    Science.gov (United States)

    Alvarez, L. S.; Moore, M.; Veruttipong, W.; Andres, E.

    1994-01-01

    The design and implementation of an antenna beam-waveguide (BWG) mirror position control system at the DSS-13 34-m antenna is presented. While it has several potential applications, a positioner on the last flat-plate BWG mirror (M6) at DSS 13 is installed to demonstrate the conical scan (conscan) angle-tracking technique at the Ka-band (32-GHz) operating frequency. Radio frequency (RF) beam-scanning predictions for the M6 mirror, computed from a diffraction analysis, are presented. From these predictions, position control system requirements are then derived. The final mechanical positioner and servo system designs, as implemented at DSS 13, are illustrated with detailed design descriptions given in the appendices. Preliminary measurements of antenna Ka-band beam scan versus M6 mirror tilt made at DSS 13 in December 1993 are presented. After reduction, the initial measurements are shown to be in agreement with the RF predicts. Plans for preliminary conscan experimentation at DSS 13 are summarized.

  11. An RF Therapy System for Breast Cancer Using Dual Deformable Mirrors — Computational Study

    Science.gov (United States)

    Arunachalam, Kavitha; Udpa, Satish S.; Udpa, Lalita

    2007-03-01

    Breast cancer is the second leading cause of cancer deaths amongst women in the United States. In the past two decades, the potential of non-ionizing high power RF waves to destroy cancerous biological tissues is actively investigated for cancer therapy. This paper presents the computational feasibility study of an alternative mode of electromagnetic radiation therapy that employs dual source and deformable mirror. The adaptive focusing capability of the deformable mirror is exploited for preferential energy deposition at the tumor site in the breast irradiated by electromagnetic radiation. The outcome of the computational study for the proposed deformable mirror-based thermal therapy for breast cancer is presented in this paper.

  12. Magic Mirrors

    Science.gov (United States)

    Mills, Allan

    2011-01-01

    "Magic mirrors" were so named because, when they were positioned to throw a reflected patch of sunlight on a nearby wall, this area contained an outline of a design cast on the back of the (bronze) mirror. Investigations begun in the 19th century showed that this was a response to heavy localized pressures exerted on the face of the thin mirror…

  13. Mirror symmetry

    CERN Document Server

    Voisin, Claire

    1999-01-01

    This is the English translation of Professor Voisin's book reflecting the discovery of the mirror symmetry phenomenon. The first chapter is devoted to the geometry of Calabi-Yau manifolds, and the second describes, as motivation, the ideas from quantum field theory that led to the discovery of mirror symmetry. The other chapters deal with more specialized aspects of the subject: the work of Candelas, de la Ossa, Greene, and Parkes, based on the fact that under the mirror symmetry hypothesis, the variation of Hodge structure of a Calabi-Yau threefold determines the Gromov-Witten invariants of its mirror; Batyrev's construction, which exhibits the mirror symmetry phenomenon between hypersurfaces of toric Fano varieties, after a combinatorial classification of the latter; the mathematical construction of the Gromov-Witten potential, and the proof of its crucial property (that it satisfies the WDVV equation), which makes it possible to construct a flat connection underlying a variation of Hodge structure in the ...

  14. Mathematical Modeling of Radiant Heat Transfer in Mirror Systems Considering Deep Reflecting Surface Defects

    Directory of Open Access Journals (Sweden)

    V. V. Leonov

    2014-01-01

    Full Text Available When designing large-sized mirror concentrating systems (MCS for high-temperature solar power plants, one must have at disposal reasonably reliable and economical methods and tools, making it possible to analyze its characteristics, to predict them depending on the operation conditions and accordingly to choose the most suitable system for the solution of particular task.Experimental determination of MCS characteristics requires complicated and expensive experimentation, having significant limitations on interpretation of the results, as well as limitations imposed due to the size of the structure. Therefore it is of particular interest to develop a mathematical model capable of estimating power characteristics of MCS considering the influence of operating conditions, design features, roughness and other surface defects.For efficient solution of the tasks the model must ensure simulation of solar radiant flux as well as simulation of geometrical and optical characteristics of reflection surface and their interaction. In this connection a statistical mathematical model of radiation heat exchange based on use of Monte Carlo methods and Finite Element Method was developed and realized in the software complex, making it possible to determine main characteristics of the MCS.In this paper the main attention is given to definition of MCS radiation characteristics with account for deep reflecting surface defects (cavities, craters. Deep cavities are not typical for MCS, but their occurrence is possible during operation as a result of erosion or any physical damage. For example, for space technology it is primarily micrometeorite erosion.

  15. Autism, emotion recognition and the mirror neuron system: the case of music.

    Science.gov (United States)

    Molnar-Szakacs, Istvan; Wang, Martha J; Laugeson, Elizabeth A; Overy, Katie; Wu, Wai-Ling; Piggot, Judith

    2009-11-16

    Understanding emotions is fundamental to our ability to navigate and thrive in a complex world of human social interaction. Individuals with Autism Spectrum Disorders (ASD) are known to experience difficulties with the communication and understanding of emotion, such as the nonverbal expression of emotion and the interpretation of emotions of others from facial expressions and body language. These deficits often lead to loneliness and isolation from peers, and social withdrawal from the environment in general. In the case of music however, there is evidence to suggest that individuals with ASD do not have difficulties recognizing simple emotions. In addition, individuals with ASD have been found to show normal and even superior abilities with specific aspects of music processing, and often show strong preferences towards music. It is possible these varying abilities with different types of expressive communication may be related to a neural system referred to as the mirror neuron system (MNS), which has been proposed as deficient in individuals with autism. Music's power to stimulate emotions and intensify our social experiences might activate the MNS in individuals with ASD, and thus provide a neural foundation for music as an effective therapeutic tool. In this review, we present literature on the ontogeny of emotion processing in typical development and in individuals with ASD, with a focus on the case of music.

  16. Free Form Mirrors for Ultra Compact High Speed Optical Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This task is to collaboratively design and fabricate the free-form WIRIS telescope primary mirror with our partner Zygo as a technology demonstration. Fabricating...

  17. Actively Cooled Silicon Lightweight Mirrors for Far Infrared and Submillimeter Optical Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Schafer proposes to demonstrate 2 different methods for actively cooling our 5-7.5 kg/m2 areal density Silicon Lightweight Mirrors (SLMS?) technology for future NASA...

  18. The Role of Emotion, Vision and Touch in Movement Learning Neuroplasticity and the Mirror Neuron System

    Directory of Open Access Journals (Sweden)

    Jeanne Masterson

    2015-09-01

    Full Text Available The brains ability to restructure, linked with positive emotional states and techniques to enhance the activation of the mirror neuron system, allows for increased motor learning. This study examines the effects of enhancing goal-oriented movement and examines various techniques used to strengthen neural networks during such movement practices. Goal oriented movement practices are commonly used when engaging in Pilates. Participants will be divided between three groups to help identify potential differences between individuals who receive sensory cueing and those who do not receive sensory cueing. It is hypothesized there will be a difference between participants who receive emotional priming and the visual enhancement of touch versus those who are not primed. Specifically, it is predicted that participants who are primed will demonstrate enhanced skill acquisition of learning during Pilates as opposed to participants assigned to either the regular Pilates condition or the control condition. These types of studies are important in that they can possibly be applied in many motor learning areas, such as physical therapy, sports, general physical activity for health, and possibly even psychological interventions. Results of the current study supported the main hypothesis in that increased physical task skill was obtained in the group receiving positive emotional cueing and visual enhancement of touch. Likewise there was a statically significant increase in physical self-efficacy scores in the group receiving these independent variables over that of the group receiving regular Pilates only. The results of the current study show that a physical task environment such as that in a Pilates class can be improved by adding techniques that enhance sensory input to the regions of the brain that recognize and process motor activity. Also that with an increase in physical skill comes a heightened physical self-efficacy. In theory this was due to an

  19. Numerical study of superradiant instability for charged stringy black hole-mirror system

    CERN Document Server

    Li, Ran

    2015-01-01

    We numerically study the superradiant instability of charged massless scalar field in the background of charged stringy black hole with mirror-like boundary condition. We compare the numerical result with the previous analytical result and show the dependencies of this instability upon various parameters of black hole charge $Q$, scalar field charge $q$, and mirror radius $r_m$. Especially, we have observed that imaginary part of BQN frequencies grows with the scalar field charge $q$ rapidly.

  20. Numerical study of superradiant instability for charged stringy black hole-mirror system

    Science.gov (United States)

    Li, Ran; Zhao, Junkun

    2015-01-01

    We numerically study the superradiant instability of charged massless scalar field in the background of charged stringy black hole with mirror-like boundary condition. We compare the numerical result with the previous analytical result and show the dependencies of this instability upon various values of black hole charge Q, scalar field charge q, and mirror radius rm. Especially, we have observed that imaginary part of BQN frequencies grows with the scalar field charge q rapidly.

  1. Numerical study of superradiant instability for charged stringy black hole–mirror system

    OpenAIRE

    Li, Ran; Zhao, Junkun

    2015-01-01

    We numerically study the superradiant instability of charged massless scalar field in the background of charged stringy black hole with mirror-like boundary condition. We compare the numerical result with the previous analytical result and show the dependencies of this instability upon various values of black hole charge Q , scalar field charge q , and mirror radius rm . Especially, we have observed that imaginary part of BQN frequencies grows with the scalar field charge q rapidly.

  2. Numerical study of superradiant instability for charged stringy black hole–mirror system

    Directory of Open Access Journals (Sweden)

    Ran Li

    2015-01-01

    Full Text Available We numerically study the superradiant instability of charged massless scalar field in the background of charged stringy black hole with mirror-like boundary condition. We compare the numerical result with the previous analytical result and show the dependencies of this instability upon various values of black hole charge Q, scalar field charge q, and mirror radius rm. Especially, we have observed that imaginary part of BQN frequencies grows with the scalar field charge q rapidly.

  3. Design of axisymmetric multi-mirror grazing incidence system to increase the numerical aperture of neutron and X-ray microscopes

    Science.gov (United States)

    Aoki, Sadao; Watanabe, Norio; Asami, Hiroshi; Shimada, Akihiro

    2016-04-01

    An axisymmetric multi-mirror system for neutron and X-ray microscopes is proposed to increase their numerical aperture and collection efficiency. A Wolter type-I mirror is used as the basis of the multi-mirror system at grazing incidence. The addition of an even number of hyperboloid mirrors to the Wolter type-I mirror can satisfy both an equal optical path length and Abbe's sine condition. The numerical aperture increases in proportion to the number of mirrors. The optical parameters of the system with four tandem mirrors are calculated for neutrons and X-rays with a wavelength of 0.4 nm by assuming that the average grazing angle of incidence is 5.4 mrad and the magnification is 10. The inner diameters of the mirrors are limited to <10 mm considering the total length of the optical system. Tolerance of off-axis distance was calculated using a ray-tracing computer simulation. Ray tracing shows that a blur size <14 nm will be possible at an off-axis displacement of 10 μm.

  4. Twin Baryogenesis

    CERN Document Server

    Farina, Marco; Shin, Chang Sub

    2016-01-01

    In the context of Twin Higgs models, we study a simple mechanism that simultaneously generates asymmetries in the dark and visible sector through the out-of-equilibrium decay of a TeV scale particle charged under a combination of baryon and twin baryon number. We predict the dark matter to be a 5 GeV twin baryon, which is easy to achieve because of the similarity between the two confinement scales. Dark matter is metastable and can decay to three quarks, yielding indirect detection signatures. The mechanism requires the introduction of a new colored particle, typically within the reach of the LHC, of which we study the rich collider phenomenology, including prompt and displaced dijets, multi-jets, monojets and monotops.

  5. Collimating Montel mirror as part of a multi-crystal analyzer system for resonant inelastic X-ray scattering.

    Science.gov (United States)

    Kim, Jungho; Shi, Xianbo; Casa, Diego; Qian, Jun; Huang, XianRong; Gog, Thomas

    2016-07-01

    Advances in resonant inelastic X-ray scattering (RIXS) have come in lockstep with improvements in energy resolution. Currently, the best energy resolution at the Ir L3-edge stands at ∼25 meV, which is achieved using a diced Si(844) spherical crystal analyzer. However, spherical analyzers are limited by their intrinsic reflection width. A novel analyzer system using multiple flat crystals provides a promising way to overcome this limitation. For the present design, an energy resolution at or below 10 meV was selected. Recognizing that the angular acceptance of flat crystals is severely limited, a collimating element is essential to achieve the necessary solid-angle acceptance. For this purpose, a laterally graded, parabolic, multilayer Montel mirror was designed for use at the Ir L3-absorption edge. It provides an acceptance larger than 10 mrad, collimating the reflected X-ray beam to smaller than 100 µrad, in both vertical and horizontal directions. The performance of this mirror was studied at beamline 27-ID at the Advanced Photon Source. X-rays from a diamond (111) monochromator illuminated a scattering source of diameter 5 µm, generating an incident beam on the mirror with a well determined divergence of 40 mrad. A flat Si(111) crystal after the mirror served as the divergence analyzer. From X-ray measurements, ray-tracing simulations and optical metrology results, it was established that the Montel mirror satisfied the specifications of angular acceptance and collimation quality necessary for a high-resolution RIXS multi-crystal analyzer system.

  6. Vibratory response of a mirror support/positioning system for the Advanced Photon Source project at Argonne National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Basdogan, I.; Shu, Deming; Kuzay, T.M. [Argonne National Lab., IL (United States); Royston, T.J.; Shabana, A.A. [Univ. of Illinois, Chicago, IL (United States)

    1996-08-01

    The vibratory response of a typical mirror support/positioning system used at the experimental station of the Advanced Photon Source (APS) project at Argonne National Laboratory is investigated. Positioning precision and stability are especially critical when the supported mirror directs a high-intensity beam aimed at a distant target. Stability may be compromised by low level, low frequency seismic and facility-originated vibrations traveling through the ground and/or vibrations caused by flow-structure interactions in the mirror cooling system. The example case system has five positioning degrees of freedom through the use of precision actuators and rotary and linear bearings. These linkage devices result in complex, multi-dimensional vibratory behavior that is a function of the range of positioning configurations. A rigorous multibody dynamical approach is used for the development of the system equations. Initial results of the study, including estimates of natural frequencies and mode shapes, as well as limited parametric design studies, are presented. While the results reported here are for a particular system, the developed vibratory analysis approach is applicable to the wide range of high-precision optical positioning systems encountered at the APS and at other comparable facilities.

  7. Granularity within the mirror system is not informative on action perception. Comment on "Grasping synergies: A motor-control approach to the mirror neuron mechanism" by D'Ausilio et al.

    Science.gov (United States)

    Cattaneo, Luigi

    2015-03-01

    The present work [1] reviews a part of the now vast literature on visuomotor stimulus-response associations in the domain of action observation, commonly referred to as mirror mechanism or mirror system. The aim of the study is to propose a solution to a currently debated problem, namely in what frame of reference are mirror neurons coding movement. The solution proposed here is that, if the mirror system is part of the motor system, then the motor responses to action observation must be in the same frames of reference as that generally observed in the production of voluntary actions. This idea is part of the very first conceptualizations of the mirror system ("Each time an individual sees an action done by another individual, neurons that represent that action are activated in the observer's premotor cortex. This automatically induced, motor representation of the observed action corresponds to that which is spontaneously generated during active action and whose outcome is known to the acting individual" [2]) and has been explicitly proposed earlier [3] in the attempt of reconciling the very different findings in the literature on the mirror system's frames of reference. The novelty of the present approach is the explicit reference to the 'motor synergy' theory of voluntary hand movements. This theory states that the high number of degrees of freedom intrinsic to hand anatomy is reduced by the motor system to few principal components named motor synergies that are the building blocks of voluntary behavior [4]. I am enthusiastic about two points proposed by D'Ausilio in the present review and I am skeptical about some other points.

  8. Risk of Oral Clefts in Twins

    DEFF Research Database (Denmark)

    Grosen, Dorthe; Bille, Camilla; Petersen, Inge

    2011-01-01

    BACKGROUND:: Small studies have indicated that twinning increases the risk of oral cleft. METHODS:: We used data from a Danish national population-based cohort study to investigate whether twinning was associated with isolated oral cleft, and to estimate the twin probandwise concordance rate...... and heritability. Twins (207 affected/130,710) and singletons (7766 affected/4,798,526) born from 1936 through 2004 in Denmark were ascertained by linkage among the Danish Facial Cleft Database, the Danish Twin Registry, and the Civil Registration System. We computed oral cleft prevalence and prevalence proportion...... ratio for twins versus singletons, stratified for 3 subphenotypes. Probandwise concordance rates and heritability for twins were estimated for 2 phenotypes-cleft lip with or without cleft palate (CL/P) and cleft palate (CP). RESULTS:: The prevalence of oral cleft was 15.8 per 10,000 twins and 16.6 per...

  9. The Mirror Alignment and Control System for CT5 of the H.E.S.S. experiment

    CERN Document Server

    Gottschall, Daniel; Bonardi, Antonio; Santangelo, Andrea

    2015-01-01

    The High Energy Stereoscopic System (H.E.S.S.) experiment is one of the largest observatories for gamma-ray astronomy. It consists of four telescopes with a reflecting dish diameter of 12m (CT1 to CT4) and a newer large telescope (CT5) with a reflecting dish diameter of 28m. On CT5 876 mirror facets are mounted, all of them equipped with a computerised system for their alignment. The design of the mirror alignment and control system and the performance of the hardware installed to the telescope are presented. Furthermore the achieved point spread function of the telescope over the full operational elevation range as well as the stability of the alignment over an extended period of time are shown.

  10. Autism and the mirror neuron system: insights from learning and teaching.

    Science.gov (United States)

    Vivanti, Giacomo; Rogers, Sally J

    2014-01-01

    Individuals with autism have difficulties in social learning domains which typically involve mirror neuron system (MNS) activation. However, the precise role of the MNS in the development of autism and its relevance to treatment remain unclear. In this paper, we argue that three distinct aspects of social learning are critical for advancing knowledge in this area: (i) the mechanisms that allow for the implicit mapping of and learning from others' behaviour, (ii) the motivation to attend to and model conspecifics and (iii) the flexible and selective use of social learning. These factors are key targets of the Early Start Denver Model, an autism treatment approach which emphasizes social imitation, dyadic engagement, verbal and non-verbal communication and affect sharing. Analysis of the developmental processes and treatment-related changes in these different aspects of social learning in autism can shed light on the nature of the neuropsychological mechanisms underlying social learning and positive treatment outcomes in autism. This knowledge in turn may assist in developing more successful pedagogic approaches to autism spectrum disorder. Thus, intervention research can inform the debate on relations among neuropsychology of social learning, the role of the MNS, and educational practice in autism.

  11. Autism and the mirror neuron system: insights from learning and teaching

    Science.gov (United States)

    Vivanti, Giacomo; Rogers, Sally J.

    2014-01-01

    Individuals with autism have difficulties in social learning domains which typically involve mirror neuron system (MNS) activation. However, the precise role of the MNS in the development of autism and its relevance to treatment remain unclear. In this paper, we argue that three distinct aspects of social learning are critical for advancing knowledge in this area: (i) the mechanisms that allow for the implicit mapping of and learning from others' behaviour, (ii) the motivation to attend to and model conspecifics and (iii) the flexible and selective use of social learning. These factors are key targets of the Early Start Denver Model, an autism treatment approach which emphasizes social imitation, dyadic engagement, verbal and non-verbal communication and affect sharing. Analysis of the developmental processes and treatment-related changes in these different aspects of social learning in autism can shed light on the nature of the neuropsychological mechanisms underlying social learning and positive treatment outcomes in autism. This knowledge in turn may assist in developing more successful pedagogic approaches to autism spectrum disorder. Thus, intervention research can inform the debate on relations among neuropsychology of social learning, the role of the MNS, and educational practice in autism. PMID:24778379

  12. Parameters optimization in a fission-fusion system with a mirror machine based neutron source

    Science.gov (United States)

    Yurov, D. V.; Anikeev, A. V.; Bagryansky, P. A.; Brednikhin, S. A.; Frolov, S. A.; Lezhnin, S. I.; Prikhodko, V. V.

    2012-06-01

    Long-lived fission products utilization is a problem of high importance for the modern nuclear reactor technology. BINP jointly with NSI RAS develops a conceptual design of a hybrid sub-critical minor actinides burner with a neutron source based on the gas dynamic mirror machine (GDT) to resolve the stated task. A number of modelling tools was created to calculate the main parameters of the device. First of the codes, GENESYS, is a zero-dimensional code, designed for plasma dynamics numerical investigation in a GDT-based neutron source. The code contains a Monte-Carlo module for the determination of linear neutron emission intensity along the machine axis. Fuel blanket characteristics calculation was implemented by means of a static Monte-Carlo code NMC. Subcritical core, which has been previously analyzed by OECD-NEA, was used as a template for the fuel blanket of the modelled device. This article represents the codes used and recent results of the described system parameters optimization. Particularly, optimum emission zone length of the source and core multiplicity dependence on buffer zone thickness were defined.

  13. Remote counseling using HyperMirror quasi space-sharing system

    Science.gov (United States)

    Hashimoto, Sayuri; Morikawa, Osamu; Hashimoto, Nobuyuki; Maesako, Takanori

    2008-08-01

    In the modern information society, networks are getting faster, costs are getting lower, and displays are getting clearer. Today, just about anyone can easily use precise, dynamic, image distribution systems in their everyday life. Now, the question is how to give the benefits of network systems to the local community, as well as to each individual.This study was designed to use communication with realistic sensations to examine the effectiveness of remote individual counseling intervention in reducing depression, anxiety and stress in child-rearing mothers. Three child-rearing mothers residing in the city of Osaka each received one session of remote counseling intervention. The results showed an alleviation of stress related to child-rearing, i.e., the reduction in state anxiety, depression and subjective stress related to child-rearing. Moreover, an experimental demonstration employed a HyperMirror system capable of presenting visual and auditory images similar to reality, in order to provide the counselees with realistic sensations. While the voice communication environment was poor, the remote counseling allowed for the communication of sensory information, i.e., skinship that communicated information related to assurance/peace of mind, and auditory information, i.e., a whispering voices in which signals of affection were transmitted; the realistic sensation contributed to a reduction in stress levels. The positive effects of the intervention were confirmed through a pre and post intervention study. The results suggested the need to conduct future studies to confirm the mid- and long-term improvements caused by the intervention, as well as the need to improve the voice transmission environment.

  14. Mirror neurons

    National Research Council Canada - National Science Library

    Rubia Vila, Francisco José

    2011-01-01

    Mirror neurons were recently discovered in frontal brain areas of the monkey. They are activated when the animal makes a specific movement, but also when the animal observes the same movement in another animal...

  15. PELATIHAN MIRROR NEURON SYSTEM SAMA DENGAN PELATIHAN CONSTRAINT INDUCED MOVEMENT THERAPY DALAM MENINGKATKAN KEMAMPUAN FUNGSIONAL ANGGOTA GERAK ATAS PASIEN STROKE

    Directory of Open Access Journals (Sweden)

    Abdul chalik meidian

    2014-03-01

    Full Text Available Stroke is an interruption of blood vasculature system in the brain that causes suddenly neurological dysfunction, resulted in clinically brain tissue damage in a relatively long time period, decreased physical mobility and functional ability impaired of upper limb. The purpose of this study is to know an increasing in upper limb functional ability among stroke patients after mirror neuron system exercise and constraint induced movement therapy exercise and to know the comparison of both exercise. This study uses an experimental research with pre-test and post-test control group design. Number of samples of the first group is 13 patients given mirror neuron system exercise for 30-60 minutes , while the second group 13 patients were given constraint induced movement therapy exercise for 30-60 minutes. The research was conducted in 2 month period time. Each patient is taught a variety of upper limb functional ability in accordance with the operational concept guidance and patients were asked to repeat the exercise independently at home as directed. Measuring test of upper limb functional ability is using the wolf motor function test instruments. The result is an increase the upper limb functional ability of 21.7% in the mirror neuron system exercise group and proved a significant difference (p<0.05 and an increase in the upper limb functional ability of 17.1% in the constraint induced movement therapy exercise group and proved a significant difference (p<0.05 while the difference of increasing of upper limb functional ability of the two groups showed no significant difference (p>0,05. It was concluded that the mirror neuron system exercise is similar with constraint induced movement therapy exercise in increasing the upper limb functional ability among stroke patients.

  16. 3D phase-shifting fringe projection system on the basis of a tailored free-form mirror.

    Science.gov (United States)

    Zwick, Susanne; Heist, Stefan; Steinkopf, Ralf; Huber, Sandra; Krause, Sylvio; Bräuer-Burchardt, Christian; Kühmstedt, Peter; Notni, Gunther

    2013-05-10

    Phase-shifting fringe projection is an effective method to perform 3D shape measurements. Conventionally, fringe projection systems utilize a digital projector that images fringes into the measurement plane. The performance of such systems is limited to the visible spectral range, as most projectors experience technical limitations in UV or IR spectral ranges. However, for certain applications these spectral ranges are of special interest. We present a wideband fringe projector that has been developed on the basis of a picture generating beamshaping mirror. This mirror generates a sinusoidal fringe pattern in the measurement plane without any additional optical elements. Phase shifting is realized without any mechanical movement by a multichip LED. As the system is based on a single mirror, it is wavelength-independent in a wide spectral range and therefore applicable in UV and IR spectral ranges. We present the design and a realized setup of this fringe projection system and the characterization of the generated intensity distribution. Experimental results of 3D shape measurements are presented.

  17. Magnetoencephalography study of right parietal lobe dysfunction of the evoked mirror neuron system in antipsychotic-free schizophrenia.

    Science.gov (United States)

    Kato, Yutaka; Muramatsu, Taro; Kato, Motoichiro; Shibukawa, Yoshiyuki; Shintani, Masuro; Mimura, Masaru

    2011-01-01

    Patients with schizophrenia commonly exhibit deficits of non-verbal communication in social contexts, which may be related to cognitive dysfunction that impairs recognition of biological motion. Although perception of biological motion is known to be mediated by the mirror neuron system, there have been few empirical studies of this system in patients with schizophrenia. Using magnetoencephalography, we examined whether antipsychotic-free schizophrenia patients displayed mirror neuron system dysfunction during observation of biological motion (jaw movement of another individual). Compared with normal controls, the patients with schizophrenia had fewer components of both the waveform and equivalent current dipole, suggesting aberrant brain activity resulting from dysfunction of the right inferior parietal cortex. They also lacked the changes of alpha band and gamma band oscillation seen in normal controls, and had weaker phase-locking factors and gamma-synchronization predominantly in right parietal cortex. Our findings demonstrate that untreated patients with schizophrenia exhibit aberrant mirror neuron system function based on the right inferior parietal cortex, which is characterized by dysfunction of gamma-synchronization in the right parietal lobe during observation of biological motion.

  18. Magnetoencephalography study of right parietal lobe dysfunction of the evoked mirror neuron system in antipsychotic-free schizophrenia.

    Directory of Open Access Journals (Sweden)

    Yutaka Kato

    Full Text Available INTRODUCTION: Patients with schizophrenia commonly exhibit deficits of non-verbal communication in social contexts, which may be related to cognitive dysfunction that impairs recognition of biological motion. Although perception of biological motion is known to be mediated by the mirror neuron system, there have been few empirical studies of this system in patients with schizophrenia. METHODS: Using magnetoencephalography, we examined whether antipsychotic-free schizophrenia patients displayed mirror neuron system dysfunction during observation of biological motion (jaw movement of another individual. RESULTS: Compared with normal controls, the patients with schizophrenia had fewer components of both the waveform and equivalent current dipole, suggesting aberrant brain activity resulting from dysfunction of the right inferior parietal cortex. They also lacked the changes of alpha band and gamma band oscillation seen in normal controls, and had weaker phase-locking factors and gamma-synchronization predominantly in right parietal cortex. CONCLUSIONS: Our findings demonstrate that untreated patients with schizophrenia exhibit aberrant mirror neuron system function based on the right inferior parietal cortex, which is characterized by dysfunction of gamma-synchronization in the right parietal lobe during observation of biological motion.

  19. 镜面无损检测系统%Non - destructive Inspection System for Characterization of Mirror - like Surfaces

    Institute of Scientific and Technical Information of China (English)

    尹燕萍; 罗庆媛; 杨晓波

    2000-01-01

    介绍了基于"魔镜"技术原理研制的镜面无损检测系统。该检测系统已应用于Si片和其他半导体抛光晶片的质量检测,且其用途已延伸到与超平镜面有关的各种技术领域,如硬盘、光盘、玻璃衬底等。%A mirror - like surface non - destructive inspection system manufactured based on the principle of "Makyoh" technology is introduced. This inspection system has recently been applied to evaluate Si wafers and other polished semiconductor wafers. The application has extended to various technological fields related to super - flat mirror surfaces, such as hard discs, optical discs, and glass substrates, etc.

  20. Highly efficient end-side-pumped Nd:YAG solar laser by a heliostat-parabolic mirror system.

    Science.gov (United States)

    Almeida, J; Liang, D; Vistas, C R; Guillot, E

    2015-03-10

    We report a large improvement in the collection and slope efficiency of an Nd:YAG solar laser pumped by a heliostat-parabolic mirror system. A conical fused silica lens was used to further concentrate the solar radiation from the focal zone of a 2 m diameter primary concentrator to a Nd:YAG single-crystal rod within a conical pump cavity, which enabled multipass pumping to the active medium. A 56 W cw laser power was measured, corresponding to 21.1  W/m2 record-high solar laser collection efficiency with the heliostat-parabolic mirror system. 4.9% slope efficiency was calculated, corresponding to 175% enhancement over our previous result.

  1. Interaction of Point Defects with Twin Boundaries in Copper

    Institute of Scientific and Technical Information of China (English)

    S. A. Ahmad; Razia Ramzan

    2007-01-01

    The interaction between small vacancy clusters and twin boundaries in copper is studied by using many-body potential developed by Ackland et al. for fcc metals. The interaction energies of single-, dj- and tri-vacancy clusters with (111) and (112) twin boundaries are computed using well established simulation techniques. For (111) twins the vacancy clusters are highly repelled when they are on the adjacent planes, and are attracted when they are away from the boundary. In the case of (112) twins, vacancy clusters are more attracted to the boundary when they are near the boundary as compared to away from it. Vacancy clusters on both the sides of the boundary are also investigated, and it is observed that the clusters energetically prefer to lie on the off-mirror sites as compared to the mirror position across the twin.

  2. Mirror reactor surface study

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, A. L.; Damm, C. C.; Futch, A. H.; Hiskes, J. R.; Meisenheimer, R. G.; Moir, R. W.; Simonen, T. C.; Stallard, B. W.; Taylor, C. E.

    1976-09-01

    A general survey is presented of surface-related phenomena associated with the following mirror reactor elements: plasma first wall, ion sources, neutral beams, director converters, vacuum systems, and plasma diagnostics. A discussion of surface phenomena in possible abnormal reactor operation is included. Several studies which appear to merit immediate attention and which are essential to the development of mirror reactors are abstracted from the list of recommended areas for surface work. The appendix contains a discussion of the fundamentals of particle/surface interactions. The interactions surveyed are backscattering, thermal desorption, sputtering, diffusion, particle ranges in solids, and surface spectroscopic methods. A bibliography lists references in a number of categories pertinent to mirror reactors. Several complete published and unpublished reports on surface aspects of current mirror plasma experiments and reactor developments are also included.

  3. Mu-wave activity in schizophrenia: Evidence of a dysfunctional mirror neuron system from an Indian study

    Directory of Open Access Journals (Sweden)

    Sayantanava Mitra

    2014-01-01

    Full Text Available Background: The ′mirror-neuron system′ is thought to play an important role in automatic decoding of biological motions and interpretation of socially adaptive environmental stimuli. Accordingly, a dysfunction in this system in schizophrenia has been hypothesised to mediate the psychotic manifestations. Materials and Methods: As a part of an ongoing study, we evaluated the mirror neuron system using ′EEG mu-wave (8-13 Hz suppression′ paradigm in 15 drug naïve/drug free patients and compared the working to 15 age, sex and education matched controls. We also correlated the psychopathology scores on PANSS with the mu wave suppression in the schizophrenia patients, at baseline. We used high (192-channel resolution EEG to record the mu rhythm while the subjects watched alternating sequences of a socially-relevant biological motion and white visual-noise on a custom made video-clip. Results: We found a significant difference in the degree of mu wave suppression between the two groups. We also found that the degree of mu suppression over right sensorimotor cortex at presentation correlated significantly and negatively with thought disorder in the patient group, and had a strong linear relationship. Conclusion: This study replicates past findings regarding a dysfunctional mirror neuron system in schizophrenia patients, and also emphasizes the role of rMNS in schizophrenic thought disorders.

  4. Controlling automatic imitative tendencies: interactions between mirror neuron and cognitive control systems.

    Science.gov (United States)

    Cross, Katy A; Torrisi, Salvatore; Reynolds Losin, Elizabeth A; Iacoboni, Marco

    2013-12-01

    Humans have an automatic tendency to imitate others. Although several regions commonly observed in social tasks have been shown to be involved in imitation control, there is little work exploring how these regions interact with one another. We used fMRI and dynamic causal modeling to identify imitation-specific control mechanisms and examine functional interactions between regions. Participants performed a pre-specified action (lifting their index or middle finger) in response to videos depicting the same two actions (biological cues) or dots moving with similar trajectories (non-biological cues). On congruent trials, the stimulus and response were similar (e.g. index finger response to index finger or left side dot stimulus), while on incongruent trials the stimulus and response were dissimilar (e.g. index finger response to middle finger or right side dot stimulus). Reaction times were slower on incongruent compared to congruent trials for both biological and non-biological stimuli, replicating previous findings that suggest the automatic imitative or spatially compatible (congruent) response must be controlled on incongruent trials. Neural correlates of the congruency effects were different depending on the cue type. The medial prefrontal cortex, anterior cingulate, inferior frontal gyrus pars opercularis (IFGpo) and the left anterior insula were involved specifically in controlling imitation. In addition, the IFGpo was also more active for biological compared to non-biological stimuli, suggesting that the region represents the frontal node of the human mirror neuron system (MNS). Effective connectivity analysis exploring the interactions between these regions, suggests a role for the mPFC and ACC in imitative conflict detection and the anterior insula in conflict resolution processes, which may occur through interactions with the frontal node of the MNS. We suggest an extension of the previous models of imitation control involving interactions between imitation

  5. Subarachnoid hemorrhage and visuospatial and visuoperceptive impairment: disruption of the mirror neuron system.

    Science.gov (United States)

    Plata-Bello, Julio; Modroño, Cristián; Acosta-López, Silvia; Pérez-Martín, Yaiza; Marcano, Francisco; García-Marín, Víctor; González-Mora, José Luis

    2016-10-12

    Nearly 20 % of patients who suffer a subarachnoid hemorrhage (SAH) still display cognitive impairment even a year after follow-up. Visuospatial and visuoperceptive domains may be impaired in this cognitive impairment and may not have been fully studied in these patients. Furthermore, these cognitively impaired domains have been associated with activity in the so-called mirror neuron system (MNS). The aim of the study is to analyze the pattern of brain activity with an MNS task-based functional magnetic resonance imaging (fMRI) study in SAH patients. A complete neuropsychological assessment and fMRI study (with observation and execution conditions) were performed in patients with a history of SAH registered in the database of the Hospital Universitario de Canarias and a healthy control group. The patients had to meet all the following inclusion criteria for the study (less than 50 years old; SAH with a Fisher score 1-3; no vasospasm or ischemia; minimum follow-up of one year). Twelve SAH patients were studied. Three of which displayed visuospatial/visuoperceptive impairment. fMRI study showed the presence of higher activity in MNS regions in these patients than in patients with normal visuospatial/visuoperceptive functions. Furthermore, there was a negative correlation between the test scores and brain activity in premotor regions of the studied patients. SAH patients with visuospatial/visuoperceptive impairment have greater activity in the MNS regions. This finding may be associated with a subcortical dysfunction, leading to a disruption of neural activity and less efficient behavior of this brain network.

  6. Comparing mirror neuron system activity between sporadic and familial cases of schizophrenia.

    Science.gov (United States)

    Mitra, Sayantanava; Nizamie, S Haque; Goyal, Nishant; Tikka, Sai Krishna; Kavoor, Anjana Rao

    2016-06-01

    Schizophrenia is a heterogenous disorder, and has often been subtyped on the basis of family history of psychotic disorders. Compared to those without, a positive family history is associated with an earlier age of onset, greater structural brain abnormalities and poorer clinical course. Given recent emphasis on mirror neuron system (MNS) in attempting to explain psychopathology in schizophrenia; present analysis tried to tease out differences in MNS functioning between these two groups. With ethical approval, 10 consenting right-handed patients with schizophrenia (ICD-10-DCR; M=8; Drug-naïve=2) were recruited and divided into two groups of five each (M=4, F=1): those with (age 29.40±5.85 years, duration of illness 50.80±30.84 months) and without (age 29.60±5.77 years, duration of illness 43.20±43.76 months) family history of schizophrenic illness (group difference p>0.05). MNS activity was assessed using event-related desynchronization of EEG Mu waves in response to biological motion on 192-channel EEG Neurofax EEG-1100K. On comparison, while patients had significantly lower mu suppression compared to controls (pschizophrenia groups did not differ between themselves, neither on MNS activity nor on psychopathology (p>0.05). Present study replicates finding of a dysfunctional MNS in schizophrenia patients, and represents a preliminary attempt at comparing two groups of symptomatic schizophrenia patients. In both these groups, MNS dysfunctions were comparable, and commensurate with respect to psychopathology. Thus, MNS dysfunction in schizophrenia might either be inherited or acquired. However, this abnormality forms a common base, and ultimate vulnerability marker, for development of psychopathology during active disease states. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Mirror, mirror on the wall

    CERN Multimedia

    2005-01-01

    RICH 2, one of the two Ring Imaging Cherenkov detectors of the LHCb experiment, is being prepared to join the other detector elements ready for the first proton-proton collisions at LHC. The mirrors of the RICH2 detector are meticulously assembled in a clean room.In a large dark room, men in white move around an immense structure some 7 metres high, 10 metres wide and nearly 2.5 metres deep. Apparently effortlessly, they are installing the two large high-precision spherical mirrors. These mirrors will focus Cherenkov light, created by the charged particles that will traverse this detector, onto the photon detectors. Each spherical mirror wall is made up of facets like a fly's eye. Twenty-eight individual thin glass mirrors will all point to the same point in space to within a few micro-radians. The development of these mirrors has been technically demanding : Ideally they should be massless, sturdy, precise and have high reflectivity. In practice, though not massless, they are made from a mere 6 mm thin gl...

  8. Ultra-high performance mirror systems for the imaging and coherence beamline I13 at the Diamond Light Source

    Science.gov (United States)

    Wagner, U. H.; Alcock, S.; Ludbrook, G.; Wiatryzk, J.; Rau, C.

    2012-05-01

    I13L is a 250m long hard x-ray beamline (6 keV to 35 keV) currently under construction at the Diamond Light Source. The beamline comprises of two independent experimental endstations: one for imaging in direct space using x-ray microscopy and one for imaging in reciprocal space using coherent diffraction based imaging techniques. To minimise the impact of thermal fluctuations and vibrations onto the beamline performance, we are developing a new generation of ultra-stable beamline instrumentation with highly repeatable adjustment mechanisms using low thermal expansion materials like granite and large piezo-driven flexure stages. For minimising the beam distortion we use very high quality optical components like large ion-beam polished mirrors. In this paper we present the first metrology results on a newly designed mirror system following this design philosophy.

  9. A 40 W cw Nd:YAG solar laser pumped through a heliostat: a parabolic mirror system

    Science.gov (United States)

    Almeida, J.; Liang, D.; Guillot, E.; Abdel-Hadi, Y.

    2013-06-01

    Solar-pumped solid-state lasers are promising for renewable extreme-temperature material processing. Here, we report a significant improvement in solar laser collection efficiency by pumping the most widely used Nd:YAG single-crystal rod through a heliostat-parabolic mirror system. A conical-shaped fused silica light guide with 3D-CPC output end is used to both transmit and compress the concentrated solar radiation from the focal zone of a 2 m diameter parabolic mirror to a 5 mm diameter Nd:YAG rod within a conical pump cavity, which enables multi-pass pumping through the laser rod. 40 W cw laser power is measured, corresponding to 13.9 W m-2 record-high collection efficiency for the solar laser pumped through a heliostat-parabolic mirror system. 2.9% slope efficiency is fitted, corresponding to 132% enhancement over that of our previous pumping scheme. A 209% reduction in threshold pump power is also registered.

  10. Design of an interferometric system for piston measurements in segmented primary mirrors

    Science.gov (United States)

    Arasa, Josep; Laguarta, Ferran; Pizarro, Carlos; Tomas, Nuria; Pinto, Agusti

    2000-10-01

    Recently, telescopes with segmented primary mirrors are becoming increasingly popular due to their ability of achieving large apertures without the inconveniences caused by the fabrication and handling of monolithic surfaces with 8m (or over) in diameter. The difference in position of each pair of adjacent segments along the local normal of their interface (called piston hereafter), however, needs to be precisely measured in order to provide a diffraction- limited image. If a system yielding the nanometric accuracy required in piston measurements worked in daylight hours, the resultant saving in observation time would be an important advance on a majority of the state-of-the-art piston measurement systems. An interferometric piston measurement instrument accomplishing such objectives has been designed starting from the usual Michelson configuration at the CD6 (Terrassa, Spain), and its final test has been carried out in the test workbench of the Instituto de Astrofisica de Canarias (IAC, Canary Islands, Spain). Its optical layout relies on projecting the reference arm of the interferometer onto one of the segments of the pair considered, along the direction of the local normal to the surface while the measurement arm is projected onto the interface which divides the pair of segments considered. The field of view and its illumination are calculated to be equivalent in both segments. The lateral shift of the fringes in both interferograms determines the piston error present. A combination of monochromatic and white light is used, in order to remove the (lambda) /2 phase ambiguities present in piston measurements without losing the required resolution in the measurement. In this paper, the optical design of this interferometric piston measurement instrument will be presented. The particular configuration used in the interferometer, the implementation of an imaging system allowing to see both the interface of the segments and the interference fringes, the effect of the

  11. [Mirror neurons].

    Science.gov (United States)

    Rubia Vila, Francisco José

    2011-01-01

    Mirror neurons were recently discovered in frontal brain areas of the monkey. They are activated when the animal makes a specific movement, but also when the animal observes the same movement in another animal. Some of them also respond to the emotional expression of other animals of the same species. These mirror neurons have also been found in humans. They respond to or "reflect" actions of other individuals in the brain and are thought to represent the basis for imitation and empathy and hence the neurobiological substrate for "theory of mind", the potential origin of language and the so-called moral instinct.

  12. Twin Diamond Crystals Grown at High Temperature and High Pressure from the Fe-Ni-C System

    Institute of Scientific and Technical Information of China (English)

    尹龙卫; 袁泉; 李木森; 刘玉先; 许斌; 郝兆印

    2002-01-01

    Twin diamond crystals grown at high temperature and high pressure (HPHT) in the presence of FeNi catalyst have been examined by transmission electron microscopy (TEM). Direct observation by TEM shows that there are a large amount of twins which lie on the {111} planes in the HPHT-grown diamonds. The twins in the diamond may be formed and may extend into the inner crystal from the twin nucleus formed in the nucleation process.The twins can be formed due to the carbon atoms falling mistakenly into positions where a twin crystal can form during diamond growth, or condensation of supersaturated vacancies on the {111} plane. Some hexagonal dislocation loops related to supersaturated vacancies are found on the twins. The Moiré fringe image reveals that stacking faults terminate on the intersecting twin boundary. This suggests that, at the temperature that the HPHT diamond is grown, the bordering partial has propagated by gliding up to the twin interface, which can be described by the reaction of a Shockley partial dislocation with a twin on the {111} plane.

  13. Fivefold twinned boron carbide nanowires.

    Science.gov (United States)

    Fu, Xin; Jiang, Jun; Liu, Chao; Yuan, Jun

    2009-09-01

    Chemical composition and crystal structure of fivefold twinned boron carbide nanowires have been determined by electron energy-loss spectroscopy and electron diffraction. The fivefold cyclic twinning relationship is confirmed by systematic axial rotation electron diffraction. Detailed chemical analysis reveals a carbon-rich boron carbide phase. Such boron carbide nanowires are potentially interesting because of their intrinsic hardness and high temperature thermoelectric property. Together with other boron-rich compounds, they may form a set of multiply twinned nanowire systems where the misfit strain could be continuously tuned to influence their mechanical properties.

  14. Granularity of the mirror neuron system: A complex endeavor. Comment on "Grasping synergies: A motor-control approach to the mirror neuron mechanism" by A. D'Ausilio et al.

    Science.gov (United States)

    Swinnen, S. P.; Alaerts, K.

    2015-03-01

    The review paper by D'Ausilio and coauthors [3] is very timely and addresses one of the long-standing issues with respect to the coding features of mirror neurons. Through the history of mirror neuron research, there has been some controversy with respect to the level of granularity of the mirror neuron system, as studied in animal and human systems. While some researchers have suggested that abstract (high level) features of movement are coded, others have claimed evidence for more muscle specific (low level) coding properties (for an example, see [1,2]). D'Ausilio et al. [3] take a strong position in their review, suggesting a convergence between basic mechanisms of movement control and the mirror neuron system. Their suggestion is inspired by Bernstein's influential work on the so-called degrees of freedom problem. Even though a goal can in principle be reached in an infinite number of ways, consistent and stereotypical patterns of kinematics and muscle activation are often observed [4]. This has led to the notion of movement synergies as the basic building blocks for movement control. Even though it is essentially possible to contract isolated muscles or even motor units, Bernstein suggested that control of complex movement relies on movement synergies or coordinative structures, referring to a group of muscles that behave as a functional unit. This reduces the computational demands of the central nervous system considerably by assigning more responsibility to the lower levels of the movement control system. Bernstein's approach has inspired the dynamical systems perspective that has focused on a better understanding of complex biological systems such as interlimb coordination in humans [8]. For example, the upper limbs behave as a coordinative structure whereby simultaneous activation of the homologous muscle groups constitutes the default or preferred coordination mode that has to be defied when alternative patterns of coordination need to be performed or

  15. Design of a white-light interferometric measuring system for co-phasing the primary mirror segments of the next generation of ground-based telescope

    Science.gov (United States)

    Song, Helun; Xian, Hao; Jiang, Wenhan; Rao, Changhui; Wang, Shengqian

    2007-12-01

    With the increase of telescope size, the manufacture of monolithic primaries becomes increasingly difficult. Instead, the use of segmented mirrors, where many individual mirrors (the segments) work together to provide good image quality and an aperture equivalent to that of a large monolithic mirror, is considered a more appropriate strategy. But, with the introduction of large telescope mirror comprised of many individual segments, the problem of insuring a smooth continuous mirror surface (co-phased mirrors) becomes critical. One of the main problems arising in the co-phasing of the segmented mirrors telescope is the problem of measurements of the vertical displacements between the individual segments (piston errors). Because of such mirrors to exhibit diffraction-limited performance, a phasing process is required in order to guarantee that the segments have to be positioned with an accuracy of a fraction of a wavelength of the incoming light.The measurements become especially complicated when the piston error is in order of wavelength fractions. To meet the performance capabilities, a novel method for phasing the segmented mirrors optical system is described. The phasing method is based on a high-aperture Michelson interferometer. The use of an interferometric technique allows the measurement of segment misalignment during daytime with high accuracy, which is a major design guideline. The innovation introduced in the optical design of the interferometer is the simultaneous use of both monochromatic and white-light sources that allows the system to measure the piston error with an uncertainty of 6nm in 50µm range. The description about the expected monochromatic and white-light illumination interferograms and the feasibility of the phasing method are presented here.

  16. Investigations on Shaped Mirror Systems in Quasi-Optical Mode Converters Based on Irradiance Moments Method

    Directory of Open Access Journals (Sweden)

    Hai Wang

    2016-01-01

    Full Text Available A method of transforming high-order Gaussian beams (GBs mode into circular symmetry fundamental Gaussian beam (FGB mode with arbitrary waist size is presented using irradiance moments method in quasi-optical (QO mode converters. The double shaped mirrors correcting amplitude and phase simultaneously are generated by a single incidence irradiance sampling data and known ideal output FGB taking advantage of linear moment matching technique and Fresnel diffraction theory, which can be applied to a wide frequency range especially significant for terahertz band. The numerical coding procedure of creating double correcting mirrors and its fast convergence speed are discussed at 325 GHz. Numerical and experimental comparisons reveal the conclusion that enhancing surface precision and increasing moments order can improve main lobe levels.

  17. Predicting Intentions of a Familiar Significant Other Beyond the Mirror Neuron System

    Directory of Open Access Journals (Sweden)

    Stephanie Cacioppo

    2017-08-01

    Full Text Available Inferring intentions of others is one of the most intriguing issues in interpersonal interaction. Theories of embodied cognition and simulation suggest that this mechanism takes place through a direct and automatic matching process that occurs between an observed action and past actions. This process occurs via the reactivation of past self-related sensorimotor experiences within the inferior frontoparietal network (including the mirror neuron system, MNS. The working model is that the anticipatory representations of others' behaviors require internal predictive models of actions formed from pre-established, shared representations between the observer and the actor. This model suggests that observers should be better at predicting intentions performed by a familiar actor, rather than a stranger. However, little is known about the modulations of the intention brain network as a function of the familiarity between the observer and the actor. Here, we combined functional magnetic resonance imaging (fMRI with a behavioral intention inference task, in which participants were asked to predict intentions from three types of actors: A familiar actor (their significant other, themselves (another familiar actor, and a non-familiar actor (a stranger. Our results showed that the participants were better at inferring intentions performed by familiar actors than non-familiar actors and that this better performance was associated with greater activation within and beyond the inferior frontoparietal network i.e., in brain areas related to familiarity (e.g., precuneus. In addition, and in line with Hebbian principles of neural modulations, the more the participants reported being cognitively close to their partner, the less the brain areas associated with action self-other comparison (e.g., inferior parietal lobule, attention (e.g., superior parietal lobule, recollection (hippocampus, and pair bond (ventral tegmental area, VTA were recruited, suggesting that the

  18. Machining and metrology systems for free-form laser printer mirrors

    Indian Academy of Sciences (India)

    D W Davis; M Walter; M Takahashi; T Masaki

    2003-10-01

    A major challenge in optics is to make optical components like mirrors and lenses smaller and cheaper. This is achieved by designing optical components that have conformal or free-form shapes. A free-form optic is defined as one that is not symmetrical about any axis. These highly demanding requirements are met by single point diamond machining in rigid ultra precision machine tools.

  19. Timecourse of mirror and counter-mirror effects measured with transcranial magnetic stimulation

    Science.gov (United States)

    Cavallo, Andrea; Heyes, Cecilia; Becchio, Cristina; Bird, Geoffrey

    2014-01-01

    The human mirror system has been the subject of much research over the past two decades, but little is known about the timecourse of mirror responses. In addition, it is unclear whether mirror and counter-mirror effects follow the same timecourse. We used single-pulse transcranial magnetic stimulation to investigate the timecourse of mirror and counter-mirror responses in the human brain. Experiment 1 demonstrated that mirror responses can be measured from around 200 ms after observed action onset. Experiment 2 demonstrated significant effects of counter-mirror sensorimotor training at all timepoints at which a mirror response was found in Experiment 1 (i.e. from 200 ms onward), indicating that mirror and counter-mirror responses follow the same timecourse. By suggesting similarly direct routes for mirror and counter-mirror responses, these results support the associative account of mirror neuron origins whereby mirror responses arise as a result of correlated sensorimotor experience during development. More generally, they contribute to theorizing regarding mirror neuron function by providing some constraints on how quickly mirror responses can influence social cognition. PMID:23709352

  20. Thorium Abundances in Solar Twins and Analogues: Implications for the Habitability of Extrasolar Planetary Systems

    CERN Document Server

    Unterborn, Cayman T; Panero, Wendy R

    2015-01-01

    We present the first investigation of Th abundances in Solar twins and analogues to understand the possible range of this radioactive element and its effect on rocky planet interior dynamics and potential habitability. The abundances of the radioactive elements Th and U are key components of a planet's energy budget, making up 30% to 50% of the Earth's (Korenaga 2008; All\\`egre et al. 2001; Schubert et al. 1980; Lyubetskaya & Korenaga 2007; The KamLAND Collaboration 2011; Huang et al. 2013). Radiogenic heat drives interior mantle convection and surface plate tectonics, which sustains a deep carbon and water cycle and thereby aides in creating Earth's habitable surface. Unlike other heat sources that are dependent on the planet's specific formation history, the radiogenic heat budget is directly related to the mantle concentration of these nuclides. As a refractory element, the stellar abundance of Th is faithfully reflected in the terrestrial planet's concentration. We find that log eps Th varies from 59%...

  1. Twin-Induced InSb Nanosails: A Convenient High Mobility Quantum System.

    Science.gov (United States)

    de la Mata, María; Leturcq, Renaud; Plissard, Sébastien R; Rolland, Chloé; Magén, César; Arbiol, Jordi; Caroff, Philippe

    2016-02-10

    Ultra narrow bandgap III-V semiconductor nanomaterials provide a unique platform for realizing advanced nanoelectronics, thermoelectrics, infrared photodetection, and quantum transport physics. In this work we employ molecular beam epitaxy to synthesize novel nanosheet-like InSb nanostructures exhibiting superior electronic performance. Through careful morphological and crystallographic characterization we show how this unique geometry is the result of a single twinning event in an otherwise pure zinc blende structure. Four-terminal electrical measurements performed in both the Hall and van der Pauw configurations reveal a room temperature electron mobility greater than 12,000 cm(2)·V(-1)·s(-1). Quantized conductance in a quantum point contact processed with a split-gate configuration is also demonstrated. We thus introduce InSb "nanosails" as a versatile and convenient platform for realizing new device and physics experiments with a strong interplay between electronic and spin degrees of freedom.

  2. Preparation and Characterization of DLC Films by Twinned ECR Microwave Plasma Enhanced CVD for Microelectromechanical Systems (MEMS) Applications

    Institute of Scientific and Technical Information of China (English)

    LI Xin; TANG Zhen-an; DENG Xin-lu; SHEN Yu-xiu; DING Hai-tao

    2004-01-01

    Diamond-like carbon (DLC) films have recently been pursued as the protection of MEMS against their friction and wear.Plasma enhanced chemical vapor deposition (PECVD) technique is very attractive to prepare DLC coating for MEMS.This paper describes the preparation of DLC films using twinned electron cyclotron resonance (ECR) microwave PECVD process.Raman spectra confirmed the DLC characteristics of the films.Fourier-transform infrared (FT-IR)characterization indicates the carbon is bonded in the form sp3 and sp2 with hydrogen participating in bonding.The surface roughness of the films is as low as approximately 0.093nm measured with an atomic force microscope.A CERT microtribometer system is employed to obtain information about the scratch resistance,friction properties,and sliding wear resistance of the films.The results show the deposited DLC films have low friction and good scratch/wear resistance properties.

  3. Mirror monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Mankos, Marian [Electron Optica, Inc., Palo Alto, CA (United States); Shadman, Khashayar [Electron Optica, Inc., Palo Alto, CA (United States)

    2014-12-02

    In this SBIR project, Electron Optica, Inc. (EOI) is developing a mirror electron monochromator (MirrorChrom) attachment to new and retrofitted electron microscopes (EMs) for improving the energy resolution of the EM from the characteristic range of 0.2-0.5 eV to the range of 10-50 meV. This improvement will enhance the characterization of materials by imaging and spectroscopy. In particular, the monochromator will refine the energy spectra characterizing materials, as obtained from transmission EMs [TEMs] fitted with electron spectrometers, and it will increase the spatial resolution of the images of materials taken with scanning EMs (SEMs) operated at low voltages. EOI’s MirrorChrom technology utilizes a magnetic prism to simultaneously deflect the electron beam off the axis of the microscope column by 90° and disperse the electrons in proportional to their energies into a module with an electron mirror and a knife-edge. The knife-edge cuts off the tails of the energy distribution to reduce the energy spread of the electrons that are reflected, and subsequently deflected, back into the microscope column. The knife-edge is less prone to contamination, and thereby charging, than the conventional slits used in existing monochromators, which improves the reliability and stability of the module. The overall design of the MirrorChrom exploits the symmetry inherent in reversing the electron trajectory in order to maintain the beam brightness – a parameter that impacts how well the electron beam can be focused downstream onto a sample. During phase I, EOI drafted a set of candidate monochromator architectures and evaluated the trade-offs between energy resolution and beam current to achieve the optimum design for three particular applications with market potential: increasing the spatial resolution of low voltage SEMs, increasing the energy resolution of low voltage TEMs (beam energy of 5-20 keV), and increasing the energy resolution of conventional TEMs (beam

  4. Study & Realization of the Real Time File Mirroring System%实时文件镜像系统的研究与实现

    Institute of Scientific and Technical Information of China (English)

    丁原; 刘玉树; 朱天焕

    2001-01-01

    By designing the scheme to construct a real-time file mirroring system, the article studies the key technologies in the construction process. The system is constructed in the Windows NT/Windows 2000 environment. Together with the cluster server system, it can be used as a disaster recovery system.

  5. White Light Focusing Mirror

    Science.gov (United States)

    Johnson, Eric; Lyndaker, Aaron; Deyhim, Alex; Sullivan, Michael; Chance, Mark; Abel, Don; Toomey, John; Hulbert, Steven

    2007-01-01

    The NSLS X28C white-light beamline is being outfitted with a focusing mirror in order to increase, as well as control, the x-ray intensity at the sample position. The new mirror is a 50 mm × 100 mm × 1100 mm single crystal silicon cylindrical 43.1mm radius substrate bendable to a toroid from infinite to 1200 m radius. The unique feature of this mirror system is the dual use of Indalloy 51 as both a mechanism for heat transfer and a buoyant support to negate the effects of gravity. The benefit of the liquid metal support is the ability to correct for minor slope errors that take the form of a parabola. A bobber mechanism is employed to displace the fluid under the mirror +/- 1.5 mm. This allows RMS slope error correction on the order of 2 urad. The unique mounting of the mirror ensures the contributions to slope error from errant mechanical stresses due to machining tolerances are virtually non-existent. After correction, the surface figure error (measured minus ideal) is <= 0.5 urad rms.

  6. Performance Assessment of a Communicable Disease Surveillance System in Response to the Twin Earthquakes of East Azerbaijan.

    Science.gov (United States)

    Babaie, Javad; Ardalan, Ali; Vatandoost, Hasan; Goya, Mohammad Mehdi; Akbari Sari, Ali

    2015-08-01

    Following the twin earthquakes on August 11, 2012, in the East Azerbaijan province of Iran, the provincial health center set up a surveillance system to monitor communicable diseases. This study aimed to assess the performance of this surveillance system. In this quantitative-qualitative study, performance of the communicable diseases surveillance system was assessed by using the updated guidelines of the Centers for Disease Control and Prevention (CDC). Qualitative data were collected through interviews with the surveillance system participants, and quantitative data were obtained from the surveillance system. The surveillance system was useful, simple, representative, timely, and flexible. The data quality, acceptability, and stability of the surveillance system were 65.6%, 10.63%, and 100%, respectively. The sensitivity and positive predictive value were not calculated owing to the absence of a gold standard. The surveillance system satisfactorily met the goals expected for its setup. The data obtained led to the control of communicable diseases in the affected areas. Required interventions based on the incidence of communicable disease were designed and implemented. The results also reassured health authorities and the public. However, data quality and acceptability should be taken into consideration and reviewed for implementation in future disasters.

  7. Superradiant instability of charged scalar field in stringy black hole mirror system

    OpenAIRE

    Li, Ran; Zhao, Junkun

    2014-01-01

    It has been shown that the mass of a charged scalar field in the background of a charged stringy black hole is never able to generate a potential well outside the event horizon to trap the superradiant modes. This is to say that the charged stringy black hole is stable against massive charged scalar perturbations. In this paper we will study the superradiant instability of the massless scalar field in the background of charged stringy black hole due to a mirror-like boundary condition. The an...

  8. Virtual reality for pediatric neuro-rehabilitation: adaptive visual feedback of movement to engage the mirror neuron system.

    Science.gov (United States)

    Kommalapati, Roopeswar; Michmizos, Konstantinos P

    2016-08-01

    Sensorimotor therapy gives optimal results when patients are cognitively engaged into highly repetitive tasks, a goal that most children find hard to pursue. This paper presents the key developments of our ongoing effort to design an interactive rehabilitation environment that motivates physically impaired children throughout their therapy. The continuous motivation is achieved by the system adapting fundamental therapeutic components to the performance of each child. The relevant movement is mirrored to an animated character projected in front of the child. We speculate that the visual observation of one's own movements will activate the "mirror neuron system", a brain system underlying the human capacity to learn by imitation. Our rehabilitation algorithm personalizes the difficulty of the tasks by adapting the difficulty of reaching virtual targets on the animated environment through changing the visual gain between real and animated movements. To track the sensorimotor performance, we estimated the time required to reach a target. To give a proof of concept for the adaptation of the visual gain, we developed a serious game driven by a Leap Motion device. In addition to becoming a testbed for studying sensorimotor integration and neuroplasticity, the proposed notion of visual gain can be integrated into a highly engaging environment in which physically impaired children will play their way to recovery.

  9. A facile reporter system for the experimental identification of twin-arginine translocation (Tat) signal peptides from all kingdoms of life.

    Science.gov (United States)

    Widdick, David A; Eijlander, Robyn T; van Dijl, Jan Maarten; Kuipers, Oscar P; Palmer, Tracy

    2008-01-18

    We have developed a reporter protein system for the experimental verification of twin-arginine signal peptides. This reporter system is based on the Streptomyces coelicolor agarase protein, which is secreted into the growth medium by the twin-arginine translocation (Tat) pathway and whose extracellular activity can be assayed colorimetrically in a semiquantitative manner. Replacement of the native agarase signal peptide with previously characterized twin-arginine signal peptides from other Gram-positive and Gram-negative bacteria resulted in efficient Tat-dependent export of agarase. Candidate twin-arginine signal peptides from archaeal proteins as well as plant thylakoid-targeting sequences were also demonstrated to mediate agarase translocation. A naturally occurring variant signal peptide with an arginine-glutamine motif instead of the consensus di-arginine was additionally recognized as a Tat-targeting sequence by Streptomyces. Application of the agarase assay to previously uncharacterized candidate Tat signal peptides from Bacillus subtilis identified two further probable Tat substrates in this organism. This is the first versatile reporter system for Tat signal peptide identification.

  10. The Qingdao Twin Registry

    DEFF Research Database (Denmark)

    Duan, Haiping; Ning, Feng; Zhang, Dongfeng;

    2013-01-01

    In 1998, the Qingdao Twin Registry was initiated as the main part of the Chinese National Twin Registry. By 2005, a total of 10,655 twin pairs had been recruited. Since then new twin cohorts have been sampled, with one longitudinal cohort of adolescent twins selected to explore determinants...... of metabolic disorders and health behaviors during puberty and young adulthood. Adult twins have been sampled for studying heritability of multiple phenotypes associated with metabolic disorders. In addition, an elderly twin cohort has been recruited with a focus on genetic studies of aging-related phenotypes...

  11. 基于 TwinCAT 的主减速器试车台监测系统设计%Design of monitoring system for a main gearbox bench based on TwinCAT

    Institute of Scientific and Technical Information of China (English)

    李雄斌; 夏继强; 满庆丰

    2015-01-01

    Against the requirements of signal acquisition and monitoring of type X helicopter main gearbox bench,the bench moni-toring system based on TwinCAT was designed.With EtherCAT and the fieldbus CANopen and PROFIBUS-DP,two distributed bus networks were constituted for a variety of signal;the soft-PLC technology TwinCAT was used for data processing,monitoring and alarming,and communicated with HMI through ADS;HMI functions including user management,display of monitoring and a-larming data,inquiry of history data were realized based on.NET,and data management through the database Microsoft SQL Serv-er 2008.The design and development of the system was introduced detailed.Practice showed that the system had a good stability and real-time performance.%针对某型号直升机主减速器试车台的信号采集与监测要求,设计了以TwinCAT为核心的试车台监测系统。采用CANopen与PROFIBUS-DP现场总线和EtherCAT总线构成二级分布式总线网络,实现对多种信号的数据采集;采用基于TwinCAT软PLC技术进行数据的处理、监测报警,并通过ADS通信与上位机人机接口( HMI)进行交互;基于.NET平台实现上位机用户管理、监测报警数据显示及历史数据查询等,使用Microsoft SQL Server 2008大型关系数据库实现数据管理。详细介绍了系统的设计与开发过程,现场应用表明,系统具有较好的稳定性和实时性。

  12. A comparative performance study of a photovoltaic concentrator system with discrete mirror and continuos profile for two different absorber shapes

    Energy Technology Data Exchange (ETDEWEB)

    H, Saiful; Rezau, K.M [University of Dhaka, Dhaka (Bangladesh)

    2000-07-01

    Profiles of parabolic concentrators of discrete mirror and continuos surface mirror have been designed for combined electrical thermal photovoltaic systems. In the design the changes of concentration ratio, effect of reflection, angle of incidence over the absorber have been taken into account for maximum energy collection. The performances of the system are studied for solar cells of modified grid finger for illuminations from 1-10 sun. The local concentration ratio (LCR) distribution over the absorbers for both the concentrator, the optical efficiency, thermal efficiency, electrical and thermal power output and overall efficiency have been evaluated for different values of beam radiation concentration ratio and focal distance. [Spanish] Se han disenado perfiles de concentradores parabolicos de espejo discreto y de superficie continua para sistemas fotovoltaicos combinados electricos y termicos. En el diseno los cambios de la proporcion de concentracion, del efecto de la reflexion, del angulo de incidencia sobre el observador se han tenido en cuenta para una maxima recoleccion de energia. Los rendimientos del sistema se han estudiado para celdas solares de parrilla modificada para iluminaciones solares de 1-10. Han sido evaluados para diferentes valores de la proporcion de la concentracion de la radiacion en el rayo y la distancia focal la proporcion de concentracion local (LCR) de la distribucion en los absorbedores, para el concentrador la eficiencia optica, la eficiencia termica, electrica, la produccion de energia termica y electrica y la eficiencia total.

  13. Collimating Montel mirror as part of a multi-crystal analyzer system for resonant inelastic x-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jungho; Shi, Xianbo; Casa, Diego; Qian, Jun; Huang, XianRong; Gog, Thomas

    2016-07-01

    Advances in resonant inelastic x-ray scattering (RIXS) have come in lockstep with improvements in energy resolution. Currently, the best energy resolution at the Ir-L3 edge stands at ~25 meV, which is achieved using a diced Si spherical analyzer. An angular dispersion analyzer system using multiple flat crystals provides a promising way to achieve higher energy resolution, namely 10 meV or better, thereby overcoming the intrinsic energy resolution limit of diced spherical crystal analyzers. One essential component for a practical use of such multi-crystal systems is the xray collimation optics. In this work, a laterally graded, parabolic collimation Montel mirror was designed with larger than 10 mrad acceptance, collimating the x-ray beam to smaller than 100 μrad divergence at the Ir-L3 absorption energy. The x-ray collimation performance was investigated at beamline 27-ID of the Advanced Photon Source, using incident photons from a Diamond (111) monochromator illuminating a controlled 40 mrad divergence scattering source of 5 μm diameter. A flat Si (111) crystal served as the analyzer. It is found from experimental data and ray-tracing simulations, combined with metrology results, that the manufactured Montel mirror satisfies the required specifications of angular acceptance and collimated x-ray divergence for a high resolution RIXS spectrometer at the Ir-L3 edge.

  14. Fingerprint recognition with identical twin fingerprints.

    Directory of Open Access Journals (Sweden)

    Xunqiang Tao

    Full Text Available Fingerprint recognition with identical twins is a challenging task due to the closest genetics-based relationship existing in the identical twins. Several pioneers have analyzed the similarity between twins' fingerprints. In this work we continue to investigate the topic of the similarity of identical twin fingerprints. Our study was tested based on a large identical twin fingerprint database that contains 83 twin pairs, 4 fingers per individual and six impressions per finger: 3984 (83*2*4*6 images. Compared to the previous work, our contributions are summarized as follows: (1 Two state-of-the-art fingerprint identification methods: P071 and VeriFinger 6.1 were used, rather than one fingerprint identification method in previous studies. (2 Six impressions per finger were captured, rather than just one impression, which makes the genuine distribution of matching scores more realistic. (3 A larger sample (83 pairs was collected. (4 A novel statistical analysis, which aims at showing the probability distribution of the fingerprint types for the corresponding fingers of identical twins which have same fingerprint type, has been conducted. (5 A novel analysis, which aims at showing which finger from identical twins has higher probability of having same fingerprint type, has been conducted. Our results showed that: (a A state-of-the-art automatic fingerprint verification system can distinguish identical twins without drastic degradation in performance. (b The chance that the fingerprints have the same type from identical twins is 0.7440, comparing to 0.3215 from non-identical twins. (c For the corresponding fingers of identical twins which have same fingerprint type, the probability distribution of five major fingerprint types is similar to the probability distribution for all the fingers' fingerprint type. (d For each of four fingers of identical twins, the probability of having same fingerprint type is similar.

  15. Design of the mirror optical systems for coherent diffractive imaging at the SPB/SFX instrument of the European XFEL

    Science.gov (United States)

    Bean, Richard J.; Aquila, Andrew; Samoylova, Liubov; Mancuso, Adrian P.

    2016-07-01

    The high degree of spatial coherence and extreme pulse energies available at x-ray free electron laser (XFEL) sources naturally support coherent diffractive imaging applications. In order to optimally exploit these unique properties, the optical systems at XFELs must be highly transmissive, focus to appropriate sizes matched to the scale of samples to be investigated and must minimally perturb the wavefront of the XFEL beam. We present the design and simulated performance of two state-of-the-art Kirkpatrik-Baez mirror systems that form the primary foci of the single particles, clusters and biomolecules and serial femtosecond crystallography (SPB/SFX) instrument of the European XFEL. The two systems, presently under construction, will produce 1 μm and 100 nm scale foci across a 3-16 keV photon energy range. Targeted applications include coherent imaging of weakly scattering, often biological, specimens.

  16. Tele-counseling and social-skill trainings using JGNII optical network and a mirror-interface system

    Science.gov (United States)

    Hashimoto, Sayuri; Hashimoto, Nobuyuki; Onozawa, Akira; Hosoya, Eiichi; Harada, Ikuo; Okunaka, Junzo

    2007-09-01

    "Tele-presence" communication using JGNII - an exclusive optical-fiber network system - was applied to social-skills training in the form of child-rearing support. This application focuses on internet counseling and social training skills that require interactive verbal and none-verbal communications. The motivation for this application is supporting local communities by constructing tele-presence education and entertainment systems using recently available, inexpensive IP networks. This latest application of tele-presence communication uses mirror-interface system which provides to users in remote locations a shared quasi-space where they can see themselves as if they were in the same room by overlapping video images from remote locations.

  17. Program user's manual: cryogen system for the analysis for the Mirror Fusion Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    1979-04-01

    The Mirror Fusion Test Facility being designed and constructed at the Lawrence Livermore Laboratory requires a liquid helium liquefaction, storage, distribution, and recovery system and a liquid nitrogen storage and distribution system. To provide a powerful analytical tool to aid in the design evolution of this system through hardware, a thermodynamic fluid flow model was developed. This model allows the Lawrence Livermore Laboratory to verify that the design meets desired goals and to play what if games during the design evolution. For example, what if the helium flow rate is changed in the magnet liquid helium flow loop; how does this affect the temperature, fluid quality, and pressure. This manual provides all the information required to run all or portions of this program as desired. In addition, the program is constructed in a modular fashion so changes or modifications can be made easily to keep up with the evolving design.

  18. Application of a white-light interferometric measuring system as co-phasing the segmented primary mirrors of the high-aperture telescope

    Science.gov (United States)

    Song, Helun; Li, Huaqiang; Xian, Hao; Huang, Jian; Wang, Shengqian; Jiang, Wenhan

    2008-03-01

    For the optical system of the telescope, with the increase in telescope size, the manufacture of monolithic primary becomes increasingly difficult. Instead, the use of segmented mirrors, where many individual mirrors (the segments) work together to provide an image quality and an aperture equivalent to that of a large monolithic mirror, is considered a more appropriate strategy. But with the introduction of the large telescope mirror comprised of many individual segments, the problem of insuring a smooth continuous mirror surface (co-phased mirrors) becomes critical. One of the main problems is the measurement of the vertical displacement between the individual segments (piston error), for such mirrors, the segment vertical misalignment (piston error) between the segments must be reduced to a small fraction of the wavelength (Michelson interferometer. The use of an interferometric technique allows the measuring of segment misalignment during the daytime with high accuracy, which is a major design guideline. The innovation introduced in the optical design of the interferometer is the simultaneous use of monochromatic light and multiwavelength combination white-light source in a direct method for improving the central fringe identification in the white-light interferometric phasing system. With theoretic analysis, we find that this multiwavelength combination technique can greatly increase the visibility difference between the central fringe and its adjacent side fringes, and thus it offers an increased signal resolution. So make the central fringe identification become easier, and enhance the measure precision of the segment phasing error. Consequently, it is suitable for high-precision measurement purpose and application in the segment piston error phasing system. The description about the expected interferograms and the feasibility of the phasing method are presented here.

  19. Subwavelength grating as both emission mirror and electrical contact for VCSELs in any material system

    Science.gov (United States)

    Czyszanowski, Tomasz; Gebski, Marcin; Dems, Maciej; Wasiak, Michał; Sarzała, Robert; Panajotov, Krassimir

    2017-01-01

    Semiconductor-metal subwavelength grating (SMSG) can serve a dual purpose in vertical-cavity surface-emitting lasers (VCSELs), as both optical coupler and current injector. SMSGs provide optical as well as lateral current confinement, eliminating the need for ring contacts and lateral build-in optical and current confinement, allowing their implementation on arbitrarily large surfaces. Using an SMSG as the top mirror enables fabrication of monolithic VCSELs from any type of semiconductor crystal. The construction of VCSELs with SMSGs requires significantly less p-type material, in comparison to conventional VCSELs. In this paper, using a three-dimensional, fully vectorial optical model, we analyse the properties of the stand-alone SMSG in a number of semiconductor materials for a broad range of wavelengths. Integrating the optical model with thermal and electrical numerical models, we then simulate the threshold operation of an exemplary SMSG VCSEL. PMID:28079149

  20. Robust entanglement between a movable mirror and a cavity field system with an optical parametric amplifier

    Science.gov (United States)

    Mi, Xianwu; Bai, Jiangxiang; Ke-hui, Song

    2013-06-01

    Robust entanglement created between an optical cavity field mode and a macroscopic vibrating mirror with an optical parametric amplifier is shown. Increasing the gain of the optical parametric amplifier makes the line of the logarithmic negativity E N move to the range of the larger detuning and higher temperature. Such optomechanical entanglement can be generated even at room temperature with current experimental parameters. Compared with other proposals, we have considered the one-to-one correspondence between the detuning and the input power, which is reasonable with the fact that the mean shift of the cavity frequency is determined by the radiation pressure which is related to the input power. Such consideration may be valuable to current experiments.

  1. Subwavelength grating as both emission mirror and electrical contact for VCSELs in any material system

    Science.gov (United States)

    Czyszanowski, Tomasz; Gebski, Marcin; Dems, Maciej; Wasiak, Michał; Sarzała, Robert; Panajotov, Krassimir

    2017-01-01

    Semiconductor-metal subwavelength grating (SMSG) can serve a dual purpose in vertical-cavity surface-emitting lasers (VCSELs), as both optical coupler and current injector. SMSGs provide optical as well as lateral current confinement, eliminating the need for ring contacts and lateral build-in optical and current confinement, allowing their implementation on arbitrarily large surfaces. Using an SMSG as the top mirror enables fabrication of monolithic VCSELs from any type of semiconductor crystal. The construction of VCSELs with SMSGs requires significantly less p-type material, in comparison to conventional VCSELs. In this paper, using a three-dimensional, fully vectorial optical model, we analyse the properties of the stand-alone SMSG in a number of semiconductor materials for a broad range of wavelengths. Integrating the optical model with thermal and electrical numerical models, we then simulate the threshold operation of an exemplary SMSG VCSEL.

  2. Abrogation of the twin arginine transport system in Salmonella enterica serovar Typhimurium leads to colonization defects during infection.

    Directory of Open Access Journals (Sweden)

    M Megan Reynolds

    Full Text Available TatC (STM3975 is a highly conserved component of the Twin Arginine Transport (Tat systems that is required for transport of folded proteins across the inner membrane in gram-negative bacteria. We previously identified a ΔtatC mutant as defective in competitive infections with wild type ATCC14028 during systemic infection of Salmonella-susceptible BALB/c mice. Here we confirm these results and show that the ΔtatC mutant is internalized poorly by cultured J774-A.1 mouse macrophages a phenotype that may be related to the systemic infection defect. This mutant is also defective for short-term intestinal and systemic colonization after oral infection of BALB/c mice and is shed in reduced numbers in feces from orally infected Salmonella-resistant (CBA/J mice. We show that the ΔtatC mutant is highly sensitive to bile acids perhaps resulting in the defect in intestinal infection that we observe. Finally, the ΔtatC mutant has an unusual combination of motility phenotypes in Salmonella; it is severely defective for swimming motility but is able to swarm well. The ΔtatC mutant has a lower amount of flagellin on the bacterial surface during swimming motility but normal levels under swarming conditions.

  3. Twin robotic x-ray system for 2D radiographic and 3D cone-beam CT imaging

    Science.gov (United States)

    Fieselmann, Andreas; Steinbrener, Jan; Jerebko, Anna K.; Voigt, Johannes M.; Scholz, Rosemarie; Ritschl, Ludwig; Mertelmeier, Thomas

    2016-03-01

    In this work, we provide an initial characterization of a novel twin robotic X-ray system. This system is equipped with two motor-driven telescopic arms carrying X-ray tube and flat-panel detector, respectively. 2D radiographs and fluoroscopic image sequences can be obtained from different viewing angles. Projection data for 3D cone-beam CT reconstruction can be acquired during simultaneous movement of the arms along dedicated scanning trajectories. We provide an initial evaluation of the 3D image quality based on phantom scans and clinical images. Furthermore, initial evaluation of patient dose is conducted. The results show that the system delivers high image quality for a range of medical applications. In particular, high spatial resolution enables adequate visualization of bone structures. This system allows 3D X-ray scanning of patients in standing and weight-bearing position. It could enable new 2D/3D imaging workflows in musculoskeletal imaging and improve diagnosis of musculoskeletal disorders.

  4. The Norwegian Twin Registry.

    Science.gov (United States)

    Nilsen, Thomas S; Brandt, Ingunn; Magnus, Per; Harris, Jennifer R

    2012-12-01

    Norway has a long-standing tradition in twin research, but the data collected in several population-based twin studies were not coordinated centrally or easily accessible to the scientific community. In 2009, the Norwegian Twin Registry was established at the Norwegian Institute of Public Health (NIPH) in Oslo with the purpose of creating a single research resource for Norwegian twin data. As of today, the Norwegian Twin Registry contains 47,989 twins covering birth years 1895-1960 and 1967-1979; 31,440 of these twins consented to participate in health-related research. In addition, DNA from approximately 4,800 of the twins is banked at the NIPH biobank and new studies are continually adding new data to the registry. The value of the Norwegian twin data is greatly enhanced by the linkage opportunities offered by Norway's many nationwide registries, spanning a broad array of medical, demographic, and socioeconomic information.

  5. Shell Separation for Mirror Replication

    Science.gov (United States)

    1999-01-01

    NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery, and materials to replicate electro-formed nickel mirrors. Optics replication uses reusable forms, called mandrels, to make telescope mirrors ready for final finishing. MSFC optical physicist Bill Jones monitors a device used to chill a mandrel, causing it to shrink and separate from the telescope mirror without deforming the mirror's precisely curved surface.

  6. The Digital Twin Paradigm for Future NASA and U.S. Air Force Vehicles

    Science.gov (United States)

    Glaessgen, Edward H.; Stargel, D. S.

    2012-01-01

    Future generations of NASA and U.S. Air Force vehicles will require lighter mass while being subjected to higher loads and more extreme service conditions over longer time periods than the present generation. Current approaches for certification, fleet management and sustainment are largely based on statistical distributions of material properties, heuristic design philosophies, physical testing and assumed similitude between testing and operational conditions and will likely be unable to address these extreme requirements. To address the shortcomings of conventional approaches, a fundamental paradigm shift is needed. This paradigm shift, the Digital Twin, integrates ultra-high fidelity simulation with the vehicle s on-board integrated vehicle health management system, maintenance history and all available historical and fleet data to mirror the life of its flying twin and enable unprecedented levels of safety and reliability.

  7. Aspects of narcissism and symbiosis, or, essential neurosis of twins.

    Science.gov (United States)

    Kahn, Charlotte

    2012-06-01

    Following a brief introduction I address the relationships of twins from five different perspectives: the Intimate Connection, the Mirror Image and Complementarity, Object- and Self-Representation, Self and Object or Rivalry, and Intersubjective Communication. This approach attempts to understand twin relationships and the individual development of twins in terms of their intense mutual dependence, akin to infantile symbiosis, and in terms of narcissism. In their similarity to each other, twins may choose each other as love objects even as they see themselves in the other. That is, a twin may "love what he himself is" or "someone who was once part of himself." This "type of object-choice … must be termed 'narcissistic'" (Freud, 1914, pp. 90, 88). Such "cathexis of an undifferentiated self-object" is considered to be "primary narcissism" (Burstein, 1977, p. 103). Hoffer (1952) describes primary narcissism as "the lack of all qualities discriminating between self and not-self, inside and outside" (p. 33).

  8. Evaluation of thermal energy storage for the proposed Twin Cities District Heating system. [using cogeneration heat production and aquifiers for heat storage

    Science.gov (United States)

    Meyer, C. F.

    1980-01-01

    The technical and economic feasibility of incorporating thermal energy storage components into the proposed Twin Cities District heating project was evaluated. The technical status of the project is reviewed and conceptual designs of district heating systems with and without thermal energy storage were compared in terms of estimated capital requirements, fuel consumption, delivered energy cost, and environmental aspects. The thermal energy storage system is based on cogeneration and the storage of heat in aquifers.

  9. MIRROR THERAPY: A REVIEW OF EVIDENCES

    Directory of Open Access Journals (Sweden)

    Aishath Najiha

    2015-06-01

    Full Text Available The aim of this review was to identify and summarize the existing evidences on mirror box therapy for the management of various musculoskeletal conditions. A systemic literature search was performed to identify studies concerning mirror therapy. The included journal articles were reviewed and assessed for its significance. Fifty one studies were identified and reviewed. Five different patient categories were studied: 24 studies focussed on mirror therapy after stroke, thirteen studies focussed on mirror therapy after an amputation, three studies focussed on mirror therapy with complex regional pain syndrome patients, two studies on mirror therapy for cerebral palsy and one study focussed on mirror therapy after a fracture. The articles reviewed showed a trend that mirror therapy is effective in stroke, phantom limb pain, complex regional pain syndrome, cerebral palsy and fracture rehabilitation.

  10. Mirror with thermally controlled radius of curvature

    Science.gov (United States)

    Neil, George R.; Shinn, Michelle D.

    2010-06-22

    A radius of curvature controlled mirror for controlling precisely the focal point of a laser beam or other light beam. The radius of curvature controlled mirror provides nearly spherical distortion of the mirror in response to differential expansion between the front and rear surfaces of the mirror. The radius of curvature controlled mirror compensates for changes in other optical components due to heating or other physical changes. The radius of curvature controlled mirror includes an arrangement for adjusting the temperature of the front surface and separately adjusting the temperature of the rear surface to control the radius of curvature. The temperature adjustment arrangements can include cooling channels within the mirror body or convection of a gas upon the surface of the mirror. A control system controls the differential expansion between the front and rear surfaces to achieve the desired radius of curvature.

  11. Myocardial hypertrophy in the recipient with twin-to-twin transfusion syndrome

    DEFF Research Database (Denmark)

    Jeppesen, D.L.; Jorgensen, F.S.; Pryds, O.A.

    2008-01-01

    In a set of monochorionic-diamniotic twins with twin-to-twin transfusion syndrome, systemic hypertension and biventricular myocardial hypertrophy were found in the recipient. The infant developed mild respiratory distress. A partial exchange transfusion was performed because of polycytaemia. Blood...... pressure measurements revealed persistent systemic hypertension. Biventricular hypertrophy was demonstrated by echocardiography. Blood pressure normalised after treatment with Nifedipine and the cardiac hypertrophy subsided over the following weeks. A potential contributing mechanism is intrauterine...

  12. Myocardial hypertrophy in the recipient with twin-to-twin transfusion syndrome

    DEFF Research Database (Denmark)

    Jeppesen, D.L.; Jorgensen, F.S.; Pryds, O.A.

    2008-01-01

    pressure measurements revealed persistent systemic hypertension. Biventricular hypertrophy was demonstrated by echocardiography. Blood pressure normalised after treatment with Nifedipine and the cardiac hypertrophy subsided over the following weeks. A potential contributing mechanism is intrauterine......In a set of monochorionic-diamniotic twins with twin-to-twin transfusion syndrome, systemic hypertension and biventricular myocardial hypertrophy were found in the recipient. The infant developed mild respiratory distress. A partial exchange transfusion was performed because of polycytaemia. Blood...

  13. Nearly diffraction-limited X-ray focusing with variable-numerical-aperture focusing optical system based on four deformable mirrors

    Science.gov (United States)

    Matsuyama, Satoshi; Nakamori, Hiroki; Goto, Takumi; Kimura, Takashi; Khakurel, Krishna P.; Kohmura, Yoshiki; Sano, Yasuhisa; Yabashi, Makina; Ishikawa, Tetsuya; Nishino, Yoshinori; Yamauchi, Kazuto

    2016-04-01

    Unlike the electrostatic and electromagnetic lenses used in electron microscopy, most X-ray focusing optical systems have fixed optical parameters with constant numerical apertures (NAs). This lack of adaptability has significantly limited application targets. In the research described herein, we developed a variable-NA X-ray focusing system based on four deformable mirrors, two sets of Kirkpatrick-Baez-type focusing mirrors, in order to control the focusing size while keeping the position of the focus unchanged. We applied a mirror deformation procedure using optical/X-ray metrology for offline/online adjustments. We performed a focusing test at a SPring-8 beamline and confirmed that the beam size varied from 108 nm to 560 nm (165 nm to 1434 nm) in the horizontal (vertical) direction by controlling the NA while maintaining diffraction-limited conditions.

  14. Nearly diffraction-limited X-ray focusing with variable-numerical-aperture focusing optical system based on four deformable mirrors.

    Science.gov (United States)

    Matsuyama, Satoshi; Nakamori, Hiroki; Goto, Takumi; Kimura, Takashi; Khakurel, Krishna P; Kohmura, Yoshiki; Sano, Yasuhisa; Yabashi, Makina; Ishikawa, Tetsuya; Nishino, Yoshinori; Yamauchi, Kazuto

    2016-04-21

    Unlike the electrostatic and electromagnetic lenses used in electron microscopy, most X-ray focusing optical systems have fixed optical parameters with constant numerical apertures (NAs). This lack of adaptability has significantly limited application targets. In the research described herein, we developed a variable-NA X-ray focusing system based on four deformable mirrors, two sets of Kirkpatrick-Baez-type focusing mirrors, in order to control the focusing size while keeping the position of the focus unchanged. We applied a mirror deformation procedure using optical/X-ray metrology for offline/online adjustments. We performed a focusing test at a SPring-8 beamline and confirmed that the beam size varied from 108 nm to 560 nm (165 nm to 1434 nm) in the horizontal (vertical) direction by controlling the NA while maintaining diffraction-limited conditions.

  15. Through the looking-glass: mirror reading.

    Science.gov (United States)

    Duñabeitia, Jon Andoni; Molinaro, Nicola; Carreiras, Manuel

    2011-02-14

    At early stages of object identification we process correctly oriented and mirrored versions of an object similarly. However, in letter and word perception, such tolerance to mirror reversals is harmful for efficient reading. Do readers successfully develop blindness mechanisms for mirror-letters and words? We conducted two masked priming experiments while recording participants' electrophysiological brain responses to briefly presented primes including mirror-letters (Experiment 1) or to shortly presented mirror-words (Experiment 2). Results showed that the human visual word recognition system is not totally blind to mirror-letters and mirror-words, since the early stages of processing mirror-letters and mirror-words produced effects on target word recognition that were highly similar to the effects produced by identical primes (N250 component). In a posterior stage of processing (N400 epoch), the effect of mirror-letters and mirror-words was different from the effect of identical primes, even though reversed primes still elicited N400 priming effects different from unrelated primes. These results demonstrate that readers perceive mirror-letters and words as correct at initial stages of word recognition, and that the visual word recognition system's neural representation is grounded on basic principles that govern object perception.

  16. Illusion-related brain activations: a new virtual reality mirror box system for use during functional magnetic resonance imaging.

    Science.gov (United States)

    Diers, Martin; Kamping, Sandra; Kirsch, Pinar; Rance, Mariela; Bekrater-Bodmann, Robin; Foell, Jens; Trojan, Joerg; Fuchs, Xaver; Bach, Felix; Maaß, Heiko; Cakmak, Hüseyin; Flor, Herta

    2015-01-12

    Extended viewing of movements of one's intact limb in a mirror as well as motor imagery have been shown to decrease pain in persons with phantom limb pain or complex regional pain syndrome and to increase the movement ability in hemiparesis following stroke. In addition, mirrored movements differentially activate sensorimotor cortex in amputees with and without phantom limb pain. However, using a so-called mirror box has technical limitations, some of which can be overcome by virtual reality applications. We developed a virtual reality mirror box application and evaluated its comparability to a classical mirror box setup. We applied both paradigms to 20 healthy controls and analyzed vividness and authenticity of the illusion as well as brain activation patterns. In both conditions, subjects reported similar intensities for the sensation that movements of the virtual left hand felt as if they were executed by their own left hand. We found activation in the primary sensorimotor cortex contralateral to the actual movement, with stronger activation for the virtual reality 'mirror box' compared to the classical mirror box condition, as well as activation in the primary sensorimotor cortex contralateral to the mirrored/virtual movement. We conclude that a virtual reality application of the mirror box is viable and that it might be useful for future research.

  17. Measuring the In-Process Figure, Final Prescription, and System Alignment of Large Optics and Segmented Mirrors Using Lidar Metrology

    Science.gov (United States)

    Ohl, Raymond; Slotwinski, Anthony; Eegholm, Bente; Saif, Babak

    2011-01-01

    The fabrication of large optics is traditionally a slow process, and fabrication capability is often limited by measurement capability. W hile techniques exist to measure mirror figure with nanometer precis ion, measurements of large-mirror prescription are typically limited to submillimeter accuracy. Using a lidar instrument enables one to measure the optical surface rough figure and prescription in virtuall y all phases of fabrication without moving the mirror from its polis hing setup. This technology improves the uncertainty of mirror presc ription measurement to the micron-regime.

  18. Lightweight Metal Mirrors

    Science.gov (United States)

    Gossett, E.; Winslow, P.

    1984-01-01

    Two "eggcrate" halves brazed together. Lightweight flat mirrors fabricated by machining pockets in two plates of beryllium and brazing machined halves together. Mirror less than half weight of same mirror made by previous design.

  19. Chemical, isotopic, and dissolved gas compositions of the hydrothermal system in Twin Falls and Jerome counties, Idaho

    Science.gov (United States)

    Mariner, R.H.; Young, H.W.; Evans, ans; Parliman, D.J.

    1991-01-01

    The chemical, isotopic, and gas compositions of the hydrothermal system in Twin Falls and Jerome counties, Idaho, change systematically as the water moves northward from the Idaho-Nevada boundary toward the Snake River. Sodium, chloride, fluoride, alkalinity, dissolved helium, and carbon-13 increase as calcium and carbon-14 decrease. Water-rock reactions may result in dissolution of plagioclase or volcanic glass and calcite, followed by precipitation of zeolites and clays. On the basis of carbon-14 age dating, apparent water ages range from 2,000 to more than 26,000 years; most apparent ages range from about 4,000 to 10,000 years. The older waters, north of the Snake River, are isotopically depleted in deuterium and are enriched in chloride relative to waters to the south. Thermal waters flowing northward beneath the Snake River may join a westward flow of older thermal water slightly north of the river. The direction of flow in the hydrothermal system seems to parallel the surface drainage.

  20. Trojan twin planets

    Science.gov (United States)

    Dvorak, R.; Loibnegger, B.; Schwarz, R.

    2017-03-01

    The Trojan asteroids are moving in the vicinity of the stable Lagrange points L_4 and L_5 of the gas giants Jupiter, Uranus and Neptune. Their motion can be described and understood with the aid of the restricted three-body problem. As an extension of this problem we investigate how stable motion close to the Lagrange points of two massive bodies can exist. This configuration can be described as the Trojan Twin Problem when we regard the two additional bodies as having a mass significantly smaller than the the two primary bodies: a star in the center (m_1) and an additional Jupiter-like mass (m_2). Using this 4-body problem we have undertaken numerical investigations concerning possible stable "twin orbits". However, these two bodies (m_3 and m_4) in Trojan-like orbits may have quite different masses. We decided to choose 6 different scenaria for this problem: as primary body, m2, we have taken a Jupiter-like planet, a Saturn-like one, and a super-Earth with 10 Earthmasses (m_{Earth}) respectively. As quasi twin planets, we have used different mass ratios namely objects for m3 and m4 from 10m_{Earth} to Moon like ones. We found different stable configurations depending on the involved masses and the initial distances between the twins (always close to the Lagrange point). Although the formation of such a configuration seems to be not very probable we should not exclude that it exists regarding the huge number of planets even in our own galaxy. This model is of special interest when the most massive planet (m_2) is moving on an orbit in the habitable zone around a main sequence star. One can use our results of stable orbits of Trojan Twin Planets (or asteroids) for extrasolar systems having as second primary a Jupiter-like, a Saturn-like or a super-Earth like planet around a star similar to our Sun.

  1. Mirror Neurons System Engagement in Late Adolescents and Adults While Viewing Emotional Gestures.

    Science.gov (United States)

    Salvia, Emilie; Süß, Moritz; Tivadar, Ruxandra; Harkness, Sarah; Grosbras, Marie-Hélène

    2016-01-01

    Observing others' actions enhances muscle-specific cortico-spinal excitability, reflecting putative mirror neurons activity. The exposure to emotional stimuli also modulates cortico-spinal excitability. We investigated how those two phenomena might interact when they are combined, i.e., while observing a gesture performed with an emotion, and whether they change during the transition between adolescence and adulthood, a period of social and brain maturation. We delivered single-pulse transcranial magnetic stimulation (TMS) over the hand area of the left primary motor cortex of 27 healthy adults and adolescents and recorded their right first dorsal interossus (FDI) muscle activity (i.e., motor evoked potential - MEP), while they viewed either videos of neutral or angry hand actions and facial expressions, or neutral objects as a control condition. We reproduced the motor resonance and the emotion effects - hand-actions and emotional stimuli induced greater cortico-spinal excitability than the faces/control condition and neutral videos, respectively. Moreover, the influence of emotion was present for faces but not for hand actions, indicating that the motor resonance and the emotion effects might be non-additive. While motor resonance was observed in both groups, the emotion effect was present only in adults and not in adolescents. We discuss the possible neural bases of these findings.

  2. Mirror Neurons System Engagement in Late Adolescents and Adults While Viewing Emotional Gestures

    Science.gov (United States)

    Salvia, Emilie; Süß, Moritz; Tivadar, Ruxandra; Harkness, Sarah; Grosbras, Marie-Hélène

    2016-01-01

    Observing others’ actions enhances muscle-specific cortico-spinal excitability, reflecting putative mirror neurons activity. The exposure to emotional stimuli also modulates cortico-spinal excitability. We investigated how those two phenomena might interact when they are combined, i.e., while observing a gesture performed with an emotion, and whether they change during the transition between adolescence and adulthood, a period of social and brain maturation. We delivered single-pulse transcranial magnetic stimulation (TMS) over the hand area of the left primary motor cortex of 27 healthy adults and adolescents and recorded their right first dorsal interossus (FDI) muscle activity (i.e., motor evoked potential – MEP), while they viewed either videos of neutral or angry hand actions and facial expressions, or neutral objects as a control condition. We reproduced the motor resonance and the emotion effects – hand-actions and emotional stimuli induced greater cortico-spinal excitability than the faces/control condition and neutral videos, respectively. Moreover, the influence of emotion was present for faces but not for hand actions, indicating that the motor resonance and the emotion effects might be non-additive. While motor resonance was observed in both groups, the emotion effect was present only in adults and not in adolescents. We discuss the possible neural bases of these findings. PMID:27489547

  3. An updated approach to the study of proton propagation in the eROSITA mirror system

    Science.gov (United States)

    Perinati, E.; Mineo, T.; Freyberg, M.; Diebold, S.; Santangelo, A.; Tenzer, C.

    2016-07-01

    The German telescope eROSITA will be the first X-ray instrument orbiting around the L-2 lagrangian point. Therefore, modelling the radiation environment in that region of space and its interaction with the instrument is particularly important, as no measured data of other X-ray detectors can be used as a reference to predict how the space conditions will impact the instrumental capabilities. The orbit around L-2 extends well beyond the Earth's magnetosphere, where the flux of galactic cosmic particles is cut by the geomagnetic field, and fluxes of energetic particles one order of magnitude higher than in low Earth orbits are expected. Furthermore, as experienced by Chandra and XMM-Newton, softer protons may be scattered through the mirror shells and funneled to the focal plane, representing a potential additional source of background. To investigate and assess this component we are developing a ray tracing simulator for protons, that follows the track of each proton from the entrance pupil down to the focal plane. In this paper we report on an updated version of the code that allows to propagate protons in both the polar and azimuthal directions in elastic regime.

  4. Mirror Neurons System Engagement in Late Adolescents and Adults While Viewing Emotional Gestures.

    Directory of Open Access Journals (Sweden)

    Emilie Salvia

    2016-07-01

    Full Text Available Observing others’ actions enhances muscle-specific cortico-spinal excitability, reflecting putative mirror neurons activity. The exposure to emotional stimuli also modulates cortico-spinal excitability. We investigated how those two phenomena might interact when they are combined, i.e. while observing a gesture performed with an emotion, and whether they change during the transition between adolescence and adulthood, a period of social and brain maturation.We delivered single-pulse transcranial magnetic stimulation (TMS over the hand area of the left primary motor cortex of 27 healthy adults and adolescents and recorded their right first dorsal interossus (FDI muscle activity (i.e. motor evoked potential – MEP, while they viewed either videos of neutral or angry hand actions and facial expressions, or neutral objects as a control condition. We reproduced the motor resonance and the emotion effects -- hand-actions and emotional stimuli induced greater cortico-spinal excitability than the faces / control condition and neutral videos, respectively. Moreover, the influence of emotion was present for faces but not for hand actions, indicating that the motor resonance and the emotion effect might be non-additive. While motor resonance was observed in both groups, the emotion effect was present only in adults and not in adolescents. We discuss the possible neural bases of these findings.

  5. [The motor organization of cerebral cortex and the role of the mirror neuron system. Clinical impact for rehabilitation].

    Science.gov (United States)

    Sallés, Laia; Gironès, Xavier; Lafuente, José Vicente

    2015-01-06

    The basic characteristics of Penfield homunculus (somatotopy and unique representation) have been questioned. The existence of a defined anatomo-functional organization within different segments of the same region is controversial. The presence of multiple motor representations in the primary motor area and in the parietal lobe interconnected by parieto-frontal circuits, which are widely overlapped, form a complex organization. Both features support the recovery of functions after brain injury. Regarding the movement organization, it is possible to yield a relevant impact through the understanding of actions and intentions of others, which is mediated by the activation of mirror-neuron systems. The implementation of cognitive functions (observation, image of the action and imitation) from the acute treatment phase allows the activation of motor representations without having to perform the action and it plays an important role in learning motor patterns.

  6. The Danish Twin Register

    DEFF Research Database (Denmark)

    Kyvik, K O; Christensen, Kaare; Skytthe, A;

    1996-01-01

    BACKGROUND: Population based twin registers represent a valuable tool for genetic epidemiological research, since twin studies aim at separating the effect of genes and environment for complex traits. The Danish Twin Register's history, size, ascertainment and completeness of data, as well as data...... accessibility and availability are described. RESULTS: The Danish Twin Register comprises 14,051 twin pairs born 1870-1930, representing all twins surviving to age six years, and 20,888 twin pairs born 1953-1982, representing 75% of those born 1953-1967 and 95% of those born 1968-1982. The birth cohorts 1931......-1952 og 1983-1993 are being ascertained at the moment. The register is available for research given certain conditions are fulfilled. CONCLUSION: This register will in a few years be the most comprehensive twin register in the world. It is a very valuable Danish research resource....

  7. The Danish Twin Register

    DEFF Research Database (Denmark)

    Kyvik, K O; Christensen, Kaare; Skytthe, A

    1996-01-01

    BACKGROUND: Population based twin registers represent a valuable tool for genetic epidemiological research, since twin studies aim at separating the effect of genes and environment for complex traits. The Danish Twin Register's history, size, ascertainment and completeness of data, as well as data...... accessibility and availability are described. RESULTS: The Danish Twin Register comprises 14,051 twin pairs born 1870-1930, representing all twins surviving to age six years, and 20,888 twin pairs born 1953-1982, representing 75% of those born 1953-1967 and 95% of those born 1968-1982. The birth cohorts 1931......-1952 og 1983-1993 are being ascertained at the moment. The register is available for research given certain conditions are fulfilled. CONCLUSION: This register will in a few years be the most comprehensive twin register in the world. It is a very valuable Danish research resource....

  8. Sulfate-water isotope geothermometry and lead isotope data for the regional geothermal system in the Twin Falls area, south-central Idaho

    Science.gov (United States)

    Mariner, R.H.; Young, H.W.; Bullen, T.D.; Janik, C.J.; ,

    1997-01-01

    Sulfate-water isotope geothermometry for the geothermal system at Twin Falls, Idaho indicates aquifer-temperatures of 90?? to 106 ??C; most sites are between 90?? and 93 ??C. 206Pb/204pb and 280Pb/204Pb of individual thermal waters are principally a function of how much lead has been dissolved from the carbonate and silicate fractions of the Paleozoic limestone collected west of Grand View Peak. Although most thermal waters are recovered from Tertiary rhyolite, very little of the dissolved lead is from the rhyolite. Recharge to this system occurs in northern Nevada and the fluid moves northward in the Paleozoic limestones. The occurrence of thermal fluid in the Idavada Volcanics near and south of Twin Falls, Idaho is the result of upward movement of this fluid from the Paleozoic limestone.

  9. Double arch mirror study

    Science.gov (United States)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    The development of a method of mounting light weight glass mirrors for astronomical telescopes compatible with the goals of the Shuttle Infrared Telescope Facility (SIRTF) was investigated. A 20 in. diameter double arch lightweight mirror previously fabricated was modified to use a new mount configuration. This mount concept was developed and fabricated. The mounting concept of the double mounting mirror is outlined. The modifications made to the mirror, fabrication of the mirror mount, and room temperature testing of the mirror and mount and the extension of the mirror and mount concept to a full size (40 in. diameter) primary mirror for SIRTF are discussed.

  10. MEMS Inertial Sensors-Based Multi-Loop Control Enhanced by Disturbance Observation and Compensation for Fast Steering Mirror System

    Directory of Open Access Journals (Sweden)

    Chao Deng

    2016-11-01

    Full Text Available In this paper, an approach to improve the disturbance suppression performance of a fast steering mirror (FSM tracking control system based on a charge-coupled device (CCD and micro-electro-mechanical system (MEMS inertial sensors is proposed. The disturbance observation and compensation (DOC control method is recommended to enhance the classical multi-loop feedback control (MFC for line-of-sight (LOS stabilization in the FSM system. MEMS accelerometers and gyroscopes have been used in the FSM system tentatively to implement MFC instead of fiber-optic gyroscopes (FOG because of its smaller, lighter, cheaper features and gradually improved performance. However, the stabilization performance of FSM is still suffering a large number of mechanical resonances and time delay induced by a low CCD sampling rate, which causes insufficient error attenuation when suffering uncertain disturbances. Thus, in order to make further improvements on the stabilization performance, a cascaded MFC enhanced by DOC method is proposed. The sensitivity of this method shows the significant improvement of the conventional MFC system. Simultaneously, the analysis of stabilization accuracy is also presented. A series of comparative experimental results demonstrate the disturbance suppression performance of the FSM control system based on the MEMS inertial sensors can be effectively improved by the proposed approach.

  11. Automated twin identification technique for use with electron backscatter diffraction.

    Energy Technology Data Exchange (ETDEWEB)

    Henrie, B. L. (Benjamin Lyman); Mason, T. A. (Thomas A.); Bingert, J. F. (John F.)

    2004-01-01

    Historically, twinning information has been obtained by optical microscopy, TEM, and neutron diffraction. Recent research has shown that automated electron backscatter diffraction (EBSD) can be used to extract reliable twinning statistics. An automated twin identification technique for use with EBSD has facilitated a greater understanding of deformation twinning in materials. The key features of this automated framework are the use of the crystallographic definition of twin relationships, the inclination of the common K, plane at a twin boundary, and the correct identification of the parent orientation in a parent/twin pair. The complex nature of the parent/twin interactions required the use of a voting scheme to correctly identify parent orientations. In those few cases were the voting scheme was unable to determine parent orientation (< 2 pct) the algorithm allows for manual selection. Twin area fractions are categorized by operative twin systems along with secondary and tertiary twinning. These statistics are reported for {alpha}-zirconium and 316L stainless steel. These improved twin statistics can help quantify deformation processes as well as provide validation of plasticity models for materials that exhibit deformation twinning.

  12. Effects of mirror distortion by thermal deformation in an interferometry beam size monitor system at PLS-II

    Science.gov (United States)

    Hwang, Ji-Gwang; Kim, Eun-San; Kim, Changbum; Huang, Jung-Yun; Kim, Dotae

    2016-10-01

    Extraction mirrors installed at the most upstream position of interferometry beam size monitor are frequently used for measuring the beam size in storage rings. These mirrors receive the high power synchrotron radiation and are distorted owing to the heat distribution that depends on the position on the mirror surface. The distortion of the mirror changes the effective separation of the slit in the interferometry beam size monitor. Estimation of the effects of the front-end mirror distortion is important for measuring the beam size accurately. In this paper, we present the result of the numerical simulation of the temperature distribution and thermal expansion of the front-end mirror using ANSYS code, the theoretical basis of the effects of mirror distortion and compare with experimental results from Pohang Light Source II (PLS-II) at the Pohang Accelerator Laboratory (PAL). The equipment in the beam diagnosis line in PLS-II and experimental set-up for measuring the distortion of the front-end mirror using a multi-hole square array Hartmann screen are described.

  13. Production of marker-free and RSV-resistant transgenic rice using a twin T-DNA system and RNAi

    Indian Academy of Sciences (India)

    Yayuan Jiang; Lin Sun; Mingsong Jiang; Kaidong Li; Yunzhi Song; Changxiang Zhu

    2013-09-01

    A twin T-DNA system is a convenient strategy for creating selectable marker-free transgenic plants. The standard transformation plasmid, pCAMBIA 1300, was modified into a binary vector consisting of two separate T-DNAs, one of which contained the hygromycin phosphotransferase (hpt) marker gene. Using this binary vector, we constructed two vectors that expressed inverted-repeat (IR) structures targeting the rice stripe virus (RSV) coat protein (CP) gene and the special-disease protein (SP) gene. Transgenic rice lines were obtained via Agrobacterium-mediated transformation. Seven independent clones harbouring both the hpt marker gene and the target genes (RSV CP or SP) were obtained in the primary transformants of pDTRSVCP and pDTRSVSP, respectively. The segregation frequencies of the target gene and the marker gene in the T1 plants were 8.72% for pDTRSVCP and 12.33% for pDTRSVSP. Two of the pDTRSVCP lines and three pDTRSVSP lines harbouring the homozygous target gene, but not the hpt gene, were strongly resistant to RSV. A molecular analysis of the resistant transgenic plants confirmed the stable integration and expression of the target genes. The resistant transgenic plants displayed lower levels of the transgene transcripts and specific small interfering RNAs, suggesting that RNAi induced the viral resistance.

  14. Identification and molecular characterization of twin-arginine translocation system (Tat) in Xanthomonas oryzae pv. oryzae strain PXO99.

    Science.gov (United States)

    Chen, Lei; Hu, Baishi; Qian, Guoliang; Wang, Chen; Yang, Wanfeng; Han, Zhicheng; Liu, Fengquan

    2009-02-01

    Xanthomonas oryzae pv. oryzae causes bacterial leaf blight, one of the most widespread and destructive bacterial diseases in rice. This study identified and characterized the contribution of the twin-arginine translocation (Tat) pathway to motility, chemotaxis, extracellular polysaccharide (EPS) production and virulence in X. oryzae pv. oryzae strain PXO99. The tatC disruption mutant (strain TCM) of strain PXO99 were generated, and confirmed both by PCR and Southern blotting. Strain PXO99 cells were highly motile in NYGB 0.3% soft agar plate. In contrast, the tatC mutation impaired motility. Furthermore, strain TCM cells lacked detectable flagella and exhibited almost no chemotaxis toward glucose under aerobic conditions, indicating that the Tat secretion pathway contributed to flagellar biogenesis and chemotactic responses. It was also observed that strain TCM exhibited a reductive production of extracellular polysaccharide (EPS) and a significant reduction of virulence on rice plants when compared with the wild type PXO99. However, the tatC mutation in strain PXO99 did not affect growth rate and the ability to induce hypersensitive response (HR) in nonhost tobacco (Nicotiana tabacum L. cv. Samsun). Our findings indicated that the Tat system of X. oryzae pv. oryzae played an important role in the pathogen's virulence.

  15. Monochorionic twin pregnancies

    NARCIS (Netherlands)

    Hack, K.E.A.

    2008-01-01

    Following widespread application of assisted reproductive technology modalities and the increased age of motherhood, the incidence of twin gestations has increased markedly. Twins are either monozygotic or dizygotic. Dizygotic (i.e. fraternal) twins result from the fertilization of two different egg

  16. Twin boundary energy and characterization of charge redistribution near the twin boundaries of cupperate superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Mahnaz [Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Khoshnevisan, Bahram, E-mail: m.mohammadi_2@grad.kashanu.ac.ir [Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of); Javad Hashemifar, S. [Department of Physics, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2014-12-15

    Highlights: • Ab initio simulation for twin boundary energy in YBCO system for the 1st time. • Study of the twin boundary energy variation versus the inserted strain. • Proportionality of twin lamella width by the inserted strain. • Local charge transfer and charge redistribution on the twin planes. • Total DOSs for the twined system at Fermi level is higher than the untwined one. • This explain the effect of twin boundaries in agreement with experimental data. - Abstract: Ab-initio calculations under general gradient approximation have been employed for the first time to find out twin boundary energy, γ, in twined YBCO systems. Despite a vast discrepancy in reported experimental values, our results show that the γ value falls in the range of 40–85 mJ/m{sup 2}. On the other hand, functional form of γ versus inserted strains shows that the mean value for the twin width lamella would tend to approach zero as the strain goes to zero. We have also investigated the local charge transfer and the modification of the electronic states of the basal and twin planes in YBCO, because the charge redistribution at interfaces can modify transport across the grains considerably and determine the applicability of high-T{sub c} superconductors in the electronic applications. The total density of electronic states at the Fermi level for the twined system is enhanced in comparison with the untwined one. Our results explain the influence of twin boundaries in superconductive properties of YBCO, in experimental situations.

  17. Profile of asymmetrical retinopathy of prematurity in twins

    Directory of Open Access Journals (Sweden)

    Azad Rajvardhan

    2010-01-01

    Full Text Available Background: In twin births, both babies have the same gestational age and pre-natal conditions. However, twins may develop a varied retinopathy of prematurity (ROP course depending on birth weight and other systemic factors. Objective: To study the profile of asymmetric ROP in twins Design: Retrospective study Setting: Tertiary ROP referral eye hospital. Materials and Methods: The profile of 56 pairs of twins with ROP were studied and analyzed for differences in zone or need for treatment, while studying possible causes for the varied outcome. Results: In 45 pairs of twins (80% the disease progressed identically in both eyes, while in 11 pairs (20% the ROP showed differences in zone or need for treatment. Four of these pairs were discordant. In 3 of these 4 pairs, the heavier birth weight twin had a more severe ROP course. Conclusions: Twins can present with asymmetric ROP course, and it is therefore essential to examine both twins as per screening protocols.

  18. The neuronal correlates of mirror therapy: an fMRI study on mirror induced visual illusions in patients with stroke.

    Science.gov (United States)

    Michielsen, Marian E; Smits, Marion; Ribbers, Gerard M; Stam, Henk J; van der Geest, Jos N; Bussmann, Johannes B J; Selles, Ruud W

    2011-04-01

    To investigate the neuronal basis for the effects of mirror therapy in patients with stroke. 22 patients with stroke participated in this study. The authors used functional MRI to investigate neuronal activation patterns in two experiments. In the unimanual experiment, patients moved their unaffected hand, either while observing it directly (no-mirror condition) or while observing its mirror reflection (mirror condition). In the bimanual experiment, patients moved both hands, either while observing the affected hand directly (no-mirror condition) or while observing the mirror reflection of the unaffected hand in place of the affected hand (mirror condition). A two-factorial analysis with movement (activity vs rest) and mirror (mirror vs no mirror) as main factors was performed to assess neuronal activity resultant of the mirror illusion. Data on 18 participants were suitable for analysis. Results showed a significant interaction effect of movement×mirror during the bimanual experiment. Activated regions were the precuneus and the posterior cingulate cortex (pmirror illusion in patients with stroke, the authors showed that during bimanual movement, the mirror illusion increases activity in the precuneus and the posterior cingulate cortex, areas associated with awareness of the self and spatial attention. By increasing awareness of the affected limb, the mirror illusion might reduce learnt non-use. The fact that the authors did not observe mirror-related activity in areas of the motor or mirror neuron system questions popular theories that attribute the clinical effects of mirror therapy to these systems.

  19. [What mirror neurons have revealed: revisited].

    Science.gov (United States)

    Murata, Akira; Maeda, Kazutaka

    2014-06-01

    The first paper on mirror neurons was published in 1992. In the span of over two decades since then, much knowledge about the relationship between social cognitive function and the motor control system has been accumulated. Direct matching of visual actions and their corresponding motor representations is the most important functional property of mirror neuron. Many studies have emphasized intrinsic simulation as a core concept for mirror neurons. Mirror neurons are thought to play a role in social cognitive function. However, the function of mirror neurons in the macaque remains unclear, because such cognitive functions are limited or lacking in macaque monkeys. It is therefore important to discuss these neurons in the context of motor function. Rizzolatti and colleagues have stressed that the most important function of mirror neurons in macaques is recognition of actions performed by other individuals. I suggest that mirror neurons in the Macaque inferior pariental lobule might be correlated with body schema. In the parieto-premotor network, matching of corollary discharge and actual sensory feedback is an essential neuronal operation. Recently, neurons showing mirror properties were found in some cortical areas outside the mirror neuron system. The current work would revisit the outcomes of mirror neuron studies to discuss the function of mirror neurons in the monkey.

  20. A novel photovoltaic power system which uses a large area concentrator mirror

    Science.gov (United States)

    Arrison, Anne; Fatemi, Navid

    1987-01-01

    A preliminary analysis has been made of a novel photovoltaic power system concept. The system is composed of a small area, dense photovoltaic array, a large area solar concentrator, and a battery system for energy storage. The feasibility of such a system is assessed for space power applications. The orbital efficiency, specific power, mass, and area of the system are calculated under various conditions and compared with those for the organic Rankine cycle solar dynamic system proposed for Space Station. Near term and advanced large area concentrator photovoltaic systems not only compare favorably to solar dynamic systems in terms of performance but offer other benefits as well.

  1. Tandem mirror and field-reversed mirror experiments

    Energy Technology Data Exchange (ETDEWEB)

    Coensgen, F.H.; Simonen, T.C.; Turner, W.C.

    1979-08-21

    This paper is largely devoted to tandem mirror and field-reversed mirror experiments at the Lawrence Livermore Laboratory (LLL), and briefly summarizes results of experiments in which field-reversal has been achieved. In the tandem experiment, high-energy, high-density plasmas (nearly identical to 2XIIB plasmas) are located at each end of a solenoid where plasma ions are electrostatically confined by the high positive poentials arising in the end plug plasma. End plug ions are magnetically confined, and electrons are electrostatically confined by the overall positive potential of the system. The field-reversed mirror reactor consists of several small field-reversed mirror plasmas linked together for economic reasons. In the LLL Beta II experiment, generation of a field-reversed plasma ring will be investigated using a high-energy plasma gun with a transverse radial magnetic field. This plasma will be further heated and sustained by injection of intense, high-energy neutral beams.

  2. Mirror neurons: their implications for group psychotherapy.

    Science.gov (United States)

    Schermer, Victor L

    2010-10-01

    Recently discovered mirror neurons in the motor cortex of the brain register the actions and intentions of both the organism and others in the environment. As such, they may play a significant role in social behavior and groups. This paper considers the potential implications of mirror neurons and related neural networks for group therapists, proposing that mirror neurons and mirror systems provide "hard-wired" support for the group therapist's belief in the centrality of relationships in the treatment process and exploring their value in accounting for group-as-a-whole phenomena. Mirror neurons further confirm the holistic, social nature of perception, action, and intention as distinct from a stimulus-response behaviorism. The implications of mirror neurons and mirroring processes for the group therapist role, interventions, and training are also discussed.

  3. Design of a rapidly cooled cryogenic mirror

    Science.gov (United States)

    Plummer, Ron; Hsu, Ike

    1993-01-01

    The paper discusses the design, analysis, and testing of a rapidly cooled beryllium cryogenic mirror, which is the primary mirror in the four-element optical system for the Long Wavelength Infrared Advanced Technology Seeker. The mirror is shown to meet the requirement of five minutes for cooling to cryogenic operating temperature; it also maintains its optical figure and vacuum integrity and meets the nuclear specification. Results of a detailed thermal analysis on the mirror showed that, using nitrogen gas at 80 K as coolant, the front face of the mirror can be cooled from an initial temperature of 300 K to less than 90 K within five minutes. In a vacuum chamber, using liquid nitrogen as coolant, the mirror can be cooled to 80 K within 1.5 min. The mirror is well thermally insulated, so that it can be maintained at less than its operating temperature for a long time without active cooling.

  4. Dynamic coherent backscattering mirror

    Energy Technology Data Exchange (ETDEWEB)

    Zeylikovich, I.; Xu, M., E-mail: mxu@fairfield.edu [Physics Department, Fairfield University, Fairfield, CT 06824 (United States)

    2016-02-15

    The phase of multiply scattered light has recently attracted considerable interest. Coherent backscattering is a striking phenomenon of multiple scattered light in which the coherence of light survives multiple scattering in a random medium and is observable in the direction space as an enhancement of the intensity of backscattered light within a cone around the retroreflection direction. Reciprocity also leads to enhancement of backscattering light in the spatial space. The random medium behaves as a reciprocity mirror which robustly converts a diverging incident beam into a converging backscattering one focusing at a conjugate spot in space. Here we first analyze theoretically this coherent backscattering mirror (CBM) phenomenon and then demonstrate the capability of CBM compensating and correcting both static and dynamic phase distortions occurring along the optical path. CBM may offer novel approaches for high speed dynamic phase corrections in optical systems and find applications in sensing and navigation.

  5. Dynamic coherent backscattering mirror

    Science.gov (United States)

    Xu, M.

    2016-01-01

    The phase of multiply scattered light has recently attracted considerable interest. Coherent backscattering is a striking phenomenon of multiple scattered light in which the coherence of light survives multiple scattering in a random medium and is observable in the direction space as an enhancement of the intensity of backscattered light within a cone around the retroreflection direction. Reciprocity also leads to enhancement of backscattering light in the spatial space. The random medium behaves as a reciprocity mirror which robustly converts a diverging incident beam into a converging backscattering one focusing at a conjugate spot in space. Here we first analyze theoretically this coherent backscattering mirror (CBM) phenomenon and then demonstrate the capability of CBM compensating and correcting both static and dynamic phase distortions occurring along the optical path. CBM may offer novel approaches for high speed dynamic phase corrections in optical systems and find applications in sensing and navigation. PMID:26937296

  6. Signed language and human action processing: evidence for functional constraints on the human mirror-neuron system.

    Science.gov (United States)

    Corina, David P; Knapp, Heather Patterson

    2008-12-01

    In the quest to further understand the neural underpinning of human communication, researchers have turned to studies of naturally occurring signed languages used in Deaf communities. The comparison of the commonalities and differences between spoken and signed languages provides an opportunity to determine core neural systems responsible for linguistic communication independent of the modality in which a language is expressed. The present article examines such studies, and in addition asks what we can learn about human languages by contrasting formal visual-gestural linguistic systems (signed languages) with more general human action perception. To understand visual language perception, it is important to distinguish the demands of general human motion processing from the highly task-dependent demands associated with extracting linguistic meaning from arbitrary, conventionalized gestures. This endeavor is particularly important because theorists have suggested close homologies between perception and production of actions and functions of human language and social communication. We review recent behavioral, functional imaging, and neuropsychological studies that explore dissociations between the processing of human actions and signed languages. These data suggest incomplete overlap between the mirror-neuron systems proposed to mediate human action and language.

  7. Twin-Arginine Protein Translocation

    NARCIS (Netherlands)

    Goosens, Vivianne J; van Dijl, Jan Maarten

    2016-01-01

    Twin-arginine protein translocation systems (Tat) translocate fully folded and co-factor-containing proteins across biological membranes. In this review, we focus on the Tat pathway of Gram-positive bacteria. The minimal Tat pathway is composed of two components, namely a TatA and TatC pair, which a

  8. Performance of the primary mirror center-of-curvature optical metrology system during cryogenic testing of the JWST Pathfinder telescope

    Science.gov (United States)

    Hadaway, James B.; Wells, Conrad; Olczak, Gene; Waldman, Mark; Whitman, Tony; Cosentino, Joseph; Connolly, Mark; Chaney, David; Telfer, Randal

    2016-07-01

    The James Webb Space Telescope (JWST) primary mirror (PM) is 6.6 m in diameter and consists of 18 hexagonal segments, each 1.5 m point-to-point. Each segment has a six degree-of-freedom hexapod actuation system and a radius of-curvature (RoC) actuation system. The full telescope will be tested at its cryogenic operating temperature at Johnson Space Center. This testing will include center-of-curvature measurements of the PM, using the Center-of-Curvature Optical Assembly (COCOA) and the Absolute Distance Meter Assembly (ADMA). The COCOA includes an interferometer, a reflective null, an interferometer-null calibration system, coarse and fine alignment systems, and two displacement measuring interferometer systems. A multiple-wavelength interferometer (MWIF) is used for alignment and phasing of the PM segments. The ADMA is used to measure, and set, the spacing between the PM and the focus of the COCOA null (i.e. the PM center-of-curvature) for determination of the ROC. The performance of these metrology systems was assessed during two cryogenic tests at JSC. This testing was performed using the JWST Pathfinder telescope, consisting mostly of engineering development and spare hardware. The Pathfinder PM consists of two spare segments. These tests provided the opportunity to assess how well the center-of-curvature optical metrology hardware, along with the software and procedures, performed using real JWST telescope hardware. This paper will describe the test setup, the testing performed, and the resulting metrology system performance. The knowledge gained and the lessons learned during this testing will be of great benefit to the accurate and efficient cryogenic testing of the JWST flight telescope.

  9. Autism: Lost in the Mirror?

    Directory of Open Access Journals (Sweden)

    Alison Barry

    2015-01-01

    Full Text Available When I began my training as an analyst I took up a placement in an early intervention centre for autistic pre-scholars. The school was run on the psychological principles of ABA and children were tutored on a reward system promoting positive behaviors. Whilst working there I noticed that a number of children had a particular fascination for their mirrored image. This fascination was pervasive and many children would do their work primarily for the reward of the mirror. Through the lens of psychoanalysis I found this very interesting and Lacan’s Mirror Phase immediately came to mind and with this it bore the question as to whether or not there was something in the Mirror Phase of development that had an impact on what we see as symptoms of Autism.

  10. Software design for the control system for Small-Size Telescopes with single-mirror of the Cherenkov Telescope Array

    CERN Document Server

    :,; Błocki, J; Bogacz, L; Borkowski, J; Bulik, T; Cadoux, F; Christov, A; Curyło, M; della Volpe, D; Dyrda, M; Favre, Y; Frankowski, A; Grudnik, Ł; Grudzińska, M; Heller, M; Idźkowski, B; Jamrozy, M; Janiak, M; Kasperek, J; Lalik, K; Lyard, E; Mach, E; Mandat, D; Marszałek, A; Michałowski, J; Moderski, R; Rameez, M; Montaruli, T; Neronov, A; Niemiec, J; Ostrowski, M; Paśko, P; Pech, M; Porcelli, A; Prandini, E; Rajda, P; Schioppa, E jr; Schovanek, P; Seweryn, K; Skowron, K; Sliusar, V; Sowiński, M; Stawarz, Ł; Stodulska, M; Stodulski, M; Pujadas, I Troyano; Toscano, S; Walter, R; Wiȩcek, M; Zagdański, A; Ziȩtara, K; Zychowski, P

    2015-01-01

    The Small-Size Telescope with single-mirror (SST-1M) is a 4 m Davies-Cotton telescope and is among the proposed telescope designs for the Cherenkov Telescope Array (CTA). It is conceived to provide the high-energy ($>$ few TeV) coverage. The SST-1M contains proven technology for the telescope structure and innovative electronics and photosensors for the camera. Its design is meant to be simple, low-budget and easy-to-build industrially. Each device subsystem of an SST-1M telescope is made visible to CTA through a dedicated industrial standard server. The software is being developed in collaboration with the CTA Medium-Size Telescopes to ensure compatibility and uniformity of the array control. Early operations of the SST-1M prototype will be performed with a subset of the CTA central array control system based on the Alma Common Software (ACS). The triggered event data are time stamped, formatted and finally transmitted to the CTA data acquisition. The software system developed to control the devices of an SS...

  11. How Bibliographic Classification Mirrors Society - the Case of the Swedish SAB-System

    Directory of Open Access Journals (Sweden)

    Joacim Hansson

    2006-01-01

    Full Text Available The article reports on a study of the Swedish Classification system, the SAB-system and its ability to reveal certain social and ideological structures in Swedish society in the beginning of the 20th century. Methodology is based on critical hermeneutics and ideological analysis. Results show that the classification system shows significant correspondences between the structure of its disciplinary hierarchies and ideals in the surrounding society.

  12. Seasonal-to-decadal predictions with the ensemble Kalman filter and the Norwegian Earth System Model: a twin experiment

    Directory of Open Access Journals (Sweden)

    Francois Counillon

    2014-03-01

    Full Text Available Here, we firstly demonstrate the potential of an advanced flow dependent data assimilation method for performing seasonal-to-decadal prediction and secondly, reassess the use of sea surface temperature (SST for initialisation of these forecasts. We use the Norwegian Climate Prediction Model (NorCPM, which is based on the Norwegian Earth System Model (NorESM and uses the deterministic ensemble Kalman filter to assimilate observations. NorESM is a fully coupled system based on the Community Earth System Model version 1, which includes an ocean, an atmosphere, a sea ice and a land model. A numerically efficient coarse resolution version of NorESM is used. We employ a twin experiment methodology to provide an upper estimate of predictability in our model framework (i.e. without considering model bias of NorCPM that assimilates synthetic monthly SST data (EnKF-SST. The accuracy of EnKF-SST is compared to an unconstrained ensemble run (FREE and ensemble predictions made with near perfect (i.e. microscopic SST perturbation initial conditions (PERFECT. We perform 10 cycles, each consisting of a 10-yr assimilation phase, followed by a 10-yr prediction. The results indicate that EnKF-SST improves sea level, ice concentration, 2 m atmospheric temperature, precipitation and 3-D hydrography compared to FREE. Improvements for the hydrography are largest near the surface and are retained for longer periods at depth. Benefits in salinity are retained for longer periods compared to temperature. Near-surface improvements are largest in the tropics, while improvements at intermediate depths are found in regions of large-scale currents, regions of deep convection, and at the Mediterranean Sea outflow. However, the benefits are often small compared to PERFECT, in particular, at depth suggesting that more observations should be assimilated in addition to SST. The EnKF-SST system is also tested for standard ocean circulation indices and demonstrates decadal

  13. Twin nucleation and migration in FeCr single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Patriarca, L. [Politecnico di Milano, Department of Mechanical Engineering, Via La Masa 34, I-20156 Milano (Italy); Abuzaid, Wael [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 W. Green St., Urbana, IL 61801 (United States); Sehitoglu, Huseyin, E-mail: huseyin@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 W. Green St., Urbana, IL 61801 (United States); Maier, Hans J. [Lehrstuhl fuer Werkstoffkunde (Materials Science), University of Paderborn, 33095 Paderborn (Germany); Chumlyakov, Y. [Physics of Plasticity and Strength of Materials Laboratory, Siberian Physical and Technical Institute, 634050 Tomsk (Russian Federation)

    2013-01-15

    Tension and compression experiments were conducted on body-centered cubic Fe -47.8 at pct. Cr single crystals. The critical resolved shear stress (CRSS) magnitudes for slip nucleation, twin nucleation and twin migration were established. We show that the nucleation of slip occurs at a CRSS of about 88 MPa, while twinning nucleates at a CRSS of about 191 MPa with an associated load drop. Following twin nucleation, twin migration proceeds at a CRSS that is lower than the initiation stress ( Almost-Equal-To 114-153 MPa). The experimental results of the nucleation stresses indicate that the Schmid law holds to a first approximation for the slip and twin nucleation cases, but to a lesser extent for twin migration particularly when considerable slip strains preceded twinning. The CRSSs were determined experimentally using digital image correlation (DIC) in conjunction with electron back scattering diffraction (EBSD). The DIC measurements enabled pinpointing the precise stress on the stress-strain curves where twins or slip were activated. The crystal orientations were obtained using EBSD and used to determine the activated twin and slip systems through trace analysis. - Highlights: Black-Right-Pointing-Pointer Digital image correlation allows to capture slip/twin initiation for bcc FeCr. Black-Right-Pointing-Pointer Crystal orientations from EBSD allow slip/twin system indexing. Black-Right-Pointing-Pointer Nucleation of slip always precedes twinning. Black-Right-Pointing-Pointer Twin growth is sustained with a lower stress than required for nucleation. Black-Right-Pointing-Pointer Twin-slip interactions provide high hardening at the onset of plasticity.

  14. METHOD FOR CALCULATION OF DISPLACEMENT FIELDS AND STRESSES IN SYSTEM OF PARALLEL LENTICULAR MECHANICAL TWINS OCCURRING IN MARTENSITIC PHASE OF Ni2MnGa-MAGNETIC ALLOY HAVING PROPERTY OF SHAPE MEMORY

    Directory of Open Access Journals (Sweden)

    E. V. Shmatok

    2015-01-01

    Full Text Available Nowadays mathematical modeling of peculiar features of a stress-strain state is considered as a perspective direction of research. In this regard the aim of this paper has been to make calculations of the stress-strain state initiated by a system of parallel lenticular residual mechanical twins that occur due to local surface deformation of  Ni2MnGa single crystal martensitic phase.The method is applied while using a superposition principle of fields and approximation of a continuous distribution of twinning dislocations on twin boundaries in a continuous elastic medium.The calculations have made it possible to obtain distribution graphs of displacement fields and stresses and point out the fact that a configuration of displacement component distribution uy is significantly different from the displacement of components ux and uz having a displacement distribution similar to each other. The highest value of displacement occurs in the component uy in twins peaks.The paper also presents results of calculations for six components of a stress field the tensor. The obtained results have revealed similarity in stress distribution character of the components  sxz and szz, but they differ numerically from each other about in two times. The largest value of the stresses occurring in the lenticular twins has been observed in components sxx, sxz, syy, syz and it has been focused mainly at the borders and peaks  of twins.A common feature of the obtained components of displacement and stresses in a lenticular twins system is symmetry with regard to OY. In addition, the stress distribution of all obtained tensor components has been mainly localized at the borders and at the tops of twins where the highest values of stresses capable of exerting a significant impact on dislocation and diffusion processes are generally concentrated.

  15. Facial mimicry and the mirror neuron system:Simultaneous acquisition of facial electromyography and functional magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Katja U Likowski

    2012-07-01

    Full Text Available Numerous studies have shown that humans automatically react with congruent facial reactions, i.e. facial mimicry, when seeing a vis-á-vis’ facial expressions. The current experiment is the first investigating the neuronal structures responsible for differences in the occurrence of such facial mimicry reactions by simultaneously measuring BOLD and facial EMG in an MRI scanner. Therefore, 20 female students viewed emotional facial expressions (happy, sad, and angry of male and female avatar characters. During Differentiation presentation, the BOLD signal as well as M. zygomaticus major and M. corrugator supercilii activity were recorded simultaneously. Results show prototypical patterns of facial mimicry after correction for MR-related artifacts: enhanced M. zygomaticus major activity in response to happy and enhanced M. corrugator supercilii activity in response to sad and angry expressions. Regression analyses show that these congruent facial reactions correlate significantly with activations in the IFG, SMA and cerebellum. Stronger zygomaticus reactions to happy faces were further associated to increased activities in the caudate, MTG and PCC. Corrugator reactions to angry expressions were further correlated with the hippocampus, insula and STS. Results are discussed in relation to core and extended models of the mirror neuron system.

  16. Neurodevelopmental investigation of the mirror neurone system in children of women receiving opioid maintenance therapy during pregnancy.

    Science.gov (United States)

    Konijnenberg, Carolien; Melinder, Annika

    2013-01-01

    Opioid maintenance therapy (OMT) is generally recommended for pregnant opioid-dependent women. Previous studies investigating the long-term effects of OMT on children's cognitive development found that children of women in OMT have an increased risk of developing deficits in motor and visual perceptual skills, which are important aspects of the mirror neurone system (MNS), a complex neural circuit involved in learning and social interactions. The aim of the current study was to investigate aspects of the MNS in children of women in OMT. A 2 (control group versus OMT group) × 2 (human versus mechanic) mixed factorial design. The Cognitive Developmental Research Unit at the University of Oslo, Norway. Fifteen children of women in OMT and 15 non-exposed children participated. Goal-directed eye movements were recorded using a Tobii 1750 eye tracker. Neurocognitive tests were employed to map children's cognitive development. The OMT group made fewer proactive goal-directed eye movements [mean = -37.73, standard deviation (SD) = 208.56] compared to the control group (mean = 181.47, SD = 228.65), F((1,28)) = 7.53, P = 0.01, η(2) = 0.21. No differences were found on tests of visual perception or goal understanding. Use of opioid maintenance therapy during pregnancy appears to be associated with impaired goal-directed eye movements in the 4-year-old infant which may affect later social adjustment adversely. © 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.

  17. Object visibility alters the relative contribution of ventral visual stream and mirror neuron system to goal anticipation during action observation.

    Science.gov (United States)

    Thioux, Marc; Keysers, Christian

    2015-01-15

    We used fMRI to study the effect of hiding the target of a grasping action on the cerebral activity of an observer whose task was to anticipate the size of the object being grasped. Activity in the putative mirror neuron system (pMNS) was higher when the target was concealed from the view of the observer and anticipating the size of the object being grasped requested paying attention to the hand kinematics. In contrast, activity in ventral visual areas outside the pMNS increased when the target was fully visible, and the performance improved in this condition. A repetition suppression analysis demonstrated that in full view, the size of the object being grasped by the actor was encoded in the ventral visual stream. Dynamic causal modeling showed that monitoring a grasping action increased the coupling between the parietal and ventral premotor nodes of the pMNS. The modulation of the functional connectivity between these nodes was correlated with the subject's capability to detect the size of hidden objects. In full view, synaptic activity increased within the ventral visual stream, and the connectivity with the pMNS was diminished. The re-enactment of observed actions in the pMNS is crucial when interpreting others' actions requires paying attention to the body kinematics. However, when the context permits, visual-spatial information processing may complement pMNS computations for improved action anticipation accuracy. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Malaysian Twin Registry.

    Science.gov (United States)

    Jahanfar, Shayesteh; Jaffar, Sharifah Halimah

    2013-02-01

    The National Malaysian Twin Registry was established in Royal College of Medicine, Perak, University Kuala Lumpur (UniKL) in June 2008 through a grant provided by UniKL. The general objective is to facilitate scientific research involving participation of twins and their family members in order to answer questions of health and wellbeing relevant to Malaysians. Recruitment is done via mass media, poster, and pamphlets. We now have 266 adult and 204 children twins registered. Several research projects including reproductive health study of twins and the role of co-bedding on growth and development of children are carried out. Registry holds annual activities for twins and seeks to provide health-related information for twins. We seek international collaboration.

  19. Synchrotron X-ray tests of an L-shaped laterally graded multilayer mirror for the analyzer system of the ultra-high-resolution IXS spectrometer at NSLS-II.

    Science.gov (United States)

    Honnicke, Marcelo G; Keister, Jeffrey W; Conley, Raymond; Kaznatcheev, Konstantine; Takacs, Peter Z; Coburn, David Scott; Reffi, Leo; Cai, Yong Q

    2011-11-01

    Characterization and testing of an L-shaped laterally graded multilayer mirror are presented. This mirror is designed as a two-dimensional collimating optics for the analyzer system of the ultra-high-resolution inelastic X-ray scattering (IXS) spectrometer at National Synchrotron Light Source II (NSLS-II). The characterization includes point-to-point reflectivity measurements, lattice parameter determination and mirror metrology (figure, slope error and roughness). The synchrotron X-ray test of the mirror was carried out reversely as a focusing device. The results show that the L-shaped laterally graded multilayer mirror is suitable to be used, with high efficiency, for the analyzer system of the IXS spectrometer at NSLS-II.

  20. Perinatal hepatic infarction in twin-twin transfusion.

    LENUS (Irish Health Repository)

    O'Sullivan, M J

    2012-02-03

    We report a case of a twin pregnancy which was complicated by a twin-twin transfusion in which the recipient twin was noted to have an intra-abdominal echogenic mass. This twin died at two days of age of hepatic infarction. The donor twin was healthy at birth, at thirty weeks\\' gestation, and did not have any subsequent problems. Fetal intra-abdominal echogenicity may be a marker of hepatic infarction.

  1. Mirror Metrology Using Nano-Probe Supports

    Science.gov (United States)

    Robinson, David; Hong, Maoling; Byron, Glenn; McClelland, Ryan; Chan, Kai-Wing

    2012-01-01

    Thin, lightweight mirrors are needed for future x-ray space telescopes in order to increase x-ray collecting area while maintaining a reduced mass and volume capable of being launched on existing rockets. However, it is very difficult to determine the undistorted shape of such thin mirrors because the mounting of the mirror during measurement causes distortion. Traditional kinematic mounts have insufficient supports to control the distortion to measurable levels and prevent the mirror from vibrating during measurement. Over-constrained mounts (non-kinematic) result in an unknown force state causing mirror distortion that cannot be determined or analytically removed. In order to measure flexible mirrors, it is necessary to over-constrain the mirror. Over-constraint causes unknown distortions to be applied to the mirror. Even if a kinematic constraint system can be used, necessary imperfections in the kinematic assumption can lead to an unknown force state capable of distorting the mirror. Previously, thicker, stiffer, and heavier mirrors were used to achieve low optical figure distortion. These mirrors could be measured to an acceptable level of precision using traditional kinematic mounts. As lighter weight precision optics have developed, systems such as the whiffle tree or hydraulic supports have been used to provide additional mounting supports while maintaining the kinematic assumption. The purpose of this invention is to over-constrain a mirror for optical measurement without causing unacceptable or unknown distortions. The invention uses force gauges capable of measuring 1/10,000 of a Newton attached to nano-actuators to support a thin x-ray optic with known and controlled forces to allow for figure measurement and knowledge of the undeformed mirror figure. The mirror is hung from strings such that it is minimally distorted and in a known force state. However, the hanging mirror cannot be measured because it is both swinging and vibrating. In order to

  2. The Twin Higgs mechanism and Composite Higgs

    CERN Document Server

    Low, Matthew; Wang, Lian-Tao

    2015-01-01

    We combine the Twin Higgs mechanism with the paradigm of Composite Higgs models. In this class of models the Higgs is a pseudo-Nambu-Goldstone boson from a strongly coupled sector near the TeV scale, and it is additionally protected by a discrete symmetry due to the twin mechanism. We discuss the model building issues associated with this setup and quantify the tuning needed to achieve the correct electroweak vacuum and the Higgs mass. In contrast to standard Composite Higgs models, the lightest resonance associated with the top sector is the uncolored mirror top, while the colored top partners can be made parameterically heavier without extra tuning. In some cases, the vector resonances are predicted to lie in the multi-TeV range. We present models where the resonances - both fermions and vectors - being heavier alleviates the pressure on naturalness coming from direct searches demonstrating that theories with low tuning may survive constraints from the Large Hadron Collider.

  3. The Brazilian Twin Registry.

    Science.gov (United States)

    Ferreira, Paulo H; Oliveira, Vinicius C; Junqueira, Daniela R; Cisneros, Lígia C; Ferreira, Lucas C; Murphy, Kate; Ordoñana, Juan R; Hopper, John L; Teixeira-Salmela, Luci F

    2016-12-01

    The Brazilian Twin Registry (BTR) was established in 2013 and has impelled twin research in South America. The main aim of the initiative was to create a resource that would be accessible to the Brazilian scientific community as well as international researchers interested in the investigation of the contribution of genetic and environmental factors in the development of common diseases, phenotypes, and human behavior traits. The BTR is a joint effort between academic and governmental institutions from Brazil and Australia. The collaboration includes the Federal University of Minas Gerais (UFMG) in Brazil, the University of Sydney and University of Melbourne in Australia, the Australian Twin Registry, as well as the research foundations CNPq and CAPES in Brazil. The BTR is a member of the International Network of Twin Registries. Recruitment strategies used to register twins have been through participation in a longitudinal study investigating genetic and environmental factors for low back pain occurrence, and from a variety of sources including media campaigns and social networking. Currently, 291 twins are registered in the BTR, with data on demographics, zygosity, anthropometrics, and health history having been collected from 151 twins using a standardized self-reported questionnaire. Future BTR plans include the registration of thousands of Brazilian twins identified from different sources and collaborate nationally and internationally with other research groups interested on twin studies.

  4. Delivery in Twin Gestation

    Directory of Open Access Journals (Sweden)

    Mark T. Peters

    1995-01-01

    Full Text Available Objective: The objective of this study was to determine whether prophylactic treatment with oral broad-spectrum antimicrobial therapy improves pregnancy outcomes in twin gestations.

  5. MIRROR THERAPY: A REVIEW OF EVIDENCES

    OpenAIRE

    Aishath Najiha; Jagatheesan Alagesan; Vandana J Rathod; Poongundran Paranthaman

    2015-01-01

    The aim of this review was to identify and summarize the existing evidences on mirror box therapy for the management of various musculoskeletal conditions. A systemic literature search was performed to identify studies concerning mirror therapy. The included journal articles were reviewed and assessed for its significance. Fifty one studies were identified and reviewed. Five different patient categories were studied: 24 studies focussed on mirror therapy after stroke, thirteen studies focusse...

  6. Mirror-Symmetric Matrices and Their Application

    Institute of Scientific and Technical Information of China (English)

    李国林; 冯正和

    2002-01-01

    The well-known centrosymmetric matrices correctly reflect mirror-symmetry with no component or only one component on the mirror plane. Mirror-symmetric matrices defined in this paper can represent mirror-symmetric structures with various components on the mirror plane. Some basic properties of mirror-symmetric matrices were studied and applied to interconnection analysis. A generalized odd/even-mode decomposition scheme was developed based on the mirror reflection relationship for mirror-symmetric multiconductor transmission lines (MTLs). The per-unit-length (PUL) impedance matrix Z and admittance matrix Y can be divided into odd-mode and even-mode PUL matrices. Thus the order of the MTL system is reduced from n to k and k+p, where p(≥0)is the conductor number on the mirror plane. The analysis of mirror-symmetric matrices is related to the theory of symmetric group, which is the most effective tool for the study of symmetry.

  7. CNS activation and regional connectivity during pantomime observation: no engagement of the mirror neuron system for deaf signers.

    Science.gov (United States)

    Emmorey, Karen; Xu, Jiang; Gannon, Patrick; Goldin-Meadow, Susan; Braun, Allen

    2010-01-01

    Deaf signers have extensive experience using their hands to communicate. Using fMRI, we examined the neural systems engaged during the perception of manual communication in 14 deaf signers and 14 hearing non-signers. Participants passively viewed blocked video clips of pantomimes (e.g., peeling an imaginary banana) and action verbs in American Sign Language (ASL) that were rated as meaningless by non-signers (e.g., TO-DANCE). In contrast to visual fixation, pantomimes strongly activated fronto-parietal regions (the mirror neuron system, MNS) in hearing non-signers, but only bilateral middle temporal regions in deaf signers. When contrasted with ASL verbs, pantomimes selectively engaged inferior and superior parietal regions in hearing non-signers, but right superior temporal cortex in deaf signers. The perception of ASL verbs recruited similar regions as pantomimes for deaf signers, with some evidence of greater involvement of left inferior frontal gyrus for ASL verbs. Functional connectivity analyses with left hemisphere seed voxels (ventral premotor, inferior parietal lobule, fusiform gyrus) revealed robust connectivity with the MNS for the hearing non-signers. Deaf signers exhibited functional connectivity with the right hemisphere that was not observed for the hearing group for the fusiform gyrus seed voxel. We suggest that life-long experience with manual communication, and/or auditory deprivation, may alter regional connectivity and brain activation when viewing pantomimes. We conclude that the lack of activation within the MNS for deaf signers does not support an account of human communication that depends upon automatic sensorimotor resonance between perception and action.

  8. [Motion control of moving mirror based on fixed-mirror adjustment in FTIR spectrometer].

    Science.gov (United States)

    Li, Zhong-bing; Xu, Xian-ze; Le, Yi; Xu, Feng-qiu; Li, Jun-wei

    2012-08-01

    The performance of the uniform motion of the moving mirror, which is the only constant motion part in FTIR spectrometer, and the performance of the alignment of the fixed mirror play a key role in FTIR spectrometer, and affect the interference effect and the quality of the spectrogram and may restrict the precision and resolution of the instrument directly. The present article focuses on the research on the uniform motion of the moving mirror and the alignment of the fixed mirror. In order to improve the FTIR spectrometer, the maglev support system was designed for the moving mirror and the phase detection technology was adopted to adjust the tilt angle between the moving mirror and the fixed mirror. This paper also introduces an improved fuzzy PID control algorithm to get the accurate speed of the moving mirror and realize the control strategy from both hardware design and algorithm. The results show that the development of the moving mirror motion control system gets sufficient accuracy and real-time, which can ensure the uniform motion of the moving mirror and the alignment of the fixed mirror.

  9. Mirror Neurons and Mirror-Touch Synesthesia.

    Science.gov (United States)

    Linkovski, Omer; Katzin, Naama; Salti, Moti

    2016-05-30

    Since mirror neurons were introduced to the neuroscientific community more than 20 years ago, they have become an elegant and intuitive account for different cognitive mechanisms (e.g., empathy, goal understanding) and conditions (e.g., autism spectrum disorders). Recently, mirror neurons were suggested to be the mechanism underlying a specific type of synesthesia. Mirror-touch synesthesia is a phenomenon in which individuals experience somatosensory sensations when seeing someone else being touched. Appealing as it is, careful delineation is required when applying this mechanism. Using the mirror-touch synesthesia case, we put forward theoretical and methodological issues that should be addressed before relying on the mirror-neurons account. © The Author(s) 2016.

  10. Operation summary of parallel twin towers in ammonia synthesis system%氨合成系统双塔并联改造运行总结

    Institute of Scientific and Technical Information of China (English)

    赵军; 吴树华

    2014-01-01

    This paper briefly introduces retrofit scheme, process flow, operation method and production operation of parallel twin towers in ammonia synthesis system, and it points out that ammonia synthesis towers has obtained good economic benefits.%简要介绍氨合成双塔并联改造方案、工艺流程、操作方法及生产运行情况,指出氨合成双塔并联改造取得了良好的经济效益。

  11. Model-based analysis of a twin-screw wet granulation system for continuous solid dosage manufacturing

    DEFF Research Database (Denmark)

    Kumar, Ashish; Vercruysse, Jurgen; Mortier, Severine T. F. C.

    2016-01-01

    Implementation of twin-screw granulation in a continuous from-powder-to-tablet manufacturing line requires process knowledge development. This is often pursued by application of mechanistic models incorporating the underlying mechanisms. In this study, granulation mechanisms considered...... the granulator under certain process conditions. Such a physical separation between the granulation regimes is promising for future design and advanced control of the continuous granulation process. (C) 2016 Elsevier Ltd. All rights reserved....

  12. Durable solar mirror films

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, Mark B.; Henderson, Andrew J.; Hebrink, Timothy J.; Katare, Rajesh K.; Jing, Naiyong; North, Diane; Peterson, Eric M.

    2017-02-14

    The present disclosure generally relates to durable solar mirror films, methods of making durable solar mirror films, and constructions including durable solar mirror films. In one embodiment, the present disclosure relates to a solar mirror film comprising: a multilayer optical film layer including having a coefficient of hygroscopic expansion of less than about 30 ppm per percent relative humidity; and a reflective layer having a coefficient of hygroscopic expansion.

  13. Deformable mirrors development program at ESO

    Science.gov (United States)

    Stroebele, Stefan; Vernet, Elise; Brinkmann, Martin; Jakob, Gerd; Lilley, Paul; Casali, Mark; Madec, Pierre-Yves; Kasper, Markus

    2016-07-01

    Over the last decade, adaptive optics has become essential in different fields of research including medicine and industrial applications. With this new need, the market of deformable mirrors has expanded a lot allowing new technologies and actuation principles to be developed. Several E-ELT instruments have identified the need for post focal deformable mirrors but with the increasing size of the telescopes the requirements on the deformable mirrors become more demanding. A simple scaling up of existing technologies from few hundred actuators to thousands of actuators will not be sufficient to satisfy the future needs of ESO. To bridge the gap between available deformable mirrors and the future needs for the E-ELT, ESO started a development program for deformable mirror technologies. The requirements and the path to get the deformable mirrors for post focal adaptive optics systems for the E-ELT is presented.

  14. The Mirror Oscilloscpoe

    NARCIS (Netherlands)

    Goudriaan, B.

    2003-01-01

    This project is about designing and realizing an oscilloscope based on a laser beam reflected by two mirrors. The ¿Mirror Oscilloscope¿ uses two voice-coils actuators with mounted mirrors to reflect laser light, such that an image of a harmonic signal is projected on a projection screen. For trackin

  15. Double curvature mirrors for linear concentrators

    Science.gov (United States)

    Lance, Tamir; Ackler, Harold; Finot, Marc

    2012-10-01

    Skyline Solar's medium concentration photovoltaic system uses quasi-parabolic mirrors and one axis tracking. Improvements in levelized cost of energy can be achieved by effective management of non-uniformity of the flux line on the panels. To reduce non uniformity of the flux line due to mirror to mirror gaps, Skyline developed a dual curvature mirror that stretches the flux line along the panel. Extensive modeling and experiments have been conducted to analyze the impact of this new design and to optimize the design.

  16. Toward a large lightweight mirror for AO: development of a 1m Ni coated CFRP mirror

    Science.gov (United States)

    Thompson, S. J.; Doel, A. P.; Brooks, D.; Strangwood, M.

    2008-07-01

    We present our recent developments towards the construction of a large, thin, single-piece mirror for adaptive optics (AO). Our current research program aims to have completed fabrication and testing of a 1m diameter, nickel coated carbon-fibre reinforced cyanate ester resin mirror by the last quarter of 2009. This composite mirror material is being developed to provide a lightweight and robust alternative to thin glass shell mirrors, with the challenge of future large deformable mirrors such as the 2.5m M4 on the E-ELT in mind. A detailed analysis of the material properties of test mirror samples is being performed at the University of Birmingham (UK), the first results of which are discussed and presented here. We discuss the project progress achieved so far, including fabrication of the 1m flat moulds for the replication process, manufacturing and testing methods for 20 cm diameter sample mirrors and system simulations.

  17. Profile measurement of a bent neutron mirror using an ultrahigh precision non-contact measurement system with an auto focus laser probe

    Science.gov (United States)

    Morita, S.; Guo, J.; Yamada, N. L.; Torikai, N.; Takeda, S.; Furusaka, M.; Yamagata, Y.

    2016-07-01

    A bent neutron mirror has been considered as one of the best solutions for focusing neutron beams from the viewpoint of cost-benefit performance. Although the form deviation of the bent profile is expected because of the large spot size, it is difficult to measure due to its geometric limitation. Here, we propose a non-contact measurement system using an auto focus (AF) laser probe on an ultrahigh precision machine tool to precisely evaluate the form deviation of the bent mirror. The AF laser probe is composed of a diode laser, a position sensitive sensor, a charge-coupled device (CCD) camera and a microscope objective lens which is actuated by an electromagnetic motor with 1 nm resolution for position sensing and control. The sensor enables a non-contact profile measurement of a high precision surface without any surface damage in contrast with contact-type ultrahigh precision coordinate measurement machines with ruby styli. In the on-machine measurement system, a personal computer simultaneously acquires a displacement signal from the AF laser probe and 3-axis positional coordinates of the ultrahigh machine tool branched between the linear laser scales and the numerical controller. The acquisition rate of the 4-axis positional data in 1 nm resolution is more than 10 Hz and the simultaneity between the axes is negligible. The profile of a neutron bent mirror was measured from a transparent side using the developed system, and the result proves that the form deviation of the mirror enlarged the the spot size of focused neuron beam.

  18. Recurrence risk for offspring of twins discordant for oral cleft: a population-based cohort study of the Danish 1936-2004 cleft twin cohort

    DEFF Research Database (Denmark)

    Grosen, Dorthe; Bille, Camilla; Pedersen, Jacob Krabbe;

    2010-01-01

    Our objective in this Danish population-based cohort study was to estimate the recurrence risk of isolated oral cleft (OC) for offspring of the unaffected co-twins of OC discordant twin pairs and to compare this risk to the recurrence risk in the offspring of the affected co-twin as well...... as to the risk in the background population. During 1936-2004, 207 twin pairs were ascertained, among whom at least one twin had an OC. The index persons were twins discordant for OC who had children (N=117), and their offspring (N=239). The participants were ascertained by linkage between The Danish Facial...... Cleft Database, The Danish Twin Registry and The Danish Civil Registration System. In the study OC recurrence risk for offspring of the affected and unaffected twin and relative risk were compared to the background prevalence. We found that among 110 children of the 54 OC affected twins, two (1...

  19. Twin anemia polycythemia sequence

    NARCIS (Netherlands)

    Slaghekke, Femke

    2014-01-01

    In this thesis we describe that Twin Anemia Polycythemia Sequence (TAPS) is a form of chronic feto-fetal transfusion in monochorionic (identical) twins based on a small amount of blood transfusion through very small anastomoses. For the antenatal diagnosis of TAPS, Middle Cerebral Artery – Peak Syst

  20. The Danish Twin Registry

    DEFF Research Database (Denmark)

    Skytthe, Axel; Ohm Kyvik, Kirsten; Vilstrup Holm, Niels

    2011-01-01

    Introduction: The Danish Twin Registry is a unique source for studies of genetic, familial and environmental factors on life events, health conditions and diseases. Content: More than 85,000 twin pairs born 1870-2008 in Denmark. Validity and coverage: Four main ascertainment methods have been emp...

  1. Twin anemia polycythemia sequence

    NARCIS (Netherlands)

    Slaghekke, Femke

    2014-01-01

    In this thesis we describe that Twin Anemia Polycythemia Sequence (TAPS) is a form of chronic feto-fetal transfusion in monochorionic (identical) twins based on a small amount of blood transfusion through very small anastomoses. For the antenatal diagnosis of TAPS, Middle Cerebral Artery – Peak

  2. What do brain lesions tell us about theories of embodied semantics and the human mirror neuron system?

    Science.gov (United States)

    Arévalo, Analia L; Baldo, Juliana V; Dronkers, Nina F

    2012-02-01

    Recent work has been mixed with respect to the notion of embodied semantics, which suggests that processing linguistic stimuli referring to motor-related concepts recruits the same sensorimotor regions of cortex involved in the execution and observation of motor acts or the objects associated with those acts. In this study, we asked whether lesions to key sensorimotor regions would preferentially impact the comprehension of stimuli associated with the use of the hand, mouth or foot. Twenty-seven patients with left-hemisphere strokes and 10 age- and education-matched controls were presented with pictures and words representing objects and actions typically associated with the use of the hand, mouth, foot or no body part at all (i.e., neutral). Picture/sound pairs were presented simultaneously, and participants were required to press a space bar only when the item pairs matched (i.e., congruent trials). We conducted two different analyses: 1) we compared task performance of patients with and without lesions in several key areas previously implicated in the putative human mirror neuron system (i.e., Brodmann areas 4/6, 1/2/3, 21 and 44/45), and 2) we conducted Voxel-based Lesion-Symptom Mapping analyses (VLSM; Bates et al., 2003) to identify additional regions associated with the processing of effector-related versus neutral stimuli. Processing of effector-related stimuli was associated with several regions across the left hemisphere, and not solely with premotor/motor or somatosensory regions. We also did not find support for a somatotopically-organized distribution of effector-specific regions. We suggest that, rather than following the strict interpretation of homuncular somatotopy for embodied semantics, these findings support theories proposing the presence of a greater motor-language network which is associated with, but not restricted to, the network responsible for action execution and observation.

  3. Altered Cortical Thickness and Tract Integrity of the Mirror Neuron System and Associated Social Communication in Autism Spectrum Disorder.

    Science.gov (United States)

    Chien, Hsiang-Yun; Gau, Susan Shur-Fen; Hsu, Yung-Chin; Chen, Yu-Jen; Lo, Yu-Chun; Shih, Yao-Chia; Tseng, Wen-Yih Isaac

    2015-12-01

    Previous studies using neural activity recording and neuroimaging techniques have reported functional deficits in the mirror neuron system (MNS) for individuals with autism spectrum disorder (ASD). However, a few studies focusing on gray and white matter structures of the MNS have yielded inconsistent results. The current study recruited adolescents and young adults with ASD (aged 15-26 years) and age-matched typically developing (TD) controls (aged 14-25 years). The cortical thickness (CT) and microstructural integrity of the tracts connecting the regions forming the classical MNS were investigated. High-resolution T1-weighted imaging and diffusion spectrum imaging were performed to quantify the CT and tract integrity, respectively. The structural covariance of the CT of the MNS regions revealed a weaker coordination of the MNS network in ASD. A strong correlation was found between the integrity of the right frontoparietal tracts and the social communication subscores measured by the Chinese version of the Social Communication Questionnaire. The results showed that there were no significant mean differences in the CTs and tract integrity between the ASD and TD groups, but revealed a moderate or even reverse age effect on the frontal MNS structures in ASD. In conclusion, aberrant structural coordination may be an underlying factor affecting the function of the MNS in ASD patients. The association between the right frontoparietal tracts and social communication performance implies a neural correlate of communication processing in the autistic brain. This study provides evidence of abnormal MNS structures and their influence on social communication in individuals with ASD.

  4. Mirror System Activity for Action and Language Is Embedded in the Integration of Dorsal and Ventral Pathways

    Science.gov (United States)

    Arbib, Michael A.

    2010-01-01

    We develop the view that the involvement of mirror neurons in embodied experience grounds brain structures that underlie language, but that many other brain regions are involved. We stress the cooperation between the dorsal and ventral streams in praxis and language. Both have perceptual and motor schemas but the perceptual schemas in the dorsal…

  5. High-repetition-rate optical delay line using a micromirror array and galvanometer mirror for a terahertz system.

    Science.gov (United States)

    Kitahara, Hideaki; Tani, Masahiko; Hangyo, Masanori

    2009-07-01

    We developed a high-repetition-rate optical delay line based on a micromirror array and galvanometer mirror for terahertz time-domain spectroscopy. The micromirror array is fabricated by using the x-ray lithographic technology. The measurement of terahertz time-domain waveforms with the new optical delay line is demonstrated successfully up to 25 Hz.

  6. Principles And Design Of Multibeam Interference Devices: A Microelectromechanical-Systems Segment-Deformable-Mirror-Based Adaptive Spectrum Attenuator

    OpenAIRE

    Huang, Z.Y.; Zhu, Y. Z.; Wang, Anbo

    2005-01-01

    Fourier analysis of multibeam interference shows that the total electric field and relative time delay of the beams form a Fourier-transform pair. Fourier-analysis-based multibeam interference analysis and device design is discussed in detail. The principle of the proposed segment-deformable-mirror-based adaptive spectrum attenuator is illustrated. (c) 2005 Optical Society of America.

  7. Mirror System Activity for Action and Language Is Embedded in the Integration of Dorsal and Ventral Pathways

    Science.gov (United States)

    Arbib, Michael A.

    2010-01-01

    We develop the view that the involvement of mirror neurons in embodied experience grounds brain structures that underlie language, but that many other brain regions are involved. We stress the cooperation between the dorsal and ventral streams in praxis and language. Both have perceptual and motor schemas but the perceptual schemas in the dorsal…

  8. VLT beryllium secondary mirror no. 1: performance review

    Science.gov (United States)

    Cayrel, Marc

    1998-08-01

    The four Very Large Telescope secondary mirrors are 1.2-m Beryllium lightweight convex mirrors. REOSC has been selected for the design and manufacturing of the optics and of their supporting system. The first mirror unit has been delivered in September, 1997. Operating from visible to near infrared, the mirror defines the telescope aperture stop and may be chopped during observation. The optical requirements are tight and a high stiffness, low weight and inertia are requested as well. Using beryllium is a technical challenge for such a large optic manufacturing, in particular regarding its stability. The requirements and design are presented, we review the mirror manufacturing steps: blank production, machining, grinding, Nickel plating, polishing, integration and testing. The optical quality control method, a problem for large convex mirrors control, is detailed. The results of acceptance testing of mirror No. 1 are summarized, we present conclusions about the mirror figure stability. The status of the three additional mirrors manufacturing is presented to conclude.

  9. Where do mirror neurons come from?

    Science.gov (United States)

    Heyes, Cecilia

    2010-03-01

    Debates about the evolution of the 'mirror neuron system' imply that it is an adaptation for action understanding. Alternatively, mirror neurons may be a byproduct of associative learning. Here I argue that the adaptation and associative hypotheses both offer plausible accounts of the origin of mirror neurons, but the associative hypothesis has three advantages. First, it provides a straightforward, testable explanation for the differences between monkeys and humans that have led some researchers to question the existence of a mirror neuron system. Second, it is consistent with emerging evidence that mirror neurons contribute to a range of social cognitive functions, but do not play a dominant, specialised role in action understanding. Finally, the associative hypothesis is supported by recent data showing that, even in adulthood, the mirror neuron system can be transformed by sensorimotor learning. The associative account implies that mirror neurons come from sensorimotor experience, and that much of this experience is obtained through interaction with others. Therefore, if the associative account is correct, the mirror neuron system is a product, as well as a process, of social interaction. (c) 2009 Elsevier Ltd. All rights reserved.

  10. Unbroken Mirror Neurons in Autism Spectrum Disorders

    Science.gov (United States)

    Fan, Yang-Teng; Decety, Jean; Yang, Chia-Yen; Liu, Ji-Lin; Cheng, Yawei

    2010-01-01

    Background: The "broken mirror" theory of autism, which proposes that a dysfunction of the human mirror neuron system (MNS) is responsible for the core social and cognitive deficits in individuals with autism spectrum disorders (ASD), has received considerable attention despite weak empirical evidence. Methods: In this electroencephalographic…

  11. Unbroken Mirror Neurons in Autism Spectrum Disorders

    Science.gov (United States)

    Fan, Yang-Teng; Decety, Jean; Yang, Chia-Yen; Liu, Ji-Lin; Cheng, Yawei

    2010-01-01

    Background: The "broken mirror" theory of autism, which proposes that a dysfunction of the human mirror neuron system (MNS) is responsible for the core social and cognitive deficits in individuals with autism spectrum disorders (ASD), has received considerable attention despite weak empirical evidence. Methods: In this electroencephalographic…

  12. More questions for mirror neurons.

    Science.gov (United States)

    Borg, Emma

    2013-09-01

    The mirror neuron system is widely held to provide direct access to the motor goals of others. This paper critically investigates this idea, focusing on the so-called 'intentional worry'. I explore two answers to the intentional worry: first that the worry is premised on too limited an understanding of mirror neuron behaviour (Sections 2 and 3), second that the appeal made to mirror neurons can be refined in such a way as to avoid the worry (Section 4). I argue that the first response requires an account of the mechanism by which small-scale gestures are supposedly mapped to larger chains of actions but that none of the extant accounts of this mechanism are plausible. Section 4 then briefly examines refinements of the mirror neuron-mindreading hypothesis which avoid the intentional worry. I conclude that these refinements may well be plausible but that they undermine many of the claims standardly made for mirror neurons. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Well baffled two-mirror corrector for a parabola.

    Science.gov (United States)

    Shafer, D R

    1977-05-01

    The two-mirror Baker corrector for a parabolic telescope mirror is a well-known, very elegant design. In some variations, both corrector mirrors are spherical. The only thing marring the beauty of this solution to providing anastigmatic performance for large parabolic telescope mirrors is that the system is difficult to baffle. An alternate two-mirror corrector is presented here-based on a different design principle-that is easy to baffle. One of the two corrector mirrors is spherical, and there is a field stop to further aid in baffling. The penalty paid is that the signs.

  14. Metrology of IXO Mirror Segments

    Science.gov (United States)

    Chan, Kai-Wing

    2011-01-01

    For future x-ray astrophysics mission that demands optics with large throughput and excellent angular resolution, many telescope concepts build around assembling thin mirror segments in a Wolter I geometry, such as that originally proposed for the International X-ray Observatory. The arc-second resolution requirement posts unique challenges not just for fabrication, mounting but also for metrology of these mirror segments. In this paper, we shall discuss the metrology of these segments using normal incidence metrological method with interferometers and null lenses. We present results of the calibration of the metrology systems we are currently using, discuss their accuracy and address the precision in measuring near-cylindrical mirror segments and the stability of the measurements.

  15. Neonatal status of twins

    Directory of Open Access Journals (Sweden)

    Božinović Dragica

    2012-01-01

    Full Text Available Multiple pregnancy is a pregnancy where more than one fetus develops simultaneously in the womb, as a result of the ovulation and fertilization of more than one egg. It is relatively rare in humans and represents the rest of the phylogenetic stages. The most common are twins and they indicate the development of two fetuses in the womb. The frequency of twin pregnancies is about 1%. Multiple pregnancies belong to a group of high-risk pregnancies because of the many complications that occur during the pregnancy: higher number of premature deliveries, bleeding, early neonatal complications and higher perinatal morbidity and mortality. Such pregnancies and infants require greater supervision and monitoring. The aim of this study was to determine the percentage of baby twins born at the maternity ward of the General Hospital in Prokuplje and their morbidity and mortality. Data on the total number of deliveries, number of twins, parity and maternal age, gestational age, body weight of twins, method of delivery, Apgar score and perinatal mortality were collected and statistically analyzed by means of retrospective analysis of operative birth and neonatal protocol for 6 years (2005 of 2010. Out of 4527 mothers who gave birth 43 were pairs of twins, or 0.95% of women gave birth to twins. These babies are more likely born by Caesarean section, but delivered with slightly lower birth weight.

  16. Mirror neurons through the lens of epigenetics.

    Science.gov (United States)

    Ferrari, Pier F; Tramacere, Antonella; Simpson, Elizabeth A; Iriki, Atsushi

    2013-09-01

    The consensus view in mirror neuron research is that mirror neurons comprise a uniform, stable execution-observation matching system. In this opinion article, we argue that, in light of recent evidence, this is at best an incomplete and oversimplified view of mirror neurons, where activity is actually variable and more plastic than previously theorized. We propose an epigenetic account for understanding developmental changes in sensorimotor systems, including variations in mirror neuron activity. Although associative and genetic accounts fail to consider the complexity of genetic and nongenetic interactions, we propose a new evolutionary developmental biology (evo-devo) perspective, which predicts that environmental differences early in development should produce variations in mirror neuron response patterns, tuning them to the social environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Perinatal risk factors and neonatal complications in discordant twins admitted to the neonatal intensive care unit

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-rui; LIU Jie; ZENG Chao-mei

    2013-01-01

    Background Many studies have shown a relationship between birth weight discordance and adverse perinatal outcomes.This study aimed to investigate the perinatal risk factors and neonatal complications of discordant twins who are admitted to the neonatal intensive care unit.Methods A total of 87 sets of twins were enrolled in this retrospective study,of which 22 sets were discordant twins and 65 sets were concordant twins.Binary Logistic regression analysis was used to identify the risk factors associated with the occurrence of discordant twins.The common neonatal complications of discordant twins were also investigated.Results Multivariate analysis showed that the use of assisted reproductive techniques,pregnancy-induced hypertension,and unequal placental sharing were risk factors for the occurrence of discordant twins.The incidence of small for gestational age infants and very low birth weight infants of discordant twins was significantly higher,while the birth weight of discordant twins was significantly lower than those of concordant twins.The duration of hospitalization of discordant twins was longer than that of concordant twins.The incidence of several neonatal complications,such as neonatal respiratory distress syndrome and intracranial hemorrhage,was higher in discordant twins than that in concordant twins.The percentage of those requiring pulmonary surfactant and mechanical ventilation was significantly higher in discordant twins than that in concordant twins.Conclusions Use of assisted reproductive techniques,pregnancy-induced hypertension,and unequal placental sharing are perinatal risk factors of discordant twins who are admitted to the neonatal intensive care unit.These infants are also much more likely to suffer from various neonatal complications,especially respiratory and central nervous system diseases.It is important to prevent the occurrence of discordant twins by decreasing these risk factors and timely treatment should be given to discordant

  18. Laying the ghost of twin paradox

    Directory of Open Access Journals (Sweden)

    Popović Marko

    2009-01-01

    Full Text Available Someone's true age is not written in his ID, but in his biomarkers. Aging process is not caused by time passing, but by thermodynamically laws. Entropy, extent of metabolic reaction, and temperature are Lorentz invariant, so these facts make twin paradox impossible because there is no way for one twin to age slower than the other even if the time in his frame is dilated. Entropy is the function of state, not time. So as much as standard thermodynamics concerns, the path between two points in space is equivalent to the path between two states. Whether the point B is reached by moving faster using the longer way (with time dilatation, or slower by using shortcut (without time dilatation, the state of the system after completing the road should be the same. This is supported by the fact that when two twins reach the same space-time point (point B in which the state parameters are the same. If we use entropy as an age parameter, then both twins have the same entropy value and are exactly the same biological age. Therefore, the twin paradox is a logical mistake based on wrong first premise. Bergson symmetry is not necessary any more to explain the impossibility of twin paradox.

  19. Twin-twin Transfusion Syndrome with a Single Ectopic Kidney in a Twin Donor. Case Presentation

    Directory of Open Access Journals (Sweden)

    Gerardo Rogelio Robaina Castellanos

    2016-10-01

    Full Text Available Twin-twin Transfusion Syndrome presents more frequently in diamniotic monochromic twins. In advanced stages and without prenatal intervention, is associated to high rates of peri natal mortality and neurological sequel in the survivors. It is presented a case of a pair of twins with severe depression at birth in which it was diagnosed a Twin-twin Transfusion Syndrome, later confirmed with the presence of anemia in the donor twin and polycythemia in the receptor twin. Both twins had an unfavourable evolution with an early neonatal death. Necropsy findings were comparable with secondary damage to the syndrome, with the particularity that both had evidences of pulmonary infection and a renal malformation in the donor twin which is not included in the proper malformations of this syndrome. The objective of this work is to point out the essential elements for the diagnosis and antenatal treatment for this disease through the peculiarities of the presented case.

  20. Fullerton Virtual Twin Study.

    Science.gov (United States)

    Segal, Nancy L

    2006-12-01

    Virtual twins (VTs; same-age unrelated siblings reared together from early infancy) have been studied at California State University (CSU), Fullerton since 1991. The current sample includes over 130 pairs. Past and current research have research have focused on siblings' similarities and differences in general intelligence and body size. Future research in these areas will continue as new pairs continue to be identified. These studies will be supplemented by analyses of personality, social relations and adjustment using monozygotic (MZ) twins, dizygotic (DZ) twins, full siblings and friends, as well as new VTs, who have participated in Twins, Adoptees, Peers and Siblings (TAPS), a collaborative project conducted between CSU Fullerton and the University of San Francisco, from 2002 to 2006.

  1. A Case of Monozygotic Twins: The Value of Discordant Monozygotic Twins in Goldenhar Syndrome—OMIM%164210

    Directory of Open Access Journals (Sweden)

    K. N. Venkateshwara Prasad

    2013-01-01

    Full Text Available Goldenhar syndrome is a rare developmental disorder characterised by hemifacial microsomia, epibulbar tumours, ear malformation, and vertebral anomalies. As monozygotic (MZ twins are believed to be genetically identical, discordance for disease phenotype between MZ twins varies with craniofacial anomalies, cardiac, vertebral, and central nervous system defects sporadically. We report a case of monozygotic female twins discordant for Goldenhar syndrome with hemifacial microsomia and the dysplasia of auricular pinna.

  2. The Solar Twin Planet Search II. A Jupiter twin around a solar twin

    CERN Document Server

    Bedell, M; Bean, J L; Ramirez, I; Asplund, M; Alves-Brito, A; Casagrande, L; Dreizler, S; Monroe, T; Spina, L; Maia, M Tucci

    2015-01-01

    Through our HARPS radial velocity survey for planets around solar twin stars, we have identified a promising Jupiter twin candidate around the star HIP11915. We characterize this Keplerian signal and investigate its potential origins in stellar activity. Our analysis indicates that HIP11915 hosts a Jupiter-mass planet with a 3600-day orbital period and low eccentricity. Although we cannot definitively rule out an activity cycle interpretation, we find that a planet interpretation is more likely based on a joint analysis of RV and activity index data. The challenges of long-period radial velocity signals addressed in this paper are critical for the ongoing discovery of Jupiter-like exoplanets. If planetary in nature, the signal investigated here represents a very close analog to the solar system in terms of both Sun-like host star and Jupiter-like planet.

  3. [Study of intellectual activity in twins. I. Developmental features].

    Science.gov (United States)

    Kantonistova, N S

    1980-01-01

    The investigation of 234 twins and 100 singletons at the age from 7 till 16 years old was carried out by WISC method. The intellectual development of twins was established to fall behind singletons at the expense of lower level of verbal intellectual functions. It is due to organic changes of nervous system, arising as the result of the action of unfavourable factors during antenatal period. Slight asphyxia and prematurity as well as the order of birth do not exert essential effect on intellectual development of twins. Low weight at birth combines with lower intellectual index only in cases when lowering of weight is due to the action of unfavourable factors during intrauterine period. "Twins situation" apparently renders positive influence on twins intellectual activity during school are, distracting children's attention in cases of unfavourable psychological situation in family. Intellectual environment renders positive influence on intellectual development of twins.

  4. 78 FR 28012 - Tier One Environmental Impact Statement for the Rochester, Minnesota to Twin Cities, Minnesota...

    Science.gov (United States)

    2013-05-13

    ... Rochester and the Twin Cities area. The system is to connect the Twin Cities and Rochester providing... population in the urban area, making it an economic driver for an area of roughly 2,300 square miles in...

  5. Atomic-Level Understanding of "Asymmetric Twins" in Boron Carbide

    Science.gov (United States)

    Xie, Kelvin Y.; An, Qi; Toksoy, M. Fatih; McCauley, James W.; Haber, Richard A.; Goddard, William A.; Hemker, Kevin J.

    2015-10-01

    Recent observations of planar defects in boron carbide have been shown to deviate from perfect mirror symmetry and are referred to as "asymmetric twins." Here, we demonstrate that these asymmetric twins are really phase boundaries that form in stoichiometric B4C (i.e., B12C3 ) but not in B13C2 . TEM observations and ab initio simulations have been coupled to show that these planar defects result from an interplay of stoichiometry, atomic positioning, icosahedral twinning, and structural hierarchy. The composition of icosahedra in B4C is B11C and translation of the carbon atom from a polar to equatorial site leads to a shift in bonding and a slight distortion of the lattice. No such distortion is observed in boron-rich B13C2 because the icosahedra do not contain carbon. Implications for tailoring boron carbide with stoichiometry and extrapolations to other hierarchical crystalline materials are discussed.

  6. Atomic-Level Understanding of "Asymmetric Twins" in Boron Carbide.

    Science.gov (United States)

    Xie, Kelvin Y; An, Qi; Toksoy, M Fatih; McCauley, James W; Haber, Richard A; Goddard, William A; Hemker, Kevin J

    2015-10-23

    Recent observations of planar defects in boron carbide have been shown to deviate from perfect mirror symmetry and are referred to as "asymmetric twins." Here, we demonstrate that these asymmetric twins are really phase boundaries that form in stoichiometric B(4)C (i.e., B(12)C(3)) but not in B(13)C(2). TEM observations and ab initio simulations have been coupled to show that these planar defects result from an interplay of stoichiometry, atomic positioning, icosahedral twinning, and structural hierarchy. The composition of icosahedra in B(4)C is B(11)C and translation of the carbon atom from a polar to equatorial site leads to a shift in bonding and a slight distortion of the lattice. No such distortion is observed in boron-rich B(13)C(2) because the icosahedra do not contain carbon. Implications for tailoring boron carbide with stoichiometry and extrapolations to other hierarchical crystalline materials are discussed.

  7. Craniofacial anomalies in twins.

    Science.gov (United States)

    Keusch, C F; Mulliken, J B; Kaplan, L C

    1991-01-01

    Studies of twins provide insight into the relative contribution of genetic and environmental factors in the causality of structural anomalies. Thirty-five affected twin pairs were identified from a group of 1114 patients with congenital craniofacial deformities evaluated from 1972 to 1989. Forty-three of these 70 twins exhibited one or more craniofacial anomalies; these were analyzed for dysmorphic characteristics, zygosity, concordance, and family history. The anomalies were categorized into two groups: malformations and deformations. The malformations (n = 36) included hemifacial microsomia (n = 10), cleft lip and palate (n = 8), cleft palate (n = 4), rare facial cleft (n = 2), craniosynostosis (n = 2), Binder syndrome (n = 2), Treacher Collins syndrome (n = 2), craniopagus (n = 2), CHARGE association (n = 1), frontonasal dysplasia (n = 2), and constricted ears (n = 1). The deformations (n = 7) included plagiocephaly (n = 5), hemifacial hypoplasia (n = 1), and micrognathia (n = 1). Twenty-one monozygotic and 14 dizygotic twin pairs were identified. The concordance rate was 33 percent for monozygotic twins and 7 percent for dizygotic twins.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Final design of the LSST primary/tertiary mirror cell assembly

    Science.gov (United States)

    Neill, Douglas R.; Muller, Gary; Hileman, Ed; DeVries, Joe; Araujo, Constanza; Gressler, William J.; Lotz, Paul J.; Mills, Dave; Sebag, Jacques; Thomas, Sandrine; Warner, Mike; Wiecha, Oliver

    2016-07-01

    The Large Synoptic Survey Telescope (LSST) primary/tertiary (M1M3) mirror cell assembly supports both on-telescope operations and off-telescope mirror coating. This assembly consists of the cast borosilicate M1M3 monolith mirror, the mirror support systems, the thermal control system, a stray light baffle ring, a laser tracker interface and the supporting steel structure. During observing the M1M3 mirror is actively supported by pneumatic figure control actuators and positioned by a hexapod. When the active system is not operating the mirror is supported by a separate passive wire rope isolator system. The center of the mirror cell supports a laser tracker which measures the relative position of the camera and secondary mirror for alignment by their hexapods. The mirror cell structure height of 2 meters provides ample internal clearance for installation and maintenance of mirror support and thermal control systems. The mirror cell also functions as the bottom of the vacuum chamber during coating. The M1M3 mirror has been completed and is in storage. The mirror cell structure is presently under construction by CAID Industries. The figure control actuators, hexapod and thermal control system are under developed and will be integrated into the mirror cell assembly by LSST personnel. The entire integrated M1M3 mirror cell assembly will the tested at the Richard F Caris Mirror Lab in Tucson, AZ (formerly Steward Observatory Mirror Lab).

  9. Twin delivery: how should the second twin be delivered?

    Science.gov (United States)

    Olofsson, P; Rydhström, H

    1985-11-01

    In a series of 803 pairs of twins born between 1973 and 1982, 0.33% of second twins were delivered by cesarean section after vaginal delivery of the first twin. During the last year the frequency has increased to 7%, calling attention to the problem of declining obstetric skills and experience. This has caused us to update the routines of intrapartum management of twin gestations. In the present program only commonly available obstetric techniques are used. The potentially hazardous twin delivery is excluded from a trial of vaginal delivery. Hopefully, the program will help other obstetricians to decide in favor of vaginal delivery in selected twin gestations.

  10. Mirror neurons and their clinical relevance.

    Science.gov (United States)

    Rizzolatti, Giacomo; Fabbri-Destro, Maddalena; Cattaneo, Luigi

    2009-01-01

    One of the most exciting events in neurosciences over the past few years has been the discovery of a mechanism that unifies action perception and action execution. The essence of this 'mirror' mechanism is as follows: whenever individuals observe an action being done by someone else, a set of neurons that code for that action is activated in the observers' motor system. Since the observers are aware of the outcome of their motor acts, they also understand what the other individual is doing without the need for intermediate cognitive mediation. In this Review, after discussing the most pertinent data concerning the mirror mechanism, we examine the clinical relevance of this mechanism. We first discuss the relationship between mirror mechanism impairment and some core symptoms of autism. We then outline the theoretical principles of neurorehabilitation strategies based on the mirror mechanism. We conclude by examining the relationship between the mirror mechanism and some features of the environmental dependency syndromes.

  11. Mirror-image-induced magnetic modes.

    Science.gov (United States)

    Xifré-Pérez, Elisabet; Shi, Lei; Tuzer, Umut; Fenollosa, Roberto; Ramiro-Manzano, Fernando; Quidant, Romain; Meseguer, Francisco

    2013-01-22

    Reflection in a mirror changes the handedness of the real world, and right-handed objects turn left-handed and vice versa (M. Gardner, The Ambidextrous Universe, Penguin Books, 1964). Also, we learn from electromagnetism textbooks that a flat metallic mirror transforms an electric charge into a virtual opposite charge. Consequently, the mirror image of a magnet is another parallel virtual magnet as the mirror image changes both the charge sign and the curl handedness. Here we report the dramatic modification in the optical response of a silicon nanocavity induced by the interaction with its image through a flat metallic mirror. The system of real and virtual dipoles can be interpreted as an effective magnetic dipole responsible for a strong enhancement of the cavity scattering cross section.

  12. Moraxella catarrhalis uses a twin-arginine translocation system to secrete the β-lactamase BRO-2.

    Science.gov (United States)

    Balder, Rachel; Shaffer, Teresa L; Lafontaine, Eric R

    2013-06-19

    Moraxella catarrhalis is a human-specific gram-negative bacterium readily isolated from the respiratory tract of healthy individuals. The organism also causes significant health problems, including 15-20% of otitis media cases in children and ~10% of respiratory infections in adults with chronic obstructive pulmonary disease. The lack of an efficacious vaccine, the rapid emergence of antibiotic resistance in clinical isolates, and high carriage rates reported in children are cause for concern. Virtually all Moraxella catarrhalis isolates are resistant to β-lactam antibiotics, which are generally the first antibiotics prescribed to treat otitis media in children. The enzymes responsible for this resistance, BRO-1 and BRO-2, are lipoproteins and the mechanism by which they are secreted to the periplasm of M. catarrhalis cells has not been described. Comparative genomic analyses identified M. catarrhalis gene products resembling the TatA, TatB, and TatC proteins of the well-characterized Twin Arginine Translocation (TAT) secretory apparatus. Mutations in the M. catarrhalis tatA, tatB and tatC genes revealed that the proteins are necessary for optimal growth and resistance to β-lactams. Site-directed mutagenesis was used to replace highly-conserved twin arginine residues in the predicted signal sequence of M. catarrhalis strain O35E BRO-2, which abolished resistance to the β-lactam antibiotic carbanecillin. Moraxella catarrhalis possesses a TAT secretory apparatus, which plays a key role in growth of the organism and is necessary for secretion of BRO-2 into the periplasm where the enzyme can protect the peptidoglycan cell wall from the antimicrobial activity of β-lactam antibiotics.

  13. Lightweight ZERODUR: Validation of Mirror Performance and Mirror Modeling Predictions

    Science.gov (United States)

    Hull, Tony; Stahl, H. Philip; Westerhoff, Thomas; Valente, Martin; Brooks, Thomas; Eng, Ron

    2017-01-01

    Upcoming spaceborne missions, both moderate and large in scale, require extreme dimensional stability while relying both upon established lightweight mirror materials, and also upon accurate modeling methods to predict performance under varying boundary conditions. We describe tests, recently performed at NASA's XRCF chambers and laboratories in Huntsville Alabama, during which a 1.2 m diameter, f/1.2988% lightweighted SCHOTT lightweighted ZERODUR(TradeMark) mirror was tested for thermal stability under static loads in steps down to 230K. Test results are compared to model predictions, based upon recently published data on ZERODUR(TradeMark). In addition to monitoring the mirror surface for thermal perturbations in XRCF Thermal Vacuum tests, static load gravity deformations have been measured and compared to model predictions. Also the Modal Response(dynamic disturbance) was measured and compared to model. We will discuss the fabrication approach and optomechanical design of the ZERODUR(TradeMark) mirror substrate by SCHOTT, its optical preparation for test by Arizona Optical Systems (AOS). Summarize the outcome of NASA's XRCF tests and model validations

  14. Close-loop performance of a high precision deflectometry controlled deformable mirror (DCDM) unit for wavefront correction in adaptive optics system

    Science.gov (United States)

    Huang, Lei; Zhou, Chenlu; Zhao, Wenchuan; Choi, Heejoo; Graves, Logan; Kim, Daewook

    2017-06-01

    We present a high precision deflectometry system (DS) controlled deformable mirror (DM) solution for optical system. Different from wavefront and non-wavefront system, the DS and the DM are set to be an individual integrated DCDM unit and can be installed in one base plate. In the DCDM unit, the DS can directly provide the influence functions and surface shape of the DM to the industrial computer in any adaptive optics system. As an integrated adaptive unit, the DCDM unit could be put into various optical systems to realize aberration compensation. In this paper, the configuration and principle of the DCDM unit is introduced first. Theoretical simulation on the close-loop performance of the DCDM unit is carried out. Finally, a verification experiment is proposed to verify the compensation capability of the DCDM unit.

  15. The Glass is Half Full and Half Empty: A population-representative twin study testing if Optimism and Pessimism are distinct systems

    Science.gov (United States)

    Bates, Timothy C.

    2015-01-01

    Optimism and pessimism are associated with important outcomes including health and depression. Yet it is unclear if these apparent polar opposites form a single dimension or reflect two distinct systems. The extent to which personality accounts for differences in optimism/pessimism is also controversial. Here, we addressed these questions in a genetically informative sample of 852 pairs of twins. Distinct genetic influences on optimism and pessimism were found. Significant family-level environment effects also emerged, accounting for much of the negative relationship between optimism and pessimism, as well as a link to neuroticism. A general positive genetics factor exerted significant links among both personality and life-orientation traits. Both optimism bias and pessimism also showed genetic variance distinct from all effects of personality, and from each other. PMID:26561494

  16. Mirror neurons: functions, mechanisms and models.

    Science.gov (United States)

    Oztop, Erhan; Kawato, Mitsuo; Arbib, Michael A

    2013-04-12

    Mirror neurons for manipulation fire both when the animal manipulates an object in a specific way and when it sees another animal (or the experimenter) perform an action that is more or less similar. Such neurons were originally found in macaque monkeys, in the ventral premotor cortex, area F5 and later also in the inferior parietal lobule. Recent neuroimaging data indicate that the adult human brain is endowed with a "mirror neuron system," putatively containing mirror neurons and other neurons, for matching the observation and execution of actions. Mirror neurons may serve action recognition in monkeys as well as humans, whereas their putative role in imitation and language may be realized in human but not in monkey. This article shows the important role of computational models in providing sufficient and causal explanations for the observed phenomena involving mirror systems and the learning processes which form them, and underlines the need for additional circuitry to lift up the monkey mirror neuron circuit to sustain the posited cognitive functions attributed to the human mirror neuron system. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. The mirror box

    Science.gov (United States)

    Thompson, Gene; Mathieson, Don

    2001-11-01

    The mirror box is an old standby in magic shows and an impressive demonstration of the law of reflection for the physics instructor. The box creates the illusion of an object floating in space by the use of a plane mirror.

  18. Advanced Mirror Technology Development

    Science.gov (United States)

    Stahl, H. Philip

    2017-01-01

    The Advanced Mirror Technology Development (AMTD) project matures critical technologies required to enable ultra-stable 4-m-or-larger monolithic or segmented ultraviolet, optical, and infrared (UVOIR) space telescope primary-mirror assemblies for general astrophysics and ultra-high-contrast observations of exoplanets.

  19. Driver ASICs for Advanced Deformable Mirrors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The program leverages on our extensive expertise in developing high-performance driver ASICs for deformable mirror systems and seeks to expand the capacities of the...

  20. High Resolution Silicon Deformable Mirrors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal describes a plan to build a prototype small stroke, high precision deformable mirror suitable for space-based operation in systems for high-resolution...

  1. High Resolution Silicon Deformable Mirrors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal we describe a plan to build a deformable mirror suitable for space-based operation in systems for high-resolution imaging. The prototype DM will be...

  2. Thermo-optically driven adaptive mirror

    Science.gov (United States)

    Reinert, Felix; Lüthy, Willy

    2006-02-01

    The ideal adaptive optical mirror combines large aperture with high spatial and temporal resolution and a phase shift of at least 2π. Further, a simple low-cost solution is preferred. No adaptive system can perfectly fulfill all these requirements. We present a system that has the potential to reach this goal with the exception of high temporal resolution. But even with a moderate temporal resolution of one second such a system can find practical applications. For example as a laser resonator mirror that allows to modify the intensity distribution of the emission, or to correct slowly varying aberrations of optical systems. Two possible mechanisms can be used to change the optical path length of the adaptive mirror: thermal expansion of the mirror substrate or the thermally induced change of the refractive index (thermal dispersion) of a medium in front of the mirror. Both mechanisms have been shown to lead to promising results. In both cases heating was performed by irradiation of light in the active medium. The thermal dispersion based adaptive mirror is built with a thin layer of a liquid in front of a mirror. To allow a modification of the refractive index by irradiation with a diode laser at 808 nm, a suitable absorber is dissolved in the water. With chopped irradiation a resolution of 3.8 Hz at 30 % contrast is measured. This mirror has been used in a laser resonator to modify the output distribution of the laser. The thermal expansion based adaptive mirror is built with a thin layer of a silicon elastomer with a gold coated front side. We present a preparation method to produce thin films of Sylgard on sapphire. With an irradiated intensity of only 370 mW/cm2 surface modulations of up to 350 nm are obtained. With a test pattern a resolution of 1.6 line-pairs per millimeter at 30 % contrast is measured. The temporal resolution is better than one second.

  3. Needle twins and right-angled twins in minerals: comparison between experiment and theory

    Science.gov (United States)

    Salje, E.K.H.; Buckley, A.; Van Tendeloo, G.; Ishibashi, Y.; Nord, G.L.

    1998-01-01

    Transformation twinning in minerals forms isolated twin walls, intesecting walls with corner junctions, and wedge-shaped twins as elements of hierarchical patterns. When cut perpendicular to the twin walls, the twins have characteristic shapes, right-angled and needle-shaped wall traces, which can be observed by transmission electron microscopy or by optical microscopy. Theoretical geometries of wall shapes recently derived for strain-related systems should hold for most displacive and order-disorder type phase transitions: 1) right-angled twins show curved junctions; 2) needle-shaped twins contain flat wall segments near the needle tip if the elastic behaviour of the mineral is dominated by its anisotroyp; 3) additional bending forces and pinning effects lead to curved walls near the junction that make the needle tip appear more blunt. Bent right-angled twins were analyzed in Gd2(MoO4)3. Linear needle tips were found in WO3, [N(CH3)4]2.ZnBr4 CrAl, BiVO4, GdBa2Cu3O7, and PbZrO. Parabolic tips occur in K2Ba(NO2)4, and GeTe whereas exponential curvatures appear in BaTiO3, KSCN, Pb3(PO4)2, CaTiO3, alkali feldspars, YBa2Cu3O7, and MnAl. The size and shape of the twin microstructure relates to its formation during the phase transition and the subsequent annealing history. The mobility of the twin walls after formation depends not only on the thermal activation but also on the structure of the wall, which may be pinned to impurities on a favorable structural site. Depinnign energies are often large compared with thermal energies for diffusion. This leads to kinetic time scales for twin coarsening that are comparable to geological time scales. Therefore, transformation twins that exhibit needle domains not only indicate that the mineral underwent a structural phase transition but also contain information about its subsequent geological history.

  4. Design and finite element analysis of lightmass silicon carbide primary mirror

    Institute of Scientific and Technical Information of China (English)

    HAN Yuan-yuan; ZHANG Yu-min; HAN Jie-cai; ZHANG Jian-han; YAO Wang; ZHOU Yu-feng

    2006-01-01

    Primary mirror is one of the key components in the space remote sensing system. To minimize the mass of the mirror without compromising its stiffness and decrease the deformation of the mirror surface at the different temperatures are the mainly two objects in the development of the primary mirror. Silicon carbide (SiC),the most promising optical material,was used as the material of the primary mirror with triangle lightmass structure in a Cassegrain system. By using finite element method,the properties of the SiC mirror were compared with that of the traditional Be mirror and fused silica mirror. The results of static,dynamic and thermo-mechanical analysis indicate that the deformation of the mirror surface caused by temperature field is much bigger than that caused by gravity field. The SiC mirror has the best overall properties,and the SiC material is much suitable for the primary mirror.

  5. Mirror neurons: from origin to function.

    Science.gov (United States)

    Cook, Richard; Bird, Geoffrey; Catmur, Caroline; Press, Clare; Heyes, Cecilia

    2014-04-01

    This article argues that mirror neurons originate in sensorimotor associative learning and therefore a new approach is needed to investigate their functions. Mirror neurons were discovered about 20 years ago in the monkey brain, and there is now evidence that they are also present in the human brain. The intriguing feature of many mirror neurons is that they fire not only when the animal is performing an action, such as grasping an object using a power grip, but also when the animal passively observes a similar action performed by another agent. It is widely believed that mirror neurons are a genetic adaptation for action understanding; that they were designed by evolution to fulfill a specific socio-cognitive function. In contrast, we argue that mirror neurons are forged by domain-general processes of associative learning in the course of individual development, and, although they may have psychological functions, they do not necessarily have a specific evolutionary purpose or adaptive function. The evidence supporting this view shows that (1) mirror neurons do not consistently encode action "goals"; (2) the contingency- and context-sensitive nature of associative learning explains the full range of mirror neuron properties; (3) human infants receive enough sensorimotor experience to support associative learning of mirror neurons ("wealth of the stimulus"); and (4) mirror neurons can be changed in radical ways by sensorimotor training. The associative account implies that reliable information about the function of mirror neurons can be obtained only by research based on developmental history, system-level theory, and careful experimentation.

  6. Large thin adaptive x-ray mirrors

    Science.gov (United States)

    Doel, Peter; Atkins, Carolyn; Thompson, Samantha; Brooks, David; Yao, Jun; Feldman, Charlotte; Willingale, Richard; Button, Tim; Zhang, Dou; James, Ady

    2007-09-01

    This paper describes the progress made in a proof of concept study and recent results of a research program into large active x-ray mirrors that is part of the UK Smart X-ray Optics project. The ultimate aim is to apply the techniques of active/adaptive optics to the next generation of nested shell astronomical X-ray space telescopes. A variety of deformable mirror technologies are currently available, the most promising of which for active X-ray mirrors are probably unimorph and bimorph piezoelectric mirrors. In this type of mirror one or more sheets of piezoelectric material are bonded to or coated with a passive reflective layer. On the back or between the piezoceramic layer/layers are series of electrodes. Application of an electric field causes the piezoelectric material to undergo local deformation thus changing the mirror shape. Starting in 2005 a proof of concept active mirror research program has been undertaken. This work included modelling and development of actively controlled thin shell mirrors. Finite element models of piezo-electric actuated mirrors have been developed and verified against experimental test systems. This has included the modelling and test of piezo-electric hexagonal unimorph segments. Various actuator types and low shrinkage conductive bonding methods have been investigated and laboratory tests of the use of piezo-electric actuators to adjust the form of an XMM-Newton space telescope engineering model mirror shell have been conducted and show that movement of the optics at the required level is achievable. Promising technological approaches have been identified including moulded piezo-ceramics and piezo-electrics fibre bundles.

  7. Action observation: Inferring intentions without mirror neurons

    DEFF Research Database (Denmark)

    Frith, Christopher; Kilner, James M

    2008-01-01

    A recent study has shown, using fMRI, that the mirror neuron system does not mediate action understanding when the observed action is novel or when it is hard to understand.......A recent study has shown, using fMRI, that the mirror neuron system does not mediate action understanding when the observed action is novel or when it is hard to understand....

  8. 光电系统中铍反射镜的发展与应用%Development and application of beryllium mirrors in optical systems

    Institute of Scientific and Technical Information of China (English)

    石磊; 许永森; 刘福贺

    2014-01-01

    The material properties and processing method of beryllium mirrors are reviewed and their applica -tions and development are also proposed .Firstly, the material properties of beryllium mirrors widely used in present and the current state-of-the-art of mirror substrate production , machining , grinding , nickel plating , polishing are introduced .Then , the latest application of the beryllium and beryllium-aluminum in the JWST ( the James Webb Space Telescope ) and the F-9120 high altitude dual band ( EO/IR) tactical reconnaissance sensor are given .Finally , the future developments and application of beryllium and beryllium-aluminum for optical systems are discussed .%综述了光电系统中铍反射镜常用材料的特性、加工方法、发展现状及最新应用。首先,介绍了目前国外铍反射镜常用材料的性能,铍反射镜基底制备、机械加工和光学加工等方面的发展现状。然后,以詹姆斯韦伯太空望远镜和F-9120航空远距离可见/红外双波段侦察相机为例,重点介绍了铍以及铍铝合金在空间和航空光电系统的反射镜及光机支撑结构上的最新应用。最后,对铍和铍铝合金在光电系统中的未来发展和应用前景提出了展望。

  9. The Texas Twin Project.

    Science.gov (United States)

    Harden, K Paige; Tucker-Drob, Elliot M; Tackett, Jennifer L

    2013-02-01

    Socioeconomic position, racial/ethnic minority status, and other characteristics of the macro-environment may be important moderators of genetic influence on a wide array of psychosocial outcomes. Designed to maximize representation of low socioeconomic status families and racial/ethnic minorities, the Texas Twin Project is an ongoing study of school-age twins (preschool through 12th grade) enrolled in public schools in the Austin, Texas and Houston, Texas metropolitan areas. School rosters are used to identify twin families from a target population with sizable populations of African American (18%), Hispanic/Latino (48%), and non-Hispanic White (27%) children and adolescents, over half of whom meet US guidelines for classification as economically disadvantaged. Initial efforts have focused on a large-scale, family-based survey study involving both parent and child reports of personality, psychopathology, physical health, academic interests, parent-child relationships, and aspects of the home environment. In addition, the Texas Twin Project is the basis for an in-laboratory study of adolescent decision-making, delinquency, and substance use. Future directions include geographic expansion of the sample to the entire state of Texas (with a population of over 25 million) and genotyping of participating twins.

  10. Hypoalbuminemia in Donors with Twin-Twin Transfusion Syndrome

    NARCIS (Netherlands)

    Verbeek, L.; Middeldorp, J. M.; Hulzebos, C. V.; Oepkes, D.; Walther, F. J.; Lopriore, E.

    2013-01-01

    Objective: To estimate the differences in albumin levels between donors and recipients with twin-twin transfusion syndrome (TTTS). Methods: We performed a matched case-control study including twin pairs with TTTS treated conservatively (conservative group) or with fetoscopic laser surgery (laser gro

  11. Twin studies in auto-immune disease.

    Science.gov (United States)

    Leslie, R D; Hawa, M

    1994-01-01

    Immune-mediated diseases affect up to 5% of the population and are a major cause of morbidity and mortality. These diseases can be organ specific, such as insulin-dependent diabetes (IDDM) and non-organ specific, such as Rheumatoid Arthritis (RA). Identical and non-identical twins have been used to establish whether these diseases are determined by genetic or environmental factors. The results of these studies have been collated in a new section of the Mendel Institute in Rome. Diseases included in these studies included IDDM, RA, Systemic Lupus Erythematosus (SLE), Multiple Sclerosis (MS) and Myasthenia. Striking differences in concordance rates between identical and non-identical twins in all these studies suggest that genetic factors are important in causing these diseases. All the diseases are known to be associated with HLA genes on chromosome 6 which may account for some or all of the genetic susceptibility. However, in the majority of pairs the affected twin has an unaffected co-twin. These observations suggest that non-genetically determined factors, probably environmental factors and not somatic mutations, are critical. The study of unaffected co-twins, who are at high disease-risk, has allowed the identification of changes which precede and predict the clinical disease. The immune-mediated destruction in many of these diseases is probably caused by T-lymphocytes. Twin studies have shown the importance of genetic factors in determining T-cell responses. Identical twins should, therefore, provide the perfect test bed to assess the role of T-cells in immune-mediated diseases.

  12. Validation of Quench Simulation and Simulation of the TWIN Solenoid

    CERN Document Server

    Pots, Rosalinde Hendrika

    2015-01-01

    For the Future Circular Collider at CERN a multi-purpose detector is proposed. The 6T TWIN Solenoid, a very large magnet system with a stored energy of 53 GJ, is being designed. It is important to protect the magnet against quenches in the system. Therefore several existing quench protection systems are evaluated and simulations have be performed on quenches in the TWIN Solenoid. The simulations on quenches in the TWIN Solenoid have been performed with promising results; the hotspot temperatures do not exceed 120 K and layer to layer voltages stay below 500 V. Adding quench heaters to the system might improve the quench protection system further.

  13. TwinFocus, a concentrated photovoltaic module based on mature technologies

    Directory of Open Access Journals (Sweden)

    Antonini Piergiorgio

    2014-01-01

    Full Text Available Among solar power generation, concentrated photovoltaics (CPV based on multijunction (MJ solar cells, is one of the most promising technology for hot climates. The fact that multijunction solar cells based on direct band gap semiconductors demonstrate lower dependence on temperature than silicon solar cells boosted their use in concentrated photovoltaics modules. Departing from the mainstream design of Fresnel lenses, the CPV module based on TwinFocus design with off-axis quasi parabolic mirrors differentiates itself for its compactness and the possibility of easy integration also in roof-top applications. A detailed description of the module and of the systems will be given together with measured performances, and expectations for the next release.

  14. Thermo-mechanical analysis of ITER first mirrors and its use for the ITER equatorial visible∕infrared wide angle viewing system optical design.

    Science.gov (United States)

    Joanny, M; Salasca, S; Dapena, M; Cantone, B; Travère, J M; Thellier, C; Fermé, J J; Marot, L; Buravand, O; Perrollaz, G; Zeile, C

    2012-10-01

    ITER first mirrors (FMs), as the first components of most ITER optical diagnostics, will be exposed to high plasma radiation flux and neutron load. To reduce the FMs heating and optical surface deformation induced during ITER operation, the use of relevant materials and cooling system are foreseen. The calculations led on different materials and FMs designs and geometries (100 mm and 200 mm) show that the use of CuCrZr and TZM, and a complex integrated cooling system can limit efficiently the FMs heating and reduce their optical surface deformation under plasma radiation flux and neutron load. These investigations were used to evaluate, for the ITER equatorial port visible∕infrared wide angle viewing system, the impact of the FMs properties change during operation on the instrument main optical performances. The results obtained are presented and discussed.

  15. Elevation scanning laser/multi-sensor hazard detection system controller and mirror/mast speed control components. [roving vehicle electromechanical devices

    Science.gov (United States)

    Craig, J.; Yerazunis, S. W.

    1978-01-01

    The electro-mechanical and electronic systems involved with pointing a laser beam from a roving vehicle along a desired vector are described. A rotating 8 sided mirror, driven by a phase-locked dc motor servo system, and monitored by a precision optical shaft encoder is used. This upper assembly is then rotated about an orthogonal axis to allow scanning into all 360 deg around the vehicle. This axis is also driven by a phase locked dc motor servo-system, and monitored with an optical shaft encoder. The electronics are realized in standard TTL integrated circuits with UV-erasable proms used to store desired coordinates of laser fire. Related topics such as the interface to the existing test vehicle are discussed.

  16. Dialysis for twins

    DEFF Research Database (Denmark)

    Gramkow, Ann-Maria; Aarup, Michael; Andersen, L. L. T.

    2014-01-01

    A 32-year-old woman with known stage-4 chronic kidney disease due to lupus nephritis presented with twin pregnancy after in vitro fertilization at a gestational age of 24 weeks + 3 days because of imminent preterm labour. Repeated ultrasound evaluations confirmed intrauterine growth restriction...... in both twins and polyhydramnios as the cause of imminent preterm labour. After initiation of haemodialysis treatment, ultrasound evaluation showed a significant decrease in amniotic fluids, and also reduction in blood urea nitrogen and in clinical complaints could be observed. At a gestational age of 28...... weeks + 4 days, delivery was performed by Caesarean section. This case study shows that effective treatment of elevated uraemic toxins significantly reduced the morbidity risks of the twins....

  17. The Danish Twin Registry

    DEFF Research Database (Denmark)

    Skytthe, Axel; Christiansen, Lene; Kyvik, Kirsten Ohm;

    2013-01-01

    decade of combining questionnaire and survey data with national demographic, social, and health registers in Statistics Denmark. Second, we describe our most recent data collection effort, which was conducted during the period 2008-2011 and included both in-person assessments of 14,000+ twins born 1931......Over the last 60 years, the resources and the research in the Danish Twin Registry (DTR) have periodically been summarized. Here, we give a short overview of the DTR and a more comprehensive description of new developments in the twenty-first century. First, we outline our experience over the last......-1969 and sampling of biological material, hereby expanding and consolidating the DTR biobank. Third, two examples of intensively studied twin cohorts are given. The new developments in the DTR in the last decade have facilitated the ongoing research and laid the groundwork for new research directions....

  18. New method for characterizing electron mediators in microbial systems using a thin-layer twin-working electrode cell.

    Science.gov (United States)

    Hassan, Md Mahamudul; Cheng, Ka Yu; Ho, Goen; Cord-Ruwisch, Ralf

    2017-01-15

    Microbial biofilms are significant ecosystems where the existence of redox gradients drive electron transfer often via soluble electron mediators. This study describes the use of two interfacing working electrodes (WEs) to simulate redox gradients within close proximity (250µm) for the detection and quantification of electron mediators. By using a common counter and reference electrode, the potentials of the two WEs were independently controlled to maintain a suitable "voltage window", which enabled simultaneous oxidation and reduction of electron mediators as evidenced by the concurrent anodic and cathodic currents, respectively. To validate the method, the electrochemical properties of different mediators (hexacyanoferrate, HCF, riboflavin, RF) were characterized by stepwise shifting the "voltage window" (ranging between 25 and 200mV) within a range of potentials after steady equilibrium current of both WEs was established. The resulting differences in electrical currents between the two WEs were recorded across a defined potential spectrum (between -1V and +0.5V vs. Ag/AgCl). Results indicated that the technique enabled identification (by the distinct peak locations at the potential scale) and quantification (by the peak of current) of the mediators for individual species as well as in an aqueous mixture. It enabled a precise determination of mid-potentials of the externally added mediators (HCF, RF) and mediators produced by pyocyanin-producing Pseudomonas aeruginosa (WACC 91) culture. The twin working electrode described is particularly suitable for studying mediator-dependent microbial electron transfer processes or simulating redox gradients as they exist in microbial biofilms.

  19. Fine alignment of a large segmented mirror

    Science.gov (United States)

    Dey, Thomas William (Inventor)

    2010-01-01

    A system for aligning a segmented mirror includes a source of radiation directed along a first axis to the segmented mirror and a beamsplitter removably inserted along the first axis for redirecting radiation from the first axis to a second axis, substantially perpendicular to the first axis. An imaging array is positioned along the second axis for imaging the redirected radiation, and a knife-edge configured for cutting the redirected radiation is serially positioned to occlude and not occlude the redirected radiation, effectively providing a variable radiation pattern detected by the imaging array for aligning the segmented mirror.

  20. Maternal nutrition in twin pregnancy.

    Science.gov (United States)

    Campbell, D M; MacGillivray, I; Tuttle, S

    1982-01-01

    Energy and protein intake as measured by 24-hour urinary nitrogen values are similar in twin and singleton pregnancies. The relationship between urinary nitrogen and nitrogen intake is equally significant in twin and singleton pregnancies. Dietary zinc, copper, and iron are not different in women with twins, nor are the levels of these elements in plasma. These observations are surprising in view of the extra fetal demands on the mother and the different adaptation of twin pregnancies.

  1. Relativistic twins or sextuplets?

    CERN Document Server

    Sheldon, E S

    2003-01-01

    A recent study of the relativistic twin 'paradox' by Soni in this journal affirmed that 'A simple solution of the twin paradox also shows anomalous behaviour of rigidly connected distant clocks' but entailed a pedagogic hurdle which the present treatment aims to surmount. Two scenarios are presented: the first 'flight-plan' is akin to that depicted by Soni, with constant-velocity segments, while the second portrays an alternative mission undertaken with sustained acceleration and deceleration, illustrated quantitatively for a two-way spacecraft flight from Earth to Polaris (465.9 light years distant) and back.

  2. Imaging of conjoined twins

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kieran [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); Kiely, Edward M.; Spitz, Lewis [Great Ormond Street Hospital for Children, Department of Surgery, London (United Kingdom)

    2006-09-15

    The incidence of conjoined twins is estimated to be around 1 in 250,000 live births. There is a distinct female predominance. In this paper the imaging of conjoined twins both antenatally and postnatally is reviewed, in particular taking into consideration recent advances with multidetector CT. Accurate counselling of parents regarding the likely outcome of the pregnancy and the likelihood of successful separation is dependent on good prenatal imaging with ultrasound and MRI. Planning of postnatal surgical separation is aided by accurate preoperative imaging which, depending on the conjoined area, will encompass many imaging modalities, but often relies heavily on CT scanning. (orig.)

  3. The Twin Interdisciplinary Neuroticism Study

    NARCIS (Netherlands)

    Riese, Harriette; Rijsdijk, Fruehling V.; Snieder, Harold; Ormel, Johan

    The Twin Interdisciplinary Neuroticism Study (TWINS) is a three-wave study including >800 twin pairs from the northern part of the Netherlands. The aim of the study is to unravel why neuroticism reflects vulnerability to mental disorders. In this study, we focus on possible mechanisms underlying

  4. Numerical study on mirror of high power laser with heatpipe cooling

    Science.gov (United States)

    Chen, Jiayuan, II; Zhu, Haihong; Cheng, Zuhai

    2008-12-01

    Mirror surface of high power laser would be deformed by the pressure of the coolant in a liquid cooling mirror system. In order to eliminate the impact of pressure and vibration of cooling water to the stability of the output beam, a cooling mirror with heatpipe is designed. With the same structure and conditions, solid mirror, water cooling mirror and heat pipe cooling mirror are simulated by ANSYS program. The time-varying thermal deformations of the group mirrors after 60s under the net heat absorption of 12W/cm2 are obtained. The maximal peak and valley difference value of mirror surface deformation of solid mirror along Z-axis, water cooling mirror and heat pipe cooling mirror after 60s is 1.33μm, 0.845 μm and 0.1094 μm respectively.

  5. Mesmerising mirror neurons.

    Science.gov (United States)

    Heyes, Cecilia

    2010-06-01

    Mirror neurons have been hailed as the key to understanding social cognition. I argue that three currents of thought-relating to evolution, atomism and telepathy-have magnified the perceived importance of mirror neurons. When they are understood to be a product of associative learning, rather than an adaptation for social cognition, mirror neurons are no longer mesmerising, but they continue to raise important questions about both the psychology of science and the neural bases of social cognition. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Laser cleaning of ITER's diagnostic mirrors

    Science.gov (United States)

    Skinner, C. H.; Gentile, C. A.; Doerner, R.

    2012-10-01

    Practical methods to clean ITER's diagnostic mirrors and restore reflectivity will be critical to ITER's plasma operations. We report on laser cleaning of single crystal molybdenum mirrors coated with either carbon or beryllium films 150 - 420 nm thick. A 1.06 μm Nd laser system provided 220 ns pulses at 8 kHz with typical power densities of 1-2 J/cm^2. The laser beam was fiber optically coupled to a scanner suitable for tokamak applications. The efficacy of mirror cleaning was assessed with a new technique that combines microscopic imaging and reflectivity measurements [1]. The method is suitable for hazardous materials such as beryllium as the mirrors remain sealed in a vacuum chamber. Excellent restoration of reflectivity for the carbon coated Mo mirrors was observed after laser scanning under vacuum conditions. For the beryllium coated mirrors restoration of reflectivity has so far been incomplete and modeling indicates that a shorter duration laser pulse is needed. No damage of the molybdenum mirror substrates was observed.[4pt][1] C.H. Skinner et al., Rev. Sci. Instrum. at press.

  7. Multilayer active shell mirrors for space telescopes

    Science.gov (United States)

    Steeves, John; Jackson, Kathryn; Pellegrino, Sergio; Redding, David; Wallace, J. Kent; Bradford, Samuel Case; Barbee, Troy

    2016-07-01

    A novel active mirror technology based on carbon fiber reinforced polymer (CFRP) substrates and replication techniques has been developed. Multiple additional layers are implemented into the design serving various functions. Nanolaminate metal films are used to provide a high quality reflective front surface. A backing layer of thin active material is implemented to provide the surface-parallel actuation scheme. Printed electronics are used to create a custom electrode pattern and flexible routing layer. Mirrors of this design are thin ( 100 μm PV) down to sub-micron precision. The system has been validated against several traditional techniques including photogrammetry and interferometry. The mirror performance has been characterized using this system, as well as closed-loop figure correction experiments on 150 mm dia. prototypes. The mirrors have demonstrated post-correction figure accuracies of 200 nm RMS (two dead actuators limiting performance).

  8. 灵长类镜像神经系统研究的最新进展%Advances in Studies of Primate Mirror Neuron System

    Institute of Scientific and Technical Information of China (English)

    姚远

    2011-01-01

    近年来,镜像神经系统成为认知神经科学的研究热点.神经生理学和脑成像的相关研究表明,镜像神经系统以运动为基础,统一了动作观察和动作执行的神经机制,为理解他人动作提供了来自"内部"的支持.镜像神经系统为个体间的自然交流提供了神经基础,具有深远的进化意义.它不仅存在于灵长类,甚至在进化距离较远的物种(如沼雀和斑雀)中也有发现.作者在综述最新相关研究的基础上,分别介绍了猴和人类镜像神经系统的生理基础和认知功能,并对前人实验中的遗留问题做了总结和展望.%Mirror neuron system has recently attracted more and more interests in the field of cognitive neuroscience. Studies using neurophysiological and brain-imaging techniques have suggested that such motor-based system provides a basic mechanism that unifies action execution and action perception. This mechanism compnses a neural basis for understanding goal-orientated actions of others from the inside.Mirror neuron system seems to be a primary and natural way whereby individuals communicate with one another. It is found not only in primates, but also in evolutionarily distant species, such as swamp sparrows and zebra finches. This paper reviews the latest progress about the mirror neuron system and discusses its physiologic basis and cognitive function in primates and human beings in detail. Finally, several questions for future research derived from previous studies have also been suggested.

  9. The simulating social mind: the role of the mirror neuron system and simulation in the social and communicative deficits of autism spectrum disorders.

    Science.gov (United States)

    Oberman, Lindsay M; Ramachandran, Vilayanur S

    2007-03-01

    The mechanism by which humans perceive others differs greatly from how humans perceive inanimate objects. Unlike inanimate objects, humans have the distinct property of being "like me" in the eyes of the observer. This allows us to use the same systems that process knowledge about self-performed actions, self-conceived thoughts, and self-experienced emotions to understand actions, thoughts, and emotions in others. The authors propose that internal simulation mechanisms, such as the mirror neuron system, are necessary for normal development of recognition, imitation, theory of mind, empathy, and language. Additionally, the authors suggest that dysfunctional simulation mechanisms may underlie the social and communicative deficits seen in individuals with autism spectrum disorders.

  10. LUTE primary mirror materials and design study report

    Science.gov (United States)

    Ruthven, Greg

    1993-02-01

    The major objective of the Lunar Ultraviolet Telescope Experiment (LUTE) Primary Mirror Materials and Design Study is to investigate the feasibility of the LUTE telescope primary mirror. A systematic approach to accomplish this key goal was taken by first understanding the optical, thermal, and structural requirements and then deriving the critical primary mirror-level requirements for ground testing, launch, and lunar operations. After summarizing the results in those requirements which drove the selection of material and the design for the primary mirror are discussed. Most important of these are the optical design which was assumed to be the MSFC baseline (i.e. 3 mirror optical system), telescope wavefront error (WFE) allocations, the telescope weight budget, and the LUTE operational temperature ranges. Mechanical load levels, reflectance and microroughness issues, and options for the LUTE metering structure were discussed and an outline for the LUTE telescope sub-system design specification was initiated. The primary mirror analysis and results are presented. The six material substrate candidates are discussed and four distinct mirror geometries which are considered are shown. With these materials and configurations together with varying the location of the mirror support points, a total of 42 possible primary mirror designs resulted. The polishability of each substrate candidate was investigated and a usage history of 0.5 meter and larger precision cryogenic mirrors (the operational low end LUTE temperature of 60 K is the reason we feel a survey of cryogenic mirrors is appropriate) that were flown or tested are presented.

  11. Authors’ response: mirror neurons: tests and testability.

    Science.gov (United States)

    Catmur, Caroline; Press, Clare; Cook, Richard; Bird, Geoffrey; Heyes, Cecilia

    2014-04-01

    Commentators have tended to focus on the conceptual framework of our article, the contrast between genetic and associative accounts of mirror neurons, and to challenge it with additional possibilities rather than empirical data. This makes the empirically focused comments especially valuable. The mirror neuron debate is replete with ideas; what it needs now are system-level theories and careful experiments – tests and testability.

  12. Anomalous Mirror Symmetry Generated by Optical Illusion

    Directory of Open Access Journals (Sweden)

    Kokichi Sugihara

    2016-04-01

    Full Text Available This paper introduces a new concept of mirror symmetry, called “anomalous mirror symmetry”, which is physically impossible but can be perceived by human vision systems because of optical illusion. This symmetry is characterized geometrically and a method for creating cylindrical surfaces that create this symmetry is constructed. Examples of solid objects constructed by a 3D printer are also shown.

  13. The Athena Mirror

    Science.gov (United States)

    Wille, Eric

    2016-07-01

    The Athena mission (Advanced Telescope for High Energy Astrophysics) requires lightweight X-ray Wolter optics with a high angular resolution and large effective area. For achieving an effective area of 2 m^2 (at 1 keV) and an angular resolution of below 5 arcsec, the Silicon Pore Optics technology was developed by ESA together with a consortium of European industry. Silicon Pore Optics are made of commercial Si wafers using process technology adapted from the semiconductor industry. We present the current design of the Athena mirror concentrating on the technology development status of the Silicon Pore Optics, ranging from the manufacturing of single mirror plates towards complete focusing mirror modules and their integration into the mirror structure.

  14. Manufacturing parabolic mirrors

    CERN Multimedia

    CERN PhotoLab

    1975-01-01

    The photo shows the construction of a vertical centrifuge mounted on an air cushion, with a precision of 1/10000 during rotation, used for the manufacture of very high=precision parabolic mirrors. (See Annual Report 1974.)

  15. The Myth of the Twin Paradox

    CERN Document Server

    Fischer, E

    2010-01-01

    One of the most discussed peculiarities of Einstein's theory of relativity is the twin paradox, the fact that the time between two events in space-time appears to depend on the path between these events. We show that this time discrepancy results only from faulty assumptions in the transition from one reference system to another. The twin paradox does not exist. But the Lorentz invariance of the theory has strong consequences, if we assume that it is valid not only locally, but also on cosmic scale.

  16. The obsidian mirror The obsidian mirror

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Reis Amorin

    2008-04-01

    Full Text Available The author James Norman is an American who has always lived in Mexico during the summer. He seems to love Mexican - Indian traditions and he is well acquainted with the pre-historic culture as it is shown in his book: "The Obsidian Mirror". "The Obsidian Mirror" is a mysterious story about an archeologist: Quigley that lives in a small village in Mexico-San Marcos. He is searching for antiques that belong to some tribes of pre-historic Indians in order to find out their mysteries. Quigley becomes so engaged in his work that his mind has reached a stage that is impossible to separate between Quigley the archeologist, and Quigley as an ancient Indian. The culture, the myth, the sensation of Omen - characteristics of the Indians are within himself. As a result, Quigley acts sometimes as a real Indian. The author James Norman is an American who has always lived in Mexico during the summer. He seems to love Mexican - Indian traditions and he is well acquainted with the pre-historic culture as it is shown in his book: "The Obsidian Mirror". "The Obsidian Mirror" is a mysterious story about an archeologist: Quigley that lives in a small village in Mexico-San Marcos. He is searching for antiques that belong to some tribes of pre-historic Indians in order to find out their mysteries. Quigley becomes so engaged in his work that his mind has reached a stage that is impossible to separate between Quigley the archeologist, and Quigley as an ancient Indian. The culture, the myth, the sensation of Omen - characteristics of the Indians are within himself. As a result, Quigley acts sometimes as a real Indian.

  17. Identical Twins Raised Apart

    Science.gov (United States)

    Farnsworth, David L.

    2015-01-01

    This article describes a bivariate data set that is interesting to students. Indeed, this particular data set, which involves twins and IQ, has sparked more student interest than any other set that I have presented. Specific uses of the data set are presented.

  18. Sleep Terrors in Twins

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-12-01

    Full Text Available In an attempt to clarify the genetic and environmental causes of sleep terrors in childhood, reasearchers in Canada followed 390 pairs of monozygotic and dizygotic twins by assessing the frequency of sleep terrors at 18 and 30 months of age using a questionnaire administered to the biological mothers.

  19. Twin Hub Network (poster)

    NARCIS (Netherlands)

    Kreutzberger, E.D.; Konings, J.W.

    2014-01-01

    Twin hub network, a European Interreg IVB project, aims at making intermodal rail transport within, to and from North West Europe more competitive, in particular between seaports and inland terminals. Improving rail competitiveness enables to shift freight flows from road to rail, providing a more s

  20. Amelia in Twin Pregnancy

    Directory of Open Access Journals (Sweden)

    Davari Tanha Fatemeh

    2009-04-01

    Full Text Available Limb bud first appears during the third week of gestation with the upper limb buds appearing a few days before the lower limb buds. Complete absence of one or more limbs, called Amelia, occurs prior to the eighth week of gestation. We report a case of Amelia in a twin gestation.