WorldWideScience

Sample records for arrows signals

  1. On the time arrows, and randomness in cosmological signals

    CERN Document Server

    Gurzadyan, V G; Yegorian, G

    2013-01-01

    Arrows of time - thermodynamical, cosmological, electromagnetic, quantum mechanical, psychological - are basic properties of Nature. For a quantum system-bath closed system the de-correlated initial conditions and no-memory (Markovian) dynamics are outlined as necessary conditions for the appearance of the thermodynamical arrow. The emergence of the arrow for the system evolving according to non-unitary dynamics due to the presence of the bath, then, is a result of limited observability, and we conjecture the arrow in the observable Universe as determined by the dark sector acting as a bath. The voids in the large scale matter distribution induce hyperbolicity of the null geodesics, with possible observational consequences.

  2. On the time arrows, and randomness in cosmological signals

    Directory of Open Access Journals (Sweden)

    Gurzadyan V.G.

    2013-09-01

    Full Text Available Arrows of time - thermodynamical, cosmological, electromagnetic, quantum mechanical, psychological - are basic properties of Nature. For a quantum system-bath closed system the de-correlated initial conditions and no-memory (Markovian dynamics are outlined as necessary conditions for the appearance of the thermodynamical arrow. The emergence of the arrow for the system evolving according to non-unitary dynamics due to the presence of the bath, then, is a result of limited observability, and we conjecture the arrow in the observable Universe as determined by the dark sector acting as a bath. The voids in the large scale matter distribution induce hyperbolicity of the null geodesics, with possible observational consequences.

  3. Arrow ribbon graphs

    CERN Document Server

    Bradford, Robert; Chmutov, Sergei

    2011-01-01

    We introduce an additional structure on ribbon graphs, arrow structure. We extend the Bollob\\'as-Riordan polynomial to ribbon graph with this structure. The extended polynomial satisfies the contraction-deletion relations and naturally behaves with respect to the partial duality of ribbon graphs. We construct an arrow ribbon graph from a virtual link whose extended Bollob\\'as-Riordan polynomial specializes to the arrow polynomial of the virtual link recently introduced by H.Dye and L.Kauffman. This result generalizes the classical Thistlethwaite theorem to the arrow polynomial of virtual links.

  4. A Computer's Arrow of Time

    Directory of Open Access Journals (Sweden)

    L. S. Schulman

    2005-10-01

    Full Text Available Abstract: Some researchers believe that the psychological or consciousness arrow of time is a consequence of the thermodynamic arrow. Some don't. As for many issues in this area, the disagreement revolves about fundamental and undebatable assumptions. As a contribution to this standoff I consider the extent to which a computer---presumably governed by nothing more than the thermodynamic arrow---can be said to possess a psychological arrow. My contention is that the parallels are sufficiently strong as to leave little room for an independent psychological arrow. Reservations are nevertheless expressed on the complete objectivity of the thermodynamic arrow.

  5. Environment Induced Time Arrow

    CERN Document Server

    Polonyi, Janos

    2012-01-01

    The spread of the time arrows from the environment to an observed subsystem is followed within a harmonic model. A similarity is pointed out between irreversibility and a phase with spontaneously broken symmetry. The causal structure of interaction might be lost in the irreversible case, as well. The Closed Time Path formalism is developed for classical systems and shown to handle the time arrow problem in a clear and flexible manner. The quantum case is considered, as well, and the common origin of irreversibility and decoherence is pointed out.

  6. MRI of menisci repaired with bioabsorbable arrows

    Energy Technology Data Exchange (ETDEWEB)

    Mustonen, Antti O.T.; Kiuru, Martti; Koskinen, Seppo K. [Helsinki University Hospital - Radiology, Helsinki (Finland); Tielinen, Laura; Lindahl, Jan; Hirvensalo, Eero [Helsinki University Hospital - Traumatology, Helsinki (Finland)

    2006-07-15

    To analyze with conventional magnetic resonance imaging (MRI) the signal appearance of menisci repaired with bioabsorbable arrows. Forty-four patients with 47 meniscal tears treated with bioabsorbable arrows underwent follow-up conventional MRI examination. The time interval between the surgery and MRI varied from 5 to 67 months (mean 26 months). Twenty-six patients also had concurrent repair of torn anterior cruciate ligament. The following grades were used to classify meniscal signal intensity: (a) G0; low signal intensity on all sequences and regular configuration in every plane, (b) G1; increased signal intensity within the meniscus, not extending to the meniscal surface, (c) G2; increased signal intensity linear in shape, which may or may not communicate with the capsular margin of the meniscus, without extending to the meniscal surface, and (d) G3; increased signal intensity extending to the meniscal surface. Thirteen menisci (27.5%) had normal signal intensity, 13 menisci (27.5%) Grade 1 signal intensity, 9 menisci (19%) Grade 2 signal intensity and 12 menisci (26%) Grade 3 signal intensity. The time difference between operation and MRI was statistically significant between the G0 (36 months) and G3 groups (14 months; P=0.0288). There was no statistical significance in different grades between medial and lateral meniscus or between patients with operated or intact ACL. On physical examination sixteen patients reported slight symptoms, seen evenly in each group. (orig.)

  7. 77 FR 35082 - Arrow Investment Advisers, LLC and Arrow Investments Trust; Notice of Application

    Science.gov (United States)

    2012-06-12

    ... COMMISSION Arrow Investment Advisers, LLC and Arrow Investments Trust; Notice of Application June 6, 2012... order under section 6(c) of the Investment Company Act of 1940 (``Act'') for an exemption from sections... Investment Advisers, LLC (``Arrow'') and Arrow Investments Trust (the ``Trust''). Summary of...

  8. Bow-arrow interaction in archery.

    Science.gov (United States)

    Kooi, B W

    1998-11-01

    A mathematical model of the flight of the arrow during its discharge from a bow was proposed by Pekalski (1990). His description of the model was incomplete. In this paper, I give a full description of the model. Furthermore, I propose some improvements that make his model more consistent with reality. One achievement is the modelling of contact of the arrow and grip; the pressure button is modelled as a unilateral elastic support. The acceleration force acting upon the arrow during the launch is predicted by an advanced mathematical model of bow dynamics. There is a satisfactory conformity of the simulation and experimental results. The new model predicts that the arrow leaves the pressure button before it leaves the string, as reported previously. The ability to model arrow dynamics can be used to improve the adjustment of the bow-arrow system for optimal performance.

  9. Modeling Time’s Arrow

    Directory of Open Access Journals (Sweden)

    Djordje Minic

    2012-03-01

    Full Text Available Quantum gravity, the initial low entropy state of the Universe, and the problem of time are interlocking puzzles. In this article, we address the origin of the arrow of time from a cosmological perspective motivated by a novel approach to quantum gravitation. Our proposal is based on a quantum counterpart of the equivalence principle, a general covariance of the dynamical phase space. We discuss how the nonlinear dynamics of such a system provides a natural description for cosmological evolution in the early Universe. We also underscore connections between the proposed non-perturbative quantum gravity model and fundamental questions in non-equilibrium statistical physics.

  10. Environmental and Molecular Science Laboratory Arrow

    Energy Technology Data Exchange (ETDEWEB)

    2016-06-24

    Arrows is a software package that combines NWChem, SQL and NOSQL databases, email, and social networks (e.g. Twitter, Tumblr) that simplifies molecular and materials modeling and makes these modeling capabilities accessible to all scientists and engineers. EMSL Arrows is very simple to use. The user just emails chemical reactions to arrows@emsl.pnnl.gov and then an email is sent back with thermodynamic, reaction pathway (kinetic), spectroscopy, and other results. EMSL Arrows parses the email and then searches the database for the compounds in the reactions. If a compound isn't there, an NWChem calculation is setup and submitted to calculate it. Once the calculation is finished the results are entered into the database and then results are emailed back.

  11. Illustrating cerebral function: the iconography of arrows.

    Science.gov (United States)

    Schott, G D

    2000-12-29

    For over a century the arrow has appeared in illustrations of cerebral function, yet the implications of using such symbols have not been previously considered. This review seeks to outline the nature, evolution, applications and limitations of this deceptively simple graphic device when it is used to picture functions of the brain. The arrow is found to have been used in several different ways: as a means of endowing anatomical structures with functional properties; as a method of displaying neural function either in free-standing form or in a structural or spatial framework; as a device for correlating functional data with underlying brain topography; and as a technique for linking functions of the brain with the world outside and with various philosophical concepts. For many of these uses the essential feature of the arrow is its directional characteristic. In contrast to the line, it is direction that enables the arrow to display information about time, which in turn can be exploited to depict functional rather than structural data. However, the use of the arrow is fraught with difficulties. It is often unclear whether an arrow has been used to illustrate fact, hypothesis, impression or possibility, or merely to provide a decorative flourish. Furthermore, the powerful symbolic nature of the arrow can so easily confer a spurious validity on the conjectural. Increasingly now there are insuperable difficulties when attempting to illustrate complex mechanisms of brain function. In the iconography of cerebral function, therefore, arrows with all their ambiguities may in certain circumstances become superseded by more non-representational symbols such as the abstract devices of the computational neuroscientist.

  12. Cosmological arrow of time in f(R) gravity

    CERN Document Server

    Yadav, Bal Krishna

    2016-01-01

    The cosmological arrow of time may be linked to the thermodynamic arrow by second law of thermodynamics. The time asymmetry is also associated with dissipative fluid as Tolman introduced a viscous fluid to generate an arrow of time in cyclic cosmology. An arrow of time in cyclic cosmology has been shown using scalar field.In this work we find out the cosmological arrow of time in f(R) gravity. Here we use the relation between a new scalar field and $f(R)$. The dynamics of this new scalar field may emerge the arrow of time.

  13. Electromyography of arrow release in archery.

    Science.gov (United States)

    Hennessy, M P; Parker, A W

    1990-01-01

    An electronic arrow movement detector was used to accurately locate the muscle activity associated with release of the arrow during shooting in archery. Digital computer analysis of the electromyograms from thirty shots for two archers facilitated an examination of the relationship between the measured activity of the muscles and their function during release. Changes present in the direct and integrated electromyograms of muscles acting at the wrist and elbow joints of the bow arm and the shoulder of the draw arm tended to anticipate the moment of arrow release. These changes would produce muscular force to reduce unwanted movement at this critical phase of the shot in the bow arm and initiate release of the bow string by the fingers. This study provides a detailed quantitative analysis of the muscular action of the technique and identifies possibilities for prevention of injury by improving the understanding of muscle action in shooting.

  14. Entanglement and the Thermodynamic Arrow of Time

    CERN Document Server

    Jennings, David

    2010-01-01

    We discuss quantum entanglement in the context of the thermodynamic arrow of time. We review the role of correlations in entropy-decreasing events and prove that the occurrence of a transformation between two thermodynamic states constitutes a new type of entanglement witness, one not defined as a separating plane in state space between separable and entangled states, but as a physical process dependent on the local initial properties of the states. Extending work by Partovi, we consider a general entangled multipartite system that allows large reversals of the thermodynamic arrow of time. We describe a hierarchy of arrows that arises from the different correlations allowed in a quantum state and examine these features in the context of Maxwell's Demon. We examine in detail the case of three qubits, and also propose some simple experimental demonstrations possible with small numbers of qubits.

  15. On the mechanics of the arrow : Archer's paradox

    NARCIS (Netherlands)

    Kooi, BW; Sparenberg, JA

    1997-01-01

    In ancient bows the grip of the bow was in the way of the arrow. The arrow needed to get round the bow while being accelerated; this phenomenon is called the 'Archer's Paradox'. In the forties it was observed experimentally with high-speed cameras that the arrow vibrates in a horizontal plane perpen

  16. Tragic Paradox in Achebe's "Arrow of God"

    Science.gov (United States)

    Soile, Sola

    1976-01-01

    Leads into a discussion of Chinua Achebe's "Arrow of God" (1964) from his earlier novel "Things Fall Apart" (1958), because such a comparative approach provides an opportunity to see Achebe's elaboration and development of a subject that is obviously dear to his heart, namely, the trials and tribulations of a dynamic society as…

  17. Remote effects in real induction arrows

    Directory of Open Access Journals (Sweden)

    A. Ádám

    2002-06-01

    Full Text Available In August 2001, Annali di Geofisica, 44 (4, pp. 659-669, published the paper: «Anomalous directional behaviour of the real parts of the induction arrows in the Eastern Alps: tectonic and palaeogeographic implications» written by Marcus Gurk and Pierre-André Schnegg. Concerning this paper we have two brief comments.

  18. Multi-Stage Programs are Generalized Arrows

    CERN Document Server

    Megacz, Adam

    2010-01-01

    The lambda calculus, subject to typing restrictions, provides a syn- tax for the internal language of cartesian closed categories. This paper establishes a parallel result: staging annotations, subject to named level restrictions, provide a syntax for the internal language of Freyd categories, which are known to be in one-to-one correspondence with Arrows. The connection is made by interpreting multi-stage type systems as indexed functors from polynomial categories to their reindexings (Definitions 15 and 16). This result applies only to multi-stage languages which are (1) homogeneous, (2) allow cross-stage persistence and (3) place no restrictions on the use of structural rules in typing derivations. Removing these restrictions and repeating the construction yields generalized arrows, of which Arrows are a particular case. A translation from well-typed multi-stage programs to single-stage GArrow terms is provided. The translation is defined by induction on the structure of the proof that the multi-stage prog...

  19. Arrows of time in unconfined systems

    CERN Document Server

    Barbour, Julian

    2016-01-01

    Entropy and the second law of thermodynamcs were discovered through study of the behaviour of gases in confined spaces. The related techniques developed in the kinetic theory of gases have failed to resolve the apparent conflict between the time-reversal symmetry of all known laws of nature and the existence of arrows of time that at all times and everywhere in the universe all point in the same direction. I will argue that the failure may due to unconscious application to the universe of the conceptual framework developed for confined systems. If, as seems plausible, the universe is an unconfined system, new concepts are needed.

  20. Feynman Clocks, Casual Networks, and the Origin of Hierarchical "Arrows of Time" in Complex Systems from the Big Bang to the Brain

    CERN Document Server

    Hitchcock, S M

    2000-01-01

    A theory of 'time' as a form of 'information' is proposed. New tools such as Feynman Clocks, Collective Excitation Networks, Sequential Excitation Networks, Plateaus of Complexity, Causal Networks, and Quantum Computation methods are used to unify previously separate 'arrows of time'. The 'direction' and 'dimension' of 'time' are found to be secondary information structures created by the 'processing' of the information carried by signals connecting 'clocks' together in networks. The 'problem of time' may be solved by identification of a fundamental 'irreversible' Quantum Arrow of Time and 'reversible' Classical Arrows of Time. These 'arrows' can used to map information flow through complex causal networks from the Big Bang to the Brain. Keywords; unification of the fundamental interactions of matter, consciousness, entangled states, time reversal, time travel, and FTL or superluminal signals

  1. Multi-Level Languages are Generalized Arrows

    CERN Document Server

    Megacz, Adam

    2010-01-01

    The lambda calculus, subject to typing restrictions, provides a syntax for the internal language of cartesian closed categories. This paper establishes a parallel result: staging annotations, subject to named level restrictions, provide a syntax for the internal language of (the codomain of) a functor which preserves a premonoidal enrichment. Such functors are uniquely determined by functors from an {\\it enriching} category to an {\\it enriched} category. An equational axiomatization for the latter form is given, and Arrows are shown to constitute a special case. This result is most useful when the enrichment is that of a category of types and terms in a category of judgments. In such a scenario, the proof of correspondence yields a translation from well typed multi-level terms to well typed one-level terms which are parameterized over an instance of a {\\it generalized arrow} (GArrow). The translation is defined by induction on the structure of the proof that the multi-level program is well typed, relying on i...

  2. The sacred weapon: bow and arrow combat in Iran

    Directory of Open Access Journals (Sweden)

    Manouchehr Moshtagh Khorasani

    2012-07-01

    Full Text Available The following article presents the development of the bow and arrow, and its important role in the history of Iran. The bow always played an important role not only on the battlefield, but also in hunting. It was also considered as a sacred weapon and additionally a royal symbol. Bow and arrow were considered as a superior weapon in comparison with other types of weapons because one could fight with them at a safer distance as one offered by swords, maces and axes. The first part of the article presents a short history of the bow in Iran. Based on historical Persian manuscripts, the next part explains the structure of the composite bow and the materials used for making it. The third part describes some types of bows based on the material, place of production, the usage, and bow type based on the length of the bow and the arrows. The following part talks about different types of arrows based on morphology of arrowheads, the type of plume/feather, the material of the shaft, the material of the arrowhead, the length of arrows, the target of arrows, the place of production of arrowheads and terms for describing its different features of an arrowhead. Then, the article talks about different types of thumb rings, bowstrings, quivers and bow cases and arrow guides for shooting short arrows. The next part discusses different principles of archery as explained in Persian manuscripts. Finally the article describes different archery targets.

  3. Probability of intrinsic time-arrow from information loss

    CERN Document Server

    Diósi, L

    2004-01-01

    Time-arrow $s=+/-$, intrinsic to a concrete physical system, is associated with the direction of information loss $\\Delta I$ displayed by the random evolution of the given system. When the information loss tends to zero the intrinsic time-arrow becomes uncertain. We propose the heuristic relationship $1/[1+exp(-s\\Delta I)]$ for the probability of the intrinsic time-arrow. The main parts of the present work are trying to confirm this heuristic equation. The probability of intrinsic time arrow is defined by Bayesian inference from the observed random process. From irreversible thermodynamic systems, the proposed heuristic probabilities follow via the Gallavotti-Cohen relations between time-reversed random processes. In order to explore the underlying microscopic mechanism, a trivial microscopic process is analyzed and an obvious discrepancy is identified. It can be resolved by quantum theory. The corresponding trivial quantum process will exactly confirm the proposed heuristic time-arrow probability.

  4. Probability of Intrinsic Time-Arrow from Information Loss

    Science.gov (United States)

    Diósi, Lajos

    Time-arrow s=±, intrinsic to a concrete physical system, is associated with the direction of information loss I displayed by the random evolution of the given system. When the information loss tends to zero the intrinsic time-arrow becomes uncertain. We propose the heuristic relationship for the probability of the intrinsic time-arrow. The main parts of the present work are trying to confirm this heuristic equation. The probability of intrinsic time arrow is defined by Bayesian inference from the observed random process. From irreversible thermodynamic systems, the proposed heuristic probabilities follow via the Gallavotti-Cohen relations between time-reversed random processes. In order to explore the underlying microscopic mechanism, a trivial microscopic process is analyzed and an obvious discrepancy is identified. It can be resolved by quantum theory. The corresponding trivial quantum process will exactly confirm the proposed heuristic time-arrow probability.

  5. Medieval Tract «Arab Archery» About the Parameters of Bows and Arrows as A Historical Source

    Directory of Open Access Journals (Sweden)

    Aleksei V. Korobeinikov

    2015-06-01

    Full Text Available The article deals with the excerpts from the tract «Arab Archery» dedicated to the parameters of the arab bows and arrows. The attention is paid to the system of archers`gestures, ballistic parameters. The work has comments. The author came to the conclusion that among the archers, in all probability, there was a specialization: skillful direction (snipers by the light arrows at high speed and a high degree of sharpening lethal hit the particularly important individual goals – armored commanders, signalers, communications, monitors, and so on. While the bulk of shooters cloud of arrows showered group goals: bezdospeshnuyu (or "lightly armored" infantry, and not caring about the accuracy of each of his shots.

  6. Study of the decays D r arrow K 3. pi

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, J.C.; Appel, J.A.; Bean, A.; Bracker, S.B.; Browder, T.E.; Cremaldi, L.M.; Duboscq, J.E.; Elliott, J.R.; Escobar, C.O.; Gibney, M.C.; Hartner, G.F.; Huber, J.; Karchin, P.E.; Kumar, B.R.; Losty, M.J.; Luste, G.J.; Mantsch, P.M.; Martin, J.F.; McHugh, S.; Menary, S.R.; Morrison, R.J.; Nash, T.; Pinfold, J.; Punkar, G.; Purohit, M.V.; Ross, W.R.; Santoro, A.F.S.; Schmidt, D.M.; Shoup, A.L.; Sliwa, K.; Sokoloff, M.D.; Souza, M.H.G.; Sperka, D.; Spalding, W.J.; Streetman, M.E.; Stundzia, A.B.; Witherell, M.S. (University of California, Santa Barbara, California, 93106 (United States) Carleton University, Ottawa, Ontario, Canada K1S5B6 ( ) Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro (Brazil) University of Cincinnati, Cincinnati, Ohio 45221 (United States) University of Colorado, Boulder, Colorado 80309 (United States) Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States) University of Mississippi, Oxford, Mississippi 38677 (United States) Nation

    1992-09-01

    We report measurements of the decays {ital D}{sup 0}{r arrow}{ital K}{sup {minus}}{pi}{sup +}{pi}{sup +}{pi}{sup {minus}}, {ital D}{sup +}{r arrow}{ital {bar K}}{sup 0}{pi}{sup +}{pi}{sup +}{pi}{sup {minus}}, {ital D}{sup +}{r arrow}{ital K}{sup {minus}}{pi}{sup +}{pi}{sup +}{pi}{sup 0}, and {ital D}{sup 0}{r arrow}{ital {bar K}}{sup 0}{pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} from Fermilab photoproduction experiment E691. A complete resonant substructure analysis is used to determine the relative fractions and phases of amplitudes contributing to the decays {ital D}{sup 0}{r arrow}{ital K}{sup {minus}}{pi}{sup +}{pi}{sup +}{pi}{sup {minus}}, {ital D}{sup +}{r arrow}{ital {bar K}}{sup 0}{pi}{sup +}{pi}{sup +}{pi}{sup {minus}}, and {ital D}{sup +}{r arrow}{ital K}{sup {minus}}{pi}{sup +}{pi}{sup +}{pi}{sup 0}.

  7. Learning about Locomotion Patterns: Effective Use of Multiple Pictures and Motion-Indicating Arrows

    Science.gov (United States)

    Imhof, Birgit; Scheiter, Katharina; Edelmann, Jorg; Gerjets, Peter

    2013-01-01

    This study investigated how enriching visualizations with arrows indicating the motion of objects may help in conveying dynamic information: Multiple static-simultaneous visualizations with motion-indicating arrows were compared with either multiple visualizations without arrows or a single visualization with arrows. Seventy-one students were…

  8. Relation between the psychological and thermodynamic arrows of time

    Science.gov (United States)

    Mlodinow, Leonard; Brun, Todd A.

    2014-05-01

    In this paper we lay out an argument that generically the psychological arrow of time should align with the thermodynamic arrow of time where that arrow is well defined. This argument applies to any physical system that can act as a memory, in the sense of preserving a record of the state of some other system. This result follows from two principles: the robustness of the thermodynamic arrow of time to small perturbations in the state, and the principle that a memory should not have to be fine-tuned to match the state of the system being recorded. This argument applies even if the memory system itself is completely reversible and nondissipative. We make the argument with a paradigmatic system, and then formulate it more broadly for any system that can be considered a memory. We illustrate these principles for a few other example systems and compare our criteria to earlier treatments of this problem.

  9. ARROW (Version 2) Commercial Software Validation and Configuration Control

    Energy Technology Data Exchange (ETDEWEB)

    HEARD, F.J.

    2000-02-10

    ARROW (Version 2), a compressible flow piping network modeling and analysis computer program from Applied Flow Technology, was installed for use at the U.S. Department of Energy Hanford Site near Richland, Washington.

  10. Modeling of the Archery Bow and Arrow Vibrations

    Directory of Open Access Journals (Sweden)

    I. Zaniewski

    2009-01-01

    Full Text Available Vibration processes in the compound and open kinematical chain with an external link, as a model of an archery bow and arrow system, are evaluated. A mechanical and mathematical model of bend oscillations of the system during accelerate motion of the external link is proposed. Correlation between longitudinal acceleration and natural frequencies is obtained. There are recommendations regarding determination of virtual forms to study arrow vibrations and buckling. The models and methods have been adapted for realization into the engineering method using well-known mathematical software packages.

  11. Universal arrows to forgetful functors from categories of topological algebra

    CERN Document Server

    Pestov, V G

    1992-01-01

    We survey the present trends in theory of universal arrows to forgetful functors from various categories of topological algebra and functional analysis to categories of topology and topological algebra. Among them are free topological groups, free locally convex spaces, free Banach-Lie algebras, and much more. An accent is put on relationship of those constructions with other areas of mathematics and their possible applications. A number of open problems is discussed; some of them belong to universal arrow theory, and others may hopefully become amenable to methods of this theory.

  12. Environment induced time arrow and the Closed Time Path method

    Science.gov (United States)

    Polonyi, Janos

    2013-06-01

    It is shown in the framework of a harmonic system that the thermodynamical time arrow is induced by the environmental initial conditions in a manner similar to spontaneous symmetry breaking. The Closed Time Path formalism is introduced in classical mechanics to handle Green functions for initial condition problems by the action principle, in a systematic manner. The application of this scheme for quantum systems shows the common dynamical origin of the thermodynamical and the quantum time arrows. It is furthermore conjectured that the quantum-classical transition is strongly coupled.

  13. Arrow y Sen: el rescate del individuo y de las instituciones Arrow and Sen: rescuing the individual and institutions

    OpenAIRE

    Cante Freddy

    1998-01-01

    La teoría de la elección social que propone Arrow y Sen es una ruptura con los desarrollos hegemónicos de la microeconomía y de la macroeconomía en dos sentidos: rescata la diversidad de gustos y valores de cada individuo en oposición a los conceptos agregados; además, muestra que la conducta racional es quizás lo menos importante con lo que abre un diálogo con la economía institucional.The theory of social choice proposed by Arrow and Sen breaks with the hegemonic developments of microeconom...

  14. Adding and Subtracting Vectors: The Problem with the Arrow Representation

    Science.gov (United States)

    Heckler, Andrew F.; Scaife, Thomas M.

    2015-01-01

    A small number of studies have investigated student understanding of vector addition and subtraction in generic or introductory physics contexts, but in almost all cases the questions posed were in the vector arrow representation. In a series of experiments involving over 1000 students and several semesters, we investigated student understanding…

  15. Entropy, biological evolution and the psychological arrow of time

    CERN Document Server

    Heinrich, Torsten; Päs, Heinrich

    2014-01-01

    We argue that in Universes where future and past differ only by the entropy content a psychological arrow of time pointing in the direction of entropy increase can arise from natural selection in biological evolution. We show that this effect can be demonstrated in very simple toy computer simulations of evolution in an entropy increasing or decreasing environment.

  16. Does quantum electrodynamics have an arrow of time?

    NARCIS (Netherlands)

    Atkinson, David

    2006-01-01

    Quantum electrodynamics is a time-symmetric theory that is part of the electroweak interaction, which is invariant under a generalized form of this symmetry, the PCT transformation. The thesis is defended that the arrow of time in electrodynamics is a consequence of the assumption of an initial stat

  17. Arrow Lakes Reservoir Fertilization Experiment, Technical Report 1999-2004.

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, E.

    2007-02-01

    The Arrow Lakes food web has been influenced by several anthropogenic stressors during the past 45 years. These include the introduction of mysid shrimp (Mysis relicta) in 1968 and 1974 and the construction of large hydroelectric impoundments in 1969, 1973 and 1983. The construction of the impoundments affected the fish stocks in Upper and Lower Arrow lakes in several ways. The construction of Hugh Keenleyside Dam (1969) resulted in flooding that eliminated an estimated 30% of the available kokanee spawning habitat in Lower Arrow tributaries and at least 20% of spawning habitat in Upper Arrow tributaries. The Mica Dam (1973) contributed to water level fluctuations and blocked upstream migration of all fish species including kokanee. The Revelstoke Dam (1983) flooded 150 km of the mainstem Columbia River and 80 km of tributary streams which were used by kokanee, bull trout, rainbow trout and other species. The construction of upstream dams also resulted in nutrient retention which ultimately reduced reservoir productivity. In Arrow Lakes Reservoir (ALR), nutrients settled out in the Revelstoke and Mica reservoirs, resulting in decreased productivity, a process known as oligotrophication. Kokanee are typically the first species to respond to oligotrophication resulting from aging impoundments. To address the ultra-oligotrophic status of ALR, a bottom-up approach was taken with the addition of nutrients (nitrogen and phosphorus in the form of liquid fertilizer from 1999 to 2004). Two of the main objectives of the experiment were to replace lost nutrients as a result of upstream impoundments and restore productivity in Upper Arrow and to restore kokanee and other sport fish abundance in the reservoir. The bottom-up approach to restoring kokanee in ALR has been successful by replacing nutrients lost as a result of upstream impoundments and has successfully restored the productivity of Upper Arrow. Primary production rates increased, the phytoplankton community responded

  18. Search for the decays {eta}{r_arrow}{mu}{ital e} and {eta}{r_arrow}{ital e}{sup +}{ital e}{sup {minus}}

    Energy Technology Data Exchange (ETDEWEB)

    White, D.B.; Tippens, W.B.; Abegg, R.; Baldisseri, A.; Boudard, A.; Briscoe, W.; Fabbro, B.; Garcon, M.; Hermes, E.A.; Jacobs, W.W.; Kessler, R.S.; Lytkin, L.; Mayer, B.; Nefkens, B.M.; Niebuhr, C.; Petrov, A.M.; Poitou, J.; Saudinos, J.; Tomasi-Gustafsson, E.; van der Schaaf, A.; van Oers, W.T.; Vigdor, S.E.; Wang, M. [UCLA Department of Physics, Los Angeles, California 90024-1547 (United States)]|[TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6TH2A3]|[Service de Physique Nucleaire, CEA-Saclay, 91191 Gif-sur-Yvette (France)]|[Center for Nuclear Studies and Department of Physics, George Washington University, Washington, D.C., 20052 (United States)]|[Physik-Institut der Universitaet Zuerich, CH-8001 Zuerich (Switzerland)]|[Laboratoire National Saturne, F-91191 Gif-sur-Yvette (France)]|[Indiana University Cyclotron Facility, 2401 Milo B. Sampson Lane, Bloomington, Indiana 47405 (United States)]|[Joint Institute for Nuclear Research, Laboratory of Nuclear Problems, 141980 Dubna, Moscow District (Russia)

    1996-06-01

    A search for the lepton-family-violating decay {eta}{r_arrow}{mu}{ital e} and the rare decay {eta}{r_arrow}{ital e}{sup +}{ital e}{sup {minus}} yields the following branching ratio ({ital B}) upper limits at a 90{percent} confidence level: {ital B}({eta}{r_arrow}{mu}{ital e}){lt}6{times}10{sup {minus}6} and {ital B}({eta}{r_arrow}{ital e}{sup +}{ital e}{sup {minus}}){lt}2{times}10{sup {minus}4}. This is the first direct search for {eta}{r_arrow}{mu}{ital e}. The measurements were carried out at the SPES2 tagged {eta} facility at Laboratoire National Saturne in the course of a measurement of {ital B}({eta}{r_arrow}{mu}{sup +}{mu}{sup {minus}}). {copyright} {ital 1996 The American Physical Society.}

  19. Measurement of the Neutral B Meson Lifetime using Partially Reconstructed Bo right arrow D (sup asterisk -) pi + Decays

    Science.gov (United States)

    Zito, M.

    2002-03-01

    The neutral B meson lifetime has been measured with the data collected by the BABAR detector at the PEP-II storage ring during the year 2000 for a total integrated luminosity of 20.3 fb to the minus 1 power. The B0 right arrow D(sup asterisk -)pi+ decays have been selected with a partial reconstruction method in which only the fast pion from the B0 decay and the slow pion from D(sup asterisk -) right arrow overline Do pi- are reconstructed. The B0 lifetime has been measured to be 1.510 + or - 0.040 + or - 0.038 ps with a sample of 6971 + or - 241 reconstructed signal events.

  20. Arrows as anchors: An analysis of the material features of electric field vector arrows

    Science.gov (United States)

    Gire, Elizabeth; Price, Edward

    2014-12-01

    Representations in physics possess both physical and conceptual aspects that are fundamentally intertwined and can interact to support or hinder sense making and computation. We use distributed cognition and the theory of conceptual blending with material anchors to interpret the roles of conceptual and material features of representations in students' use of representations for computation. We focus on the vector-arrows representation of electric fields and describe this representation as a conceptual blend of electric field concepts, physical space, and the material features of the representation (i.e., the physical writing and the surface upon which it is drawn). In this representation, spatial extent (e.g., distance on paper) is used to represent both distances in coordinate space and magnitudes of electric field vectors. In conceptual blending theory, this conflation is described as a clash between the input spaces in the blend. We explore the benefits and drawbacks of this clash, as well as other features of this representation. This analysis is illustrated with examples from clinical problem-solving interviews with upper-division physics majors. We see that while these intermediate physics students make a variety of errors using this representation, they also use the geometric features of the representation to add electric field contributions and to organize the problem situation productively.

  1. Damped Arrow-Hurwicz algorithm for sphere packing

    Science.gov (United States)

    Degond, Pierre; Ferreira, Marina A.; Motsch, Sebastien

    2017-03-01

    We consider algorithms that, from an arbitrarily sampling of N spheres (possibly overlapping), find a close packed configuration without overlapping. These problems can be formulated as minimization problems with non-convex constraints. For such packing problems, we observe that the classical iterative Arrow-Hurwicz algorithm does not converge. We derive a novel algorithm from a multi-step variant of the Arrow-Hurwicz scheme with damping. We compare this algorithm with classical algorithms belonging to the class of linearly constrained Lagrangian methods and show that it performs better. We provide an analysis of the convergence of these algorithms in the simple case of two spheres in one spatial dimension. Finally, we investigate the behaviour of our algorithm when the number of spheres is large in two and three spatial dimensions.

  2. Between Arrow and Gibbard-Satterthwaite; A representation theoretic approach

    CERN Document Server

    Falik, Dvir

    2012-01-01

    A central theme in social choice theory is that of impossibility theorems, such as Arrow's theorem and the Gibbard-Satterthwaite theorem, which state that under certain natural constraints, social choice mechanisms are impossible to construct. In recent years, beginning in Kalai`01, much work has been done in finding \\textit{robust} versions of these theorems, showing "approximate" impossibility remains even when most, but not all, of the constraints are satisfied. We study a spectrum of settings between the case where society chooses a single outcome (\\'a-la-Gibbard-Satterthwaite) and the choice of a complete order (as in Arrow's theorem). We use algebraic techniques, specifically representation theory of the symmetric group, and also prove robust versions of the theorems that we state. Our relaxations of the constraints involve relaxing of a version of "independence of irrelevant alternatives", rather than relaxing the demand of a transitive outcome, as is done in most other robustness results.

  3. Multi-Vacuum Initial Conditions and the Arrow of Time

    CERN Document Server

    Bousso, Raphael

    2012-01-01

    Depending on the type and arrangement of metastable vacua in the theory, initial conditions in a de Sitter vacuum with arbitrarily large entropy can be compatible with the observed arrow of time, if the causal patch or related measures are used to regulate divergences. An important condition, however, is that the initial vacuum cannot produce observers from rare fluctuations (Boltzmann brains). Here we consider more general initial conditions where multiple vacua have nonzero initial probability. We examine whether the prediction of an arrow of time is destroyed by a small initial admixture of vacua that can produce Boltzmann brains. We identify general criteria and apply them to two nontrivial examples of such initial probability distributions. The Hartle-Hawking state is superexponentially dominated by the vacuum with smallest positive cosmological constant, so one might expect that other initial vacua can be neglected; but in fact, their inclusion drastically narrows the range of theory parameters for whic...

  4. On the 3-arrow calculus for homotopy categories

    CERN Document Server

    Thomas, Sebastian

    2010-01-01

    We develop a localisation theory for certain categories, yielding a 3-arrow calculus: Every morphism in the localisation is represented by a diagram of length 3, and two such diagrams represent the same morphism if and only if they can be embedded in a 3-by-3 diagram in an appropriate way. The methods to construct this localisation are similar to the Ore localisation for a 2-arrow calculus; in particular, we do not have to use zigzags of arbitrary length. Applications include the localisation of an arbitrary model category with respect to its weak equivalences as well as the localisation of its full subcategories of cofibrant, fibrant and bifibrant objects, giving the homotopy category in all four cases. In contrast to the approach of Dwyer, Hirschhorn, Kan and Smith, the model category under consideration does not need to admit functorial factorisations. Moreover, our method shows that the derived category of any abelian (or idempotent splitting exact) category admits a 3-arrow calculus if we localise the ca...

  5. Arrow y Sen: el rescate del individuo y de las instituciones Arrow and Sen: rescuing the individual and institutions

    Directory of Open Access Journals (Sweden)

    Cante Freddy

    1998-12-01

    Full Text Available La teoría de la elección social que propone Arrow y Sen es una ruptura con los desarrollos hegemónicos de la microeconomía y de la macroeconomía en dos sentidos: rescata la diversidad de gustos y valores de cada individuo en oposición a los conceptos agregados; además, muestra que la conducta racional es quizás lo menos importante con lo que abre un diálogo con la economía institucional.The theory of social choice proposed by Arrow and Sen breaks with the hegemonic developments of microeconomics and macroeconomics in two senses: it rescues the diversity of tastes and values of each individual as opposed to aggregated concepts, and in addition it shows that rational behavior is perhaps the least important kind, which opens up a dialogue with institutional economics.

  6. Battling Arrow's Paradox to Discover Robust Water Management Alternatives

    Science.gov (United States)

    Kasprzyk, J. R.; Reed, P. M.; Hadka, D.

    2013-12-01

    This study explores whether or not Arrow's Impossibility Theorem, a theory of social choice, affects the formulation of water resources systems planning problems. The theorem discusses creating an aggregation function for voters choosing from more than three alternatives for society. The Impossibility Theorem is also called Arrow's Paradox, because when trying to add more voters, a single individual's preference will dictate the optimal group decision. In the context of water resources planning, our study is motivated by recent theoretical work that has generalized the insights for Arrow's Paradox to the design of complex engineered systems. In this framing of the paradox, states of society are equivalent to water planning or design alternatives, and the voters are equivalent to multiple planning objectives (e.g. minimizing cost or maximizing performance). Seen from this point of view, multi-objective water planning problems are functionally equivalent to the social choice problem described above. Traditional solutions to such multi-objective problems aggregate multiple performance measures into a single mathematical objective. The Theorem implies that a subset of performance concerns will inadvertently dictate the overall design evaluations in unpredictable ways using such an aggregation. We suggest that instead of aggregation, an explicit many-objective approach to water planning can help overcome the challenges posed by Arrow's Paradox. Many-objective planning explicitly disaggregates measures of performance while supporting the discovery of the planning tradeoffs, employing multiobjective evolutionary algorithms (MOEAs) to find solutions. Using MOEA-based search to address Arrow's Paradox requires that the MOEAs perform robustly with increasing problem complexity, such as adding additional objectives and/or decisions. This study uses comprehensive diagnostic evaluation of MOEA search performance across multiple problem formulations (both aggregated and many

  7. Of arrows and flows. Causality, determination, and specificity in the Central Dogma of molecular biology.

    Science.gov (United States)

    Fantini, Bernardino

    2006-01-01

    From its first proposal, the Central Dogma had a graphical form, complete with arrows of different types, and this form quickly became its standard presentation. In different scientific contexts, arrows have different meanings and in this particular case the arrows indicated the flow of information among different macromolecules. A deeper analysis illustrates that the arrows also imply a causal statement, directly connected to the causal role of genetic information. The author suggests a distinction between two different kinds of causal links, defined as 'physical causality' and 'biological determination', both implied in the production of biological specificity.

  8. Aeroballistic Parameters of Arab arrows On the Medieval Tract "Arab Archery"

    Directory of Open Access Journals (Sweden)

    Nikolas W. Mitiukov

    2015-06-01

    Full Text Available With a helping of simple mathematical models there was analyzed the ballistic information of the Arab arrow on medieval Arabic treatise "Arab archery". It is shown that there were no any errors on the text and the translation was correct, then, apparently, Arabian heavy arrow had specific design and can no to be in one quiver with the light arrows. Regarding light arrows, then, apparently, they have the typical design with coefficient of drag function cx ≈ 2, and firing was carried out to a maximum range Arabic archer with an elevation angle about 10°.

  9. Determination of B ( D sub s sup + r arrow. phi. pi. sup + ) via observation of D sub s sup + r arrow. phi. l sup +. nu

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, J.; Artuso, M.; Bebek, C.; Berkelman, K.; Browder, T.; Cassel, D.G.; Cheu, E.; Coffman, D.M.; Crawford, G.; DeWire, J.W.; Drell, P.S.; Ehrlich, R.; Galik, R.S.; Gittelman, B.; Gray, S.W.; Halling, A.M.; Hartill, D.L.; Heltsley, B.K.; Kandaswamy, J.; Katayama, N.; Kreinick, D.L.; Lewis, J.D.; Ludwig, G.S.; Mistry, N.B.; Mueller, J.; Nandi, S.; Nordberg, E.; O' Grady, C.; Peterson, D.; Pisharody, M.; Riley, D.; Sapper, M.; Selen, M.; Silverman, A.; Stone, S.; Worden, H.; Worris, M.; Sadoff, A.J.; Avery, P.; Besson, D.; Garren, L.; Yelton, J.; Bowcock, T.; Kinoshita, K.; Pipkin, F.M.; Procario, M.; Wilson, R.; Wolinski, J.; Xiao, D.; Zhu, Y.; Ammar, R.; Baringer, P.; Coppage, D.; Haas, P.; Kelly, M.; Kwak, N.; Lam, H.; Ro, S.; Kubota, Y.; Nelson, J.K.; Perticone, D.; Poling, R.; Fulton, R.; Jensen, T.; Johnson, D.R.; Kagan, H.; Kass, R.; Morrow, F.; Whitmore, J.; Wilson, P.; Bortoletto, D.; Chen, W.; Dominick, J.; McIlwain, R.L.; Miller, D.H.; Ng, C.R.; Schaffner, S.F.; Shibata,

    1990-09-24

    Using the CLEO detector at the Cornell Electron Storage Ring (CESR), we have determined the ratio {Gamma}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{ital l}{sup +}{nu})/{Gamma}({ital D}{sub {ital s}}{sup +} {r arrow}{phi}{pi}{sup +})=0.49{plus minus}0.10{sub {minus}0.14}{sup +0.10}. We use this measurement to derive {ital B}({ital D}{sub {ital s}}{sup +}{r arrow}{phi}{pi}{sup +}).

  10. Photon-neutrino angular correlation in the reaction {mu}{sup -28}Si(0{sup +}, O) {r_arrow}{nu}{sup 28} Al(1{sup +}, 2202) {r_arrow} {gamma}{sup 28} Al(0{sup +}, 972)

    Energy Technology Data Exchange (ETDEWEB)

    Gorringe, T.P.; Bauer, J.; Johnson, B. [and others

    1993-04-01

    The angular correlation between the photon and the neutrino in the reaction {mu}{sup {minus}} {sup 28}Si(0{sup +},0) {r_arrow} {nu} {sup 28}Al(1{sup +},2202) {r_arrow} {gamma} {sup 28}Al(0{sup +},972) is sensitive to the weak pseudoscalar coupling (g{sub p}) of the proton, and its modification in the nuclear medium. The correlation can be measured via the energy spectrum of the 1229 keV photon, since the photon is emitted from a moving source it gets a Doppler energy shift that indicates the direction of the {sup 28}Al recoil and the neutrino. Miller et al have measured the 1229 keV energy spectrum but poor signal to background limited the determination of the {gamma}-{nu} angular correlation. To improve the signal to background the authors have measured the 1229 keV photon in coincidence with the following 941 keV photon. In this experiment the 1229 keV photons are detected in a pair of Compton suppressed Ge detectors, and the 941 keV photons are detected in an array of NaI detectors. With the coincidence the authors have improved the signal to background from 1:4 to 5:1. In a recent measurement at the TRIUMF laboratory 20,000 coincidences from this reaction were collected, and the authors expect a determination of the pseudoscalar coupling to about 10%.

  11. Which mutation classes of quivers have constant number of arrows?

    CERN Document Server

    Ladkani, Sefi

    2011-01-01

    We classify the connected quivers with the property that all the quivers in their mutation class have the same number of arrows. These are the ones having at most two vertices, or the ones arising from triangulations of marked bordered oriented surfaces of two kinds: either surfaces with non-empty boundary having exactly one marked point on each boundary component and no punctures, or surfaces without boundary having exactly one puncture. This combinatorial property has also a representation-theoretic counterpart: to each such quiver there is a naturally associated potential such that the Jacobian algebras of all the QP in its mutation class are derived equivalent.

  12. Ennakkohuoltojen ja varastokirjaamisien kehittäminen Arrow Maint ohjelmistoon

    OpenAIRE

    Virta, Jarkko

    2010-01-01

    Tämän opinnäytteen tarkoituksena on parantaa ja kehittää Osuuskunta Maitomaan käytössä olevaa Arrow Maint kunnossapitojärjestelmää. Kehittämisen painopiste on varastokirjaamisissa ja pastörointilinjojen 1 ja 2 huolloissa. Alkutilanteessa varaosavaraston sisällöstä ei olut kenelläkään tarkkaa tietoa ja ennakkohuolto-ohjeistus oli puutteellinen. Opinnäyte tehtiin meijeriympäristössä, yhteistyössä kohdeyhteisön kanssa. Päättötyö vaati opiskelua, palavereja ja kenttätyötä. Varastokirjaamis...

  13. Bell's theorem and the causal arrow of time

    Science.gov (United States)

    Argaman, Nathan

    2010-10-01

    Einstein held that the formalism of quantum mechanics involves "spooky actions at a distance." In the 1960s, Bell amplified this by showing that the predictions of quantum mechanics disagree with the results of any locally causal description. It should be appreciated that accepting nonlocal descriptions while retaining causality leads to a clash with relativity. Furthermore, the causal arrow of time by definition contradicts time-reversal symmetry. For these reasons, Wheeler and Feynman, Costa de Beauregard, Cramer, Price, and others have advocated abandoning microscopic causality. In this paper, a simplistic but concrete example of this line of thought is presented, in the form of a retro-causal toy model that is stochastic and provides an appealing description of the quantum correlations discussed by Bell. It is concluded that Einstein's "spooky actions" may occur "in the past" rather than "at a distance," resolving the tension between quantum mechanics and relativity and opening unexplored possibilities for future reformulations of quantum mechanics.

  14. Cosmic update dark puzzles : arrow of time : future history

    CERN Document Server

    Adams, Fred; Mersini-Houghton, Laura; Nekoogar, Farzad

    2012-01-01

    "...The Multiversal book series is equally unique, providing book-length extensions of the lectures with enough additional depth for those who truly want to explore these fields, while also providing the kind of clarity that is appropriate for interested lay people to grasp the general principles involved." - Lawrence M. Krauss Cosmic Update covers: A novel approach to uncover the dark faces of the Standard Model of cosmology. The possibility that Dark Energy and Dark Matter are manifestations of the inhomogeneous geometry of our Universe. The history of cosmological model building and the general architecture of cosmological models. Illustrations of the Large Scale Structure of the Universe. A new perspective on the classical static Einstein Cosmos. Global properties of World Models including their Topology. The Arrow of Time in a Universe with a Positive Cosmological Constant. The exploration of the consequences of a fundamental Cosmological Constant for our Universe. The exploration of why the current ob...

  15. Quantum Solution to the Arrow-of-Time Dilemma

    Science.gov (United States)

    Maccone, Lorenzo

    2009-08-01

    The arrow-of-time dilemma states that the laws of physics are invariant for time inversion, whereas the familiar phenomena we see everyday are not (i.e., entropy increases). I show that, within a quantum mechanical framework, all phenomena which leave a trail of information behind (and hence can be studied by physics) are those where entropy necessarily increases or remains constant. All phenomena where the entropy decreases must not leave any information of their having happened. This situation is completely indistinguishable from their not having happened at all. In the light of this observation, the second law of thermodynamics is reduced to a mere tautology: physics cannot study those processes where entropy has decreased, even if they were commonplace.

  16. The Universal Arrow of Time II: Quantum mechanics case

    CERN Document Server

    Kupervasser, Oleg

    2011-01-01

    The given paper is natural continuation of our previous paper arXiv:1011.4173 We have illustrated earlier, that in the classical Hamilton mechanics for an overwhelming majority of real chaotic macroscopic systems there is alignment of their thermodynamic time arrows because of their small interaction. This fact and impossibility to observe entropy decrease at introspection explain the second low of thermodynamics. In a quantum mechanics the situation even is little bit easier - all closed systems of finite volume are periodic or nearly periodic. The proof in a quantum mechanics is in many respects similar to the proof in the classical Hamilton mechanics - it also uses small interaction between subsystems and impossibility to observe entropy decrease at introspection. However there are special cases which were not in the classical mechanics. In these cases a one microstate corresponds to a set of possible macrostates (more precisely their quantum superposition). Consideration this property with using decoheren...

  17. O debate de Amartya Sen com Kenneth Arrow e John Rawls e a abordagem das capacidades

    OpenAIRE

    2009-01-01

    O objetivo dessa dissertação é investigar em que sentido é pertinente localizar na teoria da escolha social de Kenneth Arrow e na teoria da justiça de John Rawls as duas principais raízes teóricas da abordagem das capacidades de Amartya Sen. Argumentar-se-á que a teoria da escolha social de Arrow cumpriu o papel de explicitar as deficiências da teoria econômica do bem-estar. Desse modo, as análises de Arrow apontam as limitações a serem superadas para se chegar a uma teor...

  18. The politics of attention contextualized: gaze but not arrow cuing of attention is moderated by political temperament.

    Science.gov (United States)

    Carraro, Luciana; Dalmaso, Mario; Castelli, Luigi; Galfano, Giovanni

    2015-08-01

    It is known that an averted gaze can trigger shifts of attention in an observer, a phenomenon known as gaze-cuing effect. Recently, Dodd et al. (Atten Percept Psychophys 73:24-29, 2011) have reported a reliable gaze-cuing effect for liberals but not for conservatives. The present study tested whether this result is gaze-specific or extends over nonsocial spatial signals. Conservatives and liberals took part in a spatial-cuing task in which centrally placed gaze and arrow cues, pointing rightward or leftward, were followed by a peripheral onset target requiring a simple detection response. Whereas a reliable cuing effect was present for both gaze and arrow cues in the case of liberals, conservatives showed a reduced cuing response only for gaze cues. These results provide further support for the pattern reported by Dodd et al. (2011) and are consistent with the view that conservatives are less susceptible to the influence of spatial cues provided by other individuals.

  19. Literary Translation: The Experience of Translating Chinua Achebe's "Arrow of God" into French.

    Science.gov (United States)

    d'Almeida, Irene

    1981-01-01

    Uses Achebe's "Arrow of God" as example of difficulty in translating English into French when author and translators are not native speakers of these languages. Suggests inventing French gibberish or use of translator's notes to translate Pidgin English. (BK)

  20. Existence of Arrow-Debreu Equilibrium with S-shaped Utility Function

    Institute of Scientific and Technical Information of China (English)

    Yang Xi

    2007-01-01

    This paper characterizes the optimal solution of subjective expected utility with S-shaped utility function, by using the prospect theory (PT). We also prove the existence of Arrow-Debreu equilibrium.

  1. Arrow Lakes Reservoir Fertilization Experiment; Years 4 and 5, Technical Report 2002-2003.

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, E.

    2007-02-01

    This report presents the fourth and fifth year (2002 and 2003, respectively) of a five-year fertilization experiment on the Arrow Lakes Reservoir. The goal of the experiment was to increase kokanee populations impacted from hydroelectric development on the Arrow Lakes Reservoir. The impacts resulted in declining stocks of kokanee, a native land-locked sockeye salmon (Oncorhynchus nerka), a key species of the ecosystem. Arrow Lakes Reservoir, located in southeastern British Columbia, has undergone experimental fertilization since 1999. It is modeled after the successful Kootenay Lake fertilization experiment. The amount of fertilizer added in 2002 and 2003 was similar to the previous three years. Phosphorus loading from fertilizer was 52.8 metric tons and nitrogen loading from fertilizer was 268 metric tons. As in previous years, fertilizer additions occurred between the end of April and the beginning of September. Surface temperatures were generally warmer in 2003 than in 2002 in the Arrow Lakes Reservoir from May to September. Local tributary flows to Arrow Lakes Reservoir in 2002 and 2003 were generally less than average, however not as low as had occurred in 2001. Water chemistry parameters in select rivers and streams were similar to previous years results, except for dissolved inorganic nitrogen (DIN) concentrations which were significantly less in 2001, 2002 and 2003. The reduced snow pack in 2001 and 2003 would explain the lower concentrations of DIN. The natural load of DIN to the Arrow system ranged from 7200 tonnes in 1997 to 4500 tonnes in 2003; these results coincide with the decrease in DIN measurements from water samples taken in the reservoir during this period. Water chemistry parameters in the reservoir were similar to previous years of study except for a few exceptions. Seasonal averages of total phosphorus ranged from 2.11 to 7.42 {micro}g/L from 1997 through 2003 in the entire reservoir which were indicative of oligo-mesotrophic conditions

  2. Study of the decays D sup 0 r arrow K K ,. pi. pi

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, J.; Artuso, M.; Bebek, C.; Berkelman, K.; Browder, T.; Cassel, D.G.; Cheu, E.; Coffman, D.M.; Crawford, G.; DeWire, J.W.; Drell, P.S.; Ehrlich, R.; Gittelman, B.; Gray, S.W.; Halling, A.M.; Hartill, D.L.; Heltsley, B.K.; Honscheid, K.; Kandaswamy, J.; Katayama, N.; Kreinick, D.L.; Lewis, J.D.; Ludwig, G.S.; Mistry, N.B.; Nandi, S.; Nordberg, E.; O' Grady, C.; Peterson, D.; Pisharody, M.; Riley, D.; Sapper, M.; Selen, M.; Silverman, A.; Stone, S.; Worden, H.; Worris, M.; Sadoff, A.J.; Avery, P.; Besson, D.; Garren, L.; Yelton, J.; Kinoshita, K.; Pipkin, F.M.; Procario, M.; Wilson, R.; Wolinski, J.; Xiao, D.; Zhu, Y.; Ammar, R.; Baringer, P.; Coppage, D.; Haas, P.; Kelly, M.; Kwak, N.; Lam, H.; Ro, S.; Jawahery, A.; Kubota, Y.; Nelson, J.K.; Perticone, D.; Poling, R.; Fulton, R.; Jensen, T.; Johnson, D.R.; Kagan, H.; Kass, R.; Morrow, F.; Whitmore, J.; Wilson, P.; Bortoletto, D.; Chen, W.; Dominick, J.; McIlwain, R.L.; Miller, D.H.; Ng, C.R.; Schaffner, S.F.; Shibata, E.I.; Shi

    1990-09-03

    Using the CLEO detector we have observed the Cabibbo-suppressed decays {ital D}{sup 0}{r arrow}{ital K}{sup 0}{ital {bar K}0}, {ital K}{sup +}{ital K}{sup {minus}}, and {pi}{sup +}{pi}{sup {minus}}. We determine {ital B}({ital D}{sup 0}{r arrow}{ital K}{sup 0}{ital {bar K}0})= (0.13{sup +0.07}{sub {minus}0.05}{sup +0.02}{sub {minus}0.02})%. Our measurement {ital B}({ital D}{sup 0}{r arrow}{ital K}{sup +}{ital K}{sup {minus}})/{ital B}({ital D}{sup 0}{r arrow}{pi}{sup +}{pi}{sup {minus}})=2.35{plus minus}0.37{plus minus}0.28 represents asubstantial improvement over previous results. We find no evidence for the decay {ital D}{sup 0}{r arrow}{pi}{sup 0}{pi}{sup 0}, and place a 90%-confidence-level upper limit of {ital B}({ital D}{sup 0}{r arrow}{pi}{sup 0}{pi}{sup 0}){lt}0.46%.

  3. Liquid Core ARROW Waveguides: A Promising Photonic Structure for Integrated Optofluidic Microsensors

    Directory of Open Access Journals (Sweden)

    Genni Testa

    2016-03-01

    Full Text Available In this paper, we introduce a liquid core antiresonant reflecting optical waveguide (ARROW as a novel optofluidic device that can be used to create innovative and highly functional microsensors. Liquid core ARROWs, with their dual ability to guide the light and the fluids in the same microchannel, have shown great potential as an optofluidic tool for quantitative spectroscopic analysis. ARROWs feature a planar architecture and, hence, are particularly attractive for chip scale integrated system. Step by step, several improvements have been made in recent years towards the implementation of these waveguides in a complete on-chip system for highly-sensitive detection down to the single molecule level. We review applications of liquid ARROWs for fluids sensing and discuss recent results and trends in the developments and applications of liquid ARROW in biomedical and biochemical research. The results outlined show that the strong light matter interaction occurring in the optofluidic channel of an ARROW and the versatility offered by the fabrication methods makes these waveguides a very promising building block for optofluidic sensor development.

  4. A tight quantitative version of Arrow's impossibility theorem

    CERN Document Server

    Keller, Nathan

    2010-01-01

    The well-known Impossibility Theorem of Arrow asserts that any Generalized Social Welfare Function (GSWF) with at least three alternatives, which satisfies Independence of Irrelevant Alternatives (IIA) and Unanimity and is not a dictatorship, is necessarily non-transitive. In 2002, Kalai asked whether one can obtain the following quantitative version of the theorem: For any $\\epsilon>0$, there exists $\\delta=\\delta(\\epsilon)$ such that if a GSWF on three alternatives satisfies the IIA condition and its probability of non-transitive outcome is at most $\\delta$, then the GSWF is at most $\\epsilon$-far from being a dictatorship or from breaching the Unanimity condition. In 2009, Mossel proved such quantitative version, with $\\delta(\\epsilon)=\\exp(-C/\\epsilon^{21})$, and generalized it to GSWFs with $k$ alternatives, for all $k \\geq 3$. In this paper we show that the quantitative version holds with $\\delta(\\epsilon)=C \\cdot \\epsilon^3$, and that this result is tight up to logarithmic factors. Furthermore, our res...

  5. Arrow: la elección, los valores y la ideología del mercado Arrow: choice, values and the ideology of the market

    Directory of Open Access Journals (Sweden)

    González Jorge Iván

    1998-06-01

    Full Text Available En nuestro medio se conocen más los trabajos de Arrow sobre el equilibrio que sus estudios sobre la teoría de la elección. Este artículo recuerda el postulado central de Arrow: los mecanismos de mercado son incapaces de resolver el conflicto entre valores individuales y elecció social. También existe conflicto entre la evolución de los valores y la formación de los deseos. La teoría de la elección ofrece elementos muy valiosos para entender las contradicciones a las que conduce el individualismo metodológico neoclásico. También pone en tela de juicio la forma indebida en que el discurso neoliberal se ha apropiado de la teoría neoclásica.We tend to know Arrow more for his work on equilibrium than for his studies on the theory of choice. This article recalls Arrow's central postulate: market mechanisms are incapable of resolving the conflict between individual values and social choice. There is also a conflict between the evolution of values and the formation of desires. Choice theory offers valuable elements for understanding the contradictions to which neoclassical methodological individualism leads. It also puts in doubt the undue form in which neoliberal discourse has appropriated
    neoclassical theory.

  6. Arrow Machine Track ohjelmiston hyödyntäminen päivittäisessä johtamisessa

    OpenAIRE

    Pohjala, Matti

    2016-01-01

    Tämän opinnäytetyön tarkoituksena on tutkia Teknikum Oy:n letkutuotannossa käytössä olevan Arrow Machine Track konekäyntiseurannan toimintaa ja hyödyntää saatuja tuloksia päivittäisessä johtamisessa. Arrow Machine Track ohjelmisto otettiin käyttöön letkutuotannossa keväällä 2015 kaiken kaikkiaan kuuteen tuotannon avainkoneeseen. Arrow Machine Track ohjelmisto liittyy vahvasti tuotannon virtauksen kasvattamiseen. Arrow Machine Track ohjelmistolla on tarkoitus päästä kiinni tuotannon kannal...

  7. MEGA -- A search for {mu} {r_arrow} e{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Mischke, R.E.; MEGA Collaboration

    1998-12-01

    The MEGA experiment is a search for the decay {mu} {r_arrow} e{gamma}. Even though there is no fundamental reason to expect lepton number to be a conserved quantity, processes such as {mu} {r_arrow} e{gamma} have not been observed. (The present upper limit for the branching ratio for {mu} {r_arrow} e{gamma} is 4.9 x 10{sup {minus}11}.) The minimal standard model of electroweak interactions, which is enormously successful, builds in lepton number conservation. However, the decay {mu} {r_arrow} e{gamma} is expected in many extensions to the standard model, in particular in supersymmetry models. The experimental signature for {mu} {r_arrow} e{gamma} from decays at rest is the observation of a positron and photon, each of 52.8 MeV , that are back-to-back, in time coincidence, and originate from a common spatial point. The MEGA detector consists of two spectrometers designed to measure the kinematic characteristics of positrons and photons to search for events with this signature. The primary difficulty in the analysis of these data has been the development of reconstruction algorithms that balance efficiency and resolution. Also, many calibrations and corrections are needed to get optimum resolutions. Most surviving candidate events are accidentals. Results of analysis are given.

  8. Arrows of Time in the Bouncing Universes of the No-boundary Quantum State

    CERN Document Server

    Hartle, James

    2012-01-01

    We derive the arrows of time of our universe that follow from the no-boundary theory of its quantum state (NBWF) in a minisuperspace model. Arrows of time are viewed four-dimensionally as properties of the four-dimensional Lorentzian histories of the universe. Probabilities for these histories are predicted by the NBWF. For histories with a regular `bounce' at a minimum radius we find that fluctuations are small at the bounce and grow in the direction of expansion on either side. For recollapsing classical histories with big bang and big crunch singularities we find that the fluctuations are small near one singularity and grow through the expansion and recontraction to the other singularity. The arrow of time defined by the growth in fluctuations thus points in one direction over the whole of a recollapsing spacetime but is bidirectional in a bouncing spacetime. We argue that the electromagnetic, thermodynamic, and psychological arrows of time are aligned with the fluctuation arrow. The implications of a bidi...

  9. The conflict adaptation is affected by attentional strategies: evidence from the arrow flanker task

    Institute of Scientific and Technical Information of China (English)

    CHEN Jia; LI Chang; HE ChunHong; CHEN AnTao

    2009-01-01

    Recently, several studies have considered factors affecting the occurrence of congruency sequence effect (CSE) in the arrow flanker task. In the present study, the influence of the following factors was examined: the presentation of a fixation and the intertrial interval (ITI) were considered. Results of the study showed that the CSE was significant when there was no fixation and when the ITI was long for response repetitions and response changes, but disappeared for response change trials in other conditions. These results showed that, even in the arrow flanker task, the conflict adaptation effect did contribute to the CSE. The current results suggested that the conflict adaptation effect in the arrow flanker task was based on the appropriate application of attention strategies.

  10. References and arrow notation instead of join operation in query languages

    Directory of Open Access Journals (Sweden)

    Alexandr Savinov

    2012-10-01

    Full Text Available We study properties of the join operation in query languages and describe some of its major drawbacks. We provide strong arguments against using joins as a main construct for retrieving related data elements in general purpose query languages and argue for using references instead. Since conventional references are quite restrictive when applied to data modeling and query languages, we propose to use generalized references as they are defined in the concept-oriented model (COM. These references are used by two new operations, called projection and de-projection, which are denoted by right and left arrows and therefore this access method is referred to as arrow notation. We demonstrate advantages of the arrow notation in comparison to joins and argue that it makes queries simpler, more natural, easier to understand, and the whole query writing process more productive and less error-prone.

  11. Evidence for the Decay K{sup +}{r_arrow}{pi}{sup +}{nu}{bar v}

    Energy Technology Data Exchange (ETDEWEB)

    Adler, S.; Atiya, M.S.; Chiang, I.; Diwan, M.V.; Frank, J.S.; Haggerty, J.S.; Kettell, S.H.; Kycia, T.F.; Li, K.K.; Littenberg, L.S.; Ng, C.; Sambamurti, A.; Stevens, A.; Strand, R.C.; Witzig, C. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Komatsubara, T.K.; Kuriki, M.; Muramatsu, N.; Sugimoto, S. [High Energy Accelerator Research Organization (KEK), Tanashi-branch, Midoricho, Tanashi, Tokyo 188 (Japan); Inagaki, T.; Kabe, S.; Kobayashi, M.; Kuno, Y.; Sato, T.; Shinkawa, T.; Yoshimura, Y. [High Energy Accelerator Research Organization (KEK), Oho, Tsukuba, Ibaraki 305 (Japan); Kishi, Y.; Nakano, T. [Department of Physics, Osaka University, Machikaneyama, Toyonaka, Osaka 560 (Japan); Ardebili, M.; Bazarko, A.O.; Convery, M.R.; Ito, M.M.; Marlow, D.R.; McPherson, R.A.; Meyers, P.D.; Shoemaker, F.C.; Smith, A.J.; Stone, J.R. [Joseph Henry Laboratories, Princeton University, Princeton, New Jersey 08544 (United States); Aoki, M.; Blackmore, E.W.; Bergbusch, P.C.; Bryman, D.A.; Konaka, A.; Macdonald, J.A.; Mildenberger, J.; Numao, T.; Padley, P.; Poutissou, J.; Poutissou, R.; Redlinger, G.; Roy, J.; Turcot, A.S. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada, V6T 2A3 (CANADA); Kitching, P.; Soluk, R. [Centre for Subatomic Research, University of Alberta, Edmonton, Alberta, Canada, T6G 2N5 (CANADA)

    1997-09-01

    An event consistent with the signature expected for the rare kaon decay K{sup +}{r_arrow}{pi}{sup +}{nu}{bar {nu}} has been observed. In the pion momentum region examined, 211{lt}P{lt}230 MeV/c , the backgrounds are estimated to contribute 0.08{plus_minus}0.03 events. If the event is due to K{sup +}{r_arrow}{pi}{sup +}{nu}{bar {nu}} , the branching ratio is 4.2{sup +9.7}{sub {minus}3.5}{times}10{sup {minus}10} . {copyright} {ital 1997} {ital The American Physical Society}

  12. Arrow-Elicited Cueing Effects at Short Intervals: Rapid Attentional Orienting or Cue-Target Stimulus Conflict?

    Science.gov (United States)

    Green, Jessica J.; Woldorff, Marty G.

    2012-01-01

    The observation of cueing effects (faster responses for cued than uncued targets) rapidly following centrally-presented arrows has led to the suggestion that arrows trigger rapid automatic shifts of spatial attention. However, these effects have primarily been observed during easy target-detection tasks when both cue and target remain on the…

  13. Archery by the Apaches – implications of using the bow and arrow in hunter-gatherer communities

    Directory of Open Access Journals (Sweden)

    Žiga Šmit

    2016-12-01

    Full Text Available This review focuses on the technical and social details of production, training, and use of archery equipment by a Native American tribe, the Apaches. The study aims to understand the use of the bow in the Mesolithic and Early and Middle Neolithic societies of the Old World. The paper further describes arrow ballistics. An arrow and bow with similar dimensions and materials to those used by the Apaches was reconstructed and used in ballistic experiments. Shooting and the subsequent model calculation showed that the effective range of arrows made of reed and projected by a bow of medium strength (16–18kg was not more than approx. 20m. Due to the initial flat part of the ballistic trajectory, such arrows were quite efficient in close-range contests. Within the model calculation, a regression procedure was introduced to determine the arrow air-drag parameters from an ensemble of shots.

  14. Making Sense of the Arrow-Pushing Formalism among Chemistry Majors Enrolled in Organic Chemistry

    Science.gov (United States)

    Ferguson, Robert; Bodner, George M.

    2008-01-01

    This paper reports results of a qualitative study of sixteen students enrolled in a second year organic chemistry course for chemistry and chemical engineering majors. The focus of the study was student use of the arrow-pushing formalism that plays a central role in both the teaching and practice of organic chemistry. The goal of the study was to…

  15. Ballistic parameters and trauma potential of carbon dioxide-actuated arrow pistols.

    Science.gov (United States)

    Nguyen, Tien Thanh; Grossjohann, Rico; Ekkernkamp, Axel; Bockholdt, Britta; Frank, Matthias

    2015-05-01

    Medical literature abounds with reports of injuries and fatalities caused by arrows and crossbow bolts. Crossbows are of particular forensic and traumatological interest, because their mode of construction allows for temporary mechanical storage of energy. A newly developed type of pistol (Arcus Arrowstar), which belongs to the category of air and carbon dioxide weapons, discharges arrow-shaped bolts actuated by carbon dioxide cylinders. As, to the best of the authors' knowledge, literature contains no information on this uncommon subclass of weapons it is the aim of this work to provide the experimental data and to assess the trauma potential of these projectiles based on the ascertained physical parameters. Basic kinetic parameters of these carbon dioxide-actuated bolts (velocity v = 39 m/s, energy E = 7.2 J, energy density E' = 0.26 J/mm(2)) are similar to bolts discharged by pistol crossbows. Subsequent firing resulted in a continuous and fast decrease in kinetic energy of the arrows. Test shots into ballistic soap blocks reveal a high penetration capacity, especially when compared to conventional projectiles of equal kinetic energy values (like, e.g., airgun pellets). To conclude, these data demonstrate the high efficiency of arrow-shaped projectiles, which are also characterized by a high cross-sectional density (ratio of mass to cross-sectional area of a projectile).

  16. Polarization of cumulative protons in the reaction. gamma. A r arrow pX

    Energy Technology Data Exchange (ETDEWEB)

    Avakyan, R.O.; Avetisyan, A.E.; Arestakesyan, G.A.; Bartikyan, M.V.; Garibyan, Y.A.; Grigoryan, A.E.; Eganov, V.S.; Karapetyan, A.P.; Karapetyan, M.P.; Keropyan, I.A.; and others

    1989-02-01

    The polarization of cumulative protons has been measured in the reaction {gamma}{ital A}{r arrow}{ital pX} in the proton-energy region 170--270 MeV for C and Sn nuclei in bremsstrahlung beams produced by 4.5- and 1.5-GeV electrons. The measured polarization value is close to zero.

  17. Six Impossible Mechanisms before Breakfast: Arrow Pushing as an Instructional Device in Inorganic Chemistry

    Science.gov (United States)

    Berg, Steffen; Ghosh, Abhik

    2013-01-01

    In a recent article by the authors, the suggestion was made that arrow pushing, a widely used tool in organic chemistry, could also be profitably employed in the teaching of introductory inorganic chemistry. A number of relatively simple reactions were used to illustrate this thesis, raising the question whether the same approach might rationalize…

  18. Decorating with Arrows: Toward the Development of Representational Competence in Organic Chemistry

    Science.gov (United States)

    Grove, Nathaniel P.; Cooper, Melanie M.; Rush, Kelli M.

    2012-01-01

    Much effort has been expended in developing improved methods for presenting mechanistic thinking and the curved-arrow notation to organic chemistry students; however, most of these techniques are not research-based. The little research that has been conducted has mainly focused on understanding the meaning that students associate with the…

  19. Improved upper limits on B(K{sub L}{sup 0} {r_arrow} {mu}e) and B(K{sub L}{sup 0} {r_arrow} ee) and a new value for B(K{sub L}{sup 0} {r_arrow} {mu}{mu})

    Energy Technology Data Exchange (ETDEWEB)

    Molzon, W.R.

    1998-09-01

    The author gives recent results from E791 at BNL with improved upper limits on the branching fractions B(K{sub L}{sup 0} {r_arrow} {mu}e) and B(K{sub L}{sup 0} {r_arrow} ee) of 8.5 {times} 10{sup {minus}11} and 11.6 {times} 10{sup {minus}11} at 90% C.L. He also gives a preliminary result of a new measurement B(K{sub L}{sup 0} {r_arrow} {mu}{mu}) = 7.6 {+-} 0.5(stat) {+-} 0.4(syst) {times} 10{sup {minus}9}.

  20. Phaeocroides Nanus (Arrow), Phaeocroides Mapellii Petrovitz and Phaeocroides Orientalis (Petrovitz): notes on Generic status, synonymy and types; redescriptions (Coleoptera: Hybosoridae)

    NARCIS (Netherlands)

    Kuijten, P.J.

    1988-01-01

    Phaeochrous nanus Arrow is transferred to Phaeocroides (comb. nov.); Phaeocroides mapellii Petrovitz is a synonym (syn. nov.). Commentaries on the types and spelling of the generic name, differences from the other Indian genera and redescriptions are given.

  1. Search for the decay [ital D][sup 0][r arrow][mu][sup +][mu][sup [minus

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, C.S.; Brown, C.N.; Cooper, W.E.; Gounder, K. (Fermilab, P.O. Box 500, Batavia, Illinois 60510 (United States)); Kaplan, D.M.; Martin, V.M.; Preston, R.S.; Sa, J.; Tanikella, V. (Northern Illinois University, DeKalb, Illinois 60115 (United States)); Isenhower, L.D.; Sadler, M.E.; Schnathorst, R. (Abilene Christian University, Abilene, Texas 79699 (United States)); Lederman, L.M.; Schub, M.H. (University of Chicago, Chicago, Illinois 60637 (United States)); Gidal, G.; Kowitt, M.S.; Luk, K.B. (Lawrence Berkeley Laboratory and University of California, Berkeley, California 94720 (United States)); Carey, T.A.; Jeppesen, R.E.; Kapustinsky, J.S.; Lane, D.W.; Leitch, M.J.; Lillberg, J.W.; McGaughey, P.L.; Moss, J.M.; Peng, J.C. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)); Childers, R.L.; Darden, C.W. (University of South Carolina, Columbia, South Carolina 29208 (United States)); Teng, P.K. (Institute of Physics, Academia Sinica, Taipei (Taiwan

    1994-07-01

    Using a silicon-microstrip detector array to identify secondary vertices occurring downstream of a short platinum target, we have searched for the decay [ital D][sup 0][r arrow][mu][sup +][mu][sup [minus

  2. The facile synthesis of single crystalline palladium arrow-headed tripods and their application in formic acid electro-oxidation.

    Science.gov (United States)

    Su, Na; Chen, Xueying; Ren, Yuanhang; Yue, Bin; Wang, Han; Cai, Wenbin; He, Heyong

    2015-04-28

    Single crystalline palladium arrow-headed tripods prepared via a simple one-pot strategy exhibit high electro-activity in formic acid oxidation, which could be a promising anodic catalyst for direct formic acid fuel cells.

  3. High Statistics Measurement of B arrow Λc X and Σc X

    Science.gov (United States)

    Wappler, Frank

    1997-04-01

    This analysis is based on about 5 fb-1 of data recorded by the CLEO II detector operating at CESR on the Υ(4S) resonance and at center-of-mass energies just below the threshold for the production of B\\overlineB mesons. The first observation of the inclusive decays B arrow Λ_c^+ X, Σ_c^0 X and Σ_c^++X has already been reported by ARGUS (1988) and CLEO (1992). We now present a high statistics measurement of these decay modes. Improved values for branching fractions and momentum spectra will be presented. Results of the search for the inclusive decay B arrow Σ_c^+ X, which has not yet been observed, will also be presented.

  4. Logical and historical determination of the Arrow and Sen impossibility theorems

    Directory of Open Access Journals (Sweden)

    Boričić Branislav

    2007-01-01

    Full Text Available General classification of mathematical statements divides them into universal, those of the form xA , and existential ЭxA ones. Common formulations of impossibility theorems of K. J. Arrow and A. K. Sen are represented by the statements of the form "there is no x such that A". Bearing in mind logical equivalence of formulae ¬ЭxA and x¬A, we come to the conclusion that the corpus of impossibility theorems, which appears in the theory of social choice, could make a specific and recognizable subclass of universal statements. In this paper, on the basis of the established logical and methodological criteria, we point to a sequence of extremely significant "impossibility theorems", reaching throughout the history of mathematics to the present days and the famous results of Arrow and Sen in field of mathematical economics. We close with specifying the context which makes it possible to formulate the results of Arrow and Sen accurately, presenting a new direct proof of Sen’s result, with no reliance on the notion of minimal liberalism. .

  5. Evidence for {Kappa}{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}}

    Energy Technology Data Exchange (ETDEWEB)

    Kettell, S.

    1998-12-31

    The first observation of the decay {Kappa}{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} has been reported. The E787 experiment presented evidence for the {Kappa}{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} decay, based on the observation of a single clean event from data collected during the 1995 run of the AGS (Alternating Gradient Synchrotron at Brookhaven National Laboratory). The branching ratio indicated by this observation, {Beta}({Kappa}{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}}) = 4.2{sub {minus}3.5}{sup +9.7} {times} 10{sup {minus}10}, is consistent with the Standard Model expectation although the central experimental value is four times larger. The final E787 data sample, from the 1995--98 runs, should reach a sensitivity of about five times that of the 1995 run alone. A new experiment, E949, has been given scientific approval and should start data collection in 2001. It is expected to achieve a sensitivity of more than an order of magnitude below the prediction of the Standard Model.

  6. Evidence for K{sup +} {r_arrow} {pi}{sup +} {nu}{anti {nu}}

    Energy Technology Data Exchange (ETDEWEB)

    Kettell, S.; E787 Collaboration; E949 Collaboration

    1998-12-31

    The decay K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} has been observed for the first time. The E787 experiment has presented evidence for the K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} decay, based on the observation of a single clean event from data collected during the 1995 run of the AGS (Alternating Gradient Synchrotron at Brookhaven National Laboratory). The branching ratio indicated by this observation, B(K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}}) = 4.2{sub {minus}3.5}{sup +9.7} {times} 10{sup {minus}10}, is consistent with the Standard Model expectation although the central experimental value is four times larger. The final E787 data sample, from the 1995--99 runs, should reach a sensitivity of about eight times that of the 1995 run alone. A new experiment, E949, has been approved to run, starting in the year 2000, and is expected to achieve a sensitivity of more than an order of magnitude below the prediction of the Standard Model.

  7. Form factors of the transitions {gamma}{sup *}{pi}{sup 0} {r_arrow} {gamma} and {gamma}{sup *}{eta}{r_arrow}{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Afanasev, A. [Continuous Electron Beam Accelerator Facility, Newport News, VA (United States)

    1994-04-01

    The author discusses possibilities to study {gamma}*{pi}{sup 0} and {gamma}*{eta} {r_arrow} {gamma} transition form factors at CEBAF energies. The author shows that for 4 GeV electron beam, these form factors can be measured at CEBAF for the 4-momentum transfers Q{sup 2} {le} 2.5 (GeV/c){sup 2} using virtual Compton scattering on the proton and nuclear target in the kinematic regime of low momentum transfers to the target. These measurements can be extended to Q{sup 2} {le} 4.0 (GeV/c){sup 2} using the electron beam with the energy 6 GeV.

  8. Ichthyosporidium weissii n. sp. (Microsporidia) infecting the arrow goby (Clevelandia ios).

    Science.gov (United States)

    Sanders, Justin; Myers, Mark S; Tomanek, Lars; Cali, Ann; Takvorian, Peter M; Kent, Michael L

    2012-01-01

    Gonadal infections by a novel microsporidium were discovered in 34% (13/38) of arrow gobies, Clevelandia ios, sampled over a 3-yr period from Morro Bay Marina in Morro Bay, California. Gonadal tumors had been reported in arrow gobies from this geographic area. The infected gonads, found primarily in females, typically appeared grossly as large, white-gray firm and lobulated masses. Histological examination revealed large, multilobate xenomas within the ovaries and no evidence of neoplasia. Typical of the genus Ichthyosporidium, the large xenomas were filled with developmental stages and pleomorphic spores. Wet mount preparations showed two general spore types: microspores with mean length of 6.2 (7.0-4.9, SD = 0.6, N = 20) μm and mean width of 4.3 (5.3-2.9, SD = 0.8) μm; and less numerous macrospores with mean length of 8.5 (10.1-7.1, SD = 1.0, N = 10) μm and mean width of 5.5 (6.2-4.8, SD = 0.5) μm. Transmission electron microscopy demonstrated stages consistent with the genus and 35-50 turns of the polar filament. Small subunit rDNA gene sequence analysis revealed that the parasite from arrow gobies was most closely related to, but distinct from Ichthyosporidium sp. based on sequences available in GenBank. We conclude that this microsporidium represents a new species of Ichthyosporidium, the first species of this genus described from a member of the family Gobiidae and from the Pacific Ocean.

  9. [Upsilon](1[ital S])[r arrow][gamma]+noninteracting particles

    Energy Technology Data Exchange (ETDEWEB)

    Balest, R.; Cho, K.; Ford, T.; Johnson, D.R.; Lingel, K.; Lohner, M.; Rankin, P.; Smith, J.G.; Alexander, J.P.; Bebek, C.; Berkelman, K.; Bloom, K.; Browder, T.E.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Crowcroft, D.S.; Drell, P.S.; Dumas, D.; Ehrlich, R.; Gaidarev, P.; Galik, R.S.; Garcia-Sciveres, M.; Geiser, B.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Jones, C.D.; Jones, S.L.; Kandaswamy, J.; Katayama, N.; Kim, P.C.; Kreinick, D.L.; Ludwig, G.S.; Masui, J.; Mevissen, J.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Patterson, J.R.; Peterson, D.; Riley, D.; Salman, S.; Sapper, M.; Wuerthwein, F.; Urish, M.M.; Avery, P.; Freyberger, A.; Rodriguez, J.; Yang, S.; Yelton, J.; Cinabro, D.; Liu, T.; Saulnier, M.; Wilson, R.; Yamamoto, H.; Bergfeld, T.; Eisenstein, B.I.; Gollin, G.; Ong, B.; Palmer, M.; Selen, M.; Thaler, J.J.; Edwards, K.W.; Ogg, M.; Bellerive, A.; Britton, D.I.; Hyatt, E.R.F.; MacFarlane, D.B.; Patel, P.M.; Spaan, B.; Sadoff, A.J.; Ammar, R.; Ba; (CLEO Collaboration)

    1995-03-01

    We consider the decay of [Upsilon](1[ital S]) particles produced at CESR into a photon which is observed by the CLEO detector plus particles which are not seen. These could be real particles which fall outside of our acceptance, or particles which are noninteracting. We report the results of our search fo the process [Upsilon](1[ital S])[r arrow][gamma]+ unseen'' for photon energies [gt]1 GeV, obtaining limits for the case where unseen'' is either a single particle or a particle-antiparticle pair. Our upper limits represent the highest sensitivity measurements for such decays to date.

  10. Some experimental and theoretical flutter characteristics of an arrow-wing configuration

    Science.gov (United States)

    Doggett, R. V., Jr.; Ricketts, R. H.

    1977-01-01

    Experimental and theoretical flutter results are presented for a simplified 1/50-size wind-tunnel model of an arrow-wing configuration. Transonic flutter characteristics are presented for three configurations - wing without engine nacelles, wing with flow-through nacelles, and wing with pencil nacelles (thin, streamline bodies). Experimental results are correlated with analytical results obtained from kernel-function and doublet-lattice unsteady aerodynamic theories. Theoretical results are presented that show the effects on flutter of systematic changes in structural stiffness and mass.

  11. Registro de Cyclocephala flavipennis Arrow, 1914 (Coleoptera: Melolonthidae danificando plantas de mirtileiro no Brasil

    Directory of Open Access Journals (Sweden)

    Gabriela Inés Diez-Rodríguez

    2015-02-01

    Full Text Available Larvas de Cyclocephala flavipennis Arrow, 1914, são comumente encontradas em cereais de inverno (trigo, cevada, aveia e triticale, milho e soja, no Rio Grande do Sul. Em março de 2012, larvas desta espécie foram detectadas em plantas de mirtileiro (Vaccinium ashei Reade, cultivar 'O´Neal', no município de Pelotas, RS. Os insetos alimentaram-se de raízes em áreas restritas do pomar. Este é o primeiro relato da ocorrência do coró-pequeno, C. flavipennis, em plantas de mirtileiro

  12. Arrow y sen: el rescate del individuo y de las instituciones

    OpenAIRE

    Cante, Freddy

    2010-01-01

    La teoría de la elección social que propone Arrow y Sen es una ruptura con los desarrollos hegemónicos de la microeconomía y de la macroeconomía en dos sentidos: rescata la diversidad de gustos y valores de cada individuo en oposición a los conceptos agregados; además, muestra que la conducta racional es quizás lo menos importante con lo que abre un diálogo con la economía institucional.

  13. First measurement of the rate for the inclusive radiative penguin decay {ital b}{r_arrow}{ital s}{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Alam, M.S.; Kim, I.J.; Ling, Z.; Mahmood, A.H.; O`Neill, J.J.; Severini, H.; Sun, C.R.; Wappler, F.; Crawford, G.; Daubenmier, C.M.; Fulton, R.; Fujino, D.; Gan, K.K.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Sung, M.; White, C.; Wolf, A.; Zoeller, M.M.; Butler, F.; Fu, X.; Nemati, B.; Ross, W.R.; Skubic, P.; Wood, M.; Bishai, M.; Fast, J.; Gerndt, E.; Hinson, J.W.; McIlwain, R.L.; Miao, T.; Miller, D.H.; Modesitt, M.; Payne, D.; Shibata, E.I.; Shipsey, I.P.J.; Wang, P.N.; Battle, M.; Ernst, J.; Gibbons, L.; Kwon, Y.; Roberts, S.; Thorndike, E.H.; Wang, C.H.; Coan, T.; Dominick, J.; Fadeyev, V.; Korolkov, I.; Lambrecht, M.; Sanghera, S.; Shelkov, V.; Skwarnicki, T.; Stroynowski, R.; Volobouev, I.; Wei, G.; Artuso, M.; Gao, M.; Goldberg, M.; He, D.; Horwitz, N.; Moneti, G.C.; Mountain, R.; Muheim, F.; Mukhin, Y.; Playfer, S.; Rozen, Y.; Stone, S.; Xing, X.; Zhu, G.; Bartelt, J.; Csorna, S.E.; Egyed, Z.; Jain, V.; Gibaut, D.; Kinoshita, K.; Pomianowski, P.; Barish, B.; Chadha, M.; Chan, S.; Cowen, D.F.; Eigen, G.; Miller, J.S.; O`Grady, C.; Urheim, J.; Weinstein, A.J.; Athanas, M.; Brower, W.; Masek, G.; Paar, H.P.; Gronberg, J.; Korte, C.M.; Kutschke, R.; Menary, S.; Morrison, R.J.; Nakanishi, S.; Nelson, H.N.; Nelson, T.K.; Qiao, C.; Richman, J.D.; Ryd, A.; Sperka, D.; Tajima, H.; Witherell, M.S.; Balest, R.; Cho, K.; Ford, W.T.; Johnson, D.R.; Lingel, K.; Lohner, M.; Rankin, P.; Smith, J.G.; Alexander, J.P.; Bebek, C.; Berkelman, K.; Bloom, K.; Browder, T.E.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Crowcroft, D.S.; Drell, P.S.; Dumas, D.J.; Ehrlich, R.; Gaidarev, P.; Garcia-Sciveres, M.; Geiser, B.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Jones, C.D.; Jones, S.L.; Kandaswamy, J.; Katayama, N.; Kim, P.C.; Kreinick, D.L.; Ludwig, G.S.; Masui, J.; Mevissen, J.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Patterson, J.R.; Peterson, D.; Riley, D.; Salman, S.; Sapper, M.; Wuerthwein, F.; Avery, P.; Freyberger, A.; Rodriguez, J.; (CLEO Co...

    1995-04-10

    We have measured the inclusive {ital b}{r_arrow}{ital s}{gamma} branching ratio to be (2.32{plus_minus}0.57{plus_minus}0.35){times}10{sup {minus}4}, where the first error is statistical and the second is systematic. Upper and lower limits on the branching ratio, each at 95% C.L., are {ital B}({ital b}{r_arrow}{ital s}{gamma}){lt}4.2{times}10{sup {minus}4} and {ital B}({ital b}{r_arrow}{ital s}{gamma}){gt}1.0{times}10{sup {minus}4}. These limits restrict the parameters of extensions of the standard model.

  14. Social Conflicts in Arrow Of God: Lessons in Flexibility and Good Governance

    Directory of Open Access Journals (Sweden)

    Anaso George Nworah

    2016-01-01

    Full Text Available Chinua Achebe’s second novel, Arrow of God, is concerned with the theme of conflict. According to Holman C. Hugh (1960, there are four basic levels of conflict: struggle between the protagonist and the antagonist, the protagonist with the society, struggle in the mind of the protagonist or the protagonist struggling with fate, destiny or force of nature. Conflicts in Arrow of God delineate three of these struggles in a concentration of events leading to the destruction of the social order in the community (Umuaro. However, the conflicts are linked with colonialism which is at the root of the conflict. In this view, the novel is to some extent, a protest against colonialism and the suffering that it brought to the colonised people generally and the Igbo specifically. Arising from the above, this paper draws some implications from the actions of the protagonist to reveal the connection between a leader’s flexibility and good governance as reflected in the life of the old chief priest (Ezeulu. The novel made its debut in 1964, symbolically marking a year since Nigeria’s adoption of Republican Constitution. The connection between Umuaro’s institution of Ulu and its priest as source of law and order with Nigeria’s adoption of the republican constitution is made obvious in this study. Through this, the nexus between literature and reality is thus reinforced. Keywords: Colonialism, Conflict, Myth, Protest, Governance, Republicanism

  15. Resolving conflicting views: Gaze and arrow cues do not trigger rapid reflexive shifts of attention.

    Science.gov (United States)

    Green, Jessica J; Gamble, Marissa L; Woldorff, Marty G

    2013-01-01

    It has become widely accepted that the direction of another individual's eye gaze induces rapid, automatic, attentional orienting, due to it being such a vital cue as to where in our environment we should attend. This automatic orienting has also been associated with the directional-arrow cues used in studies of spatial attention. Here, we present evidence that the response-time cueing effects reported for spatially non-predictive gaze and arrow cues are not the result of rapid, automatic shifts of attention. For both cue types, response-time effects were observed only for long-duration cue and target stimuli that overlapped temporally, were largest when the cues were presented simultaneously with the response-relevant target, and were driven by a slowing of responses for invalidly cued targets rather than speeding for validly cued ones. These results argue against automatic attention-orienting accounts and support a novel spatial-incongruency explanation for a whole class of rapid behavioral cueing effects.

  16. Exposing the cuing task: the case of gaze and arrow cues.

    Science.gov (United States)

    Hayward, Dana A; Ristic, Jelena

    2015-05-01

    The prevailing theoretical accounts of social cognitive processes propose that attention is preferentially engaged by social information. However, empirical investigations report virtually indistinguishable attention effects for social (e.g., gaze) and nonsocial (e.g., arrow) stimuli when a cuing task is used. Here, we show that this discrepancy between theory and data reflects a difference in how the extraneous processes induced by the cuing task's parameters (i.e., tonic alertness and voluntary temporal preparation) modulate cue-specific attentional effects. Overall, we found that tonic alertness and voluntary temporal preparation interacted within the cuing task, resulting in underadditive magnitudes of spatial orienting and superadditive magnitudes of the foreperiod effect. However, those interactions differentially affected social and nonsocial attention. While typical rapid social orienting was resilient to changing task parameters, sustained social orienting was eliminated only when the contribution of both extraneous processes was reduced. In contrast, orienting elicited by nonsocial arrows grew in magnitude with the reduction of voluntary temporal preparation and was delayed by the joint reduction of tonic alertness and voluntary temporal preparation. Together, these data indicate that cue-specific attention effects are masked by task dynamics of the cuing paradigm and highlight a pivotal role of the cuing task parameters in both the measurement and the theoretical attribution of spatial attention effects.

  17. Language of Mechanisms: Exam Analysis Reveals Students' Strengths, Strategies, and Errors When Using the Electron-Pushing Formalism (Curved Arrows) in New Reactions

    Science.gov (United States)

    Flynn, Alison B.; Featherstone, Ryan B.

    2017-01-01

    This study investigated students' successes, strategies, and common errors in their answers to questions that involved the electron-pushing (curved arrow) formalism (EPF), part of organic chemistry's language. We analyzed students' answers to two question types on midterms and final exams: (1) draw the electron-pushing arrows of a reaction step,…

  18. Recognition of Damaged Arrow-Road Markings by Visible Light Camera Sensor Based on Convolutional Neural Network

    Directory of Open Access Journals (Sweden)

    Husan Vokhidov

    2016-12-01

    Full Text Available Automobile driver information as displayed on marked road signs indicates the state of the road, traffic conditions, proximity to schools, etc. These signs are important to insure the safety of the driver and pedestrians. They are also important input to the automated advanced driver assistance system (ADAS, installed in many automobiles. Over time, the arrow-road markings may be eroded or otherwise damaged by automobile contact, making it difficult for the driver to correctly identify the marking. Failure to properly identify an arrow-road marker creates a dangerous situation that may result in traffic accidents or pedestrian injury. Very little research exists that studies the problem of automated identification of damaged arrow-road marking painted on the road. In this study, we propose a method that uses a convolutional neural network (CNN to recognize six types of arrow-road markings, possibly damaged, by visible light camera sensor. Experimental results with six databases of Road marking dataset, KITTI dataset, Málaga dataset 2009, Málaga urban dataset, Naver street view dataset, and Road/Lane detection evaluation 2013 dataset, show that our method outperforms conventional methods.

  19. New result on K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}} from BNL E787

    Energy Technology Data Exchange (ETDEWEB)

    REDLINGER,G.

    1999-06-21

    E787 at BNL has reported evidence for the rare decay K{sup +} {r_arrow} {pi}{sup +}{nu}{bar {nu}}, based on the observation of one candidate event. In this paper, we present the result of analyzing a new dataset of comparable sensitivity to the published result.

  20. Asymmetric transport of light in arrow-shape photonic crystal waveguides

    Science.gov (United States)

    Rahal, H.; AbdelMalek, F.

    2017-03-01

    In this paper, we report a design of an asymmetric light propagation based on the Photonic Crystal (PC) structure. The proposed PC is constructed of an arrow-shaped structure integrating different rows of air holes which offer more than 65% transmission in one direction and less than 1% in the opposite direction. The proposed PC is based on the use of two parallel PC waveguides with different air holes in a single platform. The design, optimization and performance of the PC waveguide devices are carried out by employing in-house accurate 2D Finite Difference Time Domain (2D FDTD) computational techniques. Our preliminary numerical simulation results show that complete asymmetric transmission can be achieved in the proposed single structure which would play a significant contribution on realization of high-volume nanoscale photonic integrated circuitry.

  1. Residual hydrocarbon toxicity in sediments impacted by the 1970 Arrow spill

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.; Wohlgeschaffen, G.D.; Tremblay, G.H. [Fisheries and Oceans. Inst. Maurice Lamontagne, Mont-Joli, PQ (Canada); Vandermeulen, J.H.; Mossman, D.C. [Fisheries and Oceans. Bedford Institute of Oceanography, Dartmouth, NS (Canada); Doe, K.G.; Jackman, P.M. [Environment Canada. Environmental Science Centre, Moncton, NB (Canada); Prince, R.C.; Garrett, R.M.; Haith, C.E. [Exxon Research and Engineering Co., Annandale, NJ (United States)

    1998-09-01

    An assessment of the biological effects associated with a marine oil spill that occurred more than twenty years ago was presented. In 1970, 2,045 m{sup 3} of Bunker C crude oil impacted 300 km of Nova Scotia`s coastline when the tanker Arrow ran aground. Only 10 per cent of the contaminated shoreline was subjected to cleanup. The other 90 per cent was left to degrade naturally. In 1993 and 1997, samples of sediment and interstitial water were collected in areas where residual oil from the spill was still evident. Chemical analysis has shown that the oil has undergone substantial biodegradation. As a result of natural attenuation process for more than a 20 year period, the toxicity of the residual oil has been reduced. Substantial evidence of habitat recovery was also found. 43 res., 2 tabs., 6 figs.

  2. Scan path entropy and Arrow plots: Capturing scanning behavior of multiple observers

    Directory of Open Access Journals (Sweden)

    Ignace T C Hooge

    2013-12-01

    Full Text Available Designers of visual communication material want their material to attract and retain attention. In marketing research, heat maps, dwell time, and time to AOI first hit are often used as evaluation parameters. Here we present two additional measures 1 scan path entropy to quantify gaze guidance and 2 the arrow plot to visualize the average scan path. Both are based on string representations of scan paths. The latter also incorporates transition matrices and time required for 50% of the observers to first hit AOIs (T50. The new measures were tested in an eye tracking study (48 observers, 39 advertisements. Scan path entropy is a sensible measure for gaze guidance and the new visualization method reveals aspects of the average scan path and gives a better indication in what order global scanning takes place.

  3. Symmetry and the arrow of time in theoretical black hole astrophysics

    CERN Document Server

    Garofalo, David

    2015-01-01

    While the basic laws of physics seem time-reversal invariant, our understanding of the apparent irreversibility of the macroscopic world is well grounded in the notion of entropy. Because astrophysics deals with the largest structures in the Universe, one expects evidence there for the most pronounced entropic arrow of time. However, in recent theoretical astrophysics work it appears possible to identify constructs with time-reversal symmetry, which is puzzling in the large-scale realm especially because it involves the engines of powerful outflows in active galactic nuclei which deal with macroscopic constituents such as accretion disks, magnetic fields, and black holes. Nonetheless, the underlying theoretical structure from which this accreting black hole framework emerges displays a time-symmetric harmonic behavior, a feature reminiscent of basic and simple laws of physics. While we may expect such behavior for classical black holes due to their simplicity, manifestations of such symmetry on the scale of g...

  4. On The Origin Of The Classical And Quantum Electrodynamic Arrows Of Time

    CERN Document Server

    Leiter, Darryl

    2009-01-01

    In order to describe the microscopic classical electrodynamic measurement process in an operational, relativistic, observer-participant manner, an Abelian operator symmetry of microscopic observer-participation called Measurement Color (MC) is incorporated into the field theoretic structure of the Classical Electrodynamics (CED) of interacting point charges. The new formalism, called Measurement Color Classical Electrodynamics (MC-CED), is shown to be a nonlocal, time reversal violating, classical field theory of interacting point charges in which a microscopic classical electrodynamic arrow of time emerges dynamically, independent of any external thermodynamic or cosmological assumptions. We then show how the standard canonical quantum field quantization program can be applied to the classical observer-participant MC-CED theory. This leads to the development of a relativistic, observer-participant Measurement Color Quantum Electrodynamic (MC-QED) formalism in the Heisenberg Picture, which contains an intrins...

  5. Study of advanced composite structural design concepts for an arrow wing supersonic cruise configuration

    Science.gov (United States)

    Turner, M. J.; Grande, D. L.

    1978-01-01

    Based on estimated graphite and boron fiber properties, allowable stresses and strains were established for advanced composite materials. Stiffened panel and conventional sandwich panel concepts were designed and analyzed, using graphite/polyimide and boron/polyimide materials. The conventional sandwich panel was elected as the structural concept for the modified wing structure. Upper and lower surface panels of the arrow wing structure were then redesigned, using high strength graphite/polyimide sandwich panels, retaining the titanium spars and ribs from the prior study. The ATLAS integrated analysis and design system was used for stress analysis and automated resizing of surface panels. Flutter analysis of the hybrid structure showed a significant decrease in flutter speed relative to the titanium wing design. The flutter speed was increased to that of the titanium design by selective increase in laminate thickness and by using graphite fibers with properties intermediate between high strength and high modulus values.

  6. Preparation and characterisation of irradiated crab chitosan and New Zealand Arrow squid pen chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Shavandi, Amin, E-mail: amin.shavandi@postgrad.otago.ac.nz [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Bekhit, Adnan A. [Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Alexandria, Alexandria (Egypt); Bekhit, Alaa El-Din A. [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Sun, Zhifa [Department of Physics, University of Otago, Dunedin (New Zealand); Ali, M. Azam [Department of Applied Sciences, University of Otago, Dunedin (New Zealand)

    2015-11-01

    The properties of chitosan from Arrow squid (Nototodarus sloanii) pen (CHS) and commercial crab shell (CHC) were investigated using FTIR, DSC, SEM and XRD before and after irradiation at the dose of 28 kGy in the presence or absence of 5% water. Also, the viscosity, deacetylation degree, water and oil holding capacities, colour and antimicrobial activities of the chitosan samples were determined. Irradiation decreased (P < 0.05) the viscosity of CHC from 0.21 to 0.03 Pa s and of CHS from 1.71 to 0.23 Pa s. The inclusion of water had no effect on the viscosity of irradiated chitosan. Irradiation did not affect the degree of deacetylation of CHC, but increased the deacetylation degree of CHS from 72.78 to 82.29% in samples with 5% water. Water and oil holding capacities of CHS (1197.30% and 873.3%, respectively) were higher (P < 0.05) than those found in CHC (340.70% and 264.40%, respectively). The water and oil holding capacities were decreased for both types of chitosan irradiation, but were not affected by the addition of water. Squid pen chitosan was whiter in colour (White Index = 90.06%) compared to CHC (White Index = 83.70%). Generally, the CHC samples (control and irradiated) exhibited better antibacterial activity compared to CHS, but the opposite was observed with antifungal activity. - Highlights: • Chitosan prepared from Arrow squid pens (Nototodarus sloanii). • Chitosan samples were gamma irradiated at 28 kGy. • Squid pen chitosan showed high fat and water uptake capacities compared to crab shell chitosan. • Gamma irradiation enhanced the DDA of squid pen chitosan but not crab shell chitosan.

  7. Reactions {ital pd}{r_arrow}{sup 3}He{eta} and {ital pd}{r_arrow}{sup 3}He{pi}{sup +}{pi}{sup {minus}} near the {eta} threshold

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, B.; Boudard, A.; Fabbro, B.; Garcon, M.; Kerboul, C.; Poitou, J.; Wellers, F. [Service de Physique Nucleaire, CEA Saclay, F-91191 Gif-sur-Yvette (France); Jacobs, W.W.; Saudinos, J.; Tomasi-Gustafsson, E. [Laboratoire National Saturne, F-91191 Gif-sur-Yvette (France); Mouly, J.P. [Service d`Etudes des Detecteurs, CEA Saclay, F-91191 Gif-sur-Yvette (France); Kessler, R.S.; Nefkens, B.M.; Tippens, B. [Department of Physics, University of California, Los Angeles, California 90024 (United States); van der Schaaf, A. [Physik-Institut der Universitaet Zuerich, CH-8057 Zuerich (Switzerland); Abegg, R.; van Oers, W.T. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 (CANADA); Briscoe, W.; Petrov, A. [Center for Nuclear Studies and Department of Physics, The George Washington University, Washington, D.C. 20052 (United States); Moalem, A. [Department of Physics, Ben Gurion University, Beer-Sheva 84105 (Israel)

    1996-05-01

    The reaction {ital pd}{r_arrow}{sup 3}He{eta} has been studied with the SPES2 spectrometer, for proton energies between 0.2 MeV and 11 MeV above threshold. The total cross section rises from 0.25 to 0.40 {mu}b in this region. The observed energy dependence can be attributed to the strong final state interaction. The angular distribution is nearly isotropic, consistent with {ital S} wave production. A measurement of the {ital pd}{r_arrow}{sup 3}He{pi}{sup +}{pi}{sup {minus}} cross section in the threshold region is also presented. The setup, which is capable of producing 10{sup 5} tagged {eta}/s with only a few percent background, is used to investigate rare {eta} decays. {copyright} {ital 1996 The American Physical Society.}

  8. Prospects for measuring K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}} and K{sub L}{sup 0} {r_arrow} {pi}{sup 0} {nu}{bar {nu}} at BNL

    Energy Technology Data Exchange (ETDEWEB)

    Bryman, D.A.; Littenberg, L.

    2000-09-18

    Rare kaon decay experiments underway or planned for the BNL AGS will yield new and independent determinations of V*{sub ts}V{sub td}. A measurement of B(K{sub L}{sup 0} {r_arrow} {pi}{sup 0} {nu}{bar {nu}}) allows a determination of the imaginary part of this quantity, which is the fundamental CP-violating parameter of the Standard Model, in a uniquely clean manner. Since the measurement of B(K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}}) determines {vert_bar}V*{sub ts}V{sub td}, a complete derivation of the unitarity triangle is facilitated. These results can be compared to high precision data expected to come from the B sector in a number of ways, allowing for unique tests of new physics.

  9. Observation of the Decay {ital K}{sup +} {r_arrow} {pi}{sup +}{mu}{sup +}{mu}{sup {minus}}

    Energy Technology Data Exchange (ETDEWEB)

    Adler, S.; Atiya, M.S.; Chiang, I.; Frank, J.S.; Haggerty, J.S.; Kycia, T.F.; Li, K.K.; Littenberg, L.S.; Sambamurti, A.; Stevens, A.; Strand, R.C.; Witzig, C. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Louis, W.C. [Medium Energy Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Akerib, D.S.; Ardebili, M.; Convery, M.; Ito, M.M.; Marlow, D.R.; McPherson, R.; Meyers, P.D.; Selen, M.A.; Shoemaker, F.C.; Smith, A.J. [Joseph Henry Laboratories, Princeton University, Princeton, New Jersey 08544 (United States); Blackmore, E.W.; Bryman, D.A.; Felawka, L.; Konaka, A.; Kuno, Y.; Macdonald, J.A.; Numao, T.; Padley, P.; Poutissou, J.; Poutissou, R.; Roy, J.; Turcot, A.S. [TRIUMF, Vancouver, British Columbia, Canada, V6T 2A3 (CANADA); Kitching, P.; Nakano, T.; Rozon, M.; Soluk, R. [Centre for Subatomic Research, University of Alberta, Edmonton, Alberta, Canada, T6G 2N5 (CANADA)

    1997-12-01

    We have observed the rare decay K{sup +} {r_arrow} {pi}{sup +}{mu}{sup +}{mu}{sup {minus}} and measured the branching ratio {Gamma}(K{sup +} {r_arrow} {pi}{sup +}{mu}{sup +}{mu}{sup {minus}}) /{Gamma}(K{sup +} {r_arrow} all)=[5.0{plus_minus}0.4(stat){plus_minus} 0.7(syst){plus_minus}0.6(th)]{times}10{sup {minus}8}. We compare this result with predictions from chiral perturbation theory and estimates based on the decay K{sup +} {r_arrow} {pi}{sup +}e{sup +}e{sup {minus}}. {copyright} {ital 1997} {ital The American Physical Society}

  10. Is the Hypothesis About a Low Entropy Initial State of the Universe Necessary for Explaining the Arrow of Time?

    CERN Document Server

    Goldstein, Sheldon; Zanghi, Nino

    2016-01-01

    According to statistical mechanics, micro-states of an isolated physical system (say, a gas in a box) at time $t_0$ in a given macro-state of less-than-maximal entropy typically evolve in such a way that the entropy at time $t$ increases with $|t-t_0|$ in both time directions. In order to account for the observed entropy increase in only one time direction, the thermodynamic arrow of time, one usually appeals to the hypothesis that the initial state of the universe was one of very low entropy. In certain recent models of cosmology, however, no hypothesis about the initial state of the universe is invoked. We discuss how the emergence of a thermodynamic arrow of time in such models can nevertheless be compatible with the above-mentioned consequence of statistical mechanics, appearances to the contrary notwithstanding.

  11. Beetle and plant arrow poisons of the Ju|’hoan and Hai||om San peoples of Namibia (Insecta, Coleoptera, Chrysomelidae; Plantae, Anacardiaceae, Apocynaceae, Burseraceae)

    OpenAIRE

    2016-01-01

    Abstract The use of archery to hunt appears relatively late in human history. It is poorly understood but the application of poisons to arrows to increase lethality must have occurred shortly after developing bow hunting methods; these early multi-stage transitions represent cognitive shifts in human evolution. This paper is a synthesis of widely-scattered literature in anthropology, entomology, and chemistry, dealing with San (“Bushmen”) arrow poisons. The term San (or Khoisan) covers many i...

  12. Terminal deletion of the long arm of chromosome 3 [46,XX,del(3)(q27{r_arrow}qter)

    Energy Technology Data Exchange (ETDEWEB)

    Chitayat, D.; Babul, R.; Silver, M.M. [Univ. of Toronto, Ontario (Canada)] [and others

    1996-01-02

    We report on a terminal deletion of the long arm of chromosome 3[46,XX,del(3)(q27{r_arrow}qter)] in a female newborn infant who died 45 hours after delivery and had multiple congenital abnormalities including bilateral anophthalmia, congenital heart disease, and abnormal genitalia. The findings are compared to those of four previously reported cases with terminal de (3q). 8 refs., 4 figs., 1 tab.

  13. Review of neon-like and nickel-like ions lasing on the J = 0 {r_arrow} 1 line using the prepulse and multiple pulse techniques

    Energy Technology Data Exchange (ETDEWEB)

    Nilsen, J.; Moreno, J.C.; Da Silva, L.B.; Barbee, T.W. Jr. [Lawrence Livermore National Lab., CA (United States); Li, Y.; Lu, P.; Fill, E.E. [Max-Planck-Inst. fuer Quantenoptik, Garching (Germany); Fiedorowicz, H.; Bartnik, A. [Military Univ. of Technology, Warsaw (Poland). Inst. of Optoelectronics

    1995-11-01

    The authors discuss the use of a prepulse technique to achieve lasing in low-Z neon-like ions on the 3p {r_arrow} 3s(J = 0 {r_arrow} 1) transition. Lasing has now been observed on this transitions for neon-like ions from chlorine to selenium with wavelengths ranging from 528 {angstrom} to 182 {angstrom}. For the germanium targets they present two dimensional space resolves images of the laser output with magnification of ten. Using a gas puff target as an alternative to the prepulse technique, they observe lasing at 469 {angstrom} in neon-like argon. Using a series of 100 ps pulses 400 ps apart to illuminate germanium and selenium plasmas they present results which now show the 3p {r_arrow} 3s(J = 0 {r_arrow} 1) transition to dominate the other laser lines even for selenium. Applying the multiple pulse technique to nickel-like ions they observed lasing at 79 {angstrom} on the 4d {r_arrow} 4p(J = 0 {r_arrow} 1) transition in nickel-like neodymium (Z = 60) when a series of 100--150 ps pulses which are 400--500 ps apart are used to illuminate slab targets of neodymium. To maximize the laser output for neodymium they combine the advantages of coupling two slab targets, using the traveling wave geometry, and curving the target surface.

  14. Contributions to the Dart versus Arrow Debate: New Data from Holocene Projectile Points from Southeastern and Southern Brazil

    Directory of Open Access Journals (Sweden)

    Mercedes Okumura

    2015-12-01

    Full Text Available Lithic bifacial points are very common in the southern and southeastern regions of the Brazilian territory. Dated from Early to Late Holocene, these artifacts have not been studied in terms of their propulsion system. Given the characteristics of the bow and arrow compared to the atlatl and dart, there are important differences in the size and weight of arrowheads and dart points. Applying the techniques proposed by Shott (1997, Bradbury (1997, Fenenga (1953, Hughes (1998, and Hildebrandt and King (2012 to specimens recovered from eight sites dating from the early to the late Holocene, this work aims to present preliminary results to better understand the potential presence of darts and arrows in southeastern and southern Brazil. There was a variation in the results according to the application of different techniques. At least one set of points, dated from the Early Holocene, presented quite a high proportion of specimens classified as arrows, indicating the presence of points that could be used as arrowheads.

  15. Observation of the Decay {ital K}{sup +} {r_arrow} {pi}{sup +}{gamma}{gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Kitching, P.; Nakano, T.; Rozon, M.; Soluk, R. [Centre for Subatomic Research, University of Alberta, Edmonton, Alberta, T6G 2N5 (CANADA); Adler, S.; Atiya, M.S.; Chiang, I.; Frank, J.S.; Haggerty, J.S.; Kycia, T.F.; Li, K.K.; Littenberg, L.S.; Sambamurti, A.; Stevens, A.; Strand, R.C.; Witzig, C. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Louis, W.C. [Medium Energy Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Akerib, D.S.; Ardebili, M.; Convery, M.; Ito, M.M.; Marlow, D.R.; McPherson, R.A.; Meyers, P.D.; Selen, M.A.; Shoemaker, F.C.; Smith, A.J. [Joseph Henry Laboratories, Princeton University, Princeton, New Jersey 08544 (United States); Blackmore, E.W.; Bryman, D.A.; Felawka, L.; Konaka, A.; Kuno, Y.; Macdonald, J.A.; Numao, T.; Padley, P.; Poutissou, J.; Poutissou, R.; Roy, J.; Turcot, A.S. [TRIUMF, Vancouver, British Columbia, V6T 2A3 (CANADA)

    1997-11-01

    The first observation of the decay K{sup +}{r_arrow}{pi}{sup +}{gamma}{gamma} is reported. A total of 31 events was observed with an estimated background of 5.1{plus_minus}3.3 events in the {pi}{sup +} momentum range from 100 to 180 MeV/{ital c}. The corresponding partial branching ratio, B(K{sup +}{r_arrow}{pi}{sup +}{gamma}{gamma} ,100 MeV/c{lt}P{sub {pi}{sup +} }{lt}180 MeV/c) , is [6.0{plus_minus}1.5(stat){plus_minus}0.7 (syst)]{times}10{sup {minus}7} . No K{sup +}{r_arrow}{pi}{sup +}{gamma}{gamma} decay was observed in the {pi}{sup +} momentum region greater than 215 MeV/{ital c}. The observed {pi}{sup +} momentum spectrum is compared with the predictions of chiral perturbation theory. {copyright} {ital 1997} {ital The American Physical Society}

  16. Symmetry and the Arrow of Time in Theoretical Black Hole Astrophysics

    Directory of Open Access Journals (Sweden)

    David Garofalo

    2015-01-01

    Full Text Available While the basic laws of physics seem time-reversal invariant, our understanding of the apparent irreversibility of the macroscopic world is well grounded in the notion of entropy. Because astrophysics deals with the largest structures in the Universe, one expects evidence there for the most pronounced entropic arrow of time. However, in recent theoretical astrophysics work it appears possible to identify constructs with time-reversal symmetry, which is puzzling in the large-scale realm especially because it involves the engines of powerful outflows in active galactic nuclei which deal with macroscopic constituents such as accretion disks, magnetic fields, and black holes. Nonetheless, the underlying theoretical structure from which this accreting black hole framework emerges displays a time-symmetric harmonic behavior, a feature reminiscent of basic and simple laws of physics. While we may expect such behavior for classical black holes due to their simplicity, manifestations of such symmetry on the scale of galaxies, instead, surprise. In fact, we identify a parallel between the astrophysical tug-of-war between accretion disks and jets in this model and the time symmetry-breaking of a simple overdamped harmonic oscillator. The validity of these theoretical ideas in combination with this unexpected parallel suggests that black holes are more influential in astrophysics than currently recognized and that black hole astrophysics is a more fundamental discipline.

  17. Stochasticity, decoherence and an arrow of time from the discretization of time?

    Indian Academy of Sciences (India)

    M C Valsakumar

    2005-04-01

    Certain intriguing consequences of the discreteness of time on the time evolution of dynamical systems are discussed. In the discrete-time classical mechanics proposed here, there is an arrow of time that follows from the fact that the replacement of the time derivative by the backward difference operator alone can preserve the non-negativity of the phase space density. It is seen that, even for free particles, all the degrees of freedom are correlated in principle. The forward evolution of functions of phase space variables by a finite number of time steps, in this discrete-time mechanics, depends on the entire continuous-time history in the interval [0, ∞]. In this sense, discrete time evolution is non-local in time from a continuous-time point of view. A corresponding quantum mechanical treatment is possible via the density matrix approach. The interference between non-degenerate quantum mechanical states decays exponentially. This decoherence is present, in principle, for all systems; however, it is of practical importance only in macroscopic systems, or in processes involving large energy changes.

  18. Supersonic Aerodynamic Design Improvements of an Arrow-Wing HSCT Configuration Using Nonlinear Point Design Methods

    Science.gov (United States)

    Unger, Eric R.; Hager, James O.; Agrawal, Shreekant

    1999-01-01

    This paper is a discussion of the supersonic nonlinear point design optimization efforts at McDonnell Douglas Aerospace under the High-Speed Research (HSR) program. The baseline for these optimization efforts has been the M2.4-7A configuration which represents an arrow-wing technology for the High-Speed Civil Transport (HSCT). Optimization work on this configuration began in early 1994 and continued into 1996. Initial work focused on optimization of the wing camber and twist on a wing/body configuration and reductions of 3.5 drag counts (Euler) were realized. The next phase of the optimization effort included fuselage camber along with the wing and a drag reduction of 5.0 counts was achieved. Including the effects of the nacelles and diverters into the optimization problem became the next focus where a reduction of 6.6 counts (Euler W/B/N/D) was eventually realized. The final two phases of the effort included a large set of constraints designed to make the final optimized configuration more realistic and they were successful albeit with a loss of performance.

  19. Threshold responses of Blackside Dace (Chrosomus cumberlandensis) and Kentucky Arrow Darter (Etheostoma spilotum) to stream conductivity

    Science.gov (United States)

    Hitt, Nathaniel P.; Floyd, Michael; Compton, Michael; McDonald, Kenneth

    2016-01-01

    Chrosomus cumberlandensis (Blackside Dace [BSD]) and Etheostoma spilotum (Kentucky Arrow Darter [KAD]) are fish species of conservation concern due to their fragmented distributions, their low population sizes, and threats from anthropogenic stressors in the southeastern United States. We evaluated the relationship between fish abundance and stream conductivity, an index of environmental quality and potential physiological stressor. We modeled occurrence and abundance of KAD in the upper Kentucky River basin (208 samples) and BSD in the upper Cumberland River basin (294 samples) for sites sampled between 2003 and 2013. Segmented regression indicated a conductivity change-point for BSD abundance at 343 μS/cm (95% CI: 123–563 μS/cm) and for KAD abundance at 261 μS/cm (95% CI: 151–370 μS/cm). In both cases, abundances were negligible above estimated conductivity change-points. Post-hoc randomizations accounted for variance in estimated change points due to unequal sample sizes across the conductivity gradients. Boosted regression-tree analysis indicated stronger effects of conductivity than other natural and anthropogenic factors known to influence stream fishes. Boosted regression trees further indicated threshold responses of BSD and KAD occurrence to conductivity gradients in support of segmented regression results. We suggest that the observed conductivity relationship may indicate energetic limitations for insectivorous fishes due to changes in benthic macroinvertebrate community composition.

  20. Study of advanced composite structural design concepts for an arrow wing supersonic cruise configuration, task 3

    Science.gov (United States)

    1978-01-01

    A structural design study was conducted to assess the relative merits of structural concepts using advanced composite materials for an advanced supersonic aircraft cruising at Mach 2.7. The configuration and structural arrangement developed during Task I and II of the study, was used as the baseline configuration. Allowable stresses and strains were established for boron and advanced graphite fibers based on projected fiber properties available in the next decade. Structural concepts were designed and analyzed using graphite polyimide and boron polyimide, applied to stiffened panels and conventional sandwich panels. The conventional sandwich panels were selected as the structural concept to be used on the wing structure. The upper and lower surface panels of the Task I arrow wing were redesigned using high-strength graphite polyimide sandwich panels over the titanium spars and ribs. The ATLAS computer system was used as the basis for stress analysis and resizing the surface panels using the loads from the Task II study, without adjustment for change in aeroelastic deformation. The flutter analysis indicated a decrease in the flutter speed compared to the baseline titanium wing design. The flutter analysis indicated a decrease in the flutter speed compared to the baseline titanium wing design. The flutter speed was increased to that of the titanium wing, with a weight penalty less than that of the metallic airplane.

  1. Ethogram analysis reveals new body patterning behavior of the tropical arrow squid Doryteuthis plei off the São Paulo Coast.

    Science.gov (United States)

    Postuma, Felippe A; Gasalla, Maria A

    2015-10-01

    Squids can express several body patterns, aided by a variety of visual signals that are produced by chromatophore organs. However, for several squid species, body patterning behavior during reproductive activity is still not completely understood. For example, what are the specific patterning changes and other visual signals, how do they appear, and how long do they last? To test the hypothesis that distinct chromatic components appear at different durations on the skin of the tropical arrow squid Doryteuthis plei in the Southern Hemisphere, we identified and described its body patterning behavior. Specimen squids were obtained from off the South Brazil Bight, near the coast of the São Paulo shelf. Animals were maintained and monitored in circular tanks for 62 d over six observation periods, from 2011 through 2013. An ethogram was constructed showing 19 chromatic, 5 locomotor, and 12 postural components, or body patterns, associated with reproductive behavior. New chromatic components (i.e., those not yet reported in the North Atlantic D. plei species), particularly those linked to female sexual maturity, were observed. A postural component, the "J-Posture," linked to defenses and alarm, also was noted. The average time spent for "light" components was 32 s. The corresponding "dark" components had an average duration of 28 s. Females displayed the chromatic components related to calm behavior longer than males. However, males appeared to be more dedicated to disputes over resources, and used rapid, miscellaneous visual signaling. In conclusion, new basic types of body patterns are described for D. plei. The repertoire of chromatic components reported in the ethogram is, to our knowledge, the first record for D. plei of the Southern Hemisphere.

  2. Evidence of K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}}: The BNL E787 1995 result (How did we get here)

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, I.H.; E787 Collaboration

    1998-02-01

    The kaon was studied very thoroughly since its discovery some 50 years ago. In the study of charged kaon branching ratios, it was noticed that K{sup +} {r_arrow} {pi}{sup 0}e{sup +}{nu}{sub e} is allowed while K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} is not. The latter was then empirically classified as a forbidden decay, leading to the so called strangeness changing current rule. The decay K{sup +} {r_arrow} {pi}{sup 0}e{sup +}{nu}{sub e} is mediated by the strangeness changing charged current and its branching ratio is 4.8%. By contrast K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} is a strangeness changing neutral current, which is forbidden. In 1970, the GIM model was introduced to explain this effect and in 1974, Gaillard and Lee calculated the K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} branching ratio to be on the order of 10{sup {minus}10}. In the current theory, the K{sup +} {r_arrow} {pi}{sup +}{nu}{anti {nu}} is mediated by a Flavor Changing Neutral Current (FCNC) in which the cancellation of the three quark generations should be complete down to second order except for the difference in the quark masses. The top quark is much heavier than the charm and up quarks, so that the cancellation is not complete. In other words, this decay is more dependent on the top sector. The measurement of K{sup +} {r_arrow}{pi}{sup +}{nu}{anti {nu}} branching ratio measures the modulus of the V{sub td} element of the CKM Matrix. The 1995 results of E787 were published in 1997. This report is focused on how the author achieved the goal of detecting events with such as small branching ratio.

  3. Search for anomalous WW/WZ {r_arrow} e{nu}jj production at D0; Busqueda de produccion anomala WW/WZ {r_arrow}e{nu}jj en D-Zero

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, A.S.

    1997-02-01

    A search for anomalous WW and WZ production in p{anti p} collisions at {radical}s = 1.8 TeV using the D0 detector at Fermilab is presented. With a data sample of p{anti p} {r_arrow} e{nu}jjX events corresponding to an integrated luminosity of 76.5 {+-} 4.1pb{sup {minus}1}. 399 candidate events were identified, from which 387.1 {+-} 39.8 events were estimated to be background. No deviations from the Standard Model were seen, which predicts 16.2 {+-} 2.7 events. The 95% CL limit on the cross section {sigma}(p{anti p} {r_arrow} W{sup +}W{sup {minus}}X) was calculated to be 93.8 pb. Limits on the CP-conserving anomalous WW{sub {gamma}} and WWZ coupling parameters were obtained from a binned likelihood fit to the transverse momentum spectrum of the W boson. Assuming that the WW{sub {gamma}} and WWZ coupling parameters are equal, the 95% CL limits on the CP-conserving couplings are {minus}0.56 < {Delta}{kappa} < 0.75 (with {lambda} = 0) and {minus}0.42 < {lambda} < 0.44 (with {Delta}{kappa} = 0), for a form factor scale {Lambda}{sub FF} = 1.5 TeV. Limits on other assumptions are also reported. These results were combined with the previous D0 WW, WZ {r_arrow} e{nu}jj published results (13.7 {+-} 0.7 pb{sup {minus}1}), and the limits on the anomalous coupling parameters were set to {minus}0.44 < {Delta}{kappa} < 0.60 (with {lambda} = 0) and {minus}0.34 < {lambda} 0.37 (with {Delta}{kappa} = 0), for a form factor scale {Lambda}{sub FF} = 2.0 TeV.

  4. Lattice study of semileptonic {ital B} decays: {ital {bar B}}{r_arrow}{ital Dl}{bar {nu}} decays

    Energy Technology Data Exchange (ETDEWEB)

    Bowler, K.C.; Hazel, N.M.; Henty, D.S.; Hoeber, H.; Kenway, R.D.; Richards, D.G.; Shanahan, H.P.; Simone, J.N. [Department of Physics & Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Lellouch, L. [Centre de Physique Theorique, CNRS Luminy, Case 907, F-13288 Marseille Cedex 9 (France); Nieves, J.; Sachrajda, C.T.; Wittig, H. [Physics Department, The University, Southampton SO7 1BJ (United Kingdom); (UKQCD Collaboration)

    1995-11-01

    We then use these functions, in conjunction with heavy-quark effective theory, to extract {ital V}{sub {ital c}{ital b}} with no free parameters from the {ital {bar B}}{r_arrow}{ital D}{sup *}{ital l}{bar {nu}} decay rate measured by the ALEPH, ARGUS, and CLEO Collaborations. Using the CLEO data, for instance, we obtain {vert_bar}{ital V}{sub {ital c}{ital b}}{vert_bar} =0.037{sub {minus}1{minus}2{minus}1}{sup +1+2+4}[0.99/1+{beta}{sup {ital A}}{sub 1}(1)]1/1 +{delta}{sub 1/{ital m}{ital c}}{sup 2}, where {delta}{sub 1/{ital m}{ital c}}{sup 2} is the power correction inversely proportional to the square of the charm quark mass, and {beta}{sup {ital A}}{sub 1}(1) is the relevant radiative correction at zero recoil. Here, the first set of errors is experimental, the second represents the statistical error, and the third represents the systematic error in our evaluation of the Isgur-Wise function. We also use our Isgur-Wise functions and heavy-quark effective theory to calculate branching ratios for {ital {bar B}}{sub ({ital s})}{r_arrow}{ital D}{sub ({ital s})}{ital l}{bar {nu}} and {ital {bar B}}{sub ({ital s})}{r_arrow}{ital D}{sub ({ital s})}{sup *}{ital l}{bar {nu}} decays.

  5. Clinical experience of ocular trauma with metallic arrow-headed foreign bodies%眼部弓箭射伤诊治的体会

    Institute of Scientific and Technical Information of China (English)

    林育华

    2011-01-01

    Objective To discuss surgical treatments of patients with orbital foreign bodies. Methods We analyzed 7 cases(7 eyes) of eye injury with arrow-head foreign body.The huge foreign body (arrows)was extracted after soft tissue separation was done or the removal of arrows was together with enucleation. Results Arrows were completely removed in all the patients. No sight-threatening to patients if there was no eyeball injury. The sight was lost in patients with eyeball rupture. Craniocerebral trauma and neurological complications occurred on the basis of the depth of the arrows in the patients' eyes. Conclusion It is rare that arrows are orbital foreign bodies,which should be removed timely by surgery. Computer tomography (CT) examination should done before the operation. The method of operation depends on the eye injury positions and the accompanied eyeball double perforation and craniocerebral trauma.%目的 探讨眼部弓箭射伤的手术治疗方法.方法 7例(7眼)眼部弓箭伤进行分析.7例眼部巨大异物(箭)分别采用分离软组织后拔出和眼球摘除同时拔出异物(箭).结果 7例均完整取出弓箭异物,不伤及眼球者视力完好,眼球破裂者视力丧失,伴颅脑损伤者有神经并发症.结论 眼部弓箭射伤是罕见的眼部巨大异物,需及时手术取出,术前行CT检查,手术的方式根据箭伤及的部位和是否伴有眼球贯通和颅脑伤.

  6. Attention Orienting in Response to Non-conscious Hierarchical Arrows: Individuals with Higher Autistic Traits Differ in Their Global/Local Bias

    Science.gov (United States)

    Laycock, Robin; Chan, Daniel; Crewther, Sheila G.

    2017-01-01

    One aspect of the social communication impairments that characterize autism spectrum disorder (ASD) include reduced use of often subtle non-verbal social cues. People with ASD, and those with self-reported sub-threshold autistic traits, also show impairments in rapid visual processing of stimuli unrelated to social or emotional properties. Hence, this study sought to investigate whether perceptually non-conscious visual processing is related to autistic traits. A neurotypical sample of thirty young adults completed the Subthreshold Autism Trait Questionnaire and a Posner-like attention cueing task. Continuous Flash Suppression (CFS) was employed to render incongruous hierarchical arrow cues perceptually invisible prior to consciously presented targets. This was achieved via a 10 Hz masking stimulus presented to the dominant eye that suppressed information presented to the non-dominant eye. Non-conscious arrows consisted of local arrow elements pointing in one direction, and forming a global arrow shape pointing in the opposite direction. On each trial, the cue provided either a valid or invalid cue for the spatial location of the subsequent target, depending on which level (global or local) received privileged attention. A significant autism-trait group by global cue validity interaction indicated a difference in the extent of non-conscious local/global cueing between groups. Simple effect analyses revealed that whilst participants with lower autistic traits showed a global arrow cueing effect, those with higher autistic traits demonstrated a small local arrow cueing effect. These results suggest that non-conscious processing biases in local/global attention may be related to individual differences in autistic traits. PMID:28149288

  7. Anomalous directional behaviour of the real parts of the induction arrows in the Eastern Alps: tectonic and palaeogeographic implications

    Directory of Open Access Journals (Sweden)

    P. A. Schnegg

    2001-06-01

    Full Text Available The electromagnetic induction pattern in the Eastern Alps is characterised by a (continuous large-scale zone on which the real parts of the induction arrows show anomalous directional behaviour. This zone extends from the Penninic Domain of Eastern Switzerland (Graubünden probably into the Carpathian ranges. A coarse mesh of a Magnetotelluric (MT and Geomagnetic Deep Sounding (GDS station in the Alps of Graubünden and Valais (Western Switzerland indicates that this electromagnetic anomaly is restricted to the Mesozoic sediments of the North Penninic Bündnerschiefer-facies that begins in Eastern Switzerland and extends towards the east beneath Austroalpine, South Penninic and Southalpine units. Striking similarities in position and arrangement between this zone and the magnetic signature in the Eastern Alps are found. The analysis of the GDS data with the method of the Hypothetical Event Analysis (HEA shows that current channelling affects the electromagnetic fields in this zone and causes the anomalous direction of induction arrows. Based on the combined interpretation of GDS data from the Eastern Alps and West Hungary together with our recent data from Switzerland, the following geological implications are discussed: i a spatial decoupling of induction processes from the upper to the lower crust; ii a lower crustal conductive structure caused by the indentation of the Northern Adriatic promontory or terrane; iii the eastward continuation of the Bündnerschiefer-facies at least to the tectonic window of Rechnitz.

  8. Implementing Quality Criteria in Designing and Conducting a Sequential Quan [right arrow] Qual Mixed Methods Study of Student Engagement with Learning Applied Research Methods Online

    Science.gov (United States)

    Ivankova, Nataliya V.

    2014-01-01

    In spite of recent methodological developments related to quality assurance in mixed methods research, practical examples of how to implement quality criteria in designing and conducting sequential QUAN [right arrow] QUAL mixed methods studies to ensure the process is systematic and rigorous remain scarce. This article discusses a three-step…

  9. Upper limit on the decay K{sup +}{r_arrow}e{sup +}{nu}{mu}{sup +}{mu}{sup {minus}}

    Energy Technology Data Exchange (ETDEWEB)

    Adler, S.; Atiya, M.S.; Chiang, I.; Frank, J.S.; Haggerty, J.S.; Kycia, T.F.; Li, K.K.; Littenberg, L.S.; Sambamurti, A.; Stevens, A.; Strand, R.C.; Witzig, C. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Louis, W.C. [Medium Energy Physics Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Akerib, D.S.; Ardebili, M.; Convery, M.; Ito, M.M.; Marlow, D.R.; McPherson, R.; Meyers, P.D.; Selen, M.A.; Shoemaker, F.C.; Smith, A.J. [Joseph Henry Laboratories, Princeton University, Princeton, New Jersey 08544 (United States); Blackmore, E.W.; Bryman, D.A.; Felawka, L.; Konaka, A.; Kuno, Y.; Macdonald, J.A.; Numao, T.; Padley, P.; Poutissou, R. Poutissou, J.; Roy, J.; Turcot, A.S. [TRIUMF, Vancouver, British Columbia, V6T 2A3 (CANADA); Kitching, P.; Nakano, T.; Rozon, M.; Soluk, R. [Center for Subatomic Research, University of Alberta, Edmonton, Alberta, T6G 2N5 (CANADA)

    1998-07-01

    An upper limit on the branching ratio for the decay K{sup +}{r_arrow}e{sup +}{nu}{mu}{sup +}{mu}{sup {minus}} is set at 5.0{times}10{sup {minus}7} at a 90{percent} confidence level, consistent with predictions from chiral perturbation theory. {copyright} {ital 1998} {ital The American Physical Society}

  10. Decisiones óptimas de consumo y portafolio Un enfoque de precios de estado de Arrow-Debreu

    Directory of Open Access Journals (Sweden)

    Nora Gavira Durón

    2011-01-01

    Full Text Available Esta investigación desarrolla, bajo el supuesto de mercados completos, un modelo estocástico que explica el proceso de toma de decisiones de un consumidor-inversionista racional al seleccionar un portafolio en un ambiente de riesgo de mercado sujeto a su restricción presupuestal. El modelo propuesto se desarrolla en el marco de utilidad esperada del tipo Von Neumann-Morgenstern y precios de estado del tipo Arrow-Debreu en un horizonte de planeación infinito. Los principales resultados son: 1 la proporción que el individuo asigna de su riqueza a la tenencia del activo riesgoso es constante y 2 la estrategia óptima de consumo que el agente sigue es que siempre consume la misma proporción de su riqueza.

  11. Test and evaluation report for Lockheed Idaho Technologies Company, arrow-pak packaging, docket 95-40-7A, type A container

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, D.L.

    1996-03-14

    This report incorporates the U.S. Department of Energy, Office of Facility Safety Analysis (DOE/EH-32) approval letter for packaging use. This report documents the U.S. Department of Transportation Specification 7A Type A (DOT-7A) compliance test results of the Arrow-Pak packaging. The Arrow-Pak packaging system consists of Marlex M-8000 Driscopipe, manufactured by Phillips-Driscopipe, Inc., and is sealed with two dome-shaped end caps manufactured from the same materials. The patented sealing process involves the use of electrical energy to heat opposing faces of the pipe and end caps, and hydraulic rams to press the heated surfaces together. This fusion process produces a homogeneous bonding of the end cap to the pipe. The packaging may be used with or without the two internal plywood spacers. This packaging configuration described in this report is designed to ship Type A quantities of solid radioactive materials.

  12. Final evaluation report for Lockheed Idaho Technologies Company, ARROW-PAK packaging, Docket 95-40-7A, Type A container

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, D.L.

    1995-11-01

    The report documents the U.S. Department of Transportation Specification 7A Type A (DOT-7A) compliance test results of the ARROW-PAK packaging. The ARROW-PAK packaging system consists of Marlex M-8000 Driscopipe (Series 8000 [gas] or Series 8600 [industrial]) resin pipe, manufactured by Phillips-Driscopipe, Inc., and is sealed with two dome-shaped end caps manufactured from the same materials. The patented sealing process involves the use of electrical energy to heat opposing faces of the pipe and end caps, and hydraulic rams to press the heated surfaces together. This fusion process produces a homogeneous bonding of the end cap to the pipe. The packaging may be used with or without the two internal plywood spacers. This packaging was evaluated and tested in October 1995. The packaging configuration described in this report is designed to ship Type A quantities of solid radioactive materials, Form No. 1, Form No. 2, and Form No. 3.

  13. Atomic sulfur: Frequency measurement of the J = 0 left arrow 1 fine-structure transition at 56.3 microns by laser magnetic resonance

    Science.gov (United States)

    Brown, John M.; Evenson, Kenneth M.; Zink, Lyndon R.

    1994-01-01

    The J = 0 left arrow 1 fine-structure transition in atomic sulfur (S I) in its ground (3)P state has been detected in the laboratory by far-infrared laser magnetic resonance. The fine-structure interval has been measured accurately as 5,322,492.9 +/- 2.8 MHz which corresponds to a wavelength of 56.325572 +/- 0.000030 micrometers.

  14. Prediction of accidents at full green and green arrow traffic lights in Switzerland with the aid of configuration-specific features.

    Science.gov (United States)

    Hubacher, Markus; Allenbach, Roland

    2004-09-01

    In this study it was endeavored to predict full green and green arrow accidents at traffic lights, using configuration-specific features. This was done using the statistical method known as Poisson regression. A total of 45 sets of traffic lights (criteria: in an urban area, with four approach roads) with 178 approach roads were investigated (the data from two approach roads was unable to be used). Configuration-specific features were surveyed on all approach roads (characteristics of traffic lanes, road signs, traffic lights, etc.), traffic monitored and accidents (full green and green arrow) recorded over a period of 5 consecutive years. It was demonstrated that only between 23 and 34% of variance could be explained with the models predicting both types of accidents. In green arrow accidents, the approach road topography was found to be the major contributory factor to an accident: if the approach road slopes downwards, the risk of a green arrow accident is approximately five and a half times greater (relative risk, RR = 5.56) than on a level or upward sloping approach road. With full green accidents, obstructed vision plays the major role: where vision can be obstructed by vehicles turning off, the accident risk is eight times greater (RR = 8.08) than where no comparable obstructed vision is possible. From the study it emerges that technical features of traffic lights are not able to control a driver's actions in such a way as to eradicate error. Other factors, in particular the personal characteristics of the driver (age, sex, etc.) and accident circumstances (lighting, road conditions, etc.), are likely to make an important contribution to explaining how an accident occurs.

  15. ORAL ISSUE OF THE JOURNAL "USPEKHI FIZICHESKIKH NAUK": Quantum measurements, the phenomenon of life, and time arrow: three great problems of physics (in Ginzburg's terminology) and their interrelation

    Science.gov (United States)

    Mensky, Mikhail B.

    2007-04-01

    Relations existing among "the three great problems" of physics (as enumerated by Ginzburg) — interpretation of quantum mechanics, the time arrow, and reductionism (reducing the phenomenon of life to physics) — are discussed and shown to substantially depend on how the first of them is solved, i.e., which interpretation of quantum mechanics is adopted. The Copenhagen interpretation, the Everett ('many-words') interpretation, and Extended Everett Concept proposed by the author are considered.

  16. Enhanced CP violation with B {r_arrow} KD{sup 0} ({anti D}{sup 0}) modes and extraction of the CKM angle {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    David Atwood; Isard Dunietz; Amarjit Soni

    1996-12-01

    The Gronau-London-Wyler (GLW) method extracts the CKM angle {gamma} by measuring B{sup {+-}} decay rates involving D{sup 0}/{anti D}{sup 0} mesons. Since that method necessitates the interference between two amplitudes that are significantly different in magnitude, the resulting asymmetries tend to be small. CP violation can be greatly enhanced for decays to final states that are common to both D{sup 0} and {anti D}{sup 0} and that are not CP eigenstates. In particular, large asymmetries are possible for final states f such that D{sup 0} {r_arrow} f is doubly Cabibbo suppressed while {anti D}{sup 0} {r_arrow} f is Cabibbo allowed. The measurement of interference effects in two such modes allows the extraction of {gamma} without prior knowledge of Br(B{sup {minus}} {r_arrow} K{sup {minus}} {anti D}{sup 0}), which may be difficult to determine due to backgrounds.

  17. High statistics search for v{sub e}({bar v}{sub e}){r_arrow}v{sub {tau}}({bar v}{sub {tau}}) oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.A.; Vakili, M. [University of Cincinnati, Cincinnati, Ohio 45221 (United States); Romosan, A.; Arroyo, C.G.; Bazarko, A.O.; Conrad, J.; Kim, J.H.; King, B.J.; Lefmann, W.C.; McNulty, C.; Mishra, S.R.; Quintas, P.Z.; Sciulli, F.J.; Seligman, W.G.; Shaevitz, M.H.; Spentzouris, P.; Stern, E.G. [Columbia University, New York, New York 10027 (United States); Bernstein, R.H.; Lamm, M.J.; Marsh, W.; Yu, J. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Naples, D.; Bolton, T. [Kansas State University, Manhattan, Kansas 66506 (United States); de Barbaro, L.; Schellman, H. [Northwestern University, Evanston, Illinois 60208 (United States); Drucker, R.B. [University of Oregon, Eugene, Oregon 97403 (United States); de Barbaro, P.; Bodek, A.; Budd, H.; Harris, D.A.; McFarland, K.S.; Sakumoto, W.K.; Yang, U.K. [University of Rochester, Rochester, New York 14627 (United States); Kinnel, T.; Smith, W.H. [University of Wisconsin, Madison, Wisconsin 53706 (United States)

    1999-02-01

    We present new limits on v{sub e}({bar v}{sub e}){r_arrow}v{sub {tau}}({bar v}{sub {tau}}) and v{sub e}({bar v}{sub e}){r_arrow}v{sub s} oscillations by searching for v{sub e} disappearance in the high-energy wideband CCFR neutrino beam. Sensitivity to v{sub {tau}} appearance comes from {tau} decay modes in which a large fraction of the energy deposited is electromagnetic. The beam is composed primarily of v{sub {mu}}({bar v}{sub {mu}}), but this analysis uses the 2.3{percent} v{sub e}({bar v}{sub e}) component of the beam. Electron neutrino energies range from 30 to 600 GeV and flight lengths vary from 0.9 to 1.4 km. This limit improves the sensitivity of existing limits for v{sub e}{r_arrow}v{sub {tau}} at high {Delta}m{sup 2} and obtains a lowest 90{percent} confidence upper limit in sin{sup 2}2{alpha} of 9.9{times}10{sup {minus}2} at {Delta}m{sup 2}{approximately}125 eV{sup 2}. {copyright} {ital 1998} {ital The American Physical Society}

  18. Bearing the Burden of Native Experience: A Stylistic Approach to Chinua Achebe’s Arrow of God

    Directory of Open Access Journals (Sweden)

    Debaleena Dutta

    2010-04-01

    Full Text Available Chinua Achebe has made a creative Africanization of the English language in all his literary works. In the process of writing counter-narratives to Euro-centric misrepresentations of Africa, Achebe has successfully harnessed the colonizer’s language to make it bear the burden of his native experience. The present paper proposes to take up the third novel by Achebe, namely Arrow of God (1964 to introspect the different kinds of narrative strategies involved in it. This includes a study of the kind of narrator used, and a survey of the various ways in which the language is maneuvred—through the usage of standard and pidgin English, through linguistic devices like humour, satire and irony, through symbols, proverbs, images, metaphors and songs—in order to capture a vivid picture of Nigeria of the late 1920s, in which the novel is set. In a nutshell, this stylistic criticism aims to illustrate in effect how Achebe creatively extends the frontiers of English language to accommodate the various shades of Nigerian reality within it.

  19. ‘An augury of the world’s ruin’ and the making of the tragic hero in Chinua Achebe’s Arrow of God

    Directory of Open Access Journals (Sweden)

    Ignatius Chukwumah

    2016-03-01

    Full Text Available Chinua Achebe’s Arrow of God has been adjudged by critics as a tragic work with Ezeulu as its tragic hero. However, none of these studies has paid detailed attention to the framing of Ezeulu in the historical context of his age. How he appears when compared to a classical Greek tragic hero has also been ignored. A major context giving rise to Ezeulu becoming a tragic hero is the period leading to the synthesis of two contrary histories, juxtaposed discourses and the collision of opposites and contraries in the sociocultural and political sphere of the villages of Umuaro and Okperi. This circumstance is captured by the narrator as ‘an augury of the world’s ruin’, by Nwaka as ‘the white man turned us upside down’ and by Ezeulu as ‘the world is spoilt and there is no longer head or tail in anything that is done’. Allen, an earlier District Commissioner in Things Fall Apart, but textually implicated in Arrow of God, terms it ‘great situations’. The above historical context requires more than mastery and acknowledgement by the tragic figure, in the absence of which he, a self-professed knowledgeable person, becomes a victim of what he failed to take into account. Consequently, he is set aside as a specimen for history and other men. This article will use Hegel’s and Aristotle’s theories of history and of tragedy, respectively, to explicate the above. It concludes that the tragic hero of Chinua Achebe’s Arrow of God is substantially the victim of the clash between Umuaro’s history and Hegel’s History.’n Teken van die wêreld se ondergang en die skepping van die tragiese held in Chinua Achebe se Arrow of God. Chinua Achebe se boek, Arrow of God, word deur kritici beskryf as ’n tragedie met die karakter Ezeulu as held. Niemand het egter noukeurige aandag geskenk aan hoe Ezeulu inpas in die gapings van botsende geskiedenisse soos vergestalt in die mens ten opsigte van hulle optredes, houdings, vrese en begeertes nie. Hoe

  20. New redox-related arrows in the arsenal of cardiac disease treatment.

    Science.gov (United States)

    Kirk, Jonathan A; Paolocci, Nazareno

    2014-11-10

    While great strides have been made to improve the poor prognosis with cardiac disease, heart failure in particular, cardiac affections still remain the most prevalent, difficult-to-treat, and costly human pathologies in the western world. At rest, the heart produces a significant oxidative environment inside diverse cell compartments, due to its high-energy demand. Cardiac cells have an exquisite control system to deal with this constant redox stress. However, persistent hemodynamic alterations can compromise these mechanisms, fueling further myocardial redox imbalance and dysfunction. Still, this would be a one-sided and incomplete view, because the physiological role of reactive oxygen species (ROS) should be considered as well. Indeed, ROS are multipurpose agents, serving signaling and cell defense tasks too, and, similar to antioxidants, these functions can be highly compartmentalized within the cell. The present Forum was designed to collect cutting-edge research concerning when and how to effectively counter excessive oxidative burden to preserve cardiac structure and/or to improve function, under conditions of ordinary or extraordinary stress. Another major objective was to unravel old and new intersections between different myocardial processes by which ROS may act as "on" or "off" switches, and in doing so, dictating function, always with an eye on possible, immediate therapeutic applications, as suggested by the title of the Forum itself, that is, Cardiac Therapeutics.

  1. The Production Technology of Bow and Arrow in The Pre Qin Period%先秦弓箭制作技艺考

    Institute of Scientific and Technical Information of China (English)

    陶涛; 陈新华

    2013-01-01

    射箭是我国最早的体育活动之一,是我国民族传统体育的典型代表,在中国古代历史发展过程中占有重要的地位,中国人也是世界上最早掌握射箭技术的人类群体之一。先秦时期,从王公贵族到普通百姓都喜好这项运动,这使得先秦时期的弓箭制作工艺非常高超。但由于种种原因,传统弓箭的制作工艺也逐渐走向了衰败,甚至濒临失传。因此,重新翻开历史长卷,整理和研究先秦时期弓箭制作技艺无疑是一件具有深远意义的工作。%Archery, as one of China’s earliest sports activities, is the typical representative of national traditional sports in China, and has been playing an important role in ancient Chinese history. Chinese are among the world's first groups in terms of the mastery of archery technique. In the pre-Qin periods, from Kings and nobles to ordinary people were all keen on archery, which promotes the craftsmanship and manufacturing technique of bows and arrows in the pre-Qin periods. However, due to various reasons, the traditional manufacturing process of bows and arrows declined gradually, and even were endangered to extinct. Therefore, it is significant to probe into the manufacturing techniques of bows and arrows in the pre-Qin periods.

  2. Wnt Signaling Is Required for Long-Term Memory Formation

    Directory of Open Access Journals (Sweden)

    Ying Tan

    2013-09-01

    Full Text Available Wnt signaling regulates synaptic plasticity and neurogenesis in the adult nervous system, suggesting a potential role in behavioral processes. Here, we probed the requirement for Wnt signaling during olfactory memory formation in Drosophila using an inducible RNAi approach. Interfering with β-catenin expression in adult mushroom body neurons specifically impaired long-term memory (LTM without altering short-term memory. The impairment was reversible, being rescued by expression of a wild-type β-catenin transgene, and correlated with disruption of a cellular LTM trace. Inhibition of wingless, a Wnt ligand, and arrow, a Wnt coreceptor, also impaired LTM. Wingless expression in wild-type flies was transiently elevated in the brain after LTM conditioning. Thus, inhibiting three key components of the Wnt signaling pathway in adult mushroom bodies impairs LTM, indicating that this pathway mechanistically underlies this specific form of memory.

  3. Is Time's Arrow Perspectival?

    CERN Document Server

    Rovelli, Carlo

    2015-01-01

    We observe entropy decrease towards the past. Does this imply that in the past the world was in a non-generic microstate? I point out an alternative. The subsystem to which we belong interacts with the universe via a relatively small number of quantities, which define a coarse graining. Entropy happens to depends on coarse-graining. Therefore the entropy we ascribe to the universe depends on the peculiar coupling between us and the rest of the universe. Low past entropy may be due to the fact that this coupling (rather than microstate of the universe) is non-generic. I argue that for any generic microstate of a sufficiently rich system there are always special subsystems defining a coarse graining for which the entropy of the rest is low in one time direction (the "past"). These are the subsystems allowing creatures that "live in time" ---such as those in the biosphere--- to exist. I reply to some objections raised to an earlier presentation of this idea, in particular by Bob Wald, David Albert and Jim Hartle...

  4. Episensitization: Defying Time's Arrow.

    Science.gov (United States)

    Oronsky, Bryan T; Oronsky, Arnold L; Lybeck, Michelle; Oronsky, Neil C; Scicinski, Jan J; Carter, Corey; Day, Regina M; Rodriguez Orengo, Jose F; Rodriguez-Torres, Maribel; Fanger, Gary F; Reid, Tony R

    2015-01-01

    The development of cancer is driven by complex genetic and epigenetic changes that result in aberrant and uncontrolled cellular growth. Epigenetic changes, in particular, are implicated in the silencing or activation of key genes that control cellular growth and apoptosis and contribute to transformative potential. The purpose of this review is to define and assess the treatment strategy of "episensitization," or the ability to sensitize cancer cells to subsequent therapy by resetting the epigenetic infrastructure of the tumor. One important facet is resensitization by epigenetic mechanisms, which goes against the norm, i.e., challenges the long-held doctrine in oncology that the reuse of previously tried and failed therapies is a clinically pointless endeavor. Thus, episensitization is a hybrid term, which covers recent clinically relevant observations and refers to the epigenomic mechanism of resensitization. Among the many formidable challenges in the treatment of cancer, the most inevitable is the development of acquired therapeutic resistance. Here, we present the basic principles behind episensitization and highlight the evidence suggesting that epigenetically mediated histone hypoacetylation and DNA hypermethylation events may reverse clinical drug resistance. The potential reversibility of epigenetic changes and the microenvironmental impact of epigenetic control on gene expression may mediate a return to a baseline state of treatment susceptibility. Episensitization is a novel and highly practical management strategy both to prevent the practice of permanent treatment discontinuation with the occurrence of resistance, which rapidly exhausts remaining options in the pharmaceutical armamentarium and to significantly extend patient survival. Accordingly, this review highlights several epigenetic agents including decitabine, vorinostat, entinostat, 5-azacitidine, oncolytic viruses, and RRx-001.

  5. Prediction of cyclohexane-water distribution coefficient for SAMPL5 drug-like compounds with the QMPFF3 and ARROW polarizable force fields

    Science.gov (United States)

    Kamath, Ganesh; Kurnikov, Igor; Fain, Boris; Leontyev, Igor; Illarionov, Alexey; Butin, Oleg; Olevanov, Michael; Pereyaslavets, Leonid

    2016-11-01

    We present the performance of blind predictions of water—cyclohexane distribution coefficients for 53 drug-like compounds in the SAMPL5 challenge by three methods currently in use within our group. Two of them utilize QMPFF3 and ARROW, polarizable force-fields of varying complexity, and the third uses the General Amber Force-Field (GAFF). The polarizable FF's are implemented in an in-house MD package, Arbalest. We find that when we had time to parametrize the functional groups with care (batch 0), the polarizable force-fields outperformed the non-polarizable one. Conversely, on the full set of 53 compounds, GAFF performed better than both QMPFF3 and ARROW. We also describe the torsion-restrain method we used to improve sampling of molecular conformational space and thus the overall accuracy of prediction. The SAMPL5 challenge highlighted several drawbacks of our force-fields, such as our significant systematic over-estimation of hydrophobic interactions, specifically for alkanes and aromatic rings.

  6. New Limit on Muon and Electron Lepton Number Violation from K{sup 0}{sub L} {r_arrow} {mu}{sup {plus_minus} }e{sup {minus_plus}} Decay

    Energy Technology Data Exchange (ETDEWEB)

    Ambrose, D.; Graessle, S.; Hoffmann, G.W.; Lang, K.; McDonough, J.; Milder, A.; Riley, P.J.; Ritchie, J.L.; Vassilakopoulos, V.I. [University of Texas, Austin, Texas 78712 (United States); Arroyo, C.; Hartman, K.; Hebert, M.; Irwin, G.M.; Pommot-Maia, M.; Wojcicki, S.G. [Stanford University, Stanford, California 94305 (United States); Bachman, M.; Connor, D.; Kanematsu, N.; Lee, R.; Molzon, W.R. [University of California, Irvine, California 92697 (United States); Eckhause, M.; Hancock, A.D.; Hoff, C.H.; Kane, J.R.; Kuang, Y.; Martin, R.D.; Welsh, R.E. [College of William and Mary, Williamsburg, Virginia 23187 (United States); Rubin, P.D. [University of Richmond, Richmond, Virginia 23173 (United States)

    1998-12-01

    The most sensitive experiment to date to search for the muon and electron lepton number violating decay K{sup 0}{sub L}{r_arrow}{mu}{sup {plus_minus}}e{sup {minus_plus}} has detected no events consistent with this process. Based on this result, the 90{percent} confidence level upper limit on the branching fraction is B(K{sup 0}{sub L}{r_arrow}{mu}{sup {plus_minus}} e{sup {minus_plus}}){lt}4.7{times}10{sup {minus}12} . {copyright} {ital 1998} {ital The American Physical Society}

  7. Signal Words

    Science.gov (United States)

    SIGNAL WORDS TOPIC FACT SHEET NPIC fact sheets are designed to answer questions that are commonly asked by the ... making decisions about pesticide use. What are Signal Words? Signal words are found on pesticide product labels, ...

  8. Limits on {nu}{sub {mu}}({nu}{sub {mu}}){r_arrow}{nu}{sub {tau}}({nu}{sub {tau}}) and {nu}{sub {mu}}({nu}{sub {mu}}){r_arrow}({nu}{sub {ital e}}){nu}{sub {ital e}} oscillations from a precision measurement of neutrino-nucleon neutral current interactions

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, K.S.; Naples, D.; Arroyo, C.G.; Auchincloss, P.; de Barbaro, P.; Bazarko, A.O.; Bernstein, R.H.; Bodek, A.; Bolton, T.; Budd, H.; Conrad, J.; Drucker, R.B.; Harris, D.A.; Johnson, R.A.; Kim, J.H.; King, B.J.; Kinnel, T.; Koizumi, G.; Koutsoliotas, S.; Lamm, M.J.; Lefmann, W.C.; Marsh, W.; McNulty, C.; Mishra, S.R.; Nienaber, P.; Nussbaum, M.; Oreglia, M.J.; Perera, L.; Quintas, P.Z.; Romosan, A.; Sakumoto, W.K.; Schumm, B.A.; Sciulli, F.J.; Seligman, W.G.; Shaevitz, M.H.; Smith, W.H.; Spentzouris, P.; Steiner, R.; Stern, E.G.; Vakili, M.; Yang, U.K. [Adelphi University, Garden City, New York 11530 (United States)]|[University of Chicago, Chicago, Illinois 60637 (United States)]|[University of Cincinnati, Cincinnati, Ohio 45221 (United States)]|[Columbia University, New York, New York 10027 (United States)]|[Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)]|[Kansas State University, Manhattan, Kansas 66506 (United States)]|[University of Oregon, Eugene, Oregon 97403 (United States)]|[University of Rochester, Rochester, New York 14627 (United States)]|[University of Wisconsin, Madison, Wisconsin 53706 (United States)]|[Xavier University, Cincinnati, Ohio 45207 (United States)

    1995-11-27

    We present limits on {nu}{sub {mu}}({nu}{sub {mu}}){r_arrow}{nu}{sub {tau}}({nu}{sub {tau}}) and {nu}{sub {mu}}({nu}{sub {mu}}){r_arrow}{nu}{sub {ital e}}({nu}{sub {ital e}}) oscillations based on a study of inclusive {nu}{ital N} interactions performed using the CCFR massive coarse-grained detector in the Fermilab Tevatron Quadrupole Triplet neutrino beam. The sensitivity to oscillations is from the difference in the longitudinal energy deposition pattern of {nu}{sub {mu}}{ital N} vs {nu}{sub {tau}}{ital N} or {nu}{sub {ital e}}{ital N} charged-current interactions. The {nu}{sub {mu}} energies ranged from 30 to 500 GeV with a mean of 140 GeV. The minimum and maximum {nu}{sub {mu}} flight lengths are 0.9 and 1.4 km, respectively. For {nu}{sub {mu}}{r_arrow}{nu}{sub {tau}} oscillations, the lowest 90% confidence upper limit in sin{sup 2}2{alpha} of 2.7{times}10{sup {minus}3} is obtained at {Delta}{ital m}{sup 2}{similar_to}50 eV{sup 2}. This result is the most stringent limit to date for 25{lt}{Delta}{ital m}{sup 2}{lt}90 eV{sup 2}. For {nu}{sub {mu}}{r_arrow}{nu}{sub {ital e}} oscillations, the lowest 90% confidence upper limit in sin{sup 2}2{alpha} of 1.9{times}10{sup {minus}3} is obtained at {Delta}{ital m}{sup 2}{similar_to}350 eV{sup 2}. This result is the most stringent limit to date for 250{lt}{Delta}{ital m}{sup 2}{lt}450 eV{sup 2}, and also excludes at 90% confidence much of the high {Delta}{ital m}{sup 2} region favored by the recent LSND observation. {copyright} {ital 1995} {ital The} {ital American} {ital Physical} {ital Society}.

  9. Form factor ratio measurement in {Lambda}{sup +}{sub {ital c}}{r_arrow}{Lambda}{ital e}{sup +}{nu}{sub {ital e}}

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, G.; Daubenmier, C.M.; Fulton, R.; Fujino, D.; Gan, K.K.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Sung, M.; White, C.; Wolf, A.; Zoeller, M.M.; Butler, F.; Fu, X.; Nemati, B.; Ross, W.R.; Skubic, P.; Wood, M.; Bishai, M.; Fast, J.; Gerndt, E.; Hinson, J.W.; McIlwain, R.L.; Miao, T.; Miller, D.H.; Modesitt, M.; Payne, D.; Shibata, E.I.; Shipsey, I.P.J.; Wang, P.N.; Battle, M.; Ernst, J.; Gibbons, L.; Kwon, Y.; Roberts, S.; Thorndike, E.H.; Wang, C.H.; Dominick, J.; Lambrecht, M.; Sanghera, S.; Shelkov, V.; Skwarnicki, T.; Stroynowski, R.; Volobouev, I.; Wei, G.; Zadorozhny, P.; Artuso, M.; Gao, M.; Goldberg, M.; He, D.; Horwitz, N.; Moneti, G.C.; Mountain, R.; Muheim, F.; Mukhin, Y.; Playfer, S.; Rozen, Y.; Stone, S.; Xing, X.; Zhu, G.; Bartelt, J.; Csorna, S.E.; Egyed, Z.; Jain, V.; Gibaut, D.; Kinoshita, K.; Pomianowski, P.; Barish, B.; Chadha, M.; Chan, S.; Cowen, D.F.; Eigen, G.; Miller, J.S.; O`Grady, C.; Urheim, J.; Weinstein, A.J.; Athanas, M.; Brower, W.; Masek, G.; Paar, H.P.; Gronberg, J.; Korte, C.M.; Kutschke, R.; Menary, S.; Morrison, R.J.; Nakanishi, S.; Nelson, H.N.; Nelson, T.K.; Qiao, C.; Richman, J.D.; Ryd, A.; Sperka, D.; Tajima, H.; Witherell, M.S.; Procario, M.; Balest, R.; Cho, K.; Ford, W.T.; Johnson, D.R.; Lingel, K.; Lohner, M.; Rankin, P.; Smith, J.G.; Alexander, J.P.; Bebek, C.; Berkelman, K.; Bloom, K.; Browder, T.E.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Crowcroft, D.S.; Drell, P.S.; Dumas, D.J.; Ehrlich, R.; Gaidarev, P.; Garcia-Sciveres, M.; Geiser, B.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Jones, C.D.; Jones, S.L.; Kandaswamy, J.; Katayama, N.; Kim, P.C.; Kreinick, D.L.; Ludwig, G.S.; Masui, J.; Mevissen, J.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Patterson, J.R.; Peterson, D.; Riley, D.; Salman, S.; Sapper, M.; Wuerthwein, F.; Avery, P.; Freyberger, A.; Rodriguez, J.; Yang, S.; Yelton, J.; Cinabro, D.; Liu, T.; Saulnier, M.; Wilson, R.; Yamamoto, H.; Bergfeld, T.; (CLEO Collaboration)

    1995-07-24

    The angular distributions of the decay {Lambda}{sup +}{sub {ital c}}{r_arrow}{Lambda}{ital e}{sup +}{nu}{sub {ital e}} have been studied using the CLEO II detector. By performing a three-dimensional maximum likelihood fit, the form factor ratio {ital R}={ital f}{sub 2}/{ital f}{sub 1} is determined to be {minus}0.25{plus_minus}0.14{plus_minus}0.08. The decay asymmetry parameter of the {Lambda}{sub {ital c}} averaged over {ital q}{sup 2} is calculated to be {alpha}{sub {Lambda}{sub {ital c}}}={minus}0.82{sub {minus}0.06{minus}0.03}{sup +0.09+0.06}.

  10. A simple recipe for setting up the flux equations of cyclic and linear reaction schemes of ion transport with a high number of states: The arrow scheme.

    Science.gov (United States)

    Hansen, Ulf-Peter; Rauh, Oliver; Schroeder, Indra

    2016-01-01

    The calculation of flux equations or current-voltage relationships in reaction kinetic models with a high number of states can be very cumbersome. Here, a recipe based on an arrow scheme is presented, which yields a straightforward access to the minimum form of the flux equations and the occupation probability of the involved states in cyclic and linear reaction schemes. This is extremely simple for cyclic schemes without branches. If branches are involved, the effort of setting up the equations is a little bit higher. However, also here a straightforward recipe making use of so-called reserve factors is provided for implementing the branches into the cyclic scheme, thus enabling also a simple treatment of such cases.

  11. Sensitivity of tensor analyzing power in the process d+p{r_arrow}d+X to the longitudinal isoscalar form factor of the Roper resonance electroexcitation

    Energy Technology Data Exchange (ETDEWEB)

    Tomasi-Gustafsson, E.; Rekalo, M.P. [DSM-CEA/IN2P3-CNRS, Laboratoire National Saturne, F-91191 Gif-sur-Yvette Cedex (France)]|[DAPNIA/SPhN, C.E.A./Saclay, F-91191 Gif-sur-Yvette Cedex (France); Bijker, R. [Instituto de Ciencias Nucleares, U.N.A.M., A.P. 70-543, 04510 Mexico Distrito Federal (Mexico); Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel); Iachello, F. [Center for Theoretical Physics, Sloane Laboratory, Yale University, New Haven, Connecticut 06520-8120 (United States)

    1999-03-01

    The tensor analyzing power of the process d+p{r_arrow}d+X, for forward deuteron scattering in the momentum interval 3.7 to 9 GeV/c, is studied in the framework of {omega} exchange in an algebraic collective model for the electroexcitation of nucleon resonances. We point out a special sensitivity of the tensor analyzing power to the isoscalar longitudinal form factor of the Roper resonance excitation. The main argument is that the S{sub 11}(1535),thinspD{sub 13}(1520), and S{sub 11}(1650) resonances have only isovector longitudinal form factors. It is the longitudinal form factor of the Roper excitation, which plays an important role in the {ital t} dependence of the tensor analyzing power. We discuss possible evidence of swelling of hadrons with increasing excitation energy. {copyright} {ital 1999} {ital The American Physical Society}

  12. Temporal Asymmetry, Entropic Irreversibility, and Finite-Time Thermodynamics: From Parmenides–Einstein Time-Reversal Symmetry to the Heraclitan Entropic Arrow of Time

    Directory of Open Access Journals (Sweden)

    Wassim M. Haddad

    2012-02-01

    Full Text Available In this paper, we combine the two universalisms of thermodynamics and dynamical systems theory to develop a dynamical system formalism for classical thermodynamics. Specifically, using a compartmental dynamical system energy flow model we develop a state-space dynamical system model that captures the key aspects of thermodynamics, including its fundamental laws. In addition, we establish the existence of a unique, continuously differentiable global entropy function for our dynamical system model, and using Lyapunov stability theory we show that the proposed thermodynamic model has finite-time convergent trajectories to Lyapunov stable equilibria determined by the system initial energies. Finally, using the system entropy, we establish the absence of Poincaré recurrence for our thermodynamic model and develop clear and rigorous connections between irreversibility, the second law of thermodynamics, and the entropic arrow of time.

  13. Curly arrows meet electron density transfers in chemical reaction mechanisms: from electron localization function (ELF) analysis to valence-shell electron-pair repulsion (VSEPR) inspired interpretation.

    Science.gov (United States)

    Andrés, Juan; Berski, Sławomir; Silvi, Bernard

    2016-07-07

    Probing the electron density transfers during a chemical reaction can provide important insights, making possible to understand and control chemical reactions. This aim has required extensions of the relationships between the traditional chemical concepts and the quantum mechanical ones. The present work examines the detailed chemical insights that have been generated through 100 years of work worldwide on G. N. Lewis's ground breaking paper on The Atom and the Molecule (Lewis, G. N. The Atom and the Molecule, J. Am. Chem. Soc. 1916, 38, 762-785), with a focus on how the determination of reaction mechanisms can be reached applying the bonding evolution theory (BET), emphasizing how curly arrows meet electron density transfers in chemical reaction mechanisms and how the Lewis structure can be recovered. BET that combines the topological analysis of the electron localization function (ELF) and Thom's catastrophe theory (CT) provides a powerful tool providing insight into molecular mechanisms of chemical rearrangements. In agreement with physical laws and quantum theoretical insights, BET can be considered as an appropriate tool to tackle chemical reactivity with a wide range of possible applications. Likewise, the present approach retrieves the classical curly arrows used to describe the rearrangements of chemical bonds for a given reaction mechanism, providing detailed physical grounds for this type of representation. The ideas underlying the valence-shell-electron pair-repulsion (VSEPR) model applied to non-equilibrium geometries provide simple chemical explanations of density transfers. For a given geometry around a central atom, the arrangement of the electronic domain may comply or not with the VSEPR rules according with the valence shell population of the considered atom. A deformation yields arrangements which are either VSEPR defective (at least a domain is missing to match the VSEPR arrangement corresponding to the geometry of the ligands), VSEPR compliant

  14. The expanding clinical phenotype of the tRNA{sup Leu(UUR)} A{r_arrow}G mutation at np 3243 of mitochondrial DNA: Diabetic embryopathy associated with mitochondrial cytopathy

    Energy Technology Data Exchange (ETDEWEB)

    Feigenbaum, A.; Chitayat, D.; Robinson, B.; MacGregor, D.; Myint, T. [Univ. of Toronto, Ontario (Canada)] [and others

    1996-04-24

    We describe a family which demonstrates and expands the extreme clinical variability now known to be associated with the A{r_arrow}G transition at nucleotide position 3243 of the mitochondrial DNA. The propositus presented at birth with clinical manifestations consistent with diabetic embryopathy including anal atresia, caudal dysgenesis, and multicystic dysplastic kidneys. His co-twin was normal at birth, but at 3 months of life, presented with intractable seizures later associated with developmental delay. The twins` mother developed diabetes mellitus type I at the age of 20 years and gastrointestinal problems at 22 years. Since age 19 years, the maternal aunt has had recurrent strokes, seizures, mental deterioration and deafness, later diagnosed as MELAS syndrome due to the tRNA{sup Leu(UUR)} A{r_arrow}G mutation. A maternal uncle had diabetes mellitus type I, deafness, and normal intellect, and died at 35 years after recurrent strokes. This pedigree expands the known clinical phenotype associated with tRNA{sup Leu(UUR)} A{r_arrow}G mutation and raises the possibility that, in some cases, diabetic embryopathy may be due to a mitochondrial cytopathy that affects both the mother`s pancreas (and results in diabetes mellitus and the metabolic dysfunction associated with it) and the embryonic/fetal and placental tissues which make the embryo more vulnerable to this insult. 33 refs., 1 tab.

  15. Classical solutions by inverse scattering transformation in any number of dimensions. II. Instantons and large orders of the 1/N series for the (phi-arrow-right /sup 2/)/sup 2/ theory in. nu. dimensions (1< or =. nu. < or =4)

    Energy Technology Data Exchange (ETDEWEB)

    Avan, J.; de Vega, H.J.

    1984-06-15

    Instantons of the nonlocal effective action S/sub eff/ that generates a 1/N perturbative expansion for O(N)-symmetric (phi-arrow-right /sup 2/)/sup 2/ theory are obtained for Euclidean spatial dimension 0< or =..nu..< or =4, through the inverse scattering transformation (IST). They are studied analytically to a large extent. In addition, variational methods are used when the IST does not provide a closed solution for all couplings. The values of the instanton action are given as a function of the coupling constant g for ..nu.. = 0, 1, 2, 3, and 4, and 0< or =g< or =+infinity. The large orders of the 1/N perturbative expansion are thus estimated. It is found that the 1/N perturbation series can be resummed by a Borel transform in integer dimension 0< or =..nu..< or =3. In four dimensions, the 1/N perturbation series is not Borel-summable, owing to the existence of an instanton with real positive action, for physically relevant values of the renormalized coupling constant. It is concluded that (phi-arrow-right /sup 2/)/sup 2/ theory in four dimensions is nonperturbatively unstable. The saddle-point equation of massless (phi-arrow-right /sup 2/)/sup 2/ theory in the 1/N expansion is found to be completely integrable at least for spherically symmetric fields. Explicit instanton solutions are given for this case. A large-N estimate of the decay rate of the vacuum is given.

  16. De novo partial duplication 7(q11.2{r_arrow}q21.2) in a dysmorphic, developmentally retarded boy

    Energy Technology Data Exchange (ETDEWEB)

    Ross, M.; Pinsky, L.; Teebi, A. [McGill Univ., Quebec (Canada)] [and others

    1994-09-01

    Chromosomal abnormalities involving chromosome 7q are rare; we report a case of partial duplication 7q. The propositus was born at 34 weeks by cesarian section, decided because of oligohydramnios, severe intrauterine growth retardation and fetal immobility. At birth, the baby was under the 5th percentile for height, weight and head circumference and had dysmorphic features, including slight asymmetry of the face, bilateral epicanthus, hypoplastic nasal bridge, short globular nose, asymmetrical dysplastic ears, fifth finger clinodactyly, short second and fifth toe. Ultrasound examination showed atrial and ventricular septal defects. At 18 months, the child had a fracture of the femur, secondary to a minor trauma; skeletal X-rays showed generalized osteoporosis and normal healing. The karyotype with GTG-banding showed a de novo partial duplication of the long arm of chromosome 7 (46,XX,dup(7)(q11.23{r_arrow}q21.2)). Fluorescence in situ hybridization with a painting probe specific for chromosome 7 confirmed the intra-chromosomal rearrangement. The patient`s phenotype and his chromosomal abnormality do not match the previously reported cases of partial trisomy 7q. This case confirms the importance of FISH for the delineation of the chromosomal inbalance in structural chromosomal aberrations.

  17. A new look at the ventral nerve centre of Sagitta: implications for the phylogenetic position of Chaetognatha (arrow worms and the evolution of the bilaterian nervous system

    Directory of Open Access Journals (Sweden)

    Müller Carsten HG

    2007-05-01

    Full Text Available Abstract Background The Chaetognatha (arrow worms are a group of marine carnivores whose phylogenetic relationships are still vigorously debated. Molecular studies have as yet failed to come up with a stable hypothesis on their phylogenetic position. In a wide range of metazoans, the nervous system has proven to provide a wealth of characters for analysing phylogenetic relationships (neurophylogeny. Therefore, in the present study we explored the structure of the ventral nerve centre ("ventral ganglion" in Sagitta setosa with a set of histochemical and immunohistochemical markers. Results In specimens that were immunolabeled for acetylated-alpha tubulin the ventral nerve centre appeared to be a condensed continuation of the peripheral intraepidermal nerve plexus. Yet, synapsin immunolocalization showed that the ventral nerve centre is organized into a highly ordered array of ca. 80 serially arranged microcompartments. Immunohistochemistry against RFamide revealed a set of serially arranged individually identifiable neurons in the ventral nerve centre that we charted in detail. Conclusion The new information on the structure of the chaetognath nervous system is compared to previous descriptions of the ventral nerve centre which are critically evaluated. Our findings are discussed with regard to the debate on nervous system organisation in the last common bilaterian ancestor and with regard to the phylogenetic affinities of this Chaetognatha. We suggest to place the Chaetognatha within the Protostomia and argue against hypotheses which propose a deuterostome affinity of Chaetognatha or a sister-group relationship to all other Bilateria.

  18. Natural attenuation of heavy oil on a coarse sediment beach : results from Black Duck Cove, Nova Scotia, Canada over 35 years following the Arrow oil spill

    Energy Technology Data Exchange (ETDEWEB)

    Owens, E.H. [Polaris Applied Sciences Inc., Bainbridge Island, WA (United States); Prince, R.C. [ExxonMobil Biomedical Sciences Inc., Annandale, NJ (United States); Taylor, R.B. [Natural Resources Canada, Dartmouth, NS (Canada). Geological Survey of Canada

    2008-07-01

    In 1970, the tanker Arrow spilled bunker C oil into Black Duck Cove on the Atlantic coast of Nova Scotia. The coarse sediment beaches provided an accessible natural laboratory for the study of the long-term fate and persistence of stranded oil in a coastal marine environment. Although the site is well known to the oil spill scientific community, it has not been studied systematically and much remains to be learned regarding the physical and chemical processes that have been ongoing. More information is needed pertaining to the character of the oil residues and the reasons for their persistence. This paper summarized the knowledge that has been acquired collectively over the last 35 years. The focus was primarily on coarse sediments, including cobbles and boulders. All tidal zones at the site have both surface and subsurface oil deposits. The sediments whose pore spaces remain filled with oil are examples of stable oil-sediment deposits. Wave action is slowly eroding these asphalt pavements. Intertidal pore-filled sediments are resistant to physical processes, and sequestered subsurface residues coat the cobble-boulder sediments below the zone of sediment redistribution. The subsurface oils will probably remain until the sediment is disturbed by major storms or by landward barrier migration. Although the surface oil is highly biodegraded, the subsurface oil remains similar to that of the spilled material. It was concluded that subsurface residues will likely remain sequestered and unaltered for the foreseeable future. 26 refs., 2 tabs., 6 figs.

  19. Meaurement of the target single-spin asymmetry in quasi-elastic region from the reaction {sup 3}He{up_arrow}(e,e')

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yawei [Rutgers

    2013-10-01

    A measurement of the inclusive target single-spin asymmetry has been performed using the quasi-elastic {sup 3}He{up_arrow}(e,e') reaction with a vertically polarized {sup 3}He target at Q{sup 2} values of 0.13, 0.46 and 0.97 GeV{sup 2}. This asymmetry vanishes under the one photon exchange assumption. But the interference between two-photon exchange and one-photon exchange gives rise to an imaginary amplitude, so that a non-zero A{sub y} is allowed. The experiment, conducted in Hall A of Jefferson Laboratory in 2009, used two independent spectrometers to simultaneously measure the target single-spin asymmetry. Using the effective polarization approximation, the neutron single-spin asymmetries were extracted from the measured {sup 3}He asymmetries. The measurement is to establish a non-vanishing A{sub y}. Non-zero asymmetries were observed at all Q{sup 2} points, and the overall precision is an order of magnitude improved over the existing proton data. The data provide new constraints on Generalized Parton Distribution (GPD) models and new information on the dynamics of the two-photon exchange process.

  20. Signaling aggression.

    Science.gov (United States)

    van Staaden, Moira J; Searcy, William A; Hanlon, Roger T

    2011-01-01

    From psychological and sociological standpoints, aggression is regarded as intentional behavior aimed at inflicting pain and manifested by hostility and attacking behaviors. In contrast, biologists define aggression as behavior associated with attack or escalation toward attack, omitting any stipulation about intentions and goals. Certain animal signals are strongly associated with escalation toward attack and have the same function as physical attack in intimidating opponents and winning contests, and ethologists therefore consider them an integral part of aggressive behavior. Aggressive signals have been molded by evolution to make them ever more effective in mediating interactions between the contestants. Early theoretical analyses of aggressive signaling suggested that signals could never be honest about fighting ability or aggressive intentions because weak individuals would exaggerate such signals whenever they were effective in influencing the behavior of opponents. More recent game theory models, however, demonstrate that given the right costs and constraints, aggressive signals are both reliable about strength and intentions and effective in influencing contest outcomes. Here, we review the role of signaling in lieu of physical violence, considering threat displays from an ethological perspective as an adaptive outcome of evolutionary selection pressures. Fighting prowess is conveyed by performance signals whose production is constrained by physical ability and thus limited to just some individuals, whereas aggressive intent is encoded in strategic signals that all signalers are able to produce. We illustrate recent advances in the study of aggressive signaling with case studies of charismatic taxa that employ a range of sensory modalities, viz. visual and chemical signaling in cephalopod behavior, and indicators of aggressive intent in the territorial calls of songbirds.

  1. First observation of the decay {Xi}{sup +}{sub {ital c}}{r_arrow}{Xi}{sup 0}{ital e}{sup +}{nu}{sub {ital e}} and an estimate of the {Xi}{sup +}{sub {ital c}}/{Xi}{sup 0}{sub {ital c}} lifetime ratio

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, J.P.; Bebek, C.; Berkelman, K.; Bloom, K.; Browder, T.E.; Cassel, D.G.; Cho, H.A.; Coffman, D.M.; Crowcroft, D.S.; Drell, P.S.; Dumas, D.; Ehrlich, R.; Gaidarev, P.; Garcia-Sciveres, M.; Geiser, B.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Henderson, S.; Jones, C.D.; Jones, S.L.; Kandaswamy, J.; Katayama, N.; Kim, P.C.; Kreinick, D.L.; Ludwig, G.S.; Masui, J.; Mevissen, J.; Mistry, N.B.; Ng, C.R.; Nordberg, E.; Patterson, J.R.; Peterson, D.; Riley, D.; Salman, S.; Sapper, M.; Wuerthwein, F.; Avery, P.; Freyberger, A.; Rodriguez, J.; Yang, S.; Yelton, J.; Cinabro, D.; Liu, T.; Saulnier, M.; Wilson, R.; Yamamoto, H.; Bergfeld, T.; Eisenstein, B.I.; Gollin, G.; Ong, B.; Palmer, M.; Selen, M.; Thaler, J.J.; Edwards, K.W.; Ogg, M.; Bellerive, A.; Britton, D.I.; Hyatt, E.R.F.; MacFarlane, D.B.; Patel, P.M.; Spaan, B.; Sadoff, A.J.; Ammar, R.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Copty, N.; Davis, R.; Hancock, N.; Kelly, M.; Kotov, S.; Kravchenko, I.; Kwak, N.; Lam, H.; Kubota, Y.; Lattery, M.; Momayezi, M.; Nelson, J.K.; Patton, S.; Poling, R.; Savinov, V.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Ling, Z.; Mahmood, A.H.; O`Neill, J.J.; Severini, H.; Sun, C.R.; Wappler, F.; Crawford, G.; Daubenmier, C.M.; Fulton, R.; Fujino, D.; Gan, K.K.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Skovpen, Y.; Sung, M.; White, C.; Zoeller, M.M.; Butler, F.; Fu, X.; Nemati, B.; Ross, W.R.; Skubic, P.; Wood, M.; Bishai, M.; Fast, J.; Gerndt, E.; McIlwain, R.L.; Miao, T.; Miller, D.H.; Modesitt, M.; Payne, D.; Shibata, E.I.; Shipsey, I.P.J.; Wang, P.N.; Battle, M.; Ernst, J.; Gibbons, L.; Kwon, Y.; Roberts, S.; Thorndike, E.H.; Wang, C.H.; Dominick, J.; Lambrecht, M.; Sanghera, S.; Shelkov, V.; Skwarnicki, T.; Stroynowski, R.; Volobouev, I.; Wei, G.; Zadorozhny, P.; Artuso, M.; Gao, M.; Goldberg, M.; He, D.; Horwitz, N.; Moneti, G.C.; Mountain, R.; Muheim, F.; Mukhin, Y.; Playfer, S.; Rozen, Y.; Stone, S.; Xing, X.; (CLEO Collab...

    1995-04-17

    Using the CLEO II detector at the Cornell Electron Storage Ring we have observed the decay modes {Xi}{sup +}{sub {ital c}}{r_arrow}{Xi}{sup 0}{ital e}{sup +}{nu}{sub {ital e}} and {Xi}{sup 0}{sub {ital c}}{r_arrow}{Xi}{sup {minus}}{ital e}{sup +}{nu}{sub {ital e}} by the detection of a {Xi}-positron pair of appropriate invariant mass. We find {ital B} ({Xi}{sup +}{sub {ital c}}{r_arrow}{Xi}{sup 0}{ital e}{sup +}{nu}{sub {ital e}}){sigma}({ital e}{sup +}{ital e}{sup {minus}}{r_arrow} {Xi}{sup +}{sub {ital cX}})=1.55{plus_minus}0.33{plus_minus}0.25 pb, {ital B} ({Xi}{sup 0}{sub {ital c}}{r_arrow}{Xi}{sup {minus}}{ital e}{sup +}{nu}{sub {ital e}}){sigma}({ital e}{sup +}{ital e}{sup {minus}}{r_arrow} {Xi}{sup 0}{sub {ital cX}})=0.63{plus_minus}0.12{plus_minus}0.10 pb, {ital B} ({Xi}{sup +}{sub {ital c}}{r_arrow}{Xi}{sup {minus}}{pi}{sup +}{pi}{sup +})/ {ital B} ({Xi}{sup +}{sub {ital c}}{r_arrow}{Xi}{sup 0}{ital e}{sup +}{nu}{sub {ital e}})= 0.44{plus_minus}0.11{sub {minus}0.06}{sup +0.11}, and {ital B} ({Xi}{sup 0}{sub {ital c}}{r_arrow}{Xi}{sup {minus}}{pi}{sup +})/{ital B} ({Xi}{sup 0}{sub {ital c}}{r_arrow}{Xi}{sup {minus}}{ital e}{sup +}{nu}{sub {ital e}})= 0.32{plus_minus}0.10{sub {minus}0.03}{sup +0.05}. Assuming the {Xi}{sup +}{sub {ital c}} and {Xi}{sup 0}{sub {ital c}} are equally produced in {ital e}{sup +}{ital e}{sup {minus}} annihilation events at 10 GeV, the lifetime ratio of {Xi}{sup +}{sub {ital c}}/{Xi}{sup 0}{sub {ital c}} is measured to be 2.46{plus_minus}0.70{sub {minus}0.23}{sup +0.33}.

  2. Ibrutinib, idelalisib and obinutuzumab for the treatment of patients with chronic lymphocytic leukemia: three new arrows aiming at the target.

    Science.gov (United States)

    Morabito, Fortunato; Gentile, Massimo; Seymour, John F; Polliack, Aaron

    2015-01-01

    Over the last 20 years there have been sustained and dramatic improvements in the therapy of chronic lymphocytic leukemia (CLL). Until 1990, therapy for CLL was based on alkylating agents, chlorambucil and cyclophosphamide, which did not impact meaningfully on overall survival. The more recent therapeutic regimens, built on combination chemoimmunotherapy, achieve complete responses in 40-50% of cases. However, these regimens are limited in their applicability mostly to the treatment of younger and physically fit patients due to their associated toxicity. Furthermore, since disease progression and drug resistance are considered inevitable, CLL remains incurable. Fortunately, significant progress in the understanding of CLL biology has enabled the development of new molecular drugs targeting the B-cell receptor signaling pathway, such as ibrutinib and idelalisib, which have shown impressive results in patients with relapsed/refractory disease or with TP53 mutation/deletion. Furthermore, obinutuzumab, a type II anti-CD20 antibody, which results in direct cell death and antibody-dependent cell-mediated cytotoxicity, also has proven efficacy when used in combination with chlorambucil in previously untreated and unfit patients. All these three new drugs have recently received FDA approval for the treatment of CLL. This review focuses on the role of ibrutinib, idelalisib and obinutuzumab in therapy of CLL.

  3. A precision measurement of the Z{sup 0} lineshape parameters for the process Z{sup 0} {r_arrow} {tau}{sup +}{tau}{sup {minus}}

    Energy Technology Data Exchange (ETDEWEB)

    Lahmann, R.

    1996-12-31

    In this dissertation, a measurement of the partial decay width of the process Z{sup 0} {r_arrow} {tau}{sup +}{tau}{sup {minus}} using data collected during 1993 and 1994 at the OPAL detector at CERN is described. The cross sections of this process at three center-of-mass energies near the Z{sup 0} resonance were determined, and from a fit to those cross sections, the mass of the Z{sup 0}, its total decay width and its partial decay width into {tau}{sup +}{tau}{sup {minus}} final states were determined as M{sub Z} = 91.183 {+-} 0.020 GeV, {Lambda}{sub tot} = 2.514 {+-} 0.018 GeV and {Lambda}{sub {tau}{tau}} = 84.54 {+-} 0.59 MeV. Using published results for M{sub Z}, and {Lambda}{sub tot} with higher accuracy, a value for the partial decay width of {Lambda}{sub {tau}{tau}} = 84.02 {+-} 0.20 MeV was obtained. Further using published results for the decay width of the Z{sup 0} into quark pair final states, the invisible decay width of the Z{sup 0} was determined as {Lambda}{sub inv} = 496.9 {+-} 4.1 MeV, and the number of neutrino generations was determined as N{sub {nu}} = 2.974 {+-} 0.025(exp) {+-} 0.007 (m{sub top}, M{sub Higgs}). All results were found to be in good agreement with the Standard Model predictions and were consistent with the assumption of lepton universality within the Standard Model framework.

  4. Bayesian signaling

    OpenAIRE

    Hedlund, Jonas

    2014-01-01

    This paper introduces private sender information into a sender-receiver game of Bayesian persuasion with monotonic sender preferences. I derive properties of increasing differences related to the precision of signals and use these to fully characterize the set of equilibria robust to the intuitive criterion. In particular, all such equilibria are either separating, i.e., the sender's choice of signal reveals his private information to the receiver, or fully disclosing, i.e., the outcome of th...

  5. Measurement of proton polarization in the reaction. gamma. /ital p//r arrow//ital p/. pi. /sup 0/ at an angle theta/sup *//sub. pi. /sup 0//=80/degree/ in a linearly polarized photon beam

    Energy Technology Data Exchange (ETDEWEB)

    Avakyan, R. O.; Avakyan, E. O.; Avetisyan, A. E.; Aivazyan, R. B.; Arestakesyan, G. A.; Bagdasryan, A. S.; Vartapetyan, G. A.; Garibyan, Y. A.; Eganov, V. S.; Karapetyan, A. P.; and others

    1988-12-01

    Measurements are reported of the energy dependence of the /ital p//sub /ital xz// and /ital P//sub /ital y// components of the polarization vector of the recoil protons in the reaction ..gamma../ital p//r arrow//ital p/..pi../sup 0/ for a ..pi../sup 0/-meson production angle theta/sup *//sub ..pi../sup 0// =80/degree/ in the c.m.s. in the ..gamma..-ray energy range /ital E//sub ..gamma../=730--1066 MeV. The experimental data are compared with the results of various phenomenological analyses.

  6. Real-time arrow traffic light recognition in urban scenes%城市环境中箭头型交通信号灯的实时识别算法

    Institute of Scientific and Technical Information of China (English)

    谷明琴; 蔡自兴; 黄振威; 何芬芬

    2013-01-01

    提出一种检测和识别城市环境中箭头型交通信号灯的新方法.首先,用图像颜色分割和形态滤波来定位交通信号灯的灯板位置;其次,将交通信号灯的灯板区域彩色图像转换到YCbCr空间,对Cb和Cr通道进行阈值分割,判断形态及交通信号灯与灯板的相对位置来确定红色、黄色和绿色交通信号灯候选区域.然后,用二维Gabor小波变换和二维独立分量分析来提取交通信号灯候选区域的特征;最后,用最近邻分类器识别交通信号灯的箭头方向.实验结果表明:该算法的总体识别率超过91%,每帧图像的处理时间为152 ms,能够为行驶的车辆提供实时、稳定和准确箭头型交通信号灯信息.%A novel approach for detecting and recognizing arrow traffic lights in urban scenes was proposed. Firstly, the boards of arrow traffic lights were localized by image segmentation and morphology processing. Secondly, color image of traffic light board region was converted to YCbCr color space. Candidates of traffic lights (red, yellow, green) were obtained through threshold segmentation in Cb and Cr channels, by judging morphology and relative position between candidate and its board. Thirdly, Gabor wavelet transform and 2D independent component analysis (2DICA) were used to extract traffic light candidate's features, and finally nearest neighbor classifier identifies arrow direction. Experimental results indicate that the overall recognition rates of the proposed method are over 91%, and computation time of each frame is 152 ms. So the proposed algorithm will provide real-time, robust and accurate arrow traffic lights information to moving vehicles.

  7. Regulation of wingless signaling by the CKI family in Drosophila limb development.

    Science.gov (United States)

    Zhang, Lei; Jia, Jianhang; Wang, Bing; Amanai, Kazuhito; Wharton, Keith A; Jiang, Jin

    2006-11-01

    The Wingless (Wg)/Wnt signaling pathway regulates a myriad of developmental processes and its malfunction leads to human disorders including cancer. Recent studies suggest that casein kinase I (CKI) family members play pivotal roles in the Wg/Wnt pathway. However, genetic evidence for the involvement of CKI family members in physiological Wg/Wnt signaling events is lacking. In addition, there are conflicting reports regarding whether a given CKI family member functions as a positive or negative regulator of the pathway. Here we examine the roles of seven CKI family members in Wg signaling during Drosophila limb development. We find that increased CKIepsilon stimulates whereas dominant-negative or a null CKIepsilon mutation inhibits Wg signaling. In contrast, inactivation of CKIalpha by RNA interference (RNAi) leads to ectopic Wg signaling. Interestingly, hypomorphic CKIepsilon mutations synergize with CKIalpha RNAi to induce ectopic Wg signaling, revealing a negative role for CKIepsilon. Conversely, CKIalpha RNAi enhances the loss-of-Wg phenotypes caused by CKIepsilon null mutation, suggesting a positive role for CKIalpha. While none of the other five CKI isoforms can substitute for CKIalpha in its inhibitory role in the Wg pathway, several CKI isoforms including CG12147 exhibit a positive role based on overexpression. Moreover, loss of Gilgamesh (Gish)/CKIgamma attenuates Wg signaling activity. Finally, we provide evidence that several CKI isoforms including CKIalpha and Gish/CKIgamma can phosphorylate the Wg coreceptor Arrow (Arr), which may account, at least in part, for their positive roles in the Wg pathway.

  8. The language of the arrows

    Science.gov (United States)

    2015-10-01

    I think and hope that most experienced physics and astronomy teachers would agree that teaching is both a science and a creative art. There is a way to creatively introduce vectors into introductory astronomy that lets students learn some basic, but fundamental, physics and at the same time demonstrates that mathematics need not be a barrier in a science course. The approach is entirely graphical in that it is based on the geometric properties of vectors and is implemented by drawing diagrams. Despite the simplicity, it allows astronomy students to experience genuine physics reasoning at about the same level of a conceptual physics course (and possibly a higher level).

  9. Breaking the arrows of causality

    DEFF Research Database (Denmark)

    Valsiner, Jaan

    2014-01-01

    Theoretical models of catalysis have proven to bring with them major breakthroughs in chemistry and biology, from the 1830s onward. It can be argued that the scientific status of chemistry has become established through the move from causal to catalytic models. Likewise, the central explanatory...

  10. Signal Processing

    Science.gov (United States)

    1989-03-01

    34ESPIRIT Estimation of signal parameters via rotational imvariance techin+I,-- 1\\I111;1 Smith. A. Faradani "Local and ( Moba ! tomography" I’ Nitlerer and...Feb 1 - Jul 30 Friedman, Avner IMA Gader, Paul University of Wisconsin Jun 27 - Jul 24 Games , Richard MITRE Corp Jun 27 - Aug 5 Garvan, Francis U. of...Gader, Paul University of Wisconsin Jun 27 - Jul 24 Games , Richard MITRE Corp Jun 27 - Aug 5 Garvan, Francis U. of Wisconsin Jun 26 - Jul 31 Habsieger

  11. Florigen signaling.

    Science.gov (United States)

    Tsuji, Hiroyuki; Taoka, Ken-Ichiro

    2014-01-01

    Florigen is a systemic signal that promotes flowering. Its molecular nature is a conserved FLOWERING LOCUS T (FT) protein that belongs to the PEBP family. FT is expressed in the leaf phloem and transported to the shoot apical meristem where it initiates floral transition. In the cells of the meristem, FT binds 14-3-3 proteins and bZIP transcription factor FD to form the florigen activation complex, FAC, which activates floral meristem identity genes such as AP1. The FAC model provides molecular basis for multiple functions of FT beyond flowering through changes of its partners and transcriptional targets. The surface of FT protein includes several regions essential for transport and functions, suggesting the binding of additional components that support its function. FT expression is under photoperiodic control, involving a conserved GIGANTEA-CONSTANS-FT regulatory module with species-specific modifications that contribute variations of flowering time in natural populations.

  12. 博弈论视角下藏族工布响箭文化遗产保护研究%An Game Theory-based Study of the Protection of Kongpo Whistling Arrow Cultural Heritage in Tibet

    Institute of Scientific and Technical Information of China (English)

    王兴怀; 杨建军

    2014-01-01

    通过文献资料和逻辑分析等研究方法,从博弈论的视角对藏族工布响箭文化遗产的保护主体和传承主体之间的博弈及其保护现状进行分析,为更好地保护体育非物质文化遗产提供思路。结果显示,工布响箭文化在林芝地区具有深厚的群众基础,得到了较好的传承保护,但随着西藏社会的变迁,工布响箭文化遗产的传统器材逐步被现代新型合成材料所替代;生计方式和教育方式的改变使工布响箭文化遗产生存的土壤不复存在,传承面临前所未有的困境,后备人才的匮乏是最主要的表现形式。保护主体和传承主体均对工布响箭文化遗产进行积极的传承保护是此博弈的最严格优策略均衡解。文章提出保护主体和传承主体应该充分利用学校教育的资源作为中介,使学校成为工布响箭文化遗产传承和保护的主阵地,使学校教育发挥重要的作用。%Through literature search, logic analysis and some other methods, an analysis has been done on the protection and inheritance of Kongpo whistling arrow in Tibet from the perspective of game theory so as to pro-vide some ideas for better protection of the intangible cultural heritages of sports. The results show that Kongpo whistling arrow has a sound mass base and so far has been well-protected, however, with the social change and development, the traditional sports equipment are gradually being replaced by modern synthetics, moreover, be-cause of the changes of life style and education mode, the basis for the survival of Kongpo whistling arrow cultur-al heritage is lessening, and the most serious problem is that the inheritance people of the heritage is few. In the article it is proposed that the protection and inheritance of the heritage should depend upon school education, to have schools as the main field and school education as the main channel to protect and inherit Kongpo whistling arrow

  13. Inhibitors of endocytosis prevent Wnt/Wingless signalling by reducing the level of basal β-catenin/Armadillo.

    Science.gov (United States)

    Gagliardi, Maria; Hernandez, Ana; McGough, Ian J; Vincent, Jean-Paul

    2014-11-15

    A key step in the canonical Wnt signalling pathway is the inhibition of GSK3β, which results in the accumulation of nuclear β-catenin (also known as CTNNB1), and hence regulation of target genes. Evidence suggests that endocytosis is required for signalling, yet its role and the molecular understanding remains unclear. A recent and controversial model suggests that endocytosis contributes to Wnt signalling by causing the sequestration of the ligand-receptor complex, including LRP6 and GSK3 to multivesicular bodies (MVBs), thus preventing GSK3β from accessing β-catenin. Here, we use specific inhibitors (Dynasore and Dyngo-4a) to confirm the essential role of endocytosis in Wnt/Wingless signalling in human and Drosophila cells. However, we find no evidence that, in Drosophila cells or wing imaginal discs, LRP6/Arrow traffics to MVBs or that MVBs are required for Wnt/Wingless signalling. Moreover, we show that activation of signalling through chemical blockade of GSK3β is prevented by endocytosis inhibitors, suggesting that endocytosis impacts on Wnt/Wingless signalling downstream of the ligand-receptor complex. We propose that, through an unknown mechanism, endocytosis boosts the resting pool of β-catenin upon which GSK3β normally acts.

  14. Signal Processing of Random Physiological Signals

    CERN Document Server

    Lessard, Charles

    2006-01-01

    Signal Processing of Random Physiological Signals presents the most widely used techniques in signal and system analysis. Specifically, the book is concerned with methods of characterizing signals and systems. Author Charles Lessard provides students and researchers an understanding of the time and frequency domain processes which may be used to evaluate random physiological signals such as brainwave, sleep, respiratory sounds, heart valve sounds, electromyograms, and electro-oculograms.Another aim of the book is to have the students evaluate actual mammalian data without spending most or all

  15. Basic digital signal processing

    CERN Document Server

    Lockhart, Gordon B

    1985-01-01

    Basic Digital Signal Processing describes the principles of digital signal processing and experiments with BASIC programs involving the fast Fourier theorem (FFT). The book reviews the fundamentals of the BASIC program, continuous and discrete time signals including analog signals, Fourier analysis, discrete Fourier transform, signal energy, power. The text also explains digital signal processing involving digital filters, linear time-variant systems, discrete time unit impulse, discrete-time convolution, and the alternative structure for second order infinite impulse response (IIR) sections.

  16. Coincidence /sup 16/O(e-arrow-right,e/sup '/x) reactions with polarized electrons at low momentum transfer in self-consistent random-phase approximation theory

    Energy Technology Data Exchange (ETDEWEB)

    Cavinato, M.; Marangoni, M.; Saruis, A.M.

    1988-05-01

    Coincidence /sup 16/O(e-arrow-right,e'x) reactions with polarized electrons have been investigated in the one-photon-exchange formalism. Electromagnetic transition amplitudes are decomposed into multipoles. The nuclear energy continuum is obtained in the framework of a self-consistent random-phase approximation theory with a Skyrme III interaction. We focus our attention on the electron kinematics epsilon/sub i/ = 130 MeV, theta = 50/sup 0/, and on the nuclear excitation energies ..omega.. = 21 and 35 MeV. The polarization structure functions W/sub L//sub T//sub '/ are discussed in parallel with angular distributions and asymmetries for the two hole states: 1p/sub 1/2//sup -1/ and 1p/sub 3/2//sup -1/. At 21 MeV we explore the properties of giant multipole resonances, whereas at 35 MeV, we show theoretical predictions for the competing knockout and semidirect reaction mechanisms. The neutron yield predicted in /sup 16/O(e,e'n) reactions is connected with the presence of random-phase approximation correlations in the nuclear energy continuum. Comparison is made between random-phase-approximation--Skyrme-III results and Novosibirsk experimental data.

  17. High Statistics Search for {nu}{sub {mu}}({bar {nu}}{sub {mu}}){r_arrow}{nu}{sub e}({bar {nu}}{sub e}) Oscillations in the Small Mixing Angle Regime

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.; Vakili, M. [University of Cincinnati, Cincinnati, Ohio 45221 (United States); Romosan, A.; Arroyo, C.; Bazarko, A.; Conrad, J.; Kim, J.; King, B.; Lefmann, W.; McNulty, C.; Mishra, S.; Quintas, P.; Sciulli, F.; Seligman, W.; Shaevitz, M.; Spentzouris, P.; Stern, E. [Columbia University, New York, New York 10027 (United States); Bernstein, R.; Lamm, M.; Marsh, W.; McFarland, K.; Yu, J. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Bolton, T.; Naples, D. [Kansas State University, Manhattan, Kansas 66506 (United States); de Barbaro, L.; Schellman, H. [Northwestern University, Evanston, Illinois 60208 (United States); Drucker, R. [University of Oregon, Eugene, Oregon 97403 (United States); de Barbaro, P.; Bodek, A.; Budd, H.; Harris, D.; Sakumoto, W.; Yang, U. [University of Rochester, Rochester, New York 14627 (United States); Kinnel, T.; Smith, W. [University of Wisconsin, Madison, Wisconsin 53706 (United States)

    1997-04-01

    Limits on {nu}{sub {mu}}({bar {nu}}{sub {mu}}){r_arrow}{nu}{sub e}({bar {nu}}{sub e}) oscillations based on a statistical separation of {nu}{sub e}N charged current interactions in the CCFR detector at Fermilab are presented. Neutrino energies range from 30 to 600GeV with a mean of 140GeV, and {nu}{sub {mu}} flight lengths vary from 0.9 to 1.4km. The result excludes oscillations in the region with sin{sup 2}2{alpha}{gt}1.8{times}10{sup -3} for large {Delta}m{sup 2}({gt}1000eV{sup 2}) and {Delta}m{sup 2}{gt}1.6eV{sup 2} for sin{sup 2}2{alpha}=1. This result is the most stringent limit to date for {Delta}m{sup 2}{gt}25eV{sup 2} and it excludes the high {Delta}m{sup 2} oscillation region favored by the LSND experiment. The {nu}{sub {mu}}-to-{nu}{sub e} cross-section ratio was measured as a test of {nu}{sub {mu}}({bar {nu}}{sub {mu}}){leftrightarrow}{nu}{sub e}({bar {nu}}{sub e}) universality to be 1.026{plus_minus}0.025(stat){plus_minus}0.049(syst). {copyright} {ital 1997} {ital The American Physical Society}

  18. Evidence for Exotic Meson Production in the Reaction {ital {pi}}{sup {ital {minus}}}{ital p{r_arrow}{eta}{pi}}{sup {ital {minus}}}{ital p} at 18 GeV/{ital c}

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, D.R.; Adams, T.; Bishop, J.M.; Cason, N.M.; Ivanov, E.I.; LoSecco, J.M.; Manak, J.J.; Sanjari, A.H.; Shephard, W.D.; Stienike, D.L.; Taegar, S.A. [University of Notre Dame, Notre Dame, Indiana 46556 (United States); Chung, S.U.; Hackenburg, R.W.; Olchanski, C.; Strassburger, C.; Weygand, D.P.; Willutzki, H.J. [Brookhaven National Laboratory, Upton, Long Island, New York 11973 (United States); Denisov, S.P.; Dorofeev, V.A.; Kachaev, I.A.; Lipaev, V.V.; Popov, A.V.; Ryabchikov, D.I. [Institute for High Energy Physics, Protvino (Russian Federation); Bar-Yam, Z.; Cummings, J.P.; Dowd, J.P.; Eugenio, P.; Hayek, M.; Kern, W.; King, E. [University of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747 (United States); Bodyagin, V.A.; Kodolova, O.L.; Korotkikh, V.L.; Kostin, M.A.; Ostrovidov, A.I.; Sarycheva, L.I.; Sinev, N.B.; Vardanyan, I.N.; Yershov, A.A. [Moscow State University, Moscow (Russian Federation); Brown, D.S.; Pedlar, T.K.; Seth, K.K.; Wise, J.; Zhao, D. [Northwestern University, Evanston, Illinois 60208 (United States); Adams, G.S.; Kuhn, J.; Napolitano, J.; Nozar, M.; Smith, J.A.; White, D.B.; Witkowski, M. [Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    1997-09-01

    The {eta}{pi}{sup {minus}} system has been studied in the reaction {pi}{sup {minus}}p{r_arrow}{eta}{pi}{sup {minus}}p at 18 GeV/c. A large asymmetry in the angular distribution is observed indicating interference between L-even and L-odd partial waves. The a{sub 2}(1320) is observed in the J{sup PC}=2{sup ++} wave, as is a broad enhancement between 1.2 and 1.6 GeV/c{sup 2} in the 1{sup {minus}+} wave. The observed phase difference between these waves shows that there is phase motion in addition to that due to a{sub 2}(1320) decay. The data can be fitted by interference between the a{sub 2}(1320) and an exotic 1{sup {minus}+} resonance with M=(1370{plus_minus}16{sup +50}{sub {minus}30}) MeV/c{sup 2} and {Gamma}=(385{plus_minus}40 {sup +65}{sub {minus}105}) MeV/c{sup 2} . {copyright} {ital 1997} {ital The American Physical Society}

  19. Measurement of the angular distribution of the electron from W {r_arrow} e = {nu} decay, in p pbar at {radical}s = 1.8 TeV, as function of P{sub T}{sup W}

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    The goal of this work is to study the behavior of the angular distribution of the electron from the decay of the W boson in a specific rest frame of the W, the Collins-Soper frame. More specifically, the parameter {alpha}{sub 2} from the expression d{sigma}/d(P{sub T}{sup W}){sup 2} d cos {theta}* = k(1 + {alpha}{sub 2} cos {theta}* + {alpha}{sup 2}(cos {theta}*){sup 2}), corresponding to the distribution of cos {theta}* in the Collins-Soper frame, was measured. The experimental value of {alpha}P{sub 2} was compared with the predictions made by E. Mirkes [11] who included the radiative QCD perturbations in the weak-interaction B{sub boson} {r_arrow} lepton + lepton. This experimental value was extracted for the first time using knowledge about how the radiative QCD perturbations will modify the predictions given by the Electro-Weak process only.

  20. Search for Nonstandard Higgs Bosons Using High Mass Photon Pairs in p{ovr p} {r_arrow} {gamma}{gamma} + 2 Jets at {radical} (s) =1.8 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Grinstein, S.; Mostafa, M.; Piegaia, R. [Universidad de Buenos Aires, Buenos Aires (Argentina); Alves, G.A.; Carvalho, W.; Maciel, A.K.; da Motta, H.; Santoro, A. [LAFEX, Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro (Brazil); Lima, J.G.; Oguri, V. [Universidade do Estado do Rio de Janeiro, Rio de Janeiro (Brazil); Gomez, B.; Hoeneisen, B.; Mooney, P.; Negret, J.P. [Universidad de los Andes, Bogota (Colombia); Ducros, Y. [DAPNIA/Service de Physique des Particules, CEA, Saclay (France); Beri, S.B.; Bhatnagar, V.; Kohli, J.M.; Singh, J.B. [Panjab University, Chandigarh (India); Shivpuri, R.K. [Delhi University, Delhi (India); Acharya, B.S.; Banerjee, S.; Dugad, S.R.; Gupta, A.; Krishnaswamy, M.R.; Mondal, N.K.; Narasimham, V.S.; Parua, N.; Shankar, H.C. [Tata Institute of Fundamental Research, Mumbai (India); Park, Y.M. [Kyungsung University, Pusan (Korea); Choi, S.; Kim, S.K. [Seoul National University, Seoul (Korea); Castilla-Valdez, H.; Gonzalez Solis, J.L.; Hernandez-Montoya, R.; Magana-Mendoza, L.; Sanchez-Hernandez, A. [CINVESTAV, Mexico City (Mexico); Pawlik, B. [Institute of Nuclear Physics, Krakow (Poland); Gavrilov, V.; Gershtein, Y.; Kuleshov, S. [Institute for Theoretical and Experimental Physics, Moscow (Russia); Belyaev, A.; Dudko, L.V.; Ermolov, P.; Karmanov, D.; Leflat, A.; Manankov, V.; Merkin, M.; Shabalina, E. [Moscow State University, Moscow (Russia); Abramov, V.; Babintsev, V.V.; Bezzubov, V.A.; Bojko, N.I.; Burtovoi, V.S.; Chekulaev, S.V.; Denisov, S.P.; Dyshkant, A.; Eroshin, O.V.; Evdokimov, V.N.; Galyaev, A.N.; Goncharov, P.I.; Gurzhiev, S.N.; Kostritskiy, A.V.; Kozelov, A.V.; Kozlovsky, E.A.; Mayorov, A.A. [Institute for High Energy Physics, Protvino (Russia); Babukhadia, L.; Davis, K.; Fein, D.; Forden, G.E.; Guida, J.A.; Johns, K.; Nang, F.; Narayanan, A.; Rutherfoord, J.; Shupe, M. [University of Arizona, Tuscon, Arizona 85721 (United States); Barberis, E.; Clark, A.R.; Dahl, O.I.; Grudberg, P.; and others

    1999-03-01

    A search has been carried out for events in the channel p{ovr p}{r_arrow}{gamma}{gamma}+2 jets . Such a signature can characterize the production of a nonstandard Higgs boson together with a W or Z boson. We refer to this nonstandard Higgs, having standard model couplings to vector bosons but no coupling to fermions, as a {open_quotes}bosonic Higgs.{close_quotes} With the requirement of two high transverse energy photons and two jets, the diphoton mass (m{sub {gamma}{gamma}}) distribution is consistent with expected background. A 90 (95){percent} confidence level (C.L.) upper limit on the cross section as a function of mass is calculated, ranging from 0.60 (0.80)thinspthinsppb for m{sub {gamma}{gamma}}=65 GeV/c{sup 2} to 0.26 (0.34)thinspthinsppb for m{sub {gamma}{gamma}}=150 GeV/c{sup 2} , corresponding to a 95{percent} thinspthinspC.L. lower limit on the mass of a bosonic Higgs of 78.5 GeV/c{sup 2} . {copyright} {ital 1999} {ital The American Physical Society}

  1. Interactive Digital Signal Processor

    Science.gov (United States)

    Mish, W. H.

    1985-01-01

    Interactive Digital Signal Processor, IDSP, consists of set of time series analysis "operators" based on various algorithms commonly used for digital signal analysis. Processing of digital signal time series to extract information usually achieved by applications of number of fairly standard operations. IDSP excellent teaching tool for demonstrating application for time series operators to artificially generated signals.

  2. Signals and processing for random signal radars

    Science.gov (United States)

    Moore, G. S.

    1980-06-01

    Signals and associated processing techniques are developed which improve the performance, simplify the implementation, and are more amenable to adaptive operation for radars using the random signal concept. These goals are accomplished through the use of a signal set that is composed of a deterministic spreading function, a binary random or pseudo-random noise source, and a possibly random or pseudo-random pulsing sequence. Techniques are developed for determining the parameters of the spreading function that result in signals with desirable ambiguity functions and high effective power. These techniques are based on the use of window functions for sidelobe control and the theory of chirp waveforms for effective power enhancement.

  3. Digital signal processing laboratory

    CERN Document Server

    Kumar, B Preetham

    2011-01-01

    INTRODUCTION TO DIGITAL SIGNAL PROCESSING Brief Theory of DSP ConceptsProblem SolvingComputer Laboratory: Introduction to MATLAB®/SIMULINK®Hardware Laboratory: Working with Oscilloscopes, Spectrum Analyzers, Signal SourcesDigital Signal Processors (DSPs)ReferencesDISCRETE-TIME LTI SIGNALS AND SYSTEMS Brief Theory of Discrete-Time Signals and SystemsProblem SolvingComputer Laboratory: Simulation of Continuous Time and Discrete-Time Signals and Systems ReferencesTIME AND FREQUENCY ANALYSIS OF COMMUNICATION SIGNALS Brief Theory of Discrete-Time Fourier Transform (DTFT), Discrete Fourier Transform

  4. Multiplexing oscillatory biochemical signals.

    Science.gov (United States)

    de Ronde, Wiet; ten Wolde, Pieter Rein

    2014-04-01

    In recent years it has been increasingly recognized that biochemical signals are not necessarily constant in time and that the temporal dynamics of a signal can be the information carrier. Moreover, it is now well established that the protein signaling network of living cells has a bow-tie structure and that components are often shared between different signaling pathways. Here we show by mathematical modeling that living cells can multiplex a constant and an oscillatory signal: they can transmit these two signals simultaneously through a common signaling pathway, and yet respond to them specifically and reliably. We find that information transmission is reduced not only by noise arising from the intrinsic stochasticity of biochemical reactions, but also by crosstalk between the different channels. Yet, under biologically relevant conditions more than 2 bits of information can be transmitted per channel, even when the two signals are transmitted simultaneously. These observations suggest that oscillatory signals are ideal for multiplexing signals.

  5. Multidimensional signal processing for ultrasonic signal classification

    Science.gov (United States)

    Kim, J.; Ramuhalli, P.; Udpa, L.; Udpa, S.

    2001-04-01

    Neural network based signal classification systems are being used increasingly in the analysis of large volumes of data obtained in NDE applications. One example is in the interpretation on ultrasonic signals obtained from inspection of welds where signals can be due to porosity, slag, lack of fusion and cracks in the weld region. Standard techniques rely on differences in individual A-scans to classify the signals. This paper proposes an ultrasonic signal classification technique based on the information in a group of signals and examining the statistical characteristics of the signals. The method was 2-dimensional signal processing algorithms to analyze the information in B- and B'-scan images. In this paper, 2-dimensional transform based coefficients of the images are used as features and a multilayer perceptron is used to classify them. These results are then combined to get the final classification for the inspected region. Results of applying the technique to data obtained from the inspection of welds are presented.

  6. Cell signaling review series

    Institute of Scientific and Technical Information of China (English)

    Aiming Lin; Zhenggang Liu

    2008-01-01

    @@ Signal transduction is pivotal for many, if not all, fundamental cellular functions including proliferation, differentiation, transformation and programmed cell death. Deregulation of cell signaling may result in certain types of cancers and other human diseases.

  7. Retinoid signalling during embryogenesis

    NARCIS (Netherlands)

    Pijnappel, W.W.M.; Hendriks, H.F.J.; Durston, A.J.

    1996-01-01

    Conclusion: Retinoids are suspected to have multiple functions during embryogenesis, which are carried out via various different signal transduction pathways involving active retinoids and nuclear retinoid receptors. Research focuses on the identification of the retinoid signal transduction componen

  8. Biomedical signal processing

    CERN Document Server

    Akay, Metin

    1994-01-01

    Sophisticated techniques for signal processing are now available to the biomedical specialist! Written in an easy-to-read, straightforward style, Biomedical Signal Processing presents techniques to eliminate background noise, enhance signal detection, and analyze computer data, making results easy to comprehend and apply. In addition to examining techniques for electrical signal analysis, filtering, and transforms, the author supplies an extensive appendix with several computer programs that demonstrate techniques presented in the text.

  9. Danger signals in stroke.

    Science.gov (United States)

    Gelderblom, Mathias; Sobey, Christopher G; Kleinschnitz, Christoph; Magnus, Tim

    2015-11-01

    Danger molecules are the first signals released from dying tissue after stroke. These danger signals bind to receptors on immune cells that will result in their activation and the release of inflammatory and neurotoxic mediators, resulting in amplification of the immune response and subsequent enlargement of the damaged brain volume. The release of danger signals is a central event that leads to a multitude of signals and cascades in the affected and neighbouring tissue, therefore providing a potential target for therapy.

  10. Tetrapyrrole Signaling in Plants

    Science.gov (United States)

    Larkin, Robert M.

    2016-01-01

    Tetrapyrroles make critical contributions to a number of important processes in diverse organisms. In plants, tetrapyrroles are essential for light signaling, the detoxification of reactive oxygen species, the assimilation of nitrate and sulfate, respiration, photosynthesis, and programed cell death. The misregulation of tetrapyrrole metabolism can produce toxic reactive oxygen species. Thus, it is not surprising that tetrapyrrole metabolism is strictly regulated and that tetrapyrrole metabolism affects signaling mechanisms that regulate gene expression. In plants and algae, tetrapyrroles are synthesized in plastids and were some of the first plastid signals demonstrated to regulate nuclear gene expression. In plants, the mechanism of tetrapyrrole-dependent plastid-to-nucleus signaling remains poorly understood. Additionally, some of experiments that tested ideas for possible signaling mechanisms appeared to produce conflicting data. In some instances, these conflicts are potentially explained by different experimental conditions. Although the biological function of tetrapyrrole signaling is poorly understood, there is compelling evidence that this signaling is significant. Specifically, this signaling appears to affect the accumulation of starch and may promote abiotic stress tolerance. Tetrapyrrole-dependent plastid-to-nucleus signaling interacts with a distinct plastid-to-nucleus signaling mechanism that depends on GENOMES UNCUOPLED1 (GUN1). GUN1 contributes to a variety of processes, such as chloroplast biogenesis, the circadian rhythm, abiotic stress tolerance, and development. Thus, the contribution of tetrapyrrole signaling to plant function is potentially broader than we currently appreciate. In this review, I discuss these aspects of tetrapyrrole signaling.

  11. Acoustic Signals and Systems

    DEFF Research Database (Denmark)

    2008-01-01

    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...

  12. Acoustic Signal Processing

    Science.gov (United States)

    Hartmann, William M.; Candy, James V.

    Signal processing refers to the acquisition, storage, display, and generation of signals - also to the extraction of information from signals and the re-encoding of information. As such, signal processing in some form is an essential element in the practice of all aspects of acoustics. Signal processing algorithms enable acousticians to separate signals from noise, to perform automatic speech recognition, or to compress information for more efficient storage or transmission. Signal processing concepts are the building blocks used to construct models of speech and hearing. Now, in the 21st century, all signal processing is effectively digital signal processing. Widespread access to high-speed processing, massive memory, and inexpensive software make signal processing procedures of enormous sophistication and power available to anyone who wants to use them. Because advanced signal processing is now accessible to everybody, there is a need for primers that introduce basic mathematical concepts that underlie the digital algorithms. The present handbook chapter is intended to serve such a purpose.

  13. Reliable Signal Transduction

    Science.gov (United States)

    Wollman, Roy

    Stochasticity inherent to biochemical reactions (intrinsic noise) and variability in cellular states (extrinsic noise) degrade information transmitted through signaling networks. We analyzed the ability of temporal signal modulation - that is dynamics - to reduce noise-induced information loss. In the extracellular signal-regulated kinase (ERK), calcium (Ca(2 +)) , and nuclear factor kappa-B (NF- κB) pathways, response dynamics resulted in significantly greater information transmission capacities compared to nondynamic responses. Theoretical analysis demonstrated that signaling dynamics has a key role in overcoming extrinsic noise. Experimental measurements of information transmission in the ERK network under varying signal-to-noise levels confirmed our predictions and showed that signaling dynamics mitigate, and can potentially eliminate, extrinsic noise-induced information loss. By curbing the information-degrading effects of cell-to-cell variability, dynamic responses substantially increase the accuracy of biochemical signaling networks.

  14. Micro-simulation of vehicle conflicts involving right-turn vehicles at signalized intersections based on cellular automata.

    Science.gov (United States)

    Chai, C; Wong, Y D

    2014-02-01

    At intersection, vehicles coming from different directions conflict with each other. Improper geometric design and signal settings at signalized intersection will increase occurrence of conflicts between road users and results in a reduction of the safety level. This study established a cellular automata (CA) model to simulate vehicular interactions involving right-turn vehicles (as similar to left-turn vehicles in US). Through various simulation scenarios for four case cross-intersections, the relationships between conflict occurrences involving right-turn vehicles with traffic volume and right-turn movement control strategies are analyzed. Impacts of traffic volume, permissive right-turn compared to red-amber-green (RAG) arrow, shared straight-through and right-turn lane as well as signal setting are estimated from simulation results. The simulation model is found to be able to provide reasonable assessment of conflicts through comparison of existed simulation approach and observed accidents. Through the proposed approach, prediction models for occurrences and severity of vehicle conflicts can be developed for various geometric layouts and traffic control strategies.

  15. Quantitation of signal transduction.

    Science.gov (United States)

    Krauss, S; Brand, M D

    2000-12-01

    Conventional qualitative approaches to signal transduction provide powerful ways to explore the architecture and function of signaling pathways. However, at the level of the complete system, they do not fully depict the interactions between signaling and metabolic pathways and fail to give a manageable overview of the complexity that is often a feature of cellular signal transduction. Here, we introduce a quantitative experimental approach to signal transduction that helps to overcome these difficulties. We present a quantitative analysis of signal transduction during early mitogen stimulation of lymphocytes, with steady-state respiration rate as a convenient marker of metabolic stimulation. First, by inhibiting various key signaling pathways, we measure their relative importance in regulating respiration. About 80% of the input signal is conveyed via identifiable routes: 50% through pathways sensitive to inhibitors of protein kinase C and MAP kinase and 30% through pathways sensitive to an inhibitor of calcineurin. Second, we quantify how each of these pathways differentially stimulates functional units of reactions that produce and consume a key intermediate in respiration: the mitochondrial membrane potential. Both the PKC and calcineurin routes stimulate consumption more strongly than production, whereas the unidentified signaling routes stimulate production more than consumption, leading to no change in membrane potential despite increased respiration rate. The approach allows a quantitative description of the relative importance of signal transduction pathways and the routes by which they activate a specific cellular process. It should be widely applicable.

  16. Slit-Robo signaling.

    Science.gov (United States)

    Blockus, Heike; Chédotal, Alain

    2016-09-01

    Slits are secreted proteins that bind to Roundabout (Robo) receptors. Slit-Robo signaling is best known for mediating axon repulsion in the developing nervous system. However, in recent years the functional repertoire of Slits and Robo has expanded tremendously and Slit-Robo signaling has been linked to roles in neurogenesis, angiogenesis and cancer progression among other processes. Likewise, our mechanistic understanding of Slit-Robo signaling has progressed enormously. Here, we summarize new insights into Slit-Robo evolutionary and system-dependent diversity, receptor-ligand interactions, signaling crosstalk and receptor activation.

  17. Geolocation of RF signals

    CERN Document Server

    Progri, Ilir

    2011-01-01

    ""Geolocation of RF Signals - Principles and Simulations"" offers an overview of the best practices and innovative techniques in the art and science of geolocation over the last twenty years. It covers all research and development aspects including theoretical analysis, RF signals, geolocation techniques, key block diagrams, and practical principle simulation examples in the frequency band from 100 MHz to 18 GHz or even 60 GHz. Starting with RF signals, the book progressively examines various signal bands - such as VLF, LF, MF, HF, VHF, UHF, L, S, C, X, Ku, and, K and the corresponding geoloca

  18. Digital signal processing

    CERN Document Server

    O'Shea, Peter; Hussain, Zahir M

    2011-01-01

    In three parts, this book contributes to the advancement of engineering education and that serves as a general reference on digital signal processing. Part I presents the basics of analog and digital signals and systems in the time and frequency domain. It covers the core topics: convolution, transforms, filters, and random signal analysis. It also treats important applications including signal detection in noise, radar range estimation for airborne targets, binary communication systems, channel estimation, banking and financial applications, and audio effects production. Part II considers sel

  19. Biomedical signals and systems

    CERN Document Server

    Tranquillo, Joseph V

    2013-01-01

    Biomedical Signals and Systems is meant to accompany a one-semester undergraduate signals and systems course. It may also serve as a quick-start for graduate students or faculty interested in how signals and systems techniques can be applied to living systems. The biological nature of the examples allows for systems thinking to be applied to electrical, mechanical, fluid, chemical, thermal and even optical systems. Each chapter focuses on a topic from classic signals and systems theory: System block diagrams, mathematical models, transforms, stability, feedback, system response, control, time

  20. Ubiquitination in apoptosis signaling

    NARCIS (Netherlands)

    van de Kooij, L.W.

    2014-01-01

    The work described in this thesis focuses on ubiquitination and protein degradation, with an emphasis on how these processes regulate apoptosis signaling. More specifically, our aims were: 1. To increase the understanding of ubiquitin-mediated regulation of apoptosis signaling. 2. To identify the E3

  1. SignalR blueprints

    CERN Document Server

    Ingebrigtsen, Einar

    2015-01-01

    This book is designed for software developers, primarily those with knowledge of C#, .NET, and JavaScript. Good knowledge and understanding of SignalR is assumed to allow efficient programming of core elements and applications in SignalR.

  2. Multiresolution signal decomposition schemes

    NARCIS (Netherlands)

    Goutsias, J.; Heijmans, H.J.A.M.

    1998-01-01

    [PNA-R9810] Interest in multiresolution techniques for signal processing and analysis is increasing steadily. An important instance of such a technique is the so-called pyramid decomposition scheme. This report proposes a general axiomatic pyramid decomposition scheme for signal analysis and synthes

  3. Signaling by Gasotransmitters

    OpenAIRE

    Mustafa, Asif K.; Gadalla, Moataz M.; Snyder, Solomon H

    2009-01-01

    Nitric oxide is well established as a major signaling molecule. Evidence is accumulating that carbon monoxide and hydrogen sulfide also are physiologic mediators in the cardiovascular, immune, and nervous systems. This Review focuses on mechanisms whereby they signal by binding to metal centers in metalloproteins, such as in guanylyl cyclase, or modifying sulfhydryl groups in protein targets.

  4. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, Simon Minze; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital converte

  5. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, Simon Minze; Vertregt, Maarten

    2010-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital converte

  6. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  7. Neutron signal transfer analysis

    CERN Document Server

    Pleinert, H; Lehmann, E

    1999-01-01

    A new method called neutron signal transfer analysis has been developed for quantitative determination of hydrogenous distributions from neutron radiographic measurements. The technique is based on a model which describes the detector signal obtained in the measurement as a result of the action of three different mechanisms expressed by signal transfer functions. The explicit forms of the signal transfer functions are determined by Monte Carlo computer simulations and contain only the distribution as a variable. Therefore an unknown distribution can be determined from the detector signal by recursive iteration. This technique provides a simple and efficient tool for analysis of this type while also taking into account complex effects due to the energy dependency of neutron interaction and single and multiple scattering. Therefore this method provides an efficient tool for precise quantitative analysis using neutron radiography, as for example quantitative determination of moisture distributions in porous buil...

  8. Calcium signaling and epilepsy.

    Science.gov (United States)

    Steinlein, Ortrud K

    2014-08-01

    Calcium signaling is involved in a multitude of physiological and pathophysiological mechanisms. Over the last decade, it has been increasingly recognized as an important factor in epileptogenesis, and it is becoming obvious that the excess synchronization of neurons that is characteristic for seizures can be linked to various calcium signaling pathways. These include immediate effects on membrane excitability by calcium influx through ion channels as well as delayed mechanisms that act through G-protein coupled pathways. Calcium signaling is able to cause hyperexcitability either by direct modulation of neuronal activity or indirectly through calcium-dependent gliotransmission. Furthermore, feedback mechanisms between mitochondrial calcium signaling and reactive oxygen species are able to cause neuronal cell death and seizures. Unravelling the complexity of calcium signaling in epileptogenesis is a daunting task, but it includes the promise to uncover formerly unknown targets for the development of new antiepileptic drugs.

  9. Complexity and the Arrow of Time

    Science.gov (United States)

    Lineweaver, Charles H.; Davies, Paul C. W.; Ruse, Michael

    2013-08-01

    1. What is complexity? Is it increasing? Charles H. Lineweaver, Paul C. W. Davies and Michael Ruse; 2. Directionality principles from cancer to cosmology Paul C. W. Davies; 3. A simple treatment of complexity: cosmological entropic boundary conditions on increasing complexity Charles H. Lineweaver; 4. Using complexity science to search for unity in the natural sciences Eric J. Chaisson; 5. On the spontaneous generation of complexity in the universe Seth Lloyd; 6. Emergent spatiotemporal complexity in field theory Marcelo Gleiser; 7. Life: the final frontier for complexity? Simon Conway Morris; 8. Evolution beyond Newton, Darwin, and entailing law: the origin of complexity in the evolving biosphere Stuart A. Kauffman; 9. Emergent order in processes: the interplay of complexity, robustness, correlation, and hierarchy in the biosphere D. Eric Smith; 10. The inferential evolution of biological complexity: forgetting nature by learning to nurture David C. Krakauer; 11. Information width: a way for the second law to increase complexity David Wolpert; 12. Wrestling with biological complexity: from Darwin to Dawkins Michael Ruse; 13. The role of generative entrenchment and robustness in the evolution of complexity William C. Wimsatt; 14. On the plurality of complexity-producing mechanisms Philip Clayton; Index.

  10. Episensitization: Defying Time’s Arrow

    Directory of Open Access Journals (Sweden)

    Bryan eOronsky

    2015-06-01

    Full Text Available The development of cancer is driven by complex genetic and epigenetic changes that result in aberrant and uncontrolled cellular growth. Epigenetic changes, in particular, are implicated in the silencing or activation of key genes that control cellular growth and apoptosis and contribute to transformative potential. The purpose of this review is to define and assess the treatment strategy of episensitization, or the ability to sensitize cancer cells to subsequent therapy by resetting the epigenetic infrastructure of the tumor. One important facet is resensitization by epigenetic mechanisms, which goes against the norm, i.e., challenges the long-held doctrine in oncology that the reuse of previously tried and failed therapies is a clinically pointless endeavor. Thus, episensitization is a hybrid term, which covers recent clinically relevant observations and refers to the epigenomic mechanism of resensitization. Among the many formidable challenges in the treatment of cancer, the most inevitable is the development of acquired therapeutic resistance. Here, we present the basic principles behind episensitization and highlight the evidence suggesting that epigenetically mediated histone hypoacetylation and DNA hypermethylation events may reverse clinical drug resistance. The potential reversibility of epigenetic changes and the microenvironmental impact of epigenetic control on gene expression may mediate a return to a baseline state of treatment susceptibility. Episensitization is a novel and highly practical management strategy both to prevent the practice of permanent treatment discontinuation with the occurrence of resistance, which rapidly exhausts remaining options in the pharmaceutical armamentarium and to significantly extend patient survival. Accordingly, this review highlights several epigenetic agents including decitabine, vorinostat, entinostat, 5-azacitidine, oncolytic viruses and RRx-001.

  11. Episensitization: Defying Time’s Arrow

    Science.gov (United States)

    Oronsky, Bryan T.; Oronsky, Arnold L.; Lybeck, Michelle; Oronsky, Neil C.; Scicinski, Jan J.; Carter, Corey; Day, Regina M.; Rodriguez Orengo, Jose F.; Rodriguez-Torres, Maribel; Fanger, Gary F.; Reid, Tony R.

    2015-01-01

    The development of cancer is driven by complex genetic and epigenetic changes that result in aberrant and uncontrolled cellular growth. Epigenetic changes, in particular, are implicated in the silencing or activation of key genes that control cellular growth and apoptosis and contribute to transformative potential. The purpose of this review is to define and assess the treatment strategy of “episensitization,” or the ability to sensitize cancer cells to subsequent therapy by resetting the epigenetic infrastructure of the tumor. One important facet is resensitization by epigenetic mechanisms, which goes against the norm, i.e., challenges the long-held doctrine in oncology that the reuse of previously tried and failed therapies is a clinically pointless endeavor. Thus, episensitization is a hybrid term, which covers recent clinically relevant observations and refers to the epigenomic mechanism of resensitization. Among the many formidable challenges in the treatment of cancer, the most inevitable is the development of acquired therapeutic resistance. Here, we present the basic principles behind episensitization and highlight the evidence suggesting that epigenetically mediated histone hypoacetylation and DNA hypermethylation events may reverse clinical drug resistance. The potential reversibility of epigenetic changes and the microenvironmental impact of epigenetic control on gene expression may mediate a return to a baseline state of treatment susceptibility. Episensitization is a novel and highly practical management strategy both to prevent the practice of permanent treatment discontinuation with the occurrence of resistance, which rapidly exhausts remaining options in the pharmaceutical armamentarium and to significantly extend patient survival. Accordingly, this review highlights several epigenetic agents including decitabine, vorinostat, entinostat, 5-azacitidine, oncolytic viruses, and RRx-001. PMID:26125013

  12. Film Premiere: Arrows of time at exploratorium

    CERN Multimedia

    2007-01-01

    "Join award-wimming artist and filmmaker Ken McMullen for a uniqude presentation of films engaging ideas at the forefront of science and culture on Sunday, Apri 29 at 2pm at the Exploratorium." (1/3 page)

  13. Probability, Arrow of Time and Decoherence

    CERN Document Server

    Bacciagaluppi, G

    2007-01-01

    This paper relates both to the metaphysics of probability and to the physics of time asymmetry. Using the formalism of decoherent histories, it investigates whether intuitions about intrinsic time directedness that are often associated with probability can be justified in the context of no-collapse approaches to quantum mechanics. The standard (two-vector) approach to time symmetry in the decoherent histories literature is criticised, and an alternative approach is proposed, based on two decoherence conditions ('forwards' and 'backwards') within the one-vector formalism. In turn, considerations of forwards and backwards decoherence and of decoherence and recoherence suggest that a time-directed interpretation of probabilities, if adopted, should be both contingent and perspectival.

  14. Curare: the South American arrow poison.

    Science.gov (United States)

    Lee, M R

    2005-02-01

    The history of curare is both curious and convoluted. A product of South American culture it emerged in the sixteenth century from the mists of antiquity at the same time as quinine, coca, and chocolate. Like quinine, at first came the extract but no plant, and later the plant but no chemical compound. It took more than 300 years and the efforts of many explorers and scientists to resolve the problem. These included Condamine, Humboldt, Brodie, Waterton, Bernard, Dale, Walker, and King. Finally, the pure compound d-tubocurarine was isolated from the liana Chondrodendron and synthesised. Its specific physiological action was blockade of the effect of acetylcholine at the neuro-muscular junction. Such a paralytic poison could be used to kill oneself or others. The bizarre plot to kill the Prime Minister, Lloyd George, during the First World War is described. Fortunately this nefarious plan was thwarted by the Secret Service!

  15. Time's Arrow and the Measurement Problem

    CERN Document Server

    Halabi, Tarek

    2009-01-01

    When both slits of the double slit experiment are open, closing one of the slits increases the detection rate at some points on the detection screen. This very feature underlies Feynman's famous pessimistic quote on getting lost in dark alleys when thinking about this experiment. Having heard a fire alarm, there are two trajectories the universe can take into a past in which an unintended fire had started. One, in which a fire drill strangely coinciding with the unintended fire triggers the alarm, and another whereby NO fire drill was scheduled and the unintended fire triggers the alarm. These two trajectories into a past in which an unintended fire had started are analogous to the particle trajectories through the two slits into a future in which the aforementioned detection occurs. When trajectories involving a scheduled drill are ruled out, the probability of the unintended fire rises (through Bayesian inference), much as the detection probability rises when one of the slits is closed. The enigmatic featur...

  16. Signal flow analysis

    CERN Document Server

    Abrahams, J R; Hiller, N

    1965-01-01

    Signal Flow Analysis provides information pertinent to the fundamental aspects of signal flow analysis. This book discusses the basic theory of signal flow graphs and shows their relation to the usual algebraic equations.Organized into seven chapters, this book begins with an overview of properties of a flow graph. This text then demonstrates how flow graphs can be applied to a wide range of electrical circuits that do not involve amplification. Other chapters deal with the parameters as well as circuit applications of transistors. This book discusses as well the variety of circuits using ther

  17. Signal Station Inspection Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Handwritten reports resulting from detailed inspections of US Army Signal Service Stations, 1871-1889. Features reported included instrument exposure and condition,...

  18. Lipid signaling in plants

    NARCIS (Netherlands)

    Munnik, T.

    2010-01-01

    This book highlights the current status of plant lipid signaling. Written by leading researchers in the field, the chapters include detailed information on the measurement, regulation and function of phospholipases, lipid kinases, lipid phosphatases, inositolpolyphosphates, polyphosphoinositides, ph

  19. Signals from the Cosmos.

    Science.gov (United States)

    Lichtman, Jeffrey M.

    1991-01-01

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

  20. Signaling in muscle contraction.

    Science.gov (United States)

    Kuo, Ivana Y; Ehrlich, Barbara E

    2015-02-02

    Signaling pathways regulate contraction of striated (skeletal and cardiac) and smooth muscle. Although these are similar, there are striking differences in the pathways that can be attributed to the distinct functional roles of the different muscle types. Muscles contract in response to depolarization, activation of G-protein-coupled receptors and other stimuli. The actomyosin fibers responsible for contraction require an increase in the cytosolic levels of calcium, which signaling pathways induce by promoting influx from extracellular sources or release from intracellular stores. Rises in cytosolic calcium stimulate numerous downstream calcium-dependent signaling pathways, which can also regulate contraction. Alterations to the signaling pathways that initiate and sustain contraction and relaxation occur as a consequence of exercise and pathophysiological conditions.

  1. Ultrahigh bandwidth signal processing

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo

    2016-01-01

    Optical time lenses have proven to be very versatile for advanced optical signal processing. Based on a controlled interplay between dispersion and phase-modulation by e.g. four-wave mixing, the processing is phase-preserving, an hence useful for all types of data signals including coherent multi......-level modulation founats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signa In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral...... regeneratio These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platform like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described....

  2. Topological signal processing

    CERN Document Server

    Robinson, Michael

    2014-01-01

    Signal processing is the discipline of extracting information from collections of measurements. To be effective, the measurements must be organized and then filtered, detected, or transformed to expose the desired information.  Distortions caused by uncertainty, noise, and clutter degrade the performance of practical signal processing systems. In aggressively uncertain situations, the full truth about an underlying signal cannot be known.  This book develops the theory and practice of signal processing systems for these situations that extract useful, qualitative information using the mathematics of topology -- the study of spaces under continuous transformations.  Since the collection of continuous transformations is large and varied, tools which are topologically-motivated are automatically insensitive to substantial distortion. The target audience comprises practitioners as well as researchers, but the book may also be beneficial for graduate students.

  3. Digital signal processing: Handbook

    Science.gov (United States)

    Goldenberg, L. M.; Matiushkin, B. D.; Poliak, M. N.

    The fundamentals of the theory and design of systems and devices for the digital processing of signals are presented. Particular attention is given to algorithmic methods of synthesis and digital processing equipment in communication systems (e.g., selective digital filtering, spectral analysis, and variation of the signal discretization frequency). Programs for the computer-aided analysis of digital filters are described. Computational examples are presented, along with tables of transfer function coefficients for recursive and nonrecursive digital filters.

  4. Ultrahigh bandwidth signal processing

    Science.gov (United States)

    Oxenløwe, Leif Katsuo

    2016-04-01

    Optical time lenses have proven to be very versatile for advanced optical signal processing. Based on a controlled interplay between dispersion and phase-modulation by e.g. four-wave mixing, the processing is phase-preserving, and hence useful for all types of data signals including coherent multi-level modulation formats. This has enabled processing of phase-modulated spectrally efficient data signals, such as orthogonal frequency division multiplexed (OFDM) signals. In that case, a spectral telescope system was used, using two time lenses with different focal lengths (chirp rates), yielding a spectral magnification of the OFDM signal. Utilising such telescopic arrangements, it has become possible to perform a number of interesting functionalities, which will be described in the presentation. This includes conversion from OFDM to Nyquist WDM, compression of WDM channels to a single Nyquist channel and WDM regeneration. These operations require a broad bandwidth nonlinear platform, and novel photonic integrated nonlinear platforms like aluminum gallium arsenide nano-waveguides used for 1.28 Tbaud optical signal processing will be described.

  5. Digital Signal Processing applied to Physical Signals

    CERN Document Server

    Alberto, Diego; Musa, L

    2011-01-01

    It is well known that many of the scientific and technological discoveries of the XXI century will depend on the capability of processing and understanding a huge quantity of data. With the advent of the digital era, a fully digital and automated treatment can be designed and performed. From data mining to data compression, from signal elaboration to noise reduction, a processing is essential to manage and enhance features of interest after every data acquisition (DAQ) session. In the near future, science will go towards interdisciplinary research. In this work there will be given an example of the application of signal processing to different fields of Physics from nuclear particle detectors to biomedical examinations. In Chapter 1 a brief description of the collaborations that allowed this thesis is given, together with a list of the publications co-produced by the author in these three years. The most important notations, definitions and acronyms used in the work are also provided. In Chapter 2, the last r...

  6. VLSI signal processing technology

    CERN Document Server

    Swartzlander, Earl

    1994-01-01

    This book is the first in a set of forthcoming books focussed on state-of-the-art development in the VLSI Signal Processing area. It is a response to the tremendous research activities taking place in that field. These activities have been driven by two factors: the dramatic increase in demand for high speed signal processing, especially in consumer elec­ tronics, and the evolving microelectronic technologies. The available technology has always been one of the main factors in determining al­ gorithms, architectures, and design strategies to be followed. With every new technology, signal processing systems go through many changes in concepts, design methods, and implementation. The goal of this book is to introduce the reader to the main features of VLSI Signal Processing and the ongoing developments in this area. The focus of this book is on: • Current developments in Digital Signal Processing (DSP) pro­ cessors and architectures - several examples and case studies of existing DSP chips are discussed in...

  7. Glutamate signalling in bone.

    Directory of Open Access Journals (Sweden)

    Karen eBrakspear

    2012-08-01

    Full Text Available Mechanical loading plays a key role in the physiology of bone, allowing bone to functionally adapt to its environment, however characterisation of the signalling events linking load to bone formation is incomplete. A screen for genes associated with mechanical load-induced bone formation identified the glutamate transporter GLAST, implicating the excitatory amino acid, glutamate, in the mechanoresponse. When an osteogenic load (10N, 10Hz was externally applied to the rat ulna, GLAST (EAAT1 mRNA, was significantly down-regulated in osteocytes in the loaded limb. Functional components from each stage of the glutamate signalling pathway have since been identified within bone, including proteins necessary for calcium-mediated glutamate exocytosis, receptors, transporters and signal propagation. Activation of ionotropic glutamate receptors has been shown to regulate the phenotype of osteoblasts and osteoclasts in vitro and bone mass in vivo. Furthermore, glutamatergic nerves have been identified in the vicinity of bone cells expressing glutamate receptors in vivo. However, it is not yet known how a glutamate signalling event is initiated in bone or its physiological significance. This review will examine the role of the glutamate signalling pathway in bone, with emphasis on the functions of glutamate transporters in osteoblasts.

  8. Purinergic signalling and diabetes

    DEFF Research Database (Denmark)

    Burnstock, Geoffrey; Novak, Ivana

    2013-01-01

    The pancreas is an organ with a central role in nutrient breakdown, nutrient sensing and release of hormones regulating whole body nutrient homeostasis. In diabetes mellitus, the balance is broken-cells can be starving in the midst of plenty. There are indications that the incidence of diabetes...... type 1 and 2, and possibly pancreatogenic diabetes, is rising globally. Events leading to insulin secretion and action are complex, but there is emerging evidence that intracellular nucleotides and nucleotides are not only important as intracellular energy molecules but also as extracellular signalling...... molecules in purinergic signalling cascades. This signalling takes place at the level of the pancreas, where the close apposition of various cells-endocrine, exocrine, stromal and immune cells-contributes to the integrated function. Following an introduction to diabetes, the pancreas and purinergic...

  9. Understanding signal integrity

    CERN Document Server

    Thierauf, Stephen C

    2010-01-01

    This unique book provides you with practical guidance on understanding and interpreting signal integrity (SI) performance to help you with your challenging circuit board design projects. You find high-level discussions of important SI concepts presented in a clear and easily accessible format, including question and answer sections and bulleted lists.This valuable resource features rules of thumb and simple equations to help you make estimates of critical signal integrity parameters without using circuit simulators of CAD (computer-aided design). The book is supported with over 120 illustratio

  10. TOR signalling in plants.

    Science.gov (United States)

    Rexin, Daniel; Meyer, Christian; Robaglia, Christophe; Veit, Bruce

    2015-08-15

    Although the eukaryotic TOR (target of rapamycin) kinase signalling pathway has emerged as a key player for integrating nutrient-, energy- and stress-related cues with growth and metabolic outputs, relatively little is known of how this ancient regulatory mechanism has been adapted in higher plants. Drawing comparisons with the substantial knowledge base around TOR kinase signalling in fungal and animal systems, functional aspects of this pathway in plants are reviewed. Both conserved and divergent elements are discussed in relation to unique aspects associated with an autotrophic mode of nutrition and adaptive strategies for multicellular development exhibited by plants.

  11. Electronic signal conditioning

    CERN Document Server

    NEWBY, BRUCE

    1994-01-01

    At technician level, brief references to signal conditioning crop up in a fragmented way in various textbooks, but there has been no single textbook, until now!More advanced texts do exist but they are more mathematical and presuppose a higher level of understanding of electronics and statistics. Electronic Signal Conditioning is designed for HNC/D students and City & Guilds Electronics Servicing 2240 Parts 2 & 3. It will also be useful for BTEC National, Advanced GNVQ, A-level electronics and introductory courses at degree level.

  12. Genomic signal processing

    CERN Document Server

    Shmulevich, Ilya

    2007-01-01

    Genomic signal processing (GSP) can be defined as the analysis, processing, and use of genomic signals to gain biological knowledge, and the translation of that knowledge into systems-based applications that can be used to diagnose and treat genetic diseases. Situated at the crossroads of engineering, biology, mathematics, statistics, and computer science, GSP requires the development of both nonlinear dynamical models that adequately represent genomic regulation, and diagnostic and therapeutic tools based on these models. This book facilitates these developments by providing rigorous mathema

  13. Communication Signals in Lizards.

    Science.gov (United States)

    Carpenter, Charles C.

    1983-01-01

    Discusses mechanisms and functional intent of visual communication signals in iguanid/agamid lizards. Demonstrated that lizards communicate with each other by using pushups and head nods and that each species does this in its own way, conveying different types of information. (JN)

  14. Contextual signaling in cancer.

    Science.gov (United States)

    Smithson, Laura J; Anastasaki, Corina; Chen, Ran; Toonen, Joseph A; Williams, Sidney B; Gutmann, David H

    2016-10-01

    The formation and maintenance of an organism are highly dependent on the orderly control of cell growth, differentiation, death, and migration. These processes are tightly regulated by signaling cascades in which a limited number of molecules dictate these cellular events. While these signaling pathways are highly conserved across species and cell types, the functional outcomes that result from their engagement are specified by the context in which they are activated. Using the Neurofibromatosis type 1 (NF1) cancer predisposition syndrome as an illustrative platform, we discuss how NF1/RAS signaling can create functional diversity at multiple levels (molecular, cellular, tissue, and genetic/genomic). As such, the ability of related molecules (e.g., K-RAS, H-RAS) to activate distinct effectors, as well as cell type- and tissue-specific differences in molecular composition and effector engagement, generate numerous unique functional effects. These variations, coupled with a multitude of extracellular cues and genomic/genetic changes that each modify the innate signaling properties of the cell, enable precise control of cellular physiology in both health and disease. Understanding these contextual influences is important when trying to dissect the underlying pathogenic mechanisms of cancer relevant to molecularly-targeted therapeutics.

  15. Hedgehog signaling update.

    Science.gov (United States)

    Cohen, M Michael

    2010-08-01

    In vertebrate hedgehog signaling, hedgehog ligands are processed to become bilipidated and then multimerize, which allows them to leave the signaling cell via Dispatched 1 and become transported via glypicans and megalin to the responding cells. Hedgehog then interacts with a complex of Patched 1 and Cdo/Boc, which activates endocytic Smoothened to the cilium. Patched 1 regulates the activity of Smoothened (1) via Vitamin D3, which inhibits Smoothened in the absence of hedgehog ligand or (2) via oxysterols, which activate Smoothened in the presence of hedgehog ligand. Hedgehog ligands also interact with Hip1, Patched 2, and Gas1, which regulate the range as well as the level of hedgehog signaling. In vertebrates, Smoothened is shortened at its C-terminal end and lacks most of the phosphorylation sites of importance in Drosophila. Cos2, also of importance in Drosophila, plays no role in mammalian transduction, nor do its homologs Kif7 and Kif27. The cilium may provide a function analogous to that of Cos2 by linking Smoothened to the modulation of Gli transcription factors. Disorders associated with the hedgehog signaling network follow, including nevoid basal cell carcinoma syndrome, holoprosencephaly, Smith-Lemli-Opitz syndrome, Greig cephalopolysyndactyly syndrome, Pallister-Hall syndrome, Carpenter syndrome, and Rubinstein-Taybi syndrome.

  16. Mediation as Signal

    NARCIS (Netherlands)

    Holler, M.J.; Lindner, I.

    2004-01-01

    This paper analyzes mediation as a signal. Starting from a stylized case, a game theoretical model of one-sided incomplete information, taken from Cho and Kreps (1987), is applied to discuss strategic effects of mediation. It turns out that to reject mediation can be interpreted as a ”negative signa

  17. Calcium signaling in neurodegeneration

    Directory of Open Access Journals (Sweden)

    Dreses-Werringloer Ute

    2009-05-01

    Full Text Available Abstract Calcium is a key signaling ion involved in many different intracellular and extracellular processes ranging from synaptic activity to cell-cell communication and adhesion. The exact definition at the molecular level of the versatility of this ion has made overwhelming progress in the past several years and has been extensively reviewed. In the brain, calcium is fundamental in the control of synaptic activity and memory formation, a process that leads to the activation of specific calcium-dependent signal transduction pathways and implicates key protein effectors, such as CaMKs, MAPK/ERKs, and CREB. Properly controlled homeostasis of calcium signaling not only supports normal brain physiology but also maintains neuronal integrity and long-term cell survival. Emerging knowledge indicates that calcium homeostasis is not only critical for cell physiology and health, but also, when deregulated, can lead to neurodegeneration via complex and diverse mechanisms involved in selective neuronal impairments and death. The identification of several modulators of calcium homeostasis, such as presenilins and CALHM1, as potential factors involved in the pathogenesis of Alzheimer's disease, provides strong support for a role of calcium in neurodegeneration. These observations represent an important step towards understanding the molecular mechanisms of calcium signaling disturbances observed in different brain diseases such as Alzheimer's, Parkinson's, and Huntington's diseases.

  18. Study of {Lambda}{sup 0} polarization in {ital pp}{r_arrow}{ital p}{Lambda}{sup 0}{ital K}{sup +}{pi}{sup +}{pi}{sup {minus}}{pi}{sup +}{pi}{sup {minus}} at 27.5 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Felix, J.; Avilez, C.; Moreno, G. [Instituto de Fisica, Universidad de Guanajuato, Leon, Guanajuato 37000 (Mexico); Hartouni, E.P.; Jensen, D.A.; Kreisler, M.N.; Uribe, J. [Department of Physics and Astronomy, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Christian, D.C.; Gutierrez, G.; Holmes, S.D.; Wehmann, A. [Fermilab, Batavia, Illinois 60510 (United States); Church, M.D.; Gottschalk, E.E.; Knapp, B.C.; Stern, B.J.; Wiencke, L.R. [Nevis Laboratories, Columbia University, Irvington, New York 10533 (United States); Forbush, M.; Huson, F.R.; White, J.T. [Department of Physics, Texas A& M University, College Station, Texas 77843 (United States)

    1996-01-01

    We measured the polarization of 51195 {Lambda}{sup 0}{close_quote}s produced in the specific reaction {ital pp}{r_arrow}{ital p}{Lambda}{sup 0}{ital K}{sup +}{pi}{sup +}{pi}{sup {minus}}{pi}{sup +}{pi}{sup {minus}} with 27.5GeV/{ital c} protons incident on a liquid hydrogen target. Because the reaction was measured completely, the polarization was studied versus the following: {ital x}{sub {ital F}}({minus}1to+1), {Lambda}{sup 0} transverse momentum (0 to 1.32GeV/{ital c}), correlations with the momentum vectors of the other particles in the reaction, and the invariant mass of combinations of particles in the final state. The dependence of the polarization on these variables does not always agree with theoretical expectations. {copyright} {ital 1995 The American Physical Society.}

  19. Biogenic Silica Distribution in the Sediments from Arrow Bamboo Lake in Jiuzhaigou World Nature Heritage Reserve,China: Environmental Implication%九寨沟箭竹海沉积物中BSi含量及其环境指示意义

    Institute of Scientific and Technical Information of China (English)

    李世广; 胡欣欣; 唐亚; 黄成敏

    2011-01-01

    The Biogenic silica ( Bsi) contents were determined in the sediments from Arrow Bamboo Lake in Ji-uzhaigou National Reserve. Furthermore, the relationship between sediment total organic carbon (TOC) content, grain-size fraction and Bsi content were discussed in order to trace the anthropogenic and/or natural effect on water quality and lacustrine sedimentation. The content of Bsi ranged between 5. 5 and 15. 8 mg/g, and the Bsi content in the sediments had a significantly positive correlation with TOC. Also, the Bsi content was mainly controlled by the grain-size distribution in the core sediments, and the stronger adsorption to Bsi occurred in the finer grain fraction. The variation of Bsi values from the sediments in Arrow Bamboo Lake, insignificantly coupling with the air temperature, indicated the vital effects of deforestation and tourism on lake water and sediments.%通过对九寨沟箭竹海沉积物样品中生物硅( BSi)含量的分析,讨论箭竹海沉积物中BSi含量与总有机碳(TOC)及粒度的关系,进而探讨BSi含量反映自然和人类因素对湖泊水体和沉积物的影响.箭竹海沉积物中BSi含量介于5.5~ 15.8 mg/g之间,BSi含量与TOC呈显著正相关关系.BSi含量还较显著地受到粒度影响,较细颗粒沉积物对BSi有较强的吸附作用.箭竹海沉积物中BSi含量变化与气温波动关系不密切,主要反映了森林砍伐和旅游开发等人类活动对湖泊水体和沉积物的影响.

  20. Crash patterns at signalized intersections

    OpenAIRE

    Polders, Evelien; Daniels, Stijn; HERMANS, Elke; Brijs, Tom; Wets, Geert

    2015-01-01

    Traffic signals are often implemented to provide for efficient movement and to improve traffic safety. Nevertheless, severe crashes still occur at signalized intersections. This study aims to improve the understanding of signalized intersection safety by identifying crash types, locations and factors associated with signalized intersections. For this purpose, 1295 police-reported crashes at 87 signalized intersections are analyzed based on detailed crash descriptions, i.e. crash data and c...

  1. Noisy Signaling in Monopoly

    OpenAIRE

    2011-01-01

    We study the informational role of prices in a stochastic environment. We provide a closed-form solution of the monopoly problem when the price imperfectly signals quality to the uninformed buyers. We then study the effect of noise on output, market price, information flows, and expected profits. The presence of noise may reduce the informational externality due to asymmetric information, which increases the firm's expected profits.

  2. Stereoscopic Optical Signal Processor

    Science.gov (United States)

    Graig, Glenn D.

    1988-01-01

    Optical signal processor produces two-dimensional cross correlation of images from steroscopic video camera in real time. Cross correlation used to identify object, determines distance, or measures movement. Left and right cameras modulate beams from light source for correlation in video detector. Switch in position 1 produces information about range of object viewed by cameras. Position 2 gives information about movement. Position 3 helps to identify object.

  3. Biomedical signal analysis

    CERN Document Server

    Rangayyan, Rangaraj M

    2015-01-01

    The book will help assist a reader in the development of techniques for analysis of biomedical signals and computer aided diagnoses with a pedagogical examination of basic and advanced topics accompanied by over 350 figures and illustrations. Wide range of filtering techniques presented to address various applications. 800 mathematical expressions and equations. Practical questions, problems and laboratory exercises. Includes fractals and chaos theory with biomedical applications.

  4. Olfactory signaling in insects.

    Science.gov (United States)

    Wicher, Dieter

    2015-01-01

    The detection of volatile chemical information in insects is performed by three types of olfactory receptors, odorant receptors (ORs), specific gustatory receptor (GR) proteins for carbon dioxide perception, and ionotropic receptors (IRs) which are related to ionotropic glutamate receptors. All receptors form heteromeric assemblies; an OR complex is composed of an odor-specific OrX protein and a coreceptor (Orco). ORs and GRs have a 7-transmembrane topology as for G protein-coupled receptors, but they are inversely inserted into the membrane. Ligand-gated ion channels (ionotropic receptors) and ORs operate as IRs activated by volatile chemical cues. ORs are evolutionarily young receptors, and they first appear in winged insects and seem to be evolved to allow an insect to follow sparse odor tracks during flight. In contrast to IRs, the ORs can be sensitized by repeated subthreshold odor stimulation. This process involves metabotropic signaling. Pheromone receptors are especially sensitive and require an accessory protein to detect the lipid-derived pheromone molecules. Signaling cascades involved in pheromone detection depend on intensity and duration of stimuli and underlie a circadian control. Taken together, detection and processing of volatile information in insects involve ionotropic as well as metabotropic mechanisms. Here, I review the cellular signaling events associated with detection of cognate ligands by the different types of odorant receptors.

  5. Adaptive Signal Processing Testbed

    Science.gov (United States)

    Parliament, Hugh A.

    1991-09-01

    The design and implementation of a system for the acquisition, processing, and analysis of signal data is described. The initial application for the system is the development and analysis of algorithms for excision of interfering tones from direct sequence spread spectrum communication systems. The system is called the Adaptive Signal Processing Testbed (ASPT) and is an integrated hardware and software system built around the TMS320C30 chip. The hardware consists of a radio frequency data source, digital receiver, and an adaptive signal processor implemented on a Sun workstation. The software components of the ASPT consists of a number of packages including the Sun driver package; UNIX programs that support software development on the TMS320C30 boards; UNIX programs that provide the control, user interaction, and display capabilities for the data acquisition, processing, and analysis components of the ASPT; and programs that perform the ASPT functions including data acquisition, despreading, and adaptive filtering. The performance of the ASPT system is evaluated by comparing actual data rates against their desired values. A number of system limitations are identified and recommendations are made for improvements.

  6. Sphingosine signaling and atherogenesis

    Institute of Scientific and Technical Information of China (English)

    Cang-bao XU; Jacob HANSEN-SCHWARTZ; Lars EDVINSSON

    2004-01-01

    phingosine- 1-phosphate (S1P) has diverse biological functions acting inside cells as a second messenger to regulate cell proliferation and survival, and extracellularly, as a ligand for a group of G protein-coupled receptors (GPCRs) named the endothelial differentiation gene (EDG) family. Five closely related GPCRs of EDG family (EDG1, EDG3, EDG5, EDG6, and EDG8) have recently been identified as high-affinity S1P receptors. These receptors are coupled via Gi, Gq, G12/13, and Rho. The signaling pathways are linked to vascular cell migration,proliferation, apoptosis, intracellular Ca2+ mobilization, and expression of adhesion molecules. The formation of an atherosclerotic lesion occurs through activation of cellular events that include monocyte adhesion to the endothelium and vascular smooth muscle cell (VSMC) migration and proliferation. Thus, S 1P signaling may play an important role in the pathogenesis of atherosclerotic vascular disease. This review highlights S1P signalling in vascular cells and its involvement in the formation of atherosclerotic lesions.

  7. The Signal Space Separation method

    CERN Document Server

    Taulu, S; Simola, J; Taulu, Samu; Kajola, Matti; Simola, Juha

    2004-01-01

    Multichannel measurement with hundreds of channels essentially covers all measurable degrees of freedom of a curl and source free vector field, like the magnetic field in a volume free of current sources (e.g. in magnetoencephalography, MEG). A functional expansion solution of Laplace's equation enables one to separate signals arising from the sphere enclosing the interesting sources, e.g. the currents in the brain, from the rest of the signals. The signal space separation (SSS) is accomplished by calculating individual basis vectors for each term of the functional expansion solution to create a signal basis covering all measurable signal vectors. Any signal vector has a unique SSS decomposition with separate coefficients for the interesting signals and signals coming from outside the interesting volume. Thus, SSS basis provides an elegant method to remove external disturbances, and to transform the interesting signals to virtual sensor configurations. SSS can also be used in compensating the movements of the...

  8. Arrows as Anchors: An Analysis of the Material Features of Electric Field Vector Arrows

    Science.gov (United States)

    Gire, Elizabeth; Price, Edward

    2014-01-01

    Representations in physics possess both physical and conceptual aspects that are fundamentally intertwined and can interact to support or hinder sense making and computation. We use distributed cognition and the theory of conceptual blending with material anchors to interpret the roles of conceptual and material features of representations in…

  9. Chaotic signal processing: information aspects

    CERN Document Server

    Andreyev, Y V; Efremova, E V; Anagnostopoulos, A N

    2003-01-01

    One of the features of chaotic signals that make them different of other types of signals is their special information properties. In this paper, we investigate the effect of these properties on the procedures of chaotic signal processing. On examples of cleaning chaotic signals off noise, chaotic synchronization and separation of chaotic signals we demonstrate the existence of basic limits imposed by information theory on chaotic signal processing, independent of concrete algorithms. Relations of these limits with the Second law, Shannon theorems and Landauer principle are discussed.

  10. Biomedical signal and image processing

    CERN Document Server

    Najarian, Kayvan

    2012-01-01

    INTRODUCTION TO DIGITAL SIGNAL AND IMAGE PROCESSINGSignals and Biomedical Signal ProcessingIntroduction and OverviewWhat is a ""Signal""?Analog, Discrete, and Digital SignalsProcessing and Transformation of SignalsSignal Processing for Feature ExtractionSome Characteristics of Digital ImagesSummaryProblemsFourier TransformIntroduction and OverviewOne-Dimensional Continuous Fourier TransformSampling and NYQUIST RateOne-Dimensional Discrete Fourier TransformTwo-Dimensional Discrete Fourier TransformFilter DesignSummaryProblemsImage Filtering, Enhancement, and RestorationIntroduction and Overview

  11. Phonocardiography Signal Processing

    CERN Document Server

    Abbas, Abbas K

    2009-01-01

    The auscultation method is an important diagnostic indicator for hemodynamic anomalies. Heart sound classification and analysis play an important role in the auscultative diagnosis. The term phonocardiography refers to the tracing technique of heart sounds and the recording of cardiac acoustics vibration by means of a microphone-transducer. Therefore, understanding the nature and source of this signal is important to give us a tendency for developing a competent tool for further analysis and processing, in order to enhance and optimize cardiac clinical diagnostic approach. This book gives the

  12. Biological signals classification and analysis

    CERN Document Server

    Kiasaleh, Kamran

    2015-01-01

    This authored monograph presents key aspects of signal processing analysis in the biomedical arena. Unlike wireless communication systems, biological entities produce signals with underlying nonlinear, chaotic nature that elude classification using the standard signal processing techniques, which have been developed over the past several decades for dealing primarily with standard communication systems. This book separates what is random from that which appears to be random, and yet is truly deterministic with random appearance. At its core, this work gives the reader a perspective on biomedical signals and the means to classify and process such signals. In particular, a review of random processes along with means to assess the behavior of random signals is also provided. The book also includes a general discussion of biological signals in order to demonstrate the inefficacy of the well-known techniques to correctly extract meaningful information from such signals. Finally, a thorough discussion of recently ...

  13. Multiscale Signal Analysis and Modeling

    CERN Document Server

    Zayed, Ahmed

    2013-01-01

    Multiscale Signal Analysis and Modeling presents recent advances in multiscale analysis and modeling using wavelets and other systems. This book also presents applications in digital signal processing using sampling theory and techniques from various function spaces, filter design, feature extraction and classification, signal and image representation/transmission, coding, nonparametric statistical signal processing, and statistical learning theory. This book also: Discusses recently developed signal modeling techniques, such as the multiscale method for complex time series modeling, multiscale positive density estimations, Bayesian Shrinkage Strategies, and algorithms for data adaptive statistics Introduces new sampling algorithms for multidimensional signal processing Provides comprehensive coverage of wavelets with presentations on waveform design and modeling, wavelet analysis of ECG signals and wavelet filters Reviews features extraction and classification algorithms for multiscale signal and image proce...

  14. Two-dimensional signal analysis

    CERN Document Server

    Garello, René

    2010-01-01

    This title sets out to show that 2-D signal analysis has its own role to play alongside signal processing and image processing.Concentrating its coverage on those 2-D signals coming from physical sensors (such as radars and sonars), the discussion explores a 2-D spectral approach but develops the modeling of 2-D signals and proposes several data-oriented analysis techniques for dealing with them. Coverage is also given to potential future developments in this area.

  15. GTPases in semaphorin signaling.

    Science.gov (United States)

    Püschel, Andreas W

    2007-01-01

    A hallmark of semaphorin receptors is their interaction with multiple GTPases. Plexins, the signal transducing component of semaphorin receptors, directly associate with several GTPases. In addition, they not only recruit guaninine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs) but also are the only known integral membrane proteins that show a catalytic activity as GAPs for small GTPases. GTPases function upstream of semaphorin receptors and regulate the activity of plexins through an interaction with the cytoplasmic domain. The association of Plexin-Al (Sema3A receptor) or Plexin-B1 (Sema4D receptor) with the GTPase Rnd1 and ligand-dependent receptor clustering are required for their activity as R-Ras GAPs. The GTPases R-Ras and Rho function downstream of plexins and are required for the repulsive effects of semaphorins. In this review, I will focus on the role of GTPases in signaling by two plexins that have been analyzed in most detail, Plexin-A1 and Plexin-B1.

  16. Macula densa cell signaling.

    Science.gov (United States)

    Bell, P Darwin; Lapointe, Jean Yves; Peti-Peterdi, János

    2003-01-01

    Macula densa cells are renal sensor elements that detect changes in distal tubular fluid composition and transmit signals to the glomerular vascular elements. This tubuloglomerular feedback mechanism plays an important role in regulating glomerular filtration rate and blood flow. Macula densa cells detect changes in luminal sodium chloride concentration through a complex series of ion transport-related intracellular events. NaCl entry via a Na:K:2Cl cotransporter and Cl exit through a basolateral channel lead to cell depolarization and increases in cytosolic calcium. Na/H exchange (NHE2) results in cell alkalization, whereas intracellular [Na] is regulated by an apically located H(Na)-K ATPase and not by the traditional basolateral Na:K ATPase. Communication from macula densa cells to the glomerular vascular elements involves ATP release across the macula densa basolateral membrane through a maxi-anion channel. The adaptation of multi-photon microscopy is providing new insights into macula densa-glomerular signaling.

  17. Critical nodes in signalling pathways

    DEFF Research Database (Denmark)

    Taniguchi, Cullen M; Emanuelli, Brice; Kahn, C Ronald

    2006-01-01

    Physiologically important cell-signalling networks are complex, and contain several points of regulation, signal divergence and crosstalk with other signalling cascades. Here, we use the concept of 'critical nodes' to define the important junctions in these pathways and illustrate their unique role...

  18. Genomic Signal Enhancement by Clustering

    Institute of Scientific and Technical Information of China (English)

    ZHENG Wei-Mou

    2003-01-01

    Weight matrix models for signal sequence motif are simple. A main limitation of the models is the assumption of independence between positions. Signal enhancement is achieved by taking the total likelihood as the objective function for maximization to cluster sequences into groups with different patterns. As an example, the initial and terminal signals for translation in rice genome are examined.

  19. Cellular signalling properties in microcircuits

    DEFF Research Database (Denmark)

    Toledo-Rodriguez, Maria; El Manira, Abdeljabbar; Wallén, Peter

    2005-01-01

    Molecules and cells are the signalling elements in microcircuits. Recent studies have uncovered bewildering diversity in postsynaptic signalling properties in all areas of the vertebrate nervous system. Major effort is now being invested in establishing the specialized signalling properties at th...

  20. Minimum signals in classical physics

    Institute of Scientific and Technical Information of China (English)

    邓文基; 许基桓; 刘平

    2003-01-01

    The bandwidth theorem for Fourier analysis on any time-dependent classical signal is shown using the operator approach to quantum mechanics. Following discussions about squeezed states in quantum optics, the problem of minimum signals presented by a single quantity and its squeezing is proposed. It is generally proved that all such minimum signals, squeezed or not, must be real Gaussian functions of time.

  1. Signal localization: a new approach in signal discovery.

    Science.gov (United States)

    Malov, Sergey V; Antonik, Alexey; Tang, Minzhong; Berred, Alexandre; Zeng, Yi; O'Brien, Stephen J

    2017-01-01

    A new approach for statistical association signal identification is developed in this paper. We consider a strategy for nonprecise signal identification by extending the well-known signal detection and signal identification methods applicable to the multiple testing problem. Collection of statistical instruments under the presented approach is much broader than under the traditional signal identification methods, allowing more efficient signal discovery. Further assessments of maximal value and average statistics in signal discovery are improved. While our method does not attempt to detect individual predictors, it instead detects sets of predictors that are jointly associated with the outcome. Therefore, an important application would be in genome wide association study (GWAS), where it can be used to detect genes which influence the phenotype but do not contain any individually significant single nucleotide polymorphism (SNP). We compare power of the signal identification method based on extremes of single p-values with the signal localization method based on average statistics for logarithms of p-values. A simulation analysis informs the application of signal localization using the average statistics for wide signals discovery in Gaussian white noise process. We apply average statistics and the localization method to GWAS to discover better gene influences of regulating loci in a Chinese cohort developed for risk of nasopharyngeal carcinoma (NPC).

  2. Rise-Time Distortion of Signal without Carrying Signal

    Science.gov (United States)

    Bukhman, N. S.

    2016-08-01

    The article deals with one-dimensional problem of rise-time distortion signal without carrying signal, that appears in the starting point intermittently, that is signal distortion at front edge or one of its derivative. The authors show that front edge of signal isn't distorted in case of propagation in unrestricted (including absorbing) area (amplitude of starting signal step or of one of its derivatives doesn't change) and move with the accuracy of vacuum light speed. The paper proves that it is the time interval shortage that causes signal loss with the route extension, but not the reduction of its starting amplitude, during which front edge of signal retains its starting value. The research presents new values for this time interval.

  3. Binary-Signal Recovery

    Science.gov (United States)

    Griebeler, Elmer L.

    2011-01-01

    Binary communication through long cables, opto-isolators, isolating transformers, or repeaters can become distorted in characteristic ways. The usual solution is to slow the communication rate, change to a different method, or improve the communication media. It would help if the characteristic distortions could be accommodated at the receiving end to ease the communication problem. The distortions come from loss of the high-frequency content, which adds slopes to the transitions from ones to zeroes and zeroes to ones. This weakens the definition of the ones and zeroes in the time domain. The other major distortion is the reduction of low frequency, which causes the voltage that defines the ones or zeroes to drift out of recognizable range. This development describes a method for recovering a binary data stream from a signal that has been subjected to a loss of both higher-frequency content and low-frequency content that is essential to define the difference between ones and zeroes. The method makes use of the frequency structure of the waveform created by the data stream, and then enhances the characteristics related to the data to reconstruct the binary switching pattern. A major issue is simplicity. The approach taken here is to take the first derivative of the signal and then feed it to a hysteresis switch. This is equivalent in practice to using a non-resonant band pass filter feeding a Schmitt trigger. Obviously, the derivative signal needs to be offset to halfway between the thresholds of the hysteresis switch, and amplified so that the derivatives reliably exceed the thresholds. A transition from a zero to a one is the most substantial, fastest plus movement of voltage, and therefore will create the largest plus first derivative pulse. Since the quiet state of the derivative is sitting between the hysteresis thresholds, the plus pulse exceeds the plus threshold, switching the hysteresis switch plus, which re-establishes the data zero to one transition

  4. Finding Signals for Plant Promoters

    Institute of Scientific and Technical Information of China (English)

    Weimou Zheng

    2003-01-01

    The strongest signal of plant promoter is searched with the model of single motif with two types. It turns out that the dominant type is the TATA-box. The other type may be called TATA-less signal, and may be used in gene finders for promoter recognition. While the TATA signals are very close for the monocot and the dicot, their TATA-less signals are significantly different. A general and flexible multi-motif model is also proposed for promoter analysis based on dynamic programming. By extending the Gibbs sampler to the dynamic programming and introducing temperature, an efficient algorithm is developed for searching signals in plant promoters.

  5. Signals and systems for dummies

    CERN Document Server

    Wickert, Mark

    2013-01-01

    Getting mixed signals in your signals and systems course? The concepts covered in a typical signals and systems course are often considered by engineering students to be some of the most difficult to master. Thankfully, Signals & Systems For Dummies is your intuitive guide to this tricky course, walking you step-by-step through some of the more complex theories and mathematical formulas in a way that is easy to understand. From Laplace Transforms to Fourier Analyses, Signals & Systems For Dummies explains in plain English the difficult concepts that can trip you up

  6. Detection of signals in noise

    CERN Document Server

    Whalen, Anthony D; Declaris, Nicholas

    1971-01-01

    Detection of Signals in Noise serves as an introduction to the principles and applications of the statistical theory of signal detection. The book discusses probability and random processes; narrowband signals, their complex representation, and their properties described with the aid of the Hilbert transform; and Gaussian-derived processes. The text also describes the application of hypothesis testing for the detection of signals and the fundamentals required for statistical detection of signals in noise. Problem exercises, references, and a supplementary bibliography are included after each c

  7. Signal processing unit

    Energy Technology Data Exchange (ETDEWEB)

    Boswell, J.

    1983-01-01

    The architecture of the signal processing unit (SPU) comprises an ROM connected to a program bus, and an input-output bus connected to a data bus and register through a pipeline multiplier accumulator (pmac) and a pipeline arithmetic logic unit (palu), each associated with a random access memory (ram1,2). The system pulse frequency is from 20 mhz. The pmac is further detailed, and has a capability of 20 mega operations per second. There is also a block diagram for the palu, showing interconnections between the register block (rbl), separator for bus (bs), register (reg), shifter (sh) and combination unit. The first and second rams have formats 64*16 and 32*32 bits, respectively. Further data are a 5-v power supply and 2.5 micron n-channel silicon gate mos technology with about 50000 transistors.

  8. Oxygen sensing and signaling.

    Science.gov (United States)

    van Dongen, Joost T; Licausi, Francesco

    2015-01-01

    Oxygen is an indispensable substrate for many biochemical reactions in plants, including energy metabolism (respiration). Despite its importance, plants lack an active transport mechanism to distribute oxygen to all cells. Therefore, steep oxygen gradients occur within most plant tissues, which can be exacerbated by environmental perturbations that further reduce oxygen availability. Plants possess various responses to cope with spatial and temporal variations in oxygen availability, many of which involve metabolic adaptations to deal with energy crises induced by low oxygen. Responses are induced gradually when oxygen concentrations decrease and are rapidly reversed upon reoxygenation. A direct effect of the oxygen level can be observed in the stability, and thus activity, of various transcription factors that control the expression of hypoxia-induced genes. Additional signaling pathways are activated by the impact of oxygen deficiency on mitochondrial and chloroplast functioning. Here, we describe the molecular components of the oxygen-sensing pathway.

  9. Machine intelligence and signal processing

    CERN Document Server

    Vatsa, Mayank; Majumdar, Angshul; Kumar, Ajay

    2016-01-01

    This book comprises chapters on key problems in machine learning and signal processing arenas. The contents of the book are a result of a 2014 Workshop on Machine Intelligence and Signal Processing held at the Indraprastha Institute of Information Technology. Traditionally, signal processing and machine learning were considered to be separate areas of research. However in recent times the two communities are getting closer. In a very abstract fashion, signal processing is the study of operator design. The contributions of signal processing had been to device operators for restoration, compression, etc. Applied Mathematicians were more interested in operator analysis. Nowadays signal processing research is gravitating towards operator learning – instead of designing operators based on heuristics (for example wavelets), the trend is to learn these operators (for example dictionary learning). And thus, the gap between signal processing and machine learning is fast converging. The 2014 Workshop on Machine Intel...

  10. Measuring signal generators theory & design

    CERN Document Server

    Rybin, Yuriy K

    2014-01-01

    The book brings together the following issues: Theory of deterministic, random and discrete signals reproducible in oscillatory systems of generators; Generation of periodic signals with a specified spectrum, harmonic distortion factor and random signals with specified probability density function and spectral density; Synthesis of oscillatory system structures; Analysis of oscillatory systems with non-linear elements and oscillation amplitude stabilization systems; It considers the conditions and criteria of steady-state modes in signal generators on active four-pole elements with unidirectional and bidirectional transmission of signals and on two-pole elements; analogues of Barkhausen criteria; Optimization of oscillatory system structures by harmonic distortion level, minimization of a frequency error and set-up time of the steady state mode; Theory of construction of random signal generators; Construction of discrete and digital signal generators; Practical design of main units of generators; Practical bl...

  11. EEG signal analysis: a survey.

    Science.gov (United States)

    Subha, D Puthankattil; Joseph, Paul K; Acharya U, Rajendra; Lim, Choo Min

    2010-04-01

    The EEG (Electroencephalogram) signal indicates the electrical activity of the brain. They are highly random in nature and may contain useful information about the brain state. However, it is very difficult to get useful information from these signals directly in the time domain just by observing them. They are basically non-linear and nonstationary in nature. Hence, important features can be extracted for the diagnosis of different diseases using advanced signal processing techniques. In this paper the effect of different events on the EEG signal, and different signal processing methods used to extract the hidden information from the signal are discussed in detail. Linear, Frequency domain, time - frequency and non-linear techniques like correlation dimension (CD), largest Lyapunov exponent (LLE), Hurst exponent (H), different entropies, fractal dimension(FD), Higher Order Spectra (HOS), phase space plots and recurrence plots are discussed in detail using a typical normal EEG signal.

  12. Application of ARROW central venous catheter in drainage for lung cancer patients complicated with pleural effusion and nursing care of them%ARROW中心静脉导管在肺癌患者合并胸腔积液引流中的应用及护理

    Institute of Scientific and Technical Information of China (English)

    张燕

    2012-01-01

    目的探讨ARROW单腔中心静脉导管在肺癌患者合并胸腔积液引流中的应用及护理。方法对57例肺癌患者合并胸腔积液需行胸腔穿刺放液的患者应用ARROW中心静脉导管代替传统的胸腔穿刺放液、抽液,观察其疗效、并发症,并对整个细致有效的护理过程进行总结。结果本组57例患者均1次置管成功,导管留置时间为3d至21d,未发生导管相关性感染、导管阻塞及导管脱出等并发症,置管引流后胸腔积液逐渐减少,患者呼吸困难、胸闷、心悸、气促、咳嗽等症状明显改善,病情得到缓解。结论本组应用ARROW单腔中心静脉导管引流胸腔积液,无继发感染、血气胸等并发症发生,做好穿刺部位的护理,预防感染是保证置管引流成功的关键。%Objective It probed into application of ARROW mono-chamber central venous catheter in drainage for lung cancer patients complicated with pleural effusion and nursing care of them. Methods A total of 57 lung cancer patients complicated with pleural effusion and required thoracentesis were applied ARROW central venous catheter to replace the traditional way of pleural cavity puncture and liquid drainage. The curative effect and complications of all patients had been observed. And it summarized the whole process of meticulous and effective nursing care. Results All 57patients were successful placement by once puncture. The indwelling time of catheter was 3 days to 21 days. No one had the incidence of complications such as catheter-related infections, catheter obstruction and fall-off of catheter and so on. After catheter drainage, pleural effusion of patients gradually reduced. Symptoms such as dyspnea, chest tightness, palpitations, shortness of breath, cough of patients had improved significantly. And illness conditions of them had relieved. Conclusion To apply ARROW mono-chamber central venous catheter in drainage for lung cancer patients complicated with pleural

  13. El enfoque algorítmico en el diseño de muelles helicoidales a través de los grafos bicromáticos // The algorithmic focus in the design of helical springs through the diagrams of arrows

    Directory of Open Access Journals (Sweden)

    T. Ortiz Cárdenas

    2000-01-01

    Full Text Available Por todos es conocido, la gran cantidad de variables que intervienen en el diseño de muelles de cualquier tipo, lo quedificulta en ocasiones arribar a un resultado satisfactorio, en el tiempo requerido y con la calidad adecuada.Esto se debe a que en el diseño de los muelles, además del cálculo de resistencia para llegar a las dimensiones principalesdel elemento, también se tiene en cuenta el cálculo energético a partir del cual se obtiene la rigidez. Además si las cargasque actúan sobre el muelle son variables, es necesario entonces realizar cálculos que garanticen que no se produzca unfallo por fatiga.Con la aplicación de los diagramas de flechas o grafos bicromáticos como también se conocen, se simplifica el proceso dediseño, pues de forma rápida se llega al algoritmo de cálculo que permitirá la solución del problema en cuestión.El objetivo fundamental del trabajo es introducir el enfoque algorítmico en el diseño de muelles helicoidales a partir de laintroducción de la técnica de los grafos bicromáticos.Palabras claves: muelles, grafos, algoritmo, diseño.___________________________________________________________________SummaryIt is known, the great quantity of variables included in the design of springs. This fact hinders in occasions to arrive to asatisfactory result, in the required time and with the appropriate quality.This is due to that in the spring design, they should be kept in mind the calculations of resistance and rigidity. If the loadson the springs are variable, it is necessary to carry out the calculations of the resistance fatigue.With the application of the diagrams of arrows or grafos of two colors, the design process is simplified, because in a quickway you arrives to the calculation algorithm with the solution of the problem.The fundamental objective of the work is to introduce the diagrams of arrows in the design of helical springs.Key words: Springs, grafos, algorithm, design.

  14. Ultrasound imaging using coded signals

    DEFF Research Database (Denmark)

    Misaridis, Athanasios

    Modulated (or coded) excitation signals can potentially improve the quality and increase the frame rate in medical ultrasound scanners. The aim of this dissertation is to investigate systematically the applicability of modulated signals in medical ultrasound imaging and to suggest appropriate...... of the excitation signal. Although a gain in signal-to-noise ratio of about 20 dB is theoretically possible for the time-bandwidth product available in ultrasound, it is shown that the effects of transducer weighting and tissue attenuation reduce the maximum gain at 10 dB for robust compression with low sidelobes...... is described. Application of coded excitation in array imaging is evaluated through simulations in Field II. The low degree of the orthogonality among coded signals for ultrasound systems is first discussed, and the effect of mismatched filtering in the cross-correlation properties of the signals is evaluated...

  15. Steganography in arrhythmic electrocardiogram signal.

    Science.gov (United States)

    Edward Jero, S; Ramu, Palaniappan; Ramakrishnan, S

    2015-08-01

    Security and privacy of patient data is a vital requirement during exchange/storage of medical information over communication network. Steganography method hides patient data into a cover signal to prevent unauthenticated accesses during data transfer. This study evaluates the performance of ECG steganography to ensure secured transmission of patient data where an abnormal ECG signal is used as cover signal. The novelty of this work is to hide patient data into two dimensional matrix of an abnormal ECG signal using Discrete Wavelet Transform and Singular Value Decomposition based steganography method. A 2D ECG is constructed according to Tompkins QRS detection algorithm. The missed R peaks are computed using RR interval during 2D conversion. The abnormal ECG signals are obtained from the MIT-BIH arrhythmia database. Metrics such as Peak Signal to Noise Ratio, Percentage Residual Difference, Kullback-Leibler distance and Bit Error Rate are used to evaluate the performance of the proposed approach.

  16. Integrins mediating bone signal transduction

    Institute of Scientific and Technical Information of China (English)

    HE Chuanglong; WANG Yuanliang; YANG Lihua; ZHANG Jun

    2004-01-01

    Integrin-mediated adhesions play critical roles in diverse cell functions. Integrins offers a platform on which mechanical stimuli, cytoskeletal organization, biochemical signals can concentrate. Mechanical stimuli transmitted by integrins influence the cytoskeleton, in turn, the cytoskeleton influences cell adhesion via integrins, then cell adhesion results in a series of signal transduction cascades. In skeleton, integrins also have a key role for bone resoption by osteoclasts and reformation by osteoblasts. In present review, the proteins involved in integrin signal transduction and integrin signal transduction pathways were discussed, mainly on the basic mechanisms of integrin signaling and the roles of integrins in bone signal transduction, which may give insight into new therapeutic agents to all kinds of skeletal diseases and new strategies for bone tissue engineering.

  17. Volcanic signals in oceans

    KAUST Repository

    Stenchikov, Georgiy L.

    2009-08-22

    Sulfate aerosols resulting from strong volcanic explosions last for 2–3 years in the lower stratosphere. Therefore it was traditionally believed that volcanic impacts produce mainly short-term, transient climate perturbations. However, the ocean integrates volcanic radiative cooling and responds over a wide range of time scales. The associated processes, especially ocean heat uptake, play a key role in ongoing climate change. However, they are not well constrained by observations, and attempts to simulate them in current climate models used for climate predictions yield a range of uncertainty. Volcanic impacts on the ocean provide an independent means of assessing these processes. This study focuses on quantification of the seasonal to multidecadal time scale response of the ocean to explosive volcanism. It employs the coupled climate model CM2.1, developed recently at the National Oceanic and Atmospheric Administration\\'s Geophysical Fluid Dynamics Laboratory, to simulate the response to the 1991 Pinatubo and the 1815 Tambora eruptions, which were the largest in the 20th and 19th centuries, respectively. The simulated climate perturbations compare well with available observations for the Pinatubo period. The stronger Tambora forcing produces responses with higher signal-to-noise ratio. Volcanic cooling tends to strengthen the Atlantic meridional overturning circulation. Sea ice extent appears to be sensitive to volcanic forcing, especially during the warm season. Because of the extremely long relaxation time of ocean subsurface temperature and sea level, the perturbations caused by the Tambora eruption could have lasted well into the 20th century.

  18. Signaling during Kidney Development

    Directory of Open Access Journals (Sweden)

    Mirja Krause

    2015-04-01

    Full Text Available The kidney plays an essential role during excretion of metabolic waste products, maintenance of key homeostasis components such as ion concentrations and hormone levels. It influences the blood pressure, composition and volume. The kidney tubule system is composed of two distinct cell populations: the nephrons forming the filtering units and the collecting duct system derived from the ureteric bud. Nephrons are composed of glomeruli that filter the blood to the Bowman’s capsule and tubular structures that reabsorb and concentrate primary urine. The collecting duct is a Wolffian duct-derived epithelial tube that concentrates and collects urine and transfers it via the renal pelvis into the bladder. The mammalian kidney function depends on the coordinated development of specific cell types within a precise architectural framework. Due to the availability of modern analysis techniques, the kidney has become a model organ defining the paradigm to study organogenesis. As kidney diseases are a problem worldwide, the understanding of mammalian kidney cells is of crucial importance to develop diagnostic tools and novel therapies. This review focuses on how the pattern of renal development is generated, how the inductive signals are regulated and what are their effects on proliferation, differentiation and morphogenesis.

  19. Volatile signals during pregnancy.

    Science.gov (United States)

    Vaglio, Stefano

    2010-01-01

    Scents play a key role in mediating reproductive interactions in many vertebrates including mammals. Nowadays, several studies indicate that humans seem to use remarkably olfactory communication and are even able to produce and perceive pheromones. Furthermore, over the past several years, it became increasingly clear that pheromone-like chemical signals probably play a role in offspring identification and mother recognition. Recently developed technical procedures (solid-phase microextraction and dynamic headspace extraction) now allow investigators to characterize volatile compounds with high reliability. We analyzed the volatile compounds in sweat patch samples collected from the para-axillary and nipple-areola regions of women during pregnancy and after childbirth. We hypothesized that, at the time of birth and during the first weeks of life, the distinctive olfactory pattern of the para-axillary area is probably useful to newborn babies for recognizing and distinguishing their own mother, whereas the characteristic pattern of the nipple-areola region is probably useful as a guide to nourishment.

  20. Semi-classical signal analysis

    CERN Document Server

    Laleg-Kirati, Taous-Meriem; Sorine, Michel

    2010-01-01

    This study introduces a new signal analysis method called SCSA, based on a semi-classical approach. The main idea in the SCSA is to interpret a pulse-shaped signal as a potential of a Schr\\"odinger operator and then to use the discrete spectrum of this operator for the analysis of the signal. We present some numerical examples and the first results obtained with this method on the analysis of arterial blood pressure waveforms.

  1. Notch Signaling in Pancreatic Development

    OpenAIRE

    2015-01-01

    The Notch signaling pathway plays a significant role in embryonic cell fate determination and adult tissue homeostasis. Various studies have demonstrated the deep involvement of Notch signaling in the development of the pancreas and the lateral inhibition of Notch signaling in pancreatic progenitor differentiation and maintenance. The targeted inactivation of the Notch pathway components promotes premature differentiation of the endocrine pancreas. However, there is still the contrary opinion...

  2. Introduction to digital signal processing

    CERN Document Server

    Kuc, Roman

    2008-01-01

    This book approaches digital Signal Processing and filter design in a Novel way, by presenting the relevant theory and then having the Student apply it by implementing signal processing routines on a computer. This mixture of theory and application has worked successfully. With this approach, the students receive a deeper and intuitive understanding of the theory, its applications and its limitations. This text also includes projects that require students to write Computer programs to accomplish signal processing projects.

  3. Fundamentals of statistical signal processing

    CERN Document Server

    Kay, Steven M

    1993-01-01

    A unified presentation of parameter estimation for those involved in the design and implementation of statistical signal processing algorithms. Covers important approaches to obtaining an optimal estimator and analyzing its performance; and includes numerous examples as well as applications to real- world problems. MARKETS: For practicing engineers and scientists who design and analyze signal processing systems, i.e., to extract information from noisy signals — radar engineer, sonar engineer, geophysicist, oceanographer, biomedical engineer, communications engineer, economist, statistician, physicist, etc.

  4. Semi-classical signal analysis

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2012-09-30

    This study introduces a new signal analysis method, based on a semi-classical approach. The main idea in this method is to interpret a pulse-shaped signal as a potential of a Schrödinger operator and then to use the discrete spectrum of this operator for the analysis of the signal. We present some numerical examples and the first results obtained with this method on the analysis of arterial blood pressure waveforms. © 2012 Springer-Verlag London Limited.

  5. Gibberellin Signal Transduction in Rice

    Institute of Scientific and Technical Information of China (English)

    Liu-Min Fan; Xiaoyan Feng; Yu Wang; Xing Wang Deng

    2007-01-01

    In the past decade, significant knowledge has accumulated regarding gibberellin (GA) signal transduction in rice as a result of studies using multiple approaches, particularly molecular genetics. The present review highlights the recent developments in the identification of GA signaling pathway components, the discovery of GA-induced destruction of GA signaling represser (DELLA protein), and the possible mechanism underlying the regulation of GA-responsive gene expression in rice.

  6. Rhomboids, signalling and cell biology.

    Science.gov (United States)

    Freeman, Matthew

    2016-06-15

    Here, I take a somewhat personal perspective on signalling control, focusing on the rhomboid-like superfamily of proteins that my group has worked on for almost 20 years. As well as describing some of the key and recent advances, I attempt to draw out signalling themes that emerge. One important message is that the genetic and biochemical perspective on signalling has tended to underplay the importance of cell biology. There is clear evidence that signalling pathways exploit the control of intracellular trafficking, protein quality control and degradation and other cell biological phenomena, as important regulatory opportunities.

  7. Signal transduction by growth factor receptors: signaling in an instant

    DEFF Research Database (Denmark)

    Dengjel, Joern; Akimov, Vyacheslav; Blagoev, Blagoy;

    2007-01-01

    -out by mass spectrometry-based proteomics has allowed exciting views on the very early events in signal transduction. Activation profiles of regulated phosphorylation sites on epidermal growth factor receptor and downstream signal transducers showed different kinetics within the first ten seconds...

  8. Correlation theory-based signal processing method for CMF signals

    Science.gov (United States)

    Shen, Yan-lin; Tu, Ya-qing

    2016-06-01

    Signal processing precision of Coriolis mass flowmeter (CMF) signals affects measurement accuracy of Coriolis mass flowmeters directly. To improve the measurement accuracy of CMFs, a correlation theory-based signal processing method for CMF signals is proposed, which is comprised of the correlation theory-based frequency estimation method and phase difference estimation method. Theoretical analysis shows that the proposed method eliminates the effect of non-integral period sampling signals on frequency and phase difference estimation. The results of simulations and field experiments demonstrate that the proposed method improves the anti-interference performance of frequency and phase difference estimation and has better estimation performance than the adaptive notch filter, discrete Fourier transform and autocorrelation methods in terms of frequency estimation and the data extension-based correlation, Hilbert transform, quadrature delay estimator and discrete Fourier transform methods in terms of phase difference estimation, which contributes to improving the measurement accuracy of Coriolis mass flowmeters.

  9. Adenosinergic signaling in epilepsy.

    Science.gov (United States)

    Boison, Detlev

    2016-05-01

    Despite the introduction of at least 20 new antiepileptic drugs (AEDs) into clinical practice over the past decades, about one third of all epilepsies remain refractory to conventional forms of treatment. In addition, currently used AEDs have been developed to suppress neuronal hyperexcitability, but not necessarily to address pathogenic mechanisms involved in epilepsy development or progression (epileptogenesis). For those reasons endogenous seizure control mechanisms of the brain may provide alternative therapeutic opportunities. Adenosine is a well characterized endogenous anticonvulsant and seizure terminator of the brain. Several lines of evidence suggest that endogenous adenosine-mediated seizure control mechanisms fail in chronic epilepsy, whereas therapeutic adenosine augmentation effectively prevents epileptic seizures, even those that are refractory to conventional AEDs. New findings demonstrate that dysregulation of adenosinergic mechanisms are intricately involved in the development of epilepsy and its comorbidities, whereas adenosine-associated epigenetic mechanisms may play a role in epileptogenesis. The first goal of this review is to discuss how maladaptive changes of adenosinergic mechanisms contribute to the expression of seizures (ictogenesis) and the development of epilepsy (epileptogenesis) by focusing on pharmacological (adenosine receptor dependent) and biochemical (adenosine receptor independent) mechanisms as well as on enzymatic and transport based mechanisms that control the availability (homeostasis) of adenosine. The second goal of this review is to highlight innovative adenosine-based opportunities for therapeutic intervention aimed at reconstructing normal adenosine function and signaling for improved seizure control in chronic epilepsy. New findings suggest that transient adenosine augmentation can have lasting epigenetic effects with disease modifying and antiepileptogenic outcome. This article is part of the Special Issue entitled

  10. Glycogenolysis and purinergic signaling.

    Science.gov (United States)

    Hertz, Leif; Xu, Junnan; Peng, Liang

    2014-01-01

    Both ATP and glutamate are on one hand essential metabolites in brain and on the other serve a signaling function as transmitters. However, there is the major difference that the flux in the pathway producing transmitter glutamate is comparable to the rate of glucose metabolism in brain, whereas that producing transmitter ATP is orders of magnitude smaller than the metabolic turnover between ATP and ADP. Moreover, de novo glutamate production occurs exclusively in astrocytes, whereas transmitter ATP is produced both in neurons and astrocytes. This chapter deals only with ATP and exclusively with its formation and release in astrocytes, and it focuses on potential associations with glycogenolysis, which is known to be indispensable for the synthesis of glutamate. Glycogenolysis is dependent upon an increase in free intracellular Ca(2+) concentration (Ca(2+)]i). It can be further stimulated by cAMP, but in contrast to widespread beliefs, cAMP can on its own not induce glycogenolysis. Astrocytes generate ATP from accumulated adenosine, and this process does not seem to require glycogenolysis. A minor amount of the generated ATP is utilized as a transmitter, and its synthesis requires the presence of the mainly intracellular nucleoside transporter ENT3. Many transmitters as well as extracellular K(+) concentrations high enough to open the voltage-sensitive L-channels for Ca(2+) cause a release of transmitter ATP from astrocytes. Adenosine and ATP induce release of ATP by action at several different purinergic receptors. The release evoked by transmitters or elevated K(+) concentrations is abolished by DAB, an inhibitor of glycogenolysis.

  11. Hedgehog signaling pathway and gastrointestinal stem cell signaling network (review).

    Science.gov (United States)

    Katoh, Yuriko; Katoh, Masaru

    2006-12-01

    Hedgehog, BMP/TGFbeta, FGF, WNT and Notch signaling pathways constitute the stem cell signaling network, which plays a key role in a variety of processes, such as embryogenesis, maintenance of adult tissue homeostasis, tissue repair during chronic persistent inflammation, and carcinogenesis. Sonic hedgehog (SHH), Indian hedgehog (IHH) and Desert hedgehog (DHH) bind to PTCH1/PTCH or PTCH2 receptor to release Smoothened (SMO) signal transducer from Patched-dependent suppression. SMO then activates STK36 serine/threonine kinase to stabilize GLI family members and to phosphorylate SUFU for nuclear accumulation of GLI. Hedgehog signaling activation leads to GLI-dependent transcriptional activation of target genes, such as GLI1, PTCH1, CCND2, FOXL1, JAG2 and SFRP1. GLI1-dependent positive feedback loop combined with PTCH1-dependent negative feedback loop gives rise to transient proliferation of Hedgehog target cells. Iguana homologs (DZIP1 and DZIP1L) and Costal-2 homologs (KIF7 and KIF27) are identified by comparative integromics. SHH-dependent parietal cell proliferation is implicated in gastric mucosal repair during chronic Helicobacter pylori infection. BMP-RUNX3 signaling induces IHH expression in surface differentiated epithelial cells of stomach and intestine. Hedgehog signals from epithelial cells then induces FOXL1-mediated BMP4 upregulation in mesenchymal cells. Hedgehog signaling is frequently activated in esophageal cancer, gastric cancer and pancreatic cancer due to transcriptional upregulation of Hedgehog ligands and epigenetic silencing of HHIP1/HHIP gene, encoding the Hedgehog inhibitor. However, Hedgehog signaling is rarely activated in colorectal cancer due to negative regulation by the canonical WNT signaling pathway. Hedgehog signaling molecules or targets, such as SHH, IHH, HHIP1, PTCH1 and GLI1, are applied as biomarkers for cancer diagnostics, prognostics and therapeutics. Small-molecule inhibitors for SMO or STK36 are suitable to be used for

  12. Observation of a New J{sup PC} = 1{sup {minus}+} Exotic State in the Reaction {pi}{sup {minus}}p {r_arrow} {pi}{sup +} {pi}{sup {minus}}{pi}{sup {minus}} p at 18 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Chung, S.U.; Danyo, K.; Hackenburg, R.W.; Olchanski, C.; Ostrovidov, A.I.; Weygand, D.P.; Willutzki, H.J. [Brookhaven National Laboratory, Upton, New York 11973 (United States); Bodyagin, V.A.; Kodolova, O.L.; Korotkikh, V.L.; Kostin, M.A.; Ostrovidov, A.I.; Sarycheva, L.I.; Sinev, N.B.; Vardanyan, I.N.; Yershov, A.A. [Nuclear Physics Institute, Moscow State University, Moscow, (Russia) 119899; Bar-Yam, Z.; Cummings, J.P.; Dowd, J.P.; Eugenio, P.; Hayek, M.; Kern, W.; King, E.; Ostrovidov, A.I.; Shenhav, N. [Department of Physics, University of Massachusetts Dartmouth, North Dartmouth, Massachusetts 02747 (United States); Adams, G.S.; Cummings, J.P.; Kuhn, J.; Napolitano, J.; Nozar, M.; Smith, J.A.; White, D.; Witkowski, M. [Department of Physics, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Adams, T.; Bishop, J.M.; Cason, N.M.; Ivanov, E.I.; LoSecco, J.M.; Manak, J.J.; Sanjari, A.H.; Shephard, W.D.; Stienike, D.L.; Taegar, S.A.; Thompson, D.R. [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Brabson, B.B.; Crittenden, R.R.; Dzierba, A.R.; Gunter, J.; Lindenbusch, R.; Rust, D.R.; Scott, E.; Smith, P.T.; Sulanke, T.; Teige, S. [Department of Physics, Indiana University, Bloomington, Indiana 47405 (United States); Brown, D.S.; Pedlar, T.K.; Seth, K.K.; Wise, J.; Zhao, D. [Department of Physics, Northwestern University, Evanston, Illinois 60208 (United States); Denisov, S.; Dorofeev, V.; Kachaev, I.; Lipaev, V.; Popov, A.; Ryabchikov, D. [Institute for High Energy Physics, Protvino, (Russia) 142284

    1998-12-01

    A partial-wave analysis of the reaction {pi}{sup {minus}}p{r_arrow}{pi}{sup +}{pi}{sup {minus} }{pi}{sup {minus}}p at 18 GeV/c has been performed on a data sample of 250thinsp000 events obtained by Brookhaven experiment E852. The expected J{sup PC}=1{sup ++}a{sub 1}(1260) , 2{sup ++}a{sub 2}(1320) , and 2{sup {minus}+}{pi}{sub 2}(1670) resonant states are clearly observed. The exotic J{sup PC}=1{sup {minus}+} wave produced in the natural parity exchange processes shows distinct resonancelike phase motion at about 1.6 GeV/c{sup 2} in the {rho}{pi} channel. A mass-dependent fit results in a resonance mass of 1593{plus_minus}8{sup +29}{sub {minus}47} MeV /c{sup 2} and a width of 168{plus_minus}20{sup +150}{sub {minus}12} MeV /c{sup 2} . {copyright} {ital 1998} {ital The American Physical Society }

  13. Signals and systems with MATLAB

    CERN Document Server

    Yang, Won Young; Song, Ik H; Cho, Yong S

    2009-01-01

    Covers some of the theoretical foundations and mathematical derivations that can be used in higher-level related subjects such as signal processing, communication, and control, minimizing the mathematical difficulty and computational burden. This book illustrates the usage of MATLAB and Simulink for signal and system analysis and design.

  14. Parallel Computers in Signal Processing

    Directory of Open Access Journals (Sweden)

    Narsingh Deo

    1985-07-01

    Full Text Available Signal processing often requires a great deal of raw computing power for which it is important to take a look at parallel computers. The paper reviews various types of parallel computer architectures from the viewpoint of signal and image processing.

  15. The Pseudomonas Quinolone Signal (PQS)

    DEFF Research Database (Denmark)

    Sams, Thomas; Baker, Ysobel; Hodgkinson, James;

    2015-01-01

    is now known to be under the con-trol of the quorum sensing (QS) system. Over the last15 years, the Pseudomonas quinolone signal (PQS) has beenfound to play a crucial role in QS by linking the two seg-ments (las and rhl) of the P. aeruginosa N-acylhomoserinelactone-dependent QS signaling pathways. Herein...

  16. Compressed Sensing of Analog Signals

    CERN Document Server

    Eldar, Yonina C

    2008-01-01

    A traditional assumption underlying most data converters is that the signal should be sampled at a rate which exceeds twice the highest frequency. This statement is based on a worst-case scenario in which the signal occupies the entire available bandwidth. In practice, many signals posses a sparse structure so that a large part of the bandwidth is not exploited. In this paper, we consider a framework for utilizing this sparsity in order to sample such analog signals at a low rate. More specifically, we consider continuous-time signals that lie in a shift-invariant (SI) space generated by m kernels, so that any signal in the space can be expressed as an infinite linear combination of the shifted kernels. If the period of the underlying SI space is equal to T, then such signals can be perfectly reconstructed from samples at a rate of m/T. Here we treat the case in which only k out of the m generators are active, meaning that the signal actually lies in a lower dimensional space spanned by k generators. However,...

  17. Signals in Communication Engineering History

    Science.gov (United States)

    Consonni, Denise; Silva, Magno T. M.

    2010-01-01

    This paper is a study of various electric signals, which have been employed throughout the history of communication engineering in its two main landmarks: the telegraph and the telephone. The signals are presented in their time and frequency domain representations. The historical order has been followed in the presentation: wired systems, spark…

  18. Intracellular signal modulation by nanomaterials.

    Science.gov (United States)

    Hussain, Salik; Garantziotis, Stavros; Rodrigues-Lima, Fernando; Dupret, Jean-Marie; Baeza-Squiban, Armelle; Boland, Sonja

    2014-01-01

    A thorough understanding of the interactions of nanomaterials with biological systems and the resulting activation of signal transduction pathways is essential for the development of safe and consumer friendly nanotechnology. Here we present an overview of signaling pathways induced by nanomaterial exposures and describe the possible correlation of their physicochemical characteristics with biological outcomes. In addition to the hierarchical oxidative stress model and a review of the intrinsic and cell-mediated mechanisms of reactive oxygen species (ROS) generating capacities of nanomaterials, we also discuss other oxidative stress dependent and independent cellular signaling pathways. Induction of the inflammasome, calcium signaling, and endoplasmic reticulum stress are reviewed. Furthermore, the uptake mechanisms can be of crucial importance for the cytotoxicity of nanomaterials and membrane-dependent signaling pathways have also been shown to be responsible for cellular effects of nanomaterials. Epigenetic regulation by nanomaterials, effects of nanoparticle-protein interactions on cell signaling pathways, and the induction of various cell death modalities by nanomaterials are described. We describe the common trigger mechanisms shared by various nanomaterials to induce cell death pathways and describe the interplay of different modalities in orchestrating the final outcome after nanomaterial exposures. A better understanding of signal modulations induced by nanomaterials is not only essential for the synthesis and design of safer nanomaterials but will also help to discover potential nanomedical applications of these materials. Several biomedical applications based on the different signaling pathways induced by nanomaterials are already proposed and will certainly gain a great deal of attraction in the near future.

  19. Fining Signals for Plant Promoters

    Institute of Scientific and Technical Information of China (English)

    WeimouZheng

    2003-01-01

    The strongest signal of plant promoter is searched with the model of single motif with two types.It turns out that the dominant type is the TATA-box.The other type may be called TATA-less signal,and may be used in gene finders for promoter recognition.While the TATA signals are very close for the monocot and the dicot,their TATA-less signals are significantly different.A general and flexible multi-motif model is also proposed for promoter analysis based on dynamic programming.By extending the Gibbs sampler to the dynamic programming and introducing temperature,an efficient algorithm is developed for searching signals in plant promoters.

  20. Reinforcement learning in signaling game

    CERN Document Server

    Hu, Yilei; Tarrès, Pierre

    2011-01-01

    We consider a signaling game originally introduced by Skyrms, which models how two interacting players learn to signal each other and thus create a common language. The first rigorous analysis was done by Argiento, Pemantle, Skyrms and Volkov (2009) with 2 states, 2 signals and 2 acts. We study the case of M_1 states, M_2 signals and M_1 acts for general M_1, M_2. We prove that the expected payoff increases in average and thus converges a.s., and that a limit bipartite graph emerges, such that no signal-state correspondence is associated to both a synonym and an informational bottleneck. Finally, we show that any graph correspondence with the above property is a limit configuration with positive probability.

  1. Signal focusing through active transport

    Science.gov (United States)

    Godec, Aljaž; Metzler, Ralf

    2015-07-01

    The accuracy of molecular signaling in biological cells and novel diagnostic devices is ultimately limited by the counting noise floor imposed by the thermal diffusion. Motivated by the fact that messenger RNA and vesicle-engulfed signaling molecules transiently bind to molecular motors and are actively transported in biological cells, we show here that the random active delivery of signaling particles to within a typical diffusion distance to the receptor generically reduces the correlation time of the counting noise. Considering a variety of signaling particle sizes from mRNA to vesicles and cell sizes from prokaryotic to eukaryotic cells, we show that the conditions for active focusing—faster and more precise signaling—are indeed compatible with observations in living cells. Our results improve the understanding of molecular cellular signaling and novel diagnostic devices.

  2. Engineering cell-cell signaling.

    Science.gov (United States)

    Blagovic, Katarina; Gong, Emily S; Milano, Daniel F; Natividad, Robert J; Asthagiri, Anand R

    2013-10-01

    Juxtacrine cell-cell signaling mediated by the direct interaction of adjoining mammalian cells is arguably the mode of cell communication that is most recalcitrant to engineering. Overcoming this challenge is crucial for progress in biomedical applications, such as tissue engineering, regenerative medicine, immune system engineering and therapeutic design. Here, we describe the significant advances that have been made in developing synthetic platforms (materials and devices) and synthetic cells (cell surface engineering and synthetic gene circuits) to modulate juxtacrine cell-cell signaling. In addition, significant progress has been made in elucidating design rules and strategies to modulate juxtacrine signaling on the basis of quantitative, engineering analysis of the mechanical and regulatory role of juxtacrine signals in the context of other cues and physical constraints in the microenvironment. These advances in engineering juxtacrine signaling lay a strong foundation for an integrative approach to utilize synthetic cells, advanced 'chassis' and predictive modeling to engineer the form and function of living tissues.

  3. Recovery of Sparsely Corrupted Signals

    CERN Document Server

    Studer, Christoph; Pope, Graeme; Bölcskei, Helmut

    2011-01-01

    We investigate the recovery of signals exhibiting a sparse representation in a general (i.e., possibly redundant or incomplete) dictionary that are corrupted by additive noise admitting a sparse representation in another general dictionary. This setup covers a wide range of applications, such as image inpainting, super-resolution, signal separation, and recovery of signals that are impaired by, e.g., clipping, impulse noise, or narrowband interference. We present deterministic recovery guarantees based on a novel uncertainty relation for pairs of general dictionaries and we provide corresponding practicable recovery algorithms. The recovery guarantees we find depend on the signal and noise sparsity levels, on the coherence parameters of the involved dictionaries, and on the amount of prior knowledge on the support sets of signal and noise. We finally identify situations under which the recovery guarantees are tight.

  4. Piezoelectric extraction of ECG signal

    Science.gov (United States)

    Ahmad, Mahmoud Al

    2016-11-01

    The monitoring and early detection of abnormalities or variations in the cardiac cycle functionality are very critical practices and have significant impact on the prevention of heart diseases and their associated complications. Currently, in the field of biomedical engineering, there is a growing need for devices capable of measuring and monitoring a wide range of cardiac cycle parameters continuously, effectively and on a real-time basis using easily accessible and reusable probes. In this paper, the revolutionary generation and extraction of the corresponding ECG signal using a piezoelectric transducer as alternative for the ECG will be discussed. The piezoelectric transducer pick up the vibrations from the heart beats and convert them into electrical output signals. To this end, piezoelectric and signal processing techniques were employed to extract the ECG corresponding signal from the piezoelectric output voltage signal. The measured electrode based and the extracted piezoelectric based ECG traces are well corroborated. Their peaks amplitudes and locations are well aligned with each other.

  5. Adaptive Signal Processing Testbed signal excision software: User's manual

    Science.gov (United States)

    Parliament, Hugh A.

    1992-05-01

    The Adaptive Signal Processing Testbed (ASPT) signal excision software is a set of programs that provide real-time processing functions for the excision of interfering tones from a live spread-spectrum signal as well as off-line functions for the analysis of the effectiveness of the excision technique. The processing functions provided by the ASPT signal excision software are real-time adaptive filtering of live data, storage to disk, and file sorting and conversion. The main off-line analysis function is bit error determination. The purpose of the software is to measure the effectiveness of an adaptive filtering algorithm to suppress interfering or jamming signals in a spread spectrum signal environment. A user manual for the software is provided, containing information on the different software components available to perform signal excision experiments: the real-time excision software, excision host program, file processing utilities, and despreading and bit error rate determination software. In addition, information is presented describing the excision algorithm implemented, the real-time processing framework, the steps required to add algorithms to the system, the processing functions used in despreading, and description of command sequences for post-run analysis of the data.

  6. Quorum Quenching Revisited—From Signal Decays to Signalling Confusion

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan

    2012-04-01

    Full Text Available In a polymicrobial community, while some bacteria are communicating with neighboring cells (quorum sensing, others are interrupting the communication (quorum quenching, thus creating a constant arms race between intercellular communication. In the past decade, numerous quorum quenching enzymes have been found and initially thought to inactivate the signalling molecules. Though this is widely accepted, the actual roles of these quorum quenching enzymes are now being uncovered. Recent evidence extends the role of quorum quenching to detoxification or metabolism of signalling molecules as food and energy source; this includes “signalling confusion”, a term coined in this paper to refer to the phenomenon of non-destructive modification of signalling molecules. While quorum quenching has been explored as a novel anti-infective therapy targeting, quorum sensing evidence begins to show the development of resistance against quorum quenching.

  7. Targeting FGFR Signaling in Cancer.

    Science.gov (United States)

    Touat, Mehdi; Ileana, Ecaterina; Postel-Vinay, Sophie; André, Fabrice; Soria, Jean-Charles

    2015-06-15

    The fibroblast growth factor signaling pathway (FGFR signaling) is an evolutionary conserved signaling cascade that regulates several basic biologic processes, including tissue development, angiogenesis, and tissue regeneration. Substantial evidence indicates that aberrant FGFR signaling is involved in the pathogenesis of cancer. Recent developments of deep sequencing technologies have allowed the discovery of frequent molecular alterations in components of FGFR signaling among several solid tumor types. Moreover, compelling preclinical models have demonstrated the oncogenic potential of these aberrations in driving tumor growth, promoting angiogenesis, and conferring resistance mechanisms to anticancer therapies. Recently, the field of FGFR targeting has exponentially progressed thanks to the development of novel agents inhibiting FGFs or FGFRs, which had manageable safety profiles in early-phase trials. Promising treatment efficacy has been observed in different types of malignancies, particularly in tumors harboring aberrant FGFR signaling, thus offering novel therapeutic opportunities in the era of precision medicine. The most exciting challenges now focus on selecting patients who are most likely to benefit from these agents, increasing the efficacy of therapies with the development of novel potent compounds and combination strategies, and overcoming toxicities associated with FGFR inhibitors. After examination of the basic and translational research studies that validated the oncogenic potential of aberrant FGFR signaling, this review focuses on recent data from clinical trials evaluating FGFR targeting therapies and discusses the challenges and perspectives for the development of these agents.

  8. An optical analog signal transmitter

    Energy Technology Data Exchange (ETDEWEB)

    Fudzita, K.; Itida, T.; Tanaka, Kh.

    1984-01-11

    An optical laser analog signal transmitter employing an amplitude modulated subcarrier is patented; this transmitter performs stable and high quality transmission of information signals over great distances. A feature of the proposed transmitter is a special transmitter operational mode in which the light emission reflected off the connection point to the fiber optic conduit is sent back to the laser diode in a transient period. As a result, the critical mode of the generated emission is not influenced by the reflected signal. The transmitter consists of a laser diode with biasing near the cutoff point, an amplitude modulator with a subcarrier frequency oscillator, a section of flexible fiber-optic cable of length L, which connects the laser diode to the primary optical fiber conduit, and the connector itself. The subcarrier frequency may vary over wide ranges to establish the necessary correlation between the length of the light conduit section L and the return propagation time of the reflected light signal from the connection point to the laser diode. The difference between the lasing time of the light signal and the return time to the laser diode of the signal reflected off the connector is determined by the relation tau equals 2nL/c - mtauc, where L is the length of the connecting section; n is the refractivity of the optical fiber; c is the velocity of light; tauc is the period of the high frequency subcarrier signal; and m is an integer.

  9. Microsystem for signal processing applications

    Science.gov (United States)

    Frankenstein, B.; Froehlich, K.-J.; Hentschel, D.; Reppe, G.

    2005-05-01

    Acoustic monitoring of technological processes requires methods that eliminate noise as much as possible. Sensor-near signal evaluation can contribute substantially. Frequently, a further necessity exists to integrate the measuring technique in the monitored structure. The solution described contains components for analog preprocessing of acoustic signals, their digitization, algorithms for data reduction, and digital communication. The core component is a digital signal processor (DSP). Digital signal processors perform the algorithms necessary for filtering, down sampling, FFT computation and correlation of spectral components particularly effective. A compact, sensor-near signal processing structure was realized. It meets the Match-X standard, which as specified by the German Association for Mechanical and Plant Engineering (VDMA) for development of micro-technical modules, which can be combined to applicaiton specific systems. The solution is based on AL2O3 ceramic components including different signal processing modules as ADC, as well as memory and power supply. An arbitrary waveform generator has been developed and combined with a power amplifier for piezoelectric transducers in a special module. A further module interfaces to these transducers. It contains a multi-channel preamplifier, some high-pass filters for analog signal processing and an ADC-driver. A Bluetooth communication chip for wireless data transmission and a DiscOnChip module are under construction. As a first application, the combustion behavior of safety-relevant contacts is monitored. A special waveform up to 5MHz is produced and sent to the monitored object. The resulting signal form is evaluated with special algorithms, which extract significant parameters of the signal, and transmitted via CAN-bus.

  10. The IRS-1 signaling system.

    Science.gov (United States)

    White, M F

    1994-02-01

    IRS-1 is a principal substrate of the insulin receptor tyrosine kinase. It undergoes multi-site tyrosine phosphorylation and mediates the insulin signal by associating with various signaling molecules containing Src homology 2 domains. Interleukin-4 also stimulates IRS-1 phosphorylation, and it is suspected that a few more growth factors or cytokines will be added to form a select group of receptors that utilize the IRS-1 signaling pathway. More IRS-1-like adapter molecules, such as 4PS (IRS-2), may remain to be found.

  11. Jasmonate Signal Pathway in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Xiao-Yi Shan; Zhi-Long Wang; Daoxin Xie

    2007-01-01

    Jasmonates (JAs), which include jasmonic acid and its cyclopentane derivatives are synthesized from the octadecanoid pathway and widely distributed throughout the plant kingdom. JAs modulate the expression of numerous genes and mediate responses to stress, wounding, insect attack, pathogen infection, and UV damage. They also affect a variety of processes in many plant developmental processes. The JA signal pathway involves two important events: the biosynthesis of JA and the transduction of JA signal. Several important Arabidopsis mutants in jasmonate signal pathway were described in this review.

  12. On Generalized Fractional Differentiator Signals

    Directory of Open Access Journals (Sweden)

    Hamid A. Jalab

    2013-01-01

    Full Text Available By employing the generalized fractional differential operator, we introduce a system of fractional order derivative for a uniformly sampled polynomial signal. The calculation of the bring in signal depends on the additive combination of the weighted bring-in of N cascaded digital differentiators. The weights are imposed in a closed formula containing the Stirling numbers of the first kind. The approach taken in this work is to consider that signal function in terms of Newton series. The convergence of the system to a fractional time differentiator is discussed.

  13. Inositol trisphosphate and calcium signalling

    Science.gov (United States)

    Berridge, Michael J.

    1993-01-01

    Inositol trisphosphate is a second messenger that controls many cellular processes by generating internal calcium signals. It operates through receptors whose molecular and physiological properties closely resemble the calcium-mobilizing ryanodine receptors of muscle. This family of intracellular calcium channels displays the regenerative process of calcium-induced calcium release responsible for the complex spatiotemporal patterns of calcium waves and oscillations. Such a dynamic signalling pathway controls many cellular processes, including fertilization, cell growth, transformation, secretion, smooth muscle contraction, sensory perception and neuronal signalling.

  14. Wnt signaling in cardiovascular physiology.

    Science.gov (United States)

    Marinou, K; Christodoulides, C; Antoniades, C; Koutsilieris, M

    2012-12-01

    Wnt signaling pathways play a key role in cardiac development, angiogenesis, and cardiac hypertrophy; emerging evidence suggests that they are also involved in the pathophysiology of atherosclerosis. Specifically, an important role for Wnts has been described in the regulation of endothelial inflammation, vascular calcification, and mesenchymal stem cell differentiation. Wnt signaling also induces monocyte adhesion to endothelial cells and is crucial for the regulation of vascular smooth-muscle cell (VSMC) behavior. We discuss how the Wnt pathways are implicated in vascular biology and outline the role of Wnt signaling in atherosclerosis. Dissecting Wnt pathways involved in atherogenesis and cardiovascular disease may provide crucial insights into novel mechanisms with therapeutic potential for atherosclerosis.

  15. Statistical theory of signal detection

    CERN Document Server

    Helstrom, Carl Wilhelm; Costrell, L; Kandiah, K

    1968-01-01

    Statistical Theory of Signal Detection, Second Edition provides an elementary introduction to the theory of statistical testing of hypotheses that is related to the detection of signals in radar and communications technology. This book presents a comprehensive survey of digital communication systems. Organized into 11 chapters, this edition begins with an overview of the theory of signal detection and the typical detection problem. This text then examines the goals of the detection system, which are defined through an analogy with the testing of statistical hypotheses. Other chapters consider

  16. Smoke Signal or Smoke Screen?

    DEFF Research Database (Denmark)

    Vergne, Jean-Philippe; Wernicke, Georg; Brenner, Steffen

    disapproval, whereas ambiguous signals represent a form of category straddling that attenuates disapproval. We find empirical support for this proposition in the context of CEO overcompensation in the U.S. (1995-2007) after examining two organizational signals that affect perceptions of economic fairness (i.......e. corporate philanthropy) and social fairness (i.e. employee diversity). Our integration of the signaling and categorization literatures adds to extant knowledge on firm’s social evaluations and recasts CEO compensation research within the literature on information intermediaries....

  17. Signal processing with free software practical experiments

    CERN Document Server

    Auger, François

    2014-01-01

    An ideal resource for students, industrial engineers, and researchers, Signal Processing with Free Software Practical Experiments presents practical experiments in signal processing using free software. The text introduces elementary signals through elementary waveform, signal storage files and elementary operations on signals and then presents the first tools to signal analysis such as temporal and frequency characteristics leading to Time-frequency analysis. Non-parametric spectral analysis is also discussed as well as signal processing through sampling, resampling, quantification, an

  18. Electromagnetic Signals from Bacterial DNA

    CERN Document Server

    Widom, A; Srivastava, Y N; Sivasubramanian, S

    2011-01-01

    Chemical reactions can be induced at a distance due to the propagation of electromagnetic signals during intermediate chemical stages. Although is is well known at optical frequencies, e.g. photosynthetic reactions, electromagnetic signals hold true for muck lower frequencies. In E. coli bacteria such electromagnetic signals can be generated by electric transitions between energy levels describing electrons moving around DNA loops. The electromagnetic signals between different bacteria within a community is a "wireless" version of intercellular communication found in bacterial communities connected by "nanowires". The wireless broadcasts can in principle be of both the AM and FM variety due to the magnetic flux periodicity in electron energy spectra in bacterial DNA orbital motions.

  19. Nuclear Receptor Signaling Atlas (NURSA)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Nuclear Receptor Signaling Atlas (NURSA) is designed to foster the development of a comprehensive understanding of the structure, function, and role in disease...

  20. Structural mechanisms of plexin signaling.

    Science.gov (United States)

    Pascoe, Heath G; Wang, Yuxiao; Zhang, Xuewu

    2015-09-01

    Signaling through plexin, the major cell surface receptor for semaphorin, plays critical roles in regulating processes such as neuronal axon guidance, angiogenesis and immune response. Plexin is normally kept inactive in the absence of semaphorin. Upon binding of semaphorin to the extracellular region, plexin is activated and transduces signal to the inside of the cell through its cytoplasmic region. The GTPase Activating Protein (GAP) domain in the plexin cytoplasmic region mediates the major intracellular signaling pathway. The substrate specificity and regulation mechanisms of the GAP domain have only been revealed recently. Many intracellular proteins serve as either upstream regulators or downstream transducers by directly interacting with plexin. The mechanisms of action for some of these proteins also start to emerge from recent studies. We review here these advances in the mechanistic understanding of plexin intracellular signaling from a structural perspective.

  1. Signal transforms in dynamic measurements

    CERN Document Server

    Layer, Edward

    2015-01-01

    This book is devoted to the analysis of measurement signals which requires specific mathematical operations like Convolution, Deconvolution, Laplace, Fourier, Hilbert, Wavelet or Z transform which are all presented in the present book. The different problems refer to the modulation of signals, filtration of disturbance as well as to the orthogonal signals and their use in digital form for the measurement of current, voltage, power and frequency are also widely discussed. All the topics covered in this book are presented in detail and illustrated by means of examples in MathCad and LabVIEW. This book provides a useful source for researchers, scientists and engineers who in their daily work are required to deal with problems of measurement and signal processing and can also be helpful to undergraduate students of electrical engineering.    

  2. Pub: Grid 2004, 2 signalement

    DEFF Research Database (Denmark)

    2004-01-01

    2. signalement er en af flere manifesteringer omkring det at skabe en tale omkring udfordringer. Pub: Grid 2004 indeholder en række arbejder, der afspejler et fagligt udviklingsarbejde på afdeling 6....

  3. Sentiment analysis for PTSD signals

    CERN Document Server

    Kagan, Vadim; Sapounas, Demetrios

    2013-01-01

    This book describes a computational framework for real-time detection of psychological signals related to Post-Traumatic Stress Disorder (PTSD) in online text-based posts, including blogs and web forums. Further, it explores how emerging computational techniques such as sentiment mining can be used in real-time to identify posts that contain PTSD-related signals, flag those posts, and bring them to the attention of psychologists, thus providing an automated flag and referral capability.

  4. Handbook of signal processing systems

    CERN Document Server

    Deprettere, Ed; Leupers, Rainer; Takala, Jarmo

    2013-01-01

    Handbook of Signal Processing Systems is organized in three parts. The first part motivates representative applications that drive and apply state-of-the art methods for design and implementation of signal processing systems; the second part discusses architectures for implementing these applications; the third part focuses on compilers and simulation tools, describes models of computation and their associated design tools and methodologies. This handbook is an essential tool for professionals in many fields and researchers of all levels.

  5. Decomposition of indwelling EMG signals

    OpenAIRE

    2008-01-01

    Decomposition of indwelling electromyographic (EMG) signals is challenging in view of the complex and often unpredictable behaviors and interactions of the action potential trains of different motor units that constitute the indwelling EMG signal. These phenomena create a myriad of problem situations that a decomposition technique needs to address to attain completeness and accuracy levels required for various scientific and clinical applications. Starting with the maximum a posteriori probab...

  6. Algebraic Methods to Design Signals

    Science.gov (United States)

    2015-08-27

    algebraic number theory, finite geometry, and combinatorics in designing signals as a by- product of new combinatorial designs and the corresponding... constructions of cyclic 2-class partially balanced incomplete block designs using cyclotomy in finite fields. Our results give theoretical explanations of the...very small. We call the constructed sequences perfect sequences and they serve as perfect algebraic/combinatorial objects in designing signals for

  7. Ascaroside signaling in C. elegans*

    OpenAIRE

    Ludewig, Andreas H; Schroeder, Frank C.

    2013-01-01

    Over the past 10 years, the relevance of small-molecule signaling for many aspects of C. elegans development and behavior has become apparent. One prominent group of small-molecule signals are the ascarosides, which control dauer entry and exit as well as a variety of sex-specific and social behaviors, including male attraction, hermaphrodite repulsion, olfactory plasticity, and aggregation. This wide range of biological functions is facilitated by a great diversity of ascaroside chemical str...

  8. Systemic defense signaling in tomato

    Institute of Scientific and Technical Information of China (English)

    LI Changbao; SUN Jiaqiang; JIANG Hongling; WU Xiaoyan; LI Chuanyou

    2005-01-01

    The wound-inducible expression of proteinase inhibitors (PIs) genes in tomato provides a powerful model system to elucidate the signal transduction pathway of sys- temic defense response. An increasing body of evidence indi- cates that systemin and jasmonic acid (JA) work in the same signaling pathway to activate the expression of PIs and other defense-related genes. However, little is known about how systemin and JA interact to regulate cell to cell communica- tion over long distances. Genetic analysis of the systemin/JA signaling pathway in tomato plants provides a unique opportunity to dissect the mechanism by which peptide and oxylipin signals interact to coordinate systemic expression of defense-related genes. Previously, it has been proposed that systemin is the long-distance mobile signal for systemic expression of defense related genes. However, recent genetic approach provided new evidence that jasmonic acid, rather than systemin, functions as the systemic wound signal, and that the peptide systemin works to regulate the biosynthesis of JA.

  9. Insulin Signaling and Heart Failure.

    Science.gov (United States)

    Riehle, Christian; Abel, E Dale

    2016-04-01

    Heart failure is associated with generalized insulin resistance. Moreover, insulin-resistant states such as type 2 diabetes mellitus and obesity increases the risk of heart failure even after adjusting for traditional risk factors. Insulin resistance or type 2 diabetes mellitus alters the systemic and neurohumoral milieu, leading to changes in metabolism and signaling pathways in the heart that may contribute to myocardial dysfunction. In addition, changes in insulin signaling within cardiomyocytes develop in the failing heart. The changes range from activation of proximal insulin signaling pathways that may contribute to adverse left ventricular remodeling and mitochondrial dysfunction to repression of distal elements of insulin signaling pathways such as forkhead box O transcriptional signaling or glucose transport, which may also impair cardiac metabolism, structure, and function. This article will review the complexities of insulin signaling within the myocardium and ways in which these pathways are altered in heart failure or in conditions associated with generalized insulin resistance. The implications of these changes for therapeutic approaches to treating or preventing heart failure will be discussed.

  10. SignalPlant: an open signal processing software platform.

    Science.gov (United States)

    Plesinger, F; Jurco, J; Halamek, J; Jurak, P

    2016-07-01

    The growing technical standard of acquisition systems allows the acquisition of large records, often reaching gigabytes or more in size as is the case with whole-day electroencephalograph (EEG) recordings, for example. Although current 64-bit software for signal processing is able to process (e.g. filter, analyze, etc) such data, visual inspection and labeling will probably suffer from rather long latency during the rendering of large portions of recorded signals. For this reason, we have developed SignalPlant-a stand-alone application for signal inspection, labeling and processing. The main motivation was to supply investigators with a tool allowing fast and interactive work with large multichannel records produced by EEG, electrocardiograph and similar devices. The rendering latency was compared with EEGLAB and proves significantly faster when displaying an image from a large number of samples (e.g. 163-times faster for 75  ×  10(6) samples). The presented SignalPlant software is available free and does not depend on any other computation software. Furthermore, it can be extended with plugins by third parties ensuring its adaptability to future research tasks and new data formats.

  11. Liquid Argon TPC Signal Formation, Signal Processing and Hit Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Baller, Bruce [Fermilab

    2017-03-11

    This document describes the early stage of the reconstruction chain that was developed for the ArgoNeuT and MicroBooNE experiments at Fermilab. These experiments study accelerator neutrino interactions that occur in a Liquid Argon Time Projection Chamber. Reconstructing the properties of particles produced in these interactions requires knowledge of the micro-physics processes that affect the creation and transport of ionization electrons to the readout system. A wire signal deconvolution technique was developed to convert wire signals to a standard form for hit reconstruction, to remove artifacts in the electronics chain and to remove coherent noise.

  12. Polarization enhancement in (d)over-right-arrow((p)over-right-arrow,(n)over-right-arrow)He-2 reaction : nuclear teleportation

    NARCIS (Netherlands)

    Hamieh, S

    2004-01-01

    I show that an experimental technique used in nuclear physics may be successfully applied to quantum teleportation (QT) of spin states of massive matter. A new non-local physical effect, the 'quantum-teleportation effect', is discovered for the nuclear polarization measurement. Enhancement of the ne

  13. Basophil stimulation and signaling pathways.

    Science.gov (United States)

    Knol, Edward F; Gibbs, Bernhard F

    2014-01-01

    Despite growing use of flow cytometry to analyze the functional characteristics of primary basophils the intracellular signaling cascades that control their ability to elaborate various inflammatory mediators and cytokines remain comparatively obscure. Additionally, some studies require the analysis of pro-allergic and inflammatory mediators, such as histamine, LTC4, and various basophil-derived cytokines (e.g., IL-4 and IL-13). Elucidation of intracellular signaling proteins by Western blotting, cytosolic free calcium concentration by spectrofluorophotometry, and detection of mediator releases, as well as analysis of gene expressions by RT-PCR, generally require relatively large numbers of purified basophils. In selected assays, flow cytometry can enable the analysis of relatively low cell numbers and purity for the expression of intracellular signaling proteins or measurement of cytosolic free calcium concentrations by basophil-specific gating strategies. Unfortunately, many aspects of signal transduction relevant to human basophils cannot be readily extrapolated from the use of basophil or mast cell lines. This chapter therefore focuses on how to employ primary human basophils for studying mediator releases and signaling characteristics.

  14. Calcium signaling in taste cells.

    Science.gov (United States)

    Medler, Kathryn F

    2015-09-01

    The sense of taste is a common ability shared by all organisms and is used to detect nutrients as well as potentially harmful compounds. Thus taste is critical to survival. Despite its importance, surprisingly little is known about the mechanisms generating and regulating responses to taste stimuli. All taste responses depend on calcium signals to generate appropriate responses which are relayed to the brain. Some taste cells have conventional synapses and rely on calcium influx through voltage-gated calcium channels. Other taste cells lack these synapses and depend on calcium release to formulate an output signal through a hemichannel. Beyond establishing these characteristics, few studies have focused on understanding how these calcium signals are formed. We identified multiple calcium clearance mechanisms that regulate calcium levels in taste cells as well as a calcium influx that contributes to maintaining appropriate calcium homeostasis in these cells. Multiple factors regulate the evoked taste signals with varying roles in different cell populations. Clearly, calcium signaling is a dynamic process in taste cells and is more complex than has previously been appreciated. This article is part of a Special Issue entitled: 13th European Symposium on Calcium.

  15. Applied signal processing concepts, circuits, and systems

    CERN Document Server

    Hamdy, Nadder

    2008-01-01

    Introduction What are Signals? Signal parameters Why Signal processing? Analog vs. Digital Signal processing Practical Signal processing Systems Analog Signal Processing Amplitude Shaping Frequency Spectrum Shaping Phase Errors Correction Waveform Generation Analog Filter Design Describing Equations Design Procedures Filter Specifications Approximations to the Ideal Response Realization Practical RC-Filters Design Switched Capacitor Filter Realization Design examples Data Converters Introduction A typical DSP System Specifications of Data Converters Sampling Samp

  16. Optical time-lens signal processing

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Galili, Michael; Mulvad, Hans Christian Hansen;

    2014-01-01

    This paper describes the use of optical time lenses for optical signal processing of advanced optical data signals. Examples given include 1.28 Tbaud Nyquist channel serial-to-parallel conversion and spectral magnification of OFDM signals.......This paper describes the use of optical time lenses for optical signal processing of advanced optical data signals. Examples given include 1.28 Tbaud Nyquist channel serial-to-parallel conversion and spectral magnification of OFDM signals....

  17. Sparse Signal Recovery in Hilbert Spaces

    CERN Document Server

    Pope, Graeme

    2012-01-01

    This paper reports an effort to consolidate numerous coherence-based sparse signal recovery results available in the literature. We present a single theory that applies to general Hilbert spaces with the sparsity of a signal defined as the number of (possibly infinite-dimensional) subspaces participating in the signal's representation. Our general results recover uncertainty relations and coherence-based recovery thresholds for sparse signals, block-sparse signals, multi-band signals, signals in shift-invariant spaces, and signals in finite unions of (possibly infinite-dimensional) subspaces. Moreover, we improve upon and generalize several of the existing results and, in many cases, we find shortened and simplified proofs.

  18. Purinergic signalling: an experimental perspective.

    Science.gov (United States)

    Housley, G D; Thorne, P R

    2000-07-01

    Investigation of the multiple roles of extracellular nucleotides in the cochlea has developed from analysis of ATP-activated conductances in single sensory hair cells. Molecular probes such as radiolabelled ATP analogues and radiolabelled mRNA for ATP-gated ion channel subunits (P2X receptors) rapidly revealed the extensive nature of ATP signalling in this sensory organ. This has provided a foundation for physiological investigations which put extracellular nucleotides at the centre of homeostatic regulation of the driving force for sound transduction, modulation of mechanical tuning, control of cochlear blood flow and auditory neurotransmission. The purinergic signal transduction pathways associated with these processes have several novel features of significance to the broader field of purinergic neuroscience. In turn, these studies have benefited from the recent experimental advances in the field of purinergic signalling, a significant component of which is associated with the work of Professor Geoffrey Burnstock.

  19. Signaling a Change of Heart

    DEFF Research Database (Denmark)

    Schumacher, Gijs

    2011-01-01

    before elections. This study analyses the effect of these party signals on the welfare state. Party manifesto data are used to compute the positive and negative signals parties send on welfare issues in their electoral manifestos. A pooled time-series analysis of 14 parliamentary democracies between 1972......Do Social Democrats still expand the welfare state? This article argues that a time-constant policy-oriented expectation of Social Democratic behaviour neglects parties’ aspiration for other goals such as votes and offices, and therefore cannot explain why some Social Democratic parties have...... introduced welfare state retrenchment measures. Social Democrats can win votes and join coalitions by shifting rightwards. In contrast, they can pursue policy objectives by shifting leftwards. To communicate these shifts, in other words, ‘changes of heart’, parties send signals to voters and other parties...

  20. Multichannel Coding of Applause Signals

    Directory of Open Access Journals (Sweden)

    Jeroen Breebaart

    2007-08-01

    Full Text Available We develop a parametric multichannel audio codec dedicated to coding signals consisting of a dense series of transient-type events. These signals of which applause is a typical example are known to be problematic for such audio codecs. The codec design is based on preservation of both timbre and transient-type event density. It combines a very low complexity and a low parameter bit rate (0.2 kbps. In a formal listening test, we compared the proposed codec to the recently standardised MPEG Surround multichannel codec, with an associated parameter bit rate of 9 kbps. We found the new codec to have a significantly higher audio quality than the MPEG Surround codec for the two multichannel applause signals under test. Though this seems promising, the technique presented is not fully mature, for example, because issues related to integration of the proposed codec in the MPEG Surround codec were not addressed.

  1. Hedgehog signaling and gastrointestinal cancer

    Science.gov (United States)

    Saqui-Salces, Milena; Merchant, Juanita L.

    2017-01-01

    Hedgehog (Hh) signaling is critical for embryonic development and in differentiation, proliferation, and maintenance of multiple adult tissues. De-regulation of the Hh pathway is associated with birth defects and cancer. In the gastrointestinal tract, Hh ligands Sonic (Shh) and Indian (Ihh), as well as the receptor Patched (Ptch1), and transcription factors of Glioblastoma family (Gli) are all expressed during development. In the adult, Shh expression is restricted to the stomach and colon, while Ihh expression occurs throughout the luminal gastrointestinal tract, its expression being highest in the proximal duodenum. Several studies have demonstrated a requirement for Hh signaling during gastrointestinal tract development. However to date, the specific role of the Hh pathway in the adult stomach and intestine is not completely understood. The current review will place into context the implications of recent published data related to the biochemistry and cell biology of Hh signaling on the luminal gastrointestinal tract during development, normal physiology and subsequently carcinogenesis. PMID:20307590

  2. Ocean circulation generated magnetic signals

    DEFF Research Database (Denmark)

    Manoj, C.; Kuvshinov, A.; Maus, S.

    2006-01-01

    Conducting ocean water, as it flows through the Earth's magnetic field, generates secondary electric and magnetic fields. An assessment of the ocean-generated magnetic fields and their detectability may be of importance for geomagnetism and oceanography. Motivated by the clear identification...... of ocean tidal signatures in the CHAMP magnetic field data we estimate the ocean magnetic signals of steady flow using a global 3-D EM numerical solution. The required velocity data are from the ECCO ocean circulation experiment and alternatively from the OCCAM model for higher resolution. We assume...... of the magnetic field, as compared to the ECCO simulation. Besides the expected signatures of the global circulation patterns, we find significant seasonal variability of ocean magnetic signals in the Indian and Western Pacific Oceans. Compared to seasonal variation, interannual variations produce weaker signals....

  3. Using abstract language signals power.

    Science.gov (United States)

    Wakslak, Cheryl J; Smith, Pamela K; Han, Albert

    2014-07-01

    Power can be gained through appearances: People who exhibit behavioral signals of power are often treated in a way that allows them to actually achieve such power (Ridgeway, Berger, & Smith, 1985; Smith & Galinsky, 2010). In the current article, we examine power signals within interpersonal communication, exploring whether use of concrete versus abstract language is seen as a signal of power. Because power activates abstraction (e.g., Smith & Trope, 2006), perceivers may expect higher power individuals to speak more abstractly and therefore will infer that speakers who use more abstract language have a higher degree of power. Across a variety of contexts and conversational subjects in 7 experiments, participants perceived respondents as more powerful when they used more abstract language (vs. more concrete language). Abstract language use appears to affect perceived power because it seems to reflect both a willingness to judge and a general style of abstract thinking.

  4. Acoustically-Induced Electrical Signals

    Science.gov (United States)

    Brown, S. R.

    2014-12-01

    We have observed electrical signals excited by and moving along with an acoustic pulse propagating in a sandstone sample. Using resonance we are now studying the characteristics of this acousto-electric signal and determining its origin and the controlling physical parameters. Four rock samples with a range of porosities, permeabilities, and mineralogies were chosen: Berea, Boise, and Colton sandstones and Austin Chalk. Pore water salinity was varied from deionized water to sea water. Ag-AgCl electrodes were attached to the sample and were interfaced to a 4-wire electrical resistivity system. Under computer control, the acoustic signals were excited and the electrical response was recorded. We see strong acoustically-induced electrical signals in all samples, with the magnitude of the effect for each rock getting stronger as we move from the 1st to the 3rd harmonics in resonance. Given a particular fluid salinity, each rock has its own distinct sensitivity in the induced electrical effect. For example at the 2nd harmonic, Berea Sandstone produces the largest electrical signal per acoustic power input even though Austin Chalk and Boise Sandstone tend to resonate with much larger amplitudes at the same harmonic. Two effects are potentially responsible for this acoustically-induced electrical response: one the co-seismic seismo-electric effect and the other a strain-induced resistivity change known as the acousto-electric effect. We have designed experimental tests to separate these mechanisms. The tests show that the seismo-electric effect is dominant in our studies. We note that these experiments are in a fluid viscosity dominated seismo-electric regime, leading to a simple interpretation of the signals where the electric potential developed is proportional to the local acceleration of the rock. Toward a test of this theory we have measured the local time-varying acoustic strain in our samples using a laser vibrometer.

  5. Ascaroside signaling in C. elegans.

    Science.gov (United States)

    Ludewig, Andreas H; Schroeder, Frank C

    2013-01-18

    Over the past 10 years, the relevance of small-molecule signaling for many aspects of C. elegans development and behavior has become apparent. One prominent group of small-molecule signals are the ascarosides, which control dauer entry and exit as well as a variety of sex-specific and social behaviors, including male attraction, hermaphrodite repulsion, olfactory plasticity, and aggregation. This wide range of biological functions is facilitated by a great diversity of ascaroside chemical structures. These are based on the sugar ascarylose, which is linked to fatty acid-like side chains of varying lengths and often decorated further with building blocks derived from amino acids, folate, and other primary metabolites. Different ascarosides or combinations of ascarosides mediate different phenotypes, and even small differences in chemical structures are often associated with strongly altered activity profiles. Additional complexity arises from concentration-dependent effects and synergism between different ascarosides. The ascarosides are sensed by several types of chemosensory head neurons, including the ASK, ASI, and ADL neurons as well as the male-specific CEM neurons. Ascaroside perception is mediated by diverse families of G-protein coupled membrane receptors that act upstream of conserved signal transduction pathways, including insulin/IGF-1 signaling and transforming growth factor beta (TGF-β) signaling. Biosynthesis of the ascarosides appears to integrate input from several primary metabolic pathways, including peroxisomal β-oxidation of long-chain fatty acids and amino acid catabolism. Life stage, sex, as well as food availability and other environmental factors affect ascaroside biosynthesis, suggesting that ascaroside signaling communicates detailed information about life history and metabolic state.

  6. Linear Frequency Modulated Signals VS Orthogonal Frequency Division Multiplexing Signals for Synthetic Aperture Radar Systems

    Science.gov (United States)

    2014-06-01

    FREQUENCY MODULATED SIGNALS VS ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SIGNALS FOR SYNTHETIC APERTURE RADAR SYSTEMS by Sade A. Holder June...SIGNALS VS ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SIGNALS FOR SYNTHETIC APERTURE RADAR SYSTEMS 5. FUNDING NUMBERS 6. AUTHOR(S) Sade A. Holder 7...OFDM) signal versus a linear frequency modulated or chirp signal on simulated synthetic aperture radar (SAR) imagery. Various parameters of the

  7. Signal processing for remote sensing

    CERN Document Server

    Chen, CH

    2007-01-01

    Written by leaders in the field, Signal Processing for Remote Sensing explores the data acquisitions segment of remote sensing. Each chapter presents a major research result or the most up to date development of a topic. The book includes a chapter by Dr. Norden Huang, inventor of the Huang-Hilbert transform who, along with and Dr. Steven Long discusses the application of the transform to remote sensing problems. It also contains a chapter by Dr. Enders A. Robinson, who has made major contributions to seismic signal processing for over half a century, on the basic problem of constructing seism

  8. WAVELET ANALYSIS OF MODULATED SIGNALS

    Institute of Scientific and Technical Information of China (English)

    Hu Jianwei; Yang Shaoquan

    2006-01-01

    The relationship between Haar wavelet decomposition coefficients and modulated signal parameters is discussed. A new modulation classification method is presented. The new method uses the amplitude,frequency and phase information derived from Haar wavelet decomposition as feature vectors to distinguish the modulation types of M-ary Frequency-Shift Keying (MFSK), M-ary Phase-Shift Keying (MPSK) and Quadrature Amplitude Modulation (QAM) modulation types. A parallel combined classifier is designed based on these feature vectors. The overall successful recognition rate of 92.4% can be achieved even at a low Signal-to-Noise Ratio (SNR) of 5dB.

  9. Chaotic signals in digital communications

    CERN Document Server

    Eisencraft, Marcio; Suyama, Ricardo

    2013-01-01

    Chaotic Signals in Digital Communications combines fundamental background knowledge with state-of-the-art methods for using chaotic signals and systems in digital communications. The book builds a bridge between theoretical works and practical implementation to help researchers attain consistent performance in realistic environments. It shows the possible shortcomings of the chaos-based communication systems proposed in the literature, particularly when they are subjected to non-ideal conditions. It also presents a toolbox of techniques for researchers working to actually implement such system

  10. PSpice for digital signal processing

    CERN Document Server

    Tobin, Paul

    2007-01-01

    PSpice for Digital Signal Processing is the last in a series of five books using Cadence Orcad PSpice version 10.5 and introduces a very novel approach to learning digital signal processing (DSP). DSP is traditionally taught using Matlab/Simulink software but has some inherent weaknesses for students particularly at the introductory level. The 'plug in variables and play' nature of these software packages can lure the student into thinking they possess an understanding they don't actually have because these systems produce results quicklywithout revealing what is going on. However, it must be

  11. Signal processing for cognitive radios

    CERN Document Server

    Jayaweera, Sudharman K

    2014-01-01

    This book covers power electronics, in depth, by presenting the basic principles and application details, and it can be used both as a textbook and reference book.  Introduces the specific type of CR that has gained the most research attention in recent years: the CR for Dynamic Spectrum Access (DSA). Provides signal processing solutions to each task by relating the tasks to materials covered in Part II. Specialized chapters then discuss specific signal processing algorithms required for DSA and DSS cognitive radios  

  12. Purinergic signaling at immunological synapses.

    Science.gov (United States)

    Dubyak, G R

    2000-07-01

    The early studies and hypotheses of Geoffrey Burnstock catalyzed intensive characterization of roles for nucleotides and P2 nucleotide receptors in neurotransmission and neuromodulation. These latter analyses have focused on the mechanisms of nucleotide release and action in the microenvironments of nerve endings and synapses. However, studies of various white blood cells, such as monocytes, neutrophils, and lymphocytes, suggest that locally released nucleotides also modulate intercellular signaling at so-called 'immunological synapses'. This communication describes recent findings and speculations regarding nucleotide release and signaling in several key phases of the immune and inflammatory responses.

  13. Supersymmetric photonic signals at LEP

    CERN Document Server

    López, J; Zichichi, Antonino

    1996-01-01

    We explore and contrast the single-photon and diphoton signals expected at LEP 2, that arise from neutralino-gravitino (e^+ e^- -> chi + gravitino -> gamma + E_miss) and neutralino-neutralino (e^+ e^- -> chi + chi -> gamma + gamma + E_miss) production in supersymmetric models with a light gravitino. LEP 1 limits imply that one may observe either one, but not both, of these signals at LEP 2, depending on the values of the neutralino and gravitino masses: single-photons for m_chi > Mz and m_gravitino < 3 x 10^-5 eV; diphotons for m_chi < Mz and all allowed values of m_gravitino.

  14. Mono-static GPR without transmitting anything for pavement damage inspection: interferometry by auto-correlation applied to mobile phone signals

    Science.gov (United States)

    Feld, R.; Slob, E. C.; Thorbecke, J.

    2015-12-01

    Creating virtual sources at locations where physical receivers have measured a response is known as seismic interferometry. A much appreciated benefit of interferometry is its independence of the actual source locations. The use of ambient noise as actual source is therefore not uncommon in this field. Ambient noise can be commercial noise, like for example mobile phone signals. For GPR this can be useful in cases where it is not possible to place a source, for instance when it is prohibited by laws and regulations. A mono-static GPR antenna can measure ambient noise. Interferometry by auto-correlation (AC) places a virtual source on this antenna's position, without actually transmitting anything. This can be used for pavement damage inspection. Earlier work showed very promising results with 2D numerical models of damaged pavement. 1D and 2D heterogeneities were compared, both modelled in a 2D pavement world. In a 1D heterogeneous model energy leaks away to the sides, whereas in a 2D heterogeneous model rays can reflect and therefore still add to the signal reconstruction (see illustration). In the first case the amount of stationary points is strictly limited, while in the other case the amount of stationary points is very large. We extend these models to a 3D world and optimise an experimental configuration. The illustration originates from the journal article under submission 'Non-destructive pavement damage inspection by mono-static GPR without transmitting anything' by R. Feld, E.C. Slob, and J.W. Thorbecke. (a) 2D heterogeneous pavement model with three irregular-shaped misalignments between the base and subbase layer (marked by arrows). Mono-antenna B-scan positions are shown schematically. (b) Ideal output: a real source at the receiver's position. The difference w.r.t. the trace found in the middle is shown. (c) AC output: a virtual source at the receiver's position. There is a clear overlap with the ideal output.

  15. Loco signaling pathway in longevity.

    Science.gov (United States)

    Lin, Yuh-Ru; Parikh, Hardik; Park, Yongkyu

    2011-05-01

    Despite the various roles of regulator of G protein signaling (RGS) protein in the G protein signaling pathway that have been defined, the function of RGS has not been characterized in longevity signaling pathways. We found that reduced expression of Loco, a Drosophila RGS protein, resulted in a longer lifespan of flies with stronger resistance to stress, higher MnSOD activity and increased fat content. In contrast, overexpression of the loco gene shortened the fly lifespan significantly, lowered stress resistance and reduced fat content, also indicating that the RGS domain containing GTPase-activating protein (GAP) activity is related to the regulation of longevity. Interestingly, expressional changes of yeast RGS2 and rat RGS14, homologs to the fly Loco, also affected oxidative stress resistance and longevity in the respective species. It is known that Loco inactivates inhibitory Gαi•GTP protein to reduce activity of adenylate cyclase (AC) and RGS14 interacts with activated H-Ras and Raf-1 kinases, which subsequently inhibits ERK phosphorylation. We propose that Loco/RGS14 protein may regulate stress resistance and longevity as an activator in AC-cAMP-PKA pathway and/or as a molecular scaffold that sequesters active Ras and Raf from Ras•GTP-Raf-MEK-ERK signaling pathway. Consistently, our data showed that downregulation of Loco significantly diminishes cAMP amounts and increases p-ERK levels with higher resistance to the oxidative stress.

  16. Velocimetry signal synthesis with fringen.

    Energy Technology Data Exchange (ETDEWEB)

    Dolan, Daniel H., III

    2011-02-01

    An important part of velocimetry analysis is the recovery of a known velocity history from simulated data signals. The fringen program synthesizes VISAR and PDV signals, given a specified velocity history, using exact formulations for the optical signal. Time-dependent light conditions, non-ideal measurement conditions, and various diagnostic limitations (noise, etc.) may be incorporated into the simulated signals. This report describes the fringen program, which performs forward VISAR (Velocity Interferometer System for Any Reflector) and PDV (Photonic Doppler Velocimetry, also known as heterodyne velocimetry) analysis. Nearly all effects that might occur in VISAR/PDV measurement of a single velocity can be modeled by fringen. The program operates in MATLAB, either within a graphical interface or as a user-callable function. The current stable version of fringen is 0.3, which was released in October 2010. The following sections describe the operation and use of fringen. Section 2 gives a brief overview of VISAR and PDV synthesis. Section 3 illustrates the graphical and console interface of fringen. Section 4 presents several example uses of the program. Section 5 summarizes program capabilities and discusses potential future work.

  17. EUROmediCAT signal detection

    DEFF Research Database (Denmark)

    Given, Joanne E; Loane, Maria; Luteijn, Johannes Michiel

    2016-01-01

    AIMS: To evaluate congenital anomaly (CA)-medication exposure associations produced by the new EUROmediCAT signal detection system and determine which require further investigation. METHODS: Data from 15 EUROCAT registries (1995-2011) with medication exposures at the chemical substance (5th level...

  18. Queen signaling in social wasps

    DEFF Research Database (Denmark)

    van Zweden, Jelle Stijn; Bonckaert, Wim; Wenseleers, Tom;

    2014-01-01

    saxonica, queens emit reliable chemical cues of their true fertility and that these putative queen signals decrease as the colony develops and worker reproduction increases. Moreover, these putative pheromones of D. saxonica show significant conservation with those of Vespula vulgaris and other Vespinae...

  19. Signals Intelligence - Processing - Analysis - Classification

    Science.gov (United States)

    2009-10-01

    Example: Language identification from audio signals. In a certain mission, a set of languages seems important beforehand. These languages will – with a...tasks to be performed. • OCR: determine the text parts in an image – language dependent approach, quality depends on the language. • Steganography

  20. The Signaling Theory of Symptoms

    Directory of Open Access Journals (Sweden)

    Leander Steinkopf

    2015-08-01

    Full Text Available Placebo research shows that the subjective quality of care and social support, as well as the patients’ expectations of treatment, influence therapeutic outcomes. However, this phenomenon, known as the placebo effect, does not usually cure the disease, but rather can provide symptomatic relief: It may soothe symptoms such as pain, swelling, or nausea that constitute part of an immune response. The function of this mechanism remains unclear. This article puts forward the Signaling Theory of Symptoms (STS as a possible explanation. According to STS, discernible aspects of an immune response, such as pain, swelling, or nausea, not only serve a defensive and healing function but also a signaling function: symptoms signal the need for care and treatment to potential helpers. Once help and treatment are granted, the signaling function is fulfilled and the symptoms diminish. This mechanism may have been a significant advantage in preindustrial environments, when sufferers depended on extensive social support and personal treatment. Nowadays, from the point of view of modern materialist medicine, the mobilization of social support no longer seems so crucial, and thus the placebo effect has been assigned a somewhat mysterious quality.

  1. Handbook of signal processing systems

    CERN Document Server

    Bhattacharyya, Shuvra S; Leupers, Rainer; Takala, Jarmo

    2010-01-01

    The Handbook is organized in four parts. The first part motivates representative applications that drive and apply state-of-the art methods for design and implementation of signal processing systems; the second part discusses architectures for implementing these applications; the third part focuses on compilers and simulation tools; and the fourth part describes models of computation and their associated design tools and methodologies.

  2. Signal Processing for Optical Networks

    Science.gov (United States)

    2007-11-02

    understanding and enhancing a number of important recent wavelet-based and DCT- based image coders. We show that Shapiro’s well-known EZW scheme, Said and...comparable to Shapiro’s EZW coder (J. M. Shapiro, "Embedded image coding using zerotrees of wavelet coefficients", IEEE Trans, on Signal Processing, v. 41

  3. Meeting Report: Teaching Signal Transduction

    Science.gov (United States)

    Kramer, IJsbrand; Thomas, Geraint

    2006-01-01

    In July, 2005, the European Institute of Chemistry and Biology at the campus of the University of Bordeaux, France, hosted a focused week of seminars, workshops, and discussions around the theme of "teaching signal transduction." The purpose of the summer school was to offer both junior and senior university instructors a chance to reflect on the…

  4. Text Signals Influence Team Artifacts

    Science.gov (United States)

    Clariana, Roy B.; Rysavy, Monica D.; Taricani, Ellen

    2015-01-01

    This exploratory quasi-experimental investigation describes the influence of text signals on team visual map artifacts. In two course sections, four-member teams were given one of two print-based text passage versions on the course-related topic "Social influence in groups" downloaded from Wikipedia; this text had two paragraphs, each…

  5. Biophysical Aspects of Transmembrane Signaling

    CERN Document Server

    Damjanovich, Sandor

    2005-01-01

    Transmembrane signaling is one of the most significant cell biological events in the life and death of cells in general and lymphocytes in particular. Until recently biochemists and biophysicists were not accustomed to thinking of these processes from the side of a high number of complex biochemical events and an equally high number of physical changes at molecular and cellular levels at the same time. Both types of researchers were convinced that their findings are the most decisive, having higher importance than the findings of the other scientist population. Both casts were wrong. Life, even at cellular level, has a number of interacting physical and biochemical mechanisms, which finally build up the creation of an "excited" cell that will respond to particular signals from the outer or inner world. This book handles both aspects of the signalling events, and in some cases tries to unify our concepts and help understand the signals that govern the life and death of our cells. Not only the understanding, bu...

  6. Mathematical Modelling Plant Signalling Networks

    KAUST Repository

    Muraro, D.

    2013-01-01

    During the last two decades, molecular genetic studies and the completion of the sequencing of the Arabidopsis thaliana genome have increased knowledge of hormonal regulation in plants. These signal transduction pathways act in concert through gene regulatory and signalling networks whose main components have begun to be elucidated. Our understanding of the resulting cellular processes is hindered by the complex, and sometimes counter-intuitive, dynamics of the networks, which may be interconnected through feedback controls and cross-regulation. Mathematical modelling provides a valuable tool to investigate such dynamics and to perform in silico experiments that may not be easily carried out in a laboratory. In this article, we firstly review general methods for modelling gene and signalling networks and their application in plants. We then describe specific models of hormonal perception and cross-talk in plants. This mathematical analysis of sub-cellular molecular mechanisms paves the way for more comprehensive modelling studies of hormonal transport and signalling in a multi-scale setting. © EDP Sciences, 2013.

  7. Decomposition of indwelling EMG signals.

    Science.gov (United States)

    Nawab, S Hamid; Wotiz, Robert P; De Luca, Carlo J

    2008-08-01

    Decomposition of indwelling electromyographic (EMG) signals is challenging in view of the complex and often unpredictable behaviors and interactions of the action potential trains of different motor units that constitute the indwelling EMG signal. These phenomena create a myriad of problem situations that a decomposition technique needs to address to attain completeness and accuracy levels required for various scientific and clinical applications. Starting with the maximum a posteriori probability classifier adapted from the original precision decomposition system (PD I) of LeFever and De Luca (25, 26), an artificial intelligence approach has been used to develop a multiclassifier system (PD II) for addressing some of the experimentally identified problem situations. On a database of indwelling EMG signals reflecting such conditions, the fully automatic PD II system is found to achieve a decomposition accuracy of 86.0% despite the fact that its results include low-amplitude action potential trains that are not decomposable at all via systems such as PD I. Accuracy was established by comparing the decompositions of indwelling EMG signals obtained from two sensors. At the end of the automatic PD II decomposition procedure, the accuracy may be enhanced to nearly 100% via an interactive editor, a particularly significant fact for the previously indecomposable trains.

  8. VLSI mixed signal processing system

    Science.gov (United States)

    Alvarez, A.; Premkumar, A. B.

    1993-01-01

    An economical and efficient VLSI implementation of a mixed signal processing system (MSP) is presented in this paper. The MSP concept is investigated and the functional blocks of the proposed MSP are described. The requirements of each of the blocks are discussed in detail. A sample application using active acoustic cancellation technique is described to demonstrate the power of the MSP approach.

  9. Calcium signaling in neocortical development.

    Science.gov (United States)

    Uhlén, Per; Fritz, Nicolas; Smedler, Erik; Malmersjö, Seth; Kanatani, Shigeaki

    2015-04-01

    The calcium ion (Ca(2+) ) is an essential second messenger that plays a pivotal role in neurogenesis. In the ventricular zone (VZ) of the neocortex, neural stem cells linger to produce progenitor cells and subsequently neurons and glial cells, which together build up the entire adult brain. The radial glial cells, with their characteristic radial fibers that stretch from the inner ventricular wall to the outer cortex, are known to be the neural stem cells of the neocortex. Migrating neurons use these radial fibers to climb from the proliferative VZ in the inner part of the brain to the outer layers of the cortex, where differentiation processes continue. To establish the complex structures that constitute the adult cerebral cortex, proliferation, migration, and differentiation must be tightly controlled by various signaling events, including cytosolic Ca(2+) signaling. During development, cells regularly exhibit spontaneous Ca(2+) activity that stimulates downstream effectors, which can elicit these fundamental cell processes. Spontaneous Ca(2+) activity during early neocortical development depends heavily on gap junctions and voltage dependent Ca(2+) channels, whereas later in development neurotransmitters and synapses exert an influence. Here, we provide an overview of the literature on Ca(2+) signaling and its impact on cell proliferation, migration, and differentiation in the neocortex. We point out important historical studies and review recent progress in determining the role of Ca(2+) signaling in neocortical development.

  10. Insulin Signalling: The Inside Story.

    Science.gov (United States)

    Posner, Barry I

    2017-02-01

    Insulin signalling begins with binding to its cell surface insulin receptor (IR), which is a tyrosine kinase. The insulin receptor kinase (IRK) is subsequently autophosphorylated and activated to tyrosine phosphorylate key cellular substrates that are essential for entraining the insulin response. Although IRK activation begins at the cell surface, it is maintained and augmented following internalization into the endosomal system (ENS). The peroxovanadium compounds (pVs) were discovered to activate the IRK in the absence of insulin and lead to a full insulin response. Thus, IRK activation is both necessary and sufficient for insulin signalling. Furthermore, this could be shown to occur with activation of only the endosomal IRK. The mechanism of pV action was shown to be the inhibition of IRK-associated phosphotyrosine phosphatases (PTPs). Our studies showed that the duration and intensity of insulin signalling are modulated within ENS by the recruitment of cellular substrates to ENS; intra-endosomal acidification, which promotes dissociation of insulin from the IRK; an endosomal acidic insulinase, which degrades intra-endosomal insulin; and IRK-associated PTPs, which dephosphorylate and, hence, deactivate the IRK. Therefore, the internalization of IRKs is central to insulin signalling and its regulation.

  11. On the Spectrum of Periodic Signals

    Science.gov (United States)

    Al-Smadi, Adnan

    2004-01-01

    In theory, there are many methods for the representation of signals. In practice, however, Fourier analysis involving the resolution of signals into sinusoidal components is used widely. There are several methods for Fourier analysis available for representation of signals. If the signal is periodic, then the Fourier series is used to represent…

  12. Science Signaling Podcast for 7 June 2016: Modeling signal integration.

    Science.gov (United States)

    Janes, Kevin A; VanHook, Annalisa M

    2016-06-07

    This Podcast features an interview with Kevin Janes, senior author of a Research Article that appears in the 7 June 2016 issue of Science Signaling, about a statistical modeling method that can extract useful information from complex data sets. Cells exist in very complex environments. They are constantly exposed to growth factors, hormones, nutrients, and many other factors that influence cellular behavior. When cells integrate information from multiple stimuli, the resulting output does not necessarily reflect a simple additive effect of the responses to each individual stimulus. Chitforoushzadeh et al employed a statistical modeling approach that maintained the multidimensional nature of the data to analyze the responses of colonic epithelial cells to various combinations of the proinflammatory cytokine TNF, the growth factor EGF, and insulin. As the model predicted, experiments confirmed that insulin suppressed TNF-induced proinflammatory signaling through a mechanism that involved the transcription factor GATA6.Listen to Podcast.

  13. Dynamic range control of audio signals by digital signal processing

    Science.gov (United States)

    Gilchrist, N. H. C.

    It is often necessary to reduce the dynamic range of musical programs, particularly those comprising orchestral and choral music, for them to be received satisfactorily by listeners to conventional FM and AM broadcasts. With the arrival of DAB (Digital Audio Broadcasting) a much wider dynamic range will become available for radio broadcasting, although some listeners may prefer to have a signal with a reduced dynamic range. This report describes a digital processor developed by the BBC to control the dynamic range of musical programs in a manner similar to that of a trained Studio Manager. It may be used prior to transmission in conventional broadcasting, replacing limiters or other compression equipment. In DAB, it offers the possibility of providing a dynamic range control signal to be sent to the receiver via an ancillary data channel, simultaneously with the uncompressed audio, giving the listener the option of the full dynamic range or a reduced dynamic range.

  14. Reconstruction of harmonic signals based on bispectrum

    Institute of Scientific and Technical Information of China (English)

    FAN Yangyu; SUN Jincai; LI Pingan; XU Jiadong; SHANG Jiuhao

    2000-01-01

    A method for accurate reconstruction of the harmonic signals from bispectrum is presented. Based on the analysis of the measured harmonic signal, a sinusoid signal with 0phase, 1-amplitude and half of the fundamental frequency combines with the measured signal to form a combined signal, and then the bispectrum analysis is carried out to reconstruct the phase and the amplitude of the measured signal accurately. Without the zero-phase assumption of the fundamental component, using the new method eliminates the phase shifting between the calculated Fourier phase and the true Fourier phase in the existing signal retrieval methods based on bispectrum. The simulation results show the effectiveness of the new method.

  15. Neural network signal understanding for instrumentation

    DEFF Research Database (Denmark)

    Pau, L. F.; Johansen, F. S.

    1990-01-01

    A report is presented on the use of neural signal interpretation theory and techniques for the purpose of classifying the shapes of a set of instrumentation signals, in order to calibrate devices, diagnose anomalies, generate tuning/settings, and interpret the measurement results. Neural signal......, and an explanation facility designed to help neural signal understanding is described. The results are compared to those obtained with a knowledge-based signal interpretation system using the same instrument and data...

  16. Hydrogen sulfide in signaling pathways.

    Science.gov (United States)

    Olas, Beata

    2015-01-15

    For a long time hydrogen sulfide (H₂S) was considered a toxic compound, but recently H₂S (at low concentrations) has been found to play an important function in physiological processes. Hydrogen sulfide, like other well-known compounds - nitric oxide (NO) and carbon monoxide (CO) is a gaseous intracellular signal transducer. It regulates the cell cycle, apoptosis and the oxidative stress. Moreover, its functions include neuromodulation, regulation of cardiovascular system and inflammation. In this review, I focus on the metabolism of hydrogen sulfide (including enzymatic pathways of H₂S synthesis from l- and d-cysteine) and its signaling pathways in the cardiovascular system and the nervous system. I also describe how hydrogen sulfide may be used as therapeutic agent, i.e. in the cardiovascular diseases.

  17. Acoustic Localization with Infrasonic Signals

    Science.gov (United States)

    Threatt, Arnesha; Elbing, Brian

    2015-11-01

    Numerous geophysical and anthropogenic events emit infrasonic frequencies (wind turbines and tornadoes. These sounds, which cannot be heard by the human ear, can be detected from large distances (in excess of 100 miles) due to low frequency acoustic signals having a very low decay rate in the atmosphere. Thus infrasound could be used for long-range, passive monitoring and detection of these events. An array of microphones separated by known distances can be used to locate a given source, which is known as acoustic localization. However, acoustic localization with infrasound is particularly challenging due to contamination from other signals, sensitivity to wind noise and producing a trusted source for system development. The objective of the current work is to create an infrasonic source using a propane torch wand or a subwoofer and locate the source using multiple infrasonic microphones. This presentation will present preliminary results from various microphone configurations used to locate the source.

  18. Nuclear sensor signal processing circuit

    Science.gov (United States)

    Kallenbach, Gene A.; Noda, Frank T.; Mitchell, Dean J.; Etzkin, Joshua L.

    2007-02-20

    An apparatus and method are disclosed for a compact and temperature-insensitive nuclear sensor that can be calibrated with a non-hazardous radioactive sample. The nuclear sensor includes a gamma ray sensor that generates tail pulses from radioactive samples. An analog conditioning circuit conditions the tail-pulse signals from the gamma ray sensor, and a tail-pulse simulator circuit generates a plurality of simulated tail-pulse signals. A computer system processes the tail pulses from the gamma ray sensor and the simulated tail pulses from the tail-pulse simulator circuit. The nuclear sensor is calibrated under the control of the computer. The offset is adjusted using the simulated tail pulses. Since the offset is set to zero or near zero, the sensor gain can be adjusted with a non-hazardous radioactive source such as, for example, naturally occurring radiation and potassium chloride.

  19. Notch Signaling in Neuroendocrine Tumors

    Directory of Open Access Journals (Sweden)

    Judy Sue Crabtree

    2016-04-01

    Full Text Available Carcinoids and neuroendocrine tumors (NETs are a heterogeneous group of tumors that arise from the neuroendocrine cells of the GI tract, endocrine pancreas and the respiratory system. NETs remain significantly understudied with respect to molecular mechanisms of pathogenesis, particularly the role of cell fate signaling systems like Notch. The abundance of literature on the Notch pathway is a testament to its complexity in different cellular environments. Notch receptors can function as oncogenes in some contexts, and tumor suppressors in others. The genetic heterogeneity of NETs suggests that to fully understand the roles and the potential therapeutic implications of Notch signaling in NETs, a comprehensive analysis of Notch expression patterns and potential roles across all NET subtypes is required.

  20. Multimedia signal coding and transmission

    CERN Document Server

    Ohm, Jens-Rainer

    2015-01-01

    This textbook covers the theoretical background of one- and multidimensional signal processing, statistical analysis and modelling, coding and information theory with regard to the principles and design of image, video and audio compression systems. The theoretical concepts are augmented by practical examples of algorithms for multimedia signal coding technology, and related transmission aspects. On this basis, principles behind multimedia coding standards, including most recent developments like High Efficiency Video Coding, can be well understood. Furthermore, potential advances in future development are pointed out. Numerous figures and examples help to illustrate the concepts covered. The book was developed on the basis of a graduate-level university course, and most chapters are supplemented by exercises. The book is also a self-contained introduction both for researchers and developers of multimedia compression systems in industry.

  1. Ambient temperature signalling in plants.

    Science.gov (United States)

    Wigge, Philip A

    2013-10-01

    Plants are exposed to daily and seasonal fluctuations in temperature. Within the 'ambient' temperature range (about 12-27°C for Arabidopsis) temperature differences have large effects on plant growth and development, disease resistance pathways and the circadian clock without activating temperature stress pathways. It is this developmental sensing and response to non-stressful temperatures that will be covered in this review. Recent advances have revealed key players in mediating temperature signals. The bHLH transcription factor PHYTOCHROME INTERACTING FACTOR4 (PIF4) has been shown to be a hub for multiple responses to warmer temperature in Arabidopsis, including flowering and hypocotyl elongation. Changes in chromatin state are involved in transmitting temperature signals to the transcriptome. Determining the precise mechanisms of temperature perception represents an exciting goal for the field.

  2. Acoustic vector sensor signal processing

    Institute of Scientific and Technical Information of China (English)

    SUN Guiqing; LI Qihu; ZHANG Bin

    2006-01-01

    Acoustic vector sensor simultaneously, colocately and directly measures orthogonal components of particle velocity as well as pressure at single point in acoustic field so that is possible to improve performance of traditional underwater acoustic measurement devices or detection systems and extends new ideas for solving practical underwater acoustic engineering problems. Although acoustic vector sensor history of appearing in underwater acoustic area is no long, but with huge and potential military demands, acoustic vector sensor has strong development trend in last decade, it is evolving into a one of important underwater acoustic technology. Under this background, we try to review recent progress in study on acoustic vector sensor signal processing, such as signal detection, DOA estimation, beamforming, and so on.

  3. Calcium signaling in lacrimal glands.

    Science.gov (United States)

    Putney, James W; Bird, Gary S

    2014-06-01

    Lacrimal glands provide the important function of lubricating and protecting the ocular surface. Failure of proper lacrimal gland function results in a number of debilitating dry eye diseases. Lacrimal glands secrete lipids, mucins, proteins, salts and water and these secretions are at least partially regulated by neurotransmitter-mediated cell signaling. The predominant signaling mechanism for lacrimal secretion involves activation of phospholipase C, generation of the Ca(2+)-mobilizing messenger, IP3, and release of Ca(2+) stored in the endoplasmic reticulum. The loss of Ca(2+) from the endoplasmic reticulum then triggers a process known as store-operated Ca(2+) entry, involving a Ca(2+) sensor in the endoplasmic reticulum, STIM1, which activates plasma membrane store-operated channels comprised of Orai subunits. Recent studies with deletions of the channel subunit, Orai1, confirm the important role of SOCE in both fluid and protein secretion in lacrimal glands, both in vivo and in vitro.

  4. Low power digital signal processing

    DEFF Research Database (Denmark)

    Paker, Ozgun

    2003-01-01

    This thesis introduces a novel approach to programmable and low power platform design for audio signal processing, in particular hearing aids. The proposed programmable platform is a heterogeneous multiprocessor architecture consisting of small and simple instruction set processors called mini...... data addressing capabilities lead to the design of low power mini-cores. The algorithm suite also consisted of less demanding and/or irregular algorithms (LMS, compression) that required subsample rate signal processing justifying the use of a DSP/CPU-core. The thesis also contributes to the recent...... trend in the development of intellectual property based design methodologies. The actual mini-core designs are parameterized in word-size, memory-size, etc. and can be instantiated according to the needs of the application at hand. They are intended as low power programmable building blocks...

  5. Signalling pathways in pemphigus vulgaris.

    Science.gov (United States)

    Li, Xiaoguang; Ishii, Norito; Ohata, Chika; Furumura, Minao; Hashimoto, Takashi

    2014-03-01

    Acantholysis in pemphigus vulgaris is induced by binding of autoantibodies to desmoglein 3 (Dsg3). The roles of signalling pathways on development of acantholysis have recently been extensively studied. In the study by Sayar et al., recently published in Exp Dermatol, epidermal growth factor receptor (EGFR) signalling was activated in both in vivo and in vitro pemphigus vulgaris experimental models. However, while EGFR inhibitors suppressed activity of p38 mitogen-activated protein kinase (p38MAPK) linearly, they suppressed activity of c-Myc and acantholysis in a non-linear, V-shaped relationship. These findings indicated complicated interactions among EGFR, p38MAPK and c-Myc in pemphigus vulgaris pathology.

  6. Leaf-produced floral signals.

    Science.gov (United States)

    Zeevaart, Jan A D

    2008-10-01

    Florigen is the hypothetical leaf-produced signal that induces floral initiation at the shoot apex. The nature of florigen has remained elusive for more than 70 years. But recent progress toward understanding the regulatory network for flowering in Arabidopsis has led to the suggestion that FLOWERING LOCUS T (FT) or its product is the mobile flower-inducing signal that moves from an induced leaf through the phloem to the shoot apex. In the past year, physical and chemical evidence has shown that it is FT protein, and not FT mRNA, that moves from induced leaves to the apical meristem. These results have established that FT is the main, if not the only, component of the universal florigen.

  7. The IRS-1 signaling system.

    Science.gov (United States)

    Myers, M G; Sun, X J; White, M F

    1994-07-01

    Insulin-receptor substrate 1 (IRS-1) is a principal substrate of the receptor tyrosine kinase for insulin and insulin-like growth factor 1, and a substrate for a tyrosine kinase activated by interleukin 4. IRS-1 undergoes multisite tyrosine phosphorylation and mediates downstream signals by 'docking' various proteins that contain Src homology 2 domains. IRS-1 appears to be a unique molecule; however, 4PS, a protein found mainly in hemopoietic cells, may represent another member of this family.

  8. SnapShot: Interferon Signaling.

    Science.gov (United States)

    Chow, Kwan T; Gale, Michael

    2015-12-17

    Interferons (IFNs) are crucial cytokines of antimicrobial, antitumor, and immunomodulatory activity. The three types of IFN (I, II, and III) are classified by their receptor specificity and sequence homology. IFNs are produced and secreted by cells in response to specific stimuli. Here, we review the subsequent IFN signaling events occurring through unique receptors leading to regulation of gene expression for modulation of innate and adaptive immunity. To view this SnapShot, open or download the PDF.

  9. CMOS Nonlinear Signal Processing Circuits

    OpenAIRE

    2010-01-01

    The chapter describes various nonlinear signal processing CMOS circuits, including a high reliable WTA/LTA, simple MED cell, and low-voltage arbitrary order extractor. We focus the discussion on CMOS analog circuit design with reliable, programmable capability, and low voltage operation. It is a practical problem when the multiple identical cells are required to match and realized within a single chip using a conventional process. Thus, the design of high-reliable circuit is indeed needed. Th...

  10. Cell Polarity Signaling in Arabidopsis

    OpenAIRE

    Yang, Zhenbiao

    2008-01-01

    Cell polarization is intimately linked to plant development, growth, and responses to the environment. Major advances have been made in our understanding of the signaling pathways and networks that regulate cell polarity in plants owing to recent studies on several model systems, e.g., tip growth in pollen tubes, cell morphogenesis in the leaf epidermis, and polar localization of PINs. From these studies we have learned that plant cells use conserved mechanisms such as Rho family GTPases to i...

  11. Leptin signaling and leptin resistance

    OpenAIRE

    Zhou, Yingjiang; Rui, Liangyou

    2013-01-01

    Leptin is secreted into the bloodstream by adipocytes and is required for the maintenance of energy homeostasis and body weight. Leptin deficiency or genetic defects in the components of the leptin signaling pathways causes obesity. Leptin controls energy balance and body weight primarily by targeting LEPRb-expressing neurons in the brain, particularly in the hypothalamus. These LEPRb-expressing neurons function as the first-order neurons that project to the second-order neurons located withi...

  12. Signalling properties of lysophosphatidic acid.

    Science.gov (United States)

    Durieux, M E; Lynch, K R

    1993-06-01

    Lysophosphatidic acid (LPA) is the simplest natural phospholipid, primarily known as a membrane component and metabolic intermediate. However, a remarkable variety of biological effects of this compound have come to light, seemingly pointing to an additional role for LPA as a signalling molecule. In this review, Marcel Durieux and Kevin Lynch integrate the recent information that indicates that LPA could be an intercellular messenger, possibly acting through a G protein-coupled receptor, and with a role in cell growth and motility.

  13. Detection of signals in noise

    CERN Document Server

    McDonough, Robert N

    1995-01-01

    The Second Edition is an updated revision to the authors highly successful and widely used introduction to the principles and application of the statistical theory of signal detection. This book emphasizes those theories that have been found to be particularly useful in practice including principles applied to detection problems encountered in digital communications, radar, and sonar.Detection processing based upon the fast Fourier transform

  14. Engineering Cell-Cell Signaling

    OpenAIRE

    Blagovic, Katarina; Gong, Emily S.; Milano, Daniel F.; Natividad, Robert J.; Asthagiri, Anand R

    2013-01-01

    Juxtacrine cell-cell signaling mediated by the direct interaction of adjoining mammalian cells is arguably the mode of cell communication that is most recalcitrant to engineering. Overcoming this challenge is crucial for progress in biomedical applications, such as tissue engineering, regenerative medicine, immune system engineering and therapeutic design. Here, we describe the significant advances that have been made in developing synthetic platforms (materials and devices) and synthetic cel...

  15. Neural Network Communications Signal Processing

    Science.gov (United States)

    1994-08-01

    Technical Information Report for the Neural Network Communications Signal Processing Program, CDRL A003, 31 March 1993. Software Development Plan for...track changing jamming conditions to provide the decoder with the best log- likelihood ratio metrics at a given time. As part of our development plan we...Artificial Neural Networks (ICANN-91) Volume 2, June 24-28, 1991, pp. 1677-1680. Kohonen, Teuvo, Raivio, Kimmo, Simula, Oli, Venta , 011i, Henriksson

  16. Cell signalling and phospholipid metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Boss, W.F.

    1990-01-01

    These studies explored whether phosphoinositide (PI) has a role in plants analogous to its role in animal cells. Although no parallel activity of PI in signal transduction was found in plant cells, activity of inositol phospholipid kinase was found to be modulated by light and by cell wall degrading enzymes. These studies indicate a major role for inositol phospholipids in plant growth and development as membrane effectors but not as a source of second messengers.

  17. Signal and image multiresolution analysis

    CERN Document Server

    Ouahabi, Abdelialil

    2012-01-01

    Multiresolution analysis using the wavelet transform has received considerable attention in recent years by researchers in various fields. It is a powerful tool for efficiently representing signals and images at multiple levels of detail with many inherent advantages, including compression, level-of-detail display, progressive transmission, level-of-detail editing, filtering, modeling, fractals and multifractals, etc.This book aims to provide a simple formalization and new clarity on multiresolution analysis, rendering accessible obscure techniques, and merging, unifying or completing

  18. Cell signaling underlying epileptic behavior

    Directory of Open Access Journals (Sweden)

    Yuri eBozzi

    2011-08-01

    Full Text Available Epilepsy is a complex disease, characterized by the repeated occurrence of bursts of electrical activity (seizures in specific brain areas. The behavioral outcome of seizure events strongly depends on the brain regions that are affected by overactivity. Here we review the intracellular signaling pathways involved in the generation of seizures in epileptogenic areas. Pathways activated by modulatory neurotransmitters (dopamine, norepinephrine and serotonin, involving the activation of extracellular-regulated kinases (ERKs and the induction of immediate early genes (IEGs will be first discussed in relation to the occurrence of acute seizure events. Activation of immediate early genes has been proposed to lead to long-term molecular and behavioral responses induced by acute seizures. We also review deleterious consequences of seizure activity, focusing on the contribution of apoptosis-associated signaling pathways to the progression of the disease. A deep understanding of signaling pathways involved in both acute and long-term responses to seizures continues to be crucial to unravel the origins of epileptic behaviors and ultimately identify novel therapeutic targets for the cure of epilepsy.

  19. FGFR signalling in women's cancers.

    Science.gov (United States)

    Fearon, Abbie E; Gould, Charlotte R; Grose, Richard P

    2013-12-01

    FGFs, in a complex with their receptors (FGFRs) and heparan sulfate (HS), are responsible for a range of cellular functions, from embryogenesis to metabolism. Both germ line and somatic FGFR mutations are known to play a role in a range of diseases, most notably craniosynestosis dysplasias, dwarfism and cancer. Because of the ability of FGFR signalling to induce cell proliferation, migration and survival, FGFRs are readily co-opted by cancer cells. Mutations in, and amplifications of, these receptors are found in a range of cancers with some of the most striking clinical findings relating to their contribution to pathogenesis and progression of female cancers. Here, we outline the molecular mechanisms of FGFR signalling and discuss the role of this pathway in women's cancers, focusing on breast, endometrial, ovarian and cervical carcinomas, and their associated preclinical and clinical data. We also address the rationale for therapeutic intervention and the need for FGFR-targeted therapy to selectively target cancer cells in view of the fundamental roles of FGF signalling in normal physiology.

  20. Expected geoneutrino signal at JUNO

    CERN Document Server

    Strati, Virginia; Callegari, Ivan; Mantovani, Fabio; McDonough, William F; Ricci, Barbara; Xhixha, Gerti

    2014-01-01

    Constraints on the Earth's composition and on its radiogenic energy budget come from the detection of geoneutrinos. The KamLAND and Borexino experiments recently reported the geoneutrino flux, which reflects the amount and distribution of U and Th inside the Earth. The KamLAND and Borexino experiments recently reported the geoneutrino flux, which reflects the amount and distribution of U and Th inside the Earth. The JUNO neutrino experiment, designed as a 20 kton liquid scintillator detector, will be built in an underground laboratory in South China about 53 km from the Yangjiang and Taishan nuclear power plants. Given the large detector mass and the intense reactor antineutrino flux, JUNO aims to collect high statistics antineutrino signals from reactors but also to address the challenge of discriminating the geoneutrino signal from the reactor background.The predicted geoneutrino signal at JUNO is 39.7 $^{+6.5}_{-5.2}$ TNU, based on the existing reference Earth model, with the dominant source of uncertainty...

  1. Dynamics in atomic signaling games

    KAUST Repository

    Fox, Michael J.

    2015-04-08

    We study an atomic signaling game under stochastic evolutionary dynamics. There are a finite number of players who repeatedly update from a finite number of available languages/signaling strategies. Players imitate the most fit agents with high probability or mutate with low probability. We analyze the long-run distribution of states and show that, for sufficiently small mutation probability, its support is limited to efficient communication systems. We find that this behavior is insensitive to the particular choice of evolutionary dynamic, a property that is due to the game having a potential structure with a potential function corresponding to average fitness. Consequently, the model supports conclusions similar to those found in the literature on language competition. That is, we show that efficient languages eventually predominate the society while reproducing the empirical phenomenon of linguistic drift. The emergence of efficiency in the atomic case can be contrasted with results for non-atomic signaling games that establish the non-negligible possibility of convergence, under replicator dynamics, to states of unbounded efficiency loss.

  2. Calcium Signals from the Vacuole

    Directory of Open Access Journals (Sweden)

    Gerald Schönknecht

    2013-10-01

    Full Text Available The vacuole is by far the largest intracellular Ca2+ store in most plant cells. Here, the current knowledge about the molecular mechanisms of vacuolar Ca2+ release and Ca2+ uptake is summarized, and how different vacuolar Ca2+ channels and Ca2+ pumps may contribute to Ca2+ signaling in plant cells is discussed. To provide a phylogenetic perspective, the distribution of potential vacuolar Ca2+ transporters is compared for different clades of photosynthetic eukaryotes. There are several candidates for vacuolar Ca2+ channels that could elicit cytosolic [Ca2+] transients. Typical second messengers, such as InsP3 and cADPR, seem to trigger vacuolar Ca2+ release, but the molecular mechanism of this Ca2+ release still awaits elucidation. Some vacuolar Ca2+ channels have been identified on a molecular level, the voltage-dependent SV/TPC1 channel, and recently two cyclic-nucleotide-gated cation channels. However, their function in Ca2+ signaling still has to be demonstrated. Ca2+ pumps in addition to establishing long-term Ca2+ homeostasis can shape cytosolic [Ca2+] transients by limiting their amplitude and duration, and may thus affect Ca2+ signaling.

  3. Ceramide signaling in mammalian epidermis.

    Science.gov (United States)

    Uchida, Yoshikazu

    2014-03-01

    Ceramide, the backbone structure of all sphingolipids, as well as a minor component of cellular membranes, has a unique role in the skin, by forming the epidermal permeability barrier at the extracellular domains of the outermost layer of the skin, the stratum corneum, which is required for terrestrial mammalian survival. In contrast to the role of ceramide in forming the permeability barrier, the signaling roles of ceramide and its metabolites have not yet been recognized. Ceramide and/or its metabolites regulate proliferation, differentiation, and apoptosis in epidermal keratinocytes. Recent studies have further demonstrated that a ceramide metabolite, sphingosine-1-phosphate, modulates innate immune function. Ceramide has already been applied to therapeutic approaches for treatment of eczema associated with attenuated epidermal permeability barrier function. Pharmacological modulation of ceramide and its metabolites' signaling can also be applied to cutaneous disease prevention and therapy. The author here describes the signaling roles of ceramide and its metabolites in mammalian cells and tissues, including the epidermis. This article is part of a Special Issue entitled The Important Role of Lipids in the Epidermis and their Role in the Formation and Maintenance of the Cutaneous Barrier. Guest Editors: Kenneth R. Feingold and Peter Elias.

  4. Calcium Signalling and Liver Regeneration

    Directory of Open Access Journals (Sweden)

    Isabelle Garcin

    2012-01-01

    Full Text Available After partial hepatectomy (PH the initial mass of the organ is restored through a complex network of cellular interactions that orchestrate both proliferative and hepatoprotective signalling cascades. Among agonists involved in this network many of them drive Ca2+ movements. During liver regeneration in the rat, hepatocyte cytosolic Ca2+ signalling has been shown on the one hand to be deeply remodelled and on the other hand to enhance progression of hepatocytes through the cell cycle. Mechanisms through which cytosolic Ca2+ signals impact on hepatocyte cell cycle early after PH are not completely understood, but at least they include regulation of immediate early gene transcription and ERK and CREB phosphorylation. In addition to cytosolic Ca2+, there is also evidence that mitochondrial Ca2+ and also nuclear Ca2+ may be critical for the regulation of liver regeneration. Finally, Ca2+ movements in hepatocytes, and possibly in other liver cells, not only impact hepatocyte progression in the cell cycle but more generally may regulate cellular homeostasis after PH.

  5. 49 CFR 236.514 - Interconnection of cab signal system with roadway signal system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Interconnection of cab signal system with roadway signal system. 236.514 Section 236.514 Transportation Other Regulations Relating to Transportation... Interconnection of cab signal system with roadway signal system. The automatic cab signal system shall...

  6. BLIND COMPUTATION OF A SIGNAL USING SDR

    Directory of Open Access Journals (Sweden)

    M.BHUVANESHWARAN

    2012-05-01

    Full Text Available The most challenging aspect in signal processing is its hardware design. Today we are using multiple signals and each of it is at different frequency. The signal processing unit is a block in which the signal is processed to extract the exact message in the signal and it is mainly used to analyze each and every componentsof a signal. The block which is capable of doing all these things costs much. Thus the design of hardware components necessary to analyze the signal seems to be more difficult hence it needs huge amount of investment. In order to reduce the amount of money invested in the hardware design here in this paper we are presenting a new approach in signal processing called as software defined radio. Here the GNU RADIO acts as a software defined radio software and by using it we had successfully predicted the power, frequency spectrumand its peak amplitude of a speech signal.

  7. Arrow of time and reality in search of a conciliation

    CERN Document Server

    Magnon, A

    1997-01-01

    What is Reality? What is the role of human consciousness in the shaping of such a concept? These questions are as old as mankind and gave rise to the MIND-MATTER dualism which preoccupied so many physicists: Schrödinger, Wigner, etc. This book considers the problem within the realm of contemporary physics, and shows that it could be related to that of ultimate entities. The author develops the viewpoint according to which human thinking activities are fruit of the Cosmos and of its combinatorial activity. Ultimate entities, the bricks out of which our universe is made, could be hidden, as a pr

  8. DNA?RNA: What Do Students Think the Arrow Means?

    Science.gov (United States)

    Wright, L. Kate; Fisk, J. Nick; Newman, Dina L.

    2014-01-01

    The central dogma of molecular biology, a model that has remained intact for decades, describes the transfer of genetic information from DNA to protein though an RNA intermediate. While recent work has illustrated many exceptions to the central dogma, it is still a common model used to describe and study the relationship between genes and protein…

  9. The arrow of electromagnetic time and the generalized absorber theory

    Science.gov (United States)

    Cramer, John G.

    1983-09-01

    The problem of the direction of electromagnetic time, i.e., the complete dominance of retarded electromagnetic radiation over advanced radiation in the universe, is considered in the context of a generalized form of the Wheeler-Feynman absorber theory in an open expanding universe with a singularity at T=0. It is shown that the application of a four-vector reflection boundary condition at the singularity leads to the observed dominance of retarded radiation; it also clarifies the role of advanced and retarded waves in the emission of very weakly absorbed radiation such as neutrinos.

  10. Arrow of electromagnetic time and the generalized absorber theory

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, J.G.

    1983-09-01

    The problem of the direction of electromagnetic time, i.e., the complete dominance of retarded electromagnetic radiation over advanced radiation in the universe, is considered in the context of a generalized form of the Wheeler--Feynman absorber theory in an open expanding universe with a singularity at T = 0. It is shown that the application of a four-vector reflection boundary condition at the singularity leads to the observed dominance of retarded radiation; it also clarifies the role of advanced and retarded waves in the emission of very weakly absorbed radiation such as neutrinos.

  11. Modified Noether theorem and arrow of time in quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Asadov, V V; Kechkin, O V, E-mail: asadov@neurok.co, E-mail: kechkin@gmail.co [Neur OK-III, Lomonosov Moscow State University, Vorob' jovy Gory, 119899 Moscow (Russian Federation)

    2010-06-01

    Relativistic quantum mechanics is presented with modified Noether theorem. It was shown that Noether charges are related with thermodynamic potentials in such scheme. Broken symmetries generated by thermodynamic mode lead to gravity appearance as effective quantum field.

  12. Pythagorean quantization, action(s) and the arrow of time

    Energy Technology Data Exchange (ETDEWEB)

    Schuch, Dieter, E-mail: schuch@em.uni-frankfurt.d [Institut fuer Theoretische Physik, Goethe-Universitaet Frankfurt am Main, Max-von-Laue-Str. 1, D-60438 Frankfurt am Main (Germany)

    2010-06-01

    Searching for the first well-documented attempts of introducing some kind of 'quantization' into the description of nature inevitably leads to the ancient Greeks, in particular Plato and Pythagoras. The question of finding the so-called Pythagorean triples, i.e., right-angled triangles with integer length of all three sides, is, surprisingly, connected with complex nonlinear Riccati equations that occur in time-dependent quantum mechanics. The complex Riccati equation together with the usual Newtonian equation of the system, leads to a dynamical invariant with the dimension of an action. The relation between this invariant and a conserved 'angular momentum' for the motion in the complex plane will be determined. The 'Pythagorean quantization' shows similarities with the quantum Hall effect and leads to an interpretation of Sommerfeld's fine structure constant that involves another quantum of action, the 'least Coulombic action' e{sup 2}/c. Since natural evolution is characterized by irreversibility and dissipation, the question of how these aspects can be incorporated into a quantum mechanical description arises. Two effective approaches that also both possess a dynamical invariant (like the one mentioned above) will be discussed. One uses an explicitly time-dependent (linear) Hamiltonian, whereas the other leads to a nonlinear Schroedinger equation with complex logarithmic nonlinearity. Both approaches can be transformed into each other via a non-unitary transformation that involves Schroedinger's original definition of a (complex) action via the wave function.

  13. Delayed choice experiments, the arrow of time, and quantum measurement

    Science.gov (United States)

    Schulman, L. S.

    2011-11-01

    By a radical modification of statistical mechanics the measurement process of quantum mechanics can be described in terms of pure, unitary time evolution, with no wave function collapse or many-world ideas. The key notion is "special states," rare microscopic states of a complex system. Recovering the standard probabilities requires of this theory the appearance of Cauchy-distributed noise in some measurement processes. This article treats experimental situations where such noise might be detected and correlated with the need or absence of need for special states. Included in this possibility are "delayed choice" experiments, in which the correlation contravenes conventional ideas on causality. Background material on all topics is provided.

  14. Cosmology, Time's Arrow, and That Old Double Standard

    CERN Document Server

    Price, Huw

    2009-01-01

    It is widely accepted that temporal asymmetry is largely a cosmological problem; the task of explaining temporal asymmetry reduces in the main to that of explaining an aspect of the condition of the early universe. However, cosmologists who discuss these issues often make mistakes similar to those that plagued nineteenth century discussions of the statistical foundations of thermodynamics. In particular, they are often guilty of applying temporal "double standards" of various kinds---e.g., in failing to recognise that certain statistical arguments apply with equal force in either temporal direction. This paper aims to clarify the issue as to what would count as adequate explanation of cosmological time asymmetry. A particular concern is the question whether it is possible to explain why entropy is low near the Big Bang without showing that it must also be low near a Big Crunch, in the event that the universe recollapses. I criticise some of the objections raised to this possibility, showing that these too oft...

  15. Arrows of Desire: Dance and Power in Transnational Cinema

    Directory of Open Access Journals (Sweden)

    May Telmissany

    2014-08-01

    Full Text Available Cet article s'intéresse à la pratique de danse orientale en tant qu'expression de la joie et de la puissance féminine célébrée par les réalisateurs de la diaspora arabe et nord-africaine. Associée à l'émancipation de la femme plutôt qu'à son déclin moral, la danse orientale est désormais perçue comme un symbole de la prise de parole subalterne, un site de solidarité féminine et un outil de libération sexuelle. La réhabilitation de la danse orientale dans le cinéma transnational permet de réfléchir sur les dispositifs de désir et de pouvoir comme les principes immanents permettant la réorganisation des forces dans la société. En utilisant le concept des machines désirantes de Deleuze et Guattari, cet article tente d'élucider le rapport problématique entre la danse, le désir et le pouvoir dans quatre films de réalisateurs Nord-Africains vivant en France: Satin Rouge [Raja Amari, Tunisie, 2002], Viva Laldjérie et Délice Paloma [Nadir Moknèche, Algérie, 2004 et 2007], et Whatever Lola Wants [Nabil Ayouch, Maroc, 2007 ; cf. note de l’auteur.

  16. Does time's arrow point in the wrong direction?

    CERN Document Server

    Valentin, A

    2003-01-01

    Perhaps the deepest mystery in all of physics is quantum non-locality - the ability of two distant systems to instantaneously know about each other. Non-locality means that two particles in a quantum system can be 'entangled' such that the state of one particle affects the state of the other, regardless of how far apart they are. As well as challenging our common sense, non-locality suggests that the ultimate speed limit - the speed of light - is violated. Einstein spent many years worrying about this problem because such 'superluminal' interactions seem to be incompatible with special relativity. Now Sheldon Goldstein at Rutgers University in the US and Roderich Tumulka at the University of Munich in Germany think they might have found a way to reconcile quantum non-locality and relativity. But their idea is far from conventional. (U.K.)

  17. Lake Elsinore disaster: The slings and arrows of outrageous fortune.

    Science.gov (United States)

    Sutphen, S

    1983-09-01

    A case study of a flood which occurred at Lake Elsinore, California, February, 1980, focuses upon the assistance which the community received during both the flood and recovery periods. Relevant literature on disaster research is examined, including a model of disaster recovery, and the study places the events which occurred din Lake Elsinore within that recovery model. Implications for policy include the recommendation that decision-makers consider the pre-disaster growth of the community indecisions to support recovery assistance.

  18. The slings and arrows of LHC restart schedules

    CERN Multimedia

    2015-01-01

    We should now have been celebrating the first circulating beams of LHC Run 2, but, as I reported last Tuesday, I find myself instead having to write about a delay in proceedings. Against a backdrop of great progress in the powering tests for running at 6.5 TeV, a short to ground in one of the LHC’s thousands of circuits became apparent on 21 March.   Although a simple job to repair, it is compounded by the fact that the short is in a cold section of the machine, and it might therefore require a few weeks to warm up, carry out the repair and cool down again. Nevertheless, all the signs are good for a great Run 2, and in the grand scheme of things, a delay of weeks in humankind’s quest to understand our universe is little more than the blink of an eye. The impact of the delay on the experiments will be minimal, as 2015 was always foreseen as a year for preparing the upgraded machine for full-scale physics running in 2016-2018. When the LHC’s first run got underway...

  19. The Origin of the Universe and the Arrow of Time

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Sean

    2009-02-11

    Over a century ago, Boltzmann and others provided a microscopic understanding for the tendency of entropy to increase. But this understanding relies ultimately on an empirical fact about cosmology: the early universe had very low entropy. Why was it like that? Cosmologists aspire to provide a dynamical explanation for the observed state of the universe, but have had very little to say about the dramatic asymmetry between early times and late times. I will argue that the search for a natural explanation for the observed breakdown of time-reversal symmetry in cosmology leads us directly to interesting conclusions about inflation, quantum gravity, and the multiverse.

  20. A Phase Space Approach to the Gravitational Arrow of Time

    CERN Document Server

    Rothman, T; Rothman, Tony; Anninos, Peter

    1997-01-01

    We attempt to find a function that characterizes gravitational clumping= and that increases monotonically as inhomogeneity increases. We choose $S =3D ln\\Omega$ as the candidate ``gravitational entropy'' function, where $\\Om= ega$ is the phase-space volume below the Hamiltonian H of the system under consideration. We compute $\\Omega$ for transverse electromagnetic waves a= nd for gravitational wave, radiation and density perturbations in an expanding F= LRW universe. These calculations are carried out in the linear regime under t= he assumption that the phases of the oscillators comprising the system are r= andom. Entropy is thus attributed to the lack of knowledge of the exact field configuration. We find that $\\Omega$, and hence $ln\\Omega$ behaves as required. We also carry out calculations for Bianchi IX cosmological mode= ls and find that, even in this homogeneous case, the function can be interpreted sensibly. We compare our results with Penrose's C^2 hypothesis. Because S is defined to resemble the fund...

  1. Advanced digital signal processing and noise reduction

    CERN Document Server

    Vaseghi, Saeed V

    2008-01-01

    Digital signal processing plays a central role in the development of modern communication and information processing systems. The theory and application of signal processing is concerned with the identification, modelling and utilisation of patterns and structures in a signal process. The observation signals are often distorted, incomplete and noisy and therefore noise reduction, the removal of channel distortion, and replacement of lost samples are important parts of a signal processing system. The fourth edition of Advanced Digital Signal Processing and Noise Reduction updates an

  2. Leptin signalling pathways in hypothalamic neurons.

    Science.gov (United States)

    Kwon, Obin; Kim, Ki Woo; Kim, Min-Seon

    2016-04-01

    Leptin is the most critical hormone in the homeostatic regulation of energy balance among those so far discovered. Leptin primarily acts on the neurons of the mediobasal part of hypothalamus to regulate food intake, thermogenesis, and the blood glucose level. In the hypothalamic neurons, leptin binding to the long form leptin receptors on the plasma membrane initiates multiple signaling cascades. The signaling pathways known to mediate the actions of leptin include JAK-STAT signaling, PI3K-Akt-FoxO1 signaling, SHP2-ERK signaling, AMPK signaling, and mTOR-S6K signaling. Recent evidence suggests that leptin signaling in hypothalamic neurons is also linked to primary cilia function. On the other hand, signaling molecules/pathways mitigating leptin actions in hypothalamic neurons have been extensively investigated in an effort to treat leptin resistance observed in obesity. These include SOCS3, tyrosine phosphatase PTP1B, and inflammatory signaling pathways such as IKK-NFκB and JNK signaling, and ER stress-mitochondrial signaling. In this review, we discuss leptin signaling pathways in the hypothalamus, with a particular focus on the most recently discovered pathways.

  3. Silicon Photonics for Signal Processing of Tbit/s Serial Data Signals

    DEFF Research Database (Denmark)

    Oxenløwe, Leif Katsuo; Ji, Hua; Galili, Michael

    2012-01-01

    In this paper, we describe our recent work on signal processing of terabit per second optical serial data signals using pure silicon waveguides. We employ nonlinear optical signal processing in nanoengineered silicon waveguides to perform demultiplexing and optical waveform sampling of 1.28-Tbit....../s data signals as well as wavelength conversion of up to 320-Gbit/s data signals. We demonstrate that the silicon waveguides are equally useful for amplitude and phase-modulated data signals....

  4. Neutrino signals from dark matter

    Science.gov (United States)

    Erkoca, Arif Emre

    Large-scale neutrino telescopes will be powerful tools to observe multitude of mysterious phenomena happening in the Universe. The dark matter puzzle is listed as one of them. In this study, indirect detection of dark matter via neutrino signals is presented. The upward muon, the contained muon and the hadronic shower fluxes are calculated, assuming annihilation/decay of the dark matter in the core of the astrophysical objects and in the Galactic center. Direct neutrino production and secondary neutrino production from the decay of Standard Model particles produced in the annihilation/decay of dark matter are studied. The results are contrasted to the ones previously obtained in the literature, illustrating the importance of properly treating muon propagation and energy loss for the upward muon flux. The dependence of the dark matter signals on the density profile, the dark matter mass and the detector threshold are discussed. Different dark matter models (gravitino, Kaluza-Klein and leptophilic) which can account for recent observations of some indirect searches are analyzed regarding their detection in the kilometer size neutrino detectors in the near future. Muon and shower rates and the minimum observation times in order to reach 2sigma detection significance are evaluated, with the result suggesting that the optimum cone half angles chosen about the Galactic center are about 10° (50°) for the muon (shower) events. A detailed analysis shows that for the annihilating dark matter models such as the leptophilic and Kaluza-Klein models, upward and contained muon as well as showers yield promising signals for dark matter detection in just a few years of observation, whereas for decaying dark matter models, the same observation times can only be reached with showers. The analytical results for the final fluxes are also obtained as well as parametric forms for the muon and shower fluxes for the dark matter models considered in this study.

  5. Relativistic solitons and superluminal signals

    Energy Technology Data Exchange (ETDEWEB)

    Maccari, Attilio [Technical Institute ' G. Cardano' , Piazza della Resistenza 1, Monterotondo, Rome 00015 (Italy)]. E-mail: solitone@yahoo.it

    2005-02-01

    Envelope solitons in the weakly nonlinear Klein-Gordon equation in 1 + 1 dimensions are investigated by the asymptotic perturbation (AP) method. Two different types of solitons are possible according to the properties of the dispersion relation. In the first case, solitons propagate with the group velocity (less than the light speed) of the carrier wave, on the contrary in the second case solitons always move with the group velocity of the carrier wave, but now this velocity is greater than the light speed. Superluminal signals are then possible in classical relativistic nonlinear field equations.

  6. EUROmediCAT signal detection

    DEFF Research Database (Denmark)

    Luteijn, Johannes Michiel; Morris, Joan K; Garne, Ester

    2016-01-01

    AIMS: Information about medication safety in pregnancy is inadequate. We aimed to develop a signal detection methodology to routinely identify unusual associations between medications and congenital anomalies using data collected by 15 European congenital anomaly registries. METHODS: EUROmediCAT......). CONCLUSIONS: Medication exposure data in the EUROmediCAT central database can be analyzed systematically to determine a manageable set of associations for validation and then testing in independent datasets. Detection of teratogens depends on frequency of exposure, level of risk and teratogenic specificity....

  7. Small signal microwave amplifier design

    CERN Document Server

    Grosch, Theodore

    2000-01-01

    This book explains techniques and examples for designing stable amplifiers for high-frequency applications in which the signal is small and the amplifier circuit is linear. An in-depth discussion of linear network theory provides the foundation needed to develop actual designs. Examples throughout the book will show you how to apply the knowledge gained in each chapter leading to the complex design of low noise amplifiers. Many exercises at the end of each chapter will help students to practice their skills. The solutions to these design problems are available in an accompanying solutions book

  8. Fixed-point signal processing

    CERN Document Server

    Padgett, Wayne T

    2009-01-01

    This book is intended to fill the gap between the ""ideal precision"" digital signal processing (DSP) that is widely taught, and the limited precision implementation skills that are commonly required in fixed-point processors and field programmable gate arrays (FPGAs). These skills are often neglected at the university level, particularly for undergraduates. We have attempted to create a resource both for a DSP elective course and for the practicing engineer with a need to understand fixed-point implementation. Although we assume a background in DSP, Chapter 2 contains a review of basic theory

  9. Upregulating Apoptotic Signaling in Neurofibromatosis

    Science.gov (United States)

    2009-09-01

    sNF and ST- 8814 cells were co-immunoprecipitated with a RBD/GST fusion protein and immunoblotting with anti-Ras antibody. Even loading was verified by...led us to test whether hyperactive Ras signaling could be in synergy with loss of PKC in NF deficient condition. Human sNF (MPNST) and ST- 8814 ...can only associate with the active form of Ras (Figs. 2a and b). The association of active Ras with the fusion protein was observed in sNF or ST- 8814

  10. Biomedical signals, imaging, and informatics

    CERN Document Server

    Bronzino, Joseph D

    2014-01-01

    Known as the bible of biomedical engineering, The Biomedical Engineering Handbook, Fourth Edition, sets the standard against which all other references of this nature are measured. As such, it has served as a major resource for both skilled professionals and novices to biomedical engineering.Biomedical Signals, Imaging, and Informatics, the third volume of the handbook, presents material from respected scientists with diverse backgrounds in biosignal processing, medical imaging, infrared imaging, and medical informatics.More than three dozen specific topics are examined, including biomedical s

  11. Error signals driving locomotor adaptation

    DEFF Research Database (Denmark)

    Choi, Julia T; Jensen, Peter; Nielsen, Jens Bo

    2016-01-01

    perturbations. Forces were applied to the ankle joint during the early swing phase using an electrohydraulic ankle-foot orthosis. Repetitive 80 Hz electrical stimulation was applied to disrupt cutaneous feedback from the superficial peroneal nerve (foot dorsum) and medial plantar nerve (foot sole) during...... anaesthesia (n = 5) instead of repetitive nerve stimulation. Foot anaesthesia reduced ankle adaptation to external force perturbations during walking. Our results suggest that cutaneous input plays a role in force perception, and may contribute to the 'error' signal involved in driving walking adaptation when...

  12. Detection of Transient Signals in Doppler Spectra

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Signal processing is used to detect transient signals in the presence of noise. Two embodiments are disclosed. In both embodiments, the time series from a remote...

  13. Ghost signals in Allison emittance scanners

    Energy Technology Data Exchange (ETDEWEB)

    Stockli, Martin P.; /SNS Project, Oak Ridge /Tennessee U.; Leitner, M.; /LBL, Berkeley; Moehs, D.P.; /Fermilab; Keller, R.; /LBL, Berkeley; Welton, R.F.; /SNS Project, Oak

    2004-12-01

    For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%.

  14. Bioinformatics analyses for signal transduction networks

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Research in signaling networks contributes to a deeper understanding of organism living activities. With the development of experimental methods in the signal transduction field, more and more mechanisms of signaling pathways have been discovered. This paper introduces such popular bioin-formatics analysis methods for signaling networks as the common mechanism of signaling pathways and database resource on the Internet, summerizes the methods of analyzing the structural properties of networks, including structural Motif finding and automated pathways generation, and discusses the modeling and simulation of signaling networks in detail, as well as the research situation and tendency in this area. Now the investigation of signal transduction is developing from small-scale experiments to large-scale network analysis, and dynamic simulation of networks is closer to the real system. With the investigation going deeper than ever, the bioinformatics analysis of signal transduction would have immense space for development and application.

  15. Extracting periodic driving signal from chaotic noise

    Institute of Scientific and Technical Information of China (English)

    MU Jing; TAO Chao; DU Gonghuan

    2003-01-01

    After periodic signals pass through some nonlinear systems, they are usually transformed into noise-like and wide-band chaotic signals. The discrete spectrums of the original periodic signals are often covered by the chaotic spectrums. Recovering the periodic driving signals from the chaotic signals is important not only in theory but also in practical applications. Based on the modeling theory of nonlinear dynamic system, a "polynomial-simple harmonic drive" non-autonomous equation (P-S equation) to approximate the original system is proposed and the approximation error between P-S equation and the original system is obtained. By changing the drive frequency, we obtain the curve of the approximation error vs. drive frequency. Based on the relation between this curve and the spectrums of the original periodic signals, the spectrum of the original driving signal is extracted and the original signal is recovered.

  16. Signals of extra gauge bosons and exotic leptons in SU(6){sub {ital L}}{direct_product}U(1){sub {ital Y}}

    Energy Technology Data Exchange (ETDEWEB)

    Gaitan-Lozano, R.; Hernandez-Galeana, A.; Tomas, S.A.; Ponce, W.A.; Zepeda, A. [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN, A.P. 14-740, 07000 Mexico D.F. (Mexico)]|[Departamento de Fisica, Universidad Surcolombiana, A. A. 385, Neiva (Colombia)]|[Departamento de Fisica, Universidad de Antioquia, A. A. 1226, Medellin (Colombia)]|[Escuela de Ciencias, UAEM, Unidad del Cerrillo, Piedras Blancas, Instituto Literario 100, C.P 50000, Toluca Edo. (Mexico)

    1995-06-01

    We study some of the consequences of the SU(6){sub {ital L}}{direct_product}U(1){sub {ital Y}} model of unification of electroweak interactions and families with a horizontal gauge group SU(2){sub {ital H}}, paying special attention to processes with flavor-changing neutral currents. We compute at the tree level the decays {ital K}{sup +}{r_arrow}{pi}{sup +}{mu}{sup +}{ital e}{sup {minus}}, {ital K}{sub {ital L}}{sup 0}{r_arrow}{mu}{sup +}{ital e}{sup {minus}}, and {mu}{sup {minus}}{r_arrow}{ital e}{sup {minus}}{bar {nu}}{sub {ital e}}{nu}{sub {mu}} from which we obtain lower bounds for the mass of the horizontal gauge boson associated with FCNC`s. Finally we obtain limits on the mixing between ordinary and exotic charged leptons.

  17. Using the (p-arrow-right,p-arrow-right ') reaction to study. delta. S = 0 giant resonances

    Energy Technology Data Exchange (ETDEWEB)

    Baker, F.T.; Bimbot, L.; Fergerson, R.W.; Glashausser, C.; Jones, K.; Green, A.; Nakayama, K.; Nanda, S.

    1988-03-01

    Measurements of spin-flip probabilities for inelastic scattering of 318 MeV protons from /sup 40/Ca reveal that much of the background underlying the giant dipole and quadrupole resonances at small angles is from ..delta..S = 1 transitions. This holds the promise of allowing a much better estimate of this background than has previously been possible;one model-dependent parameter is necessary. Subsequent analysis with a first estimate of this parameter is presented

  18. The detection of signals buried in noise

    CERN Document Server

    Bergamaschi, Luigi; Giordani, Laura; Mana, Giovanni; Oddone, Massimo

    2013-01-01

    This paper examines signal detection in the presence of noise, with a particular emphasis to the nuclear activation analysis. The problem is to decide what between the signal-plus-background and no-signal hypotheses fits better the data and to quantify the relevant signal amplitude or detection limit. Our solution is based on the use of Bayesian inferences to test the different hypotheses.

  19. CLASSIFICATION OF MPSK SIGNALS USING CUMULANT INVARIANTS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new feature based on higher order statistics is proposed for classification of MPSK signals, which is invariant with respect to translation(shift),scale and rotation transforms of MPSK signal constellations, and can suppress additive color or white Gaussian noise.Application of the new feature to classification of MPSK signals, at medium signal-to-noise ratio with specified sample size, results in high probability of correct identification.Finally, computer simulations and comparisons with existing algorithms are given.

  20. TOR Signaling and Nutrient Sensing.

    Science.gov (United States)

    Dobrenel, Thomas; Caldana, Camila; Hanson, Johannes; Robaglia, Christophe; Vincentz, Michel; Veit, Bruce; Meyer, Christian

    2016-04-29

    All living organisms rely on nutrients to sustain cell metabolism and energy production, which in turn need to be adjusted based on available resources. The evolutionarily conserved target of rapamycin (TOR) protein kinase is a central regulatory hub that connects environmental information about the quantity and quality of nutrients to developmental and metabolic processes in order to maintain cellular homeostasis. TOR is activated by both nitrogen and carbon metabolites and promotes energy-consuming processes such as cell division, mRNA translation, and anabolism in times of abundance while repressing nutrient remobilization through autophagy. In animals and yeasts, TOR acts antagonistically to the starvation-induced AMP-activated kinase (AMPK)/sucrose nonfermenting 1 (Snf1) kinase, called Snf1-related kinase 1 (SnRK1) in plants. This review summarizes the immense knowledge on the relationship between TOR signaling and nutrients in nonphotosynthetic organisms and presents recent findings in plants that illuminate the crucial role of this pathway in conveying nutrient-derived signals and regulating many aspects of metabolism and growth.

  1. Redox signaling in acute pancreatitis

    Directory of Open Access Journals (Sweden)

    Salvador Pérez

    2015-08-01

    Full Text Available Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On the other hand, the release of extracellular hemoglobin into the circulation from the ascitic fluid in severe necrotizing pancreatitis enhances lipid peroxidation in plasma and the inflammatory infiltrate into the lung and up-regulates the HIF–VEGF pathway, contributing to the systemic inflammatory response. Therefore, redox signaling and oxidative stress contribute to the local and systemic inflammatory response during acute pancreatitis.

  2. Redox signaling in acute pancreatitis.

    Science.gov (United States)

    Pérez, Salvador; Pereda, Javier; Sabater, Luis; Sastre, Juan

    2015-08-01

    Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On the other hand, the release of extracellular hemoglobin into the circulation from the ascitic fluid in severe necrotizing pancreatitis enhances lipid peroxidation in plasma and the inflammatory infiltrate into the lung and up-regulates the HIF-VEGF pathway, contributing to the systemic inflammatory response. Therefore, redox signaling and oxidative stress contribute to the local and systemic inflammatory response during acute pancreatitis.

  3. CCN3 and calcium signaling

    Directory of Open Access Journals (Sweden)

    Li Chang Long

    2003-08-01

    Full Text Available Abstract The CCN family of genes consists presently of six members in human (CCN1-6 also known as Cyr61 (Cystein rich 61, CTGF (Connective Tissue Growth Factor, NOV (Nephroblastoma Overexpressed gene, WISP-1, 2 and 3 (Wnt-1 Induced Secreted Proteins. Results obtained over the past decade have indicated that CCN proteins are matricellular proteins, which are involved in the regulation of various cellular functions, such as proliferation, differentiation, survival, adhesion and migration. The CCN proteins have recently emerged as regulatory factors involved in both internal and external cell signaling. CCN3 was reported to physically interact with fibulin-1C, integrins, Notch and S100A4. Considering that, the conformation and biological activity of these proteins are dependent upon calcium binding, we hypothesized that CCN3 might be involved in signaling pathways mediated by calcium ions. In this article, we review the data showing that CCN3 regulates the levels of intracellular calcium and discuss potential models that may account for the biological effects of CCN3.

  4. Expanding mTOR signaling

    Institute of Scientific and Technical Information of China (English)

    Qian Yang; Kun-Liang Guan

    2007-01-01

    The mammalian target of rapamycin (mTOR) has drawn much attention recently because of its essential role in cell growth control and its involvement in human tumorigenesis. Great endeavors have been made to elucidate the functions and regulation of mTOR in the past decade. The current prevailing view is that mTOR regulates many fundamental biological processes, such as cell growth and survival, by integrating both intracellular and extracellular signals, including growth factors, nutrients, energy levels, and cellular stress. The significance of mTOR has been highlighted most recently by the identification of mTOR-associated proteins. Amazingly, when bound to different proteins, mTOR forms distinctive complexes with very different physiological functions. These findings not only expand the roles that mTOR plays in cells but also further complicate the regulation network. Thus, it is now even more critical that we precisely understand the underlying molecular mechanisms in order to directly guide the development and usage of anti-cancer drugs targeting the mTOR signaling pathway. In this review, we will discuss different mTOR-associated proteins, the regulation of mTOR complexes, and the consequences of mTOR dysregulation under pathophysiological conditions.

  5. Extracellular nucleotide signaling in plants

    Energy Technology Data Exchange (ETDEWEB)

    Stacey, Gary [Univ. of Missouri, Columbia, MO (United States)

    2016-09-08

    Over the life of this funded project, our research group identified and characterized two key receptor proteins in plants; one mediating the innate immunity response to chitin and the other elucidating the key receptor for extracellular ATP. In the case of chitin recognition, we recently described the quaternary structure of this receptor, shedding light on how the receptor functions. Perhaps more importantly, we demonstrated that all plants have the ability to recognize both chitin oligomers and lipochitooligosacchardes, fundamentally changing how the community views the evolution of these systems and strategies that might be used, for example, to extend symbiotic nitrogen fixation to non-legumes. Our discovery of DORN1 opens a new chapter in plant physiology documenting conclusively that eATP is an important extracellular signal in plants, as it is in animals. At this point, we cannot predict just how far reaching this discovery may prove to be but we are convinced that eATP signaling is fundamental to plant growth and development and, hence, we believe that the future will be very exciting for the study of DORN1 and its overall function in plants.

  6. Analyzing visual signals as visual scenes.

    Science.gov (United States)

    Allen, William L; Higham, James P

    2013-07-01

    The study of visual signal design is gaining momentum as techniques for studying signals become more sophisticated and more freely available. In this paper we discuss methods for analyzing the color and form of visual signals, for integrating signal components into visual scenes, and for producing visual signal stimuli for use in psychophysical experiments. Our recommended methods aim to be rigorous, detailed, quantitative, objective, and where possible based on the perceptual representation of the intended signal receiver(s). As methods for analyzing signal color and luminance have been outlined in previous publications we focus on analyzing form information by discussing how statistical shape analysis (SSA) methods can be used to analyze signal shape, and spatial filtering to analyze repetitive patterns. We also suggest the use of vector-based approaches for integrating multiple signal components. In our opinion elliptical Fourier analysis (EFA) is the most promising technique for shape quantification but we await the results of empirical comparison of techniques and the development of new shape analysis methods based on the cognitive and perceptual representations of receivers. Our manuscript should serve as an introductory guide to those interested in measuring visual signals, and while our examples focus on primate signals, the methods are applicable to quantifying visual signals in most taxa.

  7. The intraflagellar transport machinery in ciliary signaling

    DEFF Research Database (Denmark)

    Mourão, André; Christensen, Søren Tvorup; Lorentzen, Esben

    2016-01-01

    environmental cues necessary for organ development and maintenance of human health. Pathways reported to rely on the cilium organelle include Hedgehog, TGF-β, Wnt, PDGFRα, integrin and DNA damage repair signaling. An emerging theme in ciliary signaling is the requirement for active transport of signaling...

  8. The Limited Facilitative Effect of Typographical Signals.

    Science.gov (United States)

    Golding, Jonathan M.; Fowler, Susan B.

    1992-01-01

    Two experiments with 188 college students investigated the facilitative effect of typographical signals such as underlining, headings, or other devices to help readers identify specific points. Results do not support a general facilitative effect of typographical signals but suggest that use of signals depends on the reader's strategic processing.…

  9. Programmable delay circuit for sparker signal analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Pathak, D.

    The sparker echo signal had been recorded along with the EPC recorder trigger on audio cassettes in a dual channel analog recorder. The sparker signal in the analog form had to be digitised for further signal processing techniques to be performed...

  10. Proteomics insights into plant signaling and development.

    NARCIS (Netherlands)

    Kaufmann, K.; Smaczniak, C.D.; Vries, de S.C.; Angenent, G.C.; Karlova, R.B.

    2011-01-01

    Mass spectrometry-based proteomics is used to gain insight into the abundance and subcellular localization of cellular signaling components, the composition of molecular complexes and the regulation of signaling pathways. Multicellular organisms have evolved signaling networks and fast responses to

  11. Radar signal analysis and processing using Matlab

    CERN Document Server

    Mahafza, Bassem R

    2008-01-01

    Offering radar-related software for the analysis and design of radar waveform and signal processing, this book provides comprehensive coverage of radar signals and signal processing techniques and algorithms. It contains numerous graphical plots, common radar-related functions, table format outputs, and end-of-chapter problems. The complete set of MATLAB[registered] functions and routines are available for download online.

  12. On the Asymptotic Distribution of Signal Fraction

    CERN Document Server

    Volobouev, Igor

    2016-01-01

    Condition of the asymptotic normality of the signal fraction estimate by maximum likelihood is derived under the null hypothesis of no signal. Consequences of this condition for determination of signal significance taking in to account the look elsewhere effect are discussed.

  13. SIMULATION STUDY ON AIRBORNE SAR ECHO SIGNAL

    Institute of Scientific and Technical Information of China (English)

    Bao Houbing; Liu Zhao

    2004-01-01

    Through analyzing the influence on echo signal by factors of kinematical parameters of airborne SAR platform and radar antenna direction, this letter, on the basis of classical SAR echo signal analogue algorithm, puts forward certain airborne SAR echo signal analogue algorithm of distance directional frequency domain pulse coherent accumulation, and goes through simulation. The simulation results have proved the effectiveness of this algorithm.

  14. Temporal expectation weights visual signals over auditory signals.

    Science.gov (United States)

    Menceloglu, Melisa; Grabowecky, Marcia; Suzuki, Satoru

    2017-04-01

    Temporal expectation is a process by which people use temporally structured sensory information to explicitly or implicitly predict the onset and/or the duration of future events. Because timing plays a critical role in crossmodal interactions, we investigated how temporal expectation influenced auditory-visual interaction, using an auditory-visual crossmodal congruity effect as a measure of crossmodal interaction. For auditory identification, an incongruent visual stimulus produced stronger interference when the crossmodal stimulus was presented with an expected rather than an unexpected timing. In contrast, for visual identification, an incongruent auditory stimulus produced weaker interference when the crossmodal stimulus was presented with an expected rather than an unexpected timing. The fact that temporal expectation made visual distractors more potent and visual targets less susceptible to auditory interference suggests that temporal expectation increases the perceptual weight of visual signals.

  15. IDSP- INTERACTIVE DIGITAL SIGNAL PROCESSOR

    Science.gov (United States)

    Mish, W. H.

    1994-01-01

    The Interactive Digital Signal Processor, IDSP, consists of a set of time series analysis "operators" based on the various algorithms commonly used for digital signal analysis work. The processing of a digital time series to extract information is usually achieved by the application of a number of fairly standard operations. However, it is often desirable to "experiment" with various operations and combinations of operations to explore their effect on the results. IDSP is designed to provide an interactive and easy-to-use system for this type of digital time series analysis. The IDSP operators can be applied in any sensible order (even recursively), and can be applied to single time series or to simultaneous time series. IDSP is being used extensively to process data obtained from scientific instruments onboard spacecraft. It is also an excellent teaching tool for demonstrating the application of time series operators to artificially-generated signals. IDSP currently includes over 43 standard operators. Processing operators provide for Fourier transformation operations, design and application of digital filters, and Eigenvalue analysis. Additional support operators provide for data editing, display of information, graphical output, and batch operation. User-developed operators can be easily interfaced with the system to provide for expansion and experimentation. Each operator application generates one or more output files from an input file. The processing of a file can involve many operators in a complex application. IDSP maintains historical information as an integral part of each file so that the user can display the operator history of the file at any time during an interactive analysis. IDSP is written in VAX FORTRAN 77 for interactive or batch execution and has been implemented on a DEC VAX-11/780 operating under VMS. The IDSP system generates graphics output for a variety of graphics systems. The program requires the use of Versaplot and Template plotting

  16. Signal trend identification with fuzzy methods.

    Energy Technology Data Exchange (ETDEWEB)

    Reifman, J.; Tsoukalas, L. H.; Wang, X.; Wei, T. Y. C.

    1999-08-19

    A fuzzy-logic-based methodology for on-line signal trend identification is introduced. Although signal trend identification is complicated by the presence of noise, fuzzy logic can help capture important features of on-line signals and classify incoming power plant signals into increasing, decreasing and steady-state trend categories. In order to verify the methodology, a code named PROTREN is developed and tested using plant data. The results indicate that the code is capable of detecting transients accurately, identifying trends reliably, and not misinterpreting a steady-state signal as a transient one.

  17. ANALYZING OF MULTICOMPONENT UNDERSAMPLED SIGNALS BY HAF

    Institute of Scientific and Technical Information of China (English)

    Tao Ran; Shan Tao; Zhou Siyong; Wang Yue

    2001-01-01

    The phenomenon of frequency ambiguity may appear in radar or communication systems. S. Barbarossa(1991) had unwrapped the frequency ambiguity of single component undersampled signals by Wigner-Ville distribution(WVD). But there has no any effective algorithm to analyze multicomponent undersampled signals by now. A new algorithm to analyze multicomponent undersampled signals by high-order ambiguity function (HAF) is proposed hera HAF analyzes polynomial phase signals by the method of phase rank reduction, its advantage is that it does not have boundary effect and is not sensitive to the cross-items of multicomponent signals.The simulation results prove the effectiveness of HAF algorithm.

  18. Probabilistic Recovery Guarantees for Sparsely Corrupted Signals

    CERN Document Server

    Pope, Graeme; Studer, Christoph

    2012-01-01

    We consider the recovery of sparse signals subject to sparse interference, as introduced in Studer et al., IEEE Trans. IT, 2012. We present novel probabilistic recovery guarantees for this framework, covering varying degrees of knowledge of the signal and interference support, which are relevant for a large number of practical applications. Our results assume that the sparsifying dictionaries are solely characterized by coherence parameters and we require randomness only in the signal and/or interference. The obtained recovery guarantees show that one can recover sparsely corrupted signals with overwhelming probability, even if the sparsity of both the signal and interference scale (near) linearly with the number of measurements.

  19. Signal extrapolation based on wavelet representation

    Science.gov (United States)

    Xia, Xiang-Gen; Kuo, C.-C. Jay; Zhang, Zhen

    1993-11-01

    The Papoulis-Gerchberg (PG) algorithm is well known for band-limited signal extrapolation. We consider the generalization of the PG algorithm to signals in the wavelet subspaces in this research. The uniqueness of the extrapolation for continuous-time signals is examined, and sufficient conditions on signals and wavelet bases for the generalized PG (GPG) algorithm to converge are given. We also propose a discrete GPG algorithm for discrete-time signal extrapolation, and investigate its convergence. Numerical examples are given to illustrate the performance of the discrete GPG algorithm.

  20. A signal theoretic introduction to random processes

    CERN Document Server

    Howard, Roy M

    2015-01-01

    A fresh introduction to random processes utilizing signal theory By incorporating a signal theory basis, A Signal Theoretic Introduction to Random Processes presents a unique introduction to random processes with an emphasis on the important random phenomena encountered in the electronic and communications engineering field. The strong mathematical and signal theory basis provides clarity and precision in the statement of results. The book also features:  A coherent account of the mathematical fundamentals and signal theory that underpin the presented material Unique, in-depth coverage of

  1. Nonlinear filtering in ECG Signal Enhancement

    Directory of Open Access Journals (Sweden)

    N. Siddiah

    2012-02-01

    Full Text Available High resolution ECG signals are needed in measuring cardiac abnormalities analysis. Generally baseline wander is one of the important artifact occurred in ECG signal extraction, this strongly affects the signal quality. In order to facilitate proper diagnosis these artifacts have to be removed. In this paper various non linear, non adaptive filtering techniques are presented for the removal of baseline wander removal from ECG signals. The performance characteristics of various filtering techniques are measured in terms of signal to noise ratio.

  2. Endocannabinoid signaling and food addiction.

    Science.gov (United States)

    D'Addario, C; Micioni Di Bonaventura, M V; Pucci, M; Romano, A; Gaetani, S; Ciccocioppo, R; Cifani, C; Maccarrone, M

    2014-11-01

    Overeating, frequently linked to an increasing incidence of overweight and obesity, has become epidemic and one of the leading global health problems. To explain the development of this eating behavior, new hypotheses involve the concept that many people might be addicted to food by losing control over their ability to regulate food intake. Among the different neurotransmitter networks that partake in the reward circuitry within the brain, a large body of evidence supports the involvement of the endocannabinoid system. Indeed, its dysfunctions might contribute to food addiction, by regulating appetite and food preference through central and peripheral mechanisms. Here, we review and discuss the role of endocannabinoid signaling in the reward circuitry, and the possible therapeutic exploitation of strategies based on its fine regulation.

  3. Engagement Assessment Using EEG Signals

    Science.gov (United States)

    Li, Feng; Li, Jiang; McKenzie, Frederic; Zhang, Guangfan; Wang, Wei; Pepe, Aaron; Xu, Roger; Schnell, Thomas; Anderson, Nick; Heitkamp, Dean

    2012-01-01

    In this paper, we present methods to analyze and improve an EEG-based engagement assessment approach, consisting of data preprocessing, feature extraction and engagement state classification. During data preprocessing, spikes, baseline drift and saturation caused by recording devices in EEG signals are identified and eliminated, and a wavelet based method is utilized to remove ocular and muscular artifacts in the EEG recordings. In feature extraction, power spectrum densities with 1 Hz bin are calculated as features, and these features are analyzed using the Fisher score and the one way ANOVA method. In the classification step, a committee classifier is trained based on the extracted features to assess engagement status. Finally, experiment results showed that there exist significant differences in the extracted features among different subjects, and we have implemented a feature normalization procedure to mitigate the differences and significantly improved the engagement assessment performance.

  4. Digital signal processing using MATLAB

    CERN Document Server

    Schilling, Robert L

    2016-01-01

    Focus on the development, implementation, and application of modern DSP techniques with DIGITAL SIGNAL PROCESSING USING MATLAB(R), 3E. Written in an engaging, informal style, this edition immediately captures your attention and encourages you to explore each critical topic. Every chapter starts with a motivational section that highlights practical examples and challenges that you can solve using techniques covered in the chapter. Each chapter concludes with a detailed case study example, a chapter summary with learning outcomes, and practical homework problems cross-referenced to specific chapter sections for your convenience. DSP Companion software accompanies each book to enable further investigation. The DSP Companion software operates with MATLAB(R) and provides intriguing demonstrations as well as interactive explorations of analysis and design concepts.

  5. Signals of Supersymmetric Dark Matter

    CERN Document Server

    Abbas, A

    2000-01-01

    The Lightest Supersymmetric Particle predicted in most of the supersymmetric scenarios is an ideal candidate for the dark matter of cosmology. Their detection is of extreme significance today. Recently there have been intriguing signals of a 59 Gev neutralino dark matter at DAMA in Gran Sasso. We look at other possible signatures of dark matter in astrophysical and geological frameworks. The passage of the earth through dense clumps of dark matter would produce large quantities of heat in the interior of this planet through the capture and subsequent annihilation of dark matter particles. This heat would lead to large-scale volcanism which could in turn have caused mass extinctions. The periodicity of such volcanic outbursts agrees with the frequency of palaeontological mass extinctions as well as the observed periodicity in the occurrence of the largest flood basalt provinces on the globe. Binary character of these extinctions is another unique aspect of this signature of dark matter. In addition dark matter...

  6. Electrical signals in avocado trees

    Science.gov (United States)

    Oyarce, Patricio

    2010-01-01

    Plant responses to environmental changes are associated with electrical excitability and signaling; automatic and continuous measurements of electrical potential differences (ΔEP) between plant tissues can be effectively used to study information transport mechanisms and physiological responses that result from external stimuli on plants. The generation and conduction of electrochemical impulses within plant different tissues and organs, resulting from abiotic and biotic changes in environmental conditions is reported. In this work, electrical potential differences are monitored continuously using Ag/AgCl microelectrodes, inserted 5 mm deep into sapwood at two positions in the trunks of several Avocado trees. Electrodes are referenced to a non polarisable Ag/AgCl microelectrode installed 20 cm deep in the soil. Systematic patterns of ΔEP during absolute darkness, day-night cycles and different conditions of soil water availability are discussed as alternative tools to assess early plant stress conditions. PMID:20592805

  7. Signal velocity in oscillator arrays

    Science.gov (United States)

    Cantos, C. E.; Veerman, J. J. P.; Hammond, D. K.

    2016-09-01

    We investigate a system of coupled oscillators on the circle, which arises from a simple model for behavior of large numbers of autonomous vehicles where the acceleration of each vehicle depends on the relative positions and velocities between itself and a set of local neighbors. After describing necessary and sufficient conditions for asymptotic stability, we derive expressions for the phase velocity of propagation of disturbances in velocity through this system. We show that the high frequencies exhibit damping, which implies existence of well-defined signal velocitiesc+ > 0 and c- < 0 such that low frequency disturbances travel through the flock as f+(x - c+t) in the direction of increasing agent numbers and f-(x - c-t) in the other.

  8. Reconstructing Boolean Models of Signaling

    Science.gov (United States)

    Karp, Richard M.

    2013-01-01

    Abstract Since the first emergence of protein–protein interaction networks more than a decade ago, they have been viewed as static scaffolds of the signaling–regulatory events taking place in cells, and their analysis has been mainly confined to topological aspects. Recently, functional models of these networks have been suggested, ranging from Boolean to constraint-based methods. However, learning such models from large-scale data remains a formidable task, and most modeling approaches rely on extensive human curation. Here we provide a generic approach to learning Boolean models automatically from data. We apply our approach to growth and inflammatory signaling systems in humans and show how the learning phase can improve the fit of the model to experimental data, remove spurious interactions, and lead to better understanding of the system at hand. PMID:23286509

  9. Fundamentals of adaptive signal processing

    CERN Document Server

    Uncini, Aurelio

    2015-01-01

    This book is an accessible guide to adaptive signal processing methods that equips the reader with advanced theoretical and practical tools for the study and development of circuit structures and provides robust algorithms relevant to a wide variety of application scenarios. Examples include multimodal and multimedia communications, the biological and biomedical fields, economic models, environmental sciences, acoustics, telecommunications, remote sensing, monitoring, and, in general, the modeling and prediction of complex physical phenomena. The reader will learn not only how to design and implement the algorithms but also how to evaluate their performance for specific applications utilizing the tools provided. While using a simple mathematical language, the employed approach is very rigorous. The text will be of value both for research purposes and for courses of study.

  10. Subaperture clutter filter with CFAR signal detection

    Energy Technology Data Exchange (ETDEWEB)

    Ormesher, Richard C.; Naething, Richard M.

    2016-08-30

    The various technologies presented herein relate to the determination of whether a received signal comprising radar clutter further comprises a communication signal. The communication signal can comprise of a preamble, a data symbol, communication data, etc. A first portion of the radar clutter is analyzed to determine a radar signature of the first portion of the radar clutter. A second portion of the radar clutter can be extracted based on the radar signature of the first portion. Following extraction, any residual signal can be analyzed to retrieve preamble data, etc. The received signal can be based upon a linear frequency modulation (e.g., a chirp modulation) whereby the chirp frequency can be determined and the frequency of transmission of the communication signal can be based accordingly thereon. The duration and/or bandwidth of the communication signal can be a portion of the duration and/or the bandwidth of the radar clutter.

  11. Optimal temporal patterns for dynamical cellular signaling

    Science.gov (United States)

    Hasegawa, Yoshihiko

    2016-11-01

    Cells use temporal dynamical patterns to transmit information via signaling pathways. As optimality with respect to the environment plays a fundamental role in biological systems, organisms have evolved optimal ways to transmit information. Here, we use optimal control theory to obtain the dynamical signal patterns for the optimal transmission of information, in terms of efficiency (low energy) and reliability (low uncertainty). Adopting an activation-deactivation decoding network, we reproduce several dynamical patterns found in actual signals, such as steep, gradual, and overshooting dynamics. Notably, when minimizing the energy of the input signal, the optimal signals exhibit overshooting, which is a biphasic pattern with transient and steady phases; this pattern is prevalent in actual dynamical patterns. We also identify conditions in which these three patterns (steep, gradual, and overshooting) confer advantages. Our study shows that cellular signal transduction is governed by the principle of minimizing free energy dissipation and uncertainty; these constraints serve as selective pressures when designing dynamical signaling patterns.

  12. Seizure detection algorithms based on EMG signals

    DEFF Research Database (Denmark)

    Conradsen, Isa

    Background: the currently used non-invasive seizure detection methods are not reliable. Muscle fibers are directly connected to the nerves, whereby electric signals are generated during activity. Therefore, an alarm system on electromyography (EMG) signals is a theoretical possibility. Objective...... on the amplitude of the signal. The other algorithm was based on information of the signal in the frequency domain, and it focused on synchronisation of the electrical activity in a single muscle during the seizure. Results: The amplitude-based algorithm reliably detected seizures in 2 of the patients, while......: to show whether medical signal processing of EMG data is feasible for detection of epileptic seizures. Methods: EMG signals during generalised seizures were recorded from 3 patients (with 20 seizures in total). Two possible medical signal processing algorithms were tested. The first algorithm was based...

  13. Neuropeptide signalling systems in flatworms.

    Science.gov (United States)

    McVeigh, P; Kimber, M J; Novozhilova, E; Day, T A

    2005-01-01

    Two distinct families of neuropeptides are known to endow platyhelminth nervous systems - the FMRFamide-like peptides (FLPs) and the neuropeptide Fs (NPFs). Flatworm FLPs are structurally simple, each 4-6 amino acids in length with a carboxy terminal aromatic-hydrophobic-Arg-Phe-amide motif. Thus far, four distinct flatworm FLPs have been characterized, with only one of these from a parasite. They have a widespread distribution within the central and peripheral nervous system of every flatworm examined, including neurones serving the attachment organs, the somatic musculature and the reproductive system. The only physiological role that has been identified for flatworm FLPs is myoexcitation. Flatworm NPFs are believed to be invertebrate homologues of the vertebrate neuropeptide Y (NPY) family of peptides. Flatworm NPFs are 36-39 amino acids in length and are characterized by a caboxy terminal GRPRFamide signature and conserved tyrosine residues at positions 10 and 17 from the carboxy terminal. Like FLPs, NPF occurs throughout flatworm nervous systems, although less is known about its biological role. While there is some evidence for a myoexcitatory action in cestodes and flukes, more compelling physiological data indicate that flatworm NPF inhibits cAMP levels in a manner that is characteristic of NPY action in vertebrates. The widespread expression of these neuropeptides in flatworm parasites highlights the potential of these signalling systems to yield new targets for novel anthelmintics. Although platyhelminth FLP and NPF receptors await identification, other molecules that play pivotal roles in neuropeptide signalling have been uncovered. These enzymes, involved in the biosynthesis and processing of flatworm neuropeptides, have recently been described and offer other distinct and attractive targets for therapeutic interference.

  14. Diversity of optical signal processing led by optical signal form conversion

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, Tsuyoshi, E-mail: konishi@mls.eng.osaka-u.ac.j [Osaka University, 2-1 Yamadaoka, Suita Osaka 565-0871 (Japan)

    2010-02-01

    This paper reviews opportunities of optical signal form conversion as typified by time-space conversion in optical signal processing. Several examples of typical ultra-fast optical signal processing using optical signal form conversion are described and their applications are introduced in respect to photonic networks, ultra-fast measurement, and so on.

  15. Validation of signal impact assessment tool in order to explore pharmacovigilance signals' follow-up actions

    NARCIS (Netherlands)

    Rolfes, Leàn; Kolfschoten, Judith; Van Hunsel, Florence; Van Puijenbroek, Eugene; van Grootheest, Kees

    2014-01-01

    Background: To determine which actions are advisable for signals arising from a spontaneous reporting system, the Netherlands Pharmacovigilance Centre Lareb uses a Signal Impact Assessment Tool (SIAT). It categorizes signals into one of four categories: strong/moderate signal strength and similarly

  16. Normalization of vibration signals generated under highly varying speed and load with application to signal separation

    Science.gov (United States)

    Urbanek, Jacek; Barszcz, Tomasz; Strączkiewicz, Marcin; Jablonski, Adam

    2017-01-01

    The paper presents a normalization dedicated to transform non-stationary vibration signals into signals characterized by purely stationary properties. For this purpose, a novel class of generalized periodic signals is defined followed by a proposition of a normalization technique, which takes advantage of available, instantaneous values of operational parameters. Within the paper, a well-known discrete-random separation (DRS) technique is recalled as an exemplary technique, which has been restricted to stationary signals so far. The authors present a step-by-step adoption of the DRS to non-stationary signals. The method is applied to simulated signal, test rig signal, and a vibration signal from industrial object. Additionally, for the purpose of synthesis of simulated signal, a new model of multi-component vibrations generated under varying regime is proposed. The presented method aims to expand existing solutions dealing with varying frequency to a more general solution dealing with independent, simultaneous varying frequency and amplitude of signal components.

  17. Prediction of signal peptides and signal anchors by a hidden Markovmodel

    DEFF Research Database (Denmark)

    Nielsen, Henrik; Krogh, Anders Stærmose

    1998-01-01

    A hidden Markov model of signal peptides has been developed. It contains submodels for the N-terminal part, the hydrophobic region and the region around the cleavage site. For known signal peptides, the model can be used to assign objective boundaries between these three regions. Applied to our d...... is the poor discrimination between signal peptides and uncleaved signal anchors, but this is substantially improved by the hidden Markov model when expanding it with a very simple signal anchor model....

  18. Prediction of signal peptides and signal anchors by a hidden Markov model

    DEFF Research Database (Denmark)

    Krogh, Anders Stærmose; Nielsen, Henrik

    1998-01-01

    A hidden Markov model of signal peptides has been developed. It contains submodels for the N-terminal part, the hydrophobic region, and the region around the cleavage site. For known signal peptides, the model can be used to assign objective boundaries between these three regions. Applied to our ...... is the poor discrimination between signal peptides and uncleaved signal anchors, but this is substantially improved by the hidden Markov model when expanding it with a very simple signal anchor model....

  19. Updating signal typing in voice: addition of type 4 signals.

    Science.gov (United States)

    Sprecher, Alicia; Olszewski, Aleksandra; Jiang, Jack J; Zhang, Yu

    2010-06-01

    The addition of a fourth type of voice to Titze's voice classification scheme is proposed. This fourth voice type is characterized by primarily stochastic noise behavior and is therefore unsuitable for both perturbation and correlation dimension analysis. Forty voice samples were classified into the proposed four types using narrowband spectrograms. Acoustic, perceptual, and correlation dimension analyses were completed for all voice samples. Perturbation measures tended to increase with voice type. Based on reliability cutoffs, the type 1 and type 2 voices were considered suitable for perturbation analysis. Measures of unreliability were higher for type 3 and 4 voices. Correlation dimension analyses increased significantly with signal type as indicated by a one-way analysis of variance. Notably, correlation dimension analysis could not quantify the type 4 voices. The proposed fourth voice type represents a subset of voices dominated by noise behavior. Current measures capable of evaluating type 4 voices provide only qualitative data (spectrograms, perceptual analysis, and an infinite correlation dimension). Type 4 voices are highly complex and the development of objective measures capable of analyzing these voices remains a topic of future investigation.

  20. The Hedgehog signalling pathway in bone formation

    Institute of Scientific and Technical Information of China (English)

    Jing Yang; Philipp Andre; Ling Ye; Ying-Zi Yang

    2015-01-01

    The Hedgehog (Hh) signalling pathway plays many important roles in development, homeostasis and tumorigenesis. The critical function of Hh signalling in bone formation has been identified in the past two decades. Here, we review the evolutionarily conserved Hh signalling mechanisms with an emphasis on the functions of the Hh signalling pathway in bone development, homeostasis and diseases. In the early stages of embryonic limb development, Sonic Hedgehog (Shh) acts as a major morphogen in patterning the limb buds. Indian Hedgehog (Ihh) has an essential function in endochondral ossification and induces osteoblast differentiation in the perichondrium. Hh signalling is also involved intramembrane ossification. Interactions between Hh and Wnt signalling regulate cartilage development, endochondral bone formation and synovial joint formation. Hh also plays an important role in bone homeostasis, and reducing Hh signalling protects against age-related bone loss. Disruption of Hh signalling regulation leads to multiple bone diseases, such as progressive osseous heteroplasia. Therefore, understanding the signalling mechanisms and functions of Hh signalling in bone development, homeostasis and diseases will provide important insights into bone disease prevention, diagnoses and therapeutics.

  1. Proteomic Study of the Brassinosteroid Signalling Network

    Institute of Scientific and Technical Information of China (English)

    Zhiyong Wang

    2012-01-01

    Plant growth is controlled by multiple environmental signals and endogenous hormones.In particular,brassinosteroid (BR) regulates a wide range of developmental processes throughout the life cycle of plants.BR acts through a receptor kinase signalling pathway,and BR signalling crosstalk with many other signalling pathways including light and gibberellin pathways as well as other receptor kinase pathways.My lab uses a combination of genetic,proteomic,and genomic approaches to elucidate not only the BR signaling pathway but also the global organization of the signaling network.We have successfully used proteomics to identify new components of the BR signalling pathway and to elucidated the mechanisms of signal transduction from the BRI1 receptor kinase to the BZR1 transcription factor.We have further uncovered mechanisms of crosstalk between different receptor kinase pathways,and we are dissecting the molecular mechanisms underlying signalling crosstalk and specificity.Our recent proteomic analysis of BR-regulated nuclear proteins has identified a potential link for BR regulation of flowering through RNA splicing and epigenetic mechanisms.I will discuss strategies and potential pitfalls in using proteomics to study signal transduction in plants.

  2. Probing Signal Design for Power System Identification

    Energy Technology Data Exchange (ETDEWEB)

    Pierre, John W.; Zhou, Ning; Tuffner, Francis K.; Hauer, John F.; Trudnowski, Daniel J.; Mittelstadt, William

    2010-05-31

    This paper investigates the design of effective input signals for low-level probing of power systems. In 2005, 2006, and 2008 the Western Electricity Coordinating Council (WECC) conducted four large-scale system wide tests of the western interconnected power system where probing signals were injected by modulating the control signal at the Celilo end of the Pacific DC intertie. A major objective of these tests is the accurate estimation of the inter-area electromechanical modes. A key aspect of any such test is the design of an effective probing signal that leads to measured outputs rich in information about the modes. This paper specifically studies low-level probing signal design for power-system identification. The paper describes the design methodology and the advantages of this new probing signal which was successfully applied during these tests. This probing input is a multi-sine signal with its frequency content focused in the range of the inter-area modes. The period of the signal is over two minutes providing high-frequency resolution. Up to 15 cycles of the signal are injected resulting in a processing gain of 15. The resulting system response is studied in the time and frequency domains. Because of the new probing signal characteristics, these results show significant improvement in the output SNR compared to previous tests.

  3. Automatic modulation recognition of communication signals

    CERN Document Server

    Azzouz, Elsayed Elsayed

    1996-01-01

    Automatic modulation recognition is a rapidly evolving area of signal analysis. In recent years, interest from the academic and military research institutes has focused around the research and development of modulation recognition algorithms. Any communication intelligence (COMINT) system comprises three main blocks: receiver front-end, modulation recogniser and output stage. Considerable work has been done in the area of receiver front-ends. The work at the output stage is concerned with information extraction, recording and exploitation and begins with signal demodulation, that requires accurate knowledge about the signal modulation type. There are, however, two main reasons for knowing the current modulation type of a signal; to preserve the signal information content and to decide upon the suitable counter action, such as jamming. Automatic Modulation Recognition of Communications Signals describes in depth this modulation recognition process. Drawing on several years of research, the authors provide a cr...

  4. Wnt signaling: the good and the bad

    Institute of Scientific and Technical Information of China (English)

    Xi Chen; Jun Yang; Paul M Evans; Chunming Liu

    2008-01-01

    Since the first Wnt gene was identified in 1982,the functions and mechanisms of Wnt signaling have been extensively studied.Wnt signaling is conserved from invertebrates to vertebrates and regulates early embryonic development as well as the homeostasis of adult tissues.In addition,both embryonic stem cells and adult stem cells are regulated by Wnt signaling.Deregulation of Wnt signaling is associated with many human diseases,particularly cancers.In this review,we will discuss in detail the functions of many components involved in the Wnt signal transduction pathway.Then,we will explore what is known about the role of Wnt signaling in stem cells and cancers.

  5. Signal processing by the endosomal system.

    Science.gov (United States)

    Villaseñor, Roberto; Kalaidzidis, Yannis; Zerial, Marino

    2016-04-01

    Cells need to decode chemical or physical signals from their environment in order to make decisions on their fate. In the case of signalling receptors, ligand binding triggers a cascade of chemical reactions but also the internalization of the activated receptors in the endocytic pathway. Here, we highlight recent studies revealing a new role of the endosomal network in signal processing. The diversity of entry pathways and endosomal compartments is exploited to regulate the kinetics of receptor trafficking, and interactions with specific signalling adaptors and effectors. By governing the spatio-temporal distribution of signalling molecules, the endosomal system functions analogously to a digital-analogue computer that regulates the specificity and robustness of the signalling response.

  6. Selection-Mutation Dynamics of Signaling Games

    Directory of Open Access Journals (Sweden)

    Josef Hofbauer

    2015-01-01

    Full Text Available We study the structure of the rest points of signaling games and their dynamic behavior under selection-mutation dynamics by taking the case of three signals as our canonical example. Many rest points of the replicator dynamics of signaling games are not isolated and, therefore, not robust under perturbations. However, some of them attract open sets of initial conditions. We prove the existence of certain rest points of the selection-mutation dynamics close to Nash equilibria of the signaling game and show that all but the perturbed rest points close to strict Nash equilibria are dynamically unstable. This is an important result for the evolution of signaling behavior, since it shows that the second-order forces that are governed by mutation can increase the chances of successful signaling.

  7. Evolution of Cooperation Via Covert Signaling

    CERN Document Server

    Smaldino, Paul E; McElreath, Richard

    2015-01-01

    Human sociality depends upon the benefits of mutual aid and extensive communication. However mutual aid is made difficult by the problems of coordinating diverse norms and preferences, and communication is harried by substantial ambiguity in meaning. Here we demonstrate that these two facts can work together to allow cooperation to develop, by the strategic use of deliberately ambiguous signals, covert signaling. Covert signaling is the transmission of information that is accurately received by its intended audience but obscured when perceived by others. Such signals may allow coordination and enhanced cooperation while also avoiding the alienation or hostile reactions of individuals with different preferences. Although the empirical literature has identified potential mechanisms of covert signaling, such as encryption in humor, there is to date no formal theory of its dynamics. We introduce a novel mathematical model to assess the conditions under which a covert signaling strategy will be favored. We show th...

  8. Signal and Image Processing with Sinlets

    CERN Document Server

    Davydov, Alexander Y

    2012-01-01

    This paper presents a new family of localized orthonormal bases - sinlets - which are well suited for both signal and image processing and analysis. One-dimensional sinlets are related to specific solutions of the time-dependent harmonic oscillator equation. By construction, each sinlet is differentiable infinitely many times and has a well-defined and smoothly-varied instantaneous frequency known in analytical form. For square-integrable transient signals with infinite support, one-dimensional sinlet basis provides an advantageous alternative to the Fourier transform by rendering accurate signal representation via a countable set of real-valued coefficients. The properties of sinlets make them suitable for analyzing many real-world signals whose frequency content changes with time including radar and sonar waveforms, music, speech, biological echolocation sounds, biomedical signals, seismic acoustic waves, and signals employed in wireless communication systems. One-dimensional sinlet bases can be used to con...

  9. ECG signal denoising via empirical wavelet transform.

    Science.gov (United States)

    Singh, Omkar; Sunkaria, Ramesh Kumar

    2016-12-29

    This paper presents new methods for baseline wander correction and powerline interference reduction in electrocardiogram (ECG) signals using empirical wavelet transform (EWT). During data acquisition of ECG signal, various noise sources such as powerline interference, baseline wander and muscle artifacts contaminate the information bearing ECG signal. For better analysis and interpretation, the ECG signal must be free of noise. In the present work, a new approach is used to filter baseline wander and power line interference from the ECG signal. The technique utilized is the empirical wavelet transform, which is a new method used to compute the building modes of a given signal. Its performance as a filter is compared to the standard linear filters and empirical mode decomposition.The results show that EWT delivers a better performance.

  10. Long Lived NMR Signal in Bone

    CERN Document Server

    Zhang, Boyang; Khitrin, Anatoly; Jerschow, Alexej

    2012-01-01

    Solids and rigid tissues such as bone, ligaments, and tendons, typically appear dark in magnetic resonance imaging (MRI), which is due to the extremely short-lived proton nuclear magnetic resonance (NMR) signals. This short lifetime is due to strong dipolar interactions between immobilized proton spins, which render it challenging to detect these signals with sufficient resolution and sensitivity. Here we show the possibility of exciting long-lived signals in cortical bone tissue with a signature consistent with that of bound water signals. Contrary to long-standing belief, it is further shown that dipolar coupling networks are an integral requirement for the excitation of these long-lived signals. The use of these signals could enhance the ability to visualize rigid tissues and solid samples with high sensitivity, resolution, and specificity via MRI.

  11. Huntington's Disease and Striatal Signaling

    Directory of Open Access Journals (Sweden)

    Emmanuel eRoze

    2011-08-01

    Full Text Available Huntington’s Disease (HD is the most frequent neurodegenerative disease caused by an expansion of polyglutamines (CAG. The main clinical manifestations of HD are chorea, cognitive impairment and psychiatric disorders. The transmission of HD is autosomal dominant with a complete penetrance. HD has a single genetic cause, a well-defined neuropathology, and informative pre-manifest genetic testing of the disease is available. Striatal atrophy begins as early as 15 years before disease onset and continues throughout the period of manifest illness. Therefore, patients could theoretically benefit from therapy at early stages of the disease. One important characteristic of HD is the striatal vulnerability to neurodegeneration, despite similar expression of the protein in other brain areas. Aggregation of the mutated Huntingtin (HTT, impaired axonal transport, excitotoxicity, transcriptional dysregulation as well as mitochondrial dysfunction and energy deficits, are all part of the cellular events that underlie neuronal dysfunction and striatal death. Among these non-exclusive mechanisms, an alteration of striatal signaling is thought to orchestrate the downstream events involved in the cascade of striatal dysfunction.

  12. Huntington's Disease and Striatal Signaling.

    Science.gov (United States)

    Roze, Emmanuel; Cahill, Emma; Martin, Elodie; Bonnet, Cecilia; Vanhoutte, Peter; Betuing, Sandrine; Caboche, Jocelyne

    2011-01-01

    Huntington's Disease (HD) is the most frequent neurodegenerative disease caused by an expansion of polyglutamines (CAG). The main clinical manifestations of HD are chorea, cognitive impairment, and psychiatric disorders. The transmission of HD is autosomal dominant with a complete penetrance. HD has a single genetic cause, a well-defined neuropathology, and informative pre-manifest genetic testing of the disease is available. Striatal atrophy begins as early as 15 years before disease onset and continues throughout the period of manifest illness. Therefore, patients could theoretically benefit from therapy at early stages of the disease. One important characteristic of HD is the striatal vulnerability to neurodegeneration, despite similar expression of the protein in other brain areas. Aggregation of the mutated Huntingtin (HTT), impaired axonal transport, excitotoxicity, transcriptional dysregulation as well as mitochondrial dysfunction, and energy deficits, are all part of the cellular events that underlie neuronal dysfunction and striatal death. Among these non-exclusive mechanisms, an alteration of striatal signaling is thought to orchestrate the downstream events involved in the cascade of striatal dysfunction.

  13. Epigenetics and nutritional environmental signals.

    Science.gov (United States)

    Mazzio, Elizabeth A; Soliman, Karam F A

    2014-07-01

    All terrestrial life is influenced by multi-directional flows of information about its environment, enabling malleable phenotypic change through signals, chemical processes, or various forms of energy that facilitate acclimatization. Billions of biological co-inhabitants of the earth, including all plants and animals, collectively make up a genetic/epigenetic ecosystem by which adaptation/survival (inputs and outputs) are highly interdependent on one another. As an ecosystem, the solar system, rotation of the planets, changes in sunlight, and gravitational pull influence cyclic epigenetic transitions and chromatin remodeling that constitute biological circadian rhythms controlling senescence. In humans, adverse environmental conditions such as poverty, stress, alcohol, malnutrition, exposure to pollutants generated from industrialization, man-made chemicals, and use of synthetic drugs can lead to maladaptive epigenetic-related illnesses with disease-specific genes being atypically activated or silenced. Nutrition and dietary practices are one of the largest facets in epigenetic-related metabolism, where specific "epi-nutrients" can stabilize the genome, given established roles in DNA methylation, histone modification, and chromatin remodeling. Moreover, food-based "epi-bioactive" constituents may reverse maladaptive epigenetic patterns, not only prior to conception and during fetal/early postnatal development but also through adulthood. In summary, in contrast to a static genomic DNA structure, epigenetic changes are potentially reversible, raising the hope for therapeutic and/or dietary interventions that can reverse deleterious epigenetic programing as a means to prevent or treat major illnesses.

  14. RSFQ Baseband Digital Signal Processing

    Science.gov (United States)

    Herr, Anna Yurievna

    Ultra fast switching speed of superconducting digital circuits enable realization of Digital Signal Processors with performance unattainable by any other technology. Based on rapid-single-flux technology (RSFQ) logic, these integrated circuits are capable of delivering high computation capacity up to 30 GOPS on a single processor and very short latency of 0.1ns. There are two main applications of such hardware for practical telecommunication systems: filters for superconducting ADCs operating with digital RF data and recursive filters at baseband. The later of these allows functions such as multiuser detection for 3G WCDMA, equalization and channel precoding for 4G OFDM MIMO, and general blind detection. The performance gain is an increase in the cell capacity, quality of service, and transmitted data rate. The current status of the development of the RSFQ baseband DSP is discussed. Major components with operating speed of 30GHz have been developed. Designs, test results, and future development of the complete systems including cryopackaging and CMOS interface are reviewed.

  15. Advances in thermographic signal reconstruction

    Science.gov (United States)

    Shepard, Steven M.; Frendberg Beemer, Maria

    2015-05-01

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

  16. Canonical and alternative MAPK signaling.

    Science.gov (United States)

    Pimienta, Genaro; Pascual, Jaime

    2007-11-01

    The archetype of MAPK cascade activation is somewhat challenged by the most recent discovery of unexpected phosphorylation patterns, alternative activation mechanisms and sub-cellular localization, in various members of this protein kinase family. In particular, activation by autophosphorylation pathways has now been described for the three best understood MAPK subgroups: ERK1/2; JNK1/2 and p38 alpha/beta. Also, a form of dosage compensation between homologs has been shown to occur in the case of ERK1/2 and JNK1/2. In this paper we summarize the MAPK activation pathway, with an emphasis on non-canonical examples. We use this information to propose a model for MAPK signal transduction that considers a cross-talk between MAPKs with different activation loop sequence motifs and unique C-terminal extensions. We highlight the occurrence of non-canonical substrate specificity during MAPK auto-activation, in strong connection with MAPK homo- and hetero-dimerization events.

  17. Corticosteroid signaling in frog metamorphosis.

    Science.gov (United States)

    Kulkarni, Saurabh S; Buchholz, Daniel R

    2014-07-01

    Stress in fetal and larval life can impact later health and fitness in humans and wildlife. Long-term effects of early life stress are mediated by altered stress physiology induced during the process of relaying environmental effects on development. Amphibian metamorphosis has been an important model system to study the role of hormones in development in an environmental context. Thyroid hormone (TH) is necessary and sufficient to initiate the dramatic morphological and physiological changes of metamorphosis, but TH alone is insufficient to complete metamorphosis. Other hormones, importantly corticosteroid hormones (CSs), influence the timing and nature of post-embryonic development. Stressors or treatments with CSs delay or accelerate metamorphic change, depending on the developmental stage of treatment. Also, TH and CSs have synergistic, antagonistic, and independent effects on gene regulation. Importantly, the identity of the endogenous corticosteroid hormone or receptor underlying any gene induction or remodeling event has not been determined. Levels of both CSs, corticosterone and aldosterone, peak at metamorphic climax, and the corticosteroid receptors, glucocorticoid and mineralocorticoid receptors, have wide expression distribution among tadpole tissues. Conclusive experiments to identify the endogenous players have been elusive due to difficulties in experimental control of corticosteroid production and signaling. Current data are consistent with the hypothesis that the two CSs and their receptors serve largely overlapping functions in regulating metamorphosis and synergy with TH. Knowledge of the endogenous players is critical to understanding the basic mechanisms and significance of corticosteroid action in regulating post-embryonic development in environmental contexts.

  18. Signal and image processing in medical applications

    CERN Document Server

    Kumar, Amit; Rahim, B Abdul; Kumar, D Sravan

    2016-01-01

    This book highlights recent findings on and analyses conducted on signals and images in the area of medicine. The experimental investigations involve a variety of signals and images and their methodologies range from very basic to sophisticated methods. The book explains how signal and image processing methods can be used to detect and forecast abnormalities in an easy-to-follow manner, offering a valuable resource for researchers, engineers, physicians and bioinformatics researchers alike.

  19. Endocannabinoid signaling in reward and addiction

    OpenAIRE

    Parsons, Loren H.; Hurd, Yasmin L.

    2015-01-01

    Brain endocannabinoid signaling influences the motivation for natural rewards (such as palatable food, sexual activity and social interaction) and modulates the rewarding effects of addictive drugs. Pathological forms of natural and drug-induced reward are associated with dysregulated endocannabinoid signaling that may derive from pre-existing genetic factors or from prolonged drug exposure. Impaired endocannabinoid signaling contributes to dysregulated synaptic plasticity, increased stress r...

  20. L1-norm minimization for quaternion signals

    CERN Document Server

    Wu, Jiasong; Wang, Xiaoqing; Senhadji, Lotfi; Shu, Huazhong

    2012-01-01

    The l1-norm minimization problem plays an important role in the compressed sensing (CS) theory. We present in this letter an algorithm for solving the problem of l1-norm minimization for quaternion signals by converting it to second-order cone programming. An application example of the proposed algorithm is also given for practical guidelines of perfect recovery of quaternion signals. The proposed algorithm may find its potential application when CS theory meets the quaternion signal processing.