Science.gov

Sample records for arrows signals

  1. Wingless/Wnt signal transduction requires distinct initiation and amplification steps that both depend on Arrow/LRP

    PubMed Central

    Baig-Lewis, Shahana; Peterson-Nedry, Wynne; Wehrli, Marcel

    2007-01-01

    Members of the Wg/Wnt family provide key intercellular signals during embryonic development and in the maintenance of homeostatic processes, but critical aspects of their signal transduction pathways remain controversial. We have found that canonical Wg signaling in Drosophila involves distinct initiation and amplification steps, both of which require Arrow/LRP. Expressing a chimeric Frizzled2-Arrow protein in flies that lack endogenous Wg or Arrow showed that this construct functions as an activated Wg receptor but is deficient in signal amplification. In contrast, a chimeric Arrow protein containing the dimerization domain of Torso acted as a potent amplifier of Wg signaling but could not initiate Wg signaling on its own. The two chimeric proteins synergized, so that their co-expression largely reconstituted the signaling levels achieved by expressing Wg itself. The amplification function of Arrow/LRP appears to be particularly important for long-range signaling, and may reflect a general mechanism for potentiating signals in the shallow part of a morphogen gradient. PMID:17433287

  2. Cellerator: extending a computer algebra system to include biochemical arrows for signal transduction simulations

    NASA Technical Reports Server (NTRS)

    Shapiro, Bruce E.; Levchenko, Andre; Meyerowitz, Elliot M.; Wold, Barbara J.; Mjolsness, Eric D.

    2003-01-01

    Cellerator describes single and multi-cellular signal transduction networks (STN) with a compact, optionally palette-driven, arrow-based notation to represent biochemical reactions and transcriptional activation. Multi-compartment systems are represented as graphs with STNs embedded in each node. Interactions include mass-action, enzymatic, allosteric and connectionist models. Reactions are translated into differential equations and can be solved numerically to generate predictive time courses or output as systems of equations that can be read by other programs. Cellerator simulations are fully extensible and portable to any operating system that supports Mathematica, and can be indefinitely nested within larger data structures to produce highly scaleable models.

  3. Cellerator: extending a computer algebra system to include biochemical arrows for signal transduction simulations.

    PubMed

    Shapiro, Bruce E; Levchenko, Andre; Meyerowitz, Elliot M; Wold, Barbara J; Mjolsness, Eric D

    2003-03-22

    Cellerator describes single and multi-cellular signal transduction networks (STN) with a compact, optionally palette-driven, arrow-based notation to represent biochemical reactions and transcriptional activation. Multi-compartment systems are represented as graphs with STNs embedded in each node. Interactions include mass-action, enzymatic, allosteric and connectionist models. Reactions are translated into differential equations and can be solved numerically to generate predictive time courses or output as systems of equations that can be read by other programs. Cellerator simulations are fully extensible and portable to any operating system that supports Mathematica, and can be indefinitely nested within larger data structures to produce highly scaleable models.

  4. Loss of Tc-arrow and canonical Wnt signaling alters posterior morphology and pair-rule gene expression in the short-germ insect, Tribolium castaneum.

    PubMed

    Bolognesi, Renata; Fischer, Tamara D; Brown, Susan J

    2009-07-01

    Wnt signaling has been implicated in posterior patterning in short-germ insects, including the red flour beetle Tribolium castaneum (Bolognesi et al. Curr Biol 18:1624-1629, 2008b; Angelini and Kaufman Dev Biol 283:409-423, 2005; Miyawaki et al. Mech Dev 121:119-130, 2004). Specifically, depletion of Wnt ligands Tc-Wnt1 and Tc-WntD/8 produces Tribolium embryos lacking abdominal segments. Similar phenotypes are produced by depletion of Tc-porcupine (Tc-porc) or Tc-pangolin (Tc-pan), indicating that the signal is transmitted through the canonical Wnt pathway (Bolognesi et al. Curr Biol 18:1624-1629, 2008b). Here we show that RNAi for the receptor Tc-arrow produced similar truncated phenotypes, providing additional evidence supporting canonical signal transduction. Furthermore, since in Tribolium segments are defined sequentially by a pair-rule gene circuit that, when interrupted, produces truncated phenotypes (Choe et al. Proc Natl Acad Sci U S A 103:6560-6564, 2006), we investigated the relationship between loss of Wnt signaling and this pair-rule gene circuit. After depletion of the receptor Tc-arrow, expression of Tc-Wnt1 was noticeably absent from the growth zone, while Tc-WntD/8 was restricted to a single spot of expression in what remained of the posterior growth zone. The primary pair-rule genes Tc-runt (Tc-run) and Tc-even-skipped (Tc-eve) were expressed normally in the anterior segments, but were reduced to a single spot in the remnants of the posterior growth zone. Thus, expression of pair-rule genes and Tc-WntD/8 are similarly affected by depletion of Wnt signal and disruption of the posterior growth zone.

  5. Time's Arrows Today

    NASA Astrophysics Data System (ADS)

    Savitt, Steven F.

    1997-06-01

    Introduction; Part I. Cosmology and Time's Arrow: 1. Time, gravity, and quantum mechanics W. Unruh; 2. Cosmology, time's arrow, and that old double standard H. Price; Part II. Quantum Theory and Time's Arrow: 3. Time's arrow and the quantum measurement problem A. Leggett; 4. Time, decoherence, and 'reversible' measurements P. Stamp; 5. Time flows, non-locality, and measurement in quantum mechanics S. McCall; 6. Stochastically branching spacetime topology R. Douglas; Part III. Thermodynamics and Time's Arrow: 7. The elusive object of desire: in pursuit of the kinetic equations and the second law L. Sklar; 8. Time in experience and in theoretical description of the world L. Sklar; 9. When and why does entropy increase? M. Barrett and E. Sober; Part IV. Time Travel and Time's Arrow: 10. Closed causal chains P Horwich; 11. Recent work on time travel J. Earman.

  6. Intrauterine Arrow Injury

    PubMed Central

    Goswami, Jayanta Kumar; Lahiri, Kaushik

    2017-01-01

    Injury of a pregnant lady risks both mother and fetus. Various modes of injuries are possible. But arrow injury is not usually heard of in today's world. We have reported a male child delivered with a cut injury on the face. It was caused by a penetrating arrow hitting his mother in her lower abdomen at term. The injury of the baby was repaired successfully. PMID:28082780

  7. Bow and arrow dynamics

    NASA Astrophysics Data System (ADS)

    Marlow, W. C.

    1981-04-01

    Past analyses of bow and arrow dynamics have assumed the string to be inextensible. This results in predictions of efficiencies that are significantly higher than measured values (efficiencies over 90% are predicted versus 70% to 85% for measurements, circa 1960). The present analysis allows for an elastic string. It is found that arrow exit then takes place when the string and bow limbs still have substantial kinetic energy, and therefore this energy is unavailable for kinetic energy of the arrow. Moreover, the potential energy remaining in the string and bow limb system can also reduce the amount of energy available for the arrow. For the Hickman model of a long bow used in this study, the elastic string prediction of efficiency is 78%, whereas the inelastic prediction is 92%. The analysis utilizes a Lagrangian distributed mass formulation to develop the governing equations of motion and to generate an equivalent point mass model. The equations of motion were numerically integrated to obtain efficiency, arrow velocity, virtual masses, string tension, string extension, arrow exit time, string and limb potential energies, system momentum, and the dynamic force required to hold the bow handle stationary. Estimates of the effect of air resistance were made and found to be less than 2% of the total system energy. The vibratory dynamics of the string and bow limbs subsequent to arrow exit was analyzed. The results of the elastic string considerations are in reasonable agreement with experimental data and negate the usual explanation for the long-standing discrepancy between theory and experiment as due to air resistance and hysteresis losses in the string and bow limbs.

  8. [Homicide by bow and arrow].

    PubMed

    Germerott, Tanja; Jänisch, Stefanie; Tröger, Hans Dieter; Günther, Detlef

    2010-01-01

    Since the invention of firearms, arrow wounds represent a rarity in the daily routine of forensic pathologists. In the present paper, we describe a homicide by a broadhead arrow shot from a compound bow in a domestic environment. Based on this homicide, we discuss the characteristics of the lesion caused by broadhead arrows and field-tip arrows. We look critically at the free saleability of this equipment mostly used for sport shooting in Germany.

  9. Aiming ARROW at Learning Targets.

    ERIC Educational Resources Information Center

    Lane, Colin

    1987-01-01

    ARROW (Aural-Read-Respond-Oral-Written) is a multisensory teaching approach where children listen to their own voices on tape recorders. Advantages of the ARROW program as demonstrated at four sites in Blackford, Somerset (England), with elementary/secondary students presenting moderate to severe learning difficulties, reading/spelling/vocabulary…

  10. A subquantum arrow of time

    NASA Astrophysics Data System (ADS)

    Nieuwenhuizen, Theo M.

    2014-04-01

    The outcome of a single quantum experiment is unpredictable, except in a pure-state limit. The definite process that takes place in the apparatus may either be intrinsically random or be explainable from a deeper theory. While the first scenario is the standard lore, the latter implies that quantum mechanics is emergent. In that case, it is likely that one has to reconsider radiation by accelerated charges as a physical effect, which thus must be compensated by an energy input. Stochastic electrodynamics, for example, asserts that the vacuum energy arises from classical fluctuations with energy 1/2hslashω per mode. In such theories the stability of the hydrogen ground state will arise from energy input from fluctuations and output by radiation, hence due to an energy throughput. That flux of energy constitutes an arrow of time, which we call the "subquantum arrow of time". It is related to the stability of matter and it is more fundamental than, e.g., the thermodynamic and cosmological arrows.

  11. Bow-arrow interaction in archery.

    PubMed

    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.

  12. Environmental and Molecular Science Laboratory Arrow

    SciTech Connect

    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.

  13. Illustrating cerebral function: the iconography of arrows.

    PubMed

    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.

  14. Illustrating cerebral function: the iconography of arrows.

    PubMed Central

    Schott, G D

    2000-01-01

    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. PMID:11205341

  15. Mathematical origin of time arrow

    NASA Astrophysics Data System (ADS)

    Shimansky, Yury

    2005-03-01

    Laws describing the main types of physical interactions are symmetrical with respect to the direction of time flow. At the same time, many virtually irreversible processes are observed. This ``time arrow'' paradox usually is associated with the law of entropy increase. The fact that physical systems obey this law regardless of their physical nature suggests that it may be based on a certain, yet unknown, mathematical principle. Here it is demonstrated that, if, on a time micro scale, the intensity of fluctuations of a certain parameter depends on the parameter's value, it would appear to an external observer on a time macro scale that the parameter tends to be modified in the direction of fluctuation intensity decrease. It is shown that the law of entropy increase is a consequence of this principle, if it is applied to entropy as a state variable of a thermodynamic system. The fundamental nature of this principle suggests that it must operate on virtually every level of physical reality. The principle is of great potential value for understanding mechanisms of self-organization, learning, adaptation, and evolution.

  16. Electromyography of arrow release in archery.

    PubMed

    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.

  17. Entanglement and the thermodynamic arrow of time

    NASA Astrophysics Data System (ADS)

    Jennings, David; Rudolph, Terry

    2010-06-01

    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.

  18. Decision Making in the Arrow of Time.

    PubMed

    Roldán, Édgar; Neri, Izaak; Dörpinghaus, Meik; Meyr, Heinrich; Jülicher, Frank

    2015-12-18

    We show that the steady-state entropy production rate of a stochastic process is inversely proportional to the minimal time needed to decide on the direction of the arrow of time. Here we apply Wald's sequential probability ratio test to optimally decide on the direction of time's arrow in stationary Markov processes. Furthermore, the steady-state entropy production rate can be estimated using mean first-passage times of suitable physical variables. We derive a first-passage time fluctuation theorem which implies that the decision time distributions for correct and wrong decisions are equal. Our results are illustrated by numerical simulations of two simple examples of nonequilibrium processes.

  19. Decision Making in the Arrow of Time

    NASA Astrophysics Data System (ADS)

    Roldán, Édgar; Neri, Izaak; Dörpinghaus, Meik; Meyr, Heinrich; Jülicher, Frank

    2015-12-01

    We show that the steady-state entropy production rate of a stochastic process is inversely proportional to the minimal time needed to decide on the direction of the arrow of time. Here we apply Wald's sequential probability ratio test to optimally decide on the direction of time's arrow in stationary Markov processes. Furthermore, the steady-state entropy production rate can be estimated using mean first-passage times of suitable physical variables. We derive a first-passage time fluctuation theorem which implies that the decision time distributions for correct and wrong decisions are equal. Our results are illustrated by numerical simulations of two simple examples of nonequilibrium processes.

  20. Arrow 227: Air transport system design simulation

    NASA Technical Reports Server (NTRS)

    Bontempi, Michael; Bose, Dave; Brophy, Georgeann; Cashin, Timothy; Kanarios, Michael; Ryan, Steve; Peterson, Timothy

    1992-01-01

    The Arrow 227 is a student-designed commercial transport for use in a overnight package delivery network. The major goal of the concept was to provide the delivery service with the greatest potential return on investment. The design objectives of the Arrow 227 were based on three parameters; production cost, payload weight, and aerodynamic efficiency. Low production cost helps to reduce initial investment. Increased payload weight allows for a decrease in flight cycles and, therefore, less fuel consumption than an aircraft carrying less payload weight and requiring more flight cycles. In addition, fewer flight cycles will allow a fleet to last longer. Finally, increased aerodynamic efficiency in the form of high L/D will decrease fuel consumption.

  1. Suicide using a compound bow and arrow.

    PubMed

    Cina, S J; Radentz, S S; Smialek, J E

    1998-03-01

    Accidental, suicidal, and homicidal injuries have been caused by arrows fired from crossbows. To our knowledge, a case of suicide using a full-size compound bow to fire a projectile has not been reported in the English literature. Described is a case of a 17-year-old man who shot himself in the chest with a broadhead hunting arrow fired from a compound bow. Examination of the footwear suggests that the decedent drew the bowstring with his left foot while holding the bow in his hands. The mechanism of injury is discussed. When dealing with a longbow-related fatality, examination of the weaponry used and reenactment of the fatal methodology are critical in determining whether self-inflicted injury is a probability.

  2. t {r_arrow} cWW and WW {r_arrow} {anti t}c + t{anti c} in extended models

    SciTech Connect

    David Atwood; Marc Sher

    1997-07-01

    Jenkins has pointed out that the process t {r_arrow} cW{sup +}W{sup {minus}}is GIM suppressed in the standard model. In this note, the authors calculate the branching ratio for a wide range of models, in which the decay occurs at tree level through exchange of a scalar, fermion or vector. In the case of scalar exchange, a scalar mass between 2m{sub W} and 200 GeV leads to a resonant enhancement, giving a branching ratio as high as a few tenths of a percent. They then note that all of these models will also allow W{sup +}W{sup {minus}} {r_arrow} {anti t}c + t{anti c}, and they calculate the single-top/single-charm production rate at the LHC. The rates aren't negligibly small, but the background from single-top/single-bottom production will probably swamp the signal.

  3. Penetrating injury of ascending aorta with arrow in situ.

    PubMed

    Lakhotia, Siddharth; Prakash, Shashi; Singh, Dinesh Kumar; Kumar, Ashok; Panigrahi, Debasish

    2012-04-01

    Penetrating injuries of the aorta are rare and highly lethal; very few patients are able to reach the hospital alive. We report a case of penetrating injury into the ascending aorta with the arrow still in situ, shot by a bow in a tribal region of India. The wound of entry into the aorta was sealed by the arrow itself. The patient came to us walking and supporting the arrow with his left hand. He was operated on, and the arrow was successfully removed from the aorta.

  4. GreenArrow version 1.0

    SciTech Connect

    2006-03-29

    GreenArrow is a visualization program for displaying directed graphs that can use text in place of lines to represent the edges between nodes. This text can be animated to show the link direction, and allow for more text to be displayed then would normally be allowed. The text is also tapered and arced to show direction. The node labels can be wrapped around the node to avoid label crossing as well. The program is interactive, and allows the user to zoom, pan and rotate a graph, as well as manipulate the individual nodes.

  5. Probability of Intrinsic Time-Arrow from Information Loss

    NASA Astrophysics Data System (ADS)

    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.

  6. Observation of [ital D][sup 0][r arrow][ital K][sup +][pi][sup [minus

    SciTech Connect

    Cinabro, D.; Henderson, S.; Liu, T.; Saulnier, M.; Wilson, R.; Yamamoto, H.; Bergfeld, T.; Eisenstein, B.I.; Gollin, G.; Ong, B.; Palmer, M.; Selen, M.; Thaler, J.J.; Sadoff, A.J.; Ammar, R.; Ball, S.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Copty, N.; Davis, R.; Hancock, N.; Kelly, M.; Kwak, N.; Lam, H.; Kubota, Y.; Lattery, M.; Nelson, J.K.; Patton, S.; Perticone, D.; Poling, R.; Savinov, V.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Nemati, B.; O'Neill, J.J.; Severini, H.; Sun, C.R.; Zoeller, M.M.; Crawford, G.; Daubenmier, C.M.; Fulton, R.; Fujino, D.; Gan, K.K.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Morrow, F.; Skovpen, Y.; Sung, M.; White, C.; Butler, F.; Fu, X.; Kalbfleisch, G.; Ross, W.R.; Skubic, P.; Snow, J.; Wang, P.L.; Wood, M.; Brown, D.N.; Fast, J.; 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.; Kwon, Y.; Roberts, S.; Thorndike, E.H.; Wang, C.H.; Dominick,

    1994-03-07

    Using the CLEO II data sample, with an integrated luminosity of 1.8 fb[sup [minus]1] at and near the [Upsilon](4[ital S]) resonance, we have observed a signal for [ital D][sup 0][r arrow][ital K][sup +][pi][sup [minus

  7. Results on {nu}{sub {mu}}{r_arrow}{nu}{sub e} oscillations from pion decay in flight neutrinos

    SciTech Connect

    Church, E.D.; McIlhany, K.; Stancu, I.; Strossman, W.; VanDalen, G.J.; Vernon, W.; Caldwell, D.O.; Yellin, S.; Smith, D.; Waltz, J.; Cohen, I.; Burman, R.L.; Donahue, J.B.; Federspiel, F.J.; Garvey, G.T.; Louis, W.C.; Mills, G.B.; Sandberg, V.; Tayloe, R.; White, D.H.; Gunasingha, R.M.; Imlay, R.; Kim, H.J.; Metcalf, W.; Wadia, N.; Johnston, K.; Reeder, R.A.; Fazely, A.; Athanassopoulos, C.; Auerbach, L.B.; Majkic, R.; Works, D.; Xiao, Y.

    1998-10-01

    A search for {nu}{sub {mu}}{r_arrow}{nu}{sub e} oscillations has been conducted at the Los Alamos Meson Physics Facility using {nu}{sub {mu}} from {pi}{sup +} decay in flight. An excess in the number of beam-related events from the {nu}{sub e}C{r_arrow}e{sup {minus}}X inclusive reaction is observed. The excess is too large to be explained by normal {nu}{sub e} contamination in the beam at a confidence level greater than 99{percent}. If interpreted as an oscillation signal, the observed oscillation probability of (2.6{plus_minus}1.0{plus_minus}0.5){times}10{sup {minus}3} is consistent with the previously reported {bar {nu}}{sub {mu}}{r_arrow}{bar {nu}}{sub e} oscillation evidence from LSND. {copyright} {ital 1998} {ital The American Physical Society}

  8. Adding and subtracting vectors: The problem with the arrow representation

    NASA Astrophysics Data System (ADS)

    Heckler, Andrew F.; Scaife, Thomas M.

    2015-06-01

    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 of vector addition and subtraction in both the arrow and algebraic notation (using i ^, j ^, k ^) in generic mathematical and physics contexts. First, we replicated a number of previous findings of student difficulties in the arrow format and discovered several additional difficulties, including the finding that different relative arrow orientations can prompt different solution paths and different kinds of mistakes, which suggests that students need to practice with a variety of relative orientations. Most importantly, we found that average performance in the i j k format was typically excellent and often much better than performance in the arrow format in either the generic or physics contexts. Further, while we find that the arrow format tends to prompt students to a more physically intuitive solution path, we also find that, when prompted, student solutions in the i j k format also display significant physical insights into the problem. We also find a hierarchy in correct answering between the two formats, with correct answering in the i j k format being more fundamental than for the arrow format. Overall, the results suggest that many student difficulties with these simple vector problems lie with the arrow representation itself. For instruction, these results imply that introducing the i j k notation (or some equivalent) with the arrow notation concurrently may be a very useful way to improve student performance as well as help students to learn physics concepts involving vector addition and subtraction.

  9. Work-place homicide by bow and arrow.

    PubMed

    Eriksson, A; Georén, B; Oström, M

    2000-07-01

    Arrow wounds represent an unusual class of wounds rarely seen by most forensic pathologists. In this paper we present a case of homicide by bow and arrow and the characteristics of such injuries. The essential characteristics of the lesions obtained from conically-tapered field points and from hunting broadhead tips are described and discussed in relation to injuries caused by firearm bullets. In the present case, three arrows struck the victim, and the order in which the injuries were sustained are analyzed. We also discuss the possibilities of localizing the shooter relative to the victim by analysis of the trajectories.

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

    ERIC Educational Resources Information Center

    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…

  11. Visuospatial Attention Is Guided by Both the Symbolic Value and the Spatial Proximity of Selected Arrows

    ERIC Educational Resources Information Center

    Pratt, Jay; Radulescu, Petre; Guo, Ruo Mu; Hommel, Bernhard

    2010-01-01

    There is considerable evidence that overlearned symbols, especially arrows, can orient attention to peripheral locations. In 2003, Pratt and Hommel showed that when 1 arrow is selected from a set of arrows, based on an attentional control setting for a specific target color, the selected arrow determines the orientation of attention. Recently,…

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

    SciTech Connect

    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.

  13. ARROW-PAK Macroencapsulation. Innovative Technology Summary Report

    SciTech Connect

    2002-04-01

    An ARROW-PAK is a high density polyethylene (HDPE) tube, about 21 feet long and 30 inches wide. Each ARROW-PAK can hold the equivalent of 21 55-gallon drums of mixed waste debris. Each tube is fused to HDPE endcaps using localized heating and high pressure contact. The sleeves and encaps form a tube for macroencapsulating mixed waste debris. The ARROW-PAK may achieve a mixed waste debris volume one-fourth that of the conventional macroencapsulation approach. The mixed waste debris is loaded into 55-gallon drums. Once filled a 'supercompactor' crushes the drums into 12-inch thick pucks. Three pucks can be loaded into a standard 85-gallon metal drum known as an 'overpack'. Seven overpacks fit into each ARROW-PAK.

  14. Relation between the psychological and thermodynamic arrows of time

    NASA Astrophysics Data System (ADS)

    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.

  15. Synthetic Minor NSR Permit: Arrow Pipeline, LLC - Station #7

    EPA Pesticide Factsheets

    This page contains the final synthetic minor permit to construct for the Arrow Pipeline, LLC, Station #7, located within the exterior boundaries of the Fort Berthold Indian Reservation in Dunn County, North Dakota.

  16. Charming penguin contributions to B{r_arrow}K{pi}

    SciTech Connect

    Isola, C.; Ladisa, M.; Nardulli, G.; Pham, T. N.; Santorelli, P.

    2001-07-01

    We present calculations of the charming-penguin long-distance contributions to B{r_arrow}K{pi} decays due to intermediate charmed meson states. Our calculation is based on the chiral effective Lagrangian for light and heavy mesons, corrected for the hard pion and kaon momenta. We find that the charming-penguin contributions increase significantly the B{r_arrow}K{pi} decay rates in comparison with the short-distance contributions, giving results in better agreement with experimental data.

  17. The bow and arrow in northern North America.

    PubMed

    Maschner, Herbert; Mason, Owen K

    2013-01-01

    There were at least four waves of bow and arrow use in northern North America. These occurred at 12000, 4500, 2400, and after about 1300 years ago. But to understand the role of the bow and arrow in the north, one must begin in the eighteenth century, when the Russians first arrived in the Aleutian Islands. At that time, the Aleut were using both the atlatl and dart and the bow and arrow (Fig. ). This is significant for two particular and important reasons. First, there are few historic cases in which both technologies were used concurrently; second, the bow and arrow in the Aleutian Islands were used almost exclusively in warfare. The atlatl was a critical technology because the bow and arrow are useless for hunting sea mammals. One cannot launch an arrow from a kayak because it is too unstable and requires that both hands remain on a paddle. To use an atlatl, it is necessary only to stabilize the kayak with a paddle on one side and launch the atlatl dart with the opposite hand. The Aleut on the Alaska Peninsula did indeed use the bow and arrow to hunt caribou there. However, in the 1,400 km of the Aleutian Islands, there are no terrestrial mammals except humans and the bow was reserved almost exclusively for conflicts among them. The most significant event in the history of the bow and arrow is not its early introduction, but rather the Asian War Complex 1300 years ago, when the recurve and backed bows first entered the region, altering regional and hemispheric political dynamics forever. [Figure: see text].

  18. Better security levels for broken arrows

    NASA Astrophysics Data System (ADS)

    Xie, Fuchun; Furon, Teddy; Fontaine, Caroline

    2010-01-01

    This paper deals with the security of the robust zero-bit watermarking technique "Broken Arrows" (BA),1 which was invented and tested for the international challenge BOWS-2.2 The results of the first episode of the challenge showed that BA is very robust and we proposed last year an enhancement called "Averaging Wavelet Coefficients" (AWC),3 which further strengthens the robustness against the worst attack disclosed during this BOWS-2's first episode.4 However, in the second and third episodes of the challenge, during which the pirates could observe plenty of pictures watermarked with the same secret key, security flaws have been revealed and discussed.5 Here we propose counterattacks to these security flaws, investigating BA and its variant AWC. We propose two counterattack directions: to use the embedding technique AWC instead of BA, and to regulate the system parameters to lighten the watermarking embedding footprint. We also discuss these directions in the context of traitor tracing.6 Experimental results show that following these recommendations is sufficient to counter these attacks.

  19. Electrodynamic arrow of time and cosmology

    NASA Astrophysics Data System (ADS)

    Radecke, Hans-Dieter

    Simplified mathematical models were used for the examination of the relationship between the arrows of time of electrodynamics and cosmology. The model of a 1-D harmonic oscillator, coupled to a scalar field, was first used. The combined system of coupled differential equations could be exactly resolved and allowed an examination of the field solution type, with regard to retard and advance in the framework of the cosmological geometry of the standard model, by which a closed universe was taken as a basis. It was shown that the oscillation radiation was clearly retarded at the big bang, and clearly advanced at the final explosion. In order to interpolate between these asymptotical boundary values, it was necessary to consider the radiation absorption of the cosmical medium. The general behavior of the considered system solutions showed that only the retarded radiation prevailed at big bang. Because of the cosmical absorption, its amplitude was completely attenuated to zero, before the universe heat death was installed. The advanced field amplitude is to be preceived after the universe contraction beginning and swings to a maximal value which is reached at the final explosion.

  20. Maxwell's demons everywhere: evolving design as the arrow of time.

    PubMed

    Bejan, Adrian

    2014-02-10

    Science holds that the arrow of time in nature is imprinted on one-way (irreversible) phenomena, and is accounted for by the second law of thermodynamics. Here I show that the arrow of time is painted much more visibly on another self-standing phenomenon: the occurrence and change (evolution in time) of flow organization throughout nature, animate and inanimate. This other time arrow has been present in science but not recognized as such since the birth of thermodynamics. It is Maxwell's demon. Translated in macroscopic terms, this is the physics of the phenomenon of design, which is the universal natural tendency of flow systems to evolve into configurations that provide progressively greater access over time, and is summarized as the constructal law of design and evolution in nature. Knowledge is the ability to effect design changes that facilitate human flows on the landscape. Knowledge too flows.

  1. Maxwell's Demons Everywhere: Evolving Design as the Arrow of Time

    PubMed Central

    Bejan, Adrian

    2014-01-01

    Science holds that the arrow of time in nature is imprinted on one-way (irreversible) phenomena, and is accounted for by the second law of thermodynamics. Here I show that the arrow of time is painted much more visibly on another self-standing phenomenon: the occurrence and change (evolution in time) of flow organization throughout nature, animate and inanimate. This other time arrow has been present in science but not recognized as such since the birth of thermodynamics. It is Maxwell's demon. Translated in macroscopic terms, this is the physics of the phenomenon of design, which is the universal natural tendency of flow systems to evolve into configurations that provide progressively greater access over time, and is summarized as the constructal law of design and evolution in nature. Knowledge is the ability to effect design changes that facilitate human flows on the landscape. Knowledge too flows. PMID:24510201

  2. Time's arrows today. Recent physical and philosophical work on the direction of time.

    NASA Astrophysics Data System (ADS)

    Savitt, S. F.

    Most of the work in this volume, the paperback version of the 1995 edition, was presented at a conference, Vancouver, B.C. (Canada), Jun 1992. The eleven contributions are arranged under the following subject headings: 1. Cosmology and time's arrow (W. Unruh, H. Price). 2. Quantum theory and time's arrow (A. Leggett, P. Stamp, S. McCall, R. Douglas). 3. Thermodynamics and time's arrow (L. Sklar, M. Barrett, E. Sober). 4. Time travel and time's arrow (P. Horwich, J. Earman).

  3. 26 CFR 48.4161(b)-1 - Imposition and rates of tax; bows and arrows.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Imposition and rates of tax; bows and arrows. 48... Imposition and rates of tax; bows and arrows. (a) Imposition of tax. Section 4161(b) imposes a tax on the... bow or arrow described in subparagraph (1) or (2) of this paragraph; and (4) Any quiver suitable...

  4. Cystic hematoma formation following use of a biodegradable arrow for meniscal repair.

    PubMed

    Hechtman, K S; Uribe, J W

    1999-03-01

    This is a case report of a cystic hematoma formation following the use of a biodegradable arrow for repair of a medial meniscus tear. A literature search found no previous report of this complication. Open hematoma debridement and arrow removal were effective in the treatment of this complication following all-inside meniscal repair with a biodegradable arrow.

  5. Elliptical Orbit [arrow right] 1/r[superscript 2] Force

    ERIC Educational Resources Information Center

    Prentis, Jeffrey; Fulton, Bryan; Hesse, Carol; Mazzino, Laura

    2007-01-01

    Newton's proof of the connection between elliptical orbits and inverse-square forces ranks among the "top ten" calculations in the history of science. This time-honored calculation is a highlight in an upper-level mechanics course. It would be worthwhile if students in introductory physics could prove the relation "elliptical orbit" [arrow right]…

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

    ERIC Educational Resources Information Center

    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…

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

    SciTech Connect

    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

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Damped Arrow-Hurwicz algorithm for sphere packing

    NASA Astrophysics Data System (ADS)

    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.

  11. Overview of the Cranked-Arrow Wing Aerodynamics Project International

    NASA Technical Reports Server (NTRS)

    Obara, Clifford J.; Lamar, John E.

    2008-01-01

    This paper provides a brief history of the F-16XL-1 aircraft, its role in the High Speed Research program and how it was morphed into the Cranked Arrow Wing Aerodynamics Project. Various flight, wind-tunnel and Computational Fluid Dynamics data sets were generated as part of the project. These unique and open flight datasets for surface pressures, boundary-layer profiles and skin-friction distributions, along with surface flow data, are described and sample data comparisons given. This is followed by a description of how the project became internationalized to be known as Cranked Arrow Wing Aerodynamics Project International and is concluded by an introduction to the results of a four year computational predictive study of data collected at flight conditions by participating researchers.

  12. Transfer entropy in physical systems and the arrow of time

    NASA Astrophysics Data System (ADS)

    Spinney, Richard E.; Lizier, Joseph T.; Prokopenko, Mikhail

    2016-08-01

    Recent developments have cemented the realization that many concepts and quantities in thermodynamics and information theory are shared. In this paper, we consider a highly relevant quantity in information theory and complex systems, the transfer entropy, and explore its thermodynamic role by considering the implications of time reversal upon it. By doing so we highlight the role of information dynamics on the nuanced question of observer perspective within thermodynamics by relating the temporal irreversibility in the information dynamics to the configurational (or spatial) resolution of the thermodynamics. We then highlight its role in perhaps the most enduring paradox in modern physics, the manifestation of a (thermodynamic) arrow of time. We find that for systems that process information such as those undergoing feedback, a robust arrow of time can be formulated by considering both the apparent physical behavior which leads to conventional entropy production and the information dynamics which leads to a quantity we call the information theoretic arrow of time. We also offer an interpretation in terms of optimal encoding of observed physical behavior.

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

    NASA Astrophysics Data System (ADS)

    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

  14. [Forensic medical assessment of injuries to the human body and clothes caused by a crossbow arrow].

    PubMed

    2011-01-01

    Analysis of the data published in the special literature revealed the lack of information for the objective comprehensive forensic medical evaluation of injuries to the human body and clothes caused by the arrows from different models of crossbows. Morphological characteristics of injuries were shown to strongly depend on the design features of the arrows. This fact can be used to differentiate between injuries inflicted by crossbow arrows and other types of missile weapons.

  15. Arrow shaft injury of the wrist and hand: case report, management, and surgical technique.

    PubMed

    Launikitis, Robert A; Viegas, Steven F

    2009-01-01

    A case of accidental, self-inflicted injury to the hand from a hollow carbon shaft arrow which broke in its midshaft while attempting to shoot the arrow from a compound bow is presented. Basic knowledge of low velocity gunshot wounds and arrow injuries was applied in the treatment of this injury along with a unique management technique. The outcome, including hand function was good without any functional loss.

  16. 75 FR 26889 - Airworthiness Directives; Arrow Falcon Exporters, Inc. (previously Utah State University) et al...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-13

    ... to read as follows: Arrow Falcon Exporters, Inc. (previously Utah State University); Firefly Aviation... International Aviation, Inc.); International Helicopters, Inc.; Precision Helicopters, LLC; Robinson Air...

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

    PubMed

    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.

  18. Time arrow is influenced by the dark energy.

    PubMed

    Allahverdyan, A E; Gurzadyan, V G

    2016-05-01

    The arrow of time and the accelerated expansion are two fundamental empirical facts of the universe. We advance the viewpoint that the dark energy (positive cosmological constant) accelerating the expansion of the universe also supports the time asymmetry. It is related to the decay of metastable states under generic perturbations, as we show on example of a microcanonical ensemble. These states will not be metastable without dark energy. The latter also ensures a hyperbolic motion leading to dynamic entropy production with the rate determined by the cosmological constant.

  19. SCAR arrow-wing active flutter suppression system

    NASA Technical Reports Server (NTRS)

    Gordon, C. K.; Visor, O. E.

    1977-01-01

    The potential performance and direct operating cost benefits of an active flutter suppression system (FSS) for the NASA arrow-wing supersonic cruise configuration were determined. A FSS designed to increase the flutter speed of the baseline airplane 20 percent. A comparison was made of the performance and direct operating cost between the FSS equipped aircraft and a previously defined configuration with structural modifications to provide the same flutter speed. Control system synthesis and evaluation indicated that a FSS could provide the increase in flutter speed without degrading airplane reliability, safety, handling qualities, or ride quality, and without increasing repeated loads or hydraulic and electrical power capacity requirements.

  20. Fundamental Aerodynamic Investigations for Development of Arrow-Stabilized Projectiles

    NASA Technical Reports Server (NTRS)

    Kurzweg, Hermann

    1947-01-01

    The numerous patent applications on arrow-stabilized projectiles indicate that the idea of projectiles without spin is not new, but has appeared in various proposals throughout the last decades. As far as projectiles for subsonic speeds are concerned, suitable shapes have been developed for sometime, for example, numerous grenades. Most of the patent applications, though, are not practicable particularly for projectiles with supersonic speed. This is because the inventor usually does not have any knowledge of aerodynamic flow around the projectile nor any particular understanding of the practical solution. The lack of wind tunnels for the development of projectiles made it necessary to use firing tests for development. These are obviously extremely tedious or expensive and lead almost always to failures. The often expressed opinion that arrow-stabilized projectiles cannot fly supersonically can be traced to this condition. That this is not the case has been shown for the first time by Roechling on long projectiles with foldable fins. Since no aerodynamic investigations were made for the development of these projectiles, only tedious series of firing tests with systematic variation of the fins could lead to satisfactory results. These particular projectiles though have a disadvantage which lies in the nature cf foldable fins. They occasionally do not open uniformly in flight, thus causing unsymmetry in flow and greater scatter. The junctions of fins and body are very bad aerodynamically and increase the drag. It must be possible to develop high-performance arrow-stabilized projectiles based on the aerodynamic research conducted during the last few years at Peenemuende and new construction ideas. Thus the final shape, ready for operational use, could be developed in the wind tunnel without loss of expensive time in firing tests. The principle of arrow-stabilized performance has been applied to a large number of caliburs which were stabilized by various means Most

  1. Search for the flavor changing neutral current B-meson decays B^+arrow μ^+ μ^- K^+ and B^0arrow μ^+ μ^-K^*0 at CDF.

    NASA Astrophysics Data System (ADS)

    Erdmann, Wolfram; Speer, Thomas

    1997-04-01

    We present a search for rare B-meson decays B^+arrow μ^+ μ^- K^+ and B^0arrow μ^+ μ^-K^*0 using data from pbarp collisions at √s = 1.8 TeV recorded with CDF during the 1994 to 95 running period. We set upper limits on BR(B^+arrow μ^+ μ^- K^+) and BR(B^0arrow μ^+ μ^-K^*0). ^ Supported by U.S. DOE DE-AC02-76CH03000. ^*We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Instituto Nazionale di Fisica Nucleare; the Ministry of Education, Science and Culture of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; and the A. P. Sloan Foundation.

  2. Monosomy 9p24{r_arrow}pter and trisomy 5q31{r_arrow}qter: Case report and review of two cases

    SciTech Connect

    Schimmenti, L.A.; Steinberger, J.; Mammel, M.C.

    1995-05-22

    Partial deletion of the short arm of chromosome 9 (p24{r_arrow}pter) and partial duplication of the long arm of chromosome 5 (q32{r_arrow}qter) were observed in an abnormal boy who died at age 8 weeks of a complex cyanotic cardiac defect. He also had minor anomalies, sagittal craniosynostosis, triphalangeal thumbs, hypospadias, and a bifid scrotum. Two other infants with similar cytogenetic abnormalities were described previously. These patients had severe congenital heart defect, genitourinary anomalies, broad nasal bridge, low hairline, apparently low-set ears, short neck, and triphalangeal thumbs, in common with our patient. We suggest that combined monosomy 9q23,24{r_arrow}pter and trisomy 5q31,32{r_arrow}qter may constitute a clinically recognizable syndrome. 13 refs., 2 figs., 2 tabs.

  3. Arrow physicians: are economics and medicine philosophically incompatible?

    PubMed

    Tsang, Sandro

    2015-06-01

    Economics is en route to its further expansion in medicine, but many in the medical community remain unconvinced that its impact will be positive. Thus, a philosophical enquiry into the compatibility of economics and medicine is necessary to resolve the disagreements. The fundamental mission of medicine obliges physicians to practise science and compassion to serve the patient's best interests. Conventional (neoclassical) economics assumes that individuals are self-interested and that competitive markets will emerge optimal states. Economics is seemingly incompatible with the emphasis of putting patients' interests first. This idea is refuted by Professor Kenneth Arrow's health economics seminal paper. Arrow emphasizes that medical practice involves agency, knowledge, trust and professionalism, and physician-patient relation critically affects care quality. The term Arrow Physician is used to mean a humanistic carer who has a concern for the patient and acts on the best available evidence with health equity in mind. To make this practice sustainable, implementing appropriate motivations, constitutions and institutions to enable altruistic agency is critical. There is substantial evidence that polycentric governance can encourage building trust and reciprocity, so as to avoid depletion of communal resources. This paper proposes building trusting institutions through granting altruistic physicians adequate autonomy to direct resources based on patients' technical needs. It also summarizes the philosophy bases of medicine and economics. It, therefore, contributes to developing a shared language to facilitate intellectual dialogues, and will encourage trans-disciplinary research into medical practice. This should lead to medicine being reoriented to care for whole persons again.

  4. New Bouncing Curved Arrow Technique for the Depiction of Organic Mechanisms

    ERIC Educational Resources Information Center

    Straumanis, Andrei R.; Ruder, Suzanne M.

    2009-01-01

    Many students fail to develop a conceptual understanding of organic chemistry. Evidence suggests this failure goes hand-in-hand with a failure to grasp the techniques, meaning, and usefulness of curved arrow notation. Use of curved arrow notation to illustrate electrophilic addition appears to be a critical juncture in student understanding.…

  5. Atypical Visual Orienting to Gaze- and Arrow-Cues in Adults with High Functioning Autism

    ERIC Educational Resources Information Center

    Vlamings, Petra H. J. M.; Stauder, Johannes E. A.; van Son, Ilona A. M.; Mottron, Laurent

    2005-01-01

    The present study investigates visual orienting to directional cues (arrow or eyes) in adults with high functioning autism (n = 19) and age matched controls (n = 19). A choice reaction time paradigm is used in which eye-or arrow direction correctly (congruent) or incorrectly (incongruent) cues target location. In typically developing participants,…

  6. Bloodstain pattern analysis in a case of suicide with a compound bow and arrow.

    PubMed

    Wilson, Christopher I; Altschul, Samuel; Mead, Anthony; Flannagan, Lisa M

    2004-03-01

    The incidence of human fatalities due to arrow injuries in the medical literature is rare. We report an incident involving a 46-year-old man who was found in his secured apartment with a fatal arrow wound of his chest and abdomen. The initial scene investigation suggested that the victim impaled himself with an arrow attached to a razor-sharp, 4-bladed broad-head hunting tip before collapsing on the floor. However, analysis of the bloodstain patterns suggested that the victim used the compound bow to propel the arrow. When investigating deaths due to bows and arrows, thorough scene investigation along with bloodstain pattern analysis is essential in determining the mechanism of injury and manner of death.

  7. New Limit for the Lepton-Family-Number Nonconserving Decay [mu][sup +][r arrow]e[sup +] [gamma

    SciTech Connect

    Wright, S.C. ); Cooper, P.S. ); Chen, Y.K.; Dzemidzic, M.; Empl, A.; Hungerford, E.V. III; Lan, K.A.; Mayes, B.W. II; von Witsch, W.H. ); Knott, J.E.; Stantz, K.M.; Szymanski, J.J. ); Brooks, M.L.; Cooper, M.D.; Hogan, G.E.; Kroupa, M.A.; Mischke, R.E.; Stanislaus, T.D.; Szymanski, J.J. ); Hughes, E.B.; Jui, C.C. ); Gagliardi, C.A.; Tribble, R.E.; Tu, X.L.; Van Ausdeln, L.A. ); Koetke, D.D.; Manweiler, R.; Stanislaus, T.D. ); Ziock, K.O. (University

    1999-08-01

    An experiment has been performed to search for the muon- and electron-number nonconserving decay [mu][sup +][r arrow]e[sup +][gamma] . The upper limit for the branching ratio is found to be [Gamma]([mu][sup +][r arrow]e[sup +][gamma] ) /[Gamma]([mu][sup +][r arrow]e[sup +][nu] [bar [nu

  8. Theoretical evaluation of high speed aerodynamics for arrow wing configurations

    NASA Technical Reports Server (NTRS)

    Dollyhigh, S. M.

    1978-01-01

    A limited study in the use of theoretical methods to calculate the high speed aerodynamics of arrow wing supersonic cruise configurations was conducted. The study consisted of correlations with existing wind tunnel data at Mach numbers from 0.8 to 2.7, using theoretical methods to extrapolate the wind tunnel data to full scale flight conditions, and presentation of a typical supersonic data package for an advanced supersonic transport application prepared using the theoretical methods. A brief description of the methods and their application was given. In general, all three methods had excellent correlation with wind tunnel data at supersonic speeds for drag and lift characteristics and fair to poor agreement with pitching moment characteristics. The VORLAX program had excellent correlation with wind tunnel data at subsonic speeds for lift and pitching moment characteristics and fair agreement in drag characteristics.

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Controlling attention to gaze and arrows in attention deficit hyperactivity disorder.

    PubMed

    Marotta, Andrea; Pasini, Augusto; Menotti, Erica; Pasquini, Alessia; Pitzianti, Maria Bernarda; Casagrande, Maria

    2017-05-01

    The aim of this research was to assess implicit processing of social and non-social distracting cues in children with ADHD. Young people with ADHD and matched controls were asked to classify target words (LEFT/RIGHT) which were accompanied by a distracter eye-gaze or arrow. Typically developing participants showed evidence of interference effects from both eye-gaze and arrow distracters. In contrast, the ADHD group showed evidence of interference effects from arrow but failed to show interference from eye-gaze. This absence of interference effects from eye-gaze observed in the participants with ADHD may reflect an attentional impairment in attending to socially relevant information.

  11. Search for the decay. pi. sup 0 r arrow. gamma. + X

    SciTech Connect

    Atiya, M.S.; Chiang, I.; Frank, J.S.; Haggerty, J.S.; Ito, M.M.; Kycia, T.F.; Li, K.K.; Littenberg, L.S.; Stevens, A.J.; Sambamurti, A.; Strand, R.C. ); Louis, W.C. ); Akerib, D.S.; Marlow, D.R.; Meyers, P.D.; Selen, M.A.; Shoemaker, F.C.; Smith, A.J.S. ); Blackmore, E.W.; Bryman, D.A.; Felawka, L.; Kitching, P.; Konaka, A.; Kuno, Y.; Macdonald, J.A.; Numao, T.; Padley, P.; Poutissou, J.; Poutissou, R.; Roy, J.; Turcot, A.S. )

    1992-08-03

    A search for the decay {pi}{sup 0}{r arrow}{gamma}{ital X}, where {ital X} is any long-lived weakly interacting neutral vector particle with mass smaller than the neutral pion pass, was performed using neutral pions tagged by {ital K}{sup +}{r arrow}{pi}{sup +}{pi}{sup 0}. A 90%-C.L. upper limit for the branching ratio of the two-body decay {ital B}({pi}{sup 0}{r arrow}{gamma}{ital X}){lt}5{times}10{sup {minus}4} is set. Limits are also set for three-body decays {pi}{sup 0}{r arrow}{gamma}{ital XX}{prime}.

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

    SciTech Connect

    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

  13. Results on {ital {nu}}{sub {ital {ital {mu}}}} {r_arrow} {ital {nu}}{sub {ital {ital e}}} Neutrino Oscillations from the LSND Experiment

    SciTech Connect

    Church, E.D.; McIlhany, K.; Stancu, I.; Strossman, W.; VanDalen, G.J.; Vernon, W.; Caldwell, D.O.; Yellin, S.; Smith, D.; Waltz, J.; Cohen, I.; Burman, R.L.; Donahue, J.B.; Federspiel, F.J.; Garvey, G.T.; Louis, W.C.; Sandberg, V.; Tayloe, R.; White, D.H.; Gunasingha, R.M.; Imlay, R.; Kim, H.J.; Mills, G.B.; Wadia, N.; Johnston, K.; Reeder, R.A.; Fazely, A.; Athanassopoulos, C.; Auerbach, L.B.; Majkic, R.; Works, D.; Xiao, Y.

    1998-08-01

    A search for {nu}{sub {mu}}{r_arrow}{nu}{sub e} oscillations has been conducted with the LSND apparatus using {nu}{sub {mu}} from {pi}{sup +} decay in flight. Two analyses observe a total of 40 beam-on high-energy (60{endash}200 MeV) electron events consistent with the {nu}{sub e}thinspC{r_arrow}e{sup {minus}} thinspX inclusive reaction. This number is significantly above the 21.9{plus_minus}2.1 events expected from the {nu}{sub e} contamination in the beam and the beam-off background. If interpreted as an oscillation signal, the observed oscillation probability of (2.6{plus_minus}1.0{plus_minus}0.5){times}10{sup {minus}3} is consistent with the previously reported {ovr {nu}}{sub {mu}}{r_arrow}{ovr {nu}}{sub e} oscillation evidence from LSND. {copyright} {ital 1998} {ital The American Physical Society}

  14. Arrows of time in the bouncing universes of the no-boundary quantum state

    NASA Astrophysics Data System (ADS)

    Hartle, James; Hertog, Thomas

    2012-05-01

    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 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 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 bidirectional arrow of time for causality are discussed.

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

    PubMed Central

    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 products. We investigated understanding of central dogma concepts and found that students are not primed to think about information when presented with the canonical figure of the central dogma. We also uncovered conceptual errors in student interpretation of the meaning of the transcription arrow in the central dogma representation; 36% of students (n = 128; all undergraduate levels) described transcription as a chemical conversion of DNA into RNA or suggested that RNA existed before the process of transcription began. Interviews confirm that students with weak conceptual understanding of information flow find inappropriate meaning in the canonical representation of central dogma. Therefore, we suggest that use of this representation during instruction can be counterproductive unless educators are explicit about the underlying meaning. PMID:26086664

  16. Arrows of time and the beginning of the universe

    NASA Astrophysics Data System (ADS)

    Vilenkin, Alexander

    2013-08-01

    I examine two cosmological scenarios in which the thermodynamic arrow of time points in opposite directions in the asymptotic past and future. The first scenario, suggested by Aguirre and Gratton, assumes that the two asymptotic regions are separated by a de Sitter-like bounce, with low-entropy boundary conditions imposed at the bounce. Such boundary conditions naturally arise from quantum cosmology with Hartle-Hawking wave function of the universe. The bounce hypersurface breaks de Sitter invariance and represents the beginning of the universe in this model. The second scenario, proposed by Carroll and Chen, assumes some generic initial conditions on an infinite spacelike Cauchy surface. They argue that the resulting spacetime will be nonsingular, apart from black holes that could be formed as the initial data is evolved, and will exhibit eternal inflation in both time directions. Here I show, assuming the null convergence condition, that the Cauchy surface in a nonsingular (apart from black holes) universe with two asymptotically inflating regions must necessarily be compact. I also argue that the size of the universe at the bounce between the two asymptotic regions cannot much exceed the de Sitter horizon. The spacetime structure is then very similar to that in the Aguirre-Gratton scenario and does require special boundary conditions at the bounce. If cosmological singularities are allowed, then an infinite Cauchy surface with “random” initial data will generally produce inflating regions in both time directions. These regions, however, will be surrounded by singularities and will have singularities in their past or future.

  17. The Arrow of Time through the Lens of Computing

    NASA Astrophysics Data System (ADS)

    Palem, Krishna V.

    The concepts of temporal logic were introduced by Amir Pnueli [1] into the realm of computer science in general and programs in particular, to great effect. Given a program specification, a crucial element of reasoning through temporal logic is our ability to assert that one program event occurs before or after the other, with an order intuitively rooted in our notion of "time". In the realm of temporal logic, such assertions are abstracted as pure mathematical facts. An alternative is to consider the physical realization by executing the specified program through, for example, a microprocessor-based system. In such a case, a mechanism is used to ensure that the desired temporal relationships from the program specification are obeyed, and quite often this mechanism takes the form of a clock. In physical instantiations however clocks and similar mechanisms have an associated energy cost. They are guided by the laws of physics in general and thermodynamics in particular, with which the arrow of time and the associated irreversibility are intimately intertwined. Viewed through this lens, a key question arises of whether the need for ensuring that the temporal norms needed for program correctness accrue an inevitable energy cost. In this paper, I sketch some of the intricacies underlying this question. I will hint at the subtle interactions between models of computing, time as it is represented in them, and the associated thermodynamic cost. In his early work, Amir relied as much on the philosophy of reasoning about time [2-4] as on the technical intricacies of mathematical logic. In recognition of the richness of his intellectual endeavor, I have developed this exposition in a philosophical style mimicking that of the ancient greek philosopher Zeno [5,6].

  18. High-resolution {upsilon}{sub OH} = 3{l_arrow}0 and {upsilon}{sub OH} = 4{l_arrow}0 overtone spectroscopy of HOD

    SciTech Connect

    Fair, J.R.; Votava, O.; Nesbitt, D.J.

    1996-12-31

    High-resolution (0.005 cm{sup -1}) IR overtone excitation with an injection seeded optical parametric oscillator (OPO) is used to investigate the spectroscopy of HOD in the {upsilon}{sub OH} = 3{l_arrow}0 region via room temperature photoacoustic detection methods. Comparison of the photoacoustic spectra from an H{sub 2}O/D{sub 2}O/HOD mixture and from pure H{sub 2}O determines the lines corresponding to {upsilon}{sub OH} = 3{l_arrow}0 absorptions in HOD. A prediction of the HOD spectrum in this region is generated from an extrapolation of {upsilon}{sub OH} = 0 and 1 rotational constants and from the {upsilon}{sub OH} = 3{l_arrow}0 band origin calculated by Tennyson and coworkers [private communication]. This predicted spectrum enables the HOD {upsilon}{sub OH} = 3{l_arrow}0 photoacoustic spectrum to be assigned; a fit of the experimental data produces the low-order rotational constants for this transition as well as a Birge-Sponer analysis of the overtone series. The vibrational dependence of the HOD rotational constants is demonstrated to be quite linear in {upsilon}{sub OH}, permitting reliable extrapolation to the {upsilon}{sub OH} = 4 manifold. As a result, the {upsilon}{sub OH} = 0, 1 and 3 constants can be used to predict the spectrum of HOD {upsilon}{sub OH} = 4{l_arrow}0, which now enables the assignment of the vibrationally mediated photodissociation spectrum measured by Crim and coworkers. The overtone spectroscopic data for HOD is further confirmed in double resonance IR and UV photolysis of HOD and HOD-containing clusters in slit supersonic expansions.

  19. Measurement of the Amplitude Ratio between the Decays B^0 arrow J/ψ \\overlineK^*0 (\\overlineK^*0arrow K^-π^+) and B^0 arrow J/ψ K^*0 (K^*0arrow K^+π^-)

    NASA Astrophysics Data System (ADS)

    Baak, Max

    2003-04-01

    We report a study of the time-dependent rate of decay for the process B^0arrow J/ψ K^*0 (K^*0arrow K^+π^-) in 82 fb-1 of e^+e^- annihilation data collected by the BaBar detector at center-of-mass energies near the Υ(4S) resonance. We search for a deviation in the B decay-time distributions from usual B^0\\overlineB^0 oscillations. Such a deviation would be an indication for a wrong-flavor amplitude B^0arrow J/ψ \\overlineK^*0 and a sign for new physics. A non-zero wrong-flavor amplitude could lead to a done by measuring the coefficients of the s(Δ m_dt) distributions for the J/ψ \\overlineK^*0. The result a limit on the potential difference between the measured values of sin(2β) using B^0/\\overlineB^0 arrow J/ψ KS and B^0/\\overlineB^0 arrow J/ψ KL decays.

  20. Fixation of osteochondral fragments in the human knee using Meniscus Arrows.

    PubMed

    Wouters, Diederick B; Burgerhof, Johannes G M; de Hosson, Jeff T M; Bos, Rudolf R M

    2011-02-01

    The aim of this study is to compare the hold in bone of Meniscus Arrows and Smart Nails, followed by the report of the results of the clinical application of Meniscus Arrows as fixation devices. First, pull-out tests were performed to analyse the holdfast of both nails in bone. Statistical analysis showed no significant difference; therefore, the thinner Meniscus Arrow was chosen as fixation device in the patient series of two patients with a symptomatic Osteochondritis dissecans fragment and three patients with an osteochondral fracture of a femur condyle. The cartilage margins were glued with Tissuecoll. All fragments consolidated. Second look arthroscopy in three patients showed fixed fragments with stable, congruent cartilage edges. At an average follow-up period of 5 years no pain, effusion, locking, restricted range of motion or signs of osteoarthritis were reported. Based on the results of the pull-out tests and available clinical studies, Meniscus Arrows and Smart Nails are both likely to perform adequately as fixation devices in the treatment of Osteochondritis dissecans and osteochondral fractures in the knee. They both provide the advantage of one stage surgery. However, based on their smaller diameter, the Meniscus Arrows should be preferred for this indication.

  1. Expression pattern of the Brachyury gene in the arrow worm paraspadella gotoi (chaetognatha).

    PubMed

    Takada, Norio; Goto, Taichiro; Satoh, Nori

    2002-03-01

    Arrow worms (the phylum Chaetognatha), which are among the major marine planktonic animals, are direct developers and exhibit features characteristic of both deuterostomes and protostomes. In particular, the embryonic development of arrow worms appears to be of the deuterostome type. Brachyury functions critically in the formation of the notochord in chordates, whereas the gene is expressed in both the blastopore and stomodeum invagination regions in embryos of hemichordates and echinoderms. Here we analyzed the expression of Brachyury (Pg-Bra) in the arrow worm Paraspadella gotoi and showed that Pg-Bra is expressed in the blastopore region and the stomodeum region in the embryo and then around the mouth opening region at the time of hatching. The expression of Pg-Bra in the embryo resembles that of Brachyury in embryos of hemichordates and echinoderms, whereas that in the mouth opening region in the hatchling appears to be novel.

  2. Electrophysiological responses to violations of expectation from eye gaze and arrow cues.

    PubMed

    Tipples, Jason; Johnston, Pat; Mayes, Angela

    2013-06-01

    Isolating processes within the brain that are specific to human behavior is a key goal for social neuroscience. The current research was an attempt to test whether recent findings of enhanced negative ERPs in response to unexpected human gaze are unique to eye gaze stimuli by comparing the effects of gaze cues with the effects of an arrow cue. ERPs were recorded while participants (N = 30) observed a virtual actor or an arrow that gazed (or pointed) either toward (object congruent) or away from (object incongruent) a flashing checkerboard. An enhanced negative ERP (N300) in response to object incongruent compared to object congruent trials was recorded for both eye gaze and arrow stimuli. The findings are interpreted as reflecting a domain general mechanism for detecting unexpected events.

  3. Demonstration of a liquid core optical ring resonator sensor coupled with an ARROW waveguide array

    NASA Astrophysics Data System (ADS)

    White, Ian M.; Oveys, Hesam; Fan, Xudong; Smith, Terry L.; Zhang, Junying

    2007-02-01

    The liquid core optical ring resonator (LCORR) sensor is a newly developed capillary-based ring resonator that integrates microfluidics with photonic sensing technology. The circular cross-section of the capillary forms a ring resonator that supports whispering gallery modes (WGM). The WGM evanescent field is exposed to the capillary core and detects the aqueous samples conducted by the capillary using a label-free protocol. The high-Q of the WGM allows for repetitive light-analyte interaction, resulting in excellent sensitivity. Recently a detection limit of the LCORR on the order of 10 -6 refractive index units was reported. In this work, we have further integrated the LCORR with an anti-resonant reflective optical waveguide (ARROW) array for multiplexed sensor development. The ARROW, with an array of 8 waveguides separated by 250 microns each, consists of a core and a lower reflective double-layer with alternating high and low refractive index, and thus has a significant evanescent field above the waveguide. The WGM is excited at each LCORR/ARROW junction simultaneously when the LCORR is brought into contact with the ARROW array. We experimentally investigated the optimal waveguide geometry for WGM excitation using a range of waveguide heights from 2 to 5 microns. Furthermore, the LCORR/ARROW system is utilized for a biomolecule sensing demonstration. The LCORR/ARROW system is not only essential for assembling a robust, practical, and densely multiplexed sensor array, but also enables on-capillary flow analysis that has broad applications in capillary electrophoresis, chromatography, and lab-on-a-chip development.

  4. Parametric flutter studies of an arrow-wing configuration: Some early results

    NASA Technical Reports Server (NTRS)

    Durham, Michael H.; Cole, Stanley R.; Cazier, F. W., Jr.; Keller, Donald F.; Parker, Ellen C.; Wilkie, W. Keats

    1988-01-01

    Some early experimental results from a combined experimental and analytical study being conducted at NASA-Langley of the transonic flutter characterisitics of a generic arrow wing configuration are presented. The planned study includes the parametric variation of a variety of structural and geometric characteristics. Presented here are flutter results of the basic arrow wing, for the basic wing with the addition of two simulated lower-surface-mounted engine nacelles, and for the basic wing with the addition of both the fin and the engine nacelles.

  5. MEGA: A search for the decay {mu}{r_arrow}{ital e}{gamma}

    SciTech Connect

    Szymanski, J.J.; Amann, J.F.; Baker, K.; Barlow, D.; Black, K.; Bolton, R.D.; Brooks, M.; Carius, S.; Chen, Y.; Cooper, M.D.; Cooper, P.S.; Crocker, J.; Dzemidzic, M.; Fisk, R.J.; Flick, J.; Foreman, W.; Gagliardi, C.A.; Haim, D.; Hallin, A.; Harrison, R.; Hart, G.; Hoffman, C.M.; Hogan, G.E.; Hughes, E.B.; Hungerford, E.V. III; Johnston, K.; Jui, C.; Kim, G.J.; Knott, J.E.

    1995-07-10

    The MEGA experiment is designed to search for the rare decay {mu}{r_arrow}{ital e}{gamma} with a branching ratio sensitivity of {similar_to}5{times}10{sup {minus}13}. Production data have been taken during 1992 and 1993, and the detector is working as expected. Following a complete analysis, the present data set should represent an improvement of 12--15 in sensitivity over the previous limit of {mu}{r_arrow}{ital e}{gamma}. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  6. Branching fractions of B{sup plus} {r_arrow} {Psi}(2S)K{sup plus} and B{sup O} {r_arrow} {Psi}(2S)K{sup {asterisk}0} decays at CDF

    SciTech Connect

    Warburton, A.

    1996-07-01

    This paper describes the observation of the decays B{sup {plus}} {r_arrow} {psi}(2S)K{sup {plus}} and B{sup 0} {r_arrow} {psi}(2S)K{sup {asterisk}}(892){sup 0} in 1.8 TeV p{ovr p} collisions and presents measurements of the branching fractions Br(B{sup {plus}} {r_arrow} {psi}(2S)K{sup {plus}}) and Br(B{sup 0} {r_arrow} {psi}(2S)K{sup {asterisk}}(892){sup 0}) relative to Br(B{sup {plus}} {r_arrow} J/{psi}K{sup {plus}}) and Br(B{sup 0} {r_arrow} J/{psi}K{sup {asterisk}}(892){sup 0}), respectively. The {psi}(2S) mesons are reconstructed in both the {psi}(2S) {r_arrow} {mu}{sup {plus}}{mu}{sup {minus}} and {psi}(2S) {r_arrow} J/{psi}{pi}{sup {plus}}{pi}{sup {minus}} channels. The world average branching fractions for the J/{psi} channels are used to extract the absolute branching fractions Br(B{sup {plus}} {r_arrow} {psi}(2S)K{sup {plus}}) = (6.8{plus_minus}1.0(stat.){plus_minus}1.4(syst.)){times}10{sup {minus}4} and Br(B{sup 0} {r_arrow} {psi}(2S)K{sup {asterisk}}(892){sup 0}) = (9.0{plus_minus}2.1(stat.){plus_minus}2. 0(syst.)){times}10{sup {minus}4}. 9 refs., 13 figs., 8 tabs.

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

    PubMed

    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).

  8. Poor vigilance affects attentional orienting triggered by central uninformative gaze and arrow cues.

    PubMed

    Marotta, Andrea; Martella, Diana; Maccari, Lisa; Sebastiani, Mara; Casagrande, Maria

    2014-11-01

    Behaviour and neuroimaging studies have shown that poor vigilance (PV) due to sleep deprivation (SD) negatively affects exogenously cued selective attention. In the current study, we assessed the impact of PV due to both partial SD and night-time hours on reflexive attentional orienting triggered by central un-informative eye-gaze and arrow cues. Subjective mood and interference performance in emotional Stroop task were also investigated. Twenty healthy participants performed spatial cueing tasks using central directional arrow and eye-gaze as a cue to orient attention. The target was a word written in different coloured inks. The participant's task was to identify the colour of the ink while ignoring the semantic content of the word (with negative or neutral emotional valence). The experiment took place on 2 days. On the first day, each participant performed a 10-min training session of the spatial cueing task. On the second day, half of participants performed the task once at 4:30 p.m. (BSL) and once at 6:30 a.m. (PV), whereas the other half performed the task in the reversed order. Results showed that mean reaction times on the spatial cueing tasks were worsened by PV, although gaze paradigm was more resistant to this effect as compared to the arrow paradigm. Moreover, PV negatively affects attentional orienting triggered by both central un-informative gaze and arrow cues. Finally, prolonged wakefulness affects self-reported mood but does not influence interference control in emotional Stroop task.

  9. Reflexive Orienting in Response to Eye Gaze and an Arrow in Children with and without Autism

    ERIC Educational Resources Information Center

    Senju, Atsushi; Tojo, Yoshikuni; Dairoku, Hitoshi; Hasegawa, Toshikazu

    2004-01-01

    Background: This study investigated whether another person's social attention, specifically the direction of their eye gaze, and a non-social directional cue, an arrow, triggered reflexive orienting in children with and without autism in an experimental situation. Methods: Children with autism and typically developed children participated in one…

  10. Upper limit on the branching ratio for the decay. pi. sup 0 r arrow. nu. nu

    SciTech Connect

    Atiya, M.S.; Chiang, I.; Frank, J.S.; Haggerty, J.S.; Ito, M.M.; Kycia, T.F.; Li, K.K.; Littenberg, L.S.; Stevens, A.; Strand, R.C. ); Louis, W.C. ); Akerib, D.S.; Marlow, D.R.; Meyers, P.D.; Selen, M.A.; Shoemaker, F.C.; Smith, A.J.S. ); Azuelos, G.; Blackmore, E.W.; Bryman, D.A.; Felawka, L.; Kitching, P.; Kuno, Y.; Macdonald, J.A.; Numao, T.; Padley, P.; Poutissou, J.; Poutissou, R.; Roy, J. V6T 2A3)

    1991-04-29

    An experimental upper limit on the branching ratio for the decay {pi}{sup 0}{r arrow}{nu}{bar {nu}} is set at 8.3{times}10{sup {minus}7} (90% C.L.). This decay is forbidden if neutrinos are purely left handed. The limit also applies to any decays of the {pi}{sup 0} to weakly interacting neutrals.

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

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

    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…

  13. Sociopolitical effects of bow and arrow technology in prehistoric coastal California.

    PubMed

    Kennett, Douglas J; Lambert, Patricia M; Johnson, John R; Culleton, Brendan J

    2013-01-01

    Bow and arrow technology spread across California between ∼AD 250 and 1200, first appearing in the intermountain deserts of the Great Basin and later spreading to the coast. We critically evaluate the available data for the initial spread in bow and arrow technology and examine its societal effects on the well-studied Northern Channel Islands off the coast of Southern California. The introduction of this technology to these islands between AD 650 and 900 appears to predate the appearance of hereditary inequality between AD 900 and 1300. We conclude, based on the available data, that this technology did not immediately trigger intergroup warfare. We argue that the introduction of the bow and arrow contributed to sociopolitical instabilities that were on the rise within the context of increasing population levels and unstable climatic conditions, which stimulated intergroup conflict and favored the development of hereditary inequality. Population aggregation and economic intensification did occur with the introduction of the bow and arrow. This observation is consistent with the hypothesis that social coercion via intra-group "law enforcement" contributed to changes in societal scale that ultimately resulted in larger groups that were favored in inter-group conflict. We argue that the interplay between intra-group "law enforcement" and inter-group warfare were both essential for the ultimate emergence of social inequality between AD 900 and 1300.

  14. How Do Selected Arrows Guide Visuospatial Attention? Dissociating Symbolic Value and Spatial Proximity

    ERIC Educational Resources Information Center

    Leblanc, Emilie; Jolicoeur, Pierre

    2010-01-01

    Previous research on the control of visuospatial attention showed that overlearned symbols like arrows have the potential to induce involuntary shifts of attention. Following work on the role of attentional control settings and of the content of working memory in the involuntary deployment of visuospatial attention, Pratt and Hommel (2003) found…

  15. Javelin, Arrow, Dart and Pin Games of Native American Women of the Plains.

    ERIC Educational Resources Information Center

    Pesavento, Wilma J.; Pesavento, Lisa C.

    This study was designed to determine (1) the arrow, dart, javelin, and pin games of Native American girls and women of the Great Plains, (2) the geographical spread of the games within the culture area, and (3) the characteristics of the various games. Data for this investigation were researched from "Annual Reports of the Bureau of American…

  16. Early Twentieth Century Arrow, Javelin, and Dart Games of the Western Native American.

    ERIC Educational Resources Information Center

    Pesavento, Wilma J.

    The general purpose of this study was to determine whether the traditional native American ball games continued to be positive culture traits of the American Indian in the early twentieth century. The investigation was centered about (1) determining the current arrow, javelin, and dart games of western native Americans, (2) determining the…

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

    ERIC Educational Resources Information Center

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

    PubMed

    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.

  19. Electroweak Penguins, Final State Interaction Phases, and {ital CP} Violation in B {r_arrow} K {pi} Decays

    SciTech Connect

    Deshpande, N.G.; He, X.; Hou, W.; He, X.; Hou, W.; Pakvasa, S.

    1999-03-01

    The recently observed B{sup {minus}} {r_arrow} K{sup {minus}} {pi} {sup 0}, {bar K}{sup 0} {pi} {sup {minus}} and {bar B} {sup 0} {r_arrow} K{sup {minus}} {pi} {sup +} decay modes appear to have nearly equal branching ratios. This suggests that tree and electroweak penguins play an important role, and inclusion of the latter improves agreement between factorization calculation and experimental data. The value of {gamma} in the range of 90{degree} {endash} 130{degree} and 220{degree} {endash} 260{degree} is favored, while the {bar B} {sup 0} {r_arrow} {bar K} {sup 0} {pi} {sup 0} rate is suppressed. Direct CP violation for B{r_arrow} K{pi} modes can be large if final state interaction phases are large. {copyright} {ital 1999} {ital The American Physical Society}

  20. Search for Proton Decay through p {r_arrow} {bar {nu}}K{sup +} in a Large Water Cherenkov Detector

    SciTech Connect

    Fukuda, Y.; Hayakawa, T.; Inoue, K.; Ishihara, K.; Ishino, H.; Itow, Y.; Kajita, T.; Kameda, J.; Kasuga, S.; Kobayashi, K.; Kobayashi, Y.; Koshio, Y.; Miura, M.; Nakahata, M.; Nakayama, S.; Obayashi, Y.; Okada, A.; Okumura, K.; Sakurai, N.; Shiozawa, M.; Suzuki, Y.; Takeuchi, H.; Takeuchi, Y.; Totsuka, Y.; Yamada, S.; Earl, M.; Habig, A.; Kearns, E.; Messier, M.D.; Scholberg, K.; Stone, J.L.; Sulak, L.R.; Walter, C.W.; Goldhaber, M.; Barszczak, T.; Casper, D.; Gajewski, W.; Kropp, W.R.; Mine, S.; Price, L.R.; Smy, M.; Sobel, H.W.; Vagins, M.R.; Haines, T.J.; Kielczewska, D.; Ganezer, K.S.; Keig, W.E.; Ellsworth, R.W.; Tasaka, S.; Kibayashi, A.; Learned, J.G.; Matsuno, S.; Stenger, V.J.; Takemori, D.; Ishii, T.; Kanzaki, J.; Kobayashi, T.; Nakamura, K.; Nishikawa, K.; Oyama, Y.; Sakai, A.; Sakuda, M.; Sasaki, O.; Echigo, S.; Kohama, M.; Suzuki, A.T.; Haines, T.J.; Blaufuss, E.; Kim, B.K.; Sanford, R.; and others

    1999-08-01

    We present results of a search for proton decays, p{r_arrow}{bar {nu}}K{sup +} , using data from a 33 kt{center_dot}yr exposure of the Super-Kamiokande detector. Two decay modes of the kaon, K{sup +}{r_arrow}{mu}{sup +}{nu}{sub {mu}} and K{sup +}{r_arrow}{pi}{sup +}{pi}{sup 0} , were studied. The data were consistent with the background expected from atmospheric neutrinos; therefore a lower limit on the partial lifetime of the proton {tau}/B(p{r_arrow}{bar {nu}} K{sup +}) was found to be 6.7{times}10{sup 32} years at 90{percent} confidence level. {copyright} {ital 1999} {ital The American Physical Society}

  1. Review of Cranked-Arrow Wing Aerodynamics Project: Its International Aeronautical Community Role

    NASA Technical Reports Server (NTRS)

    Lamar, John E.; Obara, Clifford J.

    2007-01-01

    This paper provides a brief history of the F-16XL-1 aircraft, its role in the High Speed Research (HSR) program and how it was morphed into the Cranked Arrow Wing Aerodynamics Project (CAWAP). Various flight, wind-tunnel and Computational Fluid Dynamics (CFD) data sets were generated during the CAWAP. These unique and open flight datasets for surface pressures, boundary-layer profiles and skinfriction distributions, along with surface flow data, are described and sample data comparisons given. This is followed by a description of how the project became internationalized to be known as Cranked Arrow Wing Aerodynamics Project International (CAWAPI) and is concluded by an introduction to the results of a 4 year CFD predictive study of data collected at flight conditions by participating researchers.

  2. Expression of actin genes in the arrow worm Paraspadella gotoi (Chaetognatha).

    PubMed

    Yasuda, E; Goto, T; Makabe, K W; Satoh, N

    1997-12-01

    Arrow worms (the phylum Chaetognatha), one of the major marine planktonic animals, exhibit features characteristic to both deuterostomes and protostomes, and their ancestry therefore remains unknown. As the first step to elucidate the molecular bases of arrow worm phylogeny, physiology and embryology, we isolated cDNA clones for three different actin genes (PgAct1, PgAct2 and PgAct3) from the benthic species Paraspadella gotoi, and examined their expression patterns in adults and juveniles. The amino acid sequences of the three actins resembled each other, with identities ranging from 86% to 92%. However, the patterns of the spatial expression of the genes were independent. The PgAct1 gene might encode a cytoplasmic actin and was expressed in oogenic cells, spermatogenic cells, and cells in the ventral ganglion. The PgAct2 and PgAct3 genes encoded actins of divergent types. The former was expressed in well-developed muscle of the head (gnathic) region and trunk muscle cells, whereas the latter was expressed in muscle of the trunk and tail regions and oogenic cells. These results suggest that, similarly to other metazoans, the chaetognath contains multiple forms of actins, which are expressed in various manners in the adult and juvenile arrow worm.

  3. Biostratigraphy and paleoenvironment of Morrowan (Zone 2) brachiopoda, Bird Spring Group, Arrow Canyon, Clark County, Nevada

    SciTech Connect

    Vaiden, R.C.; Langenheim, R.L.

    1985-02-01

    Comprehensive study of the Morrowan brachiopod faunas of the Bird Spring Group at Arrow Canyon, Clark County, Nevada, is important because the section has been suggested as a stratotype for the base and top of the Pennsylvanian Subsystem and for the Atoka Series. Twenty-three species of brachiopods belonging to 17 genera occur in zone 20 at Arrow Canyon. Many of these also occur in described Morrowan faunas in Wyoming, Colorado, Utah, and New Mexico; but similarities with the Mid-Continent and Appalachian assemblages are less. However, no striking regional differences are evident, and it appears that the North American Morrowan fauna is more or less homogeneous. In contrast to the exotic South American and Arctic elements known from Atokan, Missourian, and Virgilian rocks at Arrow Canyon, no foreign taxa have been noted in zone 20. Microfacies and faunal association indicate four distinct brachiopod-bearing environments; (1) relatively deep water below turbulence with few brachiopods on a soft substrate; (2) somewhat shallower, more turbulent water with many species, of which only a few are represented by large populations, living on a more firm substrate; (3) environments just below the zone of turbulence in which many species of brachiopods are represented by substantial populations on a calcarenitic substrate; and (4) crinoidal bars in the zone of turbulence with a few species represented by relatively few individuals.

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

    SciTech Connect

    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.

  5. Sociopolitical complexity and the bow and arrow in the American Southwest.

    PubMed

    VanPool, Todd L; O'Brien, Michael J

    2013-01-01

    The evolution of sociopolitical complexity, including heightened relations of cooperation and competition among large nonkin groups, has long been a central focus of anthropological research. Anthropologists suggest any number of variables that affect the waxing and waning of complexity and define the precise trajectories that groups take, including population density, subsistence strategies, warfare, the distribution of resources, and trade relationships. Changes in weaponry, here the introduction of the bow and arrow, can have profound implications for population aggregation and density, subsistence and settlement strategies, and access to resources, trade, and warfare.Bingham and Souza provide a general conceptual model for the relationship between complexity and the bow and arrow, arguing that this compound weapon system, whereby smaller projectiles travel at higher speed and are capable of hitting targets more accurately and at greater distances than hand-thrown darts, fundamentally favors the formation of larger groups because it allows for cost-effective means of dealing with conflicts of interest through social coercion, thereby dramatically transforming kin-based social relations. Here we consider the impacts the introduction of the bow and arrow had on sociopolitical complexity in the North American Southwest.

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

    SciTech Connect

    Afanasev, A.

    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.

  7. Complete leading order analysis in Chiral Perturbation Theory of the decays K{sub L}{r_arrow}{gamma}{gamma} and K{sub L}{r_arrow}l{sub +}l{sub {minus}}{gamma}

    SciTech Connect

    J. L. Goity; Longzhe Zhang

    1997-02-01

    The decays K{sub L}{r_arrow}{gamma}{gamma} and K{sub L}{r_arrow}l{sup +}l{sup {minus}}{gamma} are studied at the leading order p{sup 6} in Chiral Perturbation Theory. One-loop contributions stemming from the odd intrinsic parity {vert_bar}{Delta}S{vert_bar}=1 effective Lagrangian of order p{sup 4} are included and shown to be of possible relevance. They affect the decay K{sub L}{r_arrow}{gamma}{gamma} adding to the usual pole terms a piece free of counterterm uncertainties. In the case of the K{sub L}{r_arrow}l{sup +}l{sup {minus}}{gamma} decays the dependence of the form factor on the dilepton invariant mass requires a counterterm. The form factor may receive a sizeable contribution from chiral logarithms. Including considerations from the K{sub L}{r_arrow}{pi}{sup +}{pi}{sup {minus}}{gamma} direct emission amplitude, the authors obtain two consistent scenarios. In one scenario the long distance contributions from the one-loop terms are important, while in the other they are marginal. In both cases the counterterm is shown to be significant.

  8. Target asymmetry measurements of {gamma} p{r_arrow}{pi} {sup +}n with Phoenics at ELSA

    SciTech Connect

    Althoff, K.; Anton, G.; Arends, J.; Beulertz, W.; Bock, A.; Breuer, M.; Detemple, P.; Dutz, H.; Gehring, R.; Gemander, M.; Goertz, S.; Helbing, K.; Hey, J.; Kraemer, D.; Meyer, W.; Noeldeke, G.; Reicherz, G.; Thomas, A.; Zucht, B.

    1995-05-10

    The target asymmetry T of the reaction {gamma} p{r_arrow}{pi} {sup +}n has been measured with the Phoenics detector in combination with the Bonn frozen spin target at ELSA. For the first time the polarization observable T has been determined simultaneously over a large photon energy range (E{sub {gamma}}=220--800 MeV) and pion angles ({Theta}{sub {pi}}{sup m}=35{degree}--135{degree}) with a tagged photon facility. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  9. Supersonic pressure measurements and comparison of theory to experiment for an arrow-wing configuration

    NASA Technical Reports Server (NTRS)

    Manro, M. E.

    1976-01-01

    A wind tunnel test of an arrow-wing-body configuration consisting of flat and twisted wings, as well as leading- and trailing-edge control surface deflections, was conducted at Mach numbers from 1.54 to 2.50 to provide an experimental pressure data base for comparison with theoretical methods. Theory-to-experiment comparisons of detailed pressure distributions were made using a state-of-the-art inviscid flow, constant-pressure-panel method. Emphasis was on conditions under which this theory is valid for both flat and twisted wings.

  10. Arrow-wing supersonic cruise aircraft structural design concepts evaluation. Volume 3: Sections 12 through 14

    NASA Technical Reports Server (NTRS)

    Sakata, I. F.; Davis, G. W.

    1975-01-01

    The design of an economically viable supersonic cruise aircraft requires the lowest attainable structural-mass fraction commensurate with the selected near-term structural material technology. To achieve this goal of minimum structural-mass fraction, various combinations of promising wing and fuselage primary structure were analyzed for the load-temperature environment applicable to the arrow wing configuration. This analysis was conducted in accordance with the design criteria specified and included extensive use of computer-aided analytical methods to screen the candidate concepts and select the most promising concepts for the in-depth structural analysis.

  11. Exploratory subsonic investigation of vortex-flap concept on arrow wing configuration

    NASA Technical Reports Server (NTRS)

    Rao, D. M.

    1981-01-01

    The drag reduction potential of a vortex flap concept, utilizing the thrust contribution of separation vortices maintained over leading edge flap surfaces, was explored in subsonic wind tunnel tests on a highly swept arrow wing configuration. Several flap geometries were tested in comparison with a previous study on the same model with leading edges drooped for attached flow. The most promising vortex flap arrangements produced drag reductions comparable with leading edge droop over a range of lift coefficients from 0.3 to 0.6 (untrimmed), and also indicated beneficial effects in the longitudinal and lateral static stability characteristics.

  12. Arrow-wing supersonic cruise aircraft structural design concepts evaluation. Volume 1: Sections 1 through 6

    NASA Technical Reports Server (NTRS)

    Sakata, I. F.; Davis, G. W.

    1975-01-01

    The structural approach best suited for the design of a Mach 2.7 arrow-wing supersonic cruise aircraft was investigated. Results, procedures, and principal justification of results are presented. Detailed substantiation data are given. In general, each major analysis is presented sequentially in separate sections to provide continuity in the flow of the design concepts analysis effort. In addition to the design concepts evaluation and the detailed engineering design analyses, supporting tasks encompassing: (1) the controls system development; (2) the propulsion-airframe integration study; and (3) the advanced technology assessment are presented.

  13. Arrow-wing supersonic cruise aircraft structural design concepts evaluation. Volume 4: Sections 15 through 21

    NASA Technical Reports Server (NTRS)

    Sakata, I. F.; Davis, G. W.

    1975-01-01

    The analyses performed to provide structural mass estimates for the arrow wing supersonic cruise aircraft are presented. To realize the full potential for structural mass reduction, a spectrum of approaches for the wing and fuselage primary structure design were investigated. The objective was: (1) to assess the relative merits of various structural arrangements, concepts, and materials; (2) to select the structural approach best suited for the Mach 2.7 environment; and (3) to provide construction details and structural mass estimates based on in-depth structural design studies. Production costs, propulsion-airframe integration, and advanced technology assessment are included.

  14. Fcc r arrow bct phase transition in Th at extreme compressions: Theory

    SciTech Connect

    Eriksson, O. ); Soederlind, P. ); Wills, J.M. )

    1992-06-01

    The experimentally observed fcc{r arrow}bct crystallographic phase transition in Th, at {similar to}1 Mbar, is reproduced by means of full-potential, linear-muffin-tin-orbitals calculations. Both the calculated volume and pressure for which the transition occurs, agrees with the experimental data. The calculated pressure dependence of the {ital c}/{ital a} ratio of the bct structure is also in good agreement wtih experimental data. Calculations for La predict the fcc phase to be stable over the bct phase up to {similar to}7 Mbar.

  15. Transonic pressure measurements and comparison of theory to experiment for three arrow-wing configurations

    NASA Technical Reports Server (NTRS)

    Manro, M. E.

    1982-01-01

    Wind tunnel tests of arrow-wing body configurations consisting of flat, twisted, and cambered twisted wings, as well as a variety of leading and trailing edge control surface deflections, were conducted at Mach numbers from 0.4 to 1.05 to provide an experimental pressure data base for comparison with theoretical methods. Theory to experiment comparisons of detailed pressure distributions were made using state of the art attached flow methods. Conditions under which these theories are valid for these wings are presented.

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

    SciTech Connect

    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

    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.

  17. Theoretical evaluation of high-speed aerodynamics for arrow-wing configurations

    NASA Technical Reports Server (NTRS)

    Dollyhigh, S. M.

    1979-01-01

    The use of the theoretical methods to calculate the high-speed aerodynamic characteristics of arrow-wing supersonic cruise configurations was studied. Included are correlations of theoretical predictions with wind-tunnel data at Mach numbers from 0.8 to 2.7, examples of the use of theoretical methods to extrapolate the wind-tunnel data to full-scale flight condition, and presentation of a typical supersonic data package for an advanced supersonic transport application. A brief description of the methods and their application is given.

  18. Advanced structures technology applied to a supersonic cruise arrow-wing configuration

    NASA Technical Reports Server (NTRS)

    Sakata, I. F.; Davis, G. W.

    1976-01-01

    The application of advanced technology to a promising aerodynamic configuration was explored to investigate the improved payload range characteristics over the configuration postulated during the National SST Program. The results of an analytical study performed to determine the best structural approach for design of a Mach number 2.7 arrow-wing supersonic cruise aircraft are highlighted. The data conducted under the auspices of the Structures Directorate of the National Aeronautics and Space Administration, Langley Research Center, established firm technical bases from which further trend studies were conducted to quantitatively assess the benefits and feasibility of using advanced structures technology to arrive at a viable advanced supersonic cruise aircraft.

  19. Analysis of trace elements in the giant panda and arrow bamboo

    NASA Astrophysics Data System (ADS)

    Wang, Nengming; Chen, Suqing; Chen, Jianxuan; Zhang, Dazhong; Feng, Wenhe

    1987-04-01

    Trace elements from the giant panda including hair, liver, kidney, ovary and testis, were determined by PIXE. Comparative studies of the elemental contents in hair, liver and kidney from epileptic and normal giant pandas were performed respectively. The differences in the elemental contents of leaf, stalk, and bamboo shoots from normal and withered arrows were determined. For this research work a Van de Graaff electrostatic accelerator and a Si(Li) semiconductor spectrometer at the Institute of Nuclear Science and Technology of Sichuan University were employed.

  20. Radiative corrections to the decays K{sub L}{sup 0} {r_arrow} e{sup +}e{sup {minus}} and K{sub L}{sup 0} {r_arrow} {mu}{sup +} {mu}{sup {minus}}

    SciTech Connect

    Dicus, D.A.; Repko, W.W.

    1998-12-31

    The authors calculate the rates and lepton ({ell}) invariant mass distributions for decays of the form 0{sup {minus}+} {r_arrow} {ell}{sup +}{ell}{sup {minus}}{gamma}, which are important radiative corrections to the purely leptonic decays 0{sup {minus}+} {r_arrow} {ell}{sup +}{ell}{sup {minus}}. The approach uses the loop diagrams which arise by including the two photon intermediate state and they retain the imaginary parts of the loops--a radiative extension of the unitarity bound for the process. These results are compared with those obtained using a model in which the meson couples directly to the leptons.

  1. Measurement of the B0 Lifetime with Partial Reconstruction of overline B o right arrow D *+rho-

    NASA Astrophysics Data System (ADS)

    Soffer, A.

    2002-03-01

    A sample of about 5500 overline B0 right arrow D (sup asterisk +) rho - and 700 overline B0 right arrow D(sup asterisk +) alpha -1 events is identified, using the technique of partial reconstruction, among 22.7 million B overline B pairs collected by the BABAR experiment at the PEP-II storage ring. With these events, the B 0 lifetime is measured to be 1.616 plus or minus 0.064 plus or minus 0.075 ps. As the first time-dependent analysis conducted with partial reconstruction of overline B 0 right arrow D (sup asterisk +) rho -, this measurement serves as validation for the procedures required to measure sin(2beta + gamma) with this technique.

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

    PubMed

    Okumura, Mercedes; Araujo, Astolfo G M

    2015-01-01

    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.

  3. Determination of the {ital b}{r_arrow}{ital c} handedness using nonleptonic {Lambda}{sub {ital c}} decays

    SciTech Connect

    Koenig, B.; Koerner, J.G.; Kraemer, M.

    1994-03-01

    We consider possibilities to determine the handedness of {ital b}{r_arrow}{ital c} current transitions using semileptonic baryonic {Lambda}{sub {ital b}}{r_arrow}{Lambda}{sub {ital c}} transitions. We propose to analyze the longitudinal polarization of the daughter baryon {Lambda}{sub {ital c}} by using momentum-spin correlation measurements in the form of forward-backward (FB) asymmetry measures involving its nonleptonic decay products. We use an explicit form factor model to determine the longitudinal polarization of {Lambda}{sub {ital c}} in the semileptonic decay {Lambda}{sub {ital b}}{r_arrow}{Lambda}{sub {ital c}}+{ital l}{sup {minus}}+{bar {nu}}{sub {ital l}}. The mean longitudinal polarization of {Lambda}{sub {ital c}} is negative (positive) for left-chiral (right-chiral) {ital b}{r_arrow}{ital c} current transitions. The frame-dependent longitudinal polarization of {Lambda}{sub {ital c}} is large ({congruent}80%) in the {Lambda}{sub {ital b}} rest frame and somewhat smaller (30%--40%) in the lab frame when the {Lambda}{sub {ital b}}`s are produced on the {ital Z}{sup 0} peak. We suggest to use nonleptonic decay modes of {Lambda}{sub {ital c}} to analyze its polarization and thereby to determine the chirality of the {ital b}{r_arrow}{ital c} transition. Since {Lambda}{sub {ital b}}`s produced on the {ital Z}{sup 0} are expected to be polarized we discuss issues of the polarization transfer in {Lambda}{sub {ital b}}{r_arrow}{Lambda}{sub {ital c}} transitions. We also investigate the {ital p}{sub {perpendicular}}- and {ital p}-cut sensitivity of our predictions for the polarization of {Lambda}{sub {ital c}}.

  4. New ideas to improve searches for {mu}{sup +} {r_arrow} e{sup +}{gamma}

    SciTech Connect

    Cooper, M.D.

    1997-11-01

    Searching for decays that change total lepton family number is an excellent method to explore potential physics beyond the Standard Model because those processes are predicted to be zero except when new physics is present. Essentially all extensions of the Standard Model that introduce new, heavy particles predict the existence of these rare decays, though the most probable channel is highly model dependent. Recently, the prejudice has grown within the physics community that supersymmetry is an extension that is likely to be related to nature. Barbieri, Hall, and Strumia show that rare decays are signatures for grand unified supersymmetry and calculate the rates for {mu}{sup +} {r_arrow} e{sup +}{gamma} and related processes for a wide range of parameters of these models. They conclude that {mu}{sup +} {r_arrow} e{sup +}{gamma} has the largest rate by more than two orders of magnitude, and it ranges between the current experimental limit and 10{sup {minus}14}. Hence, there is continuing interest in the community for an experiment that could have a sensitivity near 10{sup {minus}14}. Lessons are drawn from the experience of the MEGA experiment in searching for {mu}{sup +} to e{sup +}{gamma}. In light of that experience, some ideas are evaluated regarding new searches that might take place in the ERA of a source of low-energy muons associated with a muon collider.

  5. Detailed study of the T = 0, NN interaction via N-italic-arrow-rightP- scattering at 68 MEV

    SciTech Connect

    Henneck, R.; Campbell, J.; Gysin, C.; Hammans, M.; Lorenzon, W.; Pickar, M.A.; Sick, I.; Konter, J.A.; Mango, S.; Van den Brandt, B.; and others

    1988-11-20

    We report on first results for a measurement of the spin correlation parameter A/sub z//sub z/ in n-italic-arrow-rightp-arrow-right scattering at 68 MeV, which is highly sensitive to the mixing parameter epsilon/sub 1/. A phase shift analysis of these data, together with forthcoming results of our measurements of /sup d//sup sigma//sub d//sub ..cap omega../ and A/sub y/ at the same energy is expected to allow a determination of epsilon/sub 1/ to within /similar to/ +- 0.3/sup 0/.

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

    ERIC Educational Resources Information Center

    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,…

  7. Bioaccumulation and food-chain analysis for evaluating ecological risks in terrestrial and wetland habitats: Availability-transfer factors (ATFs) in soil {r_arrow} soil macroinvertebrate {r_arrow} amphibian food chains

    SciTech Connect

    Linder, G.; Bollman, M.; Callahan, C.; Gillette, C.; Nebeker, A.; Wilborn, D.

    1998-12-31

    As part of the ecological risk assessment process for terrestrial and wetland habitats, the evaluation of bioaccumulative chemicals of concern (BCCs) is frequently pursued through food-chain analysis with a subsequent comparison of daily doses to benchmark toxicity reference values, when available. Food-chain analysis has frequently been applied to the analysis of exposure to BCCs identified as chemicals of potential ecological concern (COPECs) in the ecological risk assessment process. Here, designed studies focused on wetland food-chains such as hydric soil {r_arrow} soil macroinvertebrate {r_arrow} amphibian and terrestrial food-chains such as soil {r_arrow} plant {r_arrow} small mammal illustrate an approach for the derivation and validation of trophic transfer factors for metals considered as COPECs such as cadmium, chromium, copper, lead, and zinc. The results clearly indicate that the transfer of chemicals between trophic levels is critical in the bioaccumulation process in wetland and terrestrial food-chains and is influenced by numerous interacting abiotic and biotic factors, including physicochemical properties of soil, and the role, if any, that the metal has in the receptor as a required trace element.

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

    PubMed Central

    Vokhidov, Husan; Hong, Hyung Gil; Kang, Jin Kyu; Hoang, Toan Minh; Park, Kang Ryoung

    2016-01-01

    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. PMID:27999301

  9. Controlling Attention to Gaze and Arrows in Childhood: An fMRI Study of Typical Development and Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Vaidya, Chandan J.; Foss-Feig, Jennifer; Shook, Devon; Kaplan, Lauren; Kenworthy, Lauren; Gaillard, William D.

    2011-01-01

    Functional magnetic resonance imaging was used to examine functional anatomy of attention to social (eye gaze) and nonsocial (arrow) communicative stimuli in late childhood and in a disorder defined by atypical processing of social stimuli, Autism Spectrum Disorders (ASD). Children responded to a target word ("LEFT"/"RIGHT") in the context of a…

  10. Gender and Spatial Ability and the Use of Specific Labels and Diagrammatic Arrows in a Micro-Level Chemistry Animation

    ERIC Educational Resources Information Center

    Falvo, David A.; Suits, Jerry P.

    2009-01-01

    This study investigates the effects of using both specific labels and diagrammatic arrows in the animation of salt dissolution. Four different versions of the animation served as treatments that were developed based upon principles of educational technology and cognitive psychology. The researchers studied the effects of spatial ability (high or…

  11. Literature as Tool for Sustainable Development: A Comparative Literary Analysis of Achebe's "Arrow of God" and Tahir's "The Last Imam"

    ERIC Educational Resources Information Center

    Sani, Abubakar Mohammed

    2014-01-01

    This paper aims at a theoretical comparative textual analysis of two novels; Chinua Achebe's "Arrow of God" (1964) and Ibrahim Tahir's "The Last Imam" (1984). The focus is on their similarities generally and roles played by the heroes in their different societies as political and religious leaders of the different societies and…

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

    SciTech Connect

    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.

  13. Comparison of gunshot wounds and field-tipped arrow wounds using morphological criteria and chemical spot tests.

    PubMed

    Randall, B; Newby, P

    1989-05-01

    Arrow wounds represent an unusual class of wounds rarely seen by most death investigators. Although the edged, broadhead-tipped arrow produces a wound usually characteristic of archery/crossbow weapons, the plain, field-tipped arrow wound can be confused with gunshot injuries in those cases in which powder residue or firearm projectiles or fragments or both are not recovered. We present a case of a deer carcass with a wound of uncertain firearm or archery origin which initiated a comparison of firearm wounds and archery wounds on fresh road-killed deer. We found the following features to be valuable in the differentiation of gunshot wounds and field-tipped archery wounds: First, the majority of the gunshot wounds (but none of the arrow wounds) had identifiable, macroscopic, wipe-off material and chemically identifiable wipe-off residue by spot test. Second, the archery wound defects had very inconspicuous abrasion rings as compared to the often prominent abrasion rings of gunshot wounds. Third, the actual central defect in the archery wounds was more likely to be oblong or slit-like compared to the gunshot wound defects, which were more likely to be round.

  14. Effect of a simulated engine jet blowing above an arrow wing at Mach 2.0

    NASA Technical Reports Server (NTRS)

    Shrout, B. L.; Hayes, C.

    1977-01-01

    The effects of a gas jet simulating a turbojet engine exhaust blowing above a cambered and twisted arrow wing were investigated. Tests were conducted in the Langley 4-foot supersonic pressure tunnel at a Mach number of 2.0. Nozzle pressure ratios from 1 to 64 were tested with both helium and air used as jet gases. The tests were conducted at angles of attack from -2 deg to 8 deg at a Reynolds number of 9,840,000 per meter. Only the forces and moments on the wing were measured. Results of the investigation indicated that the jet blowing over the wing caused reductions in maximum lift-drag ratio of about 4 percent for helium and 6 percent for air at their respective design nozzle pressure ratios, relative to jet-off data. Moderate changes in the longitudinal, vertical, or angular positions of the jet relative to the wing had little effect on the wing aerodynamic characteristics.

  15. Scavenging interactions between the arrow tooth eel Synaphobranchus kaupii and the Portuguese dogfish Centroscymnus coelolepis.

    PubMed

    Jamieson, A J; Fujii, T; Bagley, P M; Priede, I G

    2011-07-01

    A scavenging interaction between the arrow tooth eel Synaphobranchus kaupii and the Portuguese dogfish Centroscymnus coelolepis, both ubiquitous components of fish assemblages at bathyal depths, was observed. Using a baited camera between 1297 and 2453 m in the eastern Atlantic Ocean continental slope, it was shown that despite consistently rapid arrival times of S. kaupii (<5 min), their feeding bouts (indicated by acute peak in numbers) did not take place until shortly after C. coelolepis arrived and removed the exterior surface of the bait (skipjack tuna Katsuwonus pelamis carcass). Change in the numbers of S. kaupii was hence dependent on the arrival of a more powerful scavenger throughout the study site, and at the deeper stations where the population of C. coelolepis declined, S. kaupii was observed to be present but waited for >2 h before feeding, thus contradicting conventional scavenging assumptions in the presence of a food fall.

  16. Scan path entropy and arrow plots: capturing scanning behavior of multiple observers

    PubMed Central

    Hooge, Ignace; Camps, Guido

    2013-01-01

    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. PMID:24399993

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Evaluation of structural design concepts for an arrow-wing supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Sakata, I. F.; Davis, G. W.

    1977-01-01

    An analytical study was performed to determine the best structural approach for design of primary wing and fuselage structure of a Mach 2.7 arrow wing supersonic cruise aircraft. Concepts were evaluated considering near term start of design. Emphasis was placed on the complex interactions between thermal stress, static aeroelasticity, flutter, fatigue and fail safe design, static and dynamic loads, and the effects of variations in structural arrangements, concepts and materials on these interactions. Results indicate that a hybrid wing structure incorporating low profile convex beaded and honeycomb sandwich surface panels of titanium alloy 6Al-4V were the most efficient. The substructure includes titanium alloy spar caps reinforced with boron polyimide composites. The fuselage shell consists of hat stiffened skin and frame construction of titanium alloy 6Al-4V. A summary of the study effort is presented, and a discussion of the overall logic, design philosophy and interaction between the analytical methods for supersonic cruise aircraft design are included.

  19. Titanium and advanced composite structures for a supersonic cruise arrow wing configuration

    NASA Technical Reports Server (NTRS)

    Turner, M. J.; Hoy, J. M.

    1976-01-01

    Structural design studies were made, based on current technology and on an estimate of technology to be available in the mid 1980's, to assess the relative merits of structural concepts and materials for an advanced arrow wing configuration cruising at Mach 2.7. Preliminary studies were made to insure compliance of the configuration with general design criteria, integrate the propulsion system with the airframe, and define an efficient structural arrangement. Material and concept selection, detailed structural analysis, structural design and airplane mass analysis were completed based on current technology. Based on estimated future technology, structural sizing for strength and a preliminary assessment of the flutter of a strength designed composite structure were completed. An advanced computerized structural design system was used, in conjunction with a relatively complex finite element model, for detailed analysis and sizing of structural members.

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

    NASA Technical Reports Server (NTRS)

    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.

  1. Solid phase microextraction Arrow for the sampling of volatile amines in wastewater and atmosphere.

    PubMed

    Helin, Aku; Rönkkö, Tuukka; Parshintsev, Jevgeni; Hartonen, Kari; Schilling, Beat; Läubli, Thomas; Riekkola, Marja-Liisa

    2015-12-24

    A new method is introduced for the sampling of volatile low molecular weight alkylamines in ambient air and wastewater by utilizing a novel SPME Arrow system, which contains a larger volume of sorbent compared to a standard SPME fiber. Parameters affecting the extraction, such as coating material, need for preconcentration, sample volume, pH, stirring rate, salt addition, extraction time and temperature were carefully optimized. In addition, analysis conditions, including desorption temperature and time as well as gas chromatographic parameters, were optimized. Compared to conventional SPME fiber, the SPME Arrow had better robustness and sensitivity. Average intermediate reproducibility of the method expressed as relative standard deviation was 12% for dimethylamine and 14% for trimethylamine, and their limit of quantification 10μg/L and 0.13μg/L respectively. Working range was from limits of quantification to 500μg/L for dimethylamine and to 130μg/L for trimethylamine. Several alkylamines were qualitatively analyzed in real samples, while target compounds dimethyl- and trimethylamines were quantified. The concentrations in influent and effluent wastewater samples were almost the same (∼80μg/L for dimethylamine, 120μg/L for trimethylamine) meaning that amines pass the water purification process unchanged or they are produced at the same rate as they are removed. For the air samples, preconcentration with phosphoric acid coated denuder was required and the concentration of trimethylamine was found to be around 1ng/m(3). The developed method was compared with optimized method based on conventional SPME and advantages and disadvantages of both approaches are discussed.

  2. The emergence of time's arrows and special science laws from physics

    PubMed Central

    Loewer, Barry

    2012-01-01

    In this paper, I will argue that there is an important connection between two questions concerning how certain features of the macro world emerge from the laws and processes of fundamental microphysics and suggest an approach to answering these questions. The approach involves a kind of emergence but quite different from ‘top-down’ emergence discussed at the conference, for which an earlier version of this paper was written. The two questions are (i) How do ‘the arrows of time’ emerge from microphysics? (ii) How do macroscopic special science laws and causation emerge from microphysics? Answering these questions is especially urgent for those, who like myself, think that a certain version of physicalism, which I call ‘micro-physical completeness’ (MC), is true. According to MC, there are fundamental dynamical laws that completely govern (deterministically or probabilistically), the evolution of all micro-physical events and there are no additional ontologically independent dynamical or causal special science laws. In other words, there is no ontologically independent ‘top-down’ causation. Of course, MC does not imply that physicists now or ever will know or propose the complete laws of physics. Or even if the complete laws were known we would know how special science properties and laws reduce to laws and properties of fundamental physics. Rather, MC is a contingent metaphysical claim about the laws of our world. After a discussion of the two questions, I will argue the key to showing how it is possible for the arrows of time and the special science laws to emerge from microphysics and a certain account of how thermodynamics is related to fundamental dynamical laws. PMID:23386956

  3. Lift-Drag Ratios for an Arrow Wing With Bodies at Mach Number 3

    NASA Technical Reports Server (NTRS)

    Jorgensen, Leland H.

    1959-01-01

    Force and moment characteristics, including lift-drag ratios, have been measured for bodies of circular and elliptic cross section alone and combined with a warped arrow wing. The test Mach number was 2.94, and the Reynolds number was 3.5 x 10(exp 6) (based on wing mean aerodynamic chord). The experimental results show that for equal volume the use of an elliptical body can result in a noticeably higher maximum lift-drag ratio than that obtained through use of a circular body. Methods for estimating the aerodynamic characteristics have been assessed by comparing computed with experimental results. Because of good agreement of the predictions with experiment, maximum lift-drag ratios have been computed for the arrow wing in combination with bodies of various sizes. These calculations have shown that, for an efficient wing-body combination, little loss in maximum lift-drag ratio results from considerable extension of afterbody length. For example, for a wing-body configuration having a maximum lift-drag ratio of about 7.1, a loss in maximum lift-drag ratio of less than 0.2 results from a 40-percent increase in body volume by extension of afterbody length. It also appears that with body length fixed, maximum lift-drag ratio decreases almost linearly with increase in body diameter. For a wing- body combination employing a body of circular cross section, a decrease in maximum lift-drag ratio from about 9.1 for zero body diameter to about 4.6 for a body diameter of 13.5 percent of the body length was computed.

  4. The emergence of time's arrows and special science laws from physics.

    PubMed

    Loewer, Barry

    2012-02-06

    In this paper, I will argue that there is an important connection between two questions concerning how certain features of the macro world emerge from the laws and processes of fundamental microphysics and suggest an approach to answering these questions. The approach involves a kind of emergence but quite different from 'top-down' emergence discussed at the conference, for which an earlier version of this paper was written. The two questions are (i) How do 'the arrows of time' emerge from microphysics? (ii) How do macroscopic special science laws and causation emerge from microphysics? Answering these questions is especially urgent for those, who like myself, think that a certain version of physicalism, which I call 'micro-physical completeness' (MC), is true. According to MC, there are fundamental dynamical laws that completely govern (deterministically or probabilistically), the evolution of all micro-physical events and there are no additional ontologically independent dynamical or causal special science laws. In other words, there is no ontologically independent 'top-down' causation. Of course, MC does not imply that physicists now or ever will know or propose the complete laws of physics. Or even if the complete laws were known we would know how special science properties and laws reduce to laws and properties of fundamental physics. Rather, MC is a contingent metaphysical claim about the laws of our world. After a discussion of the two questions, I will argue the key to showing how it is possible for the arrows of time and the special science laws to emerge from microphysics and a certain account of how thermodynamics is related to fundamental dynamical laws.

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

    SciTech Connect

    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.; Louis, W.C.; 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.; 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.; Kitching, P.; Nakano, T.; Rozon, M.; Soluk, R.

    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}

  6. The Cranked Arrow Wing Aerodynamics Project (CAWAP) and its Extension to the International Community as CAWAPI: Objectives and Overview

    NASA Technical Reports Server (NTRS)

    Lamar, John E.; Obara, Clifford J.

    2009-01-01

    This paper provides a brief history of the F-16XL-1 aircraft, its role in the High Speed Research (HSR) program and how it was morphed into the Cranked Arrow Wing Aerodynamics Project (CAWAP). Various flight, wind-tunnel and Computational Fluid Dynamics (CFD) data sets were generated during the CAWAP. These unique and open flight datasets for surface pressures, boundary-layer profiles and skin-friction distributions, along with surface flow data, are described and sample data comparisons given. This is followed by a description of how the project became internationalized to be known as Cranked Arrow Wing Aerodynamics Project International (CAWAPI) and is concluded by an introduction to the results of a 5-year CFD predictive study of data.

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

    PubMed

    Chaboo, Caroline S; Biesele, Megan; Hitchcock, Robert K; Weeks, Andrea

    2016-01-01

    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 indigenous groups using so-called 'click languages' in southern Africa. Beetles are used for arrow poison by at least eight San groups and one non-San group. Fieldwork and interviews with Ju|'hoan and Hai||om hunters in Namibia revealed major differences in the nature and preparation of arrow poisons, bow and arrow construction, and poison antidote. Ju|'hoan hunters use leaf-beetle larvae of Diamphidia Gerstaecker and Polyclada Chevrolat (Chrysomelidae: Galerucinae: Alticini) collected from soil around the host plants Commiphora africana (A. Rich.) Engl. and Commiphora angolensis Engl. (Burseracaeae). In the Nyae Nyae area of Namibia, Ju|'hoan hunters use larvae of Diamphidia nigroornata Ståhl. Larvae and adults live above-ground on the plants and eat leaves, but the San collect the underground cocoons to extract the mature larvae. Larval hemolymph is mixed with saliva and applied to arrows. Hai||om hunters boil the milky plant sap of Adenium bohemianum Schinz (Apocynaceae) to reduce it to a thick paste that is applied to their arrows. The socio-cultural, historical, and ecological contexts of the various San groups may determine differences in the sources and preparation of poisons, bow and arrow technology, hunting behaviors, poison potency, and perhaps antidotes.

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

    PubMed Central

    Chaboo, Caroline S.; Biesele, Megan; Hitchcock, Robert K.; Weeks, Andrea

    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 indigenous groups using so-called ‘click languages’ in southern Africa. Beetles are used for arrow poison by at least eight San groups and one non-San group. Fieldwork and interviews with Ju|’hoan and Hai||om hunters in Namibia revealed major differences in the nature and preparation of arrow poisons, bow and arrow construction, and poison antidote. Ju|’hoan hunters use leaf-beetle larvae of Diamphidia Gerstaecker and Polyclada Chevrolat (Chrysomelidae: Galerucinae: Alticini) collected from soil around the host plants Commiphora africana (A. Rich.) Engl. and Commiphora angolensis Engl. (Burseracaeae). In the Nyae Nyae area of Namibia, Ju|’hoan hunters use larvae of Diamphidia nigroornata Ståhl. Larvae and adults live above-ground on the plants and eat leaves, but the San collect the underground cocoons to extract the mature larvae. Larval hemolymph is mixed with saliva and applied to arrows. Hai||om hunters boil the milky plant sap of Adenium bohemianum Schinz (Apocynaceae) to reduce it to a thick paste that is applied to their arrows. The socio-cultural, historical, and ecological contexts of the various San groups may determine differences in the sources and preparation of poisons, bow and arrow technology, hunting behaviors, poison potency, and perhaps antidotes. PMID:27006594

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

    SciTech Connect

    Chitayat, D.; Babul, R.; Silver, M.M.

    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.

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

    SciTech Connect

    Kitching, P.; Nakano, T.; Rozon, M.; Soluk, R.; 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.; Louis, W.C.; 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.; 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.

    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}

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

    NASA Technical Reports Server (NTRS)

    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.

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

    USGS Publications Warehouse

    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.

  13. ARGX-87: Accident Response Group Exercise, 1987: A Broken Arrow mini exercise. [Training

    SciTech Connect

    Schuld, E.P.; Cruff, D.F.

    1987-07-01

    A Broken Arrow mini exercise dubbed ''Accident Response Group Exercise - 1987'' (ARGX-87) was conducted on June 1, 1987 at the Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories, Livermore (SNLL). The exercise started at 0445 PDT with a call from the Department of Energy (DOE) - EOC in Washington, DC, to the Albuquerque Operations (AL - ) - EOC. AL, in turn, called the Laboratory off-hour emergency number (Fire Dispatcher), who called the Laboratory Emergency Duty Officer (LEDO). The LEDO then contacted the Accident Response Group (ARG) Senior Scientific Advisor. Calls were placed to assemble appropriate members of the ARG in the ALERT Center. No phone number for SNLL was available at the Albuquerque Operations EOC, so a controller injected a message to SNLL to get them involved in the exercise. The messages received at the Laboratory identified the Air Force line item weapon system involved in the accident and the accident location. As people arrived at the ALERT Center they began discussing the details of the accident. They also started working the deployment logistics and other issues. Travel arrangements for the HOT SPOT equipment and ARG personnel were made for immediate deployment to the accident site in North Dakota. The exercise was terminated at 0840 as planned. While certain procedural deficiencies were noted, the exercise was considered a valuable learning experience. The results and observations from this experience will be used to refine the operating procedures and the training program.

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

    NASA Technical Reports Server (NTRS)

    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.

  15. The Potential Landscape of Genetic Circuits Imposes the Arrow of Time in Stem Cell Differentiation

    PubMed Central

    Wang, Jin; Xu, Li; Wang, Erkang; Huang, Sui

    2010-01-01

    Abstract Differentiation from a multipotent stem or progenitor state to a mature cell is an essentially irreversible process. The associated changes in gene expression patterns exhibit time-directionality. This “arrow of time” in the collective change of gene expression across multiple stable gene expression patterns (attractors) is not explained by the regulated activation, the suppression of individual genes which are bidirectional molecular processes, or by the standard dynamical models of the underlying gene circuit which only account for local stability of attractors. To capture the global dynamics of this nonequilibrium system and gain insight in the time-asymmetry of state transitions, we computed the quasipotential landscape of the stochastic dynamics of a canonical gene circuit that governs branching cell fate commitment. The potential landscape reveals the global dynamics and permits the calculation of potential barriers between cell phenotypes imposed by the circuit architecture. The generic asymmetry of barrier heights indicates that the transition from the uncommitted multipotent state to differentiated states is inherently unidirectional. The model agrees with observations and predicts the extreme conditions for reprogramming cells back to the undifferentiated state. PMID:20655830

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

    PubMed

    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.

  17. Two-photon excitation of the 4[ital f][sup 1][r arrow]5[ital d][sup 1] transitions of Ce[sup 3+] in LuPO[sub 4] and YPO[sub 4

    SciTech Connect

    Sytsma, J.; Piehler, D.; Edelstein, N.M. ); Boatner, L.A.; Abraham, M.M. )

    1993-06-01

    Two-photon excitation (TPE) spectra of the 4[ital f][sup 1][r arrow]5[ital d][sup 1] transitions of Ce[sup 3+] in LuPO[sub 4] and YPO[sub 4] have been investigated. For Ce[sup 3+] in LuPO[sub 4], transitions to four out of the five 5[ital d][sup 1] levels are observed as zero-phonon lines. The symmetry properties of the levels were obtained from the polarization dependence of the TPE signals. Measurements on Ce[sup 3+] in YPO[sub 4] support the given assignments. Although a crystal-field fit yields a satisfactory rms energy deviation, an unrealistic value of the spin-orbit coupling parameter, [zeta][sub 5[ital d

  18. Experimental Investigation of a Point Design Optimized Arrow Wing HSCT Configuration

    NASA Technical Reports Server (NTRS)

    Narducci, Robert P.; Sundaram, P.; Agrawal, Shreekant; Cheung, S.; Arslan, A. E.; Martin, G. L.

    1999-01-01

    The M2.4-7A Arrow Wing HSCT configuration was optimized for straight and level cruise at a Mach number of 2.4 and a lift coefficient of 0.10. A quasi-Newton optimization scheme maximized the lift-to-drag ratio (by minimizing drag-to-lift) using Euler solutions from FL067 to estimate the lift and drag forces. A 1.675% wind-tunnel model of the Opt5 HSCT configuration was built to validate the design methodology. Experimental data gathered at the NASA Langley Unitary Plan Wind Tunnel (UPWT) section #2 facility verified CFL3D Euler and Navier-Stokes predictions of the Opt5 performance at the design point. In turn, CFL3D confirmed the improvement in the lift-to-drag ratio obtained during the optimization, thus validating the design procedure. A data base at off-design conditions was obtained during three wind-tunnel tests. The entry into NASA Langley UPWT section #2 obtained data at a free stream Mach number, M(sub infinity), of 2.55 as well as the design Mach number, M(sub infinity)=2.4. Data from a Mach number range of 1.8 to 2.4 was taken at UPWT section #1. Transonic and low supersonic Mach numbers, M(sub infinity)=0.6 to 1.2, was gathered at the NASA Langley 16 ft. Transonic Wind Tunnel (TWT). In addition to good agreement between CFD and experimental data, highlights from the wind-tunnel tests include a trip dot study suggesting a linear relationship between trip dot drag and Mach number, an aeroelastic study that measured the outboard wing deflection and twist, and a flap scheduling study that identifies the possibility of only one leading-edge and trailing-edge flap setting for transonic cruise and another for low supersonic acceleration.

  19. Cross section for the process. pi. sup +. pi minus. r arrow. pi0. pi0. in the c. m. s. energy region 0. 55 lt M lt 2 GeV from the reaction. pi. sup minus p r arrow. pi0. pi0. n at 39. 1 GeV/ c

    SciTech Connect

    Apokin, V.D.; Arestov, Y.I.; Belikov, N.I.; Borisov, N.S.; Vasil'ev, A.N.; Grachev, O.A.; Derevshchikov, A.A.; Kazarinov, Y.M.; Liburg, M.Y.; Matafonov, V.N.; and others

    1989-02-01

    The total cross section for the process {pi}{sup +}{pi{minus}}{r arrow}{pi0}{pi0} in the dipion mass region 0.55{lt}{ital M}{lt}2.0 GeV is determined from the peripheral transitions {pi}{sup {minus}}{r arrow}{pi0}{pi0} in carbon and propanediol targets at an initial {pi}{sup {minus}}-meson momentum 39.1 GeV/{ital c}.

  20. Histochemical demonstration of a rhodopsin-like substance in the eye of the arrow-worm, Spadella schizoptera (Chaetognatha).

    PubMed

    Goto, T; Yoshida, M

    1988-01-01

    The presumed photoreceptive region of the arrow-worms of the species Sagitta crassa and Spadella schizoptera consists of perforated lamellae which are unique as the photoreceptive structure. The existence of a visual pigment in this region was demonstrated by a histofluorescent technique using Spadella schizoptera, whose presumed photoreceptive region was much larger than in Sagitta crassa. A specific fluorescence, indicative of the presence of retinal-based proteins, appeared only in the perforated lamellar region. The result suggests that the perforated lamellae contain a rhodopsin-like substance and could be the primary photoreceptive site.

  1. A comparison of arrow, trapezoidal and M wing concepts using a Mach 2 supersonic cruise transport mission

    NASA Technical Reports Server (NTRS)

    Martin, Glenn L.; Tice, David C.; Marcum, Don C., Jr.; Seidel, Jonathan A.

    1991-01-01

    The present analytic study of the potential performance of SST configurations radically differing from arrow-winged designs in lifting surface planform geometry gives attention to trapezoidal-wing and M-wing configurations; the trapezoidal wing is used as the baseline in the performance comparisons. The design mission was all-supersonic (Mach 2), carrying 248 passengers over a 5500 nautical-mile range. Design constraints encompassed approach speed, TO&L field length, and engine-out second-segment climb and missed-approach performance. Techniques for improving these configurations are discussed.

  2. CHARGE association in a child with de novo inverted duplication (14) (q22{r_arrow}q24.3)

    SciTech Connect

    North, K.N.; Wu, Bai Lin; Cao, B.N.

    1995-07-17

    We report on a 4-{1/2} year old girl with apparent CHARGE association who had a de novo inverted duplication (14) (q22{r_arrow}24.3), iris colobomas, ventricular septal defect, soft tissue choanal atresia, intellectual impairment, growth retardation, sensorineural deafness, apparently low set ears, and upslanting palpebral fissures. Family history was unremarkable and parental chromosomes were normal. Similarities between this and previously reported cases of 14q duplication suggest that a locus for a gene or genes causing some of the anomalies of CHARGE association may reside in the region 14q22 to 24.3. 26 refs., 2 figs., 1 tab.

  3. Measurement of the small-signal gain and saturation intensity of a XeF discharge laser

    SciTech Connect

    Parvin, Parviz; Zaeferani, Mohammad, S.; Sadigh, Rassoul; Mirabbaszadeh, Kavoos

    1997-02-01

    An optical oscillator-amplifier series driven by a Blumlein discharge has been fabricated and optimized for measuring the small-signal gain and saturation intensity of a XeF(B{r_arrow}X) laser at 352 nm. Pressure dependence of the gain and the saturation property of the laser have been investigated. {copyright} 1997 Optical Society of America

  4. Arrow diagram theory for non-orthogonal electronic groups: the continued fractions method.

    PubMed

    Wang, Yu; Kantorovich, Lev

    2009-11-25

    The group function theory by Tolpygo and McWeeny is a useful tool in treating quantum systems that can be represented as a set of localized electronic groups (e.g. atoms, molecules or bonds). It provides a general means of taking into account intra-correlation effects inside the groups without assuming that the interaction between the groups is weak. For non-orthogonal group functions the arrow diagram (AD) technique provides a convenient procedure for calculating matrix elements [Formula: see text] of arbitrary symmetrical operators [Formula: see text] which are needed, for example, for calculating the total energy of the system or its electron density. The total wavefunction of the system [Formula: see text] is represented as an antisymmetrized product of non-orthogonal electron group functions Φ(I) of each group I in the system. However, application of the AD theory to extended (e.g. infinite) systems (such as biological molecules or crystals) is not straightforward, since the calculation of the mean value of an operator requires that each term of the diagram expansion be divided by the normalization integral S = ⟨Ψ|Ψ⟩ which is given by an AD expansion as well. In our previous work, we cast the mean value [Formula: see text] of a symmetrical operator [Formula: see text] in the form of an AD expansion which is a linear combination of linked (connected) ADs multiplied by numerical pre-factors. To obtain the pre-factors, a method based on power series expansion with respect to overlap was developed and tested for a simple 1D Hartree-Fock (HF) ring model. In the present paper this method is first tested on a 2D HF model, and we find that the power series expansion for the pre-factors converges extremely slowly to the exact solution. Instead, we suggest another, more powerful, method based on a continued fraction expansion of the pre-factors that approaches the exact solution much faster. The method is illustrated on the calculation of the electron density

  5. The 5 f r arrow 6 d absorption spectrum of Pa sup 4+ /Cs sub 2 ZrCl sub 6

    SciTech Connect

    Edelstein, N.; Kot, W.K. ); Krupa, J. )

    1992-01-01

    The 5{ital f}{sup 1}{r arrow}6{ital d}{sup 1} absorption spectrum of {sup 231}Pa{sup 4+} diluted in a single crystal of Cs{sub 2}ZrCl{sub 6} has been measured at 4.2 K. Three bands corresponding to the 6{ital d}({Gamma}{sub 8{ital g}}, {Gamma}{sub 7{ital g}}, and {Gamma}{sup {prime}}{sub 8{ital g}} ) levels are assigned. Extensive vibronic structure has been observed for the lowest 5{ital f}{r arrow}6{ital d} transition and this structure is compared to that recently reported for the 6{ital d}{sup 1}{r arrow}5{ital f}{sup 1} emission spectra in the same system.

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

    PubMed Central

    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. Use of Glucose Rate of Change Arrows to Adjust Insulin Therapy Among Individuals with Type 1 Diabetes Who Use Continuous Glucose Monitoring

    PubMed Central

    Pettus, Jeremy

    2016-01-01

    Abstract Objective: This study was performed to understand and to compare differences in utilization of continuous glucose monitoring (CGM) and the rate of change (ROC) arrow to adjust insulin therapy among individuals with type 1 diabetes (T1D), comparing those treated with multiple daily insulin injections (MDI) with those treated with continuous subcutaneous insulin infusion (CSII). Research Design and Methods: We surveyed 222 T1D individuals who regularly used real-time CGM to obtain information about general CGM use and response to glucose ROC arrows in managing their diabetes. Results: The survey was completed by 222 T1D individuals. Respondents included CSII (n = 166) and MDI (n = 56) users. MDI and CSII respondents reported similar substantial increases in correction dosages (from 220 mg/dL to 120 mg/dL) in response to increasing glucose (one ROC arrow up: rising 2–3 mg/dL/min): +120% and +108%, respectively (P = 0.13). MDI and CSII respondents reported similar substantial increases in correction dosages in response to rapidly increasing glucose (two arrows up: rising >3 mg/dL/min): +146% and +138%, respectively (P = 0.72). When correcting from 220 mg/dL to 120 mg/dL, MDI respondents reported larger correction dosage reductions than CSII respondents in response to decreasing glucose (one ROC down arrow: decreasing 2–3 mg/dL/min) and rapidly decreasing glucose (two ROC down arrows: decreasing >3 mg/dL/min): −50% versus −37%, respectively (P = 0.024) and −52% versus 38%, respectively (P = 0.034). Similar between-group differences were observed in mealtime dosage adjustments. Conclusions: CGM users often rely on ROC information when determining insulin doses and tend to make larger changes than current recommendations suggest regardless of insulin delivery method. PMID:26784128

  8. Search for Proton Decay via {ital p} {r_arrow} {ital e}{sup +}{ital {pi}}{sup 0} in a Large Water Cherenkov Detector

    SciTech Connect

    Shiozawa, M.; Fukuda, Y.; Hayakawa, T.; Ichihara, E.; Inoue, K.; Ishihara, K.; Ishino, H.; Itow, Y.; Kajita, T.; Kameda, J.; Kasuga, S.; Kobayashi, K.; Kobayashi, Y.; Koshio, Y.; Miura, M.; Nakahata, M.; Nakayama, S.; Okada, A.; Oketa, M.; Okumura, K.; Ota, M.; Sakurai, N.; Suzuki, Y.; Takeuchi, Y.; Totsuka, Y.; Yamada, S.; Earl, M.; Habig, A.; Kearns, E.; Messier, M.D.; Scholberg, K.; Stone, J.L.; Sulak, L.R.; Walter, C.W.; Goldhaber, M.; Barszczak, T.; Gajewski, W.; Halverson, P.G.; Hsu, J.; Kropp, W.R.; Price, L.R.; Reines, F.; Sobel, H.W.; Vagins, M.R.; Haines, T.J.; Kielczewska, D.; Ganezer, K.S.; Keig, W.E.; Ellsworth, R.W.; Tasaka, S.; Flanagan, J.W.; Kibayashi, A.; Learned, J.G.; Matsuno, S.; Stenger, V.; Takemori, D.; Ishii, T.; Kanzaki, J.; Kobayashi, T.; Nakamura, K.; Nishikawa, K.; Oyama, Y.; Sakai, A.; Sakuda, M.; Sasaki, O.; Echigo, S.; Kohama, M.; Suzuki, A.T.; Haines, T.J.; Blaufuss, E.; and others

    1998-10-01

    We have searched for proton decay via p{r_arrow}e{sup +}{pi}{sup 0} using data from a 25.5 kton{center_dot}yr exposure of the Super-Kamiokande detector. We find no candidate events with an expected background induced by atmospheric neutrinos of 0.1thinspthinspevents. From these data, we set a lower limit on the partial lifetime of the proton {tau}/B{sub p{r_arrow}e{sup +}{pi}{sup 0}} to be 1.6{times}10{sup 33} years at a 90{percent} confidence level. {copyright} {ital 1998} {ital The American Physical Society }

  9. 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

    ERIC Educational Resources Information Center

    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…

  10. A Method for Writing Open-Ended Curved Arrow Notation Questions for Multiple-Choice Exams and Electronic-Response Systems

    ERIC Educational Resources Information Center

    Ruder, Suzanne M.; Straumanis, Andrei R.

    2009-01-01

    A critical stage in the process of developing a conceptual understanding of organic chemistry is learning to use curved arrow notation. From this stems the ability to predict reaction products and mechanisms beyond the realm of memorization. Since evaluation (i.e., testing) is known to be a key driver of student learning, it follows that a new…

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

    SciTech Connect

    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.; Louis, W.C.; 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.; 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.; Kitching, P.; Nakano, T.; Rozon, M.; Soluk, R.

    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}

  12. Test Plan for Lockheed Idaho Technologies Company (LITCO), ARROW-PAK Packaging, Docket 95-40-7A, Type A Container

    SciTech Connect

    Kelly, D.L.

    1995-10-23

    This report documents the U.S. Department of Transportation Specification 7A Type A (DOT-7A) compliance testing to be followed for qualification of the Lockheed Idaho Technologies Company, ARROW-PAK, for use as a Type A Packaging. The packaging configuration being tested is intended for transportation of radioactive solids, Form No. 1, Form No. 2, and Form No. 3.

  13. Polarization observables in {rvec p}p{r_arrow}pK{rvec Y} reactions at 2.9 GeV

    SciTech Connect

    Arvieux, J.; Balestra, F.; Bedfer, Y.; Bertini, R. |; Bland, L.C.; Bossolasco, S.; Brochard, F.; Bussa, M.P.; Falomkin, I.V.; Fava, L.; Ferrero, L.; Garfagnini, R.; Gill, D.R.; Grasso, A.; Jacobs, W.W.; Lyascenko, V.I.; Maggiora, A.; Panzieri, D.; Piragino, G.; Pontecorvo, G.B.; Serdyuk, V.; Tosello, F.; Travkin, V.I.; Vigdor, S.E.; Zalikanov, B.; Zosi, G.

    1995-07-15

    A program of exclusive measurements involving spin observables for {rvec p}p{r_arrow}pK{rvec Y} is nearing production phase. A brief description of the apparatus and its present status is given with emphasis on simulations relevant to the extraction of polarization components of {Lambda} and@ m{rvec j}{sup 0}.

  14. 78 FR 21345 - In the Matter of: Liem Duc Huynh, a/k/a Duc Huynh, 2905 South Elm, Broken Arrow, OK 74012; Order...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-10

    ... Arrow, OK 74012; Order Denying Export Privileges On April 17, 2012, in the U.S. District Court, Central District of California, Liem Duc Huynh (``Huynh'') was convicted of violating Section 38 of the Arms Export... aiding and abetting and willfully exporting Generation 3 Night Vision Goggles, defense articles listed...

  15. CSMP Mathematics for the Intermediate Grades Part IV, Teacher's Guide. The Languages of Strings and Arrows. Geometry and Measurement. Probability and Statistics.

    ERIC Educational Resources Information Center

    CEMREL, Inc., St. Ann, MO.

    This guide represents the final experimental version of a pilot project which was conducted in the United States between 1973 and 1976. The ideas and the manner of presentation are based on the works of Georges and Frederique Papy. They are recognized for having introduced colored arrow drawings ("papygrams") and models of our numeration…

  16. CSMP Mathematics for the Upper Primary Grades Part I, Teacher's Guide. The Languages of Strings and Arrows. Geometry and Measurement. Workbooks. Final Experimental Version.

    ERIC Educational Resources Information Center

    CEMREL, Inc., St. Ann, MO.

    This guide represents the final experimental version of a pilot project conducted in the Unites States between 1973 and 1976. The ideas and manner of presentation are based on the works of Georges and Frederique Papy. They are recognized as having introduced colored arrow drawings ("papygrams") and models of our numeration system (the…

  17. Nonadiabatic theory of atomic line broadening: Redistribution calculations for Sr(/sup 1/Preverse arrow /sup 1/S)+Ar

    SciTech Connect

    Julienne, P.S.; Mies, F.H.

    1986-11-01

    The close-coupled theory of collisions in a radiation field is used to calculate the absorption profile for the Sr /sup 1/Preverse arrow/sup 1/S resonance line broadened by collisions with Ar. The calculations predict the polarization ratios of Sr /sup 1/P fluorescence following line wing excitation by either linear or circular polarized light. Ab initio calculations were used to obtain the ground and excited SrAr molecular-potential curves, which were adjusted to give improved agreement with experiment. The radiative-scattering theory gives a unified description of the absorption coefficient and polarization redistribution from the small detuning impact limit region to the far spectral wings. The cross sections for elastic and inelastic depolarizing collisions of Sr /sup 1/P/sub 1/+Ar were also calculated. The calculated absorption coefficient, impact-broadening rate, linear- and circular-polarization ratios, and depolarization rate coefficients are for the most part in good agreement with experiment.

  18. Pressure data for four analytically defined arrow wings in supersonic flow. [Langley Unitary Plan Wind Tunnel tests

    NASA Technical Reports Server (NTRS)

    Townsend, J. C.

    1980-01-01

    In order to provide experimental data for comparison with newly developed finite difference methods for computing supersonic flows over aircraft configurations, wind tunnel tests were conducted on four arrow wing models. The models were machined under numeric control to precisely duplicate analytically defined shapes. They were heavily instrumented with pressure orifices at several cross sections ahead of and in the region where there is a gap between the body and the wing trailing edge. The test Mach numbers were 2.36, 2.96, and 4.63. Tabulated pressure data for the complete test series are presented along with selected oil flow photographs. Comparisons of some preliminary numerical results at zero angle of attack show good to excellent agreement with the experimental pressure distributions.

  19. Evidence for a founder effect for the IVS4 +4 A{r_arrow}T mutation in the Fanconi anemia gene FACC in a Jewish population

    SciTech Connect

    Verlander, P.C.; Kaporis, A.G.; Qian, L.

    1994-09-01

    Fanconi anemia (FA) is a genetically heterogeneous autosomal recessive disorder defined by hypersensitivity of cells to DNA cross-linking agents; a gene for complementation group C(FACC) has been cloned. Two common mutations, IVS4 +4 A{r_arrow}T and 322delG, and several rare mutations have recently been reported in affected individuals. We now report the development of amplification refractory mutation system (ARMS) assays for rapid, non-radioactive detection of these known mutations in FACC. Primer pairs specific for variant sequences were designed, with the 3{prime} terminal base of one primer matching the variant base. PCR products are separated by electrophoresis on 2.5% agarose gels; mutations are indicated by the presence of a band of a specific size. These ARMS assays can be multiplexed to allow screening for all known mutations in two PCR reactions. We have used these assays for detection of FACC mutations in affected individuals in the International Fanconi Anemia Registry (IFAR), and for carrier detection FACC families. IVS4 +4 A{r_arrow}T is the only FACC mutation found in Jewish FA patients and their families, of both Ashkenazi and Sephardic ancestry. This mutation was not found in any affected individual of non-Jewish origin. In addition, DNA samples from 1596 healthy Jewish individuals primarily of Ashkenazi ancestry were supplied to us by Dor Yeshorim. These samples, ascertained for carrier screening for Tay Sachs, cystic fibrosis, and other genetic diseases with a high frequency in the religious Jewish community served by this organization, were tested for both IVS4 +4 A{r_arrow}T and 322delG mutations; seventeen IVS4 +4 A{r_arrow}T are of Sephardic Jewish ancestry. We hypothesize that IVS4 +4 A{r_arrow}T is a very old mutation, predating the divergence of the Ashkenazi and Sephardic populations. Haplotype analysis with microsatellite markers is in progress.

  20. Analysis and Inverse Design of the HSR Arrow Wing Configuration with Fuselage, Wing, and Flow Through Nacelles

    NASA Technical Reports Server (NTRS)

    Krist, Steven E.; Bauer, Steven X. S.

    1999-01-01

    The design process for developing the natural flow wing design on the HSR arrow wing configuration utilized several design tools and analysis methods. Initial fuselage/wing designs were generated with inviscid analysis and optimization methods in conjunction with the natural flow wing design philosophy. A number of designs were generated, satisfying different system constraints. Of the three natural flow wing designs developed, the NFWAc2 configuration is the design which satisfies the constraints utilized by McDonnell Douglas Aerospace (MDA) in developing a series of optimized configurations; a wind tunnel model of the MDA designed OPT5 configuration was constructed and tested. The present paper is concerned with the viscous analysis and inverse design of the arrow wing configurations, including the effects of the installed diverters/nacelles. Analyses were conducted with OVERFLOW, a Navier-Stokes flow solver for overset grids. Inverse designs were conducted with OVERDISC, which couples OVERFLOW with the CDISC inverse design method. An initial system of overset grids was generated for the OPT5 configuration with installed diverters/nacelles. An automated regridding process was then developed to use the OPT5 component grids to create grids for the natural flow wing designs. The inverse design process was initiated using the NFWAc2 configuration as a starting point, eventually culminating in the NFWAc4 design-for which a wind tunnel model was constructed. Due to the time constraints on the design effort, initial analyses and designs were conducted with a fairly coarse grid; subsequent analyses have been conducted on a refined system of grids. Comparisons of the computational results to experiment are provided at the end of this paper.

  1. Venetoclax Adds a New Arrow Targeting Relapsed CLL to the Quiver.

    PubMed

    Rogers, Kerry A; Byrd, John C

    2016-01-11

    Inhibitors of B cell receptor signaling substantially changed the treatment of chronic lymphocytic leukemia as the first targeted agents to enter routine clinical practice. A recent paper by Roberts and colleagues describes an additional therapeutic target by reporting encouraging clinical results with venetoclax, an inhibitor of the antiapoptotic protein BCL2.

  2. Percutaneous Venous Thrombectomy Using the Arrow-Trerotola Percutaneous Thrombolytic Device (PTD) with Temporary Caval Filtration: In Vitro Investigations

    SciTech Connect

    Wildberger, Joachim Ernst Haage, Patrick; Bovelander, Jan; Pfeffer, Joachim; Weiss, Claudia; Vorwerk, Dierk; Schmitz-Rode, Thomas; Guenther, Rolf W.

    2005-04-15

    Purpose. To evaluate the size and quantity of downstream emboli after thrombectomy using the Arrow-Trerotola Percutaneous Thrombolytic Device (PTD) with or without temporary filtration for extensive iliofemoral and iliocaval thrombi in an in vitro flow model. Methods. Iliocaval thrombi were simulated by clotted bovine blood in a flow model (semilucent silicone tubings, diameter 12-16 mm). Five experimental set-ups were performed 10 times each; thrombus particles and distribution were measured in the effluent. First, after retrograde insertion, mechanical thrombectomy was performed using the PTD alone. Then a modified self-expanding tulip-shaped temporary vena cava stent filter was inserted additionally at the beginning of each declotting procedure and removed immediately after the intervention without any manipulation within or at the filter itself. In a third step, the filter was filled with thrombus only. Here, two experiments were performed: Careful closure within the flow circuit without any additional fragmentation procedure and running the PTD within the filter lumen, respectively. In the final set-up, mechanical thrombectomy was performed within the thrombus-filled tubing as well as in the filter lumen. The latter was closed at the end of the procedure and both devices were removed from the flow circuit. Results. Running the PTD in the flow circuit without filter protection led to a fragmentation of 67.9% ({+-}7.14%) of the clot into particles {<=}500 {mu}m; restoration of flow was established in all cases. Additional placement of the filter safely allowed maceration of 82.9% ({+-}5.59%) of the thrombus. Controlled closure of the thrombus-filled filter within the flow circuit without additional mechanical treatment broke up 75.2% ({+-}10.49%), while additional mechanical thrombectomy by running the PTD within the occluded filter led to dissolution of 90.4% ({+-}3.99%) of the initial clot. In the final set-up, an overall fragmentation rate of 99.6% ({+-}0

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

    SciTech Connect

    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.

  4. The decay. tau. sup minus r arrow K sup minus K sup +. pi. sup minus. nu. sub. tau. and the. nu. sub. tau. mass

    SciTech Connect

    Gomez-Cadenas, J.J. ); Gonzalez-Garcia, M.C.; Pich, A. Instituto de Fisica Corpuscular, Consejo Superior de Investigaciones Cientificas, Universidad de Valencia, Burjasot )

    1990-11-01

    In this paper, we present a model based on the effective chiral Lagrangian to describe the decay {tau}{sup {minus}}{r arrow}{ital K}{sup {minus}}{ital K}{sup +}{pi}{sup {minus}}{nu}{sub {tau}}. Using our model we study the possible limits on the {nu}{sub {tau}} mass that can be achieved by a high-statistics, high-precision experiment taking data close to the {tau}-pair production threshold.

  5. 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

    NASA Astrophysics Data System (ADS)

    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.

  6. ( D , D sub s sup + ) r arrow VV decays in two models: An SU(3)-symmetry model and a factorization model, with final-state interactions

    SciTech Connect

    Kamal, A.N.; Verma, R.C. . Theoretical Physics Institute University of Alberta, Edmonton . Department of Physics); Sinha, N. )

    1991-02-01

    We have studied all decays of the kind ({ital D},{ital D}{sub {ital s}}{sup +}){r arrow}{ital VV} in two models: an SU(3)-symmetry model with nonet symmetry and a factorization model, and the inclusion of final-state-interaction phases. We show that the factorization model makes predictions in agreement with data, with fewer free parameters. Detailed predictions for all decay modes are made and the two models contrasted.

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

    NASA Technical Reports Server (NTRS)

    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.

  8. Candidate events in a search for {bar {nu}}{sub {mu}}{r_arrow}{bar {nu}}{sub {ital e}} oscillations

    SciTech Connect

    Athanassopoulos, C.; Auerbach, L.B.; Bauer, D.A.; Bolton, R.D.; Boyd, B.; Burman, R.L.; Caldwell, D.O.; Cohen, I.; Dieterle, B.D.; Donahue, J.B.; Eisner, A.M.; Fazely, A.; Federspiel, F.J.; Garvey, G.T.; Gray, M.; Gunasingha, R.M.; Highland, V.; Imlay, R.; Johnston, K.; Louis, W.C.; Lu, A.; Margulies, J.; McIlhany, K.; Metcalf, W.; Reeder, R.A.; Sandberg, V.; Schillaci, M.; Smith, D.; Stancu, I.; Strossman, W.; Sullivan, M.K.; VanDalen, G.J.; Vernon, W.; Wang, Y.; White, D.H.; Whitehouse, D.; Works, D.; Xiao, Y.; Yellin, S. |||||||||||

    1995-10-02

    A search for {bar {nu}}{sub {ital e}}`s in excess of the number expected from conventional sources has been made using the Liquid Scintillator Neutrino Detector, located 30 m behind the Los Alamos Meson Physics Facility beam stop. The {bar {nu}}{sub {ital e}} are detected via {bar {nu}}{sub {ital e}} {ital p}{r_arrow}{ital e}{sup +}{ital n} with {ital e}{sup +} energy between 36 and 60 MeV, followed by a {gamma} ray from {ital np}{r_arrow}{ital d}{gamma} (2.2 MeV). Using strict cuts to identify {gamma} rays correlated with {ital e}{sup +} yields 9 events with only 2.1{plus_minus}0.3 background expected. A likelihood fit to the entire {ital e}{sup +} sample results in a total excess of 16.4{sub {minus}8.9}{sup +9.7}{plus_minus}3.3 events. If attributed to {bar {nu}}{sub {mu}}{r_arrow}{bar {nu}}{sub {ital e}} oscillations, this corresponds to an oscillation probability of (0.34{sub {minus}0.18}{sup +0.20}{plus_minus}0.07)%.

  9. Study of the f{sub 0}(1500)/f{sub 2}(1565) production in the exclusive annihilation {bar n}p{r_arrow}{pi}{sup +}{pi}{sup +}{pi}{sup {minus}} in flight

    SciTech Connect

    The OBELIX Collaboration

    1998-01-01

    The spin-parity analysis of the {bar n}p{r_arrow}{pi}{sup +}{pi}{sup +}{pi}{sup {minus}} exclusive reaction in flight is presented. The main aim is to study the ({pi}{sup +}{pi}{sup {minus}}) invariant mass spectrum in the region around 1500 MeV. The analysis was performed with a Breit-Wigner parametrization for all the resonant states and, for the scalar sector in the mass region below 1.2 GeV, by means of a K-matrix-like treatment. It clearly shows the need for two states, a scalar one (0{sup ++}) with mass and width (1522{plus_minus}25) MeV and (108{plus_minus}33) MeV, and a tensorial one (2{sup ++}) with mass (1575{plus_minus}18) MeV and width (119{plus_minus}24) MeV, respectively. In addition, the analysis requires the presence of a scalar state at (1280{plus_minus}55) MeV, (323{plus_minus}13) MeV broad, and of a second vectorial one, in addition to the {rho}{sup 0}(770) signal, with mass and width (1348{plus_minus}33) MeV and (275{plus_minus}10) MeV, respectively. {copyright} {ital 1997} {ital The American Physical Society}

  10. Channelopathies, painful neuropathy, and diabetes: which way does the causal arrow point?

    PubMed

    Hoeijmakers, Janneke G J; Faber, Catharina G; Merkies, Ingemar S J; Waxman, Stephen G

    2014-10-01

    Diabetes mellitus, a major global health problem, is commonly associated with painful peripheral neuropathy, which can substantially erode quality of life. Despite its clinical importance, the pathophysiology of painful diabetic neuropathy is incompletely understood. It has traditionally been thought that diabetes may cause neuropathy in patients with appropriate genetic makeup. Here, we propose a hypothesis whereby painful neuropathy is not a complication of diabetes, but rather occurs as a result of mutations that, in parallel, confer vulnerability to injury in pancreatic β cells and pain-signaling dorsal root ganglion (DRG) neurons. We suggest that mutations of sodium channel NaV1.7, which is present in both cell types, may increase susceptibility for development of diabetes via β cell injury and produce painful neuropathy via a distinct effect on DRG neurons.

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

    PubMed

    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.

  12. Heterogeneous reaction HOCl + HBr {r_arrow} BrCl + H{sub 2}O on ice films

    SciTech Connect

    Chu, L.; Chu, L.T.

    1999-02-11

    Heterogeneous reactions on the surface of polar stratospheric clouds (PSCs) are critical to an understanding of the annual appearance of the Antarctic ozone hole. The heterogeneous reaction HOCl + HBr(s) {r_arrow} BrCl + H{sub 2}O(s) on the ice surface at 189 and 220 K has been investigated in a flow reactor interfaced with a differentially pumped quadrupole mass spectrometer. Pseudo first-order decay of HOCl over the HBr-treated ice surfaces has been determined under the condition of P{sub HOCl} < P{sub HBr}. For the HBr partial pressure in the range of 1.1 {times} 10{sup {minus}7} to 6.6 {times} 10{sup {minus}5} Torr, the reaction probability ({gamma}{sub g}) was determined in the range of 0.06 to 0.38 at 189 K. The reaction probability is in the range of 0.01 to 0.07 at 220 K for HBr partial pressure from 7.2 {times} 10{sup {minus}7} to 1.3 {times} 10{sup {minus}5} Torr. The reaction probability was found to be strongly dependent on the ice surface temperature. The reaction probability is higher at the lower temperature than that at the warmer temperature and a mechanistic explanation is provided. The true reaction probabilities ({gamma}{sub t}) of the reaction were calculated using a pore diffusion model. The kinetic analysis indicates that the heterogeneous reaction of HOCl + HBr may follow the Eley-Rideal type of mechanism. Also, the heat of uptake of HOCl on ice was determined to be about {minus}8.5 {+-} 2 kcal/mol.

  13. Penguin operators in nonresonant B{sup {minus}}{r_arrow}M{bar M}{pi}{sup {minus}}(M={pi}{sup {minus}},K{sup {minus}},K{sup 0}) decays

    SciTech Connect

    Fajfer, S. |; Oakes, R.J.; Pham, T.N.

    1999-09-01

    We investigate the contributions coming from the penguin operators in the nonresonant B{sup {minus}}{r_arrow}M{bar M}{pi}{sup {minus}}(M={pi}{sup {minus}},K{sup {minus}},K{sup 0}) decays. The effective Wilson coefficients of the strong penguin operators O{sub 4} and O{sub 6} are found to be relatively larger than those for other penguin operators. We calculate the contributions arising from the O{sub 4} and O{sub 6} operators in the nonresonant decays B{sup {minus}}{r_arrow}M{bar M}{pi}{sup {minus}}(M={pi}{sup {minus}},K{sup {minus}},{bar K}{sup 0}) using a model combining heavy quark symmetry and the chiral symmetry, developed previously. We find that the CKM-forbidden nonresonant B{sup {minus}}{r_arrow}K{sup 0}{bar K}{sup 0}{pi}{sup {minus}} decay occurs through the strong penguin operators. These penguin contributions affect the branching ratios for B{sup {minus}}{r_arrow}M{bar M}{pi}{sup {minus}}(M={pi}{sup {minus}},K{sup {minus}}) by only a few percent. The branching ratio for B{sup {minus}}{r_arrow}K{sup 0}{bar K}{sup 0}{pi}{sup {minus}} is estimated to be of the order 10{sup {minus}6}. {copyright} {ital 1999} {ital The American Physical Society}

  14. Effects of wing leading-edge deflection on the low-speed aerodynamic characteristics of a low-aspect-ratio highly swept arrow-wing configuration

    NASA Technical Reports Server (NTRS)

    Coe, P. L., Jr.; Weston, R. P.

    1978-01-01

    Wing leading-edge deflection effects on the low-speed aerodynamic characteristics of a low-aspect-ratio highly swept arrow-wing configuration were determined. Static force tests were conducted in a V/STOL tunnel at a Reynolds number of about 2.5 x 1 million for an angle-of-attack range from -10 deg to 17 deg and an angle-of-sideslip range from -5 deg to 5 deg. Limited flow visualization studies were also conducted in order to provide a qualitative assessment of leading-edge upwash characteristics.

  15. Spectral functions of the one-dimensional Hubbard model in the U{r_arrow}+{infinity} limit: How to use the factorized wave function

    SciTech Connect

    Penc, K.; Hallberg, K.; Mila, F.; Shiba, H.

    1997-06-01

    We give the details of the calculation of the spectral functions of the one-dimensional Hubbard model using the spin-charge factorized wave function for several versions of the U{r_arrow}+{infinity} limit. The spectral functions are expressed as a convolution of charge and spin dynamical correlation functions. A procedure to evaluate these correlation functions very accurately for large systems is developed, and analytical results are presented for the low-energy region. These results are fully consistent with the conformal field theory. We also propose a direct method of extracting the exponents from the matrix elements in more general cases. {copyright} {ital 1997} {ital The American Physical Society}

  16. Introduction: Subduction's sharpest arrow

    NASA Astrophysics Data System (ADS)

    Eichelberger, John C.

    In the center of the 6000-km reach of Kurile-Kamchatka-Aleutian-Alaska subduction is arguably Earth's most remarkable subduction cusp. The Kamchatka-Aleutian junction is a sharp arrowhead mounted on the shaft of the Emperor Seamount Chain. This collection of papers provides context, definition, and suggestions for the origin of the junction, but a comprehensive understanding remains elusive, in part because of the newness of international collaborations. Necessary cross-border syntheses have been impeded by the adversarial international relations that characterized the 20th century. For much of this period, Kamchatka and the Kurile Islands were part of the Soviet Union, a mostly closed country. The entire region was swept by World War II, abundant remnants of which are wrecked ships and planes, unexploded ordnance, and Rommel stakes.

  17. Supercruiser Arrow HS-8

    NASA Technical Reports Server (NTRS)

    Lord, Paul; Kao, Edward; Abobo, Joey B.; Collins, Todd A.; Ma, Leong; Murad, Adnan; Naran, Hitesh; Nguyen, Thuan P.; Nuon, Timithy I.; Thomas, Dimitri D.

    1992-01-01

    Technology in aeronautics has advanced dramatically since the last design of a production High Speed Civil Transport (HSCT) aircraft. Newly projected requirements call for a new High Speed Civil Transport aircraft with a range of approximately 550 nm and at least 275 passenger capacity. The aircraft must be affordable and marketable. The new HSCT must be able to sustain long-duration flights and to absorb the abuse of daily operation. The new aircraft must be safe and simple to fly and require a minimum amount of maintenance. This aircraft must meet FAA certification criteria of FAR Part 25 and environmental constraints. Several design configurations were examined and two designs were selected for further investigation. The first design employs the delta planform wings and conventional empennage layout. The other design uses a swing wing layout and conventional empennage. Other engineering challenges, including materials and propulsion are also discussed. At a cruise flight speed between Mach 2.2 and Mach 3.0, no current generation of materials can endure the thermal loading of supersonic flight and satisfy the stringent weight requirements. A new generation of lightweight composite materials must be developed for the HSCT. With the enforcement of stage 3 noise restrictions, these new engines must be able to propel the aircraft and satisfy the noise limit. The engine with the most promise is the variable cycle engine. At low subsonic speeds the engine operates like a turbofan engine, providing the most efficient performance. At higher speeds the variable cycle engine operates as a turbojet power plant. The two large engine manufacturers, General Electric and Pratt & Whitney in the United States, are combining forces to make the variable cycle engine a reality.

  18. Measurement of the branching fraction of D{sub s} inclusive semileptonic decay D{sub s}{sup +}{r_arrow}e{sup +}X

    SciTech Connect

    Bai, J.Z.; Bian, J.G.; Chai, Z.W.; Chen, G.P.; Chen, J.C.; Chen, S.M.; Chen, Y.; Chen, Y.B.; Chen, Y.Q.; Cheng, B.S.; Cui, X.Z.; Ding, H.L.; Du, Z.Z.; Fan, X.L.; Fang, J.; Gao, C.S.; Gao, M.L.; Gao, S.Q.; Gu, J.H.; Gu, S.D.; Gu, W.X.; Gu, Y.F.; Guo, Y.N.; Han, S.W.; Han, Y.; He, J.; He, J.T.; Hu, G.Y.; Hu, J.L.; Hu, Q.H.; Hu, T.; Hu, X.Q.; Huang, X.P.; Huang, Y.Z.; Jiang, C.H.; Jin, S.; Jin, Y.; Kang, S.H.; Ke, Z.J.; Lai, Y.F.; Lan, H.B.; Lang, P.F.; Li, J.; Li, P.Q.; Li, R.B.; Li, W.; Li, W.D.; Li, W.G.; Li, X.H.; Li, X.N.; Lin, S.Z.; Lu, F.; Liu, H.M.; Liu, J.; Liu, J.H.; Liu, Q.; Liu, R.G.; Liu, Y.; Liu, Z.A.; Lu, J.G.; Lu, J.Y.; Luo, S.Q.; Luo, Y.; Ma, A.M.; Ma, E.C.; Ma, J.M.; Mao, H.S.; Mao, Z.P.; Meng, X.C.; Ni, H.L.; Nie, J.; Qi, N.D.; Qiu, J.F.; Qu, Y.H.; Que, Y.K.; Rong, G.; Shao, Y.Y.; Shen, B.W.; Shen, D.L.; Shen, H.; Shen, X.Y.; Sheng, H.Y.; Shi, H.Z.; Song, X.F.; Sun, F.; Sun, H.S.; Sun, S.J.; Tan, Y.P.; Tang, S.Q.; Tong, G.L.; Wang, F.; Wang, J.F.; Wang, L.S.; Wang, L.Z.; Wang, M.; Wang, M.; Wang, P.; Wang, P.L.; Wang, S.M.; Wang, T.J.; Wang, Y.Y.; Wei, C.L.; Wu, Y.G.; Xi, D.M.; Xia, X.M.; Xie, P.P.; Xiong, W.J.; Xu, D.Z.; Xu, G.F.; Xu, R.S.; Xu, Z.Q.; Xue, S.T.; Yan, J.; Yan, W.G.; Yang, C.M.; Yang, C.Y.; Yang, W.; Yang, X.F.; Ye, M.H.; Ye, S.Z.; Yi, K.; Yu, C.S.; Yu, C.X.; Yu, Z.Q.; Yu, Z.T.; Yuan, C.Z.; Zhang, B.Y.; Zhang, C.C.; Zhang, D.H.; Zhang, D.; Zhang, H.L.; Zhang, J.; Zhang, J.W.; Zhang, L.S.; Zhang, L.; Zhang, Q.J.; Zhang, S.Q.; Zhang, X.Y.; Zhang, Y.; Zhang, Y.Y.; Zhao, D.X.; Zhao, J.W.; Zhao, M.; Zhao, W.R.; Zheng, J.P.; Zheng, L.S.; Zheng, Z.P.; Zhou, G.P.; Zhou, H.S.; Zhou, L.; Zhou, Y.H.; Zhu, Q.M.; Zhu, Y.C.; Zhu, Y.S.; Zhuang, B.A.; Bardon, O.; Cowan, R.F.; Fero, M.; Blum, I.; Gratton, P.; Izen, J.M.; Kim, B.K.; Lou, X.C.; Lowery, B.; Standifird, J.; and others

    1997-10-01

    The absolute inclusive semileptonic branching fraction of the D{sub s} meson has been measured based on 22.3 pb{sup {minus}1} of e{sup +}e{sup {minus}} collision data collected with the Beijing Spectrometer at {radical} (s) =4.03GeV. At this energy, the D{sub s} are produced in pairs: e{sup +}e{sup {minus}}{r_arrow}D{sub s}{sup +}D{sub s}{sup {minus}}. We reconstructed 171{plus_minus}21{plus_minus}15 D{sub s} events in five hadronic decay modes. In the recoil system of these events, several D{sub s} inclusive semileptonic decays were observed and the branching fraction is estimated to be B(D{sub s}{sup +}{r_arrow}e{sup +}X)=(7.7{sub {minus}4.3{minus}2.1}{sup +5.7+2.4}){percent}. {copyright} {ital 1997} {ital The American Physical Society}

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Elevated total plasma homocysteine and 667C{r_arrow}T mutation of the 5,10-methylenetetrahydrofolate reductase gene in thrombotic vascular disease

    SciTech Connect

    De Franchis, R.; Sebastio, G.; Andria, G.

    1996-07-01

    Moderate elevation of total plasma homocysteine (tHcy) has been reported as an independent risk factor for thrombotic vascular disease, a well-known multifactorial disorder. Possible genetic causes of elevated tHcy include defects of the sulfur-containing amino acids metabolism due to deficiencies of cystathionine {Beta}-synthase, of 5,10-methylenetetrahydrofolate reductase (MTHFR), and of the enzymes of cobalamin metabolism. An impaired activity of MTHFR due to a thermolabile form of the enzyme has been observed in {le}28% of hyperhomocysteinemic patients with premature vascular disease. More recently, the molecular basis of such enzymatic thermolability has been related to a common mutation of the MTHFR gene, causing a C-to-T substitution at nt 677 (677C{r_arrow}T). This mutation was found in 38% of unselected chromosomes from 57 French Canadian individuals. The homozygous state for the mutation was present in 12% of these subjects and correlated with significantly elevated tHcy. Preliminary evidence indicates that the frequency of homozygotes for the 677C{r_arrow}T mutation may vary significantly in populations from different geographic areas. 5 refs., 2 tabs.

  1. Chiral perturbation theory for K{sup +}{r_arrow}{pi}{sup +}{pi}{sup 0} decay in the continuum and on the lattice

    SciTech Connect

    Golterman, M.F.; Leung, K.C.

    1997-09-01

    In this paper we use one-loop chiral perturbation theory in order to compare lattice computations of the K{sup +}{r_arrow}{pi}{sup +}{pi}{sup 0} decay amplitude with the experimental value. This makes it possible to investigate three systematic effects that plague lattice computations: quenching, finite-volume effects, and the fact that lattice computations have been done at unphysical values of the quark masses and pion external momenta (only this latter effect shows up at the tree level). We apply our results to the most recent lattice computation and find that all three effects are substantial. We conclude that one-loop corrections in chiral perturbation theory help in explaining the discrepancy between lattice results and the real-world value. We also reexamine B{sub K}, which is closely related to the K{sup +}{r_arrow}{pi}{sup +}{pi}{sup 0} decay amplitude by chiral symmetry. {copyright} {ital 1997} {ital The American Physical Society}

  2. Detailed study of the incoherent {mu}{sup {minus}}{r_arrow}e{sup {minus}} conversion rate: Elimination of spurious contaminations from the 1{sup {minus}} contribution

    SciTech Connect

    Schwieger, J.; Faessler, A.; Kosmas, T.S.

    1997-11-01

    The incoherent matrix elements of the exotic ({mu}{sup {minus}},e{sup {minus}}) conversion in nuclei process are studied in detail for a set of nuclei throughout the periodic table in the context of the quasiparticle random phase approximation (RPA). The contaminations, usually inserted in the 1{sup {minus}} RPA excitation modes (the most important incoherent {mu}{r_arrow}e conversion channel), are removed by explicitly constructing the purely spurious center-of-mass state. We found that mostly the lowest-lying 1{sub 1}{sup {minus}} state is affected by the use of non-self-consistent single-particle energies and a truncated model space in the RPA. To a good approximation we can regard this state as fully spurious and treat the other states as the physical ones. The elimination of the spuriousness requires a different renormalization of the interaction. This allows us to reproduce the excitation spectrum, needed to calculate reliably the incoherent matrix elements of the {mu}{r_arrow}e process, with realistic forces (Bonn potential) which cannot be achieved with the contaminated wave functions. We focus on the investigation of the incoherent rate of {sup 48}Ti, from which the best upper limit for the flavor number violation has been extracted, and {sup 208}Pb, which is currently used in the SINDRUM II experiment at PSI. {copyright} {ital 1997} {ital The American Physical Society}

  3. Signal voter

    DOEpatents

    Goodwin, Roy L.

    1981-01-01

    A voter for providing a single accurate output signal that is derived from the closest two signal levels of three input signals, each of which signals represents a measurement of the same phenomena. By means of the voting circuit, the signals are first sorted by level of amplitude and then ranked as highest, middle or lowest. The highest or lowest signal that is furthest from the middle signal is rejected, while the other highest or lowest signal is selected for processing. The selected high or low signal is then averaged with the middle signal to provide the output signal.

  4. Signal voter

    SciTech Connect

    Goodwin, R.L.

    1981-04-28

    A voter for providing a single accurate output signal that is derived from the closest two signal levels of three input signals , each of which signals represents a measurement of the same phenomena. By means of the voting circuit, the signals are first sorted by level of amplitude and then ranked as highest, middle or lowest. The highest or lowest signal that is furthest from the middle signal is rejected, while the other highest or lowest signal is selected for processing. The selected high or low signal is then averaged with the middle signal to provide the output signal.

  5. A C {r_arrow} T transition at nucleotide 592 accounts for the most frequent mutation of G6PD gene in Taiwanese aboriginal Ami tribe: detection by mutagenically separated PCR (MS-PCR)

    SciTech Connect

    Lin, S.P.; Sun, W.; Chang, J.G.

    1994-09-01

    Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the commonest known enzymopathy in Taiwan. It is estimated to affect 3% of our population, and its molecular defects have been characterized recently. There are 9 point mutations identified with a C {r_arrow} T substitution at nucleotide (nt) 592 in exon VI, the least frequently seen (0.8%) of all mutations. To characterize mutations of the G6PD gene in the Ami people, the most populous of Taiwanese minorities, we studied 21 G6PD-deficient Ami infants and their family members. Natural and amplification-created restriction sites were generated by PCR technique with 10 pairs of primers applied for the screening. By studying the first 7 cases, we found an identical C {r_arrow} T transition at nt 592. MS-PCR was then designed to rapidly detect the nt 592 mutation. As a result, 17 infants are disclosed as having the C {r_arrow} T transition at nt 592, and 2 have a G {r_arrow} T substitution at nt 1376, which were finally verified to be derived from a Chinese Min-Nan ancestor. The genetic defect of the remaining 2 infants remains unidentified. This study has shown that MS-PCR is a feasible and highly sensitive technique for screening mutation carriers in pooled DNA samples. The homogeneity of the nt 592 mutation in the Ami people has proved to be a good indicator for anthropological research.

  6. 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.

    PubMed

    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.

  7. 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

    PubMed Central

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

    2016-01-01

    abstract 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. PMID:26646356

  8. Low-speed aerodynamic characteristics from wind-tunnel tests of a large-scale advanced arrow-wing supersonic-cruise transport concept

    NASA Technical Reports Server (NTRS)

    Smith, P. M.

    1978-01-01

    Tests have been conducted to extend the existing low speed aerodynamic data base of advanced supersonic-cruise arrow wing configurations. Principle configuration variables included wing leading-edge flap deflection, wing trailing-edge flap deflection, horizontal tail effectiveness, and fuselage forebody strakes. A limited investigation was also conducted to determine the low speed aerodynamic effects due to slotted training-edge flaps. Results of this investigation demonstrate that deflecting the wing leading-edge flaps downward to suppress the wing apex vortices provides improved static longitudinal stability; however, it also results in significantly reduced static directional stability. The use of a selected fuselage forebody strakes is found to be effective in increasing the level of positive static directional stability. Drooping the fuselage nose, which is required for low-speed pilot vision, significantly improves the later-directional trim characteristics.

  9. Theoretical and experimental pressure distributions for a 71.2 degree swept arrow-wing configuration at subsonic, transonic, and supersonic speeds

    NASA Technical Reports Server (NTRS)

    Bobbitt, P. J.; Manro, M. E.

    1976-01-01

    A wind-tunnel test of an arrow-wing body configuration consisting of flat and twisted wings, as well as a variety of leading- and trailing-edge control-surface deflections, was conducted at Mach numbers from 0.40 to 2.50 to provide an experimental data base for comparison with theoretical methods. Theory-to-experiment comparisons of detailed pressure distributions were made using current state-of-the-art and newly developed attached- and separated-flow methods. Conditions were delineated under which these theories provide accurate basic and incremental aeroelastic loads predictions. Current state-of-the-art linear and nonlinear attached-flow methods were adequate only at small-angle-of-attack cruise conditions. Of the several separated-vortex methods evaluated, only the one utilizing a combination of linear source and quadratically varying doublet panels showed promise of yielding accurate loads distributions at moderate to large angles of attack.

  10. Reduced dimensionality diatom--diatom reactive scattering: Application to a model H sub 2 +A sub 2 r arrow H+HA sub 2 reaction

    SciTech Connect

    Sun, Q.; Bowman, J.M. )

    1990-01-15

    We apply a recently formulated quantum theory of diatom--diatom reactions (Q. Sun and J. M. Bowman, Int. J. Quant. Chem., Quant. Chem. Symp. {bold 23}, 9 (1989)) to a model collinear H{sub 2}+A{sub 2}{r arrow}H+HA{sub 2} reaction, where A has the mass of a hydrogen atom. The theory assumes one diatom bond is nonreactive, and the reactive scattering Hamiltonian is written in terms of hyperspherical and cylindrical coordinates. The potential-energy surface used is the PK2 H+H{sub 2} surface augmented by a harmonic degree of freedom describing the nonreactive A{sub 2}. Details of the formulation and solution of the coupled-channel equations are given, along with convergence tests, and a discussion of the new state-to-state transition probabilities. In particular, the partial quenching of the well-known collinear H+H{sub 2} resonances is noted.

  11. Absolute becoming, relational becoming and the arrow of time: Some non-conventional remarks on the relationship between physics and metaphysics

    NASA Astrophysics Data System (ADS)

    Dorato, Mauro

    The literature on the compatibility between the time of our experience-characterized by passage or becoming-and time as is represented within spacetime theories has been affected by a persistent failure to get a clear grasp of the notion of becoming, both in its relation to an ontology of events "spread" in a four-dimensional manifold, and in relation to temporally asymmetric physical processes. In the first part of my paper I try to remedy this situation by offering what I consider a clear and faithful explication of becoming, valid independently of the particular spacetime setting in which we operate. Along the way, I will show why the metaphysical debate between the so-called "presentists" and "eternalists" is completely irrelevant to the question of becoming, as the debate itself is generated by a failure to distinguish between a tensed and a tenseless sense of "existence". After a much needed distinction between absolute and relational becoming, I then show in what sense classical (non-quantum) spacetime physics presupposes both types of becoming, for the simple reason that spacetime physics presupposes an ontology of (timelike-separated) events. As a consequence, not only does it turn out that using physics to try to provide empirical evidence for the existence of becoming amounts to putting the cart before the horses, but also that the order imposed by "the arrow of becoming" is more fundamental than any other physical arrow of time, despite the fact that becoming cannot be used to explain why entropy grows, or retarded electromagnetic radiation prevails versus advanced radiation.

  12. 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.

    PubMed

    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

  13. 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

    SciTech Connect

    Feigenbaum, A.; Chitayat, D.; Robinson, B.; MacGregor, D.; Myint, T.

    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.

  14. Assignment of human potassium channel gene KCNA4 (Kv1. 4, PCN2) to chromosome 11q13. 4 [r arrow] q14. 1

    SciTech Connect

    Philipson, L.H.; Bell, G.I. ); Eddy, R.L.; Shows, T.B. )

    1993-02-01

    Both electrically excitable and nonexcitable tissues express voltage-sensitive K[sup +] channels. Since the original isolation of the Drosophila Shaker gene encoding voltage-sensitive K[sub +] channels, five additional related gene families have been described: the Shal, Shab, and Shaw families and the K-eag and Slo genes. A seventh family of slowly activating K[sup +] channels, minK of IsK, is structurally unrelated to the others. Seven human genes related to the Shaker subfamily have been described. We recently described the cloning of a fast-inactivating human voltage-gated K[sup +] channel, PCN2. Here we report the mapping of the gene encoding PNC2, designated KNCA4, to chromosome 11 by analyzing its segregation in a panel of reduced human-mouse somatic cell hybrids. In situ hybridization to prometaphase chromoxomes localized KCNA4 to the long arm of chromosome 11 in the region of bands q13.4 [r arrow] q14.1.

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

    SciTech Connect

    Zhang, Yawei

    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.

  16. Search for B_c^± arrow J/ψ μ^± X Decays in pbarp Collisions at √s=1.8 TeV

    NASA Astrophysics Data System (ADS)

    Singh, Prem

    1997-04-01

    The B_c^± meson, a bound state of charm and bottom quarks, is expected to have several narrow mass states below the B--D open flavor threshold. We describe a search for the weak decays of the B_c^± produced in a 110 pb-1 sample of √s= 1.8 TeV proton-antiproton collisions in the CDF detector at the Fermilab Tevatron. A high branching ratio of B_c^± to J/ψ decays permits an effective trigger on these events. The search is conducted through the decay B_c^± arrow J/ψ μ^± X. Supported by U.S. DOE under Contract No. DE-FG02-91ER40646. We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Science and Culture of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; and the A. P. Sloan Foundation.

  17. A theorem proving the irreversibility of the biological arrow of time, based on fixed points in the brain as a compact, Δ-complete topological space

    NASA Astrophysics Data System (ADS)

    Bounias, Michel

    2000-05-01

    A physical space can exist as a collection of closed topologies in the intersections of abstract topological subspaces provided with non-equal dimensions. Furthermore, the ordered sequence of mappings of one to another intersection provides an arrow of time which is shared by all connected systems of closed, involving those of the brain type with other types (i.e., physical objects of all categories). The topology of closed spaces associates fixed points of the Brouwer's type with fixed points of the Banach's type. The former are specific of each closed and the latter drive the information from the outside space to mental images inside a closed, through mappings of Jordan's points. The set of fixed points thus provides the properties of both perception and self in living organisms. Conditions for existence of various kinds of Banach's type fixed points are fulfilled by the mathematical brain, since it is both a discrete finite structure, thus a compact topological space, and provided with a set distance (Δ), thus Δ-complete. Finally, since (i) iterates in a sequence of mappings include at least a surjective component and (ii) not identical (if even existing) fixed points would be generated by the non-surjective property which would characterize reciprocal mappings, in either metric or nonmetric setting, the reversion of biological time would break the direct link of the self with perception functions. Thus, while time could be reversible for physics, it is perceived as irreversible for biology, although physical and biological objects share a common space.

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

    SciTech Connect

    Ross, M.; Pinsky, L.; Teebi, A.

    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.

  19. The prediction of pressure distributions on an arrow-wing configuration including the effect of camber, twist, and a wing fin

    NASA Technical Reports Server (NTRS)

    Bobbitt, P. J.; Manro, M. E.; Kulfan, R. M.

    1980-01-01

    Wind tunnel tests of an arrow wing body configuration consisting of flat, twisted, and cambered twisted wings were conducted at Mach numbers from 0.40 to 2.50 to provide an experimental data base for comparison with theoretical methods. A variety of leading and trailing edge control surface deflections were included in these tests, and in addition, the cambered twisted wing was tested with an outboard vertical fin to determine its effect on wing and control surface loads. Theory experiment comparisons show that current state of the art linear and nonlinear attached flow methods were adequate at small angles of attack typical of cruise conditions. The incremental effects of outboard fin, wing twist, and wing camber are most accurately predicted by the advanced panel method PANAIR. Results of the advanced panel separated flow method, obtained with an early version of the program, show promise that accurate detailed pressure predictions may soon be possible for an aeroelasticity deformed wing at high angles of attack.

  20. Quantum state-to-state reaction probabilities for the H+H{sub 2}O{r_arrow}H{sub 2}+OH reaction in six dimensions

    SciTech Connect

    Zhang, D.H.; Light, J.C.

    1996-07-01

    A time-dependent wave packet method has been employed to calculate the state-to-state reaction probability for the H+H{sub 2}O(0,0,0){r_arrow}H{sub 2}({ital v}{sub 1},{ital j}{sub 1})+OH({ital v}{sub 2},{ital j}{sub 2}) reaction for {ital J}=0 and initial nonrotating H{sub 2}O on the modified Schatz{endash}Elgersman potential energy surface in full six dimensions (6D). Starting from a wave packet for an atom{endash}triatom asymptotic state in atom{endash}triatom Jacobi coordinates, we transfer the wave packet to diatom{endash}diatom Jacobi coordinates after the wave packet moves into the interaction region. Propagation is then carried out in the diatom{endash}diatom Jacobi coordinates until the reaction flux measured in the diatom{endash}diatom asymptotic region is converged. {copyright} {ital 1996 American Institute of Physics.}

  1. Signaling aggression.

    PubMed

    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.

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

    PubMed

    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. Signal Words

    MedlinePlus

    ... product. The signal word can be ei- ther: DANGER,WARNING or CAUTION. Products with the DANGER signal word are the most toxic. Products with ... causes moderate eye or skin irritation. 2,4 DANGER means that the pesticide product is highly toxic ...

  4. The antibiotic resistance arrow of time: efflux pump induction is a general first step in the evolution of mycobacterial drug resistance.

    PubMed

    Schmalstieg, Aurelia M; Srivastava, Shashikant; Belkaya, Serkan; Deshpande, Devyani; Meek, Claudia; Leff, Richard; van Oers, Nicolai S C; Gumbo, Tawanda

    2012-09-01

    We hypothesize that low-level efflux pump expression is the first step in the development of high-level drug resistance in mycobacteria. We performed 28-day azithromycin dose-effect and dose-scheduling studies in our hollow-fiber model of disseminated Mycobacterium avium-M. intracellulare complex. Both microbial kill and resistance emergence were most closely linked to the within-macrophage area under the concentration-time curve (AUC)/MIC ratio. Quantitative PCR revealed that subtherapeutic azithromycin exposures over 3 days led to a 56-fold increase in expression of MAV_3306, which encodes a putative ABC transporter, and MAV_1406, which encodes a putative major facilitator superfamily pump, in M. avium. By day 7, a subpopulation of M. avium with low-level resistance was encountered and exhibited the classic inverted U curve versus AUC/MIC ratios. The resistance was abolished by an efflux pump inhibitor. While the maximal microbial kill started to decrease after day 7, a population with high-level azithromycin resistance appeared at day 28. This resistance could not be reversed by efflux pump inhibitors. Orthologs of pumps encoded by MAV_3306 and MAV_1406 were identified in Mycobacterium tuberculosis, Mycobacterium leprae, Mycobacterium marinum, Mycobacterium abscessus, and Mycobacterium ulcerans. All had highly conserved protein secondary structures. We propose that induction of several efflux pumps is the first step in a general pathway to drug resistance that eventually leads to high-level chromosomal-mutation-related resistance in mycobacteria as ordered events in an "antibiotic resistance arrow of time."

  5. Absolute Rovibrational Intensities, Self-Broadening and Self-Shift Coefficients for the X(sup 1) Sigma(+) V=3 (left arrow) V=0 Band (C-12)(O-16)

    NASA Technical Reports Server (NTRS)

    Chackerian, Charles, Jr.; Freedman, R.; Giver, L. P.; Brown, L. R.

    2001-01-01

    The rotationless transition moment squared for the x(sup 1) sigma (sup +) v=3 (left arrow) v=0 band of CO is measured to be the absolute value of R (sub 3-0) squared = 1.7127(25)x 10(exp -7) Debye squared. This value is about 8.6 percent smaller than the value assumed for HITRAN 2000. The Herman-Wallis intensity factor of this band is F=1+0.01168(11)m+0.0001065(79)m squared. The determination of self-broadening coefficients is improved with the inclusion of line narrowing; self-shifts are also reported.

  6. Low-speed wind-tunnel tests of a 1/10-scale model of an advanced arrow-wing supersonic cruise configuration designed for cruise at Mach 2.2. [Langley Full Scale Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Yip, L. P.

    1979-01-01

    The low-speed longitudinal and lateral-directional characteristics of a scale model of an advanced arrow-wing supersonic cruise configuration were investigated in tests conducted at a Reynolds number of 4.19 x 10 to the 6th power based on the mean aerodynamic chord, with an angle of attack range from - 6 deg to 23 deg and sideslip angle range from -15 deg to 20 deg. The effects of segmented leading-edge flaps, slotted trailing-edge flaps, horizontal and vertical tails, and ailerons and spoilers were determined. Extensive pressure data and flow visualization pictures with non-intrusive fluorescent mini-tufts were obtained.

  7. Effect of leading-edge contour and vertical-tail configuration on the low-speed stability characteristics of a supersonic transport model having a highly-swept arrow wing

    NASA Technical Reports Server (NTRS)

    Lockwood, V. E.

    1978-01-01

    A low-speed investigation was made on a highly-swept arrow-wing model to determine the effect of wing leading-edge contour and vertical-tail configuration on the aerodynamic characteristics in pitch and sideslip. The investigation was made with the trailing-edge flaps deflected over a range of angles of attack from 8 deg to 32 deg. The tests were made at a Mach number of 0.13, which corresponds to a Reynolds number of about 3,000,000 based on the wing reference chord.

  8. QED based on self-energy: The relativistic 2 S sub 1/2 r arrow 1 S sub 1/2 +1. gamma. decay rates of hydrogenlike atoms

    SciTech Connect

    Barut, A.O.; Salamin, Y.I. )

    1991-03-01

    Within the framework of the recently advanced formulation of QED based on self-energy, we calculate the relativistic rates of the 2{ital S}{sub 1/2}{r arrow}1{ital S}{sub 1/2}+1{gamma} transition in the hydrogen isoelectronic sequence for values of {ital Z} ranging between 1 and 92. We compare our results with those of Johnson (Phys. Rev. Lett. 29, 1123 (1972)) and Parpia and Johnson (Phys. Rev. A 26, 1142 (1982)), analytically and numerically. Although the two approaches are quite different, the formulas for decay rates are shown to be equivalent.

  9. Supersonic Aerodynamic Characteristics of a Low-Drag Aircraft Configuration having an Arrow Wing of Aspect Ratio 1.86 and a Body of Fineness Ratio 20

    NASA Technical Reports Server (NTRS)

    Gillespie, Warren, Jr.

    1960-01-01

    A free-flight rocket-propelled-model investigation was conducted at Mach numbers of 1.2 to 1.9 to determine the longitudinal and lateral aero-dynamic characteristics of a low-drag aircraft configuration. The model consisted of an aspect-ratio -1.86 arrow wing with 67.5 deg. leading-edge sweep and NACA 65A004 airfoil section and a triangular vertical tail with 60 deg. sweep and NACA 65A003 section in combination with a body of fineness ratio 20. Aerodynamic data in pitch, yaw, and roll were obtained from transient motions induced by small pulse rockets firing at intervals in the pitch and yaw directions. From the results of this brief aerodynamic investigation, it is observed that very slender body shapes can provide increased volumetric capacity with little or no increase in zero-lift drag and that body fineness ratios of the order of 20 should be considered in the design of long-range supersonic aircraft. The zero-lift drag and the drag-due-to-lift parameter of the test configuration varied linearly with Mach number. The maximum lift-drag ratio was 7.0 at a Mach number of 1.25 and decreased slightly to a value of 6.6 at a Mach number of 1.81. The optimum lift coefficient, normal-force-curve slope, lateral-force-curve slope, static stability in pitch and yaw, time to damp to one-half amplitude in pitch and yaw, the sum of the rotary damping derivatives in pitch and also in yaw, and the static rolling derivatives all decreased with an increase in Mach number. Values of certain rolling derivatives were obtained by application of the least-squares method to the differential equation of rolling motion. A comparison of the experimental and calculated total rolling-moment-coefficient variation during transient oscillations of the model indicated good agreement when the damping-in-roll contribution was included with the static rolling-moment terms.

  10. The language of the arrows

    NASA Astrophysics Data System (ADS)

    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).

  11. Predicting the intensity mapping signal for multi-J CO lines

    SciTech Connect

    Mashian, Natalie; Loeb, Abraham; Sternberg, Amiel E-mail: amiel@wise.tau.ac.il

    2015-11-01

    We present a novel approach to estimating the intensity mapping signal of any CO rotational line emitted during the Epoch of Reionization (EoR). Our approach is based on large velocity gradient (LVG) modeling, a radiative transfer modeling technique that generates the full CO spectral line energy distribution (SLED) for a specified gas kinetic temperature, volume density, velocity gradient, molecular abundance, and column density. These parameters, which drive the physics of CO transitions and ultimately dictate the shape and amplitude of the CO SLED, can be linked to the global properties of the host galaxy, mainly the star formation rate (SFR) and the SFR surface density. By further employing an empirically derived SFR−M relation for high redshift galaxies, we can express the LVG parameters, and thus the specific intensity of any CO rotational transition, as functions of the host halo mass M and redshift z. Integrating over the range of halo masses expected to host CO-luminous galaxies, we predict a mean CO(1-0) brightness temperature ranging from ∼ 0.6 μK at z = 6 to ∼ 0.03 μK at z = 10 with brightness temperature fluctuations of Δ{sub CO}{sup 2} ∼ 0.1 and 0.005 μK respectively, at k = 0.1 Mpc{sup −1}. In this model, the CO emission signal remains strong for higher rotational levels at z = 6, with ( T{sub CO} ) ∼ 0.3 and 0.05 μK for the CO J = 6arrow5 and CO J = 10arrow9 transitions respectively. Including the effects of CO photodissociation in these molecular clouds, especially at low metallicities, results in the overall reduction in the amplitude of the CO signal, with the low- and high-J lines weakening by 2–20% and 10–45%, respectively, over the redshift range 4 < z < 10.

  12. Signal Processing

    DTIC Science & Technology

    1989-03-01

    ORGANIZATION Univ of Minnesota (f*fto U. S. Army Research Office 6c. ADDRESS (City, State, and ZIP Code) 7b. ADDRESS (Wiy Stat, and ZIP Code...Minneapolis, MN 55455 P. 0. Box 12211 Research Triangle Park, NC 27709-2211 Sa. NAME Of FUNDING ISPONSORING Sb. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT...PROJECT ITASK jWORK UNIT Research Triangle Park, NC 27709-2211 EMNTO.I NO NO CESOIO 11. TITLE (Incudt Security Classifiratio") Signal Processing of, he auth

  13. Signal processing

    NASA Astrophysics Data System (ADS)

    Norman, David M.

    The application of signal processing technology to conventional weapons systems can lower operator workloads and enhance kill probabilities, while automating wide-area surveillance, target search and classification, target tracking, and aimpoint selection. Immediate opportunities exist for automatic target cueing in underwater and over-the-horizon targeting, as well as for airborne multiple-target fire control. By embedding the transit/receive electronics into conformal aircraft sensor arrays, a 'smart' skin can be created. Electronically scanned phased arrays can be used to yield accurate azimuthal and elevation positions while nullifying EW threats. Attention is given to major development thrusts in algorithm design.

  14. Simultaneous Continuous Wave Signals

    DTIC Science & Technology

    2015-09-30

    signals are transmitted from a source and incident signals are received at a receiver for processing . The processed signals provide...in Doppler resolution. This is because the narrowband signal can be filtered from the other signals and processed as if it was sent alone. [0011... signals are filtered to separate narrowband and broadband incident signals before processing each signal type. The incident signals may then be used

  15. Low-speed wind-tunnel tests of a one-tenth-scale model of a blended-arrow advanced supersonic transport. [conducted in Langley full-scale tunnel

    NASA Technical Reports Server (NTRS)

    Lemore, H. C.; Parett, L. P.

    1975-01-01

    Tests were conducted in the Langley full scale tunnel to determine the low-speed aerodynamic characteristics of a 1/10 scale model of a blended-arrow advanced supersonic transport. Tests were made for the clean configuration and a high-lift configuration with several combinations of leading- and trailing-edge flaps deflected for providing improved lift and longitudinal stability in the landing and takeoff modes. The tests were conducted for a range of angles of attack from about -6 deg to 30 deg, sideslip angles from -5 deg to 10 deg, and for Reynolds numbers from 6.78 x 1,000,000 to 13.85 x 1,000,000 corresponding to test velocities of 41 knots to 85 knots, respectively.

  16. Transonic pressure measurements and comparison of theory to experiment for an arrow-wing configuration. Volume 1: Experimental data report, base configuration and effects of wing twist and leading-edge configuration. [wind tunnel tests, aircraft models

    NASA Technical Reports Server (NTRS)

    Manro, M. E.; Manning, K. J. R.; Hallstaff, T. H.; Rogers, J. T.

    1975-01-01

    A wind tunnel test of an arrow-wing-body configuration consisting of flat and twisted wings, as well as a variety of leading- and trailing-edge control surface deflections, was conducted at Mach numbers from 0.4 to 1.1 to provide an experimental pressure data base for comparison with theoretical methods. Theory-to-experiment comparisons of detailed pressure distributions were made using current state-of-the-art attached and separated flow methods. The purpose of these comparisons was to delineate conditions under which these theories are valid for both flat and twisted wings and to explore the use of empirical methods to correct the theoretical methods where theory is deficient.

  17. Identification and molecular confirmation of a small chromosome 10q duplication [dir dup(10)(q24.2 {r_arrow}q24.3)] inherited from a mother mosiac for the abnormality

    SciTech Connect

    Tonk, V.; Schneider, N.R.; Schultz, R.A.; Delgado, M.R.; Mao, Jen-i

    1996-01-02

    We describe a family in which two siblings exhibited developmental delay, reduced muscle tone and mild muscle weakness. Cytogenetic evaluation demonstrated that both children had a tandem duplication of a small portion of the long arm of chromosome 10 [46,XX or XY, dir dup(10)(q24.2{r_arrow}q24.3)], inherited from their clinically normal mother, who was found to be mosaic for the duplicated chromosome 10. Fluorescence in situ hybridization approaches, including total chromosome painting and the use of regional specific cosmid probes, were used to confirm the chromosome 10q origin of the duplicated material. This is the smallest confirmed duplication of this portion of chromosome 10 reported to date. 28 refs., 4 figs.

  18. Experimental search for the neutrino decay {nu}{sub 3}{r_arrow}{nu}{sub {ital j}}+{ital e}{sup +}+{ital e}{sup {minus}} and limits on neutrino mixing

    SciTech Connect

    Hagner, C.; Altmann, M.; Feilitzsch, F.v.; Oberauer, L.; Declais, Y.; Kajfasz, E.

    1995-08-01

    An experiment searching for the neutrino decay {nu}{sub 3}{r_arrow}{nu}{sub {ital j}}+{ital e}{sup +}+{ital e}{sup {minus}} has been performed at the nuclear power reactor of Bugey. The experimental setup and the data analysis are presented. No evidence for this decay has been found and stringent limits on the coupling {vert_bar}{ital U}{sub {ital e}3}{vert_bar}{sup 2} of a massive neutrino in the range of 1 MeV to 10 MeV to an electron are derived. Consequences for the existence of a massive {nu}{sub {tau}} are briefly discussed in the context of astrophysical and cosmological arguments.

  19. Analytical results for O({alpha}{sub s}) radiative corrections to e{sup +}e{sup -}{yields}tt{sup {up_arrow}} up to a given gluon energy cut

    SciTech Connect

    Groote, S.; Koerner, J. G.

    2009-08-01

    We determine the O({alpha}{sub s}) radiative corrections to polarized top quark pair production in e{sup +}e{sup -} annihilations with a specified gluon energy cut. We write down fully analytical results for the unpolarized and polarized O({alpha}{sub s}) cross sections e{sup +}e{sup -}{yields}tt(G) and e{sup +}e{sup -}{yields}tt{sup {up_arrow}}(G) including their polar orientation dependence relative to the beam direction. In the soft-gluon limit we recover the usual factorizing form known from the soft-gluon approximation. In the limit when the gluon energy cut takes its maximum value we recover the totally inclusive unpolarized and polarized cross sections calculated previously. We provide some numerical results on the cutoff dependence of the various polarized and unpolarized cross sections and discuss how the exact results numerically differ from the approximate soft-gluon results.

  20. Urothelial Signaling

    PubMed Central

    Andersson, Karl-Erik

    2013-01-01

    The urothelium, which lines the inner surface of the renal pelvis, the ureters, and the urinary bladder, not only forms a high-resistance barrier to ion, solute and water flux, and pathogens, but also functions as an integral part of a sensory web which receives, amplifies, and transmits information about its external milieu. Urothelial cells have the ability to sense changes in their extracellular environment, and respond to chemical, mechanical and thermal stimuli by releasing various factors such as ATP, nitric oxide, and acetylcholine. They express a variety of receptors and ion channels, including P2X3 purinergic receptors, nicotinic and muscarinic receptors, and TRP channels, which all have been implicated in urothelial-neuronal interactions, and involved in signals that via components in the underlying lamina propria, such as interstitial cells, can be amplified and conveyed to nerves, detrusor muscle cells, and ultimately the central nervous system. The specialized anatomy of the urothelium and underlying structures, and the possible communication mechanisms from urothelial cells to various cell types within the bladder wall are described. Changes in the urothelium/lamina propria (“mucosa”) produced by different bladder disorders are discussed, as well as the mucosa as a target for therapeutic interventions. PMID:23589830

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

    PubMed

    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.

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

    PubMed Central

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

    2014-01-01

    ABSTRACT 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. PMID:25236598

  3. WNT-1 Signaling in Mammary Carcinogenesis

    DTIC Science & Technology

    2002-04-01

    embryos exhibit severe developmental defects a, Embryo at effector molecules. Here we present evidence that a new member 15.5 d.p.c. showing spina ... bifida (arrowhead), absence of a tail, malformed fore and of the low-density lipoprotein (LDL)-receptor-related protein hindlimbs (arrow) and retinal

  4. Scram signal generator

    DOEpatents

    Johanson, Edward W.; Simms, Richard

    1981-01-01

    A scram signal generating circuit for nuclear reactor installations monitors a flow signal representing the flow rate of the liquid sodium coolant which is circulated through the reactor, and initiates reactor shutdown for a rapid variation in the flow signal, indicative of fuel motion. The scram signal generating circuit includes a long-term drift compensation circuit which processes the flow signal and generates an output signal representing the flow rate of the coolant. The output signal remains substantially unchanged for small variations in the flow signal, attributable to long term drift in the flow rate, but a rapid change in the flow signal, indicative of a fast flow variation, causes a corresponding change in the output signal. A comparator circuit compares the output signal with a reference signal, representing a given percentage of the steady state flow rate of the coolant, and generates a scram signal to initiate reactor shutdown when the output signal equals the reference signal.

  5. Scram signal generator

    DOEpatents

    Johanson, E.W.; Simms, R.

    A scram signal generating circuit for nuclear reactor installations monitors a flow signal representing the flow rate of the liquid sodium coolant which is circulated through the reactor, and initiates reactor shutdown for a rapid variation in the flow signal, indicative of fuel motion. The scram signal generating circuit includes a long-term drift compensation circuit which processes the flow signal and generates an output signal representing the flow rate of the coolant. The output signal remains substantially unchanged for small variations in the flow signal, attributable to long term drift in the flow rate, but a rapid change in the flow signal, indicative of a fast flow variation, causes a corresponding change in the output signal. A comparator circuit compares the output signal with a reference signal, representing a given percentage of the steady state flow rate of the coolant, and generates a scram signal to initiate reactor shutdown when the output signal equals the reference signal.

  6. Signal transfer within a cultured asymmetric cortical neuron circuit

    NASA Astrophysics Data System (ADS)

    Isomura, Takuya; Shimba, Kenta; Takayama, Yuzo; Takeuchi, Akimasa; Kotani, Kiyoshi; Jimbo, Yasuhiko

    2015-12-01

    Objective. Simplified neuronal circuits are required for investigating information representation in nervous systems and for validating theoretical neural network models. Here, we developed patterned neuronal circuits using micro fabricated devices, comprising a micro-well array bonded to a microelectrode-array substrate. Approach. The micro-well array consisted of micrometre-scale wells connected by tunnels, all contained within a silicone slab called a micro-chamber. The design of the micro-chamber confined somata to the wells and allowed axons to grow through the tunnels bidirectionally but with a designed, unidirectional bias. We guided axons into the point of the arrow structure where one of the two tunnel entrances is located, making that the preferred direction. Main results. When rat cortical neurons were cultured in the wells, their axons grew through the tunnels and connected to neurons in adjoining wells. Unidirectional burst transfers and other asymmetric signal-propagation phenomena were observed via the substrate-embedded electrodes. Seventy-nine percent of burst transfers were in the forward direction. We also observed rapid propagation of activity from sites of local electrical stimulation, and significant effects of inhibitory synapse blockade on bursting activity. Significance. These results suggest that this simple, substrate-controlled neuronal circuit can be applied to develop in vitro models of the function of cortical microcircuits or deep neural networks, better to elucidate the laws governing the dynamics of neuronal networks.

  7. Wingless signaling and the control of cell shape in Drosophila wing imaginal discs.

    PubMed

    Widmann, Thomas J; Dahmann, Christian

    2009-10-01

    The control of cell morphology is important for shaping animals during development. Here we address the role of the Wnt/Wingless signal transduction pathway and two of its target genes, vestigial and shotgun (encoding E-cadherin), in controlling the columnar shape of Drosophila wing disc cells. We show that clones of cells mutant for arrow (encoding an essential component of the Wingless signal transduction pathway), vestigial or shotgun undergo profound cell shape changes and are extruded towards the basal side of the epithelium. Compartment-wide expression of a dominant-negative form of the Wingless transducer T-cell factor (TCF/Pangolin), or double-stranded RNA targeting vestigial or shotgun, leads to abnormally short cells throughout this region, indicating that these genes act cell autonomously to maintain normal columnar cell shape. Conversely, overexpression of Wingless, a constitutively-active form of the Wingless transducer beta-catenin/Armadillo, or Vestigial, results in precocious cell elongation. Co-expression of Vestigial partially suppresses the abnormal cell shape induced by dominant-negative TCF. We conclude that Wingless signal transduction plays a cell-autonomous role in promoting and maintaining the columnar shape of wing disc cells. Furthermore, our data suggest that Wingless controls cell shape, in part, through maintaining vestigial expression.

  8. Signal processor for processing ultrasonic receiver signals

    DOEpatents

    Fasching, George E.

    1980-01-01

    A signal processor is provided which uses an analog integrating circuit in conjunction with a set of digital counters controlled by a precision clock for sampling timing to provide an improved presentation of an ultrasonic transmitter/receiver signal. The signal is sampled relative to the transmitter trigger signal timing at precise times, the selected number of samples are integrated and the integrated samples are transferred and held for recording on a strip chart recorder or converted to digital form for storage. By integrating multiple samples taken at precisely the same time with respect to the trigger for the ultrasonic transmitter, random noise, which is contained in the ultrasonic receiver signal, is reduced relative to the desired useful signal.

  9. 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}

    SciTech Connect

    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.

  10. Signal verification can promote reliable signalling

    PubMed Central

    Broom, Mark; Ruxton, Graeme D.; Schaefer, H. Martin

    2013-01-01

    The central question in communication theory is whether communication is reliable, and if so, which mechanisms select for reliability. The primary approach in the past has been to attribute reliability to strategic costs associated with signalling as predicted by the handicap principle. Yet, reliability can arise through other mechanisms, such as signal verification; but the theoretical understanding of such mechanisms has received relatively little attention. Here, we model whether verification can lead to reliability in repeated interactions that typically characterize mutualisms. Specifically, we model whether fruit consumers that discriminate among poor- and good-quality fruits within a population can select for reliable fruit signals. In our model, plants either signal or they do not; costs associated with signalling are fixed and independent of plant quality. We find parameter combinations where discriminating fruit consumers can select for signal reliability by abandoning unprofitable plants more quickly. This self-serving behaviour imposes costs upon plants as a by-product, rendering it unprofitable for unrewarding plants to signal. Thus, strategic costs to signalling are not a prerequisite for reliable communication. We expect verification to more generally explain signal reliability in repeated consumer–resource interactions that typify mutualisms but also in antagonistic interactions such as mimicry and aposematism. PMID:24068354

  11. Retroactive Signaling in Short Signaling Pathways

    PubMed Central

    Sepulchre, Jacques-Alexandre; Merajver, Sofía D.; Ventura, Alejandra C.

    2012-01-01

    In biochemical signaling pathways without explicit feedback connections, the core signal transduction is usually described as a one-way communication, going from upstream to downstream in a feedforward chain or network of covalent modification cycles. In this paper we explore the possibility of a new type of signaling called retroactive signaling, offered by the recently demonstrated property of retroactivity in signaling cascades. The possibility of retroactive signaling is analysed in the simplest case of the stationary states of a bicyclic cascade of signaling cycles. In this case, we work out the conditions for which variables of the upstream cycle are affected by a change of the total amount of protein in the downstream cycle, or by a variation of the phosphatase deactivating the same protein. Particularly, we predict the characteristic ranges of the downstream protein, or of the downstream phosphatase, for which a retroactive effect can be observed on the upstream cycle variables. Next, we extend the possibility of retroactive signaling in short but nonlinear signaling pathways involving a few covalent modification cycles. PMID:22848403

  12. Multidimensional signal processing for ultrasonic signal classification

    NASA Astrophysics Data System (ADS)

    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.

  13. ERK Signals: Scaffolding Scaffolds?

    PubMed Central

    Casar, Berta; Crespo, Piero

    2016-01-01

    ERK1/2 MAP Kinases become activated in response to multiple intra- and extra-cellular stimuli through a signaling module composed of sequential tiers of cytoplasmic kinases. Scaffold proteins regulate ERK signals by connecting the different components of the module into a multi-enzymatic complex by which signal amplitude and duration are fine-tuned, and also provide signal fidelity by isolating this complex from external interferences. In addition, scaffold proteins play a central role as spatial regulators of ERKs signals. In this respect, depending on the subcellular localization from which the activating signals emanate, defined scaffolds specify which substrates are amenable to be phosphorylated. Recent evidence has unveiled direct interactions among different scaffold protein species. These scaffold-scaffold macro-complexes could constitute an additional level of regulation for ERK signals and may serve as nodes for the integration of incoming signals and the subsequent diversification of the outgoing signals with respect to substrate engagement. PMID:27303664

  14. Spectral Line Parameters Including Temperature Dependences of Self- and Air-Broadening in the 2 (left arrow) 0 Band of CO at 2.3 micrometers

    NASA Technical Reports Server (NTRS)

    Devi, V. Malathy; Benner, D. Chris; Smith, M. A. H.; Mantz, A. W.; Sung, K.; Brown, L. R.; Predoi-Cross, A.

    2012-01-01

    Temperature dependences of pressure-broadened half-width and pressure-induced shift coefficients along with accurate positions and intensities have been determined for transitions in the 2<--0 band of C-12 O-16 from analyzing high-resolution and high signal-to-noise spectra recorded with two different Fourier transform spectrometers. A total of 28 spectra, 16 self-broadened and 12 air-broadened, recorded using high- purity (greater than or equal to 99.5% C-12-enriched) CO samples and CO diluted with dry air(research grade) at different temperatures and pressures, were analyzed simultaneously to maximize the accuracy of the retrieved parameters. The sample temperatures ranged from 150 to 298K and the total pressures varied between 5 and 700 Torr. A multispectrum nonlinear least squares spectrum fitting technique was used to adjust the rovibrational constants (G, B, D, etc.) and intensity parameters (including Herman-Wallis coefficients), rather than determining individual line positions and intensities. Self-and air-broadened Lorentz half-width coefficients, their temperature dependence exponents, self- and air-pressure-induced shift coefficients, their temperature dependences, self- and air-line mixing coefficients, their temperature dependences and speed dependence have been retrieved from the analysis. Speed-dependent line shapes with line mixing employing off-diagonal relaxation matrix element formalism were needed to minimize the fit residuals. This study presents a precise and complete set of spectral line parameters that consistently reproduce the spectrum of carbon monoxide over terrestrial atmospheric conditions.

  15. Signaling in myxobacteria.

    PubMed

    Kaiser, Dale

    2004-01-01

    Myxobacteria use soluble and cell-contact signals during their starvation-induced formation of fruiting bodies. These signals coordinate developmental gene expression with the cell movements that build fruiting bodies. Early in development, the quorum-sensing A-signal in Myxococcus xanthus helps to assess starvation and induce the first stage of aggregation. Later, the morphogenetic C-signal helps to pattern cell movement and shape the fruiting body. C-signal is a 17-kDa cell surface protein that signals by contact between the ends of two cells. The number of C-signal molecules per cell rises 100-fold from the beginning of fruiting body development to the end, when spores are formed. Traveling waves, streams, and sporulation have increasing thresholds for C-signal activity, and this progression ensures that spores form inside fruiting bodies.

  16. Signal sciences workshop proceedings

    SciTech Connect

    Candy, J.V.

    1997-05-01

    This meeting is aimed primarily at signal processing and controls. The technical program for the 1997 Workshop includes a variety of efforts in the Signal Sciences with applications in the Microtechnology Area a new program at LLNL and a future area of application for both Signal/Image Sciences. Special sessions organized by various individuals in Seismic and Optical Signal Processing as well as Micro-Impulse Radar Processing highlight the program, while the speakers at the Signal Processing Applications session discuss various applications of signal processing/control to real world problems. For the more theoretical, a session on Signal Processing Algorithms was organized as well as for the more pragmatic, featuring a session on Real-Time Signal Processing.

  17. Danger signals in stroke.

    PubMed

    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.

  18. Staggered Costas signals

    NASA Astrophysics Data System (ADS)

    Freedman, Avraham; Levanon, Nadav

    1986-11-01

    A radar signal, based on coherent processing of a train of staggered Costas (1984) bursts is based on a minimum number of collocation of their individual ambiguity function sidelobe peaks. The resulting ambiguity function combines qualities of both 'thumbtack' and 'bed of nails' signals. Comparison with linear-FM, V-FM, and complementary phase coded signals is given, as well as comparison with hybrid signals consisting of both phase and frequency coding.

  19. A G {r_arrow} A transition at position IVS-11 +1 of the HEX A {alpha}-chain gene in a non-Ashkenazic Mexican Tay-Sachs infant

    SciTech Connect

    Miranda, S.R.P.; Gwon, S.; DeGasperi, R.

    1994-09-01

    Tay-Sachs disease (TSD) is an autosomal recessive storage disorder caused by a deficiency of the lysosomal enzyme, {beta}-N-acetylhexosaminidase A (Hex A), a heteropolymer composed of two polypeptides, {alpha} and {beta}. Mutations in the {alpha}-chain gene render the enzyme defective, resulting in the accumulation of g{sub m2} ganglioside in the nervous system. Deficiency of Hex A was detected in a non-Ashkenazic girl of Mexican origin indicating infantile onset of TSD. Molecular investigation of the {alpha}-chain gene excluded the typical Ashkenazic 4 bp insertion in the exon 11 and the intron 12 splice-junction mutations by Hae III and Dde I restriction analysis, respectively. Single strand conformation polymorphism (SSCP) analysis showed a different pattern in the sample where exon 11 and flanking regions were amplified in the patient DNA as compared to the migration of control DNA. Sequencing of PCR amplified genomic DNA containing exon 11 and flanking intronic regions showed a single base substitution (G {r_arrow} A) at position IVS-11 +1. This mutation creates a recognition site for the restriction enzyme Mbo II. Digestion of exon 11 and flanking regions with Mbo II demonstrated homozygosity of the patient for this mutation and heterozygosity in the mother. mRNA from cultured fibroblasts obtained from a normal control and from the propositus was reverse transcribed. The cDNAs coding for Hex A {alpha}-chain were amplified in four overlapping fragments. In the patient sample it was not possible to amplify the fragment containing the exon 11/intron 11 junction, indicating that this mutation alters normal RNA processing of the Hex A pre-mRNA resulting in the deficiency of Hex A activity.

  20. Tetrapyrrole Signaling in Plants

    PubMed Central

    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. PMID:27807442

  1. Signal Processing, Analysis, & Display

    SciTech Connect

    Lager, Darrell; Azevado, Stephen

    1986-06-01

    SIG is a general-purpose signal processing, analysis, and display program. Its main purpose is to perform manipulations on time- and frequency-domain signals. However, it has been designed to ultimately accommodate other representations for data such as multiplexed signals and complex matrices. Two user interfaces are provided in SIG - a menu mode for the unfamiliar user and a command mode for more experienced users. In both modes errors are detected as early as possible and are indicated by friendly, meaningful messages. An on-line HELP package is also included. A variety of operations can be performed on time- and frequency-domain signals including operations on the samples of a signal, operations on the entire signal, and operations on two or more signals. Signal processing operations that can be performed are digital filtering (median, Bessel, Butterworth, and Chebychev), ensemble average, resample, auto and cross spectral density, transfer function and impulse response, trend removal, convolution, Fourier transform and inverse window functions (Hamming, Kaiser-Bessel), simulation (ramp, sine, pulsetrain, random), and read/write signals. User definable signal processing algorithms are also featured. SIG has many options including multiple commands per line, command files with arguments,commenting lines, defining commands, and automatic execution for each item in a repeat sequence. Graphical operations on signals and spectra include: x-y plots of time signals; real, imaginary, magnitude, and phase plots of spectra; scaling of spectra for continuous or discrete domain; cursor zoom; families of curves; and multiple viewports.

  2. Satellite signaling at synapses

    PubMed Central

    O'Connor-Giles, Kate M.; Ganetzky, Barry

    2013-01-01

    Neural function requires effective communication between neurons and their targets at synapses. Thus, proper formation, growth and plasticity of synapses are critical to behavior. A retrograde (muscle to neuron) BMP signal is required to promote synaptic growth, homeostasis and stability at Drosophila neuromuscular junctions (NMJs).1-4 We recently demonstrated that this signal constitutes an instructive signal that sculpts synaptic growth in a graded manner and uncovered a presynaptic endocytic mechanism that modulates BMP signaling levels. In the absence of this regulation, excessive BMP signaling results in overgrown NMJs with a proliferation of ectopic boutons.5 PMID:20798607

  3. Acoustic Signal Processing

    NASA Astrophysics Data System (ADS)

    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.

  4. Neuronal signaling through endocytosis.

    PubMed

    Cosker, Katharina E; Segal, Rosalind A

    2014-02-01

    The distinctive morphology of neurons, with complex dendritic arbors and extensive axons, presents spatial challenges for intracellular signal transduction. The endosomal system provides mechanisms that enable signaling molecules initiated by extracellular cues to be trafficked throughout the expanse of the neuron, allowing intracellular signals to be sustained over long distances. Therefore endosomes are critical for many aspects of neuronal signaling that regulate cell survival, axonal growth and guidance, dendritic branching, and cell migration. An intriguing characteristic of neuronal signal transduction is that endosomal trafficking enables physiological responses that vary based on the subcellular location of signal initiation. In this review, we will discuss the specialized mechanisms and the functional significance of endosomal signaling in neurons, both during normal development and in disease.

  5. Neuronal Signaling through Endocytosis

    PubMed Central

    Cosker, Katharina E.; Segal, Rosalind A.

    2014-01-01

    The distinctive morphology of neurons, with complex dendritic arbors and extensive axons, presents spatial challenges for intracellular signal transduction. The endosomal system provides mechanisms that enable signaling molecules initiated by extracellular cues to be trafficked throughout the expanse of the neuron, allowing intracellular signals to be sustained over long distances. Therefore endosomes are critical for many aspects of neuronal signaling that regulate cell survival, axonal growth and guidance, dendritic branching, and cell migration. An intriguing characteristic of neuronal signal transduction is that endosomal trafficking enables physiological responses that vary based on the subcellular location of signal initiation. In this review, we will discuss the specialized mechanisms and the functional significance of endosomal signaling in neurons, both during normal development and in disease. PMID:24492712

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

    PubMed

    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.

  7. Telephone multiline signaling using common signal pair

    NASA Technical Reports Server (NTRS)

    Goodloe, R. R.; Toole, P. C.; Belt, J. L.; Leininger, D. B. (Inventor)

    1979-01-01

    An operator can rapidly and automatically produce coded electrical signals by manipulating mechanical thumb wheel switches so as to instruct a service center to connect any number of telephone lines to the console thus enabling the operator to listen and/or talk over several lines simultaneously. The system includes an on-site console having several mechanically operated thumb wheel switches to which the desired lines to be connected can be dialed in. Electrical coded signals are fed to a number of banks of line AND gates representing units, tens and hundreds, a group of channel gates, and a command gate. These signals are gated out in a controlled manner to an encoder which generates tones that are transmitted over a single line to a communication service center.

  8. Quantitation of signal transduction.

    PubMed

    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.

  9. Reviews Toy: Air swimmers Book: Their Arrows will Darken the Sun: The Evolution and Science of Ballistics Book: Physics Experiments for your Bag Book: Quantum Physics for Poets Equipment: SEP colour wheel kit Equipment: SEP colour mixing kit Software: USB DrDAQ App: iHandy Level Equipment: Photonics Explorer kit Web Watch

    NASA Astrophysics Data System (ADS)

    2012-01-01

    WE RECOMMEND Air swimmers Helium balloon swims like a fish Their Arrows will Darken the Sun: The Evolution and Science of Ballistics Ballistics book hits the spot Physics Experiments for your Bag Handy experiments for your lessons Quantum Physics for Poets Book shows the economic importance of physics SEP colour wheel kit Wheels investigate colour theory SEP colour mixing kit Cheap colour mixing kit uses red, green and blue LEDs iHandy Level iPhone app superbly measures angles Photonics Explorer kit Free optics kit given to schools WORTH A LOOK DrDAQ DrDAQ software gets an upgrade WEB WATCH Websites show range of physics

  10. Optical signal processing

    NASA Technical Reports Server (NTRS)

    Casasent, D.

    1978-01-01

    The article discusses several optical configurations used for signal processing. Electronic-to-optical transducers are outlined, noting fixed window transducers and moving window acousto-optic transducers. Folded spectrum techniques are considered, with reference to wideband RF signal analysis, fetal electroencephalogram analysis, engine vibration analysis, signal buried in noise, and spatial filtering. Various methods for radar signal processing are described, such as phased-array antennas, the optical processing of phased-array data, pulsed Doppler and FM radar systems, a multichannel one-dimensional optical correlator, correlations with long coded waveforms, and Doppler signal processing. Means for noncoherent optical signal processing are noted, including an optical correlator for speech recognition and a noncoherent optical correlator.

  11. [Growth hormone signaling pathways].

    PubMed

    Zych, Sławomir; Szatkowska, Iwona; Czerniawska-Piatkowska, Ewa

    2006-01-01

    The substantial improvement in the studies on a very complicated mechanism-- growth hormone signaling in a cell, has been noted in last decade. GH-induced signaling is characterized by activation of several pathways, including extracellular signal-regulated kinase (ERK), the signal transducer and activator of transcription and phosphatidylinositol-3 kinase (PI3) pathways. This review shows a current model of the growth hormone receptor dimerization, rotation of subunits and JAK2 kinase activation as the initial steps in the cascade of events. In the next stages of the signaling process, the GH-(GHR)2-(JAK2)2 complex may activate signaling molecules such as Stat, IRS-1 and IRS-2, and particularly all cascade proteins that activate MAP kinase. These pathways regulate basal cellular functions including target gene transcription, enzymatic activity and metabolite transport. Therefore growth hormone is considered as a major regulator of postnatal growth and metabolism, probably for mammary gland growth and development too.

  12. Wnt signaling in cancer

    PubMed Central

    Zhan, T; Rindtorff, N; Boutros, M

    2017-01-01

    Wnt signaling is one of the key cascades regulating development and stemness, and has also been tightly associated with cancer. The role of Wnt signaling in carcinogenesis has most prominently been described for colorectal cancer, but aberrant Wnt signaling is observed in many more cancer entities. Here, we review current insights into novel components of Wnt pathways and describe their impact on cancer development. Furthermore, we highlight expanding functions of Wnt signaling for both solid and liquid tumors. We also describe current findings how Wnt signaling affects maintenance of cancer stem cells, metastasis and immune control. Finally, we provide an overview of current strategies to antagonize Wnt signaling in cancer and challenges that are associated with such approaches. PMID:27617575

  13. Signaling Mechanisms for Chemotaxis

    PubMed Central

    Wang, Yu; Chen, Chun-Lin; Iijima, Miho

    2011-01-01

    Cells recognize external chemical gradients and translate these environmental cues into amplified intracellular signaling that results in elongated cell shape, actin polymerization toward the leading edge, and movement along the gradient. Mechanisms underlying chemotaxis are conserved evolutionarily from Dictyostelium amoeba to mammalian neutrophils. Recent studies have uncovered several parallel intracellular signaling pathways that crosstalk in chemotaxing cells. Here, we review these signaling mechanisms in Dictyostelium discoideum. PMID:21585354

  14. Optical Signal Processing

    DTIC Science & Technology

    1990-02-28

    compatible with the laser cation in the on-line inspection of products such as source. Thus, if the laser wavelength is z850 nm, hypodermic needles ...content for cw signals, short pulse signals, and evolving pulse signals - - the most difficult ones to analyze. We performed an extensive analysis on a...agreer.nt with the theory , and support our claims concerning the high performance level of our acousto-optir. architecture. We recognized the opportunity to

  15. Civil Navigation Signal Status

    DTIC Science & Technology

    2015-04-29

    2015 04 29 _GPS Civil Navigation Signal Status UNCLASSIFIED/APPROVED FOR PUBLIC RELEASE UNCLASSIFIED/APPROVED FOR PUBLIC RELEASE Space and Missile...Systems Center Maj Michael Zollars 29 Apr 15 Civil Navigation Signal Status Report Documentation Page Form ApprovedOMB No. 0704-0188 Public...2015 4. TITLE AND SUBTITLE Civil Navigation Signal Status 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d

  16. Slit-Robo signaling.

    PubMed

    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. Segregation and manifestations of the mtDNA tRNA[sup Lys] A[r arrow]G[sup (8344)] mutation of myoclonus epilepsy and ragged-red fibers (MERRF) syndrome

    SciTech Connect

    Larsson, N.G.; Tulinius, M.H.; Holme, E.; Oldfors, A.; Andersen, O.; Wahlstroem, J. ); Aasly, J. )

    1992-12-01

    The authors have studied the segregation and manifestations of the tRNA[sup Lys] A[r arrow]G[sup (8344)] mutation of mtDNA. Three unrelated patients with myoclonus epilepsy and ragged-red fibers (MERRF) syndrome were investigated, along with 30 of their maternal relatives. Mutated mtDNA was not always found in the offspring of women carrying the tRNA[sup Lys] mutation. Four women had 10%-33% of mutated mtDNA in lymphocytes, and no mutated mtDNA was found in 7 of their 14 investigated children. The presence of mutated mtDNA was excluded at a level of 3:1,000. Five women had a proportion of 43%-73% mutated mtDNA in lymphocytes, and mutated mtDNA was found in all their 12 investigated children. This suggests that the risk for transmission of mutated mtDNA to the offspring increases if high levels are present in the mother and that, above a threshold level of 35%-40%, it is very likely that transmission will occur to all children. The three patients with MERRF syndrone had, in muscle, both 94%-96% mutated mtDNA and biochemical and histochemical evidence of a respiratory-chain dysfunction. Four relatives had a proportion of 61%-92% mutated mtDNA in muscle, and biochemical measurements showed a normal respiratory-chain function in muscle in all cases. These findings suggest that >92% of mtDNA with the tRNA[sup Lys] mutation in muscle is required to cause a respiratory-chain dysfunction that can be detected by biochemical methods. There was a positive correlation between the levels of mtDNA with the tRNA[sup Lys] mutation in lymphocytes and the levels in muscle, in all nine investigated cases. The levels of mutated mtDNA were higher in muscle than in lymphocytes in all cases. 30 refs., 3 figs., 5 tabs.

  18. Signal Unification Block,

    DTIC Science & Technology

    A multichannel device is described for unifying the signals of thermocouples, tachometer generators and tensometers used in conducting tests on...various machines and mechanisms. The device is built on semiconductor instruments and has a block construction, permitting the easy alteration of the number of varieties of the signals being unified.

  19. MBA Quality Signals.

    ERIC Educational Resources Information Center

    Chapman, Randall S.

    1998-01-01

    A study identified quality signals for master's programs in business administration (MBAs). Traditional scholarly oriented academic signals are apparently not valued as such by external customer groups. MBA academic quality appears to be a multidimensional construct, with subdimensions of real-worldness; placement; student satisfaction; and…

  20. Probability, arrow of time and decoherence

    NASA Astrophysics Data System (ADS)

    Bacciagaluppi, Guido

    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.

  1. Episensitization: Defying Time’s Arrow

    PubMed Central

    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

  2. Beyond Bows and Arrows. Resource Manual.

    ERIC Educational Resources Information Center

    Civil Service Commission, Washington, DC. Bureau of Intergovernmental Personnel Programs.

    In spite of their visible prominence and influence on almost every aspect of our society, American Indians remain the least understood group of people. To acquaint symposium participants with the American Indian and to produce greater understanding, this resource manual documents the historical treatment and present status of Indians. Presented…

  3. Complexity and the Arrow of Time

    NASA Astrophysics Data System (ADS)

    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.

  4. Jasmonate signalling: a copycat of auxin signalling?

    PubMed

    Pérez, A Cuéllar; Goossens, A

    2013-12-01

    Plant hormones regulate almost all aspects of plant growth and development. The past decade has provided breakthrough discoveries in phytohormone sensing and signal transduction, and highlighted the striking mechanistic similarities between the auxin and jasmonate (JA) signalling pathways. Perception of auxin and JA involves the formation of co-receptor complexes in which hormone-specific E3-ubiquitin ligases of the SKP1-Cullin-F-box protein (SCF) type interact with specific repressor proteins. Across the plant kingdom, the Aux/IAA and the JASMONATE-ZIM DOMAIN (JAZ) proteins correspond to the auxin- and JA-specific repressors, respectively. In the absence of the hormones, these repressors form a complex with transcription factors (TFs) specific for both pathways. They also recruit several proteins, among which the general co-repressor TOPLESS, and thereby prevent the TFs from activating gene expression. The hormone-mediated interaction between the SCF and the repressors targets the latter for 26S proteasome-mediated degradation, which, in turn, releases the TFs to allow modulating hormone-dependent gene expression. In this review, we describe the similarities and differences in the auxin and JA signalling cascades with respect to the protein families and the protein domains involved in the formation of the pathway-specific complexes.

  5. Plant Cyclic Nucleotide Signalling

    PubMed Central

    Martinez-Atienza, Juliana; Van Ingelgem, Carl; Roef, Luc

    2007-01-01

    The presence of the cyclic nucleotides 3′,5′-cyclic adenyl monophosphate (cAMP) and 3′,5′-cyclic guanyl monophosphate (cGMP) in plants is now generally accepted. In addition, cAMP and cGMP have been implicated in the regulation of important plant processes such as stomatal functioning, monovalent and divalent cation fluxes, chloroplast development, gibberellic acid signalling, pathogen response and gene transcription. However, very little is known regarding the components of cyclic nucleotide signalling in plants. In this addendum, the evidence for specific mechanisms of plant cyclic nucleotide signalling is evaluated and discussed. PMID:19704553

  6. Aestivation: signaling and hypometabolism.

    PubMed

    Storey, Kenneth B; Storey, Janet M

    2012-05-01

    Aestivation is a survival strategy used by many vertebrates and invertebrates to endure arid environmental conditions. Key features of aestivation include strong metabolic rate suppression, strategies to retain body water, conservation of energy and body fuel reserves, altered nitrogen metabolism, and mechanisms to preserve and stabilize organs, cells and macromolecules over many weeks or months of dormancy. Cell signaling is crucial to achieving both a hypometabolic state and reorganizing multiple metabolic pathways to optimize long-term viability during aestivation. This commentary examines the current knowledge about cell signaling pathways that participate in regulating aestivation, including signaling cascades mediated by the AMP-activated kinase, Akt, ERK, and FoxO1.

  7. Quantifying Ubiquitin Signaling

    PubMed Central

    Ordureau, Alban; Münch, Christian; Harper, J. Wade

    2015-01-01

    Ubiquitin (UB)-driven signaling systems permeate biology, and are often integrated with other types of post-translational modifications (PTMs), most notably phosphorylation. Flux through such pathways is typically dictated by the fractional stoichiometry of distinct regulatory modifications and protein assemblies as well as the spatial organization of pathway components. Yet, we rarely understand the dynamics and stoichiometry of rate-limiting intermediates along a reaction trajectory. Here, we review how quantitative proteomic tools and enrichment strategies are being used to quantify UB-dependent signaling systems, and to integrate UB signaling with regulatory phosphorylation events. A key regulatory feature of ubiquitylation is that the identity of UB chain linkage types can control downstream processes. We also describe how proteomic and enzymological tools can be used to identify and quantify UB chain synthesis and linkage preferences. The emergence of sophisticated quantitative proteomic approaches will set a new standard for elucidating biochemical mechanisms of UB-driven signaling systems. PMID:26000850

  8. Signal processing in SETI

    NASA Technical Reports Server (NTRS)

    Cullers, D. K.; Linscott, I. R.; Oliver, B. M.

    1985-01-01

    It is believed that the Galaxy might contain ten billion potential life sites. In view of the physical inaccessibility of extraterrestrial life on account of the vast distances involved, a logical first step in a search for extraterrestrial intelligence (SETI) appears to be an attempt to detect signals already being radiated. The characteristics of the signals to be expected are discussed together with the search strategy of a NASA program. It is pointed out that all presently planned searches will use existing radio-astronomy antennas. If no extraterrestrial intelligence signals are discovered, society will have to decide whether SETI justifies a dedicated facility of much greater collecting area. Attention is given to a multichannel spectrum analyzer, CW signal detection, pulse detection, the pattern detector, and details of SETI system operation.

  9. Signals from the Cosmos.

    ERIC Educational Resources Information Center

    Lichtman, Jeffrey M.

    1991-01-01

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

  10. Nucleotide signalling during inflammation

    PubMed Central

    Idzko, Marco; Ferrari, Davide; Eltzschig, Holger K.

    2014-01-01

    Inflammatory conditions are associated with the extracellular release of nucleotides, particularly ATP. In the extracellular compartment, ATP predominantly functions as a signalling molecule through the activation of purinergic P2 receptors. Metabotropic P2Y receptors are G-protein-coupled, whereas ionotropic P2X receptors are ATP-gated ion channels. Here we discuss how signalling events through P2 receptors alter the outcomes of inflammatory or infectious diseases. Recent studies implicate a role for P2X/P2Ysignalling in mounting appropriate inflammatory responses critical for host defence against invading pathogens or tumours. Conversely, P2X/P2Y signalling can promote chronic inflammation during ischaemia and reperfusion injury, inflammatory bowel disease or acute and chronic diseases of the lungs. Although nucleotide signalling has been used clinically in patients before, research indicates an expanding field of opportunities for specifically targeting individual P2 receptors for the treatment of inflammatory or infectious diseases. PMID:24828189

  11. Digital signal processing

    NASA Astrophysics Data System (ADS)

    Oppenheim, A. V.; Baggeroer, A. B.; Lim, J. S.; Musicus, B. R.; Mook, D. R.; Duckworth, G. L.; Bordley, T. E.; Curtis, S. R.; Deadrick, D. S.; Dove, W. P.

    1984-01-01

    Signal and image processing research projects are described. Topics include: (1) modeling underwater acoustic propagation; (2) image restoration; (3) signal reconstruction; (4) speech enhancement; (5) pitch detection; (6) spectral analysis; (7) speech synthesis; (8) speech enhancement; (9) autoregressive spectral estimation; (10) knowledge based array processing; (11) speech analysis; (12) estimating the degree of coronary stenosis with image processing; (13) automatic target detection; and (14) video conferencing.

  12. Workshop on Cyclostationary Signals

    DTIC Science & Technology

    1993-06-30

    Time Compression, Terry M. Turpin and Leslie H. Gesell 73 iv New Cyclic Spectral Analysis Algorithms for Reducing Storage and Search, Grace Yeung and...phases of the signal, and the power of the signal and the noise), the log-likelihood ratio test yields a sufficient statistic (W)f=WHLW with linear...modeled as a random variable uniformly distributed over the period of cyclostationarity, and the resulting likelihood ratio test does not exploit the

  13. Sucrose signaling in plants

    PubMed Central

    Tognetti, Jorge A.; Pontis, Horacio G.; Martínez-Noël, Giselle M.A.

    2013-01-01

    The role of sucrose as a signaling molecule in plants was originally proposed several decades ago. However, recognition of sucrose as a true signal has been largely debated and only recently this role has been fully accepted. The best-studied cases of sucrose signaling involve metabolic processes, such as the induction of fructan or anthocyanin synthesis, but a large volume of scattered information suggests that sucrose signals may control a vast array of developmental processes along the whole life cycle of the plant. Also, wide gaps exist in our current understanding of the intracellular steps that mediate sucrose action. Sucrose concentration in plant tissues tends to be directly related to light intensity, and inversely related to temperature, and accordingly, exogenous sucrose supply often mimics the effect of high light and cold. However, many exceptions to this rule seem to occur due to interactions with other signaling pathways. In conclusion, the sucrose role as a signal molecule in plants is starting to be unveiled and much research is still needed to have a complete map of its significance in plant function. PMID:23333971

  14. Calcium signaling and cytotoxicity.

    PubMed Central

    Kass, G E; Orrenius, S

    1999-01-01

    The divalent calcium cation Ca(2+) is used as a major signaling molecule during cell signal transduction to regulate energy output, cellular metabolism, and phenotype. The basis to the signaling role of Ca(2+) is an intricate network of cellular channels and transporters that allow a low resting concentration of Ca(2+) in the cytosol of the cell ([Ca(2+)]i) but that are also coupled to major dynamic and rapidly exchanging stores. This enables extracellular signals from hormones and growth factors to be transduced as [Ca(2+)]i spikes that are amplitude and frequency encoded. There is considerable evidence that a number of toxic environmental chemicals target these Ca(2+) signaling processes, alter them, and induce cell death by apoptosis. Two major pathways for apoptosis will be considered. The first one involves Ca(2+)-mediated expression of ligands that bind to and activate death receptors such as CD95 (Fas, APO-1). In the second pathway, Ca(2+) has a direct toxic effect and its primary targets include the mitochondria and the endoplasmic reticulum (ER). Mitochondria may respond to an apoptotic Ca(2+) signal by the selective release of cytochrome c or through enhanced production of reactive oxygen species and opening of an inner mitochondrial membrane pore. Toxic agents such as the environmental pollutant tributyltin or the natural plant product thapsigargin, which deplete the ER Ca(2+) stores, will induce as a direct result of this effect the opening of plasma membrane Ca(2+) channels and an ER stress response. In contrast, under some conditions, Ca(2+) signals may be cytoprotective and antagonize the apoptotic machinery. Images Figure 1 Figure 2 Figure 3 PMID:10229704

  15. Separation of Climate Signals

    SciTech Connect

    Kamath, C; Fodor, I

    2002-11-13

    Understanding changes in global climate is a challenging scientific problem. Simulated and observed data include signals from many sources, and untangling their respective effects is difficult. In order to make meaningful comparisons between different models, and to understand human effects on global climate, we need to isolate the effects of different sources. Recent eruptions of the El Chichon and Mt. Pinatubo volcanoes coincided with large El Nino and Southern Oscillation (ENSO) events, which complicates the separation of their contributions on global temperatures. Current approaches for separating volcano and ENSO signals in global mean data involve parametric models and iterative techniques [3]. We investigate alternative methods based on principal component analysis (PCA) [2] and independent component analysis (ICA) [1]. Our goal is to determine if such techniques can automatically identify the signals corresponding to the different sources, without relying on parametric models.

  16. Plant TOR signaling components

    PubMed Central

    John, Florian; Roffler, Stefan; Wicker, Thomas; Ringli, Christoph

    2011-01-01

    Cell growth is a process that needs to be tightly regulated. Cells must be able to sense environmental factors like nutrient abundance, the energy level or stress signals and coordinate growth accordingly. The Target Of Rapamycin (TOR) pathway is a major controller of growth-related processes in all eukaryotes. If environmental conditions are favorable, the TOR pathway promotes cell and organ growth and restrains catabolic processes like autophagy. Rapamycin is a specific inhibitor of the TOR kinase and acts as a potent inhibitor of TOR signaling. As a consequence, interfering with TOR signaling has a strong impact on plant development. This review summarizes the progress in the understanding of the biological significance and the functional analysis of the TOR pathway in plants. PMID:22057328

  17. Updating dopamine reward signals

    PubMed Central

    Schultz, Wolfram

    2013-01-01

    Recent work has advanced our knowledge of phasic dopamine reward prediction error signals. The error signal is bidirectional, reflects well the higher order prediction error described by temporal difference learning models, is compatible with model-free and model-based reinforcement learning, reports the subjective rather than physical reward value during temporal discounting and reflects subjective stimulus perception rather than physical stimulus aspects. Dopamine activations are primarily driven by reward, and to some extent risk, whereas punishment and salience have only limited activating effects when appropriate controls are respected. The signal is homogeneous in terms of time course but heterogeneous in many other aspects. It is essential for synaptic plasticity and a range of behavioural learning situations. PMID:23267662

  18. Endocytosis, Signaling, and Beyond

    PubMed Central

    Di Fiore, Pier Paolo; von Zastrow, Mark

    2014-01-01

    The endocytic network comprises a vast and intricate system of membrane-delimited cell entry and cargo sorting routes running between biochemically and functionally distinct intracellular compartments. The endocytic network caters to the organization and redistribution of diverse subcellular components, and mediates appropriate shuttling and processing of materials acquired from neighboring cells or the extracellular milieu. Such trafficking logistics, despite their importance, represent only one facet of endocytic function. The endocytic network also plays a key role in organizing, mediating, and regulating cellular signal transduction events. Conversely, cellular signaling processes tightly control the endocytic pathway at different steps. The present article provides a perspective on the intimate relationships that exist between particular endocytic and cellular signaling processes in mammalian cells, within the context of understanding the impact of this nexus on integrated physiology. PMID:25085911

  19. Telemetry Ranging: Signal Processing

    NASA Astrophysics Data System (ADS)

    Hamkins, J.; Kinman, P.; Xie, H.; Vilnrotter, V.; Dolinar, S.

    2016-02-01

    This article describes the details of the signal processing used in a telemetry ranging system in which timing information is extracted from the downlink telemetry signal in order to compute spacecraft range. A previous article describes telemetry ranging concepts and architecture, which are a slight variation of a scheme published earlier. As in that earlier work, the telemetry ranging concept eliminates the need for a dedicated downlink ranging signal to communicate the necessary timing information. The present article describes the operation and performance of the major receiver functions on the spacecraft and the ground --- many of which are standard tracking loops already in use in JPL's flight and ground radios --- and how they can be used to provide the relevant information for making a range measurement. It also describes the implementation of these functions in software, and performance of an end-to-end software simulation of the telemetry ranging system.

  20. PKD signaling and pancreatitis

    PubMed Central

    Yuan, Jingzhen; Pandol, Stephen J.

    2016-01-01

    Background Acute pancreatitis is a serious medical disorder with no current therapies directed to the molecular pathogenesis of the disorder. Inflammation, inappropriate intracellular activation of digestive enzymes, and parenchymal acinar cell death by necrosis are the critical pathophysiologic processes of acute pancreatitis. Thus, it is necessary to elucidate the key molecular signals that mediate these pathobiologic processes and develop new therapeutic strategies to attenuate the appropriate signaling pathways in order to improve outcomes for this disease. A novel serine/threonine protein kinase D (PKD) family has emerged as key participants in signal transduction, and this family is increasingly being implicated in the regulation of multiple cellular functions and diseases. Methods This review summarizes recent findings of our group and others regarding the signaling pathway and the biological roles of the PKD family in pancreatic acinar cells. In particular, we highlight our studies of the functions of PKD in several key pathobiologic processes associated with acute pancreatitis in experimental models. Results Our findings reveal that PKD signaling is required for NF-κB activation/inflammation, intracellular zymogen activation, and acinar cell necrosis in rodent experimental pancreatitis. Novel small-molecule PKD inhibitors attenuate the severity of pancreatitis in both in vitro and in vivo experimental models. Further, this review emphasizes our latest advances in the therapeutic application of PKD inhibitors to experimental pancreatitis after the initiation of pancreatitis. Conclusions These novel findings suggest that PKD signaling is a necessary modulator in key initiating pathobiologic processes of pancreatitis, and that it constitutes a novel therapeutic target for treatments of this disorder. PMID:26879861

  1. Physiological Signal Conditioner

    NASA Technical Reports Server (NTRS)

    Friedericks, C.

    1999-01-01

    Sensors 2000! is developing a Physiological Signal Conditioner (PSC) for monitoring of astronauts in the ISS Human Research Facility. The PSC is battery powered and worn by the crew. The Engineering Development Unit (PSC EDU) and the form-and-fit PSC Tooling Model will be displayed along with associated graphics and text explanations. Results of a recent advanced PSC-2 feasibility study will be presented. The presentation will stimulate discussion of the functional capabilities of a wireless, crew worn Physiological Signal Conditioner. Application of advanced technology to meet the conflicting demands of size, power, and functional capability will be of interest.

  2. Universal signal conditioning amplifier

    NASA Technical Reports Server (NTRS)

    Larson, William E.; Hallberg, Carl; Medelius, Pedro J.

    1994-01-01

    Engineers at NASA's Kennedy Space Center have designed a signal conditioning amplifier which automatically matches itself to almost any kind of transducer. The product, called Universal Signal Conditioning Amplifier (USCA), uses state-of-the-art technologies to deliver high accuracy measurements. USCA's features which can be either programmable or automated include: voltage, current, or pulsed excitation, unlimited resolution gain, digital filtering and both analog and digital output. USCA will be used at Kennedy Space Center's launch pads for environmental measurements such as vibrations, strains, temperatures and overpressures. USCA is presently being commercialized through a co-funded agreement between NASA, the State of Florida, and Loral Test and Information Systems, Inc.

  3. Array signal processing

    SciTech Connect

    Haykin, S.; Justice, J.H.; Owsley, N.L.; Yen, J.L.; Kak, A.C.

    1985-01-01

    This is the first book to be devoted completely to array signal processing, a subject that has become increasingly important in recent years. The book consists of six chapters. Chapter 1, which is introductory, reviews some basic concepts in wave propagation. The remaining five chapters deal with the theory and applications of array signal processing in (a) exploration seismology, (b) passive sonar, (c) radar, (d) radio astronomy, and (e) tomographic imaging. The various chapters of the book are self-contained. The book is written by a team of five active researchers, who are specialists in the individual fields covered by the pertinent chapters.

  4. TOR signalling in plants.

    PubMed

    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.

  5. Noninvasive vital signal monitoring

    NASA Astrophysics Data System (ADS)

    Wang, Zenan; Chee, Jonny; Chua, Kok Poo; Chen, ZhouDe

    2010-05-01

    Vital signals of patients, such as heart rate, temperature and movement are crucial to monitor patients in hospital. Current heart rate measurement is obtained by using Electrocardiograph, which normally applies electrodes to the patient's body. As electrodes are extremely uncomfortable to ware and hinder patient's movement, a non-invasive vital signal-monitoring device will be a better solution. Similar to Electrocardiograph, the device detects the voltage difference across the heart by using concept of capacitance, which can be obtained by two conductive fiber sewing on the bed sheet. Simultaneous temperature reading can also be detected by using surface mounted temperature sensor. This paper will mainly focus on the heart rate monitoring.

  6. 29 CFR 1926.1422 - Signals-hand signal chart.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Signals-hand signal chart. 1926.1422 Section 1926.1422 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Construction § 1926.1422 Signals—hand signal chart. Hand signal charts must be either posted on the...

  7. 29 CFR 1926.1422 - Signals-hand signal chart.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Signals-hand signal chart. 1926.1422 Section 1926.1422 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Construction § 1926.1422 Signals—hand signal chart. Hand signal charts must be either posted on the...

  8. 29 CFR 1926.1422 - Signals-hand signal chart.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Signals-hand signal chart. 1926.1422 Section 1926.1422 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Construction § 1926.1422 Signals—hand signal chart. Hand signal charts must be either posted on the...

  9. 29 CFR 1926.1422 - Signals-hand signal chart.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Signals-hand signal chart. 1926.1422 Section 1926.1422 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION... Construction § 1926.1422 Signals—hand signal chart. Hand signal charts must be either posted on the...

  10. Hybrid ECG signal conditioner

    NASA Technical Reports Server (NTRS)

    Rinard, G. A.; Steffen, D. A.; Sturm, R. E.

    1979-01-01

    Circuit with high common-mode rejection has ability to filter and amplify accepted analog electrocardiogram (ECG) signals of varying amplitude, shape, and polarity. In addition, low power circuit develops standardized pulses that can be counted and averaged by heart/breath rate processor.

  11. Signals: Applying Academic Analytics

    ERIC Educational Resources Information Center

    Arnold, Kimberly E.

    2010-01-01

    Academic analytics helps address the public's desire for institutional accountability with regard to student success, given the widespread concern over the cost of higher education and the difficult economic and budgetary conditions prevailing worldwide. Purdue University's Signals project applies the principles of analytics widely used in…

  12. Contextual signaling in cancer.

    PubMed

    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.

  13. Communication Signals in Lizards.

    ERIC Educational Resources Information Center

    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. Signaling by Sensory Receptors

    PubMed Central

    Julius, David; Nathans, Jeremy

    2012-01-01

    Sensory systems detect small molecules, mechanical perturbations, or radiation via the activation of receptor proteins and downstream signaling cascades in specialized sensory cells. In vertebrates, the two principal categories of sensory receptors are ion channels, which mediate mechanosensation, thermosensation, and acid and salt taste; and G-protein-coupled receptors (GPCRs), which mediate vision, olfaction, and sweet, bitter, and umami tastes. GPCR-based signaling in rods and cones illustrates the fundamental principles of rapid activation and inactivation, signal amplification, and gain control. Channel-based sensory systems illustrate the integration of diverse modulatory signals at the receptor, as seen in the thermosensory/pain system, and the rapid response kinetics that are possible with direct mechanical gating of a channel. Comparisons of sensory receptor gene sequences reveal numerous examples in which gene duplication and sequence divergence have created novel sensory specificities. This is the evolutionary basis for the observed diversity in temperature- and ligand-dependent gating among thermosensory channels, spectral tuning among visual pigments, and odorant binding among olfactory receptors. The coding of complex external stimuli by a limited number of sensory receptor types has led to the evolution of modality-specific and species-specific patterns of retention or loss of sensory information, a filtering operation that selectively emphasizes features in the stimulus that enhance survival in a particular ecological niche. The many specialized anatomic structures, such as the eye and ear, that house primary sensory neurons further enhance the detection of relevant stimuli. PMID:22110046

  15. Synergistic signals in the environment.

    PubMed Central

    Arnold, S F; McLachlan, J A

    1996-01-01

    Numerous endogenous signals (such as hormones and growth factors) or environmental signals (including chemicals or temperature) contribute to determining the overall biological response produced by cells. Some combinations of endogenous or environmental signals produce synergistic activity. This commentary examines the different types of interactions between signals that contribute to synergy at the biological level. Images Figure 1. PMID:8930538

  16. Aural perception of NDE signals

    SciTech Connect

    Light, G.M.; Holt, A.E.; Polk, K.D.; Godwin, J.G.; Clayton, W.T.

    1994-12-31

    During nondestructive evaluation (NDE) of a material, the inspection signals are received typically by an NDE instrument. These signals usually are displayed electronically for visual interpretation. Work has been done to convert these signals into aural (audible) signals with the intent to enhance the accuracy of evaluation through the use of two senses (ears and eyes) instead of one. This paper describes auralization of ultrasonic NDE testing signals to improve characterization and evaluation of materials.

  17. Tailpulse signal generator

    DOEpatents

    Baker, John; Archer, Daniel E.; Luke, Stanley John; Decman, Daniel J.; White, Gregory K.

    2009-06-23

    A tailpulse signal generating/simulating apparatus, system, and method designed to produce electronic pulses which simulate tailpulses produced by a gamma radiation detector, including the pileup effect caused by the characteristic exponential decay of the detector pulses, and the random Poisson distribution pulse timing for radioactive materials. A digital signal process (DSP) is programmed and configured to produce digital values corresponding to pseudo-randomly selected pulse amplitudes and pseudo-randomly selected Poisson timing intervals of the tailpulses. Pulse amplitude values are exponentially decayed while outputting the digital value to a digital to analog converter (DAC). And pulse amplitudes of new pulses are added to decaying pulses to simulate the pileup effect for enhanced realism in the simulation.

  18. Strigolactones: promising plant signals.

    PubMed

    Gomez-Roldan, Victoria; Roux, Christophe; Girard, Daniel; Bécard, Guillaume; Puech-Pagés, Virginie

    2007-05-01

    As obligate biotrophic symbionts, Arbuscular Mycorrhizal (AM) fungi must efficiently recognize their host plant to insure their survival and complete their life cycle. Recent works have shown that some root secreted molecules, the strigolactones, activate the presymbiotic growth of AM fungi at extremely low concentrations. These compounds, derived from carotenoid biosynthesis, induce the mitochondrial metabolism of the fungus. The hypothesis that strigolactones are important plant recognition signals for AM fungi was further supported in this study by using maize seedlings treated with fluridone, an upstream inhibitor of the carotenoid metabolism. We showed that mycorrhization of the treated seedlings was significantly reduced, but restored by the addition of GR24, a strigolactone analogue. Similar results were obtained with the y9 mutant of maize defective in an upstream step of carotenoid synthesis. These data provide additional evidence that strigolactones may be essential symbiotic signals for the establishment of AM symbiosis.

  19. Signal processor chip implementation

    NASA Astrophysics Data System (ADS)

    Beraud, J. P.

    1985-03-01

    Advances in technology have made it now possible to integrate very large microprocessors on a single chip. Two basic design methodologies are available, including gate array and custom design. The present paper is concerned with a signal processor (SP) chip which is based on a mixture of the two technologies. Involved is a high-density chip which requires little manual effort for its production. The SP is characterized by separate instruction and data memories. The SP consists of three main parts which operate simultaneously. These parts include the sequencer, the address generator, and the computer portion. The chip comprises a library of predesigned building blocks. Attention is given to a signal processor block diagram, the basic TTL gate, a two-input master-slave latch, the physical library, aspects of logical design, the multiplier basic cell and adder line organization, and physical design methodology.

  20. Microglia Ontology and Signaling

    PubMed Central

    ElAli, Ayman; Rivest, Serge

    2016-01-01

    Microglia constitute the powerhouse of the innate immune system in the brain. It is now widely accepted that they are monocytic-derived cells that infiltrate the developing brain at the early embryonic stages, and acquire a resting phenotype characterized by the presence of dense branching processes, called ramifications. Microglia use these dynamic ramifications as sentinels to sense and detect any occurring alteration in brain homeostasis. Once a danger signal is detected, such as molecular factors associated to brain damage or infection, they get activated by acquiring a less ramified phenotype, and mount adequate responses that range from phagocyting cell debris to secreting inflammatory and trophic factors. Here, we review the origin of microglia and we summarize the main molecular signals involved in controlling their function under physiological conditions. In addition, their implication in the pathogenesis of multiple sclerosis and stress is discussed. PMID:27446922

  1. Pituitary Somatostatin Receptor Signaling

    PubMed Central

    Ben-Shlomo, Anat; Melmed, Shlomo

    2010-01-01

    Somatostatin (SRIF) is a major regulator of pituitary function, mostly inhibiting hormone secretion and to a lesser extent pituitary cell growth. Five SRIF receptor subtypes (SSTR1–5) are ubiquitously expressed G-protein coupled receptors. In the pituitary, SSTR1, SSTR2, SSTR3 and SSTR5 are expressed, with SSTR2 and SSTR5 predominating. As new SRIF-analogs have recently been introduced for treatment of pituitary disease, we evaluate the current knowledge of cell-specific pituitary SRIF receptor signaling and highlight areas of future research for comprehensive understanding of these mechanisms. Elucidating pituitary SRIF receptor signaling enables understanding of pituitary hormone secretion and cell growth, and also points to future therapeutic development for pituitary disorders. PMID:20149677

  2. Signals and Responses

    PubMed Central

    Lee, Angie

    2006-01-01

    The nitrogen-fixing symbiosis between bacteria in the family Rhizobiaceae and members of the legume family (Fabaceae) has been well studied, particularly from the perspective of the early signaling and recognition events. Recent studies of non-nodulating legume mutants have resulted in the identification of a number of genes that are responsive to signal molecules from the bacteria. However, a second group of nodule-forming bacteria, completely unrelated to the Rhizobiaceae, which are α-Proteobacteria, has been discovered. These bacteria belong to the β-Proteobacteria and have been designated β-rhizobia to distinguish them from the better-known α-rhizobia. Here, we review what is known in this economically important symbiosis about the interaction between legumes and α-rhizobia, and we incorporate information, where known, about the β-rhizobia. PMID:19521481

  3. Growth hormone signaling pathways.

    PubMed

    Carter-Su, Christin; Schwartz, Jessica; Argetsinger, Lawrence S

    2016-06-01

    Over 20years ago, our laboratory showed that growth hormone (GH) signals through the GH receptor-associated tyrosine kinase JAK2. We showed that GH binding to its membrane-bound receptor enhances binding of JAK2 to the GHR, activates JAK2, and stimulates tyrosyl phosphorylation of both JAK2 and GHR. The activated JAK2/GHR complex recruits a variety of signaling proteins, thereby initiating multiple signaling pathways and cellular responses. These proteins and pathways include: 1) Stat transcription factors implicated in the expression of multiple genes, including the gene encoding insulin-like growth factor 1; 2) Shc adapter proteins that lead to activation of the grb2-SOS-Ras-Raf-MEK-ERK1,2 pathway; 3) insulin receptor substrate proteins implicated in the phosphatidylinositol-3-kinase and Akt pathway; 4) signal regulatory protein α, a transmembrane scaffold protein that recruits proteins including the tyrosine phosphatase SHP2; and 5) SH2B1, a scaffold protein that can activate JAK2 and enhance GH regulation of the actin cytoskeleton. Our recent work has focused on the function of SH2B1. We have shown that SH2B1β is recruited to and phosphorylated by JAK2 in response to GH. SH2B1 localizes to the plasma membrane, cytoplasm and focal adhesions; it also cycles through the nucleus. SH2B1 regulates the actin cytoskeleton and promotes GH-dependent motility of RAW264.7 macrophages. Mutations in SH2B1 have been found in humans exhibiting severe early-onset childhood obesity and insulin resistance. These mutations impair SH2B1 enhancement of GH-induced macrophage motility. As SH2B1 is expressed ubiquitously and is also recruited to a variety of receptor tyrosine kinases, our results raise the possibility that effects of SH2B1 on the actin cytoskeleton in various cell types, including neurons, may play a role in regulating body weight.

  4. Biological Information Signal Processor

    NASA Technical Reports Server (NTRS)

    Chow, Edward T.; Peterson, John C.; Yoo, Michael M.

    1993-01-01

    Biological Information Signal Processor (BISP) is computing system analyzing data on deoxyribonucleic acid (DNA) sequences for molecular genetic analysis. Includes coprocessors, specialized microprocessors complementing present and future computers by performing rapidly most-time-consuming DNA-sequence-analyzing functions, establishing relationships (alignments) between both global sequences and defining patterns in multiple sequences. Also includes state-of-art software and data-base systems on both conventional and parallel computer systems to augment analytical abilities of developmental coprocessors.

  5. Strain Gage Signal Interpretation.

    DTIC Science & Technology

    1986-02-01

    blades and vanes in many engines have been collected, played back and examined. The engine types encompass GE’s stable of turbine engines from the small...aeromechanical engineer . 1.3 SUMMARY OF RESULTS Strain gage signals from vibrating rotor blades and vanes were collected, examined, classified, and generalized...turboprops, to turbojets and to the large high bypass turbofan engines . Test conditions include all the phases that are investigated

  6. Plant peptide hormone signalling.

    PubMed

    Motomitsu, Ayane; Sawa, Shinichiro; Ishida, Takashi

    2015-01-01

    The ligand-receptor-based cell-to-cell communication system is one of the most important molecular bases for the establishment of complex multicellular organisms. Plants have evolved highly complex intercellular communication systems. Historical studies have identified several molecules, designated phytohormones, that function in these processes. Recent advances in molecular biological analyses have identified phytohormone receptors and signalling mediators, and have led to the discovery of numerous peptide-based signalling molecules. Subsequent analyses have revealed the involvement in and contribution of these peptides to multiple aspects of the plant life cycle, including development and environmental responses, similar to the functions of canonical phytohormones. On the basis of this knowledge, the view that these peptide hormones are pivotal regulators in plants is becoming increasingly accepted. Peptide hormones are transcribed from the genome and translated into peptides. However, these peptides generally undergo further post-translational modifications to enable them to exert their function. Peptide hormones are expressed in and secreted from specific cells or tissues. Apoplastic peptides are perceived by specialized receptors that are located at the surface of target cells. Peptide hormone-receptor complexes activate intracellular signalling through downstream molecules, including kinases and transcription factors, which then trigger cellular events. In this chapter we provide a comprehensive summary of the biological functions of peptide hormones, focusing on how they mature and the ways in which they modulate plant functions.

  7. Multipoint multirate signal processing

    NASA Astrophysics Data System (ADS)

    Claypoole, Roger L., Jr.

    1994-12-01

    This thesis provides a fundamentally new, systematic study of multipoint multirate signal processing systems. The multipoint multirate operators are analyzed via equivalent circuits comprised entirely of conventional multirate operators. Interconnections of the operators are demonstrated, and the multipoint noble identities are derived. The multipoint polyphase representation is presented, and the M channel multipoint multirate system with vector length N is presented as an MN channel multipoint polyphase system. The conditions sufficient for perfect reconstruction in the multipoint multirate system are derived. These conditions constrain the multipoint filter banks to be composed of comb filters generated from paraunitary sets of conventional filters. The perfect reconstruction multipoint multirate system is then combined with the multiresolution wavelet decomposition to form the generalized wavelet decomposition with varying vector decimation length at each level. The generalized wavelet decomposition is used as an algorithm to redistribute the energy of a signal throughout the levels of the decomposition. It is shown that, for band pass and high pass signals, significant improvements can be made in the energy distribution. It is recommended that this algorithm be studied as a front end to a vector quantizer for data compression applications.

  8. Adaptive Signal Processing Testbed

    NASA Astrophysics Data System (ADS)

    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.

  9. 77 FR 35082 - Arrow Investment Advisers, LLC and Arrow Investments Trust; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    ... 2(a)(32), 5(a)(1), 22(d) and 22(e) of the Act and rule 22c-1 under the Act, under sections 6(c) and 17(b) of the Act for an exemption from sections 17(a)(1) and (a)(2) of the Act, and under section 12... exemption from sections 12(d)(1)(A) and (B) of the Act. 2. Section 6(c) of the Act provides that...

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

    ERIC Educational Resources Information Center

    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…

  11. Notch Signaling Components

    PubMed Central

    Liu, Zhi-Yan; Wu, Tao; Li, Qing; Wang, Min-Cong; Jing, Li; Ruan, Zhi-Ping; Yao, Yu; Nan, Ke-Jun; Guo, Hui

    2016-01-01

    Abstract Non-small-cell lung cancer (NSCLC) is a lethal and aggressive malignancy. Currently, the identities of prognostic and predictive makers of NSCLC have not been fully established. Dysregulated Notch signaling has been implicated in many human malignancies, including NSCLC. However, the prognostic value of measuring Notch signaling and the utility of developing Notch-targeted therapies in NSCLC remain inconclusive. The present study investigated the association of individual Notch receptor and ligand levels with lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC) prognosis using the Kaplan-Meier plotte database. This online database encompasses 2437 lung cancer samples. Hazard ratios with 95% confidence intervals were calculated. The results showed that higher Notch1, Notch2, JAG1, and DLL1 mRNA expression predicted better overall survival (OS) in lung ADC, but showed no significance in SCC patients. Elevated Notch3, JAG2, and DLL3 mRNA expression was associated with poor OS of ADC patients, but not in SCC patients. There was no association between Notch4 and OS in either lung ADC or SCC patients. In conclusion, the set of Notch1, Notch2, JAG1, DLL1 and that of Notch3, JAG2, DLL3 played opposing prognostic roles in lung ADC patients. Neither set of Notch receptors and ligands was indicative of lung SCC prognosis. Notch signaling could serve as promising marker to predict outcomes in lung ADC patients. The distinct features of lung cancer subtypes and Notch components should be considered when developing future Notch-targeted therapies. PMID:27196489

  12. Biphonation in voice signals

    SciTech Connect

    Herzel, H.; Reuter, R.

    1996-06-01

    Irregularities in voiced speech are often observed as a consequence of vocal fold lesions, paralyses, and other pathological conditions. Many of these instabilities are related to the intrinsic nonlinearities in the vibrations of the vocal folds. In this paper, a specific nonlinear phenomenon is discussed: The appearance of two independent fundamental frequencies termed biphonation. Several narrow-band spectrograms are presented showing biphonation in signals from voice patients, a newborn cry, a singer, and excised larynx experiments. Finally, possible physiological mechanisms of instabilities of the voice source are discussed. {copyright} {ital 1996 American Institute of Physics.}

  13. Optical signal computing

    NASA Astrophysics Data System (ADS)

    Cathey, Wade Thomas; Schmidt, Rodney A.; Moddel, Garret

    1989-12-01

    Architectures for optical symbolic computing were designed, devices were designed and built that were specifically for the architectures, and test circuits for some of the logic elements were designed, constructed, and operated. The research elements were designed, constructed, and operated. The research led to novel architectures for optical symbolic computing. Devices were developed that are suitable for optical 2-D memory and logic. These devices are pixilated photo-addressed spatial light modulators (SLMs) with a three terminal arrangement so that the threshold can be adjusted. Spinoff non-pixilated devices are useful as high frame rate, high resolution SLMs that can be used for many optical signal processing applications.

  14. Signal Processing Circuit Development.

    DTIC Science & Technology

    1986-07-01

    Simplified active filter circuit 64 42. Video output amplifier 66 43. 64/128 gated clock circuitry 68 44. Two pole Sallen-Key active filters 7!1 45. Switched...four quadrant multiplier, log compression, multiple pole active video filtering and black level control. In what follows in this report an attempt...chip is shown in Fiqu-e 5. This is the master synch chip which generates all of the control signals necessary for TV monitor presentation of video data

  15. A controllable water signal transistor.

    PubMed

    Wu, Lili; Zhou, Xiaoyan; Lu, Hangjun; Liang, Qing; Kou, Jianlong; Wu, Fengmin; Fan, Jintu

    2017-03-27

    We performed molecular dynamics simulations to study the regulating ability of water chains confined in a Y-shaped nanochannel. It was shown that a signal at the molecular level could be controlled by two other charge-induced signals when the water chains were confined in a Y-shaped nanochannel, demonstrating promising applications as water signal transistors in nanosignal systems. The mechanism of a water signal transistor is similar to a signal logic device. This remarkable ability to control the water signal is attributed to the strong dipole-ordering of the water chains in the nanochannel. The controllable water signal process of the Y-shaped nanochannel provides opportunities for future application in the design of molecular-scale signal devices.

  16. Signal quality of endovascular electroencephalography

    NASA Astrophysics Data System (ADS)

    He, Bryan D.; Ebrahimi, Mosalam; Palafox, Leon; Srinivasan, Lakshminarayan

    2016-02-01

    Objective, Approach. A growing number of prototypes for diagnosing and treating neurological and psychiatric diseases are predicated on access to high-quality brain signals, which typically requires surgically opening the skull. Where endovascular navigation previously transformed the treatment of cerebral vascular malformations, we now show that it can provide access to brain signals with substantially higher signal quality than scalp recordings. Main results. While endovascular signals were known to be larger in amplitude than scalp signals, our analysis in rabbits borrows a standard technique from communication theory to show endovascular signals also have up to 100× better signal-to-noise ratio. Significance. With a viable minimally-invasive path to high-quality brain signals, patients with brain diseases could one day receive potent electroceuticals through the bloodstream, in the course of a brief outpatient procedure.

  17. Calcium Signaling in the Liver

    PubMed Central

    Amaya, Maria Jimena; Nathanson, Michael H.

    2014-01-01

    Intracellular free Ca2+ ([Ca2+]i) is a highly versatile second messenger that regulates a wide range of functions in every type of cell and tissue. To achieve this versatility, the Ca2+ signaling system operates in a variety of ways to regulate cellular processes that function over a wide dynamic range. This is particularly well exemplified for Ca2+ signals in the liver, which modulate diverse and specialized functions such as bile secretion, glucose metabolism, cell proliferation, and apoptosis. These Ca2+ signals are organized to control distinct cellular processes through tight spatial and temporal coordination of [Ca2+]i signals, both within and between cells. This article will review the machinery responsible for the formation of Ca2+ signals in the liver, the types of subcellular, cellular, and intercellular signals that occur, the physiological role of Ca2+ signaling in the liver, and the role of Ca2+ signaling in liver disease. PMID:23720295

  18. Universal signal conditioning amplifier

    NASA Technical Reports Server (NTRS)

    Medelius, Pedro J.; Hallberg, Carl; Cecil, Jim

    1994-01-01

    A state-of-the-art instrumentation amplifier capable of being used with most types of transducers has been developed at the Kennedy Space Center. This Universal Signal Conditioning Amplifier (USCA) can eliminate costly measurement setup item and troubleshooting, improve system reliability and provide more accurate data than conventional amplifiers. The USCA can configure itself for maximum resolution and accuracy based on information read from a RAM chip attached to each transducer. Excitation voltages or current are also automatically configured. The amplifier uses both analog and digital state-of-the-art technology with analog-to-digital conversion performed in the early stages in order to minimize errors introduced by offset and gain drifts in the analog components. A dynamic temperature compensation scheme has been designed to achieve and maintain 12-bit accuracy of the amplifier from 0 to 70 C. The digital signal processing section allows the implementation of digital filters up to 511th order. The amplifier can also perform real-time linearizations up to fourth order while processing data at a rate of 23.438 kS/s. Both digital and analog outputs are available from the amplifier.

  19. Endocannabinoid Signaling in Autism.

    PubMed

    Chakrabarti, Bhismadev; Persico, Antonio; Battista, Natalia; Maccarrone, Mauro

    2015-10-01

    Autism spectrum disorder (ASD) is a complex behavioral condition with onset during early childhood and a lifelong course in the vast majority of cases. To date, no behavioral, genetic, brain imaging, or electrophysiological test can specifically validate a clinical diagnosis of ASD. However, these medical procedures are often implemented in order to screen for syndromic forms of the disorder (i.e., autism comorbid with known medical conditions). In the last 25 years a good deal of information has been accumulated on the main components of the "endocannabinoid (eCB) system", a rather complex ensemble of lipid signals ("endocannabinoids"), their target receptors, purported transporters, and metabolic enzymes. It has been clearly documented that eCB signaling plays a key role in many human health and disease conditions of the central nervous system, thus opening the avenue to the therapeutic exploitation of eCB-oriented drugs for the treatment of psychiatric, neurodegenerative, and neuroinflammatory disorders. Here we present a modern view of the eCB system, and alterations of its main components in human patients and animal models relevant to ASD. This review will thus provide a critical perspective necessary to explore the potential exploitation of distinct elements of eCB system as targets of innovative therapeutics against ASD.

  20. GTPases in semaphorin signaling.

    PubMed

    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.

  1. Calcium Signaling and Neurodegeneration

    PubMed Central

    2010-01-01

    Neurodegenerative disorders, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), Huntington’s disease (HD), and spinocerebellar ataxias (SCA) are very important both for fundamental science and for practical medicine. Despite extensive research into the causes of these diseases, clinical researchers have had very limited progress and, as of now, there is still no cure for any of these diseases. One of the main obstacles in the way of creating treatments for these disorders is the fact that their etiology and pathophysiology still remain unclear. This paper reviews results that support the so–called “calcium hypothesis of neurodegenerative diseases.” The calcium hypothesis states that the atrophic and degenerative processes in the neurons of AD, PD, ALS, HD, and SCA patients are accompanied by alterations in calcium homeostasis. Moreover, the calcium hypothesis states that this deregulation of calcium signaling is one of the early–stage and key processes in the pathogenesis of these diseases. Based on the results we reviewed, we conclude that the calcium channels and other proteins involved in the neuronal calcium signaling system are potential drug targets for AD, PD, ALS, HD, and SCA therapy. PMID:22649630

  2. Calcium signalling in diabetes.

    PubMed

    Guerrero-Hernandez, Agustin; Verkhratsky, Alexei

    2014-11-01

    Molecular cascades responsible for Ca(2+) homeostasis and Ca(2+) signalling could be assembled in highly plastic toolkits that define physiological adaptation of cells to the environment and which are intimately involved in all types of cellular pathology. Control over Ca(2+) concentration in different cellular compartments is intimately linked to cell metabolism, because (i) ATP production requires low Ca(2+), (ii) Ca(2+) homeostatic systems consume ATP and (iii) Ca(2+) signals in mitochondria stimulate ATP synthesis being an essential part of excitation-metabolic coupling. The communication between the ER and mitochondria plays an important role in this metabolic fine tuning. In the insulin resistance state and diabetes this communication has been impaired leading to different disorders, for instance, diminished insulin production by pancreatic β cells, reduced heart and skeletal muscle contractility, reduced NO production by endothelial cells, increased glucose production by liver, increased lipolysis by adipose cells, reduced immune responses, reduced cognitive functions, among others. All these processes eventually trigger degenerative events resulting in overt diabetes due to reduction of pancreatic β cell mass, and different complications of diabetes, such as retinopathy, nephropathy, neuropathy, and different cardiovascular diseases.

  3. Macula densa cell signaling.

    PubMed

    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.

  4. Neural Network Communications Signal Processing

    DTIC Science & Technology

    1994-08-01

    This final technical report describes the research and development- results of the Neural Network Communications Signal Processing (NNCSP) Program...The objectives of the NNCSP program are to: (1) develop and implement a neural network and communications signal processing simulation system for the...purpose of exploring the applicability of neural network technology to communications signal processing; (2) demonstrate several configurations of the

  5. Salicylic acid signaling inhibits apoplastic reactive oxygen species signaling

    PubMed Central

    2014-01-01

    Background Reactive oxygen species (ROS) are used by plants as signaling molecules during stress and development. Given the amount of possible challenges a plant face from their environment, plants need to activate and prioritize between potentially conflicting defense signaling pathways. Until recently, most studies on signal interactions have focused on phytohormone interaction, such as the antagonistic relationship between salicylic acid (SA)-jasmonic acid and cytokinin-auxin. Results In this study, we report an antagonistic interaction between SA signaling and apoplastic ROS signaling. Treatment with ozone (O3) leads to a ROS burst in the apoplast and induces extensive changes in gene expression and elevation of defense hormones. However, Arabidopsis thaliana dnd1 (defense no death1) exhibited an attenuated response to O3. In addition, the dnd1 mutant displayed constitutive expression of defense genes and spontaneous cell death. To determine the exact process which blocks the apoplastic ROS signaling, double and triple mutants involved in various signaling pathway were generated in dnd1 background. Simultaneous elimination of SA-dependent and SA-independent signaling components from dnd1 restored its responsiveness to O3. Conversely, pre-treatment of plants with SA or using mutants that constitutively activate SA signaling led to an attenuation of changes in gene expression elicited by O3. Conclusions Based upon these findings, we conclude that plants are able to prioritize the response between ROS and SA via an antagonistic action of SA and SA signaling on apoplastic ROS signaling. PMID:24898702

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

    PubMed

    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).

  7. Rise-Time Distortion of Signal without Carrying Signal

    NASA Astrophysics Data System (ADS)

    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.

  8. Binary-Signal Recovery

    NASA Technical Reports Server (NTRS)

    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

  9. Chaos-Based Signal Processing

    NASA Astrophysics Data System (ADS)

    Ogorzałek, Maciej J.

    2002-07-01

    Nonlinear systems exhibiting chaotic behavior can be considered as a source of a great variety of signals. Given a time series measured from a known or an unknown dynamical system we address a series of problems, such as section-wise approximation of the measured signal by pieces of trajectories from a chosen nonlinear dynamical system (model) signal restoration when the measured signal has been corrupted e.g. by quantization; signal coding and compression. The key to attack these problems is estimation of the initial conditions for a dynamical system which is used as the generator of approximating waveforms.

  10. Notch Signaling in Pancreatic Development

    PubMed Central

    Li, Xu-Yan; Zhai, Wen-Jun; Teng, Chun-Bo

    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 that Notch signaling specifies the endocrine lineage. Here, we review the current knowledge of the Notch signaling pathway in pancreatic development and its crosstalk with the Wingless and INT-1 (Wnt) and fibroblast growth factor (FGF) pathways. PMID:26729103

  11. Low-Energy Signals for a Minimal Gauge-Mediated Model

    SciTech Connect

    Gabrielli, E.; Sarid, U.

    1997-12-01

    The inclusive branching ratio B{r_arrow}X{sub s}{gamma} and the anomalous magnetic moment g{sub {mu}}{minus}2 of the muon are accurately calculated within a minimal gauge-mediated supersymmetry-breaking model which naturally generates a large tan{beta} . The predictions are strongly correlated, and in somewhat better agreement with current experiments; new data will soon critically test these predictions. Predictions for B{r_arrow}X{sub s}l{sup +}l{sup {minus}} branching ratios and asymmetries, to be tested at future colliders, are also presented. {copyright} {ital 1997} {ital The American Physical Society}

  12. Signal conditioning system

    NASA Technical Reports Server (NTRS)

    Zahzah, Mohamad (Inventor); Korkosz, Gregory J. (Inventor); Bohr, Gerald (Inventor)

    2000-01-01

    A current-driven signal conditioning system comprising a first terminal, a second terminal, a strain gauge, and an instrumentation amplifier is disclosed. The strain gauge is adapted to measure a deformation of a structure and to generate a resistance which corresponds to the measured deformation. The instrumentation amplifier is adapted to be connected between the first terminal and the second terminal. The instrumentation amplifier is further adapted to be connected to the strain gauge and to place an output current on the second terminal. The output current is proportional to the resistance generated by the strain gauge. An output resister is coupled between the strain gauge and the second terminal, and a capacitor is coupled between the resister and the first terminal. A zenor diode is coupled between the first terminal and the strain gauge, and a diode is also coupled between the first terminal and the strain gauge.

  13. [Signal Processing Suite Design

    NASA Technical Reports Server (NTRS)

    Sahr, John D.; Mir, Hasan; Morabito, Andrew; Grossman, Matthew

    2003-01-01

    Our role in this project was to participate in the design of the signal processing suite to analyze plasma density measurements on board a small constellation (3 or 4) satellites in Low Earth Orbit. As we are new to space craft experiments, one of the challenges was to simply gain understanding of the quantity of data which would flow from the satellites, and possibly to interact with the design teams in generating optimal sampling patterns. For example, as the fleet of satellites were intended to fly through the same volume of space (displaced slightly in time and space), the bulk plasma structure should be common among the spacecraft. Therefore, an optimal, limited bandwidth data downlink would take advantage of this commonality. Also, motivated by techniques in ionospheric radar, we hoped to investigate the possibility of employing aperiodic sampling in order to gain access to a wider spatial spectrum without suffering aliasing in k-space.

  14. Epigenetic signaling in schizophrenia

    PubMed Central

    Ibi, Daisuke; González-Maeso, Javier

    2015-01-01

    Histone modifications and DNA methylation represent central dynamic and reversible processes that regulate gene expression and contribute to cellular phenotypes. These epigenetic marks have been shown to play fundamental roles in a diverse set of signaling and behavioral outcomes. Psychiatric disorders such as schizophrenia and depression are complex and heterogeneous diseases with multiple and independent factors that may contribute to their pathophysiology, making challenging to find a link between specific elements and the underlying mechanisms responsible for the disorder and its treatment. Growing evidences suggest that epigenetic modifications in certain brain regions and neural circuits represent a key mechanism through which environmental factors interact with individual’s genetic constitution to affect risk of psychiatric conditions throughout life. This review focuses on recent advances that directly implicate epigenetic modifications in schizophrenia and antipsychotic drug action. PMID:26120009

  15. Collider Signal I :. Resonance

    NASA Astrophysics Data System (ADS)

    Tait, Tim M. P.

    2010-08-01

    These TASI lectures were part of the summer school in 2008 and cover the collider signal associated with resonances in models of physics beyond the Standard Model. I begin with a review of the Z boson, one of the best-studied resonances in particle physics, and review how the Breit-Wigner form of the propagator emerges in perturbation theory and discuss the narrow width approximation. I review how the LEP and SLAC experiments could use the kinematics of Z events to learn about fermion couplings to the Z. I then make a brief survey of models of physics beyond the Standard Model which predict resonances, and discuss some of the LHC observables which we can use to discover and identify the nature of the BSM physics. I finish up with a discussion of the linear moose that one can use for an effective theory description of a massive color octet vector particle.

  16. Oxygen sensing and signaling.

    PubMed

    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.

  17. Interactive digital signal processor

    NASA Technical Reports Server (NTRS)

    Mish, W. H.; Wenger, R. M.; Behannon, K. W.; Byrnes, J. B.

    1982-01-01

    The Interactive Digital Signal Processor (IDSP) is examined. It consists of a set of time series analysis Operators each of which operates on an input file to produce an output file. The operators can be executed in any order that makes sense and recursively, if desired. The operators are the various algorithms used in digital time series analysis work. User written operators can be easily interfaced to the sysatem. The system can be operated both interactively and in batch mode. In IDSP a file can consist of up to n (currently n=8) simultaneous time series. IDSP currently includes over thirty standard operators that range from Fourier transform operations, design and application of digital filters, eigenvalue analysis, to operators that provide graphical output, allow batch operation, editing and display information.

  18. EEG signal analysis: a survey.

    PubMed

    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.

  19. Signaling on the endocytic pathway.

    PubMed

    McPherson, P S; Kay, B K; Hussain, N K

    2001-06-01

    Ligand binding to receptor tyrosine kinases and G-protein-coupled receptors initiates signal transduction events and induces receptor endocytosis via clathrin-coated pits and vesicles. While receptor-mediated endocytosis has been traditionally considered an effective mechanism to attenuate ligand-activated responses, more recent studies demonstrate that signaling continues on the endocytic pathway. In fact, certain signaling events, such as the activation of the extracellular signal-regulated kinases, appear to require endocytosis. Protein components of signal transduction cascades can assemble at clathrin coated pits and remain associated with endocytic vesicles following their dynamin-dependent release from the plasma membrane. Thus, endocytic vesicles can function as a signaling compartment distinct from the plasma membrane. These observations demonstrate that endocytosis plays an important role in the activation and propagation of signaling pathways.

  20. Biasing GPCR signaling from inside.

    PubMed

    Shukla, Arun K

    2014-01-28

    The discovery of "functional selectivity" or "biased signaling" through G protein-coupled receptors (GPCRs) has redefined the classical GPCR signaling paradigm. Moreover, the therapeutic potential of biased signaling by and biased ligands for GPCRs is changing the landscape of GPCR drug discovery. The concept of biased signaling has primarily been developed and discussed in the context of ligands that bind to the extracellular regions of GPCRs. However, two recent reports demonstrate that it is also possible to bias GPCR signaling from inside the cell by targeting intracellular regions of these receptors. These findings present a novel handle for delineating the functional outcomes of biased signaling by GPCRs. Moreover, these approaches also uncover a previously unexplored framework for biasing GPCR signaling for drug discovery.

  1. Oxytocin receptor signalling.

    PubMed

    Devost, Dominic; Wrzal, Paulina; Zingg, Hans H

    2008-01-01

    The great diversity of the expression sites and proposed function of the oxytocin (OXT) receptor (OXTR) is paralleled by a diversity of its signalling pathways, many of which have still remained unexplored. We have used different approaches to discover novel pathways. By means of a phosphoproteomics approach, we have detected several distinct OXT-induced changes in tyrosine as well as threonine phosphorylation states of intracellular protein in myometrial cells. The most prominent change involved dephosphorylation of a 95-kDa phosphothreonine moiety. By N-terminal amino acid microsequence analysis, this moiety was shown to correspond to eukaryotic translation factor eEF2. This protein is a key regulator of protein synthesis and mediates, upon dephosphorylation, the translocation step of peptide chain elongation. These findings define a novel mechanism by which OXT assumes a so far unrecognized trophic function. We next elucidated the intracellular pathway(s) involved. We found that this effect is not mediated by any of the known pathways known to induce eEF2 dephosphorylation (mTOR, ERK1/2 or p38) but by protein kinase C. Consistent with this idea, we also found that direct stimulation of protein kinase C with a phorbol ester induced eEF2 dephosphorylation in myometrial cells. Using phosphoERK antibodies, we discovered by Western blotting that OXT induced phosphorylation of a higher molecular weight ERK-related protein. We were able to show that this band corresponded to "big MAP kinase1" or ERK5. ERK5 is part of a distinct MAPK cascade and promotes expression of the myosin light chain gene and plays an obligatory role in muscle cell development and differentiation. The role of ERK5 in myometrium has remained unexplored, but it is likely to represent an important novel pathway mediating OXT's effects on smooth muscle function. Further elucidation of these novel signalling pathways will have significant relevance for the development of novel pathway-specific OXTR

  2. Integrin endosomal signalling suppresses anoikis

    PubMed Central

    Alanko, Jonna; Mai, Anja; Jacquemet, Guillaume; Schauer, Kristine; Kaukonen, Riina; Saari, Markku; Goud, Bruno; Ivaska, Johanna

    2016-01-01

    Integrin containing focal adhesions (FAs) transmit extracellular signals across the plasma membrane to modulate cell adhesion, signalling and survival. Although integrins are known to undergo continuous endo/exocytic traffic, potential impact of endocytic traffic on integrin-induced signals is unknown. Here, we demonstrate that integrin signalling is not restricted to cell-ECM adhesions and identify an endosomal signalling platform that supports integrin signalling away from the plasma membrane. We show that active focal adhesion kinase (FAK), an established marker of integrin-ECM downstream signalling, localises with active integrins on endosomes. Integrin endocytosis positively regulates adhesion-induced FAK activation, which is early endosome antigen-1 (EEA1) and small GTPase Rab21 dependent. FAK binds directly to purified endosomes and becomes activated on them, suggesting a role for endocytosis in enhancing distinct integrin downstream signalling events. Finally, endosomal integrin signalling contributes to cancer-related processes such as anoikis resistance, anchorage-independence and metastasis. Integrins are heterodimeric cell surface adhesion receptors functioning as integrators of the extra-cellular matrix (ECM) driven cues, the cellular cytoskeleton and the cellular signalling apparatus 1.Upon adhesion, integrins trigger the formation of plasma-membrane proximal large mechanosensing and signal-transmitting protein clusters depicted as “adhesomes” 2, 3. In addition, integrins undergo constant endocytic traffic to facilitate focal adhesion turnover, cell migration, invasion and cytokinesis 4. For other receptor systems it is well established that endocytic membrane traffic regulates bioavailability of cell-surface molecules and therefore the intensity and/or specificity of receptor-initiated signals 5, 6. Although active integrins and their ligands have been detected in endosomes 7–9 and increased integrin recycling to the plasma membrane contributes

  3. Signaling pathways affecting skeletal health.

    PubMed

    Marie, Pierre J

    2012-09-01

    Skeletal health is dependent on the balance between bone resorption and formation during bone remodeling. Multiple signaling pathways play essential roles in the maintenance of skeletal integrity by positively or negatively regulating bone cells. During the last years, significant advances have been made in our understanding of the essential signaling pathways that regulate bone cell commitment, differentiation and survival. New signaling anabolic pathways triggered by parathyroid hormone, local growth factors, Wnt signaling, and calcium sensing receptor have been identified. Novel signals induced by interactions between bone cells-matrix (integrins), osteoblasts/osteocytes (cadherins, connexins), and osteoblasts/osteoclast (ephrins, Wnt-RhoA, semaphorins) have been discovered. Recent studies revealed the key pathways (MAPK, PI3K/Akt) that critically control bone cells and skeletal mass. This review summarizes the most recent knowledge on the major signaling pathways that control bone cells, and their potential impact on the development of therapeutic strategies to improve human bone health.

  4. Calcium signalling remodelling and disease.

    PubMed

    Berridge, Michael J

    2012-04-01

    A wide range of Ca2+ signalling systems deliver the spatial and temporal Ca2+ signals necessary to control the specific functions of different cell types. Release of Ca2+ by InsP3 (inositol 1,4,5-trisphosphate) plays a central role in many of these signalling systems. Ongoing transcriptional processes maintain the integrity and stability of these cell-specific signalling systems. However, these homoeostatic systems are highly plastic and can undergo a process of phenotypic remodelling, resulting in the Ca2+ signals being set either too high or too low. Such subtle dysregulation of Ca2+ signals have been linked to some of the major diseases in humans such as cardiac disease, schizophrenia, bipolar disorder and Alzheimer's disease.

  5. Steganography in arrhythmic electrocardiogram signal.

    PubMed

    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.

  6. Purinergic signaling in special senses.

    PubMed

    Housley, Gary D; Bringmann, Andreas; Reichenbach, Andreas

    2009-03-01

    We consider the impact of purinergic signaling on the physiology of the special senses of vision, smell, taste and hearing. Purines (particularly ATP and adenosine) act as neurotransmitters, gliotransmitters and paracrine factors in the sensory retina, nasal olfactory epithelium, taste buds and cochlea. The associated purinergic receptor signaling underpins the sensory transduction and information coding in these sense organs. The P2 and P1 receptors mediate fast transmission of sensory signals and have modulatory roles in the regulation of synaptic transmitter release, for example in the adaptation to sensory overstimulation. Purinergic signaling regulates bidirectional neuron-glia interactions and is involved in the control of blood supply, extracellular ion homeostasis and the turnover of sensory epithelia by modulating apoptosis and progenitor proliferation. Purinergic signaling is an important player in pathophysiological processes in sensory tissues, and has both detrimental (pro-apoptotic) and supportive (e.g. initiation of cytoprotective stress-signaling cascades) effects.

  7. Transmembrane signaling proteoglycans.

    PubMed

    Couchman, John R

    2010-01-01

    Virtually all metazoan cells contain at least one and usually several types of transmembrane proteoglycans. These are varied in protein structure and type of polysaccharide, but the total number of vertebrate genes encoding transmembrane proteoglycan core proteins is less than 10. Some core proteins, including those of the syndecans, always possess covalently coupled glycosaminoglycans; others do not. Syndecan has a long evolutionary history, as it is present in invertebrates, but many other transmembrane proteoglycans are vertebrate inventions. The variety of proteins and their glycosaminoglycan chains is matched by diverse functions. However, all assume roles as coreceptors, often working alongside high-affinity growth factor receptors or adhesion receptors such as integrins. Other common themes are an ability to signal through their cytoplasmic domains, often to the actin cytoskeleton, and linkage to PDZ protein networks. Many transmembrane proteoglycans associate on the cell surface with metzincin proteases and can be shed by them. Work with model systems in vivo and in vitro reveals roles in growth, adhesion, migration, and metabolism. Furthermore, a wide range of phenotypes for the core proteins has been obtained in mouse knockout experiments. Here some of the latest developments in the field are examined in hopes of stimulating further interest in this fascinating group of molecules.

  8. Pten signaling in gliomas.

    PubMed Central

    Knobbe, Christiane B.; Merlo, Adrian; Reifenberger, Guido

    2002-01-01

    In 1997, the PTEN gene (phosphatase and tensin homolog deleted on chromosome 10) was identified as a tumor suppressor gene on the long arm of chromosome 10. Since then, important progress has been made with respect to the understanding of the role of the Pten protein in the normal development of the brain as well as in the molecular pathogenesis of human gliomas. This review summarizes the current state of the art concerning the involvement of aberrant Pten function in the development of different biologic features of malignant gliomas, such as loss of cell-cycle control and uncontrolled cell proliferation, escape from apoptosis, brain invasion, and aberrant neoangiogenesis. Most of the tumor-suppressive properties of Pten are dependent on its lipid phosphatase activity, which inhibits the phosphatidylinositol-3'-kinase (PI3K)/Akt signaling pathway through dephosphorylation of phosphatidylinositol-(3,4,5)-triphosphate. The additional function of Pten as a dual-specificity protein phosphatase may also play a role in glioma pathogenesis. Besides the wealth of data elucidating the functional roles of Pten, recent studies suggest a diagnostic significance of PTEN gene alterations as a molecular marker for poor prognosis in anaplastic astrocytomas and anaplastic oligodendrogliomas. Furthermore, the possibility of selective targeting of PTEN mutant tumor cells by specific pharmacologic inhibitors of members of the Pten/PI3K/Akt pathway opens up new perspectives for a targeted molecular therapy of malignant gliomas. PMID:12084351

  9. Signal processor packaging design

    NASA Astrophysics Data System (ADS)

    McCarley, Paul L.; Phipps, Mickie A.

    1993-10-01

    The Signal Processor Packaging Design (SPPD) program was a technology development effort to demonstrate that a miniaturized, high throughput programmable processor could be fabricated to meet the stringent environment imposed by high speed kinetic energy guided interceptor and missile applications. This successful program culminated with the delivery of two very small processors, each about the size of a large pin grid array package. Rockwell International's Tactical Systems Division in Anaheim, California developed one of the processors, and the other was developed by Texas Instruments' (TI) Defense Systems and Electronics Group (DSEG) of Dallas, Texas. The SPPD program was sponsored by the Guided Interceptor Technology Branch of the Air Force Wright Laboratory's Armament Directorate (WL/MNSI) at Eglin AFB, Florida and funded by SDIO's Interceptor Technology Directorate (SDIO/TNC). These prototype processors were subjected to rigorous tests of their image processing capabilities, and both successfully demonstrated the ability to process 128 X 128 infrared images at a frame rate of over 100 Hz.

  10. Visualizing and quantifying adhesive signals

    PubMed Central

    Sabouri-Ghomi, Mohsen; Wu, Yi; Hahn, Klaus; Danuser, Gaudenz

    2008-01-01

    Understanding the structural adaptation and signaling of adhesion sites in response to mechanical stimuli requires in situ characterization of the dynamic activation of a large number of adhesion components. Here, we review high resolution live cell imaging approaches to measure forces, assembly and interaction of adhesion components, and the activation of adhesion-mediated signals. We conclude by outlining computational multiplexing as a framework for the integration of these data into comprehensive models of adhesion signaling pathways. PMID:18586481

  11. Postsynaptic Signaling and Plasticity Mechanisms

    NASA Astrophysics Data System (ADS)

    Sheng, Morgan; Jong Kim, Myung

    2002-10-01

    In excitatory synapses of the brain, specific receptors in the postsynaptic membrane lie ready to respond to the release of the neurotransmitter glutamate from the presynaptic terminal. Upon stimulation, these glutamate receptors activate multiple biochemical pathways that transduce signals into the postsynaptic neuron. Different kinds of synaptic activity elicit different patterns of postsynaptic signals that lead to short- or long-lasting strengthening or weakening of synaptic transmission. The complex molecular mechanisms that underlie postsynaptic signaling and plasticity are beginning to emerge.

  12. Theoretical aspects of calcium signaling

    NASA Astrophysics Data System (ADS)

    Pencea, Corneliu Stefan

    2001-08-01

    Experiments investigating intracellular calcium dynamics have revealed that calcium signals differentially affect a variety of intracellular processes, from fertilization and cell development and differentiation to subsequent cellular activity, ending with cell death. As an intracellular messenger, calcium transmits information within and between cells, thus regulating their activity. To control such a variety of processes, calcium signals have to be very flexible and also precisely regulated. The cell uses a calcium signaling ``toolkit'', where calcium ions can act in different contexts of space, amplitude and time. For different tasks, the cell selects the particular signal, or combination of signals, that triggers the appropriate physiological response. The physical foundations of such a versatile cellular signaling toolkit involving calcium are not completely understood, despite important experimental and theoretical progress made recently. The declared goal of this work is to investigate physical mechanisms on which the propagation of differential signals can be based. The dynamics of calcium near a cluster of inositol trisphosphate (IP3) activated calcium channels has been investigated analytically and numerically. Our work has demonstrated that clusters of different IP3 receptors can show similar bistable behavior, but differ in both the transient and long term dynamics. We have also investigated the conditions under which a calcium signal propagates between a pair of localized stores. We have shown that the propagation of the signal across a random distribution of such stores shows a percolation transition manifested in the shape of the wave front. More importantly, our work indicates that specific distribution of stores can be interpreted as calcium circuits that can perform important signal analyzing task, from unidirectional propagation and coincidence detection to a complete set of logic gates. We believe that phenomena like the ones described are

  13. Wavelet Preprocessing of Acoustic Signals

    DTIC Science & Technology

    1991-12-01

    wavelet transform to preprocess acoustic broadband signals in a system that discriminates between different classes of acoustic bursts. This is motivated by the similarity between the proportional bandwidth filters provided by the wavelet transform and those found in biological hearing systems. The experiment involves comparing statistical pattern classifier effects of wavelet and FFT preprocessed acoustic signals. The data used was from the DARPA Phase I database, which consists of artificially generated signals with real ocean background. The

  14. Protein modules and signalling networks

    NASA Astrophysics Data System (ADS)

    Pawson, Tony

    1995-02-01

    Communication between cells assumes particular importance in multicellular organisms. The growth, migration and differentiation of cells in the embryo, and their organization into specific tissues, depend on signals transmitted from one cell to another. In the adult, cell signalling orchestrates normal cellular behaviour and responses to wounding and infection. The consequences of breakdowns in this signalling underlie cancer, diabetes and disorders of the immune and cardiovascular systems. Conserved protein domains that act as key regulatory participants in many of these different signalling pathways are highlighted.

  15. Semaphorin signaling in cardiovascular development.

    PubMed

    Epstein, Jonathan A; Aghajanian, Haig; Singh, Manvendra K

    2015-02-03

    Semaphorins were originally identified as neuronal guidance molecules mediating their attractive or repulsive signals by forming complexes with plexin and neuropilin receptors. Subsequent research has identified functions for semaphorin signaling in many organs and tissues outside of the nervous system. Vital roles for semaphorin signaling in vascular patterning and cardiac morphogenesis have been demonstrated, and impaired semaphorin signaling has been associated with various human cardiovascular disorders, including persistent truncus arteriosus, sinus bradycardia and anomalous pulmonary venous connections. Here, we review the functions of semaphorins and their receptors in cardiovascular development and disease and highlight important recent discoveries in the field.

  16. Signal transduction abnormalities in suicide: focus on phosphoinositide signaling system.

    PubMed

    Pandey, Ghanshyam N

    2013-11-01

    Suicide is a major public health concern and each year about one million people die by suicide worldwide. Recent studies suggest that suicide may be associated with specific neurobiological abnormalities. Earlier studies of neurobiology of suicide focused on abnormalities of the serotonergic mechanism. These studies suggested that some serotonin receptor subtypes may be abnormal in the postmortem brain of suicide victims. Since these receptors are linked to signal transduction pathways, abnormalities of signaling mechanisms have been recently studied in the postmortem brain of suicide victims. Of particular interest is the 5-hydroxytryptamine2A receptor-linked phosphoinositide signaling system. Several studies have focused on the abnormalities on the component of this signaling system and these studies suggest the abnormalities of G proteins, the effectors phospholipase C and the second or the third messenger systems, such as protein kinase A. Further studies revealed abnormalities in the downstream transcription factors such as the cyclic AMP response element binding protein and some of the targeted genes of these transcription factors. The most important gene in this aspect which has been studied in the suicide is the brain-derived neurotrophic factor. Here we critically review the studies focusing on these components of the phosphoinositide signaling system in the postmortem brain of both adult and teenage suicide victims. These studies provide a better understanding of the signal transduction abnormalities in suicide focusing on the phosphoinositide signaling pathway. These studies may lead to new therapeutic agents targeting specific sites in this signaling cascade.

  17. Enhancement Of Optical Registration Signals Through Digital Signal Processing Techniques

    NASA Astrophysics Data System (ADS)

    Cote, Daniel R.; Lazo-Wasem, Jeanne

    1988-01-01

    Alignment and setup of lighography processes has largely been conducted on special test wafers. Actual product level optimization has been limited to manual techniques such as optical verniers. This is especially time consuming and prone to inconsistencies when the registration characteristics of lithographic systems are being measured. One key factor obstructing the use of automated metrology equipment on product level wafers is the inability to discern reliably, metrology features from the background noise and variations in optical registration signals. This is often the case for metal levels such as aluminum and tungsten. This paper discusses methods for enhancement of typical registration signals obtained from difficult semiconductor process levels. Brightfield and darkfield registration signals are obtained using a microscope and a 1024 element linear photodiode array. These signals are then digitized and stored on the hard disk of a computer. The techniques utilized include amplitude selective and adaptive and non-adaptive frequency domain filtering techniques. The effect of each of these techniques upon calculated registration values is analyzed by determining the positional variation of the center location of a two line registration feature. Plots of raw and processed signals obtained are presented as are plots of the power spectral density of ideal metrology feature signal and noise patterns. It is concluded that the proper application of digital signal processing (DSP) techniques to problematic optical registration signals greatly enhances the applicability of automated optical registration measurement techniques to difficult semiconductor process levels.

  18. Recognition of a signal peptide by the signal recognition particle

    PubMed Central

    Janda, Claudia Y.; Li, Jade; Oubridge, Chris; Hernández, Helena; Robinson, Carol V.; Nagai, Kiyoshi

    2010-01-01

    Targeting of proteins to appropriate sub-cellular compartments is a crucial process in all living cells. Secretory and membrane proteins usually contain an N-terminal signal peptide, which is recognised by the signal recognition particle (SRP) when nascent polypeptide chains emerge from the ribosome. The SRP-ribosome nascent chain complex is then targeted through its GTP-dependent interaction with SRP-receptor to the protein-conducting channel on endoplasmic reticulum membrane in eukaryotes or plasma membrane in bacteria. A universally conserved component of SRP1, 2, SRP54 or its bacterial homolog, fifty-four homolog (Ffh), binds the signal peptides which have a highly divergent sequence divisible into a positively charged n-region, an h-region commonly containing 8-20 hydrophobic residues and a polar c-region 3-5. No structure has been reported that exemplified SRP54 binding of any signal sequence. We have produced a fusion protein between Sulfolobus solfataricus SRP54 and a signal peptide connected via a flexible linker. This fusion protein oligomerises in solution, through interaction between the SRP54 and signal peptide moieties belonging to different chains, and it is functional, able to bind SRP RNA and SRP-receptor FtsY. Here we present the crystal structure at 3.5 Å resolution of an SRP54-signal peptide complex in the dimer, which reveals how a signal sequence is recognised by SRP54. PMID:20364120

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

    NASA Astrophysics Data System (ADS)

    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.

  20. 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

    SciTech Connect

    Chung, S.U.; Danyo, K.; Hackenburg, R.W.; Olchanski, C.; Ostrovidov, A.I.; Weygand, D.P.; Willutzki, H.J.; 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.; Bar-Yam, Z.; Cummings, J.P.; Dowd, J.P.; Eugenio, P.; Hayek, M.; Kern, W.; King, E.; Ostrovidov, A.I.; Shenhav, N.; Adams, G.S.; Cummings, J.P.; Kuhn, J.; Napolitano, J.; Nozar, M.; Smith, J.A.; White, D.; Witkowski, M.; 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.; 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.; Brown, D.S.; Pedlar, T.K.; Seth, K.K.; Wise, J.; Zhao, D.; Denisov, S.; Dorofeev, V.; Kachaev, I.; Lipaev, V.; Popov, A.; Ryabchikov, D.

    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 }

  1. Bioelectric signal analysis and measurement

    NASA Technical Reports Server (NTRS)

    Lai, D. C.

    1975-01-01

    Nonstationary time series techniques are used to analyze EEG signals for the estimation of alertness. A time varying order is extracted in sequential time series measurement of these data and strategies are devised for obtaining optimal representation of the EEG signal.

  2. Thermocouple-Signal-Conditioning Circuit

    NASA Technical Reports Server (NTRS)

    Simon, Richard A.

    1991-01-01

    Thermocouple-signal-conditioning circuit acting in conjunction with thermocouple, exhibits electrical behavior of voltage in series with resistance. Combination part of input bridge circuit of controller. Circuit configured for either of two specific applications by selection of alternative resistances and supply voltages. Includes alarm circuit detecting open circuit in thermocouple and provides off-scale output to signal malfunctions.

  3. Revisiting intracellular calcium signaling semantics.

    PubMed

    Haiech, Jacques; Audran, Emilie; Fève, Marie; Ranjeva, Raoul; Kilhoffer, Marie-Claude

    2011-12-01

    Cells use intracellular free calcium concentration changes for signaling. Signal encoding occurs through both spatial and temporal modulation of the free calcium concentration. The encoded message is detected by an ensemble of intracellular sensors forming the family of calcium-binding proteins (CaBPs) which must faithfully translate the message using a new syntax that is recognized by the cell. The cell is home to a significant although limited number of genes coding for proteins involved in the signal encoding and decoding processes. In a cell, only a subset of this ensemble of genes is expressed, leading to a genetic regulation of the calcium signal pathways. Calmodulin (CaM), the most ubiquitous expressed intracellular calcium-binding protein, plays a major role in calcium signal translation. Similar to a hub, it is central to a large and finely tuned network, receiving information, integrating it and dispatching the cognate response. In this review, we examine the different steps starting with an external stimulus up to a cellular response, with special emphasis on CaM and the mechanism by which it decodes calcium signals and translates it into exquisitely coordinated cellular events. By this means, we will revisit the calcium signaling semantics, hoping that we will ease communication between scientists dealing with calcium signals in different biological systems and different domains.

  4. Echolocation signals of wild dolphins

    NASA Astrophysics Data System (ADS)

    Au, W. W. L.

    2004-07-01

    Most of our understanding of dolphin echolocation has come from studies of captive dolphins performing various echolocation tasks. Recently, measurements of echolocation signals in the wild have expanded our understanding of the characteristics of these signals in a natural setting. Measuring undistorted dolphin echolocation signals with free swimming dolphins in the field can be a challenging task. A four hydrophone array arranged in a symmetrical star pattern was used to measure the echolocation signals of four species of dolphins in the wild. Echolocation signals of the following dolphins have been measured with the symmetrical star array: white-beaked dolphins in Iceland, Atlantic spotted dolphins in the Bahamas, killer whales in British Columbia, and dusky dolphins in New Zealand. There are many common features in the echolocation signals of the different species. Most of the signals had spectra that were bimodal: two peaks, one at low frequencies and another about an octave higher in frequency. The source level of the sonar transmission varies as a function of 20log R, suggesting a form of time-varying gain but on the transmitting end of the sonar process rather than the receiving end. The results of the field work call into question the issue of whether the signals used by captive dolphins may be shaped by the task they are required to perform rather than what they would do more naturally.

  5. Intracellular Signal Modulation by Nanomaterials

    PubMed Central

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

    2016-01-01

    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 crucially affect the cytotoxicity of nanomaterials and membrane-dependent signaling pathways can 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. PMID:24683030

  6. Signaling equilibria in sensorimotor interactions.

    PubMed

    Leibfried, Felix; Grau-Moya, Jordi; Braun, Daniel A

    2015-08-01

    Although complex forms of communication like human language are often assumed to have evolved out of more simple forms of sensorimotor signaling, less attention has been devoted to investigate the latter. Here, we study communicative sensorimotor behavior of humans in a two-person joint motor task where each player controls one dimension of a planar motion. We designed this joint task as a game where one player (the sender) possesses private information about a hidden target the other player (the receiver) wants to know about, and where the sender's actions are costly signals that influence the receiver's control strategy. We developed a game-theoretic model within the framework of signaling games to investigate whether subjects' behavior could be adequately described by the corresponding equilibrium solutions. The model predicts both separating and pooling equilibria, in which signaling does and does not occur respectively. We observed both kinds of equilibria in subjects and found that, in line with model predictions, the propensity of signaling decreased with increasing signaling costs and decreasing uncertainty on the part of the receiver. Our study demonstrates that signaling games, which have previously been applied to economic decision-making and animal communication, provide a framework for human signaling behavior arising during sensorimotor interactions in continuous and dynamic environments.

  7. Attention to natural auditory signals.

    PubMed

    Caporello Bluvas, Emily; Gentner, Timothy Q

    2013-11-01

    The challenge of understanding how the brain processes natural signals is compounded by the fact that such signals are often tied closely to specific natural behaviors and natural environments. This added complexity is especially true for auditory communication signals that can carry information at multiple hierarchical levels, and often occur in the context of other competing communication signals. Selective attention provides a mechanism to focus processing resources on specific components of auditory signals, and simultaneously suppress responses to unwanted signals or noise. Although selective auditory attention has been well-studied behaviorally, very little is known about how selective auditory attention shapes the processing on natural auditory signals, and how the mechanisms of auditory attention are implemented in single neurons or neural circuits. Here we review the role of selective attention in modulating auditory responses to complex natural stimuli in humans. We then suggest how the current understanding can be applied to the study of selective auditory attention in the context natural signal processing at the level of single neurons and populations in animal models amenable to invasive neuroscience techniques. This article is part of a Special Issue entitled "Communication Sounds and the Brain: New Directions and Perspectives".

  8. Noise Reduction by Signal Accumulation

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2006-01-01

    The aim of this paper is to show how the noise reduction by signal accumulation can be accomplished with a data acquisition system. This topic can be used for student projects. In many cases, the noise reduction is an unavoidable part of experimentation. Several techniques are known for this purpose, and among them the signal accumulation is the…

  9. Signals in Communication Engineering History

    ERIC Educational Resources Information Center

    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…

  10. Hybrid respiration-signal conditioner

    NASA Technical Reports Server (NTRS)

    Rinard, G. A.; Steffen, D. A.; Sturm, R. E.

    1979-01-01

    Hybrid impedance-pneumograph and respiration-rate signal conditioner element of hand-held vital signs monitor measures changes in impedance of chest during breathing cycle and generates analog respiration signal as output along with synchronous square wave that can be monitored by breath-rate processor.

  11. Intracellular signal modulation by nanomaterials.

    PubMed

    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.

  12. Piezoelectric extraction of ECG signal.

    PubMed

    Ahmad, Mahmoud Al

    2016-11-17

    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.

  13. Endocytosis and Signaling during Development

    PubMed Central

    Bökel, Christian

    2014-01-01

    The development of multicellular organisms relies on an intricate choreography of intercellular communication events that pattern the embryo and coordinate the formation of tissues and organs. It is therefore not surprising that developmental biology, especially using genetic model organisms, has contributed significantly to the discovery and functional dissection of the associated signal-transduction cascades. At the same time, biophysical, biochemical, and cell biological approaches have provided us with insights into the underlying cell biological machinery. Here we focus on how endocytic trafficking of signaling components (e.g., ligands or receptors) controls the generation, propagation, modulation, reception, and interpretation of developmental signals. A comprehensive enumeration of the links between endocytosis and signal transduction would exceed the limits of this review. We will instead use examples from different developmental pathways to conceptually illustrate the various functions provided by endocytic processes during key steps of intercellular signaling. PMID:24591521

  14. Engineering Cell-Cell Signaling

    PubMed Central

    Milano, Daniel F.; Natividad, Robert J.; Asthagiri, Anand R.

    2014-01-01

    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 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 based on 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 utilizing synthetic cells, advanced ‘chassis’ and predictive modeling to engineer the form and function of living tissues. PMID:23856592

  15. Engineering cell-cell signaling.

    PubMed

    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.

  16. Perception and Signaling of Strigolactones.

    PubMed

    Marzec, Marek

    2016-01-01

    Strigolactones (SLs), a recently discovered class of phytohormones, are important regulators of plant growth and development. While the biosynthetic pathway of these molecules is well documented, until recently there was not much known about the molecular mechanisms underlying SL perception and signal transduction in plants. Certain aspects of their perception and signaling, including the hormone-mediated interaction between receptor and F-box protein, degradation of suppressor proteins and activation of transcription factors, are also found in other phytohormones. However, some of SL signaling features seem to be specific for the SL signaling pathway. These include the enzymatic activity of the SL receptor and its destabilization caused by SLs. This review summarizes the current knowledge about SL signaling pathway in plants.

  17. Perception and Signaling of Strigolactones

    PubMed Central

    Marzec, Marek

    2016-01-01

    Strigolactones (SLs), a recently discovered class of phytohormones, are important regulators of plant growth and development. While the biosynthetic pathway of these molecules is well documented, until recently there was not much known about the molecular mechanisms underlying SL perception and signal transduction in plants. Certain aspects of their perception and signaling, including the hormone-mediated interaction between receptor and F-box protein, degradation of suppressor proteins and activation of transcription factors, are also found in other phytohormones. However, some of SL signaling features seem to be specific for the SL signaling pathway. These include the enzymatic activity of the SL receptor and its destabilization caused by SLs. This review summarizes the current knowledge about SL signaling pathway in plants. PMID:27602041

  18. Piezoelectric extraction of ECG signal

    NASA Astrophysics Data System (ADS)

    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.

  19. Wavelet preprocessing of acoustic signals

    NASA Astrophysics Data System (ADS)

    Huang, W. Y.; Solorzano, M. R.

    1991-12-01

    This paper describes results using the wavelet transform to preprocess acoustic broadband signals in a system that discriminates between different classes of acoustic bursts. This is motivated by the similarity between the proportional bandwidth filters provided by the wavelet transform and those found in biological hearing systems. The experiment involves comparing statistical pattern classifier effects of wavelet and FFT preprocessed acoustic signals. The data used was from the DARPA Phase 1 database, which consists of artificially generated signals with real ocean background. The results show that the wavelet transform did provide improved performance when classifying in a frame-by-frame basis. The DARPA Phase 1 database is well matched to proportional bandwidth filtering; i.e., signal classes that contain high frequencies do tend to have shorter duration in this database. It is also noted that the decreasing background levels at high frequencies compensate for the poor match of the wavelet transform for long duration (high frequency) signals.

  20. Zinc signaling through glucocorticoid and glutamate signaling in stressful circumstances.

    PubMed

    Takeda, Atsushi; Tamano, Haruna

    2010-11-01

    Humans and animals are constantly exposed to environmental stress. The hypothalamic-pituitary-adrenal (HPA) axis responds to stress, followed by glucocorticoid secretion from the adrenal glands. This response serves to maintain homeostasis in the living body through energy mobilization or to restore it. The brain is an important target for glucocorticoids. The hippocampus participates in the regulation of the HPA axis. Stress activates glutamatergic neurons in the hippocampus, and serious stress induces dyshomeostasis of extracellular glutamate. This dyshomeostasis, which is potentiated by glucocorticoids, modifies cognitive and emotional behavior. On the other hand, zinc is necessary for glucocorticoid signaling and is released from glutamatergic (zincergic) neurons to modulate synaptic glutamate signaling. Stress also induces dyshomeostasis of extracellular zinc, which may be linked to dyshomeostasis of extracellular glutamate. Thus, glucocorticoid signaling might also contribute to dyshomeostasis of extracellular zinc. It is likely that zinc signaling participates in cognitive and emotional behavior through glucocorticoid and glutamate signaling under stressful circumstances. This Mini-Review analyzes the relationship among signals of glucocorticoid, glutamate, and zinc under stressful circumstances to elucidate the significance of the zinc signaling in response to stress.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Controlling of explicit internal signal stochastic resonance by external signal

    NASA Astrophysics Data System (ADS)

    Li, Ya Ping; Wang, Pin; Li, Qian Shu

    2004-09-01

    Explicit internal signal stochastic resonance (EISSR) is investigated in a model of energy transduction of molecular machinery when noise is added to the region of oscillation in the presence of external signal (ES). It is found that EISSR could be controlled, i.e., enhanced or suppressed by adjusting frequency (ωe) and amplitude (A) of ES, and that there exits an optimal frequency for ES, which makes EISSR strength reach the maximum. Meanwhile, a critical amplitude (Ac) is found, which is a threshold of occurrence of EISSR. Finally, the difference and similarity between EISSR and IISSR (implicit internal signal stochastic resonance) are discussed.

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

    PubMed Central

    Hong, Kar-Wai; Koh, Chong-Lek; Sam, Choon-Kook; Yin, Wai-Fong; Chan, Kok-Gan

    2012-01-01

    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. PMID:22666051

  4. Subplasma membrane Ca2+ signals.

    PubMed

    McCarron, John G; Chalmers, Susan; Olson, Marnie L; Girkin, John M

    2012-07-01

    Ca(2+) may selectively activate various processes in part by the cell's ability to localize changes in the concentration of the ion to specific subcellular sites. Interestingly, these Ca(2+) signals begin most often at the plasma membrane space so that understanding subplasma membrane signals is central to an appreciation of local signaling. Several experimental procedures have been developed to study Ca(2+) signals near the plasma membrane, but probably the most prevalent involve the use of fluorescent Ca(2+) indicators and fall into two general approaches. In the first, the Ca(2+) indicators themselves are specifically targeted to the subplasma membrane space to measure Ca(2+) only there. Alternatively, the indicators are allowed to be dispersed throughout the cytoplasm, but the fluorescence emanating from the Ca(2+) signals at the subplasma membrane space is selectively measured using high resolution imaging procedures. Although the targeted indicators offer an immediate appeal because of selectivity and ease of use, their limited dynamic range and slow response to changes in Ca(2+) are a shortcoming. Use of targeted indicators is also largely restricted to cultured cells. High resolution imaging applied with rapidly responding small molecule Ca(2+) indicators can be used in all cells and offers significant improvements in dynamic range and speed of response of the indicator. The approach is technically difficult, however, and realistic calibration of signals is not possible. In this review, a brief overview of local subplasma membrane Ca(2+) signals and methods for their measurement is provided.

  5. Targeting FGFR Signaling in Cancer.

    PubMed

    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.

  6. Signal Relay During Cell Migration

    NASA Astrophysics Data System (ADS)

    Guven, Can; Rericha, Erin; Ott, Edward; Losert, Wolfgang

    2012-02-01

    We developed a signal relay model to quantify the effect of intercellular communication in presence of an external signal, during the motion of groups of Dictyostelium discoideum cells. A key parameter is the ratio of amplitude of the cAMP (cyclic adenosine monophosphate) a signaling chemical secreted from individual cells versus the external cAMP field, which defines a time scale. Another time scale is set by the degradation rate of the cAMP. In our simulations, the competition between these two time scales results rich dynamics including uniform motion, as well as streaming and clustering instabilities. The simulations are compared to experiments for a wide range of different external signal strengths for both cells that secrete cAMP and a mutant which cannot relay cAMP. Under different strength of external linear cAMP gradient, the wild type cells form streams and exhibit clustering due to the intercellular signaling through individual cAMP secretion. In contrast, cells lacking signal relay move relatively straight. We find that the model captures both independent motion and the formation of aggregates when cells relay the signal.

  7. Baird's beaked whale echolocation signals.

    PubMed

    Baumann-Pickering, Simone; Yack, Tina M; Barlow, Jay; Wiggins, Sean M; Hildebrand, John A

    2013-06-01

    Echolocation signals from Baird's beaked whales were recorded during visual and acoustic shipboard surveys of cetaceans in the California Current ecosystem and with autonomous, long-term recorders in the Southern California Bight. The preliminary measurement of the visually validated Baird's beaked whale echolocation signals from towed array data were used as a basis for identifying Baird's signals in the autonomous recorder data. Two distinct signal types were found, one being a beaked whale-like frequency modulated (FM) pulse, the other being a dolphin-like broadband click. The median FM inter-pulse interval was 230 ms. Both signal types showed a consistent multi-peak structure in their spectra with peaks at ~9, 16, 25, and 40 kHz. Depending on signal type, as well as recording aspect and distance to the hydrophone, these peaks varied in relative amplitude. The description of Baird's echolocation signals will allow for studies of their distribution and abundance using towed array data without associated visual sightings and from autonomous seafloor hydrophones.

  8. Microsystem for signal processing applications

    NASA Astrophysics Data System (ADS)

    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.

  9. Signals of Opportunity Navigation Using Wi-Fi Signals

    DTIC Science & Technology

    2011-03-24

    Signals of Opportunity Navigation Using Wi-Fi Signals THESIS Wilfred E . Noel, Captain, USAF AFIT/GE/ENG/11-30 DEPARTMENT OF THE AIR FORCE AIR...Fulfillment of the Requirements for the Degree of Master of Science in Electrical Engineering Wilfred E . Noel, B.S.E.E. Captain, USAF March 2011 APPROVED FOR...love you both more than you will ever know. Wilfred E . Noel iv Table of Contents Page Abstract

  10. Chemoattractant signaling in dictyostelium discoideum.

    PubMed

    Manahan, Carol L; Iglesias, Pablo A; Long, Yu; Devreotes, Peter N

    2004-01-01

    Dictyostelium is an accessible organism for studies of signaling via chemoattractant receptors. Chemoattractant-mediated signaling events and components are reviewed and presented as a series of connected modules, including excitation, inhibition, G protein-independent responses, early gene expression, inositol lipids, PH domain-containing proteins, cyclic AMP signaling, polarization acquisition, actin polymerization, and cortical myosin. The network incorporates information from biochemical, genetic, and cell biological experiments carried out on living cells. The modules and connections represent current understanding, and future information is expected to modify and build upon this structure.

  11. Inositol trisphosphate and calcium signalling

    NASA Astrophysics Data System (ADS)

    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.

  12. The IRS-1 signaling system.

    PubMed

    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.

  13. Emotion recognition from physiological signals.

    PubMed

    Gouizi, K; Bereksi Reguig, F; Maaoui, C

    2011-01-01

    Emotion recognition is one of the great challenges in human-human and human-computer interaction. Accurate emotion recognition would allow computers to recognize human emotions and therefore react accordingly. In this paper, an approach for emotion recognition based on physiological signals is proposed. Six basic emotions: joy, sadness, fear, disgust, neutrality and amusement are analysed using physiological signals. These emotions are induced through the presentation of International Affecting Picture System (IAPS) pictures to the subjects. The physiological signals of interest in this analysis are: electromyogram signal (EMG), respiratory volume (RV), skin temperature (SKT), skin conductance (SKC), blood volume pulse (BVP) and heart rate (HR). These are selected to extract characteristic parameters, which will be used for classifying the emotions. The SVM (support vector machine) technique is used for classifying these parameters. The experimental results show that the proposed methodology provides in general a recognition rate of 85% for different emotional states.

  14. Signaling motifs and Weber's law.

    PubMed

    Ferrell, James E

    2009-12-11

    New experimental and theoretical studies reported by Uri Alon, Marc Kirschner, and colleagues in this issue of Molecular Cell suggest that Weber's law of sensory perception may apply to a number of cell signaling processes.

  15. INTRACELLULAR SIGNALING AND DEVELOPMENTAL NEUROTOXICITY.

    EPA Science Inventory

    A book chapter in ?Molecular Toxicology: Transcriptional Targets? reviewed the role of intracellular signaling in the developmental neurotoxicity of environmental chemicals. This chapter covered a number of aspects including the development of the nervous system, role of intrace...

  16. Cell Polarity Signaling in Arabidopsis

    PubMed Central

    Yang, Zhenbiao

    2009-01-01

    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 integrate both plant-specific and conserved polarity cues and to coordinate the cytoskeketon dynamics/reorganization and vesicular trafficking required for polarity establishment and maintenance. This review focuses upon signaling mechanisms for cell polarity formation in Arabidopsis, with an emphasis on Rho GTPase signaling in polarized cell growth and how these mechanisms compare with those for cell polarity signaling in yeast and animal systems. PMID:18837672

  17. Signal processing for semiconductor detectors

    SciTech Connect

    Goulding, F.S.; Landis, D.A.

    1982-02-01

    A balanced perspective is provided on the processing of signals produced by semiconductor detectors. The general problems of pulse shaping to optimize resolution with constraints imposed by noise, counting rate and rise time fluctuations are discussed.

  18. Genetic Analyses of Integrin Signaling

    PubMed Central

    Wickström, Sara A.; Radovanac, Korana; Fässler, Reinhard

    2011-01-01

    The development of multicellular organisms, as well as maintenance of organ architecture and function, requires robust regulation of cell fates. This is in part achieved by conserved signaling pathways through which cells process extracellular information and translate this information into changes in proliferation, differentiation, migration, and cell shape. Gene deletion studies in higher eukaryotes have assigned critical roles for components of the extracellular matrix (ECM) and their cellular receptors in a vast number of developmental processes, indicating that a large proportion of this signaling is regulated by cell-ECM interactions. In addition, genetic alterations in components of this signaling axis play causative roles in several human diseases. This review will discuss what genetic analyses in mice and lower organisms have taught us about adhesion signaling in development and disease. PMID:21421914

  19. Chloroplast signaling: retrograde regulation revelations.

    PubMed

    Beale, Samuel I

    2011-05-24

    Developing chloroplasts are able to communicate their status to the nucleus and regulate expression of genes whose products are needed for photosynthesis. Heme is revealed to be a signaling molecule for this retrograde communication.

  20. Insulin Signaling and Heart Failure.

    PubMed

    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.

  1. Sonar signal processing using probabilistic signal and ocean environmental models.

    PubMed

    Culver, R Lee; Camin, H John

    2008-12-01

    Acoustic signals propagating through the ocean are refracted, scattered, and attenuated by the ocean volume and boundaries. Many aspects of how the ocean affects acoustic propagation are understood, such that the characteristics of a received signal can often be predicted with some degree of certainty. However, acoustic ocean parameters vary with time and location in a manner that is not, and cannot be, precisely known; some uncertainty will always remain. For this reason, the characteristics of the received signal can never be precisely predicted and must be described in probabilistic terms. A signal processing structure recently developed relies on knowledge of the ocean environment to predict the statistical characteristics of the received signal, and incorporates this description into the processor in order to detect and classify targets. Acoustic measurements at 250 Hz from the 1996 Strait of Gibraltar Acoustic Monitoring Experiment are used to illustrate how the processor utilizes environmental data to classify source depth and to underscore the importance of environmental model fidelity and completeness.

  2. SignalPlant: an open signal processing software platform.

    PubMed

    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.

  3. CD28: a signalling perspective.

    PubMed Central

    Ward, S G

    1996-01-01

    CD28 and the related molecule cytotoxic T lymphocyte-associated molecule-4 (CTLA-4), together with their natural ligands B7.1 and B7.2, have been implicated in the differential regulation of several immune responses. CD28 provides signals during T cell activation which are required for the production of interleukin 2 and other cytokines and chemokines, and it has also been implicated in the regulation of T cell anergy and programmed T cell death. The biochemical signals provided by CD28 are cyclosporin A-resistant and complement those provided by the T cell antigen receptor to allow full activation of T cells. Multiple signalling cascades which may be independent of, or dependent on, protein tyrosine kinase activation have been demonstrated to be activated by CD28, including activation of phospholipase C, p21ran, phosphoinositide 3-kinase, sphingomyelinase/ceramide and 5-lipoxygenase. The relative contributions of these cascades to overall CD28 signalling are still unknown, but probably depend on the state of activation of the T cell and the level of CD28 activation. The importance of these signalling cascades (in particular the phosphoinositide 3-kinase-mediated cascade) to functional indications of CD28 activation, such as interleukin 2 gene regulation, has been investigated using pharmacological and genetic manipulations. These approaches have demonstrated that CD28-activated signalling cascades regulate several transcription factors involved in interleukin 2 transcriptional activation. This review describes in detail the structure and expression of the CD28 and B7 families, the functional outcomes of CD28 ligation and the signalling events that are thought to mediate these functions. PMID:8809021

  4. Kinase signalling in Huntington's disease.

    PubMed

    Bowles, Kathryn R; Jones, Lesley

    2014-01-01

    Alterations in numerous signal transduction pathways and aberrant activity of specific kinases have been identified in multiple cell and mouse models of Huntington's disease (HD), as well as in human HD brain. The balance and integration of a network of kinase signalling pathways is paramount for the regulation of a wide range of cellular and physiological processes, such as proliferation, differentiation, inflammation, neuronal plasticity and apoptosis. Unbalanced activity within these pathways provides a potential mechanism for many of the pathological phenotypes associated with HD, such as transcriptional dysregulation, inflammation and ultimately neurodegeneration. The characterisation of aberrant kinase signalling regulation in HD has been inconsistent and may be a result of failure to consider integration between multiple signalling pathways, as well as alterations that may occur over time with both age and disease progression. Collating the information about the effect of mHTT on signalling pathways demonstrates that it has wide ranging effects on multiple pro- and anti-apoptotic kinases, resulting in the dysregulation of numerous complex interactions within a dynamic network.

  5. Piezoelectric extraction of ECG signal

    PubMed Central

    Ahmad, Mahmoud Al

    2016-01-01

    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. PMID:27853180

  6. Biomedical signal and image processing.

    PubMed

    Cerutti, Sergio; Baselli, Giuseppe; Bianchi, Anna; Caiani, Enrico; Contini, Davide; Cubeddu, Rinaldo; Dercole, Fabio; Rienzo, Luca; Liberati, Diego; Mainardi, Luca; Ravazzani, Paolo; Rinaldi, Sergio; Signorini, Maria; Torricelli, Alessandro

    2011-01-01

    Generally, physiological modeling and biomedical signal processing constitute two important paradigms of biomedical engineering (BME): their fundamental concepts are taught starting from undergraduate studies and are more completely dealt with in the last years of graduate curricula, as well as in Ph.D. courses. Traditionally, these two cultural aspects were separated, with the first one more oriented to physiological issues and how to model them and the second one more dedicated to the development of processing tools or algorithms to enhance useful information from clinical data. A practical consequence was that those who did models did not do signal processing and vice versa. However, in recent years,the need for closer integration between signal processing and modeling of the relevant biological systems emerged very clearly [1], [2]. This is not only true for training purposes(i.e., to properly prepare the new professional members of BME) but also for the development of newly conceived research projects in which the integration between biomedical signal and image processing (BSIP) and modeling plays a crucial role. Just to give simple examples, topics such as brain–computer machine or interfaces,neuroengineering, nonlinear dynamical analysis of the cardiovascular (CV) system,integration of sensory-motor characteristics aimed at the building of advanced prostheses and rehabilitation tools, and wearable devices for vital sign monitoring and others do require an intelligent fusion of modeling and signal processing competences that are certainly peculiar of our discipline of BME.

  7. Calcium signaling in taste cells.

    PubMed

    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.

  8. Signalling in the genomic era.

    PubMed

    Lo Vasco, Vincenza Rita

    2010-10-01

    For a complex organism, short range signalling is not sufficient to coordinate the behaviour of all cells composing itself. The response to stimuli is the reprogramming of cell activity (resulting in differentiation, proliferation, stand by or apoptosis depending on the set of signals). Cells own elaborate and complex systems of proteins that enable them to communicate, including both secreted signalling molecules and related factors, deriving from relic mechanisms. The intra and intercellular signalling are actively studied not only to comprehend the basic mechanisms that allowed the evolution of mammals species on earth, but also because the alteration of one or more of these pathways is recognized to be involved in a crescent number of human diseases, both degenerative and tumoural. That is, a growing body of evidences suggest that every human disease may be analyzed and classified by a "signalling disease" point of view. This approach opens new therapeutic perspectives, virtually amplifying for every single disease the number of therapeutic targets (in terms of both genes and proteins) to upstream and/or downstream, short and/or long distance proteins interacting with the altered molecule, thus individuating many other targets to which act upon.

  9. Signalling in the genomic era

    PubMed Central

    2010-01-01

    For a complex organism, short range signalling is not sufficient to coordinate the behaviour of all cells composing itself. The response to stimuli is the reprogramming of cell activity (resulting in differentiation, proliferation, stand by or apoptosis depending on the set of signals). Cells own elaborate and complex systems of proteins that enable them to communicate, including both secreted signalling molecules and related factors, deriving from relic mechanisms. The intra and intercellular signalling are actively studied not only to comprehend the basic mechanisms that allowed the evolution of mammals species on earth, but also because the alteration of one or more of these pathways is recognized to be involved in a crescent number of human diseases, both degenerative and tumoural. That is, a growing body of evidences suggest that every human disease may be analyzed and classified by a “signalling disease” point of view. This approach opens new therapeutic perspectives, virtually amplifying for every single disease the number of therapeutic targets (in terms of both genes and proteins) to upstream and/or downstream, short and/or long distance proteins interacting with the altered molecule, thus individuating many other targets to which act upon. PMID:21063501

  10. 300 Area signal cable study

    SciTech Connect

    Whattam, J.W.

    1994-09-15

    This report was prepared to discuss the alternatives available for removing the 300 Area overhead signal cable system. This system, installed in 1969, has been used for various monitoring and communication signaling needs throughout the 300 Area. Over the years this cabling system has deteriorated, has been continually reconfigured, and has been poorly documented to the point of nonreliability. The first step was to look at the systems utilizing the overhead signal cable that are still required for operation. Of the ten systems that once operated via the signal cable, only five are still required; the civil defense evacuation alarms, the public address (PA) system, the criticality alarms, the Pacific Northwest Laboratory Facilities Management Control System (FMCS), and the 384 annunciator panel. Of these five, the criticality alarms and the FMCS have been dealt with under other proposals. Therefore, this study focused on the alternatives available for the remaining three systems (evacuation alarms, PA system, and 384 panel) plus the accountability aid phones. Once the systems to be discussed were determined, then three alternatives for providing the signaling pathway were examined for each system: (1) re-wire using underground communication ducts, (2) use the Integrated Voice/Data Telecommunications System (IVDTS) already installed and operated by US West, and (3) use radio control. Each alternative was developed with an estimated cost, advantages, and disadvantages. Finally, a recommendation was provided for the best alternative for each system.

  11. Polarization signals in mantis shrimps

    NASA Astrophysics Data System (ADS)

    Cronin, Thomas W.; Chiou, Tsyr-Huei; Caldwell, Roy L.; Roberts, Nicholas; Marshall, Justin

    2009-08-01

    While color signals are well known as a form of animal communication, a number of animals communicate using signals based on patterns of polarized light reflected from specialized body parts or structures. Mantis shrimps, a group of marine crustaceans, have evolved a great diversity of such signals, several of which are based on photonic structures. These include resonant scattering devices, structures based on layered dichroic molecules, and structures that use birefringent layers to produce circular polarization. Such biological polarizers operate in different spectral regions ranging from the near-UV to medium wavelengths of visible light. In addition to the structures that are specialized for signal production, the eyes of many species of mantis shrimp are adapted to detect linearly polarized light in the ultraviolet and in the green, using specialized sets of photoreceptors with oriented, dichroic visual pigments. Finally, a few mantis shrimp species produce biophotonic retarders within their photoreceptors that permit the detection of circularly polarized light and are thus the only animals known to sense this form of polarization. Mantis shrimps use polarized light in species-specific signals related to mating and territorial defense, and their means of manipulating light's polarization can inspire designs for artificial polarizers and achromatic retarders.

  12. Mathematical model for classification of EEG signals

    NASA Astrophysics Data System (ADS)

    Ortiz, Victor H.; Tapia, Juan J.

    2015-09-01

    A mathematical model to filter and classify brain signals from a brain machine interface is developed. The mathematical model classifies the signals from the different lobes of the brain to differentiate the signals: alpha, beta, gamma and theta, besides the signals from vision, speech, and orientation. The model to develop further eliminates noise signals that occur in the process of signal acquisition. This mathematical model can be used on different platforms interfaces for rehabilitation of physically handicapped persons.

  13. The Yeast Sphingolipid Signaling Landscape

    PubMed Central

    Montefusco, David J.; Matmati, Nabil

    2014-01-01

    Sphingolipids are recognized as signaling mediators in a growing number of pathways, and represent potential targets to address many diseases. The study of sphingolipid signaling in yeast has created a number of breakthroughs in the field, and has the potential to lead future advances. The aim of this article is to provide an inclusive view of two major frontiers in yeast sphingolipid signaling. In the first section, several key studies in the field of sphingolipidomics are consolidated to create a yeast sphingolipidome that ranks nearly all known sphingolipid species by their level in a resting yeast cell. The second section presents an overview of most known phenotypes identified for sphingolipid gene mutants, presented with the intention of illuminating not yet discovered connections outside and inside of the field. PMID:24220500

  14. Using abstract language signals power.

    PubMed

    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.

  15. Hedgehog signaling and gastrointestinal cancer

    PubMed Central

    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

  16. Multiscale Representation of Genomic Signals

    PubMed Central

    Knijnenburg, Theo A.; Ramsey, Stephen A.; Berman, Benjamin P.; Kennedy, Kathleen A.; Smit, Arian F.A.; Wessels, Lodewyk F.A.; Laird, Peter W.; Aderem, Alan; Shmulevich, Ilya

    2014-01-01

    Genomic information is encoded on a wide range of distance scales, ranging from tens of base pairs to megabases. We developed a multiscale framework to analyze and visualize the information content of genomic signals. Different types of signals, such as GC content or DNA methylation, are characterized by distinct patterns of signal enrichment or depletion across scales spanning several orders of magnitude. These patterns are associated with a variety of genomic annotations, including genes, nuclear lamina associated domains, and repeat elements. By integrating the information across all scales, as compared to using any single scale, we demonstrate improved prediction of gene expression from Polymerase II chromatin immunoprecipitation sequencing (ChIP-seq) measurements and we observed that gene expression differences in colorectal cancer are not most strongly related to gene body methylation, but rather to methylation patterns that extend beyond the single-gene scale. PMID:24727652

  17. Smoke signals and seed dormancy

    PubMed Central

    Waters, Mark T; Nelson, David C

    2011-01-01

    The Arabidopsis thaliana F-box protein MAX2 has been discovered in four separate genetic screens, indicating that it has roles in leaf senescence, seedling photosensitivity, shoot outgrowth and seed germination. Both strigolactones and karrikins can regulate A. thaliana seed germination and seedling photomorphogenesis in a MAX2-dependent manner, but only strigolactones inhibit shoot branching. How MAX2 mediates specific responses to both classes of structurally-related signals, and the origin of its dual role remains unknown. The moss Physcomitrella patens utilizes strigolactones and MAX2 orthologs are present across the land plants, suggesting that this signaling system could have an ancient origin. The seed of parasitic Orobanchaceae species germinate preferentially in response to strigolactones over karrikins, and putative Orobanchaceae MAX2 orthologs form a sub-clade distinct from those of other dicots. These observations suggest that lineage-specific evolution of MAX2 may have given rise to specialized responses to these signaling molecules. PMID:22019642

  18. Intelligent signal analysis and recognition

    NASA Technical Reports Server (NTRS)

    Levinson, Robert; Helman, Daniel; Oswalt, Edward

    1987-01-01

    Progress in the research and development of self-organizing database system that can support the identification and characterization of signals in an RF environment is described. As the radio frequency spectrum becomes more crowded, there are a number of situations that require a characterization of the RF environment. This database system is designed to be practical in applications where communications and other instruments encounter a time varying and complex RF environment. The primary application of this system is the guidance and control of NASA's SETI Microwave Observing Project. Other possible applications include selection of telemety bands for communication with spacecraft, and the scheduling of antenna for radio astronomy are two examples where characterization of the RF environment is required. In these applications, the RF environment is constantly changing, and even experienced operators cannot quickly identify the multitude of signals that can be encountered. Some of these signals are repetitive, others appear to occur sporadically.

  19. Competing signals drive telencephalon diversity.

    PubMed

    Sylvester, J B; Rich, C A; Yi, C; Peres, J N; Houart, C; Streelman, J T

    2013-01-01

    The telencephalon is the most complex brain region, controlling communication, emotion, movement and memory. Its adult derivatives develop from the dorsal pallium and ventral subpallium. Despite knowledge of genes required in these territories, we do not understand how evolution has shaped telencephalon diversity. Here, using rock- and sand-dwelling cichlid fishes from Lake Malawi, we demonstrate that differences in strength and timing of opposing Hedgehog and Wingless signals establish evolutionary divergence in dorsal-ventral telencephalon patterning. Rock dwellers exhibit early, extensive Hedgehog activity in the ventral forebrain resulting in expression of foxg1 before dorsal Wingless signals, and a larger subpallium. Sand dwellers show rapid deployment of Wingless, later foxg1 expression and a larger pallium. Manipulation of the Hedgehog and Wingless pathways in cichlid and zebrafish embryos is sufficient to mimic differences between rock- versus sand-dweller brains. Our data suggest that competing ventral Hedgehog and dorsal Wingless signals mediate evolutionary diversification of the telencephalon.

  20. [Leptin Signalings and Leptin Resistance].

    PubMed

    Yang, Xiao-Ning; Zhang, Chen-Yu; Wang Bing-Wei; Zhu, Shi-Gong; Zheng, Rui-Mao

    2015-10-01

    Leptin plays a critical role in the regulation of energy balance and metabolic homeostasis. Impairment of leptin function is closely involved in the pathogenesis of obesity, diabetes mellitus and some other metabolic diseases. Leptin initiates intracellular signal transductions in the leptin-receptor-expressing neurons in the central nervous system to exert its physiological functions. The fact that high circulating levels of leptin partially or completely fail to promote weight loss in obesity has given rise to the notion of "leptin resistance". Recently, the impairment of leptin signalings in the hypothalamus has been regarded as a critical contributor to leptin resistance. In this review, the studies on leptin signaling and leptin resistance are summarized with an emphasis on the progress made during the last five years.

  1. Epigenetic Mechanisms of Serotonin Signaling.

    PubMed

    Holloway, Terrell; González-Maeso, Javier

    2015-07-15

    Histone modifications and DNA methylation represent central dynamic and reversible processes that regulate gene expression and contribute to cellular phenotypes. These epigenetic marks have been shown to play fundamental roles in a diverse set of signaling and behavioral outcomes. Serotonin is a monoamine that regulates numerous physiological responses including those in the central nervous system. The cardinal signal transduction mechanisms via serotonin and its receptors are well established, but fundamental questions regarding complex interactions between the serotonin system and heritable epigenetic modifications that exert control on gene function remain a topic of intense research and debate. This review focuses on recent advances and contributions to our understanding of epigenetic mechanisms of serotonin receptor-dependent signaling, with focus on psychiatric disorders such as schizophrenia and depression.

  2. EGFR signaling in renal fibrosis

    PubMed Central

    Zhuang, Shougang; Liu, Na

    2014-01-01

    Signaling through the epidermal growth factor receptor (EGFR) is involved in regulation of multiple biological processes, including proliferation, metabolism, differentiation, and survival. Owing to its aberrant expression in a variety of malignant tumors, EGFR has been recognized as a target in anticancer therapy. Increasingly, evidence from animal studies indicates that EGFR signaling is also implicated in the development and progression of renal fibrosis. The therapeutic value of EGFR inhibition has not yet been evaluated in human kidney disease. In this article, we summarize recent research into the role of EGFR signaling in renal fibrogenesis, discuss the mechanism by which EGFR regulates this process, and consider the potential of EGFR as an antifibrotic target. PMID:26312153

  3. Chloroplast retrograde signal regulates flowering

    PubMed Central

    Feng, Peiqiang; Guo, Hailong; Chi, Wei; Chai, Xin; Sun, Xuwu; Xu, Xiumei; Ma, Jinfang; Rochaix, Jean-David; Leister, Dario; Wang, Haiyang; Lu, Congming; Zhang, Lixin

    2016-01-01

    Light is a major environmental factor regulating flowering time, thus ensuring reproductive success of higher plants. In contrast to our detailed understanding of light quality and photoperiod mechanisms involved, the molecular basis underlying high light-promoted flowering remains elusive. Here we show that, in Arabidopsis, a chloroplast-derived signal is critical for high light-regulated flowering mediated by the FLOWERING LOCUS C (FLC). We also demonstrate that PTM, a PHD transcription factor involved in chloroplast retrograde signaling, perceives such a signal and mediates transcriptional repression of FLC through recruitment of FVE, a component of the histone deacetylase complex. Thus, our data suggest that chloroplasts function as essential sensors of high light to regulate flowering and adaptive responses by triggering nuclear transcriptional changes at the chromatin level. PMID:27601637

  4. Digital signal processor and programming system for parallel signal processing

    SciTech Connect

    Van den Bout, D.E.

    1987-01-01

    This thesis describes an integrated assault upon the problem of designing high-throughput, low-cost digital signal-processing systems. The dual prongs of this assault consist of: (1) the design of a digital signal processor (DSP) which efficiently executes signal-processing algorithms in either a uniprocessor or multiprocessor configuration, (2) the PaLS programming system which accepts an arbitrary algorithm, partitions it across a group of DSPs, synthesizes an optimal communication link topology for the DSPs, and schedules the partitioned algorithm upon the DSPs. The results of applying a new quasi-dynamic analysis technique to a set of high-level signal-processing algorithms were used to determine the uniprocessor features of the DSP design. For multiprocessing applications, the DSP contains an interprocessor communications port (IPC) which supports simple, flexible, dataflow communications while allowing the total communication bandwidth to be incrementally allocated to achieve the best link utilization. The net result is a DSP with a simple architecture that is easy to program for both uniprocessor and multi-processor modes of operation. The PaLS programming system simplifies the task of parallelizing an algorithm for execution upon a multiprocessor built with the DSP.

  5. Expected geoneutrino signal at JUNO

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    Constraints on the Earth's composition and on its radiogenic energy budget come from the detection of geoneutrinos. The Kamioka Liquid scintillator Antineutrino Detector (KamLAND) and Borexino experiments recently reported the geoneutrino flux, which reflects the amount and distribution of U and Th inside the Earth. The Jiangmen Underground Neutrino Observatory (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, each one having a planned thermal power of approximately 18 GW. Given the large detector mass and the intense reactor antineutrino flux, JUNO aims not only 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 terrestrial neutrino unit (TNU), based on the existing reference Earth model, with the dominant source of uncertainty coming from the modeling of the compositional variability in the local upper crust that surrounds (out to approximately 500 km) the detector. A special focus is dedicated to the 6° × 4° local crust surrounding the detector which is estimated to contribute for the 44% of the signal. On the basis of a worldwide reference model for reactor antineutrinos, the ratio between reactor antineutrino and geoneutrino signals in the geoneutrino energy window is estimated to be 0.7 considering reactors operating in year 2013 and reaches a value of 8.9 by adding the contribution of the future nuclear power plants. In order to extract useful information about the mantle's composition, a refinement of the abundance and distribution of U and Th in the local crust is required, with particular attention to the geochemical characterization of the accessible upper crust where 47% of the expected geoneutrino signal originates and this region contributes

  6. Ascaroside signaling in C. elegans.

    PubMed

    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.

  7. Ascaroside signaling in C. elegans.

    PubMed Central

    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 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. PMID:23355522

  8. Ubiquitin signaling in immune responses

    PubMed Central

    Hu, Hongbo; Sun, Shao-Cong

    2016-01-01

    Ubiquitination has emerged as a crucial mechanism that regulates signal transduction in diverse biological processes, including different aspects of immune functions. Ubiquitination regulates pattern-recognition receptor signaling that mediates both innate immune responses and dendritic cell maturation required for initiation of adaptive immune responses. Ubiquitination also regulates the development, activation, and differentiation of T cells, thereby maintaining efficient adaptive immune responses to pathogens and immunological tolerance to self-tissues. Like phosphorylation, ubiquitination is a reversible reaction tightly controlled by the opposing actions of ubiquitin ligases and deubiquitinases. Deregulated ubiquitination events are associated with immunological disorders, including autoimmune and inflammatory diseases. PMID:27012466

  9. Time scale independent signal transmission

    NASA Astrophysics Data System (ADS)

    Faltin, L.

    1980-05-01

    The paper presents a method which permits the conversion of time scale variations occurring during signal transmission into time shifts proportionally related to these variations. It is demonstrated that the method can be used to reject the adverse effects of the time scale variations (such as wow and flutter in magnetic tape recordings) and/or to determine the scale change exactly (such as would be required in Doppler signal processing). Finally, it is noted that since the system performance degrades with rising frequency of the time scale distortions, an upper bound for this frequency is derived.

  10. Interception of LPI Radar Signals

    DTIC Science & Technology

    1991-11-01

    AD-A246 315!I! I!! II I’ IIi INTERCEPTION OF LPI RADAR SIGNALS (U) by Jim P.Y. Lee DEFENCE RESEARCH ESTABLISHMENT OTTAWA TECHNICAL NOTE 91-23 Canadd...November 1991Ottawa 92-041269’ 2 2 18 II.2t1111111I 111111! !_ 1+1 efrc nadonds INTERCEPTION OF LPI RADAR SIGNALS (U) by Jim P.Y. Lee Radar E"Sect&ion... radar may employ against current EW receivers. The general conclusion is that it is possible to design a LPI radar which is effective against current

  11. Pharmacology of intracellular signalling pathways

    PubMed Central

    Nahorski, Stefan R

    2006-01-01

    This article provides a brief and somewhat personalized review of the dramatic developments that have occurred over the last 45 years in our understanding of intracellular signalling pathways associated with G-protein-coupled receptor activation. Signalling via cyclic AMP, the phosphoinositides and Ca2+ is emphasized and these systems have already been revealed as new pharmacological targets. The therapeutic benefits of most of such targets are, however, yet to be realized, but it is certain that the discipline of pharmacology needs to widen its boundaries to meet these challenges in the future. PMID:16402119

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Tyrosine Phosphorylation in Brassinosteroid Signaling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brassinosteroids (BRs) regulate plant growth and development through a complex signal transduction pathway involving BRASSINOSTEROID INSENSITIVE 1 (BRI1), which is the BR receptor, and its co-receptor BRI1-ASSOCIATED KINASE 1 (BAK1). Both proteins are classified as Ser/Thr protein kinases. Recently,...

  14. Cognitive Algorithms for Signal Processing

    DTIC Science & Technology

    2011-03-18

    63] L. I. Perlovsky and R. Kozma. Eds. Neurodynamics of Higher-Level Cognition and Consciousness. Heidelberg, Germany: Springer-Verlag, 2007. [64...AFRL-RY-HS-TR-2011-0013 ________________________________________________________________________ Cognitive Algorithms for Signal Processing...in more details in [46]. ..................................... 16  1 Abstract Processes in the mind: perception, cognition

  15. Deconstructing Signaling in Three Dimensions

    PubMed Central

    2015-01-01

    Cells in vivo exist within the context of a multicellular tissue, where their behavior is governed by homo- and heterotypic cell–cell interactions, the material properties of the extracellular matrix, and the distribution of various soluble and physical factors. Most methods currently used to study and manipulate cellular behavior in vitro, however, sacrifice physiological relevance for experimental expediency. The fallacy of such approaches has been highlighted by the recent development and application of three-dimensional culture models to cell biology, which has revealed striking phenotypic differences in cell survival, migration, and differentiation in genetically identical cells simply by varying culture conditions. These perplexing findings beg the question of what constitutes a three-dimensional culture and why cells behave so differently in two- and three-dimensional culture formats. In the following review, we dissect the fundamental differences between two- and three-dimensional culture conditions. We begin by establishing a basic definition of what “three dimensions” means at different biological scales and discuss how dimensionality influences cell signaling across different length scales. We identify which three-dimensional features most potently influence intracellular signaling and distinguish between conserved biological principles that are maintained across culture conditions and cellular behaviors that are sensitive to microenvironmental context. Finally, we highlight state-of-the-art molecular tools amenable to the study of signaling in three dimensions under conditions that facilitate deconstruction of signaling in a more physiologically relevant manner. PMID:24649923

  16. Loco signaling pathway in longevity.

    PubMed

    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.

  17. Eliminating ambiguity in digital signals

    NASA Technical Reports Server (NTRS)

    Weber, W. J., III

    1979-01-01

    Multiamplitude minimum shift keying (mamsk) transmission system, method of differential encoding overcomes problem of ambiguity associated with advanced digital-transmission techniques with little or no penalty in transmission rate, error rate, or system complexity. Principle of method states, if signal points are properly encoded and decoded, bits are detected correctly, regardless of phase ambiguities.

  18. Text Signals Influence Team Artifacts

    ERIC Educational Resources Information Center

    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…

  19. Meeting Report: Teaching Signal Transduction

    ERIC Educational Resources Information Center

    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…

  20. Insulin Signalling: The Inside Story.

    PubMed

    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.

  1. Signals Intelligence - Processing - Analysis - Classification

    DTIC Science & Technology

    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

  2. Intelligent sensing of EEG signals

    NASA Astrophysics Data System (ADS)

    Siddiqui, Khalid J.; Collins, Leslie E.; Fitzpatrick, Dennis; Hendricks, Shelton; Hay, D. Robert; Suen, Ching Y.

    1990-11-01

    Although physician observation is usually the most sensitive method for diagnosing and monitoring a patient''s medical condition human observation cannot be conducted continuously and consistently. It can be helpful therefore to employ specialized automated techniques for the continuous reliable and noninvasive monitoring of those parameters useful for the enhancement of physicians'' diagnostic capabilities. Signal processing systems are among the most powerful of those techniques currently available for noninvasively examining the internal structure of living biological systems. Nonetheless the capability of these systems can be substantially enhanced if supplemented with automated classification and interpretation precedures. An intelligent EEG signal sensing and interpretation system using typical signal processing techniques supplemented with heuristics and identification techniques has been designed. The system is comprised of five major components namely: the fact gathering system the knowledge/rule base the knowledge organization/learning phase the inference engine and the expert/user interface. The fact gathering system collects raw waveforms preprocesses these for noise elimination and extracts the pertinent information from the waveforms. The knowledge/rule base is an information and knowledge bank wherein the appropriate knowledge parameters useful for the decision making process are stored. The knowledge organization/learning phase structures the knowledge In the order determined by the association among pattern classes and trains the Inference engine. The structure of the inference engine is based on a hierarchical pattern classifier which categorizes the unknown signals using a layered decision making strategy

  3. Velocimetry signal synthesis with fringen.

    SciTech Connect

    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.

  4. Signal Prediction With Input Identification

    NASA Technical Reports Server (NTRS)

    Juang, Jer-Nan; Chen, Ya-Chin

    1999-01-01

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

  5. Nitric oxide signaling in yeast.

    PubMed

    Astuti, Rika Indri; Nasuno, Ryo; Takagi, Hiroshi

    2016-11-01

    As a cellular signaling molecule, nitric oxide (NO) is widely conserved from microorganisms, such as bacteria, yeasts, and fungi, to higher eukaryotes including plants and mammals. NO is mainly produced by NO synthase (NOS) or nitrite reductase (NIR) activity. There are several NO detoxification systems, including NO dioxygenase (NOD) and S-nitrosoglutathione reductase (GSNOR). NO homeostasis based on the balance between NO synthesis and degradation is important for the regulation of its physiological functions because an excess level of NO causes nitrosative stress due to the high reactivity of NO and NO-derived compounds. In yeast, NO may be involved in stress responses, but NO and its signaling have been poorly understood due to the lack of mammalian NOS orthologs in the genome. Even though the activities of NOS and NIR have been observed in yeast cells, the gene encoding NOS and the NO production mechanism catalyzed by NIR remain unclear. On the other hand, yeast cells employ NOD and GSNOR to maintain an intracellular redox balance following endogenous NO production, exogenous NO treatment, or environmental stresses. This article reviews NO metabolism (synthesis, degradation) and its regulation in yeast. The physiological roles of NO in yeast, including the oxidative stress response, are also discussed here. Such investigations into NO signaling are essential for understanding the NO-dependent genetic and physiological modulations. In addition to being responsible for the pathology and pharmacology of various degenerative diseases, NO signaling may be a potential target for the construction and engineering of industrial yeast strains.

  6. Signal processing in eukaryotic chemotaxis

    NASA Astrophysics Data System (ADS)

    Segota, Igor; Rachakonda, Archana; Franck, Carl

    2013-03-01

    Unlike inanimate condensed matter, living cells depend upon the detection of chemical signals for their existence. First, we experimentally determined the chemotaxis response of eukaryotic Dictyostelium cells to static folic acid gradients and show that they can respond to gradients as shallow as 0.2% across the cell body. Second, using Shannon's information theory, we showed that the information cells receive about the gradient exceeds the theoretically predicted information at the receptor-ligand binding step, resulting in the violation of the data processing inequality. Finally, we analyzed how eukaryotic cells can affect the gradient signals by secreting enzymes that degrade the signal. We analyzed this effect with a focus on a well described Dictyostelium cAMP chemotaxis system where cAMP signals are affected by an extracellular cAMP phosphodiesterase (PDE) and its inhibitor (PDI). Using a reaction-diffusion model of this set of interactions in the extracellular space, we show that cells can effectively sense much steeper chemical gradients than naively expected (up to a factor of 12). We also found that the rough estimates of experimental PDE and PDI secretion rates are close to the optimal values for gradient sensing as predicted by our model.

  7. Multipactor theory for multicarrier signals

    SciTech Connect

    Anza, S.; Vicente, C.; Gil, J.; Raboso, D.; Boria, V. E.

    2011-03-15

    This work presents a new theory of multipactor under multicarrier signals for parallel-plate geometries, assuming a homogeneous electric field and one-dimensional electron motion. It is the generalization of the nonstationary multipactor theory for single-carrier signals [S. Anza et al.,Phys. Plasmas 17, 062110 (2010)]. It is valid for multicarrier signals with an arbitrary number of carriers with different amplitude, arbitrary frequency, and phase conditions and for any material coating. This new theory is able to model the real dynamics of the electrons during the multipactor discharge for both single and double surface interactions. Among other parameters of the discharge, it calculates the evolution in time of the charge growth, electron absorption, and creation rates as well as the instantaneous secondary emission yield and order. An extensive set of numerical tests with particle-in-cell software has been carried out in order to validate the theory under many different conditions. This theoretical development constitutes the first multipactor theory which completely characterizes the multipactor discharge for arbitrary multicarrier signals, setting the first step for further investigations in the field.

  8. Purinergic signaling in schistosomal infection.

    PubMed

    Silva, Claudia Lucia Martins

    2016-10-01

    Human schistosomiasis is a chronic inflammatory disease caused by blood fluke worms belonging to the genus Schistosoma. Health metrics indicate that the disease is related to an elevated number of years lost-to-disability and years lost-to-life. Schistosomiasis is an intravascular disease that is related to a Th1 and Th2 immune response polarization, and the degree of polarization affects the outcome of the disease. The purinergic system is composed of adenosine and nucleotides acting as key messenger molecules. Moreover, nucleotide-transforming enzymes and cell-surface purinergic receptors are obligatory partners of this purinergic signaling. In mammalian cells, purinergic signaling modulates innate immune responses and inflammation among other functions; conversely purinergic signaling may also be modulated by inflammatory mediators. Moreover, schistosomes also express some enzymes of the purinergic system, and it is possible that worms modulate host purinergic signaling. Current data obtained in murine models of schistosomiasis support the notion that the host purinergic system is altered by the disease. The dysfunction of adenosine receptors, metabotropic P2Y and ionotropic P2X7 receptors, and NTPDases likely contributes to disease morbidity.

  9. Phosphorylation in halobacterial signal transduction.

    PubMed Central

    Rudolph, J; Tolliday, N; Schmitt, C; Schuster, S C; Oesterhelt, D

    1995-01-01

    Regulated phosphorylation of proteins has been shown to be a hallmark of signal transduction mechanisms in both Eubacteria and Eukarya. Here we demonstrate that phosphorylation and dephosphorylation are also the underlying mechanism of chemo- and phototactic signal transduction in Archaea, the third branch of the living world. Cloning and sequencing of the region upstream of the cheA gene, known to be required for chemo- and phototaxis in Halobacterium salinarium, has identified cheY and cheB analogs which appear to form part of an operon which also includes cheA and the following open reading frame of 585 nucleotides. The CheY and CheB proteins have 31.3 and 37.5% sequence identity compared with the known signal transduction proteins CheY and CheB from Escherichia coli, respectively. The biochemical activities of both CheA and CheY were investigated following their expression in E.coli, isolation and renaturation. Wild-type CheA could be phosphorylated in a time-dependent manner in the presence of [gamma-32P]ATP and Mg2+, whereas the mutant CheA(H44Q) remained unlabeled. Phosphorylated CheA was dephosphorylated rapidly by the addition of wild-type CheY. The mutant CheY(D53A) had no effect on phosphorylated CheA. The mechanism of chemo- and phototactic signal transduction in the Archaeon H.salinarium, therefore, is similar to the two-component signaling system known from chemotaxis in the eubacterium E.coli. Images PMID:7556066

  10. Males adjust their signalling behaviour according to experience of male signals and male-female signal duets.

    PubMed

    Rebar, D; Rodríguez, R L

    2016-04-01

    Sexual signals are conspicuous sources of information about neighbouring competitors, and species in which males and females signal during pair formation provide various sources of public information to which individuals can adjust their behaviour. We performed two experiments with a duetting vibrational insect, Enchenopa binotata treehoppers (Hemiptera: Membracidae), to ask whether males adjust their signalling behaviour according to (1a) their own experience of competitors' signals, (1b) how females adjust their mate preferences on the basis of their experience of male signals (described in prior work), and/or (2) their own experience of female response signals to competitors' signals. We presented males with synthetic male signals of different frequencies and combinations thereof for 2 weeks. We recorded males a day after their last signal exposure, finding that (1a) male signal rate increased in response to experience of attractive competitors, but that (1b) male signal frequency did not shift in a manner consistent with how females adjust their mate preferences in those experience treatments. Second, we presented males with different male-female duets for 2 weeks, finding that (2) male signal length increased from experience of female duets with attractive competitors. Males thus make two types of adjustment according to two sources of public information: one provided by experience of male signals and another by experience of female responses to male signals. Signalling plasticity can generate feedback loops between the adjustments that males and females make, and we discuss the potential consequences of such feedback loops for the evolution of communication systems.

  11. Neural Network Classification of Cerebral Embolic Signals

    DTIC Science & Technology

    2007-11-02

    application of new signal processing techniques to the analysis and classification of embolic signals. We applied a Wavelet Neural Network algorithm...to approximate the embolic signals, with the parameters of the wavelet nodes being used to train a Neural Network to classify these signals as resulting from normal flow, or from gaseous or solid emboli.

  12. On the Spectrum of Periodic Signals

    ERIC Educational Resources Information Center

    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…

  13. Blood pressure reprogramming adapter assists signal recording

    NASA Technical Reports Server (NTRS)

    Vick, H. A.

    1967-01-01

    Blood pressure reprogramming adapter separates the two components of a blood pressure signal, a dc pressure signal and an ac Korotkoff sounds signal, so that the Korotkoff sounds are recorded on one channel as received while the dc pressure signal is converted to FM and recorded on a second channel.

  14. Signal Reception via Multi-Platform Receivers

    DTIC Science & Technology

    2012-09-01

    interference cancellation, multi-platform receivers, signal collection, signal interception 15. NUMBER OF PAGES 71 16. PRICE CODE 17. SECURITY ...CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION OF THIS PAGE Unclassified 19. SECURITY CLASSIFICATION OF ABSTRACT Unclassified...Quadrature Phase Shift Keying SIC Successive Interference Cancellation SNR Signal-To-Noise Ratio SOI Signal Of Interest WLAN Wireless Local Area

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

    PubMed

    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.

  16. Empirical mode decomposition for analyzing acoustical signals

    NASA Technical Reports Server (NTRS)

    Huang, Norden E. (Inventor)

    2005-01-01

    The present invention discloses a computer implemented signal analysis method through the Hilbert-Huang Transformation (HHT) for analyzing acoustical signals, which are assumed to be nonlinear and nonstationary. The Empirical Decomposition Method (EMD) and the Hilbert Spectral Analysis (HSA) are used to obtain the HHT. Essentially, the acoustical signal will be decomposed into the Intrinsic Mode Function Components (IMFs). Once the invention decomposes the acoustic signal into its constituting components, all operations such as analyzing, identifying, and removing unwanted signals can be performed on these components. Upon transforming the IMFs into Hilbert spectrum, the acoustical signal may be compared with other acoustical signals.

  17. Optically isolated signal coupler with linear response

    DOEpatents

    Kronberg, James W.

    1994-01-01

    An optocoupler for isolating electrical signals that translates an electrical input signal linearly to an electrical output signal. The optocoupler comprises a light emitter, a light receiver, and a light transmitting medium. The light emitter, preferably a blue, silicon carbide LED, is of the type that provides linear, electro-optical conversion of electrical signals within a narrow wavelength range. Correspondingly, the light receiver, which converts light signals to electrical signals and is preferably a cadmium sulfide photoconductor, is linearly responsive to light signals within substantially the same wavelength range as the blue LED.

  18. FAT SIGNALS - Lipases and Lipolysis in Lipid Metabolism and Signaling

    PubMed Central

    Zechner, Rudolf; Zimmermann, Robert; Eichmann, Thomas O.; Kohlwein, Sepp D.; Haemmerle, Guenter; Lass, Achim; Madeo, Frank

    2012-01-01

    Lipolysis is defined as the catabolism of triacylglycerols stored in cellular lipid droplets. Recent discoveries of essential lipolytic enzymes and characterization of numerous regulatory proteins and mechanisms have fundamentally changed our perception of lipolysis and its impact on cellular metabolism. New findings that lipolytic products and intermediates participate in cellular signaling processes and that “lipolytic signaling” is particularly important in many nonadipose tissues unveil a previously underappreciated aspect of lipolysis, which may be relevant for human disease. PMID:22405066

  19. Cleavage of Signal Regulatory Protein α (SIRPα) Enhances Inflammatory Signaling.

    PubMed

    Londino, James D; Gulick, Dexter; Isenberg, Jeffrey S; Mallampalli, Rama K

    2015-12-25

    Signal regulatory protein α (SIRPα) is a membrane glycoprotein immunoreceptor abundant in cells of monocyte lineage. SIRPα ligation by a broadly expressed transmembrane protein, CD47, results in phosphorylation of the cytoplasmic immunoreceptor tyrosine-based inhibitory motifs, resulting in the inhibition of NF-κB signaling in macrophages. Here we observed that proteolysis of SIRPα during inflammation is regulated by a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10), resulting in the generation of a membrane-associated cleavage fragment in both THP-1 monocytes and human lung epithelia. We mapped a charge-dependent putative cleavage site near the membrane-proximal domain necessary for ADAM10-mediated cleavage. In addition, a secondary proteolytic cleavage within the membrane-associated SIRPα fragment by γ-secretase was identified. Ectopic expression of a SIRPα mutant plasmid encoding a proteolytically resistant form in HeLa cells inhibited activation of the NF-κB pathway and suppressed STAT1 phosphorylation in response to TNFα to a greater extent than expression of wild-type SIRPα. Conversely, overexpression of plasmids encoding the proteolytically cleaved SIRPα fragments in cells resulted in enhanced STAT-1 and NF-κB pathway activation. Thus, the data suggest that combinatorial actions of ADAM10 and γ-secretase on SIRPα cleavage promote inflammatory signaling.

  20. Cleavage of Signal Regulatory Protein α (SIRPα) Enhances Inflammatory Signaling*

    PubMed Central

    Londino, James D.; Gulick, Dexter; Isenberg, Jeffrey S.; Mallampalli, Rama K.

    2015-01-01

    Signal regulatory protein α (SIRPα) is a membrane glycoprotein immunoreceptor abundant in cells of monocyte lineage. SIRPα ligation by a broadly expressed transmembrane protein, CD47, results in phosphorylation of the cytoplasmic immunoreceptor tyrosine-based inhibitory motifs, resulting in the inhibition of NF-κB signaling in macrophages. Here we observed that proteolysis of SIRPα during inflammation is regulated by a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10), resulting in the generation of a membrane-associated cleavage fragment in both THP-1 monocytes and human lung epithelia. We mapped a charge-dependent putative cleavage site near the membrane-proximal domain necessary for ADAM10-mediated cleavage. In addition, a secondary proteolytic cleavage within the membrane-associated SIRPα fragment by γ-secretase was identified. Ectopic expression of a SIRPα mutant plasmid encoding a proteolytically resistant form in HeLa cells inhibited activation of the NF-κB pathway and suppressed STAT1 phosphorylation in response to TNFα to a greater extent than expression of wild-type SIRPα. Conversely, overexpression of plasmids encoding the proteolytically cleaved SIRPα fragments in cells resulted in enhanced STAT-1 and NF-κB pathway activation. Thus, the data suggest that combinatorial actions of ADAM10 and γ-secretase on SIRPα cleavage promote inflammatory signaling. PMID:26534964

  1. Database for LDV Signal Processor Performance Analysis

    NASA Technical Reports Server (NTRS)

    Baker, Glenn D.; Murphy, R. Jay; Meyers, James F.

    1989-01-01

    A comparative and quantitative analysis of various laser velocimeter signal processors is difficult because standards for characterizing signal bursts have not been established. This leaves the researcher to select a signal processor based only on manufacturers' claims without the benefit of direct comparison. The present paper proposes the use of a database of digitized signal bursts obtained from a laser velocimeter under various configurations as a method for directly comparing signal processors.

  2. Nuclear sensor signal processing circuit

    DOEpatents

    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.

  3. DNA signals at isoform promoters

    PubMed Central

    Dai, Zhiming; Xiong, Yuanyan; Dai, Xianhua

    2016-01-01

    Transcriptional heterogeneity is extensive in the genome, and most genes express variable transcript isoforms. However, whether variable transcript isoforms of one gene are regulated by common promoter elements remain to be elucidated. Here, we investigated whether isoform promoters of one gene have separated DNA signals for transcription and translation initiation. We found that TATA box and nucleosome-disfavored DNA sequences are prevalent in distinct transcript isoform promoters of one gene. These DNA signals are conserved among species. Transcript isoform has a RNA-determined unstructured region around its start site. We found that these DNA/RNA features facilitate isoform transcription and translation. These results suggest a DNA-encoded mechanism by which transcript isoform is generated. PMID:27353836

  4. Signal processing of anthropometric data

    NASA Technical Reports Server (NTRS)

    Zimmermann, W. J.

    1983-01-01

    The Anthropometric Measurements Laboratory has accumulated a large body of data from a number of previous experiments. The data is very noisy, therefore it requires the application of some signal processing schemes. Moreover, it was not regarded as time series measurements but as positional information; hence, the data is stored as coordinate points as defined by the motion of the human body. The accumulated data defines two groups or classes. Some of the data was collected from an experiment designed to measure the flexibility of the limbs, referred to as radial movement. The remaining data was collected from experiments designed to determine the surface of the reach envelope. An interactive signal processing package was designed and implemented. Since the data does not include time this package does not include a time series element. Presently the results is restricted to processing data obtained from those experiments designed to measure flexibility.

  5. Notch Signaling in Neuroendocrine Tumors

    PubMed Central

    Crabtree, Judy S.; Singleton, Ciera S.; Miele, Lucio

    2016-01-01

    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 such as 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. PMID:27148486

  6. Hydrogen sulfide in signaling pathways.

    PubMed

    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.

  7. Acoustic Localization with Infrasonic Signals

    NASA Astrophysics Data System (ADS)

    Threatt, Arnesha; Elbing, Brian

    2015-11-01

    Numerous geophysical and anthropogenic events emit infrasonic frequencies (<20 Hz), including volcanoes, hurricanes, 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.

  8. Signaling Pathways in Cartilage Repair

    PubMed Central

    Mariani, Erminia; Pulsatelli, Lia; Facchini, Andrea

    2014-01-01

    In adult healthy cartilage, chondrocytes are in a quiescent phase characterized by a fine balance between anabolic and catabolic activities. In ageing, degenerative joint diseases and traumatic injuries of cartilage, a loss of homeostatic conditions and an up-regulation of catabolic pathways occur. Since cartilage differentiation and maintenance of homeostasis are finely tuned by a complex network of signaling molecules and biophysical factors, shedding light on these mechanisms appears to be extremely relevant for both the identification of pathogenic key factors, as specific therapeutic targets, and the development of biological approaches for cartilage regeneration. This review will focus on the main signaling pathways that can activate cellular and molecular processes, regulating the functional behavior of cartilage in both physiological and pathological conditions. These networks may be relevant in the crosstalk among joint compartments and increased knowledge in this field may lead to the development of more effective strategies for inducing cartilage repair. PMID:24837833

  9. Signalling pathways in pemphigus vulgaris.

    PubMed

    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.

  10. Leptin signaling and leptin resistance.

    PubMed

    Zhou, Yingjiang; Rui, Liangyou

    2013-06-01

    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 cause obesity. Leptin controls energy balance and body weight mainly through leptin receptor b (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 within and outside the hypothalamus, forming a neural network that controls the energy homeostasis and body weight. Multiple factors, including inflammation and endoplasmic reticulum (ER) stress, contribute to leptin resistance. Leptin resistance is the key risk factor for obesity. This review is focused on recent advance about leptin action, leptin signaling, and leptin resistance.

  11. Mitochondrial metabolites: undercover signalling molecules

    PubMed Central

    2017-01-01

    Mitochondria are one of most characterized metabolic hubs of the cell. Here, crucial biochemical reactions occur and most of the cellular adenosine triphosphate (ATP) is produced. In addition, mitochondria act as signalling platforms and communicate with the rest of the cell by modulating calcium fluxes, by producing free radicals, and by releasing bioactive proteins. It is emerging that mitochondrial metabolites can also act as second messengers and can elicit profound (epi)genetic changes. This review describes the many signalling functions of mitochondrial metabolites under normal and stress conditions, focusing on metabolites of the tricarboxylic acid cycle. We provide a new framework for understanding the role of mitochondrial metabolism in cellular pathophysiology. PMID:28382199

  12. Automatic communication signal monitoring system

    NASA Technical Reports Server (NTRS)

    Bernstein, A. J. (Inventor)

    1978-01-01

    A system is presented for automatic monitoring of a communication signal in the RF or IF spectrum utilizing a superheterodyne receiver technique with a VCO to select and sweep the frequency band of interest. A first memory is used to store one band sweep as a reference for continual comparison with subsequent band sweeps. Any deviation of a subsequent band sweep by more than a predetermined tolerance level produces an alarm signal which causes the band sweep data temporarily stored in one of two buffer memories to be transferred to long-term store while the other buffer memory is switched to its store mode to assume the task of temporarily storing subsequent band sweeps.

  13. Notch Signaling Inhibits Axon Regeneration

    PubMed Central

    Bejjani, Rachid El; Hammarlund, Marc

    2013-01-01

    Summary Many neurons have limited capacity to regenerate their axons after injury. Neurons in the mammalian CNS do not regenerate, and even neurons in the PNS often fail to regenerate to their former targets. This failure is likely due in part to pathways that actively restrict regeneration; however, only a few factors that limit regeneration are known. Here, using single-neuron analysis of regeneration in vivo, we show that Notch/lin-12 signaling inhibits the regeneration of mature C. elegans neurons. Notch signaling suppresses regeneration by acting autonomously in the injured cell to prevent growth cone formation. The metalloprotease and gamma-secretase cleavage events that lead to Notch activation during development are also required for its activity in regeneration. Furthermore, blocking Notch activation immediately after injury improves regeneration. Our results define a novel, post-developmental role for the Notch pathway as a repressor of axon regeneration in vivo. PMID:22284182

  14. Signal processing of anthropometric data

    NASA Astrophysics Data System (ADS)

    Zimmermann, W. J.

    1983-09-01

    The Anthropometric Measurements Laboratory has accumulated a large body of data from a number of previous experiments. The data is very noisy, therefore it requires the application of some signal processing schemes. Moreover, it was not regarded as time series measurements but as positional information; hence, the data is stored as coordinate points as defined by the motion of the human body. The accumulated data defines two groups or classes. Some of the data was collected from an experiment designed to measure the flexibility of the limbs, referred to as radial movement. The remaining data was collected from experiments designed to determine the surface of the reach envelope. An interactive signal processing package was designed and implemented. Since the data does not include time this package does not include a time series element. Presently the results is restricted to processing data obtained from those experiments designed to measure flexibility.

  15. ASSP Advanced Sensor Signal Processor.

    DTIC Science & Technology

    1984-06-01

    and rainy days. The data base was ground truthed by vehicle type . Some of the data base was -round truthed according to different types of background...required accuracy (l1). This implies a strong potential for application to most similar engagements for extensions to other types of missions. 2.2.2...target classification by vehicle type and incorporate contextual information to further enhance system performance. -4- c) Improvement of the signal

  16. Signal Processing Fault Detection System

    DTIC Science & Technology

    2007-07-13

    of strain sensor signals is wavelet analysis which is a linear mathematical analysis technique that can analyze discontinuities and edge effects...Real wavelets are suitable for identifying discontinuities and data compression. Analytic wavelets are suitable for capturing frequency content within a...function (i.e. the time series data captured from the sensors) and l*a,.u is identified as the complex conjugate of the mother wavelet . The variable t

  17. Intracellular Signalling in Retinal Ischemia

    DTIC Science & Technology

    1990-07-01

    36) However, vascularization of the RPE is not known to occur in human diseases of photoreceptor degeneration, such as retinitis pigmentosa ...A.C. (1986) Retinitis pigmentosa and retinal neovascularization. Ophthalmology 91, 1599- 1603. Figure la: Control rat retina, 8 weeks of age, central...TITLE (Include Security Classification) Intracellular Signalling in Retinal Ischemia 12. PERSONAL AUTHOR(S) Burns, Margaret Sue; Bellhorn, Roy William

  18. AR Signaling in Breast Cancer

    PubMed Central

    Rahim, Bilal; O’Regan, Ruth

    2017-01-01

    Androgen receptor (AR, a member of the steroid hormone receptor family) status has become increasingly important as both a prognostic marker and potential therapeutic target in breast cancer. AR is expressed in up to 90% of estrogen receptor (ER) positive breast cancer, and to a lesser degree, human epidermal growth factor 2 (HER2) amplified tumors. In the former, AR signaling has been correlated with a better prognosis given its inhibitory activity in estrogen dependent disease, though conversely has also been shown to increase resistance to anti-estrogen therapies such as tamoxifen. AR blockade can mitigate this resistance, and thus serves as a potential target in ER-positive breast cancer. In HER2 amplified breast cancer, studies are somewhat conflicting, though most show either no effect or are associated with poorer survival. Much of the available data on AR signaling is in triple-negative breast cancer (TNBC), which is an aggressive disease with inferior outcomes comparative to other breast cancer subtypes. At present, there are no approved targeted therapies in TNBC, making study of the AR signaling pathway compelling. Gene expression profiling studies have also identified a luminal androgen receptor (LAR) subtype that is dependent on AR signaling in TNBC. Regardless, there seems to be an association between AR expression and improved outcomes in TNBC. Despite lower pathologic complete response (pCR) rates with neoadjuvant therapy, patients with AR-expressing TNBC have been shown to have a better prognosis than those that are AR-negative. Clinical studies targeting AR have shown somewhat promising results. In this paper we review the literature on the biology of AR in breast cancer and its prognostic and predictive roles. We also present our thoughts on therapeutic strategies. PMID:28245550

  19. Wnt Signaling and Injury Repair

    PubMed Central

    Whyte, Jemima L.; Smith, Andrew A.; Helms, Jill A.

    2012-01-01

    Wnt signaling is activated by wounding and participates in every subsequent stage of the healing process from the control of inflammation and programmed cell death, to the mobilization of stem cell reservoirs within the wound site. In this review we summarize recent data elucidating the roles that the Wnt pathway plays in the injury repair process. These data provide a foundation for potential Wnt-based therapeutic strategies aimed at stimulating tissue regeneration. PMID:22723493

  20. SnapShot: Interferon Signaling.

    PubMed

    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.