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Sample records for affective loop experiences

  1. Affective loop experiences: designing for interactional embodiment

    PubMed Central

    Höök, Kristina

    2009-01-01

    Involving our corporeal bodies in interaction can create strong affective experiences. Systems that both can be influenced by and influence users corporeally exhibit a use quality we name an affective loop experience. In an affective loop experience, (i) emotions are seen as processes, constructed in the interaction, starting from everyday bodily, cognitive or social experiences; (ii) the system responds in ways that pull the user into the interaction, touching upon end users' physical experiences; and (iii) throughout the interaction the user is an active, meaning-making individual choosing how to express themselves—the interpretation responsibility does not lie with the system. We have built several systems that attempt to create affective loop experiences with more or less successful results. For example, eMoto lets users send text messages between mobile phones, but in addition to text, the messages also have colourful and animated shapes in the background chosen through emotion-gestures with a sensor-enabled stylus pen. Affective Diary is a digital diary with which users can scribble their notes, but it also allows for bodily memorabilia to be recorded from body sensors mapping to users' movement and arousal and placed along a timeline. Users can see patterns in their bodily reactions and relate them to various events going on in their lives. The experiences of building and deploying these systems gave us insights into design requirements for addressing affective loop experiences, such as how to design for turn-taking between user and system, how to create for ‘open’ surfaces in the design that can carry users' own meaning-making processes, how to combine modalities to create for a ‘unity’ of expression, and the importance of mirroring user experience in familiar ways that touch upon their everyday social and corporeal experiences. But a more important lesson gained from deploying the systems is how emotion processes are co-constructed and

  2. Affective loop experiences: designing for interactional embodiment.

    PubMed

    Höök, Kristina

    2009-12-12

    Involving our corporeal bodies in interaction can create strong affective experiences. Systems that both can be influenced by and influence users corporeally exhibit a use quality we name an affective loop experience. In an affective loop experience, (i) emotions are seen as processes, constructed in the interaction, starting from everyday bodily, cognitive or social experiences; (ii) the system responds in ways that pull the user into the interaction, touching upon end users' physical experiences; and (iii) throughout the interaction the user is an active, meaning-making individual choosing how to express themselves-the interpretation responsibility does not lie with the system. We have built several systems that attempt to create affective loop experiences with more or less successful results. For example, eMoto lets users send text messages between mobile phones, but in addition to text, the messages also have colourful and animated shapes in the background chosen through emotion-gestures with a sensor-enabled stylus pen. Affective Diary is a digital diary with which users can scribble their notes, but it also allows for bodily memorabilia to be recorded from body sensors mapping to users' movement and arousal and placed along a timeline. Users can see patterns in their bodily reactions and relate them to various events going on in their lives. The experiences of building and deploying these systems gave us insights into design requirements for addressing affective loop experiences, such as how to design for turn-taking between user and system, how to create for 'open' surfaces in the design that can carry users' own meaning-making processes, how to combine modalities to create for a 'unity' of expression, and the importance of mirroring user experience in familiar ways that touch upon their everyday social and corporeal experiences. But a more important lesson gained from deploying the systems is how emotion processes are co-constructed and experienced

  3. Loop-the-Loop: An Easy Experiment, A Challenging Explanation

    NASA Astrophysics Data System (ADS)

    Asavapibhop, B.; Suwonjandee, N.

    2010-07-01

    A loop-the-loop built by the Institute for the Promotion of Teaching Science and Technology (IPST) was used in Thai high school teachers training program to demonstrate a circular motion and investigate the concept of the conservation of mechanical energy. We took videos using high speed camera to record the motions of a spherical steel ball moving down the aluminum inclined track at different released positions. The ball then moved into the circular loop and underwent a projectile motion upon leaving the track. We then asked the teachers to predict the landing position of the ball if we changed the height of the whole loop-the-loop system. We also analyzed the videos using Tracker, a video analysis software. It turned out that most teachers did not realize the effect of the friction between the ball and the track and could not obtain the correct relationship hence their predictions were inconsistent with the actual landing positions of the ball.

  4. Affective Productions of Mathematical Experience

    ERIC Educational Resources Information Center

    Walshaw, Margaret; Brown, Tony

    2012-01-01

    In underscoring the affective elements of mathematics experience, we work with contemporary readings of the work of Spinoza on the politics of affect, to understand what is included in the cognitive repertoire of the Subject. We draw on those resources to tell a pedagogical tale about the relation between cognition and affect in settings of…

  5. Affective Experience in a Classroom.

    ERIC Educational Resources Information Center

    Anderson, Ariel; And Others

    This study introduces a novel methodology for examining affective experiences in the classroom. The general procedure is to make auditory and visual recordings of a particular child during a normal classroom period. That child is then immediately taken from the class and placed in a private room where the recordings are replayed. The student is…

  6. Flight Testing of the Capillary Pumped Loop 3 Experiment

    NASA Technical Reports Server (NTRS)

    Ottenstein, Laura; Butler, Dan; Ku, Jentung; Cheung, Kwok; Baldauff, Robert; Hoang, Triem

    2002-01-01

    The Capillary Pumped Loop 3 (CAPL 3) experiment was a multiple evaporator capillary pumped loop experiment that flew in the Space Shuttle payload bay in December 2001 (STS-108). The main objective of CAPL 3 was to demonstrate in micro-gravity a multiple evaporator capillary pumped loop system, capable of reliable start-up, reliable continuous operation, and heat load sharing, with hardware for a deployable radiator. Tests performed on orbit included start-ups, power cycles, low power tests (100 W total), high power tests (up to 1447 W total), heat load sharing, variable/fixed conductance transition tests, and saturation temperature change tests. The majority of the tests were completed successfully, although the experiment did exhibit an unexpected sensitivity to shuttle maneuvers. This paper describes the experiment, the tests performed during the mission, and the test results.

  7. Closed-Loop HIRF Experiments Performed on a Fault Tolerant Flight Control Computer

    NASA Technical Reports Server (NTRS)

    Belcastro, Celeste M.

    1997-01-01

    ABSTRACT Closed-loop HIRF experiments were performed on a fault tolerant flight control computer (FCC) at the NASA Langley Research Center. The FCC used in the experiments was a quad-redundant flight control computer executing B737 Autoland control laws. The FCC was placed in one of the mode-stirred reverberation chambers in the HIRF Laboratory and interfaced to a computer simulation of the B737 flight dynamics, engines, sensors, actuators, and atmosphere in the Closed-Loop Systems Laboratory. Disturbances to the aircraft associated with wind gusts and turbulence were simulated during tests. Electrical isolation between the FCC under test and the simulation computer was achieved via a fiber optic interface for the analog and discrete signals. Closed-loop operation of the FCC enabled flight dynamics and atmospheric disturbances affecting the aircraft to be represented during tests. Upset was induced in the FCC as a result of exposure to HIRF, and the effect of upset on the simulated flight of the aircraft was observed and recorded. This paper presents a description of these closed- loop HIRF experiments, upset data obtained from the FCC during these experiments, and closed-loop effects on the simulated flight of the aircraft.

  8. Capillary pumped loop GAS and Hitchhiker flight experiments

    NASA Technical Reports Server (NTRS)

    Ku, J.; Kroliczek, E. J.; Butler, D.; Schweickart, R. B.; Mcintosh, R.

    1986-01-01

    Flight experiments of a capillary pumped loop (CPL) aboard the Space Shuttle on both the Get Away Special (GAS) and Hitchhiker-G (H/H-G) carriers are described. These tests have shown that a two-phase heat transfer loop utilizing a wicking material as the system pumping mechanism can operate successfully in a zero-g environment. The CPL operating modes demonstrated were start-up, heat load sharing/natural priming, liquid inventory and temperature control via the reservoir, dryout recovery, and isolation of a single pump deprime. Also investigated were high and low power limits, and inlet subcooling requirements. In these CPL flight experiments, successful system operation was demonstrated at input power levels up to 560 watts and inlet subcooling below 2 C.

  9. Flight testing of the Capillary Pumped Loop Flight Experiment

    SciTech Connect

    Butler, D.; Ottenstein, L.; Ku, J.

    1995-09-01

    The Capillary Pumped Loop Flight Experiment (CAPL) employs a passive two-phase thermal control system that uses the latent heat of vaporization of ammonia to transfer heat over long distances. CAPL was designed as a prototype of the Earth Observing System (EOS) instrument thermal control systems. The purpose of the mission was to provide validation of the system performance in micro-gravity, prior to implementation on EOS. CAPL was flown on STS-60 in February, 1994, with some unexpected results related to gravitational effects on two-phase systems. Flight test results and post flight investigations will be addressed, along with a brief description of the experiment design.

  10. The Affective Experiences of Children during Mathematics.

    ERIC Educational Resources Information Center

    Prawat, Richard S.; Anderson, Ariel L. H.

    1994-01-01

    Stimulated recall was used to examine the affective experiences of (n=32) fourth and fifth graders engaged in mathematics seatwork. Students' affect was found to be primarily negative and achievement related. Anger was the most prevalent affective response. (42 references) (MKR)

  11. THE ROLE OF ACTIVE REGION LOOP GEOMETRY. I. HOW CAN IT AFFECT CORONAL SEISMOLOGY?

    SciTech Connect

    Selwa, M.; Ofman, L.; Solanki, S. K. E-mail: leon.ofman@nasa.gov

    2011-01-01

    We present numerical results of coronal loop oscillation excitation using a three-dimensional (3D) MHD model of an idealized active region (AR) field. The AR is initialized as a potential dipole magnetic configuration with gravitationally stratified density and contains a loop with a higher density than its surroundings. We study different ways of excitation of vertical kink oscillations of this loop by velocity: as an initial condition, and as an impulsive excitation with a pulse of a given position, duration, and amplitude. We vary the geometry of the loop in the 3D MHD model and find that it affects both the period of oscillations and the synthetic observations (difference images) that we get from oscillations. Due to the overestimated effective length of the loop in the case of loops which have maximum separation between their legs above the footpoints (>50% of observed loops), the magnetic field obtained from coronal seismology can also be overestimated. The 3D MHD model shows how the accuracy of magnetic field strength determined from coronal seismology can be improved. We study the damping mechanism of the oscillations and find that vertical kink waves in 3D stratified geometry are damped mainly due to wave leakage in the horizontal direction.

  12. The experience sampling method: Investigating students' affective experience

    NASA Astrophysics Data System (ADS)

    Nissen, Jayson M.; Stetzer, MacKenzie R.; Shemwell, Jonathan T.

    2013-01-01

    Improving non-cognitive outcomes such as attitudes, efficacy, and persistence in physics courses is an important goal of physics education. This investigation implemented an in-the-moment surveying technique called the Experience Sampling Method (ESM) [1] to measure students' affective experience in physics. Measurements included: self-efficacy, cognitive efficiency, activation, intrinsic motivation, and affect. Data are presented that show contrasts in students' experiences (e.g., in physics vs. non-physics courses).

  13. On a fractional representation approach to closed-loop experiment design

    NASA Technical Reports Server (NTRS)

    Hansen, Fred R.; Franklin, Gene F.

    1988-01-01

    A plant model, based on a fractional representation of the loop, which is uniquely suited to the closed-loop experiment design problem, is proposed. The advantage of this model is that it substitutes an open-loop problem (for which there has been extensive work) for the original-closed loop problem. The results of Monte Carlo simulations which support the utility of this approach are included.

  14. Experiment to Study Alfven Wave Propagation in Plasma Loops

    NASA Astrophysics Data System (ADS)

    Kendall, Mark; Bellan, Paul

    2010-11-01

    Arched plasma-filled twisted magnetic flux tubes are generated in the laboratory using pulsed power techniques (J.F. Hansen, S.K.P. Tripathi, P.M. Bellan, 2004). Their structure and time evolution exhibit similarities with both solar coronal loops and spheromaks. We are now developing a method to excite propagating torsional Alfven wave modes in such plasma loops by superposing a ˜10kA, ˜100ns current pulse upon the ˜50kA, 10μs main discharge current that flows along the ˜20cm long, 2cm diameter arched flux tube. To achieve this high power 100ns pulse, a magnetic pulse compression technique based on saturable reactors is employed. A low power prototype has been successfully tested, and design and construction of a full-power device is nearing completion. The full-power device will compress an initial 2μs pulse by a factor of nearly 20; the final stage utilizes a water-filled transmission line with ultra-low inductance to attain the final timescale. This new pulse device will subsequently be used to investigate interactions between Alfven waves and the larger-scale loop evolution; one goal will be to directly image the wave using high-speed photography. Attention will be paid to wave propagation including dispersion and reflection, as well as dissipation mechanisms and possible energetic particle generation.

  15. Open-Loop HIRF Experiments Performed on a Fault Tolerant Flight Control Computer

    NASA Technical Reports Server (NTRS)

    Koppen, Daniel M.

    1997-01-01

    During the third quarter of 1996, the Closed-Loop Systems Laboratory was established at the NASA Langley Research Center (LaRC) to study the effects of High Intensity Radiated Fields on complex avionic systems and control system components. This new facility provided a link and expanded upon the existing capabilities of the High Intensity Radiated Fields Laboratory at LaRC that were constructed and certified during 1995-96. The scope of the Closed-Loop Systems Laboratory is to place highly integrated avionics instrumentation into a high intensity radiated field environment, interface the avionics to a real-time flight simulation that incorporates aircraft dynamics, engines, sensors, actuators and atmospheric turbulence, and collect, analyze, and model aircraft performance. This paper describes the layout and functionality of the Closed-Loop Systems Laboratory, and the open-loop calibration experiments that led up to the commencement of closed-loop real-time flight experiments.

  16. Neural network setpoint control of an advanced test reactor experiment loop simulation

    SciTech Connect

    Cordes, G.A.; Bryan, S.R.; Powell, R.H.; Chick, D.R.

    1990-09-01

    This report describes the design, implementation, and application of artificial neural networks to achieve temperature and flow rate control for a simulation of a typical experiment loop in the Advanced Test Reactor (ATR) located at the Idaho National Engineering Laboratory (INEL). The goal of the project was to research multivariate, nonlinear control using neural networks. A loop simulation code was adapted for the project and used to create a training set and test the neural network controller for comparison with the existing loop controllers. The results for three neural network designs are documented and compared with existing loop controller action. The neural network was shown to be as accurate at loop control as the classical controllers in the operating region represented by the training set. 9 refs., 28 figs., 2 tabs.

  17. Experimental and analytical studies of merging plasma loops on the Caltech solar loop experiment

    NASA Astrophysics Data System (ADS)

    Pitigoi-Aron, Gabriela

    and personal factors and perceptions with emphasis on mentors' influence; (5) Negative influence of salary difference with respect to private practitioners. The findings of this study were similar to the available studies on foreign-trained dentists and to most of the studies already done on domestically trained dentists. The major factors found were comparable with the up-to-date literature. The elevated research drive, the intellectual challenges, the work environment, the desire to teach, and the mentors' influence were among those which mirrored almost perfectly the other studies. Some fine differences were found for foreign-trained dentists, such as a lighter financial burden caused by smaller student debt and the irrelevance of military practice experience. The study provides a number of suggestions for enhancing the recruiting and retaining process for dental academia: (1) Support and enhance the research capacity of dental schools; (2) Create structures to develop mentors; (3) Invest to build prestige; (4) Find creative ways to offset lower salaries; (5) Foster a pleasant academic working environment; (6) Use international activities to recruit international dentists. The study revealed factors that have been influential in participants' decisions to choose an academic career, in general and at Pacific. It is hoped that this study will be a useful reference in the increasingly difficult endeavor of adding and retaining world-class dental educators.

  18. THE ROLE OF AFFECTIVE EXPERIENCE IN WORK MOTIVATION

    PubMed Central

    SEO, MYEONG-GU; BARRETT, LISA FELDMAN; BARTUNEK, JEAN M.

    2005-01-01

    Based on psychological and neurobiological theories of core affective experience, we identify a set of direct and indirect paths through which affective feelings at work affect three dimensions of behavioral outcomes: direction, intensity, and persistence. First, affective experience may influence these behavioral outcomes indirectly by affecting goal level and goal commitment, as well as three key judgment components of work motivation: expectancy judgments, utility judgments, and progress judgments. Second, affective experience may also affect these behavioral outcomes directly. We discuss implications of our model. PMID:16871321

  19. Academic Factors that Affect Undergraduate Research Experiences

    ERIC Educational Resources Information Center

    Taraban, Roman; Logue, Erin

    2012-01-01

    Undergraduate research experiences are considered an essential component in college curricula, and there is an ideological push to provide these experiences to all students. However, it is not clear whether engagement in research is better suited for higher ability undergraduates late in their programs or for all undergraduates and whether…

  20. Three tritium systems test assembly (TSTA) off-loop experiments

    SciTech Connect

    Talcott, C.L.; Anderson, J.L.; Carlson, R.V.; Coffin, D.O.; Walthers, C.R.; Hamerdinger, D.; Binning, K.; Trujillo, R.D.; Moya, J.S.; Hayashi, T.; Okuno, K.; Yamanishi, T.

    1993-11-01

    This report contains the results from three different experiments. Experiment one was initiated to establish the possibility of using a soft elastomer in ITER (International Thermonuclear Experimental Reactor) applications. Used in this application, the sealing material is anticipated to be in tritium at pressures in the range of 1 {times} 10{sup {minus}3} torr for many years. Here two O-ring valve seals each of Viton-A, Buna-N, and EDPM were exposed to 1, 40, or 400 torr of tritium while being cycled open and closed approximately 11,500 times in 192 days. EDPM is the least susceptible to damage from the tritium. Both Buna-N and Viton-A showed deterioration following the first cycling at 400 torr. Using commercially available materials, the Tritium Systems Test Assembly (TSTA) designed and built a Portable Water Removal (PWR) Unit to reduce tritium oxide emissions during glovebox breaches. The PWR removes 99.9% of all tritium and saves between 0.7 and 3.5 curies of tritium oxide from being stacked during each of the five tests. Finally, a series of tests are done to determine whether the presence of SF{sub 6} changes the ability of palladium and platinum to catalyze the T{sub 2}-O{sub 2} reaction to form T{sub 2}O. No deterioration of the catalytic activity is observed. This is important because the Tokamak Fusion Test Reactor (TFTR) requires information about the effect of SF{sub 6}, an electrical insulator, on the catalytic behavior of Pt and Pd in a T{sub 2} environment. This information is necessary for the accident analysis in the Safety Analysis Report for TFTR. This study is done using an apparatus supplied to TSTA by TFTR.

  1. Complex astrophysical experiments relating to jets, solar loops, and water ice dusty plasma

    NASA Astrophysics Data System (ADS)

    Bellan, P. M.; Zhai, X.; Chai, K. B.; Ha, B. N.

    2015-10-01

    > Recent results of three astrophysically relevant experiments at Caltech are summarized. In the first experiment magnetohydrodynamically driven plasma jets simulate astrophysical jets that undergo a kink instability. Lateral acceleration of the kinking jet spawns a Rayleigh-Taylor instability, which in turn spawns a magnetic reconnection. Particle heating and a burst of waves are observed in association with the reconnection. The second experiment uses a slightly different setup to produce an expanding arched plasma loop which is similar to a solar corona loop. It is shown that the plasma in this loop results from jets originating from the electrodes. The possibility of a transition from slow to fast expansion as a result of the expanding loop breaking free of an externally imposed strapping magnetic field is investigated. The third and completely different experiment creates a weakly ionized plasma with liquid nitrogen cooled electrodes. Water vapour injected into this plasma forms water ice grains that in general are ellipsoidal and not spheroidal. The water ice grains can become quite long (up to several hundred microns) and self-organize so that they are evenly spaced and vertically aligned.

  2. Locomotor Experience Affects Self and Emotion

    ERIC Educational Resources Information Center

    Uchiyama, Ichiro; Anderson, David I.; Campos, Joseph J.; Witherington, David; Frankel, Carl B.; Lejeune, Laure; Barbu-Roth, Marianne

    2008-01-01

    Two studies investigated the role of locomotor experience on visual proprioception in 8-month-old infants. "Visual proprioception" refers to the sense of self-motion induced in a static person by patterns of optic flow. A moving room apparatus permitted displacement of an entire enclosure (except for the floor) or the side walls and ceiling. In…

  3. A dynamic RNA loop in an IRES affects multiple steps of elongation factor-mediated translation initiation.

    PubMed

    Ruehle, Marisa D; Zhang, Haibo; Sheridan, Ryan M; Mitra, Somdeb; Chen, Yuanwei; Gonzalez, Ruben L; Cooperman, Barry S; Kieft, Jeffrey S

    2015-01-01

    Internal ribosome entry sites (IRESs) are powerful model systems to understand how the translation machinery can be manipulated by structured RNAs and for exploring inherent features of ribosome function. The intergenic region (IGR) IRESs from the Dicistroviridae family of viruses are structured RNAs that bind directly to the ribosome and initiate translation by co-opting the translation elongation cycle. These IRESs require an RNA pseudoknot that mimics a codon-anticodon interaction and contains a conformationally dynamic loop. We explored the role of this loop and found that both the length and sequence are essential for translation in different types of IGR IRESs and from diverse viruses. We found that loop 3 affects two discrete elongation factor-dependent steps in the IRES initiation mechanism. Our results show how the IRES directs multiple steps after 80S ribosome placement and highlights the often underappreciated significance of discrete conformationally dynamic elements within the context of structured RNAs. PMID:26523395

  4. How the Polyakov loop and the regularization affect strangeness and restoration of symmetries at finite T

    SciTech Connect

    Ruivo, M. C.; Costa, P.; Sousa, C. A. de; Hansen, H.

    2010-08-05

    The effects of the Polyakov loop and of a regularization procedure that allows the presence of high momentum quark states at finite temperature is investigated within the Polyakov-loop extended Nambu-Jona-Lasinio model. The characteristic temperatures, as well as the behavior of observables that signal deconfinement and restoration of chiral and axial symmetries, are analyzed, paying special attention to the behavior of strangeness degrees of freedom. We observe that the cumulative effects of the Polyakov loop and of the regularization procedure contribute to a better description of the thermodynamics, as compared with lattice estimations. We find a faster partial restoration of chiral symmetry and the restoration of the axial symmetry appears as a natural consequence of the full recovering of the chiral symmetry that was dynamically broken. These results show the relevance of the effects of the interplay among the Polyakov loop dynamics, the high momentum quark sates and the restoration of the chiral and axial symmetries at finite temperature.

  5. On the relevance of magnetohydrodynamic pumping in solar coronal loop simulation experiments

    NASA Astrophysics Data System (ADS)

    Tenfelde, J.; Kempkes, P.; Mackel, F.; Ridder, S.; Stein, H.; Tacke, T.; Soltwisch, H.

    2012-07-01

    A magnetohydrodynamic pumping mechanism was proposed by Bellan [Phys. Plasmas 10, 1999 (2003)] to explain the formation of highly collimated plasma-filled magnetic flux tubes in certain solar coronal loop simulation experiments. In this paper, measurements on such an experiment are compared to the predictions of Bellan's pumping and collimation model. Significant discrepancies between theoretical implications and experimental observations have prompted more elaborate investigations by making use of pertinent modifications of the experimental device. On the basis of these studies, it is concluded that the proposed MHD pumping mechanism does not play a crucial role for the formation and temporal evolution of the arched plasma structures that are generated in the coronal loop simulation experiments under consideration.

  6. Recent Experience Affects the Strength of Structural Priming

    ERIC Educational Resources Information Center

    Kaschak, Michael P.; Loney, Renrick A.; Borreggine, Kristin L.

    2006-01-01

    In two experiments, we explore how recent experience with particular syntactic constructions affects the strength of the structural priming observed for those constructions. The results suggest that (1) the strength of structural priming observed for double object and prepositional object constructions is affected by the relative frequency with…

  7. Exploring Online Game Players' Flow Experiences and Positive Affect

    ERIC Educational Resources Information Center

    Chiang, Yu-Tzu; Lin, Sunny S. J.; Cheng, Chao-Yang; Liu, Eric Zhi-Feng

    2011-01-01

    The authors conducted two studies to explore online game players' flow experiences and positive affect. Our findings indicated that online game are capable of evoking flow experiences and positive affect, and games of violent or nonviolent type may not arouse players' aggression. The players could be placed into four flow conditions: flow,…

  8. Dynamics of Affective Experience and Behavior in Depressed Adolescents

    ERIC Educational Resources Information Center

    Sheeber, Lisa B.; Allen, Nicholas B.; Leve, Craig; Davis, Betsy; Shortt, Joann Wu; Katz, Lynn Fainsilber

    2009-01-01

    Background: Depression is often characterized as a disorder of affect regulation. However, research focused on delineating the key dimensions of affective experience (other than valence) that are abnormal in depressive disorder has been scarce, especially in child and adolescent samples. As definitions of affect regulation center around processes…

  9. The EF loop in green proteorhodopsin affects conformation and photocycle dynamics.

    PubMed

    Mehler, Michaela; Scholz, Frank; Ullrich, Sandra J; Mao, Jiafei; Braun, Markus; Brown, Lynda J; Brown, Richard C D; Fiedler, Sarah A; Becker-Baldus, Johanna; Wachtveitl, Josef; Glaubitz, Clemens

    2013-07-16

    The proteorhodopsin family consists of retinal proteins of marine bacterial origin with optical properties adjusted to their local environments. For green proteorhodopsin, a highly specific mutation in the EF loop, A178R, has been found to cause a surprisingly large redshift of 20 nm despite its distance from the chromophore. Here, we analyze structural and functional consequences of this EF loop mutation by time-resolved optical spectroscopy and solid-state NMR. We found that the primary photoreaction and the formation of the K-like photo intermediate is almost pH-independent and slower compared to the wild-type, whereas the decay of the K-intermediate is accelerated, suggesting structural changes within the counterion complex upon mutation. The photocycle is significantly elongated mainly due to an enlarged lifetime of late photo intermediates. Multidimensional MAS-NMR reveals mutation-induced chemical shift changes propagating from the EF loop to the chromophore binding pocket, whereas dynamic nuclear polarization-enhanced (13)C-double quantum MAS-NMR has been used to probe directly the retinylidene conformation. Our data show a modified interaction network between chromophore, Schiff base, and counterion complex explaining the altered optical and kinetic properties. In particular, the mutation-induced distorted structure in the EF loop weakens interactions, which help reorienting helix F during the reprotonation step explaining the slower photocycle. These data lead to the conclusion that the EF loop plays an important role in proton uptake from the cytoplasm but our data also reveal a clear interaction pathway between the EF loop and retinal binding pocket, which might be an evolutionary conserved communication pathway in retinal proteins. PMID:23870260

  10. The EF Loop in Green Proteorhodopsin Affects Conformation and Photocycle dynamics

    PubMed Central

    Mehler, Michaela; Scholz, Frank; Ullrich, Sandra J.; Mao, Jiafei; Braun, Markus; Brown, Lynda J.; Brown, Richard C.D.; Fiedler, Sarah A.; Becker-Baldus, Johanna; Wachtveitl, Josef; Glaubitz, Clemens

    2013-01-01

    The proteorhodopsin family consists of retinal proteins of marine bacterial origin with optical properties adjusted to their local environments. For green proteorhodopsin, a highly specific mutation in the EF loop, A178R, has been found to cause a surprisingly large redshift of 20 nm despite its distance from the chromophore. Here, we analyze structural and functional consequences of this EF loop mutation by time-resolved optical spectroscopy and solid-state NMR. We found that the primary photoreaction and the formation of the K-like photo intermediate is almost pH-independent and slower compared to the wild-type, whereas the decay of the K-intermediate is accelerated, suggesting structural changes within the counterion complex upon mutation. The photocycle is significantly elongated mainly due to an enlarged lifetime of late photo intermediates. Multidimensional MAS-NMR reveals mutation-induced chemical shift changes propagating from the EF loop to the chromophore binding pocket, whereas dynamic nuclear polarization-enhanced 13C-double quantum MAS-NMR has been used to probe directly the retinylidene conformation. Our data show a modified interaction network between chromophore, Schiff base, and counterion complex explaining the altered optical and kinetic properties. In particular, the mutation-induced distorted structure in the EF loop weakens interactions, which help reorienting helix F during the reprotonation step explaining the slower photocycle. These data lead to the conclusion that the EF loop plays an important role in proton uptake from the cytoplasm but our data also reveal a clear interaction pathway between the EF loop and retinal binding pocket, which might be an evolutionary conserved communication pathway in retinal proteins. PMID:23870260

  11. Development and integration of the capillary pumped loop GAS and Hitchhiker flight experiments

    NASA Technical Reports Server (NTRS)

    Butler, D.; Mcintosh, R.

    1990-01-01

    The Capillary Pumped Loop (CPL) is a thermal control system with high density heat acquisition and transport capability. A small spaceflight version of the CPL was built and flown as a GAS experiment on STS 51-D in April 1985 and STS 51-G in June 1985, and as a Hitchhiker-G experiment on STS 61-C in January 1986. The purpose of the experiments was to demonstrate the capability of a capillary pumped system under microgravity conditions for use in the thermal control of large scientific instruments, advanced orbiting spacecraft, and space station components. The development, integration, and test activities of the CPL are described.

  12. The Capillary Pumped Loop Flight Experiment (CAPL): A pathfinder for EOS

    NASA Technical Reports Server (NTRS)

    Butler, D.; Hoang, T.

    1992-01-01

    The CAPL shuttle flight experiment will provide microgravity verification of the prototype capillary pumped loop (CPL) thermal control system for EOS. The design of the experiment is discussed with particular emphasis on the new technology areas in ammonia two-phase reservior design and heat pipe heat exchanger development. The thermal and hydrodynamic analysis techniques and results are also presented, including pressure losses, fluid flow, and non-orbit heat rejection capability. CAPL experiment results will be presented after the flight, presently planned for 1993.

  13. Putative pore-loops of TMEM16/anoctamin channels affect channel density in cell membranes.

    PubMed

    Adomaviciene, Aiste; Smith, Keith J; Garnett, Hannah; Tammaro, Paolo

    2013-07-15

    The recently identified TMEM16/anoctamin protein family includes Ca(2+)-activated anion channels (TMEM16A, TMEM16B), a cation channel (TMEM16F) and proteins with unclear function. TMEM16 channels consist of eight putative transmembrane domains (TMs) with TM5-TM6 flanking a re-entrant loop thought to form the pore. In TMEM16A this region has also been suggested to contain residues involved in Ca(2+) binding. The role of the putative pore-loop of TMEM16 channels was investigated using a chimeric approach. Heterologous expression of either TMEM16A or TMEM16B resulted in whole-cell anion currents with very similar conduction properties but distinct kinetics and degrees of sensitivity to Ca(2+). Furthermore, whole-cell currents mediated by TMEM16A channels were ∼six times larger than TMEM16B-mediated currents. Replacement of the putative pore-loop of TMEM16A with that of TMEM16B (TMEM16A-B channels) reduced the currents by ∼six-fold, while the opposite modification (TMEM16B-A channels) produced a ∼six-fold increase in the currents. Unexpectedly, these changes were not secondary to variations in channel gating by Ca(2+) or voltage, nor were they due to changes in single-channel conductance. Instead, they depended on the number of functional channels present on the plasma membrane. Generation of additional, smaller chimeras within the putative pore-loop of TMEM16A and TMEM16B led to the identification of a region containing a non-canonical trafficking motif. Chimeras composed of the putative pore-loop of TMEM16F transplanted into the TMEM16A protein scaffold did not conduct anions or cations. These data suggest that the putative pore-loop does not form a complete, transferable pore domain. Furthermore, our data reveal an unexpected role for the putative pore-loop of TMEM16A and TMEM16B channels in the control of the whole-cell Ca(2+)-activated Cl(-) conductance. PMID:23613533

  14. Thermoelectric Converter for Loop Heat Pipe Temperature Control: Experience and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Ottenstein, Laura

    2010-01-01

    This paper describes the theoretical background and implementation methodology of using a thermoelectric converter (TEC) for operating temperature control of a loop heat pipe (LHP). In particular, experimental results from ambient and thermal vacuum tests of an LHP are presented for illustrations. The most commonly used state-of-the-art method to control the LHP operating temperature is to cold bias its compensation chamber (CC) and use an electrical heater to maintain the CC at the desired set point temperature. Although effective, this approach has its shortcomings in that the electrical heater can only provide heating to the CC, and the required power can be large under certain conditions. An alternative method is to use a TEC, which is capable of providing both heating and cooling to the CC. In this method, one side of the TEC is attached to the CC, and the other side is connected to the evaporator via a thermal strap. Using a bipolar power supply and a control algorithm, a TEC can function as a heater or a cooler, depending on the direction of the current flow. Extensive ground tests of several LHPs have demonstrated that a TEC can provide very tight temperature control for the CC. It also offers several additional advantages: (1) The LHP can operate at temperatures below its natural operating temperature at low heat loads; (2) The required heater power for a TEC is much less than that for an electrical heater; and (3) It enhances the LHP start-up success. Although the concept of using a TEC for LHP temperature control is simple, there are many factors to be considered in its implementation for space applications because the TEC is susceptible to the shear stress and yet has to sustain the dynamic load under the spacecraft launch environment. The added features that help the TEC to withstand the dynamic load will inevitably affect the TEC thermal performance. Some experiences and lessons learned are addressed in this paper.

  15. Size, but not experience, affects the ontogeny of constriction performance in ball pythons (Python regius).

    PubMed

    Penning, David A; Dartez, Schuyler F

    2016-03-01

    Constriction is a prey-immobilization technique used by many snakes and is hypothesized to have been important to the evolution and diversification of snakes. However, very few studies have examined the factors that affect constriction performance. We investigated constriction performance in ball pythons (Python regius) by evaluating how peak constriction pressure is affected by snake size, sex, and experience. In one experiment, we tested the ontogenetic scaling of constriction performance and found that snake diameter was the only significant factor determining peak constriction pressure. The number of loops applied in a coil and its interaction with snake diameter did not significantly affect constriction performance. Constriction performance in ball pythons scaled differently than in other snakes that have been studied, and medium to large ball pythons are capable of exerting significantly higher pressures than those shown to cause circulatory arrest in prey. In a second experiment, we tested the effects of experience on constriction performance in hatchling ball pythons over 10 feeding events. By allowing snakes in one test group to gain constriction experience, and manually feeding snakes under sedation in another test group, we showed that experience did not affect constriction performance. During their final (10th) feedings, all pythons constricted similarly and with sufficiently high pressures to kill prey rapidly. At the end of the 10 feeding trials, snakes that were allowed to constrict were significantly smaller than their non-constricting counterparts. J. Exp. Zool. 9999A:XX-XX, 2016. © 2016 Wiley Periodicals, Inc. PMID:26847931

  16. W-1 Sodium Loop Safety Facility experiment centerline fuel thermocouple performance. [LMFBR

    SciTech Connect

    Meyers, S.C.; Henderson, J.M.

    1980-05-01

    The W-1 Sodium Loop Safety Facility (SLSF) experiment is the fifth in a series of experiments sponsored by the Department of Energy (DOE) as part of the National Fast Breeder Reactor (FBR) Safety Assurance Program. The experiments are being conducted under the direction of Argonne National Laboratory (ANL) and Hanford Engineering Development Laboratory (HEDL). The irradiation phase of the W-1 SLSF experiment was conducted between May 27 and July 20, 1979, and terminated with incipient fuel pin cladding failure during the final boiling transient. Experimental hardware and facility performed as designed, allowing completion of all planned tests and test objectives. This paper focuses on high temperature in-fuel thermocouples and discusses their development, fabrication, and performance in the W-1 experiment.

  17. Positioning of extracellular loop 1 affects pore gating of the cystic fibrosis transmembrane conductance regulator.

    PubMed

    Infield, Daniel T; Cui, Guiying; Kuang, Christopher; McCarty, Nael A

    2016-03-01

    The cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is a chloride ion channel, the dysfunction of which directly leads to the life-shortening disease CF. Extracellular loop 1 (ECL1) of CFTR contains several residues involved in stabilizing the open state of the channel; some, including D110, are sites of disease-associated gating mutations. Structures from related proteins suggest that the position of CFTR's extracellular loops may change considerably during gating. To better understand the roles of ECL1 in CFTR function, we utilized functional cysteine cross-linking to determine the effects of modulation of D110C-CFTR and of a double mutant of D110C with K892C in extracellular loop 4 (ECL4). The reducing agent DTT elicited a large potentiation of the macroscopic conductance of D110C/K892C-CFTR, likely due to breakage of a spontaneous disulfide bond between C110 and C892. DTT-reduced D110C/K892C-CFTR was rapidly inhibited by binding cadmium ions with high affinity, suggesting that these residues frequently come in close proximity in actively gating channels. Effects of DTT and cadmium on modulation of pore gating were demonstrated at the single-channel level. Finally, disulfided D110C/K892C-CFTR channels were found to be less sensitive than wild-type or DTT-treated D110C/K892C-CFTR channels to stimulation by IBMX, suggesting an impact of this conformational restriction on channel activation by phosphorylation. The results are best explained in the context of a model of CFTR gating wherein stable channel opening requires correct positioning of functional elements structurally influenced by ECL1. PMID:26684250

  18. Micellar lipid composition affects micelle interaction with class B scavenger receptor extracellular loops.

    PubMed

    Goncalves, Aurélie; Gontero, Brigitte; Nowicki, Marion; Margier, Marielle; Masset, Gabriel; Amiot, Marie-Josèphe; Reboul, Emmanuelle

    2015-06-01

    Scavenger receptors (SRs) like cluster determinant 36 (CD36) and SR class B type I (SR-BI) play a debated role in lipid transport across the intestinal brush border membrane. We used surface plasmon resonance to analyze real-time interactions between the extracellular protein loops and various ligands ranging from single lipid molecules to mixed micelles. Micelles mimicking physiological structures were necessary for optimal binding to both the extracellular loop of CD36 (lCD36) and the extracellular loop of SR-BI (lSR-BI). Cholesterol, phospholipid, and fatty acid micellar content significantly modulated micelle binding to and dissociation from the transporters. In particular, high phospholipid micellar concentrations inhibited micelle binding to both receptors (-53.8 and -74.4% binding at 0.32 mM compared with 0.04 mM for lCD36 and lSR-BI, respectively, P < 0.05). The presence of fatty acids was crucial for micelle interactions with both proteins (94.4 and 81.3% binding with oleic acid for lCD36 and lSR-BI, respectively, P < 0.05) and fatty acid type substitution within the micelles was the component that most impacted micelle binding to the transporters. These effects were partly due to subsequent modifications in micellar size and surface electric charge, and could be correlated to micellar vitamin D uptake by Caco-2 cells. Our findings show for the first time that micellar lipid composition and micellar properties are key factors governing micelle interactions with SRs. PMID:25833688

  19. Characterizing W-2 SLSF experiment temperature oscillations using computer graphics. [Sodium Loop Safety Facility

    SciTech Connect

    Smith, D.E.

    1983-06-23

    The W-2 SLSF (Sodium Loop Safety Facility) experiment was an instrumented in-reactor test performed to characterize the failure response of full-length, preconditioned LMFBR prototypic fuel pins to slow transient overpower (TOP) conditions. Although the test results were expected to confirm analytical predictions of upper level failure and fuel expulsion, an axial midplane failure was experienced. Extensive post-test analyses were conducted to understand all of the unexpected behavior in the experiment. (1) The initial post-test effort focused on the temperature oscillations recorded by the 54 thermocouples used in the experiment. In order to synthesize the extensive data records and identify patterns of behavior in the data records, a computer-generated film was used to present the temperature data recorded during the experiment.

  20. A dynamic RNA loop in an IRES affects multiple steps of elongation factor-mediated translation initiation

    PubMed Central

    Ruehle, Marisa D; Zhang, Haibo; Sheridan, Ryan M; Mitra, Somdeb; Chen, Yuanwei; Gonzalez, Ruben L; Cooperman, Barry S; Kieft, Jeffrey S

    2015-01-01

    Internal ribosome entry sites (IRESs) are powerful model systems to understand how the translation machinery can be manipulated by structured RNAs and for exploring inherent features of ribosome function. The intergenic region (IGR) IRESs from the Dicistroviridae family of viruses are structured RNAs that bind directly to the ribosome and initiate translation by co-opting the translation elongation cycle. These IRESs require an RNA pseudoknot that mimics a codon-anticodon interaction and contains a conformationally dynamic loop. We explored the role of this loop and found that both the length and sequence are essential for translation in different types of IGR IRESs and from diverse viruses. We found that loop 3 affects two discrete elongation factor-dependent steps in the IRES initiation mechanism. Our results show how the IRES directs multiple steps after 80S ribosome placement and highlights the often underappreciated significance of discrete conformationally dynamic elements within the context of structured RNAs. DOI: http://dx.doi.org/10.7554/eLife.08146.001 PMID:26523395

  1. Optical Phase-Locked Loops: Performance Investigation and Psk Synchronous Communication System Experiments

    NASA Astrophysics Data System (ADS)

    Atlas, Dogan A.

    1990-01-01

    This thesis study presents the design/analysis considerations, fundamental performance limitations and the experimental set-up of an optical phase-locked loop which is employed in phase-shift keying homodyne and synchronous heterodyne optical fiber communication system experiments. From an optical communication systems point of view, the characteristics of the lightwave sources to be used are important to investigate. Therefore, frequency modulation, frequency noise and intensity noise characteristics of 1320-nm (227 THz) laser-diode-pumped miniature Nd:YAG ring lasers have been investigated. The modulation and noise properties of these lasers are characterized both qualitatively and quantitatively. For applications such as optical phase-locking, phase-shift keying homodyne and synchronous heterodyne optical fiber and optical free -space communication systems, subcarrier multiplexing systems, and microwave phase array antennas diode-pumped Nd:YAG lasers are excellent lightwave sources. The reasons that make these lasers attractive candidates for such a variety of applications include the narrow laser linewidth, the uniformly flat frequency modulation response and the wide frequency modulation bandwidth. A stable second-order optical phase-locked loop has been constructed using two Nd:YAG lasers and a balanced optical receiver. The loop is designed so that the local oscillator laser locks to the frequency/phase variations of the transmitter laser. The frequency/phase tracking performance of the loop is limited by the quantum phase noise and mainly by the frequency drift induced by the temperature variations of both the transmitter and local oscillator laser cavities. Using the loop, optical phase -shift keying homodyne communication system experiments are demonstrated at modulation rates of 140 Mb/s and 2 Gb/s. The receiver sensitivity at 140 Mb/s is 25 photons/bit which is the highest sensitivity reported to date with any optical communication system. An optical

  2. Juicer Provides a One-Click System for Analyzing Loop-Resolution Hi-C Experiments.

    PubMed

    Durand, Neva C; Shamim, Muhammad S; Machol, Ido; Rao, Suhas S P; Huntley, Miriam H; Lander, Eric S; Aiden, Erez Lieberman

    2016-07-01

    Hi-C experiments explore the 3D structure of the genome, generating terabases of data to create high-resolution contact maps. Here, we introduce Juicer, an open-source tool for analyzing terabase-scale Hi-C datasets. Juicer allows users without a computational background to transform raw sequence data into normalized contact maps with one click. Juicer produces a hic file containing compressed contact matrices at many resolutions, facilitating visualization and analysis at multiple scales. Structural features, such as loops and domains, are automatically annotated. Juicer is available as open source software at http://aidenlab.org/juicer/. PMID:27467249

  3. Design and development of a two-phase reservoir for the Capillary Pumped Loop (CAPL) Flight Experiment

    NASA Technical Reports Server (NTRS)

    Wolf, David A.

    1992-01-01

    The Capillary Pumped Loop (CAPL) Flight Experiment has undergone numerous design modifications to reflect recent changes in the thermal control system baselined for Earth Observation System (EOS) spacecraft. The experiment redesign has also allowed technological advances in two-phase fluid loop components to be incorporated. The experiment's reservoir is one of the components targeted for redesign. The design and development of a new reservoir for the CAPL Flight Experiment is discussed in this paper. A prototype reservoir is described, and a hydrodynamic analysis of its wick structure is included. Testing of the prototype reservoir is also discussed.

  4. Temperature-dependent conformational change affecting Tyr11 and sweetness loops of brazzein

    PubMed Central

    Cornilescu, Claudia C.; Cornilescu, Gabriel; Rao, Hongyu; Porter, Sarah F.; Tonelli, Marco; DeRider, Michele L.; Markley, John L.; Assadi-Porter, Fariba M.

    2014-01-01

    The sweet protein brazzein, a member of the Csβα fold family, contains four disulfide bonds that lend a high degree of thermal and pH stability to its structure. Nevertheless, a variable temperature study has revealed that the protein undergoes a local, reversible conformational change between 37 and 3°C with a midpoint about 27°C that changes the orientations and side-chain hydrogen bond partners of Tyr8 and Tyr11. To test the functional significance of this effect, we used NMR saturation transfer to investigate the interaction between brazzein and the amino terminal domain of the sweet receptor subunit T1R2; the results showed a stronger interaction at 7°C than at 37°C. Thus the low temperature conformation, which alters the orientations of two loops known to be critical for the sweetness of brazzein, may represent the bound state of brazzein in the complex with the human sweet receptor. PMID:23349025

  5. [The Affect Experience and Affect Regulation Q-Sort Test (AREQ): validation and short version].

    PubMed

    Löffler-Stastka, Henriette; Stigler, Katharina

    2011-05-01

    Affect experience and affect regulation are based on varying concepts and the integration of this constructs is discussed controversy. The AREQ - Affect Experience and Affect Regulation Q-sort Test, an expert rating, covers the need of an integrated method to explore the emotional functioning of patients. This is the validation of the german version of the AREQ. Based on statistical considerations and in order to create a practicable and time efficient instrument, which is necessary to display the course and process of a therapy, we created a short version of the AREQ. In this short version only significant items are included, and therefore the time for the implementation is much shorter. The results of the statistical calculations show better psychometric properties for the short version. Especially the scales, which are defined by the original version, show better reliability and account in different samples for 60-73% of the variance. PMID:20845255

  6. Sodium Loop Safety Facility W-2 experiment fuel pin rupture detection system. [LMFBR

    SciTech Connect

    Hoffman, M.A.; Kirchner, T.L.; Meyers, S.C.

    1980-05-01

    The objective of the Sodium Loop Safety Facility (SLSF) W-2 experiment is to characterize the combined effects of a preconditioned full-length fuel column and slow transient overpower (TOP) conditions on breeder reactor (BR) fuel pin cladding failures. The W-2 experiment will meet this objective by providing data in two technological areas: (1) time and location of cladding failure, and (2) early post-failure test fuel behavior. The test involves a seven pin, prototypic full-length fast test reactor (FTR) fuel pin bundle which will be subjected to a simulated unprotected 5 cents/s reactivity transient overpower event. The outer six pins will provide the necessary prototypic thermal-hydraulic environment for the center pin.

  7. Family Transmission of Work Affectivity and Experiences to Children

    ERIC Educational Resources Information Center

    Porfeli, Erik J.; Wang, Chuang; Hartung, Paul J.

    2008-01-01

    Theory and research suggest that children develop orientations toward work appreciably influenced by their family members' own expressed work experiences and emotions. Cross-sectional data from 100 children (53 girls, 47 boys; mean age = 11.1 years) and structural equation modeling were used to assess measures of work affectivity and experiences…

  8. Experiences with the magnetism of conducting loops: Historical instruments, experimental replications, and productive confusions

    NASA Astrophysics Data System (ADS)

    Cavicchi, Elizabeth

    2003-02-01

    This study investigates nineteenth century laboratory work on electromagnetism through historical accounts and experimental replications. Oersted found that when a magnetic needle was placed in varying positions around a conducting wire, its orientation changed: in moving from a spot above the wire to one below, its sense inverted. This behavior was confusing and provocative. Early experimenters such as Johann Schweigger, Johann Poggendorff, and James Cumming engaged it by bending wire into loops. These loops, which increased the magnetic effect on a compass placed within, also provided evidence of their understanding and confusion. Coiling conducting wires around iron magnetized it, but when some wires coiled oppositely from others, the effect diminished. This effect confused contemporaries of Joseph Henry who made electromagnets, and amateurs later in the century who constructed multisection induction coils. I experienced these confusions myself while working with multilayer coils and induction coils that I made to replicate the historical instruments. This study shows how confusion can be a productive element in learning, by engaging learners to ask questions and invent experiments. By providing space for learners' confusions, teachers can support the development of their students' physical understandings.

  9. Sex differences in the neural correlates of affective experience

    PubMed Central

    Moriguchi, Yoshiya; Touroutoglou, Alexandra; Dickerson, Bradford C.

    2014-01-01

    People believe that women are more emotionally intense than men, but the scientific evidence is equivocal. In this study, we tested the novel hypothesis that men and women differ in the neural correlates of affective experience, rather than in the intensity of neural activity, with women being more internally (interoceptively) focused and men being more externally (visually) focused. Adult men (n = 17) and women (n = 17) completed a functional magnetic resonance imaging study while viewing affectively potent images and rating their moment-to-moment feelings of subjective arousal. We found that men and women do not differ overall in their intensity of moment-to-moment affective experiences when viewing evocative images, but instead, as predicted, women showed a greater association between the momentary arousal ratings and neural responses in the anterior insula cortex, which represents bodily sensations, whereas men showed stronger correlations between their momentary arousal ratings and neural responses in the visual cortex. Men also showed enhanced functional connectivity between the dorsal anterior insula cortex and the dorsal anterior cingulate cortex, which constitutes the circuitry involved with regulating shifts of attention to the world. These results demonstrate that the same affective experience is realized differently in different people, such that women’s feelings are relatively more self-focused, whereas men’s feelings are relatively more world-focused. PMID:23596188

  10. Evolution of plasma loops in a semi-toroidal pinch experiment

    SciTech Connect

    Mackel, F. Ridder, S.; Tenfelde, J.; Tacke, T.; Soltwisch, H.

    2015-04-15

    The FlareLab experiment is a pulsed-power discharge generating magnetized plasma loops similar to a pinch experiment in a semi-toroidal configuration. After gas breakdown along a circular magnetic guide field, the structure expands in its major radius as the plasma becomes highly conductive and the discharge current rises. Photographs, current and electron density measurements reveal a significant broadening in the lateral direction leading to an increasing departure from radial symmetry of plasma parameters in the cross section. It is shown that the luminosity is related to both high electron density and high current density. Simultaneous measurements of current density and electric field reveal a high parallel resistivity of the plasma leading to fast diffusion across the magnetic field. Indications for anomalous resistivity are found by comparison with the Spitzer formula. As the experiment differs from a z-pinch experiment only by the semi-circular shape of the current path, the observed evolution is unexpected and might be of more fundamental significance.

  11. The Impact of Experience on Affective Responses during Action Observation

    PubMed Central

    Kirsch, Louise P.; Snagg, Arielle; Heerey, Erin

    2016-01-01

    Perceiving others in action elicits affective and aesthetic responses in observers. The present study investigates the extent to which these responses relate to an observer’s general experience with observed movements. Facial electromyographic (EMG) responses were recorded in experienced dancers and non-dancers as they watched short videos of movements performed by professional ballet dancers. Responses were recorded from the corrugator supercilii (CS) and zygomaticus major (ZM) muscles, both of which show engagement during the observation of affect-evoking stimuli. In the first part of the experiment, participants passively watched the videos while EMG data were recorded. In the second part, they explicitly rated how much they liked each movement. Results revealed a relationship between explicit affective judgments of the movements and facial muscle activation only among those participants who were experienced with the movements. Specifically, CS activity was higher for disliked movements and ZM activity was higher for liked movements among dancers but not among non-dancers. The relationship between explicit liking ratings and EMG data in experienced observers suggests that facial muscles subtly echo affective judgments even when viewing actions that are not intentionally emotional in nature, thus underscoring the potential of EMG as a method to examine subtle shifts in implicit affective responses during action observation. PMID:27149106

  12. The Impact of Experience on Affective Responses during Action Observation.

    PubMed

    Kirsch, Louise P; Snagg, Arielle; Heerey, Erin; Cross, Emily S

    2016-01-01

    Perceiving others in action elicits affective and aesthetic responses in observers. The present study investigates the extent to which these responses relate to an observer's general experience with observed movements. Facial electromyographic (EMG) responses were recorded in experienced dancers and non-dancers as they watched short videos of movements performed by professional ballet dancers. Responses were recorded from the corrugator supercilii (CS) and zygomaticus major (ZM) muscles, both of which show engagement during the observation of affect-evoking stimuli. In the first part of the experiment, participants passively watched the videos while EMG data were recorded. In the second part, they explicitly rated how much they liked each movement. Results revealed a relationship between explicit affective judgments of the movements and facial muscle activation only among those participants who were experienced with the movements. Specifically, CS activity was higher for disliked movements and ZM activity was higher for liked movements among dancers but not among non-dancers. The relationship between explicit liking ratings and EMG data in experienced observers suggests that facial muscles subtly echo affective judgments even when viewing actions that are not intentionally emotional in nature, thus underscoring the potential of EMG as a method to examine subtle shifts in implicit affective responses during action observation. PMID:27149106

  13. Natural Circulation of Lead-Bismuth in a One-Dimensional Loop: Experiments and Code Predictions

    SciTech Connect

    Agostini, P.; Bertacci, G.; Gherardi, G.; Bianchi, F.; Meloni, P.; Nicolini, D.; Ambrosini, W.; Forgione, F.; Fruttuoso, G.; Oriolo, F.

    2002-07-01

    The paper summarizes the results obtained by an experimental and computational study jointly performed by ENEA and University of Pisa. The study is aimed at assessing the capabilities of an available thermal-hydraulic system code in simulating natural circulation in a loop in which the working fluid is the eutectic lead-bismuth alloy as in the Italian proposal for Accelerator Driven System (ADS) reactor concepts. Experiments were performed in the CHEOPE facility installed at the ENEA Brasimone Research Centre and pre- and post-test calculations were run using a version of the RELAP5/Mod.3.2, purposely modified to account for Pb-Bi liquid alloy properties and behavior. The main results obtained by the experimental tests and by the code analyses are presented in the paper providing material to discuss the present predictive capabilities of transient and steady-state behavior in liquid Pb-Bi systems. (authors)

  14. Design and Testing of a Cryogenic Capillary Pumped Loop Flight Experiment

    NASA Technical Reports Server (NTRS)

    Bugby, David C.; Kroliczek, Edward J.; Ku, Jentung; Swanson, Ted; Tomlinson, B. J.; Davis, Thomas M.; Baumann, Jane; Cullimore, Brent

    1998-01-01

    This paper details the flight configuration and pre-flight performance test results of the fifth generation cryogenic capillary pumped loop (CCPL-5). This device will fly on STS-95 in October 1998 as part of the CRYOTSU Flight Experiment. This flight represents the first in-space demonstration of a CCPL, a miniaturized two-phase fluid circulator for thermally linking cryogenic cooling sources to remote cryogenic components. CCPL-5 utilizes N2 as the working fluid and has a practical operating range of 75-110 K. Test results indicate that CCPL-5, which weighs about 200 grams, can transport over 10 W of cooling a distance of 0.25 m (or more) with less than a 5 K temperature drop.

  15. Design and Testing of a Cryogenic Capillary Pumped Loop Flight Experiment

    NASA Technical Reports Server (NTRS)

    Bugby, David C.; Kroliczek, Edward J.; Ku, Jentung; Swanson, Ted; Tomlinson, B. J.; Davis, Thomas M.; Baumann, Jane; Cullimore, Brent

    1998-01-01

    This paper details the flight configuration and pre-flight performance test results of the fifth generation cryogenic capillary pumped loop (CCPL-5). This device will fly on STS-95 in October 1998 as part of the CRYOTSU Flight Experiment. This flight represents the first in-space demonstration of a CCPL; a miniaturized two-phase fluid circulator for thermally linking cryogenic components. CCPL-5 utilizes N2 as the working fluid and has a practical operating range of 75-110 K. Test results indicate that CCPL-5, which weighs about 200 grams, can transport over 10 W of cooling a distance of 0.25 m (or more) with less than a 5 K temperature drop.

  16. Protective measures, personal experience, and the affective psychology of time.

    PubMed

    Peters, E; Kunreuther, H; Sagara, N; Slovic, P; Schley, D R

    2012-12-01

    We examined the role of time and affect in intentions to purchase a risk-protective measure (Studies 1 and 2) and explored participant abilities to factor time into the likelihood judgments that presumably underlie such intentions (Study 3). Participants worried more about losing their possessions and were more likely to purchase a protective measure given a longer term lease than a short-term lease, but only if their belongings were described in affect-poor terms. If described instead as being particularly special and affect-rich, participants neglected time and were about equally likely to purchase a risk-protective measure for shorter and longer term leases. However, and consistent with prior literature, the cognitive mechanism underlying this time-neglect-with-affect-richness effect seemed to be the greater use of the affect heuristic in the shorter term than the longer term. Study 2 results demonstrated that prior experience with having been burglarized amplified the interactive effect of time and affect. Greater deliberation did not attenuate this effect as hypothesized whether deliberation was measured through numeracy or manipulated through instructions. The results of Study 3 indicated that few participants are able to calculate correctly the risk numbers necessary to take time into account. Two possible solutions to encourage more purchases of protective measures in the long term are discussed. PMID:22548249

  17. Interconvertible lac repressor-DNA loops revealed by single-molecule experiments.

    PubMed

    Wong, Oi Kwan; Guthold, Martin; Erie, Dorothy A; Gelles, Jeff

    2008-09-30

    At many promoters, transcription is regulated by simultaneous binding of a protein to multiple sites on DNA, but the structures and dynamics of such transcription factor-mediated DNA loops are poorly understood. We directly examined in vitro loop formation mediated by Escherichia coli lactose repressor using single-molecule structural and kinetics methods. Small ( approximately 150 bp) loops form quickly and stably, even with out-of-phase operator spacings. Unexpectedly, repeated spontaneous transitions between two distinct loop structures were observed in individual protein-DNA complexes. The results imply a dynamic equilibrium between a novel loop structure with the repressor in its crystallographic "V" conformation and a second structure with a more extended linear repressor conformation that substantially lessens the DNA bending strain. The ability to switch between different loop structures may help to explain how robust transcription regulation is maintained even though the mechanical work required to form a loop may change substantially with metabolic conditions. PMID:18828671

  18. Interconvertible Lac Repressor--DNA Loops Revealed by Single-Molecule Experiments

    NASA Astrophysics Data System (ADS)

    Guthold, Martin

    2009-03-01

    At many promoters, transcription is regulated by simultaneous binding of a protein to multiple sites on DNA, but the structures and dynamics of such transcription factor-mediated DNA loops are poorly understood. We directly examined in vitro loop formation mediated by E. coli lactose repressor using single-molecule structural and kinetics methods. Small (150 bp) loops form quickly and stably, even with out-of-phase operator spacings. Unexpectedly, repeated spontaneous transitions between two distinct loop structures were observed in individual protein--DNA complexes. The results imply a dynamic equilibrium between a novel loop structure with the repressor in its crystallographic ``V'' conformation and a second structure with a more extended linear repressor conformation that substantially lessens the DNA bending strain. The ability to switch between different loop structures may help to explain how robust transcription regulation is maintained even though the mechanical work required to form a loop may change substantially with metabolic conditions.

  19. Fighting experience affects fruit fly behavior in a mating context

    NASA Astrophysics Data System (ADS)

    Teseo, Serafino; Veerus, Liisa; Mery, Frédéric

    2016-06-01

    In animals, correlations exist among behaviors within individuals, but it is unclear whether experience in a specific functional context can affect behavior across different contexts. Here, we use Drosophila melanogaster to investigate the effects of conflict-induced behavioral modifications on male mating behavior. In D. melanogaster, males fight for territories and experience a strong winner-loser effect, meaning that winners become more likely to win subsequent fights compared to losers, who continue to lose. In our protocol, males were tested for courtship intensity before and after fighting against other males. We show that male motivation to copulate before fights cannot predict the fight outcomes, but that, afterwards, losers mate less than before and less than winner and control males. Contrarily, winners show no differences between pre- and post-fight courtship intensity, and do not differ from control males. This suggests that the physiological modifications resulting from fight outcomes indirectly affect male reproductive behavior.

  20. Fighting experience affects fruit fly behavior in a mating context.

    PubMed

    Teseo, Serafino; Veerus, Liisa; Mery, Frédéric

    2016-06-01

    In animals, correlations exist among behaviors within individuals, but it is unclear whether experience in a specific functional context can affect behavior across different contexts. Here, we use Drosophila melanogaster to investigate the effects of conflict-induced behavioral modifications on male mating behavior. In D. melanogaster, males fight for territories and experience a strong winner-loser effect, meaning that winners become more likely to win subsequent fights compared to losers, who continue to lose. In our protocol, males were tested for courtship intensity before and after fighting against other males. We show that male motivation to copulate before fights cannot predict the fight outcomes, but that, afterwards, losers mate less than before and less than winner and control males. Contrarily, winners show no differences between pre- and post-fight courtship intensity, and do not differ from control males. This suggests that the physiological modifications resulting from fight outcomes indirectly affect male reproductive behavior. PMID:27108453

  1. Experiments on chemical looping combustion of coal with a NiO based oxygen carrier

    SciTech Connect

    Shen, Laihong; Wu, Jiahua; Xiao, Jun

    2009-03-15

    A chemical looping combustion process for coal using interconnected fluidized beds with inherent separation of CO{sub 2} is proposed in this paper. The configuration comprises a high velocity fluidized bed as an air reactor, a cyclone, and a spout-fluid bed as a fuel reactor. The high velocity fluidized bed is directly connected to the spout-fluid bed through the cyclone. Gas composition of both fuel reactor and air reactor, carbon content of fly ash in the fuel reactor, carbon conversion efficiency and CO{sub 2} capture efficiency were investigated experimentally. The results showed that coal gasification was the main factor which controlled the contents of CO and CH{sub 4} concentrations in the flue gas of the fuel reactor, carbon conversion efficiency in the process of chemical looping combustion of coal with NiO-based oxygen carrier in the interconnected fluidized beds. Carbon conversion efficiency reached only 92.8% even when the fuel reactor temperature was high up to 970 C. There was an inherent carbon loss in the process of chemical looping combustion of coal in the interconnected fluidized beds. The inherent carbon loss was due to an easy elutriation of fine char particles from the freeboard of the spout-fluid bed, which was inevitable in this kind of fluidized bed reactor. Further improvement of carbon conversion efficiency could be achieved by means of a circulation of fine particles elutriation into the spout-fluid bed or the high velocity fluidized bed. CO{sub 2} capture efficiency reached to its equilibrium of 80% at the fuel reactor temperature of 960 C. The inherent loss of CO{sub 2} capture efficiency was due to bypassing of gases from the fuel reactor to the air reactor, and the product of residual char burnt with air in the air reactor. Further experiments should be performed for a relatively long-time period to investigate the effects of ash and sulfur in coal on the reactivity of nickel-based oxygen carrier in the continuous CLC reactor

  2. Closed-loop control of renal perfusion pressure in physiological experiments.

    PubMed

    Campos-Delgado, D U; Bonilla, I; Rodríguez-Martínez, M; Sánchez-Briones, M E; Ruiz-Hernández, E

    2013-07-01

    This paper presents the design, experimental modeling, and control of a pump-driven renal perfusion pressure (RPP)-regulatory system to implement precise and relatively fast RPP regulation in rats. The mechatronic system is a simple, low-cost, and reliable device to automate the RPP regulation process based on flow-mediated occlusion. Hence, the regulated signal is the RPP measured in the left femoral artery of the rat, and the manipulated variable is the voltage applied to a dc motor that controls the occlusion of the aorta. The control system is implemented in a PC through the LabView software, and a data acquisition board NI USB-6210. A simple first-order linear system is proposed to approximate the dynamics in the experiment. The parameters of the model are chosen to minimize the error between the predicted and experimental output averaged from eight input/output datasets at different RPP operating conditions. A closed-loop servocontrol system based on a pole-placement PD controller plus dead-zone compensation was proposed for this purpose. First, the feedback structure was validated in simulation by considering parameter uncertainty, and constant and time-varying references. Several experimental tests were also conducted to validate in real time the closed-loop performance for stepwise and fast switching references, and the results show the effectiveness of the proposed automatic system to regulate the RPP in the rat, in a precise, accurate (mean error less than 2 mmHg) and relatively fast mode (10-15 s of response time). PMID:23358945

  3. The impact of sensorimotor experience on affective evaluation of dance

    PubMed Central

    Kirsch, Louise P.; Drommelschmidt, Kim A.; Cross, Emily S.

    2013-01-01

    Past research demonstrates that we are more likely to positively evaluate a stimulus if we have had previous experience with that stimulus. This has been shown for judgment of faces, architecture, artworks and body movements. In contrast, other evidence suggests that this relationship can also work in the inverse direction, at least in the domain of watching dance. Specifically, it has been shown that in certain contexts, people derive greater pleasure from watching unfamiliar movements they would not be able to physically reproduce compared to simpler, familiar actions they could physically reproduce. It remains unknown, however, how different kinds of experience with complex actions, such as dance, might change observers' affective judgments of these movements. Our aim was to clarify the relationship between experience and affective evaluation of whole body movements. In a between-subjects design, participants received either physical dance training with a video game system, visual and auditory experience or auditory experience only. Participants' aesthetic preferences for dance stimuli were measured before and after the training sessions. Results show that participants from the physical training group not only improved their physical performance of the dance sequences, but also reported higher enjoyment and interest in the stimuli after training. This suggests that physically learning particular movements leads to greater enjoyment while observing them. These effects are not simply due to increased familiarity with audio or visual elements of the stimuli, as the other two training groups showed no increase in aesthetic ratings post-training. We suggest these results support an embodied simulation account of aesthetics, and discuss how the present findings contribute to a better understanding of the shaping of preferences by sensorimotor experience. PMID:24027511

  4. The impact of sensorimotor experience on affective evaluation of dance.

    PubMed

    Kirsch, Louise P; Drommelschmidt, Kim A; Cross, Emily S

    2013-01-01

    Past research demonstrates that we are more likely to positively evaluate a stimulus if we have had previous experience with that stimulus. This has been shown for judgment of faces, architecture, artworks and body movements. In contrast, other evidence suggests that this relationship can also work in the inverse direction, at least in the domain of watching dance. Specifically, it has been shown that in certain contexts, people derive greater pleasure from watching unfamiliar movements they would not be able to physically reproduce compared to simpler, familiar actions they could physically reproduce. It remains unknown, however, how different kinds of experience with complex actions, such as dance, might change observers' affective judgments of these movements. Our aim was to clarify the relationship between experience and affective evaluation of whole body movements. In a between-subjects design, participants received either physical dance training with a video game system, visual and auditory experience or auditory experience only. Participants' aesthetic preferences for dance stimuli were measured before and after the training sessions. Results show that participants from the physical training group not only improved their physical performance of the dance sequences, but also reported higher enjoyment and interest in the stimuli after training. This suggests that physically learning particular movements leads to greater enjoyment while observing them. These effects are not simply due to increased familiarity with audio or visual elements of the stimuli, as the other two training groups showed no increase in aesthetic ratings post-training. We suggest these results support an embodied simulation account of aesthetics, and discuss how the present findings contribute to a better understanding of the shaping of preferences by sensorimotor experience. PMID:24027511

  5. The iso-response method: measuring neuronal stimulus integration with closed-loop experiments

    PubMed Central

    Gollisch, Tim; Herz, Andreas V. M.

    2012-01-01

    Throughout the nervous system, neurons integrate high-dimensional input streams and transform them into an output of their own. This integration of incoming signals involves filtering processes and complex non-linear operations. The shapes of these filters and non-linearities determine the computational features of single neurons and their functional roles within larger networks. A detailed characterization of signal integration is thus a central ingredient to understanding information processing in neural circuits. Conventional methods for measuring single-neuron response properties, such as reverse correlation, however, are often limited by the implicit assumption that stimulus integration occurs in a linear fashion. Here, we review a conceptual and experimental alternative that is based on exploring the space of those sensory stimuli that result in the same neural output. As demonstrated by recent results in the auditory and visual system, such iso-response stimuli can be used to identify the non-linearities relevant for stimulus integration, disentangle consecutive neural processing steps, and determine their characteristics with unprecedented precision. Automated closed-loop experiments are crucial for this advance, allowing rapid search strategies for identifying iso-response stimuli during experiments. Prime targets for the method are feed-forward neural signaling chains in sensory systems, but the method has also been successfully applied to feedback systems. Depending on the specific question, “iso-response” may refer to a predefined firing rate, single-spike probability, first-spike latency, or other output measures. Examples from different studies show that substantial progress in understanding neural dynamics and coding can be achieved once rapid online data analysis and stimulus generation, adaptive sampling, and computational modeling are tightly integrated into experiments. PMID:23267315

  6. A Moral Experience Feedback Loop: Modeling a System of Moral Self-Cultivation in Everyday Life

    ERIC Educational Resources Information Center

    Sherblom, Stephen A.

    2015-01-01

    This "systems thinking" model illustrates a common feedback loop by which people engage the moral world and continually reshape their moral sensibility. The model highlights seven processes that collectively form this feedback loop: beginning with (1) one's current moral sensibility which shapes processes of (2) perception, (3)…

  7. Effects of mediated social touch on affective experiences and trust.

    PubMed

    Erk, Stefanie M; Toet, Alexander; Van Erp, Jan B F

    2015-01-01

    This study investigated whether communication via mediated hand pressure during a remotely shared experience (watching an amusing video) can (1) enhance recovery from sadness, (2) enhance the affective quality of the experience, and (3) increase trust towards the communication partner. Thereto participants first watched a sad movie clip to elicit sadness, followed by a funny one to stimulate recovery from sadness. While watching the funny clip they signaled a hypothetical fellow participant every time they felt amused. In the experimental condition the participants responded by pressing a hand-held two-way mediated touch device (a Frebble), which also provided haptic feedback via simulated hand squeezes. In the control condition they responded by pressing a button and they received abstract visual feedback. Objective (heart rate, galvanic skin conductance, number and duration of joystick or Frebble presses) and subjective (questionnaires) data were collected to assess the emotional reactions of the participants. The subjective measurements confirmed that the sad movie successfully induced sadness while the funny movie indeed evoked more positive feelings. Although their ranking agreed with the subjective measurements, the physiological measurements confirmed this conclusion only for the funny movie. The results show that recovery from movie induced sadness, the affective experience of the amusing movie, and trust towards the communication partner did not differ between both experimental conditions. Hence, feedback via mediated hand touching did not enhance either of these factors compared to visual feedback. Further analysis of the data showed that participants scoring low on Extraversion (i.e., persons that are more introvert) or low on Touch Receptivity (i.e., persons who do not like to be touched by others) felt better understood by their communication partner when receiving mediated touch feedback instead of visual feedback, while the opposite was found for

  8. Effects of mediated social touch on affective experiences and trust

    PubMed Central

    Erk, Stefanie M.; Van Erp, Jan B.F.

    2015-01-01

    This study investigated whether communication via mediated hand pressure during a remotely shared experience (watching an amusing video) can (1) enhance recovery from sadness, (2) enhance the affective quality of the experience, and (3) increase trust towards the communication partner. Thereto participants first watched a sad movie clip to elicit sadness, followed by a funny one to stimulate recovery from sadness. While watching the funny clip they signaled a hypothetical fellow participant every time they felt amused. In the experimental condition the participants responded by pressing a hand-held two-way mediated touch device (a Frebble), which also provided haptic feedback via simulated hand squeezes. In the control condition they responded by pressing a button and they received abstract visual feedback. Objective (heart rate, galvanic skin conductance, number and duration of joystick or Frebble presses) and subjective (questionnaires) data were collected to assess the emotional reactions of the participants. The subjective measurements confirmed that the sad movie successfully induced sadness while the funny movie indeed evoked more positive feelings. Although their ranking agreed with the subjective measurements, the physiological measurements confirmed this conclusion only for the funny movie. The results show that recovery from movie induced sadness, the affective experience of the amusing movie, and trust towards the communication partner did not differ between both experimental conditions. Hence, feedback via mediated hand touching did not enhance either of these factors compared to visual feedback. Further analysis of the data showed that participants scoring low on Extraversion (i.e., persons that are more introvert) or low on Touch Receptivity (i.e., persons who do not like to be touched by others) felt better understood by their communication partner when receiving mediated touch feedback instead of visual feedback, while the opposite was found for

  9. Phenylnaphthalene Derivatives as Heat Transfer Fluids for Concentrating Solar Power: Loop Experiments and Final Report

    SciTech Connect

    McFarlane, Joanna; Bell, Jason R; Felde, David K; Joseph III, Robert Anthony; Qualls, A L; Weaver, Samuel P

    2013-02-01

    ORNL and subcontractor Cool Energy completed an investigation of higher-temperature, organic thermal fluids for solar thermal applications. Although static thermal tests showed promising results for 1-phenylnaphthalene, loop testing at temperatures to 450 C showed that the material isomerized at a slow rate. In a loop with a temperature high enough to drive the isomerization, the higher melting point byproducts tended to condense onto cooler surfaces. So, as experienced in loop operation, eventually the internal channels of cooler components such as the waste heat rejection exchanger may become coated or clogged and loop performance will decrease. Thus, pure 1-phenylnaphthalene does not appear to be a fluid that would have a sufficiently long lifetime (years to decades) to be used in a loop at the increased temperatures of interest. Hence a decision was made not to test the ORNL fluid in the loop at Cool Energy Inc. Instead, Cool Energy tested and modeled power conversion from a moderate-temperature solar loop using coupled Stirling engines. Cool Energy analyzed data collected on third and fourth generation SolarHeart Stirling engines operating on a rooftop solar field with a lower temperature (Marlotherm) heat transfer fluid. The operating efficiencies of the Stirling engines were determined at multiple, typical solar conditions, based on data from actual cycle operation. Results highlighted the advantages of inherent thermal energy storage in the power conversion system.

  10. Cross-Species Affective Neuroscience Decoding of the Primal Affective Experiences of Humans and Related Animals

    PubMed Central

    Panksepp, Jaak

    2011-01-01

    Background The issue of whether other animals have internally felt experiences has vexed animal behavioral science since its inception. Although most investigators remain agnostic on such contentious issues, there is now abundant experimental evidence indicating that all mammals have negatively and positively-valenced emotional networks concentrated in homologous brain regions that mediate affective experiences when animals are emotionally aroused. That is what the neuroscientific evidence indicates. Principal Findings The relevant lines of evidence are as follows: 1) It is easy to elicit powerful unconditioned emotional responses using localized electrical stimulation of the brain (ESB); these effects are concentrated in ancient subcortical brain regions. Seven types of emotional arousals have been described; using a special capitalized nomenclature for such primary process emotional systems, they are SEEKING, RAGE, FEAR, LUST, CARE, PANIC/GRIEF and PLAY. 2) These brain circuits are situated in homologous subcortical brain regions in all vertebrates tested. Thus, if one activates FEAR arousal circuits in rats, cats or primates, all exhibit similar fear responses. 3) All primary-process emotional-instinctual urges, even ones as complex as social PLAY, remain intact after radical neo-decortication early in life; thus, the neocortex is not essential for the generation of primary-process emotionality. 4) Using diverse measures, one can demonstrate that animals like and dislike ESB of brain regions that evoke unconditioned instinctual emotional behaviors: Such ESBs can serve as ‘rewards’ and ‘punishments’ in diverse approach and escape/avoidance learning tasks. 5) Comparable ESB of human brains yield comparable affective experiences. Thus, robust evidence indicates that raw primary-process (i.e., instinctual, unconditioned) emotional behaviors and feelings emanate from homologous brain functions in all mammals (see Appendix S1), which are regulated by higher

  11. How do musical tonality and experience affect visual working memory?

    PubMed

    Yang, Hua; Lu, Jing; Gong, Diankun; Yao, Dezhong

    2016-01-20

    The influence of music on the human brain has continued to attract increasing attention from neuroscientists and musicologists. Currently, tonal music is widely present in people's daily lives; however, atonal music has gradually become an important part of modern music. In this study, we conducted two experiments: the first one tested for differences in perception of distractibility between tonal music and atonal music. The second experiment tested how tonal music and atonal music affect visual working memory by comparing musicians and nonmusicians who were placed in contexts with background tonal music, atonal music, and silence. They were instructed to complete a delay matching memory task. The results show that musicians and nonmusicians have different evaluations of the distractibility of tonal music and atonal music, possibly indicating that long-term training may lead to a higher auditory perception threshold among musicians. For the working memory task, musicians reacted faster than nonmusicians in all background music cases, and musicians took more time to respond in the tonal background music condition than in the other conditions. Therefore, our results suggest that for a visual memory task, background tonal music may occupy more cognitive resources than atonal music or silence for musicians, leaving few resources left for the memory task. Moreover, the musicians outperformed the nonmusicians because of the higher sensitivity to background music, which also needs a further longitudinal study to be confirmed. PMID:26619232

  12. TREAT MK III Loop Thermoelastoplastic Stress Analysis for the L03 Experiment

    SciTech Connect

    Kennedy, James M.

    1981-03-01

    The STRAW code was used to analyze the static response of a TREAT MK III loop subjected to thermal and mechanical loadings arising from an accident situation for the purpose of determining the defiections and stresses. This analysis provides safety support for the L03 reactivity accident study. The analysis was subdivided into two tasks: (1) an analysis of a flow blockage accident (Cases A and B), where all the energy is assumed deposited in the test leg, resulting in a temperature increase from 530°F to 1720°F, with a small internal pressure throughout the loop and (2) an analysis of a second flow blockage accident (Cases C and D), where again, all the energy is assumed to he deposited in the test leg, resulting in a temperature rise from 530°F to 1845°F, with a small internal pressure throughout the loop. The purpose of these two tasks was to determine if loop failure can occur with the thermal differential across the pump and test legs. Also of interest is whether an undesirable amount of loop lateral deflection will be caused by the thermal differential. A two dimensional analysis of the TREAT MK III loop was performed. The analysis accounted for material nonlinearities, both as a function of temperature and stress, and geometric nonlinearities arising from large deflections. Straight beam elements with annular cross sections were used to model the loop. The analyses show that the maximum strains are less than 21% of their failure strains for all subcases of Cases A and B. For all subcases of cases C and D, the maximum strains are less than 53% of their failure strains. The failure strain is 27.9% for the material at 530°F, 38.1% at 1720°F and 17.8% at 1845°F. Large lateral deflections are observed when the loop is not constrained except at its clamped support--as much as 8.6 inches. However, by accounting for the constraint of the concrete biological shield, the maximum lateral deflection was reduced to less than 0.05 inches at the points of concern.

  13. Experiments on the acoustic solitary wave generated thermoacoustically in a looped tube

    NASA Astrophysics Data System (ADS)

    Shimizu, Dai; Sugimoto, Nobumasa

    2015-10-01

    Emergence of an acoustic solitary wave is demonstrated in a gas-filled, looped tube with an array of Helmholtz resonators connected. The solitary wave is generated thermoacoustically and spontaneously by a pair of stacks positioned diametrically on exactly the opposite side of the loop. The temperature gradient is imposed on both stacks in the same sense along the tube. The stacks made of ceramics and of many square pores are sandwiched by hot and cold heat exchangers. The pressure profile measured and the propagation speed show good agreements with the theoretical ones of the acoustic solitary wave obtained by Sugimoto (J. Acoust. Soc. Am., 99, 1971-1976 (1996)).

  14. Switch-Loop Flexibility Affects Transport of Large Drugs by the Promiscuous AcrB Multidrug Efflux Transporter

    PubMed Central

    Cha, Hi-jea; Müller, Reinke T.

    2014-01-01

    Multidrug efflux transporters recognize a variety of structurally unrelated compounds for which the molecular basis is poorly understood. For the resistance nodulation and cell division (RND) inner membrane component AcrB of the AcrAB-TolC multidrug efflux system from Escherichia coli, drug binding occurs at the access and deep binding pockets. These two binding areas are separated by an 11-amino-acid-residue-containing switch loop whose conformational flexibility is speculated to be essential for drug binding and transport. A G616N substitution in the switch loop has a distinct and local effect on the orientation of the loop and on the ability to transport larger drugs. Here, we report a distinct phenotypical pattern of drug recognition and transport for the G616N variant, indicating that drug substrates with minimal projection areas of >70 Å2 are less well transported than other substrates. PMID:24914123

  15. Midterm Experience of Ipsilateral Axillary-Axillary Arteriovenous Loop Graft as Tertiary Access for Haemodialysis

    PubMed Central

    Hunter, J. P.; Nicholson, M. L.

    2014-01-01

    Objectives. To present a series of ipsilateral axillary artery to axillary vein loop arm grafts as an alternative vascular access procedure for haemodialysis in patients with difficult access. Design. Retrospective case series. Methods. Patients who underwent an axillary loop arteriovenous graft from September 2009 to September 2012 were included. Preoperative venous imaging to exclude central venous stenosis and to image arm/axillary veins was performed. A cuffed PTFE graft was anastomosed to the distal axillary artery and axillary vein and looped on the arm. Results. 25 procedures were performed on 22 patients. Median age was 51 years, with 9 males and 13 females. Median number of previous access procedures was 3 (range 0–7). Median followup was 16.4 months (range 1–35). At 3 months and 1 year, the primary and secondary patency rates were 70% and 72% and 36% and 37%, respectively. There were 11 radiological interventions in 6 grafts including 5 angioplasties and 6 thrombectomies. There were 19 surgical procedures in 10 grafts, including thrombectomy, revision, repair for bleeding, and excision. Conclusions. Our series demonstrates that the axillary loop arm graft yields acceptable early patency rates in a complex group of patients but to maintain graft patency required high rates of surgical and radiological intervention, in particular graft thrombectomy. PMID:24778864

  16. Loop Analysis of Causal Feedback in Epidemiology: An Illustration Relating To Urban Neighborhoods and Resident Depressive Experiences

    PubMed Central

    2008-01-01

    The causal feedback implied by urban neighborhood conditions that shape human health experiences, that in turn shape neighborhood conditions through a complex causal web, raises a challenge for traditional epidemiological causal analyses. This article introduces the loop analysis method, and builds off of a core loop model linking neighborhood property vacancy rate, resident depressive symptoms, rate of neighborhood death, and rate of neighborhood exit in a feedback network. I justify and apply loop analysis to the specific example of depressive symptoms and abandoned urban residential property to show how inquiries into the behavior of causal systems can answer different kinds of hypotheses, and thereby compliment those of causal modeling using statistical models. Neighborhood physical conditions that are only indirectly influenced by depressive symptoms may nevertheless manifest in the mental health experiences of their residents; conversely, neighborhood physical conditions may be a significant mental health risk for the population of neighborhood residents. I find that participatory greenspace programs are likely to produce adaptive responses in depressive symptoms and different neighborhood conditions, which are different in character to non-participatory greenspace interventions. PMID:17706851

  17. Specific Previous Experience Affects Perception of Harmony and Meter

    ERIC Educational Resources Information Center

    Creel, Sarah C.

    2011-01-01

    Prior knowledge shapes our experiences, but which prior knowledge shapes which experiences? This question is addressed in the domain of music perception. Three experiments were used to determine whether listeners activate specific musical memories during music listening. Each experiment provided listeners with one of two musical contexts that was…

  18. In-Space technology experiments program. A high efficiency thermal interface (using condensation heat transfer) between a 2-phase fluid loop and heatpipe radiator: Experiment definition phase

    NASA Astrophysics Data System (ADS)

    Pohner, John A.; Dempsey, Brian P.; Herold, Leroy M.

    1990-07-01

    Space Station elements and advanced military spacecraft will require rejection of tens of kilowatts of waste heat. Large space radiators and two-phase heat transport loops will be required. To minimize radiator size and weight, it is critical to minimize the temperature drop between the heat source and sink. Under an Air Force contract, a unique, high-performance heat exchanger is developed for coupling the radiator to the transport loop. Since fluid flow through the heat exchanger is driven by capillary forces which are easily dominated by gravity forces in ground testing, it is necessary to perform microgravity thermal testing to verify the design. This contract consists of an experiment definition phase leading to a preliminary design and cost estimate for a shuttle-based flight experiment of this heat exchanger design. This program will utilize modified hardware from a ground test program for the heat exchanger.

  19. In-Space technology experiments program. A high efficiency thermal interface (using condensation heat transfer) between a 2-phase fluid loop and heatpipe radiator: Experiment definition phase

    NASA Technical Reports Server (NTRS)

    Pohner, John A.; Dempsey, Brian P.; Herold, Leroy M.

    1990-01-01

    Space Station elements and advanced military spacecraft will require rejection of tens of kilowatts of waste heat. Large space radiators and two-phase heat transport loops will be required. To minimize radiator size and weight, it is critical to minimize the temperature drop between the heat source and sink. Under an Air Force contract, a unique, high-performance heat exchanger is developed for coupling the radiator to the transport loop. Since fluid flow through the heat exchanger is driven by capillary forces which are easily dominated by gravity forces in ground testing, it is necessary to perform microgravity thermal testing to verify the design. This contract consists of an experiment definition phase leading to a preliminary design and cost estimate for a shuttle-based flight experiment of this heat exchanger design. This program will utilize modified hardware from a ground test program for the heat exchanger.

  20. How differentiated do children experience affect? An investigation of the within- and between-person structure of children's affect.

    PubMed

    Leonhardt, Anja; Könen, Tanja; Dirk, Judith; Schmiedek, Florian

    2016-05-01

    Research on the structure of children's affect is limited. It is possible that children's perception of their own affect might be less differentiated than that of adults. Support for the 2-factor model of positive and negative affect and the pleasure-arousal model suggests that children in middle childhood can distinguish positive and negative affect as well as valence and arousal. Whether children are able to differentiate further aspects of affect, as proposed by the 3-dimensional model of affect (good-bad mood, alertness-tiredness, calmness-tension), is an unresolved issue. The aim of our study was the comparison of these 3 affect models to establish how differentiated children experience their affect and which model best describes affect in children. We examined affect structures on the between- and within-person level, acknowledging that affect varies across time and that no valid interpretation of either level is feasible if both are confounded. For this purpose, 214 children (age 8-11 years) answered affect items once a day for 5 consecutive days on smartphones. We tested all affect models by means of 2-level confirmatory factor analysis. Although all affect models had an acceptable fit, the 3-dimensional model best described affect in children on both the within- and between-person level. Thus, children in middle childhood can already describe affect in a differentiated way. Also, affect structures were similar on the within- and between-person level. We conclude that in order to acquire a thorough picture of children's affect, measures for children should include items of all 3 affect dimensions. (PsycINFO Database Record PMID:26280488

  1. How training and experience affect the benefits of autonomy in a dirty-bomb experiment

    SciTech Connect

    David J. Bruemmer; Curtis W. Nielsen; David I. Gertman

    2008-03-01

    A dirty-bomb experiment conducted at the INL is used to evaluate the effectiveness and suitability of three different modes of robot control. The experiment uses three distinct user groups to understand how participants’ background and training affect the way in which they use and benefit from autonomy. The results show that the target mode, which involves automated mapping and plume tracing together with a point and click tasking tool, provides the best performance for each group. This is true for objective performance such as source detection and localization accuracy as well as subjective measures such as perceived workload, frustration and preference. The best overall performance is achieved by the Explosive Ordinance Disposal group which has experience in both robot teleoperation and dirty bomb response. The user group that benefits least from autonomy is the Nuclear Engineers that have no experience with either robot operation or dirty bomb response. The group that benefits most from autonomy is the Weapons of Mass Destruction Civil Response Team that has extensive experience related to the task, but no robot training.

  2. Research on phase locked loop in optical memory servo system

    NASA Astrophysics Data System (ADS)

    Qin, Liqin; Ma, Jianshe; Zhang, Jianyong; Pan, Longfa; Deng, Ming

    2005-09-01

    Phase locked loop (PLL) is a closed loop automatic control system, which can track the phase of input signal. It widely applies in each area of electronic technology. This paper research the phase locked loop in optical memory servo area. This paper introduces the configuration of digital phase locked loop (PLL) and phase locked servo system, the control theory, and analyses system's stability. It constructs the phase locked loop experiment system of optical disk spindle servo, which based on special chip. DC motor is main object, this system adopted phase locked servo technique and digital signal processor (DSP) to achieve constant linear velocity (CLV) in controlling optical spindle motor. This paper analyses the factors that affect the stability of phase locked loop in spindle servo system, and discusses the affection to the optical disk readout signal and jitter due to the stability of phase locked loop.

  3. Does bilingual experience affect early visual perceptual development?

    PubMed Central

    Schonberg, Christina; Sandhofer, Catherine M.; Tsang, Tawny; Johnson, Scott P.

    2014-01-01

    Visual attention and perception develop rapidly during the first few months after birth, and these behaviors are critical components in the development of language and cognitive abilities. Here we ask how early bilingual experiences might lead to differences in visual attention and perception. Experiments 1–3 investigated the looking behavior of monolingual and bilingual infants when presented with social (Experiment 1), mixed (Experiment 2), or non-social (Experiment 3) stimuli. In each of these experiments, infants' dwell times (DT) and number of fixations to areas of interest (AOIs) were analyzed, giving a sense of where the infants looked. To examine how the infants looked at the stimuli in a more global sense, Experiment 4 combined and analyzed the saccade data collected in Experiments 1–3. There were no significant differences between monolingual and bilingual infants' DTs, AOI fixations, or saccade characteristics (specifically, frequency, and amplitude) in any of the experiments. These results suggest that monolingual and bilingual infants process their visual environments similarly, supporting the idea that the substantial cognitive differences between monolinguals and bilinguals in early childhood are more related to active vocabulary production than perception of the environment. PMID:25566116

  4. Affective Beliefs Influence the Experience of Eating Meat

    PubMed Central

    Anderson, Eric C.; Barrett, Lisa Feldman

    2016-01-01

    People believe they experience the world objectively, but research continually demonstrates that beliefs influence perception. Emerging research indicates that beliefs influence the experience of eating. In three studies, we test whether beliefs about how animals are raised can influence the experience of eating meat. Samples of meat were paired with descriptions of animals raised on factory farms or raised on humane farms. Importantly, the meat samples in both conditions were identical. However, participants experienced the samples differently: meat paired with factory farm descriptions looked, smelled, and tasted less pleasant. Even basic properties of flavor were influenced: factory farmed samples tasted more salty and greasy. Finally, actual behavior was influenced: participants consumed less when samples were paired with factory farm descriptions. These findings demonstrate that the experience of eating is not determined solely by physical properties of stimuli—beliefs also shape experience. PMID:27556643

  5. Affective Beliefs Influence the Experience of Eating Meat.

    PubMed

    Anderson, Eric C; Barrett, Lisa Feldman

    2016-01-01

    People believe they experience the world objectively, but research continually demonstrates that beliefs influence perception. Emerging research indicates that beliefs influence the experience of eating. In three studies, we test whether beliefs about how animals are raised can influence the experience of eating meat. Samples of meat were paired with descriptions of animals raised on factory farms or raised on humane farms. Importantly, the meat samples in both conditions were identical. However, participants experienced the samples differently: meat paired with factory farm descriptions looked, smelled, and tasted less pleasant. Even basic properties of flavor were influenced: factory farmed samples tasted more salty and greasy. Finally, actual behavior was influenced: participants consumed less when samples were paired with factory farm descriptions. These findings demonstrate that the experience of eating is not determined solely by physical properties of stimuli-beliefs also shape experience. PMID:27556643

  6. Specific previous experience affects perception of harmony and meter.

    PubMed

    Creel, Sarah C

    2011-10-01

    Prior knowledge shapes our experiences, but which prior knowledge shapes which experiences? This question is addressed in the domain of music perception. Three experiments were used to determine whether listeners activate specific musical memories during music listening. Each experiment provided listeners with one of two musical contexts that was presented simultaneously with a melody. After a listener was familiarized with melodies embedded in contexts, the listener heard melodies in isolation and judged the fit of a final harmonic or metrical probe event. The probe event matched either the familiar (but absent) context or an unfamiliar context. For both harmonic (Experiments 1 and 3) and metrical (Experiment 2) information, exposure to context shifted listeners' preferences toward a probe matching the context that they had been familiarized with. This suggests that listeners rapidly form specific musical memories without explicit instruction, which are then activated during music listening. These data pose an interesting challenge for models of music perception which implicitly assume that the listener's knowledge base is predominantly schematic or abstract. PMID:21553992

  7. Closing the loop on improvement: Packaging experience in the Software Engineering Laboratory

    NASA Technical Reports Server (NTRS)

    Waligora, Sharon R.; Landis, Linda C.; Doland, Jerry T.

    1994-01-01

    As part of its award-winning software process improvement program, the Software Engineering Laboratory (SEL) has developed an effective method for packaging organizational best practices based on real project experience into useful handbooks and training courses. This paper shares the SEL's experience over the past 12 years creating and updating software process handbooks and training courses. It provides cost models and guidelines for successful experience packaging derived from SEL experience.

  8. Prior task experience affects temporal prediction and estimation

    PubMed Central

    Tobin, Simon; Grondin, Simon

    2015-01-01

    It has been shown that prior experience with a task improves temporal prediction, even when the amount of prior experience with the task is often limited. The present study targeted the role of extensive training on temporal prediction. Expert and intermediate runners had to predict the time of a 5 km running competition. Furthermore, after the race’s completion, participants had to estimate their running time so that it could be compared with the predicted time. Results show that expert runners were more accurate than intermediate runners for both predicting and estimating their running time. Furthermore, only expert runners had an estimation that was more accurate than their initial prediction. The results confirm the role of prior task experience in both temporal prediction and estimation. PMID:26217261

  9. Bridging the Cognitive-Affective Gaps: Teaching Chemistry while Advancing Affective Objectives. The Singapore Curricular Experience

    ERIC Educational Resources Information Center

    Tan, Kok Siang; Goh, Ngoh Khang; Chia, Lian Sai

    2006-01-01

    Chemistry teachers face constraints when trying to integrate cognitive and affective objectives, and hence thoughtful lesson planning is required to achieve the goal. Chemistry teachers can educate students to be knowledgeable about chemical concepts, processes and the benefits of responsible practice by the chemical industry, while being aware,…

  10. Starting Smart: How Early Experiences Affect Brain Development. Second Edition.

    ERIC Educational Resources Information Center

    Hawley, Theresa

    Based on recent research, it is now believed that brain growth is highly dependent upon children's early experiences. Neurons allow communication and coordinated functioning among various brain areas. Brain development after birth consists of an ongoing process of wiring and rewiring the connections among neurons. The forming and breaking of…

  11. Early Social Experience Affects the Development of Eye Gaze Processing.

    PubMed

    Senju, Atsushi; Vernetti, Angélina; Ganea, Natasa; Hudry, Kristelle; Tucker, Leslie; Charman, Tony; Johnson, Mark H

    2015-12-01

    Eye gaze is a key channel of non-verbal communication in humans. Eye contact with others is present from birth, and eye gaze processing is crucial for social learning and adult-infant communication. However, little is known about the effect of selectively different experience of eye contact and gaze communication on early social and communicative development. To directly address this question, we assessed 14 sighted infants of blind parents (SIBPs) longitudinally at 6-10 and 12-16 months. Face scanning and gaze following were assessed using eye tracking. In addition, naturalistic observations were made when the infants were interacting with their blind parent and with an unfamiliar sighted adult. Established measures of emergent autistic-like behaviors and standardized tests of cognitive, motor, and linguistic development were also collected. These data were then compared with those obtained from a group of infants of sighted parents. Despite showing typical social skills development overall, infants of blind parents allocated less attention to adult eye movements and gaze direction, an effect that increased between 6-10 and 12-16 months of age. The results suggest that infants adjust their use of adults' eye gaze depending on gaze communication experience from early in life. The results highlight that human functional brain development shows selective experience-dependent plasticity adaptive to the individual's specific social environment. PMID:26752077

  12. Early Social Experience Affects the Development of Eye Gaze Processing

    PubMed Central

    Senju, Atsushi; Vernetti, Angélina; Ganea, Natasa; Hudry, Kristelle; Tucker, Leslie; Charman, Tony; Johnson, Mark H.

    2015-01-01

    Summary Eye gaze is a key channel of non-verbal communication in humans [1, 2, 3]. Eye contact with others is present from birth [4], and eye gaze processing is crucial for social learning and adult-infant communication [5, 6, 7]. However, little is known about the effect of selectively different experience of eye contact and gaze communication on early social and communicative development. To directly address this question, we assessed 14 sighted infants of blind parents (SIBPs) longitudinally at 6–10 and 12–16 months. Face scanning [8] and gaze following [7, 9] were assessed using eye tracking. In addition, naturalistic observations were made when the infants were interacting with their blind parent and with an unfamiliar sighted adult. Established measures of emergent autistic-like behaviors [10] and standardized tests of cognitive, motor, and linguistic development [11] were also collected. These data were then compared with those obtained from a group of infants of sighted parents. Despite showing typical social skills development overall, infants of blind parents allocated less attention to adult eye movements and gaze direction, an effect that increased between 6–10 and 12–16 months of age. The results suggest that infants adjust their use of adults’ eye gaze depending on gaze communication experience from early in life. The results highlight that human functional brain development shows selective experience-dependent plasticity adaptive to the individual’s specific social environment. PMID:26752077

  13. Regulative Loops, Step Loops and Task Loops

    ERIC Educational Resources Information Center

    VanLehn, Kurt

    2016-01-01

    This commentary suggests a generalization of the conception of the behavior of tutoring systems, which the target article characterized as having an outer loop that was executed once per task and an inner loop that was executed once per step of the task. A more general conception sees these two loops as instances of regulative loops, which…

  14. Involvement of Sensory Regions in Affective Experience: A Meta-Analysis

    PubMed Central

    Satpute, Ajay B.; Kang, Jian; Bickart, Kevin C.; Yardley, Helena; Wager, Tor D.; Barrett, Lisa F.

    2015-01-01

    A growing body of work suggests that sensory processes may also contribute to affective experience. In this study, we performed a meta-analysis of affective experiences driven through visual, auditory, olfactory, gustatory, and somatosensory stimulus modalities including study contrasts that compared affective stimuli to matched neutral control stimuli. We found, first, that limbic and paralimbic regions, including the amygdala, anterior insula, pre-supplementary motor area, and portions of orbitofrontal cortex were consistently engaged across two or more modalities. Second, early sensory input regions in occipital, temporal, piriform, mid-insular, and primary sensory cortex were frequently engaged during affective experiences driven by visual, auditory, olfactory, gustatory, and somatosensory inputs. A classification analysis demonstrated that the pattern of neural activity across a contrast map diagnosed the stimulus modality driving the affective experience. These findings suggest that affective experiences are constructed from activity that is distributed across limbic and paralimbic brain regions and also activity in sensory cortical regions. PMID:26696928

  15. Repeated stressful experiences differently affect brain dopamine receptor subtypes

    SciTech Connect

    Puglisi-Allegra, S.; Cabib, S. , Roma ); Kempf, E.; Schleef, C. )

    1991-01-01

    The binding of tritiated spiperone (D2 antagonist) and tritiated SCH 23390 (D1 antagonist), in vivo, was investigated in the caudatus putamen (CP) and nucleus accumbens septi (NAS) of mice submitted to ten daily restraint stress sessions. Mice sacrificed 24 hr after the last stressful experience presented a 64% decrease of D2 receptor density (Bmax) but no changes in D1 receptor density in the NAS. In the CP a much smaller (11%) reduction of D2 receptor density was accompanied by a 10% increase of D1 receptors. These results show that the two types of dopamine (DA) receptors adapt in different or even opposite ways to environmental pressure, leading to imbalance between them.

  16. Experience and limited lighting may affect sleepiness of tunnel workers

    PubMed Central

    2014-01-01

    Background Working on shifts, especially on a night shift, influences the endogenous sleep regulation system leading to diminished sleep time and increased somnolence. We attempted to evaluate the impact of shifts on sleepiness and correlate the sleepiness score to the experience in a shift schedule. Materials and methods This cross-sectional study consists of 42 male and 2 female workers involved in a tunnel construction. They underwent spirometry, pulse oximetry and were asked to complete the Epworth Sleepiness Scale questionnaire. Results Statistical analysis revealed that workers of lower Epworth had a mean age of 43.6 years, compared to the mean age of 36.4 years of workers with higher Epworth. Furthermore, workers of lower Epworth were characterized by a mean number of shift years equal to 14.8, while those of higher Epworth possessed a mean number of shift years equal to 8. The shift schedule did not reveal any statistically significant correlation. Conclusions Workers employed for a longer time had diminished sleepiness. However, there is no relationship between night shifts and sleepiness, possibly because of exposure to artificial lighting in the construction site. PMID:24993796

  17. The Emotional Experience of People with Intellectual Disability: An Analysis Using the International Affective Pictures System

    ERIC Educational Resources Information Center

    Bermejo, Belen G.; Mateos, Pedro M.; Sanchez-Mateos, Juan Degado

    2014-01-01

    The present study provides information on the emotional experience of people with intellectual disability. To evaluate this emotional experience, we have used the International Affective Pictures System (IAPS). The most important result from this study is that the emotional reaction of people with intellectual disability to affective stimuli is…

  18. Conserved phosphorylation sites in the activation loop of the Arabidopsis phytosulfokine receptor PSKR1 differentially affect kinase and receptor activity

    PubMed Central

    Hartmann, Jens; Linke, Dennis; Bönniger, Christine; Tholey, Andreas; Sauter, Margret

    2015-01-01

    PSK (phytosulfokine) is a plant peptide hormone perceived by a leucine-rich repeat receptor kinase. Phosphosite mapping of epitope-tagged PSKR1 (phytosulfokine receptor 1) from Arabidopsis thaliana plants identified Ser696 and Ser698 in the JM (juxtamembrane) region and probably Ser886 and/or Ser893 in the AL (activation loop) as in planta phosphorylation sites. In vitro-expressed kinase was autophosphorylated at Ser717 in the JM, and at Ser733, Thr752, Ser783, Ser864, Ser911, Ser958 and Thr998 in the kinase domain. The LC–ESI–MS/MS spectra provided support that up to three sites (Thr890, Ser893 and Thr894) in the AL were likely to be phosphorylated in vitro. These sites are evolutionarily highly conserved in PSK receptors, indicative of a conserved function. Site-directed mutagenesis of the four conserved residues in the activation segment, Thr890, Ser893, Thr894 and Thr899, differentially altered kinase activity in vitro and growth-promoting activity in planta. The T899A and the quadruple-mutated TSTT-A (T890A/S893A/T894A/T899A) mutants were both kinase-inactive, but PSKR1(T899A) retained growth-promoting activity. The T890A and S893A/T894A substitutions diminished kinase activity and growth promotion. We hypothesize that phosphorylation within the AL activates kinase activity and receptor function in a gradual and distinctive manner that may be a means to modulate the PSK response. PMID:26472115

  19. Conserved phosphorylation sites in the activation loop of the Arabidopsis phytosulfokine receptor PSKR1 differentially affect kinase and receptor activity.

    PubMed

    Hartmann, Jens; Linke, Dennis; Bönniger, Christine; Tholey, Andreas; Sauter, Margret

    2015-12-15

    PSK (phytosulfokine) is a plant peptide hormone perceived by a leucine-rich repeat receptor kinase. Phosphosite mapping of epitope-tagged PSKR1 (phytosulfokine receptor 1) from Arabidopsis thaliana plants identified Ser(696) and Ser(698) in the JM (juxtamembrane) region and probably Ser(886) and/or Ser(893) in the AL (activation loop) as in planta phosphorylation sites. In vitro-expressed kinase was autophosphorylated at Ser(717) in the JM, and at Ser(733), Thr(752), Ser(783), Ser(864), Ser(911), Ser(958) and Thr(998) in the kinase domain. The LC-ESI-MS/MS spectra provided support that up to three sites (Thr(890), Ser(893) and Thr(894)) in the AL were likely to be phosphorylated in vitro. These sites are evolutionarily highly conserved in PSK receptors, indicative of a conserved function. Site-directed mutagenesis of the four conserved residues in the activation segment, Thr(890), Ser(893), Thr(894) and Thr(899), differentially altered kinase activity in vitro and growth-promoting activity in planta. The T899A and the quadruple-mutated TSTT-A (T890A/S893A/T894A/T899A) mutants were both kinase-inactive, but PSKR1(T899A) retained growth-promoting activity. The T890A and S893A/T894A substitutions diminished kinase activity and growth promotion. We hypothesize that phosphorylation within the AL activates kinase activity and receptor function in a gradual and distinctive manner that may be a means to modulate the PSK response. PMID:26472115

  20. Crystal structures of SIRT3 reveal that the α2-α3 loop and α3-helix affect the interaction with long-chain acyl lysine.

    PubMed

    Gai, Wei; Li, He; Jiang, Hualiang; Long, Yaqiu; Liu, Dongxiang

    2016-09-01

    SIRT1-7 play important roles in many biological processes and age-related diseases. In addition to a NAD(+) -dependent deacetylase activity, they can catalyze several other reactions, including the hydrolysis of long-chain fatty acyl lysine. To study the binding modes of sirtuins to long-chain acyl lysines, we solved the crystal structures of SIRT3 bound to either a H3K9-myristoylated- or a H3K9-palmitoylated peptide. Interaction of SIRT3 with the palmitoyl group led to unfolding of the α3-helix. The myristoyl and palmitoyl groups bind to the C-pocket and an allosteric site near the α3-helix, respectively. We found that the residues preceding the α3-helix determine the size of the C-pocket. The flexibility of the α2-α3 loop and the plasticity of the α3-helix affect the interaction with long-chain acyl lysine. PMID:27501476

  1. Is Long-Term Structural Priming Affected by Patterns of Experience with Individual Verbs?

    ERIC Educational Resources Information Center

    Kaschak, Michael P.; Borreggine, Kristin L.

    2008-01-01

    Several recent papers have reported long-term structural priming effects in experiments where previous patterns of experience with the double object and prepositional object constructions are shown to affect later patterns of language production for those constructions. The experiments reported in this paper address the extent to which these…

  2. Development of a Closed-Loop Strap Down Attitude System for an Ultrahigh Altitude Flight Experiment

    NASA Technical Reports Server (NTRS)

    Whitmore, Stephen A.; Fife, Mike; Brashear, Logan

    1997-01-01

    A low-cost attitude system has been developed for an ultrahigh altitude flight experiment. The experiment uses a remotely piloted sailplane, with the wings modified for flight at altitudes greater than 100,000 ft. Mission requirements deem it necessary to measure the aircraft pitch and bank angles with accuracy better than 1.0 deg and heading with accuracy better than 5.0 deg. Vehicle cost restrictions and gross weight limits make installing a commercial inertial navigation system unfeasible. Instead, a low-cost attitude system was developed using strap down components. Monte Carlo analyses verified that two vector measurements, magnetic field and velocity, are required to completely stabilize the error equations. In the estimating algorithm, body-axis observations of the airspeed vector and the magnetic field are compared against the inertial velocity vector and a magnetic-field reference model. Residuals are fed back to stabilize integration of rate gyros. The effectiveness of the estimating algorithm was demonstrated using data from the NASA Dryden Flight Research Center Systems Research Aircraft (SRA) flight tests. The algorithm was applied with good results to a maximum 10' pitch and bank angles. Effects of wind shears were evaluated and, for most cases, can be safely ignored.

  3. Exploring the Affective Inner Experiences of Therapists in Training: The Qualitative Interaction between Session Experience and Session Content

    ERIC Educational Resources Information Center

    Melton, John L.; Nofzinger-Collins, Dawn; Wynne, Martha E.; Susman, Marilyn

    2005-01-01

    Thirty-four 1st-year counseling students recorded their inner experiences following a simulated counseling session. Using a qualitative collective case study approach to extract emotion from a large pool of inner experience, 6 judges identified samples of affect through a triangulation process using intensity, extreme, and critical case sampling…

  4. Exercise Experiences and Changes in Affective Attitude: Direct and Indirect Effects of In Situ Measurements of Experiences

    PubMed Central

    Sudeck, Gorden; Schmid, Julia; Conzelmann, Achim

    2016-01-01

    Objectives: The purpose of this study was to examine the relationship between exercise experiences (perceptions of competence, perceived exertion, acute affective responses to exercise) and affective attitudes toward exercise. This relationship was analyzed in a non-laboratory setting during a 13-weeks exercise program. Materials and Methods: 56 women and 49 men (aged 35–65 years; Mage = 50.0 years; SD = 8.2 years) took part in the longitudinal study. Affective responses to exercise (affective valence, positive activation, calmness) as well as perceptions of competence and perceived exertion were measured at the beginning, during, and end of three exercise sessions within the 13-weeks exercise program. Affective attitude toward exercise were measured before and at the end of the exercise program. A two-level path analysis was conducted. The direct and indirect effects of exercise experiences on changes in affective attitude were analyzed on the between-person level: firstly, it was tested whether perceptions of competence and perceived exertion directly relate to changes in affective attitude. Secondly, it was assessed whether perceptions of competence and perceived exertion indirectly relate to changes in affective attitudes—imparted via the affective response during exercise. Results and Conclusion: At the between-person level, a direct effect on changes in affective attitude was found for perceptions of competence (β = 0.24, p < 0.05). The model revealed one significant indirect pathway between perceived exertion and changes in affective attitude via positive activation: on average, the less strenuous people perceive physical exercise to be, the more awake they will feel during exercise (β = -0.57, p < 0.05). Those people with higher average levels of positive activation during exercise exhibit more improvements in affective attitudes toward exercise from the beginning to the end of the 13-weeks exercise program (β = 0.24, p < 0.05). Main study results

  5. More Intense Experiences, Less Intense Forecasts: Why People Overweight Probability Specifications in Affective Forecasts

    PubMed Central

    Buechel, Eva C.; Zhang, Jiao; Morewedge, Carey K.; Vosgerau, Joachim

    2014-01-01

    We propose that affective forecasters overestimate the extent to which experienced hedonic responses to an outcome are influenced by the probability of its occurrence. The experience of an outcome (e.g., winning a gamble) is typically more affectively intense than the simulation of that outcome (e.g., imagining winning a gamble) upon which the affective forecast for it is based. We suggest that, as a result, experiencers allocate a larger share of their attention toward the outcome (e.g., winning the gamble) and less to its probability specifications than do affective forecasters. Consequently, hedonic responses to an outcome are less sensitive to its probability specifications than are affective forecasts for that outcome. The results of 6 experiments provide support for our theory. Affective forecasters overestimated how sensitive experiencers would be to the probability of positive and negative outcomes (Experiments 1 and 2). Consistent with our attentional account, differences in sensitivity to probability specifications disappeared when the attention of forecasters was diverted from probability specifications (Experiment 3) or when the attention of experiencers was drawn toward probability specifications (Experiment 4). Finally, differences in sensitivity to probability specifications between forecasters and experiencers were diminished when the forecasted outcome was more affectively intense (Experiments 5 and 6). PMID:24128184

  6. Experimental study on sintered powder wick loop heat pipe

    NASA Astrophysics Data System (ADS)

    Putra, Nandy; Saputra, Bimo, M. Iqbal; Irwansyah, Ridho; Wayan, S. Nata

    2012-06-01

    Increased of heat flux generated by electronic equipment in particular components of a computer (CPU) should always be accompanied with a good cooling in order to achieve optimal operating capability with a high level of reliability. The use of loop heat pipes in thermal management of electronic cooling becomes one of alternative solution. Before LHPs are implemented as an alternative cooling method for electronic device, a quantity of reliability factors should be considered and evaluated such as wick structure and material, type of working fluid, long term life tests, and other tests. The purposes of this experimental study are to examine and analyze the application of sintered copper powder as a wick on a loop heat pipe, type of cooling system on LHP and the orientation of LHP. The performace of nanofluid as working fluid in loop heat pipe were also investigated in this experiment. The performance of the loop heat pipe was also affected by the type of condenser; the water cooled loop heat pipe has the highest temperature reducing value compared to the heat sink fan. The orientation of loop heat pipe also affected the performance of loop heat pipe. This proved that gravity and capillary pressure affecting the performance of loop heat pipes. Temperature differences between the evaporator and condenser sections with nanofluids were less that pure water, i.e. thermal resistance of the LHP when charged with nanofluids was less. It makes nanofluid attractive as working fluid in loop heat pipe technology.

  7. Evaluation of Airborne Precision Spacing in a Human-in-the-Loop Experiment

    NASA Technical Reports Server (NTRS)

    Barmore, Bryan E.; Abbott, Terence S.; Capron, William R.

    2005-01-01

    A significant bottleneck in the current air traffic system occurs at the runway. Expanding airports and adding new runways will help solve this problem; however, this comes with significant costs: financially, politically and environmentally. A complementary solution is to safely increase the capacity of current runways. This can be achieved by precisely spacing aircraft at the runway threshold, with a resulting reduction in the spacing bu er required under today s operations. At NASA's Langley Research Center, the Airspace Systems program has been investigating airborne technologies and procedures that will assist the flight crew in achieving precise spacing behind another aircraft. A new spacing clearance allows the pilot to follow speed cues from a new on-board guidance system called Airborne Merging and Spacing for Terminal Arrivals (AMSTAR). AMSTAR receives Automatic Dependent Surveillance-Broadcast (ADS-B) reports from an assigned, leading aircraft and calculates the appropriate speed for the ownship to fly to achieve the desired spacing interval, time- or distance-based, at the runway threshold. Since the goal is overall system capacity, the speed guidance algorithm is designed to provide system-wide benefits and stability to a string of arriving aircraft. An experiment was recently performed at the NASA Langley Air Traffic Operations Laboratory (ATOL) to test the flexibility of Airborne Precision Spacing operations under a variety of operational conditions. These included several types of merge and approach geometries along with the complementary merging and in-trail operations. Twelve airline pilots and four controllers participated in this simulation. Performance and questionnaire data were collected from a total of eighty-four individual arrivals. The pilots were able to achieve precise spacing with a mean error of 0.5 seconds and a standard deviation of 4.7 seconds. No statistically significant di erences in spacing performance were found between in

  8. Uromodulin Retention in Thick Ascending Limb of Henle's Loop Affects SCD1 in Neighboring Proximal Tubule: Renal Transcriptome Studies in Mouse Models of Uromodulin-Associated Kidney Disease

    PubMed Central

    Horsch, Marion; Beckers, Johannes; Fuchs, Helmut; Gailus-Durner, Valérie; Hrabě de Angelis, Martin; Rathkolb, Birgit; Wolf, Eckhard; Aigner, Bernhard; Kemter, Elisabeth

    2014-01-01

    Uromodulin-associated kidney disease (UAKD) is a hereditary progressive renal disease which can lead to renal failure and requires renal replacement therapy. UAKD belongs to the endoplasmic reticulum storage diseases due to maturation defect of mutant uromodulin and its retention in the enlarged endoplasmic reticulum in the cells of the thick ascending limb of Henle's loop (TALH). Dysfunction of TALH represents the key pathogenic mechanism of UAKD causing the clinical symptoms of this disease. However, the molecular alterations underlying UAKD are not well understood. In this study, transcriptome profiling of whole kidneys of two mouse models of UAKD, UmodA227T and UmodC93F, was performed. Genes differentially abundant in UAKD affected kidneys of both Umod mutant lines at different disease stages were identified and verified by RT-qPCR. Additionally, differential protein abundances of SCD1 and ANGPTL7 were validated by immunohistochemistry and Western blot analysis. ANGPTL7 expression was down-regulated in TALH cells of Umod mutant mice which is the site of the mutant uromodulin maturation defect. SCD1 was expressed selectively in the S3 segment of proximal tubule cells, and SCD1 abundance was increased in UAKD affected kidneys. This finding demonstrates that a cross talk between two functionally distinct tubular segments of the kidney, the TALH segment and the S3 segment of proximal tubule, exists. PMID:25409434

  9. Investigating Affective Experiences in the Undergraduate Chemistry Laboratory: Students' Perceptions of Control and Responsibility

    ERIC Educational Resources Information Center

    Galloway, Kelli R.; Malakpa, Zoebedeh; Bretz, Stacey Lowery

    2016-01-01

    Meaningful learning requires the integration of cognitive and affective learning with the psychomotor, i.e., hands-on learning. The undergraduate chemistry laboratory is an ideal place for meaningful learning to occur. However, accurately characterizing students' affective experiences in the chemistry laboratory can be a very difficult task. While…

  10. Snapshots of Mixtures of Affective Experiences in a Day: Findings from the Health and Retirement Study

    PubMed Central

    Smith, Jacqui; Ryan, Lindsay H.; Queen, Tara L.; Becker, Sandra; Gonzalez, Richard

    2014-01-01

    In 2009, a representative subsample of participants in the Health and Retirement Study (HRS: N = 5333; Age 50–101) responded to a short day reconstruction self-administered questionnaire that asked about their time and experiences on seven activities the previous day. We evaluate the quality and reliability of responses to this 10-minute measure of experienced well-being and compare the properties and correlates of three intensity-based composites reflecting mixtures of activity-linked affective experiences (Mean Activity-Positive Affect, Activity-Negative Affect, and Net Affect), and a frequency-based index, Activity Affective Complexity, that summarizes the proportion of activities that include a mixture of positive and negative affective experiences regardless of intensity. On average, older adults reported that 36% of the activities in their day provided some mixture of feelings (e.g., interested and frustrated). Regression models revealed differential associations for the four constructs of affective well-being with socio-demographic factors, physical and mental health, and proximal indicators of the day’s context. We conclude that the HRS short day reconstruction measure is reliable and discuss the conceptual issues in assessing, summarizing, and interpreting the complexity of emotional experience in older adults. PMID:24729799

  11. Discrete state model and accurate estimation of loop entropy of RNA secondary structures.

    PubMed

    Zhang, Jian; Lin, Ming; Chen, Rong; Wang, Wei; Liang, Jie

    2008-03-28

    Conformational entropy makes important contribution to the stability and folding of RNA molecule, but it is challenging to either measure or compute conformational entropy associated with long loops. We develop optimized discrete k-state models of RNA backbone based on known RNA structures for computing entropy of loops, which are modeled as self-avoiding walks. To estimate entropy of hairpin, bulge, internal loop, and multibranch loop of long length (up to 50), we develop an efficient sampling method based on the sequential Monte Carlo principle. Our method considers excluded volume effect. It is general and can be applied to calculating entropy of loops with longer length and arbitrary complexity. For loops of short length, our results are in good agreement with a recent theoretical model and experimental measurement. For long loops, our estimated entropy of hairpin loops is in excellent agreement with the Jacobson-Stockmayer extrapolation model. However, for bulge loops and more complex secondary structures such as internal and multibranch loops, we find that the Jacobson-Stockmayer extrapolation model has large errors. Based on estimated entropy, we have developed empirical formulae for accurate calculation of entropy of long loops in different secondary structures. Our study on the effect of asymmetric size of loops suggest that loop entropy of internal loops is largely determined by the total loop length, and is only marginally affected by the asymmetric size of the two loops. Our finding suggests that the significant asymmetric effects of loop length in internal loops measured by experiments are likely to be partially enthalpic. Our method can be applied to develop improved energy parameters important for studying RNA stability and folding, and for predicting RNA secondary and tertiary structures. The discrete model and the program used to calculate loop entropy can be downloaded at http://gila.bioengr.uic.edu/resources/RNA.html. PMID:18376982

  12. Socioeconomic Status, Daily Affective and Social Experiences, and Inflammation during Adolescence

    PubMed Central

    Chiang, Jessica J.; Bower, Julienne E.; Almeida, David M.; Irwin, Michael R.; Seeman, Teresa E.; Fuligni, Andrew J.

    2015-01-01

    Objective To assess the relation between socioeconomic status (SES) and inflammation during adolescence and determine whether daily affective and social experiences across a 15-day period mediate this relation. Methods Adolescents (n = 316) completed daily diary reports of positive affect, negative affect, and negative social interactions for 15 days and provided whole blood spot samples for the assessment of C-reactive protein (CRP). Parents provided information on SES, including the highest level of education they and their spouses completed and household income. Results Lower parent education was associated with higher levels of adolescent CRP, controlling for age, gender, ethnicity, and body mass index (β = −.12; p = .031). Mean daily positive affect, negative affect, and negative social interactions were examined as potential mediators of this association. In these models, parent education was no longer associated with adolescent CRP (β = −.09; p = .12), and only positive affect was related to CRP (β = −.12; p = .025). Bootstrapping confirmed the mediating role of positive affect (indirect effect = −.015, 95% CI = [−.038, −.002]). Conclusions Adolescents with less educated parents tended to have higher levels of CRP, which may be explained by their lower levels of positive affect. Findings suggest that a lack of positive affect may be a pathway by which SES confers early risk for poor health in adulthood. It is possible that adolescents who display positive affect during daily life in circumstances of relatively adverse socioeconomic circumstances may have better health outcomes related to lower inflammatory factors. PMID:25829237

  13. Both Direct and Vicarious Experiences of Nature Affect Children’s Willingness to Conserve Biodiversity

    PubMed Central

    Soga, Masashi; Gaston, Kevin J.; Yamaura, Yuichi; Kurisu, Kiyo; Hanaki, Keisuke

    2016-01-01

    Children are becoming less likely to have direct contact with nature. This ongoing loss of human interactions with nature, the extinction of experience, is viewed as one of the most fundamental obstacles to addressing global environmental challenges. However, the consequences for biodiversity conservation have been examined very little. Here, we conducted a questionnaire survey of elementary schoolchildren and investigated effects of the frequency of direct (participating in nature-based activities) and vicarious experiences of nature (reading books or watching TV programs about nature and talking about nature with parents or friends) on their affective attitudes (individuals’ emotional feelings) toward and willingness to conserve biodiversity. A total of 397 children participated in the surveys in Tokyo. Children’s affective attitudes and willingness to conserve biodiversity were positively associated with the frequency of both direct and vicarious experiences of nature. Path analysis showed that effects of direct and vicarious experiences on children’s willingness to conserve biodiversity were mediated by their affective attitudes. This study demonstrates that children who frequently experience nature are likely to develop greater emotional affinity to and support for protecting biodiversity. We suggest that children should be encouraged to experience nature and be provided with various types of these experiences. PMID:27231925

  14. Both Direct and Vicarious Experiences of Nature Affect Children's Willingness to Conserve Biodiversity.

    PubMed

    Soga, Masashi; Gaston, Kevin J; Yamaura, Yuichi; Kurisu, Kiyo; Hanaki, Keisuke

    2016-01-01

    Children are becoming less likely to have direct contact with nature. This ongoing loss of human interactions with nature, the extinction of experience, is viewed as one of the most fundamental obstacles to addressing global environmental challenges. However, the consequences for biodiversity conservation have been examined very little. Here, we conducted a questionnaire survey of elementary schoolchildren and investigated effects of the frequency of direct (participating in nature-based activities) and vicarious experiences of nature (reading books or watching TV programs about nature and talking about nature with parents or friends) on their affective attitudes (individuals' emotional feelings) toward and willingness to conserve biodiversity. A total of 397 children participated in the surveys in Tokyo. Children's affective attitudes and willingness to conserve biodiversity were positively associated with the frequency of both direct and vicarious experiences of nature. Path analysis showed that effects of direct and vicarious experiences on children's willingness to conserve biodiversity were mediated by their affective attitudes. This study demonstrates that children who frequently experience nature are likely to develop greater emotional affinity to and support for protecting biodiversity. We suggest that children should be encouraged to experience nature and be provided with various types of these experiences. PMID:27231925

  15. Variables affecting learning in a simulation experience: a mixed methods study.

    PubMed

    Beischel, Kelly P

    2013-02-01

    The primary purpose of this study was to test a hypothesized model describing the direct effects of learning variables on anxiety and cognitive learning outcomes in a high-fidelity simulation (HFS) experience. The secondary purpose was to explain and explore student perceptions concerning the qualities and context of HFS affecting anxiety and learning. This study used a mixed methods quantitative-dominant explanatory design with concurrent qualitative data collection to examine variables affecting learning in undergraduate, beginning nursing students (N = 124). Being ready to learn, having a strong auditory-verbal learning style, and being prepared for simulation directly affected anxiety, whereas learning outcomes were directly affected by having strong auditory-verbal and hands-on learning styles. Anxiety did not quantitatively mediate cognitive learning outcomes as theorized, although students qualitatively reported debilitating levels of anxiety. This study advances nursing education science by providing evidence concerning variables affecting learning outcomes in HFS. PMID:21593285

  16. User Experience of Mobile Interactivity: How Do Mobile Websites Affect Attitudes and Relational Outcomes?

    ERIC Educational Resources Information Center

    Dou, Xue

    2013-01-01

    Mobile media offer new opportunities for fostering communications between individuals and companies. Corporate websites are being increasingly accessed via smart phones and companies are scrambling to offer a mobile-friendly user experience on their sites. However, very little is known about how interactivity in the mobile context affects user…

  17. Affective Disruptions of "the" Immigrant Experience: Becomings in Official Language Education Research in Canada

    ERIC Educational Resources Information Center

    Waterhouse, Monica; Arnott, Stephanie

    2016-01-01

    Our purpose is to use a Deleuzian-informed conceptual and theoretical framework to disrupt predominant representations of "the" immigrant experience in Canadian official language education and to open up to the affective potential of "an" immigrant life to become otherwise. Employing a rhizoanalytic research approach that…

  18. Experiences of School Principals with Newcomers from War-Affected Countries in Africa

    ERIC Educational Resources Information Center

    Okoko, Janet Mola

    2011-01-01

    This article is based on the results of an exploratory study of experiences of 2 urban school principals about leading schools with immigrants from war-affected countries in Africa. It examines how they perceived their preparation for multicultural leadership, and explores lessons that leadership development institutions can learn from their…

  19. Early Experiences Can Alter Gene Expression and Affect Long-Term Development. Working Paper #10

    ERIC Educational Resources Information Center

    National Scientific Council on the Developing Child, 2010

    2010-01-01

    New scientific research shows that environmental influences can actually affect whether and how genes are expressed. Thus, the old ideas that genes are "set in stone" or that they alone determine development have been disproven. In fact, scientists have discovered that early experiences can determine how genes are turned on and off and even…

  20. Experiences and Implications of Social Workers Practicing in a Pediatric Hospital Environment Affected by SARS

    ERIC Educational Resources Information Center

    Gearing, Robin Edward; Saini, Michael; McNeill, Ted

    2007-01-01

    This phenomenological study's purpose was threefold: to detail the experiences of social workers practicing in a hospital environment affected by severe acute respiratory syndrome (SARS), to describe essential themes and structures of social work practices within this crisis environment, and to explore recommendations for better preparedness to…

  1. Length and Amino Acid Sequence of Peptides Substituted for the 5-HT3A Receptor M3M4 Loop May Affect Channel Expression and Desensitization

    PubMed Central

    McKinnon, Nicole K.; Bali, Moez; Akabas, Myles H.

    2012-01-01

    5-HT3A receptors are pentameric neurotransmitter-gated ion channels in the Cys-loop receptor family. Each subunit contains an extracellular domain, four transmembrane segments (M1, M2, M3, M4) and a 115 residue intracellular loop between M3 and M4. In contrast, the M3M4 loop in prokaryotic homologues is <15 residues. To investigate the limits of M3M4 loop length and composition on channel function we replaced the 5-HT3A M3M4 loop with two to seven alanine residues (5-HT3A-An = 2–7). Mutants were expressed in Xenopus laevis oocytes and characterized using two electrode voltage clamp recording. All mutants were functional. The 5-HT EC50's were at most 5-fold greater than wild-type (WT). The desensitization rate differed significantly among the mutants. Desensitization rates for 5-HT3A-A2, 5-HT3A-A4, 5-HT3A-A6, and 5-HT3A-A7 were similar to WT. In contrast, 5-HT3A-A3 and 5-HT3A-A5 had desensitization rates at least an order of magnitude faster than WT. The one Ala loop construct, 5-HT3A-A1, entered a non-functional state from which it did not recover after the first 5-HT application. These results suggest that the large M3M4 loop of eukaryotic Cys-loop channels is not required for receptor assembly or function. However, loop length and amino acid composition can effect channel expression and desensitization. We infer that the cytoplasmic ends of the M3 and M4 segments may undergo conformational changes during channel gating and desensitization and/or the loop may influence the position and mobility of these segments as they undergo gating-induced conformational changes. Altering structure or conformational mobility of the cytoplasmic ends of M3 and M4 may be the basis by which phosphorylation or protein binding to the cytoplasmic loop alters channel function. PMID:22539982

  2. Out of mind, out of heart: attention affects duration of emotional experience.

    PubMed

    Freund, Alexandra M; Keil, Andreas

    2013-01-01

    It has been suggested that the extent to which a person maintains attention to pleasant versus unpleasant aspects of a given stimulus has an effect on the self-reported affective state. This assumption was empirically tested in two experiments. In Study 1, participants received the instruction either to focus on a positive emotion-eliciting event (winning a tournament chess game) or to focus their attention on an affectively neutral distraction task (describing drawings). Study 2 used negative performance feedback in a cognitive task to induce unpleasant affect and included three experimental groups (waiting condition, continuing with the same cognitive task, distraction by a different cognitive task). Results converged to show that distracting attention away from the emotion-eliciting event leads to a shorter duration of the emotional experience. These findings support the attention-focus hypothesis. PMID:22963519

  3. On the relationship between personal experience, affect and risk perception: The case of climate change

    PubMed Central

    van der Linden, Sander

    2014-01-01

    Examining the conceptual relationship between personal experience, affect, and risk perception is crucial in improving our understanding of how emotional and cognitive process mechanisms shape public perceptions of climate change. This study is the first to investigate the interrelated nature of these variables by contrasting three prominent social-psychological theories. In the first model, affect is viewed as a fast and associative information processing heuristic that guides perceptions of risk. In the second model, affect is seen as flowing from cognitive appraisals (i.e., affect is thought of as a post-cognitive process). Lastly, a third, dual-process model is advanced that integrates aspects from both theoretical perspectives. Four structural equation models were tested on a national sample (N = 808) of British respondents. Results initially provide support for the “cognitive” model, where personal experience with extreme weather is best conceptualized as a predictor of climate change risk perception and, in turn, risk perception a predictor of affect. Yet, closer examination strongly indicates that at the same time, risk perception and affect reciprocally influence each other in a stable feedback system. It is therefore concluded that both theoretical claims are valid and that a dual-process perspective provides a superior fit to the data. Implications for theory and risk communication are discussed. © 2014 The Authors. European Journal of Social Psychology published by John Wiley & Sons, Ltd. PMID:25678723

  4. Fabrication techniques for superconducting readout loops

    NASA Technical Reports Server (NTRS)

    Payne, J. E.

    1982-01-01

    Procedures for the fabrication of superconducting readout loops out of niobium on glass substrates were developed. A computer program for an existing fabrication system was developed. Both positive and negative resist procedures for the production of the readout loops were investigated. Methods used to produce satisfactory loops are described and the various parameters affecting the performance of the loops are analyzed.

  5. Belgian experience in applying the {open_quotes}leak-before-break{close_quotes} concept to the primary loop piping

    SciTech Connect

    Gerard, R.; Malekian, C.; Meessen, O.

    1997-04-01

    The Leak Before Break (LBB) concept allows to eliminate from the design basis the double-ended guillotine break of the primary loop piping, provided it can be demonstrated by a fracture mechanics analysis that a through-wall flaw, of a size giving rise to a leakage still well detectable by the plant leak detection systems, remains stable even under accident conditions (including the Safe Shutdown Earthquake (SSE)). This concept was successfully applied to the primary loop piping of several Belgian Pressurized Water Reactor (PWR) units, operated by the Utility Electrabel. One of the main benefits is to permit justification of supports in the primary loop and justification of the integrity of the reactor pressure vessel and internals in case of a Loss Of Coolant Accident (LOCA) in stretch-out conditions. For two of the Belgian PWR units, the LBB approach also made it possible to reduce the number of large hydraulic snubbers installed on the primary coolant pumps. Last but not least, the LBB concept also facilitates the steam generator replacement operations, by eliminating the need for some pipe whip restraints located close to the steam generator. In addition to the U.S. regulatory requirements, the Belgian safety authorities impose additional requirements which are described in details in a separate paper. An novel aspect of the studies performed in Belgium is the way in which residual loads in the primary loop are taken into account. Such loads may result from displacements imposed to close the primary loop in a steam generator replacement operation, especially when it is performed using the {open_quote}two cuts{close_quotes} technique. The influence of such residual loads on the LBB margins is discussed in details and typical results are presented.

  6. Modification of Loop 1 Affects the Nucleotide-Binding Properties of Myo1c, The Adaptation Motor in the Inner Ear†

    PubMed Central

    Adamek, Nancy; Lieto-Trivedi, Alena; Geeves, Michael A.; Coluccio, Lynne M.

    2010-01-01

    Myo1c is one of eight members of the mammalian myosin I family of actin-associated molecular motors. In stereocilia of the hair cells in the inner ear, Myo1c presumably serves as the adaptation motor, which regulates the opening and closing of transduction channels. Although there is conservation of sequence and structure among all myosins in the N-terminal motor domain, which contains the nucleotide- and actin-binding sites, some differences include the length and composition of surface loops, including loop 1, which lies near the nucleotide-binding domain. To investigate the role of loop 1, we expressed in insect cells mutants of a truncated form of Myo1c, Myo1c1IQ, as well as chimeras of Myo1c1IQ with the analogous loop from other myosins. We found that replacement of the charged residues in loop 1 with alanines or the whole loop with a series of alanines did not alter the ATPase activity, transient kinetics properties and Ca2+-sensitivity of Myo1c1IQ. Substitution of loop 1 with that of the corresponding region from tonic smooth muscle myosin II (Myo1c1IQ-tonic) or replacement with a single glycine (Myo1c1IQ-G) accelerated ADP release from A.M 2-3-fold in Ca2+, whereas substitution with loop 1 from phasic muscle myosin II (Myo1c1IQ-phasic) accelerated ADP release 35-fold. Motility assays with chimeras containing a single α-helix, or SAH, domain showed that Myo1cSAH-tonic translocated actin in vitro twice as fast as Myo1cSAH-WT and 3-fold faster than Myo1cSAH-G. The studies show that changes induced in Myo1c by modifying loop 1 showed no resemblance to the behaviour of the loop donor myosins or to the changes previously observed with similar Myo1b chimeras. PMID:20039646

  7. Closed-Loop System Identification Experience for Flight Control Law and Flying Qualities Evaluation of a High Performance Fighter Aircraft

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick C.

    1996-01-01

    This paper highlights some of the results and issues associated with estimating models to evaluate control law design methods and design criteria for advanced high performance aircraft. Experimental fighter aircraft such as the NASA-High Alpha Research Vehicle (HARV) have the capability to maneuver at very high angles of attack where nonlinear aerodynamics often predominate. HARV is an experimental F/A-18, configured with thrust vectoring and conformal actuated nose strakes. Identifying closed-loop models for this type of aircraft can be made difficult by nonlinearities and high order characteristics of the system. In this paper, only lateral-directional axes are considered since the lateral-directional control law was specifically designed to produce classical airplane responses normally expected with low-order, rigid-body systems. Evaluation of the control design methodology was made using low-order equivalent systems determined from flight and simulation. This allowed comparison of the closed-loop rigid-body dynamics achieved in flight with that designed in simulation. In flight, the On Board Excitation System was used to apply optimal inputs to lateral stick and pedals at five angles at attack : 5, 20, 30, 45, and 60 degrees. Data analysis and closed-loop model identification were done using frequency domain maximum likelihood. The structure of identified models was a linear state-space model reflecting classical 4th-order airplane dynamics. Input time delays associated with the high-order controller and aircraft system were accounted for in data preprocessing. A comparison of flight estimated models with small perturbation linear design models highlighted nonlinearities in the system and indicated that the closed-loop rigid-body dynamics were sensitive to input amplitudes at 20 and 30 degrees angle of attack.

  8. Closed-Loop System Identification Experience for Flight Control Law and Flying Qualities Evaluation of a High Performance Fighter Aircraft

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick C.

    1999-01-01

    This paper highlights some of the results and issues associated with estimating models to evaluate control law design methods and design criteria for advanced high performance aircraft. Experimental fighter aircraft such as the NASA High Alpha Research Vehicle (HARV) have the capability to maneuver at very high angles of attack where nonlinear aerodynamics often predominate. HARV is an experimental F/A-18, configured with thrust vectoring and conformal actuated nose strakes. Identifying closed-loop models for this type of aircraft can be made difficult by nonlinearities and high-order characteristics of the system. In this paper only lateral-directional axes are considered since the lateral-directional control law was specifically designed to produce classical airplane responses normally expected with low-order, rigid-body systems. Evaluation of the control design methodology was made using low-order equivalent systems determined from flight and simulation. This allowed comparison of the closed-loop rigid-body dynamics achieved in flight with that designed in simulation. In flight, the On Board Excitation System was used to apply optimal inputs to lateral stick and pedals at five angles of attack: 5, 20, 30, 45, and 60 degrees. Data analysis and closed-loop model identification were done using frequency domain maximum likelihood. The structure of the identified models was a linear state-space model reflecting classical 4th-order airplane dynamics. Input time delays associated with the high-order controller and aircraft system were accounted for in data preprocessing. A comparison of flight estimated models with small perturbation linear design models highlighted nonlinearities in the system and indicated that the estimated closed-loop rigid-body dynamics were sensitive to input amplitudes at 20 and 30 degrees angle of attack.

  9. Aggressive experience affects the sensitivity of neurons towards pharmacological treatment in the hypothalamic attack area.

    PubMed

    Haller, J; Abrahám, I; Zelena, D; Juhász, G; Makara, G B; Kruk, M R

    1998-09-01

    Early investigators of brain stimulation-evoked complex behaviours (attack, escape, feeding, self-grooming, sexual behaviour) reported that experience may affect the behavioural outcome of brain stimulation. This intriguing example of functional neuronal plasticity was later totally neglected. The present experiment investigated the behavioural outcome of in vivo microdialysis perfusion of the glutamate agonist kainate and/or the GABAA antagonist bicuculline into the hypothalamic attack area (HAA) of (1) animals naive to dyadic encounters; (2) animals with a recent aggressive experience (the probe being implanted 6-24 h after the last of a series of dyadic encounters); and (3) animals with an earlier aggressive experience (probe being implanted 2 weeks after the last aggressive experience). On the experimental day, rats received two 5-min infusions during a dyadic encounter lasting 35 min with an unknown opponent. Flow rate was 1.5-2 microliters/min, drug concentrations were 1.8 x 10(-5) and 1.5 x 10(-5) M for kainate and bicuculline, respectively. Behaviour was analysed before, during and after perfusions. Only the combined kainate + bicuculline treatment had significant effects on behaviour at the doses studied. A significant increase in aggressive behaviour was elicited only in animals with a recent aggressive experience, while naive animals and with an earlier experience responded to the treatments by grooming. These results appear to support early observations indicating that one important aspect of brain stimulation effects is previous experience. PMID:9832932

  10. The response of an egg parasitoid to substrate-borne semiochemicals is affected by previous experience

    PubMed Central

    Peri, Ezio; Salerno, Gianandrea; Slimani, Takoua; Frati, Francesca; Conti, Eric; Colazza, Stefano; Cusumano, Antonino

    2016-01-01

    Animals can adjust their behaviour according to previous experience gained during foraging. In parasitoids, experience plays a key role in host location, a hierarchical process in which air-borne and substrate-borne semiochemicals are used to find hosts. In nature, chemical traces deposited by herbivore hosts when walking on the plant are adsorbed by leaf surfaces and perceived as substrate-borne semiochemicals by parasitoids. Chemical traces left on cabbage leaves by adults of the harlequin bug (Murgantia histrionica) induce an innate arrestment response in the egg parasitoid Trissolcus brochymenae characterized by an intense searching behaviour on host-contaminated areas. Here we investigated whether the T. brochymenae response to host walking traces left on leaf surfaces is affected by previous experience in the context of parasitoid foraging behaviour. We found that: 1) an unrewarded experience (successive encounters with host-contaminated areas without successful oviposition) decreased the intensity of the parasitoid response; 2) a rewarded experience (successful oviposition) acted as a reinforcing stimulus; 3) the elapsed time between two consecutive unrewarded events affected the parasitoid response in a host-gender specific manner. The ecological role of these results to the host location process of egg parasitoids is discussed. PMID:27250870

  11. The response of an egg parasitoid to substrate-borne semiochemicals is affected by previous experience.

    PubMed

    Peri, Ezio; Salerno, Gianandrea; Slimani, Takoua; Frati, Francesca; Conti, Eric; Colazza, Stefano; Cusumano, Antonino

    2016-01-01

    Animals can adjust their behaviour according to previous experience gained during foraging. In parasitoids, experience plays a key role in host location, a hierarchical process in which air-borne and substrate-borne semiochemicals are used to find hosts. In nature, chemical traces deposited by herbivore hosts when walking on the plant are adsorbed by leaf surfaces and perceived as substrate-borne semiochemicals by parasitoids. Chemical traces left on cabbage leaves by adults of the harlequin bug (Murgantia histrionica) induce an innate arrestment response in the egg parasitoid Trissolcus brochymenae characterized by an intense searching behaviour on host-contaminated areas. Here we investigated whether the T. brochymenae response to host walking traces left on leaf surfaces is affected by previous experience in the context of parasitoid foraging behaviour. We found that: 1) an unrewarded experience (successive encounters with host-contaminated areas without successful oviposition) decreased the intensity of the parasitoid response; 2) a rewarded experience (successful oviposition) acted as a reinforcing stimulus; 3) the elapsed time between two consecutive unrewarded events affected the parasitoid response in a host-gender specific manner. The ecological role of these results to the host location process of egg parasitoids is discussed. PMID:27250870

  12. The play is now reality: affective turns, narrative struggles, and theorizing emotion as practical experience.

    PubMed

    Kumar, Anita

    2013-12-01

    Discursive approaches to subjectivity have been critiqued most recently for its dismissal of a living body that moves and senses. While identity as performative has proven invaluable to contemporary cultural theory for its dynamic conceptualization of power in everyday practice, the emergence of what some scholars have named an "affective turn" has prompted calls for configuring the body as more than a complex set of significations, but also a vibrant energy field in perpetual emergence. Centered on an enacted story created by two clinical therapists and two South Asian immigrant domestic violence survivors during a therapeutic support group session, this paper brings the affective turn into dialog with narrative theory. I juxtapose two different readings of this clinical "performance." One interpretation recognizes affect theory's value for highlighting sensation and the virtual in moments of transformation. Nonetheless I argue it overlooks a lived history. Thus, using a specifically dramatistic approach to narrative, the second analysis stresses the importance of personal experience and meaning-making in strengthening the link between affect and subjectivity. In doing so, the case study also argues for emotion's critical link to practical and moral experience. PMID:24132544

  13. Facilities, breed and experience affect ease of sheep handling: the livestock transporter's perspective.

    PubMed

    Burnard, C L; Pitchford, W S; Hocking Edwards, J E; Hazel, S J

    2015-08-01

    An understanding of the perceived importance of a variety of factors affecting the ease of handling of sheep and the interactions between these factors is valuable in improving profitability and welfare of the livestock. Many factors may contribute to animal behaviour during handling, and traditionally these factors have been assessed in isolation under experimental conditions. A human social component to this phenomenon also exists. The aim of this study was to gain a deeper understanding of the importance of a variety of factors affecting ease of handling, and the interactions between these from the perspective of the livestock transporter. Qualitative interviews were used to investigate the factors affecting sheep behaviour during handling. Interview transcripts underwent thematic analysis. Livestock transporters discussed the effects of attitudes and behaviours towards sheep, helpers, facilities, distractions, environment, dogs and a variety of sheep factors including breed, preparation, experience and sex on sheep behaviour during handling. Transporters demonstrated care and empathy and stated that patience and experience were key factors determining how a person might deal with difficult sheep. Livestock transporters strongly believed facilities (ramps and yards) had the greatest impact, followed by sheep experience (naivety of the sheep to handling and transport) and breed. Transporters also discussed the effects of distractions, time of day, weather, dogs, other people, sheep preparation, body condition and sheep sex on ease of handling. The concept of individual sheep temperament was indirectly expressed. PMID:25874817

  14. Time-Independent and Time-Dependent Rheological Characterization of Dispersions with Varying Contents of Chickpea Flour and Gum Arabic Employing the Multiple Loop Experiments.

    PubMed

    J, Shanthilal; Bhattacharya, Suvendu

    2016-08-01

    The chickpea (Cicer arietinum) flour dispersions as the model system with different contents of flour (37% to 43%) and gum arabic (0% to 5%) were subjected to multiple loop experiments for simultaneous determination of the time-independent and time-dependent rheological characteristics. The Herschel-Bulkley model was suitable (0.993 ≤ r ≤ 0.999) to relate the time-independent characteristics linking shear stress and shear rate data for the individual upward and downward curves. The yield stress, consistency index, and apparent viscosity increased with the increasing flour and/or gum contents while flow behavior index (n) decreased. The yield stress generally decreased with the number of loops but n increased. In the individual loop tests, the n values for the decreasing shear stress/shear rate curves were always higher than corresponding increasing curves meaning a shift toward Newtonian characteristics. The time-independent properties (yield stress, apparent viscosity, consistency index, and n), the time-dependent characteristics like the area of the loop, and liquid characteristics like pourability and the nonoral sensory attributes (viscosity, spreadability, and tackiness) were individually predicted by artificial neural networks wherein the root mean square errors were between 3.6% and 17.2%. The sensory assessment indicated that the desirable parameters for a free-flowing and easily pourable spherical chickpea batter droplets occurred when the average pourability and spreadability values were 6.9 and 5.9, respectively. The normalized indices for these 2 parameters indicated that the batter having 40% flour and 2% gum contents was most suitable exhibiting a deviation of only 10% from the ideal sensory scores; these values were 40% and 0% to 3%, and 43% and 0%, respectively exhibiting up to 20% deviation. PMID:27331658

  15. Is long-term structural priming affected by patterns of experience with individual verbs?

    PubMed Central

    Kaschak, Michael P.; Borreggine, Kristin L.

    2015-01-01

    Several recent papers have reported long-term structural priming effects in experiments where previous patterns of experience with the double object and prepositional object constructions are shown to affect later patterns of language production for those constructions. The experiments reported in this paper address the extent to which these long-term priming effects are modulated by the participants’ patterns of experience with particular verbs within the double object and prepositional object constructions. The results of three experiments show that patterns of experience with particular verbs using the double object or prepositional object constructions do not have much effect on the shape of the longterm structural priming effects reported elsewhere in the literature. These findings lend support to the claim that structural priming is the result of adaptations to the language production system that occur on an abstract, structural level of representation that is separate from representations regarding the behavior of particular lexical items in particular constructions [e.g., Chang, F., Dell, G. S., & Bock, K. (2006). Becoming syntactic. Psychological Review, 113, 234–272]. 2007 Elsevier Inc. All rights reserved. PMID:26500391

  16. Dealing with Stigma: Experiences of Persons Affected by Disabilities and Leprosy

    PubMed Central

    Zweekhorst, Marjolein B. M.; Miranda-Galarza, Beatriz; Peters, Ruth M. H.; Cummings, Sarah; Seda, Francisia S. S. E.; Bunders, Joske F. G.; Irwanto

    2015-01-01

    Persons affected by leprosy or by disabilities face forms of stigma that have an impact on their lives. This study seeks to establish whether their experiences of stigma are similar, with a view to enabling the two groups of people to learn from each other. Accounts of experiences of the impact of stigma were obtained using in-depth interviews and focus group discussion with people affected by leprosy and by disabilities not related to leprosy. The analysis shows that there are a lot of similarities in impact of stigma in terms of emotions, thoughts, behaviour, and relationships between the two groups. The main difference is that those affected by leprosy tended to frame their situation in medical terms, while those living with disabilities described their situation from a more social perspective. In conclusion, the similarities offer opportunities for interventions and the positive attitudes and behaviours can be modelled in the sense that both groups can learn and benefit. Research that tackles different aspects of stigmatization faced by both groups could lead to inclusive initiatives that help individuals to come to terms with the stigma and to advocate against exclusion and discrimination. PMID:25961008

  17. Li experiments on T-11M and T-10 in support of a steady-state tokamak concept with Li closed loop circulation

    NASA Astrophysics Data System (ADS)

    Mirnov, S. V.; Azizov, E. A.; Alekseev, A. G.; Lazarev, V. B.; Khayrutdinov, R. R.; Lyublinski, I. E.; Vertkov, A. V.; Vershkov, V. A.

    2011-07-01

    This paper presents a review of the last T-11M and T-10 tokamak activity in the field of Li plasma facing component (PFC) investigation. Attention is mainly paid to the realization of the concept of closed loop lithium circulation as a solution of the PFC problem of a steady-state DT volumetric neutron source on a tokamak basis. Realization of the Li PFC concept demands the decision of three main tasks: lithium injection into the plasma, Li collection before its deposition on the vacuum vessel and the return of Li to the injection zone from the collector. This emitter-collector concept assumes that the main heat flux from a hot plasma to the PFC (limiters and divertor plates) can be dissipated on the entire vessel wall surface by non-coronal Li radiation, which will smoothen the local heat load PFC. A rail limiter on the basis of a capillary porous system manufactured from tungsten felt and provided with W wings was successfully tested in the last T-11M experiments as a prototype of steady-state Li emitter-collector. A witness-sample analysis showed that the lateral sides of the rail and ring limiters crossing the plasma scrape-off layer can collect a significant (~80%) part of Li, injected into the plasma during discharges. This can be used in the future for closing Li loop circulation. As was shown by Li pellet injection in T-10, the probability of Li penetration into the hot plasma core from its boundary is lower than that of deuterium by a factor of 5-10. This result can explain the effect of plasma cleaning (Zeff (0) ~ 1) during T-10 Li experiments. Some different schemes of future lithium circulation loops are discussed.

  18. Local Navon letter processing affects skilled behavior: a golf-putting experiment.

    PubMed

    Lewis, Michael B; Dawkins, Gemma

    2015-04-01

    Expert or skilled behaviors (for example, face recognition or sporting performance) are typically performed automatically and with little conscious awareness. Previous studies, in various domains of performance, have shown that activities immediately prior to a task demanding a learned skill can affect performance. In sport, describing the to-be-performed action is detrimental, whereas in face recognition, describing a face or reading local Navon letters is detrimental. Two golf-putting experiments are presented that compare the effects that these three tasks have on experienced and novice golfers. Experiment 1 found a Navon effect on golf performance for experienced players. Experiment 2 found, for experienced players only, that performance was impaired following the three tasks described above, when compared with reading or global Navon tasks. It is suggested that the three tasks affect skilled performance by provoking a shift from automatic behavior to a more analytic style. By demonstrating similarities between effects in face recognition and sporting behavior, it is hoped to better understand concepts in both fields. PMID:25102927

  19. Socially anxious smokers experience greater negative affect and withdrawal during self-quit attempts.

    PubMed

    Buckner, Julia D; Langdon, Kirsten J; Jeffries, Emily R; Zvolensky, Michael J

    2016-04-01

    Despite evidence of a strong and consistent relation between smoking and elevated social anxiety, strikingly little empirical work has identified mechanisms underlying the smoking-social anxiety link. Persons with elevated social anxiety may rely on smoking to cope with more severe nicotine withdrawal and post-quit negative mood states; yet, no known studies have investigated the relation of social anxiety to withdrawal severity. The current study examined the relation of social anxiety to post-quit nicotine withdrawal severity among 51 (33.3% female, Mage = 34.6) community-recruited smokers during the first two weeks following an unaided (i.e., no treatment) cessation attempt. Ecological momentary assessment was used to collect multiple daily ratings of withdrawal and negative mood states. Baseline social anxiety was related to increases in negative affect during the monitoring period and remained significantly related to post-quit withdrawal after controlling for negative affect, gender, lapses, and substance use. Persons with elevated social anxiety experience more severe post-quit withdrawal symptoms and increases in negative affect during a cessation attempt and may therefore benefit from intervention and treatment strategies geared toward helping them learn to cope with withdrawal and negative affect to improve cessation rates among these vulnerable smokers. PMID:26790139

  20. Sequence dependence of transcription factor-mediated DNA looping

    PubMed Central

    Johnson, Stephanie; Lindén, Martin; Phillips, Rob

    2012-01-01

    DNA is subject to large deformations in a wide range of biological processes. Two key examples illustrate how such deformations influence the readout of the genetic information: the sequestering of eukaryotic genes by nucleosomes and DNA looping in transcriptional regulation in both prokaryotes and eukaryotes. These kinds of regulatory problems are now becoming amenable to systematic quantitative dissection with a powerful dialogue between theory and experiment. Here, we use a single-molecule experiment in conjunction with a statistical mechanical model to test quantitative predictions for the behavior of DNA looping at short length scales and to determine how DNA sequence affects looping at these lengths. We calculate and measure how such looping depends upon four key biological parameters: the strength of the transcription factor binding sites, the concentration of the transcription factor, and the length and sequence of the DNA loop. Our studies lead to the surprising insight that sequences that are thought to be especially favorable for nucleosome formation because of high flexibility lead to no systematically detectable effect of sequence on looping, and begin to provide a picture of the distinctions between the short length scale mechanics of nucleosome formation and looping. PMID:22718983

  1. Position of the kissing-loop interaction associated with PTE-type 3’CITEs can affect enhancement of cap-independent translation

    PubMed Central

    Chattopadhyay, Maitreyi; Kuhlmann, Micki M.; Kumar, Kalyani; Simon, Anne E.

    2014-01-01

    The Panicum mosaic virus-like translation enhancer (PTE) functions as a cap-independent translation enhancer (3’CITE) in members of several Tombusviridae genera including 7/19 carmoviruses. For nearly all PTE, a kissing-loop connects the element with a hairpin found in several conserved locations in the genomic RNA (5’ terminal hairpin or ~100 nt from the 5’end) and small subgenomic RNA (~63 nt from the 5’end). Moving the interaction closer to the 5’end in reporter mRNAs using Saguaro cactus virus (SCV) sequences had either a minimal or substantial negative effect on translation. Movement of the kissing loop from position 104 to the SCV 5’ terminal hairpin also reduced translation by 4-fold. These results suggest that relocating the PTE kissing loop closer to the 5’end reduces PTE efficiency, in contrast to results for the Barley yellow dwarf BTE and Tomato bushy stunt virus Y-shaped 3’CITEs , suggesting that different 3’CITEs have different bridging requirements. PMID:24928038

  2. Position of the kissing-loop interaction associated with PTE-type 3'CITEs can affect enhancement of cap-independent translation.

    PubMed

    Chattopadhyay, Maitreyi; Kuhlmann, Micki M; Kumar, Kalyani; Simon, Anne E

    2014-06-01

    The Panicum mosaic virus-like translation enhancer (PTE) functions as a cap-independent translation enhancer (3'CITE) in members of several Tombusviridae genera including 7/19 carmoviruses. For nearly all PTE, a kissing-loop connects the element with a hairpin found in several conserved locations in the genomic RNA (5' terminal hairpin or ~100 nt from the 5' end) and small subgenomic RNA (~63 nt from the 5' end). Moving the interaction closer to the 5' end in reporter mRNAs using Saguaro cactus virus (SCV) sequences had either a minimal or substantial negative effect on translation. Movement of the kissing loop from position 104 to the SCV 5' terminal hairpin also reduced translation by 4-fold. These results suggest that relocating the PTE kissing loop closer to the 5' end reduces PTE efficiency, in contrast to results for the Barley yellow dwarf BTE and Tomato bushy stunt virus Y-shaped 3'CITEs, suggesting that different 3'CITEs have different bridging requirements. PMID:24928038

  3. Variables Affecting Smooth Particle Hydrodynamics Simulation of High-Velocity Flyer Plate Impact Experiments

    SciTech Connect

    Somasundaram, Deepak S; Trabia, Mohamed; O'Toole, Brendan; Hixson, Robert S

    2014-01-23

    This paper describes our work to characterize the variables affecting the smoothed particle hydrodynamics (SPH) method in the LS-DYNA package for simulating high-velocity flyer plate impact experiments. LS-DYNA simulations are compared with one-dimensional experimental data of an oxygen-free high-conductivity (OFHC) copper flyer plate impacting another plate of the same material. The comparison is made by measuring the velocity of a point on the back surface of the impact plate using the velocity interferometer system for any reflector (VISAR) technique.

  4. Loop Heat Pipe Startup Behaviors

    NASA Technical Reports Server (NTRS)

    Ku, Jentung

    2016-01-01

    A loop heat pipe must start successfully before it can commence its service. The startup transient represents one of the most complex phenomena in the loop heat pipe operation. This paper discusses various aspects of loop heat pipe startup behaviors. Topics include the four startup scenarios, the initial fluid distribution between the evaporator and reservoir that determines the startup scenario, factors that affect the fluid distribution between the evaporator and reservoir, difficulties encountered during the low power startup, and methods to enhance the startup success. Also addressed are the pressure spike and pressure surge during the startup transient, and repeated cycles of loop startup and shutdown under certain conditions.

  5. SHIFTING THE PROTOTYPE: EXPERIENCE WITH FACES INFLUENCES AFFECTIVE AND ATTRACTIVENESS PREFERENCES

    PubMed Central

    Principe, Connor P.; Langlois, Judith H.

    2012-01-01

    While some researchers have suggested that preferences for attractive faces are the result of a domain-specific beauty detection module, others argue these preferences develop based on averages of stimuli through a domain-general learning mechanism. We tested whether cognitive and perceptual mechanisms sensitive to experience underlie facial preferences by familiarizing participants with human, chimpanzee, or morphed faces (60%-chimp/40%-human). Results indicated that participants familiarized with human-chimp morphs showed greater zygomaticus major activity, a physiological correlate of positive affect (Study 1), and higher explicit attractiveness ratings (Study 2) to faces morphed to some degree with chimpanzees. These results demonstrate that experience shifts attractiveness preferences away from the normative average, and suggest that a domain-general cognitive mechanism better accounts for facial preferences than a domain-specific innate beauty-detector. PMID:23226915

  6. Hippocampal morphology is differentially affected by reproductive experience in the mother.

    PubMed

    Pawluski, Jodi L; Galea, Liisa A M

    2006-01-01

    Pregnancy and mothering result in a number of hormonal, neurological, and behavioral changes that are necessary to ensure reproductive success. With subsequent reproductive experience (multiparity and mothering), further neurological and behavioral changes may result. Recent research has shown that previous motherhood enhances both hippocampus-dependent learning and memory and long-term potentiation (LTP); together with decreases in hippocampus volumes during pregnancy it is suggested that the hippocampus is affected by pregnancy and/or mothering. The present experiment aimed to investigate the effect of reproductive experience (nulli, primi-, and multiparity and mothering) on dendritic morphology in the CA1 and CA3 regions of the hippocampus. Brains were stained with a modified version of the single-section Golgi impregnation technique, and dendritic length, number of branch points, and spine density was analyzed for apical and basal regions of CA1 and CA3 pyramidal neurons. Primiparity and/or mothering resulted in dendritic remodeling in both the CA1 and CA3 hippocampal regions, and multiparity resulted in enhanced spine density in the basal CA1 region, which was positively correlated with number of male pups in a litter. These findings point to the effect of reproductive experience and offspring on plasticity in the hippocampus, an area not traditionally associated with motherhood. PMID:16216005

  7. Experience affects the use of ego-motion signals during 3D shape perception

    PubMed Central

    Jain, Anshul; Backus, Benjamin T.

    2011-01-01

    Experience has long-term effects on perceptual appearance (Q. Haijiang, J. A. Saunders, R. W. Stone, & B. T. Backus, 2006). We asked whether experience affects the appearance of structure-from-motion stimuli when the optic flow is caused by observer ego-motion. Optic flow is an ambiguous depth cue: a rotating object and its oppositely rotating, depth-inverted dual generate similar flow. However, the visual system exploits ego-motion signals to prefer the percept of an object that is stationary over one that rotates (M. Wexler, F. Panerai, I. Lamouret, & J. Droulez, 2001). We replicated this finding and asked whether this preference for stationarity, the “stationarity prior,” is modulated by experience. During training, two groups of observers were exposed to objects with identical flow, but that were either stationary or moving as determined by other cues. The training caused identical test stimuli to be seen preferentially as stationary or moving by the two groups, respectively. We then asked whether different priors can exist independently at different locations in the visual field. Observers were trained to see objects either as stationary or as moving at two different locations. Observers’ stationarity bias at the two respective locations was modulated in the directions consistent with training. Thus, the utilization of extraretinal ego-motion signals for disambiguating optic flow signals can be updated as the result of experience, consistent with the updating of a Bayesian prior for stationarity. PMID:21191132

  8. Feeding Experience of Bemisia tabaci (Hemiptera: Aleyrodidae) Affects Their Performance on Different Host Plants

    PubMed Central

    Shah, M. Mostafizur Rahman; Liu, Tong-Xian

    2013-01-01

    The sweetpotato whitefly, Bemisia tabaci biotype B is extremely polyphagous with >600 species of host plants. We hypothesized that previous experience of the whitefly on a given host plant affects their host selection and performance on the plants without previous experience. We investigated the host selection for feeding and oviposition of adults and development and survival of immatures of three host-plant-experienced populations of B. tabaci, namely Bemisia-eggplant, Bemisia-tomato and Bemisia-cucumber, on their experienced host plant and each of the three other plant species (eggplant, tomato, cucumber and pepper) without previous experience. We found that the influence of previous experience of the whiteflies varied among the populations. All populations refused pepper for feeding and oviposition, whereas the Bemisia-cucumber and the Bemisia-eggplant strongly preferred cucumber. Bemisia-tomato did not show strong preference to any of the three host palnts. Development time from egg to adult eclosion varied among the populations, being shortest on eggplant, longest on pepper, and intermediate on tomato and cucumber except for the Bemisia-cucumber developed similarly on tomato and pepper. The survivorship from egg to adult eclosion of all populations was highest on eggplant (80-98%), lowest on pepper (0-20%), and intermediate on tomato and cucumber. In conclusion, the effects of previous experience of whiteflies on host selection for feeding and oviposition, development, and survivorship varied depending on host plants, and host plants play a stronger role than previous experience. Preference of feeding and oviposition by adults may not accurately reflect host suitability of immatures. These results provided important information for understanding whitefly population dynamics and dispersal among different crop systems. PMID:24146985

  9. Integrating cognitive and affective dimensions of pain experience into health professions education

    PubMed Central

    Murinson, Beth B; Mezei, Lina; Nenortas, Elizabeth

    2011-01-01

    Pain is prevalent in clinical settings, and yet it is relatively under-represented in the education of most students in the health professions. Because pain includes both sensory-discriminative and affective features, teaching students about pain presents unique challenges and opportunities. The present article describes the evolution of a new blueprint for clinical excellence that, among other competencies, incorporates a need for the emotional development of clinical trainees. The framework has been applied to the development and implementation of two new courses in pain. The first course is designed to provide a comprehensive foundation of medical knowledge regarding pain, while integratively introducing students to the affective dimensions of pain. The second course is designed to enhance students’ appreciation for the protean effects of pain through use of the humanities to represent medical experience. It is concluded that, to be most effective, fostering the emotional development of trainees in the health professions necessitates the incorporation of affect-focused learning objectives, educational tasks and assessment methods. PMID:22184551

  10. Loop-to-loop coupling.

    SciTech Connect

    Warne, Larry Kevin; Lucero, Larry Martin; Langston, William L.; Salazar, Robert Austin; Coleman, Phillip Dale; Basilio, Lorena I.; Bacon, Larry Donald

    2012-05-01

    This report estimates inductively-coupled energy to a low-impedance load in a loop-to-loop arrangement. Both analytical models and full-wave numerical simulations are used and the resulting fields, coupled powers and energies are compared. The energies are simply estimated from the coupled powers through approximations to the energy theorem. The transmitter loop is taken to be either a circular geometry or a rectangular-loop (stripline-type) geometry that was used in an experimental setup. Simple magnetic field models are constructed and used to estimate the mutual inductance to the receiving loop, which is taken to be circular with one or several turns. Circuit elements are estimated and used to determine the coupled current and power (an equivalent antenna picture is also given). These results are compared to an electromagnetic simulation of the transmitter geometry. Simple approximate relations are also given to estimate coupled energy from the power. The effect of additional loads in the form of attached leads, forming transmission lines, are considered. The results are summarized in a set of susceptibility-type curves. Finally, we also consider drives to the cables themselves and the resulting common-to-differential mode currents in the load.

  11. Wanting to maximize the positive and minimize the negative: implications for mixed affective experience in American and Chinese contexts.

    PubMed

    Sims, Tamara; Tsai, Jeanne L; Jiang, Da; Wang, Yaheng; Fung, Helene H; Zhang, Xiulan

    2015-08-01

    Previous studies have demonstrated that European Americans have fewer mixed affective experiences (i.e., are less likely to experience the bad with the good) compared with Chinese. In this article, we argue that these cultural differences are due to "ideal affect," or how people ideally want to feel. Specifically, we predict that people from individualistic cultures want to maximize positive and minimize negative affect more than people from collectivistic cultures, and as a result, they are less likely to actually experience mixed emotions (reflected by a more negative within-person correlation between actual positive and negative affect). We find support for this prediction in 2 experience sampling studies conducted in the United States and China (Studies 1 and 2). In addition, we demonstrate that ideal affect is a distinct construct from dialectical view of the self, which has also been related to mixed affective experience (Study 3). Finally, in Study 4, we demonstrate that experimentally manipulating the desire to maximize the positive and minimize the negative alters participants' actual experience of mixed emotions during a pleasant (but not unpleasant or combined pleasant and unpleasant) TV clip in the United States and Hong Kong. Together, these findings suggest that across cultures, how people want to feel shapes how they actually feel, particularly people's experiences of mixed affect. PMID:26121525

  12. Wanting to Maximize the Positive and Minimize the Negative: Implications for Mixed Affective Experience in American and Chinese Contexts

    PubMed Central

    Sims, Tamara; Tsai, Jeanne L.; Jiang, Da; Wang, Yaheng; Fung, Helene H.; Zhang, Xiulan

    2016-01-01

    Previous studies have demonstrated that European Americans have fewer mixed affective experiences (i.e., are less likely to experience the bad with the good) compared to Chinese. In this paper, we argue that these cultural differences are due to “ideal affect,” or how people ideally want to feel. Specifically, we predict that people from individualistic cultures want to maximize positive and minimize negative affect more than people from collectivistic cultures, and as a result, they are less likely to actually experience mixed emotions (reflected by a more negative within-person correlation between actual positive and negative affect). We find support for this prediction in two experience sampling studies conducted in the U.S. and China (Studies 1 and 2). In addition, we demonstrate that ideal affect is a distinct construct from dialectical view of the self, which has also been related to mixed affective experience (Study 3). Finally, in Study 4, we demonstrate that experimentally manipulating the desire to maximize the positive and minimize the negative alters participants' actual experience of mixed emotions during a pleasant (but not unpleasant or combined pleasant and unpleasant) television clip in the U.S. and Hong Kong. Together, these findings suggest that across cultures, how people want to feel shapes how they actually feel, particularly people's mixed affective experience. PMID:26121525

  13. A frequent human coagulation Factor VII mutation (A294V, c152) in loop 140s affects the interaction with activators, tissue factor and substrates.

    PubMed Central

    Toso, Raffaella; Pinotti, Mirko; High, Katherine A; Pollak, Eleanor S; Bernardi, Francesco

    2002-01-01

    Activated Factor VII (FVIIa) is a vitamin-K-dependent serine protease that initiates blood clotting after interacting with its cofactor tissue factor (TF). The complex FVIIa-TF is responsible for the activation of Factor IX (FIX) and Factor X (FX), leading ultimately to the formation of a stable fibrin clot. Activated FX (FXa), a product of FVIIa enzymic activity, is also the most efficient activator of zymogen FVII. Interactions of FVII/FVIIa with its activators, cofactor and substrates have been investigated extensively to define contact regions and residues involved in the formation of the complexes. Site-directed mutagenesis and inhibition assays led to the identification of sites removed from the FVIIa active site that influence binding specificity and affinity of the enzyme. In this study we report the characterization of a frequent naturally occurring human FVII mutant, A294V (residue 152 in the chymotrypsin numbering system), located in loop 140s. This region undergoes major rearrangements after FVII activation and is relevant to the development of substrate specificity. FVII A294V shows delayed activation by FXa as well as reduced activity towards peptidyl and macromolecular substrates without impairing the catalytic efficiency of the triad. Also, the interaction of this FVII variant with TF was altered, suggesting that this residue, and more likely loop 140s, plays a pivotal role not only in the recognition of FX by the FVIIa-TF complex, but also in the interaction of FVII with both its activators and cofactor TF. PMID:11931672

  14. Combining Charge Couple Devices and Rate Sensors for the Feedforward Control System of a Charge Coupled Device Tracking Loop.

    PubMed

    Tang, Tao; Tian, Jing; Zhong, Daijun; Fu, Chengyu

    2016-01-01

    A rate feed forward control-based sensor fusion is proposed to improve the closed-loop performance for a charge couple device (CCD) tracking loop. The target trajectory is recovered by combining line of sight (LOS) errors from the CCD and the angular rate from a fiber-optic gyroscope (FOG). A Kalman filter based on the Singer acceleration model utilizes the reconstructive target trajectory to estimate the target velocity. Different from classical feed forward control, additive feedback loops are inevitably added to the original control loops due to the fact some closed-loop information is used. The transfer function of the Kalman filter in the frequency domain is built for analyzing the closed loop stability. The bandwidth of the Kalman filter is the major factor affecting the control stability and close-loop performance. Both simulations and experiments are provided to demonstrate the benefits of the proposed algorithm. PMID:27347970

  15. Combining Charge Couple Devices and Rate Sensors for the Feedforward Control System of a Charge Coupled Device Tracking Loop

    PubMed Central

    Tang, Tao; Tian, Jing; Zhong, Daijun; Fu, Chengyu

    2016-01-01

    A rate feed forward control-based sensor fusion is proposed to improve the closed-loop performance for a charge couple device (CCD) tracking loop. The target trajectory is recovered by combining line of sight (LOS) errors from the CCD and the angular rate from a fiber-optic gyroscope (FOG). A Kalman filter based on the Singer acceleration model utilizes the reconstructive target trajectory to estimate the target velocity. Different from classical feed forward control, additive feedback loops are inevitably added to the original control loops due to the fact some closed-loop information is used. The transfer function of the Kalman filter in the frequency domain is built for analyzing the closed loop stability. The bandwidth of the Kalman filter is the major factor affecting the control stability and close-loop performance. Both simulations and experiments are provided to demonstrate the benefits of the proposed algorithm. PMID:27347970

  16. Psychosocial challenges of young people affected by HIV: experiences from Hamilton County, Chattanooga, Tennessee.

    PubMed

    Chama, Samson; Ramirez, Octavio

    2015-01-01

    The number of young people affected by HIV and AIDS in Tennessee has steadily grown over the last few years. As a response to this situation, several organizations are working hard to address the needs of families impacted by HIV and AIDS. However, a close examination of some of the services provided suggests that young people within these families are ignored. Most of the services are geared toward HIV and AIDS-infected adult members of these families. Young people within these household are not targeted, and little is known about psychosocial challenges they experience in living with HIV-positive parents or guardians. In an attempt to address this gap, this small-scale qualitative study investigated the psychosocial challenges of young people affected by HIV and AIDS as a result of living with HIV-positive parents or guardians. Perceived sense of depression, experiencing stigma, self-blame, and lack of communication and loneliness were challenges that young people faced regularly. PMID:25495702

  17. Early experience affects the strength of vigilance for threat in rhesus monkey infants

    PubMed Central

    Mandalaywala, Tara M.; Parker, Karen J.; Maestripieri, Dario

    2014-01-01

    Both human and nonhuman primates exhibit a cognitive bias to social threat, but little is known about how this bias develops. We investigated the development of threat bias in free-ranging infant rhesus macaques (Macaca mulatta) at 3 (N = 45) and 9 (N = 46) months of age. Three-month-old infant monkeys did not display bias, but 9-month-olds exhibited increased maintenance of attention to threatening social stimuli (vigilance for threat). To examine whether the social environment affected vigilance for threat, behavioral data on maternal rank and protectiveness were collected across the first 12 weeks of life for infants tested at 9 months. Nine-month-old infants of high-ranking mothers and more protective mothers displayed greater vigilance for threat than infants of lower-ranking and less protective mothers. These results demonstrate that infant social cognition is malleable and shaped by mothers both directly (protectiveness) and indirectly (rank), as maternal characteristics affect infants’ social experiences. PMID:25125426

  18. Seagrasses are negatively affected by organic matter loading and Arenicola marina activity in a laboratory experiment.

    PubMed

    Govers, Laura L; Pieck, Timon; Bouma, Tjeerd J; Suykerbuyk, Wouter; Smolders, Alfons J P; van Katwijk, Marieke M

    2014-06-01

    When two ecosystem engineers share the same natural environment, the outcome of their interaction will be unclear if they have contrasting habitat-modifying effects (e.g., sediment stabilization vs. sediment destabilization). The outcome of the interaction may depend on local environmental conditions such as season or sediment type, which may affect the extent and type of habitat modification by the ecosystem engineers involved. We mechanistically studied the interaction between the sediment-stabilizing seagrass Zostera noltii and the bioturbating and sediment-destabilizing lugworm Arenicola marina, which sometimes co-occur for prolonged periods. We investigated (1) if the negative sediment destabilization effect of A. marina on Z. noltii might be counteracted by positive biogeochemical effects of bioirrigation (burrow flushing) by A. marina in sulfide-rich sediments, and (2) if previously observed nutrient release by A. marina bioirrigation could affect seagrasses. We tested the individual and combined effects of A. marina presence and high porewater sulfide concentrations (induced by organic matter addition) on seagrass biomass in a full factorial lab experiment. Contrary to our expectations, we did not find an effect of A. marina on porewater sulfide concentrations. A. marina activities affected the seagrass physically as well as by pumping nutrients, mainly ammonium and phosphate, from the porewater to the surface water, which promoted epiphyte growth on seagrass leaves in our experimental set-up. We conclude that A. marina bioirrigation did not alleviate sulfide stress to seagrasses. Instead, we found synergistic negative effects of the presence of A. marina and high sediment sulfide levels on seagrass biomass. PMID:24633960

  19. Learning Loops--Interactions between Guided Reflection and Experience-Based Learning in a Serious Game Activity

    ERIC Educational Resources Information Center

    Cowley, B.; Heikura, T.; Ravaja, N.

    2013-01-01

    In a study on experience-based learning in serious games, 45 players were tested for topic comprehension by a questionnaire administered before and after playing the single-player serious game Peacemaker (Impact Games 2007). Players were divided into two activity conditions: 20 played a 1-h game with a 3-min half-time break to complete an affect…

  20. Design and Performance Evaluation of a Dual Antenna Joint Carrier Tracking Loop

    PubMed Central

    Guo, Wenfei; Lin, Tao; Niu, Xiaoji; Shi, Chuang; Zhang, Hongping

    2015-01-01

    In order to track the carrier phases of Global Navigation Satellite Systems (GNSS) signals in signal degraded environments, a dual antenna joint carrier tracking loop is proposed and evaluated. This proposed tracking loop processes inputs from two antennas, namely the master antenna and the slave antenna. The master antenna captures signals in open-sky environments, while the slave antenna capture signals in degraded environments. In this architecture, a Phase Lock Loop (PLL) is adopted as a master loop to track the carrier phase of the open-sky signals. The Doppler frequency estimated by this master loop is utilized to assist weak carrier tracking in the slave loop. As both antennas experience similar signal dynamics due to satellite motion and clock frequency variations, a much narrower loop bandwidth and possibly a longer coherent integration can be adopted to track the weak signals in slave channels, by utilizing the Doppler aid from master channels. PLL tracking performance is affected by the satellite/user dynamics, clock instability, and thermal noise. In this paper, their impacts on the proposed phase tracking loop are analyzed and verified by both simulation and field data. Theoretical analysis and experimental results show that the proposed loop structure can track degraded signals (i.e., 18 dB-Hz) with a very narrow loop bandwidth (i.e., 0.5 Hz) and a TCXO clock. PMID:26437415

  1. Design and Performance Evaluation of a Dual Antenna Joint Carrier Tracking Loop.

    PubMed

    Guo, Wenfei; Lin, Tao; Niu, Xiaoji; Shi, Chuang; Zhang, Hongping

    2015-01-01

    In order to track the carrier phases of Global Navigation Satellite Systems (GNSS) signals in signal degraded environments, a dual antenna joint carrier tracking loop is proposed and evaluated. This proposed tracking loop processes inputs from two antennas, namely the master antenna and the slave antenna. The master antenna captures signals in open-sky environments, while the slave antenna capture signals in degraded environments. In this architecture, a Phase Lock Loop (PLL) is adopted as a master loop to track the carrier phase of the open-sky signals. The Doppler frequency estimated by this master loop is utilized to assist weak carrier tracking in the slave loop. As both antennas experience similar signal dynamics due to satellite motion and clock frequency variations, a much narrower loop bandwidth and possibly a longer coherent integration can be adopted to track the weak signals in slave channels, by utilizing the Doppler aid from master channels. PLL tracking performance is affected by the satellite/user dynamics, clock instability, and thermal noise. In this paper, their impacts on the proposed phase tracking loop are analyzed and verified by both simulation and field data. Theoretical analysis and experimental results show that the proposed loop structure can track degraded signals (i.e., 18 dB-Hz) with a very narrow loop bandwidth (i.e., 0.5 Hz) and a TCXO clock. PMID:26437415

  2. Training experience in gestures affects the display of social gaze in baboons' communication with a human.

    PubMed

    Bourjade, Marie; Canteloup, Charlotte; Meguerditchian, Adrien; Vauclair, Jacques; Gaunet, Florence

    2015-01-01

    Gaze behaviour, notably the alternation of gaze between distal objects and social partners that accompanies primates' gestural communication is considered a standard indicator of intentionality. However, the developmental precursors of gaze behaviour in primates' communication are not well understood. Here, we capitalized on the training in gestures dispensed to olive baboons (Papio anubis) as a way of manipulating individual communicative experience with humans. We aimed to delineate the effects of such a training experience on gaze behaviour displayed by the monkeys in relation with gestural requests. Using a food-requesting paradigm, we compared subjects trained in requesting gestures (i.e. trained subjects) to naïve subjects (i.e. control subjects) for their occurrences of (1) gaze behaviour, (2) requesting gestures and (3) temporal combination of gaze alternation with gestures. We found that training did not affect the frequencies of looking at the human's face, looking at food or alternating gaze. Hence, social gaze behaviour occurs independently from the amount of communicative experience with humans. However, trained baboons-gesturing more than control subjects-exhibited most gaze alternation combined with gestures, whereas control baboons did not. By reinforcing the display of gaze alternation along with gestures, we suggest that training may have served to enhance the communicative function of hand gestures. Finally, this study brings the first quantitative report of monkeys producing requesting gestures without explicit training by humans (controls). These results may open a window on the developmental mechanisms (i.e. incidental learning vs. training) underpinning gestural intentional communication in primates. PMID:25138999

  3. Loop Heat Pipe Startup Behaviors

    NASA Technical Reports Server (NTRS)

    Ku, Jentung

    2014-01-01

    A loop heat pipe must start successfully before it can commence its service. The start-up transient represents one of the most complex phenomena in the loop heat pipe operation. This paper discusses various aspects of loop heat pipe start-up behaviors. Topics include the four start-up scenarios, the initial fluid distribution between the evaporator and reservoir that determines the start-up scenario, factors that affect the fluid distribution between the evaporator and reservoir, difficulties encountered during the low power start-up, and methods to enhance the start-up success. Also addressed are the thermodynamic constraint between the evaporator and reservoir in the loop heat pipe operation, the superheat requirement for nucleate boiling, pressure spike and pressure surge during the start-up transient, and repeated cycles of loop start-up andshutdown under certain conditions.

  4. Increased temperatures negatively affect Juniperus communis seeds: evidence from transplant experiments along a latitudinal gradient.

    PubMed

    Gruwez, R; De Frenne, P; Vander Mijnsbrugge, K; Vangansbeke, P; Verheyen, K

    2016-05-01

    With a distribution range that covers most of the Northern hemisphere, common juniper (Juniperus communis) has one of the largest ranges of all vascular plant species. In several regions in Europe, however, populations are decreasing in size and number due to failing recruitment. One of the main causes for this failure is low seed viability. Observational evidence suggests that this is partly induced by climate warming, but our mechanistic understanding of this effect remains incomplete. Here, we experimentally assess the influence of temperature on two key developmental phases during sexual reproduction, i.e. gametogenesis and fertilisation (seed phase two, SP2) and embryo development (seed phase three, SP3). Along a latitudinal gradient from southern France to central Sweden, we installed a transplant experiment with shrubs originating from Belgium, a region with unusually low juniper seed viability. Seeds of both seed phases were sampled during three consecutive years, and seed viability assessed. Warming temperatures negatively affected the seed viability of both SP2 and SP3 seeds along the latitudinal gradient. Interestingly, the effect on embryo development (SP3) only occurred in the third year, i.e. when the gametogenesis and fertilisation also took place in warmer conditions. We found strong indications that this negative influence mostly acts via disrupting growth of the pollen tube, the development of the female gametophyte and fertilisation (SP2). This, in turn, can lead to failing embryo development, for example, due to nutritional problems. Our results confirm that climate warming can negatively affect seed viability of juniper. PMID:26465806

  5. Perch compliance and experience affect destination choice of brown tree snakes (Boiga irregularis).

    PubMed

    Mauro, A Alexander; Jayne, C Bruce

    2016-04-01

    Arboreal animals often encounter branches with variable diameters that are highly correlated with stiffness, but how surface compliance affects the perch choice of animals is poorly understood. We used artificial branches to test the effects of different diameters and compliance on the choice between two destinations for twenty brown tree snakes as they bridged gaps. When both destinations were rigid, the diameters of the surfaces did not affect perch choice. However, with increased experience snakes developed a preference for a rigid, large-diameter perch compared to a compliant, small-diameter perch that collapsed under loads that were a small fraction of the weight of the snake. In hundreds of trials, with only one exception, the snakes proceeded to crawl entirely onto all rigid perches after first touching them, whereas the snakes commonly withdrew from the compliant perch even after touching it so lightly that it did not collapse. Hence, both tactile and visual cues appear to influence how these animals select a destination while crossing a gap. The preference for the rigid, large-diameter perch compared to the compliant, small-diameter perch developed mainly from short-term learning during three successive trials per testing session per individual. Furthermore, a preference for large diameters did not persist in the final treatment which used a rigid, large-diameter perch and a rigid, small-diameter perch. Hence, brown tree snakes appeared to be able to form short-term associations between the perch appearance and stiffness, the latter of which may have been determined via tactile sensory input. PMID:26723759

  6. Negative Experiences in Physical Education and Sport: How Much Do They Affect Physical Activity Participation Later in Life?

    ERIC Educational Resources Information Center

    Cardinal, Bradley J.; Yan, Zi; Cardinal, Marita K.

    2013-01-01

    People's feelings toward physical activity are often influenced by memories of their childhood experiences in physical education and sport. Unfortunately, many adults remember negative experiences, which may affect their desire to maintain a physically active lifestyle. A survey that asked 293 students about recollections from their childhood…

  7. Volatile Drosophila Cuticular Pheromones Are Affected by Social but Not Sexual Experience

    PubMed Central

    Farine, Jean-Pierre; Ferveur, Jean-François; Everaerts, Claude

    2012-01-01

    Recognition of conspecifics and mates is based on a variety of sensory cues that are specific to the species, sex and social status of each individual. The courtship and mating activity of Drosophila melanogaster flies is thought to depend on the olfactory perception of a male-specific volatile pheromone, cis-vaccenyl acetate (cVA), and the gustatory perception of cuticular hydrocarbons (CHs), some of which are sexually dimorphic. Using two complementary sampling methods (headspace Solid Phase Micro-Extraction [SPME] and solvent extraction) coupled with GC-MS analysis, we measured the dispersion of pheromonal CHs in the air and on the substrate around the fly. We also followed the variations in CHs that were induced by social and sexual interactions. We found that all CHs present on the fly body were deposited as a thin layer on the substrate, whereas only a few of these molecules were also detected in the air. Moreover, social experience during early adult development and in mature flies strongly affected male volatile CHs but not cVA, whereas sexual interaction only had a moderate influence on dispersed CHs. Our study suggests that, in addition to their role as contact cues, CHs can influence fly behavior at a distance and that volatile, deposited and body pheromonal CHs participate in a three-step recognition of the chemical identity and social status of insects. PMID:22808151

  8. A mesocosm experiment of suspended particulate matter dynamics in nutrient- and biomass-affected waters.

    PubMed

    Tang, Fiona H M; Maggi, Federico

    2016-02-01

    An experimental study was conducted to test the hypothesis that the biomass growing after an increase in available nutrient in an aquatic ecosystem affects the flocculation dynamics of suspended particulate matter (SPM). The experiment was carried out in a settling column equipped with a turbulence generating system, a water quality monitoring system, and an automated μPIV system to acquire micro photographs of SPM. Three SPM types were tested combinatorially at five turbulence shear rates, three nutrient concentrations, and three mineral concentrations. Analyses of experimental data showed that nutrient availability together with the presence of biomass increased the SPM size by about 60% at low shear as compared to nutrient- and biomass-free conditions; a lower increase was observed at higher shears. In contrast, only 2% lower fractal (capacity) dimension and nearly invariant settling velocity were observed than in nutrient- and biomass-free conditions. Likewise, SPM size and capacity dimension were found to be insensitive to the SPM concentration. Although limited to nearly homogeneous mineral mixes (kaolinite), these experimental findings not only reject the hypothesis that SPM in natural waters can be dealt with as purely mineral systems in all instances, but also anticipate that SPM dynamics in natural waters increasingly exposed to the threat of anthropogenic nutrient discharge would lead to an increased advective flow of adsorbed chemicals and organic carbon. PMID:26641013

  9. The poplar basic helix-loop-helix transcription factor BEE3 – Like gene affects biomass production by enhancing proliferation of xylem cells in poplar

    SciTech Connect

    Noh, Seol Ah Choi, Young-Im Cho, Jin-Seong Lee, Hyoshin

    2015-06-19

    Brassinosteroids (BRs) play important roles in many aspects of plant growth and development, including regulation of vascular cambium activities and cell elongation. BR-induced BEE3 (brassinosteroid enhanced expression 3) is required for a proper BR response. Here, we identified a poplar (Populus alba × Populus glandulosa) BEE3-like gene, PagBEE3L, encoding a putative basic helix-loop-helix (bHLH)-type transcription factor. Expression of PagBEE3L was induced by brassinolide (BL). Transcripts of PagBEE3L were mainly detected in stems, with the internode having a low level of transcription and the node having a relatively higher level. The function of the PagBEE3L gene was investigated through phenotypic analyses with PagBEE3L-overexpressing (ox) transgenic lines. This work particularly focused on a potential role of PagBEE3L in stem growth and development of polar. The PagBEE3L-ox poplar showed thicker and longer stems than wild-type plants. The xylem cells from the stems of PagBEE3L-ox plants revealed remarkably enhanced proliferation, resulting in an earlier thickening growth than wild-type plants. Therefore, this work suggests that xylem development of poplar is accelerated in PagBEE3L-ox plants and PagBEE3L plays a role in stem growth by increasing the proliferation of xylem cells to promote the initial thickening growth of poplar stems. - Highlights: • We identify the BEE3-like gene form hybrid poplar (Populus alba × Populus glandulosa). • We examine effects of overexpression of PagBEE3L on growth in poplar. • We found that 35S:BEE3L transgenic plants showed more rapid growth than wild-type plants. • BEE3L protein plays an important role in the development of plant stem.

  10. The experience of altered states of consciousness in shamanic ritual: the role of pre-existing beliefs and affective factors.

    PubMed

    Polito, Vince; Langdon, Robyn; Brown, Jac

    2010-12-01

    Much attention has been paid recently to the role of anomalous experiences in the aetiology of certain types of psychopathology, e.g. in the formation of delusions. We examine, instead, the top-down influence of pre-existing beliefs and affective factors in shaping an individual's characterisation of anomalous sensory experiences. Specifically we investigated the effects of paranormal beliefs and alexithymia in determining the intensity and quality of an altered state of consciousness (ASC). Fifty five participants took part in a sweat lodge ceremony, a traditional shamanic ritual which was unfamiliar to them. Participants reported significant alterations in their state of consciousness, quantified using the 'APZ' questionnaire, a standardized measure of ASC experience. Participants endorsing paranormal beliefs compatible with shamanic mythology, and those showing difficulty identifying feelings scored higher on positive dimensions of ASC experience. Our findings demonstrate that variation in an individual's characterisation of anomalous experiences is nuanced by pre-existing beliefs and affective factors. PMID:20558090

  11. Effect of Interaction between Chromatin Loops on Cell-to-Cell Variability in Gene Expression

    PubMed Central

    Zhou, Tianshou

    2016-01-01

    According to recent experimental evidence, the interaction between chromatin loops, which can be characterized by three factors—connection pattern, distance between regulatory elements, and communication form, play an important role in determining the level of cell-to-cell variability in gene expression. These quantitative experiments call for a corresponding modeling effect that addresses the question of how changes in these factors affect variability at the expression level in a systematic rather than case-by-case fashion. Here we make such an effort, based on a mechanic model that maps three fundamental patterns for two interacting DNA loops into a 4–state model of stochastic transcription. We first show that in contrast to side-by-side loops, nested loops enhance mRNA expression and reduce expression noise whereas alternating loops have just opposite effects. Then, we compare effects of facilitated tracking and direct looping on gene expression. We find that the former performs better than the latter in controlling mean expression and in tuning expression noise, but this control or tuning is distance–dependent, remarkable for moderate loop lengths, and there is a limit loop length such that the difference in effect between two communication forms almost disappears. Our analysis and results justify the facilitated chromatin–looping hypothesis. PMID:27153118

  12. Affective and Behavioural Variables: Reforms as Experiments to Produce a Civil Society

    ERIC Educational Resources Information Center

    Fitz-Gibbon, Carol T.

    2006-01-01

    Affective and behavioural indicators of the effects of schooling, and of other interventions, might be more important than cognitive indicators, particularly in the long run and considering the urgent need for civil societies. Examples are provided of the statistical properties of affective and behavioural indicators, and of their current use in…

  13. Rollercoaster Loop Shapes

    ERIC Educational Resources Information Center

    Pendrill, Ann-Marie

    2005-01-01

    Many modern rollercoasters feature loops. Although textbook loops are often circular, real rollercoaster loops are not. In this paper, we look into the mathematical description of various possible loop shapes, as well as their riding properties. We also discuss how a study of loop shapes can be used in physics education.

  14. Rollercoaster loop shapes

    NASA Astrophysics Data System (ADS)

    Pendrill, Ann-Marie

    2005-11-01

    Many modern rollercoasters feature loops. Although textbook loops are often circular, real rollercoaster loops are not. In this paper, we look into the mathematical description of various possible loop shapes, as well as their riding properties. We also discuss how a study of loop shapes can be used in physics education.

  15. Water Stream "Loop-the-Loop"

    ERIC Educational Resources Information Center

    Jefimenko, Oleg

    1974-01-01

    Discusses the design of a modified loop-the-loop apparatus in which a water stream is used to illustrate centripetal forces and phenomena of high-velocity hydrodynamics. Included are some procedures of carrying out lecture demonstrations. (CC)

  16. Pre-Instruction, Play-Teach-Play, Processing the Experience. The Three Little P's: Teaching Affective Skills in Physical Education

    ERIC Educational Resources Information Center

    Kuhrasch, Cindy

    2007-01-01

    Physical education has long been recognized as a forum through which affective skills can be successfully introduced and practiced. Solomon found that current research supports the contention that physical education experiences provide a prime setting for promoting character development. This article describes a three-phase program for teaching…

  17. Factors that affect action possibility judgements: recent experience with the action and the current body state.

    PubMed

    Chandrasekharan, Sanjay; Binsted, Gordon; Ayres, Fabio; Higgins, Laura; Welsh, Timothy N

    2012-01-01

    It has been suggested that action possibility judgements are formed through a covert simulation of the to-be-executed action. We sought to determine whether the motor system (via a common coding mechanism) influences this simulation, by investigating whether action possibility judgements are influenced by experience with the movement task (Experiments 1 and 2) and current body states (Experiment 3). The judgement task in each experiment involved judging whether it was possible for a person's hand to accurately move between two targets at presented speeds. In Experiment 1, participants completed the action judgements before and after executing the movement they were required to judge. Results were that judged movement times after execution were closer to the actual execution time than those prior to execution. The results of Experiment 2 suggest that the effects of execution on judgements were not due to motor activation or perceptual task experience-alternative explanations of the execution-mediated judgement effects. Experiment 3 examined how judged movement times were influenced by participants wearing weights. Results revealed that wearing weights increased judged movement times. These results suggest that the simulation underlying the judgement process is connected to the motor system, and that simulations are dynamically generated, taking into account recent experience and current body state. PMID:22348464

  18. Chromosome Compaction by Active Loop Extrusion.

    PubMed

    Goloborodko, Anton; Marko, John F; Mirny, Leonid A

    2016-05-24

    During cell division, chromosomes are compacted in length by more than a 100-fold. A wide range of experiments demonstrated that in their compacted state, mammalian chromosomes form arrays of closely stacked consecutive ∼100 kb loops. The mechanism underlying the active process of chromosome compaction into a stack of loops is unknown. Here we test the hypothesis that chromosomes are compacted by enzymatic machines that actively extrude chromatin loops. When such loop-extruding factors (LEF) bind to chromosomes, they progressively bridge sites that are further away along the chromosome, thus extruding a loop. We demonstrate that collective action of LEFs leads to formation of a dynamic array of consecutive loops. Simulations and an analytically solved model identify two distinct steady states: a sparse state, where loops are highly dynamic but provide little compaction; and a dense state, where there are more stable loops and dramatic chromosome compaction. We find that human chromosomes operate at the border of the dense steady state. Our analysis also shows how the macroscopic characteristics of the loop array are determined by the microscopic properties of LEFs and their abundance. When the number of LEFs are used that match experimentally based estimates, the model can quantitatively reproduce the average loop length, the degree of compaction, and the general loop-array morphology of compact human chromosomes. Our study demonstrates that efficient chromosome compaction can be achieved solely by an active loop-extrusion process. PMID:27224481

  19. Experiences and processes affecting racial identity development: preliminary results from the biracial sibling project.

    PubMed

    Root, M P

    1998-01-01

    Siblings of mixed racial heritage often identify differently from one another. In a study of 20 sibling pairs, 4 types of experiences surfaced that appear to influence the identity process: hazing, family dysfunction, other salient identities, and the impact of integration. These experiences were explored within the framework of the ecological model of racial identity development. PMID:9713163

  20. Starting Smart: How Early Experiences Affect Brain Development. An Ounce of Prevention Fund Paper.

    ERIC Educational Resources Information Center

    Ounce of Prevention Fund.

    Recent research has provided great insight into the impact of early experience on brain development. It is now believed that brain growth is highly dependent upon early experiences. Neurons allow communication and coordinated functioning among various brain areas. Brain development after birth consists of an ongoing process of wiring and rewiring…

  1. Into the looking glass: Broadening models to explain the spectrum of sensory and affective vicarious experiences.

    PubMed

    Giummarra, Melita J; Fitzgibbon, Bernadette M

    2015-01-01

    Ward and Bannisy's proposed conceptual framework-Threshold Theory and Self-Other Theory-for mirror touch synesthesia are welcomed as an explanation of mechanisms giving rise to innocuous vicarious phenomena. Herein we propose that these vicarious, or synesthetic, experiences should be considered along a spectrum of experiences, from innocuous through to noxious or threatening sensations. In particular, we would like to see these theories considered within a broader framework to explain the multitude of vicarious experiences that seem to share fundamental neurophysiological and trait characteristics. PMID:25998034

  2. Experimenting with Water. Factors Affecting the Solubility of Substances in Water.

    ERIC Educational Resources Information Center

    Bourgeois, Simone P.; And Others

    1986-01-01

    Presents a module that focuses on the solvent property of water. Indicates the knowledge items, skills, processes, and attitudes that are developed in the unit. Includes background information as well as student directions for an experiment on solubility. (ML)

  3. Effects of Automobile Commute Characteristics on Affect and Job Candidate Evaluations: A Field Experiment

    ERIC Educational Resources Information Center

    Van Rooy, David L.

    2006-01-01

    The current study assesses the effects of the commuting environment on affective states and hiring decisions. A total of 136 undergraduate females were randomly assigned to one of four conditions based on the length (10 km vs. 30 km) and level of congestion (low vs. high) during a commute. Multivariate analyses of variance indicate that affective…

  4. Adolescents' Affective Experience of Family Behaviors: The Role of Subjective Understanding.

    ERIC Educational Resources Information Center

    Powers, Sally I.; And Others

    1994-01-01

    Argues that a new definition of affect that focuses on the subjective understanding of interpersonal events, can be used to expand models of how observed family behaviors are related to adolescent psychosocial outcomes. A method for examining adolescents' subjective understanding of family behaviors, the video-recall method, is illustrated in a…

  5. Dispositional Empathic Concern, Gender, Level of Experience, Teacher Efficacy, Attributions of Controllability and Teacher Affect

    ERIC Educational Resources Information Center

    Panik, Meredith Anne

    2010-01-01

    Teachers' pity and anger responses to students who fail often are interpreted by the students as indicative of the teachers' attributions for the cause behind the student failure. Students' interpretations of these emotional responses can affect their self-esteem and expectations for future success. The present study explored variables that may…

  6. A Sharing Experience: Development of a Group for Families Affected by HIV Infection.

    ERIC Educational Resources Information Center

    Melvin, Diane; Appleby, Sue

    1995-01-01

    Describes the establishment and development of a support group for the parents of children infected and/or affected by HIV infection. The group is hospital-based, meeting monthly since April 1992, facilitated by professionals but with a self-help and peer support emphasis. Explains the planning, setting, and running of the group. Identifies…

  7. The time between intention and action affects the experience of action

    PubMed Central

    Vinding, Mikkel C.; Jensen, Mads; Overgaard, Morten

    2015-01-01

    We present a study investigating how the delay between the intention to act and the following action, influenced the experience of action. In experiments investigating sense of agency and experience of action, the contrast is most often between voluntary and involuntary actions. It is rarely asked whether different types of intentions influence the experience of action differently. To investigate this we distinguished between proximal intentions (i.e., intentions for immediate actions) and delayed intentions (i.e., intentions with a temporal delay between intention and action). The distinction was implemented in an intentional binding paradigm, by varying the delay between the time where participants formed the intention to act and the time at which they performed the action. The results showed that delayed intentions were followed by a stronger binding effect for the tone following the action compared to proximal intentions. The actions were reported to have occurred earlier for delayed intentions than for proximal intentions. This effect was independent of the binding effect usually found in intentional binding experiments. This suggests that two perceptual shifts occurred in the contrast between delayed intentions and proximal intentions: The first being the binding effect, the second a general shift in the perceived time of action. Neither the stronger binding effect for tone, nor the earlier reports of action, differed across delays for delayed intentions. The results imply that delayed intentions and proximal intentions have a different impact on the experience of action. PMID:26150783

  8. Sexual experience affects reproductive behavior and preoptic androgen receptors in male mice

    PubMed Central

    Swaney, William T.; Dubose, Brittany N.; Curley, James P.; Champagne, Frances A.

    2012-01-01

    Reproductive behavior in male rodents is made up of anticipatory and consummatory elements which are regulated in the brain by sensory systems, reward circuits and hormone signaling. Gonadal steroids play a key role in the regulation of male sexual behavior via steroid receptors in the hypothalamus and preoptic area. Typical patterns of male reproductive behavior have been characterized, however these are not fixed but are modulated by adult experience. We assessed the effects of repeated sexual experience on male reproductive behavior of C57BL/6 mice; including measures of olfactory investigation of females, mounting, intromission and ejaculation. The effects of sexual experience on the number of cells expressing either androgen receptor (AR) or estrogen receptor alpha (ERα) in the primary brain nuclei regulating male sexual behavior was also measured. Sexually experienced male mice engaged in less sniffing of females before initiating sexual behavior and exhibited shorter latencies to mount and intromit, increased frequency of intromission, and increased duration of intromission relative to mounting. No changes in numbers of ERα-positive cells were observed, however sexually experienced males had increased numbers of AR-positive cells in the medial preoptic area (MPOA); the primary regulatory nucleus for male sexual behavior. These results indicate that sexual experience results in a qualitative change in male reproductive behavior in mice that is associated with increased testosterone sensitivity in the MPOA and that this nucleus may play a key integrative role in mediating the effects of sexual experience on male behavior. PMID:22266118

  9. Early experience affects the traits of monogamy in a sexually dimorphic manner.

    PubMed

    Bales, Karen L; Lewis-Reese, Antoniah D; Pfeifer, Lisa A; Kramer, Kristin M; Carter, C Sue

    2007-05-01

    The goal of this study was to examine the effects of early life experiences on the subsequent expression of traits characteristic of social monogamy in prairie voles (Microtus ochrogaster). During cage changes parents and their offspring were either transferred between cages in a cup (zero manipulation, MAN0) or with a gloved hand (one manipulation, MAN1). Following weaning the offspring were tested for alloparental behavior. In adulthood they were tested for the capacity to form partner preferences, behavior in an elevated plus-maze (EPM), and corticosterone levels. MAN0 males (but not females) showed lower levels of alloparental behavior than MAN1 males. MAN0 females (but not males) were less likely to form pair bonds than MAN1 females. MAN0 animals of both sexes were less exploratory in the EPM than MAN1 counterparts. These experiments support the hypothesis that behaviors used to characterize monogamy are vulnerable in a sex-specific manner to early experience. PMID:17455224

  10. Adverse childhood experiences associate to reduced glutamate levels in the hippocampus of patients affected by mood disorders.

    PubMed

    Poletti, Sara; Locatelli, Clara; Falini, Andrea; Colombo, Cristina; Benedetti, Francesco

    2016-11-01

    Adverse childhood experiences (ACE) can possibly permanently alter the stress response system, affect the glutamatergic system and influence hippocampal volume in mood disorders. The aim of the study is to investigate the association between glutamate levels in the hippocampus, measured through single proton magnetic resonance spectroscopy (1H-MRS), and ACE in patients affected by mood disorders and healthy controls. Higher levels of early stress associate to reduced levels of Glx/Cr in the hippocampus in depressed patients but not in healthy controls. Exposure to stress during early life could lead to a hypofunctionality of the glutamatergic system in the hippocampus of depressed patients. Abnormalities of glutamatergic signaling could then possibly underpin the structural and functional abnormalities observed in patients affected by mood disorders. PMID:27449360

  11. Does Nursing Home Ownership Change Affect Family Ratings on Experience with Care?

    PubMed

    Campbell, Lauren J; Li, Qinghua; Li, Yue

    2015-01-01

    Person-centeredness may suffer in nursing homes (NHs) with recent ownership changes. This study identifies associations between ownership change and reported care experiences, important measures of person-centered care for long-term residents in Maryland NHs. Care experience measures and ownership change data were collected from Maryland Health Care Commission reports, which reported data on 220 Maryland NHs from 2011 and 2012. Facility and market covariates were obtained from 2011 NH Compare and Area Health Resource Files. Linear regression was used to examine whether ownership change in 2011 was associated with lower care experience ratings reported during April to June 2012. Dependent variables were overall care rating (scale 1-10), percentage of respondents answering that they would recommend the NH, and assessments of five care and resident life domains (scale 1-4). Care experiences reported in 2012 were high; however, after controlling for covariates, ownership change was associated with significant decreases in 6 out of 7 measures, including a 0.39-point decrease in overall care rating (p = .001). NH managers and policy makers should consider strategies to improve patient-centeredness after ownership change. PMID:26162057

  12. What Factors Affect the Separation of Substances Using Thin-Layer Chromatography? An Undergraduate Experiment.

    ERIC Educational Resources Information Center

    Nash, John J.; Meyer, Jeanne A.; Everson, Barbara

    2001-01-01

    Rx values in thin-layer chromatography (TLC) depend strongly on the solvent saturation of the atmosphere above the liquid in the TLC developing chamber. Presents an experiment illustrating the potentially dramatic effects on TLC Rx values of not equilibrating the solvent atmosphere during development. (ASK)

  13. Visual Data Collection Methods for Research on the Affective Dimensions of Children's Personal Experiences of PE

    ERIC Educational Resources Information Center

    Georgakis, Steve; Light, Richard

    2009-01-01

    The rapid growth of research on Teaching Games for Understanding (TGfU) over the past decade has paid little attention to research methodology. This paper redresses this lack of attention to research methods and reports on a study conducted on children's personal experiences of Game Sense. The study focuses on the use of year six students'…

  14. An Experiment To Demonstrate How a Catalyst Affects the Rate of a Reaction.

    ERIC Educational Resources Information Center

    Copper, Christine L.; Koubeck, Edward

    1999-01-01

    Describes a chemistry experiment that allows students to calculate rates of reaction, orders of reaction, and activation energies. The activity demonstrates that to increase a reaction's rate, a catalyst need only provide any additional pathway for the reaction, not necessarily a pathway having lower activation energy. (WRM)

  15. Factors Affecting Spatial Test Performance: Sex, Handedness, Birth Order, and Experience.

    ERIC Educational Resources Information Center

    Guay, Roland B.

    Four factors have been reported in the literature as being related to spatial test performance. This study investigated the main and interaction effects of sex, handedness, birth order, and experience on three different types of spatial performance; surface development, object rotation, and coordination of viewpoints. A total of 217 undergraduate…

  16. Mathematical Discovery and "Affect": The "Effect" of Aha! Experiences on Undergraduate Mathematics Students

    ERIC Educational Resources Information Center

    Liljedahl, Peter G.

    2005-01-01

    The AHA! experience-the moment of illumination on the heels of lengthy, and seemingly fruitless, intentional effort-has long been the basis for lore in mathematics. Unfortunately, such lore is often restricted to the discussion of these phenomena in the context of great mathematicians and great mathematical advancement. But are such experiences…

  17. Does Experience in College Mathematics Courses Affect Elementary Arithmetic Performance in College Students?

    ERIC Educational Resources Information Center

    Weinstein, Lawrence; Laverghetta, Antonio

    2009-01-01

    Undergraduate and graduate students at Cameron University (N = 158) were given the D'Amore Test of Elementary Arithmetic to test whether or not experience in college mathematics courses might be associated with a relative increase in arithmetic performance compared to those students who had not taken college mathematics courses. We found that only…

  18. Vasovagal Syncope and Blood Donor Return: Examination of the Role of Experience and Affective Expectancies

    ERIC Educational Resources Information Center

    Olatunji, Bunmi O.; Etzel, Erin N.; Ciesielski, Bethany G.

    2010-01-01

    Vasovagal sensations (e.g., dizziness, nausea, and fainting) are one of the main reasons people find blood donation unpleasant. A better understanding of predictors of vasovagal sensations during blood donation could inform interventions designed to increase donor return rates. The present investigation examined the extent to which experience with…

  19. Do Tuition Fees Affect Enrollment Behavior? Evidence from a "Natural Experiment" in Germany

    ERIC Educational Resources Information Center

    Hubner, Malte

    2012-01-01

    This paper uses the introduction of tuition fees in seven of the sixteen German states in 2007 as a natural experiment to identify the effects of tuition prices on enrollment probabilities. Based on information on enrollment decisions of the entire population of high-school graduates between 2002 and 2008, I find a negative effect of tuition fees…

  20. From Affective Experience to Motivated Action: Tracking Reward-Seeking and Punishment-Avoidant Behaviour in Real-Life

    PubMed Central

    Wichers, Marieke; Kasanova, Zuzana; Bakker, Jindra; Thiery, Evert; Derom, Catherine; Jacobs, Nele; van Os, Jim

    2015-01-01

    Many of the decisions and actions in everyday life result from implicit learning processes. Important to psychopathology are, for example, implicit reward-seeking and punishment-avoidant learning processes. It is known that when specific actions get associated with a rewarding experience, such as positive emotions, that this will increase the likelihood that an organism will engage in similar actions in the future. Similarly, when actions get associated with punishing experiences, such as negative emotions, this may reduce the likelihood that the organism will engage in similar actions in the future. This study examines whether we can observe these implicit processes prospectively in the flow of daily life. If such processes take place then we expect that current behaviour can be predicted by how similar behaviour was experienced (in terms of positive and negative affect) at previous measurement moments. This was examined in a sample of 621 female individuals that had participated in an Experience Sampling data collection. Measures of affect and behaviour were collected at 10 semi-random moments of the day for 5 consecutive days. It was examined whether affective experience that was paired with certain behaviours (physical activity and social context) at previous measurements modified the likelihood to show similar behaviours at next measurement moments. Analyses were performed both at the level of observations (a time scale with units of ± 90 min) and at day level (a time scale with units of 24 h). As expected, we found that affect indeed moderated the extent to which previous behaviour predicted similar behaviour later in time, at both beep- and day-level. This study showed that it is feasible to track reward-seeking and punishment-avoidant behaviour prospectively in humans in the flow of daily life. This opens up a new toolbox to examine processes determining goal-oriented behaviour in relation to psychopathology in humans. PMID:26087323

  1. OPE for super loops

    NASA Astrophysics Data System (ADS)

    Sever, Amit; Vieira, Pedro; Wang, Tianheng

    2011-11-01

    We extend the Operator Product Expansion for Null Polygon Wilson loops to the Mason-Skinner-Caron-Huot super loop dual to non MHV gluon amplitudes. We explain how the known tree level amplitudes can be promoted into an infinite amount of data at any loop order in the OPE picture. As an application, we re-derive all one loop NMHV six gluon amplitudes by promoting their tree level expressions. We also present some new all loops predictions for these amplitudes.

  2. The preprocessed doacross loop

    NASA Technical Reports Server (NTRS)

    Saltz, Joel H.; Mirchandaney, Ravi

    1990-01-01

    Dependencies between loop iterations cannot always be characterized during program compilation. Doacross loops typically make use of a-priori knowledge of inter-iteration dependencies to carry out required synchronizations. A type of doacross loop is proposed that allows the scheduling of iterations of a loop among processors without advance knowledge of inter-iteration dependencies. The method proposed for loop iterations requires that parallelizable preprocessing and postprocessing steps be carried out during program execution.

  3. Fast flux locked loop

    DOEpatents

    Ganther, Jr., Kenneth R.; Snapp, Lowell D.

    2002-09-10

    A flux locked loop for providing an electrical feedback signal, the flux locked loop employing radio-frequency components and technology to extend the flux modulation frequency and tracking loop bandwidth. The flux locked loop of the present invention has particularly useful application in read-out electronics for DC SQUID magnetic measurement systems, in which case the electrical signal output by the flux locked loop represents an unknown magnetic flux applied to the DC SQUID.

  4. How nurses and their work environment affect patient experiences of the quality of care: a qualitative study

    PubMed Central

    2014-01-01

    Background Healthcare organisations monitor patient experiences in order to evaluate and improve the quality of care. Because nurses spend a lot of time with patients, they have a major impact on patient experiences. To improve patient experiences of the quality of care, nurses need to know what factors within the nursing work environment are of influence. The main focus of this research was to comprehend the views of Dutch nurses on how their work and their work environment contribute to positive patient experiences. Methods A descriptive qualitative research design was used to collect data. Four focus groups were conducted, one each with 6 or 7 registered nurses in mental health care, hospital care, home care and nursing home care. A total of 26 nurses were recruited through purposeful sampling. The interviews were audiotaped, transcribed and subjected to thematic analysis. Results The nurses mentioned essential elements that they believe would improve patient experiences of the quality of nursing care: clinically competent nurses, collaborative working relationships, autonomous nursing practice, adequate staffing, control over nursing practice, managerial support and patient-centred culture. They also mentioned several inhibiting factors, such as cost-effectiveness policy and transparency goals for external accountability. Nurses feel pressured to increase productivity and report a high administrative workload. They stated that these factors will not improve patient experiences of the quality of nursing care. Conclusions According to participants, a diverse range of elements affect patient experiences of the quality of nursing care. They believe that incorporating these elements into daily nursing practice would result in more positive patient experiences. However, nurses work in a healthcare context in which they have to reconcile cost-efficiency and accountability with their desire to provide nursing care that is based on patient needs and preferences, and

  5. An experiment with spectral analysis of emotional speech affected by orthodontic appliances

    NASA Astrophysics Data System (ADS)

    Přibil, Jiří; Přibilová, Anna; Ďuračková, Daniela

    2012-11-01

    The contribution describes the effect of the fixed and removable orthodontic appliances on spectral properties of emotional speech. Spectral changes were analyzed and evaluated by spectrograms and mean Welch’s periodograms. This alternative approach to the standard listening test enables to obtain objective comparison based on statistical analysis by ANOVA and hypothesis tests. Obtained results of analysis performed on short sentences of a female speaker in four emotional states (joyous, sad, angry, and neutral) show that, first of all, the removable orthodontic appliance affects the spectrograms of produced speech.

  6. Mapping the urban asthma experience: Using qualitative GIS to understand contextual factors affecting asthma control.

    PubMed

    Keddem, Shimrit; Barg, Frances K; Glanz, Karen; Jackson, Tara; Green, Sarah; George, Maureen

    2015-09-01

    Asthma is complex and connected to a number of factors including access to healthcare, crime and violence, and environmental triggers. A mixed method approach was used to examine the experiences of urban people with asthma in controlling their asthma symptoms. The study started with an initial phase of qualitative interviews in West Philadelphia, a primarily poor African American community. Data from qualitative, semi-structured interviews indicated that stress, environmental irritants, and environmental allergens were the most salient triggers of asthma. Based on the interviews, the team identified six neighborhood factors to map including crime, housing vacancy, illegal dumping, tree canopy and parks. These map layers were combined into a final composite map. These combined methodologies contextualized respondents' perceptions in the framework of the actual community and built environment which tells a more complete story about their experience with asthma. PMID:26184704

  7. Serious complications in experiments in which UV doses are affected by using different lamp heights

    NASA Astrophysics Data System (ADS)

    Flint, Stephan D.; Ryel, Ronald J.; Caldwell, Martyn M.

    2004-10-01

    Many experiments examining plant responses to enhanced UV-B radiation simply compare an enhanced UV-B radiation treatment with ambient UV-B (or no UV-B in most greenhouse and controlled environment studies). However, some experiments utilize multiple doses of UV-B radiation. A number of different techniques have been used to adjust the UV dose, each with advantages and disadvantages. One common technique is to place racks of fluorescent UV-B lamps at different heights above the plant canopy. A generally ignored consequence of this technique is that the pattern of shade which plants receive from the lamps is distributed differently over the course of the day at different lamp heights. To determine the effects of using lamps at different heights above the canopy, we grew three species (canola, sunflower, and maize) in the greenhouse under racks of unenergized lamps that were placed at two different heights above the plant canopy. Many plant growth characteristics differed between plants grown under the two lamp heights. These differences can potentially enhance or obscure true UV-B effects. Even more troubling is that changes in leaf mass per foliage area, which were observed in this experiment, could contribute to differences in plant UV-B sensitivity. We recommend the use of other techniques for achieving multiple doses of UV-B radiation. These range from simple and inexpensive approaches (wrapping individual fluorescent tubes in different layers of a neutral density filter such as cheese cloth) to more technical and expensive alternatives (electronically modulated lamp control systems). These choices should be determined by the goals of the particular experiment.

  8. Influence of Sex on Suicidal Phenotypes in Affective Disorder Patients with Traumatic Childhood Experiences

    PubMed Central

    Carlberg, Laura; Swoboda, Patrick; Ludwig, Birgit; Koller, Romina; Kapusta, Nestor D.; Aigner, Martin; Haslacher, Helmuth; Schmöger, Michaela; Kasper, Siegfried; Schosser, Alexandra

    2015-01-01

    Objectives In the current study, we aimed to investigate the impact of childhood trauma on suicidal behaviour phenotypes in a group of patients with diagnosed affective disorder (unipolar or bipolar affective disorder). Patients and Methods Patients with and without a history of childhood abuse, measured by Childhood Trauma Questionnaire (CTQ), were assessed to explore risks for suicidal behaviour (including suicide attempt, self-harm and non-suicidal self-injury). The tested sample consisted of 258 patients (111 males and 147 females, in-patients and out-patients at the Department of Psychiatry and Psychotherapy, Medical University of Vienna and University Hospital Tulln, Lower Austria). Psychiatric diagnoses were derived from the SCAN (Schedules for Clinical Assessment in Neuropsychiatry) interview. In addition, patients were administered the Lifetime Parasuicidal Count (LPC), Suicidal Behaviour Questionnaire (SBQ-R), and Viennese Suicide Risk Assessment Scale (VISURIAS) questionnaires. Results In contrast to male suicide attempters, female suicide attempters showed both significantly higher total CTQ scores (p<0.001), and higher CTQ subscores (emotional, physical and sexual abuse, as well as emotional and physical neglect) in comparison to the non-suicidal control group. Besides, females with a history of self-harming behaviour (including suicidal intention) and Non-Suicidal-Self Injury (NSSI) had significantly higher CTQ total scores (p<0.001) than the control group. Conclusion These findings suggest gender differences in suicidal behaviour after being exposed to childhood trauma. PMID:26366559

  9. Factors affecting student success in a first-year mathematics course: a South African experience

    NASA Astrophysics Data System (ADS)

    Kizito, Rita; Munyakazi, Justin; Basuayi, Clement

    2016-01-01

    In spite of sustained efforts tertiary institutions implement to try and improve student academic performance, the number of students succeeding in first-year mathematics courses remains disturbingly low. For most students, the gap between their mathematical capability and the competencies they are expected and need to develop to function effectively in these courses persists even after course instruction. In this study, an instrument for identifying and examining factors affecting student performance and success in a first-year Mathematics university course was developed and administered to 86 students. The overall Cronbach's Alpha coefficient for the questionnaire was found to be 0.916. Having identified variables from prior research known to affect student performance, factor analysis was used to identify variables exhibiting the greatest impact on student performance. The variables included prior academic knowledge, workload, student approaches to learning, assessment, student support teaching quality, methods and resources. From the analysis, students' perceptions of their workload emerged as the factor having the greatest impact on student's performance, followed by the matriculation examination score. The findings are discussed and strategies that can be used to improve teaching and contribute to student success in a first-year mathematics course in a South African context are presented.

  10. Early-life experience affects honey bee aggression and resilience to immune challenge.

    PubMed

    Rittschof, Clare C; Coombs, Chelsey B; Frazier, Maryann; Grozinger, Christina M; Robinson, Gene E

    2015-01-01

    Early-life social experiences cause lasting changes in behavior and health for a variety of animals including humans, but it is not well understood how social information ''gets under the skin'' resulting in these effects. Adult honey bees (Apis mellifera) exhibit socially coordinated collective nest defense, providing a model for social modulation of aggressive behavior. Here we report for the first time that a honey bee's early-life social environment has lasting effects on individual aggression: bees that experienced high-aggression environments during pre-adult stages showed increased aggression when they reached adulthood relative to siblings that experienced low-aggression environments, even though all bees were kept in a common environment during adulthood. Unlike other animals including humans however, high-aggression honey bees were more, rather than less, resilient to immune challenge, assessed as neonicotinoid pesticide susceptibility. Moreover, aggression was negatively correlated with ectoparasitic mite presence. In honey bees, early-life social experience has broad effects, but increased aggression is decoupled from negative health outcomes. Because honey bees and humans share aspects of their physiological response to aggressive social encounters, our findings represent a step towards identifying ways to improve individual resiliency. Pre-adult social experience may be crucial to the health of the ecologically threatened honey bee. PMID:26493190

  11. Early-life experience affects honey bee aggression and resilience to immune challenge

    PubMed Central

    Rittschof, Clare C.; Coombs, Chelsey B.; Frazier, Maryann; Grozinger, Christina M.; Robinson, Gene E.

    2015-01-01

    Early-life social experiences cause lasting changes in behavior and health for a variety of animals including humans, but it is not well understood how social information ‘‘gets under the skin’’ resulting in these effects. Adult honey bees (Apis mellifera) exhibit socially coordinated collective nest defense, providing a model for social modulation of aggressive behavior. Here we report for the first time that a honey bee’s early-life social environment has lasting effects on individual aggression: bees that experienced high-aggression environments during pre-adult stages showed increased aggression when they reached adulthood relative to siblings that experienced low-aggression environments, even though all bees were kept in a common environment during adulthood. Unlike other animals including humans however, high-aggression honey bees were more, rather than less, resilient to immune challenge, assessed as neonicotinoid pesticide susceptibility. Moreover, aggression was negatively correlated with ectoparasitic mite presence. In honey bees, early-life social experience has broad effects, but increased aggression is decoupled from negative health outcomes. Because honey bees and humans share aspects of their physiological response to aggressive social encounters, our findings represent a step towards identifying ways to improve individual resiliency. Pre-adult social experience may be crucial to the health of the ecologically threatened honey bee. PMID:26493190

  12. Students’ Factors Affecting Undergraduates’ Perceptions of their Teaching and Learning Process within ECTS Experience

    PubMed Central

    la Fuente, Jesús De; Cardelle-Elawar, María; Peralta, F. Javier; Sánchez, M. Dolores; Martínez-Vicente, José Manuel; Zapata, Lucía

    2010-01-01

    Introduction: In the present study, we investigated the potential factors that influenced the level of students satisfaction with the teaching–learning process (TLP), from the perspective of students participating in the European Credit Transfer System (ECTS) experience. Method: A total of 1490 students from the Universities of Almería and Granada (Spain) participated in an evaluation of their class discipline area. They completed the new revised protocol for evaluating the ECTS experience. Analyses of variance were carried out, taking the following factors as independent variables: student's grade average, year in school, study discipline, credit load in terms of ECTS credits assigned to a subject, the e-learning approach. Perception of the TLP was used as the dependent variable. Results: The data analyses showed variability of the degree of statistically significance among the factors that influenced students’ perceptions of the TLP. These factors included: Student's grade average (in favor of high performers), year in school (in favor of earlier years), ECTS load (in favor of subjects with a medium load of credits), and e-learning (in favor of its use). These research findings provided evidence to explore the delineation of a potential profile of factors that trigger a favorable perception of the TLP. Discussion and Conclusion: The present findings certainly have implications to deepen our understanding of the core beliefs, commitment, and the experience in shaping the implementation of the European Higher Education Area through the ECTS. PMID:21713171

  13. Early social experience affects neural activity to affiliative facial gestures in newborn nonhuman primates

    PubMed Central

    Vanderwert, Ross E.; Simpson, Elizabeth A.; Paukner, Annika; Suomi, Stephen J.; Fox, Nathan A.; Ferrari, Pier F.

    2015-01-01

    A fundamental issue in cognitive neuroscience is how the brain encodes others’ actions and intentions. The discovery of an action-production-perception mechanism underpinning such a capacity advanced our knowledge of how these processes occur; however, no study has examined how the early postnatal environment may shape action-production-perception. Here we examined the effects of social experience on action-production-perception in 3-day-old rhesus macaques that were raised either with or without their biological mothers. We measured neonatal imitation skills and brain electrical activity responses while infants produced and observed facial gestures. We hypothesized that early social experiences may shape brain activity, as assessed via electroencephalogram suppression in the alpha band (5-7 Hz in infants, known as the mu rhythm) during action observation, and lead to more proficient imitation skills. Consistent with this hypothesis, infants reared by their mothers were more likely to imitate lipsmacking—a natural, affiliative gesture—and exhibited greater mu rhythm desynchronization while viewing lipsmacking gestures than nursery-reared infants. These effects were not found in response to tongue protrusion, a meaningless gesture, or a nonsocial control. These data suggest that socially enriched early experiences in the first days after birth increase brain sensitivity to socially relevant actions. PMID:26022835

  14. Quantitation of interactions between two DNA loops demonstrates loop domain insulation in E. coli cells.

    PubMed

    Priest, David G; Kumar, Sandip; Yan, Yan; Dunlap, David D; Dodd, Ian B; Shearwin, Keith E

    2014-10-21

    Eukaryotic gene regulation involves complex patterns of long-range DNA-looping interactions between enhancers and promoters, but how these specific interactions are achieved is poorly understood. Models that posit other DNA loops--that aid or inhibit enhancer-promoter contact--are difficult to test or quantitate rigorously in eukaryotic cells. Here, we use the well-characterized DNA-looping proteins Lac repressor and phage λ CI to measure interactions between pairs of long DNA loops in E. coli cells in the three possible topological arrangements. We find that side-by-side loops do not affect each other. Nested loops assist each other's formation consistent with their distance-shortening effect. In contrast, alternating loops, where one looping element is placed within the other DNA loop, inhibit each other's formation, thus providing clear support for the loop domain model for insulation. Modeling shows that combining loop assistance and loop interference can provide strong specificity in long-range interactions. PMID:25288735

  15. Factors affecting the pore space transformation during hydrocarbon generation in source rock (shales): laboratory experiment

    NASA Astrophysics Data System (ADS)

    Giliazetdinova, D. R.; Korost, D. V.

    2014-12-01

    Oil and gas generation is a set of processes which taking place in the interior, the processes can't be observable in nature. In the process of dumping the source rock, organic matter is transformed into a complex of high-molecular compounds - precursors of oil and gas (kerogen). Entering of a source column for specific thermobaric conditions, triggers the formation of low molecular weight hydrocarbon compounds. Generation of sufficient quantities of hydrocarbons leads to the primary fluid migration within the source rock. For the experiment were selected mainly siliceous-carbonate composition rocks from Domanic horizon South-Tatar arch. The main aim of experiment was heating the rocks in the pyrolyzer to temperatures which correspond katagenes stages. For monitoring changes in the morphology of the pore space X-ray microtomography method was used. As a result, when was made a study of the composition of mineral and organic content of the rocks, as well as textural and structural features, have been identified that the majority of the rock samples within the selected collection are identical. However, characteristics such as organic content and texture of rocks are different. Thus, the experiment was divided into two parts: 1) the study of the influence of organic matter content on the morphology of the rock in the process of thermal effects; 2) study the effect of texture on the primary migration processes for the same values of organic matter. Also, an additional experiment was conducted to study the dynamics of changes in the structure of the pore space. At each stage of the experiment morphology of altered rocks characterized by the formation of new pores and channels connecting the primary voids. However, it was noted that the samples with a relatively low content of the organic matter had less changes in pore space morphology, in contrast to rocks with a high organic content. At the second stage of the research also revealed that the conversion of the pore

  16. The Madrid Affective Database for Spanish (MADS): Ratings of Dominance, Familiarity, Subjective Age of Acquisition and Sensory Experience.

    PubMed

    Hinojosa, José A; Rincón-Pérez, Irene; Romero-Ferreiro, M Verónica; Martínez-García, Natalia; Villalba-García, Cristina; Montoro, Pedro R; Pozo, Miguel A

    2016-01-01

    The current study presents ratings by 540 Spanish native speakers for dominance, familiarity, subjective age of acquisition (AoA), and sensory experience (SER) for the 875 Spanish words included in the Madrid Affective Database for Spanish (MADS). The norms can be downloaded as supplementary materials for this manuscript from https://figshare.com/s/8e7b445b729527262c88 These ratings may be of potential relevance to researches who are interested in characterizing the interplay between language and emotion. Additionally, with the aim of investigating how the affective features interact with the lexicosemantic properties of words, we performed correlational analyses between norms for familiarity, subjective AoA and SER, and scores for those affective variables which are currently included in the MADs. A distinct pattern of significant correlations with affective features was found for different lexicosemantic variables. These results show that familiarity, subjective AoA and SERs may have independent effects on the processing of emotional words. They also suggest that these psycholinguistic variables should be fully considered when formulating theoretical approaches to the processing of affective language. PMID:27227521

  17. The Madrid Affective Database for Spanish (MADS): Ratings of Dominance, Familiarity, Subjective Age of Acquisition and Sensory Experience

    PubMed Central

    Hinojosa, José A.; Rincón-Pérez, Irene; Romero-Ferreiro, Mª Verónica; Martínez-García, Natalia; Villalba-García, Cristina; Montoro, Pedro R.; Pozo, Miguel A.

    2016-01-01

    The current study presents ratings by 540 Spanish native speakers for dominance, familiarity, subjective age of acquisition (AoA), and sensory experience (SER) for the 875 Spanish words included in the Madrid Affective Database for Spanish (MADS). The norms can be downloaded as supplementary materials for this manuscript from https://figshare.com/s/8e7b445b729527262c88 These ratings may be of potential relevance to researches who are interested in characterizing the interplay between language and emotion. Additionally, with the aim of investigating how the affective features interact with the lexicosemantic properties of words, we performed correlational analyses between norms for familiarity, subjective AoA and SER, and scores for those affective variables which are currently included in the MADs. A distinct pattern of significant correlations with affective features was found for different lexicosemantic variables. These results show that familiarity, subjective AoA and SERs may have independent effects on the processing of emotional words. They also suggest that these psycholinguistic variables should be fully considered when formulating theoretical approaches to the processing of affective language. PMID:27227521

  18. A neurocognitive theory of higher mental emergence: from anoetic affective experiences to noetic knowledge and autonoetic awareness.

    PubMed

    Vandekerckhove, Marie; Panksepp, Jaak

    2011-10-01

    This essay provides an overview of evolutionary levels of consciousness, with a focus on a continuum of consciousness: from primarily affective to more advanced cognitive forms of neural processing-from anoetic (without knowledge) consciousness based on affective feelings, elaborated by brain networks that are subcortical- and can function without neocortical involvement, to noetic (knowledge based) and autonoetic (higher reflective mental) processes that permits conscious awareness. An abundance of such mind-brain linkages have been established using standard neuropsychological and brain-imaging procedures. Much of the characterization of human mental landscapes has been achieved with long accepted psychometric procedures that often do not adequately tap the lived anoetic experiential phenomenological aspects of mind. Without an understanding of affective based anoetic forms of consciousness, an adequate characterization of the human mind may never be achieved. A full synthesis will require us to view mental-experiential processes concurrently at several distinct neurophysiological levels, including foundational affective-emotional issues that are best probed with cross-species affective neuroscience strategies. This essay attempts to relate these levels of analysis to the neural systems that constitute lived experience in the human mind. PMID:21530586

  19. Soil type affects Pinus ponderosa var. scopulorum (Pinaceae) seedling growth in simulated drought experiments1

    PubMed Central

    Lindsey, Alexander J.; Kilgore, Jason S.

    2013-01-01

    • Premise of the study: Effects of drought stress and media type interactions on growth of Pinus ponderosa var. scopulorum germinants were investigated. • Methods and Results: Soil properties and growth responses under drought were compared across four growth media types: two native soils (dolomitic limestone and granite), a soil-less industry standard conifer medium, and a custom-mixed conifer medium. After 35 d of growth, the seedlings under drought stress (reduced watering) produced less shoot and root biomass than watered control seedlings. Organic media led to decreased root biomass, but increased root length and shoot biomass relative to the mineral soils. • Conclusions: Media type affected root-to-shoot biomass partitioning of P. ponderosa var. scopulorum, which may influence net photosynthetic rates, growth, and long-term seedling survival. Further work should examine how specific soil properties like bulk density and organic matter influence biomass allocation in greenhouse studies. PMID:25202578

  20. Negative affective experiences in relation to stages of eating disorder recovery.

    PubMed

    Harney, Megan B; Fitzsimmons-Craft, Ellen E; Maldonado, Christine R; Bardone-Cone, Anna M

    2014-01-01

    The purpose of this study was to examine a collection of negative affect symptoms in relation to stages of eating disorder recovery. Depressive symptoms, anxiety symptoms, loneliness, and perceived stress are known to be present in individuals with eating disorders; however, less is known about the presence of such constructs throughout the recovery process. Does this negative affect fog continue to linger in individuals who have recovered from an eating disorder? Female participants seen at some point for an eating disorder at a primary care clinic were categorized into one of three groups using a stringent definition of eating disorder recovery based on physical, behavioral, and psychological criteria: active eating disorder (n=53), partially recovered (n=15; psychological criteria not met), and fully recovered (n=20; all recovery criteria met). Additionally, data were obtained from 67 female controls who had no history of an eating disorder. Self-report data indicated that controls and women fully recovered from an eating disorder scored significantly lower than partially recovered and active eating disorder groups in perceived stress, depression, and anxiety. Controls and the fully recovered group were statistically indistinguishable from each other in these domains, as were the partially recovered and active eating disorder groups, suggesting an interesting divide depending on whether psychological criteria (e.g., normative levels of weight/shape concern) were met. In contrast, controls and fully recovered and partially recovered groups all reported feeling significantly less lonely relative to those with an active eating disorder suggesting that improved perceptions of interpersonal functioning and social support may act as a stepping stone toward more comprehensive eating disorder recovery. Future research may want to longitudinally determine if an increase in actual or perceived social support facilitates the movement toward full recovery and whether this

  1. Education majors' expectations and reported experiences with inquiry-based physics: Implications for student affect

    NASA Astrophysics Data System (ADS)

    Gaffney, Jon D. H.

    2013-06-01

    To address a perennial need to provide K-8 teachers with a solid foundation in science, there are many physics content courses throughout the United States. One such course is Physics and Astronomy for Teachers (PAT), which relies heavily on active-learning strategies. Although PAT is successful in teaching physics content, students sometimes report dissatisfaction with the course. Such instances of poor affect are worrisome because they may influence how teachers present science in their own classrooms. Therefore, this study investigates students’ affect in terms of their pedagogical expectations and potential personal learning outcomes with respect to PAT. Two sections of PAT, each containing approximately 40 students, were observed. Students in those sections were surveyed, and a sample were interviewed (N=10). An analysis of the data in terms of an expectancy violation framework shows that while students’ expectations regarding the hands-on and interactive components of PAT were met, they received substantially fewer lectures, class discussions, and opportunities to make class presentations than they had expected, even after they had been presented with the course syllabus and informed about the specific nature of the course. Additionally, students expected PAT to be more directly linked with their future teaching careers and therefore expected more opportunities to practice teaching science than they reported receiving. This investigation serves as a case study to provide insight into why students are sometimes frustrated and confused when first encountering active-learning classes, and it implies that instructors should be cognizant of those feelings and devote resources toward explicit orientation that emphasizes the purpose of the course and reasons behind their pedagogical choices.

  2. A field experiment shows that subtle linguistic cues might not affect voter behavior.

    PubMed

    Gerber, Alan S; Huber, Gregory A; Biggers, Daniel R; Hendry, David J

    2016-06-28

    One of the most important recent developments in social psychology is the discovery of minor interventions that have large and enduring effects on behavior. A leading example of this class of results is in the work by Bryan et al. [Bryan CJ, Walton GM, Rogers T, Dweck CS (2011) Proc Natl Acad Sci USA 108(31):12653-12656], which shows that administering a set of survey items worded so that subjects think of themselves as voters (noun treatment) rather than as voting (verb treatment) substantially increases political participation (voter turnout) among subjects. We revisit these experiments by replicating and extending their research design in a large-scale field experiment. In contrast to the 11 to 14% point greater turnout among those exposed to the noun rather than the verb treatment reported in the work by Bryan et al., we find no statistically significant difference in turnout between the noun and verb treatments (the point estimate of the difference is approximately zero). Furthermore, when we benchmark these treatments against a standard get out the vote message, we estimate that both are less effective at increasing turnout than a much shorter basic mobilization message. In our conclusion, we detail how our study differs from the work by Bryan et al. and discuss how our results might be interpreted. PMID:27298362

  3. Adolescent experience affects postnatal ultrasonic vocalizations and gene expression in future offspring.

    PubMed

    Bodi, Caroline M; Vassoler, Fair M; Byrnes, Elizabeth M

    2016-09-01

    The present study measured postnatal ultrasonic vocalization (USV) and gene expression to examine potential changes in communication and/or attachment in the offspring of mothers exposed to morphine during adolescence. Offspring of morphine-exposed (Mor-F1), saline-exposed (Sal-F1), or non-handled control (Con-F1) female Sprague-Dawley rats were tested for separation-induced distress calls and maternal potentiation of distress calls during early postnatal development. We also examined relative expression of dopamine D2 receptor and mu opioid receptor (oprm1) mRNA in the nucleus accumbens and hypothalamus in these offspring, as their activity has been implicated in the regulation of postnatal USV in response to maternal separation. The findings indicate that adolescent experiences of future mothers, including their 10 daily saline or morphine injections, can result in significant region-specific differences in gene expression. In addition, these experiences resulted in fewer numbers of separation-induced distress calls produced by offspring. In contrast, augmented maternal potentiation was only observed in Mor-F1 offspring. © 2016 Wiley Periodicals, Inc. Dev Psychobiol 58:714-723, 2016. PMID:26999300

  4. Gender Differences in the High School and Affective Experiences of Introductory College Physics Students

    NASA Astrophysics Data System (ADS)

    Hazari, Zahra; Sadler, Philip M.; Tai, Robert H.

    2008-10-01

    The disparity in persistence between males and females studying physics has been a topic of concern to physics educators for decades. Overall, while female students perform as well as or better than male students, they continue to lag considerably in terms of persistence. The most significant drop in females studying physics occurs between high school and college.2 Since most female physicists report that they became attracted to physics and decided to study it further while in high school, according to the International Study of Women in Physics,3 it is problematic that high school is also the stage at which females begin to opt out at much higher rates than males. Although half of the students taking one year of physics in high school are female, females are less likely than males to take a second or Advanced Placement (AP) physics course.4 In addition, the percentage of females taking the first physics course in college usually falls between 30% and 40%. In other words, although you may see gender parity in a first high school physics course, this parity does not usually persist to the next level of physics course. In addition, even if there is parity in a high school physics course, it does not mean that males and females experience the course in the same way. It is this difference in experience that may help to explain the drop in persistence of females.

  5. Juvenile social experience affects pairing success at adulthood: congruence with the loser effect?

    PubMed

    Mariette, Mylene M; Cathaud, Charlène; Chambon, Rémi; Vignal, Clémentine

    2013-09-22

    Social interactions with adults are often critical for the development of mating behaviours. However, the potential role of other primary social partners such as juvenile counterparts is rarely considered. Most interestingly, it is not known whether interactions with juvenile females improve males' courtship and whether, similar to the winner and loser effects in a fighting context--outcome of these interactions shapes males' behaviour in future encounters. We investigated the combined effects of male quality and juvenile social experience on pairing success at adulthood in zebra finches (Taeniopygia guttata). We manipulated brood size to alter male quality and then placed males in either same- or mixed-sex juvenile dyads until adulthood. We found that males from reduced broods obtained more copulations and males from mixed-sex dyads had more complete courtships. Furthermore, independent of their quality, males that failed to pair with juvenile females, but not juvenile males, had a lower pairing success at adulthood. Our study shows that negative social experience with peers during adolescence may be a potent determinant of pairing success that can override the effects of early environmental conditions on male attractiveness and thereby supports the occurrence of an analogous process to the loser effect in a mating context. PMID:23902911

  6. Accelerating the loop expansion

    SciTech Connect

    Ingermanson, R.

    1986-07-29

    This thesis introduces a new non-perturbative technique into quantum field theory. To illustrate the method, I analyze the much-studied phi/sup 4/ theory in two dimensions. As a prelude, I first show that the Hartree approximation is easy to obtain from the calculation of the one-loop effective potential by a simple modification of the propagator that does not affect the perturbative renormalization procedure. A further modification then susggests itself, which has the same nice property, and which automatically yields a convex effective potential. I then show that both of these modifications extend naturally to higher orders in the derivative expansion of the effective action and to higher orders in the loop-expansion. The net effect is to re-sum the perturbation series for the effective action as a systematic ''accelerated'' non-perturbative expansion. Each term in the accelerated expansion corresponds to an infinite number of terms in the original series. Each term can be computed explicitly, albeit numerically. Many numerical graphs of the various approximations to the first two terms in the derivative expansion are given. I discuss the reliability of the results and the problem of spontaneous symmetry-breaking, as well as some potential applications to more interesting field theories. 40 refs.

  7. Nurses' Experiences of Nonpatient Factors That Affect Nursing Workload: A Study of the PAONCIL Instrument's Nonpatient Factors

    PubMed Central

    Fagerström, Lisbeth; Vainikainen, Paula

    2014-01-01

    In the RAFAELA patient classification system, the professional assessment of optimal nursing care intensity level (PAONCIL) instrument is used to assess the optimal nursing intensity level per unit. The PAONCIL instrument contains an overall assessment of the actual nursing intensity level and an additional list of central nonpatient factors that may increase or decrease the total nursing workload (NWL). The aim of this cross-sectional study was to assess and determine which nonpatient factors affect nurses' experiences of their total NWL in both outpatient settings and hospitals, as captured through the PAONCIL instrument. The data material consisted of PAONCIL questionnaires from 38 units and 37 outpatient clinics at 11 strategically selected hospitals in Finland, and included nurses' answers (n = 1307) to the question of which factors, other than nursing intensity, affect total NWL. The methods for data analyses were qualitative content analyses. The nonpatient factors that affected nurses' experiences of total NWL are “organization of work,” “working conditions,” “self-control,” and “cooperation.” The actual list of nonpatient factors in the PAONCIL instrument is to a reasonable extent relevant, but the list should be improved to include nurses' actual working conditions and self-control. PMID:25050179

  8. The interaction of early life experiences with COMT val158met affects anxiety sensitivity.

    PubMed

    Baumann, C; Klauke, B; Weber, H; Domschke, K; Zwanzger, P; Pauli, P; Deckert, J; Reif, A

    2013-11-01

    The pathogenesis of anxiety disorders is considered to be multifactorial with a complex interaction of genetic factors and individual environmental factors. Therefore, the aim of this study was to examine gene-by-environment interactions of the genes coding for catechol-O-methyltransferase (COMT) and monoamine oxidase A (MAOA) with life events on measures related to anxiety. A sample of healthy subjects (N = 782; thereof 531 women; mean age M = 24.79, SD = 6.02) was genotyped for COMT rs4680 and MAOA-uVNTR (upstream variable number of tandem repeats), and was assessed for childhood adversities [Childhood Trauma Questionnaire (CTQ)], anxiety sensitivity [Anxiety Sensitivity Index (ASI)] and anxious apprehension [Penn State Worry Questionnaire (PSWQ)]. Main and interaction effects of genotype, environment and gender on measures related to anxiety were assessed by means of regression analyses. Association analysis showed no main gene effect on either questionnaire score. A significant interactive effect of childhood adversities and COMT genotype was observed: Homozygosity for the low-active met allele and high CTQ scores was associated with a significant increment of explained ASI variance [R(2) = 0.040, false discovery rate (FDR) corrected P = 0.04]. A borderline interactive effect with respect to MAOA-uVNTR was restricted to the male subgroup. Carriers of the low-active MAOA allele who reported more aversive experiences in childhood exhibited a trend for enhanced anxious apprehension (R(2) = 0.077, FDR corrected P = 0.10). Early aversive life experiences therefore might increase the vulnerability to anxiety disorders in the presence of homozygosity for the COMT 158met allele or low-active MAOA-uVNTR alleles. PMID:24118915

  9. Internet psychoeducation for bipolar affective disorder: basis for preparation and first experiences.

    PubMed

    Latalova, Klara; Prasko, Jan; Kamaradova, Dana; Jelenova, Daniela; Ociskova, Marie; Sedlackova, Zuzana

    2014-06-01

    There is growing evidence that patients with bipolar affective disorder (BAD), who use medication, respond well to further psychotherapeutic interventions. Internet-based psychoeducation is typically centered on the interaction between a client and therapist via the Internet. Multiple methods were required to investigate existing psychoeducational and psychotherapeutic strategies used on patients suffering from BAD. Systematic reviews and original reports of all trials of psychoeducation in BAD patients were retrieved. Patients with BAD, who were hospitalized in a psychiatric department or attended a day hospital program, were exposed to the first version of the program during the treatment, and then questioned about understandability, comprehensibility, and usefulness of each lecture. Twelve modules of the Internet E-Program for BAD were developed and the intervention was a pilot tested with twelve patients. Internet psychoeducation program for BAD is an intervention designed for universal implementation that addresses heightened learning needs of patients suffering from BAD. It is designed to promote confidence and reduce the number of episodes of the disorder by providing skills in monitoring warning signs, planning daily activities and practicing communication skills. PMID:24307178

  10. Factors Affecting Graft Survival among Patients Receiving Kidneys from Live Donors: A Single-Center Experience

    PubMed Central

    Ghoneim, Mohamed A.; Bakr, Mohamed A.; Refaie, Ayman F.; Akl, Ahmed I.; Shokeir, Ahmed A.; Shehab El-Dein, Ahmed B.; Ammar, Hesham M.; Ismail, Amani M.; Sheashaa, Hussein A.; El-Baz, Mahmoud A.

    2013-01-01

    Introduction. The aim of this report is to study the graft and patient survival in a large cohort of recipients with an analysis of factors that may affect the final outcomes. Methods. Between March 1976 and March 2008, 1967 consecutive live-donor renal transplants were carried out. Various variables that may have an impact on patients and/or graft survival were studied in two steps. Initially, a univariate analysis was carried out. Thereafter, significant variables were embedded in a stepwise regression analysis. Results. The overall graft survival was 86.7% and 65.5%, at 5 and 10 years, respectively. The projected half-life for grafts was 17.5 years and for patients was 22 years. Five factors had an independent negative impact on graft survival: donor's age, genetic considerations, the type of primary immunosuppression, number of acute rejection episodes, and total steroid dose during the first 3 months after transplantation. Conclusions. Despite refinements in tissue matching techniques and improvements in immunosuppression protocols, an important proportion of grafts is still lost following living donor kidney transplantation, presumably due to chronic allograft nephropathy. PMID:23878820

  11. Does labelling a rare cancer diagnosis 'good' affect the patient's experience of treatment and recovery?

    PubMed

    Ridgway, E; Grose, J; Charles, A; Hewett, J; Jarvis, M; Benjamin, S

    2016-05-01

    Doctors sometimes tell patients with rare but highly treatable cancers that they have 'good' cancer which some patients have found unhelpful, but this has been little explored. The aim of this study was to explore how patients reacted to being told they had a 'good' cancer. Qualitative interviews were carried out with 25 people with rare but prognostically favourable cancers who had received treatment at two hospitals within a cancer network. Results showed that despite good treatment outcomes, patients are still very shocked to hear the word cancer and react in similar ways to those with other forms of cancer. The potential effects of treatment should be recognised as having a detrimental effect on patient well-being whatever the prognosis. We should therefore avoid using 'good' and 'cancer' in the same sentence. In addition, the impact on all family members should not be underestimated. The data can be used to improve clinical practice and improve support for people affected by cancer. PMID:25335904

  12. Fracture analysis of the heat-affected zone in the NESC-1 spinning cylinder experiment

    SciTech Connect

    Keeney, J.A.

    1999-02-01

    This paper presents updated analyses of the cylinder specimen being used in the international Network for Evaluating Steel Components (NESC) large-scale spinning-cylinder project (NESC-1). The NESC was organized as an international forum to exchange information on procedures for structural integrity assessment, to collaborate on specific projects, and to promote the harmonization of international standards. The objective of the NESC-1 project is to focus on a complete procedure for assessing the structural integrity of aged reactor pressure vessels. A clad cylinder containing through-clad and subclad cracks will be tested under pressurized-thermal shock conditions at AEA Technology, Risley, U.K. Three-dimensional finite-element analyses were carried out to determine the effects of including the cladding heat-affected zone (HAZ) in the models. The cylinder was modeled with inner-surface through-clad cracks having a depth of 74 mm and aspect ratios of 2:1 and 6:1. The cylinder specimen was subjected to centrifugal loading followed by a thermal shock and analyzed with a thermoelastic-plastic material model. The peak K{sub 1} values occurred at the clad/HAZ interface for the 6:1 crack and at the HAZ/base interface for the 2:1 crack. The analytical results indicate that cleavage initiation is likely to be achieved for the 6:1 crack, but questionable for the 2:1 crack.

  13. Non-defendable resources affect peafowl lek organization: a male removal experiment.

    PubMed

    Loyau, Adeline; Jalme, Michel Saint; Sorci, Gabriele

    2007-01-10

    A lekking mating system is typically thought to be non-resource based with male providing nothing to females but genes. However, males are thought to clump their display sites on areas where they are more likely to encounter females, which may depend on non-defendable resource location. We tested this hypothesis on a feral population of peacocks. In agreement, we found that, within the lek, display site proximity to food resources had an effect on female visitation rate and male mating success. The attractiveness of display sites to male intruders was explained by the distance to the feeding place and by the female visitation rate. We randomly removed 29 territorial males from their display sites. Display sites that were more attractive to male intruders before removal remained highly attractive after removal and display sites closer to the feeding area attracted the attention of intruders significantly more after removal. Similarly, display sites that were more visited by females before removal remained more visited after removal, suggesting again that the likelihood of encountering females is determined by the display site location. Overall, these results are in agreement with non-defendable resources affecting lek spatial organization in the peafowl. PMID:17074448

  14. “So We Adapt Step by Step”: Acculturation Experiences Affecting Diabetes Management and Perceived Health for Chinese American Immigrants

    PubMed Central

    Chun, Kevin M.; Chesla, Catherine A.; Kwan, Christine M.L.

    2011-01-01

    This study examines how acculturation affects type 2 diabetes management and perceived health for Chinese American immigrants in the U.S. Acculturation experiences or cultural adaptation experiences affecting diabetes management and health were solicited from an informant group of immigrant patients and their spouses (N=40) during group, couple and individual interviews conducted in 2005 to 2008. A separate respondent group of immigrant patients and their spouses (N=19) meeting inclusion criteria reviewed and confirmed themes generated by the informant group. Using interpretive phenomenology, three key themes in patients’ and spouses’ acculturation experiences were identified: a) utilizing health care, b) maintaining family relations and roles, and c) establishing community ties and groundedness in the U.S. Acculturation experiences reflecting these themes were broad in scope and not fully captured by current self-report and proxy acculturation measures. In the current study, shifting family roles and evaluations of diabetes care and physical environment in the U.S. significantly affected diabetes management and health, yet are overlooked in acculturation and health investigations. Furthermore, the salience and impact of specific acculturation experiences respective to diabetes management and perceived health varied across participants due to individual, family, developmental, and environmental factors. In regards to salience, maintaining filial and interdependent family relations in the U.S. was of particular concern for older participants and coping with inadequate health insurance in the U.S. was especially distressing for self-described lower-middle to middle-class participants. In terms of impact, family separation and relocating to ethnically similar neighborhoods in the U.S. differentially affected diabetes management and health due to participants’ varied family relations and pre-migration family support levels and diverse cultural and linguistic

  15. Health and Illness in a Connected World: How Might Sharing Experiences on the Internet Affect People's Health?

    PubMed Central

    Ziebland, Sue; Wyke, Sally

    2012-01-01

    Context The use of the Internet for peer-to-peer connection has been one of its most dramatic and transformational features. Yet this is a new field with no agreement on a theoretical and methodological basis. The scientific base underpinning this activity needs strengthening, especially given the explosion of web resources that feature experiences posted by patients themselves. This review informs a National Institute for Health Research (NIHR) (UK) research program on the impact of online patients’ accounts of their experiences with health and health care, which includes the development and validation of a new e-health impact questionnaire. Methods We drew on realist review methods to conduct a conceptual review of literature in the social and health sciences. We developed a matrix to summarize the results, which we then distilled from a wide and diverse reading of the literature. We continued reading until we reached data saturation and then further refined the results after testing them with expert colleagues and a public user panel. Findings We identified seven domains through which online patients’ experiences could affect health. Each has the potential for positive and negative impacts. Five of the identified domains (finding information, feeling supported, maintaining relationships with others, affecting behavior, and experiencing health services) are relatively well rehearsed, while two (learning to tell the story and visualizing disease) are less acknowledged but important features of online resources. Conclusions The value of first-person accounts, the appeal and memorability of stories, and the need to make contact with peers all strongly suggest that reading and hearing others’ accounts of their own experiences of health and illnesss will remain a key feature of e-health. The act of participating in the creation of health information (e.g., through blogging and contributing to social networking on health topics) also influences patients

  16. How emotions affect logical reasoning: evidence from experiments with mood-manipulated participants, spider phobics, and people with exam anxiety

    PubMed Central

    Jung, Nadine; Wranke, Christina; Hamburger, Kai; Knauff, Markus

    2014-01-01

    Recent experimental studies show that emotions can have a significant effect on the way we think, decide, and solve problems. This paper presents a series of four experiments on how emotions affect logical reasoning. In two experiments different groups of participants first had to pass a manipulated intelligence test. Their emotional state was altered by giving them feedback, that they performed excellent, poor or on average. Then they completed a set of logical inference problems (with if p, then q statements) either in a Wason selection task paradigm or problems from the logical propositional calculus. Problem content also had either a positive, negative or neutral emotional value. Results showed a clear effect of emotions on reasoning performance. Participants in negative mood performed worse than participants in positive mood, but both groups were outperformed by the neutral mood reasoners. Problem content also had an effect on reasoning performance. In a second set of experiments, participants with exam or spider phobia solved logical problems with contents that were related to their anxiety disorder (spiders or exams). Spider phobic participants' performance was lowered by the spider-content, while exam anxious participants were not affected by the exam-related problem content. Overall, unlike some previous studies, no evidence was found that performance is improved when emotion and content are congruent. These results have consequences for cognitive reasoning research and also for cognitively oriented psychotherapy and the treatment of disorders like depression and anxiety. PMID:24959160

  17. How emotions affect logical reasoning: evidence from experiments with mood-manipulated participants, spider phobics, and people with exam anxiety.

    PubMed

    Jung, Nadine; Wranke, Christina; Hamburger, Kai; Knauff, Markus

    2014-01-01

    Recent experimental studies show that emotions can have a significant effect on the way we think, decide, and solve problems. This paper presents a series of four experiments on how emotions affect logical reasoning. In two experiments different groups of participants first had to pass a manipulated intelligence test. Their emotional state was altered by giving them feedback, that they performed excellent, poor or on average. Then they completed a set of logical inference problems (with if p, then q statements) either in a Wason selection task paradigm or problems from the logical propositional calculus. Problem content also had either a positive, negative or neutral emotional value. Results showed a clear effect of emotions on reasoning performance. Participants in negative mood performed worse than participants in positive mood, but both groups were outperformed by the neutral mood reasoners. Problem content also had an effect on reasoning performance. In a second set of experiments, participants with exam or spider phobia solved logical problems with contents that were related to their anxiety disorder (spiders or exams). Spider phobic participants' performance was lowered by the spider-content, while exam anxious participants were not affected by the exam-related problem content. Overall, unlike some previous studies, no evidence was found that performance is improved when emotion and content are congruent. These results have consequences for cognitive reasoning research and also for cognitively oriented psychotherapy and the treatment of disorders like depression and anxiety. PMID:24959160

  18. Metabolic syndrome affects breast cancer risk in postmenopausal women: National Cancer Institute of Naples experience.

    PubMed

    Capasso, Immacolata; Esposito, Emanuela; Pentimalli, Francesca; Crispo, Anna; Montella, Maurizio; Grimaldi, Maria; De Marco, MariaRosaria; Cavalcanti, Ernestina; D'Aiuto, Massimiliano; Fucito, Alfredo; Frasci, Giuseppe; Maurea, Nicola; Esposito, Giuseppe; Pedicini, Tonino; Vecchione, Aldo; D'Aiuto, Giuseppe; Giordano, Antonio

    2010-12-15

    Postmenopausal women show the highest incidence of breast cancer in the female population and are often affected by metabolic syndrome. Metabolic syndrome (MS)--characterized by central adiposity, insulin resistance, low serum high-density lipoprotein cholesterol (HDL-C), high serum triglyceride and high blood pressure--seems to be strictly correlated to breast carcinogenesis. We enrolled 777 healthy women and women with breast cancer in our nested case-control study to evaluate the association between MS and breast cancer, analyzing anthropometric parameters (weight, height, BMI, waist and hip circumference), blood pressure, serum HDL-C, triglyceride, fasting plasma glucose, insulin, testosterone and uric acid levels and administering a questionnaire about physical activity, food intake, tobacco use, alcohol abuse, personal and familial history of disease. We found an higher prevalence of metabolic syndrome (30%) in postmenopausal breast cancer patients compared to healthy women (19%). None of the individual MS features was strong enough to be considered responsible for breast carcinogenesis alone. However, of the 63 postmenopausal breast cancer cases associated to MS, 30% presented three or more MS features, suggesting that the activation of multiple molecular pathways underlying MS might contribute to tumorigenesis. Our data support the hypothesis that MS may be an indicator of breast cancer risk in postmenopausal women. The unsettlement of the hormonal arrangement in postmenopausal, along with an increase in visceral adiposity, probably favour the hormone-dependent cell proliferation, which drives tumorigenesis. Adjustments in lifestyle with physical activity intensification and healthy diet could represent modifiable factors for the primary prevention of sporadic breast cancer. PMID:20935521

  19. Factors affecting the quality of anticoagulation with warfarin: experience of one cardiac centre

    PubMed Central

    Ciurus, Tomasz; Cichocka-Radwan, Anna

    2015-01-01

    Introduction The risk of complications in anticoagulation therapy can be reduced by maximising the percentage of time spent by the patient in the optimal therapeutic range (TTR). However, little is known about the predictors of anticoagulation control. The aim of this paper was to assess the quality of anticoagulant therapy in patients on warfarin and to identify the factors affecting its deterioration. Material and methods We studied 149 patients who required anticoagulant therapy with warfarin due to non-valvular atrial fibrillation and/or venous thromboembolism. Each patient underwent proper training regarding the implemented treatment and remained under constant medical care. Results The mean age of the patients was 68.8 ± 12.6 years, and 59% were male. A total of 2460 international normalised ratio (INR) measurements were collected during the 18-month period. The mean TTR in the studied cohort was 76 ± 21%, and the median was 80%. The level at which high-quality anticoagulation was recorded for this study was based on TTR values above 80%. Seventy-five patients with TTR ≥ 80% were included in the stable anticoagulation group (TTR ≥ 80%); the remaining 74 patients constituted the unstable anticoagulation group (TTR < 80%). According to multivariate stepwise regression analysis, the independent variables increasing the risk of deterioration of anticoagulation quality were: arterial hypertension (OR 2.74 [CI 95%: 1.06-7.10]; p = 0.038), amiodarone therapy (OR 4.22 [CI 95%: 1.30-13.70]; p = 0.017), and obesity (OR 1.11 [CI 95%: 1.02-1.21]; p = 0.013). Conclusions The presence of obesity, hypertension, or amiodarone therapy decreases the quality of anticoagulation with warfarin. High quality of anticoagulation can be achieved through proper monitoring and education of patients. PMID:26855650

  20. Undergraduate African American females in the sciences: A qualitative study of student experiences affecting academic success and persistence

    NASA Astrophysics Data System (ADS)

    Essien-Wood, Idara R.

    Given the lack of literature on Undergraduate African American females in the sciences (UAAFS), this study sought to explicate their experiences at one large, predominantly White, Research I institution in the southwestern United States. In particular, the purpose of this study was to identify factors that affect the academic success and persistence of Black females in the natural and physical sciences. Data was collected via in-depth, semi-structured interviews with 15 Black female science majors. Findings from this study identified several supportive mechanisms for academic success: family, religion, teaching assistants and friends. Also identified were seven barriers to academic success: employment, lack of diversity, cultural dissonance, unwelcoming Research I environment, faculty, advisors, classmates, and lab groups. Further, an analysis of students' responses revealed numerous instances of racial and gender micro-aggressions. Recommendations are provided to address factors identified as affecting student academic success and persistence as well as a culture of micro-aggressive behavior.

  1. Social experience affects neuronal responses to male calls in adult female zebra finches.

    PubMed

    Menardy, F; Touiki, K; Dutrieux, G; Bozon, B; Vignal, C; Mathevon, N; Del Negro, C

    2012-04-01

    Plasticity studies have consistently shown that behavioural relevance can change the neural representation of sounds in the auditory system, but what occurs in the context of natural acoustic communication where significance could be acquired through social interaction remains to be explored. The zebra finch, a highly social songbird species that forms lifelong pair bonds and uses a vocalization, the distance call, to identify its mate, offers an opportunity to address this issue. Here, we recorded spiking activity in females while presenting distance calls that differed in their degree of familiarity: calls produced by the mate, by a familiar male, or by an unfamiliar male. We focused on the caudomedial nidopallium (NCM), a secondary auditory forebrain region. Both the mate's call and the familiar call evoked responses that differed in magnitude from responses to the unfamiliar call. This distinction between responses was seen both in single unit recordings from anesthetized females and in multiunit recordings from awake freely moving females. In contrast, control females that had not heard them previously displayed responses of similar magnitudes to all three calls. In addition, more cells showed highly selective responses in mated than in control females, suggesting that experience-dependent plasticity in call-evoked responses resulted in enhanced discrimination of auditory stimuli. Our results as a whole demonstrate major changes in the representation of natural vocalizations in the NCM within the context of individual recognition. The functional properties of NCM neurons may thus change continuously to adapt to the social environment. PMID:22512260

  2. Brief sensory experience differentially affects the volume of olfactory brain centres in a moth.

    PubMed

    Anton, Sylvia; Chabaud, Marie-Ange; Schmidt-Büsser, Daniela; Gadenne, Bruno; Iqbal, Javaid; Juchaux, Marjorie; List, Olivier; Gaertner, Cyril; Devaud, Jean-Marc

    2016-04-01

    Experience modifies behaviour in animals so that they adapt to their environment. In male noctuid moths, Spodoptera littoralis, brief pre-exposure to various behaviourally relevant sensory signals modifies subsequent behaviour towards the same or different sensory modalities. Correlated with a behavioural increase in responses of male moths to the female-emitted sex pheromone after pre-exposure to olfactory, acoustic or gustatory stimuli, an increase in sensitivity of olfactory neurons within the primary olfactory centre, the antennal lobe, is found for olfactory and acoustic stimuli, but not for gustatory stimuli. Here, we investigated whether anatomical changes occurring in the antennal lobes and in the mushroom bodies (the secondary olfactory centres) possibly correlated with the changes observed in behaviour and in olfactory neuron physiology. Our results showed that significant volume changes occurred in glomeruli (olfactory units) responsive to sex pheromone following exposure to both pheromone and predator sounds. The volume of the mushroom body input region (calyx) also increased significantly after pheromone and predator sound treatment. However, we found no changes in the volume of antennal lobe glomeruli or of the mushroom body calyx after pre-exposure to sucrose. These findings show a relationship of antennal lobe sensitivity changes to the pheromone with changes in the volume of the related glomeruli and the output area of antennal lobe projection neurons elicited by sensory cues causing a behavioural change. Behavioural changes observed after sucrose pre-exposure must originate from changes in higher integration centres in the brain. PMID:26463049

  3. The Dynamic Reactance Interaction - How Vested Interests Affect People's Experience, Behavior, and Cognition in Social Interactions.

    PubMed

    Steindl, Christina; Jonas, Eva

    2015-01-01

    In social interactions, individuals may sometimes pursue their own interests at the expense of their interaction partner. Such self-interested behaviors impose a threat to the interaction partner's freedom to act. The current article investigates this threat in the context of interdependence and reactance theory. We explore how vested interests influence reactance process stages of an advisor-client interaction. We aim to explore the interactional process that evolves. In two studies, participants took the perspective of a doctor (advisor) or a patient (client). In both studies we incorporated a vested interest. In Study 1 (N = 82) we found that in response to a vested interest of their interaction partner, patients indicated a stronger experience of reactance, more aggressive behavioral intentions, and more biased cognitions than doctors. A serial multiple mediation revealed that a vested interest engendered mistrust toward the interaction partner and this mistrust led to an emerging reactance process. Study 2 (N = 207) further demonstrated that doctors expressed their reactance in a subtle way: they revealed a classic confirmation bias when searching for additional information on their preliminary decision preference, indicating stronger defense motivation. We discuss how these findings can help us to understand how social interactions develop dynamically. PMID:26640444

  4. How Does Tree Density Affect Water Loss of Peatlands? A Mesocosm Experiment

    PubMed Central

    Limpens, Juul; Holmgren, Milena; Jacobs, Cor M. J.; Van der Zee, Sjoerd E. A. T. M.; Karofeld, Edgar; Berendse, Frank

    2014-01-01

    Raised bogs have accumulated more atmospheric carbon than any other terrestrial ecosystem on Earth. Climate-induced expansion of trees and shrubs may turn these ecosystems from net carbon sinks into sources when associated with reduced water tables. Increasing water loss through tree evapotranspiration could potentially deepen water tables, thus stimulating peat decomposition and carbon release. Bridging the gap between modelling and field studies, we conducted a three-year mesocosm experiment subjecting natural bog vegetation to three birch tree densities, and studied the changes in subsurface temperature, water balance components, leaf area index and vegetation composition. We found the deepest water table in mesocosms with low tree density. Mesocosms with high tree density remained wettest (i.e. highest water tables) whereas the control treatment without trees had intermediate water tables. These differences are attributed mostly to differences in evapotranspiration. Although our mesocosm results cannot be directly scaled up to ecosystem level, the systematic effect of tree density suggests that as bogs become colonized by trees, the effect of trees on ecosystem water loss changes with time, with tree transpiration effects of drying becoming increasingly offset by shading effects during the later phases of tree encroachment. These density-dependent effects of trees on water loss have important implications for the structure and functioning of peatbogs. PMID:24632565

  5. Alloparenting experience affects future parental behavior and reproductive success in prairie voles (Microtus ochrogaster).

    PubMed

    Stone, Anita Iyengar; Mathieu, Denise; Griffin, Luana; Bales, Karen Lisa

    2010-01-01

    Various hypotheses have been proposed to explain the function of alloparental behavior in cooperatively breeding species. We examined whether alloparental experience as juveniles enhanced later parental care and reproductive success in the prairie vole (Microtus ochrogaster), a cooperatively breeding rodent. Juveniles cared for one litter of siblings (1EX), two litters of siblings (2EX) or no siblings (0EX). As adults, these individuals were mated to other 0EX, 1EX or 2EX voles, yielding seven different pair combinations, and we recorded measures of parental behaviors, reproductive success, and pup development. As juveniles, individuals caring for siblings for the first time were more alloparental; and as adults, 0EX females paired with 0EX males spent more time in the nest with their pups. Taken together, these results suggest that inexperienced animals spend more time in infant care. As parents, 1EX males spent more time licking their pups than 2EX and 0EX males. Pups with either a 1EX or 2EX parent gained weight faster than pups with 0EX parents during certain developmental periods. While inexperienced animals may spend more time in pup care, long-term benefits of alloparenting may become apparent in the display of certain, particularly important parental behaviors such as licking pups, and in faster weight gain of offspring. PMID:19732810

  6. Spatial hearing in Cope's gray treefrog: I. Open and closed loop experiments on sound localization in the presence and absence of noise.

    PubMed

    Caldwell, Michael S; Bee, Mark A

    2014-04-01

    The ability to reliably locate sound sources is critical to anurans, which navigate acoustically complex breeding choruses when choosing mates. Yet, the factors influencing sound localization performance in frogs remain largely unexplored. We applied two complementary methodologies, open and closed loop playback trials, to identify influences on localization abilities in Cope's gray treefrog, Hyla chrysoscelis. We examined localization acuity and phonotaxis behavior of females in response to advertisement calls presented from 12 azimuthal angles, at two signal levels, in the presence and absence of noise, and at two noise levels. Orientation responses were consistent with precise localization of sound sources, rather than binary discrimination between sources on either side of the body (lateralization). Frogs were unable to discriminate between sounds arriving from forward and rearward directions, and accurate localization was limited to forward sound presentation angles. Within this region, sound presentation angle had little effect on localization acuity. The presence of noise and low signal-to-noise ratios also did not strongly impair localization ability in open loop trials, but females exhibited reduced phonotaxis performance consistent with impaired localization during closed loop trials. We discuss these results in light of previous work on spatial hearing in anurans. PMID:24504182

  7. Spatial hearing in Cope’s gray treefrog: I. Open and closed loop experiments on sound localization in the presence and absence of noise

    PubMed Central

    Caldwell, Michael S.; Bee, Mark A.

    2014-01-01

    The ability to reliably locate sound sources is critical to anurans, which navigate acoustically complex breeding choruses when choosing mates. Yet, the factors influencing sound localization performance in frogs remain largely unexplored. We applied two complementary methodologies, open and closed loop playback trials, to identify influences on localization abilities in Cope’s gray treefrog, Hyla chrysoscelis. We examined localization acuity and phonotaxis behavior of females in response to advertisement calls presented from 12 azimuthal angles, at two signal levels, in the presence and absence of noise, and at two noise levels. Orientation responses were consistent with precise localization of sound sources, rather than binary discrimination between sources on either side of the body (lateralization). Frogs were unable to discriminate between sounds arriving from forward and rearward directions, and accurate localization was limited to forward sound presentation angles. Within this region, sound presentation angle had little effect on localization acuity. The presence of noise and low signal-to-noise ratios also did not strongly impair localization ability in open loop trials, but females exhibited reduced phonotaxis performance consistent with impaired localization during closed loop trials. We discuss these results in light of previous work on spatial hearing in anurans. PMID:24504182

  8. Chamber QoE: a multi-instrumental approach to explore affective aspects in relation to quality of experience

    NASA Astrophysics Data System (ADS)

    De Moor, Katrien; Mazza, Filippo; Hupont, Isabelle; Ríos Quintero, Miguel; Mäki, Toni; Varela, Martín.

    2014-02-01

    Evaluating (audio)visual quality and Quality of Experience (QoE) from the user's perspective, has become a key element in optimizing users' experiences and their quality. Traditionally, the focus lies on how multi-level quality features are perceived by a human user. The interest has however gradually expanded towards human cognitive, affective and behavioral processes that may impact on, be an element of, or be influenced by QoE, and which have been underinvestigated so far. In addition, there is a major discrepancy between the new, broadly supported and more holistic conceptualization of QoE proposed by Le Callet et al. (2012) and traditional, standardized QoE assessment. This paper explores ways to tackle this discrepancy by means of a multi-instrumental approach. More concretely, it presents results from a lab study on video quality (N=27), aimed at going beyond the dominant QoE assessment paradigm and at exploring affective aspects in relation to QoE and in relation to perceived overall quality. Four types of data were collected: `traditional' QoE self-report measures were complemented with `alternative', emotional state- and user engagement-related self-report measures to evaluate QoE. In addition, we collected EEG (physiological) data, gazetracking data and facial expressions (behavioral) data. The video samples used in test were longer in duration than is common in standard tests allowing us to study e.g. more realistic experience and deeper user engagement. Our findings support the claim that the traditional QoE measures need to be reconsidered and extended with additional, affective staterelated measures.

  9. Donor race does not affect cadaver kidney transplant survival--a single center experience.

    PubMed

    Tesi, R J; DeboisBlanc, M; Saul, C; O'Donovan, R; Etheredge, E

    1995-12-27

    Black kidney transplant recipients have worse graft survival than white recipients. Speculation regarding etiology has focused on differences in human lymphocyte antigens (HLA). Some suggest that improvements in graft survival would be obtained if donor and recipient race were matched. We reviewed 236 cadaver transplants performed over 9 years at a single center using an HLA-match-driven allocation system and a uniform immunosuppressive protocol to determine the impact of donor race on graft survival. A multivariate analysis of graft survival using patient race, sex, age, transplant number, current and maximum plasma renin activity, donor race, cold ischemia time and HLA mismatch, the need for dialysis, and the presence of rejection as independent variables. Sixty percent of recipients were black, and 82% were primary transplants; 28 kidneys (12%) were from black donors. The 112 patients with the same race donor had identical 5-year graft survival as the 124 who had a different race donor (40%; P = 0.1726). The 5-year survival of the 88 white recipients of white donor organs was better than that of the 120 black recipients of white donor organs (54% vs. 42%, respectively; P = 0.0398). Black recipients (t1/2 = 37 months) did worse than white recipients (t1/2 = 60 months) regardless of organ source (P = 0.023). In the multivariate analysis, neither donor nor recipient race were an independent variable in predicting graft survival. Rejection (RR = 2.9) and the need for dialysis on the transplant admission (RR = 4.1) were the only factors that predicted poor survival. Black recipients had more rejection (P = 0.04) but not more need for dialysis posttransplant regardless of donor race. Donor race did not affect graft survival in this series. The effect of recipient race on graft survival was due to an increased incidence of rejection episodes in black recipients, which was independent of HLA mismatch. These data suggest that improvements in immunosuppression, not

  10. Closed-Loop Neuromorphic Benchmarks

    PubMed Central

    Stewart, Terrence C.; DeWolf, Travis; Kleinhans, Ashley; Eliasmith, Chris

    2015-01-01

    Evaluating the effectiveness and performance of neuromorphic hardware is difficult. It is even more difficult when the task of interest is a closed-loop task; that is, a task where the output from the neuromorphic hardware affects some environment, which then in turn affects the hardware's future input. However, closed-loop situations are one of the primary potential uses of neuromorphic hardware. To address this, we present a methodology for generating closed-loop benchmarks that makes use of a hybrid of real physical embodiment and a type of “minimal” simulation. Minimal simulation has been shown to lead to robust real-world performance, while still maintaining the practical advantages of simulation, such as making it easy for the same benchmark to be used by many researchers. This method is flexible enough to allow researchers to explicitly modify the benchmarks to identify specific task domains where particular hardware excels. To demonstrate the method, we present a set of novel benchmarks that focus on motor control for an arbitrary system with unknown external forces. Using these benchmarks, we show that an error-driven learning rule can consistently improve motor control performance across a randomly generated family of closed-loop simulations, even when there are up to 15 interacting joints to be controlled. PMID:26696820

  11. Closed-Loop Neuromorphic Benchmarks.

    PubMed

    Stewart, Terrence C; DeWolf, Travis; Kleinhans, Ashley; Eliasmith, Chris

    2015-01-01

    Evaluating the effectiveness and performance of neuromorphic hardware is difficult. It is even more difficult when the task of interest is a closed-loop task; that is, a task where the output from the neuromorphic hardware affects some environment, which then in turn affects the hardware's future input. However, closed-loop situations are one of the primary potential uses of neuromorphic hardware. To address this, we present a methodology for generating closed-loop benchmarks that makes use of a hybrid of real physical embodiment and a type of "minimal" simulation. Minimal simulation has been shown to lead to robust real-world performance, while still maintaining the practical advantages of simulation, such as making it easy for the same benchmark to be used by many researchers. This method is flexible enough to allow researchers to explicitly modify the benchmarks to identify specific task domains where particular hardware excels. To demonstrate the method, we present a set of novel benchmarks that focus on motor control for an arbitrary system with unknown external forces. Using these benchmarks, we show that an error-driven learning rule can consistently improve motor control performance across a randomly generated family of closed-loop simulations, even when there are up to 15 interacting joints to be controlled. PMID:26696820

  12. Quantitation of interactions between two DNA loops demonstrates loop domain insulation in E. coli cells

    PubMed Central

    Priest, David G.; Kumar, Sandip; Yan, Yan; Dunlap, David D.; Dodd, Ian B.; Shearwin, Keith E.

    2014-01-01

    Eukaryotic gene regulation involves complex patterns of long-range DNA-looping interactions between enhancers and promoters, but how these specific interactions are achieved is poorly understood. Models that posit other DNA loops—that aid or inhibit enhancer–promoter contact—are difficult to test or quantitate rigorously in eukaryotic cells. Here, we use the well-characterized DNA-looping proteins Lac repressor and phage λ CI to measure interactions between pairs of long DNA loops in E. coli cells in the three possible topological arrangements. We find that side-by-side loops do not affect each other. Nested loops assist each other’s formation consistent with their distance-shortening effect. In contrast, alternating loops, where one looping element is placed within the other DNA loop, inhibit each other’s formation, thus providing clear support for the loop domain model for insulation. Modeling shows that combining loop assistance and loop interference can provide strong specificity in long-range interactions. PMID:25288735

  13. Experiences and psychosocial adjustment of Darfuri female students affected by war: an exploratory study.

    PubMed

    Badri, Alia; Van den Borne, H W; Crutzen, Rik

    2013-01-01

    This paper presents the personal accounts of Darfuri students studying at Ahfad University for Women in Omdurman, Sudan. Their war-related exposure, current ongoing life challenges, emotional distress, and coping strategies were explored using a semistructured interview protocol with a sample of 20 students. Through interpretative phenomenological analysis (IPA), the Darfuri students' stories illustrated that they were exposed to an array of traumatic war events, including personal experiences of parental separation, injury and death of family members, and shortages of essential life-sustaining supplies in internally displaced camps. Also, they were confronted with myriad current life hassles and urban-cultural challenges, including being physically distant from their families, and losing the shelter of parents, the encouragement of extended family members, and their rich and familiar social support networks. Urban-cultural challenges and lack of environmental mastery applied to most Darfuri participants as they relocated to Omdurman city, which included negotiating an unfamiliar transport system, learning the routes and directions to important city landmarks, and insufficient funds for basic hygienic essentials. Emotional distress reactions were coded by forming two distinct lists: directly mentioned by the participant; and observations of emotional manifestation during the interview. Patterns emerged that may be similar to symptoms of mood and anxiety disorders; for example, the DSM-IV criteria for symptoms of generalized anxiety disorder and major depression. Strong religious practices and beliefs (such as praying and reading the Quran), ability to form interpersonal relationships, availability of social support networks, and a positive future outlook seemed to augment their ability to cope with their subsequent emotional distress owing to war-related exposures, current ongoing life hassles and urban-cultural challenges. PMID:22822771

  14. Blind loop syndrome

    MedlinePlus

    Blind loop syndrome occurs when digested food slows or stops moving through part of the intestines. This ... The name of this condition refers to the "blind loop" formed by part of the intestine that ...

  15. Individual experience and evolutionary history of predation affect expression of heritable variation in fish personality and morphology

    PubMed Central

    Dingemanse, Niels J.; Van der Plas, Fons; Wright, Jonathan; Réale, Denis; Schrama, Maarten; Roff, Derek A.; Van der Zee, Els; Barber, Iain

    2009-01-01

    Predation plays a central role in evolutionary processes, but little is known about how predators affect the expression of heritable variation, restricting our ability to predict evolutionary effects of predation. We reared families of three-spined stickleback Gasterosteus aculeatus from two populations—one with a history of fish predation (predator sympatric) and one without (predator naive)—and experimentally manipulated experience of predators during ontogeny. For a suite of ecologically relevant behavioural (‘personality’) and morphological traits, we then estimated two key variance components, additive genetic variance (VA) and residual variance (VR), that jointly shape narrow-sense heritability (h2= VA/(VA + VR)). Both population and treatment differentially affected VA versus VR, hence h2, but only for certain traits. The predator-naive population generally had lower VA and h2 values than the predator-sympatric population for personality behaviours, but not morphological traits. Values of VR and h2 were increased for some, but decreased for other personality traits in the predator-exposed treatment. For some personality traits, VA and h2 values were affected by treatment in the predator-naive population, but not in the predator-sympatric population, implying that the latter harboured less genetic variation for behavioural plasticity. Replication and experimental manipulation of predation regime are now needed to confirm that these population differences were related to variation in predator-induced selection. Cross-environment genetic correlations (rA) were tight for most traits, suggesting that predator-induced selection can affect the evolution of the same trait expressed in the absence of predators. The treatment effects on variance components imply that predators can affect evolution, not only by acting directly as selective agents, but also by influencing the expression of heritable variation. PMID:19129142

  16. Dissociable large-scale networks anchored in the right anterior insula subserve affective experience and attention1

    PubMed Central

    Touroutoglou, Alexandra; Hollenbeck, Mark; Dickerson, Bradford C.; Barrett, Lisa Feldman

    2012-01-01

    Meta-analytic summaries of neuroimaging studies point to at least two major functional-anatomic subdivisions within the anterior insula that contribute to the detection and processing of salient information: a dorsal region that is routinely active during attention tasks and a ventral region that is routinely active during affective experience. In two independent samples of cognitively normal human adults, we used intrinsic functional connectivity magnetic resonance imaging to demonstrate that the right dorsal and right ventral anterior insula are nodes in separable large-scale functional networks. Furthermore, stronger intrinsic connectivity within the right dorsal anterior insula network was associated with better performance on a task involving attention and processing speed whereas stronger connectivity within the right ventral anterior insula network was associated with more intense affective experience. These results support the hypothesis that the identification and manipulation of salient information is subserved by at least two brain networks anchored in the right anterior insula that exhibit distinct large-scale topography and dissociable behavioral correlates. PMID:22361166

  17. [How do Affected Children and Adolescents Experience their Short Stature, and what is the Point of View of their Parents?].

    PubMed

    Quitmann, Julia; Rohenkohl, Anja; Sommer, Rachel; Petzold, Sophie; Bullinger-Naber, Monika

    2014-01-01

    How do Affected Children and Adolescents Experience their Short Stature, and what is the Point of View of their Parents? Despite a large number of publications on the psychosocial situation of short statured children and their parents only a few qualitative studies focus on the perspective of the affected families. Within the European QoLISSY study ("Quality of Life in Short Stature Youth") an instrument to assess the health related quality of life of short statured children was developed. The aim of this project was to examine the self-perceived quality of life of the children themselves in comparison to their parents' perspective. During the development of the QoLISSY instrument, focus groups were conducted as a first step of this study. A total of 23 short statured children and 31 parents participated and discussed their experiences in separate groups with trained moderators. The discussions were analyzed qualitatively und results were used to generate a first list of items for the questionnaire to be developed. While parents focused on socio-emotional problems, children talked much more about their growth hormone treatment and problems in their social environment. In comparison to other studies children rated their quality of life worse than their parents. Not only medical treatment but also a psychological and socio-emotional intervention seems to be indicated. PMID:25524035

  18. Electronic Circuit Experiments and SPICE Simulation of Double Covering Bifurcation of 2-Torus Quasi-Periodic Flow in Phase-Locked Loop Circuit

    NASA Astrophysics Data System (ADS)

    Kamiyama, Kyohei; Endo, Tetsuro; Imai, Isao; Komuro, Motomasa

    2016-06-01

    Double covering (DC) bifurcation of a 2-torus quasi-periodic flow in a phase-locked loop circuit was experimentally investigated using an electronic circuit and via SPICE simulation; in the circuit, the input radio-frequency signal was frequency modulated by the sum of two asynchronous sinusoidal baseband signals. We observed both DC and period-doubling bifurcations of a discrete map on two Poincaré sections, which were realized by changing the sample timing from one baseband sinusoidal signal to the other. The results confirm the DC bifurcation of the original flow.

  19. Close-loop simulation of the medial olivocochlear anti-masking effects

    NASA Astrophysics Data System (ADS)

    Liu, Yi-Wen; Yu, Lu-Ming; Wu, Po-Jui

    2015-12-01

    The medial olivocochlear reflex (MOCR) is known to affect cochlear signal processing via the electromechanical changes it induces in outer hair cells (OHCs). Experiments showed that electrically stimulating the MOC efferents (i.e., open-loop stimulation) suppresses cochlear responses to acoustic noise while enhancing the response to tone bursts if the signal-to-noise ratio is sufficiently high [5]. However, such experiments did not reveal precisely how MOCR affects cochlear signal processing in a close loop. Presently we have built an integrated computer model for the MOCR pathway; the constituting sub-models include a model for cochlear mechanics with electromotile OHCs [11], a neurotransmitter release model for the synapse between inner hair cells (IHCs) and spiral ganglion cells [16], an electrical model for the T-multipolar (TM) cells in the cochlear nucleus [6], a relay from TM cells to the MOC interneurons, and a convolution kernel describing the change of OHC potassium conductance triggered by the MOC inhibitory post synaptic potentials. Thus, close-loop responses of the entire system can be simulated for arbitrary acoustic stimuli. Both open-loop and close-loop simulations demonstrate a decrease in the auditory nerve fiber (ANF) response to noise but an increase in the response to high-level tone bursts. The present integrated computer model can potentially be used for testing hypotheses regarding the physiological mechanisms for MOC anti-masking effects.

  20. Bimodal loop-gap resonator

    NASA Astrophysics Data System (ADS)

    Piasecki, W.; Froncisz, W.; Hyde, James S.

    1996-05-01

    A bimodal loop-gap resonator for use in electron paramagnetic resonance (EPR) spectroscopy at S band is described. It consists of two identical one-loop-one-gap resonators in coaxial juxtaposition. In one mode, the currents in the two loops are parallel and in the other antiparallel. By introducing additional capacitors between the loops, the frequencies of the two modes can be made to coincide. Details are given concerning variable coupling to each mode, tuning of the resonant frequency of one mode to that of the other, and adjustment of the isolation between modes. An equivalent circuit is given and network analysis carried out both experimentally and theoretically. EPR applications are described including (a) probing of the field distributions with DPPH, (b) continuous wave (cw) EPR with a spin-label line sample, (c) cw electron-electron double resonance (ELDOR), (d) modulation of saturation, and (e) saturation-recovery (SR) EPR. Bloch induction experiments can be performed when the sample extends half way through the structure, but microwave signals induced by Mx and My components of magnetization cancel when it extends completely through. This latter situation is particularly favorable for SR, modulation of saturation, and ELDOR experiments, which depend on observing Mz indirectly using a second weak observing microwave source.

  1. Radiation Enhanced Absorption of Frank Loops by Nanovoids in Cu

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Zhang, X.; Wang, J.

    2016-01-01

    Neutron and heavy ion irradiations generally induce voids in metallic materials, and continuous radiations typically result in void swelling and mechanical failure of the irradiated materials. Recent experiments showed that nanovoids in nanotwinned copper could act as sinks for radiation-induced Frank loops, significantly mitigating radiation damage. In this paper, we report on structural evolution of Frank loops under cascades and address the role of nanovoids in absorbing Frank loops in detail by using molecular dynamics simulations. Results show that a stand-alone Frank loop is stable under cascades. When Frank loops are adjacent to nanovoids, the diffusion of a group of atoms from the loop into nanovoids is accomplished via the formation and propagation of dislocation loops. The loop-nanovoid interactions result in the shrinkage of the nanovoids and the Frank loops.

  2. Run-time parallelization and scheduling of loops

    NASA Technical Reports Server (NTRS)

    Saltz, Joel H.; Mirchandaney, Ravi; Crowley, Kay

    1990-01-01

    Run time methods are studied to automatically parallelize and schedule iterations of a do loop in certain cases, where compile-time information is inadequate. The methods presented involve execution time preprocessing of the loop. At compile-time, these methods set up the framework for performing a loop dependency analysis. At run time, wave fronts of concurrently executable loop iterations are identified. Using this wavefront information, loop iterations are reordered for increased parallelism. Symbolic transformation rules are used to produce: inspector procedures that perform execution time preprocessing and executors or transformed versions of source code loop structures. These transformed loop structures carry out the calculations planned in the inspector procedures. Performance results are presented from experiments conducted on the Encore Multimax. These results illustrate that run time reordering of loop indices can have a significant impact on performance. Furthermore, the overheads associated with this type of reordering are amortized when the loop is executed several times with the same dependency structure.

  3. Open-loop and closed-loop control of dissociative ionization of ethanol in intense laser fields

    SciTech Connect

    Yazawa, Hiroki; Tanabe, Takasumi; Okamoto, Tatsuyoshi; Yamanaka, Mio; Kannari, Fumihiko; Itakura, Ryuji; Yamanouchi, Kaoru

    2006-05-28

    The relative yield of the C-O bond breaking with respect to the C-C bond breaking in ethanol cation C{sub 2}H{sub 5}OH{sup +} is maximized in intense laser fields (10{sup 13}-10{sup 15} W/cm{sup 2}) by open-loop and closed-loop optimization procedures. In the open-loop optimization, a train of intense laser pulses are synthesized so that the temporal separation between the first and last pulses becomes 800 fs, and the number and width of the pulses within a train are systematically varied. When the duration of 800 fs is filled with laser fields by increasing the number of pulses or by stretching all pulses in a triple pulse train, the relative yield of the C-O bond breaking becomes significantly large. In the closed-loop optimization using a self-learning algorithm, the four dispersion coefficients or the phases of 128 frequency components of an intense laser pulse are adopted as optimized parameters. From these optimization experiments it is revealed that the yield ratio of the C-O bond breaking is maximized as far as the total duration of the intense laser field reaches as long as {approx}1 ps and that the intermittent disappearance of the laser field within a pulse does not affect the relative yields of the bond breaking pathways.

  4. Assessing metacognitive skills in waking and sleep: a psychometric analysis of the Metacognitive, Affective, Cognitive Experience (MACE) questionnaire.

    PubMed

    Kahan, Tracey L; Sullivan, Kieran T

    2012-03-01

    The Metacognitive, Affective, Cognitive Experience (MACE) questionnaire was designed to assess metacognition across sleep and waking (Kahan & LaBerge, 1996). The present research evaluates the psychometric properties of the MACE. Data from two recent studies (N=185) were used to assess the inter-item consistency, test-retest reliability, and factorial, convergent, and discriminant validity of the MACE. Results show that the MACE is a reliable measure with good construct validity. Exploratory factor analyses revealed one self-regulation and two monitoring factors. One monitoring factor emphasized monitoring internal conditions; the other emphasized monitoring external conditions. This factor structure is consistent with the Metacognitive Model (Nelson & Narens, 1990). Tests of convergent and discriminant validity suggest that the MACE is assessing metacognition and is appropriately related to similar constructs such as mindfulness and self-consciousness. The implication of these findings as well as suggestions for research and clinical applications of the MACE are discussed. PMID:22197150

  5. Hearing tongue loops: Perceptual sensitivity to acoustic signatures of articulatory dynamics

    PubMed Central

    Nam, Hosung; Mooshammer, Christine; Iskarous, Khalil; Whalen, D. H.

    2013-01-01

    Previous work has shown that velar stops are produced with a forward movement during closure, forming a forward (anterior) loop for a VCV sequence, when the preceding vowels are back or mid. Are listeners aware of this aspect of articulatory dynamics? The current study used articulatory synthesis to examine how such kinematic patterns are reflected in the acoustics, and whether those acoustic patterns elicit different goodness ratings. In Experiment I, the size and direction of loops was modulated in articulatory synthesis. The resulting stimuli were presented to listeners for a naturalness judgment. Results show that listeners rate forward loops as more natural than backward loops, in agreement with typical productions. Acoustic analysis of the synthetic stimuli shows that forward loops exhibit shorter and shallower VC transitions than CV transitions. In Experiment II, three acoustic parameters were employed incorporating F3-F2 distance, transition slope, and transition length to systematically modulate the magnitude of VC and CV transitions. Listeners rated the naturalness in accord with those of Experiment I. This study reveals that there is sufficient information in the acoustic signature of “velar loops” to affect perceptual preference. Similarity to typical productions seemed to determine preferences, not acoustic distinctiveness. PMID:24180790

  6. Optimization of a closed-loop gas system for the operation of Resistive Plate Chambers at the Large Hadron Collider experiments

    NASA Astrophysics Data System (ADS)

    Capeans, M.; Glushkov, I.; Guida, R.; Hahn, F.; Haider, S.

    2012-01-01

    Resistive Plate Chambers (RPCs), thanks to their fast time resolution (˜1 ns), suitable space resolution (˜1 cm) and low production cost (˜50 €/m2), are widely employed for the muon trigger systems at the Large Hadron Collider (LHC). Their large detector volume (they cover a surface of about 4000 m2 equivalent to 16 m3 of gas volume both in ATLAS and CMS) and the use of a relatively expensive Freon-based gas mixture make a closed-loop gas circulation unavoidable. It has been observed that the return gas of RPCs operated in conditions similar to the difficult experimental background foreseen at LHC contains a large amount of impurities potentially dangerous for long-term operation. Several gas-cleaning agents are currently in use in order to avoid accumulation of impurities in the closed-loop circuits. We present the results of a systematic study characterizing each of these cleaning agents. During the test, several RPCs were operated at the CERN Gamma Irradiation Facility (GIF) in a high radiation environment in order to observe the production of typical impurities: mainly fluoride ions, molecules of the Freon group and hydrocarbons. The polluted return gas was sent to several cartridges, each containing a different cleaning agent. The effectiveness of each material was studied using gas chromatography and mass-spectrometry techniques. Results of this test have revealed an optimized configuration of filters that is now under long-term validation.Gas optimization studies are complemented with a finite element simulation of gas flow distribution in the RPCs, aiming at its eventual optimization in terms of distribution and flow rate.

  7. Loops and trees

    NASA Astrophysics Data System (ADS)

    Caron-Huot, S.

    2011-05-01

    We investigate relations between loop and tree amplitudes in quantum field theory that involve putting on-shell some loop propagators. This generalizes the so-called Feynman tree theorem which is satisfied at 1-loop. Exploiting retarded boundary conditions, we give a generalization to ℓ-loop expressing the loops as integrals over the on-shell phase space of exactly ℓ particles. We argue that the corresponding integrand for ℓ > 2 does not involve the forward limit of any physical tree amplitude, except in planar gauge theories. In that case we explicitly construct the relevant physical amplitude. Beyond the planar limit, abandoning direct integral representations, we propose that loops continue to be determined implicitly by the forward limit of physical connected trees, and we formulate a precise conjecture along this line. Finally, we set up technology to compute forward amplitudes in supersymmetric theories, in which specific simplifications occur.

  8. Decisions at the Brink: Locomotor Experience Affects Infants’ Use of Social Information on an Adjustable Drop-off

    PubMed Central

    Karasik, Lana B.; Tamis-LeMonda, Catherine S.; Adolph, Karen E.

    2016-01-01

    How do infants decide what to do at the brink of a precipice? Infants could use two sources of information to guide their actions: perceptual information generated by their own exploratory activity and social information offered by their caregivers. The current study investigated the role of locomotor experience in using social information—both encouragement and discouragement—for descending drop-offs. Mothers of 30 infants (experienced 12-month-old crawlers, novice 12-month-old walkers, and experienced 18-month-old walkers) encouraged and discouraged descent on a gradation of drop-offs (safe “steps” and risky “cliffs”). Novice walkers descended more frequently than experienced crawlers and walkers and fell while attempting to walk over impossibly high cliffs. All infants showed evidence of integrating perceptual and social information, but locomotor experience affected infants’ use of social messages, especially on risky drop-offs. Experienced crawlers and walkers selectively deferred to social information when perceptual information is ambiguous. In contrast, novice walkers took mothers’ advice inconsistently and only at extreme drop-offs. PMID:27375507

  9. Optimization of parameters affecting signal intensity in an LTQ-orbitrap in negative ion mode: A design of experiments approach.

    PubMed

    Lemonakis, Nikolaos; Skaltsounis, Alexios-Leandros; Tsarbopoulos, Anthony; Gikas, Evagelos

    2016-01-15

    A multistage optimization of all the parameters affecting detection/response in an LTQ-orbitrap analyzer was performed, using a design of experiments methodology. The signal intensity, a critical issue for mass analysis, was investigated and the optimization process was completed in three successive steps, taking into account the three main regions of an orbitrap, the ion generation, the ion transmission and the ion detection regions. Oleuropein and hydroxytyrosol were selected as the model compounds. Overall, applying this methodology the sensitivity was increased more than 24%, the resolution more than 6.5%, whereas the elapsed scan time was reduced nearly to its half. A high-resolution LTQ Orbitrap Discovery mass spectrometer was used for the determination of the analytes of interest. Thus, oleuropein and hydroxytyrosol were infused via the instruments syringe pump and they were analyzed employing electrospray ionization (ESI) in the negative high-resolution full-scan ion mode. The parameters of the three main regions of the LTQ-orbitrap were independently optimized in terms of maximum sensitivity. In this context, factorial design, response surface model and Plackett-Burman experiments were performed and analysis of variance was carried out to evaluate the validity of the statistical model and to determine the most significant parameters for signal intensity. The optimum MS conditions for each analyte were summarized and the method optimum condition was achieved by maximizing the desirability function. Our observation showed good agreement between the predicted optimum response and the responses collected at the predicted optimum conditions. PMID:26592625

  10. Changes to gonadotropin-releasing hormone (GnRH) receptor extracellular loops differentially affect GnRH analog binding and activation: evidence for distinct ligand-stabilized receptor conformations.

    PubMed

    Pfleger, Kevin D G; Pawson, Adam J; Millar, Robert P

    2008-06-01

    GnRH and its structural variants bind to GnRH receptors from different species with different affinities and specificities. By investigating chimeric receptors that combine regions of mammalian and nonmammalian GnRH receptors, a greater understanding of how different domains influence ligand binding and receptor activation can be achieved. Using human-catfish and human-chicken chimeric receptors, we demonstrate the importance of extracellular loop conformation for ligand binding and agonist potency, providing further evidence for GnRH and GnRH II stabilization of distinct active receptor conformations. We demonstrate examples of GnRH receptor gain-of-function mutations that apparently improve agonist potency independently of affinity, implicating a role for extracellular loops in stabilizing the inactive receptor conformation. We also show that entire extracellular loop substitution can overcome the detrimental effects of localized mutations, thereby demonstrating the importance of considering the conformation of entire domains when drawing conclusions from point-mutation studies. Finally, we present evidence implicating the configuration of extracellular loops 2 and 3 in combination differentiating GnRH analog binding modes. Because there are two endogenous forms of GnRH ligand but only one functional form of full-length GnRH receptor in humans, understanding how GnRH and GnRH II can elicit distinct functional effects through the same receptor is likely to provide important insights into how these ligands can have differential effects in both physiological and pathological situations. PMID:18356273

  11. Laminated BEAM loops

    NASA Astrophysics Data System (ADS)

    Danisch, Lee A.

    1996-10-01

    BEAM sensors include treated loops of optical fiber that modulate optical throughput with great sensitivity and linearity, in response to curvature of the loop out of its plane. This paper describes BEAM sensors that have two loops treated in opposed fashion, hermetically sealed in flexible laminations. The sensors include an integrated optoelectronics package that extracts curvature information from the treated portion of the loops while rejecting common mode errors. The laminated structure is used to sense various parameters including displacement, force, pressure, flow, and acceleration.

  12. Observational Evidence for Loop-Loop Interaction

    NASA Astrophysics Data System (ADS)

    Guiping, W.; Guangli, H.; Yuhua, T.; Aoao, X.

    2004-01-01

    Through analysis of the data including the hard x-ray(BASTE) microwave(NoRP) and magnetogram(MDI from SOHO) as well as the images of soft x-ray(YHKOH) and EIT(SOHO) on Apr. 151998 solar flare in the active region 8203(N30W12) we found: (1) there are similar quasi period oscillation in the profile of hard x-ray flux (25-5050-100keV) and microwave flux(1GHz) with duration of 85+/-25s every peak includes two sub-peak structures; (2) in the preheat phase of the flare active magnetic field changes apparently and a s-pole spot emerges ; (3) several EIT and soft x-ray loops exist and turn into bright . All of these may suggest that loop-loop interaction indeed exist. Through reconnection the electrons may be accelerated and the hard x-ray and microwave emission take place.

  13. Are People Emotionally Predisposed to Experience Lower Quality of Life? The Impact of Negative Affectivity on Quality of Life in Patients Recovering from Cardiac Surgery

    ERIC Educational Resources Information Center

    Panagopoulou, Efharis; Montgomery, Anthony J.; Benos, Alexis; Maes, Stan

    2006-01-01

    Negative affectivity has been defined as a predisposition to experience intense states of negative emotions. As a trait concept it is a dimension that reflects stable and pervasive differences in negative mood and self-concept. There has been systematic evidence linking negative affectivity to anxiety, depression, psychosomatic complaints, pain…

  14. Affective Education for Special Children and Youth. What Research and Experience Say to the Teacher of Exceptional Children.

    ERIC Educational Resources Information Center

    Morse, William C.; And Others

    Affective education methods in special education are the concern of the text. Goals, definitions, and processes in affective education are considered in Chapter 1, which also examines such topics as the relationship between affective education and mainstreaming, teacher role, and pupil focused affective education. Specific program content is…

  15. Loss of rare fish species from tropical floodplain food webs affects community structure and ecosystem multifunctionality in a mesocosm experiment.

    PubMed

    Pendleton, Richard M; Hoeinghaus, David J; Gomes, Luiz C; Agostinho, Angelo A

    2014-01-01

    Experiments with realistic scenarios of species loss from multitrophic ecosystems may improve insight into how biodiversity affects ecosystem functioning. Using 1000 L mesocoms, we examined effects of nonrandom species loss on community structure and ecosystem functioning of experimental food webs based on multitrophic tropical floodplain lagoon ecosystems. Realistic biodiversity scenarios were developed based on long-term field surveys, and experimental assemblages replicated sequential loss of rare species which occurred across all trophic levels of these complex food webs. Response variables represented multiple components of ecosystem functioning, including nutrient cycling, primary and secondary production, organic matter accumulation and whole ecosystem metabolism. Species richness significantly affected ecosystem function, even after statistically controlling for potentially confounding factors such as total biomass and direct trophic interactions. Overall, loss of rare species was generally associated with lower nutrient concentrations, phytoplankton and zooplankton densities, and whole ecosystem metabolism when compared with more diverse assemblages. This pattern was also observed for overall ecosystem multifunctionality, a combined metric representing the ability of an ecosystem to simultaneously maintain multiple functions. One key exception was attributed to time-dependent effects of intraguild predation, which initially increased values for most ecosystem response variables, but resulted in decreases over time likely due to reduced nutrient remineralization by surviving predators. At the same time, loss of species did not result in strong trophic cascades, possibly a result of compensation and complexity of these multitrophic ecosystems along with a dominance of bottom-up effects. Our results indicate that although rare species may comprise minor components of communities, their loss can have profound ecosystem consequences across multiple trophic

  16. Loss of Rare Fish Species from Tropical Floodplain Food Webs Affects Community Structure and Ecosystem Multifunctionality in a Mesocosm Experiment

    PubMed Central

    Pendleton, Richard M.; Hoeinghaus, David J.; Gomes, Luiz C.; Agostinho, Angelo A.

    2014-01-01

    Experiments with realistic scenarios of species loss from multitrophic ecosystems may improve insight into how biodiversity affects ecosystem functioning. Using 1000 L mesocoms, we examined effects of nonrandom species loss on community structure and ecosystem functioning of experimental food webs based on multitrophic tropical floodplain lagoon ecosystems. Realistic biodiversity scenarios were developed based on long-term field surveys, and experimental assemblages replicated sequential loss of rare species which occurred across all trophic levels of these complex food webs. Response variables represented multiple components of ecosystem functioning, including nutrient cycling, primary and secondary production, organic matter accumulation and whole ecosystem metabolism. Species richness significantly affected ecosystem function, even after statistically controlling for potentially confounding factors such as total biomass and direct trophic interactions. Overall, loss of rare species was generally associated with lower nutrient concentrations, phytoplankton and zooplankton densities, and whole ecosystem metabolism when compared with more diverse assemblages. This pattern was also observed for overall ecosystem multifunctionality, a combined metric representing the ability of an ecosystem to simultaneously maintain multiple functions. One key exception was attributed to time-dependent effects of intraguild predation, which initially increased values for most ecosystem response variables, but resulted in decreases over time likely due to reduced nutrient remineralization by surviving predators. At the same time, loss of species did not result in strong trophic cascades, possibly a result of compensation and complexity of these multitrophic ecosystems along with a dominance of bottom-up effects. Our results indicate that although rare species may comprise minor components of communities, their loss can have profound ecosystem consequences across multiple trophic

  17. Event-level associations between affect, alcohol intoxication, and acute dependence symptoms: Effects of urgency, self-control, and drinking experience

    PubMed Central

    Simons, Jeffrey S.; Dvorak, Robert D.; Batien, Bryan D.; Wray, Tyler B.

    2012-01-01

    This study used experience sampling to examine within-person associations between positive affect, anxiety, sadness, and hostility and two outcomes: alcohol intoxication and acute dependence symptoms. We examined the role of urgency, premeditation, and perseverance in predicting the alcohol outcomes and tested whether the affective associations varied as a function of urgency. Participants completed baseline assessments and 21 days of experience sampling on PDAs. Hypotheses were partially confirmed. Positive affect was positively, and sadness inversely, associated with intoxication. Hostility was associated with intoxication for men but not women. Negative urgency moderated the association between anxiety and intoxication, making it stronger. However, positive urgency did not moderate the effect of positive affect. Heavier drinkers exhibited the greatest number of symptoms, yet the association between intoxication and acute signs of alcohol disorder were attenuated among these individuals. Results support the use of experience sampling to study acute signs and symptoms of high risk drinking and dependence. PMID:20685044

  18. Experience affects immediate early gene expression in response to conspecific call notes in black-capped chickadees (Poecile atricapillus).

    PubMed

    Hahn, Allison H; Guillette, Lauren M; Lee, Daniel; McMillan, Neil; Hoang, John; Sturdy, Christopher B

    2015-01-01

    Black-capped chickadees (Poecile atricapillus) produce numerous vocalizations, including the acoustically complex chick-a-dee call that is composed of A, B, C, and D notes. D notes are longer in duration and lower in frequency than the other note types and contain information regarding flock and species identification. Adult wild-caught black-capped chickadees have been shown to have similar amounts of immediate early gene (IEG) expression following playback of vocalizations with harmonic-like acoustic structure, similar to D notes. Here we examined how different environmental experiences affect IEG response to conspecific D notes. We hand-reared black-capped chickadees under three conditions: (1) with adult conspecifics, (2) with adult heterospecific mountain chickadees, and (3) without adults. We presented all hand-reared birds and a control group of field-reared black-capped chickadees, with conspecific D notes and quantified IEG expression in the caudomedial mesopallium (CMM) and caudomedial nidopallium (NCM). We found that field-reared birds that heard normal D notes had a similar neural response as a group of field-reared birds that heard playback of reversed D notes. Field-reared birds that heard normal D notes also had a similar neural response as birds reared with adult conspecifics. Birds reared without adults had a significantly reduced IEG response, whereas the IEG expression in birds reared with heterospecifics was at intermediate levels between birds reared with conspecifics and birds reared without adults. Although acoustic characteristics have been shown to drive IEG expression, our results demonstrate that experience with adults or normal adult vocalizations is also an important factor. PMID:25813748

  19. Hyrdo-Quebec`s experience using deep slot cutting to rehabilitate concrete gravity dams affected by alkali-aggregate reaction

    SciTech Connect

    Veilleux, M.

    1995-12-31

    In recent years, Hydro-Qu{acute e}bec has cut vertical slots in concrete dams to solve structural problems stemming from aging of concrete subject to thermal cycles and alkali-aggregate reaction (AAR). In most cases, the structural disorders caused large cracks and permanent displacement. This paper describes Hydro-Qu{acute e}bec`s experience using a new slot-cutting and sealing technology to rehabilitate concrete gravity dams affected by AAR, among them rehabilitation of the Paugan (1991), La Tuque (1992-1993), Rapides Farmers (1993-1994) and Chelsea (1994) hydroelectric developments. The aim of this technology is to relieve internal stress and to create an effective expansion joint which can accommodate reversible and irreversible displacement induced by thermal cycles as well as permanent movement due to chemical concrete swelling caused by AAR. This method of rehabilitation is generally used in conjunction with grouting and drainage work and sometimes with post-tensioned anchor rods or cables.

  20. Is the learning curve for video-assisted thoracoscopic lobectomy affected by prior experience in open lobectomy?

    PubMed

    Okyere, Sharon; Attia, Rizwan; Toufektzian, Levon; Routledge, Tom

    2015-07-01

    A best evidence topic was written according to a structured protocol. The question addressed is the learning curve for video-assisted thoracoscopic (VATS) lobectomy affected by prior experience in open lobectomy? Two hundred and two studies were identified of which seven presented the best evidence on the topic. The authors, date, journal, country of publication, study type, participating surgeon and relevant outcomes are tabulated. The studies presented discuss the learning experiences of surgeons with a range of proficiency in open lobectomy in performing VATS lobectomy. Four of the studies made direct comparisons between the outcomes achieved by trainees and fully qualified surgeons. Trainees performed a total of 154 VATS lobectomies and the consultants performed 714. The reported number of open lobectomies performed by trainees ranged 14-50. In one study, a qualified surgeon who had performed 100 open lobectomies achieved a statistically significant progression in his learning curve and was able to safely perform VATS lobectomies after 6 months. A trainee who had performed only 14 open lobectomies achieved a similar blood loss to his experienced supervisors (P = 0.79). Two trainee surgeons who had each performed at least 20 open lobectomies achieved similar mean intraoperative blood loss (P = 0.2) and complication rate (P = 0.4) to their experienced consultant when performing VATS lobectomy. Average duration of chest drainage was similar between consultant and trainee groups (P = 0.34) and was improved in favour of trainees in one group (P < 0.001); this might be due to the fact that they operated on more technically straightforward cases. Four trainee surgeons who had performed at least 50 open pulmonary resections each managed to achieve a similar mean operative time to their consultant in their first 46 cases, and a lower morbidity (26 vs 34.7%). There was no increase in mortality in the trainee groups. Surgeons with limited experience in open lobectomy can

  1. A magnetohydrodynamic theory of coronal loop transients

    NASA Technical Reports Server (NTRS)

    Yeh, T.

    1982-01-01

    The physical and geometrical characteristics of solar coronal loop transients are described in an MHD model based on Archimedes' MHD buoyancy force. The theory was developed from interpretation of coronagraphic data, particularly from Skylab. The brightness of a loop is taken to indicate the electron density, and successive pictures reveal the electron enhancement in different columns. The forces which lift the loop off the sun surface are analyzed as an MHD buoyancy force affecting every mass element by imparting an inertial force necessary for heliocentrifugal motion. Thermal forces are responsible for transferring the ambient stress to the interior of the loop to begin the process. The kinematic and hydrostatic buoyancy overcome the gravitational force, and a flux rope can then curve upward, spiralling like a corkscrew with varying cross section around the unwinding solar magnetic field lines.

  2. Two Loop Higgs Unitarity Constraints

    NASA Astrophysics Data System (ADS)

    Maher, Peter Noel

    The perturbative approximation in the Symmetry Breaking sector of the Standard Model is investigated to two loops. The breakdown of perturbative unitarity seen at one loop is only slightly postponed. Attention is restricted to the coupled elastic scattering matrix of the neutral channels W^+W ^-, ZZ, HH, ZH. The high energy limit s gg M_sp{H} {2} gg M_sp{W}{2} and the Equivalence Theorem are used to simplify the calculation. The theory is renormalized on mass shell, in a way that automatically sums the tadpole graphs. Calculation of the counterterms was the most difficult part of the entire work. The running coupling and anomalous dimensions are calculated. The Landau pole of the running coupling is not significantly affected by the two loop contributions unless the coupling is large. Similarly, the anomalous dimensions are small. The eigen-amplitudes of the partial wave projected scattering matrix are analysed for breakdown of perturbative unitarity using Argand diagrams, and for term-wise convergence. It is found that if the Standard Model is to hold true up to sqrt{s} ~ 2TeV, the theory is strongly coupled and perturbative approximations are no longer trustworthy if M_{H} _sp{~}{>} 350 - 450 GeV. If the Standard Model is embedded in a perturbative grand unified theory, and assumed to hold true up to sqrt{s} = 10^ {15} GeV, then the Higgs mass is bounded M_{H} _sp{~ }{<} 160 GeV.

  3. Thermal power loops

    NASA Technical Reports Server (NTRS)

    Gottschlich, Joseph M.; Richter, Robert

    1991-01-01

    The concept of a thermal power loop (TPL) to transport thermal power over relatively large distances is presented as an alternative to heat pipes and their derivatives. The TPL is compared to heat pipes, and capillary pumped loops with respect to size, weight, conservation of thermal potential, start-up, and 1-g testing capability. Test results from a proof of feasibility demonstrator at the NASA JPL are discussed. This analysis demonstrates that the development of specific thermal power loops will result in substantial weight and cost savings for many spacecraft.

  4. Natively Unstructured Loops Differ from Other Loops

    PubMed Central

    Schlessinger, Avner; Liu, Jinfeng; Rost, Burkhard

    2007-01-01

    Natively unstructured or disordered protein regions may increase the functional complexity of an organism; they are particularly abundant in eukaryotes and often evade structure determination. Many computational methods predict unstructured regions by training on outliers in otherwise well-ordered structures. Here, we introduce an approach that uses a neural network in a very different and novel way. We hypothesize that very long contiguous segments with nonregular secondary structure (NORS regions) differ significantly from regular, well-structured loops, and that a method detecting such features could predict natively unstructured regions. Training our new method, NORSnet, on predicted information rather than on experimental data yielded three major advantages: it removed the overlap between testing and training, it systematically covered entire proteomes, and it explicitly focused on one particular aspect of unstructured regions with a simple structural interpretation, namely that they are loops. Our hypothesis was correct: well-structured and unstructured loops differ so substantially that NORSnet succeeded in their distinction. Benchmarks on previously used and new experimental data of unstructured regions revealed that NORSnet performed very well. Although it was not the best single prediction method, NORSnet was sufficiently accurate to flag unstructured regions in proteins that were previously not annotated. In one application, NORSnet revealed previously undetected unstructured regions in putative targets for structural genomics and may thereby contribute to increasing structural coverage of large eukaryotic families. NORSnet found unstructured regions more often in domain boundaries than expected at random. In another application, we estimated that 50%–70% of all worm proteins observed to have more than seven protein–protein interaction partners have unstructured regions. The comparative analysis between NORSnet and DISOPRED2 suggested that long

  5. Introduction to Loop Heat Pipes

    NASA Technical Reports Server (NTRS)

    Ku, Jentung

    2015-01-01

    This is the presentation file for the short course Introduction to Loop Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. This course will discuss operating principles and performance characteristics of a loop heat pipe. Topics include: 1) pressure profiles in the loop; 2) loop operating temperature; 3) operating temperature control; 4) loop startup; 4) loop shutdown; 5) loop transient behaviors; 6) sizing of loop components and determination of fluid inventory; 7) analytical modeling; 8) examples of flight applications; and 9) recent LHP developments.

  6. Changing nutrient stoichiometry affects phytoplankton production, DOP accumulation and dinitrogen fixation - a mesocosm experiment in the eastern tropical North Atlantic

    NASA Astrophysics Data System (ADS)

    Meyer, J.; Löscher, C. R.; Neulinger, S. C.; Reichel, A. F.; Loginova, A.; Borchard, C.; Schmitz, R. A.; Hauss, H.; Kiko, R.; Riebesell, U.

    2016-02-01

    Ocean deoxygenation due to climate change may alter redox-sensitive nutrient cycles in the marine environment. The productive eastern tropical North Atlantic (ETNA) upwelling region may be particularly affected when the relatively moderate oxygen minimum zone (OMZ) deoxygenates further and microbially driven nitrogen (N) loss processes are promoted. Consequently, water masses with a low nitrogen to phosphorus (N : P) ratio could reach the euphotic layer, possibly influencing primary production in those waters. Previous mesocosm studies in the oligotrophic Atlantic Ocean identified nitrate availability as a control of primary production, while a possible co-limitation of nitrate and phosphate could not be ruled out. To better understand the impact of changing N : P ratios on primary production and N2 fixation in the ETNA surface ocean, we conducted land-based mesocosm experiments with natural plankton communities and applied a broad range of N : P ratios (2.67-48). Silicic acid was supplied at 15 µmol L-1 in all mesocosms. We monitored nutrient drawdown, biomass accumulation and nitrogen fixation in response to variable nutrient stoichiometry. Our results confirmed nitrate to be the key factor determining primary production. We found that excess phosphate was channeled through particulate organic matter (POP) into the dissolved organic matter (DOP) pool. In mesocosms with low inorganic phosphate availability, DOP was utilized while N2 fixation increased, suggesting a link between those two processes. Interestingly this observation was most pronounced in mesocosms where nitrate was still available, indicating that bioavailable N does not necessarily suppress N2 fixation. We observed a shift from a mixed cyanobacteria-proteobacteria dominated active diazotrophic community towards a diatom-diazotrophic association of the Richelia-Rhizosolenia symbiosis. We hypothesize that a potential change in nutrient stoichiometry in the ETNA might lead to a general shift within

  7. Evaluation of the legal consequences of action affects neural activity and emotional experience during the resolution of moral dilemmas.

    PubMed

    Pletti, Carolina; Sarlo, Michela; Palomba, Daniela; Rumiati, Rino; Lotto, Lorella

    2015-03-01

    In any modern society killing is regarded as a severe violation of the legal codes that is subjected to penal judgment. Therefore, it is likely that people take legal consequences into account when deciding about the hypothetical killing of one person in classic moral dilemmas, with legal concerns contributing to decision-making. In particular, by differing for the degree of intentionality and emotional salience, Footbridge- and Trolley-type dilemmas might promote differential assignment of blame and punishment while implicating the same severity of harm. The present study was aimed at comparing the neural activity, subjective emotional reactions, and behavioral choices in two groups of participants who either took (Legal group) or did not take (No Legal group) legal consequences into account when deciding on Footbridge-type and Trolley-type moral dilemmas. Stimulus- and response-locked ERPs were measured to investigate the neural activity underlying two separate phases of the decision process. No difference in behavioral choices was found between groups. However, the No Legal group reported greater overall emotional impact, associated with lower preparation for action, suggesting greater conflict between alternative motor responses representing the different decision choices. In contrast, the Legal group showed an overall dampened affective experience during decision-making associated with greater overall action readiness and intention to act, reflecting lower conflict in responding. On these bases, we suggest that in moral dilemmas legal consequences of actions provide a sort of reference point on which people can rely to support a decision, independent of dilemma type. PMID:25638294

  8. Auditory pre-experience modulates classification of affect intensity: evidence for the evaluation of call salience by a non-human mammal, the bat Megaderma lyra

    PubMed Central

    2013-01-01

    Introduction Immediate responses towards emotional utterances in humans are determined by the acoustic structure and perceived relevance, i.e. salience, of the stimuli, and are controlled via a central feedback taking into account acoustic pre-experience. The present study explores whether the evaluation of stimulus salience in the acoustic communication of emotions is specifically human or has precursors in mammals. We created different pre-experiences by habituating bats (Megaderma lyra) to stimuli based on aggression, and response, calls from high or low intensity level agonistic interactions, respectively. Then we presented a test stimulus of opposite affect intensity of the same call type. We compared the modulation of response behaviour by affect intensity between the reciprocal experiments. Results For aggression call stimuli, the bats responded to the dishabituation stimuli independent of affect intensity, emphasising the attention-grabbing function of this call type. For response call stimuli, the bats responded to a high affect intensity test stimulus after experiencing stimuli of low affect intensity, but transferred habituation to a low affect intensity test stimulus after experiencing stimuli of high affect intensity. This transfer of habituation was not due to over-habituation as the bats responded to a frequency-shifted control stimulus. A direct comparison confirmed the asymmetric response behaviour in the reciprocal experiments. Conclusions Thus, the present study provides not only evidence for a discrimination of affect intensity, but also for an evaluation of stimulus salience, suggesting that basic assessment mechanisms involved in the perception of emotion are an ancestral trait in mammals. PMID:24341839

  9. Toward a Theory and Practice for Whole-Person Learning: Reconceptualizing Experience and the Role of Affect.

    ERIC Educational Resources Information Center

    Yorks, Lyle; Kasl, Elizabeth

    2002-01-01

    A pragmatic perspective favors reflective discourse over affect. Heron's theory of personhood takes a phenomenological approach to affective learning. Strategies from this approach can be applied to the phenomenon of learning-within-relationship, in which individuals engage their own whole-person learning and that of others. (Contains 36…

  10. Small Unmanned Aircraft Systems Integration into the National Airspace System Visual-Line-of-Sight Human-in-the-Loop Experiment

    NASA Technical Reports Server (NTRS)

    Trujillo, Anna C.; Ghatas, Rania W.; Mcadaragh, Raymon; Burdette, Daniel W.; Comstock, James R.; Hempley, Lucas E.; Fan, Hui

    2015-01-01

    As part of the Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) project, research on integrating small UAS (sUAS) into the NAS was underway by a human-systems integration (HSI) team at the NASA Langley Research Center. Minimal to no research has been conducted on the safe, effective, and efficient manner in which to integrate these aircraft into the NAS. sUAS are defined as aircraft weighing 55 pounds or less. The objective of this human system integration team was to build a UAS Ground Control Station (GCS) and to develop a research test-bed and database that provides data, proof of concept, and human factors guidelines for GCS operations in the NAS. The objectives of this experiment were to evaluate the effectiveness and safety of flying sUAS in Class D and Class G airspace utilizing manual control inputs and voice radio communications between the pilot, mission control, and air traffic control. The design of the experiment included three sets of GCS display configurations, in addition to a hand-held control unit. The three different display configurations were VLOS, VLOS + Primary Flight Display (PFD), and VLOS + PFD + Moving Map (Map). Test subject pilots had better situation awareness of their vehicle position, altitude, airspeed, location over the ground, and mission track using the Map display configuration. This configuration allowed the pilots to complete the mission objectives with less workload, at the expense of having better situation awareness of other aircraft. The subjects were better able to see other aircraft when using the VLOS display configuration. However, their mission performance, as well as their ability to aviate and navigate, was reduced compared to runs that included the PFD and Map displays.

  11. Evolution kinetics of interstitial loops in irradiated materials: a phase-field model

    SciTech Connect

    Hu, Shenyang Y.; Henager, Charles H.; Li, Yulan; Gao, Fei; Sun, Xin; Khaleel, Mohammad A.

    2012-01-01

    Interstitial loops are one of the principal evolving defects in irradiated materials. The evolution of interstitial loops, including spatial and size distributions, affects both vacancy and interstitial accumulations in the matrix, hence, void formation and volumetric swelling. In this work, a phase-field model to simulate the growth kinetics of interstitial loops in irradiated materials during aging is developed. The diffusion of vacancies and interstitials and the elastic interaction between interstitial loops and point defects are accounted in the model. The effects of interstitial concentration, chemical potential, and elastic interaction on the growth kinetics and stability of interstitial loops are investigated in two and three dimensions. It is found that the elastic interaction enhances the growth kinetics of interstitial loops. The elastic interaction also affects the stability of a small interstitial loop adjacent to a larger loop. The model predicts linear growth rates for interstitial loops that is in agreement with the previous theoretical predictions and experimental observations.

  12. The Effect of Loops on the Structural Organization of α-Helical Membrane Proteins

    PubMed Central

    Tastan, Oznur; Klein-Seetharaman, Judith; Meirovitch, Hagai

    2009-01-01

    Loops connecting the transmembrane (TM) α-helices in membrane proteins are expected to affect the structural organization of the thereby connected helices and the helical bundles as a whole. This effect, which has been largely ignored previously, is studied here by analyzing the x-ray structures of 41 α-helical membrane proteins. First we define the loop flexibility ratio, R, and find that 53% of the loops are stretched, where a stretched loop constrains the distance between the two connected helices. The significance of this constraining effect is supported by experiments carried out with bacteriorhodopsin and rhodopsin, in which cutting or eliminating their (predominately stretched) loops has led to a decrease in protein stability, and for rhodopsin, in most cases, also to the destruction of the structure. We show that for nonstretched loops in the extramembranous regions, the fraction of hydrophobic residues is comparable to that for soluble proteins; furthermore (as is also the case for soluble proteins), the hydrophobic residues in these regions are preferentially buried. This is expected to lead to the compact structural organization of the loops, which is transferred to the TM helices, causing them to assemble. We argue that a soluble protein complexed with a membrane protein similarly promotes compactness; other properties of such complexes are also studied. We calculate complementary attractive interactions between helices, including hydrogen bonds and van der Waals interactions of sequential motifs, such as GXXXG. The relative and combined effects of all these factors on the association of the TM helices are discussed and protein structures with only a few of these factors are analyzed. Our study emphasizes the need for classifying membrane proteins into groups according to structural organization. This classification should be considered when procedures for structural analysis or prediction are developed and applied. Detailed analysis of each structure

  13. Investigation of Low Power Operation in a Loop Heat Pipe

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Ottenstein, Laura; Rogers, Paul; Cheung, Kwok; Powers, Edward I. (Technical Monitor)

    2001-01-01

    This paper presents test results of an experimental study of low power operation in a loop heat pipe. The main objective was to demonstrate how changes in the vapor void fraction inside the evaporator core would affect the loop behavior, The fluid inventory and the relative tilt between the evaporator and the compensation chamber were varied so as to create different vapor void fractions in the evaporator core. The effect on the loop start-up, operating temperature, and capillary limit was investigated. Test results indicate that the vapor void fraction inside the evaporator core is the single most important factor in determining the loop operation at low powers.

  14. Does the Lack of Hands-On Experience in a Remotely Delivered Laboratory Course Affect Student Learning?

    ERIC Educational Resources Information Center

    Abdel-Salam, Tarek; Kauffman, Paul J.; Crossman, Gary

    2006-01-01

    Educators question whether performing a laboratory experiment as an observer (non-hands-on), such as conducted in a distance education context, can be as effective a learning tool as personally performing the experiment in a laboratory environment. The present paper investigates this issue by comparing the performance of distance education…

  15. Do Proficiency and Study-Abroad Experience Affect Speech Act Production? Analysis of Appropriateness, Accuracy, and Fluency

    ERIC Educational Resources Information Center

    Taguchi, Naoko

    2011-01-01

    This cross-sectional study examined the effect of general proficiency and study-abroad experience in production of speech acts among learners of L2 English. Participants were 25 native speakers of English and 64 Japanese college students of English divided into three groups. Group 1 (n = 22) had lower proficiency and no study-abroad experience.…

  16. Saccade learning with concurrent cortical and subcortical basal ganglia loops

    PubMed Central

    N'Guyen, Steve; Thurat, Charles; Girard, Benoît

    2014-01-01

    The Basal Ganglia (BG) is a central structure involved in multiple cortical and subcortical loops. Some of these loops are believed to be responsible for saccade target selection. We study here how the very specific structural relationships of these saccadic loops can affect the ability of learning spatial and feature-based tasks. We propose a model of saccade generation with reinforcement learning capabilities based on our previous BG and superior colliculus models. It is structured around the interactions of two parallel cortico-basal loops and one tecto-basal loop. The two cortical loops separately deal with spatial and non-spatial information to select targets in a concurrent way. The subcortical loop is used to make the final target selection leading to the production of the saccade. These different loops may work in concert or disturb each other regarding reward maximization. Interactions between these loops and their learning capabilities are tested on different saccade tasks. The results show the ability of this model to correctly learn basic target selection based on different criteria (spatial or not). Moreover the model reproduces and explains training dependent express saccades toward targets based on a spatial criterion. Finally, the model predicts that in absence of prefrontal control, the spatial loop should dominate. PMID:24795615

  17. Chromatin extrusion explains key features of loop and domain formation in wild-type and engineered genomes

    PubMed Central

    Sanborn, Adrian L.; Rao, Suhas S. P.; Huang, Su-Chen; Durand, Neva C.; Huntley, Miriam H.; Jewett, Andrew I.; Bochkov, Ivan D.; Chinnappan, Dharmaraj; Cutkosky, Ashok; Li, Jian; Geeting, Kristopher P.; Gnirke, Andreas; Melnikov, Alexandre; McKenna, Doug; Stamenova, Elena K.; Lander, Eric S.; Aiden, Erez Lieberman

    2015-01-01

    We recently used in situ Hi-C to create kilobase-resolution 3D maps of mammalian genomes. Here, we combine these maps with new Hi-C, microscopy, and genome-editing experiments to study the physical structure of chromatin fibers, domains, and loops. We find that the observed contact domains are inconsistent with the equilibrium state for an ordinary condensed polymer. Combining Hi-C data and novel mathematical theorems, we show that contact domains are also not consistent with a fractal globule. Instead, we use physical simulations to study two models of genome folding. In one, intermonomer attraction during polymer condensation leads to formation of an anisotropic “tension globule.” In the other, CCCTC-binding factor (CTCF) and cohesin act together to extrude unknotted loops during interphase. Both models are consistent with the observed contact domains and with the observation that contact domains tend to form inside loops. However, the extrusion model explains a far wider array of observations, such as why loops tend not to overlap and why the CTCF-binding motifs at pairs of loop anchors lie in the convergent orientation. Finally, we perform 13 genome-editing experiments examining the effect of altering CTCF-binding sites on chromatin folding. The convergent rule correctly predicts the affected loops in every case. Moreover, the extrusion model accurately predicts in silico the 3D maps resulting from each experiment using only the location of CTCF-binding sites in the WT. Thus, we show that it is possible to disrupt, restore, and move loops and domains using targeted mutations as small as a single base pair. PMID:26499245

  18. Chromatin extrusion explains key features of loop and domain formation in wild-type and engineered genomes.

    PubMed

    Sanborn, Adrian L; Rao, Suhas S P; Huang, Su-Chen; Durand, Neva C; Huntley, Miriam H; Jewett, Andrew I; Bochkov, Ivan D; Chinnappan, Dharmaraj; Cutkosky, Ashok; Li, Jian; Geeting, Kristopher P; Gnirke, Andreas; Melnikov, Alexandre; McKenna, Doug; Stamenova, Elena K; Lander, Eric S; Aiden, Erez Lieberman

    2015-11-24

    We recently used in situ Hi-C to create kilobase-resolution 3D maps of mammalian genomes. Here, we combine these maps with new Hi-C, microscopy, and genome-editing experiments to study the physical structure of chromatin fibers, domains, and loops. We find that the observed contact domains are inconsistent with the equilibrium state for an ordinary condensed polymer. Combining Hi-C data and novel mathematical theorems, we show that contact domains are also not consistent with a fractal globule. Instead, we use physical simulations to study two models of genome folding. In one, intermonomer attraction during polymer condensation leads to formation of an anisotropic "tension globule." In the other, CCCTC-binding factor (CTCF) and cohesin act together to extrude unknotted loops during interphase. Both models are consistent with the observed contact domains and with the observation that contact domains tend to form inside loops. However, the extrusion model explains a far wider array of observations, such as why loops tend not to overlap and why the CTCF-binding motifs at pairs of loop anchors lie in the convergent orientation. Finally, we perform 13 genome-editing experiments examining the effect of altering CTCF-binding sites on chromatin folding. The convergent rule correctly predicts the affected loops in every case. Moreover, the extrusion model accurately predicts in silico the 3D maps resulting from each experiment using only the location of CTCF-binding sites in the WT. Thus, we show that it is possible to disrupt, restore, and move loops and domains using targeted mutations as small as a single base pair. PMID:26499245

  19. Wilson-loop instantons

    NASA Technical Reports Server (NTRS)

    Lee, Kimyeong; Holman, Richard; Kolb, Edward W.

    1987-01-01

    Wilson-loop symmetry breaking is considered on a space-time of the form M4 x K, where M4 is a four-dimensional space-time and K is an internal space with nontrivial and finite fundamental group. It is shown in a simple model that the different vacua obtained by breaking a non-Abelian gauge group by Wilson loops are separated in the space of gauge potentials by a finite energy barrier. An interpolating gauge configuration is then constructed between these vacua and shown to have minimum energy. Finally some implications of this construction are discussed.

  20. Automatic one-loop calculations with Sherpa+OpenLoops

    NASA Astrophysics Data System (ADS)

    Cascioli, F.; Höche, S.; Krauss, F.; Maierhöfer, P.; Pozzorini, S.; Siegert, F.

    2014-06-01

    We report on the OpenLoops generator for one-loop matrix elements and its application to four-lepton production in association with up to one jet. The open loops algorithm uses a numerical recursion to construct the numerator of one-loop Feynman diagrams as functions of the loop momentum. In combination with tensor integrals this results in a highly efficient and numerically stable matrix element generator. In order to obtain a fully automated setup for the simulation of next-to-leading order scattering processes we interfaced OpenLoops to the Sherpa Monte Carlo event generator.

  1. The Energy Landscape of Hyperstable LacI-DNA Loops

    NASA Astrophysics Data System (ADS)

    Kahn, Jason

    2009-03-01

    The Escherichia coli LacI protein represses transcription of the lac operon by blocking access to the promoter through binding at a promoter-proximal DNA operator. The affinity of tetrameric LacI (and therefore the repression efficiency) is enhanced by simultaneous binding to an auxiliary operator, forming a DNA loop. Hyperstable LacI-DNA loops were previously shown to be formed on DNA constructs that include a sequence-directed bend flanked by operators. Biochemical experiments showed that two such constructs (9C14 and 11C12) with different helical phasing between the operators and the DNA bend form different DNA loop shapes. The geometry and topology of the loops and the relevance of alternative conformations suggested by probable flexible linkers in LacI remain unclear. Bulk and single molecule fluorescence resonance energy transfer (SM-FRET, with D. English) experiments on a dual fluorophore-labeled 9C14-LacI loop demonstrate that it adopts a single, stable, rigid closed-form loop conformation. Here, we characterize the LacI-9C14 loop by SM-FRET as a function of inducer isopropyl-β,D-thiogalactoside (IPTG) concentration. Energy transfer measurements reveal partial but incomplete destabilization of loop formation by IPTG. Surprisingly, there is no change in the energy transfer efficiency of the remaining looped population. Models for the regulation of the lac operon often assume complete disruption of LacI-operator complexes upon inducer binding to LacI. Our work shows that even at saturating IPTG there is still a significant population of LacI-DNA complexes in a looped state, in accord with previous in vivo experiments that show incomplete induction (with J. Maher). Finally, we will report progress on characterizing the ``energy landscape'' for DNA looping upon systematic variation of the DNA linkers between the operators and the bending locus. Rod mechanics simulations (with N. Perkins) provide testable predictions on loop stability, topology, and FRET.

  2. Lorentz invariance in loop quantum gravity

    NASA Astrophysics Data System (ADS)

    Pullin, Jorge; Rastgoo, Saeed; Gambini, Rodolfo

    2011-04-01

    We reconsider the argument of Collins, Perez, Sudarsky, Urrutia and Vucetich concerning violations of Lorentz invariance in the context of loop quantum gravity. We show that even if one introduces a lattice that violates Lorentz invariance at the Planck scale, this does not translate itself into large violations that would conflict with experiment.

  3. Livermore Compiler Analysis Loop Suite

    2013-03-01

    LCALS is designed to evaluate compiler optimizations and performance of a variety of loop kernels and loop traversal software constructs. Some of the loop kernels are pulled directly from "Livermore Loops Coded in C", developed at LLNL (see item 11 below for details of earlier code versions). The older suites were used to evaluate floating-point performances of hardware platforms prior to porting larger application codes. The LCALS suite is geared toward assissing C++ compiler optimizationsmore » and platform performance related to SIMD vectorization, OpenMP threading, and advanced C++ language features. LCALS contains 20 of 24 loop kernels from the older Livermore Loop suites, plus various others representative of loops found in current production appkication codes at LLNL. The latter loops emphasize more diverse loop constructs and data access patterns than the others, such as multi-dimensional difference stencils. The loops are included in a configurable framework, which allows control of compilation, loop sampling for execution timing, which loops are run and their lengths. It generates timing statistics for analysis and comparing variants of individual loops. Also, it is easy to add loops to the suite as desired.« less

  4. Livermore Compiler Analysis Loop Suite

    SciTech Connect

    Hornung, R. D.

    2013-03-01

    LCALS is designed to evaluate compiler optimizations and performance of a variety of loop kernels and loop traversal software constructs. Some of the loop kernels are pulled directly from "Livermore Loops Coded in C", developed at LLNL (see item 11 below for details of earlier code versions). The older suites were used to evaluate floating-point performances of hardware platforms prior to porting larger application codes. The LCALS suite is geared toward assissing C++ compiler optimizations and platform performance related to SIMD vectorization, OpenMP threading, and advanced C++ language features. LCALS contains 20 of 24 loop kernels from the older Livermore Loop suites, plus various others representative of loops found in current production appkication codes at LLNL. The latter loops emphasize more diverse loop constructs and data access patterns than the others, such as multi-dimensional difference stencils. The loops are included in a configurable framework, which allows control of compilation, loop sampling for execution timing, which loops are run and their lengths. It generates timing statistics for analysis and comparing variants of individual loops. Also, it is easy to add loops to the suite as desired.

  5. Does the Grammatical Count/Mass Distinction Affect Semantic Representations? Evidence from Experiments in English and Japanese

    ERIC Educational Resources Information Center

    Iwasaki, Noriko; Vinson, David P.; Vigliocco, Gabriella

    2010-01-01

    We investigate linguistic relativity effects by examining whether the grammatical count/mass distinction in English affects English speakers' semantic representations of noun referents, as compared with those of Japanese speakers, whose language does not grammatically distinguish nouns for countability. We used two tasks which are sensitive to…

  6. How Workplace Experiences While at School Affect Career Pathways. A National Vocational Education and Training Research and Evaluation Program Report

    ERIC Educational Resources Information Center

    Smith, Erica; Green, Annette

    2005-01-01

    This report describes and analyses how the work activities undertaken by students while at school affect their post-school pathways into and between work and study. Increasingly, students are involved with workplaces while still at school. The three major ways in which this is happening (in order of extent of engagement) are through work…

  7. Multiday Fully Closed Loop Insulin Delivery in Monitored Outpatient Conditions

    ClinicalTrials.gov

    2014-04-29

    To Demonstrate That the Closed Loop System Can be Used Safely Over a Few Consecutive Days.; To Assess Effectiveness in Maintaining Patients' Glucose Levels in the Target Range of 70 to 180 mg/dl, Measured by Blood Glucose Sensor.; To Evaluate the User Experience With a Closed Loop System

  8. Faraday induction when a loop grazes a magnet

    NASA Astrophysics Data System (ADS)

    Binder, P.-M.; Holub, Eric M.; Roberts, Marc F.; Wasser, Valerie K.

    2016-07-01

    We perform an experiment to detect electromagnetic induction when a magnet and a loop approach each other in grazing motion, oriented parallel to each other and with one magnet pole pointing at the loop. A weak emf is detected with a three-peak structure, which we explain. We also describe how a more complicated structure can arise.

  9. NETL - Chemical Looping Reactor

    SciTech Connect

    2013-07-24

    NETL's Chemical Looping Reactor unit is a high-temperature integrated CLC process with extensive instrumentation to improve computational simulations. A non-reacting test unit is also used to study solids flow at ambient temperature. The CLR unit circulates approximately 1,000 pounds per hour at temperatures around 1,800 degrees Fahrenheit.

  10. NETL - Chemical Looping Reactor

    ScienceCinema

    None

    2014-06-26

    NETL's Chemical Looping Reactor unit is a high-temperature integrated CLC process with extensive instrumentation to improve computational simulations. A non-reacting test unit is also used to study solids flow at ambient temperature. The CLR unit circulates approximately 1,000 pounds per hour at temperatures around 1,800 degrees Fahrenheit.

  11. Loops: Twisting and Scaling

    NASA Astrophysics Data System (ADS)

    Walsh, R. W.

    2004-01-01

    Loop-like structures are the fundamental magnetic building blocks of the solar atmosphere. Recent space-based EUV and X-ray satellite observations (from Yohkoh SOHO and TRACE) have challenged the view that these features are simply static gravitationally stratified plasma pipes. Rather it is now surmised that each loop may consist of a bundle of fine plasma threads that are twisted around one another and can brighten independently. This invited review will outline the latest developments in ""untangling"" the topology of these features through three dimensional magnetohydrodynamic modelling and how their properties are being deduced through spectroscopic observations coupled to theoretical scaling laws. In particular recent interest has centred on how the observed thermal profile along loops can be employed as a tool to diagnose any localised energy input to the structure and hence constrain the presence of a particular coronal heating mechanism. The dynamic nature of loops will be highlighted and the implications of superior resolution plasma thread observations (whether spatial temporal or spectral) from future space missions (SolarB STEREO SDO and Solar Orbiter) will be discussed.

  12. RNA in the Loop

    PubMed Central

    Kung, Johnny T.Y.; Lee, Jeannie T.

    2013-01-01

    Long noncoding RNAs (lncRNAs) have been implicated in a variety of biological roles, particularly as cis or trans gene expression regulators. Reporting recently in Nature, Lai et al. (2013) show that a class of gene-activating lncRNAs combines two gene regulation paradigms: enhancer-directed chromosomal looping and RNA-mediated protein effector recruitment. PMID:23537627

  13. Closing the Loop Sampler.

    ERIC Educational Resources Information Center

    California Integrated Waste Management Board, Sacramento.

    Closing the Loop (CTL) is a science curriculum designed to introduce students to integrated waste management through awareness. This document presents five lesson plans focusing on developing an understanding of natural resources, solid wastes, conservation, and the life of landfills. Contents include: (1) "What Are Natural Resources?"; (2)…

  14. Assessment of Habitat Suitability Is Affected by Plant-Soil Feedback: Comparison of Field and Garden Experiment

    PubMed Central

    Hemrová, Lucie; Knappová, Jana; Münzbergová, Zuzana

    2016-01-01

    Background Field translocation experiments (i.e., the introduction of seeds or seedlings of different species into different localities) are commonly used to study habitat associations of species, as well as factors limiting species distributions and local abundances. Species planted or sown in sites where they naturally occur are expected to perform better or equally well compared to sites at which they do not occur or are rare. This, however, contrasts with the predictions of the Janzen-Connell hypothesis and commonly reported intraspecific negative plant-soil feedback. The few previous studies indicating poorer performance of plants at sites where they naturally occur did not explore the mechanisms behind this pattern. Aims and Methods In this study, we used field translocation experiments established using both seeds and seedlings to study the determinants of local abundance of four dominant species in grasslands. To explore the possible effects of intraspecific negative plant-soil feedback on our results, we tested the effect of local species abundance on the performance of the plants in the field experiment. In addition, we set up a garden experiment to explore the intensity of intraspecific as well as interspecific feedback between the dominants used in the experiment. Key Results In some cases, the distribution and local abundances of the species were partly driven by habitat conditions at the sites, and species performed better at their own sites. However, the prevailing pattern was that the local dominants performed worse at sites where they naturally occur than at any other sites. Moreover, the success of plants in the field experiment was lower in the case of higher intraspecific abundance prior to experimental setup. In the garden feedback experiment, two of the species performed significantly worse in soils conditioned by their species than in soils conditioned by the other species. In addition, the performance of the plants was significantly

  15. Iterative LQG Controller Design Through Closed-Loop Identification

    NASA Technical Reports Server (NTRS)

    Hsiao, Min-Hung; Huang, Jen-Kuang; Cox, David E.

    1996-01-01

    This paper presents an iterative Linear Quadratic Gaussian (LQG) controller design approach for a linear stochastic system with an uncertain open-loop model and unknown noise statistics. This approach consists of closed-loop identification and controller redesign cycles. In each cycle, the closed-loop identification method is used to identify an open-loop model and a steady-state Kalman filter gain from closed-loop input/output test data obtained by using a feedback LQG controller designed from the previous cycle. Then the identified open-loop model is used to redesign the state feedback. The state feedback and the identified Kalman filter gain are used to form an updated LQC controller for the next cycle. This iterative process continues until the updated controller converges. The proposed controller design is demonstrated by numerical simulations and experiments on a highly unstable large-gap magnetic suspension system.

  16. Slipping magnetic reconnection in coronal loops.

    PubMed

    Aulanier, Guillaume; Golub, Leon; Deluca, Edward E; Cirtain, Jonathan W; Kano, Ryouhei; Lundquist, Loraine L; Narukage, Noriyuki; Sakao, Taro; Weber, Mark A

    2007-12-01

    Magnetic reconnection of solar coronal loops is the main process that causes solar flares and possibly coronal heating. In the standard model, magnetic field lines break and reconnect instantaneously at places where the field mapping is discontinuous. However, another mode may operate where the magnetic field mapping is continuous but shows steep gradients: The field lines may slip across each other. Soft x-ray observations of fast bidirectional motions of coronal loops, observed by the Hinode spacecraft, support the existence of this slipping magnetic reconnection regime in the Sun's corona. This basic process should be considered when interpreting reconnection, both on the Sun and in laboratory-based plasma experiments. PMID:18063789

  17. COLD TEST LOOP INTEGRATED TEST LOOP RESULTS

    SciTech Connect

    Abraham, TJ

    2003-10-22

    A testing facility (Cold Test Loop) was constructed and operated to demonstrate the efficacy of the Accelerated Waste Retrieval (AWR) Project's planned sluicing approach to the remediation of Silos 1 and 2 at the Fernald Environmental Management Project near Cincinnati, Ohio. The two silos contain almost 10,000 tons of radium-bearing low-level waste, which consists primarily of solids of raffinates from processing performed on ores from the Democratic Republic of Congo (commonly referred to as ''Belgium Congo ores'') for the recovery of uranium. These silos are 80 ft in diameter, 36 ft high to the center of the dome, and 26.75 ft to the top of the vertical side walls. The test facility contained two test systems, each designed for a specific purpose. The first system, the Integrated Test Loop (ITL), a near-full-scale plant including the actual equipment to be installed at the Fernald Site, was designed to demonstrate the sluicing operation and confirm the selection of a slurry pump, the optimal sluicing nozzle operation, and the preliminary design material balance. The second system, the Component Test Loop (CTL), was designed to evaluate many of the key individual components of the waste retrieval system over an extended run. The major results of the initial testing performed during July and August 2002 confirmed that the AWR approach to sluicing was feasible. The ITL testing confirmed the following: (1) The selected slurry pump (Hazleton 3-20 type SHW) performed well and is suitable for AWR application. However, the pump's motor should be upgraded to a 200-hp model and be driven by a 150-hp variable-frequency drive (VFD). A 200-hp VFD is not much more expensive and would allow the pump to operate at full speed. (2) The best nozzle performance was achieved by using 15/16-in. nozzles operated alternately. This configuration appeared to most effectively mine the surrogate. (3) The Solartron densitometer, which was tested as an alternative mass flow measurement

  18. Mechanics of Protein-Mediated DNA Looping

    NASA Astrophysics Data System (ADS)

    Meiners, Jens-Christian

    2009-03-01

    The formation of looped DNA-protein complexes in which a protein or protein assembly binds to multiple distant operator sites on the DNA is a common feature for many regulatory schemes on the transcriptional level. In a living cell, a multitude of mechanical forces and constraints act on these complexes, and it is imperative to understand their effects on biological function. For this aim, we study the lactose repressor as a model system for protein-mediated DNA looping in single-molecule experiments. Using a novel axial constant-force optical trapping scheme that allows us to manipulate sub-micron DNA fragments with well-controlled forces down to the 10 fN range, we show that mechanical tension in the substrate DNA of hundred femtonewton is sufficient to disrupt the loop formation process, which suggests that such mechanical tension may provide a mechanical pathway to controlling gene expression in vivo. From the force sensitivity of the loop formation process, we can also infer the topology of the looped complex; in our case an antiparallel conformation. In addition, we will present new tethered-particle microscopy data that shows lifetimes of the looped complexes that are two to three orders of magnitude shorter than those measured in biochemical competition assays and discuss possible interpretations, including the suggestion that operator binding of the lactose repressor tetramer leads to a destabilization of the dimer-dimer interface and that thus the loop breakdown process is mostly a dissociation of the tetramer into two dimers, instead, as widely assumed, an unbinding of the tetramer from the DNA.

  19. Maternal Employment Experiences Affect Children's Behavior via Mood, Cognitive Difficulties, and Parenting Behavior: A Reply to Otto and Atkinson.

    ERIC Educational Resources Information Center

    MacEwen, Karyl E.; Barling, Julian

    1994-01-01

    Reacts to commentary by Otto and Atkinson concerning MacEwen and Barling's 1991 article on effects of maternal employment experiences on children's behavior. Argues that analyses reported in original article did appropriately test hypotheses outlined in paper and that conclusions were appropriate and substantively similar to conclusions presented…

  20. Transforming Misconceptions: Using Transformative Experience to Promote Positive Affect and Conceptual Change in Students Learning about Biological Evolution

    ERIC Educational Resources Information Center

    Heddy, Benjamin C.; Sinatra, Gale M.

    2013-01-01

    Teaching and learning about complex scientific content, such as biological evolution, is challenging in part because students have a difficult time seeing the relevance of evolution in their everyday lives. The purpose of this study was to explore the effectiveness of the Teaching for Transformative Experiences in Science (TTES) model (Pugh, 2002)…

  1. Gaining a "Sense of Place": Students' Affective Experiences of Place Leading to Transformative Learning on International Fieldwork

    ERIC Educational Resources Information Center

    Simm, David; Marvell, Alan

    2015-01-01

    This paper reveals the extent to which undergraduate students demonstrate transformative learning whilst on international fieldwork in Barcelona, Spain. Groups of students create a series of discrete active learning situations that allow them and their peers to engage more fully with their locale and in turn experience a deeper understanding of…

  2. Teachers' and Caregivers' Perceptions of Gender Differences in Educational Experiences of Children Affected by Parental AIDS in Western Kenya

    ERIC Educational Resources Information Center

    Jepkemboi, Grace; Aldridge, Jerry

    2009-01-01

    The purpose of this qualitative case study was to describe the perceptions of teachers and caregivers concerning gender differences in the educational experiences of children influenced by the HIV status of their parents or orphaned by AIDS in 7 orphanage schools of Western Kenya. 12 teachers and 8 caregivers participated in the study. Data were…

  3. Girls' and Boys' Mathematics Achievement, Affect, and Experiences: Findings from ECLS-K

    ERIC Educational Resources Information Center

    Lubienski, Sarah T.; Robinson, Joseph P.; Crane, Corinna C.; Ganley, Colleen M.

    2013-01-01

    Amid debates about the continued salience of gender in mathematics, this report summarizes an IES-funded investigation of gender-related patterns in the Early Childhood Longitudinal Study-Kindergarten Class of 1998-99 (ECLS-K). Girls' and boys' mathematics achievement, confidence, and interest were examined, along with experiences at…

  4. Teacher Educational Experiences Program: An Affective-Based Program of Self-Selection for Undergraduate Teacher Candidates.

    ERIC Educational Resources Information Center

    Saint Francis Coll., Fort Wayne, IN.

    The Teacher Educational Experiences Program (TEE) from St. Francis College, Fort Wayne, Indiana was a 1973 Distinguished Achievement Award entry. The program was based on the concept that prospective teachers should be provided with extensive opportunities to work and observe in formal and informal educational settings early in their academic…

  5. Unraveling the Relationship between Motor Symptoms, Affective States and Contextual Factors in Parkinson’s Disease: A Feasibility Study of the Experience Sampling Method

    PubMed Central

    Kuijf, Mark L.; Van Oostenbrugge, Robert J.; van Os, Jim; Leentjens, Albert F. G.

    2016-01-01

    Background In Parkinson's disease (PD), the complex relationship between motor symptoms, affective states, and contextual factors remains to be elucidated. The Experience Sampling Method provides (ESM) a novel approach to this issue. Using a mobile device with a special purpose application (app), motor symptoms, affective states and contextual factors are assessed repeatedly at random moments in the flow of daily life, yielding an intensive time series of symptoms and experience. The aim of this study was to study the feasibility of this method. Method We studied the feasibility of a five-day period of ESM in PD and its ability to objectify diurnal fluctuations in motor symptom severity and their relation with affect and contextual factors in five PD patients with motor fluctuations. Results Participants achieved a high compliance, with 84% of assessment moments completed without disturbance of daily activities. The utility of the device was rated 8 on a 10-point scale. We were able to capture extensive diurnal fluctuations that were not revealed by routine clinical assessment. In addition, we were able to detect clinically relevant associations between motor symptoms, emotional fluctuations and contextual factors at an intra-individual level. Conclusions ESM represents a viable and novel approach to elucidate relationships between motor symptoms, affective states and contextual factors at the level of individual subjects. ESM holds promise for clinical practice and scientific research. PMID:26962853

  6. Inner mappings of Bruck loops

    NASA Astrophysics Data System (ADS)

    Kreuzer, Alexander

    1998-01-01

    K-loops have their origin in the theory of sharply 2-transitive groups. In this paper a proof is given that K-loops and Bruck loops are the same. For the proof it is necessary to show that in a (left) Bruck loop the left inner mappings L(b)L(a) L(ab)[minus sign]1 are automorphisms. This paper generalizes results of Glauberman [3], Kist [8] and Kreuzer [9].

  7. Observational evidence for atmospheric modulation of the Loop Current migrations

    NASA Astrophysics Data System (ADS)

    Lindo-Atichati, D.; Sangrà, P.

    2015-12-01

    Recent modeling studies on the shedding of Loop Current rings suggest that the intensification of the dominant zonal wind field delays the detachment of rings and affects the Loop Current migrations. The atmospheric modulation of the Loop Current migrations is analyzed here using reanalysis winds and altimetry-derived observations. A newly developed methodology is applied to locate the Loop Current front, and a wavelet-based semblance analysis is used to explore correlations with atmospheric forcing. The results show that weakening (intensification) of the zonal wind stress in the eastern Gulf of Mexico is related with the Loop Current excursions to the north (south). Semblance analyses confirm negative correlations between the zonal wind stress and the Loop Current migrations during the past 20 years. The intrusions of the Loop Current might involve an increase of the Yucatan Transport, which would balance the westward Rossby wave speed of a growing loop and delay the ring shedding. The results of this study have consequences for the interpretation of the chaotic processes of ring detachment and Loop Current intrusions, which might be modulated by wind stress.

  8. Loop Heat Pipes and Capillary Pumped Loops: An Applications Perspective

    NASA Technical Reports Server (NTRS)

    Butler, Dan; Ku, Jentung; Swanson, Theodore; Obenschain, Arthur F. (Technical Monitor)

    2001-01-01

    Capillary pumped loops (CPLS) and loop heat pipes (LHPS) are versatile two-phase heat transfer devices which have recently gained increasing acceptance in space applications. Both systems work based on the same principles and have very similar designs. Nevertheless, some differences exist in the construction of the evaporator and the hydro-accumulator, and these differences lead to very distinct operating characteristics for each loop. This paper presents comparisons of the two loops from an applications perspective, and addresses their impact on spacecraft design, integration, and test. Some technical challenges and issues for both loops are also addressed.

  9. Distribution of heat flux by working fluid in loop heat pipe

    NASA Astrophysics Data System (ADS)

    Nemec, Patrik; Malcho, Milan

    2016-03-01

    The main topics of article are construction of loop heat pipe, thermal visualization of working fluid dynamics and research results interpretation. The work deals about heat flux transport by working fluid in loop heat pipe from evaporator to condenser evolution. The result of the work give us how the hydrodynamic and thermal processes which take place inside the loop of heat pipe affect on the overall heat transport by loop heat pipe at start-up and during operation.

  10. Closed-loop anesthesia.

    PubMed

    LE Guen, Morgan; Liu, Ngai; Chazot, Thierry; Fischler, Marc

    2016-05-01

    Automated anesthesia which may offer to the physician time to control hemodynamic and to supervise neurological outcome and which may offer to the patient safety and quality was until recently consider as a holy grail. But this field of research is now increasing in every component of general anesthesia (hypnosis, nociception, neuromuscular blockade) and literature describes some successful algorithms - single or multi closed-loop controller. The aim of these devices is to control a predefined target and to continuously titrate anesthetics whatever the patients' co morbidities and surgical events to reach this target. Literature contains many randomized trials comparing manual and automated anesthesia and shows feasibility and safety of this system. Automation could quickly concern other aspects of anesthesia as fluid management and this review proposes an overview of closed-loop systems in anesthesia. PMID:26554614

  11. Melanin-concentrating hormone expression in the rat hypothalamus is not affected in an experiment of prenatal alcohol exposure.

    PubMed

    Chometton, Sandrine; Franchi-Bernard, Gabrielle; Houdayer, Christophe; Mariot, Amandine; Poncet, Fabrice; Fellmann, Dominique; Risold, Pierre-Yves

    2014-08-01

    Alcohol consumption during pregnancy can cause a "fetal alcoholic syndrome" (FAS) in the progeny. This syndrome is characterized by important brain defects often associated to a decreased expression of the morphogenic protein sonic hedgehog (Shh). The goal of this study was to verify if a FAS could modify the differentiation of hypothalamic neurons producing MCH. Indeed, the expression of this peptide and neurons producing it are dependent of a Shh controlled genetic cascade in the embryo. To address this question, female rats received a 15% ethanol solution to drink during pregnancy and lactation. Higher abortion rate and smaller pups at birth confirmed that descendants were affected by this experimental condition. MCH expression was analyzed by RT-qPCR and immunohistochemistry in embryos taken at E11 and E13, or in pups and young adults born from control and alcoholic mothers. MCH expression level, number of MCH neurons or ratio of MCH sub-populations were not modified by our experimental conditions. However, Shh expression was significantly lover at E11 and we also observed that hindbrain serotonergic neurons were affected as reported in the literature. These findings as well as other data from the literature suggest that protective mechanisms are involved to maintain peptide expressions and differentiation of some specific neuron populations in the ventral diencephalon in surviving embryos exposed to ethanol during pregnancy. PMID:25093909

  12. Multisensory integration and the concert experience: An overview of how visual stimuli can affect what we hear

    NASA Astrophysics Data System (ADS)

    Hyde, Jerald R.

    2001-05-01

    It is clear to those who ``listen'' to concert halls and evaluate their degree of acoustical success that it is quite difficult to separate the acoustical response at a given seat from the multi-modal perception of the whole event. Objective concert hall data have been collected for the purpose of finding a link with their related subjective evaluation and ultimately with the architectural correlates which produce the sound field. This exercise, while important, tends to miss the point that a concert or opera event utilizes all the senses of which the sound field and visual stimuli are both major contributors to the experience. Objective acoustical factors point to visual input as being significant in the perception of ``acoustical intimacy'' and with the perception of loudness versus distance in large halls. This paper will review the evidence of visual input as a factor in what we ``hear'' and introduce concepts of perceptual constancy, distance perception, static and dynamic visual stimuli, and the general process of the psychology of the integrated experience. A survey of acousticians on their opinions about the auditory-visual aspects of the concert hall experience will be presented. [Work supported in part from the Veneklasen Research Foundation and Veneklasen Associates.

  13. Verification of Loop Diagnostics

    NASA Technical Reports Server (NTRS)

    Winebarger, A.; Lionello, R.; Mok, Y.; Linker, J.; Mikic, Z.

    2014-01-01

    Many different techniques have been used to characterize the plasma in the solar corona: density-sensitive spectral line ratios are used to infer the density, the evolution of coronal structures in different passbands is used to infer the temperature evolution, and the simultaneous intensities measured in multiple passbands are used to determine the emission measure. All these analysis techniques assume that the intensity of the structures can be isolated through background subtraction. In this paper, we use simulated observations from a 3D hydrodynamic simulation of a coronal active region to verify these diagnostics. The density and temperature from the simulation are used to generate images in several passbands and spectral lines. We identify loop structures in the simulated images and calculate the loop background. We then determine the density, temperature and emission measure distribution as a function of time from the observations and compare with the true temperature and density of the loop. We find that the overall characteristics of the temperature, density, and emission measure are recovered by the analysis methods, but the details of the true temperature and density are not. For instance, the emission measure curves calculated from the simulated observations are much broader than the true emission measure distribution, though the average temperature evolution is similar. These differences are due, in part, to inadequate background subtraction, but also indicate a limitation of the analysis methods.

  14. Chemical Looping Combustion Kinetics

    SciTech Connect

    Edward Eyring; Gabor Konya

    2009-03-31

    One of the most promising methods of capturing CO{sub 2} emitted by coal-fired power plants for subsequent sequestration is chemical looping combustion (CLC). A powdered metal oxide such as NiO transfers oxygen directly to a fuel in a fuel reactor at high temperatures with no air present. Heat, water, and CO{sub 2} are released, and after H{sub 2}O condensation the CO{sub 2} (undiluted by N{sub 2}) is ready for sequestration, whereas the nickel metal is ready for reoxidation in the air reactor. In principle, these processes can be repeated endlessly with the original nickel metal/nickel oxide participating in a loop that admits fuel and rejects ash, heat, and water. Our project accumulated kinetic rate data at high temperatures and elevated pressures for the metal oxide reduction step and for the metal reoxidation step. These data will be used in computational modeling of CLC on the laboratory scale and presumably later on the plant scale. The oxygen carrier on which the research at Utah is focused is CuO/Cu{sub 2}O rather than nickel oxide because the copper system lends itself to use with solid fuels in an alternative to CLC called 'chemical looping with oxygen uncoupling' (CLOU).

  15. Loops of Jupiter

    NASA Astrophysics Data System (ADS)

    Opolski, Antoni

    2014-12-01

    Professor Antoni Opolski was actively interested in astronomy after his retirement in 1983. He especially liked to study the works of the famous astronomer Copernicus getting inspiration for his own work. Opolski started his work on planetary loops in 2011 continuing it to the end of 2012 . During this period calculations, drawings, tables, and basic descriptions of all the planets of the Solar System were created with the use of a piece of paper and a pencil only. In 2011 Antoni Opolski asked us to help him in editing the manuscript and preparing it for publication. We have been honored having the opportunity to work on articles on planetary loops with Antoni Opolski in his house for several months. In the middle of 2012 the detailed material on Jupiter was ready. However, professor Opolski improved the article by smoothing the text and preparing new, better drawings. Finally the article ''Loops of Jupiter'', written by the 99- year old astronomer, was published in the year of his 100th birthday.

  16. Inhibitory Control, but Not Prolonged Object-Related Experience Appears to Affect Physical Problem-Solving Performance of Pet Dogs.

    PubMed

    Müller, Corsin A; Riemer, Stefanie; Virányi, Zsófia; Huber, Ludwig; Range, Friederike

    2016-01-01

    Human infants develop an understanding of their physical environment through playful interactions with objects. Similar processes may influence also the performance of non-human animals in physical problem-solving tasks, but to date there is little empirical data to evaluate this hypothesis. In addition or alternatively to prior experiences, inhibitory control has been suggested as a factor underlying the considerable individual differences in performance reported for many species. Here we report a study in which we manipulated the extent of object-related experience for a cohort of dogs (Canis familiaris) of the breed Border Collie over a period of 18 months, and assessed their level of inhibitory control, prior to testing them in a series of four physical problem-solving tasks. We found no evidence that differences in object-related experience explain variability in performance in these tasks. It thus appears that dogs do not transfer knowledge about physical rules from one physical problem-solving task to another, but rather approach each task as a novel problem. Our results, however, suggest that individual performance in these tasks is influenced in a complex way by the subject's level of inhibitory control. Depending on the task, inhibitory control had a positive or a negative effect on performance and different aspects of inhibitory control turned out to be the best predictors of individual performance in the different tasks. Therefore, studying the interplay between inhibitory control and problem-solving performance will make an important contribution to our understanding of individual and species differences in physical problem-solving performance. PMID:26863141

  17. Inhibitory Control, but Not Prolonged Object-Related Experience Appears to Affect Physical Problem-Solving Performance of Pet Dogs

    PubMed Central

    Müller, Corsin A.; Riemer, Stefanie; Virányi, Zsófia; Huber, Ludwig; Range, Friederike

    2016-01-01

    Human infants develop an understanding of their physical environment through playful interactions with objects. Similar processes may influence also the performance of non-human animals in physical problem-solving tasks, but to date there is little empirical data to evaluate this hypothesis. In addition or alternatively to prior experiences, inhibitory control has been suggested as a factor underlying the considerable individual differences in performance reported for many species. Here we report a study in which we manipulated the extent of object-related experience for a cohort of dogs (Canis familiaris) of the breed Border Collie over a period of 18 months, and assessed their level of inhibitory control, prior to testing them in a series of four physical problem-solving tasks. We found no evidence that differences in object-related experience explain variability in performance in these tasks. It thus appears that dogs do not transfer knowledge about physical rules from one physical problem-solving task to another, but rather approach each task as a novel problem. Our results, however, suggest that individual performance in these tasks is influenced in a complex way by the subject’s level of inhibitory control. Depending on the task, inhibitory control had a positive or a negative effect on performance and different aspects of inhibitory control turned out to be the best predictors of individual performance in the different tasks. Therefore, studying the interplay between inhibitory control and problem-solving performance will make an important contribution to our understanding of individual and species differences in physical problem-solving performance. PMID:26863141

  18. Understanding how drivers learn to anticipate risk on the road: A laboratory experiment of affective anticipation of road hazards.

    PubMed

    Kinnear, Neale; Kelly, Steve W; Stradling, Stephen; Thomson, James

    2013-01-01

    This study examines whether there is evidence that converging theories from the domains of risk and decision making, neuroscience, and psychology can improve our understanding of how drivers learn to appraise on-the-road hazards. Within the domain of decision making it is suggested that there are two distinct ways in which humans appraise risk: risk as feelings and risk as analysis. Meanwhile, current neurological theory, in the form of the Somatic Marker Hypothesis, supports the role of feelings and emotion as an evolved automated system of human risk appraisal that biases judgment and decision making. This study used skin conductance responses (SCRs) to measure learner, novice and experienced drivers' psycho-physiological responses to the development of driving hazards. Experienced drivers were twice as likely to produce an SCR to developing hazards as novice drivers and three times as likely when compared with learner drivers. These differences maintained significance when age, gender and exposure were controlled for. Further analysis revealed that novice drivers who had less than 1000 miles driving experience had anticipatory physiological responses similar to learner drivers, whereas novices who had driven more than 1000 miles had scores approaching those of experienced drivers. This demonstrated a learning curve mediated by driving experience supporting experiential learning as proposed within the Somatic Marker Hypothesis. A differentiation between cognitive and psycho-physiological responses was also found supporting theory that distinguishes between conscious and non-conscious risk appraisal. PMID:22963999

  19. Sandia Sodium Purification Loop (SNAPL) description and operations manual

    SciTech Connect

    Acton, R.U.; Weatherbee, R.L.; Smith, L.A.; Mastin, F.L.; Nowotny, K.E.

    1985-08-01

    Sandia's Sodium Purification Loop was constructed to purify sodium for fast reactor safety experiments. An oxide impurity of less than 10 parts per million is required by these in-pile experiments. Commercial, reactor grade sodium is purchased in 180 kg drums. The sodium is melted and transferred into the unit. The unit is of a loop design and purification is accomplished by ''cold trapping.'' Sodium purified in this loop has been chemically analysed at one part per million oxygen by weight. 5 refs., 22 figs., 7 tabs.

  20. Intrinsic flexibility of snRNA hairpin loops facilitates protein binding.

    PubMed

    Rau, Michael; Stump, W Tom; Hall, Kathleen B

    2012-11-01

    Stem-loop II of U1 snRNA and Stem-loop IV of U2 snRNA typically have 10 or 11 nucleotides in their loops. The fluorescent nucleobase 2-aminopurine was used as a substitute for the adenines in each loop to probe the local and global structures and dynamics of these unusually long loops. Using steady-state and time-resolved fluorescence, we find that, while the bases in the loops are stacked, they are able to undergo significant local motion on the picosecond/nanosecond timescale. In addition, the loops have a global conformational change at low temperatures that occurs on the microsecond timescale, as determined using laser T-jump experiments. Nucleobase and loop motions are present at temperatures far below the melting temperature of the hairpin stem, which may facilitate the conformational change required for specific protein binding to these RNA loops. PMID:23012481

  1. Current control loop of 3-phase grid-connected inverter

    NASA Astrophysics Data System (ADS)

    Jabbar, A. F.; Mansor, M.

    2013-06-01

    This paper presents a comparative study of current control loop in 3-phase inverter which is used to control the active and reactive output power. Generally, current control loop, power control loop and phase lock-loop are the conventional parameters that can be found in an inverter system controlled by the conventional linear control type, for instance proportional (P), integral (I) and derivative (D). If the grid remains stable throughout the day, PID control can be use. However variation of magnitude, frequency, voltage dips, transient, and other related power quality issues occur in a 3-phase grid often affects the control loop. This paper aims to provide an overall review on the available current control techniques used in grid connected system.

  2. Atmospheric CO2 level affects plants' carbon use efficiency: insights from a 13C labeling experiment on sunflower stands

    NASA Astrophysics Data System (ADS)

    Gong, Xiaoying; Schäufele, Rudi; Schnyder, Hans

    2015-04-01

    The increase of atmospheric CO2 concentration has been shown to stimulate plant photosynthesis and (to a lesser extent) growth, thereby acting as a possible sink for the additional atmospheric CO2. However, this effect is dependent on the efficiency with which plants convert atmospheric carbon into biomass carbon, since a considerable proportion of assimilated carbon is returned to the atmosphere via plant respiration. As a core parameter for carbon cycling, carbon use efficiency of plants (CUE, the ratio of net primary production to gross primary production) quantifies the proportion of assimilated carbon that is incorporated into plant biomass. CUE has rarely been assessed based on measurements of complete carbon balance, due to methodological difficulties in measuring respiration rate of plants in light. Moreover, foliar respiration is known to be inhibited in light, thus foliar respiration rate is generally lower in light than in dark. However, this phenomenon, termed as inhibition of respiration in light (IRL), has rarely been assessed at the stand-scale and been incorporated into the calculation of CUE. Therefore, how CUE responses to atmospheric CO2 levels is still not clear. We studied CUE of sunflower stands grown at sub-ambient CO2 level (200 μmol mol-1) and elevated CO2 level (1000 μmol mol-1) using mesocosm-scale gas exchange facilities which enabled continuous measurements of 13CO2/12CO2 exchange. Appling steady-state 13C labeling, fluxes of respiration and photosynthesis in light were separated, and tracer kinetic in respiration was analyzed. This study provides the first data on CUE at a mesocosm-level including respiration in light in different CO2 environments. We found that CUE of sunflower was lower at an elevated CO2 level than at a sub-ambient CO2 level; and the ignorance of IRL lead to erroneous estimations of CUE. Variation in CUE at atmospheric CO2 levels was attributed to several mechanisms. In this study, CO2 enrichment i) affected the

  3. Prevalence of psychotic-like experiences in young adults with social anxiety disorder and correlation with affective dysregulation.

    PubMed

    Armando, Marco; Lin, Ashleigh; Girardi, Paolo; Righetti, Valentino; Dario, Claudia; Saba, Riccardo; Decrescenzo, Franco; Mazzone, Luigi; Vicari, Stefano; Birchwood, Maximillian; Fiori Nastro, Paolo

    2013-12-01

    Social anxiety disorder (SAD) is associated with psychotic-like experiences (PLEs) and is a frequent diagnosis in the prodromal phases of psychosis. We investigated whether psychopathological factors could discriminate which subjects with SAD are more likely to develop PLEs. A sample of 128 young adults with SAD was split into two subsamples according to the presence of clinically relevant PLEs. Correlations between PLEs and other psychopathological markers were explored. The SAD with PLEs group showed higher level of anxiety, depression, and intolerance of uncertainty (IU) compared with the SAD without PLEs group. A limitation of this study is that the cross-sectional design precluded the analysis of causality. In our sample, the presence of PLEs is related to higher levels of depression, anxiety, and IU. The current findings are consistent with hypotheses suggesting that cognitive disturbances, together with social anxiety, may result in PLEs. PMID:24284640

  4. Feeding Experience Affects the Behavioral Response of Polyphagous Gypsy Moth Caterpillars to Herbivore-induced Poplar Volatiles.

    PubMed

    McCormick, Andrea C; Reinecke, Andreas; Gershenzon, Jonathan; Unsicker, Sybille B

    2016-05-01

    Plant volatiles influence host selection of herbivorous insects. Since volatiles often vary in space and time, herbivores (especially polyphagous ones) may be able to use these compounds as cues to track variation in host plant quality based on their innate abilities and previous experience. We investigated the behavioral response of naïve (fed on artificial diet) and experienced (fed on poplar) gypsy moth (Lymantria dispar) caterpillars, a polyphagous species, towards constitutive and herbivore-induced black poplar (Populus nigra) volatiles at different stages of herbivore attack. In Y-tube olfactometer assays, both naïve and experienced caterpillars were attracted to constitutive volatiles and volatiles released after short-term herbivory (up to 6 hr). Naïve caterpillars also were attracted to volatiles released after longer-term herbivory (24-30 hr), but experienced caterpillars preferred the odor of undamaged foliage. A multivariate statistical analysis comparing the volatile emission of undamaged plants vs. plants after short and longer-term herbivory, suggested various compounds as being responsible for distinguishing between the odors of these plants. Ten compounds were selected for individual testing of caterpillar behavioral responses in a four-arm olfactometer. Naïve caterpillars spent more time in arms containing (Z)-3-hexenol and (Z)-3-hexenyl acetate than in solvent permeated arms, while avoiding benzyl cyanide and salicyl aldehyde. Experienced caterpillars avoided benzyl cyanide and preferred (Z)-3-hexenyl acetate and the homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) over solvent. Only responses to DMNT were significantly different when comparing experienced and naïve caterpillars. The results show that gypsy moth caterpillars display an innate behavioral response towards constitutive and herbivore-induced plant volatiles, but also that larval behavior is plastic and can be modulated by previous feeding experience. PMID:27170157

  5. Factors affecting adherence to treatment and follow-up of burns in children: A single centre experience

    PubMed Central

    Sener, Mustafa Talip; Aydın, Osman Enver; Ançı, Yuksel; Kara, Murat; Tan, Onder; Kok, Ahmet Nezih

    2015-01-01

    Aim: Children are prone to burn injury. Burns can be seen as a part of child abuse. The aim of this study was to investigate the factors affecting adherence to the treatment of burn patients, and to emphasize the role of the physician in identifying children's non-accidental burn injuries. Materials and Methods: Children who were hospitalized in the burn unit were analyzed retrospectively. Results were assessed for significance using the Chi-square test. Results: A total of 189 patients were included. Some patients (n = 52; 27.5%) were discharged against medical advice (DAMA) before completion of treatment. Although we could not demonstrate a relationship between non-accidental etiology and DAMA group, it was significant that these patients did not contact the outpatient clinic after discharge. It was evident from records that two of these cases were abused. The reasoning of the parents in the DAMA group for the early discharge was siblings at home, financial and accommodation problems. Conclusion: Although burns in children commonly occur due to an accident, each burn case should be examined for a non-accidental etiology and findings suggesting abuse should be noted. Physicians should be alert for the detection of signs of burn related child abuse. PMID:26807393

  6. Feasibility of intensive multimodal therapy in infants affected by rhabdoid tumors - experience of the EU-RHAB registry.

    PubMed

    Seeringer, A; Bartelheim, K; Kerl, K; Hasselblatt, M; Leuschner, I; Rutkowski, S; Timmermann, B; Kortmann, R-D; Koscielniak, E; Schneppenheim, R; Warmuth-Metz, M; Gerß, J; Siebert, R; Graf, N; Boos, J; Frühwald, M C

    2014-05-01

    Rhabdoid tumors mainly affect infants and other very young children with a marked vulnerability towards intensive therapy such as invasive surgery, high dose chemotherapy (HDCT) and dose intense radiotherapy. Radiotherapy (RT) is a promising option in rhabdoid tumors but its application in infants remains controversial. Neurocognitive and vascular side effects occur even long after completion of therapy. Therapeutic recommendations suggested by the European Rhabdoid Registry including RT, high dose chemotherapy (HDCT) and methotrexate (MTX) were developed by a consensus committee. Unique to our EU-RHAB database is the ability to analyze data of 64 of 81 registered infants (under one year of age) separate from older children. 20 (age at diagnoses 2-12 months) of these had received radiotherapy. To our knowledge, this is the first report specifically analyzing treatment data of infants suffering from malignant rhabdoid tumors. Our results suggest that radiotherapy significantly increases the mean survival time as well as the 3 year overall survival in infants. We detected a doubling of survival times in infants who received RT. Overall, our results suggest that infants benefit from RT with tolerable acute side effects. Severe long term sequelae likely due to intraventricular MTX and/or RT were reported in 4 patients (leukoencephalopathy). No differences in chemotherapy-related toxicity were observed between infants and children. We suggest that a nihilistic therapeutic approach towards young infants is not warranted and that RT may not be a priori rejected as a therapeutic option in infants. PMID:24633978

  7. THE NEW U. S. IMMIGRANTS: HOW DO THEY AFFECT OUR UNDERSTANDING OF THE AFRICAN-AMERICAN EXPERIENCE?

    PubMed Central

    Bean, Frank D.; Feliciano, Cynthia; Lee, Jennifer; Van Hook, Jennifer

    2011-01-01

    The implications of recent immigration for race relations in the United States depend importantly on family cultural orientations among Mexican Americans and how this group is culturally perceived by Anglos. Because Moynihan's 1965 work (in)famously emphasized the need to change black family culture in order to ameliorate black poverty, his work still holds implications for understanding how cultural orientations affect changing color lines. Unfortunately, his partially insightful analyses inadequately foresaw that policies designed to alleviate poverty through the modification of family cultural patterns are likely to fail without parallel changes in structural opportunities. Similar limitations also often emerge from mis-characterizations of Mexican origin family cultural situations, which all too often are incongruously reified as either being unduly familistic (thus falsely implying Mexican origin families foster self-sufficiency) or largely governed by culture of poverty tendencies (thus inaccurately suggesting Mexican origin families depend on welfare). Here we review research suggesting that Mexican origin families are neither substantially familistic nor disproportionately susceptible to moral hazard, thus indicating that future Mexican origin economic advancement is likely to turn on the availability of structural opportunities. In-depth interviews with Anglos further suggest that Mexicans are not culturally viewed with the same degree of prejudice and discrimination as blacks, implying that the integration of Mexicans into American society, contingent on adequate economic opportunity, will probably progress more steadily than often feared, while that of blacks may proceed more slowly than often expected. PMID:22199397

  8. Burden of lysosomal storage disorders in India: experience of 387 affected children from a single diagnostic facility.

    PubMed

    Sheth, Jayesh; Mistri, Mehul; Sheth, Frenny; Shah, Raju; Bavdekar, Ashish; Godbole, Koumudi; Nanavaty, Nidhish; Datar, Chaitanya; Kamate, Mahesh; Oza, Nrupesh; Ankleshwaria, Chitra; Mehta, Sanjeev; Jackson, Marie

    2014-01-01

    Lysosomal storage disorders (LSDs) are considered to be a rare metabolic disease for the national health forum, clinicians, and scientists. This study aimed to know the prevalence of different LSDs, their geographical variation, and burden on the society. It included 1,110 children from January 2002 to December 2012, having coarse facial features, hepatomegaly or hepatosplenomegaly, skeletal dysplasia, neuroregression, leukodystrophy, developmental delay, cerebral-cerebellar atrophy, and abnormal ophthalmic findings. All subjects were screened for I-cell disease, glycolipid storage disorders (Niemann-Pick disease A/B, Gaucher), and mucopolysaccharide disorders followed by confirmatory lysosomal enzymes study from leucocytes and/or fibroblasts. Niemann-Pick disease-C (NPC) was confirmed by fibroblasts study using filipin stain. Various storage disorders were detected in 387 children (34.8 %) with highest prevalence of glycolipid storage disorders in 48 %, followed by mucopolysaccharide disorders in 22 % and defective sulfatide degradation in 14 % of the children. Less common defects were glycogen degradation defect and protein degradation defect in 5 % each, lysosomal trafficking protein defect in 4 %, and transport defect in 3 % of the patients. This study demonstrates higher incidence of Gaucher disease (16 %) followed by GM2 gangliosidosis that includes Tay-Sachs disease (10 %) and Sandhoff disease (7.8 %) and mucopolysaccharide disorders among all LSDs. Nearly 30 % of the affected children were born to consanguineous parents and this was higher (72 %) in children with Batten disease. Our study also demonstrates two common mutations c.1277_1278insTATC in 14.28 % (4/28) and c.964G>T (p.D322Y) in 10.7 % (3/28) for Tay-Sachs disease in addition to the earlier reported c.1385A>T (p.E462V) mutation in 21.42 % (6/28). PMID:23852624

  9. Similarity Metrics for Closed Loop Dynamic Systems

    NASA Technical Reports Server (NTRS)

    Whorton, Mark S.; Yang, Lee C.; Bedrossian, Naz; Hall, Robert A.

    2008-01-01

    To what extent and in what ways can two closed-loop dynamic systems be said to be "similar?" This question arises in a wide range of dynamic systems modeling and control system design applications. For example, bounds on error models are fundamental to the controller optimization with modern control design methods. Metrics such as the structured singular value are direct measures of the degree to which properties such as stability or performance are maintained in the presence of specified uncertainties or variations in the plant model. Similarly, controls-related areas such as system identification, model reduction, and experimental model validation employ measures of similarity between multiple realizations of a dynamic system. Each area has its tools and approaches, with each tool more or less suited for one application or the other. Similarity in the context of closed-loop model validation via flight test is subtly different from error measures in the typical controls oriented application. Whereas similarity in a robust control context relates to plant variation and the attendant affect on stability and performance, in this context similarity metrics are sought that assess the relevance of a dynamic system test for the purpose of validating the stability and performance of a "similar" dynamic system. Similarity in the context of system identification is much more relevant than are robust control analogies in that errors between one dynamic system (the test article) and another (the nominal "design" model) are sought for the purpose of bounding the validity of a model for control design and analysis. Yet system identification typically involves open-loop plant models which are independent of the control system (with the exception of limited developments in closed-loop system identification which is nonetheless focused on obtaining open-loop plant models from closed-loop data). Moreover the objectives of system identification are not the same as a flight test and

  10. Heterotrophic respiration in drained tropical peat is greatly affected by temperature—a passive ecosystem cooling experiment

    NASA Astrophysics Data System (ADS)

    Jauhiainen, Jyrki; Kerojoki, Otto; Silvennoinen, Hanna; Limin, Suwido; Vasander, Harri

    2014-10-01

    Vast areas of deforested tropical peatlands do not receive noteworthy shading by vegetation, which increases the amount of solar radiation reaching the peat surface. Peat temperature dynamics and heterotrophic carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes were monitored under four shading conditions, i.e. unshaded, 28%, 51% and 90% shading at experiment sites established on reclaimed fallow agricultural- and degraded sites in Central Kalimantan, Indonesia. Groundwater tables on the sites were at about 50 cm depth, the sites were maintained vegetation free and root ingrowth to gas flux monitoring locations was prevented. Half of the four shading areas received NPK-fertilization 50 kg ha-1 for each of N, P and K during the experiment and the other half was unfertilized. Increases in shading created a lasting decrease in peat temperatures, and decreased diurnal temperature fluctuations, in comparison to less shaded plots. The largest peat temperature difference in the topmost 50 cm peat profile was between the unshaded and 90% shaded surface, where the average temperatures at 5 cm depth differed up to 3.7 °C, and diurnal temperatures at 5 cm depth varied up to 4.2 °C in the unshaded and 0.4 °C in the 90% shaded conditions. Highest impacts on the heterotrophic CO2 fluxes caused by the treatments were on agricultural land, where 90% shading from the full exposure resulted in a 33% lower CO2 emission average on the unfertilized plots and a 66% lower emission average on the fertilized plots. Correlation between peat temperature and CO2 flux suggested an approximately 8% (unfertilized) and 25% (fertilized) emissions change for each 1 °C temperature change at 5 cm depth on the agricultural land. CO2 flux responses to the treatments remained low on degraded peatland. Fertilized conditions negatively correlated with N2O efflux with increases in temperature, suggesting a 12-36% lower efflux for each 1 °C increase in peat temperature (at 5 cm depth) at

  11. Coupled dual loop absorption heat pump

    DOEpatents

    Sarkisian, Paul H.; Reimann, Robert C.; Biermann, Wendell J.

    1985-01-01

    A coupled dual loop absorption system which utilizes two separate complete loops. Each individual loop operates at three temperatures and two pressures. This low temperature loop absorber and condenser are thermally coupled to the high temperature loop evaporator, and the high temperature loop condenser and absorber are thermally coupled to the low temperature generator.

  12. Closing the loop.

    PubMed

    Dassau, E; Atlas, E; Phillip, M

    2011-02-01

    Closed-loop algorithms can be found in every aspect of everyday modern life. Automation and control are used constantly to provide safety and to improve quality of life. Closed-loop systems and algorithms can be found in home appliances, automobiles, aviation and more. Can one imagine nowadays driving a car without ABS, cruise control or even anti-sliding control? Similar principles of automation and control can be used in the management of diabetes mellitus (DM). The idea of an algorithmic/technological way to control glycaemia is not new and has been researched for more than four decades. However, recent improvements in both glucose-sensing technology and insulin delivery together with advanced control and systems engineering made this dream of an artificial pancreas possible. The artificial pancreas may be the next big step in the treatment of DM since the use of insulin analogues. An artificial pancreas can be described as internal or external devices that use continuous glucose measurements to automatically manage exogenous insulin delivery with or without other hormones in an attempt to restore glucose regulation in individuals with DM using a control algorithm. This device as described can be internal or external; can use different types of control algorithms with bi-hormonal or uni-hormonal design; and can utilise different ways to administer them. The different designs and implementations have transitioned recently from in silico simulations to clinical evaluation stage with practical applications in mind. This may mark the beginning of a new era in diabetes management with the introduction of semi-closed-loop systems that can prevent or minimise nocturnal hypoglycaemia, to hybrid systems that will manage blood glucose (BG) levels with minimal user intervention to finally fully automated systems that will take the user out of the loop. More and more clinical trials will be needed for the artificial pancreas to become a reality but initial encouraging

  13. Contingency learning is not affected by conflict experience: Evidence from a task conflict-free, item-specific Stroop paradigm.

    PubMed

    Levin, Yulia; Tzelgov, Joseph

    2016-02-01

    A contingency learning account of the item-specific proportion congruent effect has been described as an associative stimulus-response learning process that has nothing to do with controlling the Stroop conflict. As supportive evidence, contingency learning has been demonstrated with response conflict-free stimuli, such as neutral words. However, what gives rise to response conflict and to Stroop interference in general is task conflict. The present study investigated whether task conflict can constitute a trigger or, alternatively, a booster to the contingency learning process. This was done by employing a "task conflict-free" condition (i.e., geometric shapes) and comparing it with a "task conflict" condition (i.e., neutral words). The results showed a significant contingency learning effect in both conditions, refuting the possibility that contingency learning is triggered by the presence of a task conflict. Contingency learning was also not enhanced by the task conflict experience, indicating its complete insensitivity to Stroop conflict(s). Thus, the results showed no evidence that performance optimization as a result of contingency learning is greater under conflict, implying that contingency learning is not recruited to assist the control system to overcome conflict. PMID:26720099

  14. The Dynamic Reactance Interaction – How Vested Interests Affect People’s Experience, Behavior, and Cognition in Social Interactions

    PubMed Central

    Steindl, Christina; Jonas, Eva

    2015-01-01

    In social interactions, individuals may sometimes pursue their own interests at the expense of their interaction partner. Such self-interested behaviors impose a threat to the interaction partner’s freedom to act. The current article investigates this threat in the context of interdependence and reactance theory. We explore how vested interests influence reactance process stages of an advisor–client interaction. We aim to explore the interactional process that evolves. In two studies, participants took the perspective of a doctor (advisor) or a patient (client). In both studies we incorporated a vested interest. In Study 1 (N = 82) we found that in response to a vested interest of their interaction partner, patients indicated a stronger experience of reactance, more aggressive behavioral intentions, and more biased cognitions than doctors. A serial multiple mediation revealed that a vested interest engendered mistrust toward the interaction partner and this mistrust led to an emerging reactance process. Study 2 (N = 207) further demonstrated that doctors expressed their reactance in a subtle way: they revealed a classic confirmation bias when searching for additional information on their preliminary decision preference, indicating stronger defense motivation. We discuss how these findings can help us to understand how social interactions develop dynamically. PMID:26640444

  15. Factors affecting variation in CH4 emission from paddy soils grown with different rice cultivars: A pot experiment

    NASA Astrophysics Data System (ADS)

    Watanabe, Akira; Kimura, Makoto

    1998-08-01

    The growth of rice plants greatly influences CH4 emission from paddy fields through the supply of organic materials such as root exudates and sloughed tissues, the release of oxygen to the root environment, and the transfer of CH4 from the rhizosphere into the atmosphere through the aerenchyma. In the present pot experiments, the effects of the release of water-soluble organic substances from roots, the air space in roots, and the CH4-oxidizing capacity of roots on intervarietal differences in CH4 emission were examined using three Japonica type cultivars (Norin 25, Nipponbare, and Aoinokaze), which differ in morphological properties. The CH4 emission rates varied among the cultivars from mid-July (tillering stage) to the beginning of September (heading stage).Total CH4 emission throughout the rice growth period was largest for Norin 25, followed by Nipponbare, and Aoinokaze. In August, the rate of release of water-soluble organic substances from roots was largest for Norin 25. The air space in roots was also largest in Norin 25 and least in Aoinokaze. The stable carbon isotopic ratios (δ13C) of CH4 in roots were 3-10‰ higher than those in soil in August. The difference in δ13C values of CH4 between roots and soil was largest for Aoinokaze and smallest for Norin 25. In September, the difference in δ13C values of CH4 between roots and soil became small (2-3‰). These findings suggest that the proportion of CH4 oxidation in the rhizosphere was largest in the cultivar which emitted the smallest amount of CH4 and that the proportion became smaller with continued plant growth.

  16. Ekpyrotic loop quantum cosmology

    SciTech Connect

    Wilson-Ewing, Edward

    2013-08-01

    We consider the ekpyrotic paradigm in the context of loop quantum cosmology. In loop quantum cosmology the classical big-bang singularity is resolved due to quantum gravity effects, and so the contracting ekpyrotic branch of the universe and its later expanding phase are connected by a smooth bounce. Thus, it is possible to explicitly determine the evolution of scalar perturbations, from the contracting ekpyrotic phase through the bounce and to the post-bounce expanding epoch. The possibilities of having either one or two scalar fields have been suggested for the ekpyrotic universe, and both cases will be considered here. In the case of a single scalar field, the constant mode of the curvature perturbations after the bounce is found to have a blue spectrum. On the other hand, for the two scalar field ekpyrotic model where scale-invariant entropy perturbations source additional terms in the curvature perturbations, the power spectrum in the post-bounce expanding cosmology is shown to be nearly scale-invariant and so agrees with observations.

  17. The double loop mattress suture

    PubMed Central

    Biddlestone, John; Samuel, Madan; Creagh, Terry; Ahmad, Tariq

    2014-01-01

    An interrupted stitch type with favorable tissue characteristics will reduce local wound complications. We describe a novel high-strength, low-tension repair for the interrupted closure of skin, cartilage, and muscle, the double loop mattress stitch, and compare it experimentally with other interrupted closure methods. The performance of the double loop mattress technique in porcine cartilage and skeletal muscle is compared with the simple, mattress, and loop mattress interrupted sutures in both a novel porcine loading chamber and mechanical model. Wound apposition is assessed by electron microscopy. The performance of the double loop mattress in vivo was confirmed using a series of 805 pediatric laparotomies/laparoscopies. The double loop mattress suture is 3.5 times stronger than the loop mattress in muscle and 1.6 times stronger in cartilage (p ≤ 0.001). Additionally, the double loop mattress reduces tissue tension by 66% compared with just 53% for the loop mattress (p ≤ 0.001). Wound gapping is equal, and wound eversion appears significantly improved (p ≤ 0.001) compared with the loop mattress in vitro. In vivo, the double loop mattress performs as well as the loop mattress and significantly better than the mattress stitch in assessments of wound eversion and dehiscence. There were no episodes of stitch extrusion in our series of patients. The mechanical advantage of its intrinsic pulley arrangement gives the double loop mattress its favorable properties. Wound dehiscence is reduced because this stitch type is stronger and exerts less tension on the tissue than the mattress stitch. We advocate the use of this novel stitch wherever a high-strength, low-tension repair is required. These properties will enhance wound repair, and its application will be useful to surgeons of all disciplines. PMID:24698436

  18. The Effect of Nonspecific Binding of Lambda Repressor on DNA Looping Dynamics

    PubMed Central

    Manzo, Carlo; Zurla, Chiara; Dunlap, David D.; Finzi, Laura

    2012-01-01

    The λ repressor (CI) protein-induced DNA loop maintains stable lysogeny, yet allows efficient switching to lysis. Herein, the kinetics of loop formation and breakdown has been characterized at various concentrations of protein using tethered particle microscopy and a novel, to our knowledge, method of analysis. Our results show that a broad distribution of rate constants and complex kinetics underlie loop formation and breakdown. In addition, comparison of the kinetics of looping in wild-type DNA and DNA with mutated o3 operators showed that these sites may trigger nucleation of nonspecific binding at the closure of the loop. The average activation energy calculated from the rate constant distribution is consistent with a model in which nonspecific binding of CI between the operators shortens their effective separation, thereby lowering the energy barrier for loop formation and broadening the rate constant distribution for looping. Similarly, nonspecific binding affects the kinetics of loop breakdown by increasing the number of loop-securing protein interactions, and broadens the rate constant distribution for this reaction. Therefore, simultaneous increase of the rate constant for loop formation and reduction of that for loop breakdown stabilizes lysogeny. Given these simultaneous changes, the frequency of transitions between the looped and the unlooped state remains nearly constant. Although the loop becomes more stable thermodynamically with increasing CI concentration, it still opens periodically, conferring sensitivity to environmental changes, which may require switching to lytic conditions. PMID:23083719

  19. Modeling of compact loop antennas

    SciTech Connect

    Baity, F.W.

    1987-01-01

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively-tuned resonant double loop (RDL) antennas the model treats stub-tuned resonant double loop antennas. Calculations using the model have been compared with measurements on full-scale mockups of resonant double loop antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and for the Compact Ignition Tokamak (CIT).

  20. Heating Profiles of Coronal Loops

    NASA Astrophysics Data System (ADS)

    Plowman, Joseph; Kankelborg, Charles C.; Martens, Petrus C.

    2016-05-01

    We analyze the temperature and density profiles of coronal loops, as a function of their length, using data from SDO/AIA and Hinode/EIS. The analysis considers the location of the heating along the loop's length, and we conduct a more throrough investigation of our previous preliminary result that heating is concentrated near the loop footpoints. The work now features a larger selection of coronal loops, compared to our previous presentations, and examines their scale-height temperatures to ascertain the extent to which they are hydrostatic.

  1. Modeling of compact loop antennas

    NASA Astrophysics Data System (ADS)

    Baity, F. W.

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively-tuned resonant double loop (RDL) antennas the model treats stub-tuned resonant double loop antennas. Calculations using the model have been compared with measurements on full-scale mockups of resonant double loop antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and for the Compact Ignition Tokamak (CIT).

  2. Unstable anisotropic loop quantum cosmology

    SciTech Connect

    Nelson, William; Sakellariadou, Mairi

    2009-09-15

    We study stability conditions of the full Hamiltonian constraint equation describing the quantum dynamics of the diagonal Bianchi I model in the context of loop quantum cosmology. Our analysis has shown robust evidence of an instability in the explicit implementation of the difference equation, implying important consequences for the correspondence between the full loop quantum gravity theory and loop quantum cosmology. As a result, one may question the choice of the quantization approach, the model of lattice refinement, and/or the role of the ambiguity parameters; all these should, in principle, be dictated by the full loop quantum gravity theory.

  3. Separable Hilbert space in loop quantum gravity

    NASA Astrophysics Data System (ADS)

    Fairbairn, Winston; Rovelli, Carlo

    2004-07-01

    We study the separability of the state space of loop quantum gravity. In the standard construction, the kinematical Hilbert space of the diffeomorphism-invariant states is nonseparable. This is a consequence of the fact that the knot space of the equivalence classes of graphs under diffeomorphisms is noncountable. However, the continuous moduli labeling these classes do not appear to affect the physics of the theory. We investigate the possibility that these moduli could be only the consequence of a poor choice in the fine-tuning of the mathematical setting. We show that by simply choosing a minor extension of the functional class of the classical fields and coordinates, the moduli disappear, the knot classes become countable, and the kinematical Hilbert space of loop quantum gravity becomes separable.

  4. Loop-the-Loop: Bringing Theory into Practice

    ERIC Educational Resources Information Center

    Suwonjandee, N.; Asavapibhop, B.

    2012-01-01

    During the Thai high-school physics teacher training programme, we used an aluminum loop-the-loop system built by the Institute for the Promotion of Teaching Science and Technology (IPST) to demonstrate a circular motion and investigate the concept of the conservation of mechanical energy. There were 27 high-school teachers from three provinces,…

  5. Vortex loops and Majoranas

    SciTech Connect

    Chesi, Stefano; Jaffe, Arthur; Loss, Daniel; Pedrocchi, Fabio L.

    2013-11-15

    We investigate the role that vortex loops play in characterizing eigenstates of interacting Majoranas. We give some general results and then focus on ladder Hamiltonian examples as a test of further ideas. Two methods yield exact results: (i) A mapping of certain spin Hamiltonians to quartic interactions of Majoranas shows that the spectra of these two examples coincide. (ii) In cases with reflection-symmetric Hamiltonians, we use reflection positivity for Majoranas to characterize vortices in the ground states. Two additional methods suggest wider applicability of these results: (iii) Numerical evidence suggests similar behavior for certain systems without reflection symmetry. (iv) A perturbative analysis also suggests similar behavior without the assumption of reflection symmetry.

  6. Dynamic PID loop control

    SciTech Connect

    Pei, L.; Klebaner, A.; Theilacker, J.; Soyars, W.; Martinez, A.; Bossert, R.; DeGraff, B.; Darve, C.; /Fermilab

    2011-06-01

    The Horizontal Test Stand (HTS) SRF Cavity and Cryomodule 1 (CM1) of eight 9-cell, 1.3GHz SRF cavities are operating at Fermilab. For the cryogenic control system, how to hold liquid level constant in the cryostat by regulation of its Joule-Thompson JT-valve is very important after cryostat cool down to 2.0 K. The 72-cell cryostat liquid level response generally takes a long time delay after regulating its JT-valve; therefore, typical PID control loop should result in some cryostat parameter oscillations. This paper presents a type of PID parameter self-optimal and Time-Delay control method used to reduce cryogenic system parameters oscillation.

  7. Uranyl Nitrate Flow Loop

    SciTech Connect

    Ladd-Lively, Jennifer L

    2008-10-01

    The objectives of the work discussed in this report were to: (1) develop a flow loop that would simulate the purified uranium-bearing aqueous stream exiting the solvent extraction process in a natural uranium conversion plant (NUCP); (2) develop a test plan that would simulate normal operation and disturbances that could be anticipated in an NUCP; (3) use the flow loop to test commercially available flowmeters for use as safeguards monitors; and (4) recommend a flowmeter for production-scale testing at an NUCP. There has been interest in safeguarding conversion plants because the intermediate products [uranium dioxide (UO{sub 2}), uranium tetrafluoride (UF{sub 4}), and uranium hexafluoride (UF{sub 6})] are all suitable uranium feedstocks for producing special nuclear materials. Furthermore, if safeguards are not applied virtually any nuclear weapons program can obtain these feedstocks without detection by the International Atomic Energy Agency (IAEA). Historically, IAEA had not implemented safeguards until the purified UF{sub 6} product was declared as feedstock for enrichment plants. H. A. Elayat et al. provide a basic definition of a safeguards system: 'The function of a safeguards system on a chemical conversion plant is in general terms to verify that no useful nuclear material is being diverted to use in a nuclear weapons program'. The IAEA now considers all highly purified uranium compounds as candidates for safeguarding. DOE is currently interested in 'developing instruments, tools, strategies, and methods that could be of use to the IAEA in the application of safeguards' for materials found in the front end of the nuclear fuel cycle-prior to the production of the uranium hexafluoride or oxides that have been the traditional starting point for IAEA safeguards. Several national laboratories, including Oak Ridge, Los Alamos, Lawrence Livermore, and Brookhaven, have been involved in developing tools or techniques for safeguarding conversion plants. This study

  8. Formation of chromosomal domains in interphase by loop extrusion

    NASA Astrophysics Data System (ADS)

    Fudenberg, Geoffrey

    While genomes are often considered as one-dimensional sequences, interphase chromosomes are organized in three dimensions with an essential role for regulating gene expression. Recent studies have shown that Topologically Associating Domains (TADs) are fundamental structural and functional building blocks of human interphase chromosomes. Despite observations that architectural proteins, including CTCF, demarcate and maintain the borders of TADs, the mechanisms underlying TAD formation remain unknown. Here we propose that loop extrusion underlies the formation TADs. In this process, cis-acting loop-extruding factors, likely cohesins, form progressively larger loops, but stall at TAD boundaries due to interactions with boundary proteins, including CTCF. This process dynamically forms loops of various sizes within but not between TADs. Using polymer simulations, we find that loop extrusion can produce TADs as determined by our analyses of the highest-resolution experimental data. Moreover, we find that loop extrusion can explain many diverse experimental observations, including: the preferential orientation of CTCF motifs and enrichments of architectural proteins at TAD boundaries; TAD boundary deletion experiments; and experiments with knockdown or depletion of CTCF, cohesin, and cohesin-loading factors. Together, the emerging picture from our work is that TADs are formed by rapidly associating, growing, and dissociating loops, presenting a clear framework for understanding interphase chromosomal organization.

  9. Lateral spike conduction velocity in the visual cortex affects spatial range of synchronization and receptive field size without visual experience: a learning model with spiking neurons.

    PubMed

    Saam, M; Eckhorn, R

    2000-07-01

    Classical receptive fields (cRF) increase in size from the retina to higher visual centers. The present work shows how temporal properties, in particular lateral spike velocity and spike input correlation, can affect cRF size and position without visual experience. We demonstrate how these properties are related to the spatial range of cortical synchronization if Hebbian learning dominates early development. For this, a largely reduced model of two successive levels of the visual cortex is developed (e.g., areas V1 and V2). It consists of retinotopic networks of spiking neurons with constant spike velocity in lateral connections. Feedforward connections between level 1 and 2 are additive and determine cRF size and shape, while lateral connections within level 1 are modulatory and affect the cortical range of synchronization. Input during development is mimicked by spike trains with spatially homogeneous properties and a confined temporal correlation width. During learning, the homogeneous lateral coupling shrinks to limited coupling structures defining synchronization and related association fields (AF). The size of level-1 synchronization fields determines the lateral coupling range of developing level-1-to-2 connections and, thus, the size of level-2 cRFs, even if the feedforward connections have distance-independent delays. AFs and cRFs increase with spike velocity in the lateral network and temporal correlation width of the input. Our results suggest that AF size of V1 and cRF size of V2 neurons are confined during learning by the temporal width of input correlations and the spike velocity in lateral connections without the need of visual experience. During learning from visual experience, a similar influence of AF size on the cRF size may be operative at successive levels of processing, including other parts of the visual system. PMID:10933233

  10. Affective processing requires awareness.

    PubMed

    Lähteenmäki, Mikko; Hyönä, Jukka; Koivisto, Mika; Nummenmaa, Lauri

    2015-04-01

    Studies using backward masked emotional stimuli suggest that affective processing may occur outside visual awareness and imply primacy of affective over semantic processing, yet these experiments have not strictly controlled for the participants' awareness of the stimuli. Here we directly compared the primacy of affective versus semantic categorization of biologically relevant stimuli in 5 experiments (n = 178) using explicit (semantic and affective discrimination; Experiments 1-3) and implicit (semantic and affective priming; Experiments 4-5) measures. The same stimuli were used in semantic and affective tasks. Visual awareness was manipulated by varying exposure duration of the masked stimuli, and subjective level of stimulus awareness was measured after each trial using a 4-point perceptual awareness scale. When participants reported no awareness of the stimuli, semantic and affective categorization were at chance level and priming scores did not differ from zero. When participants were even partially aware of the stimuli, (a) both semantic and affective categorization could be performed above chance level with equal accuracy, (b) semantic categorization was faster than affective categorization, and (c) both semantic and affective priming were observed. Affective categorization speed was linearly dependent on semantic categorization speed, suggesting dependence of affective processing on semantic recognition. Manipulations of affective and semantic categorization tasks revealed a hierarchy of categorization operations beginning with basic-level semantic categorization and ending with superordinate level affective categorization. We conclude that both implicit and explicit affective and semantic categorization is dependent on visual awareness, and that affective recognition follows semantic categorization. PMID:25559654

  11. Implementing the CASPiE course-based research experience at the United States Military Academy: Affective responses and effects on critical thinking

    NASA Astrophysics Data System (ADS)

    Chase, Anthony Michael

    The Center for Authentic Science Practices in Education (CASPiE) pioneered a course-based research experience approach to teaching chemistry laboratory courses. The method had previously been studied in a variety of institutional settings. Recently, the United States Military Academy at West Point decided to develop CASPiE-style modules for the introductory honors chemistry course. This research setting presents clean experimental-control comparisons and a group of faculty who were completely new to the method. Equipping students with authentic research experiences early in their education is important regardless of the institution. However, cadets at a military academy must make decisions relatively early (the outset of their second year) as to what their career trajectory will be as eventual officers. In the new CASPiE-based experience, cadets are given the opportunity to select from one of three different modules (analytical chemistry, toxicology, and chemical engineering) in which to participate during the course. These three modules represent subsections of an overall Army waste-to-energy research project. Cadets generate unique hypotheses, real data, and research posters towards the advancement of the project. Posters are then presented in a session. that includes an audience of project stakeholders, course instructors, and other academy faculty and staff. Here, I will present my research methods, evaluative procedures, and findings in the affective domain, critical thinking, and laboratory content comprehension.

  12. RCD+: Fast loop modeling server

    PubMed Central

    López-Blanco, José Ramón; Canosa-Valls, Alejandro Jesús; Li, Yaohang; Chacón, Pablo

    2016-01-01

    Modeling loops is a critical and challenging step in protein modeling and prediction. We have developed a quick online service (http://rcd.chaconlab.org) for ab initio loop modeling combining a coarse-grained conformational search with a full-atom refinement. Our original Random Coordinate Descent (RCD) loop closure algorithm has been greatly improved to enrich the sampling distribution towards near-native conformations. These improvements include a new workflow optimization, MPI-parallelization and fast backbone angle sampling based on neighbor-dependent Ramachandran probability distributions. The server starts by efficiently searching the vast conformational space from only the loop sequence information and the environment atomic coordinates. The generated closed loop models are subsequently ranked using a fast distance-orientation dependent energy filter. Top ranked loops are refined with the Rosetta energy function to obtain accurate all-atom predictions that can be interactively inspected in an user-friendly web interface. Using standard benchmarks, the average root mean squared deviation (RMSD) is 0.8 and 1.4 Å for 8 and 12 residues loops, respectively, in the challenging modeling scenario in where the side chains of the loop environment are fully remodeled. These results are not only very competitive compared to those obtained with public state of the art methods, but also they are obtained ∼10-fold faster. PMID:27151199

  13. RCD+: Fast loop modeling server.

    PubMed

    López-Blanco, José Ramón; Canosa-Valls, Alejandro Jesús; Li, Yaohang; Chacón, Pablo

    2016-07-01

    Modeling loops is a critical and challenging step in protein modeling and prediction. We have developed a quick online service (http://rcd.chaconlab.org) for ab initio loop modeling combining a coarse-grained conformational search with a full-atom refinement. Our original Random Coordinate Descent (RCD) loop closure algorithm has been greatly improved to enrich the sampling distribution towards near-native conformations. These improvements include a new workflow optimization, MPI-parallelization and fast backbone angle sampling based on neighbor-dependent Ramachandran probability distributions. The server starts by efficiently searching the vast conformational space from only the loop sequence information and the environment atomic coordinates. The generated closed loop models are subsequently ranked using a fast distance-orientation dependent energy filter. Top ranked loops are refined with the Rosetta energy function to obtain accurate all-atom predictions that can be interactively inspected in an user-friendly web interface. Using standard benchmarks, the average root mean squared deviation (RMSD) is 0.8 and 1.4 Å for 8 and 12 residues loops, respectively, in the challenging modeling scenario in where the side chains of the loop environment are fully remodeled. These results are not only very competitive compared to those obtained with public state of the art methods, but also they are obtained ∼10-fold faster. PMID:27151199

  14. Olfactory experience affects the response of meadow voles to the opposite-sex scent donor of mixed-sex over-marks

    PubMed Central

    Ferkin, Michael H.; Ferkin, Daniel A.; Ferkin, Benjamin D.; Vlautin, Christian T.

    2010-01-01

    Scent marking and over-marking are important forms of communication between the sexes for many terrestrial mammals. Over the course of three experiments, we determined whether the amount of time individuals investigate the scent marks of opposite-sex conspecifics is affected by four days of olfactory experience with those conspecifics. In experiment 1, female meadow voles, Microtus pennsylvanicus, spent more time investigating the scent mark of the novel male conspecific than that of the familiar male donor, whereas male voles spent similar amounts of time investigating the scent mark of the familiar female and a novel female conspecific. In experiment 2, voles were exposed to a mixed-sex over-mark in which subjects did not have four days of olfactory experience with either the top-scent donor or the bottom-scent donor. During the test phase, male and female voles spent more time investigating the scent mark of the opposite-sex conspecific that provided the top-scent mark than that of a novel, opposite-sex conspecific. Male and female voles spent similar amounts of time investigating the scent mark of the bottom-scent donor and that of a novel opposite-sex conspecific. In experiment 3, voles were exposed to a mixed-sex over-mark that contained the scent mark of an opposite-sex conspecific with which they had four days of olfactory experience. During the test phase, male voles spent more time investigating the mark of the familiar, top-scent female than the scent mark of a novel female donor but spent similar amounts of time investigating the mark of the familiar, bottom-scent female and that of a novel female donor. In contrast, female voles spent more time investigating the mark of a novel male donor than that of either the familiar, top-scent male or that of the familiar, bottom-scent male. The sex differences in the responses of voles to scent marks and mixed-sex over-marks are discussed in relation to the natural history and non-monogamous mating system of

  15. Wilson Loop Diagrams and Positroids

    NASA Astrophysics Data System (ADS)

    Agarwala, Susama; Marin-Amat, Eloi

    2016-07-01

    In this paper, we study a new application of the positive Grassmannian to Wilson loop diagrams (or MHV diagrams) for scattering amplitudes in N= 4 Super Yang-Mill theory (N = 4 SYM). There has been much interest in studying this theory via the positive Grassmannians using BCFW recursion. This is the first attempt to study MHV diagrams for planar Wilson loop calculations (or planar amplitudes) in terms of positive Grassmannians. We codify Wilson loop diagrams completely in terms of matroids. This allows us to apply the combinatorial tools in matroid theory used to identify positroids (non-negative Grassmannians) to Wilson loop diagrams. In doing so, we find that certain non-planar Wilson loop diagrams define positive Grassmannians. While non-planar diagrams do not have physical meaning, this finding suggests that they may have value as an algebraic tool, and deserve further investigation.

  16. Higher dimensional loop quantum cosmology

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangdong

    2016-07-01

    Loop quantum cosmology (LQC) is the symmetric sector of loop quantum gravity. In this paper, we generalize the structure of loop quantum cosmology to the theories with arbitrary spacetime dimensions. The isotropic and homogeneous cosmological model in n+1 dimensions is quantized by the loop quantization method. Interestingly, we find that the underlying quantum theories are divided into two qualitatively different sectors according to spacetime dimensions. The effective Hamiltonian and modified dynamical equations of n+1 dimensional LQC are obtained. Moreover, our results indicate that the classical big bang singularity is resolved in arbitrary spacetime dimensions by a quantum bounce. We also briefly discuss the similarities and differences between the n+1 dimensional model and the 3+1 dimensional one. Our model serves as a first example of higher dimensional loop quantum cosmology and offers the possibility to investigate quantum gravity effects in higher dimensional cosmology.

  17. Loop-bed combustion apparatus

    DOEpatents

    Shang, Jer-Yu; Mei, Joseph S.; Slagle, Frank D.; Notestein, John E.

    1984-01-01

    The present invention is directed to a combustion apparatus in the configuration of a oblong annulus defining a closed loop. Particulate coal together with a sulfur sorbent such as sulfur or dolomite is introduced into the closed loop, ignited, and propelled at a high rate of speed around the loop. Flue gas is withdrawn from a location in the closed loop in close proximity to an area in the loop where centrifugal force imposed upon the larger particulate material maintains these particulates at a location spaced from the flue gas outlet. Only flue gas and smaller particulates resulting from the combustion and innerparticle grinding are discharged from the combustor. This structural arrangement provides increased combustion efficiency due to the essentially complete combustion of the coal particulates as well as increased sulfur absorption due to the innerparticle grinding of the sorbent which provides greater particle surface area.

  18. A Generalized Theory of DNA Looping and Cyclization

    NASA Astrophysics Data System (ADS)

    Wilson, David; Lillian, Todd; Perkins, Noel; Tkachenko, Alexei; Meiners, Jens-Christian

    2010-03-01

    We have developed a semi-analytic method for calculating the Stockmayer Jacobson J-factor for protein mediated DNA loops. The formation of DNA loops on the order of a few persistence lengths is a key component in many biological regulatory functions. The binding of LacI protein within the Lac Operon of E.coli serves as the canonical example for loop regulated transcription. We use a non-linear rod model to determine the equilibrium shape of the inter-operator DNA loop under prescribed binding constraints while taking sequence-dependent curvature and elasticity into account. Then we construct a Hamiltonian that describes thermal fluctuations about the open and looped equilibrium states, yielding the entropic and enthalpic costs of loop formation. Our work demonstrates that even for short sequences of the order one persistence length, entropic terms contribute substantially to the J factor. We also show that entropic considerations are able to determine the most favorable binding topology. The J factor can be used to compare the relative loop lifetimes of various DNA sequences, making it a useful tool in sequence design. A corollary of this work is the computation of an effective torsional persistence length, which demonstrates how torsion bending coupling in a constrained geometry affects the conversion of writhe to twist.

  19. The Effects of Hairpin loops on Ligand-DNA Interactions

    PubMed Central

    Nguyen, Binh; Wilson, W. David

    2009-01-01

    Hairpin nucleic acids are frequently used in physical studies due to their greater thermal stability compared to their equivalent duplex structures. They are also good models for more complex loop-containing structures such as quadruplexes, i-motifs, cruciforms, and molecular beacons. Although a connecting loop can increase stability, there is little information on how the loop influences the interactions of small molecules with attached base-paired nucleic acid regions. In this study, the effects of different hairpin loops on the interactions of A/T specific DNA minor groove binding agents with a common stem sequence have been investigated by spectroscopic and surface plasmon resonance (SPR) biosensor methods. The results indicate that the hairpin loop has little influence on the specific site interactions on the stem but significantly affects nonspecific binding. The use of a non-nucleotide loop (with a reduced negative charge) not only enhances the thermal stability of the hairpin but also reduces the non-specific binding at the loop without compromising the primary binding affinity on the stem. PMID:19778070

  20. Pre-learning stress differentially affects long-term memory for emotional words, depending on temporal proximity to the learning experience.

    PubMed

    Zoladz, Phillip R; Clark, Brianne; Warnecke, Ashlee; Smith, Lindsay; Tabar, Jennifer; Talbot, Jeffery N

    2011-07-01

    Stress exerts a profound, yet complex, influence on learning and memory and can enhance, impair or have no effect on these processes. Here, we have examined how the administration of stress at different times before learning affects long-term (24-hr) memory for neutral and emotional information. Participants submerged their dominant hand into a bath of ice cold water (Stress) or into a bath of warm water (No stress) for 3 min. Either immediately (Exp. 1) or 30 min (Exp. 2) after the water bath manipulation, participants were presented with a list of 30 words varying in emotional valence. The next day, participants' memory for the word list was assessed via free recall and recognition tests. In both experiments, stressed participants exhibited greater blood pressure, salivary cortisol levels, and subjective pain and stress ratings than non-stressed participants in response to the water bath manipulation. Stress applied immediately prior to learning (Exp. 1) enhanced the recognition of positive words, while stress applied 30 min prior to learning (Exp. 2) impaired free recall of negative words. Participants' recognition of positive words in Experiment 1 was positively associated with their heart rate responses to the water bath manipulation, while participants' free recall of negative words in Experiment 2 was negatively associated with their blood pressure and cortisol responses to the water bath manipulation. These findings indicate that the differential effects of pre-learning stress on long-term memory may depend on the temporal proximity of the stressor to the learning experience and the emotional nature of the to-be-learned information. PMID:21262248

  1. Local adaptations to frost in marginal and central populations of the dominant forest tree Fagus sylvatica L. as affected by temperature and extreme drought in common garden experiments

    PubMed Central

    Kreyling, Juergen; Buhk, Constanze; Backhaus, Sabrina; Hallinger, Martin; Huber, Gerhard; Huber, Lukas; Jentsch, Anke; Konnert, Monika; Thiel, Daniel; Wilmking, Martin; Beierkuhnlein, Carl

    2014-01-01

    Local adaptations to environmental conditions are of high ecological importance as they determine distribution ranges and likely affect species responses to climate change. Increased environmental stress (warming, extreme drought) due to climate change in combination with decreased genetic mixing due to isolation may lead to stronger local adaptations of geographically marginal than central populations. We experimentally observed local adaptations of three marginal and four central populations of Fagus sylvaticaL., the dominant native forest tree, to frost over winter and in spring (late frost). We determined frost hardiness of buds and roots by the relative electrolyte leakage in two common garden experiments. The experiment at the cold site included a continuous warming treatment; the experiment at the warm site included a preceding summer drought manipulation. In both experiments, we found evidence for local adaptation to frost, with stronger signs of local adaptation in marginal populations. Winter frost killed many of the potted individuals at the cold site, with higher survival in the warming treatment and in those populations originating from colder environments. However, we found no difference in winter frost tolerance of buds among populations, implying that bud survival was not the main cue for mortality. Bud late frost tolerance in April differed between populations at the warm site, mainly because of phenological differences in bud break. Increased spring frost tolerance of plants which had experienced drought stress in the preceding summer could also be explained by shifts in phenology. Stronger local adaptations to climate in geographically marginal than central populations imply the potential for adaptation to climate at range edges. In times of climate change, however, it needs to be tested whether locally adapted populations at range margins can successfully adapt further to changing conditions. PMID:25035801

  2. Studying DNA Looping by Single-Molecule FRET

    PubMed Central

    Le, Tung T.; Kim, Harold D.

    2014-01-01

    Bending of double-stranded DNA (dsDNA) is associated with many important biological processes such as DNA-protein recognition and DNA packaging into nucleosomes. Thermodynamics of dsDNA bending has been studied by a method called cyclization which relies on DNA ligase to covalently join short sticky ends of a dsDNA. However, ligation efficiency can be affected by many factors that are not related to dsDNA looping such as the DNA structure surrounding the joined sticky ends, and ligase can also affect the apparent looping rate through mechanisms such as nonspecific binding. Here, we show how to measure dsDNA looping kinetics without ligase by detecting transient DNA loop formation by FRET (Fluorescence Resonance Energy Transfer). dsDNA molecules are constructed using a simple PCR-based protocol with a FRET pair and a biotin linker. The looping probability density known as the J factor is extracted from the looping rate and the annealing rate between two disconnected sticky ends. By testing two dsDNAs with different intrinsic curvatures, we show that the J factor is sensitive to the intrinsic shape of the dsDNA. PMID:24998459

  3. Adaptive autofocusing: a closed-loop perspective.

    PubMed

    Zhang, Ying; Wen, Changyun; Soh, Yeng Chai; Fong, Aik Meng

    2005-04-01

    We present an adaptive autofocusing scheme. In this scheme, the focus measure is updated with focus tuning. To achieve this, we construct the focus measure by using image moments and develop an adaptive focus-tuning strategy to estimate the measure in closed loop. It is shown that the adaptive updating of the focus measure enables us to overcome the dependence of autofocusing on the image contents. Such an adaptive closed-loop focusing operation also effectively suppresses both the effect of the noise in optical imaging and the effect of time delay due to image processing time. Therefore a high accuracy of autofocusing is guaranteed. The effectiveness of the proposed scheme is demonstrated by simulations and experiments. PMID:15839269

  4. Closed Loop Welding Controller for Manufacturing Process

    NASA Astrophysics Data System (ADS)

    Bonaccorso, F.; Bruno, C.; Cantelli, L.; Longo, D.; Muscato, G.; Rapisarda, S.

    2011-12-01

    The aim of this paper is to investigate on the closed loop welding controller of a rapid manufacturing Shaped Metal Deposition (SMD) process. SMD was developed and patented by Rolls-Royce in order to produce mechanical parts directly from a CAD model. A simplified SMD plant has been set up in order to investigate the welding dynamics and parameters and to develop a SMD automatic controller. On the basis of the experience acquired, some basic control laws have been developed, and a closed loop controller has been implemented. This controller permits to find and to maintain the process stability condition, so that the final process results totally automatic. The control is performed adjusting the welding conditions on the basis of arc voltage information obtained from the welding machine during the deposition. The experimental results reported confirm the validity of the proposed strategy.

  5. Through the looking glass: an exploratory study of the lived experiences and unmet needs of families affected by Von Hippel–Lindau disease

    PubMed Central

    Kasparian, Nadine A; Rutstein, Alison; Sansom-Daly, Ursula M; Mireskandari, Shab; Tyler, Janet; Duffy, Jessica; Tucker, Katherine M

    2015-01-01

    Despite well-established protocols for the medical management of Von Hippel–Lindau disease (VHL), families affected by this rare tumour syndrome continue to face numerous psychological, social, and practical challenges. To our knowledge, this is one of the first qualitative studies to explore the psychosocial difficulties experienced by families affected by VHL. A semi-structured interview was developed to explore patients' and carers' experiences of VHL along several life domains, including: self-identity and self-esteem, interpersonal relationships, education and career opportunities, family communication, physical health and emotional well-being, and supportive care needs. Quantitative measures were also used to examine the prevalence of anxiety, depression, and disease-specific distress in this sample. Participants were recruited via the Hereditary Cancer Clinic at the Prince of Wales Hospital in Sydney, Australia. A total of 23 individual telephone interviews were conducted (15 patients, 8 carers), yielding a response rate of 75%. A diverse range of experiences were reported, including: sustained uncertainty about future tumour development, frustration regarding the need for lifelong medical screening, strained family relationships, difficulties communicating with others about VHL, perceived social isolation and limited career opportunities, financial and care-giving burdens, complex decisions in relation to childbearing, and difficulties accessing expert medical and psychosocial care. Participants also provided examples of psychological growth and resilience, and voiced support for continued efforts to improve supportive care services. More sophisticated systems for connecting VHL patients and their families with holistic, empathic, and person-centred medical and psychosocial care are urgently needed. PMID:24690678

  6. The challenging environment on board the International Space Station affects endothelial cell function by triggering oxidative stress through thioredoxin interacting protein overexpression: the ESA-SPHINX experiment.

    PubMed

    Versari, Silvia; Longinotti, Giulia; Barenghi, Livia; Maier, Jeanette Anne Marie; Bradamante, Silvia

    2013-11-01

    Exposure to microgravity generates alterations that are similar to those involved in age-related diseases, such as cardiovascular deconditioning, bone loss, muscle atrophy, and immune response impairment. Endothelial dysfunction is the common denominator. To shed light on the underlying mechanism, we participated in the Progress 40P mission with Spaceflight of Human Umbilical Vein Endothelial Cells (HUVECs): an Integrated Experiment (SPHINX), which consisted of 12 in-flight and 12 ground-based control modules and lasted 10 d. Postflight microarray analysis revealed 1023 significantly modulated genes, the majority of which are involved in cell adhesion, oxidative phosphorylation, stress responses, cell cycle, and apoptosis. Thioredoxin-interacting protein was the most up-regulated (33-fold), heat-shock proteins 70 and 90 the most down-regulated (5.6-fold). Ion channels (TPCN1, KCNG2, KCNJ14, KCNG1, KCNT1, TRPM1, CLCN4, CLCA2), mitochondrial oxidative phosphorylation, and focal adhesion were widely affected. Cytokine detection in the culture media indicated significant increased secretion of interleukin-1α and interleukin-1β. Nitric oxide was found not modulated. Our data suggest that in cultured HUVECs, microgravity affects the same molecular machinery responsible for sensing alterations of flow and generates a prooxidative environment that activates inflammatory responses, alters endothelial behavior, and promotes senescence. PMID:23913861

  7. The Seasonality Of The Loop Current

    NASA Astrophysics Data System (ADS)

    Hall, Cody Alan

    A total of 20 Loop Current eddy separation event dates were derived from Seasat and ERS-1 satellite altimetry, Coastal Zone Color Scanner chlorophyll-a images, Advanced Very High Resolution Radiometer sea surface temperature images, Horizon Marine, Inc. EddyWatch(TM) reports, and Climatology and Simulation of Eddies Eddy Joint Industry Project Gulf Eddy Model analyses spanning mid-1978 - 1992. There were many inconsistencies between the new "pre-altimetry" reanalysis dates derived from mostly non-altimeter data and dates published in past literature based on earlier versions of the pre-altimetry record. The reanalysis dates were derived from a larger compilation of data types and, consequently, were not as affected by intermittent and seasonal data outages common with past records. Therefore, the reanalysis dates are likely more accurate. About 30 Loop Current eddy separation dates were derived from altimetry data spanning 1993 -- 2012. The pre-altimetry and altimetry reanalysis dates along with similar altimetry dates published in other literature exhibit statistically significant seasonality. Eddy separation events are more likely in the months March, August, and September, and less likely in December. Reanalysis event dates were objectively divided into "spring" and "fall" seasons using a k-means clustering algorithm. The estimated spring and fall season centers are March 2nd and August 23 rd, respectively, with seasonal boundaries on May 22nd and December 3rd. The altimetry data suggest that Loop Current intrusion/retreat is dominantly an annual process. Loop Current metrics such as maximum northern boundary latitude and area are relatively high from January through about July and low in September and October. February metrics are statistically different than metrics in either October or November or both. This annual process is primarily driven by and dynamically linked to geostrophic currents seaward of the Campeche Bank shelf break forced by Kelvin waves

  8. Computer Simulations of Interstitial Loop Growth Kinetics in irradiated bcc Fe

    SciTech Connect

    Li, Yulan; Hu, Shenyang Y.; Henager, Charles H.; Deng, Huiqiu; Gao, Fei; Sun, Xin; Khaleel, Mohammad A.

    2012-08-01

    The growth kinetics of (001) [001] interstitial loops in bcc Fe is studied by phase-field modeling. The effect of defect (vacancy/interstitial) concentration, generation, recombination, sink strength, and elastic interaction on the growth kinetics of interstitial loops is systematically simulated. Results show that the elastic interaction between the defects and interstitial loops speeds up the growth kinetics and affects the morphology of the interstitial loops. Linear growth rate, i.e., the loop average radius is linear to time, under both aging and irradiation are predicted, which is in agreement with experimental observation. The results also show that the interstitial loop growth rate, which is directly related to the sink strength of the interstitial loop for interstitials, increases linearly with the initial interstitial concentration during aging while changing logarithmically with the interstitial generation rate under irradiation.

  9. Are feedback loops destructive to synchronization?

    NASA Astrophysics Data System (ADS)

    Sheshbolouki, A.; Zarei, M.; Sarbazi-Azad, H.

    2015-08-01

    We study the effects of directionality on synchronization of dynamical networks. Performing the linear stability analysis and the numerical simulation of the Kuramoto model in directed networks, we show that balancing in- and out-degrees of all nodes enhances the synchronization of sparse networks, especially in networks with high clustering coefficient and homogeneous degree distribution. Furthermore, by omitting all the feedback loops, we show that while hierarchical directed acyclic graphs are structurally highly synchronizable, their global synchronization is too sensitive to the choice of natural frequencies and is strongly affected by noise.

  10. Digital phase-locked loop

    NASA Technical Reports Server (NTRS)

    Cliff, R. A. (Inventor)

    1975-01-01

    An digital phase-locked loop is provided for deriving a loop output signal from an accumulator output terminal. A phase detecting exclusive OR gate is fed by the loop digital input and output signals. The output of the phase detector is a bi-level digital signal having a duty cycle indicative of the relative phase of the input and output signals. The accumulator is incremented at a first rate in response to a first output level of the phase detector and at a second rate in response to a second output level of the phase detector.

  11. Dissecting protein-induced DNA looping dynamics in real time

    PubMed Central

    Laurens, Niels; Bellamy, Stuart R. W.; Harms, August F.; Kovacheva, Yana S.; Halford, Stephen E.; Wuite, Gijs J. L.

    2009-01-01

    Many proteins that interact with DNA perform or enhance their specific functions by binding simultaneously to multiple target sites, thereby inducing a loop in the DNA. The dynamics and energies involved in this loop formation influence the reaction mechanism. Tethered particle motion has proven a powerful technique to study in real time protein-induced DNA looping dynamics while minimally perturbing the DNA–protein interactions. In addition, it permits many single-molecule experiments to be performed in parallel. Using as a model system the tetrameric Type II restriction enzyme SfiI, that binds two copies of its recognition site, we show here that we can determine the DNA–protein association and dissociation steps as well as the actual process of protein-induced loop capture and release on a single DNA molecule. The result of these experiments is a quantitative reaction scheme for DNA looping by SfiI that is rigorously compared to detailed biochemical studies of SfiI looping dynamics. We also present novel methods for data analysis and compare and discuss these with existing methods. The general applicability of the introduced techniques will further enhance tethered particle motion as a tool to follow DNA–protein dynamics in real time. PMID:19586932

  12. Phase transition of strongly interacting matter with a chemical potential dependent Polyakov loop potential

    NASA Astrophysics Data System (ADS)

    Shao, Guo-yun; Tang, Zhan-duo; Di Toro, Massimo; Colonna, Maria; Gao, Xue-yan; Gao, Ning

    2016-07-01

    We construct a hadron-quark two-phase model based on the Walecka-quantum hadrodynamics and the improved Polyakov-Nambu-Jona-Lasinio (PNJL) model with an explicit chemical potential dependence of Polyakov loop potential (μ PNJL model). With respect to the original PNJL model, the confined-deconfined phase transition is largely affected at low temperature and large chemical potential. Using the two-phase model, we investigate the equilibrium transition between hadronic and quark matter at finite chemical potentials and temperatures. The numerical results show that the transition boundaries from nuclear to quark matter move towards smaller chemical potential (lower density) when the μ -dependent Polyakov loop potential is taken. In particular, for charge asymmetric matter, we compute the local asymmetry of u , d quarks in the hadron-quark coexisting phase, and analyze the isospin-relevant observables possibly measurable in heavy-ion collision (HIC) experiments. In general new HIC data on the location and properties of the mixed phase would bring relevant information on the expected chemical potential dependence of the Polyakov loop contribution.

  13. Vortex Loops at the Superfluid Lambda Transition: An Exact Theory?

    NASA Technical Reports Server (NTRS)

    Williams, Gary A.

    2003-01-01

    A vortex-loop theory of the superfluid lambda transition has been developed over the last decade, with many results in agreement with experiments. It is a very simple theory, consisting of just three basic equations. When it was first proposed the main uncertainty in the theory was the use Flory scaling to find the fractal dimension of the random-walking vortex loops. Recent developments in high-resolution Monte Carlo simulations have now made it possible to verify the accuracy of this Flory-scaling assumption. Although the loop theory is not yet rigorously proven to be exact, the Monte Carlo results show at the least that it is an extremely good approximation. Recent loop calculations of the critical Casimir effect in helium films in the superfluid phase T < Tc will be compared with similar perturbative RG calculations in the normal phase T > Tc; the two calculations are found to match very nicely right at Tc.

  14. VERSATILE TWO-AXIS OPEN-LOOP SOLAR TRACKER CONTROLLER*

    SciTech Connect

    Ward, Christina D; Maxey, L Curt; Evans III, Boyd Mccutchen; Lapsa, Melissa Voss

    2008-01-01

    A versatile single-board controller for two-axis solar tracking applications has been developed and tested on operating solar tracking systems with over two years of field experience. The operating experience gained from the two systems and associated modifications are discussed as representative examples of the practical issues associated with implementing a new two-axis solar tracker design. In this research, open and closed loop control methods were evaluated; however, only the open loop method met the 0.125 tracking accuracy requirement and the requirement to maintain pointing accuracy in hazy and scattered cloudy skies. The open loop algorithm was finally implemented in a microcontroller-based tracking system. Methods of applying this controller hardware to different tracker geometries and hardware are discussed along with the experience gained to date.

  15. SDO Sees Brightening Magnetic Loops

    NASA Video Gallery

    Two active regions sprouted arches of bundled magnetic loops in this video from NASA’s Solar Dynamics Observatory taken on Nov. 11-12, 2015. Charged particles spin along the magnetic field, tracing...

  16. Automatic blocking of nested loops

    NASA Technical Reports Server (NTRS)

    Schreiber, Robert; Dongarra, Jack J.

    1990-01-01

    Blocked algorithms have much better properties of data locality and therefore can be much more efficient than ordinary algorithms when a memory hierarchy is involved. On the other hand, they are very difficult to write and to tune for particular machines. The reorganization is considered of nested loops through the use of known program transformations in order to create blocked algorithms automatically. The program transformations used are strip mining, loop interchange, and a variant of loop skewing in which invertible linear transformations (with integer coordinates) of the loop indices are allowed. Some problems are solved concerning the optimal application of these transformations. It is shown, in a very general setting, how to choose a nearly optimal set of transformed indices. It is then shown, in one particular but rather frequently occurring situation, how to choose an optimal set of block sizes.

  17. SDO Sees Flourishing Magnetic Loops

    NASA Video Gallery

    A bright set of loops near the edge of the sun’s face grew and shifted quickly after the magnetic field was disrupted by a small eruption on Nov. 25, 2015. Charged particles emitting light in extre...

  18. Loop Electrosurgical Excision Procedure (LEEP)

    MedlinePlus

    ... that acts like a scalpel (surgical knife). An electric current is passed through the loop, which cuts away ... A procedure in which an instrument works with electric current to destroy tissue. Local Anesthesia: The use of ...

  19. Observations of loops and prominences

    NASA Technical Reports Server (NTRS)

    Strong, Keith T.

    1994-01-01

    We review recent observations by the Yohkoh-SXT (Soft X-ray Telescope) in collaboration with other spacecraft and ground-based observatories of coronal loops and prominences. These new results point to problems that SoHO will be able to address. With a unique combination of rapid-cadence digital imaging (greater than or equal to 32 s full-disk and greater than or equal to 2 s partial-frame images), high spatial resolution (greater than or equal to 2.5 arcsec pixels), high sensitivity (EM less than or equal to 10(exp 42) cm(exp -3)), a low-scatter mirror, and large dynamic range, SXT can observe a vast range of targets on the Sun. Over the first 21 months of Yohkoh operations SXT has taken over one million images of the corona and so is building up an invaluable long-term database on the large-scale corona and loop geometry. The most striking thing about the SXT images is the range of loop sizes and shapes. The active regions are a bright tangle of magnetic field lines, surrounded by a network of large-scale quiet-Sun loops stretching over distances in excess of 105 km. The cross-section of most loops seems to be constant. Loops displaying significant Gamma's are the exception, not the rule, implying the presence of widespread currents in the corona. All magnetic structures show changes. Time scales range from seconds to months. The question of how these structures are formed, become filled with hot plasma, and are maintained is still open. While we see the propagation of brightenings along the length of active-region loops and in X-ray jets with velocities of several hundred km/s, much higher velocities are seen in the quiet Sun. In XBP flares, for example, velocities of over 1000 km/s are common. Active-region loops seem to be in constant motion, moving slowly outward, carrying plasma with them. During flares, loops often produce localized brightenings at the base and later at the apex of the loop. Quiescent filaments and prominences have been observed regularly

  20. Dynamical behaviour in coronal loops

    NASA Technical Reports Server (NTRS)

    Haisch, Bernhard M.

    1986-01-01

    Rapid variability has been found in two active region coronal loops observed by the X-ray Polychromator (XRP) and the Hard X-ray Imaging Spectrometer (HXIS) onboard the Solar Maximum Mission (SMM). There appear to be surprisingly few observations of the short-time scale behavior of hot loops, and the evidence presented herein lends support to the hypothesis that coronal heating may be impulsive and driven by flaring.

  1. The Coronal Loop Inventory Project

    NASA Astrophysics Data System (ADS)

    Schmelz, J. T.; Pathak, S.; Christian, G. M.; Dhaliwal, R. S. S.; Paul, K. S.

    2015-11-01

    Most coronal physicists now seem to agree that loops are composed of tangled magnetic strands and have both isothermal and multithermal cross-field temperature distributions. As yet, however, there is no information on the relative importance of each of these categories, and we do not know how common one is with respect to the other. In this paper, we investigate these temperature properties for all loop segments visible in the 171-Å image of AR 11294, which was observed by the Atmospheric Imaging Assembly (AIA) on 2011 September 15. Our analysis revealed 19 loop segments, but only 2 of these were clearly isothermal. Six additional segments were effectively isothermal, that is, the plasma emission to which AIA is sensitive could not be distinguished from isothermal emission, within measurement uncertainties. One loop had both isothermal transition region and multithermal coronal solutions. Another five loop segments require multithermal plasma to reproduce the AIA observations. The five remaining loop segments could not be separated reliably from the background in the crucial non-171-Å AIA images required for temperature analysis. We hope that the direction of coronal heating models and the efforts modelers spend on various heating scenarios will be influenced by these results.

  2. The Structure of Coronal Loops

    NASA Technical Reports Server (NTRS)

    Antiochos, Spiro K.

    2009-01-01

    It is widely believed that the simple coronal loops observed by XUV imagers, such as EIT, TRACE, or XRT, actually have a complex internal structure consisting of many (perhaps hundreds) of unresolved, interwoven "strands". According to the nanoflare model, photospheric motions tangle the strands, causing them to reconnect and release the energy required to produce the observed loop plasma. Although the strands, themselves, are unresolved by present-generation imagers, there is compelling evidence for their existence and for the nanoflare model from analysis of loop intensities and temporal evolution. A problem with this scenario is that, although reconnection can eliminate some of the strand tangles, it cannot destroy helicity, which should eventually build up to observable scales. we consider, therefore, the injection and evolution of helicity by the nanoflare process and its implications for the observed structure of loops and the large-scale corona. we argue that helicity does survive and build up to observable levels, but on spatial and temporal scales larger than those of coronal loops. we discuss the implications of these results for coronal loops and the corona, in general .

  3. Open-loop and closed-loop excitation of the wake behind a circular cylinder

    NASA Astrophysics Data System (ADS)

    Williams, David; Cohen, Kelly; Siegel, Stefan; McLaughlin, Tom

    2006-11-01

    Both open loop and closed loop control were used to modify the flow around a circular cylinder at Re = 20,000. Independent plasma actuators were installed on the sides of the cylinder at +/- 90^o from the forward stagnation line. The actuators could be excited in-phase or 180^o out of phase with one another. In the case of open-loop forcing, in-phase excitation at twice the von Karman vortex shedding frequency produced large changes in the wake structure, similar to the experiments done by Williams, Mansy & Amato (JFM, 1992.) Negligible changes in wake structure occurred when the out-of-phase actuation was used, although the lock-on phenomenon was observed, suggesting that the wake structure modification resulting from the interaction between the forcing field and near wake is independent of Reynolds number. Closed-loop excitation using a proportional-derivative controller was done using a hot-film probe positioned at x/D=1.5, y/D = 1.5. The amplitude of the wake oscillation was shown to be sensitive to both the gain and phase of the controller. The amplitude of oscillations at a fixed controller gain are enhanced or suppressed relative to the non-forced level, depending on the controller phase. The vortex shedding frequency is changed when the PD controller is in a region of suppression. The expert assistance of SSgt. Mary S. Church is gratefully acknowledged.

  4. Benthic metal fluxes and sediment diagenesis in a water reservoir affected by acid mine drainage: A laboratory experiment and reactive transport modeling

    NASA Astrophysics Data System (ADS)

    Torres, E.; Ayora, C.; Jiménez-Arias, J. L.; García-Robledo, E.; Papaspyrou, S.; Corzo, A.

    2014-08-01

    Reservoirs are one of the primary water supply sources. Knowledge of the metal fluxes at the water-sediment interfaces of reservoirs is essential for predicting their ecological quality. Redox oscillations in the water column are promoted by stratification; turnover events may significantly alter metal cycling, especially in reservoirs impacted by acid mine drainage (AMD). To study this phenomenon, an experiment was performed under controlled laboratory conditions. Sediment cores from an AMD-affected reservoir were maintained in a tank with reservoir water for approximately two months and subjected to alternating oxic-hypoxic conditions. A detailed metal speciation in solid phases of the sediment was initially performed by sequential extraction, and pore water was analyzed at the end of each redox period. Tank water metals concentrations were systematically monitored throughout the experiment. The experimental results were then used to calibrate a diffusion-reaction model and quantify the reaction rates and sediment-water fluxes. Under oxic conditions, pH, Fe and As concentrations decreased in the tank due to schwertmannite precipitation, whereas the concentrations of Al, Zn, Cu, Ni, and Co increased due to Al(OH)3 and sulfide dissolution. The reverse trends occurred under hypoxic conditions. Under oxic conditions, the fluxes calculated by applying Fick’s first law to experimental concentration gradients contradicted the fluxes expected based on the evolution of the tank water. According to the reactive transport calculations, this discrepancy can be attributed to the coarse resolution of sediment sampling. The one-cm-thick slices failed to capture effectively the notably narrow (1-2 mm) concentration peaks of several elements in the shallow pore water resulting from sulfide and Al(OH)3 dissolution. The diffusion-reaction model, extended to the complete year, computed that between 25% and 50% of the trace metals and less than 10% of the Al that precipitated under

  5. The Splitting Loope

    ERIC Educational Resources Information Center

    Wilkins, Jesse L. M.; Norton, Anderson

    2011-01-01

    Teaching experiments have generated several hypotheses concerning the construction of fraction schemes and operations and relationships among them. In particular, researchers have hypothesized that children's construction of splitting operations is crucial to their construction of more advanced fractions concepts (Steffe, 2002). The authors…

  6. Sequence Affects the Cyclization of DNA Minicircles.

    PubMed

    Wang, Qian; Pettitt, B Montgomery

    2016-03-17

    Understanding how the sequence of a DNA molecule affects its dynamic properties is a central problem affecting biochemistry and biotechnology. The process of cyclizing short DNA, as a critical step in molecular cloning, lacks a comprehensive picture of the kinetic process containing sequence information. We have elucidated this process by using coarse-grained simulations, enhanced sampling methods, and recent theoretical advances. We are able to identify the types and positions of structural defects during the looping process at a base-pair level. Correlations along a DNA molecule dictate critical sequence positions that can affect the looping rate. Structural defects change the bending elasticity of the DNA molecule from a harmonic to subharmonic potential with respect to bending angles. We explore the subelastic chain as a possible model in loop formation kinetics. A sequence-dependent model is developed to qualitatively predict the relative loop formation time as a function of DNA sequence. PMID:26938490

  7. Self-sustained hydrodynamic oscillations in a natural-circulation two-phase-flow boiling loop

    NASA Technical Reports Server (NTRS)

    Jain, K. C.

    1969-01-01

    Results of an experimental and theoretical study of factors affecting self-sustaining hydrodynamic oscillations in boiling-water loops are reported. Data on flow variables, and the effects of geometry, subcooling and pressure on the development of oscillatory behavior in a natural-circulation two-phase-flow boiling loop are included.

  8. Therapygenetics in mindfulness-based cognitive therapy: do genes have an impact on therapy-induced change in real-life positive affective experiences?

    PubMed Central

    Bakker, J M; Lieverse, R; Menne-Lothmann, C; Viechtbauer, W; Pishva, E; Kenis, G; Geschwind, N; Peeters, F; van Os, J; Wichers, M

    2014-01-01

    Positive affect (PA) has an important role in resilience against depression and has been shown to increase with mindfulness-based cognitive therapy (MBCT). To elucidate the underlying mechanisms of change in PA as well as develop insights that may benefit personalized medicine, the current study examined the contribution of genetic variation to individual differences in change in PA in response to MBCT. Individuals (n=126) with residual depressive symptoms were randomized to either an MBCT group or treatment as usual. PA was assessed using experience sampling methodology (ESM). Single-nucleotide polymorphisms (SNPs) in genes known to be involved in reward functioning were selected. SNPs in the genes for brain-derived neurotrophic factor (BDNF), the muscarinic acetylcholine receptor M2 (CHRM2), the dopamine receptor D4 (DRD4) and the μ1 opioid receptor (OPRM1) significantly moderated the impact of treatment condition over time on PA. Genetic variation in the genes for CHRM2 and OPRM1 specifically had an impact on the level of PA following MBCT. The current study shows that variation in response to MBCT may be contingent on genetic factors associated with the regulation of PA. These findings contribute to our understanding of the processes moderating response to treatment and prediction of treatment outcome. PMID:24755993

  9. Direct Observation of Interstitial Dislocation Loop Coarsening in α-Iron

    NASA Astrophysics Data System (ADS)

    Moll, S.; Jourdan, T.; Lefaix-Jeuland, H.

    2013-07-01

    Interstitial loop coarsening by Ostwald ripening can provide insight into single point defects but is very difficult to observe in α-iron and many other metals where nanoscale vacancy clusters dissociate and annihilate loops. We show that by implanting helium in the samples at a carefully chosen energy, it is possible to observe Ostwald ripening of loops by transmission electron microscopy during in situ isochronal annealings. This coarsening of loops results in a sharp increase of the mean loop radius at around 850 K. Using cluster dynamics simulations, we demonstrate that loops evolve due to vacancy emission and that such experiments give a robust estimation of the sum of the formation and migration free energies of vacancies. In particular, our results are in good agreement with self-diffusion experiments and confirm that entropic contributions are large for the vacancy in α-iron.

  10. Kalman Orbit Optimized Loop Tracking

    NASA Technical Reports Server (NTRS)

    Young, Lawrence E.; Meehan, Thomas K.

    2011-01-01

    Under certain conditions of low signal power and/or high noise, there is insufficient signal to noise ratio (SNR) to close tracking loops with individual signals on orbiting Global Navigation Satellite System (GNSS) receivers. In addition, the processing power available from flight computers is not great enough to implement a conventional ultra-tight coupling tracking loop. This work provides a method to track GNSS signals at very low SNR without the penalty of requiring very high processor throughput to calculate the loop parameters. The Kalman Orbit-Optimized Loop (KOOL) tracking approach constitutes a filter with a dynamic model and using the aggregate of information from all tracked GNSS signals to close the tracking loop for each signal. For applications where there is not a good dynamic model, such as very low orbits where atmospheric drag models may not be adequate to achieve the required accuracy, aiding from an IMU (inertial measurement unit) or other sensor will be added. The KOOL approach is based on research JPL has done to allow signal recovery from weak and scintillating signals observed during the use of GPS signals for limb sounding of the Earth s atmosphere. That approach uses the onboard PVT (position, velocity, time) solution to generate predictions for the range, range rate, and acceleration of the low-SNR signal. The low- SNR signal data are captured by a directed open loop. KOOL builds on the previous open loop tracking by including feedback and observable generation from the weak-signal channels so that the MSR receiver will continue to track and provide PVT, range, and Doppler data, even when all channels have low SNR.

  11. Filter for third order phase locked loops

    NASA Technical Reports Server (NTRS)

    Crow, R. B.; Tausworthe, R. C. (Inventor)

    1973-01-01

    Filters for third-order phase-locked loops are used in receivers to acquire and track carrier signals, particularly signals subject to high doppler-rate changes in frequency. A loop filter with an open-loop transfer function and set of loop constants, setting the damping factor equal to unity are provided.

  12. Study of the Open Loop and Closed Loop Oscillator Techniques

    SciTech Connect

    Imel, George R.; Baker, Benjamin; Riley, Tony; Langbehn, Adam; Aryal, Harishchandra; Benzerga, M. Lamine

    2015-04-11

    This report presents the progress and completion of a five-year study undertaken at Idaho State University of the measurement of very small worth reactivity samples comparing open and closed loop oscillator techniques.The study conclusively demonstrated the equivalency of the two techniques with regard to uncertainties in reactivity values, i.e., limited by reactor noise. As those results are thoroughly documented in recent publications, in this report we will concentrate on the support work that was necessary. For example, we describe in some detail the construction and calibration of a pilot rod for the closed loop system. We discuss the campaign to measure the required reactor parameters necessary for inverse-kinetics. Finally, we briefly discuss the transfer of the open loop technique to other reactor systems.

  13. Analysis incorporating electric conductivity and magnetic permeability on loop-loop EM data for detecting the magnetite ore body

    NASA Astrophysics Data System (ADS)

    Choi, Jihyang; Yi, Myeong-Jong; Son, Jeong-Sul; Kim, Jung-Ho; Park, Sam-Gyu

    2013-04-01

    As the price of mineral resources goes up, exploring small amount of mineral deposits, which have been considered non-economic in the past, is getting more economic. Loop-loop EM survey system can be the best choice for exploring small mineral mines because no ground contact is required and portable loops are freely positioned. EM responses are affected by electric conductivity, magnetic permeability and electric permittivity. In many cases, variation ranges of latter two components are so small and ignorable. However, changes of magnetic permeability affect the data in a serious way. Multidimensional EM inversion technique incorporating both electric conductivity and magnetic susceptibility is on the developing stage. EM responses are calculated in a model of layered earth embedding a magnetic anomaly. Considering the size of the reactions, changes of relative magnetic permeability are frequency-independent effects that can be seen as static. Loop-loop EM survey using PROMIS system was conducted on a small magnetite mine. Inversion with and without considering magnetic permeability was conducted for EM data with multi-frequency and multi-separation between a transmitter and a receiver. Ferromagnetic anomalous feature was distinguishable from the subsurface media, though, enhancement by incorporating magnetic permeability was not sufficiently noticeable.

  14. The aeta - pinatubo loop.

    PubMed

    Marler, Thomas E

    2011-11-01

    The impact of Mount Pinatubo's 1991 eruption on the traditional use of natural resources by the indigenous Aeta was devastating. The damage resulted in the immediate and sustained disconnection of traditional knowledge from the biological resources integral to practice that knowledge. The relatively slow ecosystem recovery a full 20 years after the event hinders the transfer of traditional knowledge to younger generations of Aeta. Their traditional knowledge is at risk of disappearing from the cultural fabric of the Philippines. In seeking to adapt, decisions by the Aeta to accept the development of foreign-designed ecotourism enterprises may negatively affect natural ecosystem recovery. Alternatives to the existing ecotourism practices may be warranted to safeguard Aeta traditional knowledge. PMID:22446557

  15. Gluing hexagons at three loops

    NASA Astrophysics Data System (ADS)

    Basso, Benjamin; Goncalves, Vasco; Komatsu, Shota; Vieira, Pedro

    2016-06-01

    We perform extensive three-loop tests of the hexagon bootstrap approach for structure constants in planar N = 4 SYM theory. We focus on correlators involving two BPS operators and one non-BPS operator in the so-called SL (2) sector. At three loops, such correlators receive wrapping corrections from mirror excitations flowing in either the adjacent or the opposing channel. Amusingly, we find that the first type of correction coincides exactly with the leading wrapping correction for the spectrum (divided by the one-loop anomalous dimension). We develop an efficient method for computing the second type of correction for operators with any spin. The results are in perfect agreement with the recently obtained three-loop perturbative data by Chicherin, Drummond, Heslop, Sokatchev [2] and by Eden [3]. We also derive the integrand for general multi-particle wrapping corrections, which turns out to take a remarkably simple form. As an application we estimate the loop order at which various new physical effects are expected to kick-in.

  16. Manipulation of ultracold atoms using double-loop microtraps

    NASA Astrophysics Data System (ADS)

    van Wijngaarden, W. A.; Jian, B.; Mouraviev, A.

    2016-05-01

    Ultracold atoms created using microtraps are being used in an increasing number of diverse applications. This paper reviews the double-loop microtrap which consists of two concentric circular wire loops carrying oppositely oriented currents. This generates a magnetic field configuration that traps a magnetic dipole in three-dimensions. The position of the trapped atoms relative to the atom chip surface containing the microwire loops, can be precisely controlled by applying different currents in the two loops or alternatively using a so called bias magnetic field oriented perpendicular to the chip surface. Double-loop microtraps can be daisy chained in series to create a one- or two-dimensional microtrap array. Experiments that have demonstrated a double-loop microtrap array are discussed. Future possibilities are presented as to how atoms can be transferred between adjacent microtraps as well as the use of an additional micro sized Ioffe coil to create a trap having a nonzero magnetic field minimum to reduce atom loss by suppressing Majorana transitions.

  17. Construction of the molten salt pump and valve loops

    SciTech Connect

    Bator, P.A.; Dowling, R.L. . Nuclear Equipment Div.)

    1991-05-01

    The purpose of the molten salt pump and valve test loop is to demonstrate the performance, reliability, and lifetime of full-scale hot and cold salt pumps and valves for use in commercial salt-in-tube receiver solar power plant. The test hardware consists of two pumped loops, one to simulate the hot side of the receiver at a temperature of 565{degrees}C (referred to as the hot loop) and one to simulate the receiver's cold side at 285{degrees}C (referred to as the cold loop). Each loop contains a pump and five representative valves sized for a 60-MW{sub e} commercial solar power plant using molten salt heat transport fluid. The test loop is part of the Molten Salt Subsystem/Component Test Experiment, which is being conducted to reduce the technical risk of building and operating commercial solar central receiver plants. The project, managed by Sandia National Laboratories with Babcock and Wilcox as the prime contractor, is cost shared by the US Department of Energy and six contractors. 25 figs., 9 tabs.

  18. Bandwidth controller for phase-locked-loop

    NASA Technical Reports Server (NTRS)

    Brockman, Milton H. (Inventor)

    1992-01-01

    A phase locked loop utilizing digital techniques to control the closed loop bandwidth of the RF carrier phase locked loop in a receiver provides high sensitivity and a wide dynamic range for signal reception. After analog to digital conversion, a digital phase locked loop bandwidth controller provides phase error detection with automatic RF carrier closed loop tracking bandwidth control to accommodate several modes of transmission.

  19. Tritex, a forced convection loop with Pb-17Li

    NASA Astrophysics Data System (ADS)

    Feuerstein, H.; Gräbner, H.; Kieser, G.

    1988-07-01

    The loop TRITEX is a pumped loop with circulating Pb-17Li. It is designed to study the behaviour of tritium in a liquid metal blanket. Tritium will be simulated by deuterium. Start of operation is scheduled for the end of 1987. In a number of experiments some other problems were studied. Evaporation tests showed very low evaporation rates even in vacuum. The loss of Li in case of air ingress into the system will be very important. If this happens during loop operation, 25% of Li can be lost to the oxides within one hour, while only 0.3% of Pb oxidizes. Permeation rates of deuterium through steel 1.4922 were determined. Permeation losses of deuterium will be small, and the dissolution of this gas in the structural materials will not influence the experiments.

  20. Student investigations of the forces in a roller coaster loop

    NASA Astrophysics Data System (ADS)

    Pendrill, Ann-Marie

    2013-11-01

    How does the experience of a riding in a roller coaster loop depend on your position in the train? This question has been investigated by first year engineering physics students by using multiple representations of force and motion. Theoretical considerations for a circular loop show that the differences between the forces on a rider in the front, middle or back of the train depend on the ratio between train length and radius of the loop, which can be estimated from a photograph. Numerical computations complement the analysis of a video clip, accelerometer data, and measurements of the time needed for the train to move over the highest point. A roller coaster ride gives striking examples of Newton's laws applied to your own body, and demonstrates that the experience depends on the vector character of velocity and acceleration.

  1. Soil microbial biomass and community structure affected by repeated additions of sewage sludge in four Swedish long-term field experiments

    NASA Astrophysics Data System (ADS)

    Börjesson, G.; Kätterer, T.; Kirchmann, H.

    2012-04-01

    Soil organic matter is a key attribute of soil fertility. The pool of soil organic C can be increased, either by mineral fertilisers or by adding organic amendments such as sewage sludge. Sewage sludge has positive effects on agricultural soils through the supply of organic matter and essential plant nutrients, but sludge may also contain unwanted heavy metals, xenobiotic substances and pathogens. One obvious effect of long-term sewage sludge addition is a decrease in soil pH, caused by N mineralisation followed by nitrification, sulphate formation and presence of organic acids with the organic matter added. The objective of this study was to investigate the effect of sewage sludge on the microbial biomass and community structure. Materials and methods We analysed soil samples from four sites where sewage sludge has been repeatedly applied in long-term field experiments situated in different parts of Sweden; Ultuna (59°49'N, 17°39'E, started 1956), Lanna (58°21'N, 13°06'E, started 1997-98), Petersborg (55°32'N, 13°00'E, started 1981) and Igelösa (55°45'N, 13°18'E, started 1981). In these four experiments, at least one sewage sludge treatment is included in the experimental design. In the Ultuna experiment, all organic fertilisers, including sewage sludge, are applied every second year, corresponding to 4 ton C ha-1. The Lanna experiment has a similar design, with 8 ton dry matter ha-1 applied every second year. Lanna also has an additional treatment in which metal salts (Cd, Cu, Ni and Zn) are added together with sewage sludge. At Petersborg and Igelösa, two levels of sewage sludge (4 or 12 ton dry matter ha-1 every 4th year) are compared with three levels of NPK fertiliser (0 N, ½ normal N and normal N). Topsoil samples (0-20 cm depth) from the four sites were analysed for total C, total N, pH and PLFAs (phospholipid fatty acids). In addition, crop yields were recorded. Results At all four sites, sewage sludge has had a positive effect on crop yields

  2. Loop residues and catalysis in OMP synthase.

    PubMed

    Wang, Gary P; Hansen, Michael Riis; Grubmeyer, Charles

    2012-06-01

    Residue-to-alanine mutations and a two-amino acid deletion have been made in the highly conserved catalytic loop (residues 100-109) of Salmonella typhimurium OMP synthase (orotate phosphoribosyltransferase, EC 2.4.2.10). As described previously, the K103A mutant enzyme exhibited a 10(4)-fold decrease in k(cat)/K(M) for PRPP; the K100A enzyme suffered a 50-fold decrease. Alanine mutations at His105 and Glu107 produced 40- and 7-fold decreases in k(cat)/K(M), respectively, and E101A, D104A, and G106A were slightly faster than the wild-type (WT) in terms of k(cat), with minor effects on k(cat)/K(M). Equilibrium binding of OMP or PRPP in binary complexes was affected little by loop mutation, suggesting that the energetics of ground-state binding have little contribution from the catalytic loop, or that a favorable binding energy is offset by costs of loop reorganization. Pre-steady-state kinetics for mutants showed that K103A and E107A had lost the burst of product formation in each direction that indicated rapid on-enzyme chemistry for WT, but that the burst was retained by H105A. Δ102Δ106, a loop-shortened enzyme with Ala102 and Gly106 deleted, showed a 10(4)-fold reduction of k(cat) but almost unaltered K(D) values for all four substrate molecules. The 20% (i.e., 1.20) intrinsic [1'-(3)H]OMP kinetic isotope effect (KIE) for WT is masked because of high forward and reverse commitment factors. K103A failed to express intrinsic KIEs fully (1.095 ± 0.013). In contrast, H105A, which has a smaller catalytic lesion, gave a [1'-(3)H]OMP KIE of 1.21 ± 0.0005, and E107A (1.179 ± 0.0049) also gave high values. These results are interpreted in the context of the X-ray structure of the complete substrate complex for the enzyme [Grubmeyer, C., Hansen, M. R., Fedorov, A. A., and Almo, S. C. (2012) Biochemistry 51 (preceding paper in this issue, DOI 10.1021/bi300083p )]. The full expression of KIEs by H105A and E107A may result from a less secure closure of the catalytic loop

  3. Digital phase-lock loop

    NASA Technical Reports Server (NTRS)

    Thomas, Jr., Jess B. (Inventor)

    1991-01-01

    An improved digital phase lock loop incorporates several distinctive features that attain better performance at high loop gain and better phase accuracy. These features include: phase feedback to a number-controlled oscillator in addition to phase rate; analytical tracking of phase (both integer and fractional cycles); an amplitude-insensitive phase extractor; a more accurate method for extracting measured phase; a method for changing loop gain during a track without loss of lock; and a method for avoiding loss of sampled data during computation delay, while maintaining excellent tracking performance. The advantages of using phase and phase-rate feedback are demonstrated by comparing performance with that of rate-only feedback. Extraction of phase by the method of modeling provides accurate phase measurements even when the number-controlled oscillator phase is discontinuously updated.

  4. Criteria for saturated magnetization loop

    NASA Astrophysics Data System (ADS)

    Harres, A.; Mikhov, M.; Skumryev, V.; Andrade, A. M. H. de; Schmidt, J. E.; Geshev, J.

    2016-03-01

    Proper estimation of magnetization curve parameters is vital in studying magnetic systems. In the present article, criteria for discrimination non-saturated (minor) from saturated (major) hysteresis loops are proposed. These employ the analysis of (i) derivatives of both ascending and descending branches of the loop, (ii) remanent magnetization curves, and (iii) thermomagnetic curves. Computational simulations are used in order to demonstrate their validity. Examples illustrating the applicability of these criteria to well-known real systems, namely Fe3O4 and Ni fine particles, are provided. We demonstrate that the anisotropy-field value estimated from a visual examination of an only apparently major hysteresis loop could be more than two times lower than the real one.

  5. Waves in Solar Coronal Loops

    NASA Astrophysics Data System (ADS)

    Wang, T. J.

    2016-02-01

    The corona is visible in the optical band only during a total solar eclipse or with a coronagraph. Coronal loops are believed to be plasma-filled closed magnetic flux anchored in the photosphere. Based on the temperature regime, they are generally classified into cool, warm, and hot loops. The magnetized coronal structures support propagation of various types of magnetohydrodynamics (MHD) waves. This chapter reviews the recent progress made in studies based on observations of four types of wave phenomena mainly occurring in coronal loops of active regions, including: flare-excited slow-mode waves; impulsively excited kink-mode waves; propagating slow magnetoacoustic waves; and ubiquitous propagating kink (Alfvénic) waves. This review not only comprehensively discusses these waves and coronal seismology but also topics that are newly emerging or hotly debated in order to provide the reader with useful guidance on further studies.

  6. How the Awareness of u-Healthcare Service and Health Conditions Affect Healthy Lifestyle: An Empirical Analysis Based on a u-Healthcare Service Experience

    PubMed Central

    Youm, Sekyoung

    2015-01-01

    Abstract Objective: The objectives of this study are (1) to establish a ubiquitous healthcare (u-healthcare) center for those who wish to use u-healthcare, allowing them to experience the service, and (2) to evaluate the users' awareness and expectations of the service based on their overall assessment. Materials and Methods: To establish the u-healthcare center, a kiosk, devices for health checkup, a body-type examination system, and a physical fitness assessment system were installed. Also, a u-healthcare Web site was developed. A survey was conducted on 280 individuals who visited the u-healthcare center and used the service, to determine (1) individual awareness of u-healthcare before using the service and their change of perception after use, (2) factors that affect the use of u-healthcare, and (3) the effects of disease awareness on exercise habits. Results: Only 25.4% of the participants were aware of u-healthcare, and only 36% who saw the u-healthcare center recognized that it was where the u-healthcare service was provided. The group of individuals who were willing to use the u-healthcare showed statistically significant differences in their satisfaction with the overall environment of the center, as well as the specificity of the descriptions, examination results, kindness of the staff, and their responses. Additionally, the group of individuals who were diagnosed with chronic diseases and the group who were not showed statistically significant differences in the number of days on which they exercised lightly or took a walk. Conclusions: To promote the usage of u-healthcare service, the understanding of the service and the credibility of examination results need to be increased by sharing successful cases. Furthermore, to expand the use of the system that allows a person to regularly check his or her state of health, a lifelong periodical management system linked with another medical welfare program will be needed. PMID:25635473

  7. Changing nutrient stoichiometry affects phytoplankton production, DOP build up and dinitrogen fixation - a mesocosm experiment in the eastern tropical North Atlantic

    NASA Astrophysics Data System (ADS)

    Meyer, J.; Löscher, C. R.; Neulinger, S. C.; Reichel, A. F.; Loginova, A.; Borchard, C.; Schmitz, R. A.; Hauss, H.; Kiko, R.; Riebesell, U.

    2015-07-01

    Ocean deoxygenation due to climate change may alter redox-sensitive nutrient cycles in the marine environment. The productive eastern tropical North Atlantic (ETNA) upwelling region may be particularly affected when the relatively moderate oxygen minimum zone (OMZ) deoxygenates further and microbially-driven nitrogen (N) loss processes are promoted. Consequently, water masses with a low N : P ratio could reach the euphotic layer, possibly influencing primary production in those waters. Previous mesocosm studies in the oligotrophic Atlantic Ocean identified N availability as controlling of primary production, while a possible co-limitation of nitrate and phosphate (P) could not be ruled out. To better understand the impact of changing N : P ratios on primary production and on N2 fixation in the ETNA surface ocean, we conducted land-based mesocosm experiments with natural plankton communities and applied a broad range of N : P ratios (2.67-48). Silicate was supplied at 15 μmol L-1 in all mesocosms. We monitored nutrient drawdown, bloom formation, biomass build up and diazotrophic feedback in response to variable nutrient stoichiometry. Our results confirmed N to be limiting to primary production. We found that excess P was channeled through particulate organic matter (POP) into the dissolved organic matter (DOP) pool. In mesocosms with low P availability, DOP was utilized while N2 fixation increased, suggesting a link between those two processes. Interestingly this observation was most pronounced in mesocosms where inorganic N was still available, indicating that bioavailable N does not necessarily has to have a negative impact on N2 fixation. We observed a shift from a mixed cyanobacterial/proteobacterial dominated active diazotrophic community towards diazotrophic diatom symbionts of the Richelia-Rhizosolenia symbiosis. We hypothesize that a potential change in nutrient stoichiometry in the ETNA might lead to a general shift within the diazotrophic community

  8. How do soil texture, plant community composition and earthworms affected the infiltration rate in a grassland plant diversity experiment depending on season?

    NASA Astrophysics Data System (ADS)

    Fischer, Christine; Britta, Merkel; Nico, Eisenhauer; Christiane, Roscher; Sabine, Attinger; Stefan, Scheu; Anke, Hildebrandt

    2013-04-01

    Background and aims: In this study we analyzed the influences of plant community characteristics, soil texture and earthworm presence on infiltration rates on a managed grassland plant diversity experiment assessing the role of biotic and abiotic factors on soil hydrology. Methods: We measured infiltration using a hood infiltrometer in subplots with ambient and reduced earthworm density (earthworm extraction) nested in plots of different plant species richness (1, 4, and 16), plant functional group number and composition (1 to 4; legumes, grasses, small herbs, tall herbs) in early summer (June) and autumn (September, October) 2011. Results: The presence of certain plant functional groups such as grasses and legumes influenced infiltration rates and this effect enhanced during the growing season. Infiltration was significantly higher in plots containing legumes than in plots without, and it was significantly lower in the presence of grasses than in their absence. In early summer, earthworm presence and biomass increased the infiltration rates, independently of plant species richness. In October, plant species richness only affected infiltration rates in reduced earthworm plots. At the end of the growing season earthworm populations were negatively influenced by grasses and positively by legumes. In September, infiltration rates were positive related to the proportion of finer grains. The correlation disappears when removing all plots containing legumes from the sample. For all measurements the infiltration rates decreases from early summer to autumn at the matric potentials at pressure zero and -0.02 m, but not for smaller macropores at matric potentials -0.04 and -0.06m. Conclusions: Considering infiltration rates as ecosystem function, this function will largely depend on the ecosystem composition and season, not on biodiversity per se. Our results indicate that biotic factors are of overriding influence for shaping infiltration rates mainly for larger macropores

  9. All digital pulsewidth control loop

    NASA Astrophysics Data System (ADS)

    Huang, Hong-Yi; Jan, Shiun-Dian; Pu, Ruei-Iun

    2013-03-01

    This work presents an all-digital pulsewidth control loop (ADPWCL). The proposed system accepts a wide range of input duty cycles and performs a fast correction to the target output pulsewidth. An all-digital delay-locked loop (DLL) with fast locking time using a simplified time to digital converter and a new differential two-step delay element is proposed. The area of the delay element is much smaller than that in conventional designs, while having the same delay range. A test chip is verified in a 0.18-µm CMOS process. The measured duty cycle ranges from 4% to 98% with 7-bit resolution.

  10. Loop quantum cosmology: an overview

    NASA Astrophysics Data System (ADS)

    Ashtekar, Abhay

    2009-04-01

    A brief overview of loop quantum cosmology of homogeneous isotropic models is presented with emphasis on the origin of and subtleties associated with the resolution of big bang and big crunch singularities. These results bear out the remarkable intuition that John Wheeler had. Discussion is organized at two levels. The the main text provides a bird’s eye view of the subject that should be accessible to non-experts. Appendices address conceptual and technical issues that are often raised by experts in loop quantum gravity and string theory.

  11. Modeling of compact loop antennas

    NASA Astrophysics Data System (ADS)

    Baity, F. W.

    1987-09-01

    A general compact loop antenna model which treats all elements of the antenna as lossy transmission lines has been developed. In addition to capacitively tuned resonant double loop (RDL) antennas, the model treats sub-tuned RDL antennas. Calculations using the model have been compared with measurements on full-scale mock-ups of RDL antennas for ATF and TFTR in order to refine the transmission line parameters. Results from the model are presented for RDL antenna designs for ATF, TFTR, Tore Supra, and the Compact Ignition Tokamak (CIT).

  12. Many Ways to Loop DNA

    PubMed Central

    Griffith, Jack D.

    2013-01-01

    In the 1960s, I developed methods for directly visualizing DNA and DNA-protein complexes using an electron microscope. This made it possible to examine the shape of DNA and to visualize proteins as they fold and loop DNA. Early applications included the first visualization of true nucleosomes and linkers and the demonstration that repeating tracts of adenines can cause a curvature in DNA. The binding of DNA repair proteins, including p53 and BRCA2, has been visualized at three- and four-way junctions in DNA. The trombone model of DNA replication was directly verified, and the looping of DNA at telomeres was discovered. PMID:24005675

  13. Automated Detection of Solar Loops by the Oriented Connectivity Method

    NASA Technical Reports Server (NTRS)

    Lee, Jong Kwan; Newman, Timothy S.; Gary, G. Allen

    2004-01-01

    An automated technique to segment solar coronal loops from intensity images of the Sun s corona is introduced. It exploits physical characteristics of the solar magnetic field to enable robust extraction from noisy images. The technique is a constructive curve detection approach, constrained by collections of estimates of the magnetic fields orientation. Its effectiveness is evaluated through experiments on synthetic and real coronal images.

  14. The desensitization gate of inhibitory Cys-loop receptors

    NASA Astrophysics Data System (ADS)

    Gielen, Marc; Thomas, Philip; Smart, Trevor G.

    2015-04-01

    Cys-loop neurotransmitter-gated ion channels are vital for communication throughout the nervous system. Following activation, these receptors enter into a desensitized state in which the ion channel shuts even though the neurotransmitter molecules remain bound. To date, the molecular determinants underlying this most fundamental property of Cys-loop receptors have remained elusive. Here we present a generic mechanism for the desensitization of Cys-loop GABAA (GABAARs) and glycine receptors (GlyRs), which both mediate fast inhibitory synaptic transmission. Desensitization is regulated by interactions between the second and third transmembrane segments, which affect the ion channel lumen near its intracellular end. The GABAAR and GlyR pore blocker picrotoxin prevented desensitization, consistent with its deep channel-binding site overlapping a physical desensitization gate.

  15. Instability phenomenon in an external-loop three-phase gas-liquid-solid airlift reactor

    SciTech Connect

    Douek, R.S.; Livingston, A.G.; Hewitt, G.F.

    1995-11-01

    Three-phase airlift (TPAL) reactors have applications ranging from biotechnology to catalytic hydrogenation. Circulation in a loop consisting of a riser and downcomer with top and bottom connections is induced by injecting gas at the bottom of the riser. The continuous liquid phase recirculates up the riser and down the downcomer, carrying the solid phase in suspension. A hydrodynamic model was developed for TPAL reactors which enables the prediction of main variables of a TPAL reactor (phase holdups and liquid recirculation velocity) as a function of the inlet gas superficial velocity and the solids loading. This model considers a TPAL reactor to comprise riser and downcomer sections alone; the difference in the effective densities between these regions gives rise to the recirculation. As part of a program of experimental work aimed at verifying this model, it was decided to carry out experiments on an external-loop reactor which would generate direct measurements of the required riser and downcomer hydrodynamic parameters. During the course of these experiments, however,a surprising and before now unreported instability phenomenon was observed. This behavior prevented the system from reaching a steady distribution of solids. In general, instabilities are undesirable since they could adversely affect the system control and performance. The objective of this article is to describe the observed phenomenon and attempt to explain why it occurs.

  16. Distributed Raman temperature measurement system for monitoring of nuclear power plant coolant loops

    NASA Astrophysics Data System (ADS)

    Jensen, Fredrik B. H.; Takada, Eiji; Nakazawa, Masaharu; Kakuta, Tsunemi; Yamamoto, Satoshi

    1996-09-01

    A distributed temperature sensor based on Raman scattering in optical fibers has been tested for use as coolant loop monitor in nuclear power plants. Different types of pure- silica-core, polyimide-coated fibers have been subjected to 60Co-gamma-ray and fission-reactor irradiation at varying temperatures. 60Co-gamma-ray irradiations at dose rates from 4.8 kR/h up to 1 MR/h were done. Simultaneous gamma-ray and high temperature experiments up to 300 degrees Celsius have also been performed. The induced loss of the tested fibers was found to saturate with increasing dose at the anti-Stokes and Stokes wavelengths. This feature was then made use of to develop a model for radiation induced loss which was used to make system lifetime predictions. It has also been demonstrated that the induced loss of the optical fibers is favorably affected by high-temperature use. A 10-fold decrease in the radiation- induced loss levels when the system was operated at 300 degrees Celsius was observed, as compared with room- temperature operation. The experiments have shown that with a pure-silica-core, polyimide-coated fiber the temperature sensing capabilities of the RDTS will not be degraded excessively if used at primary coolant loops with an expected upper radiation level of 200 R/hr.

  17. Speed-Accuracy Trade-Off in Skilled Typewriting: Decomposing the Contributions of Hierarchical Control Loops

    ERIC Educational Resources Information Center

    Yamaguchi, Motonori; Crump, Matthew J. C.; Logan, Gordon D.

    2013-01-01

    Typing performance involves hierarchically structured control systems: At the higher level, an outer loop generates a word or a series of words to be typed; at the lower level, an inner loop activates the keystrokes comprising the word in parallel and executes them in the correct order. The present experiments examined contributions of the outer-…

  18. Instructional Modifications, Adaptations, and Accommodations of Coteachers Who Loop: A Descriptive Case Study

    ERIC Educational Resources Information Center

    Nevin, Ann I.; Cramer, Elizabeth; Voigt, Jorine; Salazar, Liliana

    2008-01-01

    When teachers move to the next grade with their students, they are sometimes referred to as teachers who loop with the children. In this descriptive case study, the authors describe the experiences of two teachers who collaborate with others as they move with a class of students from third to fourth grade (i.e., looping). The classroom context,…

  19. Closing the Loop with Exercises

    ERIC Educational Resources Information Center

    Altizer, Andy

    2008-01-01

    Conducting exercises provides a critical bridge between the theory of an Emergency Action Plan and its effective implementation. When conducted properly, exercises can fill the gap between training and after-action review to close the preparedness loop--before an actual emergency occurs. Often exercises are planned and conducted on campus based on…

  20. Manchester transition tracking loop (MTTL)

    NASA Technical Reports Server (NTRS)

    Cellier, A.; Ma, L. N.; Huey, D. C.

    1977-01-01

    In new tracking loop, separate phase detection algorithm is incorporated for acquisition; programmed acquisition-to-track sequence includes automatic bandwidth switching. Additionally, system has very effective phase detection signal-to-noise ratio and can operate at any rate by changing master clock frequency. All system parameters remain constant.

  1. Perception as a closed-loop convergence process

    PubMed Central

    Ahissar, Ehud; Assa, Eldad

    2016-01-01

    Perception of external objects involves sensory acquisition via the relevant sensory organs. A widely-accepted assumption is that the sensory organ is the first station in a serial chain of processing circuits leading to an internal circuit in which a percept emerges. This open-loop scheme, in which the interaction between the sensory organ and the environment is not affected by its concurrent downstream neuronal processing, is strongly challenged by behavioral and anatomical data. We present here a hypothesis in which the perception of external objects is a closed-loop dynamical process encompassing loops that integrate the organism and its environment and converging towards organism-environment steady-states. We discuss the consistency of closed-loop perception (CLP) with empirical data and show that it can be synthesized in a robotic setup. Testable predictions are proposed for empirical distinction between open and closed loop schemes of perception. DOI: http://dx.doi.org/10.7554/eLife.12830.001 PMID:27159238

  2. MHD Modeling of Coronal Loops: the Transition Region Throat

    NASA Technical Reports Server (NTRS)

    Guarrasi, M.; Reale, F.; Orlando, S.; Mignone, A.; Klimchuk, J. A.

    2014-01-01

    Context. The expansion of coronal loops in the transition region may considerably influence the diagnostics of the plasma emission measure. The cross-sectional area of the loops is expected to depend on the temperature and pressure, and might be sensitive to the heating rate. Aims. The approach here is to study the area response to slow changes in the coronal heating rate, and check the current interpretation in terms of steady heating models. Methods. We study the area response with a time-dependent 2D magnetohydrodynamic (MHD) loop model, including the description of the expanding magnetic field, coronal heating and losses by thermal conduction, and radiation from optically thin plasma. We run a simulation for a loop 50 Mm long and quasi-statically heated to about 4 millikelvin. Results. We find that the area can change substantially with the quasi-steady heating rate, e.g., by approx. 40% at 0.5 millikelvin as the loop temperature varies between 1 millikelvin and 4 millikelvin, and, therefore, affects the interpretation of the differential emission measure vs. temperature (DEM(T)) curves.

  3. A modified PN code tracking loop - Its performance analysis and comparative evaluation

    NASA Astrophysics Data System (ADS)

    Yost, R. A.; Boyd, R. W.

    1982-05-01

    A modified PN code tracking loop (MCTL) has been reported by Yost and Boyd (1980). The MCTL makes it possible to reduce the hardware complexity of a noncoherent delay lock loop in multiple data rate applications. The MCTL utilizes the on-time or data channel as the reference. This concept eliminates the need for the traditional loop's sum channel (early signal plus late signal) and, hence, the hardware associated with that channel. This saving may be substantial if the channel were to be optimized for a number of different data rates. With the elimination of an entire IF channel, the MCTL complexity is nearly equivalent to the dithering loop for PN code tracking considered by Hartmann (1974). However, the MCTL does not suffer the loss in tracking performance (with respect to the traditional loop) that the dithering loop experiences.

  4. Development of closed loop roll control for magnetic balance systems

    NASA Technical Reports Server (NTRS)

    Covert, E. E.; Haldeman, C. W.; Ramohalli, G.; Way, P.

    1982-01-01

    This research was undertaken with the goal of demonstrating closed loop control of the roll degree of freedom on the NASA prototype magnetic suspension and balance system at the MIT Aerophysics Laboratory, thus, showing feasibility for a roll control system for any large magnetic balance system which might be built in the future. During the research under this grant, study was directed toward the several areas of torque generation, position sensing, model construction and control system design. These effects were then integrated to produce successful closed loop operation of the analogue roll control system. This experience indicated the desirability of microprocessor control for the angular degrees of freedom.

  5. Using DNA looping to measure sequence dependent DNA elasticity

    NASA Astrophysics Data System (ADS)

    Kandinov, Alan; Raghunathan, Krishnan; Meiners, Jens-Christian

    2012-10-01

    We are using tethered particle motion (TPM) microscopy to observe protein-mediated DNA looping in the lactose repressor system in DNA constructs with varying AT / CG content. We use these data to determine the persistence length of the DNA as a function of its sequence content and compare the data to direct micromechanical measurements with constant-force axial optical tweezers. The data from the TPM experiments show a much smaller sequence effect on the persistence length than the optical tweezers experiments.

  6. Operational Results of a Closed Brayton Cycle Test-Loop

    NASA Astrophysics Data System (ADS)

    Wright, Steven A.; Fuller, Robert; Lipinski, Ronald J.; Nichols, Kenneth; Brown, Nicholas

    2005-02-01

    A number of space and terrestrial power system designs plan to use nuclear reactors that are coupled to Closed-loop Brayton Cycle (CBC) systems to generate electrical power. Because very little experience exists regarding the operational behavior of these systems, Sandia National Laboratories (through its Laboratory Directed Research and Development program) is developing a closed-loop test bed that can be used to determine the operational behavior of these systems and to validate models for these systems. Sandia has contracted Barber-Nichols Corporation to design, fabricate, and assemble a Closed-loop Brayton Cycle (CBC) system. This system was developed by modifying commercially available hardware. It uses a 30 kWe Capstone C-30 gas-turbine unit (www.capstoneturbine.com) with a modified housing that permits the attachment of an electrical heater and a water cooled chiller that are connected to the turbo-machinery in a closed loop. The test-loop reuses the Capstone turbine, compressor, and alternator. The Capstone system's nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system are also reused. The rotational speed of the turbo-machinery is controlled either by adjusting the alternator load by either using the electrical grid or a separate load bank. This report describes the test-loop hardware SBL-30 (Sandia Brayton Loop-30kWe). Also presented are results of early testing and modeling of the unit. The SBL-30 hardware is currently configured with a heater that is limited to 80 kWth with a maximum outlet temperature of ˜1000 K.

  7. Operational results of a Closed Brayton Cycle test-loop.

    SciTech Connect

    Fuller, Robert; Wright, Steven Alan; Nichols, Kenneth Graham.; Brown, Nicholas; Lipinski, Ronald J.

    2004-11-01

    A number of space and terrestrial power system designs plan to use nuclear reactors that are coupled to Closed-loop Brayton Cycle (CBC) systems to generate electrical power. Because very little experience exists regarding the operational behavior of these systems, Sandia National Laboratories (through its Laboratory Directed Research and Development program) is developing a closed-loop test bed that can be used to determine the operational behavior of these systems and to validate models for these systems. Sandia has contracted Barber-Nichols Corporation to design, fabricate, and assemble a Closed-loop Brayton Cycle (CBC) system. This system was developed by modifying commercially available hardware. It uses a 30 kWe Capstone C-30 gas-turbine unit (www.capstoneturbine.com) with a modified housing that permits the attachment of an electrical heater and a water cooled chiller that are connected to the turbo-machinery in a closed loop. The test-loop reuses the Capstone turbine, compressor, and alternator. The Capstone system's nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system are also reused. The rotational speed of the turbo-machinery is controlled either by adjusting the alternator load by either using the electrical grid or a separate load bank. This report describes the test-loop hardware SBL-30 (Sandia Brayton Loop-30kWe). Also presented are results of early testing and modeling of the unit. The SBL-30 hardware is currently configured with a heater that is limited to 80 kW{sub th} with a maximum outlet temperature of {approx}1000 K.

  8. Loop interactions during catalysis by dihydrofolate reductase from Moritella profunda.

    PubMed

    Behiry, Enas M; Evans, Rhiannon M; Guo, Jiannan; Loveridge, E Joel; Allemann, Rudolf K

    2014-07-29

    Dihydrofolate reductase (DHFR) is often used as a model system to study the relation between protein dynamics and catalysis. We have studied a number of variants of the cold-adapted DHFR from Moritella profunda (MpDHFR), in which the catalytically important M20 and FG loops have been altered, and present a comparison with the corresponding variants of the well-studied DHFR from Escherichia coli (EcDHFR). Mutations in the M20 loop do not affect the actual chemical step of transfer of hydride from reduced nicotinamide adenine dinucleotide phosphate to the substrate 7,8-dihydrofolate in the catalytic cycle in either enzyme; they affect the steady state turnover rate in EcDHFR but not in MpDHFR. Mutations in the FG loop also have different effects on catalysis by the two DHFRs. Despite the two enzymes most likely sharing a common catalytic cycle at pH 7, motions of these loops, known to be important for progression through the catalytic cycle in EcDHFR, appear not to play a significant role in MpDHFR. PMID:25014120

  9. Self-contact modeling on beams experiencing loop formation

    NASA Astrophysics Data System (ADS)

    Gay Neto, Alfredo; Pimenta, Paulo M.; Wriggers, Peter

    2015-01-01

    Many engineering scenarios involve contact between beam structures or, eventually, self-contact. Specifically when dealing with a beam submitted to large torsion loads and considering large displacements and rotations, it is possible to occur self-contact. Beams with low bending stiffness loaded with large torsion can present a loop, followed by self-contact and sometimes a snarl formation. This work presents a numerical model and numerical procedures to solve such a kind of self-contact in beams under loop formation. Numerical examples are presented in the context of initially straight nitinol beams. Numerical tests showed that friction may influence loop and snarling formation. Numerical models could predict self-contact occurrence events with good agreement with experimental results already published in literature. Snarling patterns (when occurred) were also predicted correctly, but with delay when compared to experiments. This delay showed to be friction-dependent.

  10. What's in the loop? The anatomy of double Higgs production

    NASA Astrophysics Data System (ADS)

    Dawson, S.; Ismail, A.; Low, Ian

    2015-06-01

    Determination of Higgs self-interactions through the double Higgs production from gluon fusion is a major goal of current and future collider experiments. We point out this channel could help disentangle and resolve the nature of ultraviolet contributions to Higgs couplings to two gluons. Analytic properties of the double Higgs amplitudes near kinematic threshold are used to study features resulting from scalar and fermionic loop particles mediating the interaction. Focusing on the h h invariant mass spectrum, we consider the effect from anomalous top and bottom Yukawa couplings, as well as from scalar and fermionic loop particles. In particular, the spectrum at high h h invariant mass is sensitive to the spin of the particles in the loop.

  11. Loop and water effect on stability of intertriplex DNA

    NASA Astrophysics Data System (ADS)

    Yang, Linjing; Lee, Imshik; Wang, Chen; Li, Qing; Bai, Chunli

    1998-02-01

    Stability of four intratriplexes and one intertriplex influenced by loops and water have been investigated by molecular mechanics calculation. The four intratriplexes are 5'-d(TC) 6-d(T) m-d(CT) 6-d(C) n-d(AG) 6-3' ( m, n = 3 or 4), the corresponding intertriplex is d(TC) 6∗d(AG) 6·d(CT) 6 (·, Watson-Crick hydrogen bond; ∗, Hoogsteen hydrogen bond). We studied in detail how loops and water would effect intra- and interstrand interactions of the five triplexes, respectively. The results showed that the existence of loops may have limited impact on the stability of the concerned triplex structures, regardless of water environment. In contrast, water molecules do have appreciable effects on triplex stability. Sugar conformations of the five triplexes were also discussed in this paper. The theoretical results are in good agreement with the FT-IR experiments.

  12. Principles of agonist recognition in Cys-loop receptors

    PubMed Central

    Lynagh, Timothy; Pless, Stephan A.

    2014-01-01

    Cys-loop receptors are ligand-gated ion channels that are activated by a structurally diverse array of neurotransmitters, including acetylcholine, serotonin, glycine, and GABA. After the term “chemoreceptor” emerged over 100 years ago, there was some wait until affinity labeling, molecular cloning, functional studies, and X-ray crystallography experiments identified the extracellular interface of adjacent subunits as the principal site of agonist binding. The question of how subtle differences at and around agonist-binding sites of different Cys-loop receptors can accommodate transmitters as chemically diverse as glycine and serotonin has been subject to intense research over the last three decades. This review outlines the functional diversity and current structural understanding of agonist-binding sites, including those of invertebrate Cys-loop receptors. Together, this provides a framework to understand the atomic determinants involved in how these valuable therapeutic targets recognize and bind their ligands. PMID:24795655

  13. Evolution in a Braided Loop Ensemble

    NASA Video Gallery

    This braided loop has several loops near the 'base' that appear to be unwinding with significant apparent outflow. This is evidence of untwisting, and the braided structure also seeming to unwind w...

  14. Fragmentation of cosmic-string loops

    NASA Technical Reports Server (NTRS)

    York, Thomas

    1989-01-01

    The fragmentation of cosmic string loops is discussed, and the results of a simulation of this process are presented. The simulation can evolve any of a large class of loops essentially exactly, including allowing fragments that collide to join together. Such reconnection enhances the production of small fragments, but not drastically. With or without reconnections, the fragmentation process produces a collection of nonself-intersecting loops whose typical length is on the order of the persistence length of the initial loop.

  15. Mechanism of promoter repression by Lac repressor-DNA loops.

    PubMed

    Becker, Nicole A; Peters, Justin P; Maher, L James; Lionberger, Troy A

    2013-01-01

    The Escherichia coli lactose (lac) operon encodes the first genetic switch to be discovered, and lac remains a paradigm for studying negative and positive control of gene expression. Negative control is believed to involve competition of RNA polymerase and Lac repressor for overlapping binding sites. Contributions to the local Lac repressor concentration come from free repressor and repressor delivered to the operator from remote auxiliary operators by DNA looping. Long-standing questions persist concerning the actual role of DNA looping in the mechanism of promoter repression. Here, we use experiments in living bacteria to resolve four of these questions. We show that the distance dependence of repression enhancement is comparable for upstream and downstream auxiliary operators, confirming the hypothesis that repressor concentration increase is the principal mechanism of repression loops. We find that as few as four turns of DNA can be constrained in a stable loop by Lac repressor. We show that RNA polymerase is not trapped at repressed promoters. Finally, we show that constraining a promoter in a tight DNA loop is sufficient for repression even when promoter and operator do not overlap. PMID:23143103

  16. Run-time parallelization and scheduling of loops

    NASA Technical Reports Server (NTRS)

    Saltz, Joel H.; Mirchandaney, Ravi; Baxter, Doug

    1988-01-01

    The class of problems that can be effectively compiled by parallelizing compilers is discussed. This is accomplished with the doconsider construct which would allow these compilers to parallelize many problems in which substantial loop-level parallelism is available but cannot be detected by standard compile-time analysis. We describe and experimentally analyze mechanisms used to parallelize the work required for these types of loops. In each of these methods, a new loop structure is produced by modifying the loop to be parallelized. We also present the rules by which these loop transformations may be automated in order that they be included in language compilers. The main application area of the research involves problems in scientific computations and engineering. The workload used in our experiment includes a mixture of real problems as well as synthetically generated inputs. From our extensive tests on the Encore Multimax/320, we have reached the conclusion that for the types of workloads we have investigated, self-execution almost always performs better than pre-scheduling. Further, the improvement in performance that accrues as a result of global topological sorting of indices as opposed to the less expensive local sorting, is not very significant in the case of self-execution.

  17. Limb Looking: The effects of background subtraction on the temperature of SXT loops.

    NASA Astrophysics Data System (ADS)

    Medlin, D. A.; Blevins, H. T.; Schmelz, J. T.

    2003-05-01

    Knowing the temperature distribution along a loop is one possible test for the coronal heating models. The matter of how background subtraction may or may not affect the temperature distribution of loops could also play a crucial role in this analysis. Several instruments are currently available for loop studies, and numerous techniques are used to determine the temperature distributions along the loops. This has lead to many different, and mostly conflicting temperature results. We have chosen the Soft X-ray Telescope (SXT), aboard the Japanese satellite Yohkoh, for this study. The SXT data archives were searched for possible loop candidates. A set of loops on the limb, as well as a set of loops on the disk, were chosen for analysis. Temperature maps were generated for each loop with and without background subtraction. For each loop, we used both a uniform background subtraction as well as a pixel-by-pixel background subtraction. Once the temperature as a function of arc length has been found, it is then compared to the predictions made by different models. The Solar physics research at the University of Memphis is supported by NASA grants NAG5-9783 and NAG5-12096.

  18. Real-time open-loop control of a 1024-actuator MEMS deformable mirror

    NASA Astrophysics Data System (ADS)

    Blain, Célia; Conan, Rodolphe; Bradley, Colin; Guyon, Olivier; Gamroth, Darryl; Nash, Reston

    2010-07-01

    This article reports the progress made at the University of Victoria AO Lab, regarding the realtime open-loop control of a 1024-actuator MEMS deformable mirror (DM). The setup is an hybrid woofer-tweeter/open-loop bench. A tip-tilt mirror and a woofer DM (a 57-actuator CILAS DM) are driven in closed-loop while a 1024-actuator MEMS DM is utilized on a parallel open-loop path. Previous work shows that open-loop control providing low residual error (with frozen Kolmogorov turbulence) can be obtained without the need of DM modelling. A preliminary methodical calibration of the DM is employed instead. The MEMS electronics were upgraded to an update rate of 500 Hz and the experiment lays the groundwork for showing how these performances can also be achieved on the bench with dynamic turbulence (created with custom hot air turbulence generators). The current status of the experiment and the next milestones are presented.

  19. Hard thermal loops in static external fields

    SciTech Connect

    Frenkel, J.; Takahashi, N.; Pereira, S. H.

    2009-04-15

    We examine, in the imaginary-time formalism, the high temperature behavior of n-point thermal loops in static Yang-Mills and gravitational fields. We show that in this regime, any hard thermal loop gives the same leading contribution as the one obtained by evaluating the loop integral at zero external energies and momenta.

  20. The Statistical Loop Analyzer (SLA)

    NASA Technical Reports Server (NTRS)

    Lindsey, W. C.

    1985-01-01

    The statistical loop analyzer (SLA) is designed to automatically measure the acquisition, tracking and frequency stability performance characteristics of symbol synchronizers, code synchronizers, carrier tracking loops, and coherent transponders. Automated phase lock and system level tests can also be made using the SLA. Standard baseband, carrier and spread spectrum modulation techniques can be accomodated. Through the SLA's phase error jitter and cycle slip measurements the acquisition and tracking thresholds of the unit under test are determined; any false phase and frequency lock events are statistically analyzed and reported in the SLA output in probabilistic terms. Automated signal drop out tests can be performed in order to trouble shoot algorithms and evaluate the reacquisition statistics of the unit under test. Cycle slip rates and cycle slip probabilities can be measured using the SLA. These measurements, combined with bit error probability measurements, are all that are needed to fully characterize the acquisition and tracking performance of a digital communication system.

  1. Microgyroscope with closed loop output

    NASA Technical Reports Server (NTRS)

    Challoner, A. Dorian (Inventor); Gutierrez, Roman C. (Inventor); Tang, Tony K. (Inventor); Cargille, Donald R. (Inventor)

    2002-01-01

    A micro-gyroscope (10) having closed loop operation by a control voltage (V.sub.TY), that is demodulated by an output signal of the sense electrodes (S1, S2), providing Coriolis torque rebalance to prevent displacement of the micro-gyroscope (10) on the output axis (y-axis). The present invention provides wide-band, closed-loop operation for a micro-gyroscope (10) and allows the drive frequency to be closely tuned to a high Q sense axis resonance. A differential sense signal (S1-S2) is compensated and fed back by differentially changing the voltage on the drive electrodes to rebalance Coriolis torque. The feedback signal is demodulated in phase with the drive axis signal (K.sub..omega..crclbar..sub.x) to produce a measure of the Coriolis force.

  2. Loop connectors in dentogenic diastema.

    PubMed

    Nayar, Sanjna; Jayesh, Raghevendra; Venkateshwaran; Dinakarsamy, V

    2015-04-01

    Patients with a missing tooth along with diastema have limited treatment options to restore the edentulous space. The use of a conventional fixed partial denture (FPD) to replace the missing tooth may result in too wide anterior teeth leading to poor esthetics. Loss of anterior teeth with existing diastema may result in excess space available for pontic. This condition presents great esthetic challenge for prosthodontist. If implant supported prosthesis is not possible because of inadequate bone support, FPD along with loop connector may be a treatment option to maintain the diastema and provide optimal esthetic restoration. Here, we report a clinical case where FPD along with loop connector was used to achieve esthetic rehabilitation in maxillary anterior region in which midline diastema has been maintained. PMID:26015732

  3. The corrections from one loop and two-loop Barr-Zee type diagrams to muon MDM in BLMSSM

    NASA Astrophysics Data System (ADS)

    Zhao, Shu-Min; Feng, Tai-Fu; Zhang, Hai-Bin; Yan, Ben; Zhan, Xi-Jie

    2014-11-01

    In a supersymmetric extension of the standard model where baryon and lepton numbers are local gauge symmetries(BLMSSM) and the Yukawa couplings between Higgs doublets and exotic quarks are considered, we study the one loop diagrams and the two-loop Barr-Zee type diagrams with a closed Fermi(scalar) loop between the vector Boson and Higgs. Using the effective Lagrangian method, we deduce the Wilson coefficients of dimension 6 operators contributing to the anomalous magnetic moment of muon, which satisfies the electromagnetic gauge invariance. In the numerical analysis, we consider the experiment constraints from Higgs and neutrino data. In some parameter space, the new physics contribution is large and even reaches 24 × 10-10, which can remedy the deviation well.

  4. Affective Incoherence: When Affective Concepts and Embodied Reactions Clash

    PubMed Central

    Centerbar, David B.; Clore, Gerald L.; Schnall, Simone; Garvin, Erika

    2008-01-01

    In five studies, we examined the effects on cognitive performance of coherence and incoherence between conceptual and experiential sources of affective information. The studies crossed the priming of happy and sad concepts with affective experiences. In different experiments, these included: approach or avoidance actions, happy or sad feelings, and happy or sad expressive behaviors. In all studies, coherence between affective concepts and affective experiences led to better recall of a story than affective incoherence. We suggested that the experience of such experiential affective cues serves as evidence of the appropriateness of affective concepts that come to mind. The results suggest that affective coherence has epistemic benefits, and that incoherence is costly, for cognitive performance. PMID:18361672

  5. Polyhedra in loop quantum gravity

    SciTech Connect

    Bianchi, Eugenio; Speziale, Simone; Dona, Pietro

    2011-02-15

    Intertwiners are the building blocks of spin-network states. The space of intertwiners is the quantization of a classical symplectic manifold introduced by Kapovich and Millson. Here we show that a theorem by Minkowski allows us to interpret generic configurations in this space as bounded convex polyhedra in R{sup 3}: A polyhedron is uniquely described by the areas and normals to its faces. We provide a reconstruction of the geometry of the polyhedron: We give formulas for the edge lengths, the volume, and the adjacency of its faces. At the quantum level, this correspondence allows us to identify an intertwiner with the state of a quantum polyhedron, thus generalizing the notion of the quantum tetrahedron familiar in the loop quantum gravity literature. Moreover, coherent intertwiners result to be peaked on the classical geometry of polyhedra. We discuss the relevance of this result for loop quantum gravity. In particular, coherent spin-network states with nodes of arbitrary valence represent a collection of semiclassical polyhedra. Furthermore, we introduce an operator that measures the volume of a quantum polyhedron and examine its relation with the standard volume operator of loop quantum gravity. We also comment on the semiclassical limit of spin foams with nonsimplicial graphs.

  6. Two-loop quantum gravity

    NASA Astrophysics Data System (ADS)

    van de Ven, Anton E. M.

    1992-07-01

    We prove the existence of a nonrenormalizable infinity in the two-loop effective action of perturbative quantum gravity by means of an explicit calculation. Our final result agrees with that obtained by earlier authors. We use the background-field method in coordinate space, combined with dimensional regularization and a heat kernel representation for the propagators. General covariance is manifestly preserved. Only vacuum graphs in the presence of an on-shell background metric need to be calculated. We extend the background covariant harmonic gauge to include terms nonlinear in the quantum gravitational fields and allow for general reparametrizations of those fields. For a particular gauge choice and field parametrization only two three-graviton and six four-graviton vertices are present in the action. Calculational labor is further reduced by restricting to backgrounds, which are not only Ricci-flat, but satisfy an additional constraint bilinear in the Weyl tensor. To handle the still formidable amount of algebra, we use the symbolic manipulation program FORM. We checked that the on-shell two-loop effective action is in fact independent of all gauge and field redefinition parameters. A two-loop analysis for Yang-Mills fields is included as well, since in that case we can give full details as well as simplify earlier analyses.

  7. Polyhedra in loop quantum gravity

    NASA Astrophysics Data System (ADS)

    Bianchi, Eugenio; Doná, Pietro; Speziale, Simone

    2011-02-01

    Intertwiners are the building blocks of spin-network states. The space of intertwiners is the quantization of a classical symplectic manifold introduced by Kapovich and Millson. Here we show that a theorem by Minkowski allows us to interpret generic configurations in this space as bounded convex polyhedra in R3: A polyhedron is uniquely described by the areas and normals to its faces. We provide a reconstruction of the geometry of the polyhedron: We give formulas for the edge lengths, the volume, and the adjacency of its faces. At the quantum level, this correspondence allows us to identify an intertwiner with the state of a quantum polyhedron, thus generalizing the notion of the quantum tetrahedron familiar in the loop quantum gravity literature. Moreover, coherent intertwiners result to be peaked on the classical geometry of polyhedra. We discuss the relevance of this result for loop quantum gravity. In particular, coherent spin-network states with nodes of arbitrary valence represent a collection of semiclassical polyhedra. Furthermore, we introduce an operator that measures the volume of a quantum polyhedron and examine its relation with the standard volume operator of loop quantum gravity. We also comment on the semiclassical limit of spin foams with nonsimplicial graphs.

  8. Quantum reduced loop gravity and the foundation of loop quantum cosmology

    NASA Astrophysics Data System (ADS)

    Alesci, Emanuele; Cianfrani, Francesco

    2016-06-01

    Quantum reduced loop gravity is a promising framework for linking loop quantum gravity and the effective semiclassical dynamics of loop quantum cosmology. We review its basic achievements and its main perspectives, outlining how it provides a quantum description of the Universe in terms of a cuboidal graph which constitutes the proper framework for applying loop techniques in a cosmological setting.

  9. Brief report: When does identity lead to negative affective experiences? A comparison of Turkish-Bulgarian and Turkish-German adolescents.

    PubMed

    Aydinli-Karakulak, Arzu; Dimitrova, Radosveta

    2016-02-01

    We examine relationships between social identity domains (ethnic, national, and religious) and negative affect among Turkish-Bulgarian and Turkish-German youth. Path analysis confirmed a multiple social identities (MSI) factor that has negative relations to experiencing negative affect for Turkish youth in both countries. Beyond this negative relationship, the component of national identity showed a positive relationship to negative affect for Turkish-Bulgarians, but not for Turkish-Germans. Our findings indicate that beyond the generally adaptive effect of MSI on youth development, unique components of social identity may not always be an asset: In an assimilative acculturation context (i.e., Bulgaria), the endorsement of national identity was not adaptive. Our research therefore highlights the need for a contextually differentiated view on "healthy" identity formation among immigrants for research and practice. PMID:26478532

  10. Changes in Adolescents' Risk Factors Following Peer Sexual Coercion: Evidence for a Feedback Loop

    PubMed Central

    Young, Brennan J.; Furman, Wyndol; Jones, Meredith C.

    2012-01-01

    Investigators have identified a number of factors that increase the risk for experiencing sexual coercion, but as yet little is known about how sexual coercion in turn affects these risk factors. Using a sample of 110 adolescents, the current study examined the hypothesis that, after an incident of sexual coercion, adolescents would exhibit increases in several behaviors known to increase risk for victimization. As predicted, after experiencing sexual coercion, adolescents reported increased externalizing symptoms, more frequent sexual intercourse and a greater total number of intercourse partners. Finally, alcohol use, drug use, and problems related to substance use increased. These findings suggest the presence of a feedback loop, in which the experience of sexual coercion leads to an intensification of the factors that initially contributed risk for coercion. PMID:22559131

  11. How do Individuals with Complete Androgen Insensitivity Syndrome, Mayer-Rokitansky-Küster-Hauser Syndrome or Polycystic Ovary Syndrome Experience Contact to Other Affected Persons?

    PubMed Central

    Krupp, K.; Fliegner, M.; Brunner, F.; Brucker, S.; Rall, K.; Richter-Appelt, H.

    2012-01-01

    Persons with different sex characteristics may suffer from a feeling of being “different” or “not normal”. In this study, persons with one of 3 diagnoses (complete androgen insensitivity syndrome [CAIS]; Mayer-Rokitansky-Küster-Hauser syndrome [MRKHS], polycystic ovary syndrome [PCOS]) were asked whether they had contact to other affected persons and how they assessed this contact. The correlation between contact and psychological distress was evaluated. Material and Methods: Information on contacts to other affected individuals was obtained using a written questionnaire. Psychological distress was measured using the German version of the BSI (Brief Symptom Inventory). Results: Data from 11 individuals with CAIS, 49 women with MRKHS and 55 women with PCOS was analysed. The frequency of contacts to other affected individuals differed between the different diagnostic groups (with the highest frequency reported for the group with CAIS, and the lowest for the group with PCOS). Overall, the majority of individuals considered such contacts beneficial (CAIS 81.8 %; MRKHS 90 %; PCOS 83.3 %). The frequency of contacts and their assessment were not found to be correlated with psychological distress. The three diagnostic groups differed in the proportion of people who indicated a wish for contact with other affected persons. The desire to have contact with other affected persons was most commonly expressed by women with PCOS and high levels of psychological distress (60.9 %). Conclusion: Persons with different sex characteristics can benefit from contact to other affected individuals. Particularly women with PCOS and increased levels of psychological distress may benefit if the issue of support groups is addressed during treatment. PMID:25258457

  12. Simulations of Solar Jets Confined by Coronal Loops

    NASA Astrophysics Data System (ADS)

    Wyper, P. F.; DeVore, C. R.

    2016-03-01

    Coronal jets are collimated, dynamic events that occur over a broad range of spatial scales in the solar corona. In the open magnetic field of coronal holes, jets form quasi-radial spires that can extend far out into the heliosphere, while in closed-field regions the jet outflows are confined to the corona. We explore the application of the embedded-bipole model to jets occurring in closed coronal loops. In this model, magnetic free energy is injected slowly by footpoint motions that introduce twist within the closed dome of the jet source region, and is released rapidly by the onset of an ideal kink-like instability. Two length scales characterize the system: the width (N) of the jet source region and the footpoint separation (L) of the coronal loop that envelops the jet source. We find that both the conditions for initiation and the subsequent dynamics are highly sensitive to the ratio L/N. The longest-lasting and most energetic jets occur along long coronal loops with large L/N ratios, and share many of the features of open-field jets, while smaller L/N ratios produce shorter-duration, less energetic jets that are affected by reflections from the far-loop footpoint. We quantify the transition between these behaviors and show that our model replicates key qualitative and quantitative aspects of both quiet Sun and active-region loop jets. We also find that the reconnection between the closed dome and surrounding coronal loop is very extensive: the cumulative reconnected flux at least matches the total flux beneath the dome for small L/N, and is more than double that value for large L/N.

  13. Premeasured Chordal Loops for Mitral Valve Repair.

    PubMed

    Gillinov, Marc; Quinn, Reed; Kerendi, Faraz; Gaudiani, Vince; Shemin, Richard; Barnhart, Glenn; Raines, Edward; Gerdisch, Marc W; Banbury, Michael

    2016-09-01

    Premeasured expanded polytetrafluoroethylene chordal loops with integrated sutures for attachment to the papillary muscle and leaflet edges facilitate correction of mitral valve prolapse. Configured as a group of 3 loops (length range 12 to 24 mm), the loops are attached to a pledget that is passed through the papillary muscle and tied. Each of the loops has 2 sutures with attached needles; these needles are passed through the free edge of the leaflet and then the sutures are tied to each other, securing the chordal loop to the leaflet. PMID:27549563

  14. Z-Sum approach to loop integrals

    NASA Astrophysics Data System (ADS)

    Rottmann, Paulo A.

    We study the applicability of the Z-Sum approach to multi-loop calculations with massive particles in perturbative quantum field theory. We systematically analyze the case of one-loop scalar integrals, which represent the building blocks of any higher-loop calculation. We focus in particular on triangle one-loop integrals and identify strengths and limitations of the Z-Sum approach, extending our results to the case of one-loop box integrals when appropriate. We conclude with the calculation of a specific physical example: the calculation of heavy flavor corrections to the renormalized scattering amplitude for deep inelastic scattering.

  15. Dynamic Aperture-based Solar Loop Segmentation

    NASA Technical Reports Server (NTRS)

    Lee, Jon Kwan; Newman, Timothy S.; Gary, G. Allen

    2006-01-01

    A new method to automatically segment arc-like loop structures from intensity images of the Sun's corona is introduced. The method constructively segments credible loop structures by exploiting the Gaussian-like shape of loop cross-sectional intensity profiles. The experimental results show that the method reasonably segments most of the well-defined loops in coronal images. The method is only the second published automated solar loop segmentation method. Its advantage over the other published method is that it operates independently of supplemental time specific data.

  16. Open-loop correction of horizontal turbulence: system design and result.

    PubMed

    Mu, Quanquan; Cao, Zhaoliang; Li, Dayu; Hu, Lifa; Xuan, Li

    2008-08-10

    Adaptive optics systems often work in a closed-loop configuration due to the hysteretic and nonlinearity properties of conventional deformable mirrors. Because of the high-precision wavefront generation and nonhysteretic properties of liquid-crystal devices, the open-loop control becomes possible. Open-loop control is a requirement for advanced adaptive optics concepts. We designed an open-loop adaptive optics system with a liquid-crystal-on-silicon wavefront corrector. This system is simple, fast, and can save much more light compared to conventional liquid-crystal-based closed-loop systems. The detailed principle, construction, and operation are discussed. The 500 m horizontal turbulence correction experiment was done using a 250 mm telescope in the laboratory. The whole system can reach a 60 Hz correction frequency. Evaluation of the correction precision was done at closed-loop configuration, which is 0.2 lambda (lambda=0.633 microm) in peak to valley. The dynamic image under open-loop correction got the same resolution compared to closed-loop correction. The whole system reached 0.68 arc sec resolution capability at open-loop correction, which is slightly larger than the system's diffraction-limited resolution of 0.65 arc sec. PMID:18690274

  17. Usefulness of Magnetic Neutral Loop Discharge Plasma in Plasma Processing

    NASA Astrophysics Data System (ADS)

    Tsuboi, Hideo; Itoh, Masahiro; Tanabe, Masafumi; Hayashi, Toshio; Uchida, Taijiro

    1995-05-01

    Usefulness in plasma processing is demonstrated for a plasma produced in a closed magnetic neutral loop, which consists of zero magnetic field points connected continuously. A preliminary experiment was carried out to show the advantage of magnetic neutral loop discharge (NLD) plasma in sputter etching processing of SiO2/Si wafer in the lower Ar gas pressure range. The experiment shows that a high-density plasma was obtained for Ar gas lower than 0.1 Pa and the sputter etching rate is 3 times higher than that for the usual inductively coupled plasma (ICP). In a large-loop case, the sputter etching profile obtained has a peak at a radius along the azimuthal direction. This implies that a uniform etching profile could be realized by controlling the radius of the neutral loop during process operation. The NLD plasma current induced with an rf primary one-turn antenna coil reaches up to one-third of that of the primary.

  18. Efficient Tiled Loop Generation: D-Tiling

    NASA Astrophysics Data System (ADS)

    Kim, Daegon; Rajopadhye, Sanjay

    Tiling is an important loop optimization for exposing coarse-grained parallelism and enhancing data locality. Tiled loop generation from an arbitrarily shaped polyhedron is a well studied problem. Except for the special case of a rectangular iteration space, the tiled loop generation problem has been long believed to require heavy machinery such as Fourier-Motzkin elimination and projection, and hence to have an exponential complexity. In this paper we propose a simple and efficient tiled loop generation technique similar to that for a rectangular iteration space. In our technique, each loop bound is adjusted only once, syntactically and independently. Therefore, our algorithm runs linearly with the number of loop bounds. Despite its simplicity, we retain several advantages of recent tiled code generation schemes - unified generation for fixed, parameterized and hybrid tiled loops, scalability for multi-level tiled loop generation with the ability to separate full tiles at any levels, and compact code. We also explore various schemes for multi-level tiled loop generation. We formally prove the correctness of our scheme and experimentally validate that the efficiency of our technique is comparable to existing parameterized tiled loop generation approaches. Our experimental results also show that multi-level tiled loop generation schemes have an impact on performance of generated code. The fact that our scheme can be implemented without sophisticated machinery makes it well suited for autotuners and production compilers.

  19. Resources Predicting Positive and Negative Affect during the Experience of Stress: A Study of Older Asian Indian Immigrants in the United States.

    ERIC Educational Resources Information Center

    Diwan, Sadhna; Jonnalagadda, Satya S.; Balaswamy, Shantha

    2004-01-01

    Purpose: Using the life stress model of psychological well-being, in this study we examined risks and resources predicting the occurrence of both positive and negative affect among older Asian Indian immigrants who experienced stressful life events. Design and Methods: We collected data through a telephone survey of 226 respondents (aged 50 years…

  20. Enhancing User Experience through Emotional Interaction: Determining Users' Interests in Online Art Collections Using AMARA (Affective Museum of Art Resource Agent)

    ERIC Educational Resources Information Center

    Park, S. Joon

    2013-01-01

    The need for emotional interaction has already influenced various disciplines and industries, and online museums represent a domain where providing emotional interactions could have a significant impact. Today, online museums lack the appropriate affective and hedonic values necessary to engage art enthusiasts on an emotional level. To address…

  1. Comprehensive modelling of dynamic hysteresis loops in the rolling and transverse directions for transformer laminations

    NASA Astrophysics Data System (ADS)

    Baghel, A. P. S.; Gupta, A.; Chwastek, K.; Kulkarni, S. V.

    2015-04-01

    Magnetic properties of grain-oriented materials are affected by hysteresis, anisotropy and dynamic effects. The attempts to describe dynamic hysteresis loops are usually limited to the rolling direction (RD). On the other hand, modelling of magnetic properties for the transverse direction (TD) is important for numerical analysis of core-joints and corner regions in transformers. For this direction, hysteresis loops reveal complex shapes particularly for dynamic magnetization conditions. This paper presents a comprehensive approach for modelling of dynamic hysteresis loops in RD and TD. This work uses the magnetic viscosity-based approach, which is able to describe irregular widening of dynamic loops. The loss separation scheme is also considered for both principal directions. Variations of loss components with frequency for both directions are discussed. The computed dynamic loops in RD and TD are in a close agreement with experimental ones.

  2. Hyperstaticity and loops in frictional granular packings

    NASA Astrophysics Data System (ADS)

    Tordesillas, Antoinette; Lam, Edward; Metzger, Philip T.

    2009-06-01

    The hyperstatic nature of granular packings of perfectly rigid disks is analyzed algebraically and through numerical simulation. The elementary loops of grains emerge as a fundamental element in addressing hyperstaticity. Loops consisting of an odd number of grains behave differently than those with an even number. For odd loops, the latent stresses are exterior and are characterized by the sum of frictional forces around each loop. For even loops, the latent stresses are interior and are characterized by the alternating sum of frictional forces around each loop. The statistics of these two types of loop sums are found to be Gibbsian with a "temperature" that is linear with the friction coefficient μ when μ<1.

  3. Pleasure, affection, and love among Black men who have sex with men (MSM) versus MSM of other races: countering dehumanizing stereotypes via cross-race comparisons of reported sexual experience at last sexual event.

    PubMed

    Calabrese, Sarah K; Rosenberger, Joshua G; Schick, Vanessa R; Novak, David S

    2015-10-01

    Black men have historically been stereotyped as hedonistic, aggressive, and animalistic in their sexual interactions. This study sought to describe pleasure, affection, and love experienced by Black men who have sex with men (MSM) during their last male-partnered sexual event and to examine differences relative to White, Latino, and Asian MSM. A total of 21,696 (793 Black, 18,905 White, 1,451 Latino, and 547 Asian) U.S. men ages 18-87 (M Age = 39) were recruited from social/sexual networking sites targeting MSM in 2010-2011. Participants reported multiple dimensions of sexual experience (pleasure, affection, and love) occurring at their last male-partnered sexual event, partner relationship, and sociodemographic characteristics. Across relationship categories, a sizeable percentage of Black MSM reported pleasure (72-87  % orgasmed, 57-82 % experienced high subjective pleasure) and affection (70-91 % kissed, 47-90 % cuddled). Love was primarily reported for events involving main partners (felt love for partner: 96 %; felt loved by partner: 97 %; verbalized love to partner: 89 %). Latent class analysis with MSM of all races, adjusting for partner relationship and sociodemographic characteristics, revealed three distinct profiles of sexual experience: affection and love (Class 1); affection in the absence of love (Class 2); and neither affection nor love (Class 3). Pleasure was probable across profiles. Some racial differences in profile probability were present, but no overall pattern emerged. Contrary to Black male stereotypes, Black MSM commonly reported pleasure, affection, and love at their last male-partnered sexual event and did not show a meaningful pattern of difference from other-race MSM in their likelihood of experiencing all three. PMID:25604209

  4. Heat Load Sharing in a Capillary Pumped Loop with Multiple Evaporators and Multiple Condensers

    NASA Technical Reports Server (NTRS)

    Ku, Jentung

    2005-01-01

    This paper describes the heat load sharing function among multiple parallel evaporators in a capillary pumped loop (CPL). In the normal mode of operation, the evaporators cool the instruments by absorbing the waste heat. When an instruments is turned off, the attached evaporator can keep it warm by receiving heat from other evaporators serving the operating instruments. This is referred to as heat load sharing. A theoretical basis of heat load sharing is given first. The fact that the wicks in the powered evaporators will develop capillary pressure to force the generated vapor to flow to cold locations where the pressure is lower leads to the conclusion that heat load sharing is an inherent function of a CPL with multiple evaporators. Heat load sharing has been verified with many CPLs in ground tests. Experimental results of the Capillary Pumped Loop 3 (CAPL 3) Flight Experiment are presented in this paper. Factors that affect the amount of heat being shared are discussed. Some constraints of heat load sharing are also addressed.

  5. Overview of Loop Heat Pipe Operation

    NASA Technical Reports Server (NTRS)

    Ku, Jentung

    1999-01-01

    Loop heat pipes (LHP's) are two-phase heat transfer devices that utilize the evaporation and condensation of a working fluid to transfer heat, and the capillary forces developed in the porous wicks to circulate the fluid. The LHP was first developed in the former Soviet Union in the early 1980s, about the same time that the capillary pumped loop (CPL) was developed in the United States. The LHP is known for its high pumping capability and robust operation mainly due to the use of fine-pored metal wicks and an integral evaporator/hydro-accumulator design. The LHP technology is rapidly gaining acceptance in aerospace community. It is the baseline design for thermal control of several spacecraft, including NASA's GLAS and Chemistry, ESA's ATLID, CNES' STENTOR, RKA's OBZOR, and several commercial satellites. Numerous LHP papers have been published since the mid-1980's. Most papers presented test results and discussions on certain specific aspects of the LHP operation. LHP's and CPL's show many similarities in their operating principles and performance characteristics. However, they also display significant differences in many aspects of their operation. Some of the LHP behaviors may seem strange or mysterious, even to experienced CPL practitioners. The main purpose of this paper is to present a systematic description of the operating principles and thermal-hydraulic behaviors of LHP'S. LHP operating principles will be given first, followed by a description of the thermal-hydraulics involved in LHP operation. Operating characteristics and important parameters affecting the LHP operation will then be described in detail. Peculiar behaviors of the LHP, including temperature hysteresis and temperature overshoot during start-up, will be explained. For simplicity, most discussions will focus upon LHP's with a single evaporator and a single condenser, but devices with multiple evaporators and condensers will also be discussed. Similarities and differences between LHP's and

  6. Hierarchical looping of zigzag nucleosome chains in metaphase chromosomes

    PubMed Central

    Grigoryev, Sergei A.; Bascom, Gavin; Buckwalter, Jenna M.; Schubert, Michael B.; Woodcock, Christopher L.; Schlick, Tamar

    2016-01-01

    The architecture of higher-order chromatin in eukaryotic cell nuclei is largely unknown. Here, we use electron microscopy-assisted nucleosome interaction capture (EMANIC) cross-linking experiments in combination with mesoscale chromatin modeling of 96-nucleosome arrays to investigate the internal organization of condensed chromatin in interphase cell nuclei and metaphase chromosomes at nucleosomal resolution. The combined data suggest a novel hierarchical looping model for chromatin higher-order folding, similar to rope flaking used in mountain climbing and rappelling. Not only does such packing help to avoid tangling and self-crossing, it also facilitates rope unraveling. Hierarchical looping is characterized by an increased frequency of higher-order internucleosome contacts for metaphase chromosomes compared with chromatin fibers in vitro and interphase chromatin, with preservation of a dominant two-start zigzag organization associated with the 30-nm fiber. Moreover, the strong dependence of looping on linker histone concentration suggests a hierarchical self-association mechanism of relaxed nucleosome zigzag chains rather than longitudinal compaction as seen in 30-nm fibers. Specifically, concentrations lower than one linker histone per nucleosome promote self-associations and formation of these looped networks of zigzag fibers. The combined experimental and modeling evidence for condensed metaphase chromatin as hierarchical loops and bundles of relaxed zigzag nucleosomal chains rather than randomly coiled threads or straight and stiff helical fibers reconciles aspects of other models for higher-order chromatin structure; it constitutes not only an efficient storage form for the genomic material, consistent with other genome-wide chromosome conformation studies that emphasize looping, but also a convenient organization for local DNA unraveling and genome access. PMID:26787893

  7. Hierarchical looping of zigzag nucleosome chains in metaphase chromosomes.

    PubMed

    Grigoryev, Sergei A; Bascom, Gavin; Buckwalter, Jenna M; Schubert, Michael B; Woodcock, Christopher L; Schlick, Tamar

    2016-02-01

    The architecture of higher-order chromatin in eukaryotic cell nuclei is largely unknown. Here, we use electron microscopy-assisted nucleosome interaction capture (EMANIC) cross-linking experiments in combination with mesoscale chromatin modeling of 96-nucleosome arrays to investigate the internal organization of condensed chromatin in interphase cell nuclei and metaphase chromosomes at nucleosomal resolution. The combined data suggest a novel hierarchical looping model for chromatin higher-order folding, similar to rope flaking used in mountain climbing and rappelling. Not only does such packing help to avoid tangling and self-crossing, it also facilitates rope unraveling. Hierarchical looping is characterized by an increased frequency of higher-order internucleosome contacts for metaphase chromosomes compared with chromatin fibers in vitro and interphase chromatin, with preservation of a dominant two-start zigzag organization associated with the 30-nm fiber. Moreover, the strong dependence of looping on linker histone concentration suggests a hierarchical self-association mechanism of relaxed nucleosome zigzag chains rather than longitudinal compaction as seen in 30-nm fibers. Specifically, concentrations lower than one linker histone per nucleosome promote self-associations and formation of these looped networks of zigzag fibers. The combined experimental and modeling evidence for condensed metaphase chromatin as hierarchical loops and bundles of relaxed zigzag nucleosomal chains rather than randomly coiled threads or straight and stiff helical fibers reconciles aspects of other models for higher-order chromatin structure; it constitutes not only an efficient storage form for the genomic material, consistent with other genome-wide chromosome conformation studies that emphasize looping, but also a convenient organization for local DNA unraveling and genome access. PMID:26787893

  8. Closing the tau loop: the missing tau mutation.

    PubMed

    McCarthy, Allan; Lonergan, Roisin; Olszewska, Diana A; O'Dowd, Sean; Cummins, Gemma; Magennis, Brian; Fallon, Emer M; Pender, Niall; Huey, Edward D; Cosentino, Stephanie; O'Rourke, Killian; Kelly, Brendan D; O'Connell, Martin; Delon, Isabelle; Farrell, Michael; Spillantini, Maria Grazia; Rowland, Lewis P; Fahn, Stanley; Craig, Peter; Hutton, Michael; Lynch, Tim

    2015-10-01

    Frontotemporal lobar degeneration comprises a group of disorders characterized by behavioural, executive, language impairment and sometimes features of parkinsonism and motor neuron disease. In 1994 we described an Irish-American family with frontotemporal dementia linked to chromosome 17 associated with extensive tau pathology. We named this disinhibition-dementia-parkinsonism-amyotrophy complex. We subsequently identified mutations in the MAPT gene. Eleven MAPT gene splice site stem loop mutations were identified over time except for 5' splice site of exon 10. We recently identified another Irish family with autosomal dominant early amnesia and behavioural change or parkinsonism associated with the 'missing' +15 mutation at the intronic boundary of exon 10. We performed a clinical, neuropsychological and neuroimaging study on the proband and four siblings, including two affected siblings. We sequenced MAPT and performed segregation analysis. We looked for a biological effect of the tau variant by performing real-time polymerase chain reaction analysis of RNA extracted from human embryonic kidney cells transfected with exon trapping constructs. We found a c.915+15A>C exon 10/intron 10 stem loop mutation in all affected subjects but not in the unaffected. The c.915+15A>C variant caused a shift in tau splicing pattern to a predominantly exon 10+ pattern presumably resulting in predominant 4 repeat tau and little 3 repeat tau. This strongly suggests that the c.915+15A>C variant is a mutation and that it causes frontotemporal dementia linked to chromosome 17 in this pedigree by shifting tau transcription and translation to +4 repeat tau. Tau (MAPT) screening should be considered in families where amnesia or atypical parkinsonism coexists with behavioural disturbance early in the disease process. We describe the final missing stem loop tau mutation predicted 15 years ago. Mutations have now been identified at all predicted sites within the 'stem' when the stem-loop

  9. Loop Virasoro Lie conformal algebra

    SciTech Connect

    Wu, Henan Chen, Qiufan; Yue, Xiaoqing

    2014-01-15

    The Lie conformal algebra of loop Virasoro algebra, denoted by CW, is introduced in this paper. Explicitly, CW is a Lie conformal algebra with C[∂]-basis (L{sub i} | i∈Z) and λ-brackets [L{sub i} {sub λ} L{sub j}] = (−∂−2λ)L{sub i+j}. Then conformal derivations of CW are determined. Finally, rank one conformal modules and Z-graded free intermediate series modules over CW are classified.

  10. DNA Looping Facilitates Targeting of a Chromatin Remodeling Enzyme

    PubMed Central

    Yadon, Adam N; Singh, Badri Nath; Hampsey, Michael; Tsukiyama, Toshio

    2013-01-01

    Summary ATP-dependent chromatin remodeling enzymes are highly abundant and play pivotal roles regulating DNA-dependent processes. The mechanisms by which they are targeted to specific loci have not been well understood on a genome-wide scale. Here we present evidence that a major targeting mechanism for the Isw2 chromatin remodeling enzyme to specific genomic loci is through sequence-specific transcription factor (TF)-dependent recruitment. Unexpectedly, Isw2 is recruited in a TF-dependent fashion to a large number of loci without TF binding sites. Using the 3C assay, we show that Isw2 can be targeted by Ume6- and TFIIB-dependent DNA looping. These results identify DNA looping as a previously unknown mechanism for the recruitment of a chromatin remodeling enzyme and defines a novel function for DNA looping. We also present evidence suggesting that Ume6-dependent DNA looping is involved in chromatin remodeling and transcriptional repression, revealing a mechanism by which the three-dimensional folding of chromatin affects DNA-dependent processes. PMID:23478442

  11. Mass Measles Vaccination Campaign in Aila Cyclone-Affected Areas of West Bengal, India: An In-depth Analysis and Experiences

    PubMed Central

    Mallik, Sarmila; Mandal, Pankaj Kumar; Ghosh, Pramit; Manna, Nirmalya; Chatterjee, Chitra; Chakrabarty, Debadatta; Bagchi, Saumendra Nath; Dasgupta, Samir

    2011-01-01

    Disaster-affected populations are highly vulnerable to outbreaks of measles. Therefore, a mass vaccination against measles was conducted in Aila cyclone-affected blocks of West Bengal, India in July 2009. The objectives of the present report were to conduct an in depth analysis of the campaign, and to discuss the major challenges. A block level micro-plan, which included mapping of the villages, health facilities, temporary settlements of disaster-affected population, communications available, formation of vaccination team, information education communication, vaccine storage, waste disposal, surveillance for adverse events following immunization, supervision and monitoring was developed. The rate of six months to five years old children, who were vaccinated by measles vaccine, was 70.7% and that of those who received one dose of vitamin A was 71.3%. Wastage factor for vaccine doses and auto-disable syringes were 1.09 and 1.07, respectively. Only 13 cases of adverse events following immunization were reported. An average of 0.91 puncture-proof containers per vaccination session was used. Despite the major challenges faced due to difficult to reach areas, inadequate infrastructure, manpower and communication, problems of vaccine storage and transport, the campaign achieved a remarkable success regarding measles vaccine coverage, improvements of cold chain infrastructure, formulating an efficient surveillance and reporting system for adverse events following immunization, building self-confidence of the stakeholders, and developing a biomedical waste disposal system. PMID:23115416

  12. Role of connecting loop I in catalysis and allosteric regulation of human glucokinase

    PubMed Central

    Martinez, Juliana A; Larion, Mioara; Conejo, Maria S; Porter, Carol M; Miller, Brian G

    2014-01-01

    Glucokinase (GCK, hexokinase IV) is a monomeric enzyme with a single glucose binding site that displays steady-state kinetic cooperativity, a functional characteristic that affords allosteric regulation of GCK activity. Structural evidence suggests that connecting loop I, comprised of residues 47–71, facilitates cooperativity by dictating the rate and scope of motions between the large and small domains of GCK. Here we investigate the impact of varying the length and amino acid sequence of connecting loop I upon GCK cooperativity. We find that sequential, single amino acid deletions from the C-terminus of connecting loop I cause systematic decreases in cooperativity. Deleting up to two loop residues leaves the kcat value unchanged; however, removing three or more residues reduces kcat by 1000-fold. In contrast, the glucose K0.5 and KD values are unaffected by shortening the connecting loop by up to six residues. Substituting alanine or glycine for proline-66, which adopts a cis conformation in some GCK crystal structures, does not alter cooperativity, indicating that cis/trans isomerization of this loop residue does not govern slow conformational reorganizations linked to hysteresis. Replacing connecting loop I with the corresponding loop sequence from the catalytic domain of the noncooperative isozyme human hexokinase I (HK-I) eliminates cooperativity without impacting the kcat and glucose K0.5 values. Our results indicate that catalytic turnover requires a minimal length of connecting loop I, whereas the loop has little impact upon the binding affinity of GCK for glucose. We propose a model in which the primary structure of connecting loop I affects cooperativity by influencing conformational dynamics, without altering the equilibrium distribution of GCK conformations. PMID:24723372

  13. Role of connecting loop I in catalysis and allosteric regulation of human glucokinase.

    PubMed

    Martinez, Juliana A; Larion, Mioara; Conejo, Maria S; Porter, Carol M; Miller, Brian G

    2014-07-01

    Glucokinase (GCK, hexokinase IV) is a monomeric enzyme with a single glucose binding site that displays steady-state kinetic cooperativity, a functional characteristic that affords allosteric regulation of GCK activity. Structural evidence suggests that connecting loop I, comprised of residues 47-71, facilitates cooperativity by dictating the rate and scope of motions between the large and small domains of GCK. Here we investigate the impact of varying the length and amino acid sequence of connecting loop I upon GCK cooperativity. We find that sequential, single amino acid deletions from the C-terminus of connecting loop I cause systematic decreases in cooperativity. Deleting up to two loop residues leaves the kcat value unchanged; however, removing three or more residues reduces kcat by 1000-fold. In contrast, the glucose K0.5 and KD values are unaffected by shortening the connecting loop by up to six residues. Substituting alanine or glycine for proline-66, which adopts a cis conformation in some GCK crystal structures, does not alter cooperativity, indicating that cis/trans isomerization of this loop residue does not govern slow conformational reorganizations linked to hysteresis. Replacing connecting loop I with the corresponding loop sequence from the catalytic domain of the noncooperative isozyme human hexokinase I (HK-I) eliminates cooperativity without impacting the kcat and glucose K0.5 values. Our results indicate that catalytic turnover requires a minimal length of connecting loop I, whereas the loop has little impact upon the binding affinity of GCK for glucose. We propose a model in which the primary structure of connecting loop I affects cooperativity by influencing conformational dynamics, without altering the equilibrium distribution of GCK conformations. PMID:24723372

  14. Closed-Loop Neuroscience and Non-Invasive Brain Stimulation: A Tale of Two Loops.

    PubMed

    Zrenner, Christoph; Belardinelli, Paolo; Müller-Dahlhaus, Florian; Ziemann, Ulf

    2016-01-01

    Closed-loop neuroscience is receiving increasing attention with recent technological advances that enable complex feedback loops to be implemented with millisecond resolution on commodity hardware. We summarize emerging conceptual and methodological frameworks that are available to experimenters investigating a "brain in the loop" using non-invasive brain stimulation and briefly review the experimental and therapeutic implications. We take the view that closed-loop neuroscience in fact deals with two conceptually quite different loops: a "brain-state dynamics" loop, used to couple with and modulate the trajectory of neuronal activity patterns, and a "task dynamics" loop, that is the bidirectional motor-sensory interaction between brain and (simulated) environment, and which enables goal-directed behavioral tasks to be incorporated. Both loops need to be considered and combined to realize the full experimental and therapeutic potential of closed-loop neuroscience. PMID:27092055

  15. Lac Repressor Mediated DNA Looping: Monte Carlo Simulation of Constrained DNA Molecules Complemented with Current Experimental Results

    PubMed Central

    Biton, Yoav Y.; Kumar, Sandip; Dunlap, David; Swigon, David

    2014-01-01

    Tethered particle motion (TPM) experiments can be used to detect time-resolved loop formation in a single DNA molecule by measuring changes in the length of a DNA tether. Interpretation of such experiments is greatly aided by computer simulations of DNA looping which allow one to analyze the structure of the looped DNA and estimate DNA-protein binding constants specific for the loop formation process. We here present a new Monte Carlo scheme for accurate simulation of DNA configurations subject to geometric constraints and apply this method to Lac repressor mediated DNA looping, comparing the simulation results with new experimental data obtained by the TPM technique. Our simulations, taking into account the details of attachment of DNA ends and fluctuations of the looped subsegment of the DNA, reveal the origin of the double-peaked distribution of RMS values observed by TPM experiments by showing that the average RMS value for anti-parallel loop types is smaller than that of parallel loop types. The simulations also reveal that the looping probabilities for the anti-parallel loop types are significantly higher than those of the parallel loop types, even for loops of length 600 and 900 base pairs, and that the correct proportion between the heights of the peaks in the distribution can only be attained when loops with flexible Lac repressor conformation are taken into account. Comparison of the in silico and in vitro results yields estimates for the dissociation constants characterizing the binding affinity between O1 and Oid DNA operators and the dimeric arms of the Lac repressor. PMID:24800809

  16. Thermal Analysis of CDS Coronal Loops

    NASA Astrophysics Data System (ADS)

    Kimble, J. A.; Schmelz, J. T.; Nasraoui, K.; Rightmire, L. A.; Andrews, J. M.; Cirtain, J. W.

    2008-05-01

    The coronal loop data used for this analysis was obtained using the Coronal Diagnostic Spectrometer (CDS) aboard the Solar and Heliospheric Observatory on 2003 January 17 at 14:24:43 UT. We use the Chianti atomic physics database and the hybrid coronal abundances to determine temperatures and densities for positions along several loops. We chose six pixels along each loop as well as background pixels. The intensities of the background pixels are subtracted from each loop pixel to isolate the emission from the loop pixel, and then spectral lines with significant contributions to the loop intensities are selected. The loops were then analyzed with a forward folding process to produce differential emission measure (DEM) curves. Emission measure loci plots and DEM automatic inversions are then used to verify those conclusions. We find different results for each of these loops. One appears to be isothermal at each loop position, and the temperature does not change with height. The second appears to be multithermal at each position and the third seems to be consistent with two DEM spikes, which might indicate that there are two isothermal loops so close together, that they are not resolved by CDS. Solar physics research at the University of Memphis is supported by a Hinode subcontract from NASA/SAO as well as NSF ATM-0402729.

  17. Multidimensional smooth loops with universal elasticity

    NASA Astrophysics Data System (ADS)

    Dzhukashev, K. R.; Shelekhov, A. M.

    2015-05-01

    Let \\widetilde E be a universal (isotopically invariant) identity that is derived from the elasticity identity E\\colon (xy)x=x(yx). One of the authors has previously shown that a) each local loop of dimension r with identity \\widetilde E (briefly, a loop \\widetilde E) is a smooth middle Bol loop of dimension r; b) smooth two-dimensional loops \\widetilde E are Lie groups; c) up to isotopy, there exist only two three-dimensional loops \\widetilde E: the loops E_1 and E_2. In this paper, the loops E_1 and E_2 are extended to the multidimensional case. The fact that each smooth loop \\widetilde E of dimension r corresponds to a unique multidimensional three-web on a manifold of dimension 2r is key to our work. In addition, the class of loops under investigation is characterized by the fact that the torsion tensor of the corresponding web has rank 1 (that is, the algebra generated by this tensor has a one-dimensional derived algebra). This enables us to express the differential equations of the problem in an invariant form. The system of equations thus obtained was found to be amenable to integration in the most general case, and the equations of the required loops have been obtained in local coordinates. Bibliography: 17 titles.

  18. More on loops in reheating: non-gaussianities and tensor power spectrum

    SciTech Connect

    Katirci, Nihan; Kaya, Ali; Tarman, Merve E-mail: ali.kaya@boun.edu.tr

    2014-06-01

    We consider the single field chaotic m{sup 2}φ{sup 2} inflationary model with a period of preheating, where the inflaton decays to another scalar field χ in the parametric resonance regime. In a recent work, one of us has shown that the χ modes circulating in the loops during preheating notably modify the (ζζ) correlation function. We first rederive this result using a different gauge condition hence reconfirm that superhorizon ζ modes are affected by the loops in preheating. Further, we examine how χ loops give rise to non-gaussianity and affect the tensor perturbations. For that, all cubic and some higher order interactions involving two χ fields are determined and their contribution to the non-gaussianity parameter f{sub NL} and the tensor power spectrum are calculated at one loop. Our estimates for these corrections show that while a large amount of non-gaussianity can be produced during reheating, the tensor power spectrum receive moderate corrections. We observe that the loop quantum effects increase with more χ fields circulating in the loops indicating that the perturbation theory might be broken down. These findings demonstrate that the loop corrections during reheating are significant and they must be taken into account for precision inflationary cosmology.

  19. More on loops in reheating: non-gaussianities and tensor power spectrum

    SciTech Connect

    Katırcı, Nihan; Kaya, Ali; Tarman, Merve

    2014-06-11

    We consider the single field chaotic m{sup 2}ϕ{sup 2} inflationary model with a period of preheating, where the inflaton decays to another scalar field χ in the parametric resonance regime. In a recent work, one of us has shown that the χ modes circulating in the loops during preheating notably modify the <ζζ> correlation function. We first rederive this result using a different gauge condition hence reconfirm that superhorizon ζ modes are affected by the loops in preheating. Further, we examine how χ loops give rise to non-gaussianity and affect the tensor perturbations. For that, all cubic and some higher order interactions involving two χ fields are determined and their contribution to the non-gaussianity parameter f{sub NL} and the tensor power spectrum are calculated at one loop. Our estimates for these corrections show that while a large amount of non-gaussianity can be produced during reheating, the tensor power spectrum receive moderate corrections. We observe that the loop quantum effects increase with more χ fields circulating in the loops indicating that the perturbation theory might be broken down. These findings demonstrate that the loop corrections during reheating are significant and they must be taken into account for precision inflationary cosmology.

  20. Prevalent, Dynamic, and Conserved R-Loop Structures Associate with Specific Epigenomic Signatures in Mammals.

    PubMed

    Sanz, Lionel A; Hartono, Stella R; Lim, Yoong Wearn; Steyaert, Sandra; Rajpurkar, Aparna; Ginno, Paul A; Xu, Xiaoqin; Chédin, Frédéric

    2016-07-01

    R-loops are three-stranded nucleic acid structures formed upon annealing of an RNA strand to one strand of duplex DNA. We profiled R-loops using a high-resolution, strand-specific methodology in human and mouse cell types. R-loops are prevalent, collectively occupying up to 5% of mammalian genomes. R-loop formation occurs over conserved genic hotspots such as promoter and terminator regions of poly(A)-dependent genes. In most cases, R-loops occur co-transcriptionally and undergo dynamic turnover. Detailed epigenomic profiling revealed that R-loops associate with specific chromatin signatures. At promoters, R-loops associate with a hyper-accessible state characteristic of unmethylated CpG island promoters. By contrast, terminal R-loops associate with an enhancer- and insulator-like state and define a broad class of transcription terminators. Together, this suggests that the retention of nascent RNA transcripts at their site of expression represents an abundant, dynamic, and programmed component of the mammalian chromatin that affects chromatin patterning and the control of gene expression. PMID:27373332