Science.gov

Sample records for affective loop experiences

  1. 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…

  2. 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…

  3. 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.

  4. Estimating two-loop radiative effects in the MOLLER experiment

    SciTech Connect

    Aleksejevs, A. G.; Barkanova, S. G.; Zykunov, V. A.; Kuraev, E. A.

    2013-07-15

    Within the on-shell renormalization scheme, two-loop electroweak corrections to the parityviolating polarization asymmetry in the reaction e{sup -}e{sup -} {yields} e{sup -}e{sup -}({gamma}, {gamma}{gamma}) were estimated for the MOLLER experiment at JLab. The infrared divergence and the imaginary part of the amplitude were taken completely under control. Relevant compact expressions obtained by using asymptotic methods are free from unphysical parameters and are convenient for analysis and for numerical estimations. A numerical analysis revealed a significant scale of two-loop effects and the need for taking them into account in the MOLLER experiment.

  5. Coupling between feedback loops in autoregulatory networks affects bistability range, open-loop gain and switching times

    NASA Astrophysics Data System (ADS)

    Tiwari, Abhinav; Igoshin, Oleg A.

    2012-10-01

    Biochemical regulatory networks governing diverse cellular processes such as stress-response, differentiation and cell cycle often contain coupled feedback loops. We aim at understanding how features of feedback architecture, such as the number of loops, the sign of the loops and the type of their coupling, affect network dynamical performance. Specifically, we investigate how bistability range, maximum open-loop gain and switching times of a network with transcriptional positive feedback are affected by additive or multiplicative coupling with another positive- or negative-feedback loop. We show that a network's bistability range is positively correlated with its maximum open-loop gain and that both quantities depend on the sign of the feedback loops and the type of feedback coupling. Moreover, we find that the addition of positive feedback could decrease the bistability range if we control the basal level in the signal-response curves of the two systems. Furthermore, the addition of negative feedback has the capacity to increase the bistability range if its dissociation constant is much lower than that of the positive feedback. We also find that the addition of a positive feedback to a bistable network increases the robustness of its bistability range, whereas the addition of a negative feedback decreases it. Finally, we show that the switching time for a transition from a high to a low steady state increases with the effective fold change in gene regulation. In summary, we show that the effect of coupled feedback loops on the bistability range and switching times depends on the underlying mechanistic details.

  6. 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.

  7. [Experiences with a subcutaneous, fully resorbable bridge in construction a double loop ileo- and colostomy].

    PubMed

    Wedell, J; Banzhaf, G; Meier zu Eissen, P; Schlageter, M

    1990-01-01

    Our experience with the subcutaneous absorbable bridge for constructing a temporary loop ileostomy and loop colostomy is described. The use of this subcutaneous absorbable bridge in 15 patients - 6 with loop ileostomy and 9 with loop colostomy - was almost without complications. The absorbable bridge is a progress for maturation of the stoma and for immediate postoperative as prospective fitting of a watertight appliance. The actual trend substituting the temporary loop colostomy by the loop ileostomy may be advanced by the unlimited use of the subcutaneous absorbable bridge for constructing a temporary loop ileostomy.

  8. 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.

  9. 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).

  10. 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.

  11. Costas loop self-homodyne experiment for a diode laser receiver

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Leeb, W. R.

    1986-06-01

    An optical Costas loop self-homodyne experiment with semiconductor lasers at 0.82 micron is reported. Phase synchronization and signal demodulation for suppressed-carrier phase-shift keying modulation at 40 Mbit/s are demonstrated.

  12. Action video game experience affects oculomotor performance.

    PubMed

    West, Greg L; Al-Aidroos, Naseem; Pratt, Jay

    2013-01-01

    Action video games have been show to affect a variety of visual and cognitive processes. There is, however, little evidence of whether playing video games can also affect motor action. To investigate the potential link between experience playing action video games and changes in oculomotor action, we tested habitual action video game players (VGPs) and non-video game players (NVGPs) in a saccadic trajectory deviation task. We demonstrate that spatial curvature of a saccadic trajectory towards or away from distractor is profoundly different between VGPs and NVGPs. In addition, task performance accuracy improved over time only in VGPs. Results are discussed in the context of the competing interplay between stimulus-driven motor programming and top-down inhibition during oculomotor execution.

  13. 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.

  14. 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.

  15. Simulation experiments on two-phase natural circulation in a freon-113 flow visualization loop

    SciTech Connect

    Lee, Sang Yong; Ishii, Mamoru

    1988-01-01

    In order to study the two-phase natural circulaton and flow termination during a small break loss of coolant accident in LWR, simulation experiments have been performed using a Freon-113 flow visualization loop. The main focus of the present experiment was placed on the two-phase flow behavior in the hot-leg U-bend typical of B and W LWR systems. The loop was built based on the two-phase flow scaling criteria developed under this program to find out the effect of fluid properties, phase changes and coupling between hydrodynamic and heat transfer phenomena. Significantly different flow behaviors have been observed due to the non-equilibrium phase change phenomena such as the flashing and condensation on the Freon loop in comparison with the previous adiabatic experiment. The phenomena created much more unstable hydrodynamic conditions which lead to cyclic or oscillatory flow behaviors. Also, the void distribution and primary loop flow rate were measured in detail in addition to the important key paramaters, such as the power input, loop friction and the liquid level inside the simulated steam generator.

  16. 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.

  17. How patient and staff experiences affect outcomes.

    PubMed

    Churchill, Neil; Warden, Ruth

    Exploring patient and staff experiences is a new discipline but is providing key insights into the quality of care patients receive. This article explores how patient and staff experiences are measured and how this information is used to change practice.

  18. Sodium Loop Safety Facility experiment P4. [LMFBR

    SciTech Connect

    Ragland, W.A.; Braid, T.H.; Thompson, D.H.; Wilson, R.E.; Baldwin, R.D.; Kraimer, M.R.; Gilbert, D.M.

    1982-01-01

    SLSF experiment P4 was designed to provide an upper-limit bound on the consequences of local faults. Three of the 37 full-length FTR-type fuel pins in the test subassembly were built with 10-cm-long, sealed fuel canisters as the center sections of the fuel regions. The fuel canisters ejected molten fuel into the bundle geometry, as planned. Each ejection was accompanied by an inlet flow deceleration and persisting flow reduction. There was no evidence of energetic fuel-coolant interactions or failure propagation through the hex duct. After about 90 s of full-power operation, scram occurred on low test subassembly flow due to gas release from fuel pins as a result of elevated inlet temperature and boiling in the blockage wake. During subsequent power operation, blockage reconfiguration and flow reduction occurred 10 minutes after 60% power was reached. The DN signal began to increase from the steady state level three minutes prior to the reconfiguration.

  19. 75 FR 16732 - Action Affecting Export Privileges; Aqua-Loop Cooling Towers, Co.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-02

    ... States to Iran, via the United Arab Emirates (``U.A.E.''), without the required U.S. Government... Parto Abgardan sought to have exported from the United States to Iran. Aqua-Loop then obtained such... September 28, 2004, Aqua-Loop ordered or financed items to be exported from the United States with...

  20. 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

  1. 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…

  2. Quantitative analysis of DNA-looping kinetics from tethered particle motion experiments.

    PubMed

    Manzo, Carlo; Finzi, Laura

    2010-01-01

    In this chapter we show the application of a maximum-likelihood-based method to the reconstruction of DNA-looping single-molecule time traces from tethered particle motion experiments. The method does not require time filtering of the data and improves the time resolution by an order of magnitude with respect to the threshold-crossing approach. Moreover, it is not based on presumed kinetic models, overcoming the limitations of other approaches proposed previously, and allowing its applications to mechanisms with complex kinetic schemes. Numerical simulations have been used to test the performances of this analysis over a wide range of time scales. We have then applied this method to determine the looping kinetics of a well-known DNA-looping protein, the lambda-repressor.

  3. Experiments in a single-phase natural circulation mini-loop

    SciTech Connect

    Misale, M.; Garibaldi, P.; Passos, J.C.; de Bitencourt, G. Ghisi

    2007-08-15

    This study reports an experimental investigation related to a rectangular single-phase natural circulation mini-loop, which consists of two horizontal copper tubes (heat transfer sections) and two vertical tubes (legs) made of copper, connected by means of four glass 90 bends. The loop inner diameter is 4 mm. The lower heating section consists of an electrical heating wire made of nicromel on the outside of the copper tube; the upper cooling system consists of a coaxial cylindrical heat exchanger with a water-glycol mixture, set at controlled temperature and flowing through the annulus. The loop has an imposed heat flux in the lower heating section and an imposed temperature in the cooler. The mini-loop was placed onto a table which can assume different inclinations. The parameters investigated during the experiments were: power transferred to the fluid and inclination of the loop. The preliminary results show a stable behaviour with a steady temperature difference across the heat sinks. It has been confirmed that the fluid velocity is very small (order of millimetres per second). (author)

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

    SciTech Connect

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

    2012-07-15

    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.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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,…

  10. A prototype heat pipe heat exchanger for the capillary pumped loop flight experiment

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Yun, Seokgeun; Kroliczek, Edward J.

    1992-01-01

    A Capillary Pumped Two-Phase Heat Transport Loop (CAPL) Flight Experiment, currently planned for 1993, will provide microgravity verification of the prototype capillary pumped loop (CPL) thermal control system for EOS. CAPL employs a heat pipe heat exchanger (HPHX) to couple the condenser section of the CPL to the radiator assembly. A prototype HPHX consisting of a heat exchanger (HX), a header heat pipe (HHP), a spreader heat pipe (SHP), and a flow regulator has been designed and tested. The HX transmits heat from the CPL condenser to the HHP, while the HHP and SHP transport heat to the radiator assembly. The flow regulator controls flow distribution among multiple parallel HPHX's. Test results indicated that the prototype HPHX could transport up to 800 watts with an overall heat transfer coefficient of more than 6000 watts/sq m-deg C. Flow regulation among parallel HPHX's was also demonstrated.

  11. 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.

  12. 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/.

  13. 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

  14. 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

  15. Charge and geometry of residues in the loop 2 β hairpin differentially affect agonist and ethanol sensitivity in glycine receptors.

    PubMed

    Perkins, Daya I; Trudell, James R; Asatryan, Liana; Davies, Daryl L; Alkana, Ronald L

    2012-05-01

    Recent studies highlighted the importance of loop 2 of α1 glycine receptors (GlyRs) in the propagation of ligand-binding energy to the channel gate. Mutations that changed polarity at position 52 in the β hairpin of loop 2 significantly affected sensitivity to ethanol. The present study extends the investigation to charged residues. We found that substituting alanine with the negative glutamate at position 52 (A52E) significantly left-shifted the glycine concentration response curve and increased sensitivity to ethanol, whereas the negative aspartate substitution (A52D) significantly right-shifted the glycine EC₅₀ but did not affect ethanol sensitivity. It is noteworthy that the uncharged glutamine at position 52 (A52Q) caused only a small right shift of the glycine EC₅₀ while increasing ethanol sensitivity as much as A52E. In contrast, the shorter uncharged asparagine (A52N) caused the greatest right shift of glycine EC₅₀ and reduced ethanol sensitivity to half of wild type. Collectively, these findings suggest that charge interactions determined by the specific geometry of the amino acid at position 52 (e.g., the 1-Å chain length difference between aspartate and glutamate) play differential roles in receptor sensitivity to agonist and ethanol. We interpret these results in terms of a new homology model of GlyR based on a prokaryotic ion channel and propose that these mutations form salt bridges to residues across the β hairpin (A52E-R59 and A52N-D57). We hypothesize that these electrostatic interactions distort loop 2, thereby changing agonist activation and ethanol modulation. This knowledge will help to define the key physical-chemical parameters that cause the actions of ethanol in GlyRs.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. [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

  2. 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

  3. 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…

  4. Language Experience Affects Grouping of Musical Instrument Sounds

    ERIC Educational Resources Information Center

    Bhatara, Anjali; Boll-Avetisyan, Natalie; Agus, Trevor; Höhle, Barbara; Nazzi, Thierry

    2016-01-01

    Language experience clearly affects the perception of speech, but little is known about whether these differences in perception extend to non-speech sounds. In this study, we investigated rhythmic perception of non-linguistic sounds in speakers of French and German using a grouping task, in which complexity (variability in sounds, presence of…

  5. Disulfide bond tethering of extracellular loops does not affect the closure of OmpF porin at acidic pH.

    PubMed

    Wager, Beau; Baslé, Arnaud; Delcour, Anne H

    2010-11-01

    The permeability of the outer membrane of gram-negative bacteria is essentially controlled by pore-forming proteins of the porin family. The trimeric E. coli porin OmpF is assembled as a triple β-barrel, where each monomer contains a central pore and extracellular loops. Electrophysiological analysis of the behavior of OmpF at acidic pH reveals that the protein undergoes a conformational change leading to the sequential step-wise closure of the three monomers. A previous atomic force microscopy study suggested that the conformational change might be due to a bending of extracellular loops over the pore opening, and loop deletion experiments suggested that loops L1, L7, and L8 are involved. In order to test the hypothesis for loop movement, we engineered a series of double cysteine mutants in loops L1, L6, L7 and L8 in order to create disulfide bonds linking two loops to each other, or the two branches of a loop, or a loop to the β-barrel. Five out of the six mutants showed the formation of the disulfide bond. However, none of these had an altered response to acidic pH relative to the wildtype channel. Although we cannot dismiss the possibility that the mobility restriction introduced by each disulfide bond was too localized to impact a more global conformational change of the three loops, the fact that all of the different types of disulfide bond tethering were similarly ineffective suggests that the extracellular loops L1, L7, and L8 may not undergo a major acidic-pH induced conformational change leading to channel closure.

  6. On the Rayleigh law of magnetization. Symmetrical and asymmetric hysteresis loops. Experiment

    NASA Astrophysics Data System (ADS)

    Ponomarev, Yu. F.

    2008-03-01

    Results of an experimental study of symmetrical and asymmetric loops of magnetic hysteresis in weak ac fields are given (Rayleigh region). The asymmetric loops are observed when a dc magnetizing field is additionally applied to the ferromagnetic material together with a weak ac field. The studies have been carried out on a manganese-zinc ferrite of grade M1000NM-A. It has been shown that the symmetrical hysteresis loops obey the mathematical Rayleigh model by no means strictly. It has been revealed that if the dc magnetizing field is in the Rayleigh region, then the hysteresis loops in the ac field remain symmetrical as before. But if the dc field falls outside the Rayleigh region, then the hysteresis loops become asymmetric. This asymmetry is caused by the different values of the remanences on the ascending and descending branches of the hysteresis loop with the same quadratic dependence of magnetization on the field as in the Rayleigh case.

  7. Costas loop experiments for a 10.6 micron communications receiver

    NASA Astrophysics Data System (ADS)

    Philipp, H. K.; Scholtz, A. L.; Bonek, E.; Leeb, W. R.

    1983-08-01

    The principle of the Costas-type nonlinear phase-locked loop is transferred to the 10.6 micron wavelength of CO2 lasers. The experimental setup is described, emphasizing the peculiarities of optical Costas loops, and the measured characteristic loop parameters are presented. Results are given of a successful demonstration of carrier regeneration and coherent demodulation of binary phase-shift-keyed double-sideband suppressed-carrier input signals. It is shown that the optical Costas loop has the ability to regenerate the carrier of a binary phase-shift-keyed input signal and to perform coherent demodulation at a data rate of 20 Mbit/s. It is concluded that Costas loop communication receivers are feasible for the infrared and that optical fiber communications around 1 micron wavelength will profit from phase-locked loop coherent detection.

  8. 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

  9. Self-reported affective traits and current affective experiences of biological relatives of people with schizophrenia.

    PubMed

    Docherty, Anna R; Sponheim, Scott R; Kerns, John G

    2015-02-01

    Schizophrenia is characterized by self-reported trait anhedonia but intact hedonic responses during laboratory experiments. Affective traits of first-degree biological relatives may be similar to those of people with schizophrenia, and measures of hedonic response in relatives may be free of antipsychotic medication or cognitive confounds. Relatives also self-report increased anhedonia, yet it is unclear whether, like in patients, this anhedonia is paired with largely intact hedonic self-report. In this study, first-degree relatives of people with schizophrenia (n=33) and nonpsychiatric controls (n=25) completed a wide range of questionnaires and tasks assessing social and physical anhedonia, positive and negative affective experience, and anticipatory and consummatory pleasure. Valence, intensity, frequency, and the arousal of current emotion were assessed. Extraversion and current positive and negative affective state were also examined in relation to self-reported social anhedonia. Relatives evidenced the same disjunction of increased self-reported anhedonia and intact affective response observed in people with schizophrenia. Group differences in anhedonia were not better accounted for by decreased current positive affect, increased current negative affect, or decreased extraversion in relatives. Results suggest that, like people with schizophrenia, first-degree relatives report intact hedonic response on both questionnaire and laboratory measures despite significant elevations in self-reported social anhedonia.

  10. 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.

  11. 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

  12. 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)…

  13. 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

  14. 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

  15. 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.

  16. Operating experience with gas-bearing circulators in a high-pressure helium loop

    SciTech Connect

    Sanders, J.P.; Gat, Uri; Young, H.C.

    1987-01-01

    A high-pressure engineering test loop has been designed and constructed at the Oak Ridge National Laboratory for circulating helium through a test chamber at temperatures to 1000/sup 0/C. The purpose of this loop is to determine the thermal and structural performance of proposed components for the primary loops of gas-cooled nuclear reactors. Five MW of power is available to provide the required gas temperature at the test chamber, and an air-cooled heat exchanger, rated at 4.4 MW, serves as a heat sink. This report contains results of tests performed on gas-bearing circulators.

  17. Affect modulated startle in schizophrenia: subjective experience matters.

    PubMed

    Dominelli, Rachelle M; Boggs, Jennifer M; Bolbecker, Amanda R; O'Donnell, Brian F; Hetrick, William P; Brenner, Colleen A

    2014-12-15

    Data suggests that emotion reactivity as measured by the affect-modulated startle paradigm in those with schizophrenia (SZ) may be similar to healthy controls (HC). However, normative classification of the stimuli may not accurately reflect emotional experience, especially for those with SZ. To examine this possibility, the present study measured the affect-modulated startle response with images classified according to both normative and subjective ratings. Seventeen HC and 17 SZ completed an image viewing task during which startle probes were presented, followed by subjective valence and arousal ratings. Both groups exhibited inhibited startle responses to positive images, intermediate startle amplitudes to neutral images, and potentiated startle amplitudes to negative images. SZ rated the positive images as less positive than HC. When images were reclassified based on subjective valence ratings, both groups' startle magnitudes increased in response to subjectively rated positive images and decreased to subjectively rated neutral images. The number of trials classified into each valence condition suggested a tendency for SZ to classify neutral images as negative more often than HC. Overall, these findings suggest that affective stimuli modulate the startle response in HC and SZ in similar ways, but subjective emotional experience may differ in those with schizophrenia.

  18. 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

  19. 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

  20. 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

  1. Acceptance of cravings: how smoking cessation experiences affect craving beliefs.

    PubMed

    Nosen, Elizabeth; Woody, Sheila R

    2014-08-01

    Metacognitive models theorize that more negative appraisals of craving-related thoughts and feelings, and greater efforts to avoid or control these experiences, exacerbate suffering and increase chances the person will use substances to obtain relief. Thus far, little research has examined how attempts to quit smoking influence the way people perceive and respond to cravings. As part of a larger study, 176 adult smokers interested in quitting participated in two lab sessions, four days apart. Half the sample began a quit attempt the day after the first session; craving-related beliefs, metacognitive strategies, and negative affect were assessed at the second session. Participants who failed to abstain from smoking more strongly endorsed appraisals of craving-related thoughts as negative and personally relevant. Negative appraisals correlated strongly with distress and withdrawal symptoms. Attempting to quit smoking increased use of distraction, thought suppression and re-appraisal techniques, with no difference between successful and unsuccessful quitters. Negative beliefs about cravings and rumination predicted less change in smoking one month later. Results suggest that smoking cessation outcomes and metacognitive beliefs likely have a bidirectional relationship that is strongly related to negative affect. Greater consideration of the impact of cessation experiences on mood and craving beliefs is warranted. PMID:25014920

  2. Individual experience affects host choice in malaria vector mosquitoes

    PubMed Central

    2014-01-01

    Background Despite epidemiological importance, few studies have explored whether individual experience and learning could affect the vertebrate host choice of mosquito disease vectors. Here, we investigated whether a first successful blood meal can modulate mosquito preference during a second blood meal. Methods In no-choice situations, females of the mosquito Anopheles coluzzii, one of the primary African malaria vectors, were first allowed to feed on either human, rabbit or guinea pig. Four days later in dual-choice situations, the same mosquitoes were allowed to choose between the two uncommon hosts, rabbit and guinea pig, as a source of blood. ELISA assays were then used to determine which host mosquitoes fed on. Results Our results indicate that, overall, mosquitoes preferred to feed on rabbit over guinea pig and that the nature of the first blood meal had a significant impact on the mosquito host choice during the second blood meal. Compared to mosquitoes that previously fed on guinea pigs or humans, mosquitoes that fed on rabbits were less likely to choose this host species during a second exposition. The decreased preference for rabbit was observed four days after mosquitoes were first exposed to this host, suggesting that the effect lasts at least the duration of a gonotrophic cycle. Furthermore, this effect was observed after only one successful blood meal. Fitness measurements on mosquitoes fed on the three different vertebrate hosts showed that the origin of the blood meal affected mosquito longevity but not fecundity. In particular, human-fed mosquitoes lived longer than guinea pig-fed or rabbit-fed mosquitoes. Conclusions Our study demonstrates that individual experience affects host choice in this mosquito species and might have strong repercussions on biting patterns in natural conditions and hence on malaria transmission. PMID:24885668

  3. 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)).

  4. 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.

  5. 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

  6. Observation of Kinetic Plasma Jets in a Coronal-Loop Simulation Experiment

    SciTech Connect

    Tripathi, S. K. P.; Bellan, P. M.; Yun, G. S.

    2007-03-30

    Under certain conditions an intense kinetic plasma jet is observed to emerge from the apex of laboratory simulations of coronal plasma loops. Analytic and numerical models show that these jets result from a particle orbit instability in a helical magnetic field whereby magnetic forces radially eject rather than confine ions with sufficiently large countercurrent axial velocity.

  7. Observation of kinetic plasma jets in a coronal-loop simulation experiment.

    PubMed

    Tripathi, S K P; Bellan, P M; Yun, G S

    2007-03-30

    Under certain conditions an intense kinetic plasma jet is observed to emerge from the apex of laboratory simulations of coronal plasma loops. Analytic and numerical models show that these jets result from a particle orbit instability in a helical magnetic field whereby magnetic forces radially eject rather than confine ions with sufficiently large countercurrent axial velocity. PMID:17501208

  8. Experiences of Looping for Students with Learning Disabilities: A Phenomenological Case Study

    ERIC Educational Resources Information Center

    Brown, Laura C.

    2011-01-01

    The problem is the academic, social, and emotional needs of students with learning disabilities are not being met within the general classroom. Looping, the practice of a teacher staying with the same group of students for two or more years, has been suggested as an educational approach designed to meet the needs of students with disabilities. The…

  9. 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.

  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. 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.

  12. 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

  13. 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…

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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…

  20. 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

  1. Does Early Research Experience Affect Subsequent Career Choice?

    ERIC Educational Resources Information Center

    Pechmann, Connie A.; Pichert, James W.

    The Vanderbilt Summer Research Program in diabetes, which was designed to interest medical students in research careers and diabetes care, was evaluated. The program provides stipends to 20 sophomore and junior medical students for 12 weeks of preceptor-supervised laboratory research work, clinical experience, and classroom instruction. The…

  2. 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…

  3. 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,…

  4. 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.

  5. 11-Year Experience with Gastroschisis: Factors Affecting Mortality and Morbidity

    PubMed Central

    Erdoğan, Derya; Azılı, Müjdem Nur; Çavuşoğlu, Yusuf Hakan; Tuncer, İlker SaA; Karaman, İbrahim; Karaman, Ayşe; Özgüner, İsmet Faruk

    2012-01-01

    Objective The aim of the study was the evaluation of patients treated with a diagnosis of gastroschisis and to establish the factors which affected the morbidity and mortality. Methods Twenty-nine patients, managed for gastroschisis during 2000-2010 were reviewed retrospectively. Patients were analysed in respect to gestational age, birth weight, associated anomalies, type of delivery, operative procedures, postoperative complications, total parenteral nutrition (TPN) related complications. The factors affecting mortality and morbidity were determined. Findings Associated abnormalities were present in 24% of the patients. Eleven patients underwent elective reduction in the incubator (Bianchi procedure) without anesthesia. Eight patients had delayed reduction with silo and ten patients had primary closure. Although the type of delivery had an effect on morbidity but not mortality, gestational age, birth weight, and the operative procedure performed had no effect on morbidity or mortality. Duration until tolerance of oral intake, and of TPN and hospitalization were found to be statistically significantly shorter in the group of babies delivered by cesarean section. Conclusion In our study the most important cause of mortality was the abdominal compartment syndrome and multi-organ failure in the early years. Long hospitalization periods and sepsis were the main causes of mortality in recent years. PMID:23399980

  6. 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

  7. What experimental experience affects dogs' comprehension of human communicative actions?

    PubMed

    Hauser, Marc D; Comins, Jordan A; Pytka, Lisa M; Cahill, Donal P; Velez-Calderon, Sofia

    2011-01-01

    Studies of dogs report that individuals reliably respond to the goal-directed communicative actions (e.g., pointing) of human experimenters. All of these studies use some version of a multi-trial approach, thereby allowing for the possibility of rapid learning within an experimental session. The experiments reported here ask whether dogs can respond correctly to a communicative action based on only a single presentation, thereby eliminating the possibility of learning within the experimental context. We tested 173 dogs. For each dog reaching our test criteria, we used a single presentation of six different goal-directed actions within a session, asking whether they correctly follow to a target goal (container with concealed food) a (1) distal hand point, (2) step toward one container, (3) hand point to one container followed by step toward the other, (4) step toward one container and point to the other, (5) distal foot point with the experimenter's hands free, and (6) distal foot point with the experimenter's hands occupied. Given only a single presentation, dogs selected the correct container when the experimenter hand pointed, foot pointed with hands occupied, or stepped closer to the target container, but failed on the other actions, despite using the same method. The fact that dogs correctly followed foot pointing with hands occupied, but not hands free, suggests that they are sensitive to environmental constraints, and use this information to infer rational, goal-directed action. We discuss these results in light of the role of experience in recognizing communicative gestures, as well as the significance of coding criteria for studies of canine competence.

  8. 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.

  9. 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

  10. 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.

  11. Factors affecting overall satisfaction with a river recreation experience

    NASA Astrophysics Data System (ADS)

    Herrick, Theresa A.; McDonald, Cary D.

    1992-03-01

    Visitor satisfaction has been a consistently stated goal of outdoor recreation management. Recreation resource managers provide opportunities for the visiting public with the anticipation of satisfying the needs of the visitors. Management efforts are often evaluated in terms of visitor satisfaction. In the recent decade, a multiple satisfactions approach has been the primary research paradigm guiding visitor satisfaction research. This paradigm has focused primarily upon behavioral-type dimensions such as crowding, goal attainment, and resource impacts resulting from behavior. The purpose of this study was to examine the importance of a setting dimension relative to behavioral-type dimensions for explaining differences in visitor satisfaction. A sample of 895 river visitors were sent a questionnaire in the mail; 682 were returned for a 76.2% response rate. Regression analysis indicated the setting dimension was ranked as one of the most important dimensions for explaining differences in visitor satisfaction. Other dimensions considered included group behavior, perceived crowding, parking, past experience, encounters, use levels, and time waiting. Implications for management are discussed.

  12. 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

  13. 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…

  14. 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

  15. 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

  16. 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…

  17. 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…

  18. 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

  19. More intense experiences, less intense forecasts: why people overweight probability specifications in affective forecasts.

    PubMed

    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).

  20. More intense experiences, less intense forecasts: why people overweight probability specifications in affective forecasts.

    PubMed

    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

  1. Mutations in domain I interhelical loops affect the rate of pore formation by the Bacillus thuringiensis Cry1Aa toxin in insect midgut brush border membrane vesicles.

    PubMed

    Lebel, Geneviève; Vachon, Vincent; Préfontaine, Gabrielle; Girard, Frédéric; Masson, Luke; Juteau, Marc; Bah, Aliou; Larouche, Geneviève; Vincent, Charles; Laprade, Raynald; Schwartz, Jean-Louis

    2009-06-01

    Pore formation in the apical membrane of the midgut epithelial cells of susceptible insects constitutes a key step in the mode of action of Bacillus thuringiensis insecticidal toxins. In order to study the mechanism of toxin insertion into the membrane, at least one residue in each of the pore-forming-domain (domain I) interhelical loops of Cry1Aa was replaced individually by cysteine, an amino acid which is normally absent from the activated Cry1Aa toxin, using site-directed mutagenesis. The toxicity of most mutants to Manduca sexta neonate larvae was comparable to that of Cry1Aa. The ability of each of the activated mutant toxins to permeabilize M. sexta midgut brush border membrane vesicles was examined with an osmotic swelling assay. Following a 1-h preincubation, all mutants except the V150C mutant were able to form pores at pH 7.5, although the W182C mutant had a weaker activity than the other toxins. Increasing the pH to 10.5, a procedure which introduces a negative charge on the thiol group of the cysteine residues, caused a significant reduction in the pore-forming abilities of most mutants without affecting those of Cry1Aa or the I88C, T122C, Y153C, or S252C mutant. The rate of pore formation was significantly lower for the F50C, Q151C, Y153C, W182C, and S252C mutants than for Cry1Aa at pH 7.5. At the higher pH, all mutants formed pores significantly more slowly than Cry1Aa, except the I88C mutant, which formed pores significantly faster, and the T122C mutant. These results indicate that domain I interhelical loop residues play an important role in the conformational changes leading to toxin insertion and pore formation.

  2. 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…

  3. The emotional experience of people with intellectual disability: an analysis using the international affective pictures system.

    PubMed

    Bermejo, Belén G; Mateos, Pedro M; Sánchez-Mateos, Juan Delgado

    2014-07-01

    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 very similar to that of the control groups. The way in which people with intellectual disability express basic affect to emotional stimuli in terms of happy-sad and calm-nervous is very similar to that of the general population. However, there are also some differences in how basic affect is expressed in the affective dimensions that might be relevant to our understanding of the emotional life of people with intellectual disability.

  4. 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.

  5. 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

  6. 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

    2016-05-25

    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.

  7. 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

  8. Clouds and silver linings: positive experiences associated with primary affective disorders.

    PubMed

    Jamison, K R; Gerner, R H; Hammen, C; Padesky, C

    1980-02-01

    Clinical psychiatry has focused almost entirely on the psychopathology of the affective disorders. The authors studied responses of 61 patients (35 bipolar. 26 unipolar) to questions about perceived short- and long-term benefits (increased sensitivity, sexuality, productivity, creativity, and social outgoingness) they attributed to their affective illness. Bipolar patients strongly indicated positive experiences associated with manic-depressive illness; few unipolar patients perceived their disorder in such a way. Significant sex differences emerged in the attributions made by bipolar patients.

  9. 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

  10. On the use of dual frequency nematic material for adaptive optics systems: first results of a closed-loop experiment.

    PubMed

    Restaino, S; Dayton, D; Browne, S; Gonglewski, J; Baker, J; Rogers, S; McDermott, S; Gallegos, J; Shilko, M

    2000-01-01

    The use of liquid crystal devices for wavefront control has been suggested and implemented by several authors. In this paper we report some preliminary results on the use of Nematic based liquid crystal devices. Several experimental efforts have been carried out in the past few months. One of the main aims was to characterize a new device that uses dual frequency nematic material in a closed loop arrangement.

  11. 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.

  12. 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.

  13. On the use of dual frequency nematic material for adaptive optics systems: first results of a closed-loop experiment.

    PubMed

    Restaino, S; Dayton, D; Browne, S; Gonglewski, J; Baker, J; Rogers, S; McDermott, S; Gallegos, J; Shilko, M

    2000-01-01

    The use of liquid crystal devices for wavefront control has been suggested and implemented by several authors. In this paper we report some preliminary results on the use of Nematic based liquid crystal devices. Several experimental efforts have been carried out in the past few months. One of the main aims was to characterize a new device that uses dual frequency nematic material in a closed loop arrangement. PMID:19401740

  14. Significant Life Experiences Affect Environmental Action: A Confirmation Study in Eastern Taiwan

    ERIC Educational Resources Information Center

    Hsu, Shih-Jang

    2009-01-01

    Two field studies form the basis of this article. The major purposes of Study 1 were to examine significant life experiences affecting the cultivation of environmental activists in eastern Taiwan, and to reconstruct the life paths followed by those active people who engaged in effective environmental action. 40 usable autobiographical memories…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. Experience-dependent affective learning and risk for psychopathology in children.

    PubMed

    Pollak, Seth D

    2003-12-01

    The influence of childhood affective experiences across development may be understood in terms of preparedness to learn about emotion, combined with general immaturity and neuro-plasticity of perceptual systems. Early in development, processing resources are relatively immature and limited in capacity, thereby constraining how much information the young child can absorb. But it is clear that learning about emotions proceeds swiftly in nearly all children, suggesting biological preparedness to track associations between certain stimuli and outcomes. It is proposed here that limited processing capacity, in tandem with dispositions to filter or select key privileged stimuli in the environment, facilitates adaptive, rapid, affective learning. The developmental organization of affective systems is contingent upon those features of input that are most learnable, such as signals that are particularly salient, frequent, or predictable. Therefore, plasticity confers risk for maladaptation in that children's learning will be based upon these prominent features of the environment, however aberrant.

  6. 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

  7. 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.

  8. Let it be: Accepting negative emotional experiences predicts decreased negative affect and depressive symptoms

    PubMed Central

    Shallcross, Amanda J.; Troy, Allison S.; Boland, Matthew; Mauss, Iris B.

    2010-01-01

    The present studies examined whether a tendency to accept negative emotional experiences buffers individuals from experiencing elevated negative affect during negative emotional situations (Study 1) and from developing depressive symptoms in the face of life stress (Study 2). Both studies examined female samples. This research expands on existing acceptance research in four ways. First, it examined whether acceptance has beneficial correlates when it matters most: in emotionally taxing (versus more neutral) contexts. Second, in Study 2 a prospective design was used in which acceptance was measured before stress was encountered and before outcomes were measured. Third, depressive symptoms (rather than general functioning or trauma symptoms) were examined as a particularly relevant outcome in the context of stress. Fourth, to enhance generalizability, a community sample (versus undergraduates or a purely clinical sample) was recruited. Results indicated that acceptance was correlated with decreased negative affect during a negative emotion induction but not an affectively neutral condition (Study 1). In Study 2, acceptance interacted with life stress such that acceptance predicted lower levels of depressive symptoms after higher, but not lower, life stress. These results suggest that accepting negative experiences may protect individuals from experiencing negative affect and from developing depressive symptoms. PMID:20566191

  9. 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.

  10. 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

  11. 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.

  12. Examining the protective effects of mindfulness training on working memory capacity and affective experience.

    PubMed

    Jha, Amishi P; Stanley, Elizabeth A; Kiyonaga, Anastasia; Wong, Ling; Gelfand, Lois

    2010-02-01

    We investigated the impact of mindfulness training (MT) on working memory capacity (WMC) and affective experience. WMC is used in managing cognitive demands and regulating emotions. Yet, persistent and intensive demands, such as those experienced during high-stress intervals, may deplete WMC and lead to cognitive failures and emotional disturbances. We hypothesized that MT may mitigate these deleterious effects by bolstering WMC. We recruited 2 military cohorts during the high-stress predeployment interval and provided MT to 1 (MT, n = 31) but not the other group (military control group, MC, n = 17). The MT group attended an 8-week MT course and logged the amount of out-of-class time spent practicing formal MT exercises. The operation span task was used to index WMC at 2 testing sessions before and after the MT course. Although WMC remained stable over time in civilians (n = 12), it degraded in the MC group. In the MT group, WMC decreased over time in those with low MT practice time, but increased in those with high practice time. Higher MT practice time also corresponded to lower levels of negative affect and higher levels of positive affect (indexed by the Positive and Negative Affect Schedule). The relationship between practice time and negative, but not positive, affect was mediated by WMC, indicating that MT-related improvements in WMC may support some but not all of MT's salutary effects. Nonetheless, these findings suggest that sufficient MT practice may protect against functional impairments associated with high-stress contexts.

  13. 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

  14. 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

  15. 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

  16. Dealing with stigma: experiences of persons affected by disabilities and leprosy.

    PubMed

    Lusli, Mimi; 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.

  17. 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.

  18. A Looping Journey.

    ERIC Educational Resources Information Center

    Chapman, Janet

    1999-01-01

    Recounts a teacher's experiences staying with the same group of children for more than one year (looping) as they progress through kindergarten and first grade. Discusses advantages of more stability and less trauma for the child, and more instructional time and less stress for the teacher. Addresses possible disadvantages of children having…

  19. 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

  20. 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.

  1. 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.

  2. 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.

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

    PubMed

    Principe, Connor P; Langlois, Judith H

    2012-02-01

    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.

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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…

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

    PubMed

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

    2015-10-01

    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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. Surgical experience gained during an endourology fellowship program may affect fluoroscopy time during ureterorenoscopy.

    PubMed

    Sfoungaristos, Stavros; Lorber, Amitay; Gofrit, Ofer N; Yutkin, Vladimir; Landau, Ezekiel H; Pode, Dov; Duvdevani, Mordechai

    2015-08-01

    The purpose of this study was to identify parameters that affect fluoroscopy time during ureteroscopy or retrograde intrarenal surgery (RIRS) and to evaluate the potential role of surgical experience gained during a fellowship program in decreasing radiation exposure. A database of patients who underwent ureteroscopy or RIRS was evaluated. Procedures were performed either by an experienced Endourologist (surgeon A) or by an Endourology fellow. Operations performed by the fellow were further divided to them performed during fellow's 1st year of training (surgeon F1) and 2nd year of training (surgeon F2). The association between fluoroscopy time and several factors was evaluated. Eighteen (19.6%) procedures were performed by surgeon F1, 13 (14.1%) by surgeon F2 and 61 (66.3%) cases were performed by surgeon A. Fluoroscopy time was significantly higher in cases performed by surgeon F1 compared to surgeon F2 (p=0.025) and A (p=0.001). However, there was no difference between surgeon F2 and A (p=0.969). There was significant association between fluoroscopy time and obesity (p=0.023), stone size (p=0.009), surgical experience (p=0.001), procedure duration (p<0.001) and the insertion of a postoperative double-J stent (p<0.001). Multivariate analysis showed that procedure duration (p=0.003), postoperative stenting (p=0.009) and surgeon's experience (p<0.001) were all significant independent predictors of increased fluoroscopy time. Fluoroscopy time may widely vary during ureteroscopy and RIRS. Procedure duration, the insertion of a postoperative double-J stent and surgical experience are all independent predictors of increased fluoroscopy time. PMID:25894628

  15. 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.

  16. A magnetic pulse does not affect homing pigeon navigation: a GPS tracking experiment.

    PubMed

    Holland, Richard; Filannino, Caterina; Gagliardo, Anna

    2013-06-15

    The cues by which homing pigeons are able to return to a home loft after displacement to unfamiliar release sites remain debated. A number of experiments in which migratory birds have been treated with a magnetic pulse have produced a disruption in their orientation, which argues that a ferrimagnetic sense is used for navigation in birds. One previous experiment has also indicated an effect of magnetic pulses on homing pigeon navigation, although with inconsistent results. Previous studies have shown that some magnetic-related information is transmitted by the trigeminal nerve to the brain in some bird species, including the homing pigeon. The function of this information is still unclear. It has been suggested that this information is important for navigation. Previous studies with trigeminal nerve lesioned homing pigeons have clearly shown that the lack of trigeminally mediated information, even if magnetic, is not crucial for homing performance. However, this result does not completely exclude the possibility that other ferrimagnetic receptors in the homing pigeon play a role in navigation. Additionally, recent studies on homing pigeons suggested the existence of a ferrimagnetic sense in a novel location presumably located in the inner ear (lagena). In the present study, we tested whether any ferrimagnetic magnetoreceptors, irrespective of their location in the bird's head, are involved in pigeons' homing. To do this, we treated homing pigeons with a strong magnetic pulse before release, tracked birds with GPS loggers and analyzed whether this treatment affected homing performance. In the single previous magnetic pulse experiment on homing pigeons, only initial orientation at a release site was considered and the results were inconsistent. We observed no effect of the magnetic pulse at any of the sites used on initial orientation, homing performance, tortuosity or track efficiency, which does not support a role for the ferrimagnetic sense in homing pigeon

  17. 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

  18. 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.

  19. 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

  20. 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…

  1. 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

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

    PubMed

    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.

  3. 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.

  4. Factors affecting compliance with moving and handling policy: Student nurses' views and experiences.

    PubMed

    Cornish, Jocelyn; Jones, Anne

    2010-03-01

    The limited literature available suggests that there continues to be poor compliance by nurses with moving and handling regulations [Swain, J., Pufahl, E., Williamson, G., 2003. Do they practise what we teach? A survey of manual handling practice amongst student nurses. Journal of Clinical Nursing 12(2), 297-306; Jootun, D., MacInnes, A., 2005. Examining how well students use correct handling procedures. Nursing Times 101(4), 38-40; Smallwood, J., 2006. Patient handling: student nurses' views. Learning in Health and Social Care 5(4), 208-219; Cornish, J., Jones, A., 2007. Evaluation of moving and handling training for pre-registration nurses and its application to practice. Nurse Education in Practice 7(3), 128-134]. This paper presents the final phase of a study in which student nurses' reports of their experience in practice are drawn upon to identify possible reasons for a lack of compliance with moving and handling policy. Focus groups were conducted using a topic guide comprising themes generated from the previous two phases of this study; a questionnaire survey and unstructured interviews [Cornish, J., Jones, A., 2007. Evaluation of moving and handling training for pre-registration nurses and its application to practice. Nurse Education in Practice 7(3), 128-134]. Seventeen pre-registration students participated, representing adult, child and mental health branches from both Degree and Diploma programmes Examples of poor practice set the context for the students' experiences. Factors affecting both compliance with poor practice or compliance with moving and handling regulations leading to good practice, are identified. Methods for the management of difficult moving and handling situations are also revealed. The study informs future developments in training and support mechanisms for students in practice. PMID:19447074

  5. The Experience of Women Affected by Polycystic Ovary Syndrome: A Qualitative Study From Iran

    PubMed Central

    Nasiri Amiri, Fatemeh; Ramezani Tehrani, Fahimeh; Simbar, Masoumeh; Montazeri, Ali; Mohammadpour Thamtan, Reza Ali

    2014-01-01

    Background: Polycystic ovary syndrome (PCOS) is the most common chronic endocrine disorder. It has significant and diverse clinical consequences including reproductive, metabolic, and psychological morbidities as well as predisposition to malignancies. It is unclear how women with PCOS experience symptoms of this syndrome. Objectives: The aim of this study was to clarify the dimensions and components of quality of life in iranian women with PCOS. Patients and Methods: This study was a qualitative study to explore and document perceptions of women with PCOS about their disorder and quality of life. Semi-structured interviews with open ended questions were conducted with 23 women with PCOS. The interviews were continued to reach data saturation. The study was conducted in the Reproductive Endocrinology Research Center of Shahid Beheshti University of Medical Sciences. All the interviews were recorded and transcribed. Constant comparative analysis of the data was conducted manually according to the Strauss and Corbin analysis method. Results: The study revealed that the most important factors affecting quality of life in women with PCOS were the role functioning items as well as physical, mental, emotional, cognitive, and social dimensions. Conclusions: Comprehensive cares concerning various mental, emotional, cognitive, and social dimensions of quality of life should be planned for women with PCOS. PMID:24829583

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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)

  11. Rogowski Loop design for NSTX

    SciTech Connect

    McCormack, B.; Kaita, R.; Kugel, H.; Hatcher, R.

    2000-01-06

    The Rogowski Loop is one of the most basic diagnostics for tokamak operations. On the National Spherical Torus Experiment (NSTX), the plasma current Rogowski Loop had the constraints of the very limited space available on the center stack, 5,000 volt isolation, flexibility requirements as it remained a part of the Center Stack assembly after the first phase of operation, and a +120 C temperature requirement. For the second phase of operation, four Halo Current Rogowski Loops under the Center Stack tiles will be installed having +600 C and limited space requirements. Also as part of the second operational phase, up to ten Rogowski Loops will installed to measure eddy currents in the Passive Plate support structures with +350 C, restricted space, and flexibility requirements. This presentation will provide the details of the material selection, fabrication techniques, testing, and installation results of the Rogowski Loops that were fabricated for the high temperature operational and bakeout requirements, high voltage isolation requirements, and the space and flexibility requirements imposed upon the Rogowski Loops. In the future operational phases of NSTX, additional Rogowski Loops could be anticipated that will measure toroidal plasma currents in the vacuum vessel and in the Passive Plate assemblies.

  12. How Do Adolescent Students Experience Teacher-Student Interactions in a Seventh-Grade Classroom and How Do Those Experiences Affect Their Self-Efficacy Beliefs?

    ERIC Educational Resources Information Center

    Barg, Katherine Sanjiyan

    2009-01-01

    Studies over the past 30 years have examined teacher-student interactions in the classroom but have not focused on how those interactions may affect the self-efficacy feelings of students. Research suggests that students who connect well with their teachers experience more positive academic success. Therefore this study examined how adolescent…

  13. The Development of Affective Subscales To Reflect Variation in Students' Experiences of Studying Mathematics in Higher Education.

    ERIC Educational Resources Information Center

    Meyer, J. H. F.; Eley, M. G.

    1999-01-01

    Developed conceptually discrete subscales to represent affective sources of variation in student learning that are specific to learning mathematics. Tested these subscales, the Experiences of Studying Mathematics Inventory, with 317 South African and Australian undergraduate mathematics students and groups of 1,439 and 387 British, South African,…

  14. Experience of being the spouse/cohabitant of a person with bipolar affective disorder: a cumulative process over time.

    PubMed

    Tranvåg, Oscar; Kristoffersen, Kjell

    2008-03-01

    The aim of the study was to identify and describe spouses'/cohabitants' experiences of living with a partner with bipolar affective disorder over time. Qualitative research interviews were conducted with eight spouses/cohabitants. Transcribed interviews were analysed structurally based on Ricoeur's phenomenological hermeneutics as described by Lindseth and Norberg. The participants' shared lives ranged from 6 to 51 years, and the study found three major aspects that characterized their experience along this time-dimension; experience formed part of a cumulative process containing up to 14 experiences. Each experience created a preunderstanding that affected how subsequent experiences were perceived, and mastered. These three major aspects had a reciprocal influence on the following 14 experiences over time: Fear and the incomprehensible. Accusations. Self-doubt and doubt about own powers of judgement. Care and information vs. being overlooked or turned away by health personnel. Stigmatization and loss of social network. Uncertainty, powerlessness and hope. Loneliness. Anger and despair. The persistent threat. Own health problems. Grief over loss. Dawning acceptance. Reconciliation. New hope. A theoretical understanding using gestalt therapy theory suggests that burdensome experience can be seen as an inner imbalance in the spouse/cohabitant when she/he cannot find meaning in their experiences. When only parts of the whole are perceived, an incomplete gestalt is formed in the person's lived-experience that counteracts the equilibrium of the organism. Insight and meaning can protect them against burdensome experiences and nurses can empower them through care, health-promoting education and guidance. Nursing research should develop methods of education and guidance sensitive enough to help each spouse/cohabitant, regardless of where they are in their cumulative process. PMID:18269418

  15. Look before You Loop.

    ERIC Educational Resources Information Center

    Bellis, Marilyn

    1999-01-01

    Explores looping, which involves one teacher staying with the same group of children for more than one year. Recognizes that, with today's changing demographics, looping can be a way to foster a family-like classroom atmosphere. Discusses advantages and disadvantages to looping. Includes a chart of looping opportunities and considerations;…

  16. 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…

  17. The interplay of experience-based affective and probabilistic cues in decision making: arousal increases when experience and additional cues conflict.

    PubMed

    Glöckner, Andreas; Hochman, Guy

    2011-01-01

    In a study using behavioral and physiological measures we induced experience-based affective cues (i.e., differential anticipatory arousal) toward a risky and a safe option by letting participants repeatedly select between two decks of cards with feedback. In later test decisions we presented choice tasks between these trained and new pairs of decks. In some of the trials a low-valid probabilistic cue was provided after stimulus onset but before the decision. Although we were successful in inducing experience-based affective cues these did not influence participants' choices. In decisions without any further cues available people choose the safe and the risky option about equally often. If an additional low-valid probabilistic cue was available people followed this cue. Although experience had no effect on choices it influenced arousal. Anticipatory physiological arousal increased if the probabilistic cue and experience were conflicting. Our results are in line with recent findings indicating diminished loss aversion in experience-based decision making. They are also consistent with parallel constraint satisfaction models and shed light on the interrelation between experience, probabilistic cues, and arousal in decision making.

  18. 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.

  19. 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.

  20. 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.

  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. Variables Affecting Pharmacy Students’ Patient Care Interventions during Advanced Pharmacy Practice Experiences

    PubMed Central

    Patterson, Brandon J.; Sen, Sanchita; Bingham, Angela L.; Bowen, Jane F.; Ereshefsky, Benjamin; Siemianowski, Laura A.

    2016-01-01

    Objective. To identify the temporal effect and factors associated with student pharmacist self-initiation of interventions during acute patient care advanced pharmacy practice experiences (APPE). Methods. During the APPE, student pharmacists at an academic medical center recorded their therapeutic interventions and who initiated the intervention throughout clinical rotations. At the end of the APPE student pharmacists completed a demographic survey. Results. Sixty-two student pharmacists were included. Factors associated with lower rates of self-initiated interventions were infectious diseases and pediatrics APPEs and an intention to pursue a postgraduate residency. Timing of the APPE, previous specialty elective course completion, and previous hospital experience did not result in any significant difference in self-initiated recommendations. Conclusion. Preceptors should not base practice experience expectations for self-initiated interventions on previous student experience or future intentions. Additionally, factors leading to lower rates of self-initiated interventions on infectious diseases or pediatrics APPEs should be explored. PMID:27756924

  3. 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)

  4. Early experience affects the intergenerational transmission of infant abuse in rhesus monkeys

    PubMed Central

    Maestripieri, Dario

    2005-01-01

    Maternal abuse of offspring in macaque monkeys shares some similarities with child maltreatment in humans, including its transmission across generations. This study used a longitudinal design and a cross-fostering experiment to investigate whether abusive parenting in rhesus macaques is transmitted from mothers to daughters and whether transmission occurs through genetic or experiential factors. Nine of 16 females who were abused by their mothers in their first month of life, regardless of whether they were reared by their biological mothers or by foster mothers, exhibited abusive parenting with their firstborn offspring, whereas none of the females reared by nonabusive mothers did. These results suggest that the intergenerational transmission of infant abuse in rhesus monkeys is the result of early experience and not genetic inheritance. The extent to which the effects of early experience on the intergenerational transmission of abusive parenting are mediated by social learning or experience-induced physiological alterations remains to be established. PMID:15983367

  5. Early experience affects the intergenerational transmission of infant abuse in rhesus monkeys.

    PubMed

    Maestripieri, Dario

    2005-07-01

    Maternal abuse of offspring in macaque monkeys shares some similarities with child maltreatment in humans, including its transmission across generations. This study used a longitudinal design and a cross-fostering experiment to investigate whether abusive parenting in rhesus macaques is transmitted from mothers to daughters and whether transmission occurs through genetic or experiential factors. Nine of 16 females who were abused by their mothers in their first month of life, regardless of whether they were reared by their biological mothers or by foster mothers, exhibited abusive parenting with their firstborn offspring, whereas none of the females reared by nonabusive mothers did. These results suggest that the intergenerational transmission of infant abuse in rhesus monkeys is the result of early experience and not genetic inheritance. The extent to which the effects of early experience on the intergenerational transmission of abusive parenting are mediated by social learning or experience-induced physiological alterations remains to be established.

  6. 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.

  7. 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…

  8. 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…

  9. 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…

  10. Cognitive and Affective Costs of Bilingual Education: A Look at the Hong Kong Experience.

    ERIC Educational Resources Information Center

    Ripple, R. E.; And Others

    A study of the impact of language of instruction in schools on the divergent thinking, self-esteem, and locus of control of expatriate and Hong Kong native Chinese adolescents is reported and some of the cognitive and affective costs of the immersion method of bilingual education are examined. Hong Kong children in most schools must change…

  11. 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

  12. An Experiment to Demonstrate How a Catalyst Affects the Rate of a Reaction

    NASA Astrophysics Data System (ADS)

    Copper, Christine L.; Koubek, Edward

    1999-12-01

    By performing this experiment, students in general and introductory physical chemistry can learn more about the effect of a catalyst on a chemical reaction. This experiment, which is a modified version of the traditional iodine clock reaction, allows students to calculate rates of reaction, orders of reactants, and activation energies. It also lets students discover that to increase a reaction's rate, a catalyst need only provide any additional pathway for the reaction, not necessarily a pathway having a lower activation energy. This experiment is designed so that students will notice that the amount of catalyst used is important. Furthermore, the slight amount (~10-5 M MoO42-) of catalyst needed to increase the overall reaction rate and the abrupt color change that occurs seem to pique the interest of our students.

  13. How mothers' parenting styles affect their children's sexual efficacy and experience.

    PubMed

    Taris, T W; Semin, G R

    1998-03-01

    The relations among mothers' parenting styles and adolescents' sexual self-efficacy and sexual experience were examined in a sample of 253 British adolescent-mother pairs. Also explored was whether adolescents' self-efficacy would be positively or negatively related to their sexual experience. Mothers' parenting styles were expected to influence children's locus of control, based on the theory that mothers who are involved with their children and mothers who stress independence contribute to the development of an internal locus of control in their children, increasing the children's feelings of sexual self-efficacy. Structural equation modeling was used to test a longitudinal model. The results support the assumption that maternal involvement leads to higher levels of self-efficacy, whereas maternal control was associated with lower levels of self-efficacy. Sexual self-efficacy was associated with higher levels of sexual experience. Implications and limitations of the study are discussed.

  14. 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

  15. 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'…

  16. 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

  17. 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…

  18. How does the radiation therapist affect the cancer patients' experience of the radiation treatment?

    PubMed

    Egestad, H

    2013-09-01

    Previous studies of head and neck cancer patients going through radiation treatment have shown the treatment causes great physical as well as psychosocial problems. Although previous research acknowledges the needs of cancer patients, there is a lack of literature regarding the patient's perspective about radiation therapy. Studies have rarely focused on the whole experience of radiation treatment. The aim of this study was to illuminate how head and neck cancer patients' encounters with radiation therapists influence patients' experiences going through radiation therapy. The study was conducted via qualitative interviews, using a phenomenological hermeneutic approach. Eleven cancer patients were treated with radiation therapy. This study showed that encounters with radiation therapists have a significant influence on patients' experiences. Cancer patients' contact with radiation therapists can lead to increases or decreases in existential anxiety. When patients experience that the radiation therapist is professionally competent, the existential anxiety decreases. When the radiation therapist make time to build relationships and take responsibility for treatment and side effects, this creates a feeling of security and the treatment is easier to review. The study may indicate that the patients' existential anxiety increases when the radiation therapist shows professional incompetence. PMID:23731059

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

    PubMed Central

    Li, Qinghua; Li, Yue

    2015-01-01

    Person-centeredness may suffer in 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 2011–2012. 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–June 2012. Dependent variables were overall care rating (scale 1–10), percent 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=0.001). NH managers and policymakers should consider strategies to improve patient-centeredness post-ownership change. PMID:26162057

  20. 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)

  1. 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…

  2. 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…

  3. 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)

  4. "Doing Gender" at "Body Worlds": Embodying Field Trips as Affective Educational Experience

    ERIC Educational Resources Information Center

    Davidson, Joyce; Huff, Leah; Bridgen, Jen; Carolan, Andrea; Chang, Ashley; Ennis, Katherine; Loynes, Kathryn; Miller, Jen

    2009-01-01

    This paper discusses the background, experience and outcomes of an explicitly feminist field trip to Gunther von Hagen's "Body Worlds 2: The Anatomical Exhibition of Real Human Bodies". The cultural landscape of this exhibition materialized gendered geographies very powerfully, facilitating observation and analysis of embodied and emotional,…

  5. 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.

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

    PubMed

    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.

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

    PubMed

    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

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. Has nonoperative management of solid visceral injuries adversely affected resident operative experience?

    PubMed

    Jennings, G R; Poole, G V; Yates, N L; Johnson, R K; Brock, M

    2001-06-01

    The purpose of this study was to assess the impact of increased use of nonoperative management of blunt injuries to the spleen or liver on surgical residents' operative experience with solid visceral injuries. We conducted a 10-year retrospective study of blunt spleen and liver injuries at a state-designated Level I trauma center and a survey of chief residents' operative experience with splenic and hepatic injuries from blunt trauma during the same time period. From 1990 through 1999, 431 patients were admitted with splenic injuries and 634 patients were admitted with liver injuries; 350 splenic injuries (81%) were due to blunt trauma; 317 liver injuries (50%) were caused by blunt mechanisms. In 1990 100 per cent of patients with splenic injuries and 93 per cent of those with liver injuries underwent surgery for those injuries. These rates were 19 and 28 per cent respectively in 1999. The number of patients with blunt solid visceral injuries increased more than fourfold from 1990 through 1999. The number of operations for splenic and hepatic injuries performed by chief residents did not decline significantly during this time period (5.5 cases per chief resident in 1990; 4.6 cases per chief resident in 1999). The increased numbers of patients with solid visceral injuries were due to two factors: increased proportion of blunt trauma admissions especially from motor vehicle collisions and improved recognition of spleen and liver injuries by expanded use of CT scans. We conclude that nonoperative management of blunt solid visceral injuries does not necessarily lead to a diminution of operations nor jeopardize resident education. However, trauma volumes must be high enough to support adequate operative experience. PMID:11409812

  11. Bias to pollen odors is affected by early exposure and foraging experience.

    PubMed

    Arenas, A; Farina, W M

    2014-07-01

    In many pollinating insects, foraging preferences are adjusted on the basis of floral cues learned at the foraging site. In addition, olfactory experiences gained at early adult stages might also help them to initially choose food sources. To understand pollen search behavior of honeybees, we studied how responses elicited by pollen-based odors are biased in foraging-age workers according to (i) their genetic predisposition to collect pollen, (ii) pollen related information gained during foraging and (iii) different experiences with pollen gained at early adult ages. Bees returning to the hive carrying pollen loads, were strongly biased to unfamiliar pollen bouquets when tested in a food choice device against pure odors. Moreover, pollen foragers' orientation response was specific to the odors emitted by the pollen type they were carrying on their baskets, which suggests that foragers retrieve pollen odor information to recognize rewarding flowers outside the hive. We observed that attraction to pollen odor was mediated by the exposure to a pollen diet during the first week of life. We did not observe the same attraction in foraging-age bees early exposed to an artificial diet that did not contain pollen. Contrary to the specific response observed to cues acquired during foraging, early exposure to single-pollen diets did not bias orientation response towards a specific pollen odor in foraging-age bees (i.e. bees chose equally between the exposed and the novel monofloral pollen odors). Our results show that pollen exposure at early ages together with olfactory experiences gained in a foraging context are both relevant to bias honeybees' pollen search behavior. PMID:24852672

  12. Rehabilitation planning for flood affected areas of Thailand: experience from Phipun District.

    PubMed

    Wickramanayake, E; Shook, G A; Rojnkureesatien, T

    1995-12-01

    Floods are common in Thailand. A flood in the southern part of the country in 1988 was of unprecedented magnitude. Several villages and vast tracts of agricultural land were covered with mud slides washed away from deforested hills. Rehabilitation of the affected areas, a task which required complex planning, was a challenge for the District Development Committee (DDC), which is the local level planning body. The Committee encountered several problems, including inability to use the existing data base and lack of accurate information, human resources, adequate funds and coordination among agencies. Unable to cope with the new challenges, the DDC resorted to conventional planning which failed to address the problems caused by the flood. Guidelines should be formulated to strengthen district level planning for rehabilitation after a disaster. PMID:8564458

  13. 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

  14. 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.

  15. Remembrance of things touched: How sensorimotor experience affects the neural instantiation of object form

    PubMed Central

    Oliver, Robyn T.; Geiger, Emily J.; Lewandowski, Brian C.; Thompson-Schill, Sharon L.

    2009-01-01

    Numerous neuroimaging and neuropsychological studies have highlighted the role of the ventral, occipitotemporal visual processing stream in the representation and retrieval of semantic memory for the appearance of objects. Here, we examine the role of the parietal cortex in retrieval of object shape information. fMRI data were acquired as subjects listened to the names of common objects and made judgments about their shape. Recruitment of the left inferior parietal lobule (IPL) during shape retrieval was modulated by the amount of prior tactile experience associated with the objects. In addition, the same pattern of activity was observed in right postcentral gyrus, suggesting that the representation of object shape is distributed amongst regions that are relevant to the sensorimotor acquisition history of this attribute, as predicted by distributed models of semantic memory. PMID:18760292

  16. Disrupted by disaster: shared experiences of student registered nurse anesthetists affected by hurricane Katrina.

    PubMed

    Geisz-Everson, Marjorie A; Bennett, Marsha J; Dodd-McCue, Diane; Biddle, Chuck

    2012-01-01

    The purpose of this focused ethnography was to describe the shared experiences of student registered nurse anesthetists (SRNAs) whose senior year of education and training was disrupted by Hurricane Katrina, as well as to determine the storm's psychosocial impact on them. A convenience sample of 10 former SRNAs participated in focus groups that were audiorecorded, transcribed, and qualitatively analyzed. Three major themes emerged from the study: Seriousness of Urgency, Managing Uncertainty, and Stability Equaled Relief. The themes represented how the SRNAs appraised and coped with the stressful events surrounding Hurricane Katrina. The psychosocial impact of Hurricane Katrina on the SRNAs resulted mainly in temporary increased alcohol consumption and short-term anxiety. One person started smoking. The results of this study should serve as a guide to formulate policies regarding the education of SRNAs during and immediately after a disaster and to provide a framework for future disaster studies regarding SRNAs.

  17. Disrupted by disaster: shared experiences of student registered nurse anesthetists affected by hurricane Katrina.

    PubMed

    Geisz-Everson, Marjorie A; Bennett, Marsha J; Dodd-McCue, Diane; Biddle, Chuck

    2012-01-01

    The purpose of this focused ethnography was to describe the shared experiences of student registered nurse anesthetists (SRNAs) whose senior year of education and training was disrupted by Hurricane Katrina, as well as to determine the storm's psychosocial impact on them. A convenience sample of 10 former SRNAs participated in focus groups that were audiorecorded, transcribed, and qualitatively analyzed. Three major themes emerged from the study: Seriousness of Urgency, Managing Uncertainty, and Stability Equaled Relief. The themes represented how the SRNAs appraised and coped with the stressful events surrounding Hurricane Katrina. The psychosocial impact of Hurricane Katrina on the SRNAs resulted mainly in temporary increased alcohol consumption and short-term anxiety. One person started smoking. The results of this study should serve as a guide to formulate policies regarding the education of SRNAs during and immediately after a disaster and to provide a framework for future disaster studies regarding SRNAs. PMID:22229961

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. Investigating affective color association of media content in language and perception based on online RGB experiment

    NASA Astrophysics Data System (ADS)

    Lee, Kyung Jae

    2005-03-01

    As an investigation of color categorization in language and perception, this research intends to study the affective associations between certain colors and different media content (i.e., movie genres). Compared to non-entertainment graphics (medical imaging and engineering graphics), entertainment graphics (video games and movies) are designed to deliver emotionally stimulating content to audiences. Based on an online color survey of 19 subjects, this study investigated whether or not subjects had different color preferences on diverse movie genres. Instead of providing predefined limited number of color chips (or pictures) as stimuli, this study was conducted by asking the subjects to visualize their own images of movie genres and to select their preferred colors through an online RGB color palette. By providing a combined application interface of three color slides (red, green, blue) and 216 digital color cells, the subjects were interactively able to select their preferred colors of different movie genres. To compare the distribution of movie genres, the user selected colors were mapped on CIE chromaticity diagram. This study also investigated preferred color naming of different movie genres as well as three primary color names of the subjects" most favorite genre. The results showed that the subjects had different color associations with specific movie genres as well as certain genres showed higher individual differences. Regardless of genre differences, the subjects selected blue, red or green as their three primary color names that represent their favorite movie genres. Also, the results supports Berlin & Kay"s eleven color terms.

  4. 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

  5. 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

  6. 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

  7. Do reports on drinking water quality affect customers' concerns? Experiments in report content.

    PubMed

    Johnson, Branden B

    2003-10-01

    The Safe Drinking Water Act Amendments of 1996 required U.S. utilities to report on drinking water quality to their customers annually, beginning in fall 1999, on the assumption that such reports would alert them to quality problems and perhaps mobilize pressure for improvement. A random sample of New Jersey customers read alternative versions of a water quality report, in an experiment on reactions to water quality information under U.S. Environmental Protection Agency (USEPA) rules. Experiment design was 2 x 3 + 1: two versions each--one with, one without, a violation of a health standard--of a report that was (1) Qualitative (without water quality numbers, thus not meeting USEPA rules); (2) Basic, with minimal information meeting the rules; or (3) Extended, adding reading aids and utility performance information; plus a control instrument without any hypothetical report. Results of ANOVA suggest the reports will have less effect than hoped or feared. These manipulations were successful: people reading the Qualitative versions were less likely to say that the report gave the amounts of substances found in the water, and those reading Violation versions were more likely to report a violation of a health standard. The main differences in responses to the report involved the judged adequacy of the information, and to a lesser extent responses on a Concern scale (constructed from measures of concern, judged risk, clean-up intentions, distrust of utility information, and doubt that the utility was doing all it could to improve water quality). Overall judgments of water quality and utility performance did not change, either relative to the controls or in before versus after responses. Qualitative reports performed worse than others, confirming the decision to have utilities report actual contaminant levels. Extended reports did only slightly better than the Basic versions on these measures. Many respondents had trouble identifying the presence or absence of substance

  8. 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.

  9. Factors affecting the experiences of drug use by adolescents in a Bangkok slum.

    PubMed

    Laoniramai, Patrapan; Laosee, Orapin C; Somrongthong, Ratana; Wongchalee, Sunanta; Sitthi-Amorn, Chitr

    2005-07-01

    The purpose of this research was to study the demography, financial status, social status, knowledge of amphetamines, perceived harmfulness of amphetamines, and life skills in the prevention of drug abuse in adolescents. The factors leading to drug use among young people were also studied. The study group was composed of 354 subjects aged 12 to 22 years, living in 2 slums in Bangkok. The research showed that about 7% of the sample group had used drugs before. Four percent had never used drugs, but someone had tried to talk them into using them. Almost 20% had friends who had used drugs, and 11% had friends who were still using drugs. About 13% of the adolescents in the study group had family members who used drugs and another 9% had family members who were still using drugs. In our study, we found that the most common drug group was amphetamines. On average, the participants had a low level of understanding about drug abuse, especially of the symptoms, side effects, and legal penalties. Most of the adolescents realized how harmful amphetamines and other drugs were and had a high degree life skills. Factors influencing adolescent drug use were (1) personal factors, such as monthly income/allowance and life skills; (2) family environment, such as drug abuse history in the family; and (3) social environment, such as a drug abuse history among friends. When studying the life skill factors of the adolescents, which is an independent factor capable of influencing the experience with drugs, the researchers found that the time spent with other members of the family and the family members' drug experiences were the only factors leading to life skills in the prevention of drug abuse in adolescents. In addition to letting children learn on their own, training them to acquire life skills is beneficial when faced with problematic situations. Creating relationships between adolescents and other members of the family, friends, and society can increase their life skills

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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.

  15. Altered visual experience and acute visual deprivation affect predatory targeting by infrared-imaging Boid snakes.

    PubMed

    Grace, M S; Woodward, O M

    2001-11-23

    Boid and Crotaline snakes use both their eyes and infrared-imaging facial pit organs to target homeothermic prey. These snakes can target in complete darkness, but the eyes can also effectively direct predatory strikes. We investigated the behavioral correlates of boid snakes' simultaneous use of two imaging systems by testing whether congenital unilateral visual deprivation affects targeting performance. Normally sighted Burmese pythons exhibited average targeting angle of zero (on the midline axis of the head), but three unilaterally anophthalmic Burmese pythons targeted preferentially on the sighted side. A unilaterally anophthalmic amethystine python also targeted on the sighted side, and a unilaterally anophthalmic Brazilian rainbow boa tended to target on the sighted side, though its mean targeting angle was not significantly different from zero. When unilaterally anophthalmic Burmese pythons were temporarily blinded, mean strike angle changed to that of normally sighted snakes. These results show that while infrared-imaging snakes can shift between visual and infrared information under acute experimental conditions, loss of part of the visual field during development results in abnormal predatory targeting behavior. In contrast, normally sighted snakes subjected to temporary unilateral blinding do not target preferentially on the sighted side. Therefore, while loss of part of the visual field may be compensated for by infrared input in normal snakes, partial absence of visual input during development may alter central organization of visual information. Conversely, absence of half the visual field during development does not alter targeting performance based upon infrared input alone, suggesting that organization of the central infrared map does not depend upon normal organization of visual input.

  16. 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

  17. 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.

  18. 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

  19. Temporal call changes and prior experience affect graded signalling in the cricket frog.

    PubMed

    Burmeister; Wilczynski; Ryan

    1999-03-01

    We investigated how male cricket frogs Acris crepitans, alter their advertisement calls in response to broadcasts of synthetic calls that were either 'attractive' or 'aggressive'. The stimulus calls differed in temporal but not spectral characteristics. Male cricket frogs produced a more aggressive call when presented with the aggressive stimulus, indicating that they perceived the temporal differences between the two call categories. The direction and degree of temporal and spectral changes depended on the relative dominant frequency of the resident and opponent. If the resident's dominant frequency was initially higher than the stimulus frequency, the pattern of change in dominant frequency mirrored that seen for the temporal call characters. In contrast, if the resident's initial dominant frequency was below that of the stimulus, then the temporal and spectral changes were in opposite directions. Furthermore, stimulus order influenced whether males responded differently to playbacks of aggressive and attractive calls; males that received the aggressive call first produced more aggressive calls during the aggressive stimulus, while males that received the attractive call first produced similar calls in response to the two stimuli. This suggests that experience with different types of signals influences the subsequent calling behaviour of male cricket frogs. Copyright 1999 The Association for the Study of Animal Behaviour.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. How do online patient support communities affect the experience of inflammatory bowel disease? An online survey

    PubMed Central

    Coulson, Neil S

    2013-01-01

    Objective To explore how participation in an online support community may impact upon the experience of inflammatory bowel disease (IBD). Design An online survey. Setting Study participants recruited through 35 IBD online communities. Participants A total of 249 males and females aged 16–69 years, living with either Crohn’s disease (65.9%) or ulcerative colitis (26.1%) or awaiting formal diagnosis (8%). Results Patients reported being members for an average of two years, with the majority accessing the community on a daily (46.9%) or weekly (40%) basis. Spending on average four hours per week online, approximately two-thirds of members posted between one and five messages per week. Members joined to find others in a similar situation and to obtain and share information and emotional support. Through participation members accessed a wealth of knowledge about all aspects of living with IBD and this was helpful in terms of accepting their illness and learning to manage it. The community also helped members see their illness more positively as well as contributing to an improvement in subjective wellbeing. However, some negatives aspects were noted. Conclusions Online support communities may provide a useful shared space through which IBD patients may seek and provide both informational and emotional support. Many of these benefits may not be available through traditional healthcare. Whilst online support communities may be beneficial for those who choose to participate in them, they are not without limitations. Health professionals should be aware of the potential benefits and limitations of online communities. PMID:24040493

  5. Mesocosm experiments to assess factors affecting phosphorus retention and release in an extended Wisconsin wetland

    USGS Publications Warehouse

    Elder, J.F.; Manion, B.J.; Goddard, G.L.

    1997-01-01

    Phosphorus retention by wetland sediments and vegetation was investigated in Jackson Creek wetland, an extension of an existing prairie marsh in southeastern Wisconsin. The extended wetland construction was undertaken in 1992-93 to help reduce the phosphorus loading to a downstream eutrophic lake. Two approaches were used to study potential and actual phosphorus retention in the system. Mesocosm experiments of 20-40 days duration indicated that retention of total and dissolved reactive phosphorus in mesocosm cells containing macrophytes and/or sediments was reduced by factors of 2-20 relative to cells containing only water or a copper algicide to suppress metabolic activity. In contrast to the nutrient trapping function, these results show a potential for net phosphorus release that can be associated with increased biological richness. Measurements of water flow and nutrient loads at the wetland's inflow and outflow points demonstrated 9-39% net uptake of phosphorus on an annual scale but frequent occurrences of net phosphorus release over shorter (one-month) time scales. These episodes of release are most likely during the summer months. Thus, the wetland role in phosphorus cycling is not one of a true source or sink, although the annual budget data alone suggest substantial net retention. Effective management of the wetland for its nutrient trapping potential can be hindered by this oversimplification. The system is instead subject to relatively short-term alternation between net import and export. The periodic phosphorus export, although representing a small fraction of net annual import, could be critical for growth of macrophyte and algal communities downstream.

  6. 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

  7. 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.

  8. [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

  9. [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.

  10. 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

  11. 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.

  12. Formation of Chromosomal Domains by Loop Extrusion.

    PubMed

    Fudenberg, Geoffrey; Imakaev, Maxim; Lu, Carolyn; Goloborodko, Anton; Abdennur, Nezar; Mirny, Leonid A

    2016-05-31

    Topologically associating domains (TADs) are fundamental structural and functional building blocks of human interphase chromosomes, yet the mechanisms of TAD formation remain unclear. Here, we propose that loop extrusion underlies TAD formation. 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. Using polymer simulations, we show that this model produces TADs and finer-scale features of Hi-C data. Each TAD emerges from multiple loops dynamically formed through extrusion, contrary to typical illustrations of single static loops. Loop extrusion both explains diverse experimental observations-including the preferential orientation of CTCF motifs, enrichments of architectural proteins at TAD boundaries, and boundary deletion experiments-and makes specific predictions for the depletion of CTCF versus cohesin. Finally, loop extrusion has potentially far-ranging consequences for processes such as enhancer-promoter interactions, orientation-specific chromosomal looping, and compaction of mitotic chromosomes. PMID:27210764

  13. Run-time parallelization and scheduling of loops

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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, wavefronts 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 indexes can have a significant impact on performance.

  14. A genome-screen experiment to detect quantitative trait loci affecting resistance to facial eczema disease in sheep.

    PubMed

    Phua, S H; Dodds, K G; Morris, C A; Henry, H M; Beattie, A E; Garmonsway, H G; Towers, N R; Crawford, A M

    2009-02-01

    Facial eczema (FE) is a secondary photosensitization disease arising from liver cirrhosis caused by the mycotoxin sporidesmin. The disease affects sheep, cattle, deer and goats, and costs the New Zealand sheep industry alone an estimated NZ$63M annually. A long-term sustainable solution to this century-old FE problem is to breed for disease-resistant animals by marker-assisted selection. As a step towards finding a diagnostic DNA test for FE sensitivity, we have conducted a genome-scan experiment to screen for quantitative trait loci (QTL) affecting this trait in Romney sheep. Four F(1) sires, obtained from reciprocal matings of FE resistant and susceptible selection-line animals, were used to generate four outcross families. The resulting half-sib progeny were artificially challenged with sporidesmin to phenotype their FE traits measured in terms of their serum levels of liver-specific enzymes, namely gamma-glutamyl transferase and glutamate dehydrogenase. In a primary screen using selective genotyping on extreme progeny of each family, a total of 244 DNA markers uniformly distributed over all 26 ovine autosomes (with an autosomal genome coverage of 79-91%) were tested for linkage to the FE traits. Data were analysed using Haley-Knott regression. The primary screen detected one significant and one suggestive QTL on chromosomes 3 and 8 respectively. Both the significant and suggestive QTL were followed up in a secondary screen where all progeny were genotyped and analysed; the QTL on chromosome 3 was significant in this analysis.

  15. 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.

  16. Breeding experience and population density affect the ability of a songbird to respond to future climate variation.

    PubMed

    Wilson, Scott; Norris, D Ryan; Wilson, Amy G; Arcese, Peter

    2007-10-22

    Predicting how populations respond to climate change requires an understanding of whether individuals or cohorts within populations vary in their response to climate variation. We used mixed-effects models on a song sparrow (Melospiza melodia) population in British Columbia, Canada, to examine differences among females and cohorts in their average breeding date and breeding date plasticity in response to the El Niño Southern Oscillation. Climatic variables, age and population density were strong predictors of timing of breeding, but we also found considerable variation among individual females and cohorts. Within cohorts, females differed markedly in their breeding date and cohorts also differed in their average breeding date and breeding date plasticity. The plasticity of a cohort appeared to be due primarily to an interaction between the environmental conditions (climate and density) experienced at different ages rather than innate inter-cohort differences. Cohorts that expressed higher plasticity in breeding date experienced warmer El Niño springs in their second or third breeding season, suggesting that prior experience affects how well individuals responded to abnormal climatic conditions. Cohorts born into lower density populations also expressed higher plasticity in breeding date. Interactions between age, experience and environmental conditions have been reported previously for long-lived taxa. Our current results indicate that similar effects operate in a short-lived, temperate songbird.

  17. 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

  18. Lock detection in Costas loops

    NASA Technical Reports Server (NTRS)

    Mileant, A.; Hinedi, S.

    1992-01-01

    Previous analyses of lock detector algorithms for Costas loops have ignored the effects of the inherent correlation between samples of the phase error process. In this paper, both analysis and simulations are used to quantify the effects of phase correlation on lock detection for the 'square law' and 'absolute value' type detectors. Results are obtained which depict the lock detection probability as a function of loop signal-to-noise ratio for a given false alarm rate. It is shown that the square law detector experiences less degradation due to phase jitter than the absolute value detector and that the degradation in detector signal-to-noise ratio is more pronounced for squarewave than for sinewave signals.

  19. Lock detection in Costas loops

    NASA Astrophysics Data System (ADS)

    Mileant, A.; Hinedi, S.

    1992-03-01

    Previous analyses of lock detector algorithms for Costas loops have ignored the effects of the inherent correlation between samples of the phase error process. In this paper, both analysis and simulations are used to quantify the effects of phase correlation on lock detection for the 'square law' and 'absolute value' type detectors. Results are obtained which depict the lock detection probability as a function of loop signal-to-noise ratio for a given false alarm rate. It is shown that the square law detector experiences less degradation due to phase jitter than the absolute value detector and that the degradation in detector signal-to-noise ratio is more pronounced for squarewave than for sinewave signals.

  20. 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.

  1. 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…

  2. 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.

  3. Multiprotein DNA Looping

    NASA Astrophysics Data System (ADS)

    Vilar, Jose M. G.; Saiz, Leonor

    2006-06-01

    DNA looping plays a fundamental role in a wide variety of biological processes, providing the backbone for long range interactions on DNA. Here we develop the first model for DNA looping by an arbitrarily large number of proteins and solve it analytically in the case of identical binding. We uncover a switchlike transition between looped and unlooped phases and identify the key parameters that control this transition. Our results establish the basis for the quantitative understanding of fundamental cellular processes like DNA recombination, gene silencing, and telomere maintenance.

  4. 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

  5. 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

  6. 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

  7. Natively unstructured loops differ from other loops.

    PubMed

    Schlessinger, Avner; Liu, Jinfeng; Rost, Burkhard

    2007-07-01

    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

  8. Instructional laboratory experiment on the effect of sound reflection on the driving-point impedance loop of a small sonar transducer.

    PubMed

    Nahar, N; Stumpf, F B

    1987-03-01

    This letter presents an experiment in acoustics to be used in a laboratory course for advanced undergraduate or beginning graduate students in physics or engineering. It describes the equipment used and the effect of reflection from a plate immersed in water on the driving-point impedance of a small sonar transducer placed at the air-water surface above the plate.

  9. 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.

  10. Blind loop syndrome

    MedlinePlus

    ... operations for extreme obesity As a complication of inflammatory bowel disease Diseases such as diabetes or scleroderma may slow down movement in a segment of the intestine, leading to blind loop syndrome.

  11. 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.

  12. The relation between social behavior and negative affect in psychosis-prone individuals: an experience sampling investigation.

    PubMed

    Husky, Mathilde M; Grondin, Olivier S; Swendsen, Joel D

    2004-02-01

    Daily social behavior and negative affect were examined in a sample of individuals with a wide spectrum of psychosis-proneness scores. Using the experience sampling method, participants were signaled five times per day for a 1-week period to provide naturalistic reports of location, activity, and social behavior. Little evidence was found for a direct association between psychosis-proneness and specific behavioral profiles, but individuals with higher scores of psychosis-proneness reported spending more time doing nothing or waiting. However, the levels of anxious and depressed moods experienced in certain social and environmental contexts were also predicted by psychosis-proneness scores. The present results indicate that psychosis-proneness was associated with an increase in anxiety when individuals were with friends and an increase in depressed mood in daily task situations such as working or studying. By contrast, psychosis-proneness predicted a decrease in depressed and anxious moods in other situations when the individual was not likely to be confronted by social contact with less known individuals, and lower anxious and depressed moods when in secure environments (in one's own home, home of family or friends). The implications of these findings are discussed in terms of understanding the expression of psychosis vulnerability and the potential reinforcement of maladaptive social behavior through operant conditioning mechanisms.

  13. Unique charge distribution in surface loops confers high velocity on the fast motor protein Chara myosin.

    PubMed

    Ito, Kohji; Yamaguchi, Yukie; Yanase, Kenji; Ichikawa, Yousuke; Yamamoto, Keiichi

    2009-12-22

    Most myosins have a positively charged loop 2 with a cluster of lysine residues that bind to the negatively charged N-terminal segment of actin. However, the net charge of loop 2 of very fast Chara myosin is zero and there is no lysine cluster in it. In contrast, Chara myosin has a highly positively charged loop 3. To elucidate the role of these unique surface loops of Chara myosin in its high velocity and high actin-activated ATPase activity, we have undertaken mutational analysis using recombinant Chara myosin motor domain. It was found that net positive charge in loop 3 affected V(max) and K(app) of actin activated ATPase activity, while it affected the velocity only slightly. The net positive charge in loop 2 affected K(app) and the velocity, although it did not affect V(max). Our results suggested that Chara myosin has evolved to have highly positively charged loop 3 for its high ATPase activity and have less positively charged loop 2 for its high velocity. Since high positive charge in loop 3 and low positive charge in loop 2 seem to be one of the reasons for Chara myosin's high velocity, we manipulated charge contents in loops 2 and 3 of Dictyostelium myosin (class II). Removing positive charge from loop 2 and adding positive charge to loop 3 of Dictyostelium myosin made its velocity higher than that of the wild type, suggesting that the charge strategy in loops 2 and 3 is widely applicable.

  14. Choking loops on surfaces.

    PubMed

    Feng, Xin; Tong, Yiying

    2013-08-01

    We present a method for computing "choking" loops--a set of surface loops that describe the narrowing of the volumes inside/outside of the surface and extend the notion of surface homology and homotopy loops. The intuition behind their definition is that a choking loop represents the region where an offset of the original surface would get pinched. Our generalized loops naturally include the usual 2g handles/tunnels computed based on the topology of the genus-g surface, but also include loops that identify chokepoints or bottlenecks, i.e., boundaries of small membranes separating the inside or outside volume of the surface into disconnected regions. Our definition is based on persistent homology theory, which gives a measure to topological structures, thus providing resilience to noise and a well-defined way to determine topological feature size. More precisely, the persistence computed here is based on the lower star filtration of the interior or exterior 3D domain with the distance field to the surface being the associated 3D Morse function. PMID:23744260

  15. DNA Looping, Supercoiling and Tension

    NASA Astrophysics Data System (ADS)

    Finzi, Laura

    2007-11-01

    In complex organisms, activation or repression of gene expression by proteins bound to enhancer or silencer elements located several kilobases away from the promoter is a well recognized phenomenon. However, a mechanistic understanding of any of these multiprotein interactions is still incomplete. Part of the difficulty in characterizing long-range interactions is the complexity of the regulatory systems and also an underestimation of the effect of DNA supercoiling and tension. Supercoiling is expected to promote interactions between DNA sites because it winds the DNA into compact plectonemes in which distant DNA segments more frequently draw close. The idea that DNA is also under various levels of tension is becoming more widely accepted. Forces that stretch the double helix in vivo are the electrostatic repulsion among the negatively charged phosphate groups along the DNA backbone, the action of motor enzymes perhaps acting upon a topologically constrained sequence of DNA or chromosome segregation during cell mitosis following DNA replication. Presently, little is known about the tension acting on DNA in vivo, but characterization of how physiological regulatory processes, such as loop formation, depend on DNA tension in vitro will indicate the stretching force regimes likely to exist in vivo. In this light, the well studied CI protein of bacteriophage l, which was recently found to cause a of 3.8 kbp loop in DNA, is an ideal system in which to characterize long-range gene regulation. The large size of the loop lends itself to single-molecule techniques, which allow characterization of the dynamics of CI-mediated l DNA looping under controlled levels of supercoiling and tension. Such experiments are being used to discover the principles of long-range interactions in l and in more complex systems.

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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

  2. Modulation of DNA loop lifetimes by the free energy of loop formation

    PubMed Central

    Chen, Yi-Ju; Johnson, Stephanie; Mulligan, Peter; Spakowitz, Andrew J.; Phillips, Rob

    2014-01-01

    Storage and retrieval of the genetic information in cells is a dynamic process that requires the DNA to undergo dramatic structural rearrangements. DNA looping is a prominent example of such a structural rearrangement that is essential for transcriptional regulation in both prokaryotes and eukaryotes, and the speed of such regulations affects the fitness of individuals. Here, we examine the in vitro looping dynamics of the classic Lac repressor gene-regulatory motif. We show that both loop association and loop dissociation at the DNA-repressor junctions depend on the elastic deformation of the DNA and protein, and that both looping and unlooping rates approximately scale with the looping J factor, which reflects the system’s deformation free energy. We explain this observation by transition state theory and model the DNA–protein complex as an effective worm-like chain with twist. We introduce a finite protein–DNA binding interaction length, in competition with the characteristic DNA deformation length scale, as the physical origin of the previously unidentified loop dissociation dynamics observed here, and discuss the robustness of this behavior to perturbations in several polymer parameters. PMID:25411314

  3. 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

  4. 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…

  5. The Anderson Current Loop

    NASA Technical Reports Server (NTRS)

    Anderson, Karl F.

    1994-01-01

    Four-wire-probe concept applied to electrical-resistance transducers. Anderson current loop is excitation-and-signal-conditioning circuit suitable for use with strain gauges, resistance thermometers, and other electrical-resistance transducers mounted in harsh environments. Used as alternative to Wheatstone bridge. Simplifies signal-conditioning problem, enabling precise measurement of small changes in resistance of transducer. Eliminates some uncertainties in Wheatstone-bridge resistance-change measurements in flight research. Current loop configuration makes effects of lead-wire and contact resistances insignificantly small. Also provides output voltage that varies linearly with change in gauge resistance, and does so at double sensitivity of Wheatstone bridge.

  6. 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.

  7. Loop quantum gravity

    NASA Astrophysics Data System (ADS)

    Chiou, Dah-Wei

    2015-12-01

    This paper presents an "in-a-nutshell" yet self-contained introductory review on loop quantum gravity (LQG) — a background-independent, nonperturbative approach to a consistent quantum theory of gravity. Instead of rigorous and systematic derivations, it aims to provide a general picture of LQG, placing emphasis on the fundamental ideas and their significance. The canonical formulation of LQG, as the central topic of the paper, is presented in a logically orderly fashion with moderate details, while the spin foam theory, black hole thermodynamics, and loop quantum cosmology are covered briefly. Current directions and open issues are also summarized.

  8. 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

  9. 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

  10. 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.

  11. Does Double Loop Learning Create Reliable Knowledge?

    ERIC Educational Resources Information Center

    Blackman, Deborah; Connelly, James; Henderson, Steven

    2004-01-01

    This paper addresses doubts concerning the reliability of knowledge being created by double loop learning processes. Popper's ontological worlds are used to explore the philosophical basis of the way that individual experiences are turned into organisational knowledge, and such knowledge is used to generate organisational learning. The paper…

  12. 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.

  13. 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

  14. Counting primary loops in polymer gels

    PubMed Central

    Zhou, Huaxing; Woo, Jiyeon; Cok, Alexandra M.; Wang, Muzhou; Olsen, Bradley D.; Johnson, Jeremiah A.

    2012-01-01

    Much of our fundamental knowledge related to polymer networks is built on an assumption of ideal end-linked network structure. Real networks invariably possess topological imperfections that negatively affect mechanical properties; modifications of classical network theories have been developed to account for these defects. Despite decades of effort, there are no known experimental protocols for precise quantification of even the simplest topological network imperfections: primary loops. Here we present a simple conceptual framework that enables primary loop quantification in polymeric materials. We apply this framework to measure the fraction of primary loop junctions in trifunctional PEG-based hydrogels. We anticipate that the concepts described here will open new avenues of theoretical and experimental research related to polymer network structure. PMID:23132947

  15. 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)…

  16. Loop Quantum Gravity

    NASA Astrophysics Data System (ADS)

    Piguet, O.

    2014-09-01

    In this talk, I give a short general introduction to Loop Quantum Gravity (LQG), beginning with some motivations for quantizing General Relativity, listing various attempts and then focusing on the case of LQG. Work supported in part by the Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq (Brazil).

  17. NETL - Chemical Looping Reactor

    ScienceCinema

    None

    2016-07-12

    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.

  18. 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.

  19. "You're Facing That Machine but There's a Human Being behind It": Students' Affective Experiences on an Online Doctoral Programme

    ERIC Educational Resources Information Center

    Kennedy, Eileen; Gray, Morag

    2016-01-01

    Online students use highly emotional language to describe their experiences, indicating that learners do feel a great deal online. This paper draws on Wetherell's exploration of affective practice to theorise learners' responses to the pedagogical and technological online environment. Findings of a research project that focused on two cohorts of…

  20. 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.

  1. 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

  2. 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.…

  3. 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…

  4. Early and Later Experience with One Younger Sibling Affects Face Processing Abilities of 6-Year-Old Children

    ERIC Educational Resources Information Center

    Cassia, Viola Macchi; Proietti, Valentina; Pisacane, Antonella

    2013-01-01

    Available evidence indicates that experience with one face from a specific age group improves face-processing abilities if acquired within the first 3 years of life but not in adulthood. In the current study, we tested whether the effects of early experience endure at age 6 and whether the first 3 years of life are a sensitive period for the…

  5. 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

  6. 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.

  7. 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].

  8. 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.

  9. 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.

  10. 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…

  11. 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…

  12. 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.

  13. 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

  14. Determinants of RNA hairpin loop-loop complex stability.

    PubMed

    Gregorian, R S; Crothers, D M

    1995-05-19

    Complexes formed by RNA hairpin loops with complementary loop sequences derived from Escherichia coli RNA I and RNA II, which are involved in the control of DNA replication of plasmid ColE1, have been analyzed to determine the sequence and structural elements required to achieve full affinity. Of particular interest is the origin of the enhanced stability of the complex formed by hairpin loops whose loop sequences have been inverted 5' to 3' with respect to wild-type sequences. Full complementarity of the two interacting loops is required to achieve full or enhanced affinity, while the stems of the two hairpins can differ. The major determinant of enhanced affinity lies in the base-pairs formed at positions 1 and 7 of the loops, together with the two base-pairs of each stem which are closest to the loop. Sequence variation in the middle of the loops, or further down the stem away from the loops, exerts only a modest influence on complex stability. We incorporate these results into a model for the loop-loop interaction which accounts for the importance of positions one and seven and the first two nucleotides of the stem, while providing potentially unique structures for recognition by the RNA one modulator protein. PMID:7539081

  15. Determinants of RNA hairpin loop-loop complex stability.

    PubMed

    Gregorian, R S; Crothers, D M

    1995-05-19

    Complexes formed by RNA hairpin loops with complementary loop sequences derived from Escherichia coli RNA I and RNA II, which are involved in the control of DNA replication of plasmid ColE1, have been analyzed to determine the sequence and structural elements required to achieve full affinity. Of particular interest is the origin of the enhanced stability of the complex formed by hairpin loops whose loop sequences have been inverted 5' to 3' with respect to wild-type sequences. Full complementarity of the two interacting loops is required to achieve full or enhanced affinity, while the stems of the two hairpins can differ. The major determinant of enhanced affinity lies in the base-pairs formed at positions 1 and 7 of the loops, together with the two base-pairs of each stem which are closest to the loop. Sequence variation in the middle of the loops, or further down the stem away from the loops, exerts only a modest influence on complex stability. We incorporate these results into a model for the loop-loop interaction which accounts for the importance of positions one and seven and the first two nucleotides of the stem, while providing potentially unique structures for recognition by the RNA one modulator protein.

  16. 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).

  17. The Importance of Geometric Effects in Coronal Loop Models

    NASA Astrophysics Data System (ADS)

    Mikić, Zoran; Lionello, Roberto; Mok, Yung; Linker, Jon A.; Winebarger, Amy R.

    2013-08-01

    We systematically investigate the effects of geometrical assumptions in one-dimensional (1D) models of coronal loops. Many investigations of coronal loops have been based on restrictive assumptions, including symmetry in the loop shape and heating profile, and a uniform cross-sectional area. Starting with a solution for a symmetric uniform-area loop with uniform heating, we gradually relax these restrictive assumptions to consider the effects of nonuniform area, nonuniform heating, a nonsymmetric loop shape, and nonsymmetric heating, to show that the character of the solutions can change in important ways. We find that loops with nonuniform cross-sectional area are more likely to experience thermal nonequilibrium, and that they produce significantly enhanced coronal emission, compared with their uniform-area counterparts. We identify a process of incomplete condensation in loops experiencing thermal nonequilibrium during which the coronal parts of loops never fully cool to chromospheric temperatures. These solutions are characterized by persistent siphon flows. Their properties agree with observations (Lionello et al.) and may not suffer from the drawbacks that led Klimchuk et al. to conclude that thermal nonequilibrium is not consistent with observations. We show that our 1D results are qualitatively similar to those seen in a three-dimensional model of an active region. Our results suggest that thermal nonequilibrium may play an important role in the behavior of coronal loops, and that its dismissal by Klimchuk et al., whose model suffered from some of the restrictive assumptions we described, may have been premature.

  18. THE IMPORTANCE OF GEOMETRIC EFFECTS IN CORONAL LOOP MODELS

    SciTech Connect

    Mikic, Zoran; Lionello, Roberto; Linker, Jon A.; Mok, Yung; Winebarger, Amy R.

    2013-08-20

    We systematically investigate the effects of geometrical assumptions in one-dimensional (1D) models of coronal loops. Many investigations of coronal loops have been based on restrictive assumptions, including symmetry in the loop shape and heating profile, and a uniform cross-sectional area. Starting with a solution for a symmetric uniform-area loop with uniform heating, we gradually relax these restrictive assumptions to consider the effects of nonuniform area, nonuniform heating, a nonsymmetric loop shape, and nonsymmetric heating, to show that the character of the solutions can change in important ways. We find that loops with nonuniform cross-sectional area are more likely to experience thermal nonequilibrium, and that they produce significantly enhanced coronal emission, compared with their uniform-area counterparts. We identify a process of incomplete condensation in loops experiencing thermal nonequilibrium during which the coronal parts of loops never fully cool to chromospheric temperatures. These solutions are characterized by persistent siphon flows. Their properties agree with observations (Lionello et al.) and may not suffer from the drawbacks that led Klimchuk et al. to conclude that thermal nonequilibrium is not consistent with observations. We show that our 1D results are qualitatively similar to those seen in a three-dimensional model of an active region. Our results suggest that thermal nonequilibrium may play an important role in the behavior of coronal loops, and that its dismissal by Klimchuk et al., whose model suffered from some of the restrictive assumptions we described, may have been premature.

  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. Diversity and Collegiate Experiences Affecting Self-Perceived Gains in Critical Thinking: Which Works, and Who Benefits?

    ERIC Educational Resources Information Center

    Cole, Darnell; Zhou, Ji

    2014-01-01

    This study is grounded in the theoretical and conceptual frameworks that postulate diversity and collegiate experiences as triggers for the cognitive disequilibrium that fosters critical thinking (CT). With the assumption that CT is both a general and a discipline-specific facility, this longitudinal, single-institution study of 447 students…

  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. How Race Affects Job Placement Decisions: Results of a Vignette Experiment with a National Sample of Employers.

    ERIC Educational Resources Information Center

    Braddock, Jomills Henry, II; And Others

    The effect of job candidates' race on employers' job placement decisions was examined through an experiment in which white personnel officers were presented with a vignette describing a particular candidate, told that their company had employed that person, and asked what sort of position that person is likely to be hired in. The results suggest…

  3. Using Wenger's Social Theory of Learning to Examine University Teachers' Understanding of How Instructional Technology Affects Their Experience in Practice

    ERIC Educational Resources Information Center

    Adams, Laura L.

    2010-01-01

    The purpose of this study was to take an exploratory look at how university teachers come to understand their experience in educational practice and their professional role as teachers who integrate instructional technology into their coursework using the framework provided by Wenger's Social Theory of Learning. University faculty who teach in a…

  4. 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)…

  5. Assessing Dispositions in Pre-Service Teachers: Does Setting or Experience Affect Dispositions? A Mixed-Methods Study

    ERIC Educational Resources Information Center

    Frederiksen, Heidi

    2010-01-01

    The purpose of this study was to determine whether there was a significant difference between the perceived dispositions in pre-service teachers in urban settings versus non-urban settings. It was also the intent of this study to describe the change in perceived dispositions throughout pre-service teachers' internship experiences. Graduate…

  6. 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…

  7. 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…

  8. A Model of Research Group Microclimate: Environmental and Cultural Factors Affecting the Experiences of Overseas Research Students in the UK

    ERIC Educational Resources Information Center

    Walsh, Elaine

    2010-01-01

    Researchers from outside the European Union represent an increasing proportion of the UK doctoral student body. However, relatively little research exists on their experience from their own perspective. This research, based on interviews with students from a range of countries and scientific and engineering disciplines, seeks to address that…

  9. 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

  10. Exploring factors affecting measurements of the static coefficient of friction: An application of fractional factorial experiment design

    NASA Astrophysics Data System (ADS)

    Folkerts, Timothy J.

    2004-10-01

    The common undergraduate experiment for determining the static coefficient of friction between a wooden block and a horizontal tabletop often produces inconsistent results. We show how several factors influence the measured magnitude and consistency of the coefficient of friction. We utilize a fractional factorial experimental design, which is a method that has been specifically developed to effectively and efficiently uncover key factors that most strongly influence experimental results.

  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. The Global Non-Holonomity of the Rotating Space of the Earth Affects Hafele-Keating Experiment

    NASA Astrophysics Data System (ADS)

    Rabounski, Dmitri; Borissova, Larissa

    2013-04-01

    The deviation of time registered in the ``around-the-world clocks experiment'' (Hafele J. and Keating R., Science, 14 July 1972, 166-170) is originally explained due to: 1) General Relativity (gravitation is lower at the flying airplane's altitude); 2) Special Relativity (the airplane's speed and the Earth's rotation). However as was shown in the 1940's by Schouten and then Zelmanov, if the observer cannot be moved to the rotation-free frame, the space rotation is a non-vanishing effect of General Relativity, and is due to the non-holonomity of space (the non-orthogonality of the three-space to the lines of time). This is the case of Hafele-Keating experiment (the Earth's rotation cannot be stopped). We thus constructed the metric of the real space of the Earth which bears the gravitational field and rotation. We then proved that this metric satisfies Einstein's equations. Finally, an exact formula is deduced for Hafele-Keating experiment. Despite a hundred nanoseconds of the time correction, and the use of the GPS navigation, the obtained result is useful in the case where is no the GPS connexion, in a long-term submarine travel for instance.

  13. 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

  14. 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

  15. 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

  16. Magnetic Field in the Gravitationally Stratified Coronal Loops

    NASA Astrophysics Data System (ADS)

    Dwivedi, B. N.; Srivastava, A. K.

    2015-03-01

    We study the effect of gravitational stratification on the estimation of magnetic fields in the coronal loops. By using the method of MHD seismology of kink waves for the estimation of magnetic field of coronal loops, we derive a new formula for the magnetic field considering the effect of gravitational stratification. The fast-kink wave is a potential diagnostic tool for the estimation of magnetic field in fluxtubes. We consider the eleven kink oscillation cases observed by TRACE between July 1998 and June 2001. We calculate magnetic field in the stratified loops ( B str) and compare them with the previously calculated absolute magnetic field ( B abs). The gravitational stratification efficiently affects the magnetic field estimation in the coronal loops as it affects also the properties of kink waves. We find ≈22% increment in the magnetic field for the smallest ( L = 72 Mm) while ≈ 42% increment in the absolute magnetic field for the longest ( L = 406 Mm) coronal loops. The magnetic fields B str and B abs also increase with the number density, if the loop length does not vary much. The increment in the magnetic field due to gravitational stratification is small at the lower number densities, however, it is large at the higher number densities. We find that damping time of kink waves due to phase-mixing is less in the case of gravitationally stratified loops compared to nonstratified ones. This indicates the more rapid damping of kink waves in the stratified loops. In conclusion, we find that the gravitational stratification efficiently affects the estimation of magnetic field and damping time estimation especially in the longer coronal loops.

  17. 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.

  18. 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

  19. 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

  20. An Experience Sampling Study of Physical Activity and Positive Affect: Investigating the Role of Situational Motivation and Perceived Intensity Across Time.

    PubMed

    Guérin, Eva; Fortier, Michelle S; Sweet, Shane N

    2013-04-18

    The nature of the association between physical activity and positive affect is complex, prompting experts to recommend continued examination of moderating variables. The main purpose of this 2-week field study was to examine the influence of situational motivational regulations from self-determination theory (SDT) on changes in positive affect from pre- to post- to 3-hours post-physical activity. Another purpose was to clarify the relationship between physical activity intensity [i.e., Ratings of Perceived Exertion (RPE)] and positive affect at the stated time points. This study employed an experience sampling design using electronic questionnaires. Sixty-six healthy and active, multiple-role women provided recurrent assessments of their physical activity, situational motivation, and positive affect in their everyday lives over a 14-day period. Specifically, measures were obtained at the three time points of interest (i.e., pre-, post-, 3-hours post-physical activity). The data were analyzed using multilevel modeling. Results showed that intrinsic motivation was related to post-physical activity positive affect while the influence of identified regulation appeared 3-hours post-physical activity. In addition, RPE, which was significantly predicted by levels of introjection, was more strongly associated with an increase in positive affect post-physical activity than three hours later. The theoretical implications of these findings vis-à vis SDT, namely in regards to a viable motivational sequence predicting the influence of physical activity on affective states, are discussed. The findings regarding the differential influences of RPE and motivational regulations carries applications for facilitating women's well-being.

  1. Two loop divergences studied with one loop constrained differential renormalization

    SciTech Connect

    Seijas, Cesar . E-mail: cesar@fpaxp1.usc.es

    2007-08-15

    In the context of differential renormalization, using constrained differential renormalization rules at one-loop, we show how to obtain concrete results in two-loop calculations without making use of Ward identities. In order to do that, we obtain a list of integrals with overlapping divergences compatible with CDR that can be applied to various two-loop background field calculations. As an example, we obtain the two-loop coefficient of the beta function of QED, SuperQED and Yang-Mills theory.

  2. ‘All her children are born that way’: gendered experiences of stigma in families affected by sickle cell disorder in rural Kenya

    PubMed Central

    Marsh, Vicki M.; Kamuya, Dorcas M.; Molyneux, Sassy S.

    2011-01-01

    Objectives. To explore early experiences of sickle cell disorder (SCD) in families with a young affected child, and the way these experiences influence relations within families. To consider ways in which stigma could be counteracted in health and research programmes in sub Saharan Africa. Design. A qualitative study was conducted in a rural area of coastal Kenya including in-depth interviews with 13 families affected by SCD and 12 staff of a local biomedical research progamme. Purposive selection aimed to maximize diversity in socioeconomic and educational status, religion, severity of illness burden and religion amongst families and draw on relevant experience for staffs. Interviews were recorded, transcribed and analysed using the constant comparative method for family interviews and a thematic framework approach for staff data. Results. Low initial recognition of SCD and its cause were associated with lay practices of surveillance within affected families, contributing to stigmatisation that occurred independently of genetic knowledge. Blame was often placed on mothers, including a risk of blame for misaligned paternity. Mothers are often particularly affected by SCD through the loss of independent livelihoods and their limited options in coping with this chronic condition. Conclusions. Mothers of children with SCD were particularly vulnerable to stigmatisation within families, with underlying structural influences that suggest these findings may apply to other similar settings in Africa, and have relevance for other genetic conditions. The potential, nature and form of stigmatisation point to the role of effective communication and SCD management in addressing for blame and discriminative effects of having a child with SCD. The findings highlight the importance of broader social programmes targeting underlying gender and economic inequalities. PMID:21797722

  3. MHD stability of incompressible coronal loops with radiative energy loss

    NASA Technical Reports Server (NTRS)

    An, C.-H.

    1983-01-01

    Previous studies of the magnetohydrodynamic (MHD) stability of solar coronal loops have not taken into account the effects of radiative energy loss in the energy equation. However, since coronal loops continuously lose energy by radiation and heat conduction, it is important to understand how these energy loss mechanisms affect MHD stability. We investigate the problem assuming that a magnetic loop has cylindrical geometry. As a first step, stability is studied for a localized mode, and the result is applied to a specific equilibrium. We find that the radiative energy loss effect not only changes the growth rate of ideally unstable modes, but also alters the stability boundary predicted by ideal MHD theory.

  4. 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.

  5. High temperature storage loop :

    SciTech Connect

    Gill, David Dennis; Kolb, William J.

    2013-07-01

    A three year plan for thermal energy storage (TES) research was created at Sandia National Laboratories in the spring of 2012. This plan included a strategic goal of providing test capability for Sandia and for the nation in which to evaluate high temperature storage (>650ÀC) technology. The plan was to scope, design, and build a flow loop that would be compatible with a multitude of high temperature heat transfer/storage fluids. The High Temperature Storage Loop (HTSL) would be reconfigurable so that it was useful for not only storage testing, but also for high temperature receiver testing and high efficiency power cycle testing as well. In that way, HTSL was part of a much larger strategy for Sandia to provide a research and testing platform that would be integral for the evaluation of individual technologies funded under the SunShot program. DOEs SunShot program seeks to reduce the price of solar technologies to 6/kWhr to be cost competitive with carbon-based fuels. The HTSL project sought to provide evaluation capability for these SunShot supported technologies. This report includes the scoping, design, and budgetary costing aspects of this effort

  6. 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

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. [Optimizing the operating variables that affect the transfection experiment of antisense oligodeoxyribonucleotide by gas-filled microbubbles].

    PubMed

    Zhao, Ying-zheng; Luo, Yu-kun; Lu, Cui-tao; Xu, Jing-feng; Mei, Xing-guo; Wang, Hu-jun; Zhang, Mei

    2007-12-01

    To optimize the operating variables that affect the transfection of antisense oligodeoxyribonucleotide (AS-ODNs) by insonated gas-filled lipid microbubbles, SF6-filled microbubbles were prepared by sonication-lyophilization method. An AS-ODNs sequence and a breast cancer cell line SK-BR-3 were used to define the various operating variables determining the transfection efficiency of SF6-filled microbubbles. Three levels of mixing speed, different durations of mixing and various delay time before ultrasound were examined, separately. Transfection efficiency was detected by fluorescence microscopy. Transfection results with and without incubation of AS-ODNs and microbubbles before mixing cells were compared. From the results, there is no significant difference between the transinfection efficiency with or without incubation of AS-ODNs and microbubbles before mixing cells. AS-ODNs transfection efficiency showed an increasing trend with mixing speed and mixing duration, but there is a negative relationship with delay time before ultrasound. The optimum parameters for AS-ODNs transfection by SF6-filled microbubbles were found at a mixing speed of 40-50 r x min(-1) for 30-60 s with less than 60 s delay before ultrasound. For a successful transfection, long time of incubation with gene is essential for normal nonviral vectors such as liposomes or cationic lipid-polymer hybrids, because these vectors depend on endocytosis and membrane fusion to realize transfection. Unlike liposomes and cationic lipid-polymer hybrids, gas-filled lipid microbubbles depend on sonorporation effect to realize transfection. Therefore, the incubation of gene and microbubbles before mixing cells may not be necessary. Ultrasound-mediated AS-ODNs transfection enhanced by gas-filled lipid microbubbles represents an effective avenue for gene transfer.

  14. 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

  15. 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

  16. 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.

  17. Reproducibility of scratch assays is affected by the initial degree of confluence: Experiments, modelling and model selection.

    PubMed

    Jin, Wang; Shah, Esha T; Penington, Catherine J; McCue, Scott W; Chopin, Lisa K; Simpson, Matthew J

    2016-02-01

    Scratch assays are difficult to reproduce. Here we identify a previously overlooked source of variability which could partially explain this difficulty. We analyse a suite of scratch assays in which we vary the initial degree of confluence (initial cell density). Our results indicate that the rate of re-colonisation is very sensitive to the initial density. To quantify the relative roles of cell migration and proliferation, we calibrate the solution of the Fisher-Kolmogorov model to cell density profiles to provide estimates of the cell diffusivity, D, and the cell proliferation rate, λ. This procedure indicates that the estimates of D and λ are very sensitive to the initial density. This dependence suggests that the Fisher-Kolmogorov model does not accurately represent the details of the collective cell spreading process, since this model assumes that D and λ are constants that ought to be independent of the initial density. Since higher initial cell density leads to enhanced spreading, we also calibrate the solution of the Porous-Fisher model to the data as this model assumes that the cell flux is an increasing function of the cell density. Estimates of D and λ associated with the Porous-Fisher model are less sensitive to the initial density, suggesting that the Porous-Fisher model provides a better description of the experiments.

  18. 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,…

  19. 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.

  20. 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.

  1. Pulse thermal loop

    NASA Technical Reports Server (NTRS)

    Weislogel, Mark M. (Inventor)

    2002-01-01

    A pulse thermal loop heat transfer system includes a means to use pressure rises in a pair of evaporators to circulate a heat transfer fluid. The system includes one or more valves that iteratively, alternately couple the outlets the evaporators to the condenser. While flow proceeds from one of the evaporators to the condenser, heating creates a pressure rise in the other evaporator, which has its outlet blocked to prevent fluid from exiting the other evaporator. When the flow path is reconfigured to allow flow from the other evaporator to the condenser, the pressure in the other evaporator is used to circulate a pulse of fluid through the system. The reconfiguring of the flow path, by actuating or otherwise changing the configuration of the one or more valves, may be triggered when a predetermined pressure difference between the evaporators is reached.

  2. 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.

  3. The Loop Algorithm

    NASA Astrophysics Data System (ADS)

    Evertz, Hans Gerd

    1998-03-01

    Exciting new investigations have recently become possible for strongly correlated systems of spins, bosons, and fermions, through Quantum Monte Carlo simulations with the Loop Algorithm (H.G. Evertz, G. Lana, and M. Marcu, Phys. Rev. Lett. 70, 875 (1993).) (For a recent review see: H.G. Evertz, cond- mat/9707221.) and its generalizations. A review of this new method, its generalizations and its applications is given, including some new results. The Loop Algorithm is based on a formulation of physical models in an extended ensemble of worldlines and graphs, and is related to Swendsen-Wang cluster algorithms. It performs nonlocal changes of worldline configurations, determined by local stochastic decisions. It overcomes many of the difficulties of traditional worldline simulations. Computer time requirements are reduced by orders of magnitude, through a corresponding reduction in autocorrelations. The grand-canonical ensemble (e.g. varying winding numbers) is naturally simulated. The continuous time limit can be taken directly. Improved Estimators exist which further reduce the errors of measured quantities. The algorithm applies unchanged in any dimension and for varying bond-strengths. It becomes less efficient in the presence of strong site disorder or strong magnetic fields. It applies directly to locally XYZ-like spin, fermion, and hard-core boson models. It has been extended to the Hubbard and the tJ model and generalized to higher spin representations. There have already been several large scale applications, especially for Heisenberg-like models, including a high statistics continuous time calculation of quantum critical exponents on a regularly depleted two-dimensional lattice of up to 20000 spatial sites at temperatures down to T=0.01 J.

  4. 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

  5. "Seeing" and "feeling" architecture: how bodily self-consciousness alters architectonic experience and affects the perception of interiors.

    PubMed

    Pasqualini, Isabella; Llobera, Joan; Blanke, Olaf

    2013-01-01

    Over the centuries architectural theory evolved several notions of embodiment, proposing in the nineteenth and twentieth century that architectonic experience is related to physiological responses of the observer. Recent advances in the cognitive neuroscience of embodiment (or bodily self-consciousness) enable empirical studies of architectonic embodiment. Here, we investigated how architecture modulates bodily self-consciousness by adapting a video-based virtual reality (VR) setup previously used to investigate visuo-tactile mechanisms of bodily self-consciousness. While standing in two different interiors, participants were filmed from behind and watched their own virtual body online on a head-mounted display (HMD). Visuo-tactile strokes were applied in synchronous or asynchronous mode to the participants and their virtual body. Two interiors were simulated in the laboratory by placing the sidewalls either far or near from the participants, generating a large and narrow room. We tested if bodily self-consciousness was differently modulated when participants were exposed to both rooms and whether these changes depend on visuo-tactile stimulation. We measured illusory touch, self-identification, and performed length estimations. Our data show that synchronous stroking of the physical and the virtual body induces illusory touch and self-identification with the virtual body, independent of room-size. Moreover, in the narrow room we observed weak feelings of illusory touch with the sidewalls and of approaching walls. These subjective changes were complemented by a stroking-dependent modulation of length estimation only in the narrow room with participants judging the room-size more accurately during conditions of illusory self-identification. We discuss our findings and previous notions of architectonic embodiment in the context of the cognitive neuroscience of bodily self-consciousness and propose an empirical framework grounded in architecture, cognitive

  6. 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

  7. 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

  8. Soil seed banks and their germination responses to cadmium and salinity stresses in coastal wetlands affected by reclamation and urbanization based on indoor and outdoor experiments.

    PubMed

    Bai, Junhong; Huang, Laibin; Gao, Zhaoqin; Lu, Qiongqiong; Wang, Junjing; Zhao, Qingqing

    2014-09-15

    Indoor and outdoor seedling emergence experiments were conducted to thoroughly investigate germination patterns as affected by reclamation and urbanization, the ecological characteristics of soil seed banks, and their relationships with environmental factors in both urbanized and reclaimed regions of the Pearl River Delta in coastal wetlands. The germination rate of the soil seed bank was higher in the indoor experiment compared with that in the outdoor experiment, whereas the number and destiny of the germinated seedlings were greater in the outdoor experiment. The species diversity and number, as well as the richness and evenness indices, were higher in the urbanized region compared with the reclaimed region. However, the dominance and Sørensen similarity indices were greater in the reclaimed region compared with those indices in the urbanized region. Higher salinity and Cadmium (Cd) levels could inhibit seed germination; however, their suitable ranges (i.e. [0-2,000 mg kg(-1)] for salinity and [0-4.0 mg kg(-1)] for available Cd) can activate seedling emergence, and more seedlings germinated under the intersectional levels at 0.34 mg kg(-1) available Cd and 778.6 mg kg(-1) salinity. Seawater intrusion caused by the sea level rise will possibly result in the salt-tolerant community in this area due to increasing salinity.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. A Culture-Behavior-Brain Loop Model of Human Development.

    PubMed

    Han, Shihui; Ma, Yina

    2015-11-01

    Increasing evidence suggests that cultural influences on brain activity are associated with multiple cognitive and affective processes. These findings prompt an integrative framework to account for dynamic interactions between culture, behavior, and the brain. We put forward a culture-behavior-brain (CBB) loop model of human development that proposes that culture shapes the brain by contextualizing behavior, and the brain fits and modifies culture via behavioral influences. Genes provide a fundamental basis for, and interact with, the CBB loop at both individual and population levels. The CBB loop model advances our understanding of the dynamic relationships between culture, behavior, and the brain, which are crucial for human phylogeny and ontogeny. Future brain changes due to cultural influences are discussed based on the CBB loop model.

  15. Restriction enzyme cutting site distribution regularity for DNA looping technology.

    PubMed

    Shang, Ying; Zhang, Nan; Zhu, Pengyu; Luo, Yunbo; Huang, Kunlun; Tian, Wenying; Xu, Wentao

    2014-01-25

    The restriction enzyme cutting site distribution regularity and looping conditions were studied systematically. We obtained the restriction enzyme cutting site distributions of 13 commonly used restriction enzymes in 5 model organism genomes through two novel self-compiled software programs. All of the average distances between two adjacent restriction sites fell sharply with increasing statistic intervals, and most fragments were 0-499 bp. A shorter DNA fragment resulted in a lower looping rate, which was also directly proportional to the DNA concentration. When the length was more than 500 bp, the concentration did not affect the looping rate. Therefore, the best known fragment length was longer than 500 bp, and did not contain the restriction enzyme cutting sites which would be used for digestion. In order to make the looping efficiencies reach nearly 100%, 4-5 single cohesive end systems were recommended to digest the genome separately.

  16. Modeling loop entropy.

    PubMed

    Chirikjian, Gregory S

    2011-01-01

    Proteins fold from a highly disordered state into a highly ordered one. Traditionally, the folding problem has been stated as one of predicting "the" tertiary structure from sequential information. However, new evidence suggests that the ensemble of unfolded forms may not be as disordered as once believed, and that the native form of many proteins may not be described by a single conformation, but rather an ensemble of its own. Quantifying the relative disorder in the folded and unfolded ensembles as an entropy difference may therefore shed light on the folding process. One issue that clouds discussions of "entropy" is that many different kinds of entropy can be defined: entropy associated with overall translational and rotational Brownian motion, configurational entropy, vibrational entropy, conformational entropy computed in internal or Cartesian coordinates (which can even be different from each other), conformational entropy computed on a lattice, each of the above with different solvation and solvent models, thermodynamic entropy measured experimentally, etc. The focus of this work is the conformational entropy of coil/loop regions in proteins. New mathematical modeling tools for the approximation of changes in conformational entropy during transition from unfolded to folded ensembles are introduced. In particular, models for computing lower and upper bounds on entropy for polymer models of polypeptide coils both with and without end constraints are presented. The methods reviewed here include kinematics (the mathematics of rigid-body motions), classical statistical mechanics, and information theory.

  17. Hybrid models in loop quantum cosmology

    NASA Astrophysics Data System (ADS)

    Elizaga Navascués, Beatriz; Martín-Benito, Mercedes; Mena Marugán, Guillermo A.

    2016-06-01

    In the framework of Loop Quantum Cosmology (LQC), inhomogeneous models are usually quantized by means of a hybrid approach that combines loop quantization techniques with standard quantum field theory methods. This approach is based on a splitting of the phase space in a homogeneous sector, formed by global, zero-modes and an inhomogeneous sector, formed by the remaining, infinite number of modes, that describe the local degrees of freedom. Then, the hybrid quantization is attained by adopting a loop representation for the homogeneous gravitational sector, while a Fock representation is used for the inhomogeneities. The zero-mode of the Hamiltonian constraint operator couples the homogeneous and inhomogeneous sectors. The hybrid approach, therefore, is expected to provide a suitable quantum theory in regimes where the main quantum effects of the geometry are those affecting the zero-modes, while the inhomogeneities, still being quantum, can be treated in a more conventional way. This hybrid strategy was first proposed for the simplest cosmological midisuperspaces: the Gowdy models, and it has been later applied to the case of cosmological perturbations. This paper reviews the construction and main applications of hybrid LQC.

  18. 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

  19. How auditory discontinuities and linguistic experience affect the perception of speech and non-speech in English- and Spanish-speaking listeners

    NASA Astrophysics Data System (ADS)

    Hay, Jessica F.; Holt, Lori L.; Lotto, Andrew J.; Diehl, Randy L.

    2005-04-01

    The present study was designed to investigate the effects of long-term linguistic experience on the perception of non-speech sounds in English and Spanish speakers. Research using tone-onset-time (TOT) stimuli, a type of non-speech analogue of voice-onset-time (VOT) stimuli, has suggested that there is an underlying auditory basis for the perception of stop consonants based on a threshold for detecting onset asynchronies in the vicinity of +20 ms. For English listeners, stop consonant labeling boundaries are congruent with the positive auditory discontinuity, while Spanish speakers place their VOT labeling boundaries and discrimination peaks in the vicinity of 0 ms VOT. The present study addresses the question of whether long-term linguistic experience with different VOT categories affects the perception of non-speech stimuli that are analogous in their acoustic timing characteristics. A series of synthetic VOT stimuli and TOT stimuli were created for this study. Using language appropriate labeling and ABX discrimination tasks, labeling boundaries (VOT) and discrimination peaks (VOT and TOT) are assessed for 24 monolingual English speakers and 24 monolingual Spanish speakers. The interplay between language experience and auditory biases are discussed. [Work supported by NIDCD.

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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

    Kreyling, Juergen; Buhk, Constanze; Backhaus, Sabrina; Hallinger, Martin; Huber, Gerhard; Huber, Lukas; Jentsch, Anke; Konnert, Monika; Thiel, Daniel; Wilmking, Martin; Beierkuhnlein, Carl

    2014-03-01

    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.

  5. 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...

  6. 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.

  7. 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...

  8. 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 ...

  9. Number of cosmic string loops

    NASA Astrophysics Data System (ADS)

    Blanco-Pillado, Jose J.; Olum, Ken D.; Shlaer, Benjamin

    2014-01-01

    Using recent simulation results, we provide the mass and speed spectrum of cosmic string loops. This is the quantity of primary interest for many phenomenological signatures of cosmic strings, and it can be accurately predicted using recently acquired detailed knowledge of the loop production function. We emphasize that gravitational smoothing of long strings plays a negligible role in determining the total number of existing loops. We derive a bound on the string tension imposed by recent constraints on the stochastic gravitational wave background from pulsar timing arrays, finding Gμ ≤2.8×10-9. We also provide a derivation of the Boltzmann equation for cosmic string loops in the language of differential forms.

  10. 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.

  11. 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

  12. 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

  13. Through the looking glass: an exploratory study of the lived experiences and unmet needs of families affected by Von Hippel-Lindau disease.

    PubMed

    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

  14. 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.

  15. 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.

  16. 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

  17. THE CORONAL LOOP INVENTORY PROJECT

    SciTech Connect

    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.

  18. 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.

  19. 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…

  20. Observational constraints on loop quantum cosmology.

    PubMed

    Bojowald, Martin; Calcagni, Gianluca; Tsujikawa, Shinji

    2011-11-18

    In the inflationary scenario of loop quantum cosmology in the presence of inverse-volume corrections, we give analytic formulas for the power spectra of scalar and tensor perturbations convenient to compare with observations. Since inverse-volume corrections can provide strong contributions to the running spectral indices, inclusion of terms higher than the second-order runnings in the power spectra is crucially important. Using the recent data of cosmic microwave background and other cosmological experiments, we place bounds on the quantum corrections.

  1. Three-Loop Radiative-Recoil Corrections to Hyperfine Splitting in Muonium: Diagrams with Polarization Loops

    SciTech Connect

    Eides, Michael I.; Shelyuto, Valery A.

    2009-09-25

    We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by the diagrams with electron and muon vacuum polarizations. We calculate single-logarithmic and nonlogarithmic contributions of order alpha{sup 3}(m/M)E{sub F} generated by gauge invariant sets of diagrams with electron and muon polarization insertions in the electron and muon factors. Combining these corrections with the older results, we obtain total contribution to hyperfine splitting generated by all diagrams with electron and muon polarization loops. The calculation of this contribution completes an important stage in the implementation of the program of reduction of the theoretical uncertainty of hyperfine splitting below 10 Hz. The new results improve the theory of hyperfine splitting and affect the value of the electron-muon mass ratio extracted from experimental data on muonium hyperfine splitting.

  2. 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.

  3. 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.

  4. 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.

  5. Kinetics of Internal-Loop Formation in Polypeptide Chains: A Simulation Study

    PubMed Central

    Doucet, Dana; Roitberg, Adrian; Hagen, Stephen J.

    2007-01-01

    The speed of simple diffusional motions, such as the formation of loops in the polypeptide chain, places one physical limit on the speed of protein folding. Many experimental studies have explored the kinetics of formation of end-to-end loops in polypeptide chains; however, protein folding more often requires the formation of contacts between interior points on the chain. One expects that, for loops of fixed contour length, interior loops will form more slowly than end-to-end loops, owing to the additional excluded volume associated with the “tails”. We estimate the magnitude of this effect by generating ensembles of randomly coiled, freely jointed chains, and then using the theory of Szabo, Schulten, and Schulten to calculate the corresponding contact formation rates for these ensembles. Adding just a few residues, to convert an end-to-end loop to an internal loop, sharply decreases the contact rate. Surprisingly, the relative change in rate increases for a longer loop; sufficiently long tails, however, actually reverse the effect and accelerate loop formation slightly. Our results show that excluded volume effects in real, full-length polypeptides may cause the rates of loop formation during folding to depart significantly from the values derived from recent loop-formation experiments on short peptides. PMID:17208979

  6. 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.

  7. Sub-Poissonian light and photocurrent shot-noise suppression in closed opto-electronic loop

    NASA Technical Reports Server (NTRS)

    Masalov, A. V.; Putilin, A. A.; Vasilyev, Michael V.

    1994-01-01

    We examine experimentally photocurrent noise reduction in the opto-electronic closed loop. Photocurrent noise density 12.5 dB below the shot-noise was observed. So large suppression was not reached in previous experiments and cannot be explained in terms of an ordinary sub-Poissonian light in the loop. We propose the concept of anticorrelation state for the description of light in the loop.

  8. 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.

  9. Complete maps of molecular-loop conformational spaces.

    PubMed

    Porta, Josep M; Ros, Lluís; Thomas, Federico; Corcho, Francesc; Cantó, Josep; Pérez, Juan Jesús

    2007-10-01

    This paper presents a numerical method to compute all possible conformations of distance-constrained molecular loops, i.e., loops where some interatomic distances are held fixed, while others can vary. The method is general (it can be applied to single or multiple intermingled loops of arbitrary topology) and complete (it isolates all solutions, even if they form positive-dimensional sets). Generality is achieved by reducing the problem to finding all embeddings of a set of points constrained by pairwise distances, which can be formulated as computing the roots of a system of Cayley-Menger determinants. Completeness is achieved by expressing these determinants in Bernstein form and using a numerical algorithm that exploits such form to bound all root locations at any desired precision. The method is readily parallelizable, and the current implementation can be run on single- or multiprocessor machines. Experiments are included that show the method's performance on rigid loops, mobile loops, and multiloop molecules. In all cases, complete maps including all possible conformations are obtained, thus allowing an exhaustive analysis and visualization of all pseudo-rotation paths between different conformations satisfying loop closure.

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. Erratum: light-like polygonal Wilson loops in 3d Chern-Simons and ABJM theory

    NASA Astrophysics Data System (ADS)

    Henn, Johannes M.; Plefka, Jan; Wiegandt, Konstantin

    2011-11-01

    We correct an overall sign in the result of the matter contribution to the foursided Wilson loop in ABJM theory calculated in JHEP 1008 (2010) 032. This also affects a constant in the finite part of the full ABJM result.

  19. 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.

  20. 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-…

  1. 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,…

  2. 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.

  3. The desensitization gate of inhibitory Cys-loop receptors.

    PubMed

    Gielen, Marc; Thomas, Philip; Smart, Trevor G

    2015-01-01

    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. PMID:25891813

  4. [Significance of deficient bacterial colonization in the pathogenesis of mucosal lesions in experimental blind loop syndrome].

    PubMed

    Menge, H; Germer, C T; Stössel, R; Simes, G; Wagner, J; Hahn, H; Riecken, E O

    1985-07-20

    A complete evaluation of the bacterial flora in jejunal self-filling blind loops was performed. The results show a significant increase in bacteria of the genera E. coli, Streptococcus and Bacteroides. In further experiments, jejunal self-filling blind loops were created in germ-free animals. In spite of the germ-free state the mucosa displayed marked hyperplasia. The same was true when the blind loops had been contaminated with aerobic bacteria. These results demonstrate that other factors in addition to bacterial overgrowth contribute to the mucosal damage observed in self-filling blind loops.

  5. 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…

  6. Telomeres thrown for a loop.

    PubMed

    Haber, James E

    2004-11-19

    A remarkable paper from the de Lange lab (Wang et al., 2004) in a recent issue of Cell reveals that homologous recombination can result in the abrupt shortening of telomeres in a process that appears to involve reciprocal crossing over within the t-loop structure that protects chromosome ends.

  7. 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.

  8. 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

  9. 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

  10. The distribution of maximum temperatures of coronal active region loops

    NASA Technical Reports Server (NTRS)

    Teske, R. G.; Mayfield, E. B.

    1981-01-01

    Starting with the integrated emission measure distributions of solar active regions, the distribution of the maximum temperature parameter which characterizes individual plasma loops is determined. The observed emission measure distributions were determined by combining EUV and X-ray data from two separate experiments on ATM/Skylab. The present work sets some limits on such an approach. It is found that the distribution of maximum temperature has approximately the same shape as the integrated emission measure distributions, a result which is expected since most of the loop emission measure is near their maximum temperatures.

  11. A Triple Helix-Loop-Helix/Basic Helix-Loop-Helix Cascade Controls Cell Elongation Downstream of Multiple Hormonal and Environmental Signaling Pathways in Arabidopsis[C][W

    PubMed Central

    Bai, Ming-Yi; Fan, Min; Oh, Eunkyoo; Wang, Zhi-Yong

    2012-01-01

    Environmental and endogenous signals, including light, temperature, brassinosteroid (BR), and gibberellin (GA), regulate cell elongation largely by influencing the expression of the paclobutrazol-resistant (PRE) family helix-loop-helix (HLH) factors, which promote cell elongation by interacting antagonistically with another HLH factor, IBH1. However, the molecular mechanism by which PREs and IBH1 regulate gene expression has remained unknown. Here, we show that IBH1 interacts with and inhibits a DNA binding basic helix-loop-helix (bHLH) protein, HBI1, in Arabidopsis thaliana. Overexpression of HBI1 increased hypocotyl and petiole elongation, whereas dominant inactivation of HBI1 and its homologs caused a dwarf phenotype, indicating that HBI1 is a positive regulator of cell elongation. In vitro and in vivo experiments showed that HBI1 directly bound to the promoters and activated two EXPANSIN genes encoding cell wall–loosening enzymes; HBI1’s DNA binding and transcriptional activities were inhibited by IBH1, but the inhibitory effects of IBH1 were abolished by PRE1. The results indicate that PREs activate the DNA binding bHLH factor HBI1 by sequestering its inhibitor IBH1. Altering each of the three factors affected plant sensitivities to BR, GA, temperature, and light. Our study demonstrates that PREs, IBH1, and HBI1 form a chain of antagonistic switches that regulates cell elongation downstream of multiple external and endogenous signals. PMID:23221598

  12. 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

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. Loop quantum cosmology from quantum reduced loop gravity

    NASA Astrophysics Data System (ADS)

    Alesci, Emanuele; Cianfrani, Francesco

    2015-08-01

    We show how loop quantum cosmology can be derived as an effective semiclassical description of loop quantum gravity. Using the tools of QRLG, a gauge fixed version of LQG, we take the coherent states of the fundamental microscopic theory suitable to describe a Bianchi I Universe and we find a mapping between the expectation value of the Hamiltonian and the dynamics of LQC. Our results are in agreement with a lattice refinement framework for LQC, thus the so-called “old” and “improved-dynamics” regularization schemes can be reproduced. These amount to different choices of relations between local variables and the smeared ones entering the definition of the coherent states. The leading order of the fundamental theory corresponds to LQC, but we also find different inverse volume corrections, that depend on a purely quantum observable, namely the number of nodes of the states.

  18. 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.

  19. Electrical resistance of complex two-dimensional structures of loops

    NASA Astrophysics Data System (ADS)

    Gomes, M. A. F.; Hora, R. R.; Brito, V. P.

    2011-06-01

    This work presents a study of the dc electrical resistance of a recently discovered hierarchical two-dimensional system which has a complex topology consisting of a distribution of disordered macroscopic loops with no characteristic size and a distribution of several types of contacts between loops. In addition to its intrinsic interest in the important context of low-dimensional systems and crumpled systems, the structures under study are of relevance in a number of areas including soft condensed matter and packing of DNA in viral capsids. In the particular case discussed here, the loops are made of layers of graphite with a height of tens of nanometers deposited on a substrate of cellulose. Experiments with these systems indicate an anomalous electrical resistance of sub-diffusive type. The results reported here are explained with scaling arguments and computer simulation. A comparison with the dc electrical properties of percolation clusters is made, and some other experimental issues as future prospects are commented.

  20. Solar-relevant plasma loop expansion in strapping field

    NASA Astrophysics Data System (ADS)

    Ha, Bao; Bellan, Paul

    2014-10-01

    Tokamak-like forces may explain fundamental behaviors of solar plasma arches. The hoop force causes arched, current-carrying plasma loops to expand. This expansion was slowed and even inhibited by a magnetic ``strapping'' field in previous solar loop experiments at Caltech but no attempt was made to control the field's spatial profile. Kliem and Torok predicted an explosive-like transition from slow expansion to fast eruption if the spatial decay rate of the strapping field exceeds a threshold. Smaller, independently-powered auxiliary coils placed inside the vacuum chamber produce strapping fields with above-threshold decay rate and strong enough to act on the plasma. The plasma is observed, however, to bypass regions of stronger strapping field and expand into regions of weaker field. Added external inductance slows plasma expansion allowing the strapping coils to hold down the plasma. Different interactions between arched plasma loops and strapping magnetic fields will be presented. Supported by the NSF and AFOSR.

  1. Effects of strapping field profiles on plasma loop expansion

    NASA Astrophysics Data System (ADS)

    Ha, Bao Nguyen Quoc; Bellan, Paul

    2013-10-01

    Tokamak-like forces may explain fundamental behaviors of solar plasma arches. The hoop force causes arched, current-carrying plasma loops to expand unless additional forces are applied. This expansion was slowed and even inhibited by a magnetic field of proper polarity in previous solar loop experiments at Caltech but there was no attempt to characterize the strapping field's spatial profile. Kliem and Torok predicted an explosive-like transition from slow expansion to fast eruption if the vertical decay rate of the strapping field exceeds an instability threshold. We have constructed a new set of independently powered auxiliary coils designed to be placed inside the vacuum chamber and closer to the plasma source. The resulting strapping field has a sharper decay rate than with our previous coils and is expected to exceed the instability threshold. Progress on the interaction between arched plasma loops and strapping magnetic fields will be presented. Supported by the NSF and AFOSR.

  2. Droplet sorting in a loop of flat microfluidic channels

    NASA Astrophysics Data System (ADS)

    Kadivar, Erfan; Herminghaus, Stephan; Brinkmann, Martin

    2013-07-01

    Motivated by recent experiments, we numerically study the droplet traffic in microfluidic channels forming an asymmetric loop with a long and a short arm. The loop is connected to an inlet and an outlet channel by two right angled T-junctions. Assuming flat channels, we employ the boundary element method (BEM) to numerically solve the two-dimensional Darcy equation that governs two phase flow in the Hele-Shaw limit. The occurrence of different sorting regimes is summarized in sorting diagrams in terms of droplet size, distance between consecutive droplets in the inlet channel, and loop asymmetry for mobility ratios of the liquid phases larger and smaller than one. For large droplet distances, the traffic is regulated by the ratio of the total hydraulic resistances of the long and short arms. At high droplet densities and below a critical droplet size, droplet-droplet collisions are observed for both mobility ratios.

  3. 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...

  4. Noise Performance Of A Digital Tanlock Loop

    NASA Technical Reports Server (NTRS)

    Hurd, W. J.; Pomalaza-Raez, C. A.

    1988-01-01

    Slight improvement over sinusoidal phase-lock loop achieved. Report discusses theoretical studies and numerical simulations of performance of digital tangent phase-lock loop (DTL), in presence of noise.

  5. 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

  6. Anomalous shape of magnetic loops in the Rayleigh region

    NASA Astrophysics Data System (ADS)

    Seeck, St.; Lambeck, M.

    1995-11-01

    According to its congruency property, the Preisach model demands an equivalent shape of magnetic minor loops, the so-called Rayleigh loops. We measured these loops with an inductive setup and noticed a different anomalous shape of Rayleigh loops which depends on the magnetic history. Special materials (particularly recording media) show a concave-convex shape in contrast to the normal biconvex shape. This anomalous shape can be explained by combining the Preisach model with the Stoner-Wohlfarth model. It follows from this explanation that the degree of the anomaly depends on the material, especially in how far it fulfills the conditions of the Stoner-Wohlfarth model. The experiments show the effect that is expected according to the material. In this way the measurement of the anomalous Rayleigh loops can be used as a new method to test the Stoner-Wohlfarth properties of a material. This is more effective than using the Henkel plot [G. Bertotti and V. Basso, J. Appl. Phys. 73, 5827 (1993)].

  7. 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

  8. 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.

  9. 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.

  10. Double loop control strategy with different time steps based on human characteristics.

    PubMed

    Gu, Gwang Min; Lee, Jinoh; Kim, Jung

    2012-01-01

    This paper proposes a cooperative control strategy in consideration of the force sensitivity of human. The strategy consists of two loops: one is the intention estimation loop whose sampling time can be variable in order to investigate the effect of the sampling time; the other is the position control loop with fixed time step. A high sampling rate is not necessary for the intention estimation loop due to the bandwidth of the mechanoreceptors in humans. In addition, the force sensor implemented in the robot is sensitive to the noise induced from the sensor itself and tremor of the human. Multiple experiments were performed with the experimental protocol using various time steps of the intention estimation loop to find the suitable sampling times in physical human robot interaction. The task involves pull-and-push movement with a two-degree-of-freedom robot, and the norm of the interaction force was obtained for each experiment as the measure of the cooperative control performance.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Loop Diuretics in Clinical Practice.

    PubMed

    Oh, Se Won; Han, Sang Youb

    2015-06-01

    Diuretics are commonly used to control edema across various clinical fields. Diuretics inhibit sodium reabsorption in specific renal tubules, resulting in increased urinary sodium and water excretion. Loop diuretics are the most potent diuretics. In this article, we review five important aspects of loop diuretics, in particular furosemide, which must be considered when prescribing this medicine: (1) oral versus intravenous treatment, (2) dosage, (3) continuous versus bolus infusion, (4) application in chronic kidney disease patients, and (5) side effects. The bioavailability of furosemide differs between oral and intravenous therapy. Additionally, the threshold and ceiling doses of furosemide differ according to the particular clinical condition of the patient, for example in patients with severe edema or chronic kidney disease. To maximize the efficiency of furosemide, a clear understanding of how the mode of delivery will impact bioavailability and the required dosage is necessary.

  16. Loop Diuretics in Clinical Practice

    PubMed Central

    Oh, Se Won

    2015-01-01

    Diuretics are commonly used to control edema across various clinical fields. Diuretics inhibit sodium reabsorption in specific renal tubules, resulting in increased urinary sodium and water excretion. Loop diuretics are the most potent diuretics. In this article, we review five important aspects of loop diuretics, in particular furosemide, which must be considered when prescribing this medicine: (1) oral versus intravenous treatment, (2) dosage, (3) continuous versus bolus infusion, (4) application in chronic kidney disease patients, and (5) side effects. The bioavailability of furosemide differs between oral and intravenous therapy. Additionally, the threshold and ceiling doses of furosemide differ according to the particular clinical condition of the patient, for example in patients with severe edema or chronic kidney disease. To maximize the efficiency of furosemide, a clear understanding of how the mode of delivery will impact bioavailability and the required dosage is necessary. PMID:26240596

  17. Deconfinement and virtual quark loops

    NASA Astrophysics Data System (ADS)

    Çelik, T.; Engels, J.; Satz, H.

    1983-12-01

    We calculate paer Monte Carlo evaluation on an 83 × 3 lattice the energy density ɛG of the gluon sector of QCD, including virtual quark loops up to the fourth power in the hopping parameter expansion. For light quarks of one flavour, we observe at T/ΛL 95 +/- 10 a rapid variation of ɛG in T, accompanied by strong fluctuations from iteration to iteration. as clear signal of the deconfinement transition.

  18. 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.

  19. 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.

  20. Loops in inflationary correlation functions

    NASA Astrophysics Data System (ADS)

    Tanaka, Takahiro; Urakawa, Yuko

    2013-12-01

    We review the recent progress regarding the loop corrections to the correlation functions in the inflationary universe. A naive perturbation theory predicts that the loop corrections generated during inflation suffer from various infrared (IR) pathologies. Introducing an IR cutoff by hand is neither satisfactory nor enough to fix the problem of a secular growth, which may ruin the predictive power of inflation models if the inflation lasts sufficiently long. We discuss the origin of the IR divergences and explore the regularity conditions of the loop corrections for the adiabatic perturbation, the iso-curvature perturbation, and the tensor perturbation, in turn. These three kinds of perturbations have qualitative differences, but in discussing the IR regularity there is a feature common to all cases, which is the importance of the proper identification of observable quantities. Genuinely, observable quantities should respect the gauge invariance from the view point of a local observer. Interestingly, we find that the requirement of the IR regularity restricts the allowed quantum states.

  1. Gravitational radiation from realistic cosmic string loops

    NASA Astrophysics Data System (ADS)

    Casper, Paul; Allen, Bruce

    1995-10-01

    We examine the rates at which energy and momentum are radiated into gravitational waves by a large set of realistic cosmic string loops. The string loops are generated by numerically evolving parent loops with different initial conditions forward in time until they self-intersect, fragmenting into two child loops. The fragmentation of the child loops is followed recursively until only non-self-intersecting loops remain. The properties of the final non-self-intersecting loops are found to be independent of the initial conditions of the parent loops. We have calculated the radiated energy and momentum for a total of 11 625 stable child loops. We find that the majority of the final loops do not radiate significant amounts of spatial momentum. The velocity gained due to the rocket effect is typically small compared to the center-of-mass velocity of the fragmented loops. The distribution of gravitatoinal radiation rates in the center of mass frame of the loops, γ0≡(Gμ2)-1ΔE/Δτ, is strongly peaked in the range γ0=45-55 however, there are no loops found with γ0<40. Because the radiated spatial momentum is small, the distribution of gravitational radiation rates appears roughly the same in any reference frame. We conjecture that in the center-of-mass frame there is a lower bound γ0min>0 for the radiation rate from cosmic string loops. In a second conjecture, we identify a candidate for the loop with the minimal radiation rate and suggest that γ0min~=39.003.

  2. 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

  3. Chemical Looping Technology: Oxygen Carrier Characteristics.

    PubMed

    Luo, Siwei; Zeng, Liang; Fan, Liang-Shih

    2015-01-01

    Chemical looping processes are characterized as promising carbonaceous fuel conversion technologies with the advantages of manageable CO2 capture and high energy conversion efficiency. Depending on the chemical looping reaction products generated, chemical looping technologies generally can be grouped into two types: chemical looping full oxidation (CLFO) and chemical looping partial oxidation (CLPO). In CLFO, carbonaceous fuels are fully oxidized to CO2 and H2O, as typically represented by chemical looping combustion with electricity as the primary product. In CLPO, however, carbonaceous fuels are partially oxidized, as typically represented by chemical looping gasification with syngas or hydrogen as the primary product. Both CLFO and CLPO share similar operational features; however, the optimum process configurations and the specific oxygen carriers used between them can vary significantly. Progress in both CLFO and CLPO is reviewed and analyzed with specific focus on oxygen carrier developments that characterize these technologies.

  4. Chemical Looping Technology: Oxygen Carrier Characteristics.

    PubMed

    Luo, Siwei; Zeng, Liang; Fan, Liang-Shih

    2015-01-01

    Chemical looping processes are characterized as promising carbonaceous fuel conversion technologies with the advantages of manageable CO2 capture and high energy conversion efficiency. Depending on the chemical looping reaction products generated, chemical looping technologies generally can be grouped into two types: chemical looping full oxidation (CLFO) and chemical looping partial oxidation (CLPO). In CLFO, carbonaceous fuels are fully oxidized to CO2 and H2O, as typically represented by chemical looping combustion with electricity as the primary product. In CLPO, however, carbonaceous fuels are partially oxidized, as typically represented by chemical looping gasification with syngas or hydrogen as the primary product. Both CLFO and CLPO share similar operational features; however, the optimum process configurations and the specific oxygen carriers used between them can vary significantly. Progress in both CLFO and CLPO is reviewed and analyzed with specific focus on oxygen carrier developments that characterize these technologies. PMID:25898071

  5. High-temperature helium-loop facility

    SciTech Connect

    Tokarz, R.D.

    1981-09-01

    The high-temperature helium loop is a facility for materials testing in ultrapure helium gas at high temperatures. The closed loop system is capable of recirculating high-purity helium or helium with controlled impurities. The gas loop maximum operating conditions are as follows: 300 psi pressure, 500 lb/h flow rate, and 2100/sup 0/F temperature. The two test sections can accept samples up to 3.5 in. diameter and 5 ft long. The gas loop is fully instrumented to continuously monitor all parameters of loop operation as well as helium impurities. The loop is fully automated to operate continuously and requires only a daily servicing by a qualified operator to replenish recorder charts and helium makeup gas. Because of its versatility and high degree of parameter control, the helium loop is applicable to many types of materials research. This report describes the test apparatus, operating parameters, peripheral systems, and instrumentation system.

  6. 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.

  7. Effect of helix stability on the formation of loop-loop complexes.

    PubMed

    Sehdev, Preeti; Crews, Gordon; Soto, Ana Maria

    2012-12-01

    Kissing loop complexes are loop-loop complexes where two RNA hairpins interact through their complementary loops. In this work, we have investigated the role of the helical stems on the ability of hairpins derived from the ColE1 plasmid to associate as kissing loop complexes in the presence and absence of divalent cations. Our results show that although kissing loop complexes form more readily in the presence of Mg(2+), they are able to form in the presence of 850 mM NaCl, as long as their stems contain at least six base-pairs. Formation of the Na(+) loop-loop complexes is facilitated by changing the sequence at the stem-loop interface to include less stable AU base pairs. We suggest that the conformation at the stem-loop interface is critical in the formation of kissing loop complexes and that in the absence of Mg(2+) the conformation at the stem-loop interface is packed more loosely than with Mg(2+), to allow for a lower charge density. Consistent with this hypothesis, shortening the stems to five base pairs results in unfolding of the hairpins and formation of an extended duplex rather than a kissing loop complex because the short stems are not stable enough to tolerate the necessary conformation at the stem-loop interface to allow the formation of a kissing loop complex. PMID:23094588

  8. 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.

  9. The Experience of Change and Its Impact on Workers Who Self-Identify as Doing Well with Change that Affects Their Work

    ERIC Educational Resources Information Center

    Borgen, William A.; Butterfield, Lee D.; Amundson, Norman E.

    2010-01-01

    This study sought to understand more about the experience of workers who self-identified as doing well within the context of volatile and changing work situations. The research results indicate that even those workers who report doing well with change experience a myriad of work-related, personal life, attitude and approach, and professional life…

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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

  15. 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

  16. 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

  17. Capillary pumped loop application guide

    NASA Astrophysics Data System (ADS)

    Cullimore, Brent A.

    Capillary pumped loops (CPLs) have undergone extensive development since the late 1970's, and represent a maturing technology that is beginning to appear in spacecraft designs. Perhaps because most CPL literature is intended for CPL and heat pipe dedvelopers, or perhaps because of the myriad of component design and layout options available, many thermal control designers are either unfamiliar with the capabilities offered by CPLs, or are confused about their limitations. This survey paper is targeted toward thermal control designers who must decide when and where to use CPLs, or having chosen a CPL solution, must deal with system-level integration and test issues.

  18. Cygnus Loop: A double bubble?

    NASA Astrophysics Data System (ADS)

    West, J.; Safi-Harb, S.; Reichardt, I.; Stil, J.; Kothes, R.; Jaffe, T.; Galfacts Team

    2016-06-01

    The Cygnus Loop is a well-studied supernova remnant (SNR) that has been observed across the electromagnetic spectrum. Although widely believed to be an SNR shell with a blow-out region in the south, we consider the possibility that this object is two SNRs projected along the same line-of-sight by using multi-wavelength images and modelling. Our results show that a model of two objects including some overlap region/interaction between the two objects has the best match to the observed data.

  19. Singularities in loop quantum cosmology.

    PubMed

    Cailleteau, Thomas; Cardoso, Antonio; Vandersloot, Kevin; Wands, David

    2008-12-19

    We show that simple scalar field models can give rise to curvature singularities in the effective Friedmann dynamics of loop quantum cosmology (LQC). We find singular solutions for spatially flat Friedmann-Robertson-Walker cosmologies with a canonical scalar field and a negative exponential potential, or with a phantom scalar field and a positive potential. While LQC avoids big bang or big rip type singularities, we find sudden singularities where the Hubble rate is bounded, but the Ricci curvature scalar diverges. We conclude that the effective equations of LQC are not in themselves sufficient to avoid the occurrence of curvature singularities.

  20. 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