She bought the unicorn from the pet store: Six- to seven-year-olds are strongly inclined to generate natural explanations.

PubMed

Nancekivell, Shaylene E; Friedman, Ori

2017-06-01

In two experiments (N = 64), we told 6- to 7-year-olds about improbable or impossible outcomes (Experiment 1) and about impossible outcomes concerning ordinary or magical agents (Experiment 2). In both experiments, children claimed that the outcomes were impossible and could not happen, but nonetheless generated realistic and natural explanations for the outcomes. These findings show that 6- to 7-year-olds are strongly inclined to provide natural explanations. The findings are also informative about children's judgments about whether outcomes are possible, and further suggest that asymmetries between children's predictions and explanations may stem from differences in how these 2 forms of reasoning are constrained by possibility. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Long-term follow-up of women and men after unsuccessful IVF.

PubMed

Filetto, Juliana N; Makuch, Maria Y

2005-10-01

The experience of 92 couples, who had unsuccessfully undergone one or more IVF cycles at a university clinic, was evaluated 3-8 years following their last failed attempt. One member of each couple completed a telephone questionnaire regarding life events during their last IVF cycle performed at the clinic and at the time of the interview. Some couples had continued further treatment and some had not. Multivariate correspondence analysis was used to analyse the data. Regarding the long-term experience of couples who had undergone further treatment, for men the main experiences were psychological problems and having adopted a child. For women, the main experiences were related to problems of self-image, psychological problems, loss of hope, and having adopted a child. These women also presented a strong association with problems in their marital relationship and with adoption. For the group that did not undergo further treatment, the women showed a strong association with considering adoption, and a less intense association with psychological problems and loss of hope. The men presented psychological problems and having adopted a child as associated variables. Comparison between men and women showed that recognizing the impossibility of conceiving a child and giving up treatment were strongly associated. Men and women who had not continued with further treatment were more affected in the long term than those who had undergone further treatment after IVF failure.

Ferrate (IV) as a Possible Oxidant on the Martian Surface

NASA Astrophysics Data System (ADS)

Tsapin, Alexandre; Goldfeld, M. G.; McDonald, G. D.; Nealson, K. H.; Mohnke, J.; Moskovitz, B.; Solheid, P.; Kemner, K. H.; Orlandini, K.

Viking experiments showed that Martian soil has a very strong oxidant, which could be responsible for the results of experiments performed on Viking landers. These experiments were designed specifically to detect life on Mars. The nature of that oxidant was not determined during Viking mission. Later several groups tried to reconstruct Viking experiments and find out the nature of Martian oxidant. None of these attempts were completely successful. The general perception was that there are several chemically different oxidants on Martian surface. In this study we suggested that potassium ferrate K_2FeO_4 can be Martian oxidant responsible at least partially for the results of experiments on Viking landers. We characterized liquid and powder preparation of Fe (VI) with EPR, optical spectroscopy, Mossbauer spectroscopy, and by Fe-XANES. All properties of our preparations of (FeVI) are consistent with the proposal role of that compound as a strong oxidant on Martian surface.

The ugliness-in-averageness effect: Tempering the warm glow of familiarity.

PubMed

Carr, Evan W; Huber, David E; Pecher, Diane; Zeelenberg, Rene; Halberstadt, Jamin; Winkielman, Piotr

2017-06-01

Mere exposure (i.e., stimulus repetition) and blending (i.e., stimulus averaging) are classic ways to increase social preferences, including facial attractiveness. In both effects, increases in preference involve enhanced familiarity. Prominent memory theories assume that familiarity depends on a match between the target and similar items in memory. These theories predict that when individual items are weakly learned, their blends (morphs) should be relatively familiar, and thus liked-a beauty-in-averageness effect ( BiA ). However, when individual items are strongly learned, they are also more distinguishable. This "differentiation" hypothesis predicts that with strongly encoded items, familiarity (and thus, preference) for the blend will be relatively lower than individual items-an ugliness-in-averageness effect ( UiA ). We tested this novel theoretical prediction in 5 experiments. Experiment 1 showed that with weak learning, facial morphs were more attractive than contributing individuals (BiA effect). Experiments 2A and 2B demonstrated that when participants first strongly learned a subset of individual faces (either in a face-name memory task or perceptual-tracking task), morphs of trained individuals were less attractive than the trained individuals (UiA effect). Experiment 3 showed that changes in familiarity for the trained morph (rather than interstimulus conflict) drove the UiA effect. Using a within-subjects design, Experiment 4 mapped out the transition from BiA to UiA solely as a function of memory training. Finally, computational modeling using a well-known memory framework (REM) illustrated the familiarity transition observed in Experiment 4. Overall, these results highlight how memory processes illuminate classic and modern social preference phenomena. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The Effects of Premarital Heterosexual and Homosexual Experience on Dating and Marriage Desirability.

ERIC Educational Resources Information Center

Williams, John D.; Jacoby, Arthur P.

1989-01-01

Surveyed 365 college students to investigate their attitudes toward the effects of past sexual behavior, both heterosexual and homosexual, on one's acceptability as a dating or marriage partner. Results showed that both men and women prefer partners without previous coital or oral heterosexual experience, and both strongly rejected those with any…

The impact of childhood experiences and family members outside the household on residential environment choices.

PubMed

Blaauboer, Marjolein

2011-01-01

Choices of urban, suburban or rural residential environments have often been studied from a life-course perspective. In this paper, an examination is made of the influence of childhood experiences and of residential environment choices of family members outside the household. It is argued that socialisation, location-specific capital and the wish to maintain close family ties may result in living in a similar residential environment later in life and in similar environments to siblings and parents. Results of multinomial logistic regression analyses of data from the Netherlands Kinship Panel Study show that the residential environment during childhood is indeed strongly associated with the current residential environment. Moreover, individuals show a strong similarity to their parents and siblings in their residential environment, even after accounting for residential inertia and return migration.

Strong thermal leptogenesis and the absolute neutrino mass scale

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bari, Pasquale Di; King, Sophie E.; Fiorentin, Michele Re, E-mail: pdb1d08@soton.ac.uk, E-mail: sk1806@soton.ac.uk, E-mail: m.re-fiorentin@soton.ac.uk

We show that successful strong thermal leptogenesis, where the final asymmetry is independent of the initial conditions and in particular a large pre-existing asymmetry is efficiently washed-out, favours values of the lightest neutrino mass m{sub 1}∼>10 meV for normal ordering (NO) and m{sub 1}∼>3 meV for inverted ordering (IO) for models with orthogonal matrix entries respecting |Ω{sub ij}{sup 2}|∼<2. We show analytically why lower values of m{sub 1} require a higher level of fine tuning in the seesaw formula and/or in the flavoured decay parameters (in the electronic for NO, in the muonic for IO). We also show how this constraint existsmore » thanks to the measured values of the neutrino mixing angles and could be tightened by a future determination of the Dirac phase. Our analysis also allows us to place a more stringent constraint for a specific model or class of models, such as SO(10)-inspired models, and shows that some models cannot realise strong thermal leptogenesis for any value of m{sub 1}. A scatter plot analysis fully supports the analytical results. We also briefly discuss the interplay with absolute neutrino mass scale experiments concluding that they will be able in the coming years to either corner strong thermal leptogenesis or find positive signals pointing to a non-vanishing m{sub 1}. Since the constraint is much stronger for NO than for IO, it is very important that new data from planned neutrino oscillation experiments will be able to solve the ambiguity.« less

Identity physics experiment on internal transport barriers in JT-60U and JET

NASA Astrophysics Data System (ADS)

de Vries, P. C.; Sakamoto, Y.; Litaudon, X.; Beurskens, M. N. A.; Brix, M.; Crombé, K.; Fujita, T.; Giroud, C.; Hawkes, N. C.; Hayashi, N.; Joffrin, E.; Mantica, P.; Matsunaga, G.; Oyama, N.; Parail, V.; Salmi, A.; Shinohara, K.; Strintzi, D.; Suzuki, T.; Takechi, M.; Takenaga, H.; Tala, T.; Tsalas, M.; Urano, H.; Voitsekhovitch, I.; Yoshida, M.; EFDA contributors, JET; JT-60 Team

2009-12-01

A series of experiments have been carried out in 2008 at JT-60U and JET to find common characteristics and explain differences between internal transport barriers (ITBs). The identity experiments succeeded in matching the profiles of most dimensionless parameters at the time ITBs were triggered. Thereafter the q-profile development deviated due to differences in non-inductive current density profile, affecting the ITB. Furthermore, the ITBs in JET were more strongly influenced by the H-mode pedestal or edge localized modes. It was found to be difficult to match the plasma rotation characteristics in both devices. However, the wide range of Mach numbers obtained in these experiments shows that the rotation has little effect on the triggering of ITBs in plasmas with reversed magnetic shear. On the other hand the toroidal rotation and more specifically the rotational shear had an impact on the subsequent growth and allowed the formation of strong ITBs.

Spatiotemporal Airy Ince-Gaussian wave packets in strongly nonlocal nonlinear media.

PubMed

Peng, Xi; Zhuang, Jingli; Peng, Yulian; Li, DongDong; Zhang, Liping; Chen, Xingyu; Zhao, Fang; Deng, Dongmei

2018-03-08

The self-accelerating Airy Ince-Gaussian (AiIG) and Airy helical Ince-Gaussian (AihIG) wave packets in strongly nonlocal nonlinear media (SNNM) are obtained by solving the strongly nonlocal nonlinear Schrödinger equation. For the first time, the propagation properties of three dimensional localized AiIG and AihIG breathers and solitons in the SNNM are demonstrated, these spatiotemporal wave packets maintain the self-accelerating and approximately non-dispersion properties in temporal dimension, periodically oscillating (breather state) or steady (soliton state) in spatial dimension. In particular, their numerical experiments of spatial intensity distribution, numerical simulations of spatiotemporal distribution, as well as the transverse energy flow and the angular momentum in SNNM are presented. Typical examples of the obtained solutions are based on the ratio between the input power and the critical power, the ellipticity and the strong nonlocality parameter. The comparisons of analytical solutions with numerical simulations and numerical experiments of the AiIG and AihIG optical solitons show that the numerical results agree well with the analytical solutions in the case of strong nonlocality.

Repetition blindness has a perceptual locus: evidence from online processing of targets in RSVP streams

NASA Technical Reports Server (NTRS)

Johnston, James C.; Hochhaus, Larry; Ruthruff, Eric

2002-01-01

Four experiments tested whether repetition blindness (RB; reduced accuracy reporting repetitions of briefly displayed items) is a perceptual or a memory-recall phenomenon. RB was measured in rapid serial visual presentation (RSVP) streams, with the task altered to reduce memory demands. In Experiment 1 only the number of targets (1 vs. 2) was reported, eliminating the need to remember target identities. Experiment 2 segregated repeated and nonrepeated targets into separate blocks to reduce bias against repeated targets. Experiments 3 and 4 required immediate "online" buttonpress responses to targets as they occurred. All 4 experiments showed very strong RB. Furthermore, the online response data showed clearly that the 2nd of the repeated targets is the one missed. The present results show that in the RSVP paradigm, RB occurs online during initial stimulus encoding and decision making. The authors argue that RB is indeed a perceptual phenomenon.

Differential long-term effects of social stress during adolescence on anxiety in Wistar and wild-type rats.

PubMed

Vidal, Jose; Buwalda, Bauke; Koolhaas, Jaap M

2011-06-01

Severe and chronic stress may interfere with adolescent neuronal plasticity that turns the juvenile brain into an adult brain increasing the vulnerability to develop anxiety disorders. It is well-known from adult stress research that there is a large individual differentiation in stress vulnerability. The current study is aimed at the individual resilience and vulnerability to adolescent social stress. Two strains of rats that differ in social behavioral skills were subjected to social stress during adolescence. In three experiments we studied short and long term effects of adolescent social stress using a water conflict test in different contexts. Wistar rats which had been socially defeated on postnatal days 45 and 46 showed, following water deprivation, a strong decrease in the total amount of water consumed and time spent drinking when tested 2 days and 3 weeks later in the context where they received the defeat experience. Also a strong increase in drinking latency was noticed in the context of the previous defeat. No differences in these parameters were found between defeated and non-defeated wild-type rats. The results of the water conflict test in an environment where no association with the previous defeat experience was present showed that the adolescent social stress did not induce a generalized anxiety. In conclusion, the water conflict test is a useful tool to measure the influence of social defeat on the motivation to obtain resources under conditions with different stimulus properties. In addition, our data suggest the importance of the strain used in adolescent stress experiments. The fact that Wistar rats showed a strong association with the context at adulthood whereas no effect was observed in the wild-type rats shows that victim characteristics are important determining factors for the long term effects of adolescent social stress. Copyright © 2011 Elsevier B.V. All rights reserved.

Dynamic semantic cognition: Characterising coherent and controlled conceptual retrieval through time using magnetoencephalography and chronometric transcranial magnetic stimulation.

PubMed

Teige, Catarina; Mollo, Giovanna; Millman, Rebecca; Savill, Nicola; Smallwood, Jonathan; Cornelissen, Piers L; Jefferies, Elizabeth

2018-06-01

Distinct neural processes are thought to support the retrieval of semantic information that is (i) coherent with strongly-encoded aspects of knowledge, and (ii) non-dominant yet relevant for the current task or context. While the brain regions that support readily coherent and more controlled patterns of semantic retrieval are relatively well-characterised, the temporal dynamics of these processes are not well-understood. This study used magnetoencephalography (MEG) and dual-pulse chronometric transcranial magnetic stimulation (cTMS) in two separate experiments to examine temporal dynamics during the retrieval of strong and weak associations. MEG results revealed a dissociation within left temporal cortex: anterior temporal lobe (ATL) showed greater oscillatory response for strong than weak associations, while posterior middle temporal gyrus (pMTG) showed the reverse pattern. Left inferior frontal gyrus (IFG), a site associated with semantic control and retrieval, showed both patterns at different time points. In the cTMS experiment, stimulation of ATL at ∼150 msec disrupted the efficient retrieval of strong associations, indicating a necessary role for ATL in coherent conceptual activations. Stimulation of pMTG at the onset of the second word disrupted the retrieval of weak associations, suggesting this site may maintain information about semantic context from the first word, allowing efficient engagement of semantic control. Together these studies provide converging evidence for a functional dissociation within the temporal lobe, across both tasks and time. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Identity modulates short-term memory for facial emotion.

PubMed

Galster, Murray; Kahana, Michael J; Wilson, Hugh R; Sekuler, Robert

2009-12-01

For some time, the relationship between processing of facial expression and facial identity has been in dispute. Using realistic synthetic faces, we reexamined this relationship for both perception and short-term memory. In Experiment 1, subjects tried to identify whether the emotional expression on a probe stimulus face matched the emotional expression on either of two remembered faces that they had just seen. The results showed that identity strongly influenced recognition short-term memory for emotional expression. In Experiment 2, subjects' similarity/dissimilarity judgments were transformed by multidimensional scaling (MDS) into a 2-D description of the faces' perceptual representations. Distances among stimuli in the MDS representation, which showed a strong linkage of emotional expression and facial identity, were good predictors of correct and false recognitions obtained previously in Experiment 1. The convergence of the results from Experiments 1 and 2 suggests that the overall structure and configuration of faces' perceptual representations may parallel their representation in short-term memory and that facial identity modulates the representation of facial emotion, both in perception and in memory. The stimuli from this study may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental.

Identity modulates short-term memory for facial emotion

PubMed Central

Galster, Murray; Kahana, Michael J.; Wilson, Hugh R.; Sekuler, Robert

2010-01-01

For some time, the relationship between processing of facial expression and facial identity has been in dispute. Using realistic synthetic faces, we reexamined this relationship for both perception and short-term memory. In Experiment 1, subjects tried to identify whether the emotional expression on a probe stimulus face matched the emotional expression on either of two remembered faces that they had just seen. The results showed that identity strongly influenced recognition short-term memory for emotional expression. In Experiment 2, subjects’ similarity/dissimilarity judgments were transformed by multidimensional scaling (MDS) into a 2-D description of the faces’ perceptual representations. Distances among stimuli in the MDS representation, which showed a strong linkage of emotional expression and facial identity, were good predictors of correct and false recognitions obtained previously in Experiment 1. The convergence of the results from Experiments 1 and 2 suggests that the overall structure and configuration of faces’ perceptual representations may parallel their representation in short-term memory and that facial identity modulates the representation of facial emotion, both in perception and in memory. The stimuli from this study may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental. PMID:19897794

Spontaneous Scalarization: Dead or Alive?

NASA Astrophysics Data System (ADS)

Berti, Emanuele; Crispino, Luis; Gerosa, Davide; Gualtieri, Leonardo; Horbatsch, Michael; Macedo, Caio; Okada da Silva, Hector; Pani, Paolo; Sotani, Hajime; Sperhake, Ulrich

2015-04-01

In 1993, Damour and Esposito-Farese showed that a wide class of scalar-tensor theories can pass weak-field gravitational tests and exhibit nonperturbative strong-field deviations away from General Relativity in systems involving neutron stars. These deviations are possible in the presence of ``spontaneous scalarization,'' a phase transition similar in nature to spontaneous magnetization in ferromagnets. More than twenty years after the original proposal, binary pulsar experiments have severely constrained the possibility of spontaneous scalarization occurring in nature. I will show that these experimental constraints have important implications for the torsional oscillation frequencies of neutron stars and for the so-called ``I-Love-Q'' relations in scalar-tensor theories. I will also argue that there is still hope to observe strong scalarization effects, despite the strong experimental bounds on the original mechanism. In particular, I will discuss two mechanisms that could produce strong scalarization in neutron stars: anisotropy and multiscalarization. This work was supported by NSF CAREER Award PHY-1055103.

Spontaneous eye blinks are entrained by finger tapping.

PubMed

Cong, D-K; Sharikadze, M; Staude, G; Deubel, H; Wolf, W

2010-02-01

We studied the mutual cross-talk between spontaneous eye blinks and continuous, self-paced unimanual and bimanual tapping. Both types of motor activities were analyzed with regard to their time-structure in synchronization-continuation tapping tasks which involved different task instructions, namely "standard" finger tapping (Experiment 1), "strong" tapping (Experiment 2) requiring more forceful finger movements, and "impulse-like" tapping (Experiment 3) where upward-downward finger movements had to be very fast. In a further control condition (Experiment 4), tapping was omitted altogether. The results revealed a prominent entrainment of spontaneous blink behavior by the manual tapping, with bimanual tapping being more effective than unimanual tapping, and with the "strong" and "impulse-like" tapping showing the largest effects on blink timing. Conversely, we found no significant effects of the tapping on the timing of the eye blinks across all experiments. The findings suggest a functional overlap of the motor control structures responsible for voluntary, rhythmic finger movements and eye blinking behavior.

Shape and color naming are inherently asymmetrical: Evidence from practice-based interference.

PubMed

Protopapas, Athanassios; Markatou, Artemis; Samaras, Evangelos; Piokos, Andreas

2017-01-01

Stroop interference is characterized by strong asymmetry between word and color naming such that the former is faster and interferes with the latter but not vice versa. This asymmetry is attributed to differential experience with naming in the two dimensions, i.e., words and colors. Here we show that training on visual-verbal paired associate tasks equivalent to color and shape naming, not involving word reading, leads to strongly asymmetric interference patterns. In two experiments adults practiced naming colors and shapes, one dimension more extensively (10days) than the other (2days), depending on group assignment. One experiment used novel shapes (ideograms) and the other familiar geometric shapes, associated with nonsense syllables. In a third experiment participants practiced naming either colors or shapes using cross-category shape and color names, respectively, for 12days. Across experiments, despite equal training of the two groups in naming the two different dimensions, color naming was strongly affected by shape even after extensive practice, whereas shape naming was resistant to interference. To reconcile these findings with theoretical accounts of interference, reading may be conceptualized as involving visual-verbal associations akin to shape naming. An inherent or early-developing advantage for naming shapes may provide an evolutionary substrate for the invention and development of reading. Copyright © 2016 Elsevier B.V. All rights reserved.

Physical Vapor Transport of Mercurous Chloride Crystals: Design of a Microgravity Experiment

NASA Technical Reports Server (NTRS)

Duval, W, M. B.; Singh, N. B.; Glicksman, M. E.

1997-01-01

Flow field characteristics predicted from a computational model show that the dynamical state of the flow, for practical crystal growth conditions of mercurous chloride, can range from steady to unsteady. Evidence that the flow field can be strongly dominated by convection for ground-based conditions is provided by the prediction of asymmetric velocity profiles bv the model which show reasonable agreement with laser Doppler velocimetry experiments in both magnitude and planform. Unsteady flow is shown to be correlated with a degradation of crystal quality as quantified by light scattering pattern measurements, A microgravity experiment is designed to show that an experiment performed with parameters which yield an unsteady flow becomes steady (diffusive-advective) in a microgravity environment of 10(exp -3) g(sub 0) as predicted by the model, and hence yields crystals with optimal quality.

Biased information search in homogeneous groups: confidence as a moderator for the effect of anticipated task requirements.

PubMed

Kerschreiter, Rudolf; Schulz-Hardt, Stefan; Mojzisch, Andreas; Frey, Dieter

2008-05-01

When searching for information, groups that are homogeneous regarding their members' prediscussion decision preferences show a strong bias for information that supports rather than conflicts with the prevailing opinion (confirmation bias). The present research examined whether homogeneous groups blindly search for information confirming their beliefs irrespective of the anticipated task or whether they are sensitive to the usefulness of new information for this forthcoming task. Results of three experiments show that task sensitivity depends on the groups' confidence in the correctness of their decision: Moderately confident groups displayed a strong confirmation bias when they anticipated having to give reasons for their decision but showed a balanced information search or even a dis confirmation bias (i.e., predominately seeking conflicting information) when they anticipated having to refute counterarguments. In contrast, highly confident groups demonstrated a strong confirmation bias independent of the anticipated task requirements.

Dispersal, density dependence, and population dynamics of a fungal microbe on leaf surfaces.

PubMed

Woody, Scott T; Ives, Anthony R; Nordheim, Erik V; Andrews, John H

2007-06-01

Despite the ubiquity and importance of microbes in nature, little is known about their natural population dynamics, especially for those that occupy terrestrial habitats. Here we investigate the dynamics of the yeast-like fungus Aureobasidium pullulans (Ap) on apple leaves in an orchard. We asked three questions. (1) Is variation in fungal population density among leaves caused by variation in leaf carrying capacities and strong density-dependent population growth that maintains densities near carrying capacity? (2) Do resident populations have competitive advantages over immigrant cells? (3) Do Ap dynamics differ at different times during the growing season? To address these questions, we performed two experiments at different times in the growing season. Both experiments used a 2 x 2 factorial design: treatment 1 removed fungal cells from leaves to reveal density-dependent population growth, and treatment 2 inoculated leaves with an Ap strain engineered to express green fluorescent protein (GFP), which made it possible to track the fate of immigrant cells. The experiments showed that natural populations of Ap vary greatly in density due to sustained differences in carrying capacities among leaves. The maintenance of populations close to carrying capacities indicates strong density-dependent processes. Furthermore, resident populations are strongly competitive against immigrants, while immigrants have little impact on residents. Finally, statistical models showed high population growth rates of resident cells in one experiment but not in the other, suggesting that Ap experiences relatively "good" and "bad" periods for population growth. This picture of Ap dynamics conforms to commonly held, but rarely demonstrated, expectations of microbe dynamics in nature. It also highlights the importance of local processes, as opposed to immigration, in determining the abundance and dynamics of microbes on surfaces in terrestrial systems.

Power, propensity to negotiate, and moving first in competitive interactions.

PubMed

Magee, Joe C; Galinsky, Adam D; Gruenfeld, Deborah H

2007-02-01

Five experiments investigated how the possession and experience of power affects the initiation of competitive interaction. In Experiments 1a and 1b, high-power individuals displayed a greater propensity to initiate a negotiation than did low-power individuals. Three additional experiments showed that power increased the likelihood of making the first move in a variety of competitive interactions. In Experiment 2, participants who were semantically primed with power were nearly 4 times as likely as participants in a control condition to choose to make the opening arguments in a debate competition scenario. In Experiment 3, negotiators with strong alternatives to a negotiation were more than 3 times as likely to spontaneously express an intention to make the first offer compared to participants who lacked any alternatives. Experiment 4 showed that high-power negotiators were more likely than low-power negotiators to actually make the first offer and that making the first offer produced a bargaining advantage.

Model-independent curvature determination with 21 cm intensity mapping experiments

NASA Astrophysics Data System (ADS)

Witzemann, Amadeus; Bull, Philip; Clarkson, Chris; Santos, Mario G.; Spinelli, Marta; Weltman, Amanda

2018-06-01

Measurements of the spatial curvature of the Universe have improved significantly in recent years, but still tend to require strong assumptions to be made about the equation of state of dark energy (DE) in order to reach sub-percent precision. When these assumptions are relaxed, strong degeneracies arise that make it hard to disentangle DE and curvature, degrading the constraints. We show that forthcoming 21 cm intensity mapping experiments such as Hydrogen Intensity and Real-time Analysis eXperiment (HIRAX) are ideally designed to carry out model-independent curvature measurements, as they can measure the clustering signal at high redshift with sufficient precision to break many of the degeneracies. We consider two different model-independent methods, based on `avoiding' the DE-dominated regime and non-parametric modelling of the DE equation of state, respectively. Our forecasts show that HIRAX will be able to improve upon current model-independent constraints by around an order of magnitude, reaching percent-level accuracy even when an arbitrary DE equation of state is assumed. In the same model-independent analysis, the sample variance limit for a similar survey is another order of magnitude better.

Many-body Tunneling and Nonequilibrium Dynamics of Doublons in Strongly Correlated Quantum Dots.

PubMed

Hou, WenJie; Wang, YuanDong; Wei, JianHua; Zhu, ZhenGang; Yan, YiJing

2017-05-30

Quantum tunneling dominates coherent transport at low temperatures in many systems of great interest. In this work we report a many-body tunneling (MBT), by nonperturbatively solving the Anderson multi-impurity model, and identify it a fundamental tunneling process on top of the well-acknowledged sequential tunneling and cotunneling. We show that the MBT involves the dynamics of doublons in strongly correlated systems. Proportional to the numbers of dynamical doublons, the MBT can dominate the off-resonant transport in the strongly correlated regime. A T 3/2 -dependence of the MBT current on temperature is uncovered and can be identified as a fingerprint of the MBT in experiments. We also prove that the MBT can support the coherent long-range tunneling of doublons, which is well consistent with recent experiments on ultracold atoms. As a fundamental physical process, the MBT is expected to play important roles in general quantum systems.

Acceleration of electrons in strong beam-plasma interactions

NASA Technical Reports Server (NTRS)

Wilhelm, K.; Bernstein, W.; Kellogg, P. J.; Whalen, B. A.

1984-01-01

The effects of strong beam-plasma interactions on the electron population of the upper atmosphere have been investigated in an electron acceleration experiment performed with a sounding rocket. The rocket carried the Several Complex Experiments (SCEX) payload which included an electron accelerator, three disposable 'throwaway' detectors (TADs), and a stepped electron energy analyzer. The payload was launched in an auroral arc over the rocket at altitudes of 157 and 178 km, respectively. The performance characteristics of the instruments are discussed in detail. The data are combined with the results of laboratory measurements and show that electrons with energies of at least two and probably four times the injection energy of 2 keV were observed during strong beam-plasma interaction events. The interaction events occurred at pitch angles of 54 and 126 degrees. On the basis of the data it is proposed that the superenergization of the electrons is correlated with the length of the beam-plasma interaction region.

Late psychological sequelae of abortion: questions from a primary care perspective.

PubMed

Butler, C

1996-10-01

Research strongly supports the view that pregnancy termination is seldom associated with adverse psychological sequelae in the short to medium term, but experience shows that there is a small group of women who experience long and intense suffering. This is a report of the cases of two women who presented with psychological problems associated with a termination 19 and 5 years earlier.

Dance Lessons.

PubMed

Hahn, Emily

2015-01-01

Nursing has been described as an art and a science. The scientific aspect of nursing can be learned in nursing school and in years of practice. However, the art of nursing is enriched by each nurse's connection with life experiences. The purpose of this article is to highlight my particular life experience with dance and to show how studying dance has helped me become the strong nursing leader I am today.

Dance Lessons.

PubMed

Hahn, Emily

2018-04-01

Nursing has been described as an art and a science. The scientific aspect of nursing can be learned in nursing school and in years of practice. However, the art of nursing is enriched by each nurse's connection with life experiences. The purpose of this article is to highlight my particular life experience with dance and to show how studying dance has helped me become the strong nursing leader I am today.

GPA and Attribute Framing Effects: Are Better Students More Sensitive or More Susceptible?

ERIC Educational Resources Information Center

Dunegan, Ken

2010-01-01

Data from 2 studies show students differ in terms of how attribute framing alters perceptions and reactions in a decision-making episode. Using student GPA as a moderator, results from a role-play-decision-making exercise (Experiment 1) show perceptions and intended actions of higher GPA students were more strongly affected by attribute framing…

Measuring mixing efficiency in experiments of strongly stratified turbulence

NASA Astrophysics Data System (ADS)

Augier, P.; Campagne, A.; Valran, T.; Calpe Linares, M.; Mohanan, A. V.; Micard, D.; Viboud, S.; Segalini, A.; Mordant, N.; Sommeria, J.; Lindborg, E.

2017-12-01

Oceanic and atmospheric models need better parameterization of the mixing efficiency. Therefore, we need to measure this quantity for flows representative of geophysical flows, both in terms of types of flows (with vortices and/or waves) and of dynamical regimes. In order to reach sufficiently large Reynolds number for strongly stratified flows, experiments for which salt is used to produce the stratification have to be carried out in a large rotating platform of at least 10-meter diameter.We present new experiments done in summer 2017 to study experimentally strongly stratified turbulence and mixing efficiency in the Coriolis platform. The flow is forced by a slow periodic movement of an array of large vertical or horizontal cylinders. The velocity field is measured by 3D-2C scanned horizontal particles image velocimetry (PIV) and 2D vertical PIV. Six density-temperature probes are used to measure vertical and horizontal profiles and signals at fixed positions.We will show how we rely heavily on open-science methods for this study. Our new results on the mixing efficiency will be presented and discussed in terms of mixing parameterization.

Cultural affordances and emotional experience: socially engaging and disengaging emotions in Japan and the United States.

PubMed

Kitayama, Shinobu; Mesquita, Batja; Karasawa, Mayumi

2006-11-01

The authors hypothesized that whereas Japanese culture encourages socially engaging emotions (e.g., friendly feelings and guilt), North American culture fosters socially disengaging emotions (e.g., pride and anger). In two cross-cultural studies, the authors measured engaging and disengaging emotions repeatedly over different social situations and found support for this hypothesis. As predicted, Japanese showed a pervasive tendency to reportedly experience engaging emotions more strongly than they experienced disengaging emotions, but Americans showed a reversed tendency. Moreover, as also predicted, Japanese subjective well-being (i.e., the experience of general positive feelings) was more closely associated with the experience of engaging positive emotions than with that of disengaging emotions. Americans tended to show the reversed pattern. The established cultural differences in the patterns of emotion suggest the consistent and systematic cultural shaping of emotion over time.

Nonequilibrium steady states and resonant tunneling in time-periodically driven systems with interactions

NASA Astrophysics Data System (ADS)

Qin, Tao; Hofstetter, Walter

2018-03-01

Time-periodically driven systems are a versatile toolbox for realizing interesting effective Hamiltonians. Heating, caused by excitations to high-energy states, is a challenge for experiments. While most setups so far address the relatively weakly interacting regime, it is of general interest to study heating in strongly correlated systems. Using Floquet dynamical mean-field theory, we study nonequilibrium steady states (NESS) in the Falicov-Kimball model, with time-periodically driven kinetic energy or interaction. We systematically investigate the nonequilibrium properties of the NESS. For a driven kinetic energy, we show that resonant tunneling, where the interaction is an integer multiple of the driving frequency, plays an important role in the heating. In the strongly correlated regime, we show that this can be well understood using Fermi's golden rule and the Schrieffer-Wolff transformation for a time-periodically driven system. We furthermore demonstrate that resonant tunneling can be used to control the population of Floquet states to achieve "photodoping." For driven interactions introduced by an oscillating magnetic field near a widely adopted Feshbach resonance, we find that the double occupancy is strongly modulated. Our calculations apply to shaken ultracold-atom systems and to solid-state systems in a spatially uniform but time-dependent electric field. They are also closely related to lattice modulation spectroscopy. Our calculations are helpful to understand the latest experiments on strongly correlated Floquet systems.

Northern hemisphere nitrous oxide morphology during the 1989 AASE and the 1991-1992 AASE 2 campaigns

NASA Technical Reports Server (NTRS)

Podolske, James R.; Loewenstein, Max; Weaver, Alex; Strahan, Susan E.; Chan, K. Roland

1993-01-01

Nitrous oxide vertical profiles and latitudinal distributions for the 1989 Airborne Antarctic Ozone Experiment (AASE) and 1992 AASE 2 northern polar winters are developed from the ATLAS N2O dataset, using both potential temperature and pressure as vertical coordinates. Morphologies show strong descent occuring poleward of the polar jet. The AASE 2 morphology shows a mid latitude 'surf zone', characterized by strong horizontal mixing, and a horizontal gradient south of 30 deg N due to the sub-tropical jet. These features are similar to those produced by two-dimensional photochemical models which include coupling between transport, radiation, and chemistry.

High-field instability of a field-induced triplon Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

Rakhimov, Abdulla; Sherman, E. Ya.; Kim, Chul Koo

2010-01-01

We study properties of magnetic field-induced Bose-Einstein condensate of triplons as a function of temperature and the field within the Hartree-Fock-Bogoliubov approach including the anomalous density. We show that the magnetization is continuous across the transition, in agreement with the experiment. In sufficiently strong fields the condensate becomes unstable due to triplon-triplon repulsion. As a result, the system is characterized by two critical magnetic fields: one producing the condensate and the other destroying it. We show that nonparabolic triplon dispersion arising due to the gapped bare spectrum and the crystal structure has a strong influence on the phase diagram.

Echolocation versus echo suppression in humans

PubMed Central

Wallmeier, Ludwig; Geßele, Nikodemus; Wiegrebe, Lutz

2013-01-01

Several studies have shown that blind humans can gather spatial information through echolocation. However, when localizing sound sources, the precedence effect suppresses spatial information of echoes, and thereby conflicts with effective echolocation. This study investigates the interaction of echolocation and echo suppression in terms of discrimination suppression in virtual acoustic space. In the ‘Listening’ experiment, sighted subjects discriminated between positions of a single sound source, the leading or the lagging of two sources, respectively. In the ‘Echolocation’ experiment, the sources were replaced by reflectors. Here, the same subjects evaluated echoes generated in real time from self-produced vocalizations and thereby discriminated between positions of a single reflector, the leading or the lagging of two reflectors, respectively. Two key results were observed. First, sighted subjects can learn to discriminate positions of reflective surfaces echo-acoustically with accuracy comparable to sound source discrimination. Second, in the Listening experiment, the presence of the leading source affected discrimination of lagging sources much more than vice versa. In the Echolocation experiment, however, the presence of both the lead and the lag strongly affected discrimination. These data show that the classically described asymmetry in the perception of leading and lagging sounds is strongly diminished in an echolocation task. Additional control experiments showed that the effect is owing to both the direct sound of the vocalization that precedes the echoes and owing to the fact that the subjects actively vocalize in the echolocation task. PMID:23986105

Coherent band excitations in CePd 3: A comparison of neutron scattering and ab initio theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goremychkin, Eugene A.; Park, Hyowon; Osborn, Raymond

In common with many strongly correlated electron systems, intermediate valence compounds are believed to display a crossover from a high-temperature regime of incoherently fluctuating local moments to a low-temperature regime of coherent hybridized bands. In this work, we show that inelastic neutron scattering measurements of the dynamic magnetic susceptibility of CePd 3 provides a benchmark for ab initio calculations based on dynamical mean field theory. The magnetic response is strongly momentum dependent thanks to the formation of coherent f-electron bands at low temperature, with an amplitude that is strongly enhanced by local particle-hole interactions. Finally, the agreement between experiment andmore » theory shows that we have a robust first-principles understanding of the temperature dependence of f-electron coherence.« less

Probing Sub-GeV Mass Strongly Interacting Dark Matter with a Low-Threshold Surface Experiment.

PubMed

Davis, Jonathan H

2017-11-24

Using data from the ν-cleus detector, based on the surface of Earth, we place constraints on dark matter in the form of strongly interacting massive particles (SIMPs) which interact with nucleons via nuclear-scale cross sections. For large SIMP-nucleon cross sections, the sensitivity of traditional direct dark matter searches using underground experiments is limited by the energy loss experienced by SIMPs, due to scattering with the rock overburden and experimental shielding on their way to the detector apparatus. Hence, a surface-based experiment is ideal for a SIMP search, despite the much larger background resulting from the lack of shielding. We show using data from a recent surface run of a low-threshold cryogenic detector that values of the SIMP-nucleon cross section up to approximately 10^{-27}  cm^{2} can be excluded for SIMPs with masses above 100 MeV.

Heat transfer from nanoparticles: a corresponding state analysis.

PubMed

Merabia, Samy; Shenogin, Sergei; Joly, Laurent; Keblinski, Pawel; Barrat, Jean-Louis

2009-09-08

In this contribution, we study situations in which nanoparticles in a fluid are strongly heated, generating high heat fluxes. This situation is relevant to experiments in which a fluid is locally heated by using selective absorption of radiation by solid particles. We first study this situation for different types of molecular interactions, using models for gold particles suspended in octane and in water. As already reported in experiments, very high heat fluxes and temperature elevations (leading eventually to particle destruction) can be observed in such situations. We show that a very simple modeling based on Lennard-Jones (LJ) interactions captures the essential features of such experiments and that the results for various liquids can be mapped onto the LJ case, provided a physically justified (corresponding state) choice of parameters is made. Physically, the possibility of sustaining very high heat fluxes is related to the strong curvature of the interface that inhibits the formation of an insulating vapor film.

Momentum-resolved spectroscopy of a Fermi liquid

PubMed Central

Doggen, Elmer V. H.; Kinnunen, Jami J.

2015-01-01

We consider a recent momentum-resolved radio-frequency spectroscopy experiment, in which Fermi liquid properties of a strongly interacting atomic Fermi gas were studied. Here we show that by extending the Brueckner-Goldstone model, we can formulate a theory that goes beyond basic mean-field theories and that can be used for studying spectroscopies of dilute atomic gases in the strongly interacting regime. The model hosts well-defined quasiparticles and works across a wide range of temperatures and interaction strengths. The theory provides excellent qualitative agreement with the experiment. Comparing the predictions of the present theory with the mean-field Bardeen-Cooper-Schrieffer theory yields insights into the role of pair correlations, Tan's contact, and the Hartree mean-field energy shift. PMID:25941948

Quasi elastic and inelastic neutron scattering study of vitamin C aqueous solutions

NASA Astrophysics Data System (ADS)

Migliardo, F.; Branca, C.; Magazù, S.; Migliardo, P.; Coppolino, S.; Villari, A.; Micali, N.

2002-02-01

In this paper, new results obtained by quasi elastic and inelastic neutron scattering experiments performed on vitamin C ( L-ascorbic acid)/H 2O mixtures are reported. The data analysis of the QENS measurements, by a separation of the diffusive dynamics of hydrated L-ascorbic acid from that of water, furnishes quantitative evidences of a random jump diffusion motion of vitamin C and shows that the water dynamics is strongly affected by the presence of L-ascorbic acid. Concerning the INS experiment, we are able, through the behaviour of neutron spectra across the glass transition temperature ( T g≈233 K for the vitamin C/water system), to collocate the investigated system in the Angell “strong-fragile” scheme.

Geochemical Fate and Transport of Sildenafil in Natural Soils

NASA Astrophysics Data System (ADS)

Turner, A. E.; Vulava, V. M.

2016-12-01

In recent years, pharmaceutical drugs have become of increasing concern to the health of our environment. As a result of wastewater treatment plant discharge and various sources of surface runoff, pharmaceuticals can be found in trace amounts in our most common water resources. Sildenafil, a drug marketed to treat erectile dysfunction, is amongst the top 20 most prescribed pharmaceutical products in the U.S. Sildenafil is a complex polar organic molecule with multiple amine functional groups, which gives it acid-base functionality. The most common pKa of this molecule is approximately 6.0 and water solubility ranges from 3.5 to 4.6 mg/L. The goal of this project is to examine the sorption and transport behavior of sildenafil in natural organic matter- (OM) and clay-rich soils. Soils used for this study were collected from undisturbed forested areas in Francis Marion National Forest, Charleston, SC. A series of batch sorption isotherm and column transport experiments were conducted with these soils. Sildenafil was analyzed using high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC-MS) techniques. Batch sorption isotherm experiments produced nonlinear data for both OM- and clay-rich soil types. The data shows that sildenafil sorbs more strongly to the clay-rich soils than to the OM-rich soils. This suggests that sildenafil behaved as a cation and preferentially sorbed with the negatively-charged clay minerals. The transport behavior of sildenafil as determined by experiments with soil-packed glass chromatography columns confirmed this behavior. The resulting breakthrough curves show that sildenafil is strongly retarded in clay-rich soils. Our studies do not show degradation or transformation of sildenafil in soils. The results from this study have strong implications for environmental management of pharmaceutical chemical effluents and disposal.

Extending a Lippmann style seismometer's dynamic range by using a non-linear feedback circuit

NASA Astrophysics Data System (ADS)

Romeo, Giovanni; Spinelli, Giuseppe

2013-04-01

A Lippmann style seismometer uses a single-coil velocity-feedback method in order to extend toward lower frequencies a geophone's frequency response. Strong seismic signals may saturate the electronics, sometimes producing a characteristic whale-shaped recording. Adding a non linear feedback in the electronic circuit may avoid saturation, allowing the strong-motion use of the seismometer without affecting the usual performance. We show results from both simulations and experiments, using a Teledyne Geotech s13 as a mechanical part.

Optical Sensing of Aromatic Amino Acids and Dipeptides by a Crown-Ether-Functionalized Perylene Bisimide Fluorophore.

PubMed

Weißenstein, Annike; Saha-Möller, Chantu R; Würthner, Frank

2018-06-04

The host-guest binding properties of a fluorescent perylene bisimide (PBI) receptor equipped with crown ether were studied in detail with a series of aromatic amino acids and dipeptides by UV/Vis, fluorescence and NMR spectroscopy. Fluorescence titration experiments showed that electron-rich aromatic amino acids and dipeptides strongly quench the fluorescence of the electron-poor PBI host molecule. Benesi-Hildebrand plots of fluorescence titration data confirmed the formation of host-guest complexes with 1:2 stoichiometry. Binding constants determined by global analysis of UV/Vis and fluorescence titration experiments revealed values between 10 3  m -1 and 10 5  m -1 in acetonitrile/methanol (9:1) at 23 °C. These data showed that amino acid l-Trp having an indole group and dipeptides containing this amino acid bind to the PBI receptor more strongly than other amino acids and dipeptides investigated here. For dipeptides containing l-Trp or l-Tyr, the binding strength is dependent on the distance between the ammonium group and the aromatic unit of the amino acids and dipeptides leading to a strong sensitivity for Ala-Trp dipeptide. 1D and 2D NMR experiments also corroborated 1:2 host-guest complexation and indicated formation of two diastereomeric species of host-guest complexes. The studies have shown that a properly functionalized PBI fluorophore functions as a molecular probe for the optical sensing of aromatic amino acids and dipeptides. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Axion-Plasmon Polaritons in Strongly Magnetized Plasmas.

PubMed

Terças, H; Rodrigues, J D; Mendonça, J T

2018-05-04

Axions are hypothetical particles related to the violation of the charge-parity symmetry within the strong sector of the standard model, being one of the most prone candidates for dark matter. Multiple attempts to prove their existence are currently performed in different physical systems. Here, we predict that axions may couple to the electrostatic (Langmuir) modes of a strongly magnetized plasma, and show that a new quasiparticle can be defined, the axion-plasmon polariton. The excitation of axions can be inferred from the pronounced modification of the dispersion relation of the Langmuir waves, a feature that we estimate to be accessible in state-of-the-art plasma-based experiments.

Axion-Plasmon Polaritons in Strongly Magnetized Plasmas

NASA Astrophysics Data System (ADS)

Terças, H.; Rodrigues, J. D.; Mendonça, J. T.

2018-05-01

Axions are hypothetical particles related to the violation of the charge-parity symmetry within the strong sector of the standard model, being one of the most prone candidates for dark matter. Multiple attempts to prove their existence are currently performed in different physical systems. Here, we predict that axions may couple to the electrostatic (Langmuir) modes of a strongly magnetized plasma, and show that a new quasiparticle can be defined, the axion-plasmon polariton. The excitation of axions can be inferred from the pronounced modification of the dispersion relation of the Langmuir waves, a feature that we estimate to be accessible in state-of-the-art plasma-based experiments.

Ramsey Interference in One-Dimensional Systems: The Full Distribution Function of Fringe Contrast as a Probe of Many-Body Dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kitagawa, Takuya; Pielawa, Susanne; Demler, Eugene

2010-06-25

We theoretically analyze Ramsey interference experiments in one-dimensional quasicondensates and obtain explicit expressions for the time evolution of full distribution functions of fringe contrast. We show that distribution functions contain unique signatures of the many-body mechanism of decoherence. We argue that Ramsey interference experiments provide a powerful tool for analyzing strongly correlated nature of 1D interacting systems.

Transition between strong and weak topological insulator in ZrTe5 and HfTe5

NASA Astrophysics Data System (ADS)

Fan, Zongjian; Liang, Qi-Feng; Chen, Y. B.; Yao, Shu-Hua; Zhou, Jian

2017-04-01

ZrTe5 and HfTe5 have attracted increasingly attention recently since the theoretical prediction of being topological insulators (TIs). However, subsequent works show many contradictions about their topolog-ical nature. Three possible phases, i.e. strong TI, weak TI, and Dirac semi-metal, have been observed in different experiments until now. Essentially whether ZrTe5 or HfTe5 has a band gap or not is still a question. Here, we present detailed first-principles calculations on the electronic and topological prop-erties of ZrTe5 and HfTe5 on variant volumes and clearly demonstrate the topological phase transition from a strong TI, going through an intermediate Dirac semi-metal state, then to a weak TI when the crystal expands. Our work might give a unified explain about the divergent experimental results and propose the crucial clue to further experiments to elucidate the topological nature of these materials.

Quenched bond randomness: Superfluidity in porous media and the strong violation of universality

NASA Astrophysics Data System (ADS)

Falicov, Alexis; Berker, A. Nihat

1997-04-01

The effects of quenched bond randomness are most readily studied with superfluidity immersed in a porous medium. A lattice model for3He-4He mixtures and incomplete4He fillings in aerogel yields the signature effect of bond randomness, namely the conversion of symmetry-breaking first-order phase transitions into second-order phase transitions, the λ-line reaching zero temperature, and the elimination of non-symmetry-breaking first-order phase transitions. The model recognizes the importance of the connected nature of aerogel randomness and thereby yields superfluidity at very low4He concentrations, a phase separation entirely within the superfluid phase, and the order-parameter contrast between mixtures and incomplete fillings, all in agreement with experiments. The special properties of the helium mixture/aerogel system are distinctly linked to the aerogel properties of connectivity, randomness, and tenuousness, via the additional study of a regularized “jungle-gym” aerogel. Renormalization-group calculations indicate that a strong violation of the empirical universality principle of critical phenomena occurs under quenched bond randomness. It is argued that helium/aerogel critical properties reflect this violation and further experiments are suggested. Renormalization-group analysis also shows that, adjoiningly to the strong universality violation (which hinges on the occurrence or non-occurrence of asymptotic strong coupling—strong randomness under rescaling), there is a new “hyperuniversality” at phase transitions with asymptotic strong coupling—strong randomness behavior, for example assigning the same critical exponents to random- bond tricriticality and random- field criticality.

Handedness Shapes Children's Abstract Concepts

ERIC Educational Resources Information Center

Casasanto, Daniel; Henetz, Tania

2012-01-01

Can children's handedness influence how they represent abstract concepts like "kindness" and "intelligence"? Here we show that from an early age, right-handers associate rightward space more strongly with positive ideas and leftward space with negative ideas, but the opposite is true for left-handers. In one experiment, children indicated where on…

Women and Men Have Different Discourse Biases for Pronoun Interpretation

ERIC Educational Resources Information Center

Arnold, Jennifer E.

2015-01-01

Two experiments examine how men and women interpret pronouns in discourse. Adults are known to show a strong "first-mention bias": When two characters are mentioned ("Michael played with William…"), comprehenders tend to interpret subsequent pronouns as coreferential with the first of the two characters and to find pronouns…

From the Knowledge of Understanding to Military Deception

DTIC Science & Technology

2008-05-21

and decision-making. Experimental research could lead to a validation of the theory. In the experiment, I tried to cause a decrease in ambiguity and...strong evidence that indicate a relationship. Further research with a larger sample size might show a significant statistical relationship. In order...2 Research question

Orienting in virtual environments: How are surface features and environmental geometry weighted in an orientation task?

PubMed

Kelly, Debbie M; Bischof, Walter F

2008-10-01

We investigated how human adults orient in enclosed virtual environments, when discrete landmark information is not available and participants have to rely on geometric and featural information on the environmental surfaces. In contrast to earlier studies, where, for women, the featural information from discrete landmarks overshadowed the encoding of the geometric information, Experiment 1 showed that when featural information is conjoined with the environmental surfaces, men and women encoded both types of information. Experiment 2 showed that, although both types of information are encoded, performance in locating a goal position is better if it is close to a geometrically or featurally distinct location. Furthermore, although features are relied upon more strongly than geometry, initial experience with an environment influences the relative weighting of featural and geometric cues. Taken together, these results show that human adults use a flexible strategy for encoding spatial information.

Peer effects in unethical behavior: standing or reputation?

PubMed

Pascual-Ezama, David; Dunfield, Derek; Gil-Gómez de Liaño, Beatriz; Prelec, Drazen

2015-01-01

Recent empirical evidence shows that working in an unsupervised, isolated situation under competition, can increase dishonest behavior to achieve prestige. However, could working in a common space, in the presence of colleagues affect cheating? Here, we examine how familiar-peer influence, supervision and social incentives affect worker performance and dishonest behavior. First, we show that working in the presence of peers is an effective mechanism to constrain honest/dishonest behavior compared to an isolated work situation (experiment 1). Second, we demonstrate that the mere suspicion of dishonesty from another peer is not enough to affect individual cheating behavior (experiment 2), suggesting that reputation holds great importance in a worker's self-image acting as a strong social incentives. Third, we show that when the suspicion of dishonesty increases with multiple peers behaving dishonestly, the desire to increase standing is sufficient to nudge individuals' behavior back to cheating at the same levels as isolated situations (experiment 3).

Peer Effects in Unethical Behavior: Standing or Reputation?

PubMed Central

2015-01-01

Recent empirical evidence shows that working in an unsupervised, isolated situation under competition, can increase dishonest behavior to achieve prestige. However, could working in a common space, in the presence of colleagues affect cheating? Here, we examine how familiar-peer influence, supervision and social incentives affect worker performance and dishonest behavior. First, we show that working in the presence of peers is an effective mechanism to constrain honest/dishonest behavior compared to an isolated work situation (experiment 1). Second, we demonstrate that the mere suspicion of dishonesty from another peer is not enough to affect individual cheating behavior (experiment 2), suggesting that reputation holds great importance in a worker’s self-image acting as a strong social incentives. Third, we show that when the suspicion of dishonesty increases with multiple peers behaving dishonestly, the desire to increase standing is sufficient to nudge individuals’ behavior back to cheating at the same levels as isolated situations (experiment 3). PMID:25853716

Selectivity of Electronic Coherence and Attosecond Ionization Delays in Strong-Field Double Ionization

NASA Astrophysics Data System (ADS)

Kobayashi, Yuki; Reduzzi, Maurizio; Chang, Kristina F.; Timmers, Henry; Neumark, Daniel M.; Leone, Stephen R.

2018-06-01

Experiments are presented on real-time probing of coherent electron dynamics in xenon initiated by strong-field double ionization. Attosecond transient absorption measurements allow for characterization of electronic coherences as well as relative ionization timings in multiple electronic states of Xe+ and Xe2 + . A high degree of coherence g =0.4 is observed between P3 2 0-P3 0 0 of Xe2 + , whereas for other possible pairs of states the coherences are below the detection limits of the experiments. A comparison of the experimental results with numerical simulations based on an uncorrelated electron-emission model shows that the coherences produced by strong-field double ionization are more selective than predicted. Surprisingly short ionization time delays, 0.85 fs, 0.64 fs, and 0.75 fs relative to Xe+ formation, are also measured for the P2 3 , P0 3 , and P1 3 states of Xe2 + , respectively. Both the unpredicted selectivity in the formation of coherence and the subfemtosecond time delays of specific states provide new insight into correlated electron dynamics in strong-field double ionization.

Disengagement beliefs in smokers: do they influence the effects of a tailored persuasive message advocating smoking cessation?

PubMed

Dijkstra, A

2009-09-01

Disengagement beliefs function to reduce cognitive dissonance and a number of predictions with regard to disengagement beliefs have been tested and verified. However, the influence of disengagement beliefs on persuasion has not been studied yet. In a field-experiment, 254 smokers were randomly assigned to a persuasive message condition or a no-information control condition. First, it was assessed to what extent disengagement beliefs influenced persuasion. In smokers with low adherence to disengagement beliefs, quitting activity (attempting to quit) in the control condition was high, but this was not further increased by persuasive information on the negative outcomes of smoking. In contrast, smokers who strongly adhered to disengagement beliefs showed low quitting activity in the control condition, but significantly more quitting activity when they received the persuasive message. Second, it was studied what smokers do when they experience negative affect caused by the persuasive message. The results show that in smokers who strongly adhered to disengagement beliefs, negative affect was associated with less quitting activity. Although these results show that quitting activity as assessed at 2 and 8 months follow-ups was influenced by disengagement beliefs, point prevalence seven-day quitting was not. This study shows that adherence to disengagement beliefs is a relevant individual difference in understanding effects of smoking cessation interventions.

Handedness shapes children's abstract concepts.

PubMed

Casasanto, Daniel; Henetz, Tania

2012-03-01

Can children's handedness influence how they represent abstract concepts like kindness and intelligence? Here we show that from an early age, right-handers associate rightward space more strongly with positive ideas and leftward space with negative ideas, but the opposite is true for left-handers. In one experiment, children indicated where on a diagram a preferred toy and a dispreferred toy should go. Right-handers tended to assign the preferred toy to a box on the right and the dispreferred toy to a box on the left. Left-handers showed the opposite pattern. In a second experiment, children judged which of two cartoon animals looked smarter (or dumber) or nicer (or meaner). Right-handers attributed more positive qualities to animals on the right, but left-handers to animals on the left. These contrasting associations between space and valence cannot be explained by exposure to language or cultural conventions, which consistently link right with good. Rather, right- and left-handers implicitly associated positive valence more strongly with the side of space on which they can act more fluently with their dominant hands. Results support the body-specificity hypothesis (Casasanto, 2009), showing that children with different kinds of bodies think differently in corresponding ways. Copyright © 2011 Cognitive Science Society, Inc.

Characterizing isolated attosecond pulses with angular streaking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Siqi; Guo, Zhaoheng; Coffee, Ryan N.

Here, we present a reconstruction algorithm for isolated attosecond pulses, which exploits the phase dependent energy modulation of a photoelectron ionized in the presence of a strong laser field. The energy modulation due to a circularly polarized laser field is manifest strongly in the angle-resolved photoelectron momentum distribution, allowing for complete reconstruction of the temporal and spectral profile of an attosecond burst. We show that this type of reconstruction algorithm is robust against counting noise and suitable for single-shot experiments. This algorithm holds potential for a variety of applications for attosecond pulse sources.

Characterizing isolated attosecond pulses with angular streaking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Sigi; Guo, Zhaoheng; Coffee, Ryan N.

We present a reconstruction algorithm for isolated attosecond pulses, which exploits the phase dependent energy modulation of a photoelectron ionized in the presence of a strong laser field. The energy modulation due to a circularly polarized laser field is manifest strongly in the angle-resolved photoelectron momentum distribution, allowing for complete reconstruction of the temporal and spectral profile of an attosecond burst. We show that this type of reconstruction algorithm is robust against counting noise and suitable for single-shot experiments. This algorithm holds potential for a variety of applications for attosecond pulse sources.

Solving SAT Problem Based on Hybrid Differential Evolution Algorithm

NASA Astrophysics Data System (ADS)

Liu, Kunqi; Zhang, Jingmin; Liu, Gang; Kang, Lishan

Satisfiability (SAT) problem is an NP-complete problem. Based on the analysis about it, SAT problem is translated equally into an optimization problem on the minimum of objective function. A hybrid differential evolution algorithm is proposed to solve the Satisfiability problem. It makes full use of strong local search capacity of hill-climbing algorithm and strong global search capability of differential evolution algorithm, which makes up their disadvantages, improves the efficiency of algorithm and avoids the stagnation phenomenon. The experiment results show that the hybrid algorithm is efficient in solving SAT problem.

Characterizing isolated attosecond pulses with angular streaking

DOE PAGES

Li, Siqi; Guo, Zhaoheng; Coffee, Ryan N.; ...

2018-02-12

Here, we present a reconstruction algorithm for isolated attosecond pulses, which exploits the phase dependent energy modulation of a photoelectron ionized in the presence of a strong laser field. The energy modulation due to a circularly polarized laser field is manifest strongly in the angle-resolved photoelectron momentum distribution, allowing for complete reconstruction of the temporal and spectral profile of an attosecond burst. We show that this type of reconstruction algorithm is robust against counting noise and suitable for single-shot experiments. This algorithm holds potential for a variety of applications for attosecond pulse sources.

Characterizing isolated attosecond pulses with angular streaking

DOE PAGES

Li, Sigi; Guo, Zhaoheng; Coffee, Ryan N.; ...

2018-02-13

We present a reconstruction algorithm for isolated attosecond pulses, which exploits the phase dependent energy modulation of a photoelectron ionized in the presence of a strong laser field. The energy modulation due to a circularly polarized laser field is manifest strongly in the angle-resolved photoelectron momentum distribution, allowing for complete reconstruction of the temporal and spectral profile of an attosecond burst. We show that this type of reconstruction algorithm is robust against counting noise and suitable for single-shot experiments. This algorithm holds potential for a variety of applications for attosecond pulse sources.

Experiential, Autonomic, and Neural Responses During Threat Anticipation Vary as a Function of Threat Intensity and Neuroticism

PubMed Central

Drabant, Emily M; Kuo, Janice R; Ramel, Wiveka; Blechert, Jens; Edge, Michael D; Cooper, Jeff R; Goldin, Philippe R; Hariri, Ahmad R; Gross, James J

2011-01-01

Anticipatory emotional responses play a crucial role in preparing individuals for impending challenges. They do this by triggering a coordinated set of changes in behavioral, autonomic, and neural response systems. In the present study, we examined the biobehavioral impact of varying levels of anticipatory anxiety, using a shock anticipation task in which unpredictable electric shocks were threatened and delivered to the wrist at variable intervals and intensities (safe, medium, strong). This permitted investigation of a dynamic range of anticipatory anxiety responses. In two studies, 95 and 51 healthy female participants, respectively, underwent this shock anticipation task while providing continuous ratings of anxiety experience and electrodermal responding (Study 1) and during fMRI BOLD neuroimaging (Study 2). Results indicated a step-wise pattern of responding in anxiety experience and electrodermal responses. Several brain regions showed robust responses to shock anticipation relative to safe trials, including the hypothalamus, periaqueductal gray, caudate, precentral gyrus, thalamus, insula, ventrolateral PFC, dorsomedial PFC, and ACC. A subset of these regions demonstrated a linear pattern of increased responding from safe to medium to strong trials, including the bilateral insula, ACC, and inferior frontal gyrus. These responses were modulated by individual differences in neuroticism, such that those high in neuroticism showed exaggerated anxiety experience across the entire task, and reduced brain activation from medium to strong trials in a subset of brain regions. These findings suggest that individual differences in neuroticism may influence sensitivity to anticipatory threat and provide new insights into the mechanism through which neuroticism may confer risk for developing anxiety disorders via dysregulated anticipatory responses. PMID:21093595

Characterization of the key aroma compounds in pork soup stock by using an aroma extract dilution analysis.

PubMed

Takakura, Yukiko; Osanai, Hiroki; Masuzawa, Takuya; Wakabayashi, Hidehiko; Nishimura, Toshihide

2014-01-01

The aroma extract dilution analysis of an extract prepared from pork stock and subsequent experiments led to the identification of 15 aroma-active compounds in the flavor dilution factor range of 64-2048. Omission experiments to select the most aroma-active compounds from the 15 odor compounds suggested acetol, octanoic acid, δ-decalactone, and decanoic acid as the main active compounds contributing to the aroma of pork stock. Aroma recombination, addition, and omission experiments of these four aroma compounds in taste-reconstituted pork stock showed that each compound had an individual aroma profile. A comparison of the overall aroma between this recombined mixture and pork stock showed strong similarity, suggesting that the key aroma compounds had been successfully identified.

Low-cost nonlinear optics experiment for undergraduate instructional laboratory and lecture demonstration

NASA Astrophysics Data System (ADS)

Turchiello, Rozane de F.; Pereira, Luiz A. A.; Gómez, Sergio L.

2017-07-01

This paper presents a simple and affordable experiment on the thermal lens effect, suitable for an undergraduate educational laboratory or as a tabletop demonstration in a lecture on nonlinear optics. Such an experiment exploits the formation of a lens in an absorbing medium illuminated by a laser beam with a Gaussian intensity profile. As an absorber, we use a commercial soy sauce, which exhibits a strong thermal lensing effect. Additionally, we show how to measure the radius of a Gaussian beam using the knife-edge method, and how to estimate the focal length of the induced thermal lens.

Are awareness questionnaires valid? Investigating the use of posttest questionnaires for assessing awareness in implicit memory tests.

PubMed

Barnhardt, Terrence M; Geraci, Lisa

2008-01-01

Two experiments--one employing a perceptual implicit memory test and the other a conceptual implicit memory test--investigated the validity of posttest questionnaires for determining the incidence of awareness in implicit memory tests. In both experiments, a condition in which none of the studied words could be used as test responses (i.e., the none-studied condition) was compared with a standard implicit test condition. Results showed that reports of awareness on the posttest questionnaire were much less frequent in the none-studied condition than in the standard condition. This was especially true after deep processing at study. In both experiments, 83% of the participants in the none-studied condition stated they were unaware even though there were strong demands for claiming awareness. Although there was a small bias in the questionnaire (i.e., 17% of the participants in the none-studied condition stated they were aware), overall, there was strong support for the validity of awareness questionnaires.

Heat transfer from nanoparticles: A corresponding state analysis

PubMed Central

Merabia, Samy; Shenogin, Sergei; Joly, Laurent; Keblinski, Pawel; Barrat, Jean-Louis

2009-01-01

In this contribution, we study situations in which nanoparticles in a fluid are strongly heated, generating high heat fluxes. This situation is relevant to experiments in which a fluid is locally heated by using selective absorption of radiation by solid particles. We first study this situation for different types of molecular interactions, using models for gold particles suspended in octane and in water. As already reported in experiments, very high heat fluxes and temperature elevations (leading eventually to particle destruction) can be observed in such situations. We show that a very simple modeling based on Lennard–Jones (LJ) interactions captures the essential features of such experiments and that the results for various liquids can be mapped onto the LJ case, provided a physically justified (corresponding state) choice of parameters is made. Physically, the possibility of sustaining very high heat fluxes is related to the strong curvature of the interface that inhibits the formation of an insulating vapor film. PMID:19571000

Neural and behavioural responses to face-likeness of objects in adolescents with autism spectrum disorder.

PubMed

Akechi, Hironori; Kikuchi, Yukiko; Tojo, Yoshikuni; Osanai, Hiroo; Hasegawa, Toshikazu

2014-01-27

Numerous studies have revealed atypical face processing in autism spectrum disorders (ASD) characterized by social interaction and communication difficulties. This study investigated sensitivity to face-likeness in ASD. In Experiment 1, we found a strong positive correlation between the face-likeness ratings of non-face objects in the ASD (11-19 years old) and the typically developing (TD) group (9-21 years old). In Experiment 2 (the scalp-recorded event-related potential experiment), the participants of both groups (ASD, 12-19 years old; TD, 12-18 years old) exhibited an enhanced face-sensitive N170 amplitude to a face-like object. Whereas the TD adolescents showed an enhanced N170 during the face-likeness judgements, adolescents with ASD did not. Thus, both individuals with ASD and TD individuals have a perceptual and neural sensitivity to face-like features in objects. When required to process face-like features, a face-related brain system reacts more strongly in TD individuals but not in individuals with ASD.

Observations of energitic radiation bursts from thunder activities

NASA Astrophysics Data System (ADS)

Tsuchiya, H.; Enoto, T.; Torii, T.; Yuasa, T.; Yamada, S.; Kitacuhi, T.; Nakazawa, K.; Kato, H.; Okano, M.; Makishima, K.

2009-04-01

Energetic radiation bursts have been observed during strong thunderstorms by ground-based detectors as well as high-mountain ones. Those radiation bursts are thought to result from runaway electrons originating from electrons accelerated by strong electric field in lightning discharges and thunderclouds, and hence provide a valuable key to understand particle acceleration in thunder activity. Interestingly, they can be categorized into two bursts by their duration. One consists of short bursts lasting for milli-seconds or less. The other comprises long bursts having duration of a few seconds. In order to better understand both short and long bursts, we have conducted experiments at coastal area of the Japan Sea and a 2770-m altitude observatory. In this talk, we will report on those experiments, showing the two experiments has successfully observed both short and long bursts. Especially, we will focus on high-energy radiations extending over MeV energies, and then discuss a plausible model to explain how those high-energy radiations are produced in thunder activity.

Impact of Propene on Secondary Organic Aerosol Formation from m-Xylene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Chen; Na, Kwangsam; Warren, Bethany

2007-10-15

Propene is widely used in smog chamber experiments to increase the hydroxyl radical (OH) level based on the assumption that the formation of secondary organic aerosol (SOA) from parent hydrocarbon is unaffected. A series ofm-xylene/NOx photooxidation experiments were conducted in the presence of propene in the University of California CECERT atmospheric chamber facility. The experimental data are compared with previousm-xylene/NOx photooxidation work performed in the same chamber facility in the absence of propene (Song et al. Environ. Sci. Technol. 2005, 39, 3143-3149). The result shows that, for similar initial conditions, experiments with propene have lower reaction rates of m-xylene thanmore » those without propene, which indicates that propene reduces OH in the system. Furthermore, experiments with propene showed more than 15% reduction in SOA yield compared to experiments in the absence of propene. Additional experiments ofm-xylene/NOx with CO showed similar trends of suppressing OH and SOA formation. These results indicate that SOA from m-xylene/NOx photooxidation is strongly dependent on the OH level present, which provides evidence for the critical role of OH in SOA formation from aromatic hydrocarbons.« less

Strangeness production in deep inelastic muon nucleon scattering at 280 GeV

NASA Astrophysics Data System (ADS)

Arneodo, M.; Arvidson, A.; Aubert, J. J.; Badelek, B.; Beaufays, J.; Bee, C. P.; Benchouk, C.; Berghoff, G.; Bird, I.; Blum, D.; Böhm, E.; de Bouard, X.; Brasse, F. W.; Braun, H.; Broll, C.; Brown, S.; Brück, H.; Calen, H.; Chima, J. S.; Ciborowski, J.; Clifft, R.; Coignet, G.; Combley, F.; Coughlan, J.; D'Agostini, G.; Dahlgren, S.; Dengler, F.; Derado, I.; Dreyer, T.; Drees, J.; Düren, M.; Eckhardt, V.; Edwards, A.; Edwards, M.; Ernst, T.; Eszes, G.; Favier, J.; Ferrero, M. I.; Figiel, J.; Flauger, W.; Foster, J.; Gabathuler, E.; Gajewski, J.; Gamet, R.; Gayler, J.; Geddes, N.; Grafström, P.; Grard, F.; Haas, J.; Hagberg, E.; Hasert, F. J.; Hayman, P.; Heusse, P.; Jaffré, M.; Jacholkowska, A.; Janata, F.; Jancso, G.; Johnson, A. S.; Kabuss, E. M.; Kellner, G.; Korbel, V.; Krüger, J.; Kullander, S.; Landgraf, U.; Lanske, D.; Loken, J.; Long, K.; Maire, M.; Malecki, P.; Manz, A.; Maselli, S.; Mohr, W.; Montanet, F.; Montgomery, H. E.; Nagy, E.; Nassalski, J.; Norton, P. R.; Oakham, F. G.; Osborne, A. M.; Pascaud, C.; Pawlik, B.; Payre, P.; Peroni, C.; Peschel, H.; Pessard, H.; Pettingale, J.; Pietrzyk, B.; Pönsgen, B.; Pötsch, M.; Renton, P.; Ribarics, P.; Rith, K.; Rondio, E.; Sandacz, A.; Scheer, M.; Schlagböhmer, A.; Schiemann, H.; Schmifz, N.; Schneegans, M.; Scholz, M.; Schröder, T.; Schouten, M.; Schultze, K.; Sloan, T.; Stier, H. E.; Studt, M.; Taylor, G. N.; Thénard, J. M.; Thompson, J. C.; de La Torre, A.; Toth, J.; Urban, L.; Wallucks, W.; Whalley, M.; Wheeler, S.; Williams, W. S. C.; Wimpenny, S. J.; Windmolders, R.

1987-09-01

The production of strange particles has been studied in a 280 GeV muon nucleon scattering experiment with acceptance and particle identification over a large kinematical range. The data show that at large values of x Bj the interactions take place mostly on a u valence quark in agreement with the basic quarkparton model predictions. This feature results in a strong forward-backward asymmetry in the distribution of strangeness along the rapidity axis. The data are compatible with a strange to non-strange quark suppression factor of ≈0.3 and with a strong suppression of strange diquarks. The distributions of K + K - pairs show that the two kaons are preferentially produced at neighbouring values of rapidity.

Single-photon interference experiment for high schools

NASA Astrophysics Data System (ADS)

Bondani, Maria

2014-07-01

We follow the reductio ad absurdum reasoning described in the book "Sneaking a Look at God's Cards" by Giancarlo Ghirardi to demonstrate the wave-particle duality of light in a Mach-Zehnder interferometric setup analog to the conventional Young double-slit experiment. We aim at showing the double nature of light by measuring the existence of interference fringes down to the single-photon level. The setup includes a strongly attenuated laser, polarizing beam splitters, half-waveplates, polarizers and single-photon detectors.

Design of General-purpose Industrial signal acquisition system in a large scientific device

NASA Astrophysics Data System (ADS)

Ren, Bin; Yang, Lei

2018-02-01

In order to measure the industrial signal of a large scientific device experiment, a set of industrial data general-purpose acquisition system has been designed. It can collect 4~20mA current signal and 0~10V voltage signal. Through the practical experiments, it shows that the system is flexible, reliable, convenient and economical, and the system has characters of high definition and strong anti-interference ability. Thus, the system fully meets the design requirements..

Contextual cueing by global features

PubMed Central

Kunar, Melina A.; Flusberg, Stephen J.; Wolfe, Jeremy M.

2008-01-01

In visual search tasks, attention can be guided to a target item, appearing amidst distractors, on the basis of simple features (e.g. find the red letter among green). Chun and Jiang’s (1998) “contextual cueing” effect shows that RTs are also speeded if the spatial configuration of items in a scene is repeated over time. In these studies we ask if global properties of the scene can speed search (e.g. if the display is mostly red, then the target is at location X). In Experiment 1a, the overall background color of the display predicted the target location. Here the predictive color could appear 0, 400 or 800 msec in advance of the search array. Mean RTs are faster in predictive than in non-predictive conditions. However, there is little improvement in search slopes. The global color cue did not improve search efficiency. Experiments 1b-1f replicate this effect using different predictive properties (e.g. background orientation/texture, stimuli color etc.). The results show a strong RT effect of predictive background but (at best) only a weak improvement in search efficiency. A strong improvement in efficiency was found, however, when the informative background was presented 1500 msec prior to the onset of the search stimuli and when observers were given explicit instructions to use the cue (Experiment 2). PMID:17355043

Operator adaptation to changes in system reliability under adaptable automation.

PubMed

Chavaillaz, Alain; Sauer, Juergen

2017-09-01

This experiment examined how operators coped with a change in system reliability between training and testing. Forty participants were trained for 3 h on a complex process control simulation modelling six levels of automation (LOA). In training, participants either experienced a high- (100%) or low-reliability system (50%). The impact of training experience on operator behaviour was examined during a 2.5 h testing session, in which participants either experienced a high- (100%) or low-reliability system (60%). The results showed that most operators did not often switch between LOA. Most chose an LOA that relieved them of most tasks but maintained their decision authority. Training experience did not have a strong impact on the outcome measures (e.g. performance, complacency). Low system reliability led to decreased performance and self-confidence. Furthermore, complacency was observed under high system reliability. Overall, the findings suggest benefits of adaptable automation because it accommodates different operator preferences for LOA. Practitioner Summary: The present research shows that operators can adapt to changes in system reliability between training and testing sessions. Furthermore, it provides evidence that each operator has his/her preferred automation level. Since this preference varies strongly between operators, adaptable automation seems to be suitable to accommodate these large differences.

Quenched bond randomness: Superfluidity in porous media and the strong violation of universality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Falicov, A.; Berker, A.N.

1997-04-01

The effects of quenched bond randomness are most readily studied with superfluidity immersed in a porous medium. A lattice model for {sup 3}He-{sup 4}He mixtures and incomplete {sup 4}He fillings in aerogel yields the signature effect of bond randomness, namely the conversion of symmetry-breaking first-order phase transitions into second-order phase transitions, the A-line reaching zero temperature, and the elimination of non-symmetry-breaking first-order phase transitions. The model recognizes the importance of the connected nature of aerogel randomness and thereby yields superfluidity at very low {sup 4}He concentrations, a phase separation entirely within the superfluid phase, and the order-parameter contrast between mixturesmore » and incomplete fillings, all in agreement with experiments. The special properties of the helium mixture/aerogel system are distinctly linked to the aerogel properties of connectivity, randomness, and tenuousness, via the additional study of a regularized {open_quote}jungle-gym{close_quotes} aerogel. Renormalization-group calculations indicate that a strong violation of the empirical universality principle of critical phenomena occurs under quenched bond randomness. It is argued that helium/aerogel critical properties reflect this violation and further experiments are suggested. Renormalization-group analysis also shows that, adjoiningly to the strong universality violation (which hinges on the occurrence or non-occurrence of asymptotic strong coupling-strong randomness under resealing), there is a new {open_quotes}hyperuniversality{close_quotes} at phase transitions with asymptotic strong coupling-strong randomness behavior, for example assigning the same critical exponents to random-bond tricriticality and random-field criticality.« less

The role of digital tomosynthesis in reducing the number of equivocal breast reportings

NASA Astrophysics Data System (ADS)

Alakhras, Maram; Mello-Thoms, Claudia; Rickard, Mary; Bourne, Roger; Brennan, Patrick C.

2015-03-01

Purpose To compare radiologists' confidence in assessing breast cancer using combined digital mammography (DM) and digital breast tomosynthesis (DBT) compared with DM alone as a function of previous experience with DBT. Materials and Methods Institutional ethics approval was obtained. Twenty-three experienced breast radiologists reviewed 50 cases in two modes, DM alone and DM+DBT. Twenty-seven cases presented with breast cancer. Each radiologist was asked to detect breast lesions and give a confidence score of 1-5 (1- Normal, 2- Benign, 3- Equivocal, 4- Suspicious, 5- Malignant). Radiologists were divided into three sub-groups according to their prior experience with DBT (none, workshop experience, and clinical experience). Confidence scores using DM+DBT were compared with DM alone for all readers combined and for each DBT experience subgroup. Statistical analyses, using GraphPad Prism 5, were carried out using the Wilcoxon signed-rank test with statistical significance set at p< 0.05. Results Confidence scores were higher for true positive cancer cases using DM+DBT compared with DM alone for all readers (p < 0.0001). Confidence scores for normal cases were lower (indicating greater confidence in the non-cancer diagnosis) with DM+DBT compared with DM alone for all readers (p= 0.018) and readers with no prior DBT experience (p= 0.035). Conclusion Addition of DBT to DM increases the confidence level of radiologists in scoring cancer and normal/benign cases. This finding appears to apply across radiologists with varying levels of DBT experience, however further work involving greater numbers of radiologists is required.

Systematic and heuristic processing of majority and minority-endorsed messages: the effects of varying outcome relevance and levels of orientation on attitude and message processing.

PubMed

Martin, Robin; Hewstone, Miles; Martin, Pearl Y

2007-01-01

Two experiments investigated the conditions under which majority and minority sources instigate systematic processing of their messages. Both experiments crossed source status (majority vs. minority) with message quality (strong vs. weak arguments). In each experiment, message elaboration was manipulated by varying either motivational (outcome relevance, Experiment 1) or cognitive (orientating tasks, Experiment 2) factors. The results showed that when either motivational or cognitive factors encouraged low message elaboration, there was heuristic acceptance of the majority position without detailed message processing. When the level of message elaboration was intermediate, there was message processing only for the minority source. Finally, when message elaboration was high, there was message processing for both source conditions. These results show that majority and minority influence is sensitive to motivational and cognitive factors that constrain or enhance message elaboration and that both sources can lead to systematic processing under specific circumstances.

Abstract numerical discrimination learning in rats.

PubMed

Taniuchi, Tohru; Sugihara, Junko; Wakashima, Mariko; Kamijo, Makiko

2016-06-01

In this study, we examined rats' discrimination learning of the numerical ordering positions of objects. In Experiments 1 and 2, five out of seven rats successfully learned to respond to the third of six identical objects in a row and showed reliable transfer of this discrimination to novel stimuli after being trained with three different training stimuli. In Experiment 3, the three rats from Experiment 2 continued to be trained to respond to the third object in an object array, which included an odd object that needed to be excluded when identifying the target third object. All three rats acquired this selective-counting task of specific stimuli, and two rats showed reliable transfer of this selective-counting performance to test sets of novel stimuli. In Experiment 4, the three rats from Experiment 3 quickly learned to respond to the third stimulus in object rows consisting of either six identical or six different objects. These results offer strong evidence for abstract numerical discrimination learning in rats.

\\mathscr{H}_2 optimal control techniques for resistive wall mode feedback in tokamaks

NASA Astrophysics Data System (ADS)

Clement, Mitchell; Hanson, Jeremy; Bialek, Jim; Navratil, Gerald

2018-04-01

DIII-D experiments show that a new, advanced algorithm enables resistive wall mode (RWM) stability control in high performance discharges using external coils. DIII-D can excite strong, locked or nearly locked external kink modes whose rotation frequencies and growth rates are on the order of the magnetic flux diffusion time of the vacuum vessel wall. Experiments have shown that modern control techniques like linear quadratic Gaussian (LQG) control require less current than the proportional controller in use at DIII-D when using control coils external to DIII-D’s vacuum vessel. Experiments were conducted to develop control of a rotating n  =  1 perturbation using an LQG controller derived from VALEN and external coils. Feedback using this LQG algorithm outperformed a proportional gain only controller in these perturbation experiments over a range of frequencies. Results from high βN experiments also show that advanced feedback techniques using external control coils may be as effective as internal control coil feedback using classical control techniques.

Relationships between adverse childhood experiences and adult mental well-being: results from an English national household survey.

PubMed

Hughes, Karen; Lowey, Helen; Quigg, Zara; Bellis, Mark A

2016-03-03

Individuals' childhood experiences can strongly influence their future health and well-being. Adverse childhood experiences (ACEs) such as abuse and dysfunctional home environments show strong cumulative relationships with physical and mental illness yet less is known about their effects on mental well-being in the general population. A nationally representative household survey of English adults (n = 3,885) measuring current mental well-being (Short Edinburgh-Warwick Mental Well-being Scale SWEMWBS) and life satisfaction and retrospective exposure to nine ACEs. Almost half of participants (46.4 %) had suffered at least one ACE and 8.3 % had suffered four or more. Adjusted odds ratios (AORs) for low life satisfaction and low mental well-being increased with the number of ACEs. AORs for low ratings of all individual SWEMWBS components also increased with ACE count, particularly never or rarely feeling close to others. Of individual ACEs, growing up in a household affected by mental illness and suffering sexual abuse had the most relationships with markers of mental well-being. Childhood adversity has a strong cumulative relationship with adult mental well-being. Comprehensive mental health strategies should incorporate interventions to prevent ACEs and moderate their impacts from the very earliest stages of life.

Optical wave turbulence and the condensation of light

NASA Astrophysics Data System (ADS)

Bortolozzo, Umberto; Laurie, Jason; Nazarenko, Sergey; Residori, Stefania

2009-11-01

In an optical experiment, we report a wave turbulence regime that, starting with weakly nonlinear waves with randomized phases, shows an inverse cascade of photons towards the lowest wavenumbers. We show that the cascade is induced by a six-wave resonant interaction process and is characterized by increasing nonlinearity. At low wavenumbers the nonlinearity becomes strong and leads to modulational instability developing into solitons, whose number is decreasing further along the beam.

A novel rotating experimental platform in a superconducting magnet.

PubMed

Chen, Da; Cao, Hui-Ling; Ye, Ya-Jing; Dong, Chen; Liu, Yong-Ming; Shang, Peng; Yin, Da-Chuan

2016-08-01

This paper introduces a novel platform designed to be used in a strong static magnetic field (in a superconducting magnet). The platform is a sample holder that rotates in the strong magnetic field. Any samples placed in the platform will rotate due to the rotation of the sample holder. With this platform, a number of experiments such as material processing, culture of biological systems, chemical reactions, or other processes can be carried out. In this report, we present some preliminary experiments (protein crystallization, cell culture, and seed germination) conducted using this platform. The experimental results showed that the platform can affect the processes, indicating that it provides a novel environment that has not been investigated before and that the effects of such an environment on many different physical, chemical, or biological processes can be potentially useful for applications in many fields.

Quantum Fluctuations in Quasi-One-Dimensional Dipolar Bose-Einstein Condensates

NASA Astrophysics Data System (ADS)

Edler, D.; Mishra, C.; Wächtler, F.; Nath, R.; Sinha, S.; Santos, L.

2017-08-01

Recent experiments have revealed that beyond-mean-field corrections are much more relevant in weakly interacting dipolar condensates than in their nondipolar counterparts. We show that in quasi-one-dimensional geometries quantum corrections in dipolar and nondipolar condensates are strikingly different due to the peculiar momentum dependence of the dipolar interactions. The energy correction of the condensate presents not only a modified density dependence, but it may even change from attractive to repulsive at a critical density due to the surprising role played by the transversal directions. The anomalous quantum correction translates into a strongly modified physics for quantum-stabilized droplets and dipolar solitons. Moreover, and for similar reasons, quantum corrections of three-body correlations, and hence of three-body losses, are strongly modified by the dipolar interactions. This intriguing physics can be readily probed in current experiments with magnetic atoms.

First-Principles Investigation to Ionization of Argon Under Conditions Close to Typical Sonoluminescence Experiments

PubMed Central

Kang, Wei; Zhao, Shijun; Zhang, Shen; Zhang, Ping; Chen, Q. F.; He, Xian-Tu

2016-01-01

Mott effect, featured by a sharp increase of ionization, is one of the unique properties of partially ionized plasmas, and thus of great interest to astrophysics and inertial confinement fusion. Recent experiments of single bubble sonoluminescence (SBSL) revealed that strong ionization took place at a density two orders lower than usual theoretical expectation. We show from the perspective of electronic structures that the strong ionization is unlikely the result of Mott effect in a pure argon plasma. Instead, first-principles calculations suggest that other ion species from aqueous environments can energetically fit in the gap between the continuum and the top of occupied states of argon, making the Mott effect possible. These results would help to clarify the relationship between SBSL and Mott effect, and further to gain an better understanding of partially ionized plasmas. PMID:26853107

Quantum Fluctuations in Quasi-One-Dimensional Dipolar Bose-Einstein Condensates.

PubMed

Edler, D; Mishra, C; Wächtler, F; Nath, R; Sinha, S; Santos, L

2017-08-04

Recent experiments have revealed that beyond-mean-field corrections are much more relevant in weakly interacting dipolar condensates than in their nondipolar counterparts. We show that in quasi-one-dimensional geometries quantum corrections in dipolar and nondipolar condensates are strikingly different due to the peculiar momentum dependence of the dipolar interactions. The energy correction of the condensate presents not only a modified density dependence, but it may even change from attractive to repulsive at a critical density due to the surprising role played by the transversal directions. The anomalous quantum correction translates into a strongly modified physics for quantum-stabilized droplets and dipolar solitons. Moreover, and for similar reasons, quantum corrections of three-body correlations, and hence of three-body losses, are strongly modified by the dipolar interactions. This intriguing physics can be readily probed in current experiments with magnetic atoms.

Testing for reproductive interference in the population dynamics of two congeneric species of herbivorous mites.

PubMed

Sato, Y; Alba, J M; Sabelis, M W

2014-12-01

When phylogenetically close, two competing species may reproductively interfere, and thereby affect their population dynamics. We tested for reproductive interference (RI) between two congeneric haplo-diploid spider mites, Tetranychus evansi and Tetranychus urticae, by investigating their interspecific mating and their population dynamics when they competed on the same plants. They are both pests of tomato, but differ in the host plant defences that they suppress or induce. To reduce the effect of plant-mediated interaction, we used a mutant tomato plant lacking jasmonate-mediated anti-herbivore defences in the competition experiment. In addition, to manipulate the effect of RI, we introduced founder females already mated with conspecific males in mild RI treatments or founder, virgin females in strong RI treatments (in either case together with heterospecific and conspecific males). As females show first-male sperm precedence, RI should occur especially in the founder generation under strong RI treatments. We found that T. urticae outcompeted T. evansi in mild, but not in strong RI treatments. Thus, T. evansi interfered reproductively with T. urticae. This result was supported by crossing experiments showing frequent interspecific copulations, strong postmating reproductive isolation and a preference of T. evansi males to mate with T. urticae (instead of conspecific) females, whereas T. urticae males preferred conspecific females. We conclude that interspecific mating comes at a cost due to asymmetric mate preferences of males. Because RI by T. evansi can improve its competitiveness to T. urticae, we propose that RI partly explains why T. evansi became invasive in Europe where T. urticae is endemic.

Testing for reproductive interference in the population dynamics of two congeneric species of herbivorous mites

PubMed Central

Sato, Y; Alba, J M; Sabelis, M W

2014-01-01

When phylogenetically close, two competing species may reproductively interfere, and thereby affect their population dynamics. We tested for reproductive interference (RI) between two congeneric haplo-diploid spider mites, Tetranychus evansi and Tetranychus urticae, by investigating their interspecific mating and their population dynamics when they competed on the same plants. They are both pests of tomato, but differ in the host plant defences that they suppress or induce. To reduce the effect of plant-mediated interaction, we used a mutant tomato plant lacking jasmonate-mediated anti-herbivore defences in the competition experiment. In addition, to manipulate the effect of RI, we introduced founder females already mated with conspecific males in mild RI treatments or founder, virgin females in strong RI treatments (in either case together with heterospecific and conspecific males). As females show first-male sperm precedence, RI should occur especially in the founder generation under strong RI treatments. We found that T. urticae outcompeted T. evansi in mild, but not in strong RI treatments. Thus, T. evansi interfered reproductively with T. urticae. This result was supported by crossing experiments showing frequent interspecific copulations, strong postmating reproductive isolation and a preference of T. evansi males to mate with T. urticae (instead of conspecific) females, whereas T. urticae males preferred conspecific females. We conclude that interspecific mating comes at a cost due to asymmetric mate preferences of males. Because RI by T. evansi can improve its competitiveness to T. urticae, we propose that RI partly explains why T. evansi became invasive in Europe where T. urticae is endemic. PMID:24865602

Vanishing Point--or Meeting in the Middle? Student/Supervisor Transformation in a Self-Study Thesis

ERIC Educational Resources Information Center

Pratt, Dee; Peat, Beth

2014-01-01

This account explores the divergent perspectives of supervisor and student interacting in self-study research, showing how both participants were transformed by the experience. Although both supervisor and student had faced similar problems as mature students engaging in doctoral study, and both possessed strong convictions about their chosen…

Single mode CO2 laser frequency modulation up to 350 MHz

NASA Technical Reports Server (NTRS)

Leeb, W. R.; Peruso, C. J.

1977-01-01

Experiments on internal frequency modulation (FM) of a CO2 laser showed no limitation of FM by the linewidth. However, distortions in the form of strong enhancement of sideband amplitude arise for frequencies equal to the cavity resonant frequencies, most pronounced if the modulator is positioned near a cavity mirror.

Model-independent curvature determination with 21cm intensity mapping experiments

NASA Astrophysics Data System (ADS)

Witzemann, Amadeus; Bull, Philip; Clarkson, Chris; Santos, Mario G.; Spinelli, Marta; Weltman, Amanda

2018-04-01

Measurements of the spatial curvature of the Universe have improved significantly in recent years, but still tend to require strong assumptions to be made about the equation of state of dark energy (DE) in order to reach sub-percent precision. When these assumptions are relaxed, strong degeneracies arise that make it hard to disentangle DE and curvature, degrading the constraints. We show that forthcoming 21cm intensity mapping experiments such as HIRAX are ideally designed to carry out model-independent curvature measurements, as they can measure the clustering signal at high redshift with sufficient precision to break many of the degeneracies. We consider two different model-independent methods, based on `avoiding' the DE-dominated regime and non-parametric modelling of the DE equation of state respectively. Our forecasts show that HIRAX will be able to improve upon current model-independent constraints by around an order of magnitude, reaching percent-level accuracy even when an arbitrary DE equation of state is assumed. In the same model-independent analysis, the sample variance limit for a similar survey is another order of magnitude better.

Single macroscopic pillars as model system for bioinspired adhesives: influence of tip dimension, aspect ratio, and tilt angle.

PubMed

Micciché, Maurizio; Arzt, Eduard; Kroner, Elmar

2014-05-28

The goal of our study is to better understand the design parameters of bioinspired dry adhesives inspired by geckos. For this, we fabricated single macroscopic pillars of 400 μm diameter with different aspect ratios and different tip shapes (i.e., flat tips, spherical tips with different radii, and mushroom tips with different diameters). Tilt-angle-dependent adhesion measurements showed that although the tip shape of the pillars strongly influences the pull-off force, the pull-off strength is similar for flat and mushroom-shaped tips. We found no tilt-angle dependency of adhesion for spherical tip structures and, except for high tilt angle and low preload experiments, no tilt-angle effect for mushroom-tip pillars. For flat-tip pillars, we found a strong influence of tilt angle on adhesion, which decreased linearly with increasing aspect ratio. The experiments show that for the tested aspect ratios between 1 and 5, a linear decrease of tilt-angle dependency is found. The results of our studies will help to design bioinspired adhesives for application on smooth and rough surfaces.

Gaze Estimation Method Using Analysis of Electrooculogram Signals and Kinect Sensor

PubMed Central

Tanno, Koichi

2017-01-01

A gaze estimation system is one of the communication methods for severely disabled people who cannot perform gestures and speech. We previously developed an eye tracking method using a compact and light electrooculogram (EOG) signal, but its accuracy is not very high. In the present study, we conducted experiments to investigate the EOG component strongly correlated with the change of eye movements. The experiments in this study are of two types: experiments to see objects only by eye movements and experiments to see objects by face and eye movements. The experimental results show the possibility of an eye tracking method using EOG signals and a Kinect sensor. PMID:28912800

Contemplating the ultimate sacrifice: identity fusion channels pro-group affect, cognition, and moral decision making.

PubMed

Swann, William B; Gómez, Angel; Buhrmester, Michael D; López-Rodríguez, Lucía; Jiménez, Juan; Vázquez, Alexandra

2014-05-01

Although most people acknowledge the moral virtue in sacrificing oneself to save others, few actually endorse self-sacrifice. Seven experiments explored the cognitive and emotional mechanisms that underlie such endorsements. Participants responded to 1 of 2 moral dilemmas in which they could save 5 members of their country only by sacrificing themselves. Over 90% of participants acknowledged that the moral course of action was to sacrifice oneself to save others (Experiment 1), yet only those who were strongly fused with the group preferentially endorsed self-sacrifice (Experiments 2-7). The presence of a concern with saving group members rather than the absence of a concern with self-preservation motivated strongly fused participants to endorse sacrificing themselves for the group (Experiment 3). Analyses of think aloud protocols suggested that saving others was motivated by emotional engagement with the group among strongly fused participants but by utilitarian concerns among weakly fused participants (Experiment 4). Hurrying participants' responses increased self-sacrifice among strongly fused participants but decreased self-sacrifice among weakly fused participants (Experiment 5). Priming the personal self increased endorsement of self-sacrifice among strongly fused participants but further reduced endorsement of self-sacrifice among weakly fused participants (Experiment 6). Strongly fused participants ignored utilitarian considerations, but weakly fused persons endorsed self-sacrifice more when it would save more people (Experiment 7). Apparently, the emotional engagement with the group experienced by strongly fused persons overrides the desire for self-preservation and compels them to translate their moral beliefs into self-sacrificial behavior.

Mature Thunderstorm Cloud-Top Structure and Dynamics: A Three-Dimensional Numerical Simulation Study.

NASA Astrophysics Data System (ADS)

Schlesinger, Robert E.

1984-05-01

An anelastic three-dimensional model is used to investigate the effects of vertical wind shear regime on cloud-top structure and internal properties of mature isolated midlatitude thunderstorms. Four comparative experiments, designated A through D, are performed with varying shear profiles in otherwise identical initializations. Cases A-C assume strong shear, differing only in the veering of the low-level hodograph: moderate in A, strong in B and none in C. Weak shear, everywhere 40% as great as in C, is assumed in case D.The strong-shear cases A-C show moderately vigorous quasi-steady mature updrafts with strong midlevel mesovortex couplets, and marked anvil elongation along the net vertical shear vector. Differences are modest, especially at cloud top, though with low-level hodograph curvature the updraft is enhanced and skewed toward the cyclonic right flank. The weak-shear case D shows a weaker and less persistent mature updraft than A-C, along with weaker midlevel rotation and a much more newly circular anvil.In the strong-shear experiments, the cloud top considerably resembles geostationary satellite observations of tornadic storms (Negri, 1982), even though the model storm interiors lack the significant low-level mesocyclone and very strong concentrated updraft typical of observed tornadic storms. Both model and observations show a persistent cloud-top temperature pattern featuring a cold area slightly upshear of the cloud summit, with a warm area downshear in the absence of a local height minimum, though in the model the thermal couplet is smaller-scale with lower amplitude and lacks the well-developed `V' shape seen in the observations. The thermal couplet is also present with weak shear, but is only about half as strong, largely due to a much weaker cold area.Several dynamic features of the cloud-top thermal couplet are revealed by backward and forward parcel trajectory analyses for Case B: 1) The cold and warm areas at cloud top result from ascent and descent, respectively, of stratospheric air from upshear. 2) Only slightly below cloud top, shallow downward extensions of the warm and cold areas consist of air that originates from downshear in the lower troposphere, traverses' the updraft core and overshoots the tropopause. 3) Strong turbulent mixing between these contrasting airflow branches takes place astride the cloud top. 4) Parcels intercepting the cold region subside subsequently into the warm region. 5) The perturbation vertical pressure gradient force is an important factor in the trajectories.

Life adverse experiences in relation with obesity and binge eating disorder: A systematic review

PubMed Central

Palmisano, Giovanni Luca; Innamorati, Marco; Vanderlinden, Johan

2016-01-01

Background and aims Several studies report a positive association between adverse life experiences and adult obesity. Despite the high comorbidity between binge eating disorder (BED) and obesity, few authors have studied the link between trauma and BED. In this review the association between exposure to adverse life experiences and a risk for the development of obesity and BED in adulthood is explored. Methods Based on a scientific literature review in Medline, PubMed and PsycInfo databases, the results of 70 studies (N = 306,583 participants) were evaluated including 53 studies on relationship between adverse life experiences and obesity, 7 studies on post-traumatic stress disorder (PTSD) symptoms in relation to obesity, and 10 studies on the association between adverse life experiences and BED. In addition, mediating factors between the association of adverse life experiences, obesity and BED were examined. Results The majority of studies (87%) report that adverse life experiences are a risk factor for developing obesity and BED. More precisely a positive association between traumatic experiences and obesity and PTSD and obesity were found, respectively, in 85% and 86% of studies. Finally, the great majority of studies (90%) between trauma and the development of BED in adulthood strongly support this association. Meanwhile, different factors mediating between the trauma and obesity link were identified. Discussion and conclusions Although research data show a strong association between life adverse experiences and the development of obesity and BED, more research is needed to explain this association. PMID:28092189

Study on the PTC/NTC effect of carbon black-filled polymer composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Hao; Chen, Xinfang; Luo, Yunxia

1995-12-01

In this work, the effect of processing condition and radiation-crosslinking on the electrical and dynamic behaviors of carbon black filled low density polyethylene (LDPE) composites were investigated. Compared with the solution counterpart, the mechanical composites have a strong PTC effect and a great dynamic elastic mold, which results from the strong interaction between carbon black and LDPE. The experiment result shows that the NTC effect is caused by the decrease of elastic mold of LDPE at high temperature, and it can be declined significantly by radiation-crosslinking. We conclude that the strong interaction between polymer and carbon black is essentially importantmore » for composites to have a great PTC intensity good electrical reproducibility and high dynamic elastic sold.« less

You see what you have learned. Evidence for an interrelation of associative learning and visual selective attention.

PubMed

Feldmann-Wüstefeld, Tobias; Uengoer, Metin; Schubö, Anna

2015-11-01

Besides visual salience and observers' current intention, prior learning experience may influence deployment of visual attention. Associative learning models postulate that observers pay more attention to stimuli previously experienced as reliable predictors of specific outcomes. To investigate the impact of learning experience on deployment of attention, we combined an associative learning task with a visual search task and measured event-related potentials of the EEG as neural markers of attention deployment. In the learning task, participants categorized stimuli varying in color/shape with only one dimension being predictive of category membership. In the search task, participants searched a shape target while disregarding irrelevant color distractors. Behavioral results showed that color distractors impaired performance to a greater degree when color rather than shape was predictive in the learning task. Neurophysiological results show that the amplified distraction was due to differential attention deployment (N2pc). Experiment 2 showed that when color was predictive for learning, color distractors captured more attention in the search task (ND component) and more suppression of color distractor was required (PD component). The present results thus demonstrate that priority in visual attention is biased toward predictive stimuli, which allows learning experience to shape selection. We also show that learning experience can overrule strong top-down control (blocked tasks, Experiment 3) and that learning experience has a longer-term effect on attention deployment (tasks on two successive days, Experiment 4). © 2015 Society for Psychophysiological Research.

An experimental test of a fundamental food web motif.

PubMed

Rip, Jason M K; McCann, Kevin S; Lynn, Denis H; Fawcett, Sonia

2010-06-07

Large-scale changes to the world's ecosystem are resulting in the deterioration of biostructure-the complex web of species interactions that make up ecological communities. A difficult, yet crucial task is to identify food web structures, or food web motifs, that are the building blocks of this baroque network of interactions. Once identified, these food web motifs can then be examined through experiments and theory to provide mechanistic explanations for how structure governs ecosystem stability. Here, we synthesize recent ecological research to show that generalist consumers coupling resources with different interaction strengths, is one such motif. This motif amazingly occurs across an enormous range of spatial scales, and so acts to distribute coupled weak and strong interactions throughout food webs. We then perform an experiment that illustrates the importance of this motif to ecological stability. We find that weak interactions coupled to strong interactions by generalist consumers dampen strong interaction strengths and increase community stability. This study takes a critical step by isolating a common food web motif and through clear, experimental manipulation, identifies the fundamental stabilizing consequences of this structure for ecological communities.

Positive affect, meaning in life, and future time perspective: an application of socioemotional selectivity theory.

PubMed

Hicks, Joshua A; Trent, Jason; Davis, William E; King, Laura A

2012-03-01

Four studies tested the prediction that positive affect (PA) would relate more strongly to meaning in life (MIL) as a function of perceived time limitations. In Study 1 (N = 360), adults completed measures of PA and MIL. As predicted, PA related more strongly to MIL for older, compared to younger, participants. In Studies 2 and 3, adults (N = 514) indicated their current position in their life span, and rated their MIL. PA, whether naturally occurring (Study 2) or induced (Study 3), was a stronger predictor of MIL for individuals who perceived themselves as having a limited amount of time left to live. Finally, in Study 4 (N = 98) students completed a measure of PA, MIL, and future time perspective (FTP). Results showed that PA was more strongly linked to MIL for those who believed they had fewer opportunities left to pursue their goals. Overall, these findings suggest that the experience of PA becomes increasingly associated with the experience of MIL as the perception of future time becomes limited. The contribution of age related processes to judgments of well-being are discussed.

Quantum tomography enhanced through parametric amplification

NASA Astrophysics Data System (ADS)

Knyazev, E.; Spasibko, K. Yu; Chekhova, M. V.; Khalili, F. Ya

2018-01-01

Quantum tomography is the standard method of reconstructing the Wigner function of quantum states of light by means of balanced homodyne detection. The reconstruction quality strongly depends on the photodetectors quantum efficiency and other losses in the measurement setup. In this article we analyze in detail a protocol of enhanced quantum tomography, proposed by Leonhardt and Paul [1] which allows one to reduce the degrading effect of detection losses. It is based on phase-sensitive parametric amplification, with the phase of the amplified quadrature being scanned synchronously with the local oscillator phase. Although with sufficiently strong amplification the protocol enables overcoming any detection inefficiency, it was so far not implemented in the experiment, probably due to the losses in the amplifier. Here we discuss a possible proof-of-principle experiment with a traveling-wave parametric amplifier. We show that with the state-of-the-art optical elements, the protocol enables high fidelity tomographic reconstruction of bright non-classical states of light. We consider two examples: bright squeezed vacuum and squeezed single-photon state, with the latter being a non-Gaussian state and both strongly affected by the losses.

The role of minerals in the thermal alteration of organic matter. III - Generation of bitumen in laboratory experiments

NASA Technical Reports Server (NTRS)

Huizinga, Bradley J.; Tannenbaum, Eli; Kaplan, I. R.

1987-01-01

A series of pyrolysis experiments, utilizing two different immature kerogens (from the Monterey and Green River Formations) mixed with common sedimentary minerals (calcite, illite, or Na-montmorillonite), was conducted to study the impact of the mineral matrix on the bitumen that was generated. Calcite has no significant influence on the thermal evolution of bitumen and also shows virtually no adsorption capacity for any of the pyrolysate. In contrast, montmorillonite (M) and illite, to a lesser extent, alter bitumen during dry pyrolysis. M and illite also display strong adsorption capacities for the polar constituents of bitumen. By this process, hydrocarbons are substantially concentrated within the pyrolysate that is not strongly adsorbed on the clay matrices. The effects of the clay minerals are significantly reduced during hydrous pyrolysis. The strong adsorption capacities of M and illite, as well as their thermocatalytic properties, may in part explain why light oils and gases are generated from certain argillaceous source-rock assemblages, whereas heavy immature oils are often derived from carbonate source rocks.

Detailed Investigation of Self-Similarity of Strong Shock Reflection Phenomena

NASA Astrophysics Data System (ADS)

Kobayashi, Susumu; Adachi, Takashi

2012-04-01

This paper experimentally investigates the validity of self-similarity of strong shock reflection phenomena in a shock tube. The models used for the shock-tube experiment are ordinary wedges with various reflecting wedge angles. The triple-point trajectory is approximately a straight line through the wedge apex for each reflecting wedge. However, a detailed measurement of the angle made by the incident and reflected shocks shows that the wave angle varies as the incident shock proceeds. This means that the shock reflection configuration deviates from self-similarity. The most remarkable phenomenon is the dynamic transition from regular to Mach reflection during shock propagation, where the validity of self-similarity breaks down. The flow-field behind the Mach stem is subsonic with respect to the triple point, so the condition on the solid boundary can catch up with the triple point and affect the flow around it. We also explain why the discrepancy between theory and experiment has gone unnoticed for strong shock waves and demonstrate that it is due to the transport properties of the fluid, such as the viscosity.

Isolation and Characterization of Actinomycete Antagonists of a Fungal Root Pathogen †

PubMed Central

Crawford, Don L.; Lynch, James M.; Whipps, John M.; Ousley, Margaret A.

1993-01-01

By use of selective media, 267 actinomycete strains were isolated from four rhizosphere-associated and four non-rhizosphere-associated British soils. Organic media with low nutrient concentrations were found to be best for isolating diverse actinomycetes while avoiding contamination and overgrowth of isolation media by eubacteria and fungi. While all isolates grew well at pHs 6.5 to 8.0, a few were unable to grow at pH 6.0 and a significant number failed to grow at pH 5.5. Eighty-two selected isolates were screened for in vitro antagonism towards Pythium ultimum by use of a Difco cornmeal agar assay procedure. Five isolates were very strong antagonists of the fungus, four were strong antagonists, and ten others were weakly antagonistic. The remaining isolates showed no antagonism by this assay. Additional studies showed that several of the P. ultimum antagonists also strongly inhibited growth of other root-pathogenic fungi. Twelve isolates showing antifungal activity in the in vitro assay were also tested for their effects on the germination and short-term growth of lettuce plants in glasshouse pot studies in the absence of pathogens. None of the actinomycetes prevented seed germination, although half of the isolates retarded seed germination and outgrowth of the plants by 1 to 3 days. During 18-day growth experiments, biomass yields of some actinomycete-inoculated plants were reduced in comparison with untreated control plants, although all plants appeared healthy and well rooted. None of the actinomycetes significantly enhanced plant growth over these short-term experiments. For some, but not all, actinomycetes, some correlations between delayed seed germination and reduced 18-day plant biomass yields were seen. For others, plant biomass yields were not reduced despite an actinomycete-associated delay in seed germination and plant outgrowth. Preliminary glasshouse experiments indicated that some of the actinomycetes protect germinating lettuce seeds against damping-off caused by P. ultimum. PMID:16349093

Isolation and characterization of actinomycete antagonists of a fungal root pathogen.

PubMed

Crawford, D L; Lynch, J M; Whipps, J M; Ousley, M A

1993-11-01

By use of selective media, 267 actinomycete strains were isolated from four rhizosphere-associated and four non-rhizosphere-associated British soils. Organic media with low nutrient concentrations were found to be best for isolating diverse actinomycetes while avoiding contamination and overgrowth of isolation media by eubacteria and fungi. While all isolates grew well at pHs 6.5 to 8.0, a few were unable to grow at pH 6.0 and a significant number failed to grow at pH 5.5. Eighty-two selected isolates were screened for in vitro antagonism towards Pythium ultimum by use of a Difco cornmeal agar assay procedure. Five isolates were very strong antagonists of the fungus, four were strong antagonists, and ten others were weakly antagonistic. The remaining isolates showed no antagonism by this assay. Additional studies showed that several of the P. ultimum antagonists also strongly inhibited growth of other root-pathogenic fungi. Twelve isolates showing antifungal activity in the in vitro assay were also tested for their effects on the germination and short-term growth of lettuce plants in glasshouse pot studies in the absence of pathogens. None of the actinomycetes prevented seed germination, although half of the isolates retarded seed germination and outgrowth of the plants by 1 to 3 days. During 18-day growth experiments, biomass yields of some actinomycete-inoculated plants were reduced in comparison with untreated control plants, although all plants appeared healthy and well rooted. None of the actinomycetes significantly enhanced plant growth over these short-term experiments. For some, but not all, actinomycetes, some correlations between delayed seed germination and reduced 18-day plant biomass yields were seen. For others, plant biomass yields were not reduced despite an actinomycete-associated delay in seed germination and plant outgrowth. Preliminary glasshouse experiments indicated that some of the actinomycetes protect germinating lettuce seeds against damping-off caused by P. ultimum.

Predicting transport regime and local electrostatic environment from Coulomb blockade diamond sizes

NASA Astrophysics Data System (ADS)

Olsen, Stine T.; Hansen, Thorsten; Mikkelsen, Kurt V.

2017-03-01

Electron transport through a molecule is often described in one of the two regimes: the coherent tunnelling regime or the Coulomb blockade regime. The twilight zone of the two regimes still possesses many unsolved questions. A theoretical analysis of the oligophenylenevinylene OPV3 experiments by Bjørnholm and co-workers is performed. The experiments showed how two OPV3 derivatives performed very differently despite the strong similarity of the molecular structure, hence the experimental data showed two different transport mechanisms. The different transport mechanisms of the two OPV3 derivatives are explained from quantum mechanical calculations of the molecular redox energies and from the experimentally accessible window size.

Experimental violation of multipartite Bell inequalities with trapped ions.

PubMed

Lanyon, B P; Zwerger, M; Jurcevic, P; Hempel, C; Dür, W; Briegel, H J; Blatt, R; Roos, C F

2014-03-14

We report on the experimental violation of multipartite Bell inequalities by entangled states of trapped ions. First, we consider resource states for measurement-based quantum computation of between 3 and 7 ions and show that all strongly violate a Bell-type inequality for graph states, where the criterion for violation is a sufficiently high fidelity. Second, we analyze Greenberger-Horne-Zeilinger states of up to 14 ions generated in a previous experiment using stronger Mermin-Klyshko inequalities, and show that in this case the violation of local realism increases exponentially with system size. These experiments represent a violation of multipartite Bell-type inequalities of deterministically prepared entangled states. In addition, the detection loophole is closed.

Comparative study on sample stacking by moving reaction boundary formed with weak acid and weak or strong base in capillary electrophoresis: II. Experiments.

PubMed

Zhang, Wei; Fan, Liuyin; Shao, Jing; Li, Si; Li, Shan; Cao, Chengxi

2011-04-15

To demonstrate the theoretic method on the stacking of zwitterion with moving reaction boundary (MRB) in the accompanying paper, the relevant experiments were performed. The experimental results quantitatively show that (1) MRB velocity, including the comparisons between MRB and zwitterionic velocities, possesses key importance to the design of MRB stacking; (2) a much long front alkaline plug without sample should be injected before the sample injection for a complete stacking of zwitterion if sample buffer is prepared with strong base, conversely no such plug is needed if using a weak base as the sample buffer with proper concentration and pH value; (3) the presence of salt in MRB system holds dramatic effect on the MRB stacking if sample solution is a strong base, but has no effect if a weak alkali is used as sample solution; (4) all of the experiments of this paper, including the previous work, quantitatively manifest the theory and predictions shown in the accompanying paper. In addition, the so-called derivative MRB-induced re-stacking and transient FASI-induced re-stacking were also observed during the experiments, and the relevant mechanisms were briefly demonstrated with the results. The theory and its calculation procedures developed in the accompanying paper can be well used for the predictions to the MRB stacking of zwitterion in CE. Copyright © 2011 Elsevier B.V. All rights reserved.

Effect of Fuel Composition on Particulate Matter Emissions from a Gasoline Direct Injection Engine

NASA Astrophysics Data System (ADS)

Smallwood, Bryden Alexander

The effects of fuel composition on reducing PM emissions were investigated using a Ford Focus wall-guided gasoline direct injection engine (GDI). Initial results with a 65% isooctane and 35% toluene blend showed significant reductions in PM emissions. Further experiments determined that this decrease was due to a lack of light-end components in that fuel blend. Tests with pentane content lower than 15% were found to have PN concentrations 96% lower than tests with 20% pentane content. This indicates that there is a shift in mode of soot production. Pentane significantly increases the vapour pressure of the fuel blend, potentially resulting in surface boiling, less homogeneous mixtures, or decreased fuel rebound from the piston. PM mass measurements and PN Index values both showed strong correlations with the PN concentration emissions. In the gaseous exhaust, THC, pentane, and 1,3 butadiene showed strong correlations with the PM emissions.

Free recall in Williams syndrome: is there a dissociation between short- and long-term memory?

PubMed

Brock, Jon; Brown, Gordon D A; Boucher, Jill

2006-04-01

Two experiments used the free recall paradigm to investigate verbal memory abilities in Williams syndrome (WS)--a rare genetic disorder. In an earlier free recall study, Vicari et al. (1996a) reported that, unlike TD controls, children with WS showed a recency effect but failed to show a primacy effect. These authors interpreted their findings as evidence for a dissociation between relatively strong verbal short-term memory and relatively impaired verbal long-term memory. In Experiment 1 of the current study, children with WS and TD controls showed comparable improvements in performance with repeated testing of the same material, indicating similar long-term learning of the test items. Neither group showed evidence of primacy effects. However, the extent of primacy effects in free recall is known to depend on the rehearsal strategy that participants adopt. In Experiment 2, therefore, participants were encouraged to engage in overt cumulative rehearsal. This manipulation resulted in significant and comparable primacy effects in both groups, although neither group demonstrated a significant change in overall performance. There was therefore no evidence from either experiment for a dissociation between short- and long-term verbal memory in WS.

Intermittency and emergence of coherent structures in wave turbulence of a vibrating plate.

PubMed

Mordant, Nicolas; Miquel, Benjamin

2017-10-01

We report numerical investigations of wave turbulence in a vibrating plate. The possibility to implement advanced measurement techniques and long-time numerical simulations makes this system extremely valuable for wave turbulence studies. The purely 2D character of dynamics of the elastic plate makes it much simpler to handle compared to much more complex 3D physical systems that are typical of geo- and astrophysical issues (ocean surface or internal waves, magnetized plasmas or strongly rotating and/or stratified flows). When the forcing is small the observed wave turbulence is consistent with the predictions of the weak turbulent theory. Here we focus on the case of stronger forcing for which coherent structures can be observed. These structures look similar to the folds and D-cones that are commonly observed for strongly deformed static thin elastic sheets (crumpled paper) except that they evolve dynamically in our forced system. We describe their evolution and show that their emergence is associated with statistical intermittency (lack of self similarity) of strongly nonlinear wave turbulence. This behavior is reminiscent of intermittency in Navier-Stokes turbulence. Experimental data show hints of the weak to strong turbulence transition. However, due to technical limitations and dissipation, the strong nonlinear regime remains out of reach of experiments and therefore has been explored numerically.

Intermittency and emergence of coherent structures in wave turbulence of a vibrating plate

NASA Astrophysics Data System (ADS)

Mordant, Nicolas; Miquel, Benjamin

2017-10-01

We report numerical investigations of wave turbulence in a vibrating plate. The possibility to implement advanced measurement techniques and long-time numerical simulations makes this system extremely valuable for wave turbulence studies. The purely 2D character of dynamics of the elastic plate makes it much simpler to handle compared to much more complex 3D physical systems that are typical of geo- and astrophysical issues (ocean surface or internal waves, magnetized plasmas or strongly rotating and/or stratified flows). When the forcing is small the observed wave turbulence is consistent with the predictions of the weak turbulent theory. Here we focus on the case of stronger forcing for which coherent structures can be observed. These structures look similar to the folds and D-cones that are commonly observed for strongly deformed static thin elastic sheets (crumpled paper) except that they evolve dynamically in our forced system. We describe their evolution and show that their emergence is associated with statistical intermittency (lack of self similarity) of strongly nonlinear wave turbulence. This behavior is reminiscent of intermittency in Navier-Stokes turbulence. Experimental data show hints of the weak to strong turbulence transition. However, due to technical limitations and dissipation, the strong nonlinear regime remains out of reach of experiments and therefore has been explored numerically.

Experiential, autonomic, and neural responses during threat anticipation vary as a function of threat intensity and neuroticism.

PubMed

Drabant, Emily M; Kuo, Janice R; Ramel, Wiveka; Blechert, Jens; Edge, Michael D; Cooper, Jeff R; Goldin, Philippe R; Hariri, Ahmad R; Gross, James J

2011-03-01

Anticipatory emotional responses play a crucial role in preparing individuals for impending challenges. They do this by triggering a coordinated set of changes in behavioral, autonomic, and neural response systems. In the present study, we examined the biobehavioral impact of varying levels of anticipatory anxiety, using a shock anticipation task in which unpredictable electric shocks were threatened and delivered to the wrist at variable intervals and intensities (safe, medium, strong). This permitted investigation of a dynamic range of anticipatory anxiety responses. In two studies, 95 and 51 healthy female participants, respectively, underwent this shock anticipation task while providing continuous ratings of anxiety experience and electrodermal responding (Study 1) and during fMRI BOLD neuroimaging (Study 2). Results indicated a step-wise pattern of responding in anxiety experience and electrodermal responses. Several brain regions showed robust responses to shock anticipation relative to safe trials, including the hypothalamus, periaqueductal gray, caudate, precentral gyrus, thalamus, insula, ventrolateral PFC, dorsomedial PFC, and ACC. A subset of these regions demonstrated a linear pattern of increased responding from safe to medium to strong trials, including the bilateral insula, ACC, and inferior frontal gyrus. These responses were modulated by individual differences in neuroticism, such that those high in neuroticism showed exaggerated anxiety experience across the entire task, and reduced brain activation from medium to strong trials in a subset of brain regions. These findings suggest that individual differences in neuroticism may influence sensitivity to anticipatory threat and provide new insights into the mechanism through which neuroticism may confer risk for developing anxiety disorders via dysregulated anticipatory responses. Copyright © 2010 Elsevier Inc. All rights reserved.

When sexual threat cues shape attitudes toward immigrants: the role of insecurity and benevolent sexism

PubMed Central

Sarrasin, Oriane; Fasel, Nicole; Green, Eva G. T.; Helbling, Marc

2015-01-01

Drawing on psychological and political science research on individuals’ sensitivity to threat cues, the present study examines reactions to political posters that depict male immigrants as a sexual danger. We expect anti-immigrant attitudes to be more strongly predicted by feelings of insecurity or representations of men and women as strong and fragile when individuals are exposed to sexual threat cues than when they are not. Results from two online experiments conducted in Switzerland and Germany largely confirmed these assumptions. Comparing two anti-immigrant posters (general and non-sexual threat vs. sexual threat), Experiment 1 (n = 142) showed that feelings of insecurity were related to an increased support for expelling immigrants from the host country in both cases. However, only in the sexual threat cues condition and among female participants, were perceptions of women as fragile—as measured with benevolent sexism items—related to support for expelling immigrants. Further distinguishing between different forms of violence threat cues, Experiment 2 (n = 181) showed that collective feelings of insecurity were most strongly related to support for expelling immigrants when a male immigrant was presented as a violent criminal. In contrast, benevolent sexist beliefs were related to anti-immigrant stances only when participants were exposed to a depiction of a male immigrant as a rapist. In both cases attitudes were polarized: on the one hand, representations of immigrants as criminals provoked reactance reactions—that is, more positive attitudes—among participants scoring low in insecurity feelings or benevolent sexism. On the other hand, those scoring high in these dimensions expressed slightly more negative attitudes. Overall, by applying social psychological concepts to the study of anti-immigrant political campaigning, the present study demonstrated that individuals are sensitive to specific threat cues in posters. PMID:26283985

When sexual threat cues shape attitudes toward immigrants: the role of insecurity and benevolent sexism.

PubMed

Sarrasin, Oriane; Fasel, Nicole; Green, Eva G T; Helbling, Marc

2015-01-01

Drawing on psychological and political science research on individuals' sensitivity to threat cues, the present study examines reactions to political posters that depict male immigrants as a sexual danger. We expect anti-immigrant attitudes to be more strongly predicted by feelings of insecurity or representations of men and women as strong and fragile when individuals are exposed to sexual threat cues than when they are not. Results from two online experiments conducted in Switzerland and Germany largely confirmed these assumptions. Comparing two anti-immigrant posters (general and non-sexual threat vs. sexual threat), Experiment 1 (n = 142) showed that feelings of insecurity were related to an increased support for expelling immigrants from the host country in both cases. However, only in the sexual threat cues condition and among female participants, were perceptions of women as fragile-as measured with benevolent sexism items-related to support for expelling immigrants. Further distinguishing between different forms of violence threat cues, Experiment 2 (n = 181) showed that collective feelings of insecurity were most strongly related to support for expelling immigrants when a male immigrant was presented as a violent criminal. In contrast, benevolent sexist beliefs were related to anti-immigrant stances only when participants were exposed to a depiction of a male immigrant as a rapist. In both cases attitudes were polarized: on the one hand, representations of immigrants as criminals provoked reactance reactions-that is, more positive attitudes-among participants scoring low in insecurity feelings or benevolent sexism. On the other hand, those scoring high in these dimensions expressed slightly more negative attitudes. Overall, by applying social psychological concepts to the study of anti-immigrant political campaigning, the present study demonstrated that individuals are sensitive to specific threat cues in posters.

[Morphofunctional and molecular bases of pineal gland aging].

PubMed

Khavinson, V Kh; Lin'kova, N S

2012-01-01

The review analyzed morphology, molecular and functional aspects of pineal gland aging and methods of it correction. The pineal gland is central organ, which regulates activity of neuroimmunoendocrine, antioxidant and other organisms systems. Functional activity of pineal gland is discreased at aging, which is the reason of melatonin level changing. The molecular and morphology research demonstrated, that pineal gland hadn't strongly pronounced atrophy at aging. Long-term experience showed, that peptides extract of pineal gland epithalamin and synthetic tetrapeptide on it base epithalon restored melatonin secretion in pineal gland and had strong regulatory activity at neuroimmunoendocrine and antioxidant organism systems.

Software for MR image overlay guided needle insertions: the clinical translation process

NASA Astrophysics Data System (ADS)

Ungi, Tamas; U-Thainual, Paweena; Fritz, Jan; Iordachita, Iulian I.; Flammang, Aaron J.; Carrino, John A.; Fichtinger, Gabor

2013-03-01

PURPOSE: Needle guidance software using augmented reality image overlay was translated from the experimental phase to support preclinical and clinical studies. Major functional and structural changes were needed to meet clinical requirements. We present the process applied to fulfill these requirements, and selected features that may be applied in the translational phase of other image-guided surgical navigation systems. METHODS: We used an agile software development process for rapid adaptation to unforeseen clinical requests. The process is based on iterations of operating room test sessions, feedback discussions, and software development sprints. The open-source application framework of 3D Slicer and the NA-MIC kit provided sufficient flexibility and stable software foundations for this work. RESULTS: All requirements were addressed in a process with 19 operating room test iterations. Most features developed in this phase were related to workflow simplification and operator feedback. CONCLUSION: Efficient and affordable modifications were facilitated by an open source application framework and frequent clinical feedback sessions. Results of cadaver experiments show that software requirements were successfully solved after a limited number of operating room tests.

The Lived Experience and Training Needs of Librarians Serving at the Clinical Point-of-Care

PubMed Central

Kuntz, Gretchen M.; Edwards, Mary E.; Butson, Linda C.; Auten, Beth

2016-01-01

This study examines the emotional experiences and perceptions of librarians embedded into clinical care teams and how those perceptions affect their training and preparation needs. Qualitative research methodologies were applied to textual data drawn from focus groups (n=21), interviews (n=2), and an online survey (n=167), supplemented by quantitative survey data. Phenomenological results show librarians experience strongly effective responses to clinical rounding. Important factors include personal confidence; relationships with team members, patients, and families; and the stressful environment. Analysis of librarians’ perceived educational needs indicates that training must address specialized subjects including medical knowledge, clinical culture, and institutional politics. PMID:26211792

The Lived Experience and Training Needs of Librarians Serving at the Clinical Point-of-Care.

PubMed

Lyon, Jennifer A; Kuntz, Gretchen M; Edwards, Mary E; Butson, Linda C; Auten, Beth

2015-01-01

This study examines the emotional experiences and perceptions of librarians embedded into clinical care teams and how those perceptions affect their training and preparation needs. Qualitative research methodologies were applied to textual data drawn from focus groups (n = 21), interviews (n = 2), and an online survey (n = 167), supplemented by quantitative survey data. Phenomenological results show librarians experience strongly affective responses to clinical rounding. Important factors include personal confidence; relationships with team members, patients, and families; and the stressful environment. Analysis of librarians' perceived educational needs indicates that training must address specialized subjects including medical knowledge, clinical culture, and institutional politics.

Global gyrokinetic simulations of intrinsic rotation in ASDEX Upgrade Ohmic L-mode plasmas

NASA Astrophysics Data System (ADS)

Hornsby, W. A.; Angioni, C.; Lu, Z. X.; Fable, E.; Erofeev, I.; McDermott, R.; Medvedeva, A.; Lebschy, A.; Peeters, A. G.; The ASDEX Upgrade Team

2018-05-01

Non-linear, radially global, turbulence simulations of ASDEX Upgrade (AUG) plasmas are performed and the nonlinear generated intrinsic flow shows agreement with the intrinsic flow gradients measured in the core of Ohmic L-mode plasmas at nominal parameters. Simulations utilising the kinetic electron model show hollow intrinsic flow profiles as seen in a predominant number of experiments performed at similar plasma parameters. In addition, significantly larger flow gradients are seen than in a previous flux-tube analysis (Hornsby et al 2017 Nucl. Fusion 57 046008). Adiabatic electron model simulations can show a flow profile with opposing sign in the gradient with respect to a kinetic electron simulation, implying a reversal in the sign of the residual stress due to kinetic electrons. The shaping of the intrinsic flow is strongly determined by the density gradient profile. The sensitivity of the residual stress to variations in density profile curvature is calculated and seen to be significantly stronger than to neoclassical flows (Hornsby et al 2017 Nucl. Fusion 57 046008). This variation is strong enough on its own to explain the large variations in the intrinsic flow gradients seen in some AUG experiments. Analysis of the symmetry breaking properties of the turbulence shows that profile shearing is the dominant mechanism in producing a finite parallel wave-number, with turbulence gradient effects contributing a smaller portion of the parallel wave-vector.

How to Make Data a Blessing to Parametric Uncertainty Quantification and Reduction?

NASA Astrophysics Data System (ADS)

Ye, M.; Shi, X.; Curtis, G. P.; Kohler, M.; Wu, J.

2013-12-01

In a Bayesian point of view, probability of model parameters and predictions are conditioned on data used for parameter inference and prediction analysis. It is critical to use appropriate data for quantifying parametric uncertainty and its propagation to model predictions. However, data are always limited and imperfect. When a dataset cannot properly constrain model parameters, it may lead to inaccurate uncertainty quantification. While in this case data appears to be a curse to uncertainty quantification, a comprehensive modeling analysis may help understand the cause and characteristics of parametric uncertainty and thus turns data into a blessing. In this study, we illustrate impacts of data on uncertainty quantification and reduction using an example of surface complexation model (SCM) developed to simulate uranyl (U(VI)) adsorption. The model includes two adsorption sites, referred to as strong and weak sites. The amount of uranium adsorption on these sites determines both the mean arrival time and the long tail of the breakthrough curves. There is one reaction on the weak site but two reactions on the strong site. The unknown parameters include fractions of the total surface site density of the two sites and surface complex formation constants of the three reactions. A total of seven experiments were conducted with different geochemical conditions to estimate these parameters. The experiments with low initial concentration of U(VI) result in a large amount of parametric uncertainty. A modeling analysis shows that it is because the experiments cannot distinguish the relative adsorption affinity of the strong and weak sites on uranium adsorption. Therefore, the experiments with high initial concentration of U(VI) are needed, because in the experiments the strong site is nearly saturated and the weak site can be determined. The experiments with high initial concentration of U(VI) are a blessing to uncertainty quantification, and the experiments with low initial concentration help modelers turn a curse into a blessing. The data impacts on uncertainty quantification and reduction are quantified using probability density functions of model parameters obtained from Markov Chain Monte Carlo simulation using the DREAM algorithm. This study provides insights to model calibration, uncertainty quantification, experiment design, and data collection in groundwater reactive transport modeling and other environmental modeling.

Economic irrationality is optimal during noisy decision making

PubMed Central

Moreland, James; Chater, Nick; Usher, Marius; Summerfield, Christopher

2016-01-01

According to normative theories, reward-maximizing agents should have consistent preferences. Thus, when faced with alternatives A, B, and C, an individual preferring A to B and B to C should prefer A to C. However, it has been widely argued that humans can incur losses by violating this axiom of transitivity, despite strong evolutionary pressure for reward-maximizing choices. Here, adopting a biologically plausible computational framework, we show that intransitive (and thus economically irrational) choices paradoxically improve accuracy (and subsequent economic rewards) when decision formation is corrupted by internal neural noise. Over three experiments, we show that humans accumulate evidence over time using a “selective integration” policy that discards information about alternatives with momentarily lower value. This policy predicts violations of the axiom of transitivity when three equally valued alternatives differ circularly in their number of winning samples. We confirm this prediction in a fourth experiment reporting significant violations of weak stochastic transitivity in human observers. Crucially, we show that relying on selective integration protects choices against “late” noise that otherwise corrupts decision formation beyond the sensory stage. Indeed, we report that individuals with higher late noise relied more strongly on selective integration. These findings suggest that violations of rational choice theory reflect adaptive computations that have evolved in response to irreducible noise during neural information processing. PMID:26929353

Economic irrationality is optimal during noisy decision making.

PubMed

Tsetsos, Konstantinos; Moran, Rani; Moreland, James; Chater, Nick; Usher, Marius; Summerfield, Christopher

2016-03-15

According to normative theories, reward-maximizing agents should have consistent preferences. Thus, when faced with alternatives A, B, and C, an individual preferring A to B and B to C should prefer A to C. However, it has been widely argued that humans can incur losses by violating this axiom of transitivity, despite strong evolutionary pressure for reward-maximizing choices. Here, adopting a biologically plausible computational framework, we show that intransitive (and thus economically irrational) choices paradoxically improve accuracy (and subsequent economic rewards) when decision formation is corrupted by internal neural noise. Over three experiments, we show that humans accumulate evidence over time using a "selective integration" policy that discards information about alternatives with momentarily lower value. This policy predicts violations of the axiom of transitivity when three equally valued alternatives differ circularly in their number of winning samples. We confirm this prediction in a fourth experiment reporting significant violations of weak stochastic transitivity in human observers. Crucially, we show that relying on selective integration protects choices against "late" noise that otherwise corrupts decision formation beyond the sensory stage. Indeed, we report that individuals with higher late noise relied more strongly on selective integration. These findings suggest that violations of rational choice theory reflect adaptive computations that have evolved in response to irreducible noise during neural information processing.

Students' Dichotomous Experiences of the Illuminating and Illusionary Nature of Pattern Recognition in Mathematics

ERIC Educational Resources Information Center

Mhlolo, Michael Kainose

2016-01-01

The concept of pattern recognition lies at the heart of numerous deliberations concerned with new mathematics curricula, because it is strongly linked to improved generalised thinking. However none of these discussions has made the deceptive nature of patterns an object of exploration and understanding. Yet there is evidence showing that pattern…

"End-of-Life" Biases in Moral Evaluations of Others

ERIC Educational Resources Information Center

Newman, George E.; Lockhart, Kristi L.; Keil, Frank C.

2010-01-01

When evaluating the moral character of others, people show a strong bias to more heavily weigh behaviors at the end of an individual's life, even if those behaviors arise in light of an overwhelmingly longer duration of contradictory behavior. Across four experiments, we find that this "end-of-life" bias uniquely applies to intentional changes in…

The Implicit Relational Assessment Procedure (IRAP) as a Measure of Implicit Relative Preferences: A First Study

ERIC Educational Resources Information Center

Power, Patricia; Barnes-Holmes, Dermot; Barnes-Holmes, Yvonne; Stewart, Ian

2009-01-01

The Implicit Relational Assessment Procedure (IRAP) was designed to examine implicit beliefs or attitudes. In Experiment 1, response latencies obtained from Irish participants on the IRAP showed a strong preference for Irish over Scottish and American over African. In contrast, responses to explicit Likert measures diverged from the IRAP…

Dark incoherent soliton splitting and "phase-memory" effects: Theory and experiment.

PubMed

Coskun, T H; Christodoulides, D N; Chen, Z; Segev, M

1999-05-01

We report on an experimental observation of dark incoherent soliton Y splitting. The effects of incoherence on the evolution of incoherent dark soliton doublets are investigated both theoretically and experimentally. We show that the dynamics of these incoherent self-trapped entities are associated with strong "phase-memory" effects that are otherwise absent in the linear regime.

Neonatal Odor-Shock Conditioning Alters the Neural Network Involved in Odor Fear Learning at Adulthood

ERIC Educational Resources Information Center

Sevelinges, Yannick; Sullivan, Regina M.; Messaoudi, Belkacem; Mouly, Anne-Marie

2008-01-01

Adult learning and memory functions are strongly dependent on neonatal experiences. We recently showed that neonatal odor-shock learning attenuates later life odor fear conditioning and amygdala activity. In the present work we investigated whether changes observed in adults can also be observed in other structures normally involved, namely…

Teacher Candidates Speak Out: Exploring Concerns Related to Pupil Learning and Efficacy When Learning to Teach

ERIC Educational Resources Information Center

Derosier, Sharline; Soslau, Elizabeth

2014-01-01

Research shows that teachers' efficacy relates to pupil achievement. Strong efficacy, or a self-belief that one can positively impact pupil learning, is risked when teachers develop concerns related to pupil learning. This study explored the perceived concerns of teacher candidates (N = 3) throughout an eight-week clinical field experience.…

Relationships between Drugs and Delinquency in Adolescence: Influence of Gender and Victimization Experiences

ERIC Educational Resources Information Center

Brunelle, Natacha; Tremblay, Joël; Blanchette-Martin, Nadine; Gendron, Annie; Tessier, Mélanie

2014-01-01

A total of 726 youths presenting a severe addiction were evaluated at the time of their request for services in an addiction rehabilitation center. Results show that the more delinquent youths have a more severe profile of substance use, thus confirming the strong association between psychoactive substance (PAS) use severity and delinquency. Girls…

Living in History and Changing the World: An Investigation into the Culture of All Stars Project, Inc.

ERIC Educational Resources Information Center

Gubow, Rachel

2016-01-01

This article focuses on the experiences of individuals organizing at All Stars Project Inc. in New York City. Interview and observation were employed to understand individuals' involvement and commitment to the organization. Results show that the perceived successes of the organization can be attributed to strong leadership, fostering community,…

Chinese Undergraduate Students' Work Values: The Role of Parental Work Experience and Part-Time Work Quality

ERIC Educational Resources Information Center

Cheung, Francis Yue-lok; Tang, Catherine So-kum

2012-01-01

In this study, the authors investigated the association of perceived parental job insecurity and students' part-time work quality on work values among 341 Hong Kong Chinese undergraduate students. Correlation and regression results showed that work values were strongly related to students' part-time work satisfaction and work quality. In…

North Sea coastal peatlands - is a climate-smart revival possible?

NASA Astrophysics Data System (ADS)

van Huissteden, Ko; Lippmann, Tanya; Hendriks, Dimmie; Heijmans, Monique

2017-04-01

Coastal peatlands around the southern North Sea basin have been very widespread in the past, but centuries-long drainage and exploitation for agriculture and fuel has decreased the peatland area strongly. It has resulted in severe soil subsidence with adverse effects on flood safety and water quality, and large scale emission of CO2. However, the remedy of rewetting of drained peatlands that is often proposed, has uncertain outcomes as it may reduce CO2 emission, but enhance CH4 emission, in some cases dramatically. We present greenhouse gas balance examples from two peatland restoration experiments in the Netherlands. These are experiments with nature conservation as primary goal. These experiments show that the type of management of vegetation may have a very strong influence on the CH4 emission. A nutrient-rich wetland dominated by Typha sp. showed sustained, high emission of CH4 over many years. By contrast, a site where nutrient-rich topsoil was removed and a mesotrophic fen-like vegetation was established, showed very minor CH4 emission. The high emissions at the Typha site appears to result from a recently deposited peat layer of very labile organic matter. A third control site with lower water table and agricultural grassland showed considerably higher CO2 emission than the two nature conservation sites. The data from this site also shows the potential effects of climate extremes: an exceptionally warm and dry period in September 2016 showed an almost doubling of CO2 emission with respect to normal summer conditions. The future of coastal peatlands is attracting more attention from policy and spatial planning. Besides a return to (semi)natural peatland vegetation, there is a growing interest in agricultural products that allow a high water table (paludiculture). However, the effects of land use change on the peat greenhouse gas balance are very poorly known. This calls for more extensive quantification of the greenhouse gas balance under various management scenarios, which needs to be facilitated by cost-effective methods. At the sites presented here, we are experimenting with a combination of automated chamber measurements and development of a predictive model that combines hydrological modeling with modeling of the peat soil carbon balance and vegetation succession

The impact of age vs. life experience on the gender role attitudes of women in different cohorts.

PubMed

Lynott, P P; McCandless, N J

2000-01-01

Much research has concluded that the gender role attitudes of older women are more traditional in orientation. This line of research, however, has often confounded the impact of age and cohort. Consequently, cohort differences in life experiences have not been systematically explored. This study addresses the relationship between age and gender role attitudes, taking into account the potential mediating effects of life experiences and controlling for cohort. The conclusions suggest that the impact of age on gender role attitudes is not as strong as might be expected. Rather, the results show that the life experiences of different cohorts are better predictors of gender role attitudes among older women, though such experiences do not have the same impact on all women.

Perception and the temporal properties of speech

NASA Astrophysics Data System (ADS)

Gordon, Peter C.

1991-11-01

Four experiments addressing the role of attention in phonetic perception are reported. The first experiment shows that the relative importance of two cues to the voicing distinction changes when subjects must perform an arithmetic distractor task at the same time as identifying a speech stimulus. The voice onset time cue loses phonetic significance when subjects are distracted, while the F0 onset frequency cue does not. The second experiment shows a similar pattern for two cues to the distinction between the vowels /i/ (as in 'beat') and /I/ (as in 'bit'). Together these experiments indicate that careful attention to speech perception is necessary for strong acoustic cues to achieve their full phonetic impact, while weaker acoustic cues achieve their full phonetic impact without close attention. Experiment 3 shows that this pattern is obtained when the distractor task places little demand on verbal short term memory. Experiment 4 provides a large data set for testing formal models of the role of attention in speech perception. Attention is shown to influence the signal to noise ratio in phonetic encoding. This principle is instantiated in a network model in which the role of attention is to reduce noise in the phonetic encoding of acoustic cues. Implications of this work for understanding speech perception and general theories of the role of attention in perception are discussed.

Mesoscale numerical modeling of meteorological events in a strong topographic gradient in the northeastern part of Mexico

NASA Astrophysics Data System (ADS)

Pineda-Martinez, Luis F.; Carbajal, Noel

2009-08-01

A series of numerical experiments were carried out to study the effect of meteorological events such as warm and cold air masses on climatic features and variability of a understudied region with strong topographic gradients in the northeastern part of Mexico. We applied the mesoscale model MM5. We investigated the influence of soil moisture availability in the performance of the model under two representative events for winter and summer. The results showed that a better resolution in land use cover improved the agreement among observed and calculated data. The topography induces atmospheric circulation patterns that determine the spatial distribution of climate and seasonal behavior. The numerical experiments reveal regions favorable to forced convection on the eastern side of the mountain chains Eastern Sierra Madre and Sierra de Alvarez. These processes affect the vertical and horizontal structure of the meteorological variables along the topographic gradient.

Beam-based measurements of long-range transverse wakefields in the Compact Linear Collider main-linac accelerating structure

DOE PAGES

Zha, Hao; Latina, Andrea; Grudiev, Alexej; ...

2016-01-20

The baseline design of CLIC (Compact Linear Collider) uses X-band accelerating structures for its main linacs. In order to maintain beam stability in multibunch operation, long-range transverse wakefields must be suppressed by 2 orders of magnitude between successive bunches, which are separated in time by 0.5 ns. Such strong wakefield suppression is achieved by equipping every accelerating structure cell with four damping waveguides terminated with individual rf loads. A beam-based experiment to directly measure the effectiveness of this long-range transverse wakefield and benchmark simulations was made in the FACET test facility at SLAC using a prototype CLIC accelerating structure. Furthermore,more » the experiment showed good agreement with the simulations and a strong suppression of the wakefields with an unprecedented minimum resolution of 0.1 V/(pC mm m).« less

Replicable Facets of Positive Emotionality and Their Relations to Psychopathology.

PubMed

Stanton, Kasey; Watson, David

2015-12-01

General individual differences in positive emotionality are negatively related to depression, social anxiety, and schizotypy/schizophrenia, and positively related to mania. However, the structure of positive emotionality remains unclear at the facet level, as there are significant disparities in the types of content assessed across emotionality measures. This study analyzed the lower order structure of positive emotionality in two samples, finding evidence for a replicable two-factor structure of Joviality and Experience Seeking. These factors demonstrated a markedly different pattern of relations in both direction and magnitude with internalizing, externalizing, and schizotypal symptoms. Joviality seems to represent an adaptive variant of positive emotionality, as it showed strong positive relations with well-being and moderate negative relations with measures of depression, social anxiety, and social anhedonia. In contrast, Experience Seeking appears to be somewhat maladaptive. It generally related positively to psychopathology, correlating most strongly with indicators of manic and externalizing symptoms. © The Author(s) 2014.

Modal processing for acoustic communications in shallow water experiment.

PubMed

Morozov, Andrey K; Preisig, James C; Papp, Joseph

2008-09-01

Acoustical array data from the Shallow Water Acoustics experiment was processed to show the feasibility of broadband mode decomposition as a preprocessing method to reduce the effective channel delay spread and concentrate received signal energy in a small number of independent channels. The data were collected by a vertical array designed at the Woods Hole Oceanographic Institution. Phase-shift Keying (PSK) m-sequence modulated signals with different carrier frequencies were transmitted at a distance 19.2 km from the array. Even during a strong internal waves activity a low bit error rate was achieved.

A study of the utilization of ERTS-1 data from the Wabash River Basin

NASA Technical Reports Server (NTRS)

Landgrebe, D. A. (Principal Investigator)

1974-01-01

The author has identified the following significant results. The identification and area estimation of crops experiment tested the usefulness of ERTS data for crop survey and produced results indicating that crop statistics could be obtained from ERTS imagery. Soil association mapping results showed that strong relationships exist between ERTS data derived maps and conventional soil maps. Urban land use analysis experiment results indicate potential for accurate gross land use mapping. Water resources mapping demonstrated the feasibility of mapping water bodies using ERTS imagery.

Fast inertial particle manipulation in oscillating flows

NASA Astrophysics Data System (ADS)

Thameem, Raqeeb; Rallabandi, Bhargav; Hilgenfeldt, Sascha

2017-05-01

It is demonstrated that micron-sized particles suspended in fluid near oscillating interfaces experience strong inertial displacements above and beyond the fluid streaming. Experiments with oscillating bubbles show rectified particle lift over extraordinarily short (millisecond) times. A quantitative model on both the oscillatory and the steady time scales describes the particle displacement relative to the fluid motion. The formalism yields analytical predictions confirming the observed scaling behavior with particle size and experimental control parameters. It applies to a large class of oscillatory flows with applications from particle trapping to size sorting.

Erosion waves: Transverse instabilities and fingering

NASA Astrophysics Data System (ADS)

Malloggi, F.; Lanuza, J.; Andreotti, B.; Clément, E.

2006-09-01

Two laboratory scale experiments of dry and underwater avalanches of non-cohesive granular materials are investigated. We trigger solitary waves and study the conditions under which the front is transversally stable. We show the existence of a linear instability followed by a coarsening dynamics and finally the onset of a fingering pattern. Due to the different operating conditions, both experiments strongly differ by the spatial and time scales involved. Nevertheless, the quantitative agreement between the stability diagram, the wavelengths selected and the avalanche morphology suggest a common scenario for an erosion/deposition process.

MODIS comparisons with northeastern Pacific in situ stratocumulus microphysics

NASA Astrophysics Data System (ADS)

Noble, Stephen R.; Hudson, James G.

2015-08-01

Vertical sounding measurements within stratocumuli during two aircraft field campaigns, Marine Stratus/stratocumulus Experiment (MASE) and Physics of Stratocumulus Top (POST), are used to validate Moderate Resolution Imaging Spectroradiometer (MODIS) cloud optical thickness (COT), cloud liquid water path (LWP), and cloud effective radius (re). In situ COT, LWP, and re were calculated using 5 m vertically averaged droplet probe measurements of complete vertical cloud penetrations. MODIS COT, LWP, and re 1 km pixels were averaged along these penetrations. COT comparisons in POST showed strong correlations and a near 1:1 relationship. In MASE, comparisons showed strong correlations; however, MODIS COT exceeded in situ COT, likely due to larger temporal differences between MODIS and in situ measurements. LWP comparisons between two cloud probes show good agreement for POST but not MASE, giving confidence to POST data. Both projects provided strong LWP correlations but MODIS exceeded in situ by 14-36%. MODIS in situ re correlations were strong, but MODIS 2.1 µm re exceeded in situ re, which contributed to LWP bias; in POST, MODIS re was 20-30% greater than in situ re. Maximum in situ re near cloud top showed comparisons nearer 1:1. Other MODIS re bands (3.7 µm and 1.6 µm) showed similar comparisons. Temporal differences between MODIS and in situ measurements, airplane speed differences, and cloud probe artifacts were likely causes of weaker MASE correlations. POST COT comparison was best for temporal differences under 20 min. POST data validate MODIS COT but it also implies a positive MODIS re bias that propagates to LWP while still capturing variability.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beck, M. A., E-mail: mabeck2@wisc.edu; Isaacs, J. A.; Booth, D.

We describe the design and characterization of superconducting coplanar waveguide cavities tailored to facilitate strong coupling between superconducting quantum circuits and single trapped Rydberg atoms. For initial superconductor–atom experiments at 4.2 K, we show that resonator quality factors above 10{sup 4} can be readily achieved. Furthermore, we demonstrate that the incorporation of thick-film copper electrodes at a voltage antinode of the resonator provides a route to enhance the zero-point electric fields of the resonator in a trapping region that is 40 μm above the chip surface, thereby minimizing chip heating from scattered trap light. The combination of high resonator quality factor andmore » strong electric dipole coupling between the resonator and the atom should make it possible to achieve the strong coupling limit of cavity quantum electrodynamics with this system.« less

Probing electron delays in above-threshold ionization

DOE PAGES

Zipp, Lucas J.; Natan, Adi; Bucksbaum, Philip H.

2014-11-21

Recent experiments have revealed attosecond delays in the emission of electrons from atoms ionized by extreme UV light, offering a glimpse into the ultrafast nature of light-induced electron dynamics. In this work, we extend these measurements to the strong-field above-threshold ionization (ATI) regime, by measuring delays in the photoemission of electrons from argon in the presence of an intense laser field. We probe the ATI process with a weak coherent reference, at half the laser frequency. The interfering ionization signal reveals the relative spectral phase of adjacent ATI channels, with an equivalent resolution of a few attoseconds. These relative delaysmore » depend on the strong field, and approach zero at higher intensity. Our phase measurements of ATI electrons show how strong fields alter ionization dynamics in atoms.« less

Active elimination of radio frequency interference for improved signal-to-noise ratio for in-situ NMR experiments in strong magnetic field gradients

NASA Astrophysics Data System (ADS)

Ibrahim, M.; Pardi, C. I.; Brown, T. W. C.; McDonald, P. J.

2018-02-01

Improvement in the signal-to-noise ratio of Nuclear Magnetic Resonance (NMR) systems may be achieved either by increasing the signal amplitude or by decreasing the noise. The noise has multiple origins - not all of which are strictly "noise": incoherent thermal noise originating in the probe and pre-amplifiers, probe ring down or acoustic noise and coherent externally broadcast radio frequency transmissions. The last cannot always be shielded in open access experiments. In this paper, we show that pulsed, low radio-frequency data communications are a significant source of broadcast interference. We explore two signal processing methods of de-noising short T2∗ NMR experiments corrupted by these communications: Linear Predictive Coding (LPC) and the Discrete Wavelet Transform (DWT). Results are shown for numerical simulations and experiments conducted under controlled conditions with pseudo radio frequency interference. We show that both the LPC and DWT methods have merit.

Recurrent Reverse Evolution Maintains Polymorphism after Strong Bottlenecks in Commensal Gut Bacteria

PubMed Central

Ramiro, Ricardo S.; Barroso-Batista, João; Güleresi, Daniela; Lourenço, Marta; Gordo, Isabel

2017-01-01

Abstract The evolution of new strains within the gut ecosystem is poorly understood. We used a natural but controlled system to follow the emergence of intraspecies diversity of commensal Escherichia coli, during three rounds of adaptation to the mouse gut (∼1,300 generations). We previously showed that, in the first round, a strongly beneficial phenotype (loss-of-function for galactitol consumption; gat-negative) spread to >90% frequency in all colonized mice. Here, we show that this loss-of-function is repeatedly reversed when a gat-negative clone colonizes new mice. The regain of function occurs via compensatory mutation and reversion, the latter leaving no trace of past adaptation. We further show that loss-of-function adaptive mutants reevolve, after colonization with an evolved gat-positive clone. Thus, even under strong bottlenecks a regime of strong-mutation-strong-selection dominates adaptation. Coupling experiments and modeling, we establish that reverse evolution recurrently generates two coexisting phenotypes within the microbiota that can or not consume galactitol (gat-positive and gat-negative, respectively). Although the abundance of the dominant strain, the gat-negative, depends on the microbiota composition, gat-positive abundance is independent of the microbiota composition and can be precisely manipulated by supplementing the diet with galactitol. These results show that a specific diet is able to change the abundance of specific strains. Importantly, we find polymorphism for these phenotypes in indigenous Enterobacteria of mice and man. Our results demonstrate that natural selection can greatly overwhelm genetic drift at structuring the strain diversity of gut commensals and that competition for limiting resources may be a key mechanism for maintaining polymorphism in the gut. PMID:28961745

'I still believe...' Reconstructing spirituality, culture and mental health across cultural divides.

PubMed

Mayer, Claude-Hélène; Viviers, Rian

2014-06-01

Whilst striving to create a balanced and healthy life, individuals experience challenges across their life span. Spirituality can contribute to mental health and well-being, as can cultural constructs. In South Africa, apartheid categories are still vivid, which affect spiritual, cultural and racial mental constructs and impact on the mental health of individuals across cultural groups. This article focuses on the long-term development of spiritual and cultural concepts within a selected individual in Cape Town, South Africa, during 11 years of field work. It also explores the impact of spirituality and culture on the researcher-researched relationship. A mixed-method approach was used, including various qualitative methods of data collection as well as content analysis to analyse the data and intersubjective validation to interpret them. Findings show a strong intrapersonal interlinkage of spirituality, culture and mental health and the researcher-researched relationship having a strong impact on spiritual, cultural and mental health constructions. We are not human beings having a spiritual experience. We are spiritual beings having a human experience. (Pierre Teilhard de Chardin, 1976).

Neural and behavioural responses to face-likeness of objects in adolescents with autism spectrum disorder

PubMed Central

Akechi, Hironori; Kikuchi, Yukiko; Tojo, Yoshikuni; Osanai, Hiroo; Hasegawa, Toshikazu

2014-01-01

Numerous studies have revealed atypical face processing in autism spectrum disorders (ASD) characterized by social interaction and communication difficulties. This study investigated sensitivity to face-likeness in ASD. In Experiment 1, we found a strong positive correlation between the face-likeness ratings of non-face objects in the ASD (11–19 years old) and the typically developing (TD) group (9–21 years old). In Experiment 2 (the scalp-recorded event-related potential experiment), the participants of both groups (ASD, 12–19 years old; TD, 12–18 years old) exhibited an enhanced face-sensitive N170 amplitude to a face-like object. Whereas the TD adolescents showed an enhanced N170 during the face-likeness judgements, adolescents with ASD did not. Thus, both individuals with ASD and TD individuals have a perceptual and neural sensitivity to face-like features in objects. When required to process face-like features, a face-related brain system reacts more strongly in TD individuals but not in individuals with ASD. PMID:24464152

Species invasion shifts the importance of predator dependence.

PubMed

Griffen, Blaine D; Delaney, David G

2007-12-01

The strength of interference between foraging individuals can influence per capita consumption rates, with important consequences for predator and prey populations and system stability. Here we demonstrate how the replacement of a previously established invader, the predatory crab Carcinus maenas, by the recently invading predatory crab Hemigrapsus sanguineus shifts predation from a species that experiences strong predator interference (strong predator dependence) to one that experiences weak predator interference (weak predator dependence). We demonstrate using field experiments that differences in the strength of predator dependence persist for these species both when they forage on a single focal prey species only (the mussel Mytilus edulis) and when they forage more broadly across the entire prey community. This shift in predator dependence with species replacement may be altering the biomass across trophic levels, consistent with theoretical predictions, as we show that H. sanguineus populations are much larger than C. maenas populations throughout their invaded ranges. Our study highlights that predator dependence may differ among predator species and demonstrates that different predatory impacts of two conspicuous invasive predators may be explained at least in part by different strengths of predator dependence.

Looking forwards and backwards: The real-time processing of Strong and Weak Crossover

PubMed Central

Lidz, Jeffrey; Phillips, Colin

2017-01-01

We investigated the processing of pronouns in Strong and Weak Crossover constructions as a means of probing the extent to which the incremental parser can use syntactic information to guide antecedent retrieval. In Experiment 1 we show that the parser accesses a displaced wh-phrase as an antecedent for a pronoun when no grammatical constraints prohibit binding, but the parser ignores the same wh-phrase when it stands in a Strong Crossover relation to the pronoun. These results are consistent with two possibilities. First, the parser could apply Principle C at antecedent retrieval to exclude the wh-phrase on the basis of the c-command relation between its gap and the pronoun. Alternatively, retrieval might ignore any phrases that do not occupy an Argument position. Experiment 2 distinguished between these two possibilities by testing antecedent retrieval under Weak Crossover. In Weak Crossover binding of the pronoun is ruled out by the argument condition, but not Principle C. The results of Experiment 2 indicate that antecedent retrieval accesses matching wh-phrases in Weak Crossover configurations. On the basis of these findings we conclude that the parser can make rapid use of Principle C and c-command information to constrain retrieval. We discuss how our results support a view of antecedent retrieval that integrates inferences made over unseen syntactic structure into constraints on backward-looking processes like memory retrieval. PMID:28936483

Structural and magnetic studies of nanocrystalline Y{sub 2}Ir{sub 2}O{sub 7}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dwivedi, Vinod Kumar, E-mail: vinodd@iitk.ac.in; Mukhopadhyay, Soumik

2015-06-24

In this paper, we discuss synthesis of Y{sub 2}Ir{sub 2}O{sub 7} nanoparticles via chemical solution process. Structural analysis shows single cubic phase with Fd-3m space group symmetry. The particle size and distribution were studied by Transmission Electron Microscopy experiments. The average particle size turns out to be 50nm, which is in good agreement with the XRD results. Magnetic characterization shows no evidence of long range ordering even in presence of strong correlations.

REVERSAL LEARNING SET AND FUNCTIONAL EQUIVALENCE IN CHILDREN WITH AND WITHOUT AUTISM

PubMed Central

Lionello-DeNolf, Karen M.; McIlvane, William J.; Canovas, Daniela S.; de Souza, Deisy G.; Barros, Romariz S.

2009-01-01

To evaluate whether children with and without autism could exhibit (a) functional equivalence in the course of yoked repeated-reversal training and (b) reversal learning set, 6 children, in each of two experiments, were exposed to simple discrimination contingencies with three sets of stimuli. The discriminative functions of the set members were yoked and repeatedly reversed. In Experiment 1, all the children (of preschool age) showed gains in the efficiency of reversal learning across reversal problems and behavior that suggested formation of functional equivalence. In Experiment 2, 3 nonverbal children with autism exhibited strong evidence of reversal learning set and 2 showed evidence of functional equivalence. The data suggest a possible relationship between efficiency of reversal learning and functional equivalence test outcomes. Procedural variables may prove important in assessing the potential of young or nonverbal children to classify stimuli on the basis of shared discriminative functions. PMID:20186287

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.

Can MOND type hypotheses be tested in a free fall laboratory environment?

NASA Astrophysics Data System (ADS)

Das, Saurya; Patitsas, S. N.

2013-05-01

The extremely small accelerations of objects required for the onset of modified Newtonian dynamics, or modified Newtonian dynamics (MOND), makes testing the hypothesis in conventional terrestrial laboratories virtually impossible. This is due to the large background acceleration of Earth, which is transmitted to the acceleration of test objects within an apparatus. We show, however, that it may be possible to test MOND-type hypotheses with experiments using a conventional apparatus capable of tracking very small accelerations of its components but performed in locally inertial frames such as artificial satellites and other freely falling laboratories. For example, experiments involving an optical interferometer or a torsion balance in these laboratories would show nonlinear dynamics and displacement amplitudes larger than expected. These experiments may also be able to test potential violations of the strong equivalence principle by MOND and to distinguish between its two possible interpretations (modified inertia and modified gravity).

Bubble-Induced Color Doppler Feedback for Histotripsy Tissue Fractionation.

PubMed

Miller, Ryan M; Zhang, Xi; Maxwell, Adam D; Cain, Charles A; Xu, Zhen

2016-03-01

Histotripsy therapy produces cavitating bubble clouds to increasingly fractionate and eventually liquefy tissue using high-intensity ultrasound pulses. Following cavitation generated by each pulse, coherent motion of the cavitation residual nuclei can be detected using metrics formed from ultrasound color Doppler acquisitions. In this paper, three experiments were performed to investigate the characteristics of this motion as real-time feedback on histotripsy tissue fractionation. In the first experiment, bubble-induced color Doppler (BCD) and particle image velocimetry (PIV) analysis monitored the residual cavitation nuclei in the treatment region in an agarose tissue phantom treated with two-cycle histotripsy pulses at [Formula: see text] using a 500-kHz transducer. Both BCD and PIV results showed brief chaotic motion of the residual nuclei followed by coherent motion first moving away from the transducer and then rebounding back. Velocity measurements from both PIV and BCD agreed well, showing a monotonic increase in rebound time up to a saturation point for increased therapy dose. In a second experiment, a thin layer of red blood cells (RBC) was added to the phantom to allow quantification of the fractionation of the RBC layer to compare with BCD metrics. A strong linear correlation was observed between the fractionation level and the time to BCD peak rebound velocity over histotripsy treatment. Finally, the correlation between BCD feedback and histotripsy tissue fractionation was validated in ex vivo porcine liver evaluated histologically. BCD metrics showed strong linear correlation with fractionation progression, suggesting that BCD provides useful quantitative real-time feedback on histotripsy treatment progression.

Bubble-induced Color Doppler Feedback for Histotripsy Tissue Fractionation

PubMed Central

Miller, Ryan M.; Zhang, Xi; Maxwell, Adam; Cain, Charles; Xu, Zhen

2016-01-01

Histotripsy therapy produces cavitating bubble clouds to increasingly fractionate and eventually liquefy tissue using high intensity ultrasound pulses. Following cavitation generated by each pulse, coherent motion of the cavitation residual nuclei can be detected using metrics formed from ultrasound color Doppler acquisitions. In this paper, three experiments were performed to investigate the characteristics of this motion as real-time feedback on histotripsy tissue fractionation. In the first experiment, bubble-induced color Doppler (BCD) and particle image velocimetry (PIV) analysis monitored the residual cavitation nuclei in the treatment region in an agarose tissue phantom treated with 2-cycle histotripsy pulses at > 30 MPa using a 500 kHz transducer. Both BCD and PIV results showed brief chaotic motion of the residual nuclei followed by coherent motion first moving away from the transducer and then rebounding back. Velocity measurements from both PIV and BCD agreed well, showing a monotonic increase in rebound time up to a saturation point for increased therapy dose. In a second experiment, a thin layer of red blood cells (RBC) was added to the phantom to allow quantification of the fractionation of the RBC layer to compare with BCD metrics. A strong linear correlation was observed between the fractionation level and the time to BCD peak rebound velocity over histotripsy treatment. Finally, the correlation between BCD feedback and histotripsy tissue fractionation was validated in ex vivo porcine liver evaluated histologically. BCD metrics showed strong linear correlation with fractionation progression, suggesting that BCD provides useful quantitative real-time feedback on histotripsy treatment progression. PMID:26863659

Broadband sidebands generated by parametric instability in lower hybrid current drive experiments on EAST

NASA Astrophysics Data System (ADS)

Amicucci, L.; Ding, B. J.; Castaldo, C.; Cesario, R.; Giovannozzi, E.; Li, M. H.; Tuccillo, A. A.

2015-12-01

Modern research on nuclear fusion energy, based on the tokamak concept, has strong need of tools for actively driving non-inductive current especially at the periphery of plasma column, where tools available so far have poor efficiency. This is essential for solving one of the most critical problems for thermonuclear reactor, consisting in how to achieve the figure of fusion gain in the context of sufficient stability. The lower hybrid current drive (LHCD) effect has the potential capability of driving current at large radii of reactor plasma with high efficiency [1]. Experiments recently carried out on EAST showed that a strong activity of LH sideband waves (from the RF probe spectra), accompanied by weak core penetration of the coupled LH power, is present when operating at relatively high plasma densities. Previous theoretical results, confirmed by experiments on FTU, showed that the LH sideband phenomenon is produced by parametric instability (PI), which are mitigated by higher plasma edge temperatures. This condition is thus useful for enabling the LH power propagation when operating with profiles having high plasma densities even at the edge. In the present work, we show new PI modeling of EAST plasmas data, obtained in condition of higher plasma edge temperature due to chamber lithisation. The obtained trend of the PI frequencies and growth rates is consistent with data of RF probe spectra, available in different regimes of lithisated and not lithisated vessel. Moreover, these spectra are interpreted as PI effect occurring at the periphery of plasma column, however in the low field side where the LH power is coupled.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weidl, Martin S.; Winske, Dan; Jenko, Frank

We present two-dimensional hybrid kinetic/magnetohydrodynamic simulations of planned laser-ablation experiments in the Large Plasma Device (LAPD). Our results, based on parameters which have been validated in previous experiments, show that a parallel collisionless shock can begin forming within the available space. Carbon-debris ions that stream along the magnetic- eld direction with a blow-o speed of four times the Alfv en velocity excite strong magnetic uctuations, eventually transfering part of their kinetic energy to the surrounding hydrogen ions. This acceleration and compression of the background plasma creates a shock front, which satis es the Rankine{Hugoniot conditions and can therefore propagate onmore » its own. Furthermore, we analyze the upstream turbulence and show that it is dominated by the right-hand resonant instability.« less

$$\\mathscr{H}_2$$ optimal control techniques for resistive wall mode feedback in tokamaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clement, Mitchell; Hanson, Jeremy; Bialek, Jim

DIII-D experiments show that a new, advanced algorithm improves resistive wall mode (RWM) stability control in high performance discharges using external coils. DIII-D can excite strong, locked or nearly locked external kink modes whose rotation frequencies and growth rates are on the order of the magnetic ux di usion time of the vacuum vessel wall. The VALEN RWM model has been used to gauge the e ectiveness of RWM control algorithms in tokamaks. Simulations and experiments have shown that modern control techniques like Linear Quadratic Gaussian (LQG) control will perform better, using 77% less current, than classical techniques when usingmore » control coils external to DIII-D's vacuum vessel. Experiments were conducted to develop control of a rotating n = 1 perturbation using an LQG controller derived from VALEN and external coils. Feedback using this LQG algorithm outperformed a proportional gain only controller in these perturbation experiments over a range of frequencies. Results from high N experiments also show that advanced feedback techniques using external control coils may be as e ective as internal control coil feedback using classical control techniques.« less

$$\\mathscr{H}_2$$ optimal control techniques for resistive wall mode feedback in tokamaks

DOE PAGES

Clement, Mitchell; Hanson, Jeremy; Bialek, Jim; ...

2018-02-28

DIII-D experiments show that a new, advanced algorithm improves resistive wall mode (RWM) stability control in high performance discharges using external coils. DIII-D can excite strong, locked or nearly locked external kink modes whose rotation frequencies and growth rates are on the order of the magnetic ux di usion time of the vacuum vessel wall. The VALEN RWM model has been used to gauge the e ectiveness of RWM control algorithms in tokamaks. Simulations and experiments have shown that modern control techniques like Linear Quadratic Gaussian (LQG) control will perform better, using 77% less current, than classical techniques when usingmore » control coils external to DIII-D's vacuum vessel. Experiments were conducted to develop control of a rotating n = 1 perturbation using an LQG controller derived from VALEN and external coils. Feedback using this LQG algorithm outperformed a proportional gain only controller in these perturbation experiments over a range of frequencies. Results from high N experiments also show that advanced feedback techniques using external control coils may be as e ective as internal control coil feedback using classical control techniques.« less

The representation of conceptual knowledge: visual, auditory, and olfactory imagery compared with semantic processing.

PubMed

Palmiero, Massimiliano; Di Matteo, Rosalia; Belardinelli, Marta Olivetti

2014-05-01

Two experiments comparing imaginative processing in different modalities and semantic processing were carried out to investigate the issue of whether conceptual knowledge can be represented in different format. Participants were asked to judge the similarity between visual images, auditory images, and olfactory images in the imaginative block, if two items belonged to the same category in the semantic block. Items were verbally cued in both experiments. The degree of similarity between the imaginative and semantic items was changed across experiments. Experiment 1 showed that the semantic processing was faster than the visual and the auditory imaginative processing, whereas no differentiation was possible between the semantic processing and the olfactory imaginative processing. Experiment 2 revealed that only the visual imaginative processing could be differentiated from the semantic processing in terms of accuracy. These results showed that the visual and auditory imaginative processing can be differentiated from the semantic processing, although both visual and auditory images strongly rely on semantic representations. On the contrary, no differentiation is possible within the olfactory domain. Results are discussed in the frame of the imagery debate.

Relative expertise affects N170 during selective attention to superimposed face-character images.

PubMed

Ip, Chengteng; Wang, Hailing; Fu, Shimin

2017-07-01

It remains unclear whether the N170 of ERPs reflects domain-specific or domain-general visual object processing. In this study, we used superimposed images of a face and a Chinese character such that participants' relative expertise for the two object types was either similar (Experiment 1 and 2) or different (Experiment 3). Experiment 1 showed that N170 amplitude was larger when participants attended to the character instead of the face of a face-character combination. This result was unchanged in Experiment 2, in which task difficulty was selectively increased for the face component of the combined stimuli. Experiment 3 showed that, although this N170 enhancement for attending to characters relative to faces persisted for false characters with recognizable parts, it disappeared for unrecognizable characters. Therefore, N170 amplitude was significantly greater for Chinese characters than for faces presented within a combined image, independent of the relative task difficulty. This result strongly calls N170 face selectivity into question, demonstrating that, contrary to the expectations established by a domain-specific account, N170 is modulated by expertise. © 2017 Society for Psychophysiological Research.

Familiarity and recollection produce distinct eye movement, pupil and medial temporal lobe responses when memory strength is matched.

PubMed

Kafkas, Alexandros; Montaldi, Daniela

2012-11-01

Two experiments explored eye measures (fixations and pupil response patterns) and brain responses (BOLD) accompanying the recognition of visual object stimuli based on familiarity and recollection. In both experiments, the use of a modified remember/know procedure led to high confidence and matched accuracy levels characterising strong familiarity (F3) and recollection (R) responses. In Experiment 1, visual scanning behaviour at retrieval distinguished familiarity-based from recollection-based recognition. Recollection, relative to strength-matched familiarity, involved significantly larger pupil dilations and more dispersed fixation patterns. In Experiment 2, the hippocampus was selectively activated for recollected stimuli, while no evidence of activation was observed in the hippocampus for strong familiarity of matched accuracy. Recollection also activated the parahippocampal cortex (PHC), while the adjacent perirhinal cortex (PRC) was actively engaged in response to strong familiarity (than to recollection). Activity in prefrontal and parietal areas differentiated familiarity and recollection in both the extent and the magnitude of activity they exhibited, while the dorsomedial thalamus showed selective familiarity-related activity, and the ventrolateral and anterior thalamus selective recollection-related activity. These findings are consistent with the view that the hippocampus and PRC play contrasting roles in supporting recollection and familiarity and that these differences are not a result of differences in memory strength. Overall, the combined pupil dilation, eye movement and fMRI data suggest the operation of recognition mechanisms drawing differentially on familiarity and recollection, whose neural bases are distinct within the MTL. Copyright © 2012 Elsevier Ltd. All rights reserved.

"All the Stories That We Have": Adolescents' Insights about Literacy and Learning in Secondary Schools. Kids InSight, K-12.

ERIC Educational Resources Information Center

Moje, Elizabeth Birr

Based on the premise that young people have important stories to tell, this book presents adolescents' lives and experiences to show the importance of understanding their literacy practices, to generate ideas for relating those practices to teaching and curriculum development, and to advance the idea that all children need strong, abiding…

The Effects of an Equine Assisted Learning Supervision Intervention on Counselors'-in-Training Performance Anxiety, Counseling Self-Efficacy, and Supervisory Working Alliance

ERIC Educational Resources Information Center

Meola, Cheryl C.

2017-01-01

Due to the complexity of the counseling process, counselors-in-training often experience performance anxiety when entering the counseling profession. Research shows that higher counseling self-efficacy (the belief in oneself to perform counseling skills successfully) helps decrease performance anxiety. Further, a strong supervisory working…

Overview of TJ-II experiments

NASA Astrophysics Data System (ADS)

Sánchez, J.; Acedo, M.; Alonso, A.; Alonso, J.; Alvarez, P.; de Aragón, F.; Ascasíbar, E.; Baciero, A.; Balbín, R.; Barrera, L.; Blanco, E.; Botija, J.; Brañas, B.; de la Cal, E.; Calderón, E.; Calvo, I.; Cappa, A.; Carmona, J. A.; Carreras, B. A.; Carrasco, R.; Castejón, F.; Catalán, G.; Chmyga, A. A.; Dreval, N. B.; Chamorro, M.; Eguilior, S.; Encabo, J.; Eliseev, L.; Estrada, T.; Fernández, A.; Fernández, R.; Ferreira, J. A.; Fontdecaba, J. M.; Fuentes, C.; de la Gama, J.; García, A.; García, L.; García-Cortés, I.; García-Regaña, J. M.; Gonçalves, B.; Guasp, J.; Herranz, J.; Hidalgo, A.; Hidalgo, C.; Jiménez-Gómez, R.; Jiménez, J. A.; Jiménez, D.; Kirpitchev, I.; Komarov, A. D.; Kozachok, A. S.; Krupnik, L.; Lapayese, F.; Liniers, M.; López-Bruna, D.; López-Fraguas, A.; López-Rázola, J.; López-Sánchez, A.; de la Luna, E.; Marcon, G.; Martín, F.; Martínez-Fresno, L.; McCarthy, K. J.; Medina, F.; Medrano, M.; Melnikov, A. V.; Méndez, P.; Mirones, E.; van Milligen, B.; Nedzelskiy, I. S.; Ochando, M.; Olivares, J.; Orozco, R.; Ortiz, P.; de Pablos, J. L.; Pacios, L.; Pastor, I.; Pedrosa, M. A.; de la Peña, A.; Pereira, A.; Pérez-Risco, D.; Petrov, A.; Petrov, S.; Portas, A.; Rapisarda, D.; Ríos, L.; Rodríguez, C.; Rodríguez-Rodrigo, L.; Rodríguez-Solano, E.; Romero, J.; Ros, A.; Salas, A.; Sánchez, E.; Sánchez, M.; Sánchez-Sarabia, E.; Sarasola, X.; Sarksian, K.; Silva, C.; Schchepetov, S.; Skvortsova, N.; Soleto, A.; Tabarés, F.; Tafalla, D.; Tera, J.; Tolkachev, A.; Tribaldos, V.; Vargas, V. I.; Vega, J.; Velasco, G.; Weber, M.; Wolfers, G.; Zweben, S. J.; Zurro, B.

2007-10-01

This paper presents an overview of experimental results and progress made in investigating the link between magnetic topology, electric fields and transport in the TJ-II stellarator. The smooth change from positive to negative electric field observed in the core region as the density is raised is correlated with global and local transport data. A statistical description of transport is emerging as a new way to describe the coupling between profiles, plasma flows and turbulence. TJ-II experiments show that the location of rational surfaces inside the plasma can, in some circumstances, provide a trigger for the development of core transitions, providing a critical test for the various models that have been proposed to explain the appearance of transport barriers in relation to magnetic topology. In the plasma core, perpendicular rotation is strongly coupled to plasma density, showing a reversal consistent with neoclassical expectations. In contrast, spontaneous sheared flows in the plasma edge appear to be coupled strongly to plasma turbulence, consistent with the expectation for turbulent driven flows. The local injection of hydrocarbons through a mobile limiter and the erosion produced by plasmas with well-known edge parameters opens the possibility of performing carbon transport studies, relevant for understanding co-deposit formation in fusion devices.

Theory of nucleosome corkscrew sliding in the presence of synthetic DNA ligands.

PubMed

Mohammad-Rafiee, Farshid; Kulić, Igor M; Schiessel, Helmut

2004-11-12

Histone octamers show a heat-induced mobility along DNA. Recent theoretical studies have established two mechanisms that are qualitatively and quantitatively compatible with in vitro experiments on nucleosome sliding: octamer repositioning through one-base-pair twist defects and through ten-base-pair bulge defects. A recent experiment demonstrated that the repositioning is strongly suppressed in the presence of minor-groove binding DNA ligands. In the present study, we give a quantitative theory for nucleosome repositioning in the presence of such ligands. We show that the experimentally observed octamer mobilities are consistent with the picture of bound ligands blocking the passage of twist defects through the nucleosome. This strongly supports the model of twist defects inducing a corkscrew motion of the nucleosome as the underlying mechanism of nucleosome sliding. We provide a theoretical estimate of the nucleosomal mobility without adjustable parameters, as a function of ligand concentration, binding affinity, binding site orientation, temperature and DNA anisotropy. Having this mobility in hand, we speculate on the interaction between a nucleosome and a transcribing RNA polymerase, and suggest a novel mechanism that might account for polymerase-induced nucleosome repositioning on short DNA templates.

Universal charge relaxation resistance and electrochemical capacitance suppression in an interacting coherent capacitor

NASA Astrophysics Data System (ADS)

Liu, Wei; Guo, Huazhong; He, Jianhong; Gao, Jie

2018-05-01

We have measured the dynamic admittance of an interacting coherent capacitor in the quantum Hall regime. Our experiments demonstrate that, in the fully coherent regime, the charge relaxation resistance is universal and independent of the transmission even in the presence of strong charge interactions. Conversely, we observe strong suppression of the electrochemical capacitance, which is related to the density of states of the charge excitations due to strong interactions. Our experiments form the building blocks for the realization of electron quantum optics experiments with strong charge interactions, and they should prove useful for quantum bits in interacting ballistic conductors.

Thermomechanical Response of Self-Assembled Nanoparticle Membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yifan; Chan, Henry; Narayanan, Badri

2017-07-21

Monolayers composed of colloidal nanoparticles, with a thickness of less than 10 nm, have remarkable mechanical moduli and can suspend over micrometer-sized holes to form free-standing membranes. In this paper, we discuss experiment's and coarse-grained molecular dynamics simulations characterizing the thermomechanical properties of these self-assembled nanoparticle membranes. These membranes remain strong and resilient up to temperatures much higher than previous simulation predictions and exhibit an unexpected hysteretic behavior during the first heating cooling cycle. We show this hysteretic behavior can be explained by an asymmetric ligand configuration from the self assembly process and can be controlled by changing the ligandmore » coverage or cross-linking the ligand molecules. Finally, we show the screening effect of water molecules on the ligand interactions can strongly affect the moduli and thermomechanical behavior.« less

Explaining Cold-Pulse Dynamics in Tokamak Plasmas Using Local Turbulent Transport Models

NASA Astrophysics Data System (ADS)

Rodriguez-Fernandez, P.; White, A. E.; Howard, N. T.; Grierson, B. A.; Staebler, G. M.; Rice, J. E.; Yuan, X.; Cao, N. M.; Creely, A. J.; Greenwald, M. J.; Hubbard, A. E.; Hughes, J. W.; Irby, J. H.; Sciortino, F.

2018-02-01

A long-standing enigma in plasma transport has been resolved by modeling of cold-pulse experiments conducted on the Alcator C-Mod tokamak. Controlled edge cooling of fusion plasmas triggers core electron heating on time scales faster than an energy confinement time, which has long been interpreted as strong evidence of nonlocal transport. This Letter shows that the steady-state profiles, the cold-pulse rise time, and disappearance at higher density as measured in these experiments are successfully captured by a recent local quasilinear turbulent transport model, demonstrating that the existence of nonlocal transport phenomena is not necessary for explaining the behavior and time scales of cold-pulse experiments in tokamak plasmas.

Tunnel ionization of atoms and molecules: How accurate are the weak-field asymptotic formulas?

NASA Astrophysics Data System (ADS)

Labeye, Marie; Risoud, François; Maquet, Alfred; Caillat, Jérémie; Taïeb, Richard

2018-05-01

Weak-field asymptotic formulas for the tunnel ionization rate of atoms and molecules in strong laser fields are often used for the analysis of strong field recollision experiments. We investigate their accuracy and domain of validity for different model systems by confronting them to exact numerical results, obtained by solving the time dependent Schrödinger equation. We find that corrections that take the dc-Stark shift into account are a simple and efficient way to improve the formula. Furthermore, analyzing the different approximations used, we show that error compensation plays a crucial role in the fair agreement between exact and analytical results.

Do we harm others even if we don't need to?

PubMed Central

Cacault, M. Paula; Goette, Lorenz; Lalive, Rafael; Thoenig, Mathias

2015-01-01

Evolutionary explanations of the co-existence of large-scale cooperation and warfare in human societies rest on the hypothesis of parochial altruism, the view that in-group pro-sociality and out-group anti-sociality have co-evolved. We designed an experiment that allows subjects to freely choose between actions that are purely pro-social, purely anti-social, or a combination of the two. We present behavioral evidence on the existence of strong aggression—a pattern of non-strategic behaviors that are welfare-reducing for all individuals (i.e., victims and perpetrators). We also show how strong aggression serves to dynamically stabilize in-group pro-sociality. PMID:26082737

Cesium migration in Hanford sediment: a multisite cation exchange model based on laboratory transport experiments.

PubMed

Steefel, Carl I; Carroll, Susan; Zhao, Pihong; Roberts, Sarah

2003-12-01

Cs+ transport experiments carried out in columns packed with uncontaminated Hanford formation sediment from the SX tank farm provide strong support for the use of a multisite, multicomponent cation exchange model to describe Cs+ migration in the Hanford vadose zone. The experimental results indicate a strong dependence of the effective Cs+ Kd on the concentrations of other cations, including Na+ that is present at high to extremely high concentrations in fluids leaking from the Hanford SX tanks. A strong dependence of the Cs+ Kd on the aqueous Cs+ concentration is also apparent, with retardation of Cs+ increasing from a value of 41 at a Cs+ concentration of 10(-4) M in the feed solution to as much as 282 at a Cs+ concentration of 5x10(-7) M, all in a background of 1 M NaNO3. The total cation exchange capacity (CEC) of the Hanford sediment was determined using 22Na isotopic equilibrium exchange in a flow-through column experiment. The value for the CEC of 120 microeq/g determined with this method is compatible with a value of 121.9 microeq/g determined by multi-cation elution. While two distinct exchange sites were proposed by Zachara et al. [Geochim. Cosmochim. Acta 66 (2002) 193] based on binary batch exchange experiments, a third site is proposed in this study to improve the fit of the Cs+-Na+ and Cs+-Ca+ exchange data and to capture self-sharpened Cs+ breakthrough curves at low concentrations of Cs+. Two of the proposed exchange sites represent frayed edge sites (FES) on weathered micas and constitute 0.02% and 0.22% of the total CEC. Both of the FES show a very strong selectivity for Cs+ over Na+ (K(Na-Cs)=10(7.22) and 10(4.93), respectively). The third site, accounting for over 99% of the total CEC, is associated with planar sites on expansible clays and shows a smaller Na+-Cs+ selectivity coefficient of 10(1.99). Parameters derived from a fit of binary batch experiments alone tend to under predict Cs+ retardation in the column experiments. The transport experiments indicate 72-90% of the Cs+ sorbed in experiments targeting exchange on FES was desorbed over a 10- and 24-day period, respectively. At high Cs+ concentrations, where sorption is controlled primarily by exchange on planar sites, 95% of the Cs+ desorption was desorbed. Most of the difficulty in desorbing Cs+ from FES is a result of the extremely high selectivity of these sites for Cs+, although truly irreversible sorption as high as 23% was suggested in one experiment. The conclusion that Cs+ exchange is largely reversible in a thermodynamic sense is supported by the ability to match Cs+ desorption curves almost quantitatively with an equilibrium reactive transport simulation. The model for Cs+ retardation developed here qualitatively explains the behavior of Cs+ in the Hanford vadose zone underneath a variety of leaking tanks with differing salt concentrations. The high selectivity of FES for Cs+ implies that future desorption and migration is very unlikely to occur under natural recharge conditions.

Application of the hydroxyl tagging velocimetry to direct-connect supersonic combustor experiment

NASA Astrophysics Data System (ADS)

Ye, Jingfeng; Li, Guohua; Shao, Jun; Hu, Zhiyun; Zhao, Xinyan; Song, WenYan

2017-05-01

For the purpose of measuring the flow velocity in a scramjet test model, an special designed measurement system was established, including the strong vibration suppression, optical transport consideration, the movable device etc. The interference of the strong vibration to the velocity measurements was avoided by two ICCD cameras capturing the reference tag lines image and moved tag lines image together during an experiment. According to the tag lines image feature, data processing including correlation algorithm, data fitting by a Gauss function were used respectively to extract the positions of the reference tag lines and the moved tag lines. The velocity measurements were carried out at the isolation section and the cavity section. The results showed that the well SNR could be achieved in the H2/air combustion heating flow, but in the kerosene fuel combustion flow, the measurements images might be interfered by the strong OH background from the chemical reaction, and the signal intensity could be reduced due to the tag laser attenuation through the absorption by kerosene vapor. But when the combustor model was run at a low chemical equivalent, the interference could be suppressed to an accepted level.

Restoring Agency to the Human Actor.

PubMed

Swann, William B; Jetten, Jolanda

2017-05-01

A cursory read of the social psychological literature suggests that when people find themselves in strong situations, they fail to display agency. The early classic studies of conformity, obedience, and bystander intervention, for example, are renowned for showing that when challenged by strong situational pressures, participants acquiesced-even if it meant abandoning their moral principles or disregarding their own sensory data. Later studies of learned helplessness, ego depletion, and stereotype threat echoed this "power of the situation" theme, demonstrating that exposure to (or the expectation of) a frustrating or unpleasant experience suppressed subsequent efforts to actualize goals and abilities. Although this work has provided many valuable insights into the influence of situational pressures, it has been used to buttress an unbalanced and misleading portrait of human agency. This portrait fails to recognize that situations are not invariably enemies of agency. Instead, strong situational forces often allow for, and may even encourage, expressions of human agency. We examine the nature, causes, and consequences of this phenomenon. We endorse a broader approach that emphasizes how responding to situational pressure can coexist with agency. This new emphasis should create greater convergence between social psychological models and the experience of agency in everyday life.

Evolution of Indian land surface biases in the seasonal hindcasts from the Met Office Global Seasonal Forecasting System GloSea5

NASA Astrophysics Data System (ADS)

Chevuturi, Amulya; Turner, Andrew G.; Woolnoug, Steve J.; Martin, Gill

2017-04-01

In this study we investigate the development of biases over the Indian region in summer hindcasts of the UK Met Office coupled initialised global seasonal forecasting system, GloSea5-GC2. Previous work has demonstrated the rapid evolution of strong monsoon circulation biases over India from seasonal forecasts initialised in early May, together with coupled strong easterly wind biases on the equator. These mean state biases lead to strong precipitation errors during the monsoon over the subcontinent. We analyse a set of three springtime start dates for the 20-year hindcast period (1992-2011) and fifteen total ensemble members for each year. We use comparisons with variety of observations to assess the evolution of the mean state biases over the Indian land surface. All biases within the model develop rapidly, particularly surface heat and radiation flux biases. Strong biases are present within the model climatology from pre-monsoon (May) in the surface heat fluxes over India (higher sensible / lower latent heat fluxes) when compared to observed estimates. The early evolution of such biases prior to onset rains suggests possible problems with the land surface scheme or soil moisture errors. Further analysis of soil moisture over the Indian land surface shows a dry bias present from the beginning of the hindcasts during the pre-monsoon. This lasts until the after the monsoon develops (July) after which there is a wet bias over the region. Soil moisture used for initialization of the model also shows a dry bias when compared against the observed estimates, which may lead to the same in the model. The early dry bias in the model may reduce local moisture availability through surface evaporation and thus may possibly limit precipitation recycling. On this premise, we identify and test the sensitivity of the monsoon in the model against higher soil moisture forcing. We run sensitivity experiments initiated using gridpoint-wise annual soil moisture maxima over the Indian land surface as input for experiments in the atmosphere-only version of the model. We plan to analyse the response of the sensitivity experiments on seasonal forecasting of surface heat fluxes and subsequently monsoon precipitation.

Competitive and non-competitive adsorption/desorption of paraquat, diquat and difenzoquat in vineyard-devoted soils.

PubMed

Pateiro-Moure, M; Arias-Estévez, M; Simal-Gándara, J

2010-06-15

Mobility of agrochemicals in soils plays an important role in the fate and transport of contaminants in the environment. Competitive and non-competitive sorption experiments of three ammonium quaternary herbicides (paraquat, diquat and difenzoquat) onto eight vineyard soils was measured in batch experiments. Non-competitive experiments show that paraquat (PQ) is the most strongly adsorbed (70-97% of added PQ) followed by diquat (DQ) and difenzoquat (DFQ). The best fits were obtained with the Freundlich equation. In competitive experiments with variable mole ratios, it was found a large influence between the divalent cationic herbicides PQ and DQ, and between them and the monovalent herbicide DFQ, but DFQ did only show a scarce influence on PQ and DQ sorption. Desorption of herbicides into CaCl(2) showed very low values: around 11, 19 and 31% for, respectively, PQ, DQ and DFQ. In order to assess the ability of herbicides to displace others, desorption experiments were carried out by replacing Cl(2)Ca by any of the other two herbicides. In this case, the highest percentage of desorption was obtained when DFQ was desorbed with PQ (>72%) and DQ (>73%), but also when PQ was used to desorb DQ (100%) and vice versa (100%). Copyright 2010 Elsevier B.V. All rights reserved.

Syntactic priming in American Sign Language.

PubMed

Hall, Matthew L; Ferreira, Victor S; Mayberry, Rachel I

2015-01-01

Psycholinguistic studies of sign language processing provide valuable opportunities to assess whether language phenomena, which are primarily studied in spoken language, are fundamentally shaped by peripheral biology. For example, we know that when given a choice between two syntactically permissible ways to express the same proposition, speakers tend to choose structures that were recently used, a phenomenon known as syntactic priming. Here, we report two experiments testing syntactic priming of a noun phrase construction in American Sign Language (ASL). Experiment 1 shows that second language (L2) signers with normal hearing exhibit syntactic priming in ASL and that priming is stronger when the head noun is repeated between prime and target (the lexical boost effect). Experiment 2 shows that syntactic priming is equally strong among deaf native L1 signers, deaf late L1 learners, and hearing L2 signers. Experiment 2 also tested for, but did not find evidence of, phonological or semantic boosts to syntactic priming in ASL. These results show that despite the profound differences between spoken and signed languages in terms of how they are produced and perceived, the psychological representation of sentence structure (as assessed by syntactic priming) operates similarly in sign and speech.

Can false memories be created through nonconscious processes?

PubMed

Zeelenberg, René; Plomp, Gijs; Raaijmakers, Jeroen G W

2003-09-01

Presentation times of study words presented in the Deese/Roediger and McDermott (DRM) paradigm varied from 20 to 2000 ms per word in an attempt to replicate the false memory effect following extremely short presentations reported by. Both in a within-subjects design (Experiment 1) and in a between-subjects design (Experiment 2) subjects showed memory for studied words as well as a false memory effect for related critical lures in the 2000-ms condition. However, in the conditions with shorter presentation times (20 ms in Experiment 1; 20 and 40 ms in Experiment 2) no memory for studied words, nor a false memory effect was found. We argue that there is at present no strong evidence supporting the claim for a nonconscious basis of the false memory effect.

Summer Internships: 12 Years' Experience with Undergraduate Medical Students in Summer Employment in Various Areas of Preventive Medicine

PubMed Central

Mackenzie, C. J. G.; Elliot, G. R. F.

1965-01-01

Twelve years' experience in providing summer employment for students in official health agencies in British Columbia is reviewed and a two-week orientation course given prior to employment in 1964 is described. In the program, which provides experience in teaching, research and community service, a total of 43 students have been employed. Students seeking this type of employment and accepted for it tend to have high academic standing. They prefer employment in or near Vancouver irrespective of their original home location. Two main employers have been available: specialized agencies in metropolitan Vancouver, or “rural” health units. Students serving in health units showed a strong tendency to enter general practice after graduation. Urban experience tended to lead to specialization. PMID:14278027

Enhancement of superexchange pairing in the periodically driven Hubbard model

NASA Astrophysics Data System (ADS)

Coulthard, J. R.; Clark, S. R.; Al-Assam, S.; Cavalleri, A.; Jaksch, D.

2017-08-01

Recent experiments performed on cuprates and alkali-doped fullerides have demonstrated that key signatures of superconductivity can be induced above the equilibrium critical temperature by optical modulation. These observations in disparate physical systems may indicate a general underlying mechanism. Multiple theories have been proposed, but these either consider specific features, such as competing instabilities, or focus on conventional BCS-type superconductivity. Here we show that periodic driving can enhance electron pairing in strongly correlated systems. Focusing on the strongly repulsive limit of the doped Hubbard model, we investigate in-gap, spatially inhomogeneous, on-site modulations. We demonstrate that such modulations substantially reduce electronic hopping, while simultaneously sustaining superexchange interactions and pair hopping via driving-induced virtual charge excitations. We calculate real-time dynamics for the one-dimensional case, starting from zero- and finite-temperature initial states, and we show that enhanced singlet-pair correlations emerge quickly and robustly in the out-of-equilibrium many-body state. Our results reveal a fundamental pairing mechanism that might underpin optically induced superconductivity in some strongly correlated quantum materials.

Various topological Mott insulators and topological bulk charge pumping in strongly-interacting boson system in one-dimensional superlattice

NASA Astrophysics Data System (ADS)

Kuno, Yoshihito; Shimizu, Keita; Ichinose, Ikuo

2017-12-01

In this paper, we study a one-dimensional boson system in a superlattice potential. This system is experimentally feasible by using ultracold atomic gases, and attracts much attention these days. It is expected that the system has a topological phase called a topological Mott insulator (TMI). We show that in strongly-interacting cases, the competition between the superlattice potential and the on-site interaction leads to various TMIs with a non-vanishing integer Chern number. Compared to the hard-core case, the soft-core boson system exhibits rich phase diagrams including various non-trivial TMIs. By using the exact diagonalization, we obtain detailed bulk-global phase diagrams including the TMIs with high Chern numbers and also various non-topological phases. We also show that in adiabatic experimental setups, the strongly-interacting bosonic TMIs exhibit the topological particle transfer, i.e., the topological charge pumping phenomenon, similarly to weakly-interacting systems. The various TMIs are characterized by topological charge pumping as it is closely related to the Chern number, and therefore the Chern number is to be observed in feasible experiments.

Microgravity experiments on the effect of internal flow on solidification of Fe-Cr-Ni stainless steels.

PubMed

Hanlon, Alaina B; Matson, Douglas M; Hyers, Robert W

2006-09-01

A new hypothesis has been developed to explain the effect of internal fluid flow on the lifetime of a metastable phase in solidifying Fe-Cr-Ni alloys. The hypothesis shows excellent agreement with available experimental results, but microgravity experiments are required for complete validation. Certain Fe-Cr-Ni stainless steel alloys solidify from an undercooled melt by a two-step process in which the metastable ferrite phase forms first followed by the stable austenite phase. Recent experiments using containerless processing techniques have shown that the lifetime of the metastable phase is strongly influenced by flow within the molten sample. Simulations using a commercial computational fluid dynamics (CFD) package, FIDAP, were performed to determine the time required for collision of dendrites and compared to experimental delay time. If the convective velocities are strong enough to bend the primary arms, then the secondary arms of adjacent dendrites can touch. The points of collision form low-angle boundaries and result in high-energy sites that can serve as nuclei for the transformation to the stable phase. It has been determined that the convective velocities in electrostatic levitation (ESL) are not strong enough to cause collision. However, in ground-based electromagnetic levitation (EML), the convective velocities are strong enough to cause the dendrites to deflect so that the secondary arms of adjacent dendrites collide. There is quantitative agreement between the numerically determined time to collision and the experimentally observed delay time in EML. The strong internal velocity due to convection within the EML samples is the reason for the observed difference in delay times between ESL and EML. Microgravity testing is essential because the significant change in nucleation behavior occurs between the ranges accessible by ground-based ESL and EML. Testing in microgravity using EML will permit a large range of internal convective velocities including those that are inaccessible in 1 g.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noble, Stephen R.; Hudson, James G.

Here, vertical sounding measurements within stratocumuli during two aircraft field campaigns, Marine Stratus/stratocumulus Experiment (MASE) and Physics of Stratocumulus Top (POST), are used to validate Moderate Resolution Imaging Spectroradiometer (MODIS) cloud optical thickness (COT), cloud liquid water path (LWP), and cloud effective radius (r e). In situ COT, LWP, and r e were calculated using 5 m vertically averaged droplet probe measurements of complete vertical cloud penetrations. MODIS COT, LWP, and r e 1 km pixels were averaged along these penetrations. COT comparisons in POST showed strong correlations and a near 1:1 relationship. In MASE, comparisons showed strong correlations; however,more » MODIS COT exceeded in situ COT, likely due to larger temporal differences between MODIS and in situ measurements. LWP comparisons between two cloud probes show good agreement for POST but not MASE, giving confidence to POST data. Both projects provided strong LWP correlations but MODIS exceeded in situ by 14–36%. MODIS in situ r e correlations were strong, but MODIS 2.1 µm r e exceeded in situ r e, which contributed to LWP bias; in POST, MODIS r e was 20–30% greater than in situ r e. Maximum in situ r e near cloud top showed comparisons nearer 1:1. Other MODIS r e bands (3.7 µm and 1.6 µm) showed similar comparisons. Temporal differences between MODIS and in situ measurements, airplane speed differences, and cloud probe artifacts were likely causes of weaker MASE correlations. POST COT comparison was best for temporal differences under 20 min. POST data validate MODIS COT but it also implies a positive MODIS r e bias that propagates to LWP while still capturing variability.« less

MODIS comparisons with northeastern Pacific in situ stratocumulus microphysics

PubMed Central

Noble, Stephen R.

2015-01-01

Abstract Vertical sounding measurements within stratocumuli during two aircraft field campaigns, Marine Stratus/stratocumulus Experiment (MASE) and Physics of Stratocumulus Top (POST), are used to validate Moderate Resolution Imaging Spectroradiometer (MODIS) cloud optical thickness (COT), cloud liquid water path (LWP), and cloud effective radius (r e). In situ COT, LWP, and r e were calculated using 5 m vertically averaged droplet probe measurements of complete vertical cloud penetrations. MODIS COT, LWP, and r e 1 km pixels were averaged along these penetrations. COT comparisons in POST showed strong correlations and a near 1:1 relationship. In MASE, comparisons showed strong correlations; however, MODIS COT exceeded in situ COT, likely due to larger temporal differences between MODIS and in situ measurements. LWP comparisons between two cloud probes show good agreement for POST but not MASE, giving confidence to POST data. Both projects provided strong LWP correlations but MODIS exceeded in situ by 14–36%. MODIS in situ r e correlations were strong, but MODIS 2.1 µm r e exceeded in situ r e, which contributed to LWP bias; in POST, MODIS r e was 20–30% greater than in situ r e. Maximum in situ r e near cloud top showed comparisons nearer 1:1. Other MODIS r e bands (3.7 µm and 1.6 µm) showed similar comparisons. Temporal differences between MODIS and in situ measurements, airplane speed differences, and cloud probe artifacts were likely causes of weaker MASE correlations. POST COT comparison was best for temporal differences under 20 min. POST data validate MODIS COT but it also implies a positive MODIS r e bias that propagates to LWP while still capturing variability. PMID:27708990

MODIS comparisons with northeastern Pacific in situ stratocumulus microphysics

DOE PAGES

Noble, Stephen R.; Hudson, James G.

2015-07-22

Here, vertical sounding measurements within stratocumuli during two aircraft field campaigns, Marine Stratus/stratocumulus Experiment (MASE) and Physics of Stratocumulus Top (POST), are used to validate Moderate Resolution Imaging Spectroradiometer (MODIS) cloud optical thickness (COT), cloud liquid water path (LWP), and cloud effective radius (r e). In situ COT, LWP, and r e were calculated using 5 m vertically averaged droplet probe measurements of complete vertical cloud penetrations. MODIS COT, LWP, and r e 1 km pixels were averaged along these penetrations. COT comparisons in POST showed strong correlations and a near 1:1 relationship. In MASE, comparisons showed strong correlations; however,more » MODIS COT exceeded in situ COT, likely due to larger temporal differences between MODIS and in situ measurements. LWP comparisons between two cloud probes show good agreement for POST but not MASE, giving confidence to POST data. Both projects provided strong LWP correlations but MODIS exceeded in situ by 14–36%. MODIS in situ r e correlations were strong, but MODIS 2.1 µm r e exceeded in situ r e, which contributed to LWP bias; in POST, MODIS r e was 20–30% greater than in situ r e. Maximum in situ r e near cloud top showed comparisons nearer 1:1. Other MODIS r e bands (3.7 µm and 1.6 µm) showed similar comparisons. Temporal differences between MODIS and in situ measurements, airplane speed differences, and cloud probe artifacts were likely causes of weaker MASE correlations. POST COT comparison was best for temporal differences under 20 min. POST data validate MODIS COT but it also implies a positive MODIS r e bias that propagates to LWP while still capturing variability.« less

Breast-cancer-isation explored: Social experiences of gynaecological cancer in a Norwegian context.

PubMed

Solbraekke, Kari Nyheim; Lorem, Geir

2016-11-01

This article's point of departure is recent claims that breast cancer survivorship displaying positivity and self-growth represents the gold standard for all forms of cancer survivorship in English-speaking Western cultures. An interview study of Norwegian women regarding gynaecological cancer followed by hysterectomy is used to explore whether this process is taking place beyond this setting. Results show that the women's experiences of having to display survivorship in this manner are not as notable as found in English-speaking Western countries, neither is their experience of social othering. Reasons for this may be strong norms of social egalitarianism marking Norwegian culture and breast cancer informational campaigns that have not yet totally defined Norwegian norms for how to survive cancer. At the clinic and in the public sphere, however, the women experience gynaecological cancer as clearly having lower status than breast cancer, leading to a strong sense that the bodily site of their disease is taboo. Hence, as found in English-speaking cultures, the complex embodied nature of having gynaecological cancer and life beyond treatment seems to be silenced by the media and medical institutions. Finally, implications for future research and health care related to cancer survivorship are also discussed. © 2016 Foundation for the Sociology of Health & Illness.

Using affinity capillary electrophoresis and computational models for binding studies of heparinoids with p-selectin and other proteins.

PubMed

Mozafari, Mona; Balasupramaniam, Shantheya; Preu, Lutz; El Deeb, Sami; Reiter, Christian G; Wätzig, Hermann

2017-06-01

A fast and precise affinity capillary electrophoresis (ACE) method has been developed and applied for the investigation of the binding interactions between P-selectin and heparinoids as potential P-selectin inhibitors in the presence and absence of calcium ions. Furthermore, model proteins and vitronectin were used to appraise the binding behavior of P-selectin. The normalized mobility ratios (∆R/R f ), which provided information about the binding strength and the overall charge of the protein-ligand complex, were used to evaluate the binding affinities. It was found that P-selectin interacts more strongly with heparinoids in the presence of calcium ions. P-selectin was affected by heparinoids at the concentration of 3 mg/L. In addition, the results of the ACE experiments showed that among other investigated proteins, albumins and vitronectin exhibited strong interactions with heparinoids. Especially with P-selectin and vitronectin, the interaction may additionally induce conformational changes. Subsequently, computational models were applied to interpret the ACE experiments. Docking experiments explained that the binding of heparinoids on P-selectin is promoted by calcium ions. These docking models proved to be particularly well suited to investigate the interaction of charged compounds, and are therefore complementary to ACE experiments. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The emotional power of poetry: neural circuitry, psychophysiology and compositional principles

PubMed Central

Koelsch, Stefan; Wagner, Valentin; Jacobsen, Thomas; Menninghaus, Winfried

2017-01-01

Abstract It is a common experience—and well established experimentally—that music can engage us emotionally in a compelling manner. The mechanisms underlying these experiences are receiving increasing scrutiny. However, the extent to which other domains of aesthetic experience can similarly elicit strong emotions is unknown. Using psychophysiology, neuroimaging and behavioral responses, we show that recited poetry can act as a powerful stimulus for eliciting peak emotional responses, including chills and objectively measurable goosebumps that engage the primary reward circuitry. Importantly, while these responses to poetry are largely analogous to those found for music, their neural underpinnings show important differences, specifically with regard to the crucial role of the nucleus accumbens. We also go beyond replicating previous music-related studies by showing that peak aesthetic pleasure can co-occur with physiological markers of negative affect. Finally, the distribution of chills across the trajectory of poems provides insight into compositional principles of poetry. PMID:28460078

What determines the interfacial configuration of Nb/Al2O3 and Nb/MgO interface

PubMed Central

Du, J. L.; Fang, Y.; Fu, E. G.; Ding, X.; Yu, K. Y.; Wang, Y. G.; Wang, Y. Q.; Baldwin, J. K.; Wang, P. P.; Bai, Q.

2016-01-01

Nb films are deposited on single crystal Al2O3 (110) and MgO(111) substrates by e-beam evaporation technique. Structure of Nb films and orientation relationships (ORs) of Nb/Al2O3 and Nb/MgO interface are studied and compared by the combination of experiments and simulations. The experiments show that the Nb films obtain strong (110) texture, and the Nb film on Al2O3(110) substrate shows a higher crystalline quality than that on MgO(111) substrate. First principle calculations show that both the lattice mismatch and the strength of interface bonding play major roles in determining the crystalline perfection of Nb films and ORs between Nb films and single crystal ceramic substrates. The fundamental mechanisms for forming the interfacial configuration in terms of the lattice mismatch and the strength of interface bonding are discussed. PMID:27698458

Proton beam shaped by “particle lens” formed by laser-driven hot electrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhai, S. H.; Shen, B. F., E-mail: bfshen@mail.shcnc.ac.cn, E-mail: wwpvin@hotmail.com, E-mail: yqgu@caep.cn; Wang, W. P., E-mail: bfshen@mail.shcnc.ac.cn, E-mail: wwpvin@hotmail.com, E-mail: yqgu@caep.cn

2016-05-23

Two-dimensional tailoring of a proton beam is realized by a “particle lens” in our experiment. A large quantity of electrons, generated by an intense femtosecond laser irradiating a polymer target, produces an electric field strong enough to change the trajectory and distribution of energetic protons flying through the electron area. The experiment shows that a strip pattern of the proton beam appears when hot electrons initially converge inside the plastic plate. Then the shape of the proton beam changes to a “fountain-like” pattern when these hot electrons diffuse after propagating a distance.

Experimental industrial signal acquisition board in a large scientific device

NASA Astrophysics Data System (ADS)

Zeng, Xiangzhen; Ren, Bin

2018-02-01

In order to measure the industrial signal of neutrino experiment, a set of general-purpose industrial data acquisition board has been designed. It includes the function of switch signal input and output, and the function of analog signal input. The main components are signal isolation amplifier and filter circuit, ADC circuit, microcomputer systems and isolated communication interface circuit. Through the practical experiments, it shows that the system is flexible, reliable, convenient and economical, and the system has characters of high definition and strong anti-interference ability. Thus, the system fully meets the design requirements.

Flashline Mars Arctic Research Station (FMARS) 2009 Crew Perspectives

NASA Technical Reports Server (NTRS)

Ferrone, Kristine; Cusack, Stacy L.; Garvin, Christy; Kramer, Walter Vernon; Palaia, Joseph E., IV; Shiro, Brian

2010-01-01

A crew of six "astronauts" inhabited the Mars Society s Flashline Mars Arctic Research Station (FMARS) for the month of July 2009, conducting a simulated Mars exploration mission. In addition to the various technical achievements during the mission, the crew learned a vast amount about themselves and about human factors relevant to a future mission to Mars. Their experiences, detailed in their own words, show the passion of those with strong commitment to space exploration and detail the human experiences for space explorers including separation from loved ones, interpersonal conflict, dietary considerations, and the exhilaration of surmounting difficult challenges.

Object-based selection in the Baylis and Driver (1993) paradigm is subject to space-based attentional modulation.

PubMed

Müller, Hermann J; O'Grady, Rebecca; Krummenacher, Joseph; Heller, Dieter

2008-11-01

Three experiments re-examined Baylis and Driver's (1993) strong evidence for object-based selection, that making relative apex location judgments is harder between two objects than within a single object, with object (figure-ground) segmentation determined solely by color-based perceptual set. Using variations of the Baylis and Driver paradigm, the experiments replicated a two-object cost. However, they also showed a large part of the two-object cost to be attributable to space-based factors, though there remained an irreducible cost consistent with 'true' object-based selection.

Nanosecond laser photolysis studies of vitamin K 3 in aqueous solution

NASA Astrophysics Data System (ADS)

Chen, J. F.; Ge, X. W.; Chu, G. S.; Zhang, Z. C.; Zhang, M. W.; Yao, S. D.; Lin, N. Y.

1999-06-01

Vitamin K 3 in aqueous solution was investigated by 248 nm laser flash photolysis. Laser-induced transient species were characterized according to kinetic analysis and quenching experiments by Mn 2+ and O 2. In neutral solutions, the intermediates recorded were assigned to excited triplet states and dehydrogenated radicals of vitamin K 3. In comparison with the results of pulse radiolytical experiment, vitamin K 3 not only has strong electron affinity but could also could be photoionized by UV laser light. All this shows that vitamin K 3 acts as an effective electron carrier and electron transfer agent.

The Psychological Characteristics of Experiences That Influence Science Motivation and Content Knowledge

ERIC Educational Resources Information Center

Bathgate, Meghan; Schunn, Christian

2017-01-01

While motivational changes towards science are common during adolescence, our work asks which perceived classroom experiences are most strongly related to these changes. Additionally, we examine which experiences are most strongly associated with learning classroom content. In particular, using self-reports from a sample of approximately 3000…

Local Climate Changes Forced by Changes in Land Use and topography in the Aburrá Valley, Colombia.

NASA Astrophysics Data System (ADS)

Zapata Henao, M. Z.; Hoyos Ortiz, C. D.

2017-12-01

One of the challenges in the numerical weather models is the adequate representation of soil-vegetation-atmosphere interaction at different spatial scales, including scenarios with heterogeneous land cover and complex mountainous terrain. The interaction determines the energy, mass and momentum exchange at the surface and could affect different variables including precipitation, temperature and wind. In order to quantify the long-term climate impact of changes in local land use and to assess the role of topography, two numerical experiments were examined. The first experiment allows assessing the continuous growth of urban areas within the Aburrá Valley, a complex terrain region located in Colombian Andes. The Weather Research Forecast model (WRF) is used as the basis of the experiment. The basic setup involves two nested domains, one representing the continental scale (18 km) and the other the regional scale (2 km). The second experiment allows drastic topography modification, including changing the valley configuration to a plateau. The control run for both experiments corresponds to a climatological scenario. In both experiments the boundary conditions correspond to the climatological continental domain output. Surface temperature, surface winds and precipitation are used as the main variables to compare both experiments relative to the control run. The results of the first experiment show a strong relationship between land cover and the variables, specially for surface temperature and wind speed, due to the strong forcing land cover imposes on the albedo, heat capacity and surface roughness, changing temperature and wind speed magnitudes. The second experiment removes the winds spatial variability related with hill slopes, the direction and magnitude are modulated only by the trade winds and roughness of land cover.

Weak beacon detection for air-to-ground optical wireless link establishment.

PubMed

Han, Yaoqiang; Dang, Anhong; Tang, Junxiong; Guo, Hong

2010-02-01

In an air-to-ground free-space optical communication system, strong background interference seriously affects the beacon detection, which makes it difficult to establish the optical link. In this paper, we propose a correlation beacon detection scheme under strong background interference conditions. As opposed to traditional beacon detection schemes, the beacon is modulated by an m-sequence at the transmitting terminal with a digital differential matched filter (DDMF) array introduced at the receiving end to detect the modulated beacon. This scheme is capable of suppressing both strong interference and noise by correlation reception of the received image sequence. In addition, the DDMF array enables each pixel of the image sensor to have its own DDMF of the same structure to process its received image sequence in parallel, thus it makes fast beacon detection possible. Theoretical analysis and an outdoor experiment have been demonstrated and show that the proposed scheme can realize fast and effective beacon detection under strong background interference conditions. Consequently, the required beacon transmission power can also be reduced dramatically.

Scattering from Rock and Rock Outcrops

DTIC Science & Technology

2013-09-30

whose orientations and size distributions reflect the internal fault organization of the bedrock. A mathematical model of the leeward side of an...scattering from facets oriented close to normal incidence to the sonar system. Diffraction from sharp edges may also contribute strong scattering that 5 is...collected in a recent field experiment and are currently being analyzed. Figure 5 shows PhD student Derek Olson alongside the photogrammetry system

Strong-field and attosecond physics in solids

DOE PAGES

Ghimire, Shambhu; Ndabashimiye, Georges; DiChiara, Anthony D.; ...

2014-10-08

We review the status of strong-field and attosecond processes in bulk transparent solids near the Keldysh tunneling limit. For high enough fields and low-frequency excitations, the optical and electronic properties of dielectrics can be transiently and reversibly modified within the applied pulse. In Ghimire et al (2011 Phys. Rev. Lett. 107 167407) non-parabolic band effects were seen in photon-assisted tunneling experiments in ZnO crystals in a strong mid-infrared field. Using the same ZnO crystals, Ghimire et al (2011 Nat. Phys. 7 138–41) reported the first observation of non-pertubative high harmonics, extending well above the bandgap into the vacuum ultraviolet. Recent experiments by Schubert et al (2014 Nat. Photonics 8 119–23) showed a carrier envelope phase dependence in the harmonic spectrum in strong-field 30 THz driven GaSe crystals which is the most direct evidence yet of the role of sub-cycle electron dynamics in solid-state harmonic generation. The harmonic generation mechanism is different from the gas phase owing to the high density and periodicity of the crystal. For example, this results in a linear dependence of the high-energy cutoff with the applied field in contrast to the quadratic dependence in the gas phase. Sub-100 attosecond pulses could become possible if the harmonic spectrum can be extended into the extreme ultraviolet (XUV). Here we report harmonics generated in bulk MgO crystals, extending tomore » $$\\sim 26$$ eV when driven by ~35 fs, 800 nm pulses focused to a ~1 VÅ$$^{-1}$$ peak field. The fundamental strong-field and attosecond response also leads to Wannier–Stark localization and reversible semimetallization as seen in the sub-optical cycle behavior of XUV absorption and photocurrent experiments on fused silica by Schiffrin et al (2013 Nature 493 70–4) and Schultze et al (2013 Nature 493 75–8). These studies are advancing our understanding of fundamental strong-field and attosecond physics in solids with potential applications for compact coherent short-wavelength sources and ultra-high speed optoelectronics.« less

Grain boundary stability and influence on ionic conductivity in a disordered perovskite -- a first-principles investigation of lithium lanthanum titanate

DOE PAGES

Alexander, Kathleen C.; Ganesh, P.; Chi, Miaofang; ...

2016-12-01

The origin of ionic conductivity in bulk lithium lanthanum titanate, a promising solid electrolyte for Li-ion batteries, has long been under debate, with experiments showing lower conductivity than predictions. Recent microscopy images show Type I and Type II grain boundaries. Using first-principles based calculations we find that experimentally observed Type I boundaries are more stable compared to the Type II grain boundaries, consistent with their observed relative abundance. Grain boundary stability appears to strongly anti-correlate with the field strength as well as the spatial extent of the space charge region. Ion migration is faster along Type II grain boundaries thanmore » across, consistent with recent experiments of increased conductivity when Type II densities were increased.« less

Hybrid simulations of a parallel collisionless shock in the large plasma device

DOE PAGES

Weidl, Martin S.; Winske, Dan; Jenko, Frank; ...

2016-12-01

We present two-dimensional hybrid kinetic/magnetohydrodynamic simulations of planned laser-ablation experiments in the Large Plasma Device (LAPD). Our results, based on parameters which have been validated in previous experiments, show that a parallel collisionless shock can begin forming within the available space. Carbon-debris ions that stream along the magnetic- eld direction with a blow-o speed of four times the Alfv en velocity excite strong magnetic uctuations, eventually transfering part of their kinetic energy to the surrounding hydrogen ions. This acceleration and compression of the background plasma creates a shock front, which satis es the Rankine{Hugoniot conditions and can therefore propagate onmore » its own. Furthermore, we analyze the upstream turbulence and show that it is dominated by the right-hand resonant instability.« less

Diffeomorphic demons: efficient non-parametric image registration.

PubMed

Vercauteren, Tom; Pennec, Xavier; Perchant, Aymeric; Ayache, Nicholas

2009-03-01

We propose an efficient non-parametric diffeomorphic image registration algorithm based on Thirion's demons algorithm. In the first part of this paper, we show that Thirion's demons algorithm can be seen as an optimization procedure on the entire space of displacement fields. We provide strong theoretical roots to the different variants of Thirion's demons algorithm. This analysis predicts a theoretical advantage for the symmetric forces variant of the demons algorithm. We show on controlled experiments that this advantage is confirmed in practice and yields a faster convergence. In the second part of this paper, we adapt the optimization procedure underlying the demons algorithm to a space of diffeomorphic transformations. In contrast to many diffeomorphic registration algorithms, our solution is computationally efficient since in practice it only replaces an addition of displacement fields by a few compositions. Our experiments show that in addition to being diffeomorphic, our algorithm provides results that are similar to the ones from the demons algorithm but with transformations that are much smoother and closer to the gold standard, available in controlled experiments, in terms of Jacobians.

a Study of the Interaction of Atoms with Strong Laser Fields.

NASA Astrophysics Data System (ADS)

Edwards, Mark

1984-02-01

In this thesis three aspects of the interactions of atoms with high intensity laser fields were treated. All three were motivated by experiment. The first investigation was prompted by a recent experiment (Kruit et al. 1983) involving multiphoton ionization of Xe. In this experiment it was found that the photoelectron energy spectrum contained peaks which corresponded to the absorption of more than the minimum number of photons required to ionize the atom. The effective orders of nonlinearity, furthermore, showed a striking uniformity. These effects were investigated using a model approximation consisting of a single bound state and m continua. Simple analytic expressions were obtained for the quantities measured in the experiment and the limit m (--->) (INFIN) was obtained. The results showed good qualitative agreement with experiment. An experiment (Grove et al. 1977) designed to test a theoretical calculation of the dynamical Stark effect stimulated the second part of this thesis. When experimental conditions were varied slightly, strong field turn-on effects were observed in the resonance fluorescence spectrum from a two-level atom (TLA). This experimental result led to the present study of how an adiabatically and near-adiabatically changing field intensity affects the resonance fluorescence spectrum of a TLA. It was found that there is an asymmetry in the spectrum for off-resonance excitation produced because the field turn-on repopulates the dressed state that is depopulated by spontaneous emission. The experimental result was not explained by this result, however. The third part of this thesis was based on an experiment (Granneman and Van der Wiel 1976) which attempted to verify a perturbation calculation of the two-photon ionization cross section of Cs. A discrepancy of four orders of magnitude near a minimum in the cross section was found between theory and experiment. To explain this discrepancy it was suggested (Armstrong and Beers 1977) that the effective order of nonlinearity (k) for this process varied significantly around the minimum. The present study involves a perturbation calculation of k. It was found that k varies rapidly around the minimum, and that this variation should be experimentally observable for laser intensities of the order of tens of GW cm('-2).

Optical Wave Turbulence and Wave Condensation in a Nonlinear Optical Experiment

NASA Astrophysics Data System (ADS)

Laurie, Jason; Bortolozzo, Umberto; Nazarenko, Sergey; Residori, Stefania

We present theory, numerical simulations and experimental observations of a 1D optical wave system. We show that this system is of a dual cascade type, namely, the energy cascading directly to small scales, and the photons or wave action cascading to large scales. In the optical context the inverse cascade is particularly interesting because it means the condensation of photons. We show that the cascades are induced by a six-wave resonant interaction process described by weak turbulence theory. We show that by starting with weakly nonlinear randomized waves as an initial condition, there exists an inverse cascade of photons towards the lowest wavenumbers. During the cascade nonlinearity becomes strong at low wavenumbers and, due to the focusing nature of the nonlinearity, it leads to modulational instability resulting in the formation of solitons. Further interaction of the solitons among themselves and with incoherent waves leads to the final condensate state dominated by a single strong soliton. In addition, we show the existence of the direct energy cascade numerically and that it agrees with the wave turbulence prediction.

The invisible cues that guide king penguin chicks home: use of magnetic and acoustic cues during orientation and short-range navigation.

PubMed

Nesterova, Anna P; Chiffard, Jules; Couchoux, Charline; Bonadonna, Francesco

2013-04-15

King penguins (Aptenodytes patagonicus) live in large and densely populated colonies, where navigation can be challenging because of the presence of many conspecifics that could obstruct locally available cues. Our previous experiments demonstrated that visual cues were important but not essential for king penguin chicks' homing. The main objective of this study was to investigate the importance of non-visual cues, such as magnetic and acoustic cues, for chicks' orientation and short-range navigation. In a series of experiments, the chicks were individually displaced from the colony to an experimental arena where they were released under different conditions. In the magnetic experiments, a strong magnet was attached to the chicks' heads. Trials were conducted in daylight and at night to test the relative importance of visual and magnetic cues. Our results showed that when the geomagnetic field around the chicks was modified, their orientation in the arena and the overall ability to home was not affected. In a low sound experiment we limited the acoustic cues available to the chicks by putting ear pads over their ears, and in a loud sound experiment we provided additional acoustic cues by broadcasting colony sounds on the opposite side of the arena to the real colony. In the low sound experiment, the behavior of the chicks was not affected by the limited sound input. In the loud sound experiment, the chicks reacted strongly to the colony sound. These results suggest that king penguin chicks may use the sound of the colony while orienting towards their home.

Moral identity and the experience of moral elevation in response to acts of uncommon goodness.

PubMed

Aquino, Karl; McFerran, Brent; Laven, Marjorie

2011-04-01

Four studies using survey and experimental designs examined whether people whose moral identity is highly self-defining are more susceptible to experiencing a state of moral elevation after being exposed to acts of uncommon moral goodness. Moral elevation consists of a suite of responses that motivate prosocial action tendencies. Study 1 showed that people higher (vs. lower) in moral identity centrality reported experiencing more intense elevating emotions, had more positive views of humanity, and were more desirous of becoming a better person after reading about an act of uncommon goodness than about a merely positive situation or an act of common benevolence. Study 2 showed that those high in moral identity centrality were more likely to recall acts of moral goodness and experience moral elevation in response to such events more strongly. These experiences were positively related to self-reported prosocial behavior. Study 3 showed a direct effect on behavior using manipulated, rather than measured, moral identity centrality. Study 4 replicated the effect of moral identity on the states of elevation as well as on self-reported physical sensations and showed that the elevation mediates the relationship between moral identity, witnessing uncommon goodness, and prosocial behavior.

Conversation Salons: A Flexible Format for Open Discourse in Dental Education.

PubMed

Quick, Karin K

2016-04-01

A series of conversation salons was created at the University of Minnesota School of Dentistry as an innovative format with the objective of engaging students, faculty, staff, and practitioners in discussion to promote reflection. The aim of this study was to explore the nature of students' abilities in the salons to connect experiences through reflection and apply what they learned to practice. Reflective essays (written during the summer and fall semesters of 2014) from 108 fourth-year dental students (all members of the Class of 2015) were read and assessed for the nature of reflection, number of connections, references to the past, applications to the future, and use of examples. For analysis, the theoretical works of Schön and Mezirow provided a useful framework. Overall, the results showed that the participants found the salon experience to be positive, and student participation was strong. When asked about learning, the most frequent responses were topic-related. At this stage of dental education, the students were largely focused on their future practice and found it easier to connect to an imagined future than a past experience. In terms of student abilities to reflect, the majority were skilled at simple reflection, based on these essays since only 18% were non-reflective and 15% showed strong critical reflection skills. The open and respectful environment of the salons enabled discussion and promoted reflection. These results suggest that more opportunities for collegial conversations and instruction in reflective practice earlier in the dental curriculum may be beneficial.

An experimental study of ^{{{{Fe}}^{2 + } {-}{{Mg}}}} K_{{D}} between orthopyroxene and rhyolite: a strong dependence on H2O in the melt

NASA Astrophysics Data System (ADS)

Waters, Laura E.; Lange, Rebecca A.

2017-06-01

The effect of temperature, pressure, and dissolved H2O in the melt on the Fe2+-Mg exchange coefficient between orthopyroxene and rhyolite melt was investigated with a series of H2O fluid-saturated phase-equilibrium experiments. Experiments were conducted in a rapid-quench cold-seal pressure vessel over a temperature and pressure range of 785-850 °C and 80-185 MPa, respectively. Oxygen fugacity was buffered with the solid Ni-NiO assemblage in a double-capsule assembly. These experiments, when combined with H2O-undersaturated experiments in the literature, show that ^{{{{Fe}}^{2 + } {-}{{Mg}}}} K_{{D}} between orthopyroxene and rhyolite liquid increases strongly (from 0.23 to 0.54) as a function of dissolved water in the melt (from 2.7 to 5.6 wt%). There is no detectable effect of temperature or pressure over an interval of 65 °C and 100 MPa, respectively, on the Fe2+-Mg exchange coefficient values. The data show that Fe-rich orthopyroxene is favored at high water contents, whereas Mg-rich orthopyroxene crystallizes at low water contents. It is proposed that the effect of dissolved water in the melt on the composition of orthopyroxene is analogous to its effect on the composition of plagioclase. In the latter case, dissolved hydroxyl groups preferentially complex with Na+ relative to Ca2+, which reduces the activity of the albite component, leading to a more anorthite-rich (calcic) plagioclase. Similarly, it is proposed that dissolved hydroxyl groups preferentially complex with Mg2+ relative to Fe2+, thus lowering the activity of the enstatite component, leading to a more Fe-rich orthopyroxene at high water contents in the melt. The experimental results presented in this study show that reversely zoned pyroxene (i.e., Mg-rich rims) in silicic magmas may be a result of H2O degassing and not necessarily the result of mixing with a more mafic magma.

Adsorption and desorption for dynamics transport of hexavalent chromium Cr(Ⅵ) in soil column

NASA Astrophysics Data System (ADS)

Tong, J.

2017-12-01

Batch experiments have been carried out to study the adsorption of heavy metals in soils, and the migration and transformation of hexavalent chromium Cr(Ⅵ) in the soil of a vegetable base were studied by dynamic adsorption and desorption soil column experiments. The aim of this study was to investigate the effect of initial concentration and pH value on the adsorption process of Cr(Ⅵ). Breakthrough curve were used to evaluate the capacity of Cr(Ⅵ) adsorption in soil columns. The results show that the higher the initial concentration, the worse the adsorption capacity of Cr(Ⅵ). The adsorption of Cr(Ⅵ) was strongly sensitive to pH value. The capacity of Cr(Ⅵ) adsorption is maximized at very low pH value. This may be due to changes in pH that cause a series of complex reactions in Cr(Ⅵ). In a strongly acidic environment, the reaction of Cr(Ⅵ) with hydrogen ions is accompanied by the formation of Cr3+, which reacts with the soil free iron-aluminum oxide to produce hydroxide in the soil. The results of the desorption experiments indicate that Cr(Ⅵ) is more likely to leach from this soil, but if the eluent is strong acid solution, the leaching process will be slow and persistent. The program CXTFIT was used to fit the breakthrough curve to estimate parameters. The results of the calculation of the dispersion coefficient (D) can be obtained by this program. The two-site model fit the breakthrough curve data of Cr(Ⅵ) well, and the parameters calculated by CXTFIT can be used to explain the behavior of Cr(Ⅵ) migration and transformation in soil columns. When pH=2, the retardation factor (R) reach at 79.71 while the value of the R is generally around 10 in other experiments. The partitioning coefficient β shows that more than half of the adsorption sites are rate-limited in this adsorption process and non-equilibrium effects the Cr(Ⅵ) transport process in this soil.

Constraining Crustal Anisotropy by Receiver Functions at the Deep Continental Drilling Site KTB in Southern Germany

NASA Astrophysics Data System (ADS)

Bianchi, Irene; Qorbani, Ehsan; Bokelmann, Götz

2016-04-01

As one of the rare observational tools for studying deformation and stress within the Earth, seismic anisotropy has been one of the focuses of geophysical studies over the last decade. In order to unravel the anisotropic properties of the crust, the teleseismic receiver functions (RF) methodology has started to be widely applied recently. Such effects of anisotropy on RF were illustrated in theoretical studies, showing the strong backazimuthal dependence of RF on the 3D characteristics of the media sampled by the waves. The use of teleseismic RF has the advantage of not being affected by a heterogeneous depth distribution of local earthquakes, since teleseismic rays sample the entire crust beneath the stations. The application of this technique however, needs to be critically assessed using a suitable field test. To test the technique, we need a crustal block where the underground structure is reasonably well-known, e.g., where there is extensive knowledge from local seismic experiments and drilling. A field experiment has thus been carried out around the KTB (Kontinental Tiefbohrung) site in the Oberpfalz area in Southeastern Germany, in order to compare with previous results from deep drilling, and high-frequency seismic experiments around the drill site. The investigated region has been studied extensively by local geophysical experiments, and geological studies. The deep borehole was placed into gneiss rocks of the Zone Erbendorf-Vohenstrauss. The drilling activity lasted from 1987 to 1994, and descended down to a depth of 9101 meters, sampling an alternating sequence of paragneiss and amphibolite, with metamorphism of upper amphibolite facies conditions, and ductile deformation produced a strong foliation of the rocks. The application of the RFs reveals strong seismic anisotropy in the upper crust related to the so-called Erbendorf body. The SKS shear-wave splitting method has been applied as well, revealing coherent results for the whole region with exception of the southernmost station, for which the seismic waves show larger delays. We use the RF observations to test the effect of crustal anisotropy on the SKS records, which sample entire crust and upper mantle.

The good, the bad and the plenty: interactive effects of food quality and quantity on the growth of different Daphnia species.

PubMed

Bukovinszky, Tibor; Verschoor, Antonie M; Helmsing, Nico R; Bezemer, T Martijn; Bakker, Elisabeth S; Vos, Matthijs; de Senerpont Domis, Lisette N

2012-01-01

Effects of food quality and quantity on consumers are neither independent nor interchangeable. Although consumer growth and reproduction show strong variation in relation to both food quality and quantity, the effects of food quality or food quantity have usually been studied in isolation. In two experiments, we studied the growth and reproduction in three filter-feeding freshwater zooplankton species, i.e. Daphnia galeata x hyalina, D. pulicaria and D. magna, on their algal food (Scenedesmus obliquus), varying in carbon to phosphorus (C∶P) ratios and quantities (concentrations). In the first experiment, we found a strong positive effect of the phosphorus content of food on growth of Daphnia, both in their early and late juvenile development. Variation in the relationship between the P-content of animals and their growth rate reflected interspecific differences in nutrient requirements. Although growth rates typically decreased as development neared maturation, this did not affect these species-specific couplings between growth rate and Daphnia P-content. In the second experiment, we examined the effects of food quality on Daphnia growth at different levels of food quantity. With the same decrease in P-content of food, species with higher estimated P-content at zero growth showed a larger increase in threshold food concentrations (i.e. food concentration sufficient to meet metabolic requirements but not growth). These results suggest that physiological processes such as maintenance and growth may in combination explain effects of food quality and quantity on consumers. Our study shows that differences in response to variation in food quality and quantity exist between species. As a consequence, species-specific effects of food quality on consumer growth will also determine how species deal with varying food levels, which has implications for resource-consumer interactions.

The Good, the Bad and the Plenty: Interactive Effects of Food Quality and Quantity on the Growth of Different Daphnia Species

PubMed Central

Bukovinszky, Tibor; Verschoor, Antonie M.; Helmsing, Nico R.; Bezemer, T. Martijn; Bakker, Elisabeth S.; Vos, Matthijs; de Senerpont Domis, Lisette N.

2012-01-01

Effects of food quality and quantity on consumers are neither independent nor interchangeable. Although consumer growth and reproduction show strong variation in relation to both food quality and quantity, the effects of food quality or food quantity have usually been studied in isolation. In two experiments, we studied the growth and reproduction in three filter-feeding freshwater zooplankton species, i.e. Daphnia galeata x hyalina, D. pulicaria and D. magna, on their algal food (Scenedesmus obliquus), varying in carbon to phosphorus (C∶P) ratios and quantities (concentrations). In the first experiment, we found a strong positive effect of the phosphorus content of food on growth of Daphnia, both in their early and late juvenile development. Variation in the relationship between the P-content of animals and their growth rate reflected interspecific differences in nutrient requirements. Although growth rates typically decreased as development neared maturation, this did not affect these species-specific couplings between growth rate and Daphnia P-content. In the second experiment, we examined the effects of food quality on Daphnia growth at different levels of food quantity. With the same decrease in P-content of food, species with higher estimated P-content at zero growth showed a larger increase in threshold food concentrations (i.e. food concentration sufficient to meet metabolic requirements but not growth). These results suggest that physiological processes such as maintenance and growth may in combination explain effects of food quality and quantity on consumers. Our study shows that differences in response to variation in food quality and quantity exist between species. As a consequence, species-specific effects of food quality on consumer growth will also determine how species deal with varying food levels, which has implications for resource-consumer interactions. PMID:23049734

Towards a better preclinical model of PTSD: characterizing animals with weak extinction, maladaptive stress responses and low plasma corticosterone.

PubMed

Reznikov, Roman; Diwan, Mustansir; Nobrega, José N; Hamani, Clement

2015-02-01

Most of the available preclinical models of PTSD have focused on isolated behavioural aspects and have not considered individual variations in response to stress. We employed behavioural criteria to identify and characterize a subpopulation of rats that present several features analogous to PTSD-like states after exposure to classical fear conditioning. Outbred Sprague-Dawley rats were segregated into weak- and strong-extinction groups on the basis of behavioural scores during extinction of conditioned fear responses. Animals were subsequently tested for anxiety-like behaviour in the open-field test (OFT), novelty suppressed feeding (NSF) and elevated plus maze (EPM). Baseline plasma corticosterone was measured prior to any behavioural manipulation. In a second experiment, rats underwent OFT, NSF and EPM prior to being subjected to fear conditioning to ascertain whether or not pre-stress levels of anxiety-like behaviours could predict extinction scores. We found that 25% of rats exhibit low extinction rates of conditioned fear, a feature that was associated with increased anxiety-like behaviour across multiple tests in comparison to rats showing strong extinction. In addition, weak-extinction animals showed low levels of corticosterone prior to fear conditioning, a variable that seemed to predict extinction recall scores. In a separate experiment, anxiety measures taken prior to fear conditioning were not predictive of a weak-extinction phenotype, suggesting that weak-extinction animals do not show detectable traits of anxiety in the absence of a stressful experience. These findings suggest that extinction impairment may be used to identify stress-vulnerable rats, thus providing a useful model for elucidating mechanisms and investigating potential treatments for PTSD. Copyright © 2014 Elsevier Ltd. All rights reserved.

Centrifuge models simulating magma emplacement during oblique rifting

NASA Astrophysics Data System (ADS)

Corti, Giacomo; Bonini, Marco; Innocenti, Fabrizio; Manetti, Piero; Mulugeta, Genene

2001-07-01

A series of centrifuge analogue experiments have been performed to model the mechanics of continental oblique extension (in the range of 0° to 60°) in the presence of underplated magma at the base of the continental crust. The experiments reproduced the main characteristics of oblique rifting, such as (1) en-echelon arrangement of structures, (2) mean fault trends oblique to the extension vector, (3) strain partitioning between different sets of faults and (4) fault dips higher than in purely normal faults (e.g. Tron, V., Brun, J.-P., 1991. Experiments on oblique rifting in brittle-ductile systems. Tectonophysics 188, 71-84). The model results show that the pattern of deformation is strongly controlled by the angle of obliquity ( α), which determines the ratio between the shearing and stretching components of movement. For α⩽35°, the deformation is partitioned between oblique-slip and normal faults, whereas for α⩾45° a strain partitioning arises between oblique-slip and strike-slip faults. The experimental results show that for α⩽35°, there is a strong coupling between deformation and the underplated magma: the presence of magma determines a strain localisation and a reduced strain partitioning; deformation, in turn, focuses magma emplacement. Magmatic chambers form in the core of lower crust domes with an oblique trend to the initial magma reservoir and, in some cases, an en-echelon arrangement. Typically, intrusions show an elongated shape with a high length/width ratio. In nature, this pattern is expected to result in magmatic and volcanic belts oblique to the rift axis and arranged en-echelon, in agreement with some selected natural examples of continental rifts (i.e. Main Ethiopian Rift) and oceanic ridges (i.e. Mohns and Reykjanes Ridges).

Light-Induced Nuclear Synthesis of Spinach Chloroplast Fructose-1,6-bisphosphatase 1

PubMed Central

Chueca, Ana; Lázaro, Juan José; Gorgé, Julio López

1984-01-01

Etiolated spinach (Spinacia oleracea L. var Winter Giant) seedlings show a residual photosynthetic fructose-1,6-bisphosphatase activity, which sharply rises under illumination. This increase in activity is due to a light-induced de novo synthesis, as it has been demonstrated by enzyme labeling experiments with 2H2O and [35S]methionine. The rise of bisphosphatase activity under illumination is strongly inhibited by cycloheximide, but not by the 70S ribosome inhibitor lincocin, which shows the nuclear origin of this chloroplastic enzyme. Images Fig. 3 PMID:16663662

Bias in masked word identification: unconscious influences of repetition priming.

PubMed

Masson, Michael E J

2002-12-01

The beneficial influence of a prior study episode on subsequent identification of a word includes a large bias component, revealed in the forced-choice variant of the masked word identification test. In that type of test, subjects show a preference for a studied probe over a nonstudied probe, regardless of which one matches the masked target word. The forced-choice test was used in the present experiments to test the possibility that this bias effect is due to conscious recollection. Results show that bias was strongly attenuated (1) by changes in modality between study and test, and (2) under certain conditions, by using a conceptually driven study task. The bias effect was found only when probes were orthographically similar to one another, as predicted by the counter model (Ratcliff & McKoon, 1997). These results provide strong evidence that the bias effect is not mediated by conscious recollection.

Plant root proliferation in nitrogen-rich patches confers competitive advantage

PubMed Central

Robinson, D.; Hodge, A.; Griffiths, B. S.; Fitter, A. H.

1999-01-01

Plants respond strongly to environmental heterogeneity, particularly below ground, where spectacular root proliferations in nutrient-rich patches may occur. Such 'foraging' responses apparently maximize nutrient uptake and are now prominent in plant ecological theory. Proliferations in nitrogen-rich patches are difficult to explain adaptively, however. The high mobility of soil nitrate should limit the contribution of proliferation to N capture. Many experiments on isolated plants show only a weak relation between proliferation and N uptake. We show that N capture is associated strongly with proliferation during interspecific competition for finite, locally available, mixed N sources, precisely the conditions under which N becomes available to plants on generally infertile soils. This explains why N-induced root proliferation is an important resource-capture mechanism in N-limited plant communities and suggests that increasing proliferation by crop breeding or genetic manipulation will have a limited impact on N capture by well-fertilized monocultures.

Integrated fusion simulation with self-consistent core-pedestal coupling

DOE PAGES

Meneghini, O.; Snyder, P. B.; Smith, S. P.; ...

2016-04-20

In this study, accurate prediction of fusion performance in present and future tokamaks requires taking into account the strong interplay between core transport, pedestal structure, current profile and plasma equilibrium. An integrated modeling workflow capable of calculating the steady-state self- consistent solution to this strongly-coupled problem has been developed. The workflow leverages state-of-the-art components for collisional and turbulent core transport, equilibrium and pedestal stability. Validation against DIII-D discharges shows that the workflow is capable of robustly pre- dicting the kinetic profiles (electron and ion temperature and electron density) from the axis to the separatrix in good agreement with the experiments.more » An example application is presented, showing self-consistent optimization for the fusion performance of the 15 MA D-T ITER baseline scenario as functions of the pedestal density and ion effective charge Z eff.« less

Accurate Calculation of Oscillator Strengths for CI II Lines Using Non-orthogonal Wavefunctions

NASA Technical Reports Server (NTRS)

Tayal, S. S.

2004-01-01

Non-orthogonal orbitals technique in the multiconfiguration Hartree-Fock approach is used to calculate oscillator strengths and transition probabilities for allowed and intercombination lines in Cl II. The relativistic corrections are included through the Breit-Pauli Hamiltonian. The Cl II wave functions show strong term dependence. The non-orthogonal orbitals are used to describe the term dependence of radial functions. Large sets of spectroscopic and correlation functions are chosen to describe adequately strong interactions in the 3s(sup 2)3p(sup 3)nl (sup 3)Po, (sup 1)Po and (sup 3)Do Rydberg series and to properly account for the important correlation and relaxation effects. The length and velocity forms of oscillator strength show good agreement for most transitions. The calculated radiative lifetime for the 3s3p(sup 5) (sup 3)Po state is in good agreement with experiment.

SiC-based neutron detector in quasi-realistic working conditions: efficiency and stability at room and high temperature under fast neutron irradiations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferone, Raffaello; Issa, Fatima; Ottaviani, Laurent

In the framework of the European I SMART project, we have designed and made new SiC-based nuclear radiation detectors able to operate in harsh environments and to detect both fast and thermal neutrons. In this paper, we report experimental results of fast neutron irradiation campaign at high temperature (106 deg. C) in quasi-realistic working conditions. Our device does not suffer from high temperature, and spectra do show strong stability, preserving features. These experiments, as well as others in progress, show the I SMART SiC-based device skills to operate in harsh environments, whereas other materials would strongly suffer from degradation. Workmore » is still demanded to test our device at higher temperatures and to enhance efficiency in order to make our device fully exploitable from an industrial point of view. (authors)« less

Nonlinear focusing of ultrasonic waves by an axisymmetric diffraction grating embedded in water

NASA Astrophysics Data System (ADS)

Jiménez, N.; Romero-García, V.; Picó, R.; Garcia-Raffi, L. M.; Staliunas, K.

2015-11-01

We report the nonlinear focusing of ultrasonic waves by an axisymmetric diffraction grating immersed in water. In the linear regime, the system presents high focal gain (32 dB), with a narrow beam-width and intense side lobes as it is common in focusing by Fresnel-like lenses. Activating the nonlinearity of the host medium by using high amplitude incident waves, the focusing properties of the lens dramatically change. Theoretical predictions show that the focal gain of the system extraordinary increases in the strongly nonlinear regime (Mach number of 6.1 × 10-4). Particularly, the harmonic generation is locally activated at the focal spot, and the second harmonic beam is characterized by strongly reduced side-lobes and an excellent beam profile as experiments show in agreement with theory. The results can motivate applications in medical therapy or second harmonic imaging.

Strong fields and QED as function of the g-factor

NASA Astrophysics Data System (ADS)

Rafelski, Johann; Labun, Lance

2012-10-01

Precision QED experiments (muon g-2 and Lamb shift) require understanding of QED with arbitrary gyromagnetic ratio g>2. We will first show that the need to have a renormalizable theory requires for g>2 reformulation in terms of Klein-Gordon-Pauli (KGP) equation. Using KGP, we obtain the nonperturbative effective action of QED within Schwinger proper time method in arbitrarily strong quasi-constant external electromagnetic fields as a function of g. The expression is divergent for |g|>2, given the magnetic instability of the vacuum due to the lowest Landau orbit eigenenergy having an indefinite value in strong magnetic fields. The spectrum of Landau eigenvalues for KGP in a magnetic field is an exact periodic function of g, no states are disappearing from the spectrum. This periodicity allows to establish a generalized form of the effective action valid for all g. We show the presence of a cusp at the periodic points g=-6,-2,2,6. Consequently, the QED beta function and parts of light-by-light scattering differ from perturbative computation near to g=2 and an asymptotically free domain of g for QED arises. We further show that only for g=(2N+1) there is exact correspondence of a field-dependent quasi-temperature and the Unruh Temperature.

Control deprivation and styles of thinking.

PubMed

Zhou, Xinyue; He, Lingnan; Yang, Qing; Lao, Junpeng; Baumeister, Roy F

2012-03-01

Westerners habitually think in analytical ways, whereas East Asians tend to favor holistic styles of thinking. We replicated this difference but showed that it disappeared after control deprivation (Experiment 1). Brief experiences of control deprivation, which stimulate increased desire for control, caused Chinese participants to shift toward Western-style analytical thinking in multiple ways (Experiments 2-5). Western Caucasian participants also increased their use of analytical thinking after control deprivation (Experiment 6). Manipulations that required Chinese participants to think in Western, analytical ways caused their sense of personal control to increase (Experiments 7-9). Prolonged experiences of control deprivation, which past work suggested foster an attitude more akin to learned helplessness than striving for control, had the opposite effect of causing Chinese participants to shift back toward a strongly holistic style of thinking (Experiments 10-12). Taken together, the results support the reality of cultural differences in cognition but also the cross-cultural similarity of using analytical thinking when seeking to enhance personal control.

Interactions of 14C-labeled multi-walled carbon nanotubes with soil minerals in water.

PubMed

Zhang, Liwen; Petersen, Elijah J; Zhang, Wen; Chen, Yongsheng; Cabrera, Miguel; Huang, Qingguo

2012-07-01

Carbon nanotubes are often modified to be stable in the aqueous phase by adding extensive hydrophilic surface functional groups. The stability of such CNTs in water with soil or sediment is one critical factor controlling their environmental fate. We conducted a series of experiments to quantitatively assess the association between water dispersed multi-walled carbon nanotubes (MWCNTs) and three soil minerals (kaolinite, smectite, or shale) in aqueous solution under different sodium concentrations. (14)C-labeling was used in these experiments to unambiguously quantify MWCNTs. The results showed that increasing ionic strength strongly promoted the removal of MWCNTs from aqueous phase. The removal tendency is inversely correlated with the soil minerals' surface potential and directly correlated with their hydrophobicity. This removal can be interpreted by the extended Derjaguin-Landau-Verwey-Overbeek (EDLVO) theory especially for kaolinite and smectite. Shale, which contains large and insoluble organic materials, sorbed MWCNTs the most strongly. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dismissive and deceptive car dealerships create barriers to electric vehicle adoption at the point of sale

NASA Astrophysics Data System (ADS)

Zarazua de Rubens, Gerardo; Noel, Lance; Sovacool, Benjamin K.

2018-06-01

As most consumers do not have pre-existing knowledge of electric vehicles (EVs), and current market conditions favour petrol and diesel vehicles, car dealership experiences may strongly influence EV purchasing decisions. Here, we show that car dealerships pose a significant barrier at the point of sale due to a perceived lack of business case viability in relation to petrol and diesel vehicles. In 126 shopping experiences at 82 car dealerships across Denmark, Finland, Iceland, Norway and Sweden, we find that dealers were dismissive of EVs, misinformed shoppers on vehicle specifications, omitted EVs from the sales conversation and strongly oriented customers towards petrol and diesel vehicle options. Dealers' technological orientation, willingness to sell and displayed knowledge of EVs were the main contributors to likely purchase intentions. These findings combined with expert interviews suggest that government and industry signalling affect sales strategies and purchasing trends. Policy and business strategies that address barriers at the point of sale are needed to accelerate EV adoption.

Deployment of spatial attention to words in central and peripheral vision.

PubMed

Ducrot, Stéphanie; Grainger, Jonathan

2007-05-01

Four perceptual identification experiments examined the influence of spatial cues on the recognition of words presented in central vision (with fixation on either the first or last letter of the target word) and in peripheral vision (displaced left or right of a central fixation point). Stimulus location had a strong effect on word identification accuracy in both central and peripheral vision, showing a strong right visual field superiority that did not depend on eccentricity. Valid spatial cues improved word identification for peripherally presented targets but were largely ineffective for centrally presented targets. Effects of spatial cuing interacted with visual field effects in Experiment 1, with valid cues reducing the right visual field superiority for peripherally located targets, but this interaction was shown to depend on the type of neutral cue. These results provide further support for the role of attentional factors in visual field asymmetries obtained with targets in peripheral vision but not with centrally presented targets.

Transition Theory and Experimental Comparisons on (I) Amplification into Streets and (II) a Strongly Nonlinear Break-up Criterion

NASA Astrophysics Data System (ADS)

Smith, F. T.; Bowles, R. I.

1992-10-01

The two stages I, II are studied by using recent nonlinear theory and then compared with the experiments of Nishioka et al. (1979) on the transition of plane Poiseuille flow. The first stage I starts at low amplitude from warped input, which is deformed through weakly nonlinear interaction into a blow-up in amplitude and phase accompanied by spanwise focusing into streets. This leads into the strongly nonlinear stage II. It holds for a broad range of interactive boundary layers and related flows, to all of which the nonlinear break-up criterion applies. The experimental comparisons on I, II for channel flow overall show encouraging quantitative agreement, supporting recent comparisons (in the boundary-layer setting) of the description of stage I in Stewart & Smith (1992) with the experiments of Klebanoff & Tidstrom (1959) and of the break-up criterion of Smith (1988a) with the computations of Peridier et al. (1991 a, b).

Interdependent Utilities: How Social Ranking Affects Choice Behavior

PubMed Central

Bault, Nadège; Coricelli, Giorgio; Rustichini, Aldo

2008-01-01

Organization in hierarchical dominance structures is prevalent in animal societies, so a strong preference for higher positions in social ranking is likely to be an important motivation of human social and economic behavior. This preference is also likely to influence the way in which we evaluate our outcome and the outcome of others, and finally the way we choose. In our experiment participants choose among lotteries with different levels of risk, and can observe the choice that others have made. Results show that the relative weight of gains and losses is the opposite in the private and social domain. For private outcomes, experience and anticipation of losses loom larger than gains, whereas in the social domain, gains loom larger than losses, as indexed by subjective emotional evaluations and physiological responses. We propose a theoretical model (interdependent utilities), predicting the implication of this effect for choice behavior. The relatively larger weight assigned to social gains strongly affects choices, inducing complementary behavior: faced with a weaker competitor, participants adopt a more risky and dominant behavior. PMID:18941538

Lithium niobate ultrasonic transducer design for Enhanced Oil Recovery.

PubMed

Wang, Zhenjun; Xu, Yuanming; Gu, Yuting

2015-11-01

Due to the strong piezoelectric effect possessed by lithium niobate, a new idea that uses lithium niobate to design high-power ultrasonic transducer for Enhanced Oil Recovery technology is proposed. The purpose of this paper is to lay the foundation for the further research and development of high-power ultrasonic oil production technique. The main contents of this paper are as follows: firstly, structure design technique and application of a new high-power ultrasonic transducer are introduced; secondly, the experiment for reducing the viscosity of super heavy oil by this transducer is done, the optimum ultrasonic parameters for reducing the viscosity of super heavy oil are given. Experimental results show that heavy large molecules in super heavy oil can be cracked into light hydrocarbon substances under strong cavitation effect caused by high-intensity ultrasonic wave. Experiment proves that it is indeed feasible to design high-power ultrasonic transducer for ultrasonic oil production technology using lithium niobate. Copyright © 2015 Elsevier B.V. All rights reserved.

Nike Experiment to Observe Strong Areal Mass Oscillations in a Rippled Target Hit by a Short Laser Pulse

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Karasik, M.; Velikovich, A. L.; Serlin, V.; Weaver, J. L.; Kessler, T. J.; Schmitt, A. J.; Obenschain, S. P.; Metzler, N.; Oh, J.

2010-11-01

When a short (sub-ns) laser pulse deposits finite energy in a target, the shock wave launched into it is immediately followed by a rarefaction wave. If the irradiated surface is rippled, theory and simulations predict strong oscillations of the areal mass perturbation amplitude in the target [A. L. Velikovich et al., Phys. Plasmas 10, 3270 (2003).] The first experiment designed to observe this effect has become possible by adding short-driving-pulse capability to the Nike laser, and has been scheduled for the fall of 2010. Simulations show that while the driving pulse of 0.3 ns is on, the areal mass perturbation amplitude grows by a factor ˜2 due to ablative Richtmyer-Meshkov instability. It then decreases, reverses phase, and reaches another maximum, also about twice its initial value, shortly after the shock breakout at the rear target surface. This signature behavior is observable with the monochromatic x-ray imaging diagnostics fielded on Nike.

Lensing of Fast Radio Bursts as a Probe of Compact Dark Matter

NASA Astrophysics Data System (ADS)

Muñoz, Julian B.; Kovetz, Ely D.; Dai, Liang; Kamionkowski, Marc

2016-08-01

The possibility that part of the dark matter is made of massive compact halo objects (MACHOs) remains poorly constrained over a wide range of masses, and especially in the 20 - 100 M⊙ window. We show that strong gravitational lensing of extragalactic fast radio bursts (FRBs) by MACHOs of masses larger than ˜20 M⊙ would result in repeated FRBs with an observable time delay. Strong lensing of a FRB by a lens of mass ML induces two images, separated by a typical time delay ˜few×(ML/30 M⊙) msec . Considering the expected FRB detection rate by upcoming experiments, such as canadian hydrogen intensity mapping experiment (CHIME), of 1 04 FRBs per year, we should observe from tens to hundreds of repeated bursts yearly, if MACHOs in this window make up all the dark matter. A null search for echoes with just 1 04 FRBs would constrain the fraction fDM of dark matter in MACHOs to fDM≲0.08 for ML≳20 M⊙ .

Vibrational spectroscopy of (SO4(2-)).(H2O)n clusters, n=1-5: harmonic and anharmonic calculations and experiment.

PubMed

Miller, Yifat; Chaban, Galina M; Zhou, Jia; Asmis, Knut R; Neumark, Daniel M; Gerber, R Benny

2007-09-07

The vibrational spectroscopy of (SO4(2-)).(H2O)n is studied by theoretical calculations for n=1-5, and the results are compared with experiments for n=3-5. The calculations use both ab initio MP2 and DFT/B3LYP potential energy surfaces. Both harmonic and anharmonic calculations are reported, the latter with the CC-VSCF method. The main findings are the following: (1) With one exception (H2O bending mode), the anharmonicity of the observed transitions, all in the experimental window of 540-1850 cm(-1), is negligible. The computed anharmonic coupling suggests that intramolecular vibrational redistribution does not play any role for the observed linewidths. (2) Comparison with experiment at the harmonic level of computed fundamental frequencies indicates that MP2 is significantly more accurate than DFT/B3LYP for these systems. (3) Strong anharmonic effects are, however, calculated for numerous transitions of these systems, which are outside the present observation window. These include fundamentals as well as combination modes. (4) Combination modes for the n=1 and n=2 clusters are computed. Several relatively strong combination transitions are predicted. These show strong anharmonic effects. (5) An interesting effect of the zero point energy (ZPE) on structure is found for (SO4(2-)).(H2O)(5): The global minimum of the potential energy corresponds to a C(s) structure, but with incorporation of ZPE the lowest energy structure is C2v, in accordance with experiment. (6) No stable structures were found for (OH-).(HSO4-).(H2O)n, for n

Vibrational spectroscopy of (SO42-).(H2O)n clusters, n=1-5: Harmonic and anharmonic calculations and experiment

NASA Astrophysics Data System (ADS)

Miller, Yifat; Chaban, Galina M.; Zhou, Jia; Asmis, Knut R.; Neumark, Daniel M.; Benny Gerber, R.

2007-09-01

The vibrational spectroscopy of (SO42-)•(H2O)n is studied by theoretical calculations for n =1-5, and the results are compared with experiments for n =3-5. The calculations use both ab initio MP2 and DFT/B3LYP potential energy surfaces. Both harmonic and anharmonic calculations are reported, the latter with the CC-VSCF method. The main findings are the following: (1) With one exception (H2O bending mode), the anharmonicity of the observed transitions, all in the experimental window of 540-1850cm-1, is negligible. The computed anharmonic coupling suggests that intramolecular vibrational redistribution does not play any role for the observed linewidths. (2) Comparison with experiment at the harmonic level of computed fundamental frequencies indicates that MP2 is significantly more accurate than DFT/B3LYP for these systems. (3) Strong anharmonic effects are, however, calculated for numerous transitions of these systems, which are outside the present observation window. These include fundamentals as well as combination modes. (4) Combination modes for the n=1 and n =2 clusters are computed. Several relatively strong combination transitions are predicted. These show strong anharmonic effects. (5) An interesting effect of the zero point energy (ZPE) on structure is found for (SO42-)•(H2O)5: The global minimum of the potential energy corresponds to a Cs structure, but with incorporation of ZPE the lowest energy structure is C2v, in accordance with experiment. (6) No stable structures were found for (OH-)•(HSO4-)•(H2O)n, for n ⩽5.

South Atlantic Ocean circulation: Simulation experiments with a quasi-geostrophic model and assimilation of TOPEX/POSEIDON and ERS 1 altimeter data

NASA Astrophysics Data System (ADS)

Florenchie, P.; Verron, J.

1998-10-01

Simulation experiments of South Atlantic Ocean circulations are conducted with a 1/6°, four-layered, quasi-geostrophic model. By means of a simple nudging data assimilation procedure along satellite tracks, TOPEX/POSEIDON and ERS 1 altimeter measurements are introduced into the model to control the simulation of the basin-scale circulation for the period from October 1992 to September 1994. The model circulation appears to be strongly influenced by the introduction of altimeter data, offering a consistent picture of South Atlantic Ocean circulations. Comparisons with observations show that the assimilating model successfully simulates the kinematic behavior of a large number of surface circulation components. The assimilation procedure enables us to produce schematic diagrams of South Atlantic circulation in which patterns ranging from basin-scale currents to mesoscale eddies are portrayed in a realistic way, with respect to their complexity. The major features of the South Atlantic circulation are described and analyzed, with special emphasis on the Brazil-Malvinas Confluence region, the Subtropical Gyre with the formation of frontal structures, and the Agulhas Retroflection. The Agulhas eddy-shedding process has been studied extensively. Fourteen eddies appear to be shed during the 2-year experiment. Because of their strong surface topographic signature, Agulhas eddies have been tracked continuously during the assimilation experiment as they cross the South Atlantic basin westward. Other effects of the assimilation procedure are shown, such as the intensification of the Subtropical Gyre, the appearance of a strong seasonal cycle in the Brazil Current transport, and the increase of the mean Brazil Current transport. This last result, combined with the westward oriention of the Agulhas eddies' trajectories, leads to a southward transport of mean eddy kinetic energy across 30°S.

Explaining Cold-Pulse Dynamics in Tokamak Plasmas Using Local Turbulent Transport Models

DOE PAGES

Rodriguez-Fernandez, P.; White, A. E.; Howard, N. T.; ...

2018-02-16

A long-standing enigma in plasma transport has been resolved by modeling of cold-pulse experiments conducted on the Alcator C-Mod tokamak. Controlled edge cooling of fusion plasmas triggers core electron heating on time scales faster than an energy confinement time, which has long been interpreted as strong evidence of nonlocal transport. Here, this Letter shows that the steady-state profiles, the cold-pulse rise time, and disappearance at higher density as measured in these experiments are successfully captured by a recent local quasilinear turbulent transport model, demonstrating that the existence of nonlocal transport phenomena is not necessary for explaining the behavior and timemore » scales of cold-pulse experiments in tokamak plasmas.« less

Explaining Cold-Pulse Dynamics in Tokamak Plasmas Using Local Turbulent Transport Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rodriguez-Fernandez, P.; White, A. E.; Howard, N. T.

A long-standing enigma in plasma transport has been resolved by modeling of cold-pulse experiments conducted on the Alcator C-Mod tokamak. Controlled edge cooling of fusion plasmas triggers core electron heating on time scales faster than an energy confinement time, which has long been interpreted as strong evidence of nonlocal transport. Here, this Letter shows that the steady-state profiles, the cold-pulse rise time, and disappearance at higher density as measured in these experiments are successfully captured by a recent local quasilinear turbulent transport model, demonstrating that the existence of nonlocal transport phenomena is not necessary for explaining the behavior and timemore » scales of cold-pulse experiments in tokamak plasmas.« less

Explaining impossible phenomena: object permanence beliefs and memory failures in adults.

PubMed

Subbotsky, E V

1996-03-01

In three experiments, adult subjects' explanations of the observed nonpermanence of a physical object and their recollections of the order of the events during the experiment were obtained and analysed. The data showed that in order to conserve their strong beliefs in object permanence subjects systematically distorted the real temporal succession of events preceding the phenomenon. The frequency of the distortions depended on the salience of the nonpermanence phenomenon ("disappearance" versus "appearance" of the physical object) and on the time interval between the events whose temporal order was reversed, but not on subjects' nationality (English versus German), gender, type of reproduction (immediate versus delayed), role in the experiment (subject versus observer), and degree of prompting in questioning.

Depth resolved grazing incidence neutron scattering experiments from semi-infinite interfaces: a statistical analysis of the scattering contributions

NASA Astrophysics Data System (ADS)

Adlmann, Franz A.; Herbel, Jörg; Korolkovas, Airidas; Bliersbach, Andreas; Toperverg, Boris; Van Herck, Walter; Pálsson, Gunnar K.; Kitchen, Brian; Wolff, Max

2018-04-01

Grazing incidence neutron scattering experiments offer surface sensitivity by reflecting from an interface at momentum transfers close to total external reflection. Under these conditions the penetration depth is strongly non-linear and may change by many orders of magnitude. This fact imposes severe challenges for depth resolved experiments, since the brilliance of neutron beams is relatively low in comparison to e.g. synchrotron radiation. In this article we use probability density functions to calculate the contribution of scattering at different distances from an interface to the intensities registered on the detector. Our method has the particular advantage that the depth sensitivity is directly extracted from the scattering pattern itself. Hence for perfectly known samples exact resolution functions can be calculated and visa versa. We show that any tails in the resolution function, e.g. Gaussian shaped, hinders depth resolved experiments. More importantly we provide means for a descriptive statistical analysis of detector images with respect to the scattering contributions and show that even for perfect resolution near surface scattering is hardly accessible.

Surface boundary layer turbulence in the Southern ocean

NASA Astrophysics Data System (ADS)

Merrifield, Sophia; St. Laurent, Louis; Owens, Breck; Naveira Garabato, Alberto

2015-04-01

Due to the remote location and harsh conditions, few direct measurements of turbulence have been collected in the Southern Ocean. This region experiences some of the strongest wind forcing of the global ocean, leading to large inertial energy input. While mixed layers are known to have a strong seasonality and reach 500m depth, the depth structure of near-surface turbulent dissipation and diffusivity have not been examined using direct measurements. We present data collected during the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) field program. In a range of wind conditions, the wave affected surface layer (WASL), where surface wave physics are actively forcing turbulence, is contained to the upper 15-20m. The lag-correlation between wind stress and turbulence shows a strong relationship up to 6 hours (˜1/2 inertial period), with the winds leading the oceanic turbulent response, in the depth range between 20-50m. We find the following characterize the data: i) Profiles that have a well-defined hydrographic mixed layer show that dissipation decays in the mixed layer inversely with depth, ii) WASLs are typically 15 meters deep and 30% of mixed layer depth, iii) Subject to strong winds, the value of dissipation as a function of depth is significantly lower than predicted by theory. Many dynamical processes are known to be missing from upper-ocean parameterizations of mixing in global models. These include surface-wave driven processes such as Langmuir turbulence, submesocale frontal processes, and nonlocal representations of mixing. Using velocity, hydrographic, and turbulence measurements, the existence of coherent structures in the boundary layer are investigated.

Endogenous Noxa Determines the Strong Proapoptotic Synergism of the BH3-Mimetic ABT-737 with Chemotherapeutic Agents in Human Melanoma Cells12

PubMed Central

Weber, Arnim; Kirejczyk, Zofia; Potthoff, Stephanie; Ploner, Christian; Häcker, Georg

2009-01-01

Human melanoma cells are very resistant to treatment with chemotherapeutic agents, and melanoma shows poor response to chemotherapeutic therapy. We describe a strong synergistic proapoptotic effect of the Bcl-2 family inhibitor ABT-737 and the standard antimelanoma drugs, namely, dacarbazine and fotemustine, and the experimental agent, imiquimod. Experiments with human melanoma cells, keratinocytes, and embryonic fibroblasts showed that all three agents activated the mitochondrial apoptosis pathway. ABT-737 on its own was ineffective in melanoma cells unless Mcl-1 was experimentally downregulated. However, ABT-737 strongly enhanced the proapoptotic activity of the chemotherapeutic drugs. Whereas cell death induction by all three agents involved the activity of both BH3-only proteins, Bim and Noxa, the combination with ABT-737 overcame the requirement for Bim. However, the synergism between ABT-737 and imiquimod or dacarbazine required endogenous Noxa, as demonstrated by experiments with Noxa-specific RNAi. Surprisingly, although Bim was activated, it was unable to replace Noxa. Studies of mitochondrial cytochrome c release using BH3 peptides confirmed that a main effect of dacarbazine, fotemustine, and imiquimod was to neutralize Mcl-1, thereby sensitizing mitochondria to the inhibition of other Bcl-2 family members through ABT-737. ABT-737 is thus a promising agent for combination therapy for human melanoma. Importantly, the efficacy of this therapy depends on endogenous Noxa, and the ability of chemotherapeutic drugs to activate Noxa may be a valuable predictor of their synergism with Bcl-2-targeting drugs. PMID:19412422

Why Chemical Vapor Deposition Grown MoS2 Samples Outperform Physical Vapor Deposition Samples: Time-Domain ab Initio Analysis.

PubMed

Li, Linqiu; Long, Run; Prezhdo, Oleg V

2018-06-13

Two-dimensional transition metal dichalcogenides (TMDs) have drawn strong attention due to their unique properties and diverse applications. However, TMD performance depends strongly on material quality and defect morphology. Experiments show that samples grown by chemical vapor deposition (CVD) outperform those obtained by physical vapor deposition (PVD). Experiments also show that CVD samples exhibit vacancy defects, while antisite defects are frequently observed in PVD samples. Our time-domain ab initio study demonstrates that both antisites and vacancies accelerate trapping and nonradiative recombination of charge carriers, but antisites are much more detrimental than vacancies. Antisites create deep traps for both electrons and holes, reducing energy gaps for recombination, while vacancies trap primarily holes. Antisites also perturb band-edge states, creating significant overlap with the trap states. In comparison, vacancy defects overlap much less with the band-edge states. Finally, antisites can create pairs of electron and hole traps close to the Fermi energy, allowing trapping by thermal activation from the ground state and strongly contributing to charge scattering. As a result, antisites accelerate charge recombination by more than a factor of 8, while vacancies enhance the recombination by less than a factor of 2. Our simulations demonstrate a general principle that missing atoms are significantly more benign than misplaced atoms, such as antisites and adatoms. The study rationalizes the existing experimental data, provides theoretical insights into the diverse behavior of different classes of defects, and generates guidelines for defect engineering to achieve high-performance electronic, optoelectronic, and solar-cell devices.

Shock wave/turbulent boundary layer interaction in the flow field of a tri-dimension wind tunnel

NASA Technical Reports Server (NTRS)

Benay, R.; Pot, T.

1986-01-01

The first results of a thorough experimental analysis of a strong three-dimensional shock-wave/turbulent boundary-layer interaction occurring in a three dimensional transonic channel are presented. The aim of this experiment is to help in the physical understanding of a complex field, including several separations, and to provide a well documented case to test computational methods. The flowfield has been probed in many points by means of a three-component laser Doppler velocimeter. The results presented relate only to the mean velocity field. They clearly show the formation in the flow of a strong vortical motion resulting from the shock wave interaction.

Airport Flight Departure Delay Model on Improved BN Structure Learning

NASA Astrophysics Data System (ADS)

Cao, Weidong; Fang, Xiangnong

An high score prior genetic simulated annealing Bayesian network structure learning algorithm (HSPGSA) by combining genetic algorithm(GA) with simulated annealing algorithm(SAA) is developed. The new algorithm provides not only with strong global search capability of GA, but also with strong local hill climb search capability of SAA. The structure with the highest score is prior selected. In the mean time, structures with lower score are also could be choice. It can avoid efficiently prematurity problem by higher score individual wrong direct growing population. Algorithm is applied to flight departure delays analysis in a large hub airport. Based on the flight data a BN model is created. Experiments show that parameters learning can reflect departure delay.

Noble gas trapping and fractionation during synthesis of carbonaceous matter. [in meteorites

NASA Technical Reports Server (NTRS)

Frick, U.; Mack, R.; Chang, S.

1979-01-01

An investigation of noble gas entrapment during synthesis of carbonaceous, macromolecular, and kerogen-like substances is presented. High molecular weight organic matter synthesized in aqueous condensation reactions contained little gas, and the composition was consistent with fractionation due to noble gas solubility in water; however, propane soot produced during a modified Miller-Urey experiment in an aritificial gas mixture contained high concentrations of trapped noble gases that displayed strong elemental fractionation from their reservoirs. It is concluded that theses experiemnts show that processes exist for synthesis of carbonaceous carriers that result in high noble gas concentrations and strong elemental fractionation at temperatures well above those required by absorption to achieve similar effects.

Illusory conjunctions and perceptual grouping in a visual search task in schizophrenia.

PubMed

Carr, V J; Dewis, S A; Lewin, T J

1998-07-27

This report describes part of a series of experiments, conducted within the framework of feature integration theory, to determine whether patients with schizophrenia show deficits in preattentive processing. Thirty subjects with a DSM-III-R diagnosis of schizophrenia and 30 age-, gender-, and education-matched normal control subjects completed two computerized experimental tasks, a visual search task assessing the frequency of illusory conjunctions (i.e. false perceptions) under conditions of divided attention (Experiment 3) and a task which examined the effects of perceptual grouping on illusory conjunctions (Experiment 4). We also assessed current symptomatology and its relationship to task performance. Contrary to our hypotheses, schizophrenia subjects did not show higher rates of illusory conjunctions, and the influence of perceptual grouping on the frequency of illusory conjunctions was similar for schizophrenia and control subjects. Nonetheless, specific predictions from feature integration theory about the impact of different target types (Experiment 3) and perceptual groups (Experiment 4) on the likelihood of forming an illusory conjunction were strongly supported, thereby confirming the integrity of the experimental procedures. Overall, these studies revealed no firm evidence that schizophrenia is associated with a preattentive abnormality in visual search using stimuli that differ on the basis of physical characteristics.

Comfort and experience with online learning: trends over nine years and associations with knowledge.

PubMed

Cook, David A; Thompson, Warren G

2014-07-01

Some evidence suggests that attitude toward computer-based instruction is an important determinant of success in online learning. We sought to determine how comfort using computers and perceptions of prior online learning experiences have changed over the past decade, and how these associate with learning outcomes. Each year from 2003-2011 we conducted a prospective trial of online learning. As part of each year's study, we asked medicine residents about their comfort using computers and if their previous experiences with online learning were favorable. We assessed knowledge using a multiple-choice test. We used regression to analyze associations and changes over time. 371 internal medicine and family medicine residents participated. Neither comfort with computers nor perceptions of prior online learning experiences showed a significant change across years (p > 0.61), with mean comfort rating 3.96 (maximum 5 = very comfortable) and mean experience rating 4.42 (maximum 6 = strongly agree [favorable]). Comfort showed no significant association with knowledge scores (p = 0.39) but perceptions of prior experiences did, with a 1.56% rise in knowledge score for a 1-point rise in experience score (p = 0.02). Correlations among comfort, perceptions of prior experiences, and number of prior experiences were all small and not statistically significant. Comfort with computers and perceptions of prior experience with online learning remained stable over nine years. Prior good experiences (but not comfort with computers) demonstrated a modest association with knowledge outcomes, suggesting that prior course satisfaction may influence subsequent learning.

Efficiency for preforming molecules from mixtures of light Fermi and heavy Bose atoms in optical lattices: The strong-coupling-expansion method

NASA Astrophysics Data System (ADS)

Hu, Anzi; Freericks, J. K.; Maśka, M. M.; Williams, C. J.

2011-04-01

We discuss the application of a strong-coupling expansion (perturbation theory in the hopping) for studying light-Fermi-heavy-Bose (like K40-Rb87) mixtures in optical lattices. We use the strong-coupling method to evaluate the efficiency for preforming molecules, the entropy per particle, and the thermal fluctuations. We show that within the strong interaction regime (and at high temperature), the strong-coupling expansion is an economical way to study this problem. In some cases, it remains valid even down to low temperatures. Because the computational effort is minimal, the strong-coupling approach allows us to work with much larger system sizes, where boundary effects can be eliminated, which is particularly important at higher temperatures. Since the strong-coupling approach is so efficient and accurate, it allows one to rapidly scan through parameter space in order to optimize the preforming of molecules on a lattice (by choosing the lattice depth and interspecies attraction). Based on the strong-coupling calculations, we test the thermometry scheme based on the fluctuation-dissipation theorem and find the scheme gives accurate temperature estimation even at very low temperature. We believe this approach and the calculation results will be useful in the design of the next generation of experiments and will hopefully lead to the ability to form dipolar matter in the quantum degenerate regime.

Interactive Effects of the BIS and the BAS on Trajectories of Alcohol Misuse after University Graduation.

PubMed

Keough, Matthew T; O'Connor, Roisin M

2015-01-01

Reinforcement Sensitivity Theory predicts that those with a strong behavioral inhibition system (BIS) likely experience considerable anxiety and uncertainty during the transition out of university. Accordingly, they may continue to drink heavily to cope during this time (a period associated with normative reductions in heavy drinking), but only if they also have a strong behavioral approach system (BAS) to enhance the anxiolytic effects of drinking. The purpose of this study was to test this hypothesis. Participants completed online measures prior to and at 3-month intervals over the course of the year following graduation. As hypothesized, results showed that an elevated BIS predicted impeded maturing out, but only when the impulsivity facet of BAS was also elevated. In contrast, a strong BIS predicted rapid maturing out if BAS impulsivity was weak. Study findings advance our understanding of BIS-related alcohol misuse trajectories in young adulthood and provide direction for clinical interventions.

Suppressing electron turbulence and triggering internal transport barriers with reversed magnetic shear in the National Spherical Torus Experimenta)

NASA Astrophysics Data System (ADS)

Peterson, J. L.; Bell, R.; Candy, J.; Guttenfelder, W.; Hammett, G. W.; Kaye, S. M.; LeBlanc, B.; Mikkelsen, D. R.; Smith, D. R.; Yuh, H. Y.

2012-05-01

The National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 (2000)] can achieve high electron plasma confinement regimes that are super-critically unstable to the electron temperature gradient driven (ETG) instability. These plasmas, dubbed electron internal transport barriers (e-ITBs), occur when the magnetic shear becomes strongly negative. Using the gyrokinetic code GYRO [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)], the first nonlinear ETG simulations of NSTX e-ITB plasmas reinforce this observation. Local simulations identify a strongly upshifted nonlinear critical gradient for thermal transport that depends on magnetic shear. Global simulations show e-ITB formation can occur when the magnetic shear becomes strongly negative. While the ETG-driven thermal flux at the outer edge of the barrier is large enough to be experimentally relevant, the turbulence cannot propagate past the barrier into the plasma interior.

Specific heat and effects of strong pairing fluctuations in a superfluid Fermi atom gas in the BCS-BEC crossover region

NASA Astrophysics Data System (ADS)

van Wyk, Pieter; Inotani, Daisuke; Ohashi, Yoji

2018-03-01

We theoretically investigate the specific heat at constant volume C V in the BCS(Bardeen-Cooper-Schrieffer)-BEC(Bose-Einstein-condensation)-crossover regime of an ultracold Fermi gas, below the superfluid phase transition temperature T c. Within the strong-coupling framework developed by Nozières and Schmitt-Rink, we show that the temperature dependence of C V drastically changes as one passes through the crossover region, and is sensitive to strong fluctuations in the Cooper channel near the unitarity limit. We also compare our results to a recent experiment on a 6Li unitary Fermi gas. Since fluctuation effects are a crucial key in the BCS-BEC-crossover phenomenon, our results would be helpful in considering how the fermionic BCS superfluid changes into BEC with increasing the interaction strength, from the viewpoint of specific heat.

Coherent quantum depletion of an interacting atom condensate

PubMed Central

Kira, M.

2015-01-01

Sufficiently strong interactions promote coherent quantum transitions in spite of thermalization and losses, which are the adversaries of delicate effects such as reversibility and correlations. In atomic Bose–Einstein condensates (BECs), strong atom–atom interactions can eject atoms from the BEC to the normal component, yielding quantum depletion instead of temperature depletion. A recent experiment has already been verified to overcome losses. Here I show that it also achieves coherent quantum-depletion dynamics in a BEC swept fast enough from weak to strong atom–atom interactions. The elementary coherent process first excites the normal component into a liquid state that evolves into a spherical shell state, where the atom occupation peaks at a finite momentum to shield 50% of the BEC atoms from annihilation. The identified coherent processes resemble ultrafast semiconductor excitations expanding the scope of BEC explorations to many-body non-equilibrium studies. PMID:25767044

More 'altruistic' punishment in larger societies.

PubMed

Marlowe, Frank W; Berbesque, J Colette

2008-03-07

If individuals will cooperate with cooperators, and punish non-cooperators even at a cost to themselves, then this strong reciprocity could minimize the cheating that undermines cooperation. Based upon numerous economic experiments, some have proposed that human cooperation is explained by strong reciprocity and norm enforcement. Second-party punishment is when you punish someone who defected on you; third-party punishment is when you punish someone who defected on someone else. Third-party punishment is an effective way to enforce the norms of strong reciprocity and promote cooperation. Here we present new results that expand on a previous report from a large cross-cultural project. This project has already shown that there is considerable cross-cultural variation in punishment and cooperation. Here we test the hypothesis that population size (and complexity) predicts the level of third-party punishment. Our results show that people in larger, more complex societies engage in significantly more third-party punishment than people in small-scale societies.

Shopping versus Nature? An Exploratory Study of Everyday Experiences.

PubMed

Craig, Tony P; Fischer, Anke; Lorenzo-Arribas, Altea

2018-01-01

Although a growing volume of empirical research shows that being in nature is important for human wellbeing, the definition of what constitutes an 'experience in nature,' and how this is different from other types of experiences, is very often left implied. In this paper we contrast everyday experiences involving nature with a category of everyday experience in which most people regularly partake. We present an exploratory study in which people ( N = 357) were explicitly asked to describe a memory they had of an everyday 'experience which involved nature,' as well as an everyday 'experience which involved shopping.' The open-ended responses to these questions were analyzed both quantitatively and qualitatively. Nature experiences were generally found to be more positive than shopping experiences, and they were more likely to be rated as 'peaceful' and 'active' compared to shopping experiences. Follow-up analyses indicate a significant interaction between experience category (nature or shopping), and the relationship between connectedness to nature and the amount of pleasure associated with that experience: The more strongly connected to nature a respondent was, the larger the disparity between the pleasantness of the shopping experience and that of the experience in nature tended to be.

Sub-ion scale plasmoids during collisionless reconnection on TREX

NASA Astrophysics Data System (ADS)

Olson, Joseph; Egedal, Jan; Myers, Rachel; Greess, Sam; Clark, Mike; Wallace, John; Forest, Cary; Wisconsin Plasma Astrophysics Laboratory Collaboration

2016-10-01

The Terrestrial Reconnection Experiment (TREX), operating at the Wisconsin Plasma Astrophysics Laboratory, is able to explore a collisionless regime inaccessible to previous reconnection experiments. To date, TREX has already achieved Lundquist numbers up to 104 where kinetic effects, such as electron pressure anisotropy, become important to the reconnection dynamics. During a recent run campaign in this collisionless regime, the spontaneous formation of magnetic islands (plasmoids) inside the ion diffusion region was observed. It is known that long current layers are susceptible to tearing, leading to the formation of plasmoids, and that these plasmoids have strong effects on the reconnection rate and particle energization. However, contrary to theoretical and numerical predictions, the TREX experiments show that the plasmoid instability is active even when the current layer is less than one di long. Analysis of these events shows that smaller plasmoids occur at a higher rate than larger ones, suggesting that magnetic islands could be seeded in plasmas more effectively than previously thought.

Quantum spin liquid signatures in Kitaev-like frustrated magnets

NASA Astrophysics Data System (ADS)

Gohlke, Matthias; Wachtel, Gideon; Yamaji, Youhei; Pollmann, Frank; Kim, Yong Baek

2018-02-01

Motivated by recent experiments on α -RuCl3 , we investigate a possible quantum spin liquid ground state of the honeycomb-lattice spin model with bond-dependent interactions. We consider the K -Γ model, where K and Γ represent the Kitaev and symmetric-anisotropic interactions between spin-1/2 moments on the honeycomb lattice. Using the infinite density matrix renormalization group, we provide compelling evidence for the existence of quantum spin liquid phases in an extended region of the phase diagram. In particular, we use transfer-matrix spectra to show the evolution of two-particle excitations with well-defined two-dimensional dispersion, which is a strong signature of a quantum spin liquid. These results are compared with predictions from Majorana mean-field theory and used to infer the quasiparticle excitation spectra. Further, we compute the dynamical structure factor using finite-size cluster computations and show that the results resemble the scattering continuum seen in neutron-scattering experiments on α -RuCl3 . We discuss these results in light of recent and future experiments.

Testing aggressive behaviour in a feeding context: Importance of ethologically relevant stimuli.

PubMed

González, Daniel; Szenczi, Péter; Bánszegi, Oxána; Hudson, Robyn

2018-05-01

The choice of stimuli used in tests of animal behaviour can have a critical effect on the outcome. Here we report two experiments showing how different foods influenced aggressive behaviour in competition tests at weaning among littermates of the domestic cat. Whereas in Experiment 1 canned food elicited almost no overt competition, a piece of raw beef rib elicited clearly aggressive behaviour among littermates. In Experiment 2 the food stimuli were chosen to differ from raw beef rib in various combinations of taste/smell, texture and monopolizability. Kittens showed different levels of aggression in response to the five stimuli tested, which suggests that the strong effect of beef rib in eliciting aggressive behaviour was due to a complex combination of features. We suggest that using stimuli approximating the evolved, functional significance to the species concerned is more likely to result in robust, biologically relevant behaviours than more artificial stimuli. Copyright © 2018 Elsevier B.V. All rights reserved.

The 1980 US/Canada wheat and barley exploratory experiment, volume 1

NASA Technical Reports Server (NTRS)

Bizzell, R. M.; Prior, H. L.; Payne, R. W.; Disler, J. M.

1983-01-01

The results from the U.S./Canada Wheat and Barley Exploratory Experiment which was completed during FY 1980 are presented. The results indicate that the new crop identification procedures performed well for spring small grains and that they are conductive to automation. The performance of the machine processing techniques shows a significant improvement over previously evaluated technology. However, the crop calendars will require additional development and refinements prior to integration into automated area estimation technology. The evaluation showed the integrated technology to be capable of producing accurate and consistent spring small grains proportion estimates. However, barley proportion estimation technology was not satisfactorily evaluated. The low-density segments examined were judged not to give indicative or unequivocal results. It is concluded that, generally, the spring small grains technology is ready for evaluation in a pilot experiment focusing on sensitivity analyses to a variety of agricultural and meteorological conditions representative of the global environment. It is further concluded that a strong potential exists for establishing a highly efficient technology or spring small grains.

The effect of induced sadness and moderate depression on attention networks.

PubMed

Bellaera, Lauren; von Mühlenen, Adrian

2017-09-01

This study investigates how sadness and minor/moderate depression influences the three functions of attention: alerting, orienting, and executive control using the Attention Network Test. The aim of the study is to investigate whether minor-to-moderate depression is more similar to sadness or clinical depression with regard to attentional processing. It was predicted that both induced sadness and minor-to-moderate depression will influence executive control by narrowing spatial attention and in turn this will lead to less interference from the flanker items (i.e. less effects of congruency) due to a focused attentional state. No differences were predicted for alerting or orienting functions. The results from the two experiments, the first inducing sadness (Experiment 1) and the second measuring subclinical depression (Experiment 2), show that, as expected, participants who are sad or minor to moderately depressed showed less flanker interference compared to participants who were neither sad nor depressed. This study provides strong evidence, that irrespective of its aetiology, sadness and minor/moderate depression have similar effects on spatial attention.

Ice Accretion Formations on a NACA 0012 Swept Wing Tip in Natural Icing Conditions

NASA Technical Reports Server (NTRS)

Vargas, Mario; Giriunas, Julius A.; Ratvasky, Thomas P.

2002-01-01

An experiment was conducted in the DeHavilland DHC-6 Twin Otter Icing Research Aircraft at NASA Glenn Research Center to study the formation of ice accretions on swept wings in natural icing conditions. The experiment was designed to obtain ice accretion data to help determine if the mechanisms of ice accretion formation observed in the Icing Research Tunnel are present in natural icing conditions. The experiment in the Twin Otter was conducted using a NACA 0012 swept wing tip. The model enabled data acquisition at 0 deg, 15 deg, 25 deg, 30 deg, and 45 deg sweep angles. Casting data, ice shape tracings, and close-up photographic data were obtained. The results showed that the mechanisms of ice accretion formation observed in-flight agree well with the ones observed in the Icing Research Tunnel. Observations on the end cap of the airfoil showed the same strong effect of the local sweep angle on the formation of scallops as observed in the tunnel.

Methodenvergleich zur Bestimmung der hydraulischen Durchlässigkeit

NASA Astrophysics Data System (ADS)

Storz, Katharina; Steger, Hagen; Wagner, Valentin; Bayer, Peter; Blum, Philipp

2017-06-01

Knowing the hydraulic conductivity (K) is a precondition for understanding groundwater flow processes in the subsurface. Numerous laboratory and field methods for the determination of hydraulic conductivity exist, which can lead to significantly different results. In order to quantify the variability of these various methods, the hydraulic conductivity was examined for an industrial silica sand (Dorsilit) using four different methods: (1) grain-size analysis, (2) Kozeny-Carman approach, (3) permeameter tests and (4) flow rate experiments in large-scale tank experiments. Due to the large volume of the artificially built aquifer, the tank experiment results are assumed to be the most representative. Hydraulic conductivity values derived from permeameter tests show only minor deviation, while results of the empirically evaluated grain-size analysis are about one magnitude higher and show great variances. The latter was confirmed by the analysis of several methods for the determination of K-values found in the literature, thus we generally question the suitability of grain-size analyses and strongly recommend the use of permeameter tests.

Opacity from two-photon processes

DOE PAGES

More, Richard M.; Hansen, Stephanie B.; Nagayama, Taisuke

2017-07-22

Here, the recent iron opacity measurements performed at Sandia National Laboratory by Bailey and collaborators have raised questions about the completeness of the physical models normally used to understand partially ionized hot dense plasmas. We describe calculations of two-photon absorption, which is a candidate for the observed extra opacity. Our calculations do not yet match the experiments but show that the two-photon absorption process is strong enough to require careful consideration.

Towards long coherence superconducting qubits

NASA Astrophysics Data System (ADS)

Steffen, Matthias; Corcoles, Antonio; Chow, Jerry; Rigetti, Chad; Ketchen, Mark; Rothwell, Mary Beth; Keefe, George; Rozen, Jim; Borstelmann, Mark; Rohrs, Jack; Divincenzo, David

2011-03-01

The capacitively shunted flux qubit (CSFQ) has recently been shown to have coherence times of 1-2 microseconds repeatedly over many devices at typical qubit operating frequencies. Experiments in our group strongly suggest that losses associated with the shunting capacitor limit the current coherence times. As a result we propose novel approaches towards decreasing capacitive losses by employing geometric and/or materials developments. We show experimental data and compare these with theoretical predictions

Why do seals have cones? Behavioural evidence for colour-blindness in harbour seals.

PubMed

Scholtyssek, Christine; Kelber, Almut; Dehnhardt, Guido

2015-03-01

All seals and cetaceans have lost at least one of two ancestral cone classes and should therefore be colour-blind. Nevertheless, earlier studies showed that these marine mammals can discriminate colours and a colour vision mechanism has been proposed which contrasts signals from cones and rods. However, these earlier studies underestimated the brightness discrimination abilities of these animals, so that they could have discriminated colours using brightness only. Using a psychophysical discrimination experiment, we showed that a harbour seal can solve a colour discrimination task by means of brightness discrimination alone. Performing a series of experiments in which two harbour seals had to discriminate the brightness of colours, we also found strong evidence for purely scotopic (rod-based) vision at light levels that lead to mesopic (rod-cone-based) vision in other mammals. This finding speaks against rod-cone-based colour vision in harbour seals. To test for colour-blindness, we used a cognitive approach involving a harbour seal trained to use a concept of same and different. We tested this seal with pairs of isoluminant stimuli that were either same or different in colour. If the seal had perceived colour, it would have responded to colour differences between stimuli. However, the seal responded with "same", providing strong evidence for colour-blindness.

Phase diagrams and Hofstadter butterflies in the strongly correlated bosonic systems on the lattices with Dirac points

NASA Astrophysics Data System (ADS)

Sajna, A. S.; Polak, T. P.

2018-06-01

Gauge potentials with different configurations have been recently realized in the optical lattice experiments. It is remarkable that one of the simplest gauge potential can generate particle energy spectrum with the self-similar structure known as a Hofstadter butterfly. We investigate theoretically the impact of strong on-site interaction on such a spectrum in the bosonic Mott insulator within Bose-Hubbard model. In particular, it is shown that the fractal structure is encoded in the quasi-particle and hole bosonic branches for different lattice backgrounds. For example a square lattice and other structures (brick-wall and staggered magnetic flux lattice) which contain Dirac points in energy dispersions are considered. This shows that single-particle physics is still present even in the strong interaction limit for whole Hofstadter spectrum. Additionally we observe, that although in brick-wall and staggered flux lattices the quasi-particle densities of states look qualitatively similar, the corresponding Hofstadter butterfly assumes different forms. In particular, we use a superposition of two different synthetic gauge fields which appears to be a generator of non-trivial phenomena in the optical lattice systems. We also discuss the consequences of these phenomena on the phase diagrams between bosonic Mott insulator and superfluid phase. The analysis is carried out within the strong coupling expansion method on the finite size lattices and also at finite temperatures which are relevant for the currently made experiments.

Cultural modes of expressing emotions influence how emotions are experienced.

PubMed

Immordino-Yang, Mary Helen; Yang, Xiao-Fei; Damasio, Hanna

2016-10-01

The brain's mapping of bodily responses during emotion contributes to emotional experiences, or feelings. Culture influences emotional expressiveness, that is, the magnitude of individuals' bodily responses during emotion. So, are cultural influences on behavioral expressiveness associated with differences in how individuals experience emotion? Chinese and American young adults reported how strongly admiration- and compassion-inducing stories made them feel, first in a private interview and then during functional magnetic resonance imaging (fMRI). As expected, Americans were more expressive in the interview. Although expressiveness did not predict stronger reported feelings or neural responses during fMRI, in both cultural groups more-expressive people showed tighter trial-by-trial correlations between their experienced strength of emotion and activations in visceral-somatosensory cortex, even after controlling for individuals' overall strength of reactions (neural and felt). Moreover, expressiveness mediated a previously described cultural effect in which activations in visceral-somatosensory cortex correlated with feeling strength among Americans but not among Chinese. Post hoc supplementary analyses revealed that more-expressive individuals reached peak activation of visceral-somatosensory cortex later in the emotion process and took longer to decide how strongly they felt. The results together suggest that differences in expressiveness correspond to differences in how somatosensory mechanisms contribute to constructing conscious feelings. By influencing expressiveness, culture may therefore influence how individuals know how strongly they feel, what conscious feelings are based on, or possibly what strong versus weak emotions "feel like." (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Cultural Modes of Expressing Emotions Influence How Emotions Are Experienced

PubMed Central

Immordino-Yang, Mary Helen; Yang, Xiao-Fei; Damasio, Hanna

2016-01-01

The brain’s mapping of bodily responses during emotion contributes to emotional experiences, or feelings. Culture influences emotional expressiveness, i.e. the magnitude of individuals’ bodily responses during emotion. So, are cultural influences on behavioral expressiveness associated with differences in how individuals experience emotion? Chinese and American young adults reported how strongly admiration and compassion-inducing stories made them feel, first in a private interview and then during fMRI. As expected, Americans were more expressive in the interview. While expressiveness did not predict stronger reported feelings or neural responses during fMRI, in both cultural groups more expressive people showed tighter trial-by-trial correlations between their experienced strength of emotion and activations in visceral-somatosensory cortex, even after controlling for individuals’ overall strength of reactions (neural and felt). Moreover, expressiveness mediated a previously described cultural effect in which activations in visceral-somatosensory cortex correlated with feeling strength among Americans but not among Chinese. Post-hoc supplementary analyses revealed that more expressive individuals reached peak activation of visceral-somatosensory cortex later in the emotion process and took longer to decide how strongly they felt. The results together suggest that differences in expressiveness correspond to differences in how somatosensory mechanisms contribute to constructing conscious feelings. By influencing expressiveness, culture may therefore influence how individuals know how strongly they feel, what conscious feelings are based on, or possibly what strong versus weak emotions “feel like.” PMID:27270077

Serotonin inhibits low-threshold spike interneurons in the striatum

PubMed Central

Cains, Sarah; Blomeley, Craig P; Bracci, Enrico

2012-01-01

Low-threshold spike interneurons (LTSIs) are important elements of the striatal architecture and the only known source of nitric oxide in this nucleus, but their rarity has so far prevented systematic studies. Here, we used transgenic mice in which green fluorescent protein is expressed under control of the neuropeptide Y (NPY) promoter and striatal NPY-expressing LTSIs can be easily identified, to investigate the effects of serotonin on these neurons. In sharp contrast with its excitatory action on other striatal interneurons, serotonin (30 μm) strongly inhibited LTSIs, reducing or abolishing their spontaneous firing activity and causing membrane hyperpolarisations. These hyperpolarisations persisted in the presence of tetrodotoxin, were mimicked by 5-HT2C receptor agonists and reversed by 5-HT2C antagonists. Voltage-clamp slow-ramp experiments showed that serotonin caused a strong increase in an outward current activated by depolarisations that was blocked by the specific M current blocker XE 991. In current-clamp experiments, XE 991 per se caused membrane depolarisations in LTSIs and subsequent application of serotonin (in the presence of XE 991) failed to affect these neurons. We concluded that serotonin strongly inhibits striatal LTSIs acting through postsynaptic 5-HT2C receptors and increasing an M type current. PMID:22495583

Contraception in The Netherlands: the low abortion rate explained.

PubMed

Ketting, E; Visser, A P

1994-07-01

This article gives a review of the main factors that are related to the low abortion rate in the Netherlands. Attention is payed to figures on abortion and the use of contraceptive methods since the beginning of the 1960s up to the end of the 1980s. The strong acceptance of family planning was influenced by changing values regarding sexuality and the family, the transition from an agricultural to a modern industrial society, rapid economic growth, declining influence of the churches on daily life, introduction of modern mass media and the increased general educational level. The introduction of modern contraceptives (mainly the pill and contraceptive sterilization) was stimulated by a strong voluntary family planning movement, fear for overpopulation, a positive role of GPs, and the public health insurance system. A reduction of unwanted pregnancies has been accomplished through successful strategies for the prevention of teenage pregnancy (including sex education, open discussions on sexuality in mass media, educational campaigns and low barrier services) as well as through wide acceptance of sterilization. The Dutch experience with family planning shows the following characteristics: a strong wish to reduce reliance on abortion, ongoing sexual and contraceptive education related to the actual experiences of the target groups, and low barrier family planning services.

Mathematical anxiety is linked to reduced cognitive reflection: a potential road from discomfort in the mathematics classroom to susceptibility to biases.

PubMed

Morsanyi, Kinga; Busdraghi, Chiara; Primi, Caterina

2014-09-01

When asked to solve mathematical problems, some people experience anxiety and threat, which can lead to impaired mathematical performance (Curr Dir Psychol Sci 11:181-185, 2002). The present studies investigated the link between mathematical anxiety and performance on the cognitive reflection test (CRT; J Econ Perspect 19:25-42, 2005). The CRT is a measure of a person's ability to resist intuitive response tendencies, and it correlates strongly with important real-life outcomes, such as time preferences, risk-taking, and rational thinking. In Experiments 1 and 2 the relationships between maths anxiety, mathematical knowledge/mathematical achievement, test anxiety and cognitive reflection were analysed using mediation analyses. Experiment 3 included a manipulation of working memory load. The effects of anxiety and working memory load were analysed using ANOVAs. Our experiments with university students (Experiments 1 and 3) and secondary school students (Experiment 2) demonstrated that mathematical anxiety was a significant predictor of cognitive reflection, even after controlling for the effects of general mathematical knowledge (in Experiment 1), school mathematical achievement (in Experiment 2) and test anxiety (in Experiments 1-3). Furthermore, Experiment 3 showed that mathematical anxiety and burdening working memory resources with a secondary task had similar effects on cognitive reflection. Given earlier findings that showed a close link between cognitive reflection, unbiased decisions and rationality, our results suggest that mathematical anxiety might be negatively related to individuals' ability to make advantageous choices and good decisions.

Orosensory responsiveness to and preference for hydroxide-containing salts in mice.

PubMed

St John, Steven J; Boughter, John D

2009-07-01

Historically, taste researchers have considered the possibility that the gustatory system detects basic compounds, such as those containing the hydroxide ion, but evidence for an "alkaline taste" has not been strong. We found that, in 48 h, 2-bottle preference tests, C3HeB/FeJ (C3) mice showed a preference for Ca(OH)(2), whereas SWR/J (SW) mice showed avoidance. Strain differences were also apparent to NaOH but not CaCl(2). Follow-up studies showed that the strain difference for Ca(OH)(2) was stable over time (Experiment 2) but that C3 and SW mice did not differ in their responses to Ca(OH)(2) or NaOH in brief-access tests, where both mice avoided high concentrations of these compounds (Experiment 3). In order to assess the perceived quality of Ca(OH)(2), mice were tested in 2 taste aversion generalization experiments (Experiments 4 and 5). Aversions to Ca(OH)(2) generalized to NaOH but not CaCl(2) in both strains, suggesting that the generalization was based on the hydroxide ion. Both strains also generalized aversions to quinine, suggesting the possibility that the hydroxide ion has a bitter taste quality to these mice, despite the preference shown by C3 mice to middle concentrations in long-term tests.

Something to smile about: the interrelationship between attractiveness and emotional expression.

PubMed

Golle, Jessika; Mast, Fred W; Lobmaier, Janek S

2014-01-01

Previous studies have suggested a link between the processing of the emotional expression of a face and how attractive it appears. In two experiments we investigated the interrelationship between attractiveness and happiness. In Experiment 1 we presented morphed faces varying in attractiveness and happiness and asked participants to choose the more attractive of two simultaneously presented faces. In the second experiment we used the same stimuli as in Experiment 1 and asked participants to choose the happier face. The results of Experiment 1 revealed that the evaluation of attractiveness is strongly influenced by the intensity of a smile expressed on a face: A happy facial expression could even compensate for relative unattractiveness. Conversely, the findings of Experiment 2 showed that facial attractiveness also influences the evaluation of happiness: It was easier to choose the happier of two faces if the happier face was also more attractive. We discuss the interrelationship of happiness and attractiveness with regard to evolutionary relevance of positive affective status and rewarding effects.

A controlled experiment on the impact of software structure on maintainability

NASA Technical Reports Server (NTRS)

Rombach, Dieter H.

1987-01-01

The impact of software structure on maintainability aspects including comprehensibility, locality, modifiability, and reusability in a distributed system environment is studied in a controlled maintenance experiment involving six medium-size distributed software systems implemented in LADY (language for distributed systems) and six in an extended version of sequential PASCAL. For all maintenance aspects except reusability, the results were quantitatively given in terms of complexity metrics which could be automated. The results showed LADY to be better suited to the development of maintainable software than the extension of sequential PASCAL. The strong typing combined with high parametrization of units is suggested to improve the reusability of units in LADY.

Reynolds and Maxwell stress measurements in the reversed field pinch experiment Extrap-T2R

NASA Astrophysics Data System (ADS)

Vianello, N.; Antoni, V.; Spada, E.; Spolaore, M.; Serianni, G.; Cavazzana, R.; Bergsåker, H.; Cecconello, M.; Drake, J. R.

2005-08-01

The complete Reynolds stress (RS) has been measured in the edge region of the Extrap-T2R reversed field pinch experiment. The RS exhibits a strong gradient in the region where a high E × B shear takes place. Experimental results show this gradient to be almost entirely due to the electrostatic contribution. This has been interpreted as experimental evidence of flow generation via turbulence mechanism. The scales involved in flow generation are deduced from the frequency decomposition of RS tensor. They are found related to magnetohydrodynamic activity but are different with respect to the scales responsible for turbulent transport.

Integrating teaching and authentic research in the field and laboratory settings

NASA Astrophysics Data System (ADS)

Daryanto, S.; Wang, L.; Kaseke, K. F.; Ravi, S.

2016-12-01

Typically authentic research activities are separated from rigorous classroom teaching. Here we assessed the potential of integrating teaching and research activities both in the field and in the laboratory. We worked with students from both US and abroad without strong science background to utilize advanced environmental sensors and statistical tool to conduct innovative projects. The students include one from Namibia and two local high school students in Indianapolis (through Project SEED, Summer Experience for the Economically Disadvantaged). They conducted leaf potential measurements, isotope measurements and meta-analysis. The experience showed us the great potential of integrating teaching and research in both field and laboratory settings.

Enhanced zero-bias Majorana peak in the differential tunneling conductance of disordered multisubband quantum-wire/superconductor junctions.

PubMed

Pientka, Falko; Kells, Graham; Romito, Alessandro; Brouwer, Piet W; von Oppen, Felix

2012-11-30

A recent experiment Mourik et al. [Science 336, 1003 (2012)] on InSb quantum wires provides possible evidence for the realization of a topological superconducting phase and the formation of Majorana bound states. Motivated by this experiment, we consider the signature of Majorana bound states in the differential tunneling conductance of multisubband wires. We show that the weight of the Majorana-induced zero-bias peak is strongly enhanced by mixing of subbands, when disorder is added to the end of the quantum wire. We also consider how the topological phase transition is reflected in the gap structure of the current-voltage characteristic.

Learning in innovation networks: Some simulation experiments

NASA Astrophysics Data System (ADS)

Gilbert, Nigel; Ahrweiler, Petra; Pyka, Andreas

2007-05-01

According to the organizational learning literature, the greatest competitive advantage a firm has is its ability to learn. In this paper, a framework for modeling learning competence in firms is presented to improve the understanding of managing innovation. Firms with different knowledge stocks attempt to improve their economic performance by engaging in radical or incremental innovation activities and through partnerships and networking with other firms. In trying to vary and/or to stabilize their knowledge stocks by organizational learning, they attempt to adapt to environmental requirements while the market strongly selects on the results. The simulation experiments show the impact of different learning activities, underlining the importance of innovation and learning.

Avoidance response of juvenile Pacific treefrogs to chemical cues of introduced predatory bullfrogs.

PubMed

Chivers, D P; Wildy, E L; Kiesecker, J M; Blaustein, A R

2001-08-01

Bullfrogs (Rana catesbeiana), native to eastern North America, were introduced into Oregon in the 1930's. Bullfrogs are highly efficient predators that are known to eat a variety of prey including other amphibians. In laboratory experiments, we investigated whether juvenile Pacific treefrogs (Hyla regilla) recognize adult bullfrogs as a predatory threat. The ability of prey animals to acquire recognition of an introduced predator has important implications for survival of the prey. We found that treefrogs from a population that co-occurred with bullfrogs showed a strong avoidance of chemical cues of bullfrogs. In contrast, treefrogs from a population that did not co-occur with bullfrogs, did not respond to the bullfrog cues. Additional experiments showed that both populations of treefrogs use chemical cues to mediate predation risk. Treefrogs from both populations avoided chemical alarm cues from injured conspecifics.

Reciprocity and the Tragedies of Maintaining and Providing the Commons.

PubMed

Gächter, Simon; Kölle, Felix; Quercia, Simone

2017-09-01

Social cooperation often requires collectively beneficial but individually costly restraint to maintain a public good1-4, or it needs costly generosity to create one1,5. Status quo effects6 predict that maintaining a public good is easier than providing a new one. Here we show experimentally and with simulations that even under identical incentives, low levels of cooperation (the 'tragedy of the commons'2) are systematically more likely in Maintenance than Provision. Across three series of experiments, we find that strong and weak positive reciprocity, known to be fundamental tendencies underpinning human cooperation7-10, are substantially diminished under Maintenance compared to Provision. As we show in a fourth experiment, the opposite holds for negative reciprocity ('punishment'). Our findings suggest that incentives to avoid the 'tragedy of the commons' need to contend with dilemma-specific reciprocity.

Experimental results from magnetized-jet experiments executed at the Jupiter Laser Facility

NASA Astrophysics Data System (ADS)

Manuel, M. J.-E.; Kuranz, C. C.; Rasmus, A. M.; Klein, S. R.; MacDonald, M. J.; Trantham, M. R.; Fein, J. R.; Belancourt, P. X.; Young, R. P.; Keiter, P. A.; Drake, R. P.; Pollock, B. B.; Park, J.; Hazi, A. U.; Williams, G. J.; Chen, H.

2015-12-01

Recent experiments at the Jupiter Laser Facility investigated magnetization effects on collimated plasma jets. Laser-irradiated plastic-cone-targets produced collimated, millimeter-scale plasma flows as indicated by optical interferometry. Proton radiography of these jets showed no indication of strong, self-generated magnetic fields, suggesting a dominantly hydrodynamic collimating mechanism. Targets were placed in a custom-designed solenoid capable of generating field strengths up to 5 T. Proton radiographs of the well-characterized B-field, without a plasma jet, suggested an external source of trapped electrons that affects proton trajectories. The background magnetic field was aligned with the jet propagation direction, as is the case in many astrophysical systems. Optical interferometry showed that magnetization of the plasma results in disruption of the collimated flow and instead produces a hollow cavity. This result is a topic of ongoing investigation.

Thermodynamic constraints on the amplitude of quantum oscillations

DOE PAGES

Shekhter, Arkady; Modic, K. A.; McDonald, R. D.; ...

2017-03-23

Magneto-quantum oscillation experiments in high-temperature superconductors show a strong thermally induced suppression of the oscillation amplitude approaching the critical dopings [B. J. Ramshaw et al., Science 348, 317 (2014); H. Shishido et al., Phys. Rev. Lett. 104, 057008 (2010); P. Walmsley et al., Phys. Rev. Lett. 110, 257002 (2013)]—in support of a quantum-critical origin of their phase diagrams. In this paper, we suggest that, in addition to a thermodynamic mass enhancement, these experiments may directly indicate the increasing role of quantum fluctuations that suppress the quantum oscillation amplitude through inelastic scattering. Finally, we show that the traditional theoretical approaches beyondmore » Lifshitz-Kosevich to calculate the oscillation amplitude in correlated metals result in a contradiction with the third law of thermodynamics and suggest a way to rectify this problem.« less

The Temporal Dynamics of Two Response-Focused Forms of Emotion Regulation: Experiential, Expressive, and Autonomic Consequences

PubMed Central

Dan-Glauser, Elise S.; Gross, James J.

2011-01-01

This study examines the early affective consequences of two close forms of suppression. Participants (N=37) were shown negative, positive, and neutral pictures and cued either to attend to the pictures, or to perform expressive or physiological suppression (i.e. reduce body reactions). Continuous measures of experience, expressivity, and autonomic responses showed that both suppression strategies produced rapid response modulation. Common effects of the two strategies included a transient increase in negative feeling, a durable decrease in positive feeling, and a decrease in expressivity, cardiovascular activity, and oxygenation. The two strategies were significantly different only in response to positive stimuli, with physiological suppression showing a larger decrease in experience intensity and blood pressure. These results suggest a strong overlap between the two suppression strategies in terms of their early impact on emotional responses. PMID:21361967

Context-Inappropriate Anger, Emotion Knowledge Deficits, and Negative Social Experiences in Preschool

PubMed Central

Locke, Robin L.; Miller, Alison L.; Seifer, Ronald; Heinze, Justin E.

2015-01-01

This study examined contextually-inappropriate (CI) anger in relation to emotion recognition and situation knowledge, negative social experiences, and externalizing behavior among low-income 4-year-olds attending Head Start (n=134). Approximately one-quarter of children (23%) showed anger when presented with positive/neutral slides and videos (valence-incongruent CI anger), whereas 2/5 of children (40%) showed anger when presented with negative slides and videos (valence-congruent CI anger). Valence-incongruent CI anger was associated with lower emotion situation knowledge (for boys only), more self-reported peer rejection and loneliness, and greater negative nominations by teachers and peers. Both valence-incongruent and (for boys only) valence-congruent CI anger were positively associated with externalizing behavior. Overall, valence-incongruent CI anger was more strongly associated with negative child outcomes than valence-congruent CI anger. PMID:26376288

Korean preschoolers' advanced inhibitory control and its relation to other executive skills and mental state understanding.

PubMed

Oh, Seungmi; Lewis, Charlie

2008-01-01

This study assessed executive function and mental state understanding in Korean preschoolers. In Experiment 1, forty 3.5- and 4-year-old Koreans showed ceiling performance on inhibition and switching measures, although their performance on working memory and false belief was comparable to that of Western children. Experiment 2 revealed a similar advantage in a sample of seventy-six 3- and 4-year-old Koreans compared with sixty-four age-matched British children. Korean children younger than 3.5 years of age showed ceiling effects on some inhibition measures despite more stringent protocols and the link between executive function and mental state understanding was not as strong as in the British sample. The results raise key questions about the nature and development of the executive system and its relation to social understanding.

Unambiguous Signature of the Berry Phase in Intense Laser Dissociation of Diatomic Molecules.

PubMed

Bouakline, Foudhil

2018-05-03

We report strong evidence of Berry phase effects in intense laser dissociation of D 2 + molecules, manifested as Aharonov-Bohm-like oscillations in the photofragment angular distribution (PAD). Our calculations show that this interference pattern strongly depends on the parity of the diatom initial rotational state, (-1) j . Indeed, the PAD local maxima (minima) observed in one case ( j odd) correspond to local minima (maxima) in the other case ( j even). Using simple topological arguments, we clearly show that such interference conversion is a direct signature of the Berry phase. The sole effect of the latter on the rovibrational wave function is a sign change of the relative phase between two interfering components, which wind in opposite senses around a light-induced conical intersection (LICI). Therefore, encirclement of the LICI leads to constructive ( j odd) or destructive ( j even) self-interference of the initial nuclear wavepacket in the dissociative limit. To corroborate our theoretical findings, we suggest an experiment of strong-field indirect dissociation of D 2 + molecules, comparing the PAD of the ortho and para molecular species in directions nearly perpendicular to the laser polarization axis.

Accurate experimental and theoretical comparisons between superconductor-insulator-superconductor mixers showing weak and strong quantum effects

NASA Technical Reports Server (NTRS)

Mcgrath, W. R.; Richards, P. L.; Face, D. W.; Prober, D. E.; Lloyd, F. L.

1988-01-01

A systematic study of the gain and noise in superconductor-insulator-superconductor mixers employing Ta based, Nb based, and Pb-alloy based tunnel junctions was made. These junctions displayed both weak and strong quantum effects at a signal frequency of 33 GHz. The effects of energy gap sharpness and subgap current were investigated and are quantitatively related to mixer performance. Detailed comparisons are made of the mixing results with the predictions of a three-port model approximation to the Tucker theory. Mixer performance was measured with a novel test apparatus which is accurate enough to allow for the first quantitative tests of theoretical noise predictions. It is found that the three-port model of the Tucker theory underestimates the mixer noise temperature by a factor of about 2 for all of the mixers. In addition, predicted values of available mixer gain are in reasonable agreement with experiment when quantum effects are weak. However, as quantum effects become strong, the predicted available gain diverges to infinity, which is in sharp contrast to the experimental results. Predictions of coupled gain do not always show such divergences.

Strong and radiative decays of the low-lying S - and P -wave singly heavy baryons

NASA Astrophysics Data System (ADS)

Wang, Kai-Lei; Yao, Ya-Xiong; Zhong, Xian-Hui; Zhao, Qiang

2017-12-01

The strong and radiative decays of the low-lying S - and P -wave Λc (b ), Σc (b ), Ξc (b ), Ξc(b )', and Ωc (b ) baryons are systematically studied in a constituent quark model. We find that the radiative decay mode Λb0γ could be very useful for us to establish the missing neutral states Σb0 and Σb*0. Our calculation shows that most of those missing λ -mode P -wave singly heavy baryons have a relatively narrow decay width of less than 30 MeV. Their dominant strong and radiative decay channels can be ideal for searching for their signals in future experiments. The Σc(2800 ) resonance may be assigned to |Σc2Pλ 3/2-⟩ with JP=3 /2- or |Σc4Pλ 5/2-⟩ with JP=5 /2-. In general, the excitations of |2Pλ 3/2-⟩ and |4Pλ5/2-⟩ of the 6F multiplet have similar strong decay properties. In order to identify them, angular distributions of their decays in either strong decay modes or radiative transitions should be needed.

Transport in a disordered ν = 2 / 3 fractional quantum Hall junction

NASA Astrophysics Data System (ADS)

Protopopov, I. V.; Gefen, Yuval; Mirlin, A. D.

2017-10-01

Electric and thermal transport properties of a ν = 2 / 3 fractional quantum Hall junction are analyzed. We investigate the evolution of the electric and thermal two-terminal conductances, G and GQ, with system size L and temperature T. This is done both for the case of strong interaction between the 1 and 1/ 3 modes (when the low-temperature physics of the interacting segment of the device is controlled by the vicinity of the strong-disorder Kane-Fisher-Polchinski fixed point) and for relatively weak interaction, for which the disorder is irrelevant at T = 0 in the renormalization-group sense. The transport properties in both cases are similar in several respects. In particular, G(L) is close to 4/3 (in units of e2 / h) and GQ to 2 (in units of πT / 6 ħ) for small L, independently of the interaction strength. For large L the system is in an incoherent regime, with G given by 2/3 and GQ showing the Ohmic scaling, GQ ∝ 1 / L, again for any interaction strength. The hallmark of the strong-disorder fixed point is the emergence of an intermediate range of L, in which the electric conductance shows strong mesoscopic fluctuations and the thermal conductance is GQ = 1. The analysis is extended also to a device with floating 1/3 mode, as studied in a recent experiment (Grivnin et al. 2014).

Effects of Stratospheric Lapse Rate on Thunderstorm Cloud-Top Structure in a Three-Dimensional Numerical Simulation. Part I: Some Basic Results of Comparative Experiments.

NASA Astrophysics Data System (ADS)

Schlesinger, Robert E.

1988-05-01

An anelastic three-dimensional model is used to investigate the effects of stratospheric temperature lapse rate on cloud top height/temperature structure for strongly sheared mature isolated midlatitude thunderstorms. Three comparative experiments are performed, differing only with respect to the stratospheric stability. The assumed stratospheric lapse rate is 0 K km1 (isothermal) in the first experiment, 3 K km1 in the second, and 3 K km1 (inversion) in the third.Kinematic storm structure is very similar in all three cases, especially in the troposphere. A strong quasi-steady updraft evolves splitting into a dominant cyclonic overshooting right-mover and a weaker anticyclonic left-mover that does not reach the tropopause. Strongest downdrafts occur at low to middle levels between the updrafts, and in the lower stratosphere a few kilometers upshear and downshear of the tapering updraft summit.Each storm shows a cloud-top thermal couplet, relatively cold near and upshear of the summit, and with a `close-in' warm region downshear. Both cold and warm regions become warmer, with significant morphological changes and a lowering of the cloud summit, as stratospheric stability is increased, though the temperature spread is not greatly affected.The coldest and highest cloud-top points are nearly colocated in the absence of a stratospheric inversion, but the coldest point is offset well upshear of the summit when an inversion is present. The cold region as a whole in each case shows at least a transient `V' shape, with the arms pointing downshear, although this shape is persistent only with the inversion.In the experiment with a 3 K km1 stratospheric lapse rate (weakest stability), the warm region is small and separates into two spots with secondary cold spots downshear of them. The warm region becomes larger, and remains single, as stratospheric stability increase. In each run, the warm regions are not accompanied by corresponding cloud-top height minima except very briefly.The cold cloud-top points are near or slightly downwind of relative vertical velocity maxima, usually positive, while the warm points are imbedded in subsidence downwind of the principal cloud-top downdraft core. The storm-relative cloud-top horizontal wind fields are consistent with the `V' shape of the cold region, showing strong diffluent flow directed downshear along the flanks from an upshear stagnation zone.

Linking the pharmacological content of ecstasy tablets to the subjective experiences of drug users.

PubMed

Brunt, Tibor M; Koeter, Maarten W; Niesink, Raymond J M; van den Brink, Wim

2012-04-01

Most studies on the subjective effects of ecstasy are based on the assumption that the substance that was taken is 3,4-methylenedioxymethamphetamine (MDMA). However, many tablets sold as ecstasy contain other substances and MDMA in varying doses. So far, few attempts have been made to take this into account while assessing subjective effects. This study aims to link the pharmacological content of tablets sold as ecstasy to the subjective experiences reported by ecstasy users. Self-reported effects on ecstasy tablets were available from 5,786 drug users who handed in their tablets for chemical analysis at the Drug Information and Monitoring System (DIMS) in the Netherlands. Logistic regression was employed to link the pharmacological content of ecstasy tablets to the self-reported subjective effects and compare effects with MDMA to other substances present. MDMA showed a strong association with desirable subjective effects, unparalleled by any other psychoactive substance. However, the association of MDMA was dose-dependent, with higher doses (>120 mg/tablet) likely to evoke more adverse effects. The novel psychostimulants mephedrone and p-fluoroamphetamine were considered relatively desirable, whereas meta-chlorophenylpiperazine (mCPP) and p-methoxymethamphetamine (PMMA) were strongly associated with adverse subjective effects. Also, 3,4-methylene-dioxyamphetamine (MDA) and benzylpiperazine (BZP) were not appreciated as replacement for MDMA. Linking the pharmacological content of ecstasy sold on the street to subjective experiences contributes to a better understanding of the wide range of subjective effects ascribed to ecstasy and provides a strong rationale for the prolonged endurance of MDMA as the key ingredient of the ecstasy market.

Experimental study on transmission of an overdriven detonation wave from propane/oxygen to propane/air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, J.; Lai, W.H.; Chung, K.

2008-08-15

Two sets of experiments were performed to achieve a strong overdriven state in a weaker mixture by propagating an overdriven detonation wave via a deflagration-to-detonation transition (DDT) process. First, preliminary experiments with a propane/oxygen mixture were used to evaluate the attenuation of the overdriven detonation wave in the DDT process. Next, experiments were performed wherein a propane/oxygen mixture was separated from a propane/air mixture by a thin diaphragm to observe the transmission of an overdriven detonation wave. Based on the characteristic relations, a simple wave intersection model was used to calculate the state of the transmitted detonation wave. The resultsmore » showed that a rarefaction effect must be included to ensure that there is no overestimate of the post-transmission wave properties when the incident detonation wave is overdriven. The strength of the incident overdriven detonation wave plays an important role in the wave transmission process. The experimental results showed that a transmitted overdriven detonation wave occurs instantaneously with a strong incident overdriven detonation wave. The near-CJ state of the incident wave leads to a transmitted shock wave, and then the transition to the overdriven detonation wave occurs downstream. The attenuation process for the overdriven detonation wave decaying to a near-CJ state occurs in all tests. After the attenuation process, an unstable detonation wave was observed in most tests. This may be attributed to the increase in the cell width in the attenuation process that exceeds the detonability cell width limit. (author)« less

Internal structure of a vortex breakdown

NASA Technical Reports Server (NTRS)

Nakamura, Y.; Leonard, A.; Spalart, P. R.

1986-01-01

An axisymmetric vortex breakdown was well simulated by the vortex filament method. The agreement with the experiment was qualitatively good. In particular, the structure in the interior of the vortex breakdown was ensured to a great degree by the present simulation. The second breakdown, or spiral type, which occurs downstream of the first axisymmetric breakdown, was simulated more similarly to the experiment than before. It shows a kink of the vortex filaments and strong three-dimensionality. Furthermore, a relatively low velocity region was observed near the second breakdown. It was also found that it takes some time for this physical phenomenon to attain its final stage. The comparison with the experiment is getting better as time goes on. In this paper, emphasis is placed on the comparison of the simulated results with the experiment. The present results help to make clear the mechanism of a vortex breakdown.

Student Perceptions of Science Ability, Experiences, Expectations, and Career Choices

NASA Astrophysics Data System (ADS)

Cherney, Michael; Cherney, I.

2006-12-01

The decision to study physics or astronomy is affected by many factors, including preferences, motivations, and expectations for success. Differing cognitive profiles contribute to the learning of science through a complex process in which intrinsic capacities are tuned both by everyday experience and by instruction. In an attempt to identify the developmental pathways and intrinsic factors that most strongly influence the choice to study science, we administered an extensive survey to a sample of 400 students. The survey questions were based on Eccles et al.’s model of achievement-related choices and findings showing that previous play experiences, spatial experiences, task beliefs, as well as perceived mathematics ability, motivational and personality characteristics affect mathematics achievement and science career choices. The perceptions of students planning a science career are compared with those planning a career in other areas. Gender differences are also discussed.

Preliminary experiments on the reduction of the uranyl ion to uraninite by carbonaceous substances

USGS Publications Warehouse

Breger, Irving A.; Moore, Richard T.

1955-01-01

An aqueous solution of uranyl sulfate containing a suspension of subbituminous coal has been heated at 210 C for three days. Examination of the coal at the end of the experiment showed it to contain 31.8 percent uranium recognizable as uraninite by a sharp, strong X-ray diffraction pattern. A similar experiment with degraded spruce wood also led to the formation of uraninite but in lesser quantity and with broader lines in the X-ray diffraction pattern. The ability of coal or wood to reduce the uranyl ion is a critical factor in the correlation of studies of uraniferous coals containing the uranyl ion with studies of uraninite-bearing coalified wood from the Colorado Plateau. Although these results are based an preliminary experiments, they are extremely important geochemically and warrant the development of the series of controlled studies that are proposed.

Beam test results of STS prototype modules for the future accelerator experiments FAIR/CBM and NICA/MPD projects

NASA Astrophysics Data System (ADS)

Kharlamov, Petr; Dementev, Dmitrii; Shitenkov, Mikhail

2017-10-01

High-energy heavy-ion collision experiments provide the unique possibility to create and investigate extreme states of strongly-interacted matter and address the fundamental aspects of QCD. The experimental investigation the QCD phase diagram would be a major breakthrough in our understanding of the properties of nuclear matter. The reconstruction of the charged particles created in the nuclear collisions, including the determination of their momenta, is the central detection task in high-energy heavy-ion experiments. It is taken up by the Silicon Tracking System in CBM@FAIR and by Inner Tracker in MPD@NICA currently under development. These experiments requires very fast and radiation hard detectors, a novel data read-out and analysis concept including free streaming front-end electronics. Thermal and beam tests of prototype detector modules for these tracking systems showed the stability of sensors and readout electronics operation.

First experiments probing the collision of parallel magnetic fields using laser-produced plasmas

DOE PAGES

Rosenberg, M. J.; Li, C. K.; Fox, W.; ...

2015-04-08

Novel experiments to study the strongly-driven collision of parallel magnetic fields in β~10, laser-produced plasmas have been conducted using monoenergetic proton radiography. These experiments were designed to probe the process of magnetic flux pileup, which has been identified in prior laser-plasma experiments as a key physical mechanism in the reconnection of anti-parallel magnetic fields when the reconnection inflow is dominated by strong plasma flows. In the present experiments using colliding plasmas carrying parallel magnetic fields, the magnetic flux is found to be conserved and slightly compressed in the collision region. Two-dimensional (2D) particle-in-cell (PIC) simulations predict a stronger flux compressionmore » and amplification of the magnetic field strength, and this discrepancy is attributed to the three-dimensional (3D) collision geometry. Future experiments may drive a stronger collision and further explore flux pileup in the context of the strongly-driven interaction of magnetic fields.« less

On the Stability of Deinoxanthin Exposed to Mars Conditions during a Long-Term Space Mission and Implications for Biomarker Detection on Other Planets

PubMed Central

Leuko, Stefan; Bohmeier, Maria; Hanke, Franziska; Böettger, Ute; Rabbow, Elke; Parpart, Andre; Rettberg, Petra; de Vera, Jean-Pierre P.

2017-01-01

Outer space, the final frontier, is a hostile and unforgiving place for any form of life as we know it. The unique environment of space allows for a close simulation of Mars surface conditions that cannot be simulated as accurately on the Earth. For this experiment, we tested the resistance of Deinococcus radiodurans to survive exposure to simulated Mars-like conditions in low-Earth orbit for a prolonged period of time as part of the Biology and Mars experiment (BIOMEX) project. Special focus was placed on the integrity of the carotenoid deinoxanthin, which may serve as a potential biomarker to search for remnants of life on other planets. Survival was investigated by evaluating colony forming units, damage inflicted to the 16S rRNA gene by quantitative PCR, and the integrity and detectability of deinoxanthin by Raman spectroscopy. Exposure to space conditions had a strong detrimental effect on the survival of the strains and the 16S rRNA integrity, yet results show that deinoxanthin survives exposure to conditions as they prevail on Mars. Solar radiation is not only strongly detrimental to the survival and 16S rRNA integrity but also to the Raman signal of deinoxanthin. Samples not exposed to solar radiation showed only minuscule signs of deterioration. To test whether deinoxanthin is able to withstand the tested parameters without the protection of the cell, it was extracted from cell homogenate and exposed to high/low temperatures, vacuum, germicidal UV-C radiation, and simulated solar radiation. Results obtained by Raman investigations showed a strong resistance of deinoxanthin against outer space and Mars conditions, with the only exception of the exposure to simulated solar radiation. Therefore, deinoxanthin proved to be a suitable easily detectable biomarker for the search of Earth-like organic pigment-containing life on other planets. PMID:28966605

On the Stability of Deinoxanthin Exposed to Mars Conditions during a Long-Term Space Mission and Implications for Biomarker Detection on Other Planets.

PubMed

Leuko, Stefan; Bohmeier, Maria; Hanke, Franziska; Böettger, Ute; Rabbow, Elke; Parpart, Andre; Rettberg, Petra; de Vera, Jean-Pierre P

2017-01-01

Outer space, the final frontier, is a hostile and unforgiving place for any form of life as we know it. The unique environment of space allows for a close simulation of Mars surface conditions that cannot be simulated as accurately on the Earth. For this experiment, we tested the resistance of Deinococcus radiodurans to survive exposure to simulated Mars-like conditions in low-Earth orbit for a prolonged period of time as part of the Biology and Mars experiment (BIOMEX) project. Special focus was placed on the integrity of the carotenoid deinoxanthin, which may serve as a potential biomarker to search for remnants of life on other planets. Survival was investigated by evaluating colony forming units, damage inflicted to the 16S rRNA gene by quantitative PCR, and the integrity and detectability of deinoxanthin by Raman spectroscopy. Exposure to space conditions had a strong detrimental effect on the survival of the strains and the 16S rRNA integrity, yet results show that deinoxanthin survives exposure to conditions as they prevail on Mars. Solar radiation is not only strongly detrimental to the survival and 16S rRNA integrity but also to the Raman signal of deinoxanthin. Samples not exposed to solar radiation showed only minuscule signs of deterioration. To test whether deinoxanthin is able to withstand the tested parameters without the protection of the cell, it was extracted from cell homogenate and exposed to high/low temperatures, vacuum, germicidal UV-C radiation, and simulated solar radiation. Results obtained by Raman investigations showed a strong resistance of deinoxanthin against outer space and Mars conditions, with the only exception of the exposure to simulated solar radiation. Therefore, deinoxanthin proved to be a suitable easily detectable biomarker for the search of Earth-like organic pigment-containing life on other planets.

How Do Symbols Affect 3- to 4-Year-Olds' Executive Function? Evidence from a Reverse-Contingency Task

ERIC Educational Resources Information Center

Apperly, Ian A.; Carroll, Daniel J.

2009-01-01

In two experiments, 330 3- to 4-year-olds competed for stickers in a game in which the optimal response strategy was to point to an empty box that their opponent would receive in order to obtain a baited box for themselves. When the baited box contained stickers, children showed a strong tendency to point at the baited box and therefore lose the…

L band push broom microwave radiometer: Soil moisture verification and time series experiment Delmarva Peninsula

NASA Technical Reports Server (NTRS)

Jackson, T. J.; Shiue, J.; Oneill, P.; Wang, J.; Fuchs, J.; Owe, M.

1984-01-01

The verification of a multi-sensor aircraft system developed to study soil moisture applications is discussed. This system consisted of a three beam push broom L band microwave radiometer, a thermal infrared scanner, a multispectral scanner, video and photographic cameras and an onboard navigational instrument. Ten flights were made of agricultural sites in Maryland and Delaware with little or no vegetation cover. Comparisons of aircraft and ground measurements showed that the system was reliable and consistent. Time series analysis of microwave and evaporation data showed a strong similarity that indicates a potential direction for future research.

Solar Energetic Particle Transport Near a Heliospheric Current Sheet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Battarbee, Markus; Dalla, Silvia; Marsh, Mike S., E-mail: mbattarbee@uclan.ac.uk

2017-02-10

Solar energetic particles (SEPs), a major component of space weather, propagate through the interplanetary medium strongly guided by the interplanetary magnetic field (IMF). In this work, we analyze the implications that a flat Heliospheric Current Sheet (HCS) has on proton propagation from SEP release sites to the Earth. We simulate proton propagation by integrating fully 3D trajectories near an analytically defined flat current sheet, collecting comprehensive statistics into histograms, fluence maps, and virtual observer time profiles within an energy range of 1–800 MeV. We show that protons experience significant current sheet drift to distant longitudes, causing time profiles to exhibitmore » multiple components, which are a potential source of confusing interpretations of observations. We find that variation of the current sheet thickness within a realistic parameter range has little effect on particle propagation. We show that the IMF configuration strongly affects the deceleration of protons. We show that in our model, the presence of a flat equatorial HCS in the inner heliosphere limits the crossing of protons into the opposite hemisphere.« less

Linker Dependent Bond Rupture Force Measurements in Single-Molecule Junctions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frei M.; Hybertsen M.; Aradhya S.V.

We use a modified conducting atomic force microscope to simultaneously probe the conductance of a single-molecule junction and the force required to rupture the junction formed by alkanes terminated with four different chemical link groups which vary in binding strength and mechanism to the gold electrodes. Molecular junctions with amine, methylsulfide, and diphenylphosphine terminated molecules show clear conductance signatures and rupture at a force that is significantly smaller than the measured 1.4 nN force required to rupture the single-atomic gold contact. In contrast, measurements with a thiol terminated alkane which can bind covalently to the gold electrode show conductance andmore » force features unlike those of the other molecules studied. Specifically, the strong Au-S bond can cause structural rearrangements in the electrodes, which are accompanied by substantial conductance changes. Despite the strong Au-S bond and the evidence for disruption of the Au structure, the experiments show that on average these junctions also rupture at a smaller force than that measured for pristine single-atom gold contacts.« less

Dependence of SOL widths on plasma current and density in NSTX H-mode plasmas

NASA Astrophysics Data System (ADS)

Ahn, J.-W.; Maingi, R.; Boedo, J. A.; Soukhanovskii, V.; NSTX Team

2009-06-01

The dependence of various SOL widths on the line-averaged density ( n) and plasma current ( Ip) for the quiescent H-mode plasmas with Type-V ELMs in the National Spherical Torus Experiment (NSTX) was investigated. It is found that the heat flux SOL width ( λq), measured by the IR camera, is virtually insensitive to n and has a strong negative dependence on Ip. This insensitivity of λq to n¯e is consistent with the scaling law from JET H-mode plasmas that shows a very weak dependence on the upstream density. The electron temperature, ion saturation current density, electron density, and electron pressure decay lengths ( λTe, λjsat, λne, and λpe, respectively) measured by the probe showed that λTe and λjsat have strong negative dependence on Ip, whereas λne and λpe revealed only a little or no dependence. The dependence of λTe on Ip is consistent with the scaling law in the literature, while λne and λpe dependence shows a different trend.

Formation of graded vanadium oxide (V-O compound) under strong gravitational field

NASA Astrophysics Data System (ADS)

Khandaker, Jahirul Islam; Tokuda, Makoto; Ogata, Yudai; Januszko, Kamila; Nishiyama, Tadao; Yoshiasa, Akira; Mashimo, Tsutomu

2015-05-01

Sedimentation of atoms induced under strong gravitational field gives a tool for controlling elemental compositions in condensed matter. We performed a strong-gravity experiment (0.397 × 106 G at 400 °C for 24 h) on a V2O5 polycrystal using the high-temperature ultracentrifuge to examine the composition change and further the structure change. The graded composition structure of V and O was formed along gravity direction, where V increases and O decreases with gravity. It was found by the x-ray diffraction and Raman scattering method that VO2 and V2O3 phases appeared and the amounts increased, while one of the V2O5 phase decreased gradually along gravity direction. The X-ray absorption near edge structure spectra analysis identified the chemical valency decrease (+5 to +3). The UV-Vis absorption spectroscopy addressed the shifting in center of major absorption peak to longer wavelength (red shift) with the increase in gravitational field. The tail absorption peak (band gap 2.09 eV) at strong gravity region in the graded structure showed transparent conductive oxide.

Effects of monsoon trough interannual variation on tropical cyclogenesis over the western North Pacific

NASA Astrophysics Data System (ADS)

Cao, Xi; Li, Tim; Peng, Melinda; Chen, Wen; Chen, Guanghua

2014-06-01

The western North Pacific monsoon trough (MT) exhibits marked interannual variation (IAV) associated with El Niño-Southern Oscillation forcing. The role of MT IAV in tropical cyclone (TC) development was investigated using the Advanced Research Weather Research and Forecasting model placed on a beta plane. It was found that MT IAV has a great influence on vortex development. In strong years, the MT provides more favorable environmental conditions—primarily through enhanced low-level vorticity, convergence and midlevel moisture—for TC formation and vice versa in weak years. Sensitivity experiments that separated the dynamic and thermodynamic (moisture) factors from strong MT IAV showed that the thermodynamic impact associated with MT IAV is comparable to the dynamic impact.

The Role of Chromohalobacter on Transport of Lanthanides and Cesium in the Dolomite Mineral System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zengotita, Frances; Emerson, Hilary Palmer; Dittrich, Timothy M.

2017-12-01

The chemical behavior of actinide series elements and fission products is a concern for the Waste Isolation Pilot Plant repository due to their uncertain mobility in the subsurface salt formation. In this work, we are observing the behavior of the halophilic bacterium, Chromohalobacter, and its effect on the mobility of lanthanides and cesium in the presence of dolomite. Batch and minicolumn experiments were conducted with Cs + and lanthanides (Nd 3+, Eu 3+) to quantify potential transport with bacteria. Preliminary results show that Cs does not interact strongly with dolomite or Chromohalobacter, while the lanthanides can interact strongly with bothmore » minerals and bacteria depending on which the Ln contacts first.« less

Numerical study of the current-convective instability driven by asymmetry of detachment in inner and outer divertors

NASA Astrophysics Data System (ADS)

Stepanenko, A. A.; Krasheninnikov, S. I.

2018-01-01

One of the possible mechanisms responsible for strong radiation fluctuations observed in recent experiments with detached plasmas at ASDEX Upgrade [Potzel et al., Nucl. Fusion 54, 013001 (2014)] can be related to the onset of the current-convective instability (CCI) driven by strong asymmetry of detachment in the inner and outer divertors of the tokamak [S. Krasheninnikov and A. Smolyakov, Phys. Plasmas 23, 092505 (2016)]. In this study, we present the physical model, used to simulate the CCI, and the first numerical results of modeling of the CCI dynamics in ASDEX Upgrade-like conditions. The simulation results provide frequency spectra of turbulent divertor plasma oscillations showing reasonably good agreement with the available experimental data.

Prospect relativity: how choice options influence decision under risk.

PubMed

Stewart, Neil; Chater, Nick; Stott, Henry P; Reimers, Stian

2003-03-01

In many theories of decision under risk (e.g., expected utility theory, rank-dependent utility theory, and prospect theory), the utility of a prospect is independent of other options in the choice set. The experiments presented here show a large effect of the available options, suggesting instead that prospects are valued relative to one another. The judged certainty equivalent for a prospect is strongly influenced by the options available. Similarly, the selection of a preferred prospect is strongly influenced by the prospects available. Alternative theories of decision under risk (e.g., the stochastic difference model, multialternative decision field theory, and range frequency theory), where prospects are valued relative to one another, can provide an account of these context effects.

Gyrokinetic studies on turbulence-driven and neoclassical nondiffusive toroidal-momentum transport and the effect of residual fluctuations in strong E x B shear.

PubMed

Wang, W X; Hahm, T S; Ethier, S; Rewoldt, G; Lee, W W; Tang, W M; Kaye, S M; Diamond, P H

2009-01-23

A significant inward flux of toroidal momentum is found in global gyrokinetic simulations of ion temperature gradient turbulence, leading to core plasma rotation spin-up. The underlying mechanism is identified to be the generation of residual stress due to the k parallel symmetry breaking induced by global quasistationary zonal flow shear. Simulations also show a significant off-diagonal element associated with the ion temperature gradient in the neoclassical momentum flux, while the overall neoclassical flux is small. In addition, the residual turbulence found in the presence of strong E x B flow shear may account for neoclassical-level ion heat and anomalous momentum transport widely observed in experiments.

Unified Time and Frequency Picture of Ultrafast Atomic Excitation in Strong Laser Fields

NASA Astrophysics Data System (ADS)

Zimmermann, H.; Patchkovskii, S.; Ivanov, M.; Eichmann, U.

2017-01-01

Excitation and ionization in strong laser fields lies at the heart of such diverse research directions as high-harmonic generation and spectroscopy, laser-induced diffraction imaging, emission of femtosecond electron bunches from nanotips, self-guiding, filamentation and mirrorless lasing during propagation of light in atmospheres. While extensive quantum mechanical and semiclassical calculations on strong-field ionization are well backed by sophisticated experiments, the existing scattered theoretical work aiming at a full quantitative understanding of strong-field excitation lacks experimental confirmation. Here we present experiments on strong-field excitation in both the tunneling and multiphoton regimes and their rigorous interpretation by time dependent Schrödinger equation calculations, which finally consolidates the seemingly opposing strong-field regimes with their complementary pictures. Most strikingly, we observe an unprecedented enhancement of excitation yields, which opens new possibilities in ultrafast strong-field control of Rydberg wave packet excitation and laser intensity characterization.

Double perovskites with strong spin-orbit coupling

NASA Astrophysics Data System (ADS)

Cook, Ashley M.

We first present theoretical analysis of powder inelastic neutron scattering experiments in Ba2FeReO6 performed by our experimental collaborators. Ba2FeReO6, a member of the double perovskite family of materials, exhibits half-metallic behavior and high Curie temperatures Tc, making it of interest for spintronics applications. To interpret the experimental data, we develop a local moment model, which incorporates the interaction of Fe spins with spin-orbital locked magnetic moments on Re, and show that it captures the experimental observations. We then develop a tight-binding model of the double perovskite Ba 2FeReO6, a room temperature ferrimagnet with correlated and spin-orbit coupled Re t2g electrons moving in the background of Fe moments stabilized by Hund's coupling. We show that for such 3d/5d double perovskites, strong correlations on the 5d-element (Re) are essential in driving a half-metallic ground state. Incorporating both strong spin-orbit coupling and the Hubbard repulsion on Re leads to a band structure consistent with ab initio calculations. The uncovered interplay of strong correlations and spin-orbit coupling lends partial support to our previous work, which used a local moment description to capture the spin wave dispersion found in neutron scattering measurements. We then adapt this tight-binding model to study {111}-grown bilayers of half-metallic double perovskites such as Sr2FeMoO6. The combination of spin-orbit coupling, inter-orbital hybridization and symmetry-allowed trigonal distortion leads to a rich phase diagram with tunable ferromagnetic order, topological C= +/-1, +/-2 Chern bands, and a C = +/-2 quantum anomalous Hall insulator regime. We have also performed theoretical analysis of inelastic neutron scattering (INS) experiments to investigate the magnetic excitations in the weakly distorted face-centered-cubic (fcc) iridate double perovskites La2ZnIrO 6 and La2MgIrO6. Models with dominant Kitaev exchange seem to most naturally account for the neutron data as well as the measured frustration parameters of these materials, while the uniaxial Ising anisotropy does not. Our findings highlight how even seemingly conventional magnetic orders in oxide materials containing heavy transition metal ions may be driven by highly-directional exchange interactions rooted in strong spin-orbit coupling. Motivated by experiments on the double perovskites La2ZnIrO 6 and La2MgIrO6, we lastly study the magnetism of spin-orbit coupled jeff =1/2 iridium moments on the three-dimensional, geometrically frustrated, facecentered cubic lattice. The symmetry-allowed nearest-neighbor interaction includes Heisenberg, Kitaev, and symmetric off-diagonal exchange. A Luttinger-Tisza analysis shows a rich variety of orders, including collinear AII type antiferromagnetism, stripe order with moments along the {111}-direction, and incommensurate non-coplanar spirals, and we use Monte Carlo simulations to determine their magnetic ordering temperatures.

The Perceptual Characteristics of Sodium Chloride to Sodium-Depleted Rats

PubMed Central

2017-01-01

Three experiments assessed potential changes in the rat’s perception of sodium chloride (NaCl) during a state of sodium appetite. In Experiment 1, sodium-sufficient rats licking a range of NaCl concentrations (0.028–0.89M) in 15s trials showed an inverted U-shaped concentration response function peaking at 0.281M. Depleted rats (furosemide) showed an identical function, merely elevated, suggesting altered qualitative or hedonic perception but no change in perceived intensity. In Experiment 2, sodium-depleted rats were tested with NaCl, sodium gluconate, and potassium chloride (KCl; 0.028–0.89M) similar to Experiment 1. KCl was licked at the same rate as water except for a slight elevation at 0.158; sodium gluconate and NaCl were treated similarly, but rats showed more licking for hypertonic sodium gluconate than hypertonic NaCl. Sodium-depleted rats were also tested with NaCl mixed in amiloride (10–300 μM). Amiloride reduced licking but did not alter the shape of the concentration–response function. Collectively, these results suggest that transduction of sodium by epithelial sodium channels (which are blocked by amiloride and are more dominant in sodium gluconate than NaCl transduction) is crucial for the perception of sodium during physiological sodium depletion. In Experiment 3, sodium-deplete rats were tested with NaCl as in Experiment 1 but after taste aversion conditioning to 0.3M NaCl or sucrose. Rats conditioned to avoid NaCl but not sucrose failed to express a sodium appetite, strongly suggesting that NaCl does not undergo a change in taste quality during sodium appetite—rats show no confusion between sucrose and NaCl in this paradigm. PMID:27660150

The Perceptual Characteristics of Sodium Chloride to Sodium-Depleted Rats.

PubMed

St John, Steven J

2017-02-01

Three experiments assessed potential changes in the rat's perception of sodium chloride (NaCl) during a state of sodium appetite. In Experiment 1, sodium-sufficient rats licking a range of NaCl concentrations (0.028-0.89M) in 15s trials showed an inverted U-shaped concentration response function peaking at 0.281M. Depleted rats (furosemide) showed an identical function, merely elevated, suggesting altered qualitative or hedonic perception but no change in perceived intensity. In Experiment 2, sodium-depleted rats were tested with NaCl, sodium gluconate, and potassium chloride (KCl; 0.028-0.89M) similar to Experiment 1. KCl was licked at the same rate as water except for a slight elevation at 0.158; sodium gluconate and NaCl were treated similarly, but rats showed more licking for hypertonic sodium gluconate than hypertonic NaCl. Sodium-depleted rats were also tested with NaCl mixed in amiloride (10-300 μM). Amiloride reduced licking but did not alter the shape of the concentration-response function. Collectively, these results suggest that transduction of sodium by epithelial sodium channels (which are blocked by amiloride and are more dominant in sodium gluconate than NaCl transduction) is crucial for the perception of sodium during physiological sodium depletion. In Experiment 3, sodium-deplete rats were tested with NaCl as in Experiment 1 but after taste aversion conditioning to 0.3M NaCl or sucrose. Rats conditioned to avoid NaCl but not sucrose failed to express a sodium appetite, strongly suggesting that NaCl does not undergo a change in taste quality during sodium appetite-rats show no confusion between sucrose and NaCl in this paradigm. Published by Oxford University Press on behalf of US Government 2016.

Cuttlefish dynamic camouflage: responses to substrate choice and integration of multiple visual cues.

PubMed

Allen, Justine J; Mäthger, Lydia M; Barbosa, Alexandra; Buresch, Kendra C; Sogin, Emilia; Schwartz, Jillian; Chubb, Charles; Hanlon, Roger T

2010-04-07

Prey camouflage is an evolutionary response to predation pressure. Cephalopods have extensive camouflage capabilities and studying them can offer insight into effective camouflage design. Here, we examine whether cuttlefish, Sepia officinalis, show substrate or camouflage pattern preferences. In the first two experiments, cuttlefish were presented with a choice between different artificial substrates or between different natural substrates. First, the ability of cuttlefish to show substrate preference on artificial and natural substrates was established. Next, cuttlefish were offered substrates known to evoke three main camouflage body pattern types these animals show: Uniform or Mottle (function by background matching); or Disruptive. In a third experiment, cuttlefish were presented with conflicting visual cues on their left and right sides to assess their camouflage response. Given a choice between substrates they might encounter in nature, we found no strong substrate preference except when cuttlefish could bury themselves. Additionally, cuttlefish responded to conflicting visual cues with mixed body patterns in both the substrate preference and split substrate experiments. These results suggest that differences in energy costs for different camouflage body patterns may be minor and that pattern mixing and symmetry may play important roles in camouflage.

Solo status and self-construal: being distinctive influences racial self-construal and performance apprehension in African American women.

PubMed

Sekaquaptewa, Denise; Waldman, Andrew; Thompson, Mischa

2007-10-01

A preliminary study and main experiment tested the hypothesis that racial solo status (being the only member of one's race in a group) increases racial self-construal among African Americans. The preliminary study showed that African American men and women reported greater collectivist (i.e., group-based) over individualist self-construal under solo compared to nonsolo status, whereas Whites did not. The main experiment showed that the increased collectivism among African American solo women appears to be strongly reflected in racial identity becoming a salient aspect of self-construal. African American participants were also more likely than Whites to perceive that their anticipated performance would be generalized to their race, to feel like representatives of their race, and to show greater performance apprehension (indirectly evidenced by increased self-handicapping) when in racial solo status. The implications of solo status for African Americans in evaluative situations (such as academic testing sessions) are discussed. 2007 APA

Uncovering the Affective Core of Conscientiousness: The Role of Self-Conscious Emotions

PubMed Central

Fayard, Jennifer V.; Roberts, Brent W.; Robins, Richard W.; Watson, David

2013-01-01

We conducted 3 studies to test the idea that guilt is a key affective component of Conscientiousness and that it can account for the relation between Conscientiousness and negative affect. Study 1 used meta-analysis to show that Conscientiousness was associated with specific emotions and overall negative affect but was most strongly associated with guilt. Conscientiousness was negatively related to guilt experience but positively related to guilt proneness. Also, guilt experience mediated the relation between Conscientiousness and negative affect. Study 2 (N = 142) examined the relation between facets of Conscientiousness and guilt. We replicated results from Study 1 and showed that the relation between Conscientiousness and guilt was not due to overlap with Extraversion and Neuroticism. Study 3 (n = 176) examined the interplay between Conscientiousness and guilt on grades in a short-term longitudinal study. These studies showed that Conscientiousness is primarily related to guilt and highlighted the importance of examining the emotional substrate of Conscientiousness. PMID:21241309

Uncovering the affective core of conscientiousness: the role of self-conscious emotions.

PubMed

Fayard, Jennifer V; Roberts, Brent W; Robins, Richard W; Watson, David

2012-02-01

We conducted 3 studies to test the idea that guilt is a key affective component of Conscientiousness and that it can account for the relation between Conscientiousness and negative affect. Study 1 used meta-analysis to show that Conscientiousness was associated with specific emotions and overall negative affect but was most strongly associated with guilt. Conscientiousness was negatively related to guilt experience but positively related to guilt proneness. Also, guilt experience mediated the relation between Conscientiousness and negative affect. Study 2 (N = 142) examined the relation between facets of Conscientiousness and guilt. We replicated results from Study 1 and showed that the relation between Conscientiousness and guilt was not due to overlap with Extraversion and Neuroticism. Study 3 (n = 176) examined the interplay between Conscientiousness and guilt on grades in a short-term longitudinal study. These studies showed that Conscientiousness is primarily related to guilt and highlighted the importance of examining the emotional substrate of Conscientiousness. © 2012 The Authors. Journal of Personality © 2012, Wiley Periodicals, Inc.

Crossover from Commensurate to Incommensurate Antiferromagnetism in Stoichiometric NaFeAs Revealed by Single-Crystal 23Na,75As-NMR Experiments

NASA Astrophysics Data System (ADS)

Kitagawa, Kentaro; Mezaki, Yuji; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya; Takigawa, Masashi

2011-03-01

We report the results of 23Na and 75As nuclear magnetic resonance (NMR) experiments on a self-flux grown high-quality single crystal of stoichiometric NaFeAs. The NMR spectra reveal a tetragonal to twinned-orthorhombic structural phase transition at TO = 57 K and an antiferromagnetic (AF) transition at TAF = 45 K. The divergent behavior of nuclear relaxation rate near TAF shows significant anisotropy, indicating that the critical slowing down of stripe-type AF fluctuations are strongly anisotropic in spin space. The NMR spectra at sufficiently low temperatures consist of sharp peaks showing a commensurate stripe AF order with a small moment of ˜0.3 μB. However, the spectra just below TAF exhibit a highly asymmetric broadening pointing to an incommensurate modulation. The commensurate-incommensurate crossover in NaFeAs shows a certain similarity to the behavior of SrFe2As2 under high pressure.

Comfort and experience with online learning: trends over nine years and associations with knowledge

PubMed Central

2014-01-01

Background Some evidence suggests that attitude toward computer-based instruction is an important determinant of success in online learning. We sought to determine how comfort using computers and perceptions of prior online learning experiences have changed over the past decade, and how these associate with learning outcomes. Methods Each year from 2003–2011 we conducted a prospective trial of online learning. As part of each year’s study, we asked medicine residents about their comfort using computers and if their previous experiences with online learning were favorable. We assessed knowledge using a multiple-choice test. We used regression to analyze associations and changes over time. Results 371 internal medicine and family medicine residents participated. Neither comfort with computers nor perceptions of prior online learning experiences showed a significant change across years (p > 0.61), with mean comfort rating 3.96 (maximum 5 = very comfortable) and mean experience rating 4.42 (maximum 6 = strongly agree [favorable]). Comfort showed no significant association with knowledge scores (p = 0.39) but perceptions of prior experiences did, with a 1.56% rise in knowledge score for a 1-point rise in experience score (p = 0.02). Correlations among comfort, perceptions of prior experiences, and number of prior experiences were all small and not statistically significant. Conclusions Comfort with computers and perceptions of prior experience with online learning remained stable over nine years. Prior good experiences (but not comfort with computers) demonstrated a modest association with knowledge outcomes, suggesting that prior course satisfaction may influence subsequent learning. PMID:24985690

Electrochromatographic retention of peptides on strong cation-exchange stationary phases.

PubMed

Nischang, Ivo; Höltzel, Alexandra; Tallarek, Ulrich

2010-03-01

We analyze the systematic and substantial electrical field-dependence of electrochromatographic retention for four counterionic peptides ([Met5]enkephalin, oxytocin, [Arg8]vasopressin, and luteinizing hormone releasing hormone (LHRH) ) on a strong cation-exchange (SCX) stationary phase. Our experiments show that retention behavior in the studied system depends on the charge-selectivity of the stationary phase particles, the applied voltage, and the peptides' net charge. Retention factors of twice positively charged peptides ([Arg8]vasopressin and LHRH at pH 2.7) decrease with increasing applied voltage, whereas lower charged peptides (oxytocin and [Met5]enkephalin at pH 2.7, [Arg8]vasopressin and LHRH at pH 7.0) show a concomitant increase in their retention factors. The observed behavior is explained on the basis of electrical field-induced concentration polarization (CP) that develops around the SCX particles of the packing. The intraparticle concentration of charged species (buffer ions, peptides) increases with increasing applied voltage due to diffusive backflux from the enriched CP zone associated with each SCX particle. For twice charged and on the SCX phase strongly retained peptides the local increase in mobile phase ionic strength reduces the electrostatic interactions with the stationary phase, which explains the decrease of retention factors with increasing applied voltage and CP intensity. Lower charged and weaker retained peptides experience a much stronger relative intraparticle enrichment than the twice-charged peptides, which results in a net increase of retention factors with increasing applied voltage. The CP-related contribution to electrochromatographic retention of peptides on the SCX stationary phase is modulated by the applied voltage, the mobile phase ionic strength, and the peptides' net charge and could be used for selectivity tuning in difficult separations.

Spatio-Temporal Evolution of Sound Speed Channels on the Chukchi Shelf

NASA Astrophysics Data System (ADS)

Eickmeier, J.; Badiey, M.; Wan, L.

2017-12-01

The physics of an acoustic waveguide are influenced by various boundary conditions as well as spatial and temporal fluctuations in temperature and salinity profiles the water column. The shallow water Canadian Basin Acoustic Propagation Experiment (CANAPE) experiment was designed to study the effect of oceanographic variability on the acoustic field. A pilot study was conducted in the summer of 2015, full deployment of acoustic and environmental moorings took place in 2016, and recovery will occur in late 2017. An example of strong oceanographic variability in the SW region is depicted in Figure 1. Over the course of 7 days, warm Bering Sea water arrived on the Chukchi Shelf and sank in the water column to between 25 m and 125 m depth. This warm water spread to a range of 10 km and a potential eddy of warm water formed causing an increase in sound speed between 15 km and 20 km range in Fig. 1(b). Due to the increased sound speed, a strong sound channel evolved between 100 m and 200 m for acoustic waves arriving from off the shelf, deep water sources. In Fig. 1(a), the initial formation of the acoustic channel is only evident in 50 m to 100 m of water out to a range of 5 km. Recorded environmental data will be used to study fluctuations in sound speed channel formation on the Chukchi Shelf. Data collected in 2015 and 2016 have shown sound duct evolution over 7 days and over a one-month period. Analysis is projected to show sound channel formation over a new range of spatio-temporal scales. This analysis will show a cycle of sound channels opening and closing on the shelf, where this cycle strongly influences the propagation path, range and attenuation of acoustic waves.

Old and in pain: Enduring and situational effects of cultural aging stereotypes on older people's pain experiences.

PubMed

Bernardes, S F; Marques, S; Matos, M

2015-08-01

This study aimed to investigate the interplay between enduring and situational aging stereotype (AS) effects in older adults' self-reports of clinical and experimentally induced pain. We expected that, as compared with the situational activation of positive AS or a neutral condition, the activation of negative AS would lead to more severe self-reports of clinical pain (H1, hypothesis 1), higher cold pressor task (CPT) pain threshold (H2) and lower CPT pain tolerance (H3), especially among older adults who more strongly endorsed AS. This was a prospective study across two moments in time. At time 1 (T1), 52 older adults (Mage  = 74.7; 51.9% women) filled out measures of cultural AS endorsement, clinical pain severity and interference. Three months afterwards (T2), some of these participants collaborated in an experimental study on the effects of AS activation on reported clinical pain (n = 40) and experimentally induced (using CPT) pain threshold and tolerance (n = 35). Our results supported H2, i.e., as compared with the activation of positive AS or a neutral condition, when negative AS were activated older adults showed higher CPT pain thresholds, but this effect was more salient among those who more strongly endorsed AS at T1. This study stresses the influence of cultural AS in older adults' pain experiences showing that the situational activation of negative AS greatly increases experimentally induced pain thresholds of elders who more strongly endorse those stereotypes. It also highlights the relevance of interventions at the level of the physical and/or social environments surrounding elders in pain. © 2014 European Pain Federation - EFIC®

Effective model with strong Kitaev interactions for α -RuCl3

NASA Astrophysics Data System (ADS)

Suzuki, Takafumi; Suga, Sei-ichiro

2018-04-01

We use an exact numerical diagonalization method to calculate the dynamical spin structure factors of three ab initio models and one ab initio guided model for a honeycomb-lattice magnet α -RuCl3 . We also use thermal pure quantum states to calculate the temperature dependence of the heat capacity, the nearest-neighbor spin-spin correlation function, and the static spin structure factor. From the results obtained from these four effective models, we find that, even when the magnetic order is stabilized at low temperature, the intensity at the Γ point in the dynamical spin structure factors increases with increasing nearest-neighbor spin correlation. In addition, we find that the four models fail to explain heat-capacity measurements whereas two of the four models succeed in explaining inelastic-neutron-scattering experiments. In the four models, when temperature decreases, the heat capacity shows a prominent peak at a high temperature where the nearest-neighbor spin-spin correlation function increases. However, the peak temperature in heat capacity is too low in comparison with that observed experimentally. To address these discrepancies, we propose an effective model that includes strong ferromagnetic Kitaev coupling, and we show that this model quantitatively reproduces both inelastic-neutron-scattering experiments and heat-capacity measurements. To further examine the adequacy of the proposed model, we calculate the field dependence of the polarized terahertz spectra, which reproduces the experimental results: the spin-gapped excitation survives up to an onset field where the magnetic order disappears and the response in the high-field region is almost linear. Based on these numerical results, we argue that the low-energy magnetic excitation in α -RuCl3 is mainly characterized by interactions such as off-diagonal interactions and weak Heisenberg interactions between nearest-neighbor pairs, rather than by the strong Kitaev interactions.

Convexities move because they contain matter.

PubMed

Barenholtz, Elan

2010-09-22

Figure-ground assignment to a contour is a fundamental stage in visual processing. The current paper introduces a novel, highly general dynamic cue to figure-ground assignment: "Convex Motion." Across six experiments, subjects showed a strong preference to assign figure and ground to a dynamically deforming contour such that the moving contour segment was convex rather than concave. Experiments 1 and 2 established the preference across two different kinds of deformational motion. Additional experiments determined that this preference was not due to fixation (Experiment 3) or attentional mechanisms (Experiment 4). Experiment 5 found a similar, but reduced bias for rigid-as opposed to deformational-motion, and Experiment 6 demonstrated that the phenomenon depends on the global motion of the effected contour. An explanation of this phenomenon is presented on the basis of typical natural deformational motion, which tends to involve convex contour projections that contain regions consisting of physical "matter," as opposed to concave contour indentations that contain empty space. These results highlight the fundamental relationship between figure and ground, perceived shape, and the inferred physical properties of an object.

Strong magnetization and Chern insulators in compressed graphene/CrI 3 van der Waals heterostructures

NASA Astrophysics Data System (ADS)

Zhang, Jiayong; Zhao, Bao; Zhou, Tong; Xue, Yang; Ma, Chunlan; Yang, Zhongqin

2018-02-01

Graphene-based heterostructures are a promising material system for designing the topologically nontrivial Chern insulating devices. Recently, a two-dimensional monolayer ferromagnetic insulator CrI3 was successfully synthesized in experiments [B. Huang et al., Nature (London) 546, 270 (2017), 10.1038/nature22391]. Here, these two interesting materials are proposed to build a heterostructure (Gr /CrI3). Our first-principles calculations show that the system forms a van der Waals (vdW) heterostructure, which is relatively facilely fabricated in experiments. A Chern insulating state is acquired in the Gr /CrI3 heterostructure if the vdW gap is compressed to a distance between about 3.3 and 2.4 Å, corresponding to a required external pressure between about 1.4 and 18.3 GPa. Amazingly, very strong magnetization (about 150 meV) is found in graphene, induced by the substrate CrI3, despite the vdW interactions between them. A low-energy effective model is employed to understand the mechanism. The work functions, contact types, and band alignments of the Gr /CrI3 heterostructure system are also studied. Our work demonstrates that the Gr /CrI3 heterostructure is a promising system to observe the quantum anomalous Hall effect at high temperatures (up to 45 K) in experiments.

The Influence of Chronic and Situational Social Status on Stereotype Susceptibility

PubMed Central

Pillaud, Vincent; Rigaud, David; Clémence, Alain

2015-01-01

We tested whether stereotypical situations would affect low-status group members' performance more strongly than high-status group members'. Experiment 1 and 2 tested this hypothesis using gender as a proxy of chronic social status and a gender-neutral task that has been randomly presented to favor boys (men superiority condition), favor girls (women superiority condition), or show no gender preference (control condition). Both experiments found that women’s (Experiment 1) and girls’ performance (Experiment 2) suffered more from the evoked stereotypes than did men's and boys’ ones. This result was replicated in Experiment 3, indicating that short men (low-status group) were more affected compared to tall men (high-status group). Additionally, men were more affected compared to women when they perceived height as a threat. Hence, individuals are more or less vulnerable to identity threats as a function of the chronic social status at play; enjoying a high status provides protection and endorsing a low one weakens individual performance in stereotypical situations. PMID:26645829

Crowded and sparse domains in object recognition: consequences for categorization and naming.

PubMed

Gale, Tim M; Laws, Keith R; Foley, Kerry

2006-03-01

Some models of object recognition propose that items from structurally crowded categories (e.g., living things) permit faster access to superordinate semantic information than structurally dissimilar categories (e.g., nonliving things), but slower access to individual object information when naming items. We present four experiments that utilize the same matched stimuli: two examine superordinate categorization and two examine picture naming. Experiments 1 and 2 required participants to sort pictures into their appropriate superordinate categories and both revealed faster categorization for living than nonliving things. Nonetheless, the living thing superiority disappeared when the atypical categories of body parts and musical instruments were excluded. Experiment 3 examined naming latency and found no difference between living and nonliving things. This finding was replicated in Experiment 4 where the same items were presented in different formats (e.g., color and line-drawn versions). Taken as a whole, these experiments show that the ease with which people categorize items maps strongly onto the ease with which they name them.

The Influence of Chronic and Situational Social Status on Stereotype Susceptibility.

PubMed

Pillaud, Vincent; Rigaud, David; Clémence, Alain

2015-01-01

We tested whether stereotypical situations would affect low-status group members' performance more strongly than high-status group members'. Experiment 1 and 2 tested this hypothesis using gender as a proxy of chronic social status and a gender-neutral task that has been randomly presented to favor boys (men superiority condition), favor girls (women superiority condition), or show no gender preference (control condition). Both experiments found that women's (Experiment 1) and girls' performance (Experiment 2) suffered more from the evoked stereotypes than did men's and boys' ones. This result was replicated in Experiment 3, indicating that short men (low-status group) were more affected compared to tall men (high-status group). Additionally, men were more affected compared to women when they perceived height as a threat. Hence, individuals are more or less vulnerable to identity threats as a function of the chronic social status at play; enjoying a high status provides protection and endorsing a low one weakens individual performance in stereotypical situations.

Responsibility and the sense of agency enhance empathy for pain

PubMed Central

Lepron, Evelyne; Causse, Michaël; Farrer, Chlöé

2015-01-01

Being held responsible for our actions strongly determines our moral judgements and decisions. This study examined whether responsibility also influences our affective reaction to others' emotions. We conducted two experiments in order to assess the effect of responsibility and of a sense of agency (the conscious feeling of controlling an action) on the empathic response to pain. In both experiments, participants were presented with video clips showing an actor's facial expression of pain of varying intensity. The empathic response was assessed with behavioural (pain intensity estimation from facial expressions and unpleasantness for the observer ratings) and electrophysiological measures (facial electromyography). Experiment 1 showed enhanced empathic response (increased unpleasantness for the observer and facial electromyography responses) as participants' degree of responsibility for the actor's pain increased. This effect was mainly accounted for by the decisional component of responsibility (compared with the execution component). In addition, experiment 2 found that participants' unpleasantness rating also increased when they had a sense of agency over the pain, while controlling for decision and execution processes. The findings suggest that increased empathy induced by responsibility and a sense of agency may play a role in regulating our moral conduct. PMID:25473014

Perceptual Biases in Relation to Paranormal and Conspiracy Beliefs

PubMed Central

van Elk, Michiel

2015-01-01

Previous studies have shown that one’s prior beliefs have a strong effect on perceptual decision-making and attentional processing. The present study extends these findings by investigating how individual differences in paranormal and conspiracy beliefs are related to perceptual and attentional biases. Two field studies were conducted in which visitors of a paranormal conducted a perceptual decision making task (i.e. the face / house categorization task; Experiment 1) or a visual attention task (i.e. the global / local processing task; Experiment 2). In the first experiment it was found that skeptics compared to believers more often incorrectly categorized ambiguous face stimuli as representing a house, indicating that disbelief rather than belief in the paranormal is driving the bias observed for the categorization of ambiguous stimuli. In the second experiment, it was found that skeptics showed a classical ‘global-to-local’ interference effect, whereas believers in conspiracy theories were characterized by a stronger ‘local-to-global interference effect’. The present study shows that individual differences in paranormal and conspiracy beliefs are associated with perceptual and attentional biases, thereby extending the growing body of work in this field indicating effects of cultural learning on basic perceptual processes. PMID:26114604

Perceptual Biases in Relation to Paranormal and Conspiracy Beliefs.

PubMed

van Elk, Michiel

2015-01-01

Previous studies have shown that one's prior beliefs have a strong effect on perceptual decision-making and attentional processing. The present study extends these findings by investigating how individual differences in paranormal and conspiracy beliefs are related to perceptual and attentional biases. Two field studies were conducted in which visitors of a paranormal conducted a perceptual decision making task (i.e. the face/house categorization task; Experiment 1) or a visual attention task (i.e. the global/local processing task; Experiment 2). In the first experiment it was found that skeptics compared to believers more often incorrectly categorized ambiguous face stimuli as representing a house, indicating that disbelief rather than belief in the paranormal is driving the bias observed for the categorization of ambiguous stimuli. In the second experiment, it was found that skeptics showed a classical 'global-to-local' interference effect, whereas believers in conspiracy theories were characterized by a stronger 'local-to-global interference effect'. The present study shows that individual differences in paranormal and conspiracy beliefs are associated with perceptual and attentional biases, thereby extending the growing body of work in this field indicating effects of cultural learning on basic perceptual processes.

Adsorption of hydraulic fracturing fluid components 2-butoxyethanol and furfural onto granular activated carbon and shale rock.

PubMed

Manz, Katherine E; Haerr, Gregory; Lucchesi, Jessica; Carter, Kimberly E

2016-12-01

The objective of this study was to understand the adsorption ability of a surfactant and a non-surfactant chemical additive used in hydraulic fracturing onto shale and GAC. Experiments were performed at varying temperatures and sodium chloride concentrations to establish these impacts on the adsorption of the furfural (a non-surfactant) and 2-Butoxyethanol (2-BE) (a surfactant). Experiments were carried out in continuously mixed batch experiments with Langmuir and Freundlich isotherm modeling. The results of the experiments showed that adsorption of these compounds onto shale does not occur, which may allow these compounds to return to the surface in flowback and produced waters. The adsorption potential for these chemicals onto GAC follows the assumptions of the Langmuir model more strongly than those of the Freundlich model. The results show uptake of furfural and 2-BE occurs within 23 h in the presence of DI water, 0.1 mol L -1 sodium chloride, and in lab synthesized hydraulic fracturing brine. Based on the data, 83% of the furfural and 62% of the 2-BE was adsorbed using GAC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Shopping versus Nature? An Exploratory Study of Everyday Experiences

PubMed Central

Craig, Tony P.; Fischer, Anke; Lorenzo-Arribas, Altea

2018-01-01

Although a growing volume of empirical research shows that being in nature is important for human wellbeing, the definition of what constitutes an ‘experience in nature,’ and how this is different from other types of experiences, is very often left implied. In this paper we contrast everyday experiences involving nature with a category of everyday experience in which most people regularly partake. We present an exploratory study in which people (N = 357) were explicitly asked to describe a memory they had of an everyday ‘experience which involved nature,’ as well as an everyday ‘experience which involved shopping.’ The open-ended responses to these questions were analyzed both quantitatively and qualitatively. Nature experiences were generally found to be more positive than shopping experiences, and they were more likely to be rated as ‘peaceful’ and ‘active’ compared to shopping experiences. Follow-up analyses indicate a significant interaction between experience category (nature or shopping), and the relationship between connectedness to nature and the amount of pleasure associated with that experience: The more strongly connected to nature a respondent was, the larger the disparity between the pleasantness of the shopping experience and that of the experience in nature tended to be. PMID:29410642

Interactions with soil biota shift from negative to positive when a tree species is moved outside its native range.

PubMed

Gundale, Michael J; Kardol, Paul; Nilsson, Marie-Charlotte; Nilsson, Urban; Lucas, Richard W; Wardle, David A

2014-04-01

Studies evaluating plant-soil biota interactions in both native and introduced plant ranges are rare, and thus far have lacked robust experimental designs to account for several potential confounding factors. Here, we investigated the effects of soil biota on growth of Pinus contorta, which has been introduced from Canada to Sweden. Using Swedish and Canadian soils, we conducted two glasshouse experiments. The first experiment utilized unsterilized soil from each country, with a full-factorial cross of soil origin, tree provenance, and fertilizer addition. The second experiment utilized gamma-irradiated sterile soil from each country, with a full-factorial cross of soil origin, soil biota inoculation treatments, tree provenance, and fertilizer addition. The first experiment showed higher seedling growth on Swedish soil relative to Canadian soil. The second experiment showed this effect was due to differences in soil biotic communities between the two countries, and occurred independently of all other experimental factors. Our results provide strong evidence that plant interactions with soil biota can shift from negative to positive following introduction to a new region, and are relevant for understanding the success of some exotic forest plantations, and invasive and range-expanding native species. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Mathematical anxiety is linked to reduced cognitive reflection: a potential road from discomfort in the mathematics classroom to susceptibility to biases

PubMed Central

2014-01-01

Background When asked to solve mathematical problems, some people experience anxiety and threat, which can lead to impaired mathematical performance (Curr Dir Psychol Sci 11:181–185, 2002). The present studies investigated the link between mathematical anxiety and performance on the cognitive reflection test (CRT; J Econ Perspect 19:25–42, 2005). The CRT is a measure of a person’s ability to resist intuitive response tendencies, and it correlates strongly with important real-life outcomes, such as time preferences, risk-taking, and rational thinking. Methods In Experiments 1 and 2 the relationships between maths anxiety, mathematical knowledge/mathematical achievement, test anxiety and cognitive reflection were analysed using mediation analyses. Experiment 3 included a manipulation of working memory load. The effects of anxiety and working memory load were analysed using ANOVAs. Results Our experiments with university students (Experiments 1 and 3) and secondary school students (Experiment 2) demonstrated that mathematical anxiety was a significant predictor of cognitive reflection, even after controlling for the effects of general mathematical knowledge (in Experiment 1), school mathematical achievement (in Experiment 2) and test anxiety (in Experiments 1–3). Furthermore, Experiment 3 showed that mathematical anxiety and burdening working memory resources with a secondary task had similar effects on cognitive reflection. Conclusions Given earlier findings that showed a close link between cognitive reflection, unbiased decisions and rationality, our results suggest that mathematical anxiety might be negatively related to individuals’ ability to make advantageous choices and good decisions. PMID:25179230

Reciprocity and the Tragedies of Maintaining and Providing the Commons

PubMed Central

Gächter, Simon; Kölle, Felix; Quercia, Simone

2017-01-01

Social cooperation often requires collectively beneficial but individually costly restraint to maintain a public good1–4, or it needs costly generosity to create one1,5. Status quo effects6 predict that maintaining a public good is easier than providing a new one. Here we show experimentally and with simulations that even under identical incentives, low levels of cooperation (the ‘tragedy of the commons’2) are systematically more likely in Maintenance than Provision. Across three series of experiments, we find that strong and weak positive reciprocity, known to be fundamental tendencies underpinning human cooperation7–10, are substantially diminished under Maintenance compared to Provision. As we show in a fourth experiment, the opposite holds for negative reciprocity (‘punishment’). Our findings suggest that incentives to avoid the ‘tragedy of the commons’ need to contend with dilemma-specific reciprocity. PMID:28944297

A minimal physical model captures the shapes of crawling cells

NASA Astrophysics Data System (ADS)

Tjhung, E.; Tiribocchi, A.; Marenduzzo, D.; Cates, M. E.

2015-01-01

Cell motility in higher organisms (eukaryotes) is crucial to biological functions ranging from wound healing to immune response, and also implicated in diseases such as cancer. For cells crawling on hard surfaces, significant insights into motility have been gained from experiments replicating such motion in vitro. Such experiments show that crawling uses a combination of actin treadmilling (polymerization), which pushes the front of a cell forward, and myosin-induced stress (contractility), which retracts the rear. Here we present a simplified physical model of a crawling cell, consisting of a droplet of active polar fluid with contractility throughout, but treadmilling connected to a thin layer near the supporting wall. The model shows a variety of shapes and/or motility regimes, some closely resembling cases seen experimentally. Our work strongly supports the view that cellular motility exploits autonomous physical mechanisms whose operation does not need continuous regulatory effort.

Cis-regulatory changes in Kit ligand expression and parallel evolution of pigmentation in sticklebacks and humans

PubMed Central

Miller, Craig T.; Beleza, Sandra; Pollen, Alex A.; Schluter, Dolph; Kittles, Rick A.; Shriver, Mark D.; Kingsley, David M.

2010-01-01

SUMMARY Dramatic pigmentation changes have evolved within most vertebrate groups, including fish and humans. Here we use genetic crosses in sticklebacks to investigate the parallel origin of pigmentation changes in natural populations. High-resolution mapping and expression experiments show that light gills and light ventrums map to a divergent regulatory allele of the Kit ligand (Kitlg) gene. The divergent allele reduces expression in gill and skin tissue, and is shared by multiple derived freshwater populations with reduced pigmentation. In humans, Europeans and East Asians also share derived alleles at the KITLG locus. Strong signatures of selection map to regulatory regions surrounding the gene, and admixture mapping shows that the KITLG genomic region has a significant effect on human skin color. These experiments suggest that regulatory changes in Kitlg contribute to natural variation in vertebrate pigmentation, and that similar genetic mechanisms may underlie rapid evolutionary change in fish and humans. PMID:18083106

Competitive counterion complexation allows the true host : guest binding constants from a single titration by ionic receptors.

PubMed

Pessêgo, Márcia; Basílio, Nuno; Muñiz, M Carmen; García-Río, Luis

2016-07-06

Counterion competitive complexation is a background process currently ignored by using ionic hosts. Consequently, guest binding constants are strongly affected by the design of the titration experiments in such a way that the results are dependent on the guest concentration and on the presence of added salts, usually buffers. In the present manuscript we show that these experimental difficulties can be overcome by just considering the counterion competitive complexation. Moreover a single titration allows us to obtain not only the true binding constants but also the stoichiometry of the complex showing the formation of 1 : 1 : 1 (host : guest : counterion) complexes. The detection of high stoichiometry complexes is not restricted to a single titration experiment but also to a displacement assay where both competitive and competitive-cooperative complexation models are taken into consideration.

Simulation of field-induced molecular dissociation in atom-probe tomography: Identification of a neutral emission channel

NASA Astrophysics Data System (ADS)

Zanuttini, David; Blum, Ivan; Rigutti, Lorenzo; Vurpillot, François; Douady, Julie; Jacquet, Emmanuelle; Anglade, Pierre-Matthieu; Gervais, Benoit

2017-06-01

We investigate the dynamics of dicationic metal-oxide molecules under large electric-field conditions, on the basis of ab initio calculations coupled to molecular dynamics. Applied to the case of ZnO2 + in the field of atom probe tomography (APT), our simulation reveals the dissociation into three distinct exit channels. The proportions of these channels depend critically on the field strength and on the initial molecular orientation with respect to the field. For typical field strength used in APT experiments, an efficient dissociation channel leads to emission of neutral oxygen atoms, which escape detection. The calculated composition biases and their dependence on the field strength show remarkable consistency with recent APT experiments on ZnO crystals. Our work shows that bond breaking in strong static fields may lead to significant neutral atom production, and therefore to severe elemental composition biases in measurements.

Experimental results from magnetized-jet experiments executed at the Jupiter Laser Facility

DOE PAGES

Manuel, M. J. -E.; Kuranz, C. C.; Rasmus, A. M.; ...

2014-08-20

Recent experiments at the Jupiter Laser Facility investigated magnetization effects on collimated plasma jets. Laser-irradiated plastic-cone-targets produced collimated, millimeter-scale plasma flows as indicated by optical interferometry. Proton radiography of these jets showed no indication of strong, self-generated magnetic fields, suggesting a dominantly hydrodynamic collimating mechanism. Targets were placed in a custom-designed solenoid capable of generating field strengths up to 5 T. Proton radiographs of the well-characterized B-field, without a plasma jet, suggested an external source of trapped electrons that affects proton trajectories. The background magnetic field was aligned with the jet propagation direction, as is the case in many astrophysicalmore » systems. Optical interferometry showed that magnetization of the plasma results in disruption of the collimated flow and instead produces a hollow cavity. Furthermore, this result is a topic of ongoing investigation.« less

Experimental results from magnetized-jet experiments executed at the Jupiter Laser Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manuel, M. J. -E.; Kuranz, C. C.; Rasmus, A. M.

Recent experiments at the Jupiter Laser Facility investigated magnetization effects on collimated plasma jets. Laser-irradiated plastic-cone-targets produced collimated, millimeter-scale plasma flows as indicated by optical interferometry. Proton radiography of these jets showed no indication of strong, self-generated magnetic fields, suggesting a dominantly hydrodynamic collimating mechanism. Targets were placed in a custom-designed solenoid capable of generating field strengths up to 5 T. Proton radiographs of the well-characterized B-field, without a plasma jet, suggested an external source of trapped electrons that affects proton trajectories. The background magnetic field was aligned with the jet propagation direction, as is the case in many astrophysicalmore » systems. Optical interferometry showed that magnetization of the plasma results in disruption of the collimated flow and instead produces a hollow cavity. Furthermore, this result is a topic of ongoing investigation.« less

Hearing impairment, social networks, and coping: the need for families with hearing-impaired children to relate to other parents and to hearing-impaired adults.

PubMed

Hintermair, M

2000-03-01

For a report on the stress experiences of parents with hearing-impaired children in Germany, 317 parents completed a survey on how their families communicate and socialize, among other issues. The report focuses on how contacts with other parents and with hearing-impaired adults affect stress experiences, in the context of the child's hearing status and the means of communication. Parents who frequently meet with other parents show evidence of a warm, accepting, trusting relationship with their child. Parents who have many contacts with hearing-impaired adults show evidence of a strong sense of competence in regard to their child's upbringing. The findings confirm the implication found in most reports describing empirical studies. Social support is to be regarded as a cornerstone of psychosocial intervention and has to play as great a role as possible in institutional programs.

The rate of the reaction between CN and C2H2 at interstellar temperatures.

PubMed

Woon, D E; Herbst, E

1997-03-01

The rate coefficient for the important interstellar reaction between CN and C2H2 has been calculated as a function of temperature between 10 and 300 K. The potential surface for this reaction has been determined through ab initio quantum chemical techniques; the potential exhibits no barrier in the entrance channel but does show a small exit channel barrier, which lies below the energy of reactants. Phase-space calculations for the reaction dynamics, which take the exit channel barrier into account, show the same unusual temperature dependence as determined by experiment, in which the rate coefficient at first increases as the temperature is reduced below room temperature and then starts to decrease as the temperature drops below 50-100 K. The agreement between theory and experiment provides strong confirmation that the reaction occurs appreciably at cool interstellar temperatures.

Current drive at plasma densities required for thermonuclear reactors.

PubMed

Cesario, R; Amicucci, L; Cardinali, A; Castaldo, C; Marinucci, M; Panaccione, L; Santini, F; Tudisco, O; Apicella, M L; Calabrò, G; Cianfarani, C; Frigione, D; Galli, A; Mazzitelli, G; Mazzotta, C; Pericoli, V; Schettini, G; Tuccillo, A A

2010-08-10

Progress in thermonuclear fusion energy research based on deuterium plasmas magnetically confined in toroidal tokamak devices requires the development of efficient current drive methods. Previous experiments have shown that plasma current can be driven effectively by externally launched radio frequency power coupled to lower hybrid plasma waves. However, at the high plasma densities required for fusion power plants, the coupled radio frequency power does not penetrate into the plasma core, possibly because of strong wave interactions with the plasma edge. Here we show experiments performed on FTU (Frascati Tokamak Upgrade) based on theoretical predictions that nonlinear interactions diminish when the peripheral plasma electron temperature is high, allowing significant wave penetration at high density. The results show that the coupled radio frequency power can penetrate into high-density plasmas due to weaker plasma edge effects, thus extending the effective range of lower hybrid current drive towards the domain relevant for fusion reactors.

Biotic interactions affect the colonization behavior of aquatic detritivorous macroinvertebrates in a heterogeneous environment

NASA Astrophysics Data System (ADS)

Verschut, Thomas A.; Meineri, Eric; Basset, Alberto

2015-05-01

It has previously been suggested that macroinvertebrates actively search for suitable patches to colonize. However, it is not well understood how the spatial arrangement of patches can affect colonization rates. In this study, we determined the importance of the environmental factors (distance, connectivity and resource availability) for patch colonization in an experimental system using Gammarus aequicauda (Amphipoda), Lekanesphaera hookeri (Isopoda) and Ecrobia ventrosa (Gastropoda). Furthermore, we also assessed how the relative importance of each of these environmental factors differed in interactions between the three species. The single species experiments showed that distance was the most important factor for G. aequicauda and E. ventrosa. However, while E. ventrosa preferred patches close to the release point, G. aequicauda strongly preferred patches further from the release point. High resource availability was a strong determinant for the patch colonization of G. aequicauda and L. hookeri. Connectivity was only of moderate importance in the study system for L. hookeri and E. ventrosa. The effects of the environmental factors were strongly affected by interspecific interactions in the multispecies experiments. For G. aequicauda, the distance preference was lowered in the presence of E. ventrosa. Moreover, while for L. hookeri the effect of resource availability was ruled out by the species interactions, resource availability gained importance for E. ventrosa in the presence of any of the other species. Our results suggest a strong link between environmental factors and biotic interactions in the colonization of habitat patches and indicate that the effect of biotic interactions is especially important for species sharing similar traits.

Validation of OpenFoam for heavy gas dispersion applications.

PubMed

Mack, A; Spruijt, M P N

2013-11-15

In the present paper heavy gas dispersion calculations were performed with OpenFoam. For a wind tunnel test case, numerical data was validated with experiments. For a full scale numerical experiment, a code to code comparison was performed with numerical results obtained from Fluent. The validation was performed in a gravity driven environment (slope), where the heavy gas induced the turbulence. For the code to code comparison, a hypothetical heavy gas release into a strongly turbulent atmospheric boundary layer including terrain effects was selected. The investigations were performed for SF6 and CO2 as heavy gases applying the standard k-ɛ turbulence model. A strong interaction of the heavy gas with the turbulence is present which results in a strong damping of the turbulence and therefore reduced heavy gas mixing. Especially this interaction, based on the buoyancy effects, was studied in order to ensure that the turbulence-buoyancy coupling is the main driver for the reduced mixing and not the global behaviour of the turbulence modelling. For both test cases, comparisons were performed between OpenFoam and Fluent solutions which were mainly in good agreement with each other. Beside steady state solutions, the time accuracy was investigated. In the low turbulence environment (wind tunnel test) which for both codes (laminar solutions) was in good agreement, also with the experimental data. The turbulent solutions of OpenFoam were in much better agreement with the experimental results than the Fluent solutions. Within the strong turbulence environment, both codes showed an excellent comparability. Copyright © 2013 Elsevier B.V. All rights reserved.

Maintaining sexual desire in intimate relationships: the importance of approach goals.

PubMed

Impett, Emily At; Strachman, Amy; Finkel, Eli J; Gable, Shelly L

2008-05-01

Three studies tested whether adopting strong (relative to weak) approach goals in relationships (i.e., goals focused on the pursuit of positive experiences in one's relationship such as fun, growth, and development) predict greater sexual desire. Study 1 was a 6-month longitudinal study with biweekly assessments of sexual desire. Studies 2 and 3 were 2-week daily experience studies with daily assessments of sexual desire. Results showed that approach relationship goals buffered against declines in sexual desire over time and predicted elevated sexual desire during daily sexual interactions. Approach sexual goals mediated the association between approach relationship goals and daily sexual desire. Individuals with strong approach goals experienced even greater desire on days with positive relationship events and experienced less of a decrease in desire on days with negative relationships events than individuals who were low in approach goals. In two of the three studies, the association between approach relationship goals and sexual desire was stronger for women than for men. Implications of these findings for maintaining sexual desire in long-term relationships are discussed. (c) 2008 APA, all rights reserved

Strong decays of DJ(3000 ) and Ds J(3040 )

NASA Astrophysics Data System (ADS)

Li, Si-Chen; Wang, Tianhong; Jiang, Yue; Tan, Xiao-Ze; Li, Qiang; Wang, Guo-Li; Chang, Chao-Hsi

2018-03-01

In this paper, we systematically calculate two-body strong decays of newly observed DJ(3000 ) and Ds J(3040 ) with 2 P (1+) and 2 P (1+') assignments in an instantaneous approximation of the Bethe-Salpeter equation method. Our results show that both resonances can be explained as the 2 P (1+') with broad width via 3P1 and 1P1 mixing in D and Ds families. For DJ(3000 ), the total width is 229.6 MeV in our calculation, close to the upper limit of experimental data, and the dominant decay channels are D2*π , D*π , and D*(2600 )π . For Ds J(3040 ), the total width is 157.4 MeV in our calculation, close to the lower limit of experimental data, and the dominant channels are D*K and D*K*. These results are consistent with observed channels in experiments. Given the very little information that has been obtained from experiments and the large error bars of the total decay widths, we recommend the detection of dominant channels in our calculation.

Stick or Switch: A Selection Heuristic Predicts when People Take the Perspective of Others or Communicate Egocentrically.

PubMed

Rogers, Shane L; Fay, Nicolas

2016-01-01

This paper examines a cognitive mechanism that drives perspective-taking and egocentrism in interpersonal communication. Using a conceptual referential communication task, in which participants describe a range of abstract geometric shapes, Experiment 1 shows that perspective-taking and egocentric communication are frequent communication strategies. Experiment 2 tests a selection heuristic account of perspective-taking and egocentric communication. It uses participants' shape description ratings to predict their communication strategy. Participants' communication strategy was predicted by how informative they perceived the different shape descriptions to be. When participants' personal shape description was perceived to be more informative than their addressee's shape description, there was a strong bias to communicate egocentrically. By contrast, when their addressee's shape description was perceived to be more informative, there was a strong bias to take their addressee's perspective. When the shape descriptions were perceived to be equally informative, there was a moderate bias to communicate egocentrically. This simple, but powerful, selection heuristic may be critical to the cumulative cultural evolution of human communication systems, and cumulative cultural evolution more generally.

Gyrokinetic Studies of Turbulence Reduction with Reverse Shear ETG Transport Barriers or Lithium Walls

NASA Astrophysics Data System (ADS)

Hammett, G. W.; Peterson, J. L.; Granstedt, E. M.; Bell, R.; Guttenfelder, W.; Kaye, S.; Leblanc, B.; Mikkelsen, D. R.; Smith, D. R.; Yuh, H. Y.; Candy, J.

2012-03-01

The National Spherical Torus Experiment (NSTX) can achieve high electron confinement regimes that are super-critically unstable to the electron temperature gradient (ETG) instability. These electron internal transport barriers (e-ITBs) occur when the magnetic shear becomes strongly negative. Using the gyrokinetic code GYRO, the first nonlinear ETG simulations of NSTX e-ITB plasmas demonstrate reduced turbulence consistent with this observation. This is qualitatively consistent with a secondary instability picture of reduced ETG turbulence at negative shear (Jenko and Dorland PRL 2002). Local simulations identify a strongly upshifted nonlinear critical gradient for thermal transport that depends on magnetic shear. Global simulations show that ETG-driven turbulence outside of the barrier is large enough to be experimentally relevant, but cannot propagate very far into the barrier. We also use GYRO to study turbulence in regimes that might be expected in the Lithium Torus eXperiment (LTX). While lithium has experimentally been shown to raise the edge temperature and improve performance, there can still be some turbulence from density-gradient-driven trapped electron modes, and a temperature pinch is found in some cases. (Supported by DOE.)

Food availability affects the strength of mutualistic host–microbiota interactions in Daphnia magna

PubMed Central

Callens, Martijn; Macke, Emilie; Muylaert, Koenraad; Bossier, Peter; Lievens, Bart; Waud, Michael; Decaestecker, Ellen

2016-01-01

The symbiotic gut microbial community is generally known to have a strong impact on the fitness of its host. Nevertheless, it is less clear how the impact of symbiotic interactions on the hosts' fitness varies according to environmental circumstances such as changes in the diet. This study aims to get a better understanding of host–microbiota interactions under different levels of food availability. We conducted experiments with the invertebrate, experimental model organism Daphnia magna and compared growth, survival and reproduction of conventionalized symbiotic Daphnia with germ-free individuals given varying quantities of food. Our experiments revealed that the relative importance of the microbiota for the hosts' fitness varied according to dietary conditions. The presence of the microbiota had strong positive effects on Daphnia when food was sufficient or abundant, but had weaker effects under food limitation. Our results indicate that the microbiota can be a potentially important factor in determining host responses to changes in dietary conditions. Characterization of the host-associated microbiota further showed that Aeromonas sp. was the most prevalent taxon in the digestive tract of Daphnia. PMID:26405832

[Hi-Fi simulation: Teaching crisis resource management to surgery residents].

PubMed

Georgescu, Mihai; Tanoubi, Issam; Drolet, Pierre; Robitaille, Arnaud; Perron, Roger; Patenaude, Jean Victor

2015-02-01

High-fidelity (HiFi) simulation has shown its effectiveness for teaching crisis resource management (CRM) principles, and our institutional experience in this area is mainly with anesthesiology residents. We recently added to our postgraduate curriculum a new CRM course designed to cater to the specific needs of surgical residents. This short communication describes the experience of the University of Montreal Simulation Centre (Centre d'Apprentissage des Attitudes et Habiletés Cliniques CAAHC) regarding HiFi simulationbased CRM and communication skills teaching for surgical residents. Thirty residents agreed to participate in a simulation course with pre-established scenarios and educational CRM objectives on a voluntary basis. When surveyed immediately after the activity, all residents agreed that the educational objectives were well defined (80% "strongly agree" and 20% "agree"). The survey also showed that the course was well accepted by all participants (96% "strongly agree" and 4% "agree"). Further trials with randomized groups and more reliable assessment tools are needed to validate our results. Still, integrating HiFi simulation based CRM learning in the surgical residency curriculum seems like an interesting step.

Lensing of Fast Radio Bursts as a Probe of Compact Dark Matter.

PubMed

Muñoz, Julian B; Kovetz, Ely D; Dai, Liang; Kamionkowski, Marc

2016-08-26

The possibility that part of the dark matter is made of massive compact halo objects (MACHOs) remains poorly constrained over a wide range of masses, and especially in the 20-100  M_{⊙} window. We show that strong gravitational lensing of extragalactic fast radio bursts (FRBs) by MACHOs of masses larger than ∼20  M_{⊙} would result in repeated FRBs with an observable time delay. Strong lensing of a FRB by a lens of mass M_{L} induces two images, separated by a typical time delay ∼few×(M_{L}/30  M_{⊙})  msec. Considering the expected FRB detection rate by upcoming experiments, such as canadian hydrogen intensity mapping experiment (CHIME), of 10^{4} FRBs per year, we should observe from tens to hundreds of repeated bursts yearly, if MACHOs in this window make up all the dark matter. A null search for echoes with just 10^{4} FRBs would constrain the fraction f_{DM} of dark matter in MACHOs to f_{DM}≲0.08 for M_{L}≳20  M_{⊙}.

Age and the experience of strong self-conscious emotion.

PubMed

Henry, Julie D; von Hippel, William; Nangle, Matthew R; Waters, Michele

2018-04-01

It remains unclear whether there are age-related changes in the experience of strong self-conscious emotion, such as shame, guilt, pride and embarrassment. Because shame and guilt figure prominently in the aetiology of depressive symptoms and other mental health problems, a better understanding of how age affects the strong experience of these two negative self-conscious emotions is of particular importance. Thirty younger, 30 middle-aged and 30 older adults were compared on standardised cognitive assessments, in addition to an interview-based measure that assessed whether there are age differences in the likelihood of strongly experiencing four different types of self-conscious emotion within the past five years (shame, guilt, embarrassment and pride). The three groups did not differ in their likelihood of reporting an event that strongly elicited the positive self-conscious emotion of pride. However, older adults were more likely to report sources of pride that were other (as opposed to self) focused. Older adults were also less likely to report experiencing events that elicited all three negative self-conscious emotions, in particular, shame. Strong negative self-conscious emotion, and in particular shame, appears to be experienced less by older than younger adults.

Study of axial double layer in helicon plasma by optical emission spectroscopy and simple probe

NASA Astrophysics Data System (ADS)

Gao, ZHAO; Wanying, ZHU; Huihui, WANG; Qiang, CHEN; Chang, TAN; Jiting, OUYANG

2018-07-01

In this work we used a passive measurement method based on a high-impedance electrostatic probe and an optical emission spectroscope (OES) to investigate the characteristics of the double layer (DL) in an argon helicon plasma. The DL can be confirmed by a rapid change in the plasma potential along the axis. The axial potential variation of the passive measurement shows that the DL forms near a region of strong magnetic field gradient when the plasma is operated in wave-coupled mode, and the DL strength increases at higher powers in this experiment. The emission intensity of the argon atom line, which is strongly dependent on the metastable atom concentration, shows a similar spatial distribution to the plasma potential along the axis. The emission intensity of the argon atom line and the argon ion line in the DL suggests the existence of an energetic electron population upstream of the DL. The electron density upstream is much higher than that downstream, which is mainly caused by these energetic electrons.

An experimental approach in revisiting the magnetic orientation of cattle.

PubMed

Weijers, Debby; Hemerik, Lia; Heitkönig, Ignas M A

2018-01-01

In response to the increasing number of observational studies on an apparent south-north orientation in non-homing, non-migrating terrestrial mammals, we experimentally tested the alignment hypothesis using strong neodymium magnets on the resting orientation of individual cattle in Portugal. Contrary to the hypothesis, the 34 cows in the experiment showed no directional preference, neither with, nor without a strong neodymium magnet fixed to their collar. The concurrently performed 2,428 daytime observations-excluding the hottest part of the day-of 659 resting individual cattle did not show a south-north alignment when at rest either. The preferred compass orientation of these cows was on average 130 degrees from the magnetic north (i.e., south east). Cow compass orientation correlated significantly with sun direction, but not with wind direction. In as far as we can determine, this is the first experimental test on magnetic orientation in larger, non-homing, non-migrating mammals. These experimental and observational findings do not support previously published suggestions on the magnetic south-north alignment in these mammals.

Photoluminescence and gain/absorption spectra of a driven-dissipative electron-hole-photon condensate

NASA Astrophysics Data System (ADS)

Hanai, Ryo; Littlewood, Peter B.; Ohashi, Yoji

2018-06-01

We investigate theoretically nonequilibrium effects on photoluminescence and gain/absorption spectra of a driven-dissipative exciton-polariton condensate, by employing the combined Hartree-Fock-Bogoliubov theory with the generalized random phase approximation extended to the Keldysh formalism. Our calculated photoluminescence spectra is in semiquantitative agreement with experiments, where features such as a blue shift of the emission from the condensate, the appearance of the dispersionless feature of a diffusive Goldstone mode, and the suppression of the dispersive profile of the mode are obtained. We show that the nonequilibrium nature of the exciton-polariton condensate strongly suppresses the visibility of the Bogoliubov dispersion in the negative energy branch (ghost branch) in photoluminescence spectra. We also show that the trace of this branch can be captured as a hole burning effect in gain/absorption spectra. Our results indicate that the nonequilibrium nature of the exciton-polariton condensate strongly reduces quantum depletion, while a scattering channel to the ghost branch is still present.

Ellagitannin HeT obtained from strawberry leaves is oxidized by bacterial membranes and inhibits the respiratory chain.

PubMed

Martos, Gustavo G; Mamani, Alicia; Filippone, María P; Abate, Pedro O; Katz, Néstor E; Castagnaro, Atilio P; Díaz Ricci, Juan C

2018-02-01

Plant secondary metabolism produces a variety of tannins that have a wide range of biological activities, including activation of plant defenses and antimicrobial, anti-inflammatory and antitumoral effects. The ellagitannin HeT (1- O -galloyl-2,3;4,6-bis-hexahydroxydiphenoyl-β-d-glucopyranose) from strawberry leaves elicits a strong plant defense response, and exhibits antimicrobial activity associated to the inhibition of the oxygen consumption, but its mechanism of action is unknown. In this paper we investigate the influence of HeT on bacterial cell membrane integrity and its effect on respiration. A β-galactosidase unmasking experiment showed that HeT does not disrupt membrane integrity. Raman spectroscopy analysis revealed that HeT strongly interacts with the cell membrane. Spectrochemical analysis indicated that HeT is oxidized in contact with bacterial cell membranes, and functional studies showed that HeT inhibits oxygen consumption, NADH and MTT reduction. These results provide evidence that HeT inhibits the respiratory chain.

Harmonic generation beyond the Strong-Field Approximation: the physics behind the short-wave-infrared scaling laws.

PubMed

Pérez-Hernández, J A; Roso, L; Plaja, L

2009-06-08

The physics of laser-mater interactions beyond the perturbative limit configures the field of extreme non-linear optics. Although most experiments have been done in the near infrared ( lambda

Apparent competition drives community-wide parasitism rates and changes in host abundance across ecosystem boundaries

PubMed Central

Frost, Carol M.; Peralta, Guadalupe; Rand, Tatyana A.; Didham, Raphael K.; Varsani, Arvind; Tylianakis, Jason M.

2016-01-01

Species have strong indirect effects on others, and predicting these effects is a central challenge in ecology. Prey species sharing an enemy (predator or parasitoid) can be linked by apparent competition, but it is unknown whether this process is strong enough to be a community-wide structuring mechanism that could be used to predict future states of diverse food webs. Whether species abundances are spatially coupled by enemy movement across different habitats is also untested. Here, using a field experiment, we show that predicted apparent competitive effects between species, mediated via shared parasitoids, can significantly explain future parasitism rates and herbivore abundances. These predictions are successful even across edges between natural and managed forests, following experimental reduction of herbivore densities by aerial spraying of insecticide over 20 hectares. This result shows that trophic indirect effects propagate across networks and habitats in important, predictable ways, with implications for landscape planning, invasion biology and biological control. PMID:27577948

Nonequilibrium thermodynamics of dilute polymer solutions in flow.

PubMed

Latinwo, Folarin; Hsiao, Kai-Wen; Schroeder, Charles M

2014-11-07

Modern materials processing applications and technologies often occur far from equilibrium. To this end, the processing of complex materials such as polymer melts and nanocomposites generally occurs under strong deformations and flows, conditions under which equilibrium thermodynamics does not apply. As a result, the ability to determine the nonequilibrium thermodynamic properties of polymeric materials from measurable quantities such as heat and work is a major challenge in the field. Here, we use work relations to show that nonequilibrium thermodynamic quantities such as free energy and entropy can be determined for dilute polymer solutions in flow. In this way, we determine the thermodynamic properties of DNA molecules in strong flows using a combination of simulations, kinetic theory, and single molecule experiments. We show that it is possible to calculate polymer relaxation timescales purely from polymer stretching dynamics in flow. We further observe a thermodynamic equivalence between nonequilibrium and equilibrium steady-states for polymeric systems. In this way, our results provide an improved understanding of the energetics of flowing polymer solutions.

Effect of Coulomb Correlation on the Magnetic Properties of Mn Clusters.

PubMed

Huang, Chengxi; Zhou, Jian; Deng, Kaiming; Kan, Erjun; Jena, Puru

2018-05-03

In spite of decades of research, a fundamental understanding of the unusual magnetic behavior of small Mn clusters remains a challenge. Experiments show that Mn 2 is antiferromagnetic while small clusters containing up to five Mn atoms are ferromagnetic with magnetic moments of 5 μ B /atom and become ferrimagnetic as they grow further. Theoretical studies based on density functional theory (DFT), however, find Mn 2 to be ferromagnetic, with ferrimagnetic order setting in at different sizes that depend upon the computational methods used. While quantum chemical techniques correctly account for the antiferromagnetic ground state of Mn 2 , they are computationally too demanding to treat larger clusters, making it difficult to understand the evolution of magnetism. These studies clearly point to the importance of correlation and the need to find ways to treat it effectively for larger clusters and nanostructures. Here, we show that the DFT+ U method can be used to account for strong correlation. We determine the on-site Coulomb correlation, Hubbard U self-consistently by using the linear response theory and study its effect on the magnetic coupling of Mn clusters containing up to five atoms. With a calculated U value of 4.8 eV, we show that the ground state of Mn 2 is antiferromagnetic with a Mn-Mn distance of 3.34 Å, which agrees well with the electron spin resonance experiment. Equally important, we show that on-site Coulomb correlation also plays an important role in the evolution of magnetic coupling in larger clusters, as the results differ significantly from standard DFT calculations. We conclude that for a proper understanding of magnetism of Mn nanostructures (clusters, chains, and layers) one must take into account the effect of strong correlation.

The Relationship of a Pilot's Educational Background, Aeronautical Experience and Recency of Experience to Performance In Initial Training at a Regional Airline

NASA Astrophysics Data System (ADS)

Shane, Nancy R.

The purpose of this study was to determine how a pilot's educational background, aeronautical experience and recency of experience relate to their performance during initial training at a regional airline. Results show that variables in pilots' educational background, aeronautical experience and recency of experience do predict performance in training. The most significant predictors include years since graduation from college, multi-engine time, total time and whether or not a pilot had military flying experience. Due to the pilot shortage, the pilots entering regional airline training classes since August 2013 have varied backgrounds, aeronautical experience and recency of experience. As explained by Edward Thorndike's law of exercise and the law of recency, pilots who are actively using their aeronautical knowledge and exercising their flying skills should exhibit strong performance in those areas and pilots who have not been actively using their aeronautical knowledge and exercising their flying skills should exhibit degraded performance in those areas. Through correlation, chi-square and multiple regression analysis, this study tests this theory as it relates to performance in initial training at a regional airline.

Research and Analysis of Image Processing Technologies Based on DotNet Framework

NASA Astrophysics Data System (ADS)

Ya-Lin, Song; Chen-Xi, Bai

Microsoft.Net is a kind of most popular program development tool. This paper gave a detailed analysis concluded about some image processing technologies of the advantages and disadvantages by .Net processed image while the same algorithm is used in Programming experiments. The result shows that the two best efficient methods are unsafe pointer and Direct 3D, and Direct 3D used to 3D simulation development, and the others are useful in some fields while these technologies are poor efficiency and not suited to real-time processing. The experiment results in paper will help some projects about image processing and simulation based DotNet and it has strong practicability.

Chiral Magnetic Effect in Heavy Ion Collisions

DOE PAGES

Liao, Jinfeng

2016-12-01

The Chiral Magnetic Effect (CME) is a remarkable phenomenon that stems from highly nontrivial interplay of QCD chiral symmetry, axial anomaly, and gluonic topology. We show it is of fundamental importance to search for the CME in experiments. The heavy ion collisions provide a unique environment where a hot chiral-symmetric quark-gluon plasma is created, gluonic topological fluctuations generate chirality imbalance, and very strong magnetic fields |Β →|~m 2 π are present during the early stage of such collisions. Significant efforts have been made to look for CME signals in heavy ion collision experiments. Lastly, in this contribution we give amore » brief overview on the status of such efforts.« less

The contribution of physical activity and media use during childhood and adolescence to adult women's body image.

PubMed

Slater, Amy; Tiggemann, Marika

2006-07-01

This study aimed to investigate the effects of both past and current physical activity and media use on women's body image. A sample of 144 female undergraduate students completed measures of current physical activity, media use and body image, as well as providing retrospective reports of their physical activity participation and media usage during childhood and adolescence. Regression analyses showed that childhood experiences of physical activity and media use predicted adult body-image concerns more strongly than current activities. It was concluded that early experiences of both physical activity and media use during childhood and adolescence play an important role in the development of adult women's body image.

Excess vibrational density of states and the brittle to ductile transition in crystalline and amorphous solids.

PubMed

Babu, Jeetu S; Mondal, Chandana; Sengupta, Surajit; Karmakar, Smarajit

2016-01-28

The conditions which determine whether a material behaves in a brittle or ductile fashion on mechanical loading are still elusive and comprise a topic of active research among materials physicists and engineers. In this study, we present the results of in silico mechanical deformation experiments from two very different model solids in two and three dimensions. The first consists of particles interacting with isotropic potentials and the other has strongly direction dependent interactions. We show that in both cases, the excess vibrational density of states is one of the fundamental quantities which characterizes the ductility of the material. Our results can be checked using careful experiments on colloidal solids.

Potential sources of variability in mesocosm experiments on the response of phytoplankton to ocean acidification

NASA Astrophysics Data System (ADS)

Moreno de Castro, Maria; Schartau, Markus; Wirtz, Kai

2017-04-01

Mesocosm experiments on phytoplankton dynamics under high CO2 concentrations mimic the response of marine primary producers to future ocean acidification. However, potential acidification effects can be hindered by the high standard deviation typically found in the replicates of the same CO2 treatment level. In experiments with multiple unresolved factors and a sub-optimal number of replicates, post-processing statistical inference tools might fail to detect an effect that is present. We propose that in such cases, data-based model analyses might be suitable tools to unearth potential responses to the treatment and identify the uncertainties that could produce the observed variability. As test cases, we used data from two independent mesocosm experiments. Both experiments showed high standard deviations and, according to statistical inference tools, biomass appeared insensitive to changing CO2 conditions. Conversely, our simulations showed earlier and more intense phytoplankton blooms in modeled replicates at high CO2 concentrations and suggested that uncertainties in average cell size, phytoplankton biomass losses, and initial nutrient concentration potentially outweigh acidification effects by triggering strong variability during the bloom phase. We also estimated the thresholds below which uncertainties do not escalate to high variability. This information might help in designing future mesocosm experiments and interpreting controversial results on the effect of acidification or other pressures on ecosystem functions.

The Word Composite Effect Depends on Abstract Lexical Representations But Not Surface Features Like Case and Font.

PubMed

Ventura, Paulo; Fernandes, Tânia; Leite, Isabel; Almeida, Vítor B; Casqueiro, Inês; Wong, Alan C-N

2017-01-01

Prior studies have shown that words show a composite effect: When readers perform a same-different matching task on a target-part of a word, performance is affected by the irrelevant part, whose influence is severely reduced when the two parts are misaligned. However, the locus of this word composite effect is largely unknown. To enlighten it, in two experiments, Portuguese readers performed the composite task on letter strings: in Experiment 1, in written words varying in surface features (between-participants: courier, notera, alternating-cAsE), and in Experiment 2 in pseudowords. The word composite effect, signaled by a significant interaction between alignment of the two word parts and congruence between parts was found in the three conditions of Experiment 1, being unaffected by NoVeLtY of the configuration or by handwritten form. This effect seems to have a lexical locus, given that in Experiment 2 only the main effect of congruence between parts was significant and was not modulated by alignment. Indeed, the cross-experiment analysis showed that words presented stronger congruence effects than pseudowords only in the aligned condition, because when misaligned the whole lexical item configuration was disrupted. Therefore, the word composite effect strongly depends on abstract lexical representations, as it is unaffected by surface features and is specific to lexical items.

Coincidence velocity map imaging using Tpx3Cam, a time stamping optical camera with 1.5 ns timing resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Arthur; van Beuzekom, Martin; Bouwens, Bram

Here, we demonstrate a coincidence velocity map imaging apparatus equipped with a novel time-stamping fast optical camera, Tpx3Cam, whose high sensitivity and nanosecond timing resolution allow for simultaneous position and time-of-flight detection. This single detector design is simple, flexible, and capable of highly differential measurements. We show detailed characterization of the camera and its application in strong field ionization experiments.

Coincidence velocity map imaging using Tpx3Cam, a time stamping optical camera with 1.5 ns timing resolution

DOE PAGES

Zhao, Arthur; van Beuzekom, Martin; Bouwens, Bram; ...

2017-11-07

Here, we demonstrate a coincidence velocity map imaging apparatus equipped with a novel time-stamping fast optical camera, Tpx3Cam, whose high sensitivity and nanosecond timing resolution allow for simultaneous position and time-of-flight detection. This single detector design is simple, flexible, and capable of highly differential measurements. We show detailed characterization of the camera and its application in strong field ionization experiments.

Boundary and Interface Conditions for High Order Finite Difference Methods Applied to the Euler and Navier-Strokes Equations

NASA Technical Reports Server (NTRS)

Nordstrom, Jan; Carpenter, Mark H.

1998-01-01

Boundary and interface conditions for high order finite difference methods applied to the constant coefficient Euler and Navier-Stokes equations are derived. The boundary conditions lead to strict and strong stability. The interface conditions are stable and conservative even if the finite difference operators and mesh sizes vary from domain to domain. Numerical experiments show that the new conditions also lead to good results for the corresponding nonlinear problems.

Unitarity of the Cabibbo-Kobayashi-Maskawa matrix and a nonuniversal gauge interaction model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Kang Young

2007-12-01

Recent measurements of |V{sub us}| from kaon decays strongly support the unitarity of the Cabibbo-Kobayashi-Maskawa matrix. The unitarity provides a stringent constraint on the parameter space of the nonuniversal gauge interaction model based on the separate SU(2){sub L} gauge group acting on the third generation fermions. I show that this constraint is stronger than those from the CERN LEP and SLC data and low-energy experiment data.

Constraints on cosmic superstrings from Kaluza-Klein emission.

PubMed

Dufaux, Jean-François

2012-07-06

Cosmic superstrings interact generically with a tower of light and/or strongly coupled Kaluza-Klein (KK) modes associated with the geometry of the internal space. We study the production of KK particles by cosmic superstring loops, and show that it is constrained by big bang nucleosynthesis. We study the resulting constraints in the parameter space of the underlying string theory model and highlight their complementarity with the regions that can be probed by current and upcoming gravitational wave experiments.

New chromanone acids with antibacterial activity from Calophyllum brasiliense.

PubMed

Cottiglia, Filippo; Dhanapal, Boopathy; Sticher, Otto; Heilmann, Jörg

2004-04-01

Six novel chromanone acids (1-6) were isolated from the bark of Calophyllum brasiliense Cambess. Their structures were elucidated on the basis of 1D and 2D NMR experiments, as well as mass spectrometry. All compounds showed moderate to strong antibacterial activity against Bacillus cereus and Staphylococcus epidermidis, with 1 and 2 being most active. None of the compounds were cytotoxic against KB, Jurkat T, and myosarcoma cancer cells up to 20 microg/mL.

Airport low-level wind shear lidar observation at beijing capital international airport

NASA Astrophysics Data System (ADS)

Zhang, Hongwei; Wu, Songhua; Wang, Qichao; Liu, Bingyi; Zhai, Xiaochun

2018-04-01

Ocean University of China lidar team operated a pulse coherent Doppler lidar (PCDL) for the low level wind shear monitoring at the Beijing Capital International Airport (BCIA) in 2015. The experiment configuration, observation modes is presented. A case study shows that the low level wind shear events at the southern end of 18R/36L runway were mainly caused by the trees and buildings along the glide path under strong northwest wind conditions.

Why Do Participants Initiate Free Recall of Short Lists of Words with the First List Item? Toward a General Episodic Memory Explanation

ERIC Educational Resources Information Center

Spurgeon, Jessica; Ward, Geoff; Matthews, William J.

2014-01-01

Participants who are presented with a short list of words for immediate free recall (IFR) show a strong tendency to initiate their recall with the 1st list item and then proceed in forward serial order. We report 2 experiments that examined whether this tendency was underpinned by a short-term memory store, of the type that is argued by some to…

The implications of Big Five standing for the distribution of trait manifestation in behavior: fifteen experience-sampling studies and a meta-analysis.

PubMed

Fleeson, William; Gallagher, Patrick

2009-12-01

One of the fundamental questions in personality psychology is whether and how strongly trait standing relates to the traits that people actually manifest in their behavior when faced with real pressures and real consequences of their actions. One reason this question is fundamental is the common belief that traits do not predict how individuals behave, which leads to the reasonable conclusion that traits are not important to study. However, this conclusion is surprising given that there is almost no data on the ability of traits to predict distributions of naturally occurring, representative behaviors of individuals (and that there are many studies showing that traits do indeed predict specific behaviors). The authors describe a meta-analysis of 15 experience-sampling studies, conducted over the course of 8 years, amassing over 20,000 reports of trait manifestation in behavior. Participants reported traits on typical self-report questionnaires, then described their current behavior multiple times per day for several days as the behavior was occurring. Results show that traits, contrary to expectations, were strongly predictive of individual differences in trait manifestation in behavior, predicting average levels with correlations between .42 and .56 (approaching .60 for stringently restricted studies). Several other ways of summarizing trait manifestation in behavior were also predicted from traits. These studies provide evidence that traits are powerful predictors of actual manifestation of traits in behavior.

Adaptation to a latitudinal thermal gradient within a widespread copepod species: the contributions of genetic divergence and phenotypic plasticity

PubMed Central

2017-01-01

Understanding how populations adapt to heterogeneous thermal regimes is essential for comprehending how latitudinal gradients in species diversification are formed, and how taxa will respond to ongoing climate change. Adaptation can occur by innate genetic factors, by phenotypic plasticity, or by a combination of both mechanisms. Yet, the relative contribution of such mechanisms to large-scale latitudinal gradients of thermal tolerance across conspecific populations remains unclear. We examine thermal performance in 11 populations of the intertidal copepod Tigriopus californicus, ranging from Baja California Sur (Mexico) to British Columbia (Canada). Common garden experiments show that survivorship to acute heat-stress differs between populations (by up to 3.8°C in LD50 values), reflecting a strong genetic thermal adaptation. Using a split-brood experiment with two rearing temperatures, we also show that developmental phenotypic plasticity is beneficial to thermal tolerance (by up to 1.3°C), and that this effect differs across populations. Although genetic divergence in heat tolerance strongly correlates with latitude and temperature, differences in the plastic response do not. In the context of climate warming, our results confirm the general prediction that low-latitude populations are most susceptible to local extinction because genetic adaptation has placed physiological limits closer to current environmental maxima, but our results also contradict the prediction that phenotypic plasticity is constrained at lower latitudes. PMID:28446698

A Strain-Based Method to Detect Tires' Loss of Grip and Estimate Lateral Friction Coefficient from Experimental Data by Fuzzy Logic for Intelligent Tire Development.

PubMed

Yunta, Jorge; Garcia-Pozuelo, Daniel; Diaz, Vicente; Olatunbosun, Oluremi

2018-02-06

Tires are a key sub-system of vehicles that have a big responsibility for comfort, fuel consumption and traffic safety. However, current tires are just passive rubber elements which do not contribute actively to improve the driving experience or vehicle safety. The lack of information from the tire during driving gives cause for developing an intelligent tire. Therefore, the aim of the intelligent tire is to monitor tire working conditions in real-time, providing useful information to other systems and becoming an active system. In this paper, tire tread deformation is measured to provide a strong experimental base with different experiments and test results by means of a tire fitted with sensors. Tests under different working conditions such as vertical load or slip angle have been carried out with an indoor tire test rig. The experimental data analysis shows the strong relation that exists between lateral force and the maximum tensile and compressive strain peaks when the tire is not working at the limit of grip. In the last section, an estimation system from experimental data has been developed and implemented in Simulink to show the potential of strain sensors for developing intelligent tire systems, obtaining as major results a signal to detect tire's loss of grip and estimations of the lateral friction coefficient.

A Strain-Based Method to Detect Tires’ Loss of Grip and Estimate Lateral Friction Coefficient from Experimental Data by Fuzzy Logic for Intelligent Tire Development

PubMed Central

Garcia-Pozuelo, Daniel; Diaz, Vicente; Olatunbosun, Oluremi

2018-01-01

Tires are a key sub-system of vehicles that have a big responsibility for comfort, fuel consumption and traffic safety. However, current tires are just passive rubber elements which do not contribute actively to improve the driving experience or vehicle safety. The lack of information from the tire during driving gives cause for developing an intelligent tire. Therefore, the aim of the intelligent tire is to monitor tire working conditions in real-time, providing useful information to other systems and becoming an active system. In this paper, tire tread deformation is measured to provide a strong experimental base with different experiments and test results by means of a tire fitted with sensors. Tests under different working conditions such as vertical load or slip angle have been carried out with an indoor tire test rig. The experimental data analysis shows the strong relation that exists between lateral force and the maximum tensile and compressive strain peaks when the tire is not working at the limit of grip. In the last section, an estimation system from experimental data has been developed and implemented in Simulink to show the potential of strain sensors for developing intelligent tire systems, obtaining as major results a signal to detect tire’s loss of grip and estimations of the lateral friction coefficient. PMID:29415513

Demand and willingness-to-pay for bed nets in Tanzania: results from a choice experiment.

PubMed

Gingrich, Chris D; Ricotta, Emily; Kahwa, Amos; Kahabuka, Catherine; Koenker, Hannah

2017-07-14

Universal coverage campaigns for long-lasting insecticide-treated nets do not always reach the goal of one net for every two household members, and even when ownership of at least one net per household is high, many households may not own enough nets. The retail market provides these households options for replacing or increasing the number of nets they own with products that best fit their needs since a variety of net shapes, sizes, and colours are available. Hence, it is important to understand the factors affecting private net demand. This study explores private demand for nets in Tanzania using a discrete choice experiment. The experiment provides participants the option to buy nets with their own money, and thus should prove more accurate than a hypothetical survey of net preferences. Nearly 800 participants sampled in two regions showed an overall strong demand for nets, with 40% choosing to buy a net across all seven combinations of net prices and characteristics such as size, shape, and insecticide treatment. Only 8% of all participants chose not to buy a single net. A key factor influencing demand was whether a participant's household currently owned sufficient nets for all members, with rural participants showing lower net coverage and greater demand than urban participants. Both poor and less poor households showed strong evidence of making purchase decisions based on more than price alone. Mean willingness-to-pay values for a net started at US$1.10 and grew by US$0.50-1.40 for various attributes such as rectangular shape, large size, and insecticide treatment. The impact of price on demand was negative but small, with elasticity values between -0.25 and -0.45. The results suggest that private demand for nets in Tanzania could potentially supplement future coverage campaigns. Net manufacturers and retailers should advertise and promote consumers' preferred net attributes to improve sales and further expand net access and coverage. To overcome household liquidity concerns and best replicate the experiment results, policy makers should consider making credit available for interested buyers.

Effects of wind-wave disturbances on adsorption and desorption of tetracycline and sulfadimidine in water-sediment systems.

PubMed

Liao, Qianjiahua; Huang, Zheng; Li, Shu; Wang, Yi; Liu, Yuqing; Luo, Ran; Shang, Jingge

2018-05-28

Wind-wave disturbances frequently disperse sediment particles into overlying water, which facilitates the adsorption and desorption of contaminants in aquatic ecosystems. Tetracycline (TC) and sulfadimidine (SM2) are common antibiotics that are frequently found in aquatic environments. This study utilized microcosms, comprising sediment and water from Lake Taihu, China, to examine the adsorption and desorption of TC and SM2 under different wind-wave disturbances in a shallow lake environment. The adsorption experiments were conducted with three different concentrations (1, 5, 10 mg/L) of TC and SM2 in the overlying water, and two different (background and strong) wind-wave conditions for 72 h. Subsequently, four microcosms were employed in a 12-h desorption study. Analysis of adsorption progress showed that TC concentration in the overlying water decreased quickly, while SM2 remained almost constant. In the desorption experiments, SM2 released to the overlying water was an order of magnitude greater than TC. These results indicate that sediment particles strongly adsorb TC but weakly adsorb SM2. Compared to background conditions, the strong wind-wave conditions resulted in higher concentrations of TC and SM2 in sediment and facilitated their migration to deeper sediment during adsorption, correspondingly promoting greater release of TC and SM2 from sediment particles into the overlying water during desorption.

The VEPP-2000 electron-positron collider: First experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berkaev, D. E., E-mail: D.E.Berkaev@inp.nsk.su; Shwartz, D. B.; Shatunov, P. Yu.

2011-08-15

In 2007, at the Institute of Nuclear Physics (Novosibirsk), the construction of the VEPP-2000 electron-positron collider was completed. The first electron beam was injected into the accelerator structure with turned-off solenoids of the final focus. This mode was used to tune all subsystems of the facility and to train the vacuum chamber using synchrotron radiation at electron currents of up to 150 mA. The VEPP-2000 structure with small beta functions and partially turned-on solenoids was used for the first testing of the 'round beams' scheme at an energy of 508 MeV. Beam-beam effects were studied in strong-weak and strong-strong modes.more » Measurements of the beam sizes in both cases showed a dependence corresponding to model predictions for round colliding beams. Using a modernized SND (spherical neutral detector), the first energy calibration of the VEPP-2000 collider was performed by measuring the excitation curve of the phimeson resonance; the phi-meson mass is known with high accuracy from previous experiments at VEEP-2M. In October 2009, a KMD-3 (cryogenic magnetic detector) was installed at the VEPP-2000 facility, and the physics program with both the SND and LMD-3 particle detectors was started in the energy range of 1-1.9 GeV. This first experimental season was completed in summer 2010 with precision energy calibration by resonant depolarization.« less

Strong support for relocation to other work tasks: A cross-sectional study of attitudes to sickness insurance regulations in Sweden.

PubMed

Hensing, G; Holmgren, K; Rohdén, H

2015-01-01

Profound changes are taking place in the Swedish welfare state. The general population's attitudes are important insofar changes will be perceived as fair and effective to become implemented. The aim was to study attitudes to the strictness of the sick-leave rules, relocation to other work tasks after 3 months of sick leave and applications for new jobs after 6 months of sick leave. Eligible for this questionnaire study were 1,140 individuals aged 19 to 64 years. Their attitudes were analyzed in relation to age, gender, political ideology and health status. Health status was measured as sick-leave experiences, self-reported health and level of symptoms. Showed that 42% considered the sick-leave rules to be too strict, 60% found relocation to other work tasks to be good while 35% found that applications for new work were good. In logistic regression analyses, high sick-leave experience was associated with increased odds of finding the sick-leave rules too strict and disagreement with relocation to other work tasks or application for new jobs. In conclusion, strong support was found for relocation to other work tasks with the present employer. Earlier research on returning to work has found workplace interventions to be efficient. From a policy perspective it seems relevant to promote such interventions given the strong public opinion in their favor.

Pattern Analyses Reveal Separate Experience-Based Fear Memories in the Human Right Amygdala.

PubMed

Braem, Senne; De Houwer, Jan; Demanet, Jelle; Yuen, Kenneth S L; Kalisch, Raffael; Brass, Marcel

2017-08-23

Learning fear via the experience of contingencies between a conditioned stimulus (CS) and an aversive unconditioned stimulus (US) is often assumed to be fundamentally different from learning fear via instructions. An open question is whether fear-related brain areas respond differently to experienced CS-US contingencies than to merely instructed CS-US contingencies. Here, we contrasted two experimental conditions where subjects were instructed to expect the same CS-US contingencies while only one condition was characterized by prior experience with the CS-US contingency. Using multivoxel pattern analysis of fMRI data, we found CS-related neural activation patterns in the right amygdala (but not in other fear-related regions) that dissociated between whether a CS-US contingency had been instructed and experienced versus merely instructed. A second experiment further corroborated this finding by showing a category-independent neural response to instructed and experienced, but not merely instructed, CS presentations in the human right amygdala. Together, these findings are in line with previous studies showing that verbal fear instructions have a strong impact on both brain and behavior. However, even in the face of fear instructions, the human right amygdala still shows a separable neural pattern response to experience-based fear contingencies. SIGNIFICANCE STATEMENT In our study, we addressed a fundamental problem of the science of human fear learning and memory, namely whether fear learning via experience in humans relies on a neural pathway that can be separated from fear learning via verbal information. Using two new procedures and recent advances in the analysis of brain imaging data, we localized purely experience-based fear processing and memory in the right amygdala, thereby making a direct link between human and animal research. Copyright © 2017 the authors 0270-6474/17/378116-15$15.00/0.

Role of the vomeronasal system in intersexual attraction in female mice.

PubMed

Martínez-Ricós, J; Agustín-Pavón, C; Lanuza, E; Martínez-García, F

2008-05-02

Although it is generally accepted that rodents' sociosexual behavior relies mainly on chemosignals, the specific roles played by the vomeronasal and olfactory systems in detecting these signals are presently unclear. This work reports the results of three experiments aimed at clarifying the role of the vomeronasal system on gender recognition and intersexual attraction, by analyzing the effects of lesions of the accessory olfactory bulbs (AOB) in chemically naïve female mice. The first experiment demonstrates that lesions of the AOB abolish the preference that females show for male-soiled bedding in tests in which the females can contact the bedding, thus having access to both volatile and involatile male chemosignals. The second experiment shows that airborne male-derived chemosignals are not attractive to intact, chemically naïve females but tend to be preferentially explored by females whose AOB has been lesioned. However, repeated exposure to male-soiled bedding has opposite effects in sham-operated and AOB-lesioned female mice. Whereas after this experience sham-operated females show an (acquired) attraction toward male airborne chemosignals, in AOB-lesioned females the same experience makes male-derived volatiles aversive. Finally, in the third experiment we have confirmed that our AOB-lesioned females are able to detect urine-borne male odorants, as well as to discriminate them from the synthetic terpene geraniol. These findings strongly suggest that in mice, the involatile male sexual pheromone that is intrinsically attractive is detected by the vomeronasal system of the females. In addition, the repeated experience of females with male-soiled bedding would probably allow the association of this pheromone, acting as unconditioned stimulus, with olfactory stimuli (odorants) that therefore would become conditioned attractors to the females.

Orosensory Responsiveness to and Preference for Hydroxide-Containing Salts in Mice

PubMed Central

St. John, Steven J.; Boughter, John D.

2009-01-01

Historically, taste researchers have considered the possibility that the gustatory system detects basic compounds, such as those containing the hydroxide ion, but evidence for an “alkaline taste” has not been strong. We found that, in 48 h, 2-bottle preference tests, C3HeB/FeJ (C3) mice showed a preference for Ca(OH)2, whereas SWR/J (SW) mice showed avoidance. Strain differences were also apparent to NaOH but not CaCl2. Follow-up studies showed that the strain difference for Ca(OH)2 was stable over time (Experiment 2) but that C3 and SW mice did not differ in their responses to Ca(OH)2 or NaOH in brief-access tests, where both mice avoided high concentrations of these compounds (Experiment 3). In order to assess the perceived quality of Ca(OH)2, mice were tested in 2 taste aversion generalization experiments (Experiments 4 and 5). Aversions to Ca(OH)2 generalized to NaOH but not CaCl2 in both strains, suggesting that the generalization was based on the hydroxide ion. Both strains also generalized aversions to quinine, suggesting the possibility that the hydroxide ion has a bitter taste quality to these mice, despite the preference shown by C3 mice to middle concentrations in long-term tests. PMID:19423656

Collisionless plasma interpenetration in a strong magnetic field for laboratory astrophysics experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korneev, Ph., E-mail: korneev@theor.mephi.ru; National Research Nuclear University “MEPhI”, 115409, Moscow; D'Humières, E.

A theoretical analysis for astrophysics-oriented laser-matter interaction experiments in the presence of a strong ambient magnetic field is presented. It is shown that the plasma collision in the ambient magnetic field implies significant perturbations in the electron density and magnetic field distribution. This transient stage is difficult to observe in astrophysical phenomena, but it could be investigated in laboratory experiments. Analytic models are presented, which are supported by particles-in-cell simulations.

Enhanced subliminal emotional responses to dynamic facial expressions.

PubMed

Sato, Wataru; Kubota, Yasutaka; Toichi, Motomi

2014-01-01

Emotional processing without conscious awareness plays an important role in human social interaction. Several behavioral studies reported that subliminal presentation of photographs of emotional facial expressions induces unconscious emotional processing. However, it was difficult to elicit strong and robust effects using this method. We hypothesized that dynamic presentations of facial expressions would enhance subliminal emotional effects and tested this hypothesis with two experiments. Fearful or happy facial expressions were presented dynamically or statically in either the left or the right visual field for 20 (Experiment 1) and 30 (Experiment 2) ms. Nonsense target ideographs were then presented, and participants reported their preference for them. The results consistently showed that dynamic presentations of emotional facial expressions induced more evident emotional biases toward subsequent targets than did static ones. These results indicate that dynamic presentations of emotional facial expressions induce more evident unconscious emotional processing.

An electron-beam dose deposition experiment: TIGER 1-D simulation code versus thermoluminescent dosimetry

NASA Astrophysics Data System (ADS)

Murrill, Steven R.; Tipton, Charles W.; Self, Charles T.

1991-03-01

The dose absorbed in an integrated circuit (IC) die exposed to a pulse of low-energy electrons is a strong function of both electron energy and surrounding packaging materials. This report describes an experiment designed to measure how well the Integrated TIGER Series one-dimensional (1-D) electron transport simulation program predicts dose correction factors for a state-of-the-art IC package and package/printed circuit board (PCB) combination. These derived factors are compared with data obtained experimentally using thermoluminescent dosimeters (TLD's) and the FX-45 flash x-ray machine (operated in electron-beam (e-beam) mode). The results of this experiment show that the TIGER 1-D simulation code can be used to accurately predict FX-45 e-beam dose deposition correction factors for reasonably complex IC packaging configurations.

Splitting attention across the two visual fields in visual short-term memory.

PubMed

Delvenne, Jean-Francois; Holt, Jessica L

2012-02-01

Humans have the ability to attentionally select the most relevant visual information from their extrapersonal world and to retain it in a temporary buffer, known as visual short-term memory (VSTM). Research suggests that at least two non-contiguous items can be selected simultaneously when they are distributed across the two visual hemifields. In two experiments, we show that attention can also be split between the left and right sides of internal representations held in VSTM. Participants were asked to remember several colors, while cues presented during the delay instructed them to orient their attention to a subset of memorized colors. Experiment 1 revealed that orienting attention to one or two colors strengthened equally participants' memory for those colors, but only when they were from separate hemifields. Experiment 2 showed that in the absence of attentional cues the distribution of the items in the visual field per se had no effect on memory. These findings strongly suggest the existence of independent attentional resources in the two hemifields for selecting and/or consolidating information in VSTM. Copyright © 2011 Elsevier B.V. All rights reserved.

Learning Is Better with the Hands Free: The Role of Posture in the Memory of Manipulable Objects.

PubMed

Dutriaux, Léo; Gyselinck, Valérie

2016-01-01

Grounded cognition proposes that memory shares processing resources with sensorimotor systems. The aim of the present study was to show that motor simulation participates in the conceptual representation of manipulable objects in long-term memory. In two experiments, lists of manipulable and nonmanipulable objects were presented. Participants were instructed to memorize the items while adopting different postures. In the control condition, they had to keep their hands at rest in front of them. In the interference condition, participants had to keep their hands crossed behind their back to make their hands less free for action. After each list, participants had to perform first a distractive task, and then an oral free recall. The results showed that the interfering posture produced a specific decrease in the recall of manipulable objects, but not of nonmanipulable ones. This decrease was similar when the items were presented as pictures (Experiment 1) or as words (Experiment 2), thus excluding a purely visual effect. These results provide strong evidence that the motor simulation plays a role in the memory trace of the object.

Electrodeposition in microgravity: Ground-based experiments

NASA Technical Reports Server (NTRS)

Riley, C.; Coble, H. D.

1982-01-01

Electrodeposition was studied at one-hundreth g and compared with bench studies at 1 g. The low gravity was achieved during KC-135 aircraft parobolic flights. Flow in a simple cobalt cell (1 M CoSO4) operating under typical commercial conditions (10 to 20 mA/sq cm and 1 V) was monitored with a Schlieren optical system. Natural convection was absent at one-hundreth g. Quantitative comparisons on a cobalt cell with shielded electrodes using interferometry were carried out. Fringe shift differences indicate greater semi-infinite linear diffusion at 1 g than at one-hundreth g for cobalt. Since a shielded electrode operates under diffusion controlled conditions, no differences between 1 g and one-hundreth g would be expected. Similar comparisons on a shielded electrode copper cell were inconclusive. Bench codeposition experiments using polystyrene neutral buoyancy particles coupled with a shielded electrode cobalt cell were begun. Tracking of 12 micron particles showed no measurable difference between thermal/Brownian motion when the cell was operational or nonoperational. Initial experiments on codeposition quality showed a strong dependence upon cathode surface preparation in a shielded electrode configuration.

Mere exposure to money increases endorsement of free-market systems and social inequality.

PubMed

Caruso, Eugene M; Vohs, Kathleen D; Baxter, Brittani; Waytz, Adam

2013-05-01

The present research tested whether incidental exposure to money affects people's endorsement of social systems that legitimize social inequality. We found that subtle reminders of the concept of money, relative to nonmoney concepts, led participants to endorse more strongly the existing social system in the United States in general (Experiment 1) and free-market capitalism in particular (Experiment 4), to assert more strongly that victims deserve their fate (Experiment 2), and to believe more strongly that socially advantaged groups should dominate socially disadvantaged groups (Experiment 3). We further found that reminders of money increased preference for a free-market system of organ transplants that benefited the wealthy at the expense of the poor even though this was not the prevailing system (Experiment 5) and that this effect was moderated by participants' nationality. These results demonstrate how merely thinking about money can influence beliefs about the social order and the extent to which people deserve their station in life. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Structure transition in lipids and nucleic acids of tumor cells under anticancer drugs applications

NASA Astrophysics Data System (ADS)

Dovbeshko, G. I.; Repnytska, O. P.; Tryndiak, V. P.; Todor, I. N.

2003-12-01

Interaction of DNA and phospholipids from Carcinoma Guerina resistant and sensitive cells of Wistar line rats with anti-cancer drugs - cis-platin and doxorubicin (DOX) have been studied in vivo and in vitro experiments. Surface enhanced infrared absorption (SEIRA) spectroscopy was applied for registration of conformational changes in DNA and lipids induced by anti-cancer drugs. It has been shown in vivo experiment that doxorubicin influences less structural disordering of the membrane than cis-platin. Cis-platin creates irreversible complex with memebrane phospholipids, strongly interacting with phosophates and carbohydrate chains. Doxorubicin influences the ordering of carbohydrate chains and does not strongly influence phosphate heads. This change seems to be partially reversible. In contrast, in vivo experiment the doxorubicin strongly influences the DNA structure, leading to DNA stabilization and formation of new H-bonds in DNA-doxorubicin complex. We have not registered the interaction of DNA with cis-platin in vivo experiment. Experiment in vitro for cis-platin incubation with phospholipids from cancer cells during 0.5 hour at 37°C has not shown those drastic structural peculiarities that it was observed in vivo experiments.

Modeling and simulation of protein elution in linear pH and salt gradients on weak, strong and mixed cation exchange resins applying an extended Donnan ion exchange model.

PubMed

Wittkopp, Felix; Peeck, Lars; Hafner, Mathias; Frech, Christian

2018-04-13

Process development and characterization based on mathematic modeling provides several advantages and has been applied more frequently over the last few years. In this work, a Donnan equilibrium ion exchange (DIX) model is applied for modelling and simulation of ion exchange chromatography of a monoclonal antibody in linear chromatography. Four different cation exchange resin prototypes consisting of weak, strong and mixed ligands are characterized using pH and salt gradient elution experiments applying the extended DIX model. The modelling results are compared with the results using a classic stoichiometric displacement model. The Donnan equilibrium model is able to describe all four prototype resins while the stoichiometric displacement model fails for the weak and mixed weak/strong ligands. Finally, in silico chromatogram simulations of pH and pH/salt dual gradients are performed to verify the results and to show the consistency of the developed model. Copyright © 2018 Elsevier B.V. All rights reserved.

Social-bond strength influences vocally mediated recruitment to mobbing

PubMed Central

2016-01-01

Strong social bonds form between individuals in many group-living species, and these relationships can have important fitness benefits. When responding to vocalizations produced by groupmates, receivers are expected to adjust their behaviour depending on the nature of the bond they share with the signaller. Here we investigate whether the strength of the signaller–receiver social bond affects response to calls that attract others to help mob a predator. Using field-based playback experiments on a habituated population of wild dwarf mongooses (Helogale parvula), we first demonstrate that a particular vocalization given on detecting predatory snakes does act as a recruitment call; receivers were more likely to look, approach and engage in mobbing behaviour than in response to control close calls. We then show that individuals respond more strongly to these recruitment calls if they are from groupmates with whom they are more strongly bonded (those with whom they preferentially groom and forage). Our study, therefore, provides novel evidence about the anti-predator benefits of close bonds within social groups. PMID:27903776

Vibrational-vibrational coupling in air at low humidities

NASA Technical Reports Server (NTRS)

Zuckerwar, Allan J.; Miller, Keith W.

1988-01-01

Calculations of sound absorption in air are traditionally based on the assumption that molecular relaxations in N2 and O2 are independent. In binary mixtures of these two gases, however, they are not independent; rather, molecular relaxation is known to be controlled by a very strong vibrational-vibrational (V-V) coupling, which influences both the relaxation frequencies and the relaxation strengths. This article shows that small concentrations of the air constituents CO2 and H2O, which themselves possess a strong V-V coupling to N2 and O2, serve to decouple the N2 and O2 relaxations. To characterize the N2-O2 coupling a coupling strength is derived which depends upon the constituent concentrations and the related reaction rate constants. It is found that the molecular relaxations associated with N2 and O2 in air experience a gradual transition from strong to weak coupling as the humidity increases beyond approximately 0.001 mole percent.

Experimental demonstration of single-mode fiber coupling over relatively strong turbulence with adaptive optics.

PubMed

Chen, Mo; Liu, Chao; Xian, Hao

2015-10-10

High-speed free-space optical communication systems using fiber-optic components can greatly improve the stability of the system and simplify the structure. However, propagation through atmospheric turbulence degrades the spatial coherence of the signal beam and limits the single-mode fiber (SMF) coupling efficiency. In this paper, we analyze the influence of the atmospheric turbulence on the SMF coupling efficiency over various turbulences. The results show that the SMF coupling efficiency drops from 81% without phase distortion to 10% when phase root mean square value equals 0.3λ. The simulations of SMF coupling with adaptive optics (AO) indicate that it is inevitable to compensate the high-order aberrations for SMF coupling over relatively strong turbulence. The SMF coupling efficiency experiments, using an AO system with a 137-element deformable mirror and a Hartmann-Shack wavefront sensor, obtain average coupling efficiency increasing from 1.3% in open loop to 46.1% in closed loop under a relatively strong turbulence, D/r₀=15.1.

More ‘altruistic’ punishment in larger societies

PubMed Central

Marlowe, Frank W; Berbesque, J. Colette; Barr, Abigail; Barrett, Clark; Bolyanatz, Alexander; Cardenas, Juan Camilo; Ensminger, Jean; Gurven, Michael; Gwako, Edwins; Henrich, Joseph; Henrich, Natalie; Lesorogol, Carolyn; McElreath, Richard; Tracer, David

2007-01-01

If individuals will cooperate with cooperators, and punish non-cooperators even at a cost to themselves, then this strong reciprocity could minimize the cheating that undermines cooperation. Based upon numerous economic experiments, some have proposed that human cooperation is explained by strong reciprocity and norm enforcement. Second-party punishment is when you punish someone who defected on you; third-party punishment is when you punish someone who defected on someone else. Third-party punishment is an effective way to enforce the norms of strong reciprocity and promote cooperation. Here we present new results that expand on a previous report from a large cross-cultural project. This project has already shown that there is considerable cross-cultural variation in punishment and cooperation. Here we test the hypothesis that population size (and complexity) predicts the level of third-party punishment. Our results show that people in larger, more complex societies engage in significantly more third-party punishment than people in small-scale societies. PMID:18089534

Cross continental increase in methane ebullition under climate change.

PubMed

Aben, Ralf C H; Barros, Nathan; van Donk, Ellen; Frenken, Thijs; Hilt, Sabine; Kazanjian, Garabet; Lamers, Leon P M; Peeters, Edwin T H M; Roelofs, Jan G M; de Senerpont Domis, Lisette N; Stephan, Susanne; Velthuis, Mandy; Van de Waal, Dedmer B; Wik, Martin; Thornton, Brett F; Wilkinson, Jeremy; DelSontro, Tonya; Kosten, Sarian

2017-11-22

Methane (CH 4 ) strongly contributes to observed global warming. As natural CH 4 emissions mainly originate from wet ecosystems, it is important to unravel how climate change may affect these emissions. This is especially true for ebullition (bubble flux from sediments), a pathway that has long been underestimated but generally dominates emissions. Here we show a remarkably strong relationship between CH 4 ebullition and temperature across a wide range of freshwater ecosystems on different continents using multi-seasonal CH 4 ebullition data from the literature. As these temperature-ebullition relationships may have been affected by seasonal variation in organic matter availability, we also conducted a controlled year-round mesocosm experiment. Here 4 °C warming led to 51% higher total annual CH 4 ebullition, while diffusion was not affected. Our combined findings suggest that global warming will strongly enhance freshwater CH 4 emissions through a disproportional increase in ebullition (6-20% per 1 °C increase), contributing to global warming.

Distinguishing between the partial-mapping preparation hypothesis and the failure-to-engage hypothesis of residual switch costs.

PubMed

Lindsen, Job P; de Jong, Ritske

2010-10-01

Lien, Ruthruff, Remington, & Johnston (2005) reported residual switch cost differences between stimulus-response (S-R) pairs and proposed the partial-mapping preparation (PMP) hypothesis, which states that advance preparation will typically be limited to a subset of S-R pairs because of structural capacity limitations, to account for these differences. Alternatively, the failure-to-engage (FTE) hypothesis does not allow for differences in probability of advance preparation between S-R pairs within a set; it accounts for residual switch cost differences by assuming that benefits of advance preparation may differ between S-R pairs. Three Experiments were designed to test between these hypotheses. No capacity limitations of the type assumed by the PMP hypothesis were found for many participants in Experiment 1. In Experiments 2 and 3, no evidence was found for the dependency of residual switch cost differences between S-R pairs on response-stimulus interval that is predicted by the PMP hypothesis. Mixture-model analysis of reaction times distributions in Experiment 3 provided strong support for the FTE hypothesis over the PMP hypothesis. Simulation studies with a computational implementation of the FTE hypothesis showed that it is able to account in great detail for the results of the present study. Together, these results provide strong evidence against the PMP hypothesis and support the FTE hypothesis that advance preparation probabilistically fails or succeeds at the level of the task set. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Nonlinear elasticity in resonance experiments

NASA Astrophysics Data System (ADS)

Li, Xun; Sens-Schönfelder, Christoph; Snieder, Roel

2018-04-01

Resonant bar experiments have revealed that dynamic deformation induces nonlinearity in rocks. These experiments produce resonance curves that represent the response amplitude as a function of the driving frequency. We propose a model to reproduce the resonance curves with observed features that include (a) the log-time recovery of the resonant frequency after the deformation ends (slow dynamics), (b) the asymmetry in the direction of the driving frequency, (c) the difference between resonance curves with the driving frequency that is swept upward and downward, and (d) the presence of a "cliff" segment to the left of the resonant peak under the condition of strong nonlinearity. The model is based on a feedback cycle where the effect of softening (nonlinearity) feeds back to the deformation. This model provides a unified interpretation of both the nonlinearity and slow dynamics in resonance experiments. We further show that the asymmetry of the resonance curve is caused by the softening, which is documented by the decrease of the resonant frequency during the deformation; the cliff segment of the resonance curve is linked to a bifurcation that involves a steep change of the response amplitude when the driving frequency is changed. With weak nonlinearity, the difference between the upward- and downward-sweeping curves depends on slow dynamics; a sufficiently slow frequency sweep eliminates this up-down difference. With strong nonlinearity, the up-down difference results from both the slow dynamics and bifurcation; however, the presence of the bifurcation maintains the respective part of the up-down difference, regardless of the sweep rate.

Statistical modeling of isoform splicing dynamics from RNA-seq time series data.

PubMed

Huang, Yuanhua; Sanguinetti, Guido

2016-10-01

Isoform quantification is an important goal of RNA-seq experiments, yet it remains problematic for genes with low expression or several isoforms. These difficulties may in principle be ameliorated by exploiting correlated experimental designs, such as time series or dosage response experiments. Time series RNA-seq experiments, in particular, are becoming increasingly popular, yet there are no methods that explicitly leverage the experimental design to improve isoform quantification. Here, we present DICEseq, the first isoform quantification method tailored to correlated RNA-seq experiments. DICEseq explicitly models the correlations between different RNA-seq experiments to aid the quantification of isoforms across experiments. Numerical experiments on simulated datasets show that DICEseq yields more accurate results than state-of-the-art methods, an advantage that can become considerable at low coverage levels. On real datasets, our results show that DICEseq provides substantially more reproducible and robust quantifications, increasing the correlation of estimates from replicate datasets by up to 10% on genes with low or moderate expression levels (bottom third of all genes). Furthermore, DICEseq permits to quantify the trade-off between temporal sampling of RNA and depth of sequencing, frequently an important choice when planning experiments. Our results have strong implications for the design of RNA-seq experiments, and offer a novel tool for improved analysis of such datasets. Python code is freely available at http://diceseq.sf.net G.Sanguinetti@ed.ac.uk Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Characterization of Atmospheric Pressure Plasma Torch and the Surface Interaction for Material Removal

NASA Astrophysics Data System (ADS)

McWilliams, Anthony Joseph

An atmospheric pressure plasma torch has been developed and characterized for removal of organic based coatings. The focus of the Strategic Environmental Research & Development Program (SERDP) project WP-1762, that funded the bulk of this dissertation work, is removal of paint from US Navy vessels. The goal is to develop a novel technology for coating removal that is capable of reducing the amount of environmental waste produced during the commonly used grit blasting process. The atmospheric pressure air plasma torch was identified as having the capacity to remove the paint systems while using only compressed air and electricity as a media-less removal system with drastically reduced waste generation. Any improvements to the existing technology need to be based on scientific knowledge and thus the plasma removal mechanisms or material warranted investigation. The removal of material does not show a strong relation to the plasma parameters of power, frequency, and gas flow, nor is there a strong relation to the presences of inorganic fillers impeding or altering the removal rates. The underlying removal mechanisms also do not show a strong correlation to the rotational temperature of the plasma but do show a strong correlation to the optical emission intensity. Primarily, the emission from atomic oxygen and molecular nitrogen were identified significant contributors and were investigated further. The plasma feed gas was then varied from the nitrogen and oxygen ratio present in ambient air to pure nitrogen to identify the effect of oxygen on the removal mechanism. From these experiments it was concluded that the oxygen present in air does contribute to the overall removal mechanism; however, it is not the sole contributing factor with the other major factor being nitrogen.

Major collapse of the South Pacific Convergence Zone in the future and its consequences on tropical cyclones.

NASA Astrophysics Data System (ADS)

Menkes, C.; Dutheil, C.; Bador, M.; Lengaigne, M.; Lefèvre, J.; Jourdain, N.; Jullien, S.; Vialard, J.; Peltier, A.

2017-12-01

The South Pacific convergence zone (SPCZ) is poorly represented in global climate models, with trademark biases such as the "double ITCZ" or related cold tongue biases. Such biases decrease our confidence in climate change projections for this region. We first show that WRF atmospheric simulations using a 1°x1° regional configuration capture the SPCZ mean state and interannual variability well over the 1980-2016 period. We then perform climate change experiments by adding the RCP8.5, 2080-2100 CMIP5 multi-model mean boundary anomalies to the present conditions. We find a 4° equatorward shift of the SPCZ west of 170°W, and associated 40% rainfall reduction in the southwestern Pacific. These results strongly contrast with previous studies based on CMIP5 simulations that suggest a much weaker southwestern Pacific drying ( 7%). Regional sensitivity experiments show that this CMIP5 weak response can be tracked to climatological CMIP5 SST biases, which weaken the humidity transport reduction in the south Pacific in the future and result in an underestimated projected drying of the southwest Pacific. Our experiments also point toward a large increase in the future SPCZ variability with increased frequency of zonal SPCZ events. Next we explore the fate of tropical cyclones by downscaling the previous models to 20 km. The seasonal and spatial distribution of TC genesis and occurrence are in good agreement with the observations albeit with weaker than observed annual numbers. Our reference simulation is able to simulate intense category 4 and 5 TCs. In the future climate, we show a drastic decrease in the number of TCs ( 75%), and the disappearance of the most intense (Cat 4-5) cyclones. Additional regional simulations using a completely different set of physical parameterizations yield very similar results for the SPCZ collapse, including the strong decrease of TC numbers ( 63%), underlining the robustness of our results.

Simultaneous Rheoelectric Measurements of Strongly Conductive Complex Fluids

NASA Astrophysics Data System (ADS)

Helal, Ahmed; Divoux, Thibaut; McKinley, Gareth H.

2016-12-01

We introduce an modular fixture designed for stress-controlled rheometers to perform simultaneous rheological and electrical measurements on strongly conductive complex fluids under shear. By means of a nontoxic liquid metal at room temperature, the electrical connection to the rotating shaft is completed with minimal additional mechanical friction, allowing for simultaneous stress measurements at values as low as 1 Pa. Motivated by applications such as flow batteries, we use the capabilities of this design to perform an extensive set of rheoelectric experiments on gels formulated from attractive carbon-black particles, at concentrations ranging from 4 to 15 wt %. First, experiments on gels at rest prepared with different shear histories show a robust power-law scaling between the elastic modulus G0' and the conductivity σ0 of the gels—i.e., G0'˜σ0α, with α =1.65 ±0.04 , regardless of the gel concentration. Second, we report conductivity measurements performed simultaneously with creep experiments. Changes in conductivity in the early stage of the experiments, also known as the Andrade-creep regime, reveal for the first time that plastic events take place in the bulk, while the shear rate γ ˙ decreases as a weak power law of time. The subsequent evolution of the conductivity and the shear rate allows us to propose a local yielding scenario that is in agreement with previous velocimetry measurements. Finally, to establish a set of benchmark data, we determine the constitutive rheological and electrical behavior of carbon-black gels. Corrections first introduced for mechanical measurements regarding shear inhomogeneity and wall slip are carefully extended to electrical measurements to accurately distinguish between bulk and surface contributions to the conductivity. As an illustrative example, we examine the constitutive rheoelectric properties of five different grades of carbon-black gels and we demonstrate the relevance of this rheoelectric apparatus as a versatile characterization tool for strongly conductive complex fluids and their applications.

Interaction of color and geometric cues in depth perception: when does "red" mean "near"?

PubMed

Guibal, Christophe R C; Dresp, Birgitta

2004-12-01

Luminance and color are strong and self-sufficient cues to pictorial depth in visual scenes and images. The present study investigates the conditions under which luminance or color either strengthens or overrides geometric depth cues. We investigated how luminance contrast associated with the color red and color contrast interact with relative height in the visual field, partial occlusion, and interposition to determine the probability that a given figure presented in a pair is perceived as "nearer" than the other. Latencies of "near" responses were analyzed to test for effects of attentional selection. Figures in a pair were supported by luminance contrast (Experiment 1) or isoluminant color contrast (Experiment 2) and combined with one of the three geometric cues. The results of Experiment 1 show that the luminance contrast of a color (here red), when it does not interact with other colors, produces the same effects as achromatic luminance contrasts. The probability of "near" increases with the luminance contrast of the color stimulus, the latencies for "near" responses decrease with increasing luminance contrast. Partial occlusion is found to be a strong enough pictorial cue to support a weaker red luminance contrast. Interposition cues lose out against cues of spatial position and partial occlusion. The results of Experiment 2, with isoluminant displays of varying color contrast, reveal that red color contrast on a light background supported by any of the three geometric cues wins over green or white supported by any of the three geometric cues. On a dark background, red color contrast supported by the interposition cue loses out against green or white color contrast supported by partial occlusion. These findings reveal that color is not an independent depth cue, but is strongly influenced by luminance contrast and stimulus geometry. Systematically shorter response latencies for stronger "near" percepts demonstrate that selective visual attention reliably detects the most likely depth cue combination in a given configuration.

A robust preference for cheap-and-easy strategies over reliable strategies when verifying personal memories.

PubMed

Nash, Robert A; Wade, Kimberley A; Garry, Maryanne; Adelman, James S

2017-08-01

People depend on various sources of information when trying to verify their autobiographical memories. Yet recent research shows that people prefer to use cheap-and-easy verification strategies, even when these strategies are not reliable. We examined the robustness of this cheap strategy bias, with scenarios designed to encourage greater emphasis on source reliability. In three experiments, subjects described real (Experiments 1 and 2) or hypothetical (Experiment 3) autobiographical events, and proposed strategies they might use to verify their memories of those events. Subjects also rated the reliability, cost, and the likelihood that they would use each strategy. In line with previous work, we found that the preference for cheap information held when people described how they would verify childhood or recent memories (Experiment 1), personally important or trivial memories (Experiment 2), and even when the consequences of relying on incorrect information could be significant (Experiment 3). Taken together, our findings fit with an account of source monitoring in which the tendency to trust one's own autobiographical memories can discourage people from systematically testing or accepting strong disconfirmatory evidence.

Color preferences change after experience with liked/disliked colored objects.

PubMed

Strauss, Eli D; Schloss, Karen B; Palmer, Stephen E

2013-10-01

How are color preferences formed, and can they be changed by affective experiences with correspondingly colored objects? We examined these questions by testing whether affectively polarized experiences with images of colored objects would cause changes in color preferences. Such changes are implied by the ecological valence theory (EVT), which posits that color preferences are determined by people's average affective responses to correspondingly colored objects (Palmer & Schloss, Proceedings of the National Academy of Sciences, 107, 8877-8882, 2010). Seeing images of strongly liked (and disliked) red and green objects, therefore, should lead to increased (and decreased) preferences for correspondingly colored red and green color patches. Experiment 1 showed that this crossover interaction did occur, but only if participants were required to evaluate their preferences for the colored objects when they saw them. Experiment 2 showed that these overall changes decreased substantially over a 24-h delay, but the degree to which the effect lasted for individuals covaried with the magnitude of the effects immediately after object exposure. Experiment 3 demonstrated a similar, but weaker, effect of affectively biased changes in color preferences when participants did not see, but only imagined, the colored objects. The overall pattern of results indicated that color preferences are not fixed, but rather are shaped by affective experiences with colored objects. Possible explanations for the observed changes in color preferences were considered in terms of associative learning through evaluative conditioning and/or priming of prior knowledge in memory.

Customer service providers' attitudes relating to customer service and customer satisfaction in the customer-server exchange.

PubMed

Susskind, Alex M; Kacmar, K Michele; Borchgrevink, Carl P

2003-02-01

The authors proposed and tested a model describing the relationship between customer service providers' perceptions and attitudes toward their service-related duties and their customers' perceptions of satisfaction with their service experiences. Results indicated that the perception of having standards for service delivery in an organization is strongly related to line-level employees' perceptions of support from coworkers and supervisors. Perceived support from coworkers was significantly related to service providers' customer orientation, whereas perceived support from supervisors showed a weaker relationship to a customer orientation. Ultimately, service providers' customer orientation was strongly related to customers' satisfaction with service. Finally, a set of post hoc analyses indicated that coworker and supervisory support explained a greater proportion of incremental variance in the model than did perceived organizational support alone.

Photovoltaic effect in Bi{sub 2}TeO{sub 5} photorefractive crystal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveira, Ivan de, E-mail: ivan@ft.unicamp.brg; Capovilla, Danilo Augusto; Carvalho, Jesiel F.

2015-10-12

We report on the presence of a strong photovoltaic effect on nominally undoped photorefractive Bi{sub 2}TeO{sub 5} crystals and estimated their Glass photovoltaic constant and photovoltaic field for λ = 532 nm illumination. We directly measured the photovoltaic-based photocurrent in this material under λ = 532 nm wavelength laser light illumination and compared its behavior with that of a well known photovoltaic Fe-doped Lithium Niobate crystal. We also show the photovoltaic current to strongly depend on the polarization direction of light. Holographic diffraction efficiency oscillation during recording and the behavior of fringe-locked running holograms in self-stabilized experiments are also demonstrated here as additional indirect proofs ofmore » the photovoltaic nature of this material.« less

Modification of jet-like correlations in Pb-Au collisions at 158A GeV/c

NASA Astrophysics Data System (ADS)

Ceres Collaboration; Adamová, D.; Agakichiev, G.; Antończyk, D.; Appelshäuser, H.; Belaga, V.; Bielčíková, J.; Braun-Munzinger, P.; Busch, O.; Cherlin, A.; Damjanović, S.; Dietel, T.; Dietrich, L.; Drees, A.; Dubitzky, W.; Esumi, S. I.; Filimonov, K.; Fomenko, K.; Fraenkel, Z.; Garabatos, C.; Glässel, P.; Holeczek, J.; Kalisky, M.; Kniege, S.; Kushpil, V.; Maas, A.; Marín, A.; Milošević, J.; Milov, A.; Miśkowiec, D.; Panebrattsev, Yu.; Petchenova, O.; Petráček, V.; Pfeiffer, A.; Płoskoń, M.; Rak, J.; Ravinovich, I.; Rehak, P.; Sako, H.; Schmitz, W.; Schuchmann, S.; Sedykh, S.; Shimansky, S.; Stachel, J.; Šumbera, M.; Tilsner, H.; Tserruya, I.; Wessels, J. P.; Wienold, T.; Wurm, J. P.; Xie, W.; Yurevich, S.; Yurevich, V.

2009-07-01

Results of a two-particle correlation analysis of high-p charged particles in Pb-Au collisions at 158A GeV/c are presented. The data have been recorded by the CERES experiment at the CERN-SPS. The correlations are studied as function of transverse momentum, particle charge and collision centrality. We observe a jet-like structure in the vicinity of a high-p trigger particle and a broad back-to-back distribution. The yields of associated particles per trigger show a strong dependence on the trigger/associate charge combination. A comparison to PYTHIA confirms the jet-like pattern at the near-side but suggests a strong modification at the away-side, implying significant energy transfer of the hard-scattered parton to the medium.

Evidence of an Improper Displacive Phase Transition in Cd2 Re2 O7 via Time-Resolved Coherent Phonon Spectroscopy

NASA Astrophysics Data System (ADS)

Harter, J. W.; Kennes, D. M.; Chu, H.; de la Torre, A.; Zhao, Z. Y.; Yan, J.-Q.; Mandrus, D. G.; Millis, A. J.; Hsieh, D.

2018-01-01

We have used a combination of ultrafast coherent phonon spectroscopy, ultrafast thermometry, and time-dependent Landau theory to study the inversion symmetry breaking phase transition at Tc=200 K in the strongly spin-orbit coupled correlated metal Cd2 Re2 O7 . We establish that the structural distortion at Tc is a secondary effect through the absence of any softening of its associated phonon mode, which supports a purely electronically driven mechanism. However, the phonon lifetime exhibits an anomalously strong temperature dependence that decreases linearly to zero near Tc. We show that this behavior naturally explains the spurious appearance of phonon softening in previous Raman spectroscopy experiments and should be a prevalent feature of correlated electron systems with linearly coupled order parameters.

Application of ECH to the study of transport in ITER baseline scenario-like discharges in DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinsker, R. I.; Austin, M. E.; Ernst, D. R.

Recent DIII-D experiments in the ITER Baseline Scenario (IBS) have shown strong increases in fluctuations and correlated reduction of confinement associated with entering the electron-heating-dominated regime with strong electron cyclotron heating (ECH). The addition of 3.2 MW of 110 GHz EC power deposited at ρ~0.42 to IBS discharges with ~3 MW of neutral beam injection causes large increases in low-k and medium-k turbulent density fluctuations observed with Doppler backscatter (DBS), beam emission spectroscopy (BES) and phase-contrast imaging (PCI) diagnostics, correlated with decreases in the energy, particle, and momentum confinement times. Power balance calculations show the electron heat diffusivity χ emore » increases significantly in the mid-radius region 0.4« less

Application of ECH to the study of transport in ITER baseline scenario-like discharges in DIII-D

DOE PAGES

Pinsker, R. I.; Austin, M. E.; Ernst, D. R.; ...

2015-03-12

Recent DIII-D experiments in the ITER Baseline Scenario (IBS) have shown strong increases in fluctuations and correlated reduction of confinement associated with entering the electron-heating-dominated regime with strong electron cyclotron heating (ECH). The addition of 3.2 MW of 110 GHz EC power deposited at ρ~0.42 to IBS discharges with ~3 MW of neutral beam injection causes large increases in low-k and medium-k turbulent density fluctuations observed with Doppler backscatter (DBS), beam emission spectroscopy (BES) and phase-contrast imaging (PCI) diagnostics, correlated with decreases in the energy, particle, and momentum confinement times. Power balance calculations show the electron heat diffusivity χ emore » increases significantly in the mid-radius region 0.4« less

Sperm quality but not relatedness predicts sperm competition success in threespine sticklebacks (Gasterosteus aculeatus).

PubMed

Mehlis, Marion; Rahn, Anna K; Bakker, Theo C M

2015-04-26

Mating between close relatives often leads to a reduction of an individual's fitness, due to an increased expression of deleterious alleles. Thus, in many animal taxa pre- as well as postcopulatory inbreeding avoidance mechanisms have evolved. An increased risk of inbreeding and hence a loss of genetic variation may occur during founder events as in most cases only few individuals establish a new population. The threespine stickleback (Gasterosteus aculeatus) is a small externally fertilizing fish species subject to strong sperm competition. Sticklebacks inhabit both marine and freshwater environments and anadromous populations have repeatedly established new genetically less diverse freshwater populations. Previous studies showed that anadromous sticklebacks strongly suffer from inbreeding depression and when given the choice females prefer to mate with unrelated males. The present study aimed to address whether there exists a postcopulatory inbreeding avoidance mechanism solely based on sperm-egg interactions in sperm competition experiments. We used F1 individuals that originated either from a large, genetically heterogeneous anadromous population or from a small, genetically less diverse freshwater population. For each population, eggs of two different females were in vitro fertilized by the same two males' sperm in a paired study design. In the main experiment one male was the female's full-sib brother and in the control experiment all individuals were unrelated. The results revealed that fertilization success was independent of relatedness in both populations suggesting a general lack of a postcopulatory inbreeding avoidance mechanism. Instead, male quality (i.e. sperm morphology) predicted paternity success during competitive fertilization trials. In sticklebacks, there is no evidence for postcopulatory inbreeding avoidance. Sperm morphology predicted paternity instead, thus sperm quality traits are under strong sexual selection, presumably driven by the high risk of sperm competition under natural conditions.

The novel white spot syndrome virus-induced gene, PmERP15, encodes an ER stress-responsive protein in black tiger shrimp, Penaeus monodon.

PubMed

Leu, Jiann-Horng; Liu, Kuan-Fu; Chen, Kuan-Yu; Chen, Shu-Hwa; Wang, Yu-Bin; Lin, Chung-Yen; Lo, Chu-Fang

2015-04-01

By microarray screening, we identified a white spot syndrome virus (WSSV)-strongly induced novel gene in gills of Penaeus monodon. The gene, PmERP15, encodes a putative transmembrane protein of 15 kDa, which only showed some degree of similarity (54-59%) to several unknown insect proteins, but had no hits to shrimp proteins. RT-PCR showed that PmERP15 was highly expressed in the hemocytes, heart and lymphoid organs, and that WSSV-induced strong expression of PmERP15 was evident in all tissues examined. Western blot analysis likewise showed that WSSV strongly up-regulated PmERP15 protein levels. In WSSV-infected hemocytes, immunofluorescence staining showed that PmERP15 protein was colocalized with an ER enzyme, protein disulfide isomerase, and in Sf9 insect cells, PmERP15-EGFP fusion protein colocalized with ER -Tracker™ Red dye as well. GRP78, an ER stress marker, was found to be up-regulated in WSSV-infected P. monodon, and both PmERP15 and GRP78 were up-regulated in shrimp injected with ER stress inducers tunicamycin and dithiothreitol. Silencing experiments showed that although PmERP15 dsRNA-injected shrimp succumbed to WSSV infection more rapidly, the WSSV copy number had no significant changes. These results suggest that PmERP15 is an ER stress-induced, ER resident protein, and its induction in WSSV-infected shrimp is caused by the ER stress triggered by WSSV infection. Furthermore, although PmERP15 has no role in WSSV multiplication, its presence is essential for the survival of WSSV-infected shrimp. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experiment-theory comparison for low frequency BAE modes in the strongly shaped H-1NF stellarator

DOE PAGES

Haskey, S. R.; Blackwell, B. D.; Nuhrenberg, C.; ...

2015-08-12

Here, recent advances in the modeling, analysis, and measurement of fluctuations have significantly improved the diagnosis and understanding of Alfvén eigenmodes in the strongly shaped H-1NF helical axis stellarator. Experimental measurements, including 3D tomographic inversions of high resolution visible light images, are in close agreement with beta-induced Alfvén eigenmodes (BAEs) calculated using the compressible ideal MHD code, CAS3D. This is despite the low β in H-1NF, providing experimental evidence that these modes can exist due to compression that is induced by the strong shaping in stellarators, in addition to high β, as is the case in tokamaks. This is confirmedmore » using the CONTI and CAS3D codes, which show significant gap structures at lower frequencies which contain BAE and beta-acoustic Alfvén eigenmodes (BAAEs). The BAEs are excited in the absence of a well confined energetic particle source, further confirming previous studies that thermal particles, electrons, or even radiation fluctuations can drive these modes. Datamining of magnetic probe data shows the experimentally measured frequency of these modes has a clear dependence on the rotational transform profile, which is consistent with a frequency dependency due to postulated confinement related temperature variations.« less

A Fast Superpixel Segmentation Algorithm for PolSAR Images Based on Edge Refinement and Revised Wishart Distance

PubMed Central

Zhang, Yue; Zou, Huanxin; Luo, Tiancheng; Qin, Xianxiang; Zhou, Shilin; Ji, Kefeng

2016-01-01

The superpixel segmentation algorithm, as a preprocessing technique, should show good performance in fast segmentation speed, accurate boundary adherence and homogeneous regularity. A fast superpixel segmentation algorithm by iterative edge refinement (IER) works well on optical images. However, it may generate poor superpixels for Polarimetric synthetic aperture radar (PolSAR) images due to the influence of strong speckle noise and many small-sized or slim regions. To solve these problems, we utilized a fast revised Wishart distance instead of Euclidean distance in the local relabeling of unstable pixels, and initialized unstable pixels as all the pixels substituted for the initial grid edge pixels in the initialization step. Then, postprocessing with the dissimilarity measure is employed to remove the generated small isolated regions as well as to preserve strong point targets. Finally, the superiority of the proposed algorithm is validated with extensive experiments on four simulated and two real-world PolSAR images from Experimental Synthetic Aperture Radar (ESAR) and Airborne Synthetic Aperture Radar (AirSAR) data sets, which demonstrate that the proposed method shows better performance with respect to several commonly used evaluation measures, even with about nine times higher computational efficiency, as well as fine boundary adherence and strong point targets preservation, compared with three state-of-the-art methods. PMID:27754385

Responding to social and symbolic extrafoveal cues: cue shape trumps biological relevance.

PubMed

Hermens, Frouke; Bindemann, Markus; Mike Burton, A

2017-01-01

Social cues presented at visual fixation have been shown to strongly influence an observer's attention and response selection. Here we ask whether the same holds for cues (initially) presented away from fixation, as cues are commonly perceived in natural vision. In six experiments, we show that extrafoveally presented cues with a distinct outline, such as pointing hands, rotated heads, and arrow cues result in strong cueing of responses (either to the cue itself, or a cued object). In contrast, cues without a clear outline, such as gazing eyes and direction words exert much weaker effects on participants' responses to a target cue. We also show that distraction effects on response times are relatively weak, but that strong interference effects can be obtained by measuring mouse trajectories. Eye tracking suggests that gaze cues are slower to respond to because their direction cannot easily be perceived in extrafoveal vision. Together, these data suggest that the strength of an extrafoveal cue is determined by the shape of the cue outline, rather than its biological relevance (i.e., whether the cue is provided by another human being), and that this shape effect is due to how easily the direction of a cue can be perceived in extrafoveal vision.

Observation of Gigawatt-Class THz Pulses from a Compact Laser-Driven Particle Accelerator

NASA Astrophysics Data System (ADS)

Gopal, A.; Herzer, S.; Schmidt, A.; Singh, P.; Reinhard, A.; Ziegler, W.; Brömmel, D.; Karmakar, A.; Gibbon, P.; Dillner, U.; May, T.; Meyer, H.-G.; Paulus, G. G.

2013-08-01

We report the observation of subpicosecond terahertz (T-ray) pulses with energies ≥460μJ from a laser-driven ion accelerator, thus rendering the peak power of the source higher even than that of state-of-the-art synchrotrons. Experiments were performed with intense laser pulses (up to 5×1019W/cm2) to irradiate thin metal foil targets. Ion spectra measured simultaneously showed a square law dependence of the T-ray yield on particle number. Two-dimensional particle-in-cell simulations show the presence of transient currents at the target rear surface which could be responsible for the strong T-ray emission.

Repulsion of polarized particles from two-dimensional materials

NASA Astrophysics Data System (ADS)

Rodríguez-Fortuño, Francisco J.; Picardi, Michela F.; Zayats, Anatoly V.

2018-05-01

Repulsion of nanoparticles, molecules, and atoms from surfaces can have important applications in nanomechanical devices, microfluidics, optical manipulation, and atom optics. Here, through the solution of a classical scattering problem, we show that a dipole source oscillating at a frequency ω can experience a robust and strong repulsive force when its near-field interacts with a two-dimensional material. As an example, the case of graphene is considered, showing that a broad bandwidth of repulsion can be obtained at frequencies for which propagation of plasmon modes is allowed 0 <ℏ ω <(5 /3 ) μc , where μc is the chemical potential tunable electrically or by chemical doping.

Improved Performance of High Areal Density Indirect Drive Implosions at the National Ignition Facility using a Four-Shock Adiabat Shaped Drive

DOE PAGES

Casey, D. T.; Milovich, J. L.; Smalyuk, V. A.; ...

2015-09-01

Hydrodynamic instabilities can cause capsule defects and other perturbations to grow and degrade implosion performance in ignition experiments at the National Ignition Facility (NIF). Here, we show the first experimental demonstration that a strong unsupported first shock in indirect drive implosions at the NIF reduces ablation front instability growth leading to a 3 to 10 times higher yield with fuel ρR > 1 g=cm 2. This work shows the importance of ablation front instability growth during the National Ignition Campaign and may provide a path to improved performance at the high compression necessary for ignition.

Achiral-to-chiral transition in benzil solidification: analogies with racemic conglomerates systems showing deracemization.

PubMed

El-Hachemi, Zoubir; Arteaga, Oriol; Canillas, Adolf; Crusats, Joaquim; Sorrenti, Alessandro; Veintemillas-Verdaguer, Sabino; Ribo, Josep M

2013-07-01

Experimental results show that benzil (1,2-diphenyl-1,2-ethanedione), an achiral compound that crystallizes as a racemic conglomerate, yields by solidification polycrystalline scalemic mixtures of high enantiomeric excesses. These results are related to those previously reported in this type of compounds on deracemizations of racemic mixtures of crystal enantiomorphs obtained by wet grinding. However, the present results strongly suggest that these experiments cannot be explained without taking into account chiral recognition interactions at the level of precritical clusters. The conditions that would define a general thermodynamic scenario for such deracemizations are discussed. © 2013 Wiley Periodicals, Inc.

Strong scintillations during atmospheric occultations Theoretical intensity spectra. [radio scattering during spacecraft occultations by planetary atmospheres

NASA Technical Reports Server (NTRS)

Hinson, D. P.

1986-01-01

Each of the two Voyager spacecraft launched in 1977 has completed a reconnaissance of the Jovian and Saturnian systems. In connection with occultation experiments, strong scintillations were observed. Further theoretical work is required before these scintillations can be interpreted. The present study is, therefore, concerned with the derivation of a theory for strong scattering during atmospheric occultation experiments, taking into account as fundamental quantity of interest the spatial spectrum (or spectral density) of intensity fluctuations. Attention is given to a theory for intensity spectra, and numerical calculations. The new formula derived for Phi-i accounts for strong scattering of electromagnetic waves during atmospheric occultations.

Study of iron oxide nanoparticles in soil for remediation of arsenic

NASA Astrophysics Data System (ADS)

Shipley, Heather J.; Engates, Karen E.; Guettner, Allison M.

2011-06-01

There is a growing interest in the use of nanoparticles for environmental applications due to their unique physical and chemical properties. One possible application is the removal of contaminants from water. In this study, the use of iron oxide nanoparticles (19.3 nm magnetite and 37.0 nm hematite) were examined to remove arsenate and arsenite through column studies. The columns contained 1.5 or 15 wt% iron oxide nanoparticles and soil. Arsenic experiments were conducted with 1.5 wt% iron oxides at 1.5 and 6 mL/h with initial arsenate and arsenite concentrations of 100 μg/L. Arsenic release occurred after 400 PV, and 100% release was reached. A long-term study was conducted with 15 wt% magnetite nanoparticles in soil at 0.3 mL/h with an initial arsenate concentration of 100 μg/L. A negligible arsenate concentration occurred for 3559.6 pore volumes (PVs) (132.1 d). Eventually, the arsenate concentration reached about 20% after 9884.1 PV (207.9 d). A retardation factor of about 6742 was calculated indicating strong adsorption of arsenic to the magnetite nanoparticles in the column. Also, increased adsorption was observed after flow interruption. Other experiments showed that arsenic and 12 other metals (V, Cr, Co, Mn, Se, Mo, Cd, Pb, Sb, Tl, Th, U) could be simultaneously removed by the iron oxide nanoparticles in soil. Effluent concentrations were less than 10% for six out of the 12 metals. Desorption experiment showed partial irreversible sorption of arsenic to the iron oxide nanoparticle surface. Strong adsorption, large retardation factor, and resistant desorption suggest that magnetite and hematite nanoparticles have the potential to be used to remove arsenic in sandy soil possibly through in situ techniques.

Heavy-ion anisotropy measured by ALTEA in the International Space Station.

PubMed

Di Fino, L; Casolino, M; De Santis, C; Larosa, M; La Tessa, C; Narici, L; Picozza, P; Zaconte, V

2011-09-01

The uneven shielding of the International Space Station from the vessel hull, racks and experiments produces a modulation of the internal radiation environment. A detailed knowledge of this environment, and therefore of the Station's shielding effectiveness, is mandatory for an accurate assessment of radiation risk. We present here the first 3D measurements of the Station's radiation environment, discriminating particle trajectories and LET, made possible using the detection capability of the ALTEA-space detector. We provide evidence for a strong (factor ≈ 3) anisotropy in the inner integral LET for high-LET particles (LET > 50 keV/µm) showing a minimum along the longitudinal station axis (most shielded) and a maximum normal to it. Integrating over all measured LETs, the anisotropy is strongly reduced, showing that unstopped light ions plus the fragments produced by heavier ions approximately maintain flux/LET isotropy. This suggests that, while changing the quality of radiation, the extra shielding along the station main axis is not producing a benefit in terms of total LET. These features should be taken into account (1) when measuring radiation with detectors that cannot distinguish the direction of the impinging radiation or that are unidirectional, (2) when planning radiation biology experiments on the ISS, and (3) when simulating the space radiation environment for experiments on the ground. A novel analysis technique that fully exploits the ability to retrieve the angular distribution of the radiation is also presented as well as the angular particle flux and LET characteristic of three geomagnetic zones measured during 2009 by the ALTEA-space detector. This technique is applied to the ALTEA-space detector, but a wider applicability to other detectors is suggested.

Numerical simulation of the observed near-surface East India Coastal Current on the continental slope

NASA Astrophysics Data System (ADS)

Mukherjee, A.; Shankar, D.; Chatterjee, Abhisek; Vinayachandran, P. N.

2018-06-01

We simulate the East India Coastal Current (EICC) using two numerical models (resolution 0.1° × 0.1°), an oceanic general circulation model (OGCM) called Modular Ocean Model and a simpler, linear, continuously stratified (LCS) model, and compare the simulated current with observations from moorings equipped with acoustic Doppler current profilers deployed on the continental slope in the western Bay of Bengal (BoB). We also carry out numerical experiments to analyse the processes. Both models simulate well the annual cycle of the EICC, but the performance degrades for the intra-annual and intraseasonal components. In a model-resolution experiment, both models (run at a coarser resolution of 0.25° × 0.25°) simulate well the currents in the equatorial Indian Ocean (EIO), but the performance of the high-resolution LCS model as well as the coarse-resolution OGCM, which is good in the EICC regime, degrades in the eastern and northern BoB. An experiment on forcing mechanisms shows that the annual EICC is largely forced by the local alongshore winds in the western BoB and remote forcing due to Ekman pumping over the BoB, but forcing from the EIO has a strong impact on the intra-annual EICC. At intraseasonal periods, local (equatorial) forcing dominates in the south (north) because the Kelvin wave propagates equatorward in the western BoB. A stratification experiment with the LCS model shows that changing the background stratification from EIO to BoB leads to a stronger surface EICC owing to strong coupling of higher order vertical modes with wind forcing for the BoB profiles. These high-order modes, which lead to energy propagating down into the ocean in the form of beams, are important only for the current and do not contribute significantly to the sea level.

Examining the Relationship of an All-Cause Harm Patient Safety Measure and Critical Performance Measures at the Frontline of Care.

PubMed

Sammer, Christine; Hauck, Loran D; Jones, Cason; Zaiback-Aldinger, Julie; Li, Michael; Classen, David

2018-02-07

In 2015, the Institute of Medicine Vital Signs report called for a new patient safety composite measure to lessen the reporting burden of patient harm. Before this report, two patient safety organizations had developed an electronic all-cause harm measurement system leveraging data from the electronic health record, which identified and grouped harms into five broad categories and consolidated them into one all-cause harm outcome measure. The objective of this study was to examine the relationship between this all-cause harm patient safety measure and the following three performance measures important to overall hospital safety performance: safety culture, employee engagement, and patient experience. We studied the relationship between all-cause harm and three performance measures on eight inpatient care units at one hospital for 7 months. The findings demonstrated strong correlations between an all-cause harm measure and patient safety culture, employee engagement, and patient experience at the hospital unit level. Four safety culture domains showed significant negative correlations with all-cause harm at a P value of 0.05 or less. Six employee engagement domains were significantly negatively correlated with all-cause harm at a P value of 0.01 or less, and six of the ten patient experience measures were significantly correlated with all-cause harm at a P value of 0.05 or less. The results show that there is a strong relationship between all-cause harm and these performance measures indicating that when there is a positive patient safety culture, a more engaged employee, and a more satisfying patient experience, there may be less all-cause harm.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

The dynamic effect of reading direction habit on spatial asymmetry of image perception.

PubMed

Afsari, Zaeinab; Ossandón, José P; König, Peter

2016-09-01

Exploration of images after stimulus onset is initially biased to the left. Here, we studied the causes of such an asymmetry and investigated effects of reading habits, text primes, and priming by systematically biased eye movements on this spatial bias in visual exploration. Bilinguals first read text primes with right-to-left (RTL) or left-to-right (LTR) reading directions and subsequently explored natural images. In Experiment 1, native RTL speakers showed a leftward free-viewing shift after reading LTR primes but a weaker rightward bias after reading RTL primes. This demonstrates that reading direction dynamically influences the spatial bias. However, native LTR speakers who learned an RTL language late in life showed a leftward bias after reading either LTR or RTL primes, which suggests the role of habit formation in the production of the spatial bias. In Experiment 2, LTR bilinguals showed a slightly enhanced leftward bias after reading LTR text primes in their second language. This might contribute to the differences of native RTL and LTR speakers observed in Experiment 1. In Experiment 3, LTR bilinguals read normal (LTR, habitual reading) and mirrored left-to-right (mLTR, nonhabitual reading) texts. We observed a strong leftward bias in both cases, indicating that the bias direction is influenced by habitual reading direction and is not secondary to the actual reading direction. This is confirmed in Experiment 4, in which LTR participants were asked to follow RTL and LTR moving dots in prior image presentation and showed no change in the normal spatial bias. In conclusion, the horizontal bias is a dynamic property and is modulated by habitual reading direction.

Low dose mTHPC photodynamic therapy for cholangiocarcinoma

NASA Astrophysics Data System (ADS)

Stepp, Herbert; Kniebühler, Gesa; Pongratz, Thomas; Betz, Christian S.; Göke, Burkhard; Sroka, Ronald; Schirra, Jörg

2013-06-01

Objective: Demonstration of whether a low dose of mTHPC (temoporfin , Foscan) is sufficient to induce an efficient clinical response in palliative PDT of non-resectable cholangiocarcinoma (CC), while showing a low side effect profile as compared to the standard Photofrin PDT. Materials and Methods: 13 patients (14 treatment sessions) with non-resectable CC were treated with stenting and PDT (3 mg Foscan per treatment, 0.032-0.063 mg/kg body weight, 652 nm, 50 J/cm). Fluorescence measurements were performed with a single bare fiber for 5/13 patients prior to PDT at the tumor site to determine the fluorescence contrast. For another 7/13 patients, long-term fluorescence-kinetics were measured on the oral mucosa to determine the time of maximal relative fluorescence intensity. Results: Foscan fluorescence could clearly be identified spectroscopically as early as 20 hours after administration. It was not significantly different between lesion and normal tissue within the bile duct. Fluorescence kinetics assessed at the oral mucosa were highest at 72-96 hours after administration. The DLI was therefore extended from 20 hours to approx. 70 hours for the last 5 patients treated. The treatment effect was promising with a median survival of 11 months for the higher grade tumors (Bismuth types III and IV). Local side effects occurred in one patient (pancreatitis), systemic side effects were much reduced compared to prior experience with Photofrin. Conclusion: Combined stenting and photodynamic therapy (PDT) performed with a low dose of Foscan results in comparable survival times relative to standard Photofrin PDT, while lowering the risk of side effects significantly.

Experimental investigation of gravity effects on sediment sorting on Mars

NASA Astrophysics Data System (ADS)

Kuhn, Nikolaus J.; Kuhn, Brigitte; Gartmann, Andres

2016-04-01

Introduction: Sorting of sedimentary rocks is a proxy for the environmental conditions at the time of deposition, in particular the runoff that moved and deposited the material forming the rocks. Settling of sediment in water is strongly influenced by the gravity of a planetary body. As a consequence, sorting of a sedimentary rock varies with gravity for a given depth and velocity of surface runoff. Theoretical considerations for spheres indicate that sorting is more uniform on Mars than on Earth for runoff of identical depth. In reality, such considerations have to be applied with great caution because the shape of a particle strongly influences drag. Drag itself can only be calculated directly for an irregularly shaped particle with great computational effort, if at all. Therefore, even for terrestrial applications, sediment settling velocities are often determined directly, e.g. by measurements using settling tubes. Experiments: In this study the results of settling tube tests conducted under reduced gravity during three Mars Sedimentation Experiment (MarsSedEx I, II and III) flights, conducted between 2012 and 2015, are presented. Ten types of sediment, ranging in size, shape and density were tested in custom-designed settling tubes during parabolas of Martian gravity lasting 20 to 25 seconds. Results: The experiments conducted during the MarsSedEx reduced gravity experiments showed that the violation of fluid dynamics caused by using empirical models and parameter values developed for sediment transport on Earth lead to significant miscalculations for Mars, specifically an underetsimation of settling velcoity because of an overestimation of turbulant drag. The error is caused by the flawed representation of particle drag on Mars. Drag coefficients are not a property of a sediment particle, but a property of the flow around the particle, and thus strongly affected by gravity. Conlcusions: The observed errors in settling velocity when using terrestrial models and parameter values on Mars have implications for sediment movement and sorting, in particular for sandstones and conglomerates, and thus analogies drawn between Earth and Mars. Most significantly, sorting on Mars is less pronounced for given flow conditions than on Earth. References: [1] Kuhn N. J. (2014) Experiments in Reduced Gravity - Sediment Settling on Mars, Elsevier.

Stresses, deformation, and seismic events on scaled experimental faults with heterogeneous fault segments and comparison to numerical modeling

NASA Astrophysics Data System (ADS)

Buijze, Loes; Guo, Yanhuang; Niemeijer, André R.; Ma, Shengli; Spiers, Christopher J.

2017-04-01

Faults in the upper crust cross-cut many different lithologies, which cause the composition of the fault rocks to vary. Each different fault rock segment may have specific mechanical properties, e.g. there may be stronger and weaker segments, and segments prone to unstable slip or creeping. This leads to heterogeneous deformation and stresses along such faults, and a heterogeneous distribution of seismic events. We address the influence of fault variability on stress, deformation, and seismicity using a combination of scaled laboratory fault and numerical modeling. A vertical fault was created along the diagonal of a 30 x 20 x 5 cm block of PMMA, along which a 2 mm thick gouge layer was deposited. Gouge materials of different characteristics were used to create various segments along the fault; quartz (average strength, stable sliding), kaolinite (weak, stable sliding), and gypsum (average strength, unstable sliding). The sample assembly was placed in a horizontal biaxial deformation apparatus, and shear displacement was enforced along the vertical fault. Multiple observations were made: 1) Acoustic emissions were continuously recorded at 3 MHz to observe the occurrence of stick-slips (micro-seismicity), 2) Photo-elastic effects (indicative of the differential stress) were recorded in the transparent set of PMMA wall-rocks using a high-speed camera, and 3) particle tracking was conducted on a speckle painted set of PMMA wall-rocks to study the deformation in the wall-rocks flanking the fault. All three observation methods show how the heterogeneous fault gouge exerts a strong control on the fault behavior. For example, a strong, unstable segment of gypsum flanked by two weaker kaolinite segments show strong stress concentrations develop near the edges of the strong segment, with at the same time most of acoustic emissions being located at the edge of this strong segment. The measurements of differential stress, strain and acoustic emissions provide a strong means to compare the scaled experiment to modeling results. In a finite-element model we reproduce the laboratory experiments, and compare the modeled stresses and strains to the observations and we compare the nucleation of seismic instability to the location of acoustic emissions. The model aids in understanding how the stresses and strains may vary as a result of fault heterogeneity, but also as a result of the boundary conditions inherent to a laboratory setup. The scaled experimental setup and modeling results also provide a means explain and compare with observations made at a larger scale, for example geodetic and seismological measurements along crustal scale faults.

Wave Tank Studies of Strong Modulation of Wind Ripples Due To Long Waves

NASA Astrophysics Data System (ADS)

Ermakov, S.; Sergievskaya, I.; Shchegolkov, Yu.

Modulation of wind capillary-gravity ripples due to long waves has been studied in wave tank experiment at low wind speeds using Ka-band radar. The experiments were carried out both for clean water and the water surface covered with surfactant films. It is obtained that the modulation of radar signals is quite strong and can increase with surfactant concentration and fetch. It is shown that the hydrodynamic Modulation Transfer Function (MTF) calculated for free wind ripples and taking into account the kinematic (straining) effect, variations of the wind stress and variations of surfactant concentration strongly underestimates experimental MTF-values. The effect of strong modulation is assumed to be connected with nonlinear harmonics of longer dm-cm- scale waves - bound waves ("parasitic ripples"). The intensity of bound waves depends strongly on the amplitude of decimetre-scale waves, therefore even weak modulation of the dm-scale waves due to long waves results to strong ("cascade") modulation of bound waves. Modulation of the system of "free/bound waves" is estimated using results of wave tank studies of bound waves generation and is shown to be in quali- tative agreement with experiment. This work was supported by MOD, UK via DERA Winfrith (Project ISTC 1774P) and by RFBR (Project 02-05-65102).

Pupillary Responses to Static Images of Men and Women: A Possible Measure of Sexual Interest?

PubMed

Snowden, Robert J; McKinnon, Aimee; Fitoussi, Julie; Gray, Nicola S

2017-12-08

The pupil dilates to images that are arousing. In Experiment 1, we examined if the pupil's response to brief presentations (2,000 ms) of static images could be used to identify individuals' sexual orientation. Participants were grouped according to their self-reported gender and sexual orientation (male heterosexual, N = 20; male bisexual, N = 13; male homosexual, N = 19; female heterosexual, N = 28; female bisexual, N = 21; female homosexual, N = 17). Pupil size was monitored to images of men in seminude poses, women in seminude poses, or neutral images. Every group showed the same pattern of responses, with the greatest dilation to male images, then female images, and least dilation to the neutral images. Experiment 2 used more tightly controlled stimuli and tested at two different image durations (150 and 3,000 ms). Both heterosexual men (N = 18) and women (N = 20) showed greater pupil dilation to images of nude men than to nude women. However, in Experiment 3, where we reduced the erotic content by using images of clothed models, both heterosexual men and women showed greater pupil dilation to images of women. The results showed that while the pupil does dilate strongly to sexual imagery, its response to these brief static images does not correspond to a person's sexual orientation in a simple manner.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kholmetskii, Alexander L., E-mail: alkholmetskii@gmail.com; Yarman, Tolga; Yarman, Ozan

We show that a new attempt by Corda (2016), just like his previous attempt (Corda, 2015) that we had answered before (A.L. Kholmetskii et al., 2015), to reinterpret Mössbauer experiments in a rotating system as a “new, strong and independent proof of the correctness of Einstein’s vision of gravity” is erroneous. In addition, we demonstrate that Corda’s criticism of Yarman–Arik–Kholmetskii gravitation theory (in short YARK), is based on the application of ill-posed logic; thus rendering his claims against YARK as unfounded.

Wavelength-Dependence on the Initiation of Iron-Based Photoactive Explosives

NASA Astrophysics Data System (ADS)

Brown, Kathryn; Myers, Thomas; Clarke, Steven

2017-06-01

Photoactive explosives show promise to be relatively insensitive to impact and friction compared to PETN and other detonator materials, but can be more easily initiated with laser light. Metal-ligand charge transfer (MLCT) complexes have been shown to have tunable explosive properties and absorption profiles, making them strong candidates for laser detonator material. Here, we discuss the synthesis and characterization of several iron-based MLCT complexes, as well as results from recent experiments on their sensitivity to initiation from different wavelengths of laser light.

Orientation influence on grain size-effects in ultrafine-grained magnesium

DOE PAGES

Fan, Haidong; Aubry, Sylvie; Arsenlis, A.; ...

2014-11-08

The mechanical behavior of ultrafine-grained magnesium was studied by discrete dislocation dynamics (DDD) simulations. Our results show basal slip yields a strong size effect, while prismatic and pyramidal slips produce a weak one. We developed a new size-strength model that considers dislocation transmission across grain boundaries. Good agreement between this model, current DDD simulations and previous experiments is observed. These results reveal that the grain size effect depends on 3 factors: Peierls stress, dislocation source strength and grain boundary strength.

Superpropulsion of Droplets and Soft Elastic Solids

NASA Astrophysics Data System (ADS)

Raufaste, Christophe; Chagas, Gabriela Ramos; Darmanin, Thierry; Claudet, Cyrille; Guittard, Frédéric; Celestini, Franck

2017-09-01

We investigate the behavior of droplets and soft elastic objects propelled with a catapult. Experiments show that the ejection velocity depends on both the projectile deformation and the catapult acceleration dynamics. With a subtle matching given by a peculiar value of the projectile/catapult frequency ratio, a 250% kinetic energy gain is obtained as compared to the propulsion of a rigid projectile with the same engine. This superpropulsion has strong potentialities: actuation of droplets, sorting of objects according to their elastic properties, and energy saving for propulsion engines.

Description of Contaminant Sediment-Water Interactions Using RECOVERY

DTIC Science & Technology

1993-04-01

organic carbon) ( Hamaker and Thompson 1972). Table 2 L Values for Each Contaminant Sediment FonnFIIaDtlfP 1 Mark Twain 9.25 x 107 1.37 x 10’ 9.25 x...Results from this study and previous studies conducted by Gunnison et al. (1991) showed that organic and inorganic contaminants are strongly bound to the...Waterways Experiment Station, Vicksburg, MS. Hamaker , J. W., and Thompson, J. M. 1972. "Adsorption," In Organic Chemicals in the Soil Environment. C. A. I

13 CFR 301.8 - Application evaluation criteria.

Code of Federal Regulations, 2013 CFR

2013-01-01

... private sector investment resulting from an Investment. (b) Has strong organizational leadership. An Investment will have strong leadership, relevant Project management experience and a significant commitment... leadership and support by local elected officials; and (3) Strong cooperation among the business sector...

13 CFR 301.8 - Application evaluation criteria.

Code of Federal Regulations, 2014 CFR

2014-01-01

... private sector investment resulting from an Investment. (b) Has strong organizational leadership. An Investment will have strong leadership, relevant Project management experience and a significant commitment... leadership and support by local elected officials; and (3) Strong cooperation among the business sector...

13 CFR 301.8 - Application evaluation criteria.

Code of Federal Regulations, 2012 CFR

2012-01-01

... private sector investment resulting from an Investment. (b) Has strong organizational leadership. An Investment will have strong leadership, relevant Project management experience and a significant commitment... leadership and support by local elected officials; and (3) Strong cooperation among the business sector...

Antimicrobial activity and stability of protonectin with D-amino acid substitutions.

PubMed

Qiu, Shuai; Zhu, Ranran; Zhao, Yanyan; An, Xiaoping; Jia, Fengjing; Peng, Jinxiu; Ma, Zelin; Zhu, Yuanyuan; Wang, Jiayi; Su, Jinhuan; Wang, Qingjun; Wang, Hailin; Li, Yuan; Wang, Kairong; Yan, Wenjin; Wang, Rui

2017-05-01

The misuse and overuse of antibiotics result in the emergence of resistant bacteria and fungi, which make an urgent need of the new antimicrobial agents. Nowadays, antimicrobial peptides have attracted great attention of researchers. However, the low physiological stability in biological system limits the application of naturally occurring antimicrobial peptides as novel therapeutics. In the present study, we synthesized derivatives of protonectin by substituting all the amino acid residues or the cationic lysine residue with the corresponding D-amino acids. Both the D-enantiomer of protonectin (D-prt) and D-Lys-protonectin (D-Lys-prt) exhibited strong antimicrobial activity against bacteria and fungi. Moreover, D-prt showed strong stability against trypsin, chymotrypsin and the human serum, while D-Lys-prt only showed strong stability against trypsin. Circular dichroism analysis revealed that D-Lys-prt still kept typical α-helical structure in the membrane mimicking environment, while D-prt showed left hand α-helical structure. In addition, propidium iodide uptake assay and bacteria and fungi killing experiments indicated that all D-amino acid substitution or partially D-amino acid substitution analogs could disrupt the integrity of membrane and lead the cell death. In summary, these findings suggested that D-prt and D-Lys-prt might be promising candidate antibiotic agents for therapeutic application against resistant bacteria and fungi infection. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

Assessment of the simulation of Indian Ocean Dipole in the CESM—Impacts of atmospheric physics and model resolution

NASA Astrophysics Data System (ADS)

Yao, Zhixiong; Tang, Youmin; Chen, Dake; Zhou, Lei; Li, Xiaojing; Lian, Tao; Ul Islam, Siraj

2016-12-01

This study examines the possible impacts of coupling processes on simulations of the Indian Ocean Dipole (IOD). Emphasis is placed on the atmospheric model resolution and physics. Five experiments were conducted for this purpose, including one control run of the ocean-only model, four coupled experiments using two different versions of the Community Atmosphere Model (CAM4 and CAM5) and two different resolutions. The results show that the control run could effectively simulate various features of the IOD. The coupled experiments run at the higher resolution yielded more realistic IOD period and intensity than their counterparts at the low resolution. The coupled experiments using CAM5 generally showed a better simulation skill in the tropical Indian SST climatology and phase-locking than those using CAM4, but the wind anomalies were stronger and the IOD period were longer in the former experiments than in the latter. In all coupled experiments, the IOD intensity was much stronger than the observed intensity, which is attributable to wind-thermocline depth feedback and thermocline depth-subsurface temperature feedback. The CAM5 physics seems beneficial for the simulation of summer rainfall over the eastern equatorial Indian Ocean and the CAM4 physics tends to produce less biases over the western equatorial Indian Ocean, whereas the higher resolution tends to generate unrealistically strong meridional winds. The IOD-ENSO relationship was captured reasonably well in coupled experiments, with improvements in CAM5 relative to CAM4. However, the teleconnection of the IOD-Indian summer monsoon and ENSO-Indian summer monsoon was not realistically simulated in all experiments.

Dynamic heterogeneity in crossover spin facilitated model of supercooled liquid and fractional Stokes-Einstein relation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Seo-Woo; Kim, Soree; Jung, YounJoon, E-mail: yjjung@snu.ac.kr

Kinetically constrained models have gained much interest as models that assign the origins of interesting dynamic properties of supercooled liquids to dynamical facilitation mechanisms that have been revealed in many experiments and numerical simulations. In this work, we investigate the dynamic heterogeneity in the fragile-to-strong liquid via Monte Carlo method using the model that linearly interpolates between the strong liquid-like behavior and the fragile liquid-like behavior by an asymmetry parameter b. When the asymmetry parameter is sufficiently small, smooth fragile-to-strong transition is observed both in the relaxation time and the diffusion constant. Using these physical quantities, we investigate fractional Stokes-Einsteinmore » relations observed in this model. When b is fixed, the system shows constant power law exponent under the temperature change, and the exponent has the value between that of the Frederickson-Andersen model and the East model. Furthermore, we investigate the dynamic length scale of our systems and also find the crossover relation between the relaxation time. We ascribe the competition between energetically favored symmetric relaxation mechanism and entropically favored asymmetric relaxation mechanism to the fragile-to-strong crossover behavior.« less

Experimental study on the fire protection properties of PVC sheath for old and new cables.

PubMed

Xie, Qiyuan; Zhang, Heping; Tong, Lin

2010-07-15

The objective of the present study is to analyze the fire protection properties of old and new cables through TG, FTIR and MCC experiments. The results show that the mass loss of old cable sheath is clearly larger than the new one when the temperature is higher than 550 K in air or nitrogen atmosphere. It suggests that the old cable sheath starts to pyrolyze generally at the same temperature based on the analysis of the onset temperatures of mass loss. The results also show that there is a main peak DTG for the old and new cable sheath under each condition. However, the main peak DTG of old cable sheath is larger than that of the new cable sheath, especially in air atmosphere. The FTIR experiments show that the HCl is released by the new cable later but more quickly than the old cable. The MCC experiments suggest that compared with the new one, the peak heat release rate is larger for the old cable. It illustrates that the old cable sheath generally pyrolyzes and combusts more strongly and completely than the new one. Namely, the fire protection properties of the old cable in old buildings are relatively weak. 2010 Elsevier B.V. All rights reserved.

"Words So Strong": Maxine Hong Kingston's "No Name Woman" Introduces Students to the Power of Words.

ERIC Educational Resources Information Center

Petit, Angela

2003-01-01

Presents a powerful story that helps students to realize that words can order the world around them and form realities of their own. Attempts to capture the rich reading experiences that Kingston's "No Name Woman" offers to students developing an understanding of words so strong. Concludes that reflecting on Kingston's experiences,…

The total ozone and UV solar radiation over Stara Zagora, Bulgaria

NASA Astrophysics Data System (ADS)

Mendeva, B. D.; Gogosheva, Ts. N.; Petkov, B. H.; Krastev, D. G.

The results from direct ground-based solar UV irradiance measurements and the total ozone content (TOC) over Stara Zagora (42° 25'N, 25° 37'E), Bulgaria are presented. During the period 1999-2003 the TOC data show seasonal variations, typical for the middle latitudes - maximum in the spring and minimum in the autumn. The comparison between TOC ground-based data and Global Ozone Monitoring Experiment (GOME) satellite-borne ones shows a seasonal dependence of the differences between them. A strong negative relationship between the total ozone and the 305 nm wavelength irradiance was found. The dependence between the two variables is significant ( r = -0.62 ± 0.18) at 98% confidence level. The direct sun UV doses for some specific biological effects (erythema and eyes) are obtained. The estimation of the radiation amplification factor RAF shows that the ozone reduction by 1% increases the erythemal dose by 2.3%. The eye-damaging doses are more influenced by the TOC changes and in this case RAF = -2.7%. The amount of these biological doses depended on the solar altitude over the horizon. This dependence was not so strong when the total ozone content in the atmosphere was lower.

Influence of temperature on the aging behavior of 18650-type lithium ion cells: A comprehensive approach combining electrochemical characterization and post-mortem analysis

NASA Astrophysics Data System (ADS)

Friesen, Alex; Mönnighoff, Xaver; Börner, Markus; Haetge, Jan; Schappacher, Falko M.; Winter, Martin

2017-02-01

The understanding of the aging behavior of lithium ion batteries in automotive and energy storage applications is essential for the acceptance of the technology. Therefore, aging experiments were conducted on commercial 18650-type state-of-the-art cells to determine the influence of the temperature during electrochemical cycling on the aging behavior of the different cell components. The cells, based on Li(Ni0.5Co0.2Mn0.3)O2 (NCM532)/graphite, were aged at 20 °C and 45 °C to different states of health. The electrochemical performance of the investigated cells shows remarkable differences depending on the cycling temperature. At contrast to the expected behavior, the cells cycled at 45 °C show a better electrochemical performance over lifetime than the cells cycled at 20 °C. Comprehensive post-mortem analyses revealed the main aging mechanisms, showing a complex interaction between electrodes and electrolyte. The main aging mechanisms of the cells cycled at 45 °C differ strongly at contrast to cells cycled at 20 °C. A strong correlation between the formed SEI, the electrolyte composition and the electrochemical performance over lifetime was observed.

Particle transport in low-collisionality H-mode plasmas on DIII-D

DOE PAGES

Mordijck, Saskia; Wang, Xin; Doyle, Edward J.; ...

2015-10-05

In this article we show that changing from an ion temperature gradient (ITG) to trapped electron mode (TEM) dominant turbulence regime (based on linear gyrokinetic simulations) results experimentally in a strong density pump-out (defined as a reduction in line-averaged density) in low collisionality, low power H-mode plasmas. We vary the turbulence drive by changing the heating from pre-dominantly ion heatedusing neutral beam injection to electron heated using electron cyclotron heating, which changes the T e/T i ratio and the temperature gradients. Perturbed gas puff experiments show an increase in transport outside ρ = 0.6, through a strong increase in themore » perturbed diffusion coefficient and a decrease in the inward pinch. Linear gyrokinetic simulations with TGLF show an increase in the particle flux outside the mid-radius. In conjunction an increase in intermediate-scale length density fluctuations is observed, which indicates an increase in turbulence intensity at typical TEM wavelengths. However, although the experimental changes in particle transport agree with a change from ITG to TEM turbulence regimes, we do not observe a reduction in the core rotation at mid-radius, nor a rotation reversal.« less

Ca(2+) -complex stability of GAPAGPLIVPY peptide in gas and aqueous phase, investigated by affinity capillary electrophoresis and molecular dynamics simulations and compared to mass spectrometric results.

PubMed

Nachbar, Markus; El Deeb, Sami; Mozafari, Mona; Alhazmi, Hassan A; Preu, Lutz; Redweik, Sabine; Lehmann, Wolf Dieter; Wätzig, Hermann

2016-03-01

Strong, sequence-specific gas-phase bindings between proline-rich peptides and alkaline earth metal ions in nanoESI-MS experiments were reported by Lehmann et al. (Rapid Commun. Mass Spectrom. 2006, 20, 2404-2410), however its relevance for physiological-like aqueous phase is uncertain. Therefore, the complexes should also be studied in aqueous solution and the relevance of the MS method for binding studies be evaluated. A mobility shift ACE method was used for determining the binding between the small peptide GAPAGPLIVPY and various metal ions in aqueous solution. The findings were compared to the MS results and further explained using computational methods. While the MS data showed a strong alkaline earth ion binding, the ACE results showed nonsignificant binding. The proposed vacuum state complex also decomposed during a molecular dynamic simulation in aqueous solution. This study shows that the formed stable peptide-metal ion adducts in the gas phase by ESI-MS does not imply the existence of analogous adducts in the aqueous phase. Comparing peptide-metal ion interaction under the gaseous MS and aqueous ACE conditions showed huge difference in binding behavior. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Achievement goals affect metacognitive judgments

PubMed Central

Ikeda, Kenji; Yue, Carole L.; Murayama, Kou; Castel, Alan D.

2017-01-01

The present study examined the effect of achievement goals on metacognitive judgments, such as judgments of learning (JOLs) and metacomprehension judgments, and actual recall performance. We conducted five experiments manipulating the instruction of achievement goals. In each experiment, participants were instructed to adopt mastery-approach goals (i.e., develop their own mental ability through a memory task) or performance-approach goals (i.e., demonstrate their strong memory ability through getting a high score on a memory task). The results of Experiments 1 and 2 showed that JOLs of word pairs in the performance-approach goal condition tended to be higher than those in the mastery-approach goal condition. In contrast, cued recall performance did not differ between the two goal conditions. Experiment 3 also demonstrated that metacomprehension judgments of text passages were higher in the performance-approach goal condition than in the mastery-approach goals condition, whereas test performance did not differ between conditions. These findings suggest that achievement motivation affects metacognitive judgments during learning, even when achievement motivation does not influence actual performance. PMID:28983496

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, D. S.; Milovich, J. L.; Hinkel, D. E.

Recent experimental results using the “high foot” pulse shape for inertial confinement fusion ignition experiments on the National Ignition Facility (NIF) [Moses et al., Phys. Plasmas 16, 041006 (2009)] have shown encouraging progress compared to earlier “low foot” experiments. These results strongly suggest that controlling ablation front instability growth can significantly improve implosion performance even in the presence of persistent, large, low-mode distortions. Simultaneously, hydrodynamic growth radiography experiments have confirmed that ablation front instability growth is being modeled fairly well in NIF experiments. It is timely then to combine these two results and ask how current ignition pulse shapes couldmore » be modified to improve one-dimensional implosion performance while maintaining the stability properties demonstrated with the high foot. This paper presents such a survey of pulse shapes intermediate between the low and high foot extremes in search of an intermediate foot optimum. Of the design space surveyed, it is found that a higher picket version of the low foot pulse shape shows the most promise for improved compression without loss of stability.« less

Parental experiences of racial discrimination and youth racial socialization in two-parent African American families.

PubMed

McNeil Smith, Shardé; Reynolds, Jamila E; Fincham, Frank D; Beach, Steven R H

2016-04-01

Parents experiencing racial discrimination are likely to transmit racial socialization messages to their children to protect them from future injustices. This study was conducted to better understand the role of parents' racial discrimination in their racial socialization practices for 2-parent African American families. Using a sample from the Promoting Strong African American Families (N = 322 couples) program, we examined the effects of experienced discrimination on one's own and one's partner's racial socialization practices with male (n = 154) and female (n = 168) offspring. Multiple-group actor-partner interdependence models showed that racial discrimination was associated with racial socialization practices. In addition, maternal experiences of discrimination had stronger relations to socialization messages relayed to daughters and greater paternal experiences of discrimination had stronger relations to socialization messages given to sons. This study demonstrates variability in how male and female children in African American families are socialized as a result of their parents' experiences with racial discrimination. (c) 2016 APA, all rights reserved).

Holographic Floquet states I: a strongly coupled Weyl semimetal

NASA Astrophysics Data System (ADS)

Hashimoto, Koji; Kinoshita, Shunichiro; Murata, Keiju; Oka, Takashi

2017-05-01

Floquet states can be realized in quantum systems driven by continuous time-periodic perturbations. It is known that a state known as the Floquet Weyl semimetal can be realized when free Dirac fermions are placed in a rotating electric field. What will happen if strong interaction is introduced to this system? Will the interaction wash out the characteristic features of Weyl semimetals such as the Hall response? Is there a steady state and what is its thermodynamic behavior? We answer these questions using AdS/CFT correspondence in the N = 2 supersymmetric massless QCD in a rotating electric field in the large N c limit realizing the first example of a "holographic Floquet state". In this limit, gluons not only mediate interaction, but also act as an energy reservoir and stabilize the nonequilibrium steady state (NESS). We obtain the electric current induced by a rotating electric field: in the high frequency region, the Ohm's law is satisfied, while we recover the DC nonlinear conductivity at low frequency, which was obtained holographically in a previous work. The thermodynamic properties of the NESS, e.g., fluctuation-dissipation relation, is characterized by the effective Hawking temperature that is defined from the effective horizon giving a holographic meaning to the "periodic thermodynamic" concept. In addition to the strong (pump) rotating electric field, we apply an additional weak (probe) electric field in the spirit of the pump-probe experiments done in condensed matter experiments. Weak DC and AC probe analysis in the background rotating electric field shows Hall currents as a linear response, therefore the Hall response of Floquet Weyl semimetals survives at the strong coupling limit. We also find frequency mixed response currents, i.e., a heterodyning effect, characteristic to periodically driven Floquet systems.

Overview of the Frontal Air-Sea Interaction Experiment (FASINEX) - A study of air-sea interaction in a region of strong oceanic gradients

NASA Technical Reports Server (NTRS)

Weller, Robert A.

1991-01-01

From 1984 to 1986 the cooperative Frontal Air-Sea Interaction Experiment (FASINEX) was conducted in the subtropical convergence zone southwest of Bermuda. The overall objective of the experiment was to study air-sea interaction on 1- to 100-km horizontal scales in a region of the open ocean characterized by strong horizontal gradients in upper ocean and sea surface properties. Ocean fronts provided both large spatial gradients in sea surface temperature and strong jetlike flows in the upper ocean. The motivation for and detailed objectives of FASINEX are reviewed. Then the components of the field program are summarized. Finally, selected results are presented in order to provide an overview of the outcome of FASINEX.

Elucidating the Structure-Reactivity Correlations of Phenothiazine-Based Fluorescent Probes toward ClO.

PubMed

Wang, Shichao; Zhang, Boyu; Wang, Wenjing; Feng, Gang; Yuan, Daqiang; Zhang, Xuanjun

2018-06-07

In this work, with the aim of developing effective molecular probes and investigating the structure-reactivity correlation, a short series of phenothiazine-based fluorescent probes are designed for the detection of ClO - with differing electron push-pull groups. Sensing experiment results and single-crystal X-ray analysis with the aid of time-dependent DFT (TD-DFT) calculations reveal that substituting groups with increasing electron-withdrawing ability can increase the dihedral angle of the phenothiazine moiety and reduce the gap energy of the probes, leading to enhanced reactivity toward ClO - . Both PT1 and PT2 show two-color switching upon detection of ClO - . PT1, with the strong electron-donating group thiophene, shows a fluorescence color switch from salmon to blue. PT2, with a medium electron-donating/accepting group benzothiazole, shows a fluorescence color switch from red to green. However, both PT1 and PT2 show almost no response to ONOO - . Through the introduction of strong electron-withdrawing ketone combined with a cyano group, PT3 shows a cyan emission upon detection of ClO - and weak red emission upon detection of ONOO - . HRMS and 1 H NMR results confirm that PT1 and PT2 have the same sensing mode, in which the divalent sulfur of phenothiazine can be oxidized to sulfoxide by ClO - . Upon reaction with ClO - , PT3 experiences two-step reactions. It is first oxidized into the sulfone structure by ClO - , and then transformed into sulfoxide phenothiazine aldehyde. Upon encountering ONOO - , PT3 changes into an aldehyde structure and some nonfluorescent byproducts. Owing to their special selectivity and high sensitivity, PT1 and PT2 are applied to image the endogenous ClO - in macrophage cells and zebrafish larvae. This study is expected to provide useful guidelines for probe design for various applications. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Behavioral immune system and ingroup derogation: the effects of infectious diseases on ingroup derogation attitudes.

PubMed

Wu, Qi; Tan, Chuan; Wang, Bo; Zhou, Ping

2015-01-01

From evolutionary reasoning, we derived a novel hypothesis that ingroup derogation is an evolved response of behavioral immune system which follows the smoke detector principle and the functional flexibility principle. This hypothesis was tested and supported across three experiments. In Experiment 1, participants' group membership was manipulated by using a minimal group paradigm. The results indicated that mere social categorization alone - a heuristic cue that implies the differentiation between "us" and "them" - was sufficient to elicit ingroup derogation among Chinese participants, and, such an intergroup bias was positively associated with the perceived vulnerability to diseases, which was also more consistently associated with ingroup attitudes. Experiment 2 extended and partially replicated Experiment 1 by showing that when there were cues of diseases in the immediate physical environment, Chinese participants exaggerated their attitudes of ingroup derogation. The results also showed that this effect was mainly driven by outgroup attraction. Experiment 3 changed the method of disease manipulation, and found that Chinese participants responded more strongly to disease cues originating from ingroup members and that they endorsed more ingroup derogation attitudes even when the ingroup and outgroup members were both displaying cues of diseases. Taken together, these results reveal the previously unexplored effects of infectious diseases on ingroup derogation attitudes, and suggest an interesting linkage between the evolved behavioral immune system and the ingroup derogation.

Borderline Personality Features in Students: the Predicting Role of Schema, Emotion Regulation, Dissociative Experience and Suicidal Ideation.

PubMed

Sajadi, Seyede Fateme; Arshadi, Nasrin; Zargar, Yadolla; Mehrabizade Honarmand, Mahnaz; Hajjari, Zahra

2015-06-01

Numerous studies have demonstrated that early maladaptive schemas, emotional dysregulation are supposed to be the defining core of borderline personality disorder. Many studies have also found a strong association between the diagnosis of borderline personality and the occurrence of suicide ideation and dissociative symptoms. The present study was designed to investigate the relationship between borderline personality features and schema, emotion regulation, dissociative experiences and suicidal ideation among high school students in Shiraz City, Iran. In this descriptive correlational study, 300 students (150 boys and 150 girls) were selected from the high schools in Shiraz, Iran, using the multi-stage random sampling. Data were collected using some instruments including borderline personality feature scale for children, young schema questionnaire-short form, difficulties in emotion-regulation scale (DERS), dissociative experience scale and beck suicide ideation scale. Data were analyzed using the Pearson correlation coefficient and multivariate regression analysis. The results showed a significant positive correlation between schema, emotion regulation, dissociative experiences and suicide ideation with borderline personality features. Moreover, the results of multivariate regression analysis suggested that among the studied variables, schema was the most effective predicting variable of borderline features (P < 0.001). The findings of this study are in accordance with findings from previous studies, and generally show a meaningful association between schema, emotion regulation, dissociative experiences, and suicide ideation with borderline personality features.

The risk of male adult alcohol dependence: The role of the adverse childhood experiences and ecological executive function.

PubMed

Liu, Zengxun; Yang, Ying; Shi, Zhenchun; Liu, Jintong; Wang, Yang

2016-07-01

To explore the association between male adult alcohol dependence and their adverse childhood experiences as well as ecological executive function. The questionnaires of Adverse Childhood Experiences (ACEs) and Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) were adopted for the assessments of 102 alcohol dependent patients who were diagnosed according to the criteria defined by the International Classification of diseases and related health problems (ICD-10) and 106 healthy volunteers, and the differences between patients and healthy volunteers were analyzed. The percentage of adverse childhood experiences in alcohol dependent patients was significantly higher than that in healthy volunteers (χ(2)=17.28, P<0.01); and the incidences of emotional abuse, physical neglect, violence witness, and substance abuse were significantly higher in alcohol dependent patients than those in healthy volunteers (χ(2)=4.59, 4.46, 10.51, and 44.09 respectively; P<0.05). The ecological executive function analysis showed that the BRIEF total score and scores for each item were all significantly higher in alcohol dependent patients than those of healthy volunteers (P<0.01). The adult alcohol dependence was associated with their adverse childhood experiences and ecological executive function. Then physical neglect and substance abuse of parents in childhood, and emotional control defect in the ecological executive function showed strong association with adult alcohol dependence. Copyright © 2016 Elsevier Inc. All rights reserved.

Investigation of the S1/ICT equilibrium in fucoxanthin by ultrafast pump-dump-probe and femtosecond stimulated Raman scattering spectroscopy.

PubMed

Redeckas, Kipras; Voiciuk, Vladislava; Vengris, Mikas

2016-05-01

Time-resolved multi-pulse spectroscopic methods-pump-dump-probe (PDP) and femtosecond stimulated Raman spectroscopy-were used to investigate the excited state photodynamics of the carbonyl group containing carotenoid fucoxanthin (FX). PDP experiments show that S1 and ICT states in FX are strongly coupled and that the interstate equilibrium is rapidly (<5 ps) reestablished after one of the interacting states is deliberately depopulated. Femtosecond stimulated Raman scattering experiments indicate that S1 and ICT are vibrationally distinct species. Identification of the FSRS modes on the S1 and ICT potential energy surfaces allows us to predict a possible coupling channel for the state interaction.

Study on effect of microparticle's size on cavitation erosion in solid-liquid system

NASA Astrophysics Data System (ADS)

Chen, Haosheng; Liu, Shihan; Wang, Jiadao; Chen, Darong

2007-05-01

Five different solutions containing microparticles in different sizes were tested in a vibration cavitation erosion experiment. After the experiment, the number of erosion pits on sample surfaces, free radicals HO• in solutions, and mass loss all show that the cavitation erosion strength is strongly related to the particle size, and 500nm particles cause more severe cavitation erosion than other smaller or larger particles do. A model is presented to explain such result considering both nucleation and bubble-particle collision effects. Particle of a proper size will increase the number of heterogeneous nucleation and at the same time reduce the number of bubble-particle combinations, which results in more free bubbles in the solution to generate stronger cavitation erosion.

Ar 3p photoelectron sideband spectra in two-color XUV + NIR laser fields

NASA Astrophysics Data System (ADS)

Minemoto, Shinichirou; Shimada, Hiroyuki; Komatsu, Kazma; Komatsubara, Wataru; Majima, Takuya; Mizuno, Tomoya; Owada, Shigeki; Sakai, Hirofumi; Togashi, Tadashi; Yoshida, Shintaro; Yabashi, Makina; Yagishita, Akira

2018-04-01

We performed photoelectron spectroscopy using femtosecond XUV pulses from a free-electron laser and femtosecond near-infrared pulses from a synchronized laser, and succeeded in measuring Ar 3p photoelectron sideband spectra due to the two-color above-threshold ionization. In our calculations of the first-order time-dependent perturbation theoretical model based on the strong field approximation, the photoelectron sideband spectra and their angular distributions are well reproduced by considering the timing jitter between the XUV and the NIR pulses, showing that the timing jitter in our experiments was distributed over the width of {1.0}+0.4-0.2 ps. The present approach can be used as a method to evaluate the timing jitter inevitable in FEL experiments.

Decentralized control experiments on the JPL flexible spacecraft

NASA Technical Reports Server (NTRS)

Ozguner, U.; Ossman, K.; Donne, J.; Boesch, M.; Ahmed, A.

1990-01-01

Decentralized control experiments were successfully demonstrated for the JPL/AFAL Flexible Structure. A simulation package using MATRIXx showed strong correlation between the simulations and experimental result, while providing a means for test and debug of the various control strategies. Implementation was simplified by a modular software design that was easily transported from the simulation environment to the experimental environment. Control designs worked well for suppression of the dominant modes of the structure. Static decentralized output feedback dampened the excited modes of the structure, but sometimes excited higher order modes upon startup of the controller. A second-order frequency shaping controller helped to eliminate excitation of the higher order modes by attenuating high frequencies in the control effort. However, it also resulted in slightly longer settling times.

Adult fruit fly attraction to larvae biases experience and mediates social learning.

PubMed

Durisko, Zachary; Anderson, Blake; Dukas, Reuven

2014-04-01

We investigated whether adult fruit flies (Drosophila melanogaster) use cues of larvae as social information in their food patch choice decisions. Adult male and female fruit flies showed attraction to odours emanating from foraging larvae, and females preferred to lay eggs on food patches occupied by larvae over similar unoccupied patches. Females learned and subsequently preferred to lay eggs at patches with novel flavours previously associated with feeding larvae over patches with novel flavours previously associated with no larvae. However, when we controlled for the duration of exposure to each flavoured patch, females no longer preferred the flavour previously associated with feeding larvae. This suggests that social learning in this context is indirect, as a result of strong social attraction biasing experience.

Stereotype Strength and Attentional Bias: Preference for Confirming versus Disconfirming Information Depends on Processing Capacity

PubMed Central

Allen, Thomas J.; Sherman, Jeffrey W.; Conrey, Frederica R.; Stroessner, Steven J.

2009-01-01

In two experiments, we investigated the relationships among stereotype strength, processing capacity, and the allocation of attention to stereotype-consistent versus stereotype-inconsistent information describing a target person. The results of both experiments showed that, with full capacity, greater stereotype strength was associated with increased attention toward stereotype-consistent versus stereotype-inconsistent information. However, when capacity was diminished, greater stereotype strength was associated with increased attention toward inconsistent versus consistent information. Thus, strong stereotypes may act as self-confirming filters when processing capacity is plentiful, but as efficient information gathering devices that maximize the acquisition of novel (disconfirming) information when capacity is depleted. Implications for models of stereotyping and stereotype change are discussed. PMID:20161043

Does eating good-tasting food influence body weight?

PubMed

Tordoff, Michael G; Pearson, Jordan A; Ellis, Hillary T; Poole, Rachel L

2017-03-01

Does eating good-tasting food influence body weight? To investigate, we first established some concentrations of sucralose and mineral oil in chow that mice strongly preferred. Then, in Experiment 1, we compared groups of 16 mice fed plain chow (i.e., chow with no additives) to groups fed chow with added (a) sucralose, (b) mineral oil, (c) sucralose and mineral oil, or (d) sucralose on odd days and mineral oil on even days. During a 6-week test, the body weights and body compositions of the five groups never differed. In Experiment 2, we compared groups of 18 mice fed plain chow or plain high-fat diet to groups fed these diets with added sucralose. During a 9-week test, the high-fat diet caused weight gain, but the body weights of mice fed the sucralose-sweetened diets did not differ from those fed the corresponding plain versions. Two-cup choice tests conducted at the end of each experiment showed persisting strong preferences for the diets with added sucralose and/or mineral oil. In concert with earlier work, our results challenge the hypothesis that the orosensory properties of a food influence body weight gain. A good taste can stimulate food intake acutely, and guide selection toward nutrient-dense foods that cause weight gain, but it does not determine how much is eaten chronically. Copyright © 2016 Elsevier Inc. All rights reserved.

Does eating good-tasting food influence body weight?

PubMed Central

Tordoff, Michael G.; Pearson, Jordan A.; Ellis, Hillary T.; Poole, Rachel L.

2016-01-01

Does eating good-tasting food influence body weight? To investigate, we first established some concentrations of sucralose and mineral oil in chow that mice strongly preferred. Then, in Experiment 1, we compared groups of 16 mice fed plain chow (i.e., chow with no additives) to groups fed chow with added (a) sucralose, (b) mineral oil, (c) sucralose and mineral oil, or (d) sucralose on odd days and mineral oil on even days. During a 6-week test, the body weights and body compositions of the five groups never differed. In Experiment 2, we compared groups of 18 mice fed plain chow or plain high-fat diet to groups fed these diets with added sucralose. During a 9-week test, the high-fat diet caused weight gain, but the body weights of mice fed the sucralose-sweetened diets did not differ from those fed the corresponding plain versions. Two-cup choice tests conducted at the end of each experiment showed persisting strong preferences for the diets with added sucralose and/or mineral oil. In concert with earlier work, our results challenge the hypothesis that the orosensory properties of a food influence body weight gain. A good taste can stimulate food intake acutely, and guide selection toward nutrient-dense foods that cause weight gain, but it does not determine how much is eaten chronically. PMID:27988248

A new investigation on the water isotopes in the Badain Jaran Desert, China, for inferring water origination

NASA Astrophysics Data System (ADS)

Wu, X.; Wang, Y.; Wang, X. S.; Hu, B.

2017-12-01

Stable isotope δ2H, δ18O and d-excess values of water have previously been used to study the hydraulic connection of groundwater between the surrounding areas such as Heihe River Basin, Qilian Mountain and the Badain Jaran desert (BJD), China. We choose to focus on the effects of strong evaporation on the isotopic characteristics of water in the desert to better understand the origin of water in the BJD. A series of evaporation experiments were conducted in the desert to examine how it may change during evaporation and infiltration under local environmental conditions. Evaporation from open water was monitored in two experiments using local groundwater and lake water, respectively. And evaporation of soil water was observed in three pits which were excavated to different depths below a flat ground surface to install the evaporation-infiltration systems. Water samples were also collected from lakes, a spring and local unconfined aquifer for analyses of stable hydrogen and oxygen isotope ratios, and d-excess values in the BJD. The results show that water isotope contents became progressively enriched along an evaporation line, and the d-excess values decreased with the evaporation. The strong relationship of d-excess and δ18O values was observed from both the experiments and the water samples of groundwater and lakes, which is considered to be a signature of strong evaporation. Also, all the values of groundwater and lake water samples fall along with the evaporation line established through the evaporation experiments, indicating that lakes and groundwater in the study area have evolved from meteoric precipitation under modern or similar to modern climatic conditions. Analysis of a few previously published d-excess and δ18O values of groundwater from the BJD, Lake Eyre Basin, Australia, and Jabal Hafit mountain, United Arab Emirates reveals strong relationships between the two, suggesting similar recharge processes as observed in the BJD. This study demonstrated that the characteristic water isotopic patterns resulting from evaporation could be utilized to help resolve ambiguities in the interpretation of water isotope data in terms of recharge sources, especially, in the arid regions, such as the central Australia and the deserts of United Arab Emirates.

Ammonium Uptake by Phytoplankton Regulates Nitrification in the Sunlit Ocean

PubMed Central

Smith, Jason M.; Chavez, Francisco P.; Francis, Christopher A.

2014-01-01

Nitrification, the microbial oxidation of ammonium to nitrate, is a central part of the nitrogen cycle. In the ocean’s surface layer, the process alters the distribution of inorganic nitrogen species available to phytoplankton and produces nitrous oxide. A widely held idea among oceanographers is that nitrification is inhibited by light in the ocean. However, recent evidence that the primary organisms involved in nitrification, the ammonia-oxidizing archaea (AOA), are present and active throughout the surface ocean has challenged this idea. Here we show, through field experiments coupling molecular genetic and biogeochemical approaches, that competition for ammonium with phytoplankton is the strongest regulator of nitrification in the photic zone. During multiday experiments at high irradiance a single ecotype of AOA remained active in the presence of rapidly growing phytoplankton. Over the course of this three day experiment, variability in the intensity of competition with phytoplankton caused nitrification rates to decline from those typical of the lower photic zone (60 nmol L−1 d−1) to those in well-lit layers (<1 nmol L−1 d−1). During another set of experiments, nitrification rates exhibited a diel periodicity throughout much of the photic zone, with the highest rates occurring at night when competition with phytoplankton is lowest. Together, the results of our experiments indicate that nitrification rates in the photic zone are more strongly regulated by competition with phytoplankton for ammonium than they are by light itself. This finding advances our ability to model the impact of nitrification on estimates of new primary production, and emphasizes the need to more strongly consider the effects of organismal interactions on nutrient standing stocks and biogeochemical cycling in the surface of the ocean. PMID:25251022

Awake canine fMRI predicts dogs’ preference for praise vs food

PubMed Central

Cook, Peter F.; Prichard, Ashley; Spivak, Mark

2016-01-01

Dogs are hypersocial with humans, and their integration into human social ecology makes dogs a unique model for studying cross-species social bonding. However, the proximal neural mechanisms driving dog–human social interaction are unknown. We used functional magnetic resonance imaging in 15 awake dogs to probe the neural basis for their preferences for social interaction and food reward. In a first experiment, we used the ventral caudate as a measure of intrinsic reward value and compared activation to conditioned stimuli that predicted food, praise or nothing. Relative to the control stimulus, the caudate was significantly more active to the reward-predicting stimuli and showed roughly equal or greater activation to praise vs food in 13 of 15 dogs. To confirm that these differences were driven by the intrinsic value of social praise, we performed a second imaging experiment in which the praise was withheld on a subset of trials. The difference in caudate activation to the receipt of praise, relative to its withholding, was strongly correlated with the differential activation to the conditioned stimuli in the first experiment. In a third experiment, we performed an out-of-scanner choice task in which the dog repeatedly selected food or owner in a Y-maze. The relative caudate activation to food- and praise-predicting stimuli in Experiment 1 was a strong predictor of each dog’s sequence of choices in the Y-maze. Analogous to similar neuroimaging studies of individual differences in human social reward, our findings demonstrate a neural mechanism for preference in domestic dogs that is stable within, but variable between, individuals. Moreover, the individual differences in the caudate responses indicate the potentially higher value of social than food reward for some dogs and may help to explain the apparent efficacy of social interaction in dog training. PMID:27521302

Ammonium uptake by phytoplankton regulates nitrification in the sunlit ocean.

PubMed

Smith, Jason M; Chavez, Francisco P; Francis, Christopher A

2014-01-01

Nitrification, the microbial oxidation of ammonium to nitrate, is a central part of the nitrogen cycle. In the ocean's surface layer, the process alters the distribution of inorganic nitrogen species available to phytoplankton and produces nitrous oxide. A widely held idea among oceanographers is that nitrification is inhibited by light in the ocean. However, recent evidence that the primary organisms involved in nitrification, the ammonia-oxidizing archaea (AOA), are present and active throughout the surface ocean has challenged this idea. Here we show, through field experiments coupling molecular genetic and biogeochemical approaches, that competition for ammonium with phytoplankton is the strongest regulator of nitrification in the photic zone. During multiday experiments at high irradiance a single ecotype of AOA remained active in the presence of rapidly growing phytoplankton. Over the course of this three day experiment, variability in the intensity of competition with phytoplankton caused nitrification rates to decline from those typical of the lower photic zone (60 nmol L-1 d-1) to those in well-lit layers (<1 nmol L-1 d-1). During another set of experiments, nitrification rates exhibited a diel periodicity throughout much of the photic zone, with the highest rates occurring at night when competition with phytoplankton is lowest. Together, the results of our experiments indicate that nitrification rates in the photic zone are more strongly regulated by competition with phytoplankton for ammonium than they are by light itself. This finding advances our ability to model the impact of nitrification on estimates of new primary production, and emphasizes the need to more strongly consider the effects of organismal interactions on nutrient standing stocks and biogeochemical cycling in the surface of the ocean.

Effect of liquid surface tension on circular and linear hydraulic jumps; theory and experiments

NASA Astrophysics Data System (ADS)

Bhagat, Rajesh Kumar; Jha, Narsing Kumar; Linden, Paul F.; Wilson, David Ian

2017-11-01

The hydraulic jump has attracted considerable attention since Rayleigh published his account in 1914. Watson (1964) proposed the first satisfactory explanation of the circular hydraulic jump by balancing the momentum and hydrostatic pressure across the jump, but this solution did not explain what actually causes the jump to form. Bohr et al. (1992) showed that the hydraulic jump happens close to the point where the local Froude number equals to one, suggesting a balance between inertial and hydrostatic contributions. Bush & Aristoff (2003) subsequently incorporated the effect of surface tension and showed that this is important when the jump radius is small. In this study, we propose a new account to explain the formation and evolution of hydraulic jumps under conditions where the jump radius is strongly influenced by the liquid surface tension. The theory is compared with experiments employing liquids of different surface tension and different viscosity, in circular and linear configurations. The model predictions and the experimental results show excellent agreement. Commonwealth Scholarship Commission, St. John's college, University of Cambridge.

A normative set of 98 pairs of nonsensical pictures (droodles).

PubMed

Nishimoto, Takehiko; Ueda, Takashi; Miyawaki, Kaori; Une, Yuko; Takahashi, Masaru

2010-08-01

Our purpose in the present study is to provide a normative set of nonsensical pictures known as droodles and to demonstrate the role of semantic comprehension in facilitating recall of pictorial stimuli. The set consists of 98 pairs of droodles. Experiment 1 standardized these pictorial stimuli with respect to several variables, such as appropriateness of verbal labels, relationship between two droodles, and correct recall. Appropriateness of verbal labels was rated higher for pictures presented in pairs than for pictures presented singly. Experiment 2 used the standardized set of droodles in a recall experiment similar to those of Bower, Karlin, and Dueck (1975) and others. As we expected, semantic interpretation can strongly facilitate recall. Multiple regression analysis showed that several measures had significant power of explanation for recall performance. The full set of norms and pictures from this article may be downloaded from http://brm.psychonomic-journals.org/content/supplemental.

Analogical transfer as guided by an abstraction process: the case of learning by doing in text editing.

PubMed

Sander, E; Richard, J F

1997-11-01

The authors proposed that not only are the first attempts to solve a problem made by analogy but also that progress in learning can be guided by referring to more abstract knowledge, which affords new possibilities. Two experiments investigated this view in a situation of learning how to use a text editor. Experiments 1A to 1C identified the knowledge associated with 3 domains hypothesized as sources of transfer at increasing levels of abstraction (typewriting, writing in general, manipulating objects). Experiment 2 tested whether participants first use their knowledge about typewriting, then about writing in general, and then about manipulating objects. The data showed that the order of acquisition of text editor functions appeared to be strongly related to this hierarchy, supporting the idea that part of learning consists of discovering properties of objects by accessing increasingly general domains.

Simulation studies of vapor bubble generation by short-pulse lasers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amendt, P.; London, R.A.; Strauss, M.

1997-10-26

Formation of vapor bubbles is characteristic of many applications of short-pulse lasers in medicine. An understanding of the dynamics of vapor bubble generation is useful for developing and optimizing laser-based medical therapies. To this end, experiments in vapor bubble generation with laser light deposited in an aqueous dye solution near a fiber-optic tip have been performed. Numerical hydrodynamic simulations have been developed to understand and extrapolate results from these experiments. Comparison of two-dimensional simulations with the experiment shows excellent agreement in tracking the bubble evolution. Another regime of vapor bubble generation is short-pulse laser interactions with melanosomes. Strong shock generationmore » and vapor bubble generation are common physical features of this interaction. A novel effect of discrete absorption by melanin granules within a melanosome is studied as a possible role in previously reported high Mach number shocks.« less