WorldWideScience

Sample records for surprisingly large effect

  1. What is the mechanism of Ketamine's rapid-onset antidepressant effect? A concise overview of the surprisingly large number of possibilities.

    Science.gov (United States)

    Strasburger, S E; Bhimani, P M; Kaabe, J H; Krysiak, J T; Nanchanatt, D L; Nguyen, T N; Pough, K A; Prince, T A; Ramsey, N S; Savsani, K H; Scandlen, L; Cavaretta, M J; Raffa, R B

    2017-04-01

    Abundant clinical data now confirm that ketamine produces a remarkable rapid-onset antidepressant effect - hours or days - in contrast to the delayed onset (typically weeks) of current antidepressant drugs. This surprising and revolutionary finding may lead to the development of life-saving pharmacotherapy for depressive illness by reducing the high suicide risk associated with the delayed onset of effect of current drugs. As ketamine has serious self-limiting drawbacks that restrict its widespread use for this purpose, a safer alternative is needed. Our objective is to review the proposed mechanism(s) of ketamine's rapid-onset antidepressant action for new insights into the physiological basis of depressive illness that may lead to new and novel targets for antidepressant drug discovery. A search was conducted on published literature (e.g. PubMed) and Internet sources to identify information relevant to ketamine's rapid-acting antidepressant action and, specifically, to the possible mechanism(s) of this action. Key search words included 'ketamine', 'antidepressant', 'mechanism of action', 'depression' and 'rapid acting', either individually or in combination. Information was sought that would include less well-known, as well as well-known, basic pharmacologic properties of ketamine and that identified and evaluated the several hypotheses about ketamine's mechanism of antidepressant action. Whether the mechanistic explanation for ketamine's rapid-onset antidepressant action is related to its well-known antagonism of the NMDA (N-Methyl-d-aspartate) subtype of glutamate receptor or to something else has not yet been fully elucidated. The evidence from pharmacologic, medicinal chemistry, animal model and drug-discovery sources reveals a wide variety of postulated mechanisms. The surprising discovery of ketamine's rapid-onset antidepressant effect is a game-changer for the understanding and treatment of depressive illness. There is some convergence on NMDA receptor

  2. Effects of Surprisal and Locality on Danish Sentence Processing

    DEFF Research Database (Denmark)

    Balling, Laura Winther; Kizach, Johannes

    2017-01-01

    An eye-tracking experiment in Danish investigates two dominant accounts of sentence processing: locality-based theories that predict a processing advantage for sentences where the distance between the major syntactic heads is minimized, and the surprisal theory which predicts that processing time...... constructions with two postverbal NP-objects. An eye-tracking experiment showed a clear advantage for local syntactic relations, with only a marginal effect of lexicalised surprisal and no effect of syntactic surprisal. We conclude that surprisal has a relatively marginal effect, which may be clearest for verbs...

  3. Carbon Dioxide: Surprising Effects on Decision Making and Neurocognitive Performance

    Science.gov (United States)

    James, John T.

    2013-01-01

    The occupants of modern submarines and the International Space Station (ISS) have much in common as far as their air quality is concerned. Air is polluted by materials offgassing, use of utility compounds, leaks of systems chemicals, and anthropogenic sources. The primary anthropogenic compound of concern to submariners and astronauts has been carbon dioxide (CO2). NASA and the US Navy rely on the National Research Council Committee on Toxicology (NRC-COT) to help formulate exposure levels to CO2 that are thought to be safe for exposures of 3-6 months. NASA calls its limits Spacecraft Maximum Allowable Concentrations (SMACs). Years of experience aboard the ISS and a recent publication on deficits in decision making in ground-based subjects exposed briefly to 0.25% CO2 suggest that exposure levels that have been presumed acceptable to preserve health and performance need to be reevaluated. The current CO2 exposure limits for 3-6 months set by NASA and the UK Navy are 0.7%, and the limit for US submariners is 0.5%, although the NRC-COT recommended a 90-day level of 0.8% as safe a few years ago. NASA has set a 1000-day SMAC at 0.5% for exploration-class missions. Anecdotal experience with ISS operations approaching the current 180-day SMAC of 0.7% suggest that this limit is too high. Temporarily, NASA has limited exposures to 0.5% until further peer-reviewed data become available. In the meantime, a study published last year in the journal Environmental Health Perspectives (Satish U, et al. 2012) demonstrated that complexdecision- making performance is somewhat affected at 0.1% CO2 and becomes "dysfunctional" for at least half of the 9 indices of performance at concentrations approaching 0.25% CO2. The investigators used the Strategic Management Simulation (SMS) method of testing for decisionmaking ability, and the results were so surprising to the investigators that they declared that their findings need to be independently confirmed. NASA has responded to the

  4. Effects of Surprisal and Locality on Danish Sentence Processing: An Eye-Tracking Investigation.

    Science.gov (United States)

    Balling, Laura Winther; Kizach, Johannes

    2017-03-22

    An eye-tracking experiment in Danish investigates two dominant accounts of sentence processing: locality-based theories that predict a processing advantage for sentences where the distance between the major syntactic heads is minimized, and the surprisal theory which predicts that processing time increases with big changes in the relative entropy of possible parses, sometimes leading to anti-locality effects. We consider both lexicalised surprisal, expressed in conditional trigram probabilities, and syntactic surprisal expressed in the manipulation of the expectedness of the second NP in Danish constructions with two postverbal NP-objects. An eye-tracking experiment showed a clear advantage for local syntactic relations, with only a marginal effect of lexicalised surprisal and no effect of syntactic surprisal. We conclude that surprisal has a relatively marginal effect, which may be clearest for verbs in verb-final languages, while locality is a robust predictor of sentence processing.

  5. Imaging enhancement of malignancy by cyclophosphamide: surprising chemotherapy opposite effects

    Science.gov (United States)

    Yamauchi, Kensuke; Yang, Meng; Hayashi, Katsuhiro; Jiang, Ping; Xu, Mingxu; Yamamoto, Norio; Tsuchiya, Hiroyuki; Tomita, Katsuro; Moossa, A. R.; Bouvet, Michael; Hoffman, Robert M.

    2008-02-01

    Although side effects of cancer chemotherapy are well known, "opposite effects" of chemotherapy which enhance the malignancy of the treated cancer are not well understood. We have observed a number of steps of malignancy that are enhanced by chemotherapy pre-treatment of mice before transplantation of human tumor cells. The induction of intravascular proliferation, extravasation, and colony formation by cancer cells, critical steps of metastasis was enhanced by pretreatment of host mice with the commonly-used chemotherapy drug cyclophosphamide. Cyclophosphamide appears to interfere with a host process that inhibits intravascular proliferation, extravasation, and extravascular colony formation by at least some tumor cells. Cyclophosphamide does not directly affect the cancer cells since cyclophosphamide has been cleared by the time the cancer cells were injected. Without cyclophosphamide pretreatment, human colon cancer cells died quickly after injection in the portal vein of nude mice. Extensive clasmocytosis (destruction of the cytoplasm) of the cancer cells occurred within 6 hours. The number of apoptotic cells rapidly increased within the portal vein within 12 hours of injection. However, when the host mice were pretreated with cyclophosphamide, the cancer cells survived and formed colonies in the liver after portal vein injection. These results suggest that a cyclophosphamide-sensitive host cellular system attacked the cancer cells. This review describes an important unexpected "opposite effects" of chemotherapy that enhances critical steps in malignancy rather than inhibiting them, suggesting that certain current approaches to cancer chemotherapy should be modified.

  6. Surprising Existence of Massive and Large Molecular Gas Reservoirs in A Distant Protocluster

    Science.gov (United States)

    Dannerbauer, Helmut

    2017-07-01

    We know that environment has a critical impact on galaxy growth and evolution. What we do not know is when it starts to have an impact and how it does it. I present results of our on-going survey of low surface brightness emission of cold molecular gas in protoclusters galaxies and their halos with the Australian Telescope Compact Array (ATCA). These findings alter our view of the important topics of the development and gas phase distribution of the "proto-intracluster medium": how ram pressure stripping may operate in protoclusters, how the galaxies may contribute to the proto-intracluster medium and how their star formation may be limited by dynamics. Finally, I present our new ATCA Large Program, COALAS (CO ATCA Legacy Archive of Star-Forming Galaxies), which will extend significantly our study of environmental effects on cluster and field galaxies.

  7. Surprise, Memory, and Retrospective Judgment Making: Testing Cognitive Reconstruction Theories of the Hindsight Bias Effect

    Science.gov (United States)

    Ash, Ivan K.

    2009-01-01

    Hindsight bias has been shown to be a pervasive and potentially harmful decision-making bias. A review of 4 competing cognitive reconstruction theories of hindsight bias revealed conflicting predictions about the role and effect of expectation or surprise in retrospective judgment formation. Two experiments tested these predictions examining the…

  8. Ontological Surprises

    DEFF Research Database (Denmark)

    Leahu, Lucian

    2016-01-01

    This paper investigates how we might rethink design as the technological crafting of human-machine relations in the context of a machine learning technique called neural networks. It analyzes Google’s Inceptionism project, which uses neural networks for image recognition. The surprising output of...... a hybrid approach where machine learning algorithms are used to identify objects as well as connections between them; finally, it argues for remaining open to ontological surprises in machine learning as they may enable the crafting of different relations with and through technologies....

  9. Surprise Trips

    DEFF Research Database (Denmark)

    Korn, Matthias; Kawash, Raghid; Andersen, Lisbet Møller

    We report on a platform that augments the natural experience of exploration in diverse indoor and outdoor environments. The system builds on the theme of surprises in terms of user expectations and finding points of interest. It utilizes physical icons as representations of users' interests and a...

  10. Investigating locality effects and surprisal in written English syntactic choice phenomena.

    Science.gov (United States)

    Rajkumar, Rajakrishnan; van Schijndel, Marten; White, Michael; Schuler, William

    2016-10-01

    We investigate the extent to which syntactic choice in written English is influenced by processing considerations as predicted by Gibson's (2000) Dependency Locality Theory (DLT) and Surprisal Theory (Hale, 2001; Levy, 2008). A long line of previous work attests that languages display a tendency for shorter dependencies, and in a previous corpus study, Temperley (2007) provided evidence that this tendency exerts a strong influence on constituent ordering choices. However, Temperley's study included no frequency-based controls, and subsequent work on sentence comprehension with broad-coverage eye-tracking corpora found weak or negative effects of DLT-based measures when frequency effects were statistically controlled for (Demberg & Keller, 2008; van Schijndel, Nguyen, & Schuler 2013; van Schijndel & Schuler, 2013), calling into question the actual impact of dependency locality on syntactic choice phenomena. Going beyond Temperley's work, we show that DLT integration costs are indeed a significant predictor of syntactic choice in written English even in the presence of competing frequency-based and cognitively motivated control factors, including n-gram probability and PCFG surprisal as well as embedding depth (Wu, Bachrach, Cardenas, & Schuler, 2010; Yngve, 1960). Our study also shows that the predictions of dependency length and surprisal are only moderately correlated, a finding which mirrors Dember & Keller's (2008) results for sentence comprehension. Further, we demonstrate that the efficacy of dependency length in predicting the corpus choice increases with increasing head-dependent distances. At the same time, we find that the tendency towards dependency locality is not always observed, and with pre-verbal adjuncts in particular, non-locality cases are found more often than not. In contrast, surprisal is effective in these cases, and the embedding depth measures further increase prediction accuracy. We discuss the implications of our findings for theories of

  11. Charming surprise

    CERN Multimedia

    Antonella Del Rosso

    2011-01-01

    The CP violation in charm quarks has always been thought to be extremely small. So, looking at particle decays involving matter and antimatter, the LHCb experiment has recently been surprised to observe that things might be different. Theorists are on the case.   The study of the physics of the charm quark was not in the initial plans of the LHCb experiment, whose letter “b” stands for “beauty quark”. However, already one year ago, the Collaboration decided to look into a wider spectrum of processes that involve charm quarks among other things. The LHCb trigger allows a lot of these processes to be selected, and, among them, one has recently shown interesting features. Other experiments at b-factories have already performed the same measurement but this is the first time that it has been possible to achieve such high precision, thanks to the huge amount of data provided by the very high luminosity of the LHC. “We have observed the decay modes of t...

  12. Charming surprise

    CERN Multimedia

    Antonella Del Rosso

    2011-01-01

    The CP violation in charm quarks has always been thought to be extremely small. So, looking at particle decays involving matter and antimatter, the LHCb experiment has recently been surprised to observe that things might be different. Theorists are on the case. The study of the physics of the charm quark was not in the initial plans of the LHCb experiment, whose letter “b” stands for “beauty quark”. However, already one year ago, the Collaboration decided to look into a wider spectrum of processes that involve charm quarks among other things. The LHCb trigger allows a lot of these processes to be selected, and, among them, one has recently shown interesting features. Other experiments at b-factories have already performed the same measurement but this is the first time that it has been possible to achieve such high precision, thanks to the huge amount of data provided by the very high luminosity of the LHC. “We have observed the decay modes of the D0, a pa...

  13. Evaluative Appraisals of Environmental Mystery and Surprise

    Science.gov (United States)

    Nasar, Jack L.; Cubukcu, Ebru

    2011-01-01

    This study used a desktop virtual environment (VE) of 15 large-scale residential streets to test the effects of environmental mystery and surprise on response. In theory, mystery and surprise should increase interest and visual appeal. For each VE, participants walked through an approach street and turned right onto a post-turn street. We designed…

  14. Evaluative Appraisals of Environmental Mystery and Surprise

    Science.gov (United States)

    Nasar, Jack L.; Cubukcu, Ebru

    2011-01-01

    This study used a desktop virtual environment (VE) of 15 large-scale residential streets to test the effects of environmental mystery and surprise on response. In theory, mystery and surprise should increase interest and visual appeal. For each VE, participants walked through an approach street and turned right onto a post-turn street. We designed…

  15. Surprisingly low frequency attenuation effects in long tubes when measuring turbulent fluxes at tall towers

    DEFF Research Database (Denmark)

    Ibrom, Andreas; Brændholt, Andreas; Pilegaard, Kim

    2016-01-01

    by reducing both the water vapour dilution correction and the cross sensitivity effects on the N2O and CO flux measurements. Here we present the set-up of the concentration step change experiment and its results and compare them with recently developed theories for the behaviour of gases in turbulent tube......The eddy covariance technique relies on the fast and accurate measurement of gas concentration fluctuations. While for some gasses robust and compact sensors are available, measurement of, e.g., non CO2 greenhouse gas fluxes is often performed with sensitive equipment that cannot be run on a tower...... that the concentration signal was hardly biased during the ca 10 s travel through the tube. Due to the larger turbulence time scales at large measurement heights the low-pass correction was for the majority of the measurements effect...

  16. Corn Ethanol: The Surprisingly Effective Route for Natural Gas Consumption in the Transportation Sector

    Energy Technology Data Exchange (ETDEWEB)

    Szybist, James P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Curran, Scott [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-05-01

    Proven reserves and production of natural gas (NG) in the United States have increased dramatically in the last decade, due largely to the commercialization of hydraulic fracturing. This has led to a plentiful supply of NG, resulting in a significantly lower cost on a gallon of gasoline-equivalent (GGE) basis. Additionally, NG is a domestic, non-petroleum source of energy that is less carbon-intensive than coal or petroleum products, and thus can lead to lower greenhouse gas emissions. Because of these factors, there is a desire to increase the use of NG in the transportation sector in the United States (U.S.). However, using NG directly in the transportation sector requires that several non-trivial challenges be overcome. One of these issues is the fueling infrastructure. There are currently only 1,375 NG fueling stations in the U.S. compared to 152,995 fueling stations for gasoline in 2014. Additionally, there are very few light-duty vehicles that can consume this fuel directly as dedicated or bi-fuel options. For example, in model year 2013Honda was the only OEM to offer a dedicated CNG sedan while a number of others offered CNG options as a preparation package for LD trucks and vans. In total, there were a total of 11 vehicle models in 2013 that could be purchased that could use natural gas directly. There are additional potential issues associated with NG vehicles as well. Compared to commercial refueling stations, the at-home refueling time for NG vehicles is substantial – a result of the small compressors used for home refilling. Additionally, the methane emissions from both refueling (leakage) and from tailpipe emissions (slip) from these vehicles can add to their GHG footprint, and while these emissions are not currently regulated it could be a barrier in the future, especially in scenarios with broad scale adoption of CNG vehicles. However, NG consumption already plays a large role in other sectors of the economy, including some that are important to

  17. Organometallic Ru(II) Photosensitizers Derived from π-Expansive Cyclometalating Ligands: Surprising Theranostic PDT Effects.

    Science.gov (United States)

    Sainuddin, Tariq; McCain, Julia; Pinto, Mitch; Yin, Huimin; Gibson, Jordan; Hetu, Marc; McFarland, Sherri A

    2016-01-04

    The purpose of the present study was to investigate the influence of π-expansive cyclometalating ligands on the photophysical and photobiological properties of organometallic Ru(II) compounds. Four compounds with increasing π conjugation on the cyclometalating ligand were prepared, and their structures were confirmed by HPLC, 1D and 2D (1)H NMR, and mass spectrometry. The properties of these compounds differed substantially from their Ru(II) polypyridyl counterparts. Namely, they were characterized by red-shifted absorption, very weak to no room temperature phosphorescence, extremely short phosphorescence state lifetimes ( 300 μM) but was phototoxic to cells in the nanomolar regime. Exceptionally large phototherapeutic margins, exceeding 3 orders of magnitude in some cases, were accompanied by bright ligand-centered intracellular fluorescence in cancer cells. Thus, Ru(II) organometallic systems derived from π-expansive cyclometalating ligands, such 4,9,16-triazadibenzo[a,c]napthacene (pbpn), represent the first class of potent light-responsive Ru(II) cyclometalating agents with theranostic potential.

  18. [Less need for insulin, a surprising effect of phototherapy in insulin-dependent diabetes mellitus].

    Science.gov (United States)

    Nieuwenhuis, R F; Spooren, P F M J; Tilanus, J J D

    2009-01-01

    A 40-year-old woman with insulin-dependent diabetes mellitus was treated successfully with phototherapy for a seasonal affective disorder. Following sessions of phototherapy she developed hypoglycaemias and required less insulin. A review of the literature showed that melatonin has an inhibiting effect on insulin sensitivity. The melatonin secretion, which is suppressed by phototherapy, may cause an immediate decrease in the plasma glucose levels. This decrease may well be important for patients with insulin-resistant diabetes mellitus and seasonal affective disorder.

  19. Accurate reaction barrier heights of pericyclic reactions: Surprisingly large deviations for the CBS-QB3 composite method and their consequences in DFT benchmark studies.

    Science.gov (United States)

    Karton, Amir; Goerigk, Lars

    2015-04-05

    Accurate barrier heights are obtained for the 26 pericyclic reactions in the BHPERI dataset by means of the high-level Wn-F12 thermochemical protocols. Very often, the complete basis set (CBS)-type composite methods are used in similar situations, but herein it is shown that they in fact result in surprisingly large errors with root mean square deviations (RMSDs) of about 2.5 kcal mol(-1). In comparison, other composite methods, particularly G4-type and estimated coupled cluster with singles, doubles, and quasiperturbative triple excitations [CCSD(T)/CBS] approaches, show deviations well below the chemical-accuracy threshold of 1 kcal mol(-1). With the exception of SCS-MP2 and the herein newly introduced MP3.5 approach, all other tested Møller-Plesset perturbative procedures give poor performance with RMSDs of up to 8.0 kcal mol(-1). The finding that CBS-type methods fail for barrier heights of these reactions is unexpected and it is particularly troublesome given that they are often used to obtain reference values for benchmark studies. Significant differences are identified in the interpretation and final ranking of density functional theory (DFT) methods when using the original CBS-QB3 rather than the new Wn-F12 reference values for BHPERI. In particular, it is observed that the more accurate Wn-F12 benchmark results in lower statistical errors for those methods that are generally considered to be robust and accurate. Two examples are the PW6B95-D3(BJ) hybrid-meta-general-gradient approximation and the PWPB95-D3(BJ) double-hybrid functionals, which result in the lowest RMSDs of the entire DFT study (1.3 and 1.0 kcal mol(-1), respectively). These results indicate that CBS-QB3 should be applied with caution in computational modeling and benchmark studies involving related systems.

  20. More Supernova Surprises

    Science.gov (United States)

    2010-09-24

    SEP 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE More Supernova Surprises 5a. CONTRACT NUMBER 5b. GRANT...PERSPECTIVES More Supernova Surprises ASTRONOMY J. Martin Laming Spectroscopic observations of the supernova SN1987A are providing a new window into high...a core-collapse supernova ) have stretched and motivated research that has expanded our knowledge of astrophysics. The brightest such event in

  1. Surprises with Nonrelativistic Naturalness

    CERN Document Server

    Horava, Petr

    2016-01-01

    We explore the landscape of technical naturalness for nonrelativistic systems, finding surprises which challenge and enrich our relativistic intuition already in the simplest case of a single scalar field. While the immediate applications are expected in condensed matter and perhaps in cosmology, the study is motivated by the leading puzzles of fundamental physics involving gravity: The cosmological constant problem and the Higgs mass hierarchy problem.

  2. Surprises in astrophysical gasdynamics

    CERN Document Server

    Balbus, Steven A

    2016-01-01

    Much of astrophysics consists of the study of ionised gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetised fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one's a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an enlightening twist. We cover a broad range of topics including the instabilities acting in accretion discs, the hydrodynamics governing the convective zone of the Sun, the magnetic shielding of a cooling galaxy cluster, and the behaviour of thermal instabilities and evaporating clouds. The aim of this review is to surprise and intrigue even veteran astrophysical theorists with an idiosynchratic choice of problems and counterintuitive results. At the same time, we endeavour to bring forth the fundamental ideas, to set out import...

  3. Surprises in astrophysical gasdynamics

    Science.gov (United States)

    Balbus, Steven A.; Potter, William J.

    2016-06-01

    Much of astrophysics consists of the study of ionized gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetized fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one’s a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an enlightening twist. We cover a broad range of topics including the instabilities acting in accretion discs, the hydrodynamics governing the convective zone of the Sun, the magnetic shielding of a cooling galaxy cluster, and the behaviour of thermal instabilities and evaporating clouds. The aim of this review is to surprise and intrigue even veteran astrophysical theorists with an idiosyncratic choice of problems and counterintuitive results. At the same time, we endeavour to bring forth the fundamental ideas, to set out important assumptions, and to describe carefully whatever novel techniques may be appropriate to the problem at hand. By beginning at the beginning, and analysing a wide variety of astrophysical settings, we seek not only to make this review suitable for fluid dynamic veterans, but to engage novice recruits as well with what we hope will be an unusual and instructive introduction to the subject.

  4. Surprises in astrophysical gasdynamics.

    Science.gov (United States)

    Balbus, Steven A; Potter, William J

    2016-06-01

    Much of astrophysics consists of the study of ionized gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetized fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one's a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an enlightening twist. We cover a broad range of topics including the instabilities acting in accretion discs, the hydrodynamics governing the convective zone of the Sun, the magnetic shielding of a cooling galaxy cluster, and the behaviour of thermal instabilities and evaporating clouds. The aim of this review is to surprise and intrigue even veteran astrophysical theorists with an idiosyncratic choice of problems and counterintuitive results. At the same time, we endeavour to bring forth the fundamental ideas, to set out important assumptions, and to describe carefully whatever novel techniques may be appropriate to the problem at hand. By beginning at the beginning, and analysing a wide variety of astrophysical settings, we seek not only to make this review suitable for fluid dynamic veterans, but to engage novice recruits as well with what we hope will be an unusual and instructive introduction to the subject.

  5. Feedback first: the surprisingly weak effects of magnetic fields, viscosity, conduction, and metal diffusion on galaxy formation

    CERN Document Server

    Su, Kung-Yi; Hayward, Christopher C; Faucher-Giguere, Claude-Andre; Keres, Dusan; Ma, Xiangcheng; Robles, Victor H

    2016-01-01

    Using high-resolution simulations with explicit treatment of stellar feedback physics based on the FIRE (Feedback in Realistic Environments) project, we study how galaxy formation and the interstellar medium (ISM) are affected by magnetic fields, anisotropic Spitzer-Braginskii conduction and viscosity, and sub-grid turbulent metal diffusion. We consider controlled simulations of isolated (non-cosmological) galaxies but also a limited set of cosmological "zoom-in" simulations. Although simulations have shown significant effects from these physics with weak or absent stellar feedback, the effects are much weaker than those of stellar feedback when the latter is modeled explicitly. The additional physics have no systematic effect on galactic star formation rates (SFRs). In contrast, removing stellar feedback leads to SFRs being over-predicted by factors of $\\sim 10 -100$. Without feedback, neither galactic winds nor volume filling hot-phase gas exist, and discs tend to runaway collapse to ultra-thin scale-height...

  6. The effects of black-tailed prairie dogs on plant communities within a complex urban landscape: an ecological surprise?

    Science.gov (United States)

    Beals, Stower C; Hartley, Laurel M; Prevéy, Janet S; Seastedt, Timothy R

    2014-05-01

    Historically, prairie dogs (Cynomys spp.) have been considered essential keystone species of western United States grassland ecosystems because they provide unique services and increase vegetation community richness, evenness, and diversity. However, the effects of black-tailed prairie dogs (Cynomys ludovicianus) on lands adjacent to or surrounded by urban areas may not result in the same ecosystem benefits historically associated with their presence. An urban landscape presents prairie dogs with movement challenges unparalleled in natural landscapes, as well as suites of nonnative plant species that are more common in disturbed areas. This study examined a complex ecosystem where vegetation communities are being influenced by directional environmental change, and quantified the synergistic effects resulting from the protective management of a native keystone species. The data set for this analysis was comprised of 71 paired (occupied by prairie dogs vs. unoccupied) vegetation surveys and 156 additional unpaired surveys collected from around the city of Boulder, Colorado, USA for 14 yr. Linear mixed models were used to compare data from transects occupied and unoccupied by prairie dogs, as well as to evaluate the effect of prairie dog occupation duration. In the absence of prairie dogs, vegetation in this region exhibited declines in native grasses, no changes in introduced grasses, and increases in native and nonnative forbs and bare soil over the study interval. In the presence of prairie dogs, these observed directional changes were nearly all amplified at rates four to 10 times greater than when prairie dogs were absent. Areas in Boulder occupied by prairie dogs also had significantly lower richness, evenness, and diversity of plant species, compared to unoccupied areas. Analysis of plant functional groups revealed the significant reduction of perennial native grasses, as well as a significantly higher cover of introduced forbs in occupied areas. Prairie dogs

  7. Surprising quantum bounces

    CERN Document Server

    Nesvizhevsky, Valery

    2015-01-01

    This unique book demonstrates the undivided unity and infinite diversity of quantum mechanics using a single phenomenon: quantum bounces of ultra-cold particles. Various examples of such "quantum bounces" are: gravitational quantum states of ultra-cold neutrons (the first observed quantum states of matter in a gravitational field), the neutron whispering gallery (an observed matter-wave analog of the whispering gallery effect well known in acoustics and for electromagnetic waves), and gravitational and whispering gallery states for anti-matter atoms that remain to be observed. These quantum states are an invaluable tool in the search for additional fundamental short-range forces, for exploring the gravitational interaction and quantum effects of gravity, for probing physics beyond the standard model, and for furthering studies into the foundations of quantum mechanics, quantum optics, and surface science.

  8. More statistics, less surprise

    CERN Multimedia

    Antonella Del Rosso & the LHCb collaboration

    2013-01-01

    The LHCb collaboration has recently announced new results for a parameter that measures the CP violation effect in particles containing charm quarks. The new values obtained with a larger data set and with a new independent method are showing that the effect is smaller than previous measurements had  suggested. The parameter is back into the Standard Model picture.   CP violation signals – in particles containing charm quarks, such as the D0 particle, is a powerful probe of new physics. Indeed, such effects could result in unexpected values of parameters whose expectation values in the Standard Model are known. Although less precise than similar approaches used in particles made of b quarks, the investigation of the charm system has proven  to be intriguing. The LHCb collaboration has reported new measurements of ΔACP, the difference in CP violation between the D0→K+K– and D0→π+π– decays. The results are ob...

  9. The surprising superconductor

    Directory of Open Access Journals (Sweden)

    Taner Yildirim

    2002-04-01

    The serendipitous discovery by Akimitsu’s group1 of the superconductivity of MgB2 at Tc=39 K, almost twice the temperature of other simple intermetallic compounds, has sparked a race to uncover its basic properties and to find other related diborides with even higher Tcs. After the first announcement, the number of preprints appearing on the Los Alamos preprint server (Fig. 1 grew almost exponentially, reaching a maximum of about 60 studies in March (two papers a day, then decreasing linearly down to a paper every other day in August, and staying steady at about this rate until now. During the first year of the MgB2 era, more than 300 studies were published, exploring both fundamental and practical issues, such as the mechanism of the superconductivity; synthesis of MgB2 in the form of powder, thin films, wires, and tapes; the effect on Tc of substitution with various elements and on critical current and fields.

  10. Surprise... Surprise..., An Empirical Investigation on How Surprise is Connected to Customer Satisfaction

    NARCIS (Netherlands)

    J. Vanhamme (Joëlle)

    2003-01-01

    textabstractThis research investigates the specific influence of the emotion of surprise on customer transaction-specific satisfaction. Four empirical studies-two field studies (a diary study and a cross section survey) and two experiments-were conducted. The results show that surprise positively

  11. Surprise... Surprise..., An Empirical Investigation on How Surprise is Connected to Customer Satisfaction

    NARCIS (Netherlands)

    J. Vanhamme (Joëlle)

    2003-01-01

    textabstractThis research investigates the specific influence of the emotion of surprise on customer transaction-specific satisfaction. Four empirical studies-two field studies (a diary study and a cross section survey) and two experiments-were conducted. The results show that surprise positively [n

  12. Inflating with large effective fields

    Science.gov (United States)

    Burgess, C. P.; Cicoli, M.; Quevedo, F.; Williams, M.

    2014-11-01

    We re-examine large scalar fields within effective field theory, in particular focussing on the issues raised by their use in inflationary models (as suggested by BICEP2 to obtain primordial tensor modes). We argue that when the large-field and low-energy regimes coincide the scalar dynamics is most effectively described in terms of an asymptotic large-field expansion whose form can be dictated by approximate symmetries, which also help control the size of quantum corrections. We discuss several possible symmetries that can achieve this, including pseudo-Goldstone inflatons characterized by a coset G/H (based on abelian and non-abelian, compact and non-compact symmetries), as well as symmetries that are intrinsically higher dimensional. Besides the usual trigonometric potentials of Natural Inflation we also find in this way simple large-field power laws (like V propto phi2) and exponential potentials, V(phi) = ∑kVxe-kphi/M. Both of these can describe the data well and give slow-roll inflation for large fields without the need for a precise balancing of terms in the potential. The exponential potentials achieve large r through the limit |η| ll epsilon and so predict r simeq (8/3)(1-ns) consequently ns simeq 0.96 gives r simeq 0.11 but not much larger (and so could be ruled out as measurements on r and ns improve). We examine the naturalness issues for these models and give simple examples where symmetries protect these forms, using both pseudo-Goldstone inflatons (with non-abelian non-compact shift symmetries following familiar techniques from chiral perturbation theory) and extra-dimensional models.

  13. Inflating with large effective fields

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, C.P. [PH-TH Division, CERN, CH-1211, Genève 23 (Switzerland); Cicoli, M. [Dipartimento di Fisica e Astronomia, Università di Bologna, Via Irnerio 46, 40126 Bologna (Italy); Quevedo, F. [Abdus Salam ICTP, Strada Costiera 11, Trieste 34014 (Italy); Williams, M., E-mail: cburgess@perimeterinstitute.ca, E-mail: mcicoli@ictp.it, E-mail: f.quevedo@damtp.cam.ac.uk, E-mail: mwilliams@perimeterinsititute.ca [Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton ON (Canada)

    2014-11-01

    We re-examine large scalar fields within effective field theory, in particular focussing on the issues raised by their use in inflationary models (as suggested by BICEP2 to obtain primordial tensor modes). We argue that when the large-field and low-energy regimes coincide the scalar dynamics is most effectively described in terms of an asymptotic large-field expansion whose form can be dictated by approximate symmetries, which also help control the size of quantum corrections. We discuss several possible symmetries that can achieve this, including pseudo-Goldstone inflatons characterized by a coset G/H (based on abelian and non-abelian, compact and non-compact symmetries), as well as symmetries that are intrinsically higher dimensional. Besides the usual trigonometric potentials of Natural Inflation we also find in this way simple large-field power laws (like V ∝ φ{sup 2}) and exponential potentials, V(φ) = ∑{sub k}V{sub x}e{sup −kφ/M}. Both of these can describe the data well and give slow-roll inflation for large fields without the need for a precise balancing of terms in the potential. The exponential potentials achieve large r through the limit |η| || ε and so predict r ≅ (8/3)(1-n{sub s}); consequently n{sub s} ≅ 0.96 gives r ≅ 0.11 but not much larger (and so could be ruled out as measurements on r and n{sub s} improve). We examine the naturalness issues for these models and give simple examples where symmetries protect these forms, using both pseudo-Goldstone inflatons (with non-abelian non-compact shift symmetries following familiar techniques from chiral perturbation theory) and extra-dimensional models.

  14. Inflating with Large Effective Fields

    CERN Document Server

    Burgess, C P; Quevedo, F; Williams, M

    2014-01-01

    We re-examine large scalar fields within effective field theory, in particular focussing on the issues raised by their use in inflationary models (as suggested by BICEP2 to obtain primordial tensor modes). We argue that when the large-field and low-energy regimes coincide the scalar dynamics is most effectively described in terms of an asymptotic large-field expansion whose form can be dictated by approximate symmetries, which also help control the size of quantum corrections. We discuss several possible symmetries that can achieve this, including pseudo-Goldstone inflatons characterized by a coset $G/H$ (based on abelian and non-abelian, compact and non-compact symmetries), as well as symmetries that are intrinsically higher dimensional. Besides the usual trigonometric potentials of Natural Inflation we also find in this way simple {\\em large-field} power laws (like $V \\propto \\phi^2$) and exponential potentials, $V(\\phi) = \\sum_{k} V_k \\; e^{-k \\phi/M}$. Both of these can describe the data well and give slo...

  15. Surprise as a design strategy

    NARCIS (Netherlands)

    Ludden, G.D.S.; Schifferstein, H.N.J.; Hekkert, P.P.M.

    2008-01-01

    Imagine yourself queuing for the cashier’s desk in a supermarket. Naturally, you have picked the wrong line, the one that does not seem to move at all. Soon, you get tired of waiting. Now, how would you feel if the cashier suddenly started to sing? Many of us would be surprised and, regardless of

  16. Surprise as a design strategy

    NARCIS (Netherlands)

    Ludden, G.D.S.; Schifferstein, H.N.J.; Hekkert, P.P.M.

    2008-01-01

    Imagine yourself queuing for the cashier’s desk in a supermarket. Naturally, you have picked the wrong line, the one that does not seem to move at all. Soon, you get tired of waiting. Now, how would you feel if the cashier suddenly started to sing? Many of us would be surprised and, regardless of th

  17. Large-scale biophysical evaluation of protein PEGylation effects

    DEFF Research Database (Denmark)

    Vernet, Erik; Popa, Gina; Pozdnyakova, Irina

    2016-01-01

    PEGylation is the most widely used method to chemically modify protein biopharmaceuticals, but surprisingly limited public data is available on the biophysical effects of protein PEGylation. Here we report the first large-scale study, with site-specific mono-PEGylation of 15 different proteins...... and characterization of 61 entities in total using a common set of analytical methods. Predictions of molecular size were typically accurate in comparison with actual size determined by size-exclusion chromatography (SEC) or dynamic light scattering (DLS). In contrast, there was no universal trend regarding the effect...

  18. Young Galaxy's Magnetism Surprises Astronomers

    Science.gov (United States)

    2008-10-01

    Astronomers have made the first direct measurement of the magnetic field in a young, distant galaxy, and the result is a big surprise. Looking at a faraway protogalaxy seen as it was 6.5 billion years ago, the scientists measured a magnetic field at least 10 times stronger than that of our own Milky Way. They had expected just the opposite. The GBT Robert C. Byrd Green Bank Telescope CREDIT: NRAO/AUI/NSF The scientists made the discovery using the National Science Foundation's ultra-sensitive Robert C. Byrd Green Bank Telescope (GBT) in West Virginia. "This new measurement indicates that magnetic fields may play a more important role in the formation and evolution of galaxies than we have realized," said Arthur Wolfe, of the University of California-San Diego (UCSD). At its great distance, the protogalaxy is seen as it was when the Universe was about half its current age. According to the leading theory, cosmic magnetic fields are generated by the dynamos of rotating galaxies -- a process that would produce stronger fields with the passage of time. In this scenario, the magnetic fields should be weaker in the earlier Universe, not stronger. The new, direct magnetic-field measurement comes on the heels of a July report by Swiss and American astronomers who made indirect measurements that also implied strong magnetic fields in the early Universe. "Our results present a challenge to the dynamo model, but they do not rule it out," Wolfe said. There are other possible explanations for the strong magnetic field seen in the one protogalaxy Wolfe's team studied. "We may be seeing the field close to the central region of a massive galaxy, and we know such fields are stronger toward the centers of nearby galaxies. Also, the field we see may have been amplified by a shock wave caused by the collision of two galaxies," he said. The protogalaxy studied with the GBT, called DLA-3C286, consists of gas with little or no star formation occurring in it. The astronomers suspect that

  19. Brazilian rescue plan sparks surprise

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    According to Financial Times,when Guido Mantega,Brazil's finance minister,suddenly proposed a “Bric” rescue package for the eurozone this week,he caught not only other world leaders by surprise but also many of his fellow countrymen.Even as officials from other members of the so-called Bric grouping,Russia,India and China,said it was the first they heard of the idea,many ordinary Brazilians expressed shock at the notion of bailing out the world's richest trading bloc.

  20. Some Surprises in Relativistic Gravity

    CERN Document Server

    Santos, N O

    2016-01-01

    General Relativity has had tremendous success both on the theoretical and the experimental fronts for over a century now. However, the contents of the theory are far from exhausted. Only very recently, with the detection of gravitational waves from colliding black holes, we have started probing the behavior of gravity in the strongly non-linear regime. Even today, the studies of black holes keep revealing more and more paradoxes and bizarre results. In this paper, inspired by David Hilbert's startling observation, we show that, contrary to the conventional wisdom, a freely falling test particle feels gravitational repulsion by a black hole as seen by the asymptotic observer. We dig deeper into this surprising behavior of relativistic gravity and offer some explanations.

  1. Some Surprising Introductory Physics Facts and Numbers

    Science.gov (United States)

    Mallmann, A. James

    2016-01-01

    In the entertainment world, people usually like, and find memorable, novels, short stories, and movies with surprise endings. This suggests that classroom teachers might want to present to their students examples of surprising facts associated with principles of physics. Possible benefits of finding surprising facts about principles of physics are…

  2. Pupil size tracks perceptual content and surprise.

    Science.gov (United States)

    Kloosterman, Niels A; Meindertsma, Thomas; van Loon, Anouk M; Lamme, Victor A F; Bonneh, Yoram S; Donner, Tobias H

    2015-04-01

    Changes in pupil size at constant light levels reflect the activity of neuromodulatory brainstem centers that control global brain state. These endogenously driven pupil dynamics can be synchronized with cognitive acts. For example, the pupil dilates during the spontaneous switches of perception of a constant sensory input in bistable perceptual illusions. It is unknown whether this pupil dilation only indicates the occurrence of perceptual switches, or also their content. Here, we measured pupil diameter in human subjects reporting the subjective disappearance and re-appearance of a physically constant visual target surrounded by a moving pattern ('motion-induced blindness' illusion). We show that the pupil dilates during the perceptual switches in the illusion and a stimulus-evoked 'replay' of that illusion. Critically, the switch-related pupil dilation encodes perceptual content, with larger amplitude for disappearance than re-appearance. This difference in pupil response amplitude enables prediction of the type of report (disappearance vs. re-appearance) on individual switches (receiver-operating characteristic: 61%). The amplitude difference is independent of the relative durations of target-visible and target-invisible intervals and subjects' overt behavioral report of the perceptual switches. Further, we show that pupil dilation during the replay also scales with the level of surprise about the timing of switches, but there is no evidence for an interaction between the effects of surprise and perceptual content on the pupil response. Taken together, our results suggest that pupil-linked brain systems track both the content of, and surprise about, perceptual events.

  3. Education in Japan: Surprising Lessons.

    Science.gov (United States)

    Deasy, Richard J.

    1986-01-01

    Reports on an indepth probe of the Japanese educational system by American educators. This study shows that the United States cannot expect to achieve economic growth by copying the Japanese system, which has been shaped largely by its geography and culture and society. (MD)

  4. Effects of land management on large trees and carbon stocks

    Science.gov (United States)

    Kauppi, P. E.; Birdsey, R. A.; Pan, Y.; Ihalainen, A.; Nöjd, P.; Lehtonen, A.

    2015-02-01

    Large trees are important and unique organisms in forests, providing ecosystem services including carbon dioxide removal from the atmosphere and long-term storage. Some reports have raised concerns about the global decline of large trees. Based on observations from two regions in Finland and three regions in the United States we report that trends of large trees during recent decades have been surprisingly variable among regions. In southern Finland, the growing stock volume of trees larger than 30 cm at breast height increased nearly five-fold during the second half of the 20th century, yet more recently ceased to expand. In the United States, large hardwood trees have become increasingly common in the Northeast since the 1950s, while large softwood trees declined until the mid 1990s as a consequence of harvests in the Pacific region, and then rebounded when harvesting there was reduced. We conclude that in the regions studied, the history of land use and forest management governs changes of the diameter-class distributions of tree populations. Large trees have significant benefits; for example, they can constitute a large proportion of the carbon stock and affect greatly the carbon density of forests. Large trees usually have deeper roots and long lifetimes. They affect forest structure and function and provide habitats for other species. An accumulating stock of large trees in existing forests may have negligible direct biophysical effects on climate through transpiration or forest albedo. Understanding changes in the demography of tree populations makes a contribution to estimating the past impact and future potential of forests in the global carbon budget and to assessing other ecosystem services of forests.

  5. Surprises and mysteries in urban soils

    Science.gov (United States)

    Groffman, P. M.

    2015-12-01

    In the Baltimore Ecosystem Study, one of two urban long-term ecological research (LTER) projects funded by the U.S. National Science Foundation, we are using "the watershed approach" to integrate ecological, physical and social sciences. Urban and suburban watershed input/output budgets for nitrogen have shown surprisingly high retention which has led to detailed analysis of sources and sinks in soils these watersheds. Home lawns, thought to be major sources of reactive nitrogen in suburban watersheds, have more complex coupled carbon and nitrogen dynamics than previously thought, and are likely the site of much nitrogen retention. Riparian zones, thought to be an important sink for reactive nitrogen in many watersheds, have turned out be nitrogen sources in urban watersheds due to hydrologic changes that disconnect streams from their surrounding landscape. Urban effects on atmospheric carbon dioxide levels and nitrogen deposition have strong effects on soil nitrogen cycling processes and soil:atmosphere fluxes of nitrous oxide, carbon dioxide and methane. Efforts to manage urban soils and watersheds through geomorphic stream restoration, creation of stormwater management features and changes in lawn and forest management can have significant effects on watershed carbon and nitrogen dynamics. Urban soils present a basic and applied science frontier that challenges our understanding of biological, physical, chemical and social science processes. The watershed approach provides an effective platform for integrating these disciplines and for articulating critical questions that arise from surprising results. This approach can help us to meet the challenge of urban soils, which is critical to achieving sustainability goals in cities across the world.

  6. Effects of land management on large trees and carbon stocks

    Directory of Open Access Journals (Sweden)

    P. E. Kauppi

    2014-02-01

    Full Text Available Large trees are important and unique organisms in forests, providing ecosystem services including carbon dioxide removal from the atmosphere and long-term storage. There is concern about reports of global decline of big trees. Based on observations from Finland and the United States we report that trends of big trees during recent decades have been surprisingly variable among regions. In southern Finland, the growing stock volume of trees larger than 30 cm at breast height increased nearly five-fold during the second half of the 20th century, yet more recently ceased to expand. In the United States, large hardwood trees have become increasingly common since the 1950s, while large softwood trees declined until the mid 1990's as a consequence of harvests in the Pacific region, and then rebounded when harvesting there was reduced. We conclude that in the regions studied, the history of land use and forest management governs changes of tree populations especially with reference to large trees. Large trees affect greatly the carbon density of forests and usually have deeper roots and relatively lower mortality than small trees. An accumulating stock of large trees in forests may have negligible direct biophysical effects on climate because from changes in transpiration or forest albedo. Large trees have particular ecological importance and often constitute an unusually large proportion of biomass carbon stocks in a forest. Understanding the changes in big tree distributions in different regions of the world and the demography of tree populations makes a contribution to estimating the past impact and future potential of the role of forests in the global carbon budget.

  7. Analyst Information Precision and Small Earnings Surprises

    NARCIS (Netherlands)

    S. Bissessur; D. Veenman

    2014-01-01

    Prior research attributes zero and small positive earnings surprises to managers’ incentives for earnings management. In contrast, this study introduces and empirically tests an explanation for zero and small positive earnings surprises based on predictable variation in analyst forecast errors. We a

  8. Cognitive and Social Perspectives on Surprise

    Science.gov (United States)

    Adhami, Mundler

    2007-01-01

    Meanings of "surprise" are wide and include uplifting and engaging facets like wonder and amazement on the one hand as well as ones that may be of the opposite nature like interruption and disrupt on the other. Pedagogically, educators who use surprise in class activities are focusing on students being "taken aback" by a situation, hopefully…

  9. Not Everybody Needs Help to Seek Help: Surprising Effects of Metacognitive Instructions to Foster Help-Seeking in an Online-Learning Environment

    Science.gov (United States)

    Stahl, Elmar; Bromme, Rainer

    2009-01-01

    Offering help functions is a standard feature of computer-based interactive learning environments (ILE). Nevertheless, a number of recent studies indicate that learners are not using such help facilities effectively. We compared the effects of different metacognitive supports to foster learners' help-seeking behavior in an ILE for plant…

  10. A toolkit for detecting technical surprise.

    Energy Technology Data Exchange (ETDEWEB)

    Trahan, Michael Wayne; Foehse, Mark C.

    2010-10-01

    The detection of a scientific or technological surprise within a secretive country or institute is very difficult. The ability to detect such surprises would allow analysts to identify the capabilities that could be a military or economic threat to national security. Sandia's current approach utilizing ThreatView has been successful in revealing potential technological surprises. However, as data sets become larger, it becomes critical to use algorithms as filters along with the visualization environments. Our two-year LDRD had two primary goals. First, we developed a tool, a Self-Organizing Map (SOM), to extend ThreatView and improve our understanding of the issues involved in working with textual data sets. Second, we developed a toolkit for detecting indicators of technical surprise in textual data sets. Our toolkit has been successfully used to perform technology assessments for the Science & Technology Intelligence (S&TI) program.

  11. Deciphering network community structure by surprise

    National Research Council Canada - National Science Library

    Aldecoa, Rodrigo; Marín, Ignacio

    2011-01-01

    .... A fundamental, unsolved problem is how to characterize the community structure of a network. Here, using both standard and novel benchmarks, we show that maximization of a simple global parameter, which we call Surprise...

  12. A Surprising Culprit Behind Celiac Disease?

    Science.gov (United States)

    ... news/fullstory_164503.html A Surprising Culprit Behind Celiac Disease? Study suggests harmless viruses may set stage ... typically harmless type of virus might sometimes trigger celiac disease, a new study suggests. Celiac disease is ...

  13. Effective Language Teaching in Large Classes

    Institute of Scientific and Technical Information of China (English)

    张丽丽

    2010-01-01

    <正>With more and more people who are jumping into the line of learning the second language (especially English),and also due to the limited resources in language teaching,many foreign language teachers are nowadays confronting the large classes when teaching.So how to teach foreign language effectively in large classes has become an issue as well as a special field to make researches in.

  14. Surprises in numerical expressions of physical constants

    CERN Document Server

    Amir, Ariel; Tokieda, Tadashi

    2016-01-01

    In science, as in life, `surprises' can be adequately appreciated only in the presence of a null model, what we expect a priori. In physics, theories sometimes express the values of dimensionless physical constants as combinations of mathematical constants like pi or e. The inverse problem also arises, whereby the measured value of a physical constant admits a `surprisingly' simple approximation in terms of well-known mathematical constants. Can we estimate the probability for this to be a mere coincidence, rather than an inkling of some theory? We answer the question in the most naive form.

  15. Surface effects on large deflection of nanowires

    Institute of Scientific and Technical Information of China (English)

    杨帆

    2015-01-01

    Surface effects play an important role in the mechanical behavior of nanosized structural elements owing to the increased ratio of surface area to volume. The surface effects on the large deflection of nanowires were considered. Both geometric nonlinearity in finite deformation and surface effects at nanoscale were taken into account to analyze the bending of nanowires subjected to a concentrated force. For simply supported beams and clamped-clamped beams, the influence of surface effects and geometric nonlinearity were discussed in detail. It is found that both surface effects and geometric nonlinearity tend to decrease the deflection of bending nanowires and thus increase the effective elastic modulus of nanowires. Surface effects yield the size dependent behavior of nanowires.

  16. Exploring the concept of climate surprises. A review of the literature on the concept of surprise and how it is related to climate change

    Energy Technology Data Exchange (ETDEWEB)

    Glantz, M.H.; Moore, C.M. [National Center for Atmospheric Research, Boulder, CO (United States); Streets, D.G.; Bhatti, N.; Rosa, C.H. [Argonne National Lab., IL (United States). Decision and Information Sciences Div.; Stewart, T.R. [State Univ. of New York, Albany, NY (United States)

    1998-01-01

    This report examines the concept of climate surprise and its implications for environmental policymaking. Although most integrated assessment models of climate change deal with average values of change, it is usually the extreme events or surprises that cause the most damage to human health and property. Current models do not help the policymaker decide how to deal with climate surprises. This report examines the literature of surprise in many aspects of human society: psychology, military, health care, humor, agriculture, etc. It draws together various ways to consider the concept of surprise and examines different taxonomies of surprise that have been proposed. In many ways, surprise is revealed to be a subjective concept, triggered by such factors as prior experience, belief system, and level of education. How policymakers have reacted to specific instances of climate change or climate surprise in the past is considered, particularly with regard to the choices they made between proactive and reactive measures. Finally, the report discusses techniques used in the current generation of assessment models and makes suggestions as to how climate surprises might be included in future models. The report concludes that some kinds of surprises are simply unpredictable, but there are several types that could in some way be anticipated and assessed, and their negative effects forestalled.

  17. Surprising Connections between Partitions and Divisors

    Science.gov (United States)

    Osler, Thomas J.; Hassen, Abdulkadir; Chandrupatla, Tirupathi R.

    2007-01-01

    The sum of the divisors of a positive integer is one of the most interesting concepts in multiplicative number theory, while the number of ways of expressing a number as a sum is a primary topic in additive number theory. In this article, we describe some of the surprising connections between and similarities of these two concepts.

  18. Surprises from extragalactic propagation of UHECRs

    CERN Document Server

    Boncioli, Denise; Grillo, Aurelio

    2015-01-01

    Ultra-high energy cosmic ray experimental data are now of very good statistical significance even in the region of the expected GZK feature. The identification of their sources requires sophisticate analysis of their propagation in the extragalactic space. When looking at the details of this propagation some unforeseen features emerge. We will discuss some of these "surprises".

  19. A Shocking Surprise in Stephan's Quintet

    Science.gov (United States)

    2006-01-01

    This false-color composite image of the Stephan's Quintet galaxy cluster clearly shows one of the largest shock waves ever seen (green arc). The wave was produced by one galaxy falling toward another at speeds of more than one million miles per hour. The image is made up of data from NASA's Spitzer Space Telescope and a ground-based telescope in Spain. Four of the five galaxies in this picture are involved in a violent collision, which has already stripped most of the hydrogen gas from the interiors of the galaxies. The centers of the galaxies appear as bright yellow-pink knots inside a blue haze of stars, and the galaxy producing all the turmoil, NGC7318b, is the left of two small bright regions in the middle right of the image. One galaxy, the large spiral at the bottom left of the image, is a foreground object and is not associated with the cluster. The titanic shock wave, larger than our own Milky Way galaxy, was detected by the ground-based telescope using visible-light wavelengths. It consists of hot hydrogen gas. As NGC7318b collides with gas spread throughout the cluster, atoms of hydrogen are heated in the shock wave, producing the green glow. Spitzer pointed its infrared spectrograph at the peak of this shock wave (middle of green glow) to learn more about its inner workings. This instrument breaks light apart into its basic components. Data from the instrument are referred to as spectra and are displayed as curving lines that indicate the amount of light coming at each specific wavelength. The Spitzer spectrum showed a strong infrared signature for incredibly turbulent gas made up of hydrogen molecules. This gas is caused when atoms of hydrogen rapidly pair-up to form molecules in the wake of the shock wave. Molecular hydrogen, unlike atomic hydrogen, gives off most of its energy through vibrations that emit in the infrared. This highly disturbed gas is the most turbulent molecular hydrogen ever seen. Astronomers were surprised not only by the turbulence

  20. Large Chiroptical Effects in Planar Chiral Metamaterials

    Science.gov (United States)

    Ye, Weimin; Yuan, Xiaodong; Guo, Chucai; Zhang, Jianfa; Yang, Biao; Zhang, Shuang

    2017-05-01

    Chiroptical effects characterized by different optical responses for left- (LCP) and right-handed circularly polarized light (RCP) are powerful and valuable tools in optics with wide applications in polarization-resolved imaging and sensing. Previously observed strong chiroptical effects are limited to metamaterials with complex three-dimensional chiral structures at the subwavelength scale. Although asymmetrical transmission of LCP and RCP have been investigated in planar chiral metasurfaces, the observed weak chiroptical effects result from anisotropic Ohmic dissipation of the metal constituents. Here, we demonstrate by theory and proof-of-concept experiments that a large difference in transmittances of LCP and RCP can be attained in a single-layer planar chiral metamaterial with a subwavelength thickness. Without violating the reciprocity and mirror symmetry, the strong chiroptical effect, independent of dielectric loss, arises from a mechanism of multimode interference. The described effect may lead to a gateway towards chiral manipulations of light and chiral optical devices.

  1. Radar Design to Protect Against Surprise

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    Technological and doctrinal surprise is about rendering preparations for conflict as irrelevant or ineffective . For a sensor, this means essentially rendering the sensor as irrelevant or ineffective in its ability to help determine truth. Recovery from this sort of surprise is facilitated by flexibility in our own technology and doctrine. For a sensor, this mean s flexibility in its architecture, design, tactics, and the designing organizations ' processes. - 4 - Acknowledgements This report is the result of a n unfunded research and development activity . Sandia National Laboratories is a multi - program laboratory manage d and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

  2. Surprise Leads to Noisier Perceptual Decisions

    Directory of Open Access Journals (Sweden)

    Marta I Garrido

    2011-02-01

    Full Text Available Surprising events in the environment can impair task performance. This might be due to complete distraction, leading to lapses during which performance is reduced to guessing. Alternatively, unpredictability might cause a graded withdrawal of perceptual resources from the task at hand and thereby reduce sensitivity. Here we attempt to distinguish between these two mechanisms. Listeners performed a novel auditory pitch—duration discrimination, where stimulus loudness changed occasionally and incidentally to the task. Responses were slower and less accurate in the surprising condition, where loudness changed unpredictably, than in the predictable condition, where the loudness was held constant. By explicitly modelling both lapses and changes in sensitivity, we found that unpredictable changes diminished sensitivity but did not increase the rate of lapses. These findings suggest that background environmental uncertainty can disrupt goal-directed behaviour. This graded processing strategy might be adaptive in potentially threatening contexts, and reflect a flexible system for automatic allocation of perceptual resources.

  3. Radar Design to Protect Against Surprise.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W.

    2015-02-01

    Technological and doctrinal surprise is about rendering preparations for conflict as irrelevant or ineffective . For a sensor, this means essentially rendering the sensor as irrelevant or ineffective in its ability to help determine truth. Recovery from this sort of surprise is facilitated by flexibility in our own technology and doctrine. For a sensor, this mean s flexibility in its architecture, design, tactics, and the designing organizations ' processes. - 4 - Acknowledgements This report is the result of a n unfunded research and development activity . Sandia National Laboratories is a multi - program laboratory manage d and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

  4. Surprise-Based Learning for Autonomous Systems

    Science.gov (United States)

    2009-02-28

    for scientific theories containing recursive theoretical terms". British Journal of Philosophy of Science, 44. 641-652, 1993. Piaget J.. "The Origins...paradigm stems from Piaget’s theory of Developmental Psychology [5], Herben Simon’s theory on dual-space search for knowledge and problem solving [6...34, Twenty-First Conference on Uncertainty in Artificial Intelligence, Edinburgh, Scotland, July 2005. [34] Itti L., Baldi P., "A Surprising Theory of

  5. Revisiting the Effectiveness of Large Optical Telescopes

    Directory of Open Access Journals (Sweden)

    V. V. Sychev

    2015-01-01

    back action of design elements and propagation medium on the transmitted radiation wave-front;- lack of a basic source of radiation on the laser radiation wavelength, which is necessary for the adaptive correction methods to be applied to distorted wave-front;- inherent only in laser systems additional distorting factors available in transmitting systems.Such distorting factors are as follows:• length of optical path because of spacing necessary for a high-power laser source with a large number of the consistent optical elements;• thermal self-influence of powerful laser radiation in the channel of radiation transportation before its input in the forming optical system;• instability of spatiotemporal characteristics of laser radiation source itself, which worsens passing radiation conditions both in an optical path and in the free atmosphere;• thermal heterogeneity and thermal deformations.It is shown that adaptive systems are distinguished from active optics by the fact that correction of the radiation wave-front distortions occurs in real time on the entire set of the distorting factors (not only on influence of the atmosphere with the speed much exceeding action of distortions. Thus, the quality correction is assessed according to criterion of quality of primary image.Thus, correction continuously considers information on the current spatial, temperature, temporary, and justified parameters of the optical system, providing quality maintenance of the image under conditions of distorting factors.The main postulates of adaptive correction are formulated and offered.Postulates represent the set of statements and provisions allowing us to realize effective remedies of adaptive correction of distortions.It is also shown what real opportunities are open by using methods and means of adaptive optics in effective application of laser radiation power and what ways allow us to solve these tasks. First of all, it is:- forming a system of assumptions and minimizing the

  6. Some surprising facts about (the problem of) surprising facts (from the Dusseldorf Conference, February 2011).

    Science.gov (United States)

    Mayo, D

    2014-03-01

    A common intuition about evidence is that if data x have been used to construct a hypothesis H, then x should not be used again in support of H. It is no surprise that x fits H, if H was deliberately constructed to accord with x. The question of when and why we should avoid such "double-counting" continues to be debated in philosophy and statistics. It arises as a prohibition against data mining, hunting for significance, tuning on the signal, and ad hoc hypotheses, and as a preference for predesignated hypotheses and "surprising" predictions. I have argued that it is the severity or probativeness of the test--or lack of it--that should determine whether a double-use of data is admissible. I examine a number of surprising ambiguities and unexpected facts that continue to bedevil this debate.

  7. Stroke Recovery: Surprising Influences and Residual Consequences

    Directory of Open Access Journals (Sweden)

    Argye E. Hillis

    2014-01-01

    Full Text Available There is startling individual variability in the degree to which people recover from stroke and the duration of time over which recovery of some symptoms occurs. There are a variety of mechanisms of recovery from stroke which take place at distinct time points after stroke and are influenced by different variables. We review recent studies from our laboratory that unveil some surprising findings, such as the role of education in chronic recovery. We also report data showing that the consequences that most plague survivors of stroke and their caregivers are loss of high level cortical functions, such as empathy or written language. These results have implications for rehabilitation and management of stroke.

  8. 河南灵宝市西坡遗址发现一座仰韶文化中期特大房址%A Surprisingly Large House of the Middle Yangshao Period Discovered on the Xipo Site in Lingbao, Henan

    Institute of Scientific and Technical Information of China (English)

    中国社会科学院考古研究所河南一队; 河南省文物考古研究所; 三门峡市文物考古研究所; 灵宝市文物保护管理所; 荆山黄帝陵管理所

    2005-01-01

    After the discovery of House F105. which is 204 sq m in floor area, another surprisingly large semi-subterranean House F106 was exposed at tile Xipo site, Lingbao. Henan, in 2004. The house, about 240 sq m in floor area. ix rectangular in shape. In the middle of its north wall ix a doorway with an azimuth of 24°. The walls of its subterrarlearl part are buih of rammed earth, pasted with fine clay and painted in red Oll the surface.The floor, with a total thickness of 25.5 era. eonsists of seven sub-layers of fine clay and rammed earth and is also painted red oil the surface. 45 postholes were found —— 41 in the walls and four in the middle of the floor. Some traces indicate the existence of rammed earth outer walls in the periphery of the subterranean part. The discoveryof F106 is very important to a better understanding of alehiteetural teehniques during the middle Yangshao period(ea. 6000 BC - ea. 5500 BC).

  9. The conceptualization model problem—surprise

    Science.gov (United States)

    Bredehoeft, John

    2005-03-01

    The foundation of model analysis is the conceptual model. Surprise is defined as new data that renders the prevailing conceptual model invalid; as defined here it represents a paradigm shift. Limited empirical data indicate that surprises occur in 20-30% of model analyses. These data suggest that groundwater analysts have difficulty selecting the appropriate conceptual model. There is no ready remedy to the conceptual model problem other than (1) to collect as much data as is feasible, using all applicable methods—a complementary data collection methodology can lead to new information that changes the prevailing conceptual model, and (2) for the analyst to remain open to the fact that the conceptual model can change dramatically as more information is collected. In the final analysis, the hydrogeologist makes a subjective decision on the appropriate conceptual model. The conceptualization problem does not render models unusable. The problem introduces an uncertainty that often is not widely recognized. Conceptual model uncertainty is exacerbated in making long-term predictions of system performance. C'est le modèle conceptuel qui se trouve à base d'une analyse sur un modèle. On considère comme une surprise lorsque le modèle est invalidé par des données nouvelles; dans les termes définis ici la surprise est équivalente à un change de paradigme. Des données empiriques limitées indiquent que les surprises apparaissent dans 20 à 30% des analyses effectuées sur les modèles. Ces données suggèrent que l'analyse des eaux souterraines présente des difficultés lorsqu'il s'agit de choisir le modèle conceptuel approprié. Il n'existe pas un autre remède au problème du modèle conceptuel que: (1) rassembler autant des données que possible en utilisant toutes les méthodes applicables—la méthode des données complémentaires peut conduire aux nouvelles informations qui vont changer le modèle conceptuel, et (2) l'analyste doit rester ouvert au fait

  10. A Neural Mechanism for Surprise-related Interruptions of Visuospatial Working Memory.

    Science.gov (United States)

    Wessel, Jan R

    2016-11-30

    Surprising perceptual events recruit a fronto-basal ganglia mechanism for inhibition, which suppresses motor activity following surprise. A recent study found that this inhibitory mechanism also disrupts the maintenance of verbal working memory (WM) after surprising tones. However, it is unclear whether this same mechanism also relates to surprise-related interruptions of non-verbal WM. We tested this hypothesis using a change-detection task, in which surprising tones impaired visuospatial WM. Participants also performed a stop-signal task (SST). We used independent component analysis and single-trial scalp-electroencephalogram to test whether the same inhibitory mechanism that reflects motor inhibition in the SST relates to surprise-related visuospatial WM decrements, as was the case for verbal WM. As expected, surprising tones elicited activity of the inhibitory mechanism, and this activity correlated strongly with the trial-by-trial level of surprise. However, unlike for verbal WM, the activity of this mechanism was unrelated to visuospatial WM accuracy. Instead, inhibition-independent activity that immediately succeeded the inhibitory mechanism was increased when visuospatial WM was disrupted. This shows that surprise-related interruptions of visuospatial WM are not effected by the same inhibitory mechanism that interrupts verbal WM, and instead provides evidence for a 2-stage model of distraction.

  11. The role of surprising events in a math game on proportional reasoning

    NARCIS (Netherlands)

    Wouters, P.; Oostendorp, van H.; Vrugte, ter J.; Jong, de T.; Vandercruysse, S.; Elen, J.

    2015-01-01

    This study examines whether surprising events can be used to stimulate students’ playful learning in a GBL environment in the domain of proportional reasoning. The assumed effect of surprise is that unexpected events interrupt an expectation and therefore triggers the player to evaluate the new situ

  12. Surprising characteristics of visual systems of invertebrates.

    Science.gov (United States)

    González-Martín-Moro, J; Hernández-Verdejo, J L; Jiménez-Gahete, A E

    2017-01-01

    To communicate relevant and striking aspects about the visual system of some close invertebrates. Review of the related literature. The capacity of snails to regenerate a complete eye, the benefit of the oval shape of the compound eye of many flying insects as a way of stabilising the image during flight, the potential advantages related to the extreme refractive error that characterises the ocelli of many insects, as well as the ability to detect polarised light as a navigation system, are some of the surprising capabilities present in the small invertebrate eyes that are described in this work. The invertebrate eyes have capabilities and sensorial modalities that are not present in the human eye. The study of the eyes of these animals can help us to improve our understanding of our visual system, and inspire the development of optical devices. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  13. Surprises from Saturn: Implications for Other Environments

    Science.gov (United States)

    Coates, A. J.

    2014-05-01

    The exploration of Saturn by Cassini has provided many surprises regarding: Saturn's rapidly rotating magnetosphere, interactions with its diverse moons, and interactions with the solar wind. Enceladus, orbiting at 4 Saturn radii (RS), was found to have plumes of water vapour and ice which are the dominant source for the inner magnetosphere. Charged water clusters, charged dust and photoelectrons provide key populations in the 'dusty plasma' observed. Direct pickup is seen near Enceladus and field-aligned currents create a spot in Saturn's aurora. At Titan, orbiting at 20 RS, unexpected heavy negative and positive ions are seen in the ionosphere, which provide the source for Titan's haze. Ionospheric plasma is seen in Titan's tail, enabling ion escape to be estimated at 7 tonnes per day. Saturn's ring ionosphere was seen early in the mission and a return will be made in 2017. In addition, highly accelerated electrons are seen at Saturn's high Mach number (MA˜100) quasi-parallel bow shock. Here we review some of these key new results, and discuss the implications for other solar system objects.

  14. Environmental Effects of Large Impacts on Mars

    Science.gov (United States)

    Segura, Teresa L.; Toon, Owen B.; Colaprete, Anthony; Zahnle, Kevin

    2002-12-01

    The martian valley networks formed near the end of the period of heavy bombardment of the inner solar system, about 3.5 billion years ago. The largest impacts produced global blankets of very hot ejecta, ranging in thickness from meters to hundreds of meters. Our simulations indicated that the ejecta warmed the surface, keeping it above the freezing point of water for periods ranging from decades to millennia, depending on impactor size, and caused shallow subsurface or polar ice to evaporate or melt. Large impacts also injected steam into the atmosphere from the craters or from water innate to the impactors. From all sources, a typical 100-, 200-, or 250-kilometers asteroid injected about 2, 9, or 16 meters, respectively, of precipitable water into the atmosphere, which eventually rained out at a rate of about 2 meters per year. The rains from a large impact formed rivers and contributed to recharging aquifers.

  15. The Energetic Universe: a Nobel Surprise

    Science.gov (United States)

    Kirshner, Robert P.

    2015-01-01

    he history of cosmic expansion can be accurately traced using Type Ia supernovae (SN Ia) as standard candles. Over the past 40 years, this effort has improved its precision and extended its reach in redshift. Recently, the distances to SN Ia have been measured to a precision of ~5% using luminosity information that is encoded in the shape of the supernova's rest frame optical light curve. By combining observations of supernova distances as measured from their light curves and redshifts measured from spectra, we can detect changes in the cosmic expansion rate. This empirical approach was successfully exploited by the High-Z Supernova Team and by the Supernova Cosmology Project to detect cosmic expansion and to infer the presence of dark energy. The 2011 Nobel Prize in Physics was awarded to Perlmutter, Schmidt and Riess for this discovery. The world's sample of well-observed SN Ia light curves at high redshift and low, approaching 1000 objects, is now large enough to make statistical errors due to sample size a thing of the past. Systematic errors are now the challenge. To learn the properties of dark energy and determine, for example, whether it has an equation-of-state that is different from the cosmological constant demands higher precision and better accuracy. The largest systematic uncertainties come from light curve fitters, photometric calibration errors, and from uncertain knowledge of the scattering properties of dust along the line of sight. Efforts to use SN Ia spectra as luminosity indicators have had some success, but have not yet produced a big step forward. Fortunately, observations of SN Ia in the near infrared (NIR), from 1 to 2 microns, offer a very promising path to better knowledge of the Hubble constant and to improved constraints on dark energy. In the NIR, SN Ia are better standard candles and the effects of dust absorption are smaller. We have begun an HST program dubbed RAISIN (SN IA in the IR) to tighten our grip on dark energy properties

  16. The Flynn effect in Korea: Large gains

    NARCIS (Netherlands)

    te Nijenhuis, J.; Cho, S.H.; Murphy, R.; Lee, K.H.

    2012-01-01

    Secular gains in IQ test scores have been reported for many Western countries. This is the first study of secular IQ gains in South Korea, using various datasets. The first question is what the size of the Flynn effect in South Korea is. The gains per decade are 7.7 points for persons born between 1

  17. The Flynn effect in Korea: Large gains

    NARCIS (Netherlands)

    te Nijenhuis, J.; Cho, S.H.; Murphy, R.; Lee, K.H.

    2012-01-01

    Secular gains in IQ test scores have been reported for many Western countries. This is the first study of secular IQ gains in South Korea, using various datasets. The first question is what the size of the Flynn effect in South Korea is. The gains per decade are 7.7 points for persons born between

  18. The Influence of Negative Surprise on Hedonic Adaptation

    Directory of Open Access Journals (Sweden)

    Ana Paula Kieling

    2016-01-01

    Full Text Available After some time using a product or service, the consumer tends to feel less pleasure with consumption. This reduction of pleasure is known as hedonic adaptation. One of the emotions that interfere in this process is surprise. Based on two experiments, we suggest that negative surprise – differently to positive – influences with the level of pleasure foreseen and experienced by the consumer. Study 1 analyzes the influence of negative (vs. positive surprise on the consumer’s post-purchase hedonic adaptation expectation. Results showed that negative surprise influences the intensity of adaptation, augmenting its strength. Study 2 verifies the influence of negative (vs positive surprise over hedonic adaptation. The findings suggested that negative surprise makes adaptation happen more intensively and faster as time goes by, which brings consequences to companies and consumers in the post-purchase process, such as satisfaction and loyalty.

  19. Psychosurgery: National Commission Issues Surprisingly Favorable Report

    Science.gov (United States)

    Culliton, Barbara J.

    1976-01-01

    Presents results of a national commission's investigation of psychosurgery. Results indicate the procedure to be effective in the cure of patients suffering from pain accompanied by depression, while avoiding the destruction caused by prefrontal lobotomies. (SL)

  20. Mesocosms Reveal Ecological Surprises from Climate Change.

    Science.gov (United States)

    Fordham, Damien A

    2015-12-01

    Understanding, predicting, and mitigating the impacts of climate change on biodiversity poses one of the most crucial challenges this century. Currently, we know more about how future climates are likely to shift across the globe than about how species will respond to these changes. Two recent studies show how mesocosm experiments can hasten understanding of the ecological consequences of climate change on species' extinction risk, community structure, and ecosystem functions. Using a large-scale terrestrial warming experiment, Bestion et al. provide the first direct evidence that future global warming can increase extinction risk for temperate ectotherms. Using aquatic mesocosms, Yvon-Durocher et al. show that human-induced climate change could, in some cases, actually enhance the diversity of local communities, increasing productivity. Blending these theoretical and empirical results with computational models will improve forecasts of biodiversity loss and altered ecosystem processes due to climate change.

  1. Mesocosms Reveal Ecological Surprises from Climate Change.

    Directory of Open Access Journals (Sweden)

    Damien A Fordham

    2015-12-01

    Full Text Available Understanding, predicting, and mitigating the impacts of climate change on biodiversity poses one of the most crucial challenges this century. Currently, we know more about how future climates are likely to shift across the globe than about how species will respond to these changes. Two recent studies show how mesocosm experiments can hasten understanding of the ecological consequences of climate change on species' extinction risk, community structure, and ecosystem functions. Using a large-scale terrestrial warming experiment, Bestion et al. provide the first direct evidence that future global warming can increase extinction risk for temperate ectotherms. Using aquatic mesocosms, Yvon-Durocher et al. show that human-induced climate change could, in some cases, actually enhance the diversity of local communities, increasing productivity. Blending these theoretical and empirical results with computational models will improve forecasts of biodiversity loss and altered ecosystem processes due to climate change.

  2. Probability and Surprisal in Auditory Comprehension of Morphologically Complex Words

    DEFF Research Database (Denmark)

    Balling, Laura Winther; Baayen, R. Harald

    2012-01-01

    Two auditory lexical decision experiments document for morphologically complex words two points at which the probability of a target word given the evidence shifts dramatically. The first point is reached when morphologically unrelated competitors are no longer compatible with the evidence....... Adapting terminology from Marslen-Wilson (1984), we refer to this as the word’s initial uniqueness point (UP1). The second point is the complex uniqueness point (CUP) introduced by Balling and Baayen (2008), at which morphologically related competitors become incompatible with the input. Later initial...... in the course of the word co-determines response latencies. The presence of effects of surprisal, both at the initial uniqueness point of complex words, and cumulatively throughout the word, challenges the Shortlist B model of Norris and McQueen (2008), and suggests that a Bayesian approach to auditory...

  3. The Orion Nebula: Still Full of Surprises

    Science.gov (United States)

    2011-01-01

    shows the glowing hydrogen gas, were coloured red. Light in the yellow-green part of the spectrum is coloured green, blue light is coloured blue and light that passed through an ultraviolet filter has been coloured purple. The exposure times were about 52 minutes through each filter. This image was processed by ESO using the observational data found by Igor Chekalin (Russia) [1], who participated in ESO's Hidden Treasures 2010 astrophotography competition [2], organised by ESO in October-November 2010, for everyone who enjoys making beautiful images of the night sky using real astronomical data. Notes [1] Igor searched through ESO's archive and identified datasets that he used to compose his image of Messier 42, which was the seventh highest ranked entry in the competition, out of almost 100 entries. His original work can be seen here. Igor Chekalin was awarded the first prize of the competition for his composition of Messier 78, and he also submitted an image of NGC3169, NGC3166 and SN 2003cg, which was ranked second highest. [2] ESO's Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO's vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. Participants submitted nearly 100 entries and ten skilled people were awarded some extremely attractive prizes, including an all expenses paid trip for the overall winner to ESO's Very Large Telescope (VLT) on Cerro Paranal, in Chile, the world's most advanced optical telescope. The ten winners submitted a total of 20 images that were ranked as the highest entries in the competition out of the near 100 images. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal

  4. Surprise and Sense Making: Undergraduate Placement Experiences in SMEs

    Science.gov (United States)

    Walmsley, Andreas; Thomas, Rhodri; Jameson, Stephanie

    2006-01-01

    Purpose: This paper seeks to explore undergraduate placement experiences in tourism and hospitality SMEs, focusing on the notions of surprise and sense making. It aims to argue that surprises and sense making are important elements not only of the adjustment process when entering new work environments, but also of the learning experience that…

  5. Smartphone Response System Using Twitter to Enable Effective Interaction and Improve Engagement in Large Classrooms

    Science.gov (United States)

    Kim, Yeongjun; Jeong, Soonmook; Ji, Yongwoon; Lee, Sangeun; Kwon, Key Ho; Jeon, Jae Wook

    2015-01-01

    This paper proposes a method for seamless interaction between students and their professor using Twitter, one of the typical social network service (SNS) platforms, in large lectures. During the lecture, the professor poses surprise questions in the form of a quiz on an overhead screen at unexpected moments, and students submit their answers…

  6. Neural Responses to Rapid Facial Expressions of Fear and Surprise

    Directory of Open Access Journals (Sweden)

    Ke Zhao

    2017-05-01

    Full Text Available Facial expression recognition is mediated by a distributed neural system in humans that involves multiple, bilateral regions. There are six basic facial expressions that may be recognized in humans (fear, sadness, surprise, happiness, anger, and disgust; however, fearful faces and surprised faces are easily confused in rapid presentation. The functional organization of the facial expression recognition system embodies a distinction between these two emotions, which is investigated in the present study. A core system that includes the right parahippocampal gyrus (BA 30, fusiform gyrus, and amygdala mediates the visual recognition of fear and surprise. We found that fearful faces evoked greater activity in the left precuneus, middle temporal gyrus (MTG, middle frontal gyrus, and right lingual gyrus, whereas surprised faces were associated with greater activity in the right postcentral gyrus and left posterior insula. These findings indicate the importance of common and separate mechanisms of the neural activation that underlies the recognition of fearful and surprised faces.

  7. Comment exploiter les 'corpus-surprise' ?

    Directory of Open Access Journals (Sweden)

    Rittaud-Hutinet, Chantal

    2009-01-01

    Full Text Available To what extent non-recorded oral corpora may constitute objects of analysis of pragmatic meaning?These corpora are heard by chance: on the radio, on television, in the street, a shop, a means of transport or generally in any conversational interaction in which the linguist participates, but had not previously planned to record for his research. The problem of the use of these corpora in linguistics is all the more crucial since the aim, in phonopragmatics, is to discover the functions and significations of their phonic part. I shall attempt to answer the following questions:–The accuracy of the transcription with respect to the original. To what extent can we ignore our own phonological code, our regional variants, mastered/partly known styles of speech?–The reliability of the oral reproduction carried out by the linguist – for example, during a talk at a conference. What is his capacity for deferred mimicry?–The relation between a significant discrepancy and the elocutionary habits of the speaker.–The relation between the comprehension of the external auditors and the effect produced on the 'real' person addressed.Considering that transparency is (sometimes? often? an illusion, I shall also examine what precautions should be taken so that these corpora offer guarantees as to the veracity.

  8. Surprise Gift” Purchases of Small Electric Appliances: A Pilot Study

    NARCIS (Netherlands)

    J. Vanhamme (Joëlle); C.J.P.M. de Bont (Cees)

    2005-01-01

    textabstractUnderstanding decision-making processes for gifts is of strategic importance for companies selling small electrical appliances as gifts account for a large part of their sales. Among all gifts, the ones that are surprising are the most valued by recipients. However, research about

  9. The surprising diversity of clostridial hydrogenases: a comparative genomic perspective.

    Science.gov (United States)

    Calusinska, Magdalena; Happe, Thomas; Joris, Bernard; Wilmotte, Annick

    2010-06-01

    Among the large variety of micro-organisms capable of fermentative hydrogen production, strict anaerobes such as members of the genus Clostridium are the most widely studied. They can produce hydrogen by a reversible reduction of protons accumulated during fermentation to dihydrogen, a reaction which is catalysed by hydrogenases. Sequenced genomes provide completely new insights into the diversity of clostridial hydrogenases. Building on previous reports, we found that [FeFe] hydrogenases are not a homogeneous group of enzymes, but exist in multiple forms with different modular structures and are especially abundant in members of the genus Clostridium. This unusual diversity seems to support the central role of hydrogenases in cell metabolism. In particular, the presence of multiple putative operons encoding multisubunit [FeFe] hydrogenases highlights the fact that hydrogen metabolism is very complex in this genus. In contrast with [FeFe] hydrogenases, their [NiFe] hydrogenase counterparts, widely represented in other bacteria and archaea, are found in only a few clostridial species. Surprisingly, a heteromultimeric Ech hydrogenase, known to be an energy-converting [NiFe] hydrogenase and previously described only in methanogenic archaea and some sulfur-reducing bacteria, was found to be encoded by the genomes of four cellulolytic strains: Clostridum cellulolyticum, Clostridum papyrosolvens, Clostridum thermocellum and Clostridum phytofermentans.

  10. Defense Science Board (DSB) Summer Study Report on Strategic Surprise

    Science.gov (United States)

    2015-07-01

    DSB Summer Study Report on Strategic Surprise July 2015 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden...SUBTITLE DSB Summer Study Report on Strategic Surprise 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Defense Science Board ( DSB ),The Pentagon ,OUSD(AT&L

  11. Atom Surprise: Using Theatre in Primary Science Education

    Science.gov (United States)

    Peleg, Ran; Baram-Tsabari, Ayelet

    2011-10-01

    Early exposure to science may have a lifelong effect on children's attitudes towards science and their motivation to learn science in later life. Out-of-class environments can play a significant role in creating favourable attitudes, while contributing to conceptual learning. Educational science theatre is one form of an out-of-class environment, which has received little research attention. This study aims to describe affective and cognitive learning outcomes of watching such a play and to point to connections between theatrical elements and specific outcomes. "Atom Surprise" is a play portraying several concepts on the topic of matter. A mixed methods approach was adopted to investigate the knowledge and attitudes of children (grades 1-6) from two different school settings who watched the play. Data were gathered using questionnaires and in-depth interviews. Analysis suggested that in both schools children's knowledge on the topic of matter increased after the play with younger children gaining more conceptual knowledge than their older peers. In the public school girls showed greater gains in conceptual knowledge than boys. No significant changes in students' general attitudes towards science were found, however, students demonstrated positive changes towards science learning. Theatrical elements that seemed to be important in children's recollection of the play were the narrative, props and stage effects, and characters. In the children's memory, science was intertwined with the theatrical elements. Nonetheless, children could distinguish well between scientific facts and the fictive narrative.

  12. Surprising Sensitivities in Simulations of Radiative Convective Equilibrium

    Science.gov (United States)

    Drotos, Gabor; Becker, Tobias; Mauritsen, Thorsten; Stevens, Bjorn

    2017-04-01

    The climate and climate-sensitivity of a global model run in radiative equilibrium is explored. Results from simulations with ECHAM6.3 coupled to a slab ocean and run in a wide range of configurations are presented. Simulations both with and without a parameterised representation of deep convection are conducted for CO2 concentrations ranging from one eighth of present day values to thirty-two times the present day, and for variations in the solar constant of more than a factor of two. Very long simulations, in some case more than a thousand years, are performed to adequately sample the attractor of the different climate states of the model, and provide robust estimates of the system's climate sensitivity parameter. For the standard configuration of the model the climate sensitivity progressively decreases from very large values (6-7K) for the coldest climates to well below 1 K for the warmest climates. For very high CO2 levels (16 and 32 times the present value) fluctuations of globally averaged temperature as large as 10 K arise on decadal time-scales. These fluctuations manifest as quasi-period coolings, driven by large and persistent global scale decks of stratiform low clouds, so that for a period of several years global temperatures drop to levels below the lowest temperatures of the climate with present day values of CO2. The same configuration of the model has more modest sensitivities when the insolation is reduced, but runaway warming results for small (10%) increases. Simulations without parameterised convection have colder (by roughly 10K) climates and smaller (1K) sensitivities, allowing a stable climate with earth-like temperatures even for insolation much (50%) larger than the present day. Such values of insolation are possible because over a large range of the insolation the climate sensitivity parameter is very near zero. The surprising sensitivities of the system, and the limit-cycle like behaviour of the very CO2 rich climates, can be traced to

  13. Optimal counterterrorism and the recruitment effect of large terrorist attacks

    DEFF Research Database (Denmark)

    Jensen, Thomas

    2011-01-01

    We analyze a simple dynamic model of the interaction between terrorists and authorities. Our primary aim is to study optimal counterterrorism and its consequences when large terrorist attacks lead to a temporary increase in terrorist recruitment. First, we show that an increase in counterterrorism...... makes it more likely that terrorist cells plan small rather than large attacks and therefore may increase the probability of a successful attack. Analyzing optimal counterterrorism we see that the recruitment effect makes authorities increase the level of counterterrorism after large attacks. Therefore......, in periods following large attacks a new attack is more likely to be small compared to other periods. Finally, we analyze the long-run consequences of the recruitment effect. We show that it leads to more counterterrorism, more small attacks, and a higher sum of terrorism damage and counterterrorism costs...

  14. Optimal counterterrorism and the recruitment effect of large terrorist attacks

    DEFF Research Database (Denmark)

    Jensen, Thomas

    2011-01-01

    We analyze a simple dynamic model of the interaction between terrorists and authorities. Our primary aim is to study optimal counterterrorism and its consequences when large terrorist attacks lead to a temporary increase in terrorist recruitment. First, we show that an increase in counterterrorism...... makes it more likely that terrorist cells plan small rather than large attacks and therefore may increase the probability of a successful attack. Analyzing optimal counterterrorism we see that the recruitment effect makes authorities increase the level of counterterrorism after large attacks. Therefore...

  15. The effects of large beach debris on nesting sea turtles

    Science.gov (United States)

    Fujisaki, Ikuko; Lamont, Margaret M.

    2016-01-01

    A field experiment was conducted to understand the effects of large beach debris on sea turtle nesting behavior as well as the effectiveness of large debris removal for habitat restoration. Large natural and anthropogenic debris were removed from one of three sections of a sea turtle nesting beach and distributions of nests and false crawls (non-nesting crawls) in pre- (2011–2012) and post- (2013–2014) removal years in the three sections were compared. The number of nests increased 200% and the number of false crawls increased 55% in the experimental section, whereas a corresponding increase in number of nests and false crawls was not observed in the other two sections where debris removal was not conducted. The proportion of nest and false crawl abundance in all three beach sections was significantly different between pre- and post-removal years. The nesting success, the percent of successful nests in total nesting attempts (number of nests + false crawls), also increased from 24% to 38%; however the magnitude of the increase was comparably small because both the number of nests and false crawls increased, and thus the proportion of the nesting success in the experimental beach in pre- and post-removal years was not significantly different. The substantial increase in sea turtle nesting activities after the removal of large debris indicates that large debris may have an adverse impact on sea turtle nesting behavior. Removal of large debris could be an effective restoration strategy to improve sea turtle nesting.

  16. Large displacement of a static bending nanowire with surface effects

    Science.gov (United States)

    Liu, J. L.; Mei, Y.; Xia, R.; Zhu, W. L.

    2012-07-01

    Nanowires are widely used as building blocks of micro/nano devices, such as micro-sensors, probes, transistors and actuators in micro/nano-electro-mechanical systems (M/NEMS) and biotechnology. In this study, we investigated the large deformation behavior of a nanowire in consideration of its surface effects (surface elasticity and residual surface stress). For nanowires of large displacements with different boundary conditions, we established the governing equation set in combination with the residual surface stress and surface elasticity. Then a computer program of shooting method by using the commercial software MathCAD was developed to solve the boundary value problem numerically. Furthermore, the influences of surface effects on the large and infinitesimal deformation of the nanowires were quantitatively compared. These findings are beneficial to understanding the mechanism of the surface effects, and can also provide some inspirations to characterize the mechanical properties of nano-materials, and engineer new micro/nano-scaled devices.

  17. Dispersion flattened single mode optical fiber with large effective area

    Science.gov (United States)

    Babita, Rastogi, Vipul

    2013-06-01

    In this paper we present design of a fiber having ultra-flattened dispersion with large effective area over a wide range of wavelengths. The maximum value of the dispersion and dispersion slope within the spectral range 1450-1600 nm are 1.0 ps/km/nm and 0.05 ps/km/nm2 respectively. Effective mode area within the aforementioned wavelength range varies from 100-295 μm2.

  18. Did the FED Surprise the Markets in 2001? A Case Study for Vars with Sign Restrictions

    NARCIS (Netherlands)

    Uhlig, H.F.H.V.S.

    2001-01-01

    In 2001, the Fed has lowered interest rates in a series of cuts, starting from 6.5 % at the end of 2000 to 2.0 % by early November.This paper asks, whether the Federal Reserve Bank has been surprising the markets, taking as given the conventional view about the effect of monetary policy shocks.New

  19. Did the FED Surprise the Markets in 2001? A Case Study for Vars with Sign Restrictions

    NARCIS (Netherlands)

    Uhlig, H.F.H.V.S.

    2001-01-01

    In 2001, the Fed has lowered interest rates in a series of cuts, starting from 6.5 % at the end of 2000 to 2.0 % by early November.This paper asks, whether the Federal Reserve Bank has been surprising the markets, taking as given the conventional view about the effect of monetary policy shocks.New e

  20. Avoiding surprises when implementing a single quality system.

    Science.gov (United States)

    Donawa, Maria

    2009-01-01

    European medical device manufacturers are sometimes surprised to learn that operating ISO 13485 alone is not sufficient to meet United States (US) quality system requirements. This article discusses important considerations for meeting US and European requirements when operating under a single quality system.

  1. Reconsiderations: Donald Murray and the Pedagogy of Surprise

    Science.gov (United States)

    Ballenger, Bruce

    2008-01-01

    Toward the end of his life, Donald Murray felt that his approach to writing instruction was no longer appreciated by journals in his field. Nevertheless, his emphasis on encouraging students to surprise themselves through informal writing still has considerable value. (Contains 1 note.)

  2. Reconsiderations: Donald Murray and the Pedagogy of Surprise

    Science.gov (United States)

    Ballenger, Bruce

    2008-01-01

    Toward the end of his life, Donald Murray felt that his approach to writing instruction was no longer appreciated by journals in his field. Nevertheless, his emphasis on encouraging students to surprise themselves through informal writing still has considerable value. (Contains 1 note.)

  3. Errors and surprise in patients with focal brain lesions

    NARCIS (Netherlands)

    Ullsperger, M.

    2016-01-01

    Recent theories of performance monitoring suggest that not only errors and negative action outcomes but also valence-free expectancy violations can trigger cognitive and behavioral adaptations. EEG and fMRI evidence suggests that monitoring of both errors and surprising but valence-free action

  4. Effective constitutive relations for large repetitive frame-like structures

    Science.gov (United States)

    Nayfeh, A. H.; Hefzy, M. S.

    1981-01-01

    Effective mechanical properties for large repetitive framelike structures are derived using combinations of strength of material and orthogonal transformation techniques. Symmetry considerations are used in order to identify independent property constants. The actual values of these constants are constructed according to a building block format which is carried out in the three consecutive steps: (1) all basic planar lattices are identified; (2) effective continuum properties are derived for each of these planar basic grids using matrix structural analysis methods; and (3) orthogonal transformations are used to determine the contribution of each basic set to the overall effective continuum properties of the structure.

  5. Large scale obscuration and related climate effects open literature bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Russell, N.A.; Geitgey, J.; Behl, Y.K.; Zak, B.D.

    1994-05-01

    Large scale obscuration and related climate effects of nuclear detonations first became a matter of concern in connection with the so-called ``Nuclear Winter Controversy`` in the early 1980`s. Since then, the world has changed. Nevertheless, concern remains about the atmospheric effects of nuclear detonations, but the source of concern has shifted. Now it focuses less on global, and more on regional effects and their resulting impacts on the performance of electro-optical and other defense-related systems. This bibliography reflects the modified interest.

  6. Steric effects in the dynamics of electrolytes at large applied voltages: I. Double-layer charging

    CERN Document Server

    Kilic, M S; Ajdari, A; Kilic, Mustafa Sabri; Bazant, Martin Z.; Ajdari, Armand

    2006-01-01

    The classical Poisson-Boltzmann (PB) theory of electrolytes assumes a dilute solution of point charges with mean-field electrostatic forces. Even for very dilute solutions, however, it predicts absurdly large ion concentrations (exceeding close packing) for surface potentials of only a few tenths of a volt, which are often exceeded, e.g. in microfluidic pumps and electrochemical sensors. Since the 1950s, several modifications of the PB equation have been proposed to account for the finite size of ions in equilibrium, but in this two-part series, we consider steric effects on diffuse charge dynamics (in the absence of electro-osmotic flow). In this first part, we review the literature and analyze two simple models for the charging of a thin double layer, which must form a condensed layer of close-packed ions near the surface at high voltage. A surprising prediction is that the differential capacitance typically varies non-monotonically with the applied voltage, and thus so does the response time of an electrol...

  7. The effective field theory of cosmological large scale structures

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco, John Joseph M. [Stanford Univ., Stanford, CA (United States); Hertzberg, Mark P. [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Senatore, Leonardo [Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2012-09-20

    Large scale structure surveys will likely become the next leading cosmological probe. In our universe, matter perturbations are large on short distances and small at long scales, i.e. strongly coupled in the UV and weakly coupled in the IR. To make precise analytical predictions on large scales, we develop an effective field theory formulated in terms of an IR effective fluid characterized by several parameters, such as speed of sound and viscosity. These parameters, determined by the UV physics described by the Boltzmann equation, are measured from N-body simulations. We find that the speed of sound of the effective fluid is c2s ≈ 10–6c2 and that the viscosity contributions are of the same order. The fluid describes all the relevant physics at long scales k and permits a manifestly convergent perturbative expansion in the size of the matter perturbations δ(k) for all the observables. As an example, we calculate the correction to the power spectrum at order δ(k)4. As a result, the predictions of the effective field theory are found to be in much better agreement with observation than standard cosmological perturbation theory, already reaching percent precision at this order up to a relatively short scale k ≃ 0.24h Mpc–1.

  8. Effect of Large Dose Methylcobalamin on Diabetic Peripheral Neuropathy

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The effects of large dose methylcobalamin injection on diabetic peripheral neuropathy in patients were observed to observe the subjective symptom of diabetic perpheral neuropathy (DPN) patients and detect the motor nerve conduction velocity (MCV) and sense nerve conduction velocity (SCV). Fifteen patients were received large dose methylcobalamin injection for two weeks as treatment group, another eleven patients were received muscular injection VitB1 100mg/ d, VitB12 500ug/ d for two weeks as control group. After 2 weeks treatment the subjective symptoms and signs were significantly improved with a total effective rate of 82.9% in the treatment group however the effective rate only has 52.0% in the control group. The result has obvious difference in statistics nerve MCV in median common peroneal nerve, SCV in median and superficial peroneal nerve were improved significantly in the treatment group and no such changes were observed in the control group. So, large dose methylcobalamin is an effective and safe agent for treatment of diabetic peripheral neuropathy.

  9. Turbulent large-scale structure effects on wake meandering

    Science.gov (United States)

    Muller, Y.-A.; Masson, C.; Aubrun, S.

    2015-06-01

    This work studies effects of large-scale turbulent structures on wake meandering using Large Eddy Simulations (LES) over an actuator disk. Other potential source of wake meandering such as the instablility mechanisms associated with tip vortices are not treated in this study. A crucial element of the efficient, pragmatic and successful simulations of large-scale turbulent structures in Atmospheric Boundary Layer (ABL) is the generation of the stochastic turbulent atmospheric flow. This is an essential capability since one source of wake meandering is these large - larger than the turbine diameter - turbulent structures. The unsteady wind turbine wake in ABL is simulated using a combination of LES and actuator disk approaches. In order to dedicate the large majority of the available computing power in the wake, the ABL ground region of the flow is not part of the computational domain. Instead, mixed Dirichlet/Neumann boundary conditions are applied at all the computational surfaces except at the outlet. Prescribed values for Dirichlet contribution of these boundary conditions are provided by a stochastic turbulent wind generator. This allows to simulate large-scale turbulent structures - larger than the computational domain - leading to an efficient simulation technique of wake meandering. Since the stochastic wind generator includes shear, the turbulence production is included in the analysis without the necessity of resolving the flow near the ground. The classical Smagorinsky sub-grid model is used. The resulting numerical methodology has been implemented in OpenFOAM. Comparisons with experimental measurements in porous-disk wakes have been undertaken, and the agreements are good. While temporal resolution in experimental measurements is high, the spatial resolution is often too low. LES numerical results provide a more complete spatial description of the flow. They tend to demonstrate that inflow low frequency content - or large- scale turbulent structures - is

  10. Isolating relativistic effects in large-scale structure

    CERN Document Server

    Bonvin, Camille

    2014-01-01

    We present a fully relativistic calculation of the observed galaxy number counts in the linear regime. We show that besides the density fluctuations and redshift-space distortions, various relativistic effects contribute to observations at large scales. These effects all have the same physical origin: they result from the fact that our coordinate system, namely the galaxy redshift and the incoming photons' direction, is distorted by inhomogeneities in our universe. We then discuss the impact of the relativistic effects on the angular power spectrum and on the two-point correlation function in configuration space. We show that the latter is very well adapted to isolate the relativistic effects since it naturally makes use of the symmetries of the different contributions. In particular, we discuss how the Doppler effect and the gravitational redshift distortions can be isolated by looking for a dipole in the cross-correlation function between a bright and a faint population of galaxies.

  11. Assessing the Effects of Construction Delays on MARA Large Projects

    Directory of Open Access Journals (Sweden)

    Aftab Hameed Memon

    2011-01-01

    Full Text Available Construction industry in Malaysia is facing a serious issue of construction delay causing a significant amount of time over run and cost over run. Various studies have addressed the issue of construction delay, however, most of studies focused on identifying causes of delay. Less attention has been paid of assessing effects of construction delay. Hence this study is aimed to assess effects of construction delay on MARA large projects. Investigation approach for study includes the site study of 30 MARA  large projects selected from various areas of Malaysia and structured questionnaire survey among client, consultant and contractor personnel’s. It is important to note that 90% of MARA projects are experiencing time overrun. Data was analyzed with statistical analysis  to calculate rank of the effects of delays and correlation with spearman formula to identify the interrelationship between attributes of effects. Results showed that time over-run and cost over-run are most significant effects of delay on MARA construction projects. Time over-run has high degree of correlation with cost over-run and moderate degree of correlation with disputes.

  12. Sleeping beauties in theoretical physics 26 surprising insights

    CERN Document Server

    Padmanabhan, Thanu

    2015-01-01

    This book addresses a fascinating set of questions in theoretical physics which will both entertain and enlighten all students, teachers and researchers and other physics aficionados. These range from Newtonian mechanics to quantum field theory and cover several puzzling issues that do not appear in standard textbooks. Some topics cover conceptual conundrums, the solutions to which lead to surprising insights; some correct popular misconceptions in the textbook discussion of certain topics; others illustrate deep connections between apparently unconnected domains of theoretical physics; and a few provide remarkably simple derivations of results which are not often appreciated. The connoisseur of theoretical physics will enjoy a feast of pleasant surprises skilfully prepared by an internationally acclaimed theoretical physicist. Each topic is introduced with proper background discussion and special effort is taken to make the discussion self-contained, clear and comprehensible to anyone with an undergraduate e...

  13. Monitoring the effects of floods on submerged macrophytes in a large river.

    Science.gov (United States)

    Ibáñez, Carles; Caiola, Nuno; Rovira, Albert; Real, Montserrat

    2012-12-01

    The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton to a macrophyte-dominated system. Macrophytes started to spread at the end of the 1990s and since 2002 artificial floods (flushing flows) of short duration (1-2 days) are released from the Riba-roja dam once or twice a year in order to reduce macrophyte density. The aim of this study was to analyse the spatiotemporal trends of the submerged macrophytes in two stretches of the lower Ebro River using high-resolution hydroacoustic methods, in order to elucidate the effects of artificial floods and natural floods on its distribution and abundance. Results showed that the mean cover in the two studied stretches (Móra and Ginestar) was not reduced after a flushing flow (from 36.59% to 55.85% in Móra, and from 21.18% to 21.05% in Ginestar), but it was greatly reduced after the natural flood (down to 9.79% in Móra and 2.04% in Ginestar); surprisingly the cover increased in Móra after the artificial flood. In order to increase the efficiency of floods in controlling macrophyte spreading, the magnitude and frequency of them should largely increase, as well as the suspended sediment load, approaching as much as possible to the original flood pattern before dam construction. Hydroacoustic methods combined with geostatistics and interpolation in GIS can accurately monitor spatiotemporal trends of submerged macrophytes in large rivers. This is the first article to apply this monitoring system to submerged macrophytes in rivers. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. The June surprises: balls, strikes, and the fog of war.

    Science.gov (United States)

    Fried, Charles

    2013-04-01

    At first, few constitutional experts took seriously the argument that the Patient Protection and Affordable Care Act exceeded Congress's power under the commerce clause. The highly political opinions of two federal district judges - carefully chosen by challenging plaintiffs - of no particular distinction did not shake that confidence that the act was constitutional. This disdain for the challengers' arguments was only confirmed when the act was upheld by two highly respected conservative court of appeals judges in two separate circuits. But after the hostile, even mocking questioning of the government's advocate in the Supreme Court by the five Republican-appointed justices, the expectation was that the act would indeed be struck down on that ground. So it came as no surprise when the five opined the act did indeed exceed Congress's commerce clause power. But it came as a great surprise when Chief Justice John Roberts, joined by the four Democrat-appointed justices, ruled that the act could be sustained as an exercise of Congress's taxing power - a ground urged by the government almost as an afterthought. It was further surprising, even shocking, that Justices Antonin Scalia, Anthony Kennedy, Clarence Thomas, and Samuel Alito not only wrote a joint opinion on the commerce clause virtually identical to that of their chief, but that in writing it they did not refer to or even acknowledge his opinion. Finally surprising was the fact that Justices Ruth Bader Ginsburg and Stephen Breyer joined the chief in holding that aspects of the act's Medicaid expansion were unconstitutional. This essay ponders and tries to unravel some of these puzzles.

  15. Stars Form Surprisingly Close to Milky Way's Black Hole

    Science.gov (United States)

    2005-10-01

    million low mass, sun-like stars in and around the ring, whereas in the disk model, the number of low mass stars could be much less. Nayakshin and his coauthor, Rashid Sunyaev of the Max Plank Institute for Physics in Garching, Germany, used Chandra observations to compare the X-ray glow from the region around Sgr A* to the X-ray emission from thousands of young stars in the Orion Nebula star cluster. They found that the Sgr A* star cluster contains only about 10,000 low mass stars, thereby ruling out the migration model. "We can now say that the stars around Sgr A* were not deposited there by some passing star cluster, rather they were born there," said Sunyaev . "There have been theories that this was possible, but this is the first real evidence. Many scientists are going to be very surprised by these results." Because the Galactic Center is shrouded in dust and gas, it has not been possible to look for the low-mass stars in optical observations. In contrast, X-ray data have allowed astronomers to penetrate the veil of gas and dust and look for these low mass stars. Scenario Dismissed by Chandra Results Scenario Dismissed by Chandra Results "In one of the most inhospitable places in our Galaxy, stars have prevailed," said Nayakshin. "It appears that star formation is much more tenacious than we previously believed." The results suggest that the "rules" of star formation change when stars form in the disk of a giant black hole. Because this environment is very different from typical star formation regions, there is a change in the proportion of stars that form. For example, there is a much higher percentage of massive stars in the disks around black holes. And, when these massive stars explode as supernovae, they will "fertilize" the region with heavy elements such as oxygen. This may explain the large amounts of such elements observed in the disks of young supermassive black holes. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for

  16. Surprising electronic structure of the BeH- dimer: a full-configuration-interaction study.

    Science.gov (United States)

    Verdicchio, Marco; Bendazzoli, Gian Luigi; Evangelisti, Stefano; Leininger, Thierry

    2013-01-10

    The electronic structure of the beryllium hydride anion, BeH(-), was investigated at valence full-configuration-interaction (FCI) level, using large cc-pV6Z basis sets. It appears that there is a deep change of the wave function nature as a function of the internuclear distance: the ion structure goes from a weakly bonded Be···H(-) complex, at long distance, to a rather strongly bonded system (more than 2 eV) at short distance, having a (:Be-H)(-) Lewis structure. In this case, it is the beryllium atom that formally bears the negative charge, a surprising result in view of the fact that it is the hydrogen atom that has a larger electronegativity. Even more surprisingly, at very short distances the average position of the total electronic charge is close to the beryllium atom but on the opposite side with respect to the hydrogen position.

  17. Modeling skin effect in large magnetized iron detectors

    CERN Document Server

    Incurvati, M

    2003-01-01

    The experimental problem of the calibration of magnetic field in large iron detectors is discussed. Emphasis is laid on techniques based on ballistic measurements as the ones employed by MINOS or OPERA.In particular, we provide analytical formulas to model the behavior of the apparatus in the transient regime, keeping into account eddy current effects and the finite penetration velocity of the driving fields. These formulas ease substantially the design of the calibration apparatus.Results are compared with experimental data coming from a prototype of the OPERA spectrometer.

  18. Large Scale Obscuration and Related Climate Effects Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Zak, B.D.; Russell, N.A.; Church, H.W.; Einfeld, W.; Yoon, D.; Behl, Y.K. [eds.

    1994-05-01

    A Workshop on Large Scale Obsurcation and Related Climate Effects was held 29--31 January, 1992, in Albuquerque, New Mexico. The objectives of the workshop were: to determine through the use of expert judgement the current state of understanding of regional and global obscuration and related climate effects associated with nuclear weapons detonations; to estimate how large the uncertainties are in the parameters associated with these phenomena (given specific scenarios); to evaluate the impact of these uncertainties on obscuration predictions; and to develop an approach for the prioritization of further work on newly-available data sets to reduce the uncertainties. The workshop consisted of formal presentations by the 35 participants, and subsequent topical working sessions on: the source term; aerosol optical properties; atmospheric processes; and electro-optical systems performance and climatic impacts. Summaries of the conclusions reached in the working sessions are presented in the body of the report. Copies of the transparencies shown as part of each formal presentation are contained in the appendices (microfiche).

  19. Spin effects in large rapidity neutral pion production at STAR

    CERN Document Server

    Ogawa, A

    2005-01-01

    First measurements of large Feynman x (x_F) neutral pion production in polarized proton collisions at sqrt(s)=200 GeV were reported previously. Cross section measurements at =3.3 and 3.8$ and analyzing power (A_N) measurements at =3.8 were completed for 0.3 < x_F < 0.6. The cross section was found to be consistent with next-to-leading order perturbative QCD calculations. In that framework, the dominant subprocess is partonic collisions of valence quarks on low Bjorken-x gluons. The A_N was found to be large and positive and increasing with x_F, and consistent with phenomonological calculations based on the Collins effect, the Sivers effect and initial-state and final-state higher twist contributions. Subsequent data have been acquired with transverse polarized proton collisions at RHIC at sqrt(s)=200 GeV. The status of the analysis and preliminary results will be presented.

  20. A large solvent isotope effect on protein association thermodynamics.

    Science.gov (United States)

    Eginton, Christopher; Beckett, Dorothy

    2013-09-24

    Solvent reorganization can contribute significantly to the energetics of protein-protein interactions. However, our knowledge of the magnitude of the energetic contribution is limited, in part, by a dearth of quantitative experimental measurements. The biotin repressor forms a homodimer as a prerequisite to DNA binding to repress transcription initiation. At 20 °C, the dimerization reaction, which is thermodynamically coupled to binding of a small ligand, bio-5'-AMP, is characterized by a Gibbs free energy of -7 kcal/mol. This modest net dimerization free energy reflects underlying, very large opposing enthalpic and entropic driving forces of 41 ± 3 and -48 ± 3 kcal/mol, respectively. The thermodynamics have been interpreted as indicating coupling of solvent release to dimerization. In this work, this interpretation has been investigated by measuring the effect of replacing H2O with D2O on the dimerization thermodynamics. Sedimentation equilibrium measurements performed at 20 °C reveal a solvent isotope effect of -1.5 kcal/mol on the Gibbs free energy of dimerization. Analysis of the temperature dependence of the reaction in D2O indicates enthalpic and entropic contributions of 28 and -37 kcal/mol, respectively, considerably smaller than the values measured in H2O. These large solvent isotope perturbations to the thermodynamics are consistent with a significant contribution of solvent release to the dimerization reaction.

  1. Implementing randomized effectiveness trials in large insurance systems.

    Science.gov (United States)

    Choudhry, Niteesh K; Shrank, William H

    2013-08-01

    The need to identify how best to structure health insurance and to deliver health care services is a central priority for comparative effectiveness research. Studies designed to evaluate these issues are frequently conducted in large insurance systems. We sought to describe the challenges faced when conducting trials in this context. Using the Post-Myocardial Infarction Free Rx Event and Economic Evaluation (MI FREEE) trial as an example, we describe the methodological and practical challenges of conducting trials in large insurance systems. We encountered six key challenges while conducting MI FREEE trial, namely the need to obtain plan sponsor permission to experiment, the desire of plan sponsors to have all of their beneficiaries receive the same intervention, the inaccuracy of claims-based identification methods and the impact of claims lag on the timely enrollment of potentially eligible patients, the reluctance of patients to participate in insurance-based interventions and the potential need for informed consent, the frequent introduction of new cointerventions in real-world delivery systems, and the high rates of loss to follow-up because of insurance "churn." We describe the approaches we used to overcome these challenges. Studies in insurance settings are a powerful and necessary design for evaluating comparative effectiveness interventions. There are numerous strategies to address the potential logistical and methodological challenges that this research environment uniquely creates. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. The effect of large scale inhomogeneities on the luminosity distance

    Science.gov (United States)

    Brouzakis, Nikolaos; Tetradis, Nikolaos; Tzavara, Eleftheria

    2007-02-01

    We study the form of the luminosity distance as a function of redshift in the presence of large scale inhomogeneities, with sizes of order 10 Mpc or larger. We approximate the Universe through the Swiss-cheese model, with each spherical region described by the Lemaitre Tolman Bondi metric. We study the propagation of light beams in this background, assuming that the locations of the source and the observer are random. We derive the optical equations for the evolution of the beam area and shear. Through their integration we determine the configurations that can lead to an increase of the luminosity distance relative to the homogeneous cosmology. We find that this can be achieved if the Universe is composed of spherical void-like regions, with matter concentrated near their surface. For inhomogeneities consistent with the observed large scale structure, the relative increase of the luminosity distance is of the order of a few per cent at redshifts near 1, and falls short of explaining the substantial increase required by the supernova data. On the other hand, the effect we describe is important for the correct determination of the energy content of the Universe from observations.

  3. Estimations of expectedness and potential surprise in possibility theory

    Science.gov (United States)

    Prade, Henri; Yager, Ronald R.

    1992-01-01

    This note investigates how various ideas of 'expectedness' can be captured in the framework of possibility theory. Particularly, we are interested in trying to introduce estimates of the kind of lack of surprise expressed by people when saying 'I would not be surprised that...' before an event takes place, or by saying 'I knew it' after its realization. In possibility theory, a possibility distribution is supposed to model the relative levels of mutually exclusive alternatives in a set, or equivalently, the alternatives are assumed to be rank-ordered according to their level of possibility to take place. Four basic set-functions associated with a possibility distribution, including standard possibility and necessity measures, are discussed from the point of view of what they estimate when applied to potential events. Extensions of these estimates based on the notions of Q-projection or OWA operators are proposed when only significant parts of the possibility distribution are retained in the evaluation. The case of partially-known possibility distributions is also considered. Some potential applications are outlined.

  4. 10 years of surprises at Saturn: CAPS and INMS highlights

    Science.gov (United States)

    Coates, A. J.; Waite, J. H.

    2014-04-01

    The Cassini mission at Saturn has provided many surprises on Saturn's rapidly rotating magnetosphere and its interaction with the diverse moons, as well as its interaction with the solar wind. One of the early discoveries was the water-rich composition of the magnetosphere. Its structure and dynamics indicate remarkable injections, periodicities and interchange events. Enceladus, orbiting at 4 RS, was found to have plumes of water vapour and ice which are the dominant source for the inner magnetosphere. Charged water clusters, charged dust and photoelectrons provide key populations in the 'dusty plasma' seen here, as well as chemical complexity in the plume material. Direct pickup is seen near Enceladus and field aligned currents create a spot in Saturn's aurora. At Titan, orbiting at 20 RS, heavy negative and positive ions are seen in the ionosphere, as well as neutrals, all of which have surprising chemical complexity. These provide the source for Titan's haze. Ionospheric plasma is seen in Titan's tail, enabling ion escape to be estimated at 7 tonnes per day. Saturn's ring ionosphere was seen early in the mission, which was oxygen rich and produced photoelectrons; a return will be made in 2017. At Rhea, pickup positive and negative ions indicated weak atmospheres sustained by energetic particle impact, seen in the neutrals also. A weak atmosphere was also seen at Dione. The exosphere production process operates at Jupiter's moons also. Here we review some of the key new results, and discuss the implications for other solar system contexts.

  5. Large piezoresistive effect in surface conductive nanocrystalline diamond

    Energy Technology Data Exchange (ETDEWEB)

    Janssens, S. D., E-mail: stoffel.d.janssens@gmail.com; Haenen, K., E-mail: ken.haenen@uhasselt.be [Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek (Belgium); IMOMEC, IMEC vzw, Wetenschapspark 1, B-3590 Diepenbeek (Belgium); Drijkoningen, S. [Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek (Belgium)

    2014-09-08

    Surface conductivity in hydrogen-terminated single crystal diamond is an intriguing phenomenon for fundamental reasons as well as for application driven research. Surface conductivity is also observed in hydrogen-terminated nanocrystalline diamond although the electronic transport mechanisms remain unclear. In this work, the piezoresistive properties of intrinsic surface conductive nanocrystalline diamond are investigated. A gauge factor of 35 is calculated from bulging a diamond membrane of 350 nm thick, with a diameter of 656 μm and a sheet resistance of 1.45 MΩ/sq. The large piezoresistive effect is reasoned to originate directly from strain-induced changes in the resistivity of the grain boundaries. Additionally, we ascribe a small time-dependent fraction of the piezoresistive effect to charge trapping of charge carriers at grain boundaries. In conclusion, time-dependent piezoresistive effect measurements act as a tool for deeper understanding the complex electronic transport mechanisms induced by grain boundaries in a polycrystalline material or nanocomposite.

  6. Highly Effective Action from Large N Gauge Fields

    CERN Document Server

    Yang, Hyun Seok

    2014-01-01

    Recently John H. Schwarz put forward a conjecture that the world-volume action of a probe $D3$-brane in an AdS5 x S5 background of type IIB superstring theory can be reinterpreted as the highly effective action (HEA) of four-dimensional N=4 superconformal field theory on the Coulomb branch. We argue that the HEA can be derived from the noncommutative (NC) field theory representation of the AdS/CFT correspondence and the Seiberg-Witten (SW) map defining a spacetime field redefinition between ordinary and NC gauge fields. It is based only on the well-known facts that the master fields of large N matrices are higher-dimensional NC U(1) gauge fields and the SW map is a local coordinate transformation eliminating U(1) gauge fields known as the Darboux theorem in symplectic geometry.

  7. Supermagnetic Neutron Star Surprises Scientists, Forces Revision of Theories

    Science.gov (United States)

    2006-08-01

    magnetars because their magnetic fields are 100-1,000 times stronger than those of typical pulsars. It is the decay of those incredibly strong fields that powers their strange X-ray emission. "The magnetic field from a magnetar would make an aircraft carrier spin around and point north quicker than a compass needle moves on Earth," said David Helfand, of Columbia University. A magnetar's field is 1,000 trillion times stronger than Earth's, Helfand pointed out. The new object -- named XTE J1810-197 -- was first discovered by NASA's Rossi X-ray Timing Explorer when it emitted a strong burst of X-rays in 2003. While the X-rays were fading in 2004, Jules Halpern of Columbia University and collaborators identified the magnetar as a radio-wave emitter using the National Science Foundation's (NSF) Very Large Array (VLA) radio telescope in New Mexico. Any radio emission is highly unusual for a magnetar. Because magnetars had not been seen to regularly emit radio waves, the scientists presumed that the radio emission was caused by a cloud of particles thrown off the neutron star at the time of its X-ray outburst, an idea they soon would realize was wrong. With knowledge that the magnetar emitted some form of radio waves, Camilo and his colleagues observed it with the Parkes radio telescope in Australia in March and immediately detected astonishingly strong radio pulsations every 5.5 seconds, corresponding to the previously-determined rotation rate of the neutron star. As they continued to observe XTE J1810-197, the scientists got more surprises. Whereas most pulsars become weaker at higher radio frequencies, XTE J1810-197 does not, remaining a strong emitter at frequencies up to 140 GHz, the highest frequency ever detected from a radio pulsar. In addition, unlike normal pulsars, the object's radio emission fluctuates in strength from day to day, and the shape of the pulsations changes as well. These variations likely indicate that the magnetic fields around the pulsar are changing

  8. Chandra Finds Surprising Black Hole Activity In Galaxy Cluster

    Science.gov (United States)

    2002-09-01

    Scientists at the Carnegie Observatories in Pasadena, California, have uncovered six times the expected number of active, supermassive black holes in a single viewing of a cluster of galaxies, a finding that has profound implications for theories as to how old galaxies fuel the growth of their central black holes. The finding suggests that voracious, central black holes might be as common in old, red galaxies as they are in younger, blue galaxies, a surprise to many astronomers. The team made this discovery with NASA'S Chandra X-ray Observatory. They also used Carnegie's 6.5-meter Walter Baade Telescope at the Las Campanas Observatory in Chile for follow-up optical observations. "This changes our view of galaxy clusters as the retirement homes for old and quiet black holes," said Dr. Paul Martini, lead author on a paper describing the results that appears in the September 10 issue of The Astrophysical Journal Letters. "The question now is, how do these black holes produce bright X-ray sources, similar to what we see from much younger galaxies?" Typical of the black hole phenomenon, the cores of these active galaxies are luminous in X-ray radiation. Yet, they are obscured, and thus essentially undetectable in the radio, infrared and optical wavebands. "X rays can penetrate obscuring gas and dust as easily as they penetrate the soft tissue of the human body to look for broken bones," said co-author Dr. Dan Kelson. "So, with Chandra, we can peer through the dust and we have found that even ancient galaxies with 10-billion-year-old stars can have central black holes still actively pulling in copious amounts of interstellar gas. This activity has simply been hidden from us all this time. This means these galaxies aren't over the hill after all and our theories need to be revised." Scientists say that supermassive black holes -- having the mass of millions to billions of suns squeezed into a region about the size of our Solar System -- are the engines in the cores of

  9. Effects of large herbivores on grassland arthropod diversity

    NARCIS (Netherlands)

    van Klink, R.; van der Plas, F.; van Noordwijk, C. G. E. (Toos); WallisDeVries, M. F.; Olff, H.

    Both arthropods and large grazing herbivores are important components and drivers of biodiversity in grassland ecosystems, but a synthesis of how arthropod diversity is affected by large herbivores has been largely missing. To fill this gap, we conducted a literature search, which yielded 141

  10. Measured Zero Net Energy Performance: Results, Lessons, and Surprises

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Carrie; LaRue, Anna; Pigman, Margaret; Roberts, Jon; Kaneda, David; Connelly, Dylan; Elliott, John; Pless, Shanti; Pande, Abhijeet; Dean, Edward; Anbarlilar, Can

    2016-08-26

    As more and more zero net energy (ZNE) buildings are built and monitored, we can learn from both careful case studies of individual projects as well as a broader perspective of trends over time. In a forum sponsored by Pacific Gas and Electric Company (PG&E), eight expert speakers discussed: results and lessons from monitoring occupied ZNE buildings; best practices for setting performance targets and getting actionable performance information, and; things that have surprised them about monitored ZNE buildings. This paper distills the content of the forum by laying out the most common hurdles that are encountered in setting up monitoring projects, frequent performance issues that the monitoring uncovers, and lessons learned that can be applied to future projects.

  11. Surprising hair analysis results following acute carbofuran intoxication.

    Science.gov (United States)

    Dulaurent, S; Gaulier, J M; Zouaoui, K; Moesch, C; François, B; Lachâtre, G

    2011-10-10

    We present two non fatal cases of intoxication with carbofuran (CBF) documented by hair analysis. Carbofuran and 3-hydroxycarbofuran (OHCBF, its main metabolite) hair concentrations were determined using a liquid chromatography-tandem mass spectrometry method. The obtained results were surprising if we consider several hair analyses previously published and based on a theory of the presence of xenobiotic in the only segment that comprised its intake. Among the two intoxication cases, we noticed the presence of CBF and OHCBF in hair segments corresponding to 45 days before, and more than 100 days after, the day of intoxication. Additionally, repeated hair samplings and subsequent analysis revealed a decrease of the carbofuran's concentration during the hair life.

  12. Physics Nobel prize 2004: Surprising theory wins physics Nobel

    CERN Multimedia

    2004-01-01

    From left to right: David Politzer, David Gross and Frank Wilczek. For their understanding of counter-intuitive aspects of the strong force, which governs quarks inside protons and neutrons, on 5 October three American physicists were awarded the 2004 Nobel Prize in Physics. David J. Gross (Kavli Institute of Theoretical Physics, University of California, Santa Barbara), H. David Politzer (California Institute of Technology), and Frank Wilczek (Massachusetts Institute of Technology) made a key theoretical discovery with a surprising result: the closer quarks are together, the weaker the force - opposite to what is seen with electromagnetism and gravity. Rather, the strong force is analogous to a rubber band stretching, where the force increases as the quarks get farther apart. These physicists discovered this property of quarks, known as asymptotic freedom, in 1976. It later became a key part of the theory of quantum chromodynamics (QCD) and the Standard Model, the current best theory to describe the interac...

  13. 2014 Presidential elections in Romania – surprising result or strategy

    Directory of Open Access Journals (Sweden)

    Dan Mihalache

    2015-03-01

    Full Text Available The presidential elections in Romania which took place in November 2014 were won by Klaus Iohannis, who clearly defeated the incumbent prime-minister Victor Ponta by 10%. The result was considered by many a surprise, as none of the opinion polls were able to predict it. This article reveals a part of the strategy of Klaus Iohannis’s campaign and it offers a few clues about how this is result was possible, without having the aim to explain it fully. As the authors were accountable for strategy and political message in the electoral campaign for Klaus Iohannis, the scientific approach is combined with the inside view, to provide the reader a better understanding of the November 2014 events.

  14. Effects of mud supply on large-scale estuarine morphology

    Science.gov (United States)

    Braat, Lisanne; Kleinhans, Maarten; van Kessel, Thijs; Wongsoredjo, Samor; Bergsma, Laura

    2016-04-01

    Sandy river estuaries have great economic and ecologic values, but a better understanding is required about the effect of mud on large-scale morphodynamics to optimise maintenance strategies. Very few studies actually include sand-mud interaction effects on morphodynamics on decadal and centennial timescales due to model limitations and lack of spatially and temporally dense data of mud in the bed. Here we study effects of cohesive sediment supply on equilibrium estuary shape, bar-channel patterns and dynamics, during formation from idealised initial conditions over a time scale of centuries and millennia. On the basis of related modelling and experimentation of river and delta patterns we hypothesise that mud will settle into mud flats flanking the estuary that resist erosion and thus self-confine and narrow the estuary and reduce braiding index and channel-bar mobility. We applied the process-based numerical model Delft3D in depth-averaged mode starting from idealised convergent estuaries. Mixed sediment was modelled with an active layer and storage module with fluxes predicted by the Partheniades-Krone relations for the cohesive regime, and Engelund-Hansen for the non-cohesive regime depending on the fraction of mud. This was subjected to a range of different mud inputs from the river or from the sea and a range of river discharge and tidal amplitudes. Our modelling results show that mud is predominantly stored in mudflats on the sides of the estuary. Higher mud concentration at the river inflow leads to narrower and shorter estuaries. Channels within the estuary also become narrower due to increased cohesion in the channel banks. This trend is confirmed in preliminary experiments. However, channels do not increase in depth; this is in contrast with what is observed in rivers and we do not yet fully understand this. Migration rates of channels and bars and bar splitting and merging also reduce with increasing mud concentration. For higher discharge channel

  15. Postulated weather modification effects of large energy releases

    Energy Technology Data Exchange (ETDEWEB)

    Ramsdell, J.V.; Scott, B.C.; Orgill, M.M.; Renne, D.S.; Hubbard, J.E.; McGinnis, K.A.

    1977-02-01

    Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing each impact. The primary and secondary atmospheric modifications may affect recreation, transportation, and aesthetics as well as agriculture and forestry. Economic values can be placed on some of the effects. However, the willingness of people to pay to gain benefits and avoid damages in many cases can only be determined through extensive surveys. The economic consequences of a given energy release would be highly site specific.

  16. Surprise and Opportunity for Learning in Grand Canyon: the Glen Canyon Dam Adaptive Management Program

    Science.gov (United States)

    Melis, T. S.; Walters, C. J.; Korman, J.

    2013-12-01

    With a focus on resources of the Colorado River ecosystem downstream of Glen Canyon Dam in Glen Canyon National Recreation Area (GCNRA) and Grand Canyon National Park (GCNP) of northern Arizona, the Glen Canyon Dam Adaptive Management Program has evaluated experimental flow and nonflow policy tests since 1990. Flow experiments have consisted of a variety of water releases from the dam within pre-existing annual downstream delivery agreements. The daily experimental dam operation, termed the Modified Low Fluctuating Flow (MLFF), implemented in 1996 to increase daily low flows and decrease daily peaks were intended to limit daily flow range to conserve tributary sand inputs and improve navigation among other objectives, including hydropower energy. Other flow tests have included controlled floods with some larger releases bypassing the dam's hydropower plant to rebuild and maintain eroded sandbars in GCNP. Experimental daily hydropeaking tests beyond MLFF have also been evaluated for managing the exotic recreational rainbow trout fishery in the dam's GCNRA tailwater. Experimental nonflow policies, such as physical removal of exotic fish below the tailwater, and experimental translocation of endangered native humpback chub from spawning habitats in the Little Colorado River (the largest natal origin site for chub in the basin) to other tributaries within GCNP have also been monitored. None of these large-scale field experiments has yet produced unambiguous results in terms of management prescriptions, owing to inadequate monitoring programs and confounding of treatment effects with effects of ongoing natural changes; most notably, a persistent warming of the river resulting from reduced storage in the dam's reservoir after 2003. But there have been several surprising results relative to predictions from models developed to identify monitoring needs and evaluate experimental design options at the start of the adaptive ecosystem assessment and management program in 1997

  17. Young stars in old galaxies - surprising discovery with the world's leading telescopes

    Science.gov (United States)

    2002-06-01

    similar to the way a palaeontologist uses the skeletons of dinosaurs to deduce information about the era in which they lived. A surprising discovery The team combined images of a number of galaxies from Hubble's Wide Field and Planetary Camera 2 with infrared images obtained from the multi-mode ISAAC instrument on the 8.2m VLT Antu telescope at the ESO Paranal Observatory (Chile). To their great surprise, they discovered that many of the globular clusters in one of these galaxies, NGC 4365, a member of the large Virgo cluster of galaxies, were only a few thousand million years old, much younger than most of the other stars in this galaxy (roughly 12 thousand million years old). The astronomers were able to identify three major groups of stellar clusters. There is an old population of clusters of metal-poor stars, some clusters of old but metal-rich stars and now, seen for the first time, a population of clusters with young and metal-rich stars. These results have been fully confirmed by spectroscopic observations made with another of the world's giant telescopes, the 10-metre Keck on Hawaii. "It is a great pleasure to see two projects wholly or partly funded by Europe - VLT and Hubble - work in concert to produce such an important scientific result", says Piero Benvenuti, ESA Hubble Project Scientist. "The synergy between the most advanced ground and space telescopes continues to prove its effectiveness, paving the way to impressive new discoveries that would not otherwise be possible." The discovery of young globular clusters within old galaxies is surprising since the stars in the giant elliptical galaxies were until now believed to have formed during a single period early in the history of the Universe. It is now clear that some of the galaxies may be hiding their true nature and have indeed experienced much more recent periods of major star formation. Notes for editors This press release is issued in coordination between ESA and ESO. The Hubble Space Telescope project

  18. Novelty biases attention and gaze in a surprise trial.

    Science.gov (United States)

    Horstmann, Gernot; Herwig, Arvid

    2016-01-01

    While the classical distinction between task-driven and stimulus-driven biasing of attention appears to be a dichotomy at first sight, there seems to be a third category that depends on the contrast or discrepancy between active representations and the upcoming stimulus, and may be termed novelty, surprise, or prediction failure. For previous demonstrations of the discrepancy-attention link, stimulus-driven components (saliency) may have played a decisive role. The present study was conducted to evaluate the discrepancy-attention link in a display where novel and familiar stimuli are equated for saliency. Eye tracking was used to determine fixations on novel and familiar stimuli as a proxy for attention. Results show a prioritization of attention by the novel color, and a de-prioritization of the familiar color, which is clearly present at the second fixation, and spans over the next couple of fixations. Saliency, on the other hand, did not prioritize items in the display. The results thus reinforce the notion that novelty captures and binds attention.

  19. A Well-Known But Still Surprising Generator

    Science.gov (United States)

    Haugland, Ole Anton

    2014-12-01

    The bicycle generator is often mentioned as an example of a method to produce electric energy. It is cheap and easily accessible, so it is a natural example to use in teaching. There are different types, but I prefer the old side-wall dynamo. The most common explanation of its working principle seems to be something like the illustration in Fig. 1. The illustration is taken from a popular textbook in the Norwegian junior high school.1 Typically it is explained as a system of a moving magnet or coils that directly results in a varying magnetic field through the coils. According to Faraday's law a voltage is induced in the coils. Simple and easy! A few times I have had a chance to glimpse into a bicycle generator, and I was somewhat surprised to sense that the magnet rotated parallel to the turns of the coil. How could the flux through the coil change and induce a voltage when the magnet rotated parallel to the turns of the coil? When teaching electromagnetic induction I have showed the students a dismantled generator and asked them how this could work. They naturally found that this was more difficult to understand than the principle illustrated in Fig. 1. Other authors in this journal have discussed even more challenging questions concerning electric generators.2,3

  20. The Effects of Moore's Law and Slacking on Large Computations

    CERN Document Server

    Gottbrath, C; Meakin, C; Thompson, T; Charfman, J J

    1999-01-01

    We show that, in the context of Moore's Law, overall productivity can be increased for large enough computations by `slacking' or waiting for some period of time before purchasing a computer and beginning the calculation.

  1. Effects of large-scale deforestation on precipitation in the monsoon regions: remote versus local effects.

    Science.gov (United States)

    Devaraju, N; Bala, Govindasamy; Modak, Angshuman

    2015-03-17

    In this paper, using idealized climate model simulations, we investigate the biogeophysical effects of large-scale deforestation on monsoon regions. We find that the remote forcing from large-scale deforestation in the northern middle and high latitudes shifts the Intertropical Convergence Zone southward. This results in a significant decrease in precipitation in the Northern Hemisphere monsoon regions (East Asia, North America, North Africa, and South Asia) and moderate precipitation increases in the Southern Hemisphere monsoon regions (South Africa, South America, and Australia). The magnitude of the monsoonal precipitation changes depends on the location of deforestation, with remote effects showing a larger influence than local effects. The South Asian Monsoon region is affected the most, with 18% decline in precipitation over India. Our results indicate that any comprehensive assessment of afforestation/reforestation as climate change mitigation strategies should carefully evaluate the remote effects on monsoonal precipitation alongside the large local impacts on temperatures.

  2. Surprise disrupts cognition via a fronto-basal ganglia suppressive mechanism.

    Science.gov (United States)

    Wessel, Jan R; Jenkinson, Ned; Brittain, John-Stuart; Voets, Sarah H E M; Aziz, Tipu Z; Aron, Adam R

    2016-04-18

    Surprising events markedly affect behaviour and cognition, yet the underlying mechanism is unclear. Surprise recruits a brain mechanism that globally suppresses motor activity, ostensibly via the subthalamic nucleus (STN) of the basal ganglia. Here, we tested whether this suppressive mechanism extends beyond skeletomotor suppression and also affects cognition (here, verbal working memory, WM). We recorded scalp-EEG (electrophysiology) in healthy participants and STN local field potentials in Parkinson's patients during a task in which surprise disrupted WM. For scalp-EEG, surprising events engage the same independent neural signal component that indexes action stopping in a stop-signal task. Importantly, the degree of this recruitment mediates surprise-related WM decrements. Intracranially, STN activity is also increased post surprise, especially when WM is interrupted. These results suggest that surprise interrupts cognition via the same fronto-basal ganglia mechanism that interrupts action. This motivates a new neural theory of how cognition is interrupted, and how distraction arises after surprising events.

  3. Assessment of Management to Mitigate Anthropogenic Effects on Large Whales

    Science.gov (United States)

    Van Der Hoop, Julie M; Moore, Michael J; Barco, Susan G; Cole, Timothy VN; Daoust, Pierre-Yves; Henry, Allison G; McAlpine, Donald F; McLellan, William A; Wimmer, Tonya; Solow, Andrew R

    2013-01-01

    Abstract United States and Canadian governments have responded to legal requirements to reduce human-induced whale mortality via vessel strikes and entanglement in fishing gear by implementing a suite of regulatory actions. We analyzed the spatial and temporal patterns of mortality of large whales in the Northwest Atlantic (23.5°N to 48.0°N), 1970 through 2009, in the context of management changes. We used a multinomial logistic model fitted by maximum likelihood to detect trends in cause-specific mortalities with time. We compared the number of human-caused mortalities with U.S. federally established levels of potential biological removal (i.e., species-specific sustainable human-caused mortality). From 1970 through 2009, 1762 mortalities (all known) and serious injuries (likely fatal) involved 8 species of large whales. We determined cause of death for 43% of all mortalities; of those, 67% (502) resulted from human interactions. Entanglement in fishing gear was the primary cause of death across all species (n = 323), followed by natural causes (n = 248) and vessel strikes (n = 171). Established sustainable levels of mortality were consistently exceeded in 2 species by up to 650%. Probabilities of entanglement and vessel-strike mortality increased significantly from 1990 through 2009. There was no significant change in the local intensity of all or vessel-strike mortalities before and after 2003, the year after which numerous mitigation efforts were enacted. So far, regulatory efforts have not reduced the lethal effects of human activities to large whales on a population-range basis, although we do not exclude the possibility of success of targeted measures for specific local habitats that were not within the resolution of our analyses. It is unclear how shortfalls in management design or compliance relate to our findings. Analyses such as the one we conducted are crucial in critically evaluating wildlife-management decisions. The results of these analyses can

  4. Cluster Galaxy Dynamics and the Effects of Large Scale Environment

    CERN Document Server

    White, Martin; Smit, Renske

    2010-01-01

    We use a high-resolution N-body simulation to study how the influence of large-scale structure in and around clusters causes correlated signals in different physical probes and discuss some implications this has for multi-physics probes of clusters. We pay particular attention to velocity dispersions, matching galaxies to subhalos which are explicitly tracked in the simulation. We find that not only do halos persist as subhalos when they fall into a larger host, groups of subhalos retain their identity for long periods within larger host halos. The highly anisotropic nature of infall into massive clusters, and their triaxiality, translates into an anisotropic velocity ellipsoid: line-of-sight galaxy velocity dispersions for any individual halo show large variance depending on viewing angle. The orientation of the velocity ellipsoid is correlated with the large-scale structure, and thus velocity outliers correlate with outliers caused by projection in other probes. We quantify this orientation uncertainty and ...

  5. Effects of Turbine Spacings in Very Large Wind Farms

    DEFF Research Database (Denmark)

    farm. LES simulations of large wind farms are performed with full aero-elastic Actuator Lines. The simulations investigate the inherent dynamics inside wind farms in the absence of atmospheric turbulence compared to cases with atmospheric turbulence. Resulting low frequency structures are inherent......The Dynamic Wake Meandering model(DWM) by Larsen et al.(2007) is considered state of the art for modelling the wake behind a wind turbine. DWM assumes a quasi-steady wake deficit transported as a passive tracer by large atmospheric scales. The approach is also applied to wake interaction within...

  6. Properties and Surprises of Solar Activity XXIII Cycle

    Science.gov (United States)

    Ishkov, V. N.

    2010-12-01

    The main properties of the 23rd cycle match almost completely those of average-magnitude solar cycles, and some of the features of the cycle may indicate a change in the generation mode of magnetic fields in the solar convection zone. If this is the case, the Sun enters a period of intermediate and weak cycles of solar activity (SA) in terms of the Wolf number, which may last for 3 to 6 solar cycles. The main development stages of solar cycle 23 are the following: minimum of solar cycle 22: April 1996 (W* = 8.0); maximum of the smoothed relative sunspot number: April 2000; global polarity reversal of the general solar magnetic field: July to December 2000; secondary maximum of the relative sunspot number: November 2001; maximum of the 10.7-cm radio flux: February 2002; phase of the cycle maximum: October 1999 to June 2002; beginning of the decrease phase: July 2002; the point of minimum of the current SA cycle: December 2008. Solar cycle 23 has presented two powerful flare-active sunspot groups, in September 2005 and December 2006 (+5.5 and +6.6 years from the maximum) which by flare potential occupy 4th and 20th place among the most flare-active regions for the last four solar cycles. The unprecedented duration of the relative sunspot numbers fall that has led to already record duration of the last solar cycle among authentic cycles (since 1849) became the next surprise of development of solar activity during the last cycle. The phase of the minimum began in May 2005 and lasted for 4.5 years. Thus, the new solar cycle 24 has begun in January 2009.

  7. Dracunculiasis eradication - Finishing the job before surprises arise

    Institute of Scientific and Technical Information of China (English)

    Benjamin Jelle Visser

    2012-01-01

    ABSTRACT Dracunculiasis(Guinea worm disease) is a preventable waterborne parasitic disease that affects the poorest people living in remote rural areas in sub-SaharanAfrican countries, who do not have access to safe drinking water.The Guinea Worm Eradication Program, a25-year old campaign to rid the world ofGuineaWorm disease has now reached its final stage accelerating to zero cases in all endemic countries.During the19th and20th centuries, dracunculiasis was common in much ofSouthernAsia and theAfrican continent.The overall number of cases has been reduced tremendously by≥99%, from the3.32 million cases estimated to have occurred in1986 inAfrica to only1797 cases reported in2010 reported in only five countries(Sudan,Mali,Ethiopia,Chad andGhana) andAsia free of the disease.This achievement is unique in its kind - the only previously eradicated disease is smallpox, a viral infection for which vaccination was possible - and it has been achieved through primary community-based prevention and health education programs.Most efforts need to be taken in two countries,SouthSudan(comprising94% or1698 out of1797 of the cases reported world-wide in2010) andMali because of frequent movements of nomads in a vast area inside and outsideMali’s borders.All factors favourable to dracunculiasis eradication are available including adequate financial resources, community and political support and high levels of advocacy.Thus there is no reason that this disabling parasitic disease cannot be eradicated soon before surprises arise such as new civil conflicts in currently endemic countries.

  8. Large Differences in the Optical Spectrum Associated with the Same Complex: The Effect of the Anisotropy of the Embedding Lattice

    DEFF Research Database (Denmark)

    Aramburu, José Antonio; García-Fernández, Pablo; García Lastra, Juan Maria

    2017-01-01

    of the electric field created by the rest of lattice ions over the complex. To illustrate this concept we analyze the origin of the surprisingly large differences in the d–d optical transitions of two systems containing square-planar CuF42– complexes, CaCuF4, and center II in Cu2+-doped Ba2ZnF6, even though...

  9. On the Effective Description of Large Volume Compactifications

    CERN Document Server

    Gallego, Diego

    2011-01-01

    We study the reliability of the Two-Step moduli stabilization in the type-IIB Large Volume Scenarios with matter and gauge interactions. The general analysis is based on a family of N=1 Supergravity models with a factorizable invariant Kaehler function, where the decoupling between two sets of fields without a mass hierarchy is easily understood. For the Large Volume Scenario particular analyses are performed for explicit models, one of such developed for the first time here, finding that the simplified version, where the Dilaton and Complex structure moduli are regarded as frozen by a previous stabilization, is a reliable supersymmetric description whenever the neglected fields stand at their leading F-flatness conditions and be neutral. The terms missed by the simplified approach are either suppressed by powers of the Calabi-Yau volume, or are higher order operators in the matter fields, and then irrelevant for the moduli stabilization rocedure. Although the power of the volume suppressing such corrections ...

  10. An effective filter for IBD detection in large data sets.

    KAUST Repository

    Huang, Lin

    2014-03-25

    Identity by descent (IBD) inference is the task of computationally detecting genomic segments that are shared between individuals by means of common familial descent. Accurate IBD detection plays an important role in various genomic studies, ranging from mapping disease genes to exploring ancient population histories. The majority of recent work in the field has focused on improving the accuracy of inference, targeting shorter genomic segments that originate from a more ancient common ancestor. The accuracy of these methods, however, is achieved at the expense of high computational cost, resulting in a prohibitively long running time when applied to large cohorts. To enable the study of large cohorts, we introduce SpeeDB, a method that facilitates fast IBD detection in large unphased genotype data sets. Given a target individual and a database of individuals that potentially share IBD segments with the target, SpeeDB applies an efficient opposite-homozygous filter, which excludes chromosomal segments from the database that are highly unlikely to be IBD with the corresponding segments from the target individual. The remaining segments can then be evaluated by any IBD detection method of choice. When examining simulated individuals sharing 4 cM IBD regions, SpeeDB filtered out 99.5% of genomic regions from consideration while retaining 99% of the true IBD segments. Applying the SpeeDB filter prior to detecting IBD in simulated fourth cousins resulted in an overall running time that was 10,000x faster than inferring IBD without the filter and retained 99% of the true IBD segments in the output.

  11. Effects of Turbine Spacing in Very Large Wind Farms

    Science.gov (United States)

    Andersen, Søren Juhl; Sørensen, Jens Nørkær; Mikkelsen, Robert Flemming

    2015-11-01

    The Dynamic Wake Meandering model(DWM) by Larsen et al. (2007) is considered state of the art for modelling the wake behind a wind turbine. DWM assumes a quasi-steady wake deficit transported as a passive tracer by large atmospheric scales. The approach is also applied to wake interaction within wind farms, although certain aspects of the complex wake interaction are not captured, see Churchfield et al. (2014). Recent studies have shown how turbines introduce low frequencies in the wake, which could describe some of the shortcomings. Chamorro et al. (2015) identified three regions of different lengths scales. Iungo et al. (2013) related low frequencies to the hub vortex instability. Okulov et al. (2014) found Strouhal numbers in the far wake stemming from the rotating helical vortex core. Simulations by Andersen et al. (2013) found low frequencies to be inherent in the flow inside an infinite wind farm. LES simulations of large wind farms are performed with full aero-elastic Actuator Lines. The simulations investigate the inherent dynamics inside wind farms in the absence of atmospheric turbulence compared to cases with atmospheric turbulence. Resulting low frequency structures are inherent in wind farms for certain turbine spacings and affect both power production and loads. Funded by Danish Council for Strategic Research (grant 2104-09-067216/DSF), the Nordic Consortium on Optimization and Control of Wind Farms, and EuroTech wind project. The proprietary data for Vestas' NM80 turbine has been used.

  12. Are seismic hazard assessment errors and earthquake surprises unavoidable?

    Science.gov (United States)

    Kossobokov, Vladimir

    2013-04-01

    Why earthquake occurrences bring us so many surprises? The answer seems evident if we review the relationships that are commonly used to assess seismic hazard. The time-span of physically reliable Seismic History is yet a small portion of a rupture recurrence cycle at an earthquake-prone site, which makes premature any kind of reliable probabilistic statements about narrowly localized seismic hazard. Moreover, seismic evidences accumulated to-date demonstrate clearly that most of the empirical relations commonly accepted in the early history of instrumental seismology can be proved erroneous when testing statistical significance is applied. Seismic events, including mega-earthquakes, cluster displaying behaviors that are far from independent or periodic. Their distribution in space is possibly fractal, definitely, far from uniform even in a single segment of a fault zone. Such a situation contradicts generally accepted assumptions used for analytically tractable or computer simulations and complicates design of reliable methodologies for realistic earthquake hazard assessment, as well as search and definition of precursory behaviors to be used for forecast/prediction purposes. As a result, the conclusions drawn from such simulations and analyses can MISLEAD TO SCIENTIFICALLY GROUNDLESS APPLICATION, which is unwise and extremely dangerous in assessing expected societal risks and losses. For example, a systematic comparison of the GSHAP peak ground acceleration estimates with those related to actual strong earthquakes, unfortunately, discloses gross inadequacy of this "probabilistic" product, which appears UNACCEPTABLE FOR ANY KIND OF RESPONSIBLE SEISMIC RISK EVALUATION AND KNOWLEDGEABLE DISASTER PREVENTION. The self-evident shortcomings and failures of GSHAP appeals to all earthquake scientists and engineers for an urgent revision of the global seismic hazard maps from the first principles including background methodologies involved, such that there becomes: (a) a

  13. Segmentation, diarization and speech transcription : surprise data unraveled

    NARCIS (Netherlands)

    Huijbregts, Marijn Anthonius Henricus

    2008-01-01

    In this thesis, research on large vocabulary continuous speech recognition for unknown audio conditions is presented. For automatic speech recognition systems based on statistical methods, it is important that the conditions of the audio used for training the statistical models match the conditions

  14. Segmentation, Diarization and Speech Transcription: Surprise Data Unraveled

    NARCIS (Netherlands)

    Huijbregts, M.A.H.

    2008-01-01

    In this thesis, research on large vocabulary continuous speech recognition for unknown audio conditions is presented. For automatic speech recognition systems based on statistical methods, it is important that the conditions of the audio used for training the statistical models match the conditions

  15. Large-Scale Structure and Gravitational Waves III: Tidal Effects

    CERN Document Server

    Schmidt, Fabian; Zaldarriaga, Matias

    2013-01-01

    The leading locally observable effect of a long-wavelength metric perturbation corresponds to a tidal field. We derive the tidal field induced by scalar, vector, and tensor perturbations, and use second order perturbation theory to calculate the effect on the locally measured small-scale density fluctuations. For sub-horizon scalar perturbations, we recover the standard perturbation theory result ($F_2$ kernel). For tensor modes of wavenumber $k_L$, we find that effects persist for $k_L\\tau \\gg 1$, i.e. even long after the gravitational wave has entered the horizon and redshifted away, i.e. it is a "fossil" effect. We then use these results, combined with the "ruler perturbations" of arXiv:1204.3625, to predict the observed distortion of the small-scale matter correlation function induced by a long-wavelength tensor mode. We also estimate the observed signal in the B mode of the cosmic shear from a gravitational wave background, including both tidal (intrinsic alignment) and projection (lensing) effects. The ...

  16. Large Seebeck effect by charge-mobility engineering

    Science.gov (United States)

    Sun, Peijie; Wei, Beipei; Zhang, Jiahao; Tomczak, Jan M.; Strydom, A. M.; Søndergaard, M.; Iversen, Bo B.; Steglich, Frank

    2015-06-01

    The Seebeck effect describes the generation of an electric potential in a conducting solid exposed to a temperature gradient. In most cases, it is dominated by an energy-dependent electronic density of states at the Fermi level, in line with the prevalent efforts towards superior thermoelectrics through the engineering of electronic structure. Here we demonstrate an alternative source for the Seebeck effect based on charge-carrier relaxation: a charge mobility that changes rapidly with temperature can result in a sizeable addition to the Seebeck coefficient. This new Seebeck source is demonstrated explicitly for Ni-doped CoSb3, where a marked mobility change occurs due to the crossover between two different charge-relaxation regimes. Our findings unveil the origin of pronounced features in the Seebeck coefficient of many other elusive materials characterized by a significant mobility mismatch. When utilized appropriately, this effect can also provide a novel route to the design of improved thermoelectric materials.

  17. Large strengthening effect of a hip-flexor training programme

    DEFF Research Database (Denmark)

    Thorborg, Kristian; Bandholm, Thomas Quaade; Zebis, Mette;

    2016-01-01

    PURPOSE: To investigate the effect on hip-flexion strength of a 6-week hip-flexor training programme using elastic bands as resistance. We hypothesized that the training group, compared to a control group, would increase their hip-flexion strength more. METHODS: Thirty-three healthy subjects (45 ...

  18. Large anomalous Hall effect in a half-Heusler antiferromagnet

    Science.gov (United States)

    Suzuki, T.; Chisnell, R.; Devarakonda, A.; Liu, Y.-T.; Feng, W.; Xiao, D.; Lynn, J. W.; Checkelsky, J. G.

    2016-12-01

    The quantum mechanical (Berry) phase of the electronic wavefunction plays a critical role in the anomalous and spin Hall effects, including their quantized limits. While progress has been made in understanding these effects in ferromagnets, less is known in antiferromagnetic systems. Here we present a study of antiferromagnet GdPtBi, whose electronic structure is similar to that of the topologically non-trivial HgTe (refs ,,), and where the Gd ions offer the possibility to tune the Berry phase via control of the spin texture. We show that this system supports an anomalous Hall angle ΘAH > 0.1, comparable to the largest observed in bulk ferromagnets and significantly larger than in other antiferromagnets. Neutron scattering measurements and electronic structure calculations suggest that this effect originates from avoided crossing or Weyl points that develop near the Fermi level due to a breaking of combined time-reversal and lattice symmetries. Berry phase effects associated with such symmetry breaking have recently been explored in kagome networks; our results extend this to half-Heusler systems with non-trivial band topology. The magnetic textures indicated here may also provide pathways towards realizing the topological insulating and semimetallic states predicted in this material class.

  19. Large D-instanton effects in string theory

    NARCIS (Netherlands)

    Pioline, B.; Vandoren, S.J.G.

    2009-01-01

    By reduction along the time direction, black holes in 4 dimensions yield instantons in 3 dimensions. Each of these instantons contributes individually at order exp(−|Q|/gs) to certain protected couplings in the three-dimensional effective action, but the number of distinct instantons is expected to

  20. Expectation and surprise determine neural population responses in the ventral visual stream.

    Science.gov (United States)

    Egner, Tobias; Monti, Jim M; Summerfield, Christopher

    2010-12-08

    Visual cortex is traditionally viewed as a hierarchy of neural feature detectors, with neural population responses being driven by bottom-up stimulus features. Conversely, "predictive coding" models propose that each stage of the visual hierarchy harbors two computationally distinct classes of processing unit: representational units that encode the conditional probability of a stimulus and provide predictions to the next lower level; and error units that encode the mismatch between predictions and bottom-up evidence, and forward prediction error to the next higher level. Predictive coding therefore suggests that neural population responses in category-selective visual regions, like the fusiform face area (FFA), reflect a summation of activity related to prediction ("face expectation") and prediction error ("face surprise"), rather than a homogenous feature detection response. We tested the rival hypotheses of the feature detection and predictive coding models by collecting functional magnetic resonance imaging data from the FFA while independently varying both stimulus features (faces vs houses) and subjects' perceptual expectations regarding those features (low vs medium vs high face expectation). The effects of stimulus and expectation factors interacted, whereby FFA activity elicited by face and house stimuli was indistinguishable under high face expectation and maximally differentiated under low face expectation. Using computational modeling, we show that these data can be explained by predictive coding but not by feature detection models, even when the latter are augmented with attentional mechanisms. Thus, population responses in the ventral visual stream appear to be determined by feature expectation and surprise rather than by stimulus features per se.

  1. The surprising diversity of clostridial hydrogenases: a comparative genomic perspective

    OpenAIRE

    Calusinska, Magdalena; Happe, Thomas; Joris, Bernard; Wilmotte, Annick

    2010-01-01

    Among the large variety of micro-organisms capable of fermentative hydrogen production, strict anaerobes such as members of the genus Clostridium are the most widely studied. They can produce hydrogen by a reversible reduction of protons accumulated during fermentation to dihydrogen, a reaction which is catalysed by hydrogenases. Sequenced genomes provide completely new insights into the diversity of clostridial hydrogenases. Building on previous reports, we found that [FeFe] hydrogenases are...

  2. Syncope with Surprise: An Unexpected Finding of Huge Gastric Diverticulum

    Directory of Open Access Journals (Sweden)

    Mauro Podda

    2016-01-01

    Full Text Available A gastric diverticulum is a pouch protruding from the gastric wall. The vague long clinical history ranging between dyspepsia, postprandial fullness, and upper gastrointestinal bleeding makes this condition a diagnostic challenge. We present a case of large gastric diverticulum that has been diagnosed during clinical investigations for suspected cardiovascular issues in a patient admitted at the medical ward for syncope. A 51-year-old man presented to the medical department due to a syncopal episode occurring while he was resting on the beach after having his lunch, with concomitant vague epimesogastric gravative pain without any other symptom. A diagnosis of neuromediated syncopal episode was made by the cardiologist. Due to the referred epimesogastric pain, an abdominal ultrasound scan was carried out, showing perisplenic fluid. A CT scan of the abdomen was performed to exclude splenic lesions. The CT scan revealed a large diverticulum protruding from the gastric fundus. The upper gastrointestinal endoscopy visualized a large diverticular neck situated in the posterior wall of the gastric fundus, partially filled by undigested food. The patient underwent surgery, with an uneventful postoperative course. Histologic examination showed a full-thickness stomach specimen, indicative of a congenital diverticulum. At the 2nd month of follow-up, the patient was asymptomatic.

  3. Longitudinal intensity effects in the CERN Large Hadron Collider

    CERN Document Server

    AUTHOR|(CDS)2081238; Rivkin, Leonid

    This PhD thesis provides an improved knowledge of the LHC longitudinal impedance model and a better understanding of the longitudinal intensity effects. These effects can limit the LHC performance and lead to a reduction of the integrated luminosity. The LHC longitudinal impedance was measured with beams. Results obtained using traditional techniques are consistent with the expectations based on the impedance model, although the measurement precision was proven insufficient for the low impedance of the LHC. Innovative methods to probe the LHC reactive impedance were successfully used. One of the methods is based on exciting the beam with a sinusoidal rf phase modulation to estimate the synchrotron frequency shift from potential-well distortion. In the second method, the impedance is estimated from the loss of Landau damping threshold, which is also found to be in good agreement with analytical estimations. Beam-based impedance measurements agree well with estimations using the LHC impedance model. Macropartic...

  4. How Large are Nonadiabatic Effects in Atomic and Diatomic Systems?

    CERN Document Server

    Yang, Yubo; Tubman, Norm; Krogel, Jaron; Hammes-Schiffer, Sharon; Ceperley, David

    2015-01-01

    With recent developments in simulating nonadiabatic systems to high accuracy, it has become possible to determine how much energy is attributed to nuclear quantum effects beyond zero-point energy. In this work we calculate the non-relativistic ground-state energies of atomic and molecular systems without the Born-Oppenheimer approximation. For this purpose we utilize the fixed-node diffusion Monte Carlo method, in which the nodes depend on both the electronic and ionic positions. We report ground-state energies for all systems studied, ionization energies for the first-row atoms and atomization energies for the first-row hydrides. We find the ionization energies of the atoms to be nearly independent of the Born-Oppenheimer approximation, within the accuracy of our results. The atomization energies of molecular systems, however, show small effects of the nonadiabatic coupling between electrons and nuclei.

  5. Large-scale Contextual Effects in Early Human Visual Cortex

    Directory of Open Access Journals (Sweden)

    Sung Jun Joo

    2012-10-01

    Full Text Available A commonly held view about neurons in early visual cortex is that they serve as localized feature detectors. Here, however, we demonstrate that the responses of neurons in early visual cortex are sensitive to global visual patterns. Using multiple methodologies–psychophysics, fMRI, and EEG–we measured neural responses to an oriented Gabor (“target” embedded in various orientation patterns. Specifically, we varied whether a central target deviated from its context by changing distant orientations while leaving the immediately neighboring flankers unchanged. The results of psychophysical contrast adaptation and fMRI experiments show that a target that deviates from its context results in more neural activity compared to a target that is grouped into an alternating pattern. For example, the neural response to a vertically oriented target was greater when it deviated from the orientation of flankers (HHVHH compared to when it was grouped into an alternating pattern (VHVHV. We then found that this pattern-sensitive response manifests in the earliest sensory component of the event-related potential to the target. Finally, in a forced-choice classification task of “noise” stimuli, perceptions are biased to “see” an orientation that deviates from its context. Our results show that neurons in early visual cortex are sensitive to large-scale global patterns in images in a way that is more sophisticated than localized feature detection. Our results showing a reduced neural response to statistical redundancies in images is not only optimal from an information theory perspective but also takes into account known energy constraints in neural processing.

  6. New surprises in the largest magnetosphere of our solar system.

    Science.gov (United States)

    Krupp, Norbert

    2007-10-12

    En route to its ultimate rendezvous with Pluto, the New Horizons spacecraft passed through the magnetic and plasma environment of Jupiter in February 2007. Onboard instruments collected high-resolution images, spectroscopic data, and information about charged particles. The results have revealed unusual structure and variation in Jupiter's plasma and large plasmoids that travel down the magnetotail. Data on Jupiter's aurora provide details of the interaction with the solar wind, and a major volcanic eruption from the moon Io was observed during the encounter.

  7. Trait Anxiety Is Associated with Negative Interpretations When Resolving Valence Ambiguity of Surprised Faces.

    Science.gov (United States)

    Park, Gewnhi; Vasey, Michael W; Kim, Grace; Hu, Dixie D; Thayer, Julian F

    2016-01-01

    The current research examines whether trait anxiety is associated with negative interpretation bias when resolving valence ambiguity of surprised faces. To further isolate the neuro-cognitive mechanism, we presented angry, happy, and surprised faces at broad spatial frequency (BSF), high spatial frequency (HSF), and low spatial frequency (LSF) and asked participants to determine the valence of each face. High trait anxiety was associated with more negative interpretations of BSF (i.e., intact) surprised faces. However, the modulation of trait anxiety on the negative interpretation of surprised faces disappeared at HSF and LSF. The current study provides evidence that trait anxiety modulates negative interpretations of BSF surprised faces. However, the negative interpretation of LSF surprised faces appears to be a robust default response that occurs regardless of individual differences in trait anxiety.

  8. Trait anxiety is associated with negative interpretations when resolving valence ambiguity of surprised faces

    Directory of Open Access Journals (Sweden)

    Gewnhi Park

    2016-08-01

    Full Text Available The current research examines whether trait anxiety is associated with negative interpretation bias when resolving valence ambiguity of surprised faces. To further isolate the neuro-cognitive mechanism, we presented angry, happy, and surprised faces at broad, high, and low spatial frequency and asked participants to determine the valence of each face. High trait anxiety was associated with more negative interpretations of broad spatial frequency (i.e., intact surprised faces. However, the modulation of trait anxiety on the negative interpretation of surprised faces disappeared at high and low spatial frequencies. The current study provides evidence that trait anxiety modulates negative interpretations of broad spatial frequency surprised faces. However, the negative interpretation of low spatial frequency surprised faces appears to be a robust default response that occurs regardless of individual differences in trait anxiety.

  9. Marine Protected Areas, Multiple-Agency Management, and Monumental Surprise in the Northwestern Hawaiian Islands

    Directory of Open Access Journals (Sweden)

    John N. Kittinger

    2011-01-01

    Full Text Available Large, regional-scale marine protected areas (MPAs and MPA networks face different challenges in governance systems than locally managed or community-based MPAs. An emerging theme in large-scale MPA management is the prevalence of governance structures that rely on institutional collaboration, presenting new challenges as agencies with differing mandates and cultures work together to implement ecosystem-based management. We analyzed qualitative interview data to investigate multi-level social interactions and institutional responses to the surprise establishment of the Papahānaumokuākea Marine National Monument (monument in the northwestern Hawaiian Islands (NWHI. The governance arrangement for the monument represents a new model in US MPA management, requiring two federal agencies and the State of Hawai‘i to collaboratively manage the NWHI. We elucidate the principal barriers to institutional cotrusteeship, characterize institutional transformations that have occurred among the partner agencies in the transition to collaborative management, and evaluate the governance arrangement for the monument as a model for MPAs. The lessons learned from the NWHI governance arrangement are critical as large-scale MPAs requiring multiple-agency management become a prevalent feature on the global seascape.

  10. Large magnetocaloric effect in sintered ferromagnetic EuS

    Science.gov (United States)

    Matsumoto, Koichi; Li, Liang; Hirai, Shinji; Nakamura, Eiji; Murayama, Daiki; Ura, Yutaro; Abe, Satoshi

    2016-10-01

    We present magnetocaloric effect measurements of the ferromagnetic semiconductor EuS in the vicinity of its ordering temperature. Single phase EuS powder was synthesized by CS2 gas sulfurization of Eu2O3. A sintered compact with relative density over 95% was prepared by pulsed electric current sintering of the powder. Temperature and magnetic field dependence of the magnetization and specific heat were characteristic of a paramagnetic to ferromagnetic second order phase transition. The entropy change induced by an external magnetic field and the specific heat were both close to those of a single crystal. We obtained an entropy-temperature (S-T) diagram of the EuS sintered compact. Carnot cycle liquefaction of hydrogen using EuS was compared with several other materials, with results indicating that sintered EuS is an excellent magnetic refrigerant for hydrogen liquefaction.

  11. Trait Anxiety Is Associated with Negative Interpretations When Resolving Valence Ambiguity of Surprised Faces

    OpenAIRE

    Gewnhi Park; Vasey, Michael W.; Grace Kim; Dixie D Hu; Thayer, Julian F

    2016-01-01

    The current research examines whether trait anxiety is associated with negative interpretation bias when resolving valence ambiguity of surprised faces. To further isolate the neuro-cognitive mechanism, we presented angry, happy, and surprised faces at broad, high, and low spatial frequency and asked participants to determine the valence of each face. High trait anxiety was associated with more negative interpretations of broad spatial frequency (i.e., intact) surprised faces. However, the mo...

  12. a Surprise from the Pulsar in the Crab Nebula

    Science.gov (United States)

    1995-11-01

    before the discovery of pulsars, as the possible central remnant of the Crab Nebula [3]. This was fully confirmed when its pulsed radio emission was detected in 1968. At this optical brightness, about 10,000 times fainter than the faintest stars that can be perceived with the unaided eye, the Crab Pulsar is still by far the brightest of the few known neutron stars whose optical light has been detected. It is in fact more than 1,000 times brighter than the next brightest pulsar, PSR 0540-69 in the Large Magellanic Cloud, a satellite galaxy to the Milky Way system in which we live. Observations of the Crab Pulsar Spectrum Thus it was possible for American astronomer J. Beverley Oke (Caltech) to perform the first optical measurements of the Crab Pulsar spectrum already in 1969. Although this was quite an observational feat at the time, the information content of that measurement is not very high by modern standards; the spectral resolution was only about 200 A (20 nm). Oke's spectrum of the Crab Pulsar qualitatively confirmed the theoretical expectations by being flat and featureless and no isolated spectral features were seen at this low resolution. It appears that since 1969, nobody has obtained spectrum of the Crab pulsar with a better spectral resolution than Oke. This seems amazing, but may at least partly be explained by the fact that this object is deeply embedded in the much brighter Crab Nebula of expanding gas. Any spectrum of the pulsar is therefore necessarily strongly contaminated by that of the surrounding nebula, making it difficult to obtain a `pure' spectrum of the pulsar. Now, however, the group of Italian astronomers has performed a much improved spectral measurement of the Crab Pulsar with the EMMI multi-mode instrument at the ESO NTT. The resulting spectrum has a resolution of 2 A (0.2 nm), i.e. dramatically better than the one achieved in 1969, and reflecting the incredible evolution of astronomical instrumentation during the intervening quarter of a

  13. Modeling the Effect of Climate Change on Large Fire Size, Counts, and Intensities Using the Large Fire Simulator (FSim)

    Science.gov (United States)

    Riley, K. L.; Haas, J. R.; Finney, M.; Abatzoglou, J. T.

    2013-12-01

    Changes in climate can be expected to cause changes in wildfire activity due to a combination of shifts in weather (temperature, precipitation, relative humidity, wind speed and direction) and vegetation. Changes in vegetation could include type conversions, altered forest structure, and shifts in species composition, the effects of which could be mitigated or exacerbated by management activities. Further, changes in suppression response and effectiveness may alter potential wildfire activity, as well as the consequences of wildfire. Feedbacks among these factors are extremely complex and uncertain. The ability to anticipate changes driven by fire weather (largely outside of human control) can lead to development of fire and fuel management strategies aimed at mitigating current and future risk. Therefore, in this study we focus on isolating the effects of climate-induced changes in weather on wildfire activity. Specifically, we investigated the effect of changes in weather on fire activity in the Canadian Rockies ecoregion, which encompasses Glacier National Park and several large wilderness areas to the south. To model the ignition, growth, and containment of wildfires, we used the Large Fire Simulator (FSim), which we coupled with current and projected future climatic conditions. Weather streams were based on data from 14 downscaled Global Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) using the Representative Concentration Pathways (RCP) 45 and 85 for the years 2040-2060. While all GCMs indicate increases in temperature for this area, which would be expected to exacerbate fire activity, precipitation predictions for the summer wildfire season are more variable, ranging from a decrease of approximately 50 mm to an increase of approximately 50 mm. Windspeeds are generally predicted to decrease, which would reduce rates of spread and fire intensity. The net effect of these weather changes on the size, number, and intensity

  14. Latin America: how a region surprised the experts.

    Science.gov (United States)

    De Sherbinin, A

    1993-02-01

    In 1960-1970, family planning specialists and demographers worried that poverty, limited education, Latin machismo, and strong catholic ideals would obstruct family planning efforts to reduce high fertility in Latin America. It had the highest annual population growth rate in the world (2.8%), which would increase the population 2-fold in 25 years. Yet, the UN's 1992 population projection for Latin America and the Caribbean in the year 2000 was about 20% lower than its 1963 projection (just over 500 vs. 638 million). Since life expectancy increased simultaneously from 57 to 68 years, this reduced projection was caused directly by a large decline in fertility from 5.9 to 3. A regression analysis of 11 Latin American and Caribbean countries revealed that differences in the contraceptive prevalence rates accounted for 90% of the variation in the total fertility rate between countries. Thus, contraception played a key role in the fertility decline. The second most significant determinant of fertility decline was an increase in the average age at first marriage from about 20 to 23 years. Induced abortion and breast feeding did not contribute significantly to fertility decline. The major socioeconomic factors responsible for the decline included economic development and urbanization, resulting in improvements in health care, reduced infant and child mortality, and increases in female literacy, education, and labor force participation. Public and private family planning programs also contributed significantly to the decline. They expanded from cities to remote rural areas, thereby increasing access to contraception. By the early 1990s, Brazil, Mexico, and Colombia had among the lowest levels of unmet need (13-24%) in developing countries. Other key factors of fertility decline were political commitment, strong communication efforts, and stress on quality services. Latin America provides hope to other regions where religion and culture promote a large family size.

  15. Automated Atmospheric Composition Dataset Level Metadata Discovery. Difficulties and Surprises

    Science.gov (United States)

    Strub, R. F.; Falke, S. R.; Kempler, S.; Fialkowski, E.; Goussev, O.; Lynnes, C.

    2015-12-01

    The Atmospheric Composition Portal (ACP) is an aggregator and curator of information related to remotely sensed atmospheric composition data and analysis. It uses existing tools and technologies and, where needed, enhances those capabilities to provide interoperable access, tools, and contextual guidance for scientists and value-adding organizations using remotely sensed atmospheric composition data. The initial focus is on Essential Climate Variables identified by the Global Climate Observing System - CH4, CO, CO2, NO2, O3, SO2 and aerosols. This poster addresses our efforts in building the ACP Data Table, an interface to help discover and understand remotely sensed data that are related to atmospheric composition science and applications. We harvested GCMD, CWIC, GEOSS metadata catalogs using machine to machine technologies - OpenSearch, Web Services. We also manually investigated the plethora of CEOS data providers portals and other catalogs where that data might be aggregated. This poster is our experience of the excellence, variety, and challenges we encountered.Conclusions:1.The significant benefits that the major catalogs provide are their machine to machine tools like OpenSearch and Web Services rather than any GUI usability improvements due to the large amount of data in their catalog.2.There is a trend at the large catalogs towards simulating small data provider portals through advanced services. 3.Populating metadata catalogs using ISO19115 is too complex for users to do in a consistent way, difficult to parse visually or with XML libraries, and too complex for Java XML binders like CASTOR.4.The ability to search for Ids first and then for data (GCMD and ECHO) is better for machine to machine operations rather than the timeouts experienced when returning the entire metadata entry at once. 5.Metadata harvest and export activities between the major catalogs has led to a significant amount of duplication. (This is currently being addressed) 6.Most (if not

  16. EFFECTS OF LARGE-SCALE POULTRY FARMS ON AQUATIC MICROBIAL COMMUNITIES: A MOLECULAR INVESTIGATION.

    Science.gov (United States)

    The effects of large-scale poultry production operations on water quality and human health are largely unknown. Poultry litter is frequently applied as fertilizer to agricultural lands adjacent to large poultry farms. Run-off from the land introduces a variety of stressors into t...

  17. EFFECTS OF LARGE-SCALE POULTRY FARMS ON AQUATIC MICROBIAL COMMUNITIES: A MOLECULAR INVESTIGATION.

    Science.gov (United States)

    The effects of large-scale poultry production operations on water quality and human health are largely unknown. Poultry litter is frequently applied as fertilizer to agricultural lands adjacent to large poultry farms. Run-off from the land introduces a variety of stressors into t...

  18. The Surprisingly Modest Relationship between SES and Educational Achievement

    Science.gov (United States)

    Harwell, Michael; Maeda, Yukiko; Bishop, Kyoungwon; Xie, Aolin

    2017-01-01

    Measures of socioeconomic status (SES) are routinely used in analyses of achievement data to increase statistical power, statistically control for the effects of SES, and enhance causality arguments under the premise that the SES-achievement relationship is moderate to strong. Empirical evidence characterizing the strength of the SES-achievement…

  19. Surprises from the resummation of ladders in the ABJ(M) cusp anomalous dimension

    CERN Document Server

    Bonini, Marisa; Preti, Michelangelo; Seminara, Domenico

    2016-01-01

    We study the cusp anomalous dimension in N=6 ABJ(M) theory, identifying a scaling limit in which the ladder diagrams dominate. The resummation is encoded into a Bethe-Salpeter equation that is mapped to a Schroedinger problem, exactly solvable due to the surprising supersymmetry of the effective Hamiltonian. In the ABJ case the solution implies the diagonalization of the U(N) and U(M) building blocks, suggesting the existence of two independent cusp anomalous dimensions and an unexpected exponentiation structure for the related Wilson loops. While consistent with previous perturbative analysis, the strong coupling limit of our result does not agree with the string theory computation, emphasizing a difference with the analogous resummation in the N=4 case.

  20. The Surprising Role of Amyloid Fibrils in HIV Infection.

    Science.gov (United States)

    Castellano, Laura M; Shorter, James

    2012-01-01

    Despite its discovery over 30 years ago, human immunodeficiency virus (HIV) continues to threaten public health worldwide. Semen is the principal vehicle for the transmission of this retrovirus and several endogenous peptides in semen, including fragments of prostatic acid phosphatase (PAP248-286 and PAP85-120) and semenogelins (SEM1 and SEM2), assemble into amyloid fibrils that promote HIV infection. For example, PAP248-286 fibrils, termed SEVI (Semen derived Enhancer of Viral Infection), potentiate HIV infection by up to 105-fold. Fibrils enhance infectivity by facilitating virion attachment and fusion to target cells, whereas soluble peptides have no effect. Importantly, the stimulatory effect is greatest at low viral titers, which mimics mucosal transmission of HIV, where relatively few virions traverse the mucosal barrier. Devising a method to rapidly reverse fibril formation (rather than simply inhibit it) would provide an innovative and urgently needed preventative strategy for reducing HIV infection via the sexual route. Targeting a host-encoded protein conformer represents a departure from traditional microbicidal approaches that target the viral machinery, and could synergize with direct antiviral approaches. Here, we review the identification of these amyloidogenic peptides, their mechanism of action, and various strategies for inhibiting their HIV-enhancing effects.

  1. Surprising structures hiding in Penrose’s future null infinity

    Science.gov (United States)

    Newman, Ezra T.

    2017-07-01

    Since the late1950s, almost all discussions of asymptotically flat (Einstein-Maxwell) space-times have taken place in the context of Penrose’s null infinity, I+. In addition, almost all calculations have used the Bondi coordinate and tetrad systems. Beginning with a known asymptotically flat solution to the Einstein-Maxwell equations, we show first, that there are other natural coordinate systems, near I+, (analogous to light-cones in flat-space) that are based on (asymptotically) shear-free null geodesic congruences (analogous to the flat-space case). Using these new coordinates and their associated tetrad, we define the complex dipole moment, (the mass dipole plus i times angular momentum), from the l  =  1 harmonic coefficient of a component of the asymptotic Weyl tensor. Second, from this definition, from the Bianchi identities and from the Bondi-Sachs mass and linear momentum, we show that there exists a large number of results—identifications and dynamics—identical to those of classical mechanics and electrodynamics. They include, among many others, {P}=M{v}+..., {L}= {r} × {P} , spin, Newton’s second law with the rocket force term (\\dotM v) and radiation reaction, angular momentum conservation and others. All these relations take place in the rather mysterious H-space rather than in space-time. This leads to the enigma: ‘why do these well known relations of classical mechanics take place in H-space?’ and ‘What is the physical meaning of H-space?’

  2. Virome Assembly and Annotation: A Surprise in the Namib Desert

    Science.gov (United States)

    Hesse, Uljana; van Heusden, Peter; Kirby, Bronwyn M.; Olonade, Israel; van Zyl, Leonardo J.; Trindade, Marla

    2017-01-01

    Sequencing, assembly, and annotation of environmental virome samples is challenging. Methodological biases and differences in species abundance result in fragmentary read coverage; sequence reconstruction is further complicated by the mosaic nature of viral genomes. In this paper, we focus on biocomputational aspects of virome analysis, emphasizing latent pitfalls in sequence annotation. Using simulated viromes that mimic environmental data challenges we assessed the performance of five assemblers (CLC-Workbench, IDBA-UD, SPAdes, RayMeta, ABySS). Individual analyses of relevant scaffold length fractions revealed shortcomings of some programs in reconstruction of viral genomes with excessive read coverage (IDBA-UD, RayMeta), and in accurate assembly of scaffolds ≥50 kb (SPAdes, RayMeta, ABySS). The CLC-Workbench assembler performed best in terms of genome recovery (including highly covered genomes) and correct reconstruction of large scaffolds; and was used to assemble a virome from a copper rich site in the Namib Desert. We found that scaffold network analysis and cluster-specific read reassembly improved reconstruction of sequences with excessive read coverage, and that strict data filtering for non-viral sequences prior to downstream analyses was essential. In this study we describe novel viral genomes identified in the Namib Desert copper site virome. Taxonomic affiliations of diverse proteins in the dataset and phylogenetic analyses of circovirus-like proteins indicated links to the marine habitat. Considering additional evidence from this dataset we hypothesize that viruses may have been carried from the Atlantic Ocean into the Namib Desert by fog and wind, highlighting the impact of the extended environment on an investigated niche in metagenome studies. PMID:28167933

  3. Virome Assembly and Annotation: A Surprise in the Namib Desert.

    Science.gov (United States)

    Hesse, Uljana; van Heusden, Peter; Kirby, Bronwyn M; Olonade, Israel; van Zyl, Leonardo J; Trindade, Marla

    2017-01-01

    Sequencing, assembly, and annotation of environmental virome samples is challenging. Methodological biases and differences in species abundance result in fragmentary read coverage; sequence reconstruction is further complicated by the mosaic nature of viral genomes. In this paper, we focus on biocomputational aspects of virome analysis, emphasizing latent pitfalls in sequence annotation. Using simulated viromes that mimic environmental data challenges we assessed the performance of five assemblers (CLC-Workbench, IDBA-UD, SPAdes, RayMeta, ABySS). Individual analyses of relevant scaffold length fractions revealed shortcomings of some programs in reconstruction of viral genomes with excessive read coverage (IDBA-UD, RayMeta), and in accurate assembly of scaffolds ≥50 kb (SPAdes, RayMeta, ABySS). The CLC-Workbench assembler performed best in terms of genome recovery (including highly covered genomes) and correct reconstruction of large scaffolds; and was used to assemble a virome from a copper rich site in the Namib Desert. We found that scaffold network analysis and cluster-specific read reassembly improved reconstruction of sequences with excessive read coverage, and that strict data filtering for non-viral sequences prior to downstream analyses was essential. In this study we describe novel viral genomes identified in the Namib Desert copper site virome. Taxonomic affiliations of diverse proteins in the dataset and phylogenetic analyses of circovirus-like proteins indicated links to the marine habitat. Considering additional evidence from this dataset we hypothesize that viruses may have been carried from the Atlantic Ocean into the Namib Desert by fog and wind, highlighting the impact of the extended environment on an investigated niche in metagenome studies.

  4. Surprisingly rational: probability theory plus noise explains biases in judgment.

    Science.gov (United States)

    Costello, Fintan; Watts, Paul

    2014-07-01

    The systematic biases seen in people's probability judgments are typically taken as evidence that people do not use the rules of probability theory when reasoning about probability but instead use heuristics, which sometimes yield reasonable judgments and sometimes yield systematic biases. This view has had a major impact in economics, law, medicine, and other fields; indeed, the idea that people cannot reason with probabilities has become a truism. We present a simple alternative to this view, where people reason about probability according to probability theory but are subject to random variation or noise in the reasoning process. In this account the effect of noise is canceled for some probabilistic expressions. Analyzing data from 2 experiments, we find that, for these expressions, people's probability judgments are strikingly close to those required by probability theory. For other expressions, this account produces systematic deviations in probability estimates. These deviations explain 4 reliable biases in human probabilistic reasoning (conservatism, subadditivity, conjunction, and disjunction fallacies). These results suggest that people's probability judgments embody the rules of probability theory and that biases in those judgments are due to the effects of random noise.

  5. Surprisal-based comparison between a symbolic and a connectionist model of sentence processing

    NARCIS (Netherlands)

    Frank, S.L.; Taatgen, N.; van Rijn, H.

    2009-01-01

    The 'unlexicalized surprisal' of a word in sentence context is defined as the negative logarithm of the probability of the word's part-of-speech given the sequence of previous parts-of-speech of the sentence. Unlexicalized surprisal is known to correlate with word reading time. Here, it is shown

  6. Distinct medial temporal networks encode surprise during motivation by reward versus punishment.

    Science.gov (United States)

    Murty, Vishnu P; LaBar, Kevin S; Adcock, R Alison

    2016-10-01

    Adaptive motivated behavior requires predictive internal representations of the environment, and surprising events are indications for encoding new representations of the environment. The medial temporal lobe memory system, including the hippocampus and surrounding cortex, encodes surprising events and is influenced by motivational state. Because behavior reflects the goals of an individual, we investigated whether motivational valence (i.e., pursuing rewards versus avoiding punishments) also impacts neural and mnemonic encoding of surprising events. During functional magnetic resonance imaging (fMRI), participants encountered perceptually unexpected events either during the pursuit of rewards or avoidance of punishments. Despite similar levels of motivation across groups, reward and punishment facilitated the processing of surprising events in different medial temporal lobe regions. Whereas during reward motivation, perceptual surprises enhanced activation in the hippocampus, during punishment motivation surprises instead enhanced activation in parahippocampal cortex. Further, we found that reward motivation facilitated hippocampal coupling with ventromedial PFC, whereas punishment motivation facilitated parahippocampal cortical coupling with orbitofrontal cortex. Behaviorally, post-scan testing revealed that reward, but not punishment, motivation resulted in greater memory selectivity for surprising events encountered during goal pursuit. Together these findings demonstrate that neuromodulatory systems engaged by anticipation of reward and punishment target separate components of the medial temporal lobe, modulating medial temporal lobe sensitivity and connectivity. Thus, reward and punishment motivation yield distinct neural contexts for learning, with distinct consequences for how surprises are incorporated into predictive mnemonic models of the environment.

  7. Effects of introduction and exclusion of large herbivores on small rodent communities

    NARCIS (Netherlands)

    Smit, R.; Bokdam, J.; Ouden, J. den; Olff, H.; Schot-Opschoor, H.; Schrijvers, M.

    2001-01-01

    In this study we analysed the effects of large herbivores on small rodent communities in different habitats using large herbivore exclosures. We studied the effects of three year grazing introduction by red deer (Cervus elaphus L.) in previously ungrazed pine and oak woodland and the exclusion of gr

  8. The Nucleus of Comet 67P/Churyumov-Gerasimenko: Lots of Surprises

    Science.gov (United States)

    Weissman, Paul R.; Rosetta Science Working Team

    2016-10-01

    ESA's Rosetta mission has made many new and unexpected discoveries since its arrival at comet 67P/Churyumov-Gerasimenko in August 2014. The first of these was the unusual shape of the cometary nucleus. Although bilobate nuclei had been seen before, the extreme concavities on 67P were unexpected. Evidence gathered during the mission suggests that two independent bodies came together to form 67P, rather than the nucleus being a single body that was sculpted by sublimation and/or other processes. Although not a surprise, early observations showed that the nucleus rotation period had decreased by ~22 minutes since the previous aphelion passage. A similar rotation period decrease was seen post-perihelion during the encounter. These changes likely arise from asymmetric jetting forces from the irregular nucleus. Initially, Rosetta's instruments found little evidence for water ice on the surface; the presence of surface water ice increased substantially as the nucleus approached perihelion. The nucleus bulk density, 533 ± 6 kg/m3, was measured with Radio Science and OSIRIS imaging of the nucleus volume. This confirmed previous estimates based on indirect methods that the bulk density of cometary nuclei was on the order of 500-600 kg/m3 and on measurement of the density of 9P/Tempel 1's nucleus by Deep Impact. Nucleus topography proved to be highly varied, from smooth dust-covered plains to shallow circular basins, to the very rough terrain where the Philae lander came to rest. Evidence of thermal cracking is everywhere. The discovery of cylindrical pits on the surface, typically 100-200m in diameter with similar depths was a major surprise and has been interpreted as sinkholes. "Goose-bump" terrain consisting of apparently random piles of boulders 2-3 m in diameter was another unexpected discovery. Apparent layering with scales of meters to many tens of meters was seen but there was little or no evidence for impact features. Radar tomography of the interior of the "head

  9. Carbon monoxide and bile pigments: surprising mediators of vascular function.

    Science.gov (United States)

    Durante, William

    2002-08-01

    Heme oxygenase (HO) catalyzes the degradation of heme to CO, iron, and biliverdin. Biliverdin is subsequently metabolized to bilirubin by the enzyme biliverdin reductase. Although long considered irrelevant byproducts of heme catabolism, recent studies indicate that CO and the bile pigments biliverdin and bilirubin may play an important physiological role in the circulation. The release of CO by vascular cells may modulate blood flow and blood fluidity by inhibiting vasomotor tone, smooth muscle cell proliferation, and platelet aggregation. CO may also maintain the integrity of the vessel wall by directly blocking vascular cell apoptosis and by inhibiting the release of pro-apoptotic inflammatory cytokines from the vessel wall. These effects of CO are mediated via multiple pathways, including activation of soluble guanylate cyclase, potassium channels, p38 mitogen-activated protein kinase, or inhibition of cytochrome P450. In addition, the release of bile pigments may serve to sustain vascular homeostasis by protecting vascular cells from oxidative stress and by inhibiting the adhesion and infiltration of leukocytes into the vessel wall. Induction of HO-1 gene expression and the subsequent release of CO and bile pigments are observed in numerous vascular disorders and may provide an important adaptive mechanism to preserve homeostasis at sites of vascular injury. Thus, the HO-catalyzed formation of CO and bile pigments by vascular cells may function as a critical endogenous vasoprotective system. Moreover, pharmacological or genetic approaches targeting HO-1 to the vessel wall may represent a novel therapeutic approach in treating vascular disease.

  10. Previously seen and expected stimuli elicit surprise in the context of visual search.

    Science.gov (United States)

    Retell, James D; Becker, Stefanie I; Remington, Roger W

    2016-04-01

    In the context of visual search, surprise is the phenomenon by which a previously unseen and unexpected stimulus exogenously attracts spatial attention. Capture by such a stimulus occurs, by definition, independent of task goals and is thought to be dependent on the extent to which the stimulus deviates from expectations. However, the relative contributions of prior-exposure and explicit knowledge of an unexpected event to the surprise response have not yet been systematically investigated. Here observers searched for a specific color while ignoring irrelevant cues of different colors presented prior to the target display. After a brief familiarization period, we presented an irrelevant motion cue to elicit surprise. Across conditions we varied prior exposure to the motion stimulus - seen versus unseen - and top-down expectations of occurrence - expected versus unexpected - to assess the extent to which each of these factors contributes to surprise. We found no attenuation of the surprise response when observers were pre-exposed to the motion cue and or had explicit knowledge of its occurrence. Our results show that it is neither sufficient nor necessary that a stimulus be new and unannounced to elicit surprise and suggest that the expectations that determine the surprise response are highly context specific.

  11. A surprisingly simple correlation between the classical and quantum structural networks in liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Hamm, Peter; Fanourgakis, George S.; Xantheas, Sotiris S.

    2017-08-14

    Nuclear quantum effects in liquid water have profound implications for several of its macroscopic properties related to structure, dynamics, spectroscopy and transport. Although several of water’s macroscopic properties can be reproduced by classical descriptions of the nuclei using potentials effectively parameterized for a narrow range of its phase diagram, a proper account of the nuclear quantum effects is required in order to ensure that the underlying molecular interactions are transferable across a wide temperature range covering different regions of that diagram. When performing an analysis of the hydrogen bonded structural networks in liquid water resulting from the classical (class.) and quantum (q.m.) descriptions of the nuclei with the transferable, flexible, polarizable TTM3-F interaction potential, we found that the two results can be superimposed over the temperature range of T=270-350 K using a surprisingly simple, linear scaling of the two temperatures according to T(q.m.)=aT(class)- T , where a=1.2 and T=51 K. The linear scaling and constant shift of the temperature scale can be considered as a generalization of the previously reported temperature shifts (corresponding to structural changes and the melting T) induced by quantum effects in liquid water.

  12. A Statistical Analysis of the Relationship between Harmonic Surprise and Preference in Popular Music.

    Science.gov (United States)

    Miles, Scott A; Rosen, David S; Grzywacz, Norberto M

    2017-01-01

    Studies have shown that some musical pieces may preferentially activate reward centers in the brain. Less is known, however, about the structural aspects of music that are associated with this activation. Based on the music cognition literature, we propose two hypotheses for why some musical pieces are preferred over others. The first, the Absolute-Surprise Hypothesis, states that unexpected events in music directly lead to pleasure. The second, the Contrastive-Surprise Hypothesis, proposes that the juxtaposition of unexpected events and subsequent expected events leads to an overall rewarding response. We tested these hypotheses within the framework of information theory, using the measure of "surprise." This information-theoretic variable mathematically describes how improbable an event is given a known distribution. We performed a statistical investigation of surprise in the harmonic structure of songs within a representative corpus of Western popular music, namely, the McGill Billboard Project corpus. We found that chords of songs in the top quartile of the Billboard chart showed greater average surprise than those in the bottom quartile. We also found that the different sections within top-quartile songs varied more in their average surprise than the sections within bottom-quartile songs. The results of this study are consistent with both the Absolute- and Contrastive-Surprise Hypotheses. Although these hypotheses seem contradictory to one another, we cannot yet discard the possibility that both absolute and contrastive types of surprise play roles in the enjoyment of popular music. We call this possibility the Hybrid-Surprise Hypothesis. The results of this statistical investigation have implications for both music cognition and the human neural mechanisms of esthetic judgments.

  13. Pooling designs with surprisingly high degree of error correction in a finite vector space

    CERN Document Server

    Guo, Jun

    2011-01-01

    Pooling designs are standard experimental tools in many biotechnical applications. It is well-known that all famous pooling designs are constructed from mathematical structures by the "containment matrix" method. In particular, Macula's designs (resp. Ngo and Du's designs) are constructed by the containment relation of subsets (resp. subspaces) in a finite set (resp. vector space). Recently, we generalized Macula's designs and obtained a family of pooling designs with more high degree of error correction by subsets in a finite set. In this paper, as a generalization of Ngo and Du's designs, we study the corresponding problems in a finite vector space and obtain a family of pooling designs with surprisingly high degree of error correction. Our designs and Ngo and Du's designs have the same number of items and pools, respectively, but the error-tolerant property is much better than that of Ngo and Du's designs, which was given by D'yachkov et al. \\cite{DF}, when the dimension of the space is large enough.

  14. You'll Never Guess Who Wrote That: 78 Surprising Authors of Psychological Publications.

    Science.gov (United States)

    Lilienfeld, Scott O; Lynn, Steven Jay

    2016-07-01

    One can find psychological authors in the most unexpected places. We present a capsule summary of scholarly publications of psychological interest authored or coauthored by 78 surprising individuals, most of whom are celebrities or relatives of celebrities, historical figures, or people who have otherwise achieved visibility in academic circles, politics, religion, art, and diverse realms of popular culture. Still other publications are authored by individuals who are far better known for their contributions to popular than to academic psychology. The publications, stretching across more than two centuries, encompass a wide swath of domains of psychological inquiry and highlight the intersection of psychology with fields that fall outside its traditional borders, including public health, economics, law, neurosurgery, and even magic. Many of these scholarly contributions have enriched psychology and its allied disciplines, such as psychiatry, in largely unappreciated ways, and they illustrate the penetration of psychological knowledge into multiple scientific disciplines and everyday life. At the same time, our author list demonstrates that remarkable intellectual accomplishments in one scientific domain, such as physics, do not necessarily translate into success in psychology and underscores the distinction between intelligence, on the one hand, and critical thinking and wisdom, on the other.

  15. October Surprises.

    Science.gov (United States)

    2016-10-01

    Ushered in with the rampage of Hurricane Matthew, later days brightened in this month that has often been harbinger of both good and bad news for Cuba and the world. Hurricane Matthew ripped through Eastern Cuba, devastating the historic town of Baracoa (Cuba's first capital, founded in 1511) and the village of Maisí, where the morning sun first rises over Cuban territory. Wind and flood leveled hundreds of homes, brought down the power grid and destroyed crops. Yet there was no loss of human life, unlike in neighboring Haiti and other countries in Matthew's path, and unlike in Cuba in 1963, when Hurricane Flora caused more than 1200 deaths. In Haiti, efforts of health workers-including hundreds of Haitian graduates from Cuba's Latin American Medical School and 600 Cuban health professionals already there-were bolstered by dozens of specially trained Cuban disaster medical personnel in the wake of the storm.

  16. Surprising Resists

    Science.gov (United States)

    Morton, Stephie

    2007-01-01

    In this article, the author discusses an art adventure with her third, fourth, and fifth grade enrichment kids to the Fort Collins Museum of Contemporary Art in Colorado. The author demonstrates and teaches her students how to use the art tissue paper and oil pastel complementing the creative spirit of the Jaune Quick-to-See Smith work presented…

  17. Hypersingular integral equations, waveguiding effects in Cantorian Universe and genesis of large scale structures

    Energy Technology Data Exchange (ETDEWEB)

    Iovane, G. [Dipartimento di Ingegneria, dell' Informazione e Matematica Applicata, Universita di Salerno, Salerno (Italy)] e-mail: iovane@diima.unisa.it; Giordano, P. [Dipartimento di Ingegneria, dell' Informazione e Matematica Applicata, Universita di Salerno, Salerno (Italy)

    2005-08-01

    In this work we introduce the hypersingular integral equations and analyze a realistic model of gravitational waveguides on a cantorian space-time. A waveguiding effect is considered with respect to the large scale structure of the Universe, where the structure formation appears as if it were a classically self-similar random process at all astrophysical scales. The result is that it seems we live in an El Naschie's o {sup ({infinity})} Cantorian space-time, where gravitational lensing and waveguiding effects can explain the appearing Universe. In particular, we consider filamentary and planar large scale structures as possible refraction channels for electromagnetic radiation coming from cosmological structures. From this vision the Universe appears like a large self-similar adaptive mirrors set, thanks to three numerical simulations. Consequently, an infinite Universe is just an optical illusion that is produced by mirroring effects connected with the large scale structure of a finite and not a large Universe.

  18. A Verilog-A large signal model for InP DHBT including thermal effects

    Science.gov (United States)

    Yuxia, Shi; Zhi, Jin; Zhijian, Pan; Yongbo, Su; Yuxiong, Cao; Yan, Wang

    2013-06-01

    A large signal model for InP/InGaAs double heterojunction bipolar transistors including thermal effects has been reported, which demonstrated good agreements of simulations with measurements. On the basis of the previous model in which the double heterojunction effect, current blocking effect and high current effect in current expression are considered, the effect of bandgap narrowing with temperature has been considered in transport current while a formula for model parameters as a function of temperature has been developed. This model is implemented by Verilog-A and embedded in ADS. The proposed model is verified with DC and large signal measurements.

  19. Cerebrovascular effects of angiotensin converting enzyme inhibition involve large artery dilatation in rats

    DEFF Research Database (Denmark)

    Postiglione, A; Bobkiewicz, T; Vinholdt-Pedersen, E

    1991-01-01

    The aim of the study was to selectively examine the effects of converting enzyme inhibition on the large brain arteries by using concomitant inhibition of carbonic anhydrase to cause severe dilatation of mainly parenchymal resistance vessels....

  20. The role of loudness in detection of surprising events in music recordings

    OpenAIRE

    Holonowicz, Piotr; Herrera, Perfecto; Purwins, Hendrik

    2009-01-01

    The abrupt change of loudness is a salient event that is not always expected by a music listener. Therefore loudness is an important cue when seeking for events in a music stream that could violate human expectations. The concept of expectation and surprise in music has become recently the subject of extensive research, however mostly using symbolic data. The aim of this work is to investigate the circumstances when a change of sound intensity could be surprising for a listener. Then, using t...

  1. Dispersion in Rectangular Networks: Effective Diffusivity and Large-Deviation Rate Function

    Science.gov (United States)

    Tzella, Alexandra; Vanneste, Jacques

    2016-09-01

    The dispersion of a diffusive scalar in a fluid flowing through a network has many applications including to biological flows, porous media, water supply, and urban pollution. Motivated by this, we develop a large-deviation theory that predicts the evolution of the concentration of a scalar released in a rectangular network in the limit of large time t ≫1 . This theory provides an approximation for the concentration that remains valid for large distances from the center of mass, specifically for distances up to O (t ) and thus much beyond the O (t1 /2) range where a standard Gaussian approximation holds. A byproduct of the approach is a closed-form expression for the effective diffusivity tensor that governs this Gaussian approximation. Monte Carlo simulations of Brownian particles confirm the large-deviation results and demonstrate their effectiveness in describing the scalar distribution when t is only moderately large.

  2. Model of a fluid at small and large length scales and the hydrophobic effect

    OpenAIRE

    tenWolde, Pieter Rein; Sun, Sean X.; Chandler, David

    2001-01-01

    We present a statistical field theory to describe large length scale effects induced by solutes in a cold and otherwise placid liquid. The theory divides space into a cubic grid of cells. The side length of each cell is of the order of the bulk correlation length of the bulk liquid. Large length scale states of the cells are specified with an Ising variable. Finer length scale effects are described with a Gaussian field, with mean and variance affected by both the large length scale field and...

  3. Computational surprisal analysis speeds-up genomic characterization of cancer processes.

    Science.gov (United States)

    Kravchenko-Balasha, Nataly; Simon, Simcha; Levine, R D; Remacle, F; Exman, Iaakov

    2014-01-01

    Surprisal analysis is increasingly being applied for the examination of transcription levels in cellular processes, towards revealing inner network structures and predicting response. But to achieve its full potential, surprisal analysis should be integrated into a wider range computational tool. The purposes of this paper are to combine surprisal analysis with other important computation procedures, such as easy manipulation of the analysis results--e.g. to choose desirable result sub-sets for further inspection--, retrieval and comparison with relevant datasets from public databases, and flexible graphical displays for heuristic thinking. The whole set of computation procedures integrated into a single practical tool is what we call Computational Surprisal Analysis. This combined kind of analysis should facilitate significantly quantitative understanding of different cellular processes for researchers, including applications in proteomics and metabolomics. Beyond that, our vision is that Computational Surprisal Analysis has the potential to reach the status of a routine method of analysis for practitioners. The resolving power of Computational Surprisal Analysis is here demonstrated by its application to a variety of cellular cancer process transcription datasets, ours and from the literature. The results provide a compact biological picture of the thermodynamic significance of the leading gene expression phenotypes in every stage of the disease. For each transcript we characterize both its inherent steady state weight, its correlation with the other transcripts and its variation due to the disease. We present a dedicated website to facilitate the analysis for researchers and practitioners.

  4. Computational surprisal analysis speeds-up genomic characterization of cancer processes.

    Directory of Open Access Journals (Sweden)

    Nataly Kravchenko-Balasha

    Full Text Available Surprisal analysis is increasingly being applied for the examination of transcription levels in cellular processes, towards revealing inner network structures and predicting response. But to achieve its full potential, surprisal analysis should be integrated into a wider range computational tool. The purposes of this paper are to combine surprisal analysis with other important computation procedures, such as easy manipulation of the analysis results--e.g. to choose desirable result sub-sets for further inspection--, retrieval and comparison with relevant datasets from public databases, and flexible graphical displays for heuristic thinking. The whole set of computation procedures integrated into a single practical tool is what we call Computational Surprisal Analysis. This combined kind of analysis should facilitate significantly quantitative understanding of different cellular processes for researchers, including applications in proteomics and metabolomics. Beyond that, our vision is that Computational Surprisal Analysis has the potential to reach the status of a routine method of analysis for practitioners. The resolving power of Computational Surprisal Analysis is here demonstrated by its application to a variety of cellular cancer process transcription datasets, ours and from the literature. The results provide a compact biological picture of the thermodynamic significance of the leading gene expression phenotypes in every stage of the disease. For each transcript we characterize both its inherent steady state weight, its correlation with the other transcripts and its variation due to the disease. We present a dedicated website to facilitate the analysis for researchers and practitioners.

  5. Large reversible magnetocaloric effect in a Ni-Co-Mn-In magnetic shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, L.; Cong, D. Y.; Ma, L.; Nie, Z. H.; Wang, Z. L.; Suo, H. L.; Ren, Y.; Wang, Y. D.

    2016-01-18

    Reversibility of the magnetocaloric effect in materials with first-order magnetostructural transformation is of vital significance for practical magnetic refrigeration applications. Here, we report a large reversible magnetocaloric effect in a Ni49.8Co1.2Mn33.5In15.5 magnetic shape memory alloy. A large reversible magnetic entropy change of 14.6 J/(kg K) and a broad operating temperature window of 18 K under 5 T were simultaneously achieved, correlated with the low thermal hysteresis (-8 K) and large magnetic-field-induced shift of transformation temperatures (4.9 K/T) that lead to a narrow magnetic hysteresis (1.1 T) and small average magnetic hysteresis loss (48.4 J/kg under 5 T) as well. Furthermore, a large reversible effective refrigeration capacity (76.6 J/kg under 5 T) was obtained, as a result of the large reversible magnetic entropy change, broad operating temperature window, and small magnetic hysteresis loss. The large reversible magnetic entropy change and large reversible effective refrigeration capacity are important for improving the magnetocaloric performance, and the small magnetic hysteresis loss is beneficial to reducing energy dissipation during magnetic field cycle in potential applications.

  6. Communication Management and Trust: Their Role in Building Resilience to "Surprises" Such As Natural Disasters, Pandemic Flu, and Terrorism

    Directory of Open Access Journals (Sweden)

    P. H. Longstaff

    2008-06-01

    Full Text Available In times of public danger such as natural disasters and health emergencies, a country's communication systems will be some of its most important assets because access to information will make individuals and groups more resilient. Communication by those charged with dealing with the situation is often critical. We analyzed reports from a wide variety of crisis incidents and found a direct correlation between trust and an organization's preparedness and internal coordination of crisis communication and the effectiveness of its leadership. Thus, trust is one of the most important variables in effective communication management in times of "surprise."

  7. Surprise responses in the human brain demonstrate statistical learning under high concurrent cognitive demand

    Science.gov (United States)

    Garrido, Marta Isabel; Teng, Chee Leong James; Taylor, Jeremy Alexander; Rowe, Elise Genevieve; Mattingley, Jason Brett

    2016-06-01

    The ability to learn about regularities in the environment and to make predictions about future events is fundamental for adaptive behaviour. We have previously shown that people can implicitly encode statistical regularities and detect violations therein, as reflected in neuronal responses to unpredictable events that carry a unique prediction error signature. In the real world, however, learning about regularities will often occur in the context of competing cognitive demands. Here we asked whether learning of statistical regularities is modulated by concurrent cognitive load. We compared electroencephalographic metrics associated with responses to pure-tone sounds with frequencies sampled from narrow or wide Gaussian distributions. We showed that outliers evoked a larger response than those in the centre of the stimulus distribution (i.e., an effect of surprise) and that this difference was greater for physically identical outliers in the narrow than in the broad distribution. These results demonstrate an early neurophysiological marker of the brain's ability to implicitly encode complex statistical structure in the environment. Moreover, we manipulated concurrent cognitive load by having participants perform a visual working memory task while listening to these streams of sounds. We again observed greater prediction error responses in the narrower distribution under both low and high cognitive load. Furthermore, there was no reliable reduction in prediction error magnitude under high-relative to low-cognitive load. Our findings suggest that statistical learning is not a capacity limited process, and that it proceeds automatically even when cognitive resources are taxed by concurrent demands.

  8. Effects of electrolyte gating on photoluminescence spectra of large-area WSe2monolayer films

    KAUST Repository

    Matsuki, Keiichiro

    2016-05-24

    We fabricated electric double-layer transistors comprising large-area WSe2 monolayers and investigated the effects of electrolyte gating on their photoluminescence (PL) spectra. Using the efficient gating effects of electric double layers, we succeeded in the application of a large electric field (>107Vcm%1) and the accumulation of high carrier density (>1013cm%2). As a result, we observed PL spectra based on both positively and negatively charged excitons and their gate-voltage-dependent redshifts, suggesting the effects of both an electric field and charge accumulation. © 2016 The Japan Society of Applied Physics.

  9. Effectiveness of feeding large kibbles with mechanical cleaning properties in cats with gingivitis

    NARCIS (Netherlands)

    Vrieling, HE; Theyse, LFH; van Winkelhoff, AJ; Dijkshoorn, NA; Logan, EI; Picovet, P

    2005-01-01

    Effectiveness of feeding large kibbles with mechanical cleaning properties in cats with gingivitis periodontal disease is the most common acquired oral disease in cats. it starts with plaque accumulation and gingivitis. The aim of this study was to evaluate the effectiveness of different types of

  10. Effectiveness of feeding large kibbles with mechanical cleaning properties in cats with gingivitis

    NARCIS (Netherlands)

    Vrieling, HE; Theyse, LFH; van Winkelhoff, AJ; Dijkshoorn, NA; Logan, EI; Picovet, P

    2005-01-01

    Effectiveness of feeding large kibbles with mechanical cleaning properties in cats with gingivitis periodontal disease is the most common acquired oral disease in cats. it starts with plaque accumulation and gingivitis. The aim of this study was to evaluate the effectiveness of different types of ki

  11. Analysing Item Position Effects due to Test Booklet Design within Large-Scale Assessment

    Science.gov (United States)

    Hohensinn, Christine; Kubinger, Klaus D.; Reif, Manuel; Schleicher, Eva; Khorramdel, Lale

    2011-01-01

    For large-scale assessments, usually booklet designs administering the same item at different positions within a booklet are used. Therefore, the occurrence of position effects influencing the difficulty of the item is a crucial issue. Not taking learning or fatigue effects into account would result in a bias of estimated item difficulty. The…

  12. Gravitational effect of centre mass with electric charge and a large number of magnetic monopoles

    Institute of Scientific and Technical Information of China (English)

    Gong Tian-Xi; Li Ai-Gen; Wang Yong-Jiu

    2005-01-01

    In this paper, using an elegant mathematical method advanced by us, we calculate the orbital effect in the gravitational field of the centre mass with electric charge and a large number of magnetic monopoles. Generalizing the effect in the Schwarzschild field, we obtain interesting results by discussing the parameters of the celestial body that provide a feasible experimental verification of the general relativity.

  13. Effectiveness of feeding large kibbles with mechanical cleaning properties in cats with gingivitis

    NARCIS (Netherlands)

    Vrieling, HE; Theyse, LFH; van Winkelhoff, AJ; Dijkshoorn, NA; Logan, EI; Picovet, P

    2005-01-01

    Effectiveness of feeding large kibbles with mechanical cleaning properties in cats with gingivitis periodontal disease is the most common acquired oral disease in cats. it starts with plaque accumulation and gingivitis. The aim of this study was to evaluate the effectiveness of different types of ki

  14. Estimation of effects of quantitative trait loci in large complex pedigrees

    NARCIS (Netherlands)

    Meuwissen, T.H.E.; Goddard, M.E.

    1997-01-01

    A method was derived to estimate effects of quantitative trait loci (QTL) using incomplete genotype information in large outbreeding populations with complex pedigrees. The method accounts for background genes by estimating polygenic effects. The basic equations used are very similar to the usual li

  15. The analysis of eight transcriptomes from all poriferan classes reveals surprising genetic complexity in sponges.

    Science.gov (United States)

    Riesgo, Ana; Farrar, Nathan; Windsor, Pamela J; Giribet, Gonzalo; Leys, Sally P

    2014-05-01

    Sponges (Porifera) are among the earliest evolving metazoans. Their filter-feeding body plan based on choanocyte chambers organized into a complex aquiferous system is so unique among metazoans that it either reflects an early divergence from other animals prior to the evolution of features such as muscles and nerves, or that sponges lost these characters. Analyses of the Amphimedon and Oscarella genomes support this view of uniqueness-many key metazoan genes are absent in these sponges-but whether this is generally true of other sponges remains unknown. We studied the transcriptomes of eight sponge species in four classes (Hexactinellida, Demospongiae, Homoscleromorpha, and Calcarea) specifically seeking genes and pathways considered to be involved in animal complexity. For reference, we also sought these genes in transcriptomes and genomes of three unicellular opisthokonts, two sponges (A. queenslandica and O. carmela), and two bilaterian taxa. Our analyses showed that all sponge classes share an unexpectedly large complement of genes with other metazoans. Interestingly, hexactinellid, calcareous, and homoscleromorph sponges share more genes with bilaterians than with nonbilaterian metazoans. We were surprised to find representatives of most molecules involved in cell-cell communication, signaling, complex epithelia, immune recognition, and germ-lineage/sex, with only a few, but potentially key, absences. A noteworthy finding was that some important genes were absent from all demosponges (transcriptomes and the Amphimedon genome), which might reflect divergence from main-stem lineages including hexactinellids, calcareous sponges, and homoscleromorphs. Our results suggest that genetic complexity arose early in evolution as shown by the presence of these genes in most of the animal lineages, which suggests sponges either possess cryptic physiological and morphological complexity and/or have lost ancestral cell types or physiological processes.

  16. Paws without claws? Ecological effects of large carnivores in anthropogenic landscapes

    Science.gov (United States)

    Sahlén, E.; Elmhagen, B.; Chamaillé-Jammes, S.; Sand, H.; Lone, K.; Cromsigt, J. P. G. M.

    2016-01-01

    Large carnivores are frequently presented as saviours of biodiversity and ecosystem functioning through their creation of trophic cascades, an idea largely based on studies coming primarily out of relatively natural landscapes. However, in large parts of the world, particularly in Europe, large carnivores live in and are returning to strongly human-modified ecosystems. At present, we lack a coherent framework to predict the effects of large carnivores in these anthropogenic landscapes. We review how human actions influence the ecological roles of large carnivores by affecting their density or behaviour or those of mesopredators or prey species. We argue that the potential for density-mediated trophic cascades in anthropogenic landscapes is limited to unproductive areas where even low carnivore numbers may impact prey densities or to the limited parts of the landscape where carnivores are allowed to reach ecologically functional densities. The potential for behaviourally mediated trophic cascades may be larger and more widespread, because even low carnivore densities affect prey behaviour. We conclude that predator–prey interactions in anthropogenic landscapes will be highly context-dependent and human actions will often attenuate the ecological effects of large carnivores. We highlight the knowledge gaps and outline a new research avenue to study the role of carnivores in anthropogenic landscapes. PMID:27798302

  17. Effect of Large Finite-Size Wind Farms and Their Wakes on Atmospheric Boundary Layer Dynamics

    Science.gov (United States)

    Wu, Ka Ling; Porté-Agel, Fernando

    2016-04-01

    Through the use of large-eddy simulation, the effect of large finite-size wind farms and their wakes on conventionally-neutral atmospheric boundary layer (ABL) dynamics and power extraction is investigated. Specifically, this study focuses on a wind farm that comprises 25 rows of wind turbines, spanning a distance of 10 km. It is shown that large wind farms have a significant effect on internal boundary layer growth both inside and downwind of the wind farms. If the wind farm is large enough, the internal boundary layer interacts with the thermally-stratified free atmosphere above, leading to a modification of the ABL height and power extraction. In addition, it is shown that large wind farms create extensive wakes, which could have an effect on potential downwind wind farms. Specifically, for the case considered here, a power deficit as large as 8% is found at a distance of 10 km downwind from the wind farm. Furthermore, this study compares the wind farm wake dynamics for cases in which the conventionally neutral ABLs are driven by a unidirectional pressure gradient and Coriolis forces.

  18. Efficient reduction of complex noise in passive millimeter-wavelength video utilizing Bayesian surprise

    Science.gov (United States)

    Mundhenk, T. Nathan; Baron, Josh; Matic, Roy M.

    2011-06-01

    Passive millimeter wavelength (PMMW) video holds great promise given its ability to see targets and obstacles through fog, smoke and rain. However, current imagers produce undesirable complex noise. This can come as a mixture of fast shot (snow like) noise and a slower forming circular fixed pattern. Shot noise can be removed by a simple gain style filter. However, this can produce blurring of objects in the scene. To alleviate this, we measure the amount of Bayesian surprise in videos. Bayesian surprise is feature change in time which is abrupt, but cannot be accounted for as shot noise. Surprise is used to attenuate the shot noise filter in locations of high surprise. Since high Bayesian surprise in videos is very salient to observers, this reduces blurring particularly in places where people visually attend. Fixed pattern noise is removed after the shot noise using a combination of Non-uniformity correction (NUC) and Eigen Image Wavelet Transformation. The combination allows for online removal of time varying fixed pattern noise even when background motion may be absent. It also allows for online adaptation to differing intensities of fixed pattern noise. The fixed pattern and shot noise filters are all efficient allowing for real time video processing of PMMW video. We show several examples of PMMW video with complex noise that is much cleaner as a result of the noise removal. Processed video clearly shows cars, houses, trees and utility poles at 20 frames per second.

  19. A methodology of estimation on air pollution and its health effects in large Japanese cities.

    OpenAIRE

    Hirota, Keiko; Shibuya, Satoshi; Sakamoto, Shogo; Kashima, Shigeru

    2011-01-01

    The correlation between air pollution and health effects in large Japanese cities presents a great challenge owing to the limited availability of data on the exposure to pollution, health effects and the uncertainty of mixed causes. A methodology for quantitative relationships (between the emission volume and air quality, and the air quality and health effects) is analysed with a statistical method in this article; the correlation of air pollution reduction policy in Japan from 1974 to 2007. ...

  20. Memory Effects in Turbulent Dynamo Generation and Propagation of Large Scale Magnetic Field

    CERN Document Server

    Fedotov, S; Zubarev, A; Fedotov, Sergei; Ivanov, Alexey; Zubarev, Andrey

    2001-01-01

    We are concerned with large scale magnetic field dynamo generation and propagation of magnetic fronts in turbulent electrically conducting fluids. An effective equation for the large scale magnetic field is developed here that takes into account the finite correlation times of the turbulent flow. This equation involves the memory integrals corresponding to the dynamo source term describing the alpha-effect and turbulent transport of magnetic field. We find that the memory effects can drastically change the dynamo growth rate, in particular, non-local turbulent transport might increase the growth rate several times compared to the conventional gradient transport expression. Moreover, the integral turbulent transport term leads to a large decrease of the speed of magnetic front propagation.

  1. A closed form large deformation solution of plate bending with surface effects.

    Science.gov (United States)

    Liu, Tianshu; Jagota, Anand; Hui, Chung-Yuen

    2017-01-04

    We study the effect of surface stress on the pure bending of a finite thickness plate under large deformation. The surface is assumed to be isotropic and its stress consists of a part that can be interpreted as a residual stress and a part that stiffens as the surface increases its area. Our results show that residual surface stress and surface stiffness can both increase the overall bending stiffness but through different mechanisms. For sufficiently large residual surface tension, we discover a new type of instability - the bending moment reaches a maximum at a critical curvature. Effects of surface stress on different stress components in the bulk of the plate are discussed and the possibility of self-bending due to asymmetry of the surface properties is also explored. The results of our calculations provide insights into surface stress effects in the large deformation regime and can be used as a test for implementation of finite element methods for surface elasticity.

  2. Imprint of non-linear effects on HI intensity mapping on large scales

    Science.gov (United States)

    Umeh, Obinna

    2017-06-01

    Intensity mapping of the HI brightness temperature provides a unique way of tracing large-scale structures of the Universe up to the largest possible scales. This is achieved by using a low angular resolution radio telescopes to detect emission line from cosmic neutral Hydrogen in the post-reionization Universe. We use general relativistic perturbation theory techniques to derive for the first time the full expression for the HI brightness temperature up to third order in perturbation theory without making any plane-parallel approximation. We use this result and the renormalization prescription for biased tracers to study the impact of nonlinear effects on the power spectrum of HI brightness temperature both in real and redshift space. We show how mode coupling at nonlinear order due to nonlinear bias parameters and redshift space distortion terms modulate the power spectrum on large scales. The large scale modulation may be understood to be due to the effective bias parameter and effective shot noise.

  3. Computational study of thermal effects of large blood vessels in human knee joint.

    Science.gov (United States)

    Xue, Xu; He, Zhi Zhu; Liu, Jing

    2013-01-01

    This paper is dedicated to present a comprehensive investigation on the thermal effects of large blood vessels of human knee joint during topical cooling and fomentation treatment. A three-dimensional (3D) finite element analysis by taking full use of the anatomical CAD model of human knee joint was developed to accurately simulate the treatment process. Based on the classical Pennes bio-heat transfer equation, the time evolution of knee joint's temperature distribution and heat flux from large blood vessels was obtained. In addition, we compared several influencing factors and obtained some key conclusions which cannot be easily acquired through clinical experiments. The results indicated that the thermal effects of large blood vessels could remarkably affect the temperature distribution of knee joint during treatment process. Fluctuations of blood flow velocity and metabolic heat production rate affect little on the thermal effects of large blood vessels. Changing the temperature of blood and regimes of treatment could effectively regulate this phenomenon, which is important for many physiological activities. These results provide a guideline to the basic and applied research for the thermally significant large blood vessels in the knee organism.

  4. Conference of “Uncertainty and Surprise: Questions on Working with the Unexpected and Unknowable”

    CERN Document Server

    McDaniel, Reuben R; Uncertainty and Surprise in Complex Systems : Questions on Working with the Unexpected

    2005-01-01

    Complexity science has been a source of new insight in physical and social systems and has demonstrated that unpredictability and surprise are fundamental aspects of the world around us. This book is the outcome of a discussion meeting of leading scholars and critical thinkers with expertise in complex systems sciences and leaders from a variety of organizations sponsored by the Prigogine Center at The University of Texas at Austin and the Plexus Institute to explore strategies for understanding uncertainty and surprise. Besides distributions to the conference it includes a key digest by the editors as well as a commentary by the late nobel laureat Ilya Prigogine, "Surprises in half of a century". The book is intended for researchers and scientists in complexity science as well as for a broad interdisciplinary audience of both practitioners and scholars. It will well serve those interested in the research issues and in the application of complexity science to physical and social systems.

  5. What is a surprise earthquake? The example of the 2002, San Giuliano (Italy event

    Directory of Open Access Journals (Sweden)

    M. Mucciarelli

    2005-06-01

    Full Text Available Both in scientific literature and in the mass media, some earthquakes are defined as «surprise earthquakes». Based on his own judgment, probably any geologist, seismologist or engineer may have his own list of past «surprise earthquakes». This paper tries to quantify the underlying individual perception that may lead a scientist to apply such a definition to a seismic event. The meaning is different, depending on the disciplinary approach. For geologists, the Italian database of seismogenic sources is still too incomplete to allow for a quantitative estimate of the subjective degree of belief. For seismologists, quantification is possible defining the distance between an earthquake and its closest previous neighbor. Finally, for engineers, the San Giuliano quake could not be considered a surprise, since probabilistic site hazard estimates reveal that the change before and after the earthquake is just 4%.

  6. Salience and Attention in Surprisal-Based Accounts of Language Processing

    Science.gov (United States)

    Zarcone, Alessandra; van Schijndel, Marten; Vogels, Jorrig; Demberg, Vera

    2016-01-01

    The notion of salience has been singled out as the explanatory factor for a diverse range of linguistic phenomena. In particular, perceptual salience (e.g., visual salience of objects in the world, acoustic prominence of linguistic sounds) and semantic-pragmatic salience (e.g., prominence of recently mentioned or topical referents) have been shown to influence language comprehension and production. A different line of research has sought to account for behavioral correlates of cognitive load during comprehension as well as for certain patterns in language usage using information-theoretic notions, such as surprisal. Surprisal and salience both affect language processing at different levels, but the relationship between the two has not been adequately elucidated, and the question of whether salience can be reduced to surprisal / predictability is still open. Our review identifies two main challenges in addressing this question: terminological inconsistency and lack of integration between high and low levels of representations in salience-based accounts and surprisal-based accounts. We capitalize upon work in visual cognition in order to orient ourselves in surveying the different facets of the notion of salience in linguistics and their relation with models of surprisal. We find that work on salience highlights aspects of linguistic communication that models of surprisal tend to overlook, namely the role of attention and relevance to current goals, and we argue that the Predictive Coding framework provides a unified view which can account for the role played by attention and predictability at different levels of processing and which can clarify the interplay between low and high levels of processes and between predictability-driven expectation and attention-driven focus. PMID:27375525

  7. Salience and attention in surprisal-based accounts of language processing

    Directory of Open Access Journals (Sweden)

    Alessandra eZarcone

    2016-06-01

    Full Text Available The notion of salience has been singled out as the explanatory factor for a diverse range oflinguistic phenomena. In particular, perceptual salience (e.g. visual salience of objects in the world,acoustic prominence of linguistic sounds and semantic-pragmatic salience (e.g. prominence ofrecently mentioned or topical referents have been shown to influence language comprehensionand production. A different line of research has sought to account for behavioral correlates ofcognitive load during comprehension as well as for certain patterns in language usage usinginformation-theoretic notions, such as surprisal. Surprisal and salience both affect languageprocessing at different levels, but the relationship between the two has not been adequatelyelucidated, and the question of whether salience can be reduced to surprisal / predictability isstill open. Our review identifies two main challenges in addressing this question: terminologicalinconsistency and lack of integration between high and low levels of representations in salience-based accounts and surprisal-based accounts. We capitalise upon work in visual cognition inorder to orient ourselves in surveying the different facets of the notion of salience in linguisticsand their relation with models of surprisal. We find that work on salience highlights aspects oflinguistic communication that models of surprisal tend to overlook, namely the role of attentionand relevance to current goals, and we argue that the Predictive Coding framework provides aunified view which can account for the role played by attention and predictability at different levelsof processing and which can clarify the interplay between low and high levels of processes andbetween predictability-driven expectation and attention-driven focus.

  8. The effects of incentive framing on performance decrements for large monetary outcomes: behavioral and neural mechanisms.

    Science.gov (United States)

    Chib, Vikram S; Shimojo, Shinsuke; O'Doherty, John P

    2014-11-05

    There is a nuanced interplay between the provision of monetary incentives and behavioral performance. Individuals' performance typically increases with increasing incentives only up to a point, after which larger incentives may result in decreases in performance, a phenomenon known as "choking." We investigated the influence of incentive framing on choking effects in humans: in one condition, participants performed a skilled motor task to obtain potential monetary gains; in another, participants performed the same task to avoid losing a monetary amount. In both the gain and loss frame, the degree of participants' behavioral loss aversion was correlated with their susceptibility to choking effects. However, the effects were markedly different in the gain and loss frames: individuals with higher loss aversion were susceptible to choking for large prospective gains and not susceptible to choking for large prospective losses, whereas individuals with low loss aversion choked for large prospective losses but not for large prospective gains. Activity in the ventral striatum was predictive of performance decrements in both the gain and loss frames. Moreover, a mediation analysis revealed that behavioral loss aversion hindered performance via the influence of ventral striatal activity on motor performance. Our findings indicate that the framing of an incentive has a profound effect on an individual's susceptibility to choking effects, which is contingent on their loss aversion. Furthermore, we demonstrate that the ventral striatum serves as an interface between incentive-driven motivation and instrumental action, regardless of whether incentives are framed in terms of potential losses or gains.

  9. Electroviscous effect on fluid drag in a microchannel with large zeta potential.

    Science.gov (United States)

    Jing, Dalei; Bhushan, Bharat

    2015-01-01

    The electroviscous effect has been widely studied to investigate the effect of surface charge-induced electric double layers (EDL) on the pressure-driven flow in a micro/nano channel. EDL has been reported to reduce the velocity of fluid flow and increase the fluid drag. Nevertheless, the study on the combined effect of EDL with large zeta potential up to several hundred millivolts and surface charge depenedent-slip on the micro/nano flow is still needed. In this paper, the nonlinear Poisson-Boltzmann equation for electrical potential and ion distribution in non-overlapping EDL is first analytically solved. Then, the modified Navier-Stokes equation for the flow considering the effect of surface charge on the electrical conductivity of the electrolyte and slip length is analytically solved. This analysis is used to study the effect of non-overlapping EDL with large zeta potential on the pressure-driven flow in a microchannel with no-slip and charge-dependent slip conditions. The results show that the EDL leads to an increase in the fluid drag, but that slip can reduce the fluid drag. When the zeta potential is large enough, the electroviscous effect disappears for flow in the microchannel under a no-slip condition. However, the retardation of EDL on the flow and the enhancement of slip on the flow counteract each other under a slip condition. The underlying mechanisms of the effect of EDL with large zeta potential on fluid drag are the high net ionic concentration near the channel wall and the fast decay of electrical potential in the EDL when the zeta potential is large enough.

  10. One In Five Inpatient Emergency Department Cases May Lead To Surprise Bills.

    Science.gov (United States)

    Garmon, Christopher; Chartock, Benjamin

    2017-01-01

    A surprise medical bill is a bill from an out-of-network provider that was not expected by the patient or that came from an out-of-network provider not chosen by the patient. In 2014, 20 percent of hospital inpatient admissions that originated in the emergency department (ED), 14 percent of outpatient visits to the ED, and 9 percent of elective inpatient admissions likely led to a surprise medical bill. Project HOPE—The People-to-People Health Foundation, Inc.

  11. Risk, surprises and black swans fundamental ideas and concepts in risk assessment and risk management

    CERN Document Server

    Aven, Terje

    2014-01-01

    Risk, Surprises and Black Swans provides an in depth analysis of the risk concept with a focus on the critical link to knowledge; and the lack of knowledge, that risk and probability judgements are based on.Based on technical scientific research, this book presents a new perspective to help you understand how to assess and manage surprising, extreme events, known as 'Black Swans'. This approach looks beyond the traditional probability-based principles to offer a broader insight into the important aspects of uncertain events and in doing so explores the ways to manage them.

  12. Large spin-filtering effect in Ti-doped defective zigzag graphene nanoribbon.

    Science.gov (United States)

    Tawfik, Sherif Abdulkader; Cui, X Y; Ringer, S P; Stampfl, C

    2016-06-28

    Through first-principles calculations using the nonequilibrium Green's function formalism together with density functional theory, we study the conductance of double-vacancy zigzag graphene nanoribbons doped with four transition metal atoms Ti, V, Cr and Fe. We show that Ti doping induces large spin-filtering with an efficiency in excess of 90% for bias voltages below 0.5 V, while the other metal adatoms do not induce large spin filtering. This is despite the fact that the Ti dopant possesses small spin moment, while large moments reside on V, Cr and Fe dopants. Our analysis shows that the suppression of transmission in the spin-down channel in the Ti-doped graphene nanoribbon, thus the large spin filtering efficiency, is due to transmission anti-resonance arising from destructive quantum interference. These findings suggest that the decoration of graphene with titanium, and possibly other transition metals, can act as effective spin filters for nanospintronic applications.

  13. The Effect of Large Scale Magnetic Turbulence on the Acceleration of Electrons by Perpendicular Collisionless Shocks

    CERN Document Server

    Guo, Fan

    2010-01-01

    We study the physics of electron acceleration at collisionless shocks that move through a plasma containing large-scale magnetic fluctuations. We numerically integrate the trajectories of a large number of electrons, which are treated as test particles moving in the time dependent electric and magnetic fields determined from 2-D hybrid simulations (kinetic ions, fluid electron). The large-scale magnetic fluctuations effect the electrons in a number of ways and lead to efficient and rapid energization at the shock front. Since the electrons mainly follow along magnetic lines of force, the large-scale braiding of field lines in space allows the fast-moving electrons to cross the shock front several times, leading to efficient acceleration. Ripples in the shock front occuring at various scales will also contribute to the acceleration by mirroring the electrons. Our calculation shows that this process favors electron acceleration at perpendicular shocks. The current study is also helpful in understanding the inje...

  14. Direct observation of large quantum interference effect in anthraquinone solid-state junctions.

    Science.gov (United States)

    Rabache, Vincent; Chaste, Julien; Petit, Philippe; Della Rocca, Maria Luisa; Martin, Pascal; Lacroix, Jean-Christophe; McCreery, Richard L; Lafarge, Philippe

    2013-07-17

    Quantum interference in cross-conjugated molecules embedded in solid-state devices was investigated by direct current-voltage and differential conductance transport measurements of anthraquinone (AQ)-based large area planar junctions. A thin film of AQ was grafted covalently on the junction base electrode by diazonium electroreduction, while the counter electrode was directly evaporated on top of the molecular layer. Our technique provides direct evidence of a large quantum interference effect in multiple CMOS compatible planar junctions. The quantum interference is manifested by a pronounced dip in the differential conductance close to zero voltage bias. The experimental signature is well developed at low temperature (4 K), showing a large amplitude dip with a minimum >2 orders of magnitude lower than the conductance at higher bias and is still clearly evident at room temperature. A temperature analysis of the conductance curves revealed that electron-phonon coupling is the principal decoherence mechanism causing large conductance oscillations at low temperature.

  15. Large object investigation by digital holography with effective spectrum multiplexing under single-exposure approach

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ning, E-mail: coolboy006@sohu.com; Zhang, Yingying; Xie, Jun [College of Physics and Electronics, Nanjing XiaoZhuang University, Nanjing, Jiangsu Province 211171 (China)

    2014-10-13

    We present a method to investigate large object by digital holography with effective spectrum multiplexing under single-exposure approach. This method splits the original reference beam and redirects one of its branches as a second object beam. Through the modified Mach-Zehnder interferometer, the two object beams can illuminate different parts of the large object and create a spectrum multiplexed hologram onto the focal plane array of the charge-coupled device/complementary metal oxide semiconductor camera. After correct spectrum extraction and image reconstruction, the large object can be fully observed within only one single snap-shot. The flexibility and great performance make our method a very attractive and promising technique for large object investigation under common 632.8 nm illumination.

  16. Large magnetocaloric effect, moment, and coercivity enhancement after coating Ni nanoparticles with Ag.

    Science.gov (United States)

    Srinath, Sanyadanam; Poddar, Pankaj; Das, Raja; Sidhaye, Deepti; Prasad, Bhagavatula Lakshmi Vara; Gass, James; Srikanth, Hariharan

    2014-06-06

    We observe a large magnetocaloric effect in monodisperse Ni and Ni(core)Ag(shell) nanoparticles in the superparamagnetic region. The organically passivated Ni nanospheres show a large magnetic entropy change of 0.9 J kg(-1)  K for a 3 T magnetic field change. In comparison to the surfactant-coated Ni nanoparticles, the Ni(core)Ag(shell) nanoparticles show an enhanced coercivity, magnetization, and magnetocaloric effect (1.3 kg K for a 3 T magnetic field change). The coercivity at 10 K increases from 360 Oe for Ni nanoparticles to nearly 610 Oe for Ni(core)Ag(shell) particles. This large enhancement is attributed to the enhanced inter-particle interaction, which is mediated by the metallic shell, over the relatively weaker dipolar interaction in the surfactant-coated Ni nanoparticles, and to modification of the surface spin structure.

  17. An Audit of the Effectiveness of Large Group Neurology Tutorials for Irish Undergraduate Medical Students

    LENUS (Irish Health Repository)

    Kearney, H

    2016-07-01

    The aim of this audit was to determine the effectiveness of large group tutorials for teaching neurology to medical students. Students were asked to complete a questionnaire rating their confidence on a ten point Likert scale in a number of domains in the undergraduate education guidelines from the Association of British Neurologists (ABN). We then arranged a series of interactive large group tutorials for the class and repeated the questionnaire one month after teaching. In the three core domains of neurological: history taking, examination and differential diagnosis, none of the students rated their confidence as nine or ten out of ten prior to teaching. This increased to 6% for history taking, 12 % in examination and 25% for differential diagnosis after eight weeks of tutorials. This audit demonstrates that in our centre, large group tutorials were an effective means of teaching, as measured by the ABN guidelines in undergraduate neurology.

  18. Feasibility of large-scale power plants based on thermoelectric effects

    Science.gov (United States)

    Liu, Liping

    2014-12-01

    Heat resources of small temperature difference are easily accessible, free and enormous on the Earth. Thermoelectric effects provide the technology for converting these heat resources directly into electricity. We present designs for electricity generators based on thermoelectric effects that utilize heat resources of small temperature difference, e.g., ocean water at different depths and geothermal resources, and conclude that large-scale power plants based on thermoelectric effects are feasible and economically competitive. The key observation is that the power factor of thermoelectric materials, unlike the figure of merit, can be improved by orders of magnitude upon laminating good conductors and good thermoelectric materials. The predicted large-scale power generators based on thermoelectric effects, if validated, will have the advantages of the scalability, renewability, and free supply of heat resources of small temperature difference on the Earth.

  19. Co-occurrence frequency evaluated with large language corpora boosts semantic priming effects.

    Science.gov (United States)

    Brunellière, Angèle; Perre, Laetitia; Tran, ThiMai; Bonnotte, Isabelle

    2017-09-01

    In recent decades, many computational techniques have been developed to analyse the contextual usage of words in large language corpora. The present study examined whether the co-occurrence frequency obtained from large language corpora might boost purely semantic priming effects. Two experiments were conducted: one with conscious semantic priming, the other with subliminal semantic priming. Both experiments contrasted three semantic priming contexts: an unrelated priming context and two related priming contexts with word pairs that are semantically related and that co-occur either frequently or infrequently. In the conscious priming presentation (166-ms stimulus-onset asynchrony, SOA), a semantic priming effect was recorded in both related priming contexts, which was greater with higher co-occurrence frequency. In the subliminal priming presentation (66-ms SOA), no significant priming effect was shown, regardless of the related priming context. These results show that co-occurrence frequency boosts pure semantic priming effects and are discussed with reference to models of semantic network.

  20. Improvement of effective solid angle using virtual-pivot holder and large EDS detector.

    Science.gov (United States)

    Koshiya, Shogo; Kimoto, Koji

    2017-02-01

    This paper describes the effective solid angle improvement achieved using a large-area silicon drift detector together with a virtual-pivot double-tilt specimen holder. The virtual-pivot mechanism enables various designs of specimen-retaining and can reduce the shadowing effect. Energy-dispersive X-ray spectra were measured and converted into effective solid angles using different types of specimen holders and specimens. The investigated shadowing-free mechanical system yielded effective solid angles approaching the nominal solid angle of 0.464sr. In addition, we have demonstrated the availability of the plastic (polyetheretherketone) specimen holder for low system noise.

  1. The Effectiveness of Lecture-Integrated, Web-Supported Case Studies in Large Group Teaching

    Science.gov (United States)

    Azzawi, May; Dawson, Maureen M.

    2007-01-01

    The effectiveness of lecture-integrated and web-supported case studies in supporting a large and academically diverse group of undergraduate students was evaluated in the present study. Case studies and resource (web)-based learning were incorporated as two complementary interactive learning strategies into the traditional curriculum. A truncated…

  2. Effect on the application of large granule urea to irrigated rice

    Institute of Scientific and Technical Information of China (English)

    CHENWei; LUWanfang

    1993-01-01

    The effects of large granule urea(LOU) to irrigated rice were studied at the farm of China National Rice Research Institute. Experiment soil contained organic C 19.0g/kg, total N 2.2g/kg, total P 0.60g/kg, total K 20.1g/kg and pH6.9.

  3. Nurture Groups: A Large-Scale, Controlled Study of Effects on Development and Academic Attainment

    Science.gov (United States)

    Reynolds, Sue; MacKay, Tommy; Kearney, Maura

    2009-01-01

    Nurture groups have contributed to inclusive practices in primary schools in the UK for some time now and have frequently been the subject of articles in this journal. This large-scale, controlled study of nurture groups across 32 schools in the City of Glasgow provides further evidence for their effectiveness in addressing the emotional…

  4. The Sheffield experiment: the effects of centralising accident and emergency services in a large urban setting

    OpenAIRE

    Simpson, A.; Wardrope, J; Burke, D

    2001-01-01

    Objectives—To assess the effects of centralisation of accident and emergency (A&E) services in a large urban setting. The end points were the quality of patient care judged by time to see a doctor or nurse practitioner, time to admission and the cost of the A&E service as a whole.

  5. Effect of the Flow of Large Water Droplets on the Water Mist Sprays

    Directory of Open Access Journals (Sweden)

    Beda László

    2014-12-01

    Full Text Available The purpose of this study is to investigate the velocity field generated by water droplets with relatively large diameter that has great effect on the movement of several orders of magnitude smaller particles. A CFD model, Fire Dynamic Simulator (FDS version 5.5.3 was used for the numerical simulation. The data obtained from the numerical studies are analysed.

  6. The effect of sex on the meat quality charachteristics of large white ...

    African Journals Online (AJOL)

    The effect of sex on the meat quality charachteristics of large white pigs. ... Although, sex related differences in tenderness, juiciness and flavor were not ... After 14 days of frozen storage, 89% of the taste panelists judged from the flavor ...

  7. Effective Lagrangian of C PN -1 models in the large N limit

    Science.gov (United States)

    Rossi, Paolo

    2016-08-01

    The effective low energy Lagrangian of C PN -1 models in d <4 dimensions can be constructed in the large N limit by solving the saddle point equations in the presence of a constant field strength. The two-dimensional case is explicitly worked out, and possible applications are briefly discussed.

  8. An experimental apparatus for measuring the Casimir effect at large distances

    Energy Technology Data Exchange (ETDEWEB)

    Antonini, P; Carugno, G; Messineo, G [INFN sez di Padova, via Marzolo 8, 35131 Padova (Italy); Bimonte, G [Dipartimento di Scienze Fisiche Universita di Napoli Federico II Complesso Universitario MSA, Via Cintia, 80126 Napoli, Italy and INFN, Sezione di Napoli, Napoli (Italy); Bressi, G [INFN sez. di Pavia, via Bassi 6, 27100 Pavia (Italy); Galeazzi, G [Dipartimento di Fisica, Universita di Padova, via Marzolo 8, 35131 Padova (Italy); Ruoso, G, E-mail: Giuseppe.Ruoso@lnl.infn.i [INFN Lab. Naz. Legnaro, viale dell' Universita 2, 35020 Legnaro (Italy)

    2009-04-01

    An experimental set-up for the measurement of the Casimir effect at separations larger than a few microns is presented. The apparatus is based on a mechanical resonator and uses a homodyne detection technique to sense the Casimir force in the plane-parallel configuration. First measurements in the 3-10 micrometer range show an unexpected large force probably due to patch effects.

  9. Large anomalous Hall effect in a non-collinear antiferromagnet at room temperature.

    Science.gov (United States)

    Nakatsuji, Satoru; Kiyohara, Naoki; Higo, Tomoya

    2015-11-12

    In ferromagnetic conductors, an electric current may induce a transverse voltage drop in zero applied magnetic field: this anomalous Hall effect is observed to be proportional to magnetization, and thus is not usually seen in antiferromagnets in zero field. Recent developments in theory and experiment have provided a framework for understanding the anomalous Hall effect using Berry-phase concepts, and this perspective has led to predictions that, under certain conditions, a large anomalous Hall effect may appear in spin liquids and antiferromagnets without net spin magnetization. Although such a spontaneous Hall effect has now been observed in a spin liquid state, a zero-field anomalous Hall effect has hitherto not been reported for antiferromagnets. Here we report empirical evidence for a large anomalous Hall effect in an antiferromagnet that has vanishingly small magnetization. In particular, we find that Mn3Sn, an antiferromagnet that has a non-collinear 120-degree spin order, exhibits a large anomalous Hall conductivity of around 20 per ohm per centimetre at room temperature and more than 100 per ohm per centimetre at low temperatures, reaching the same order of magnitude as in ferromagnetic metals. Notably, the chiral antiferromagnetic state has a very weak and soft ferromagnetic moment of about 0.002 Bohr magnetons per Mn atom (refs 10, 12), allowing us to switch the sign of the Hall effect with a small magnetic field of around a few hundred oersted. This soft response of the large anomalous Hall effect could be useful for various applications including spintronics--for example, to develop a memory device that produces almost no perturbing stray fields.

  10. Interactive effects of fire and large herbivores on web-building spiders.

    Science.gov (United States)

    Foster, C N; Barton, P S; Wood, J T; Lindenmayer, D B

    2015-09-01

    Altered disturbance regimes are a major driver of biodiversity loss worldwide. Maintaining or re-creating natural disturbance regimes is therefore the focus of many conservation programmes. A key challenge, however, is to understand how co-occurring disturbances interact to affect biodiversity. We experimentally tested for the interactive effects of prescribed fire and large macropod herbivores on the web-building spider assemblage of a eucalypt forest understorey and investigated the role of vegetation in mediating these effects using path analysis. Fire had strong negative effects on the density of web-building spiders, which were partly mediated by effects on vegetation structure, while negative effects of large herbivores on web density were not related to changes in vegetation. Fire amplified the effects of large herbivores on spiders, both via vegetation-mediated pathways and by increasing herbivore activity. The importance of vegetation-mediated pathways and fire-herbivore interactions differed for web density and richness and also differed between web types. Our results demonstrate that for some groups of web-building spiders, the effects of co-occurring disturbance drivers may be mostly additive, whereas for other groups, interactions between drivers can amplify disturbance effects. In our study system, the use of prescribed fire in the presence of high densities of herbivores could lead to reduced densities and altered composition of web-building spiders, with potential cascading effects through the arthropod food web. Our study highlights the importance of considering both the independent and interactive effects of disturbances, as well as the mechanisms driving their effects, in the management of disturbance regimes.

  11. Examining item-position effects in large-scale assessment using the Linear Logistic Test Model

    Directory of Open Access Journals (Sweden)

    CHRISTINE HOHENSINN

    2008-09-01

    Full Text Available When administering large-scale assessments, item-position effects are of particular importance because the applied test designs very often contain several test booklets with the same items presented at different test positions. Establishing such position effects would be most critical; it would mean that the estimated item parameters do not depend exclusively on the items’ difficulties due to content but also on their presentation positions. As a consequence, item calibration would be biased. By means of the linear logistic test model (LLTM, item-position effects can be tested. In this paper, the results of a simulation study demonstrating how LLTM is indeed able to detect certain position effects in the framework of a large-scale assessment are presented first. Second, empirical item-position effects of a specific large-scale competence assessment in mathematics (4th grade students are analyzed using the LLTM. The results indicate that a small fatigue effect seems to take place. The most important consequence of the given paper is that it is advisable to try pertinent simulation studies before an analysis of empirical data takes place; the reason is, that for the given example, the suggested Likelihood-Ratio test neither holds the nominal type-I-risk, nor qualifies as “robust”, and furthermore occasionally shows very low power.

  12. Virtual Volatility, an Elementary New Concept with Surprising Stock Market Consequences

    Science.gov (United States)

    Prange, Richard; Silva, A. Christian

    2006-03-01

    Textbook investors start by predicting the future price distribution, PDF, of a candidate stock (or portfolio) at horizon T, e.g. a year hence. A (log)normal PDF with center (=drift =expected return) μT and width (=volatility) σT is often assumed on Central Limit Theorem grounds, i.e. by a random walk of daily (log)price increments δs. The standard deviation, stdev, of historical (ex post) δs `s is usually a fair predictor of the coming year's (ex ante) stdev(δs) = σdaily, but the historical mean E(δs) at best roughly limits the true, to be predicted, drift by μtrueT˜ μhistT ± σhistT. Textbooks take a PDF with σ ˜ σdaily and μ as somehow known, as if accurate predictions of μ were possible. It is elementary and presumably new to argue that an average of PDF's over a range of μ values should be taken, e.g. an average over forecasts by different analysts. We estimate that this leads to a PDF with a `virtual' volatility σ ˜ 1.3σdaily. It is indeed clear that uncertainty in the value of the expected gain parameter increases the risk of investment in that security by most measures, e. g. Sharpe's ratio μT/σT will be 30% smaller because of this effect. It is significant and surprising that there are investments which benefit from this 30% virtual increase in the volatility

  13. The Most Distant Mature Galaxy Cluster - Young, but surprisingly grown-up

    Science.gov (United States)

    2011-03-01

    Astronomers have used an armada of telescopes on the ground and in space, including the Very Large Telescope at ESO's Paranal Observatory in Chile to discover and measure the distance to the most remote mature cluster of galaxies yet found. Although this cluster is seen when the Universe was less than one quarter of its current age it looks surprisingly similar to galaxy clusters in the current Universe. "We have measured the distance to the most distant mature cluster of galaxies ever found", says the lead author of the study in which the observations from ESO's VLT have been used, Raphael Gobat (CEA, Paris). "The surprising thing is that when we look closely at this galaxy cluster it doesn't look young - many of the galaxies have settled down and don't resemble the usual star-forming galaxies seen in the early Universe." Clusters of galaxies are the largest structures in the Universe that are held together by gravity. Astronomers expect these clusters to grow through time and hence that massive clusters would be rare in the early Universe. Although even more distant clusters have been seen, they appear to be young clusters in the process of formation and are not settled mature systems. The international team of astronomers used the powerful VIMOS and FORS2 instruments on ESO's Very Large Telescope (VLT) to measure the distances to some of the blobs in a curious patch of very faint red objects first observed with the Spitzer space telescope. This grouping, named CL J1449+0856 [1], had all the hallmarks of being a very remote cluster of galaxies [2]. The results showed that we are indeed seeing a galaxy cluster as it was when the Universe was about three billion years old - less than one quarter of its current age [3]. Once the team knew the distance to this very rare object they looked carefully at the component galaxies using both the NASA/ESA Hubble Space Telescope and ground-based telescopes, including the VLT. They found evidence suggesting that most of the

  14. Surprising convergence of the Monte Carlo renormalization group for the three-dimensional Ising model.

    Science.gov (United States)

    Ron, Dorit; Brandt, Achi; Swendsen, Robert H

    2017-05-01

    We present a surprisingly simple approach to high-accuracy calculations of the critical properties of the three-dimensional Ising model. The method uses a modified block-spin transformation with a tunable parameter to improve convergence in the Monte Carlo renormalization group. The block-spin parameter must be tuned differently for different exponents to produce optimal convergence.

  15. Bagpipes and Artichokes: Surprise as a Stimulus to Learning in the Elementary Music Classroom

    Science.gov (United States)

    Jacobi, Bonnie Schaffhauser

    2016-01-01

    Incorporating surprise into music instruction can stimulate student attention, curiosity, and interest. Novelty focuses attention in the reticular activating system, increasing the potential for brain memory storage. Elementary ages are ideal for introducing novel instruments, pieces, composers, or styles of music. Young children have fewer…

  16. The Educational Philosophies of Mordecai Kaplan and Michael Rosenak: Surprising Similarities and Illuminating Differences

    Science.gov (United States)

    Schein, Jeffrey; Caplan, Eric

    2014-01-01

    The thoughts of Mordecai Kaplan and Michael Rosenak present surprising commonalities as well as illuminating differences. Similarities include the perception that Judaism and Jewish education are in crisis, the belief that Jewish peoplehood must include commitment to meaningful content, the need for teachers to teach from a position of…

  17. Three-nucleon force at large distances: Insights from chiral effective field theory and the large-N_c expansion

    CERN Document Server

    Epelbaum, E; Krebs, H; Schat, C

    2014-01-01

    We confirm the claim of Ref. [D.R. Phillips, C. Schat, Phys. Rev. C88 (2013) 3, 034002] that 20 operators are sufficient to represent the most general local isospin-invariant three-nucleon force and derive explicit relations between the two sets of operators suggested in Refs. [D.R. Phillips, C. Schat, Phys. Rev. C88 (2013) 3, 034002] and [H. Krebs, A.M. Gasparyan, E. Epelbaum, Phys.Rev. C87 (2013) 5, 054007]. We use the set of 20 operators to discuss the chiral expansion of the long- and intermediate-range parts of the three-nucleon force up to next-to-next-to-next-to-next-to-leading order in the standard formulation without explicit Delta(1232) degrees of freedom. We also address implications of the large-N_c expansion in QCD for the size of the various three-nucleon force contributions.

  18. Nongray-gas Effects in Modeling of Large-scale Oxy-fuel Combustion Processes

    DEFF Research Database (Denmark)

    Yin, Chungen

    2012-01-01

    , among which radiative heat transfer under oxy-fuel conditions is one of the fundamental issues. This paper demonstrates the nongray-gas effects in modeling of large-scale oxy-fuel combustion processes. Oxy-fuel combustion of natural gas in a large-scale utility boiler is numerically investigated...... cases. The simulation results show that the gray and non-gray calculations of the same oxy-fuel WSGGM make distinctly different predictions in the wall radiative heat transfer, incident radiative flux, radiative source, gas temperature and species profiles. In relative to the non-gray implementation...

  19. Limited evidence on the effectiveness of interventions to reduce livestock predation by large carnivores.

    Science.gov (United States)

    Eklund, Ann; López-Bao, José Vicente; Tourani, Mahdieh; Chapron, Guillaume; Frank, Jens

    2017-05-18

    Successful coexistence between large carnivores and humans is conditional upon effective mitigation of the impact of these species on humans, such as through livestock depredation. It is therefore essential for conservation practitioners, carnivore managing authorities, or livestock owners to know the effectiveness of interventions intended to reduce livestock predation by large carnivores. We reviewed the scientific literature (1990-2016), searching for evidence of the effectiveness of interventions. We found experimental and quasi-experimental studies were rare within the field, and only 21 studies applied a case-control study design (3.7% of reviewed publications). We used a relative risk ratio to evaluate the studied interventions: changing livestock type, keeping livestock in enclosures, guarding or livestock guarding dogs, predator removal, using shock collars on carnivores, sterilizing carnivores, and using visual or auditory deterrents to frighten carnivores. Although there was a general lack of scientific evidence of the effectiveness of any of these interventions, some interventions reduced the risk of depredation whereas other interventions did not result in reduced depredation. We urge managers and stakeholders to move towards an evidence-based large carnivore management practice and researchers to conduct studies of intervention effectiveness with a randomized case-control design combined with systematic reviewing to evaluate the evidence.

  20. Effects of reinforcement on test-enhanced learning in a large, diverse introductory college psychology course.

    Science.gov (United States)

    Trumbo, Michael C; Leiting, Kari A; McDaniel, Mark A; Hodge, Gordon K

    2016-06-01

    A robust finding within laboratory research is that structuring information as a test confers benefit on long-term retention-referred to as the testing effect. Although well characterized in laboratory environments, the testing effect has been explored infrequently within ecologically valid contexts. We conducted a series of 3 experiments within a very large introductory college-level course. Experiment 1 examined the impact of required versus optional frequent low-stakes testing (quizzes) on student grades, revealing students were much more likely to take advantage of quizzing if it was a required course component. Experiment 2 implemented a method of evaluating pedagogical intervention within a single course (thereby controlling for instructor bias and student self-selection), which revealed a testing effect. Experiment 3 ruled out additional exposure to information as an explanation for the findings of Experiment 2 and suggested that students at the college level, enrolled in very large sections, accept frequent quizzing well. (PsycINFO Database Record

  1. Does primary productivity modulate the indirect effects of large herbivores? A global meta-analysis.

    Science.gov (United States)

    Daskin, Joshua H; Pringle, Robert M

    2016-07-01

    Indirect effects of large mammalian herbivores (LMH), while much less studied than those of apex predators, are increasingly recognized to exert powerful influences on communities and ecosystems. The strength of these effects is spatiotemporally variable, and several sets of authors have suggested that they are governed in part by primary productivity. However, prior theoretical and field studies have generated conflicting results and predictions, underscoring the need for a synthetic global analysis. We conducted a meta-analysis of the direction and magnitude of large mammalian herbivore-initiated indirect interactions using 67 published studies comprising 456 individual responses. We georeferenced 41 of these studies (comprising 253 responses from 33 locations on five continents) to a satellite-derived map of primary productivity. Because predator assemblages might also influence the impact of large herbivores, we conducted a similar analysis using a global map of large carnivore species richness. In general, LMH reduced the abundance of other consumer species and also tended to reduce consumer richness, although the latter effect was only marginally significant. There was a pronounced reduction in the strength of negative (i.e. suppressive, due e.g., to competition) indirect effects of LMH on consumer abundance in more productive ecosystems. In contrast, positive (facilitative) indirect effects were not significantly correlated with productivity, likely because these comprised a more heterogeneous array of mechanisms. We found no effect of carnivore species richness on herbivore-initiated indirect effect strength. Our findings help to resolve the fundamental problem of ecological contingency as it pertains to the strength of an understudied class of multitrophic interactions. Moreover, these results will aid in predicting the indirect effects of anthropogenic wildlife declines and irruptions, and how these effects might be mediated by climatically driven shifts

  2. Renormalization-group flow of the effective action of cosmological large-scale structures

    CERN Document Server

    Floerchinger, Stefan

    2017-01-01

    Following an approach of Matarrese and Pietroni, we derive the functional renormalization group (RG) flow of the effective action of cosmological large-scale structures. Perturbative solutions of this RG flow equation are shown to be consistent with standard cosmological perturbation theory. Non-perturbative approximate solutions can be obtained by truncating the a priori infinite set of possible effective actions to a finite subspace. Using for the truncated effective action a form dictated by dissipative fluid dynamics, we derive RG flow equations for the scale dependence of the effective viscosity and sound velocity of non-interacting dark matter, and we solve them numerically. Physically, the effective viscosity and sound velocity account for the interactions of long-wavelength fluctuations with the spectrum of smaller-scale perturbations. We find that the RG flow exhibits an attractor behaviour in the IR that significantly reduces the dependence of the effective viscosity and sound velocity on the input ...

  3. How large are the nonspecific effects of acupuncture? A meta-analysis of randomized controlled trials

    Directory of Open Access Journals (Sweden)

    Schneider Antonius

    2010-11-01

    Full Text Available Abstract Background While several recent large randomized trials found clinically relevant effects of acupuncture over no treatment or routine care, blinded trials comparing acupuncture to sham interventions often reported only minor or no differences. This raises the question whether (sham acupuncture is associated with particularly potent nonspecific effects. We aimed to investigate the size of nonspecific effects associated with acupuncture interventions. Methods MEDLINE, Embase, Cochrane Central Register of Controlled Clinical Trials and reference lists were searched up to April 2010 to identify randomized trials of acupuncture for any condition, including both sham and no acupuncture control groups. Data were extracted by one reviewer and verified by a second. Pooled standardized mean differences were calculated using a random effects model with the inverse variance method. Results Thirty-seven trials with a total of 5754 patients met the inclusion criteria. The included studies varied strongly regarding patients, interventions, outcome measures, methodological quality and effect sizes reported. Among the 32 trials reporting a continuous outcome measure, the random effects standardized mean difference between sham acupuncture and no acupuncture groups was -0.45 (95% confidence interval, -0.57, -0.34; I2 = 54%; Egger's test for funnel plot asymmetry, P = 0.25. Trials with larger effects of sham over no acupuncture reported smaller effects of acupuncture over sham intervention than trials with smaller nonspecific effects (β = -0.39, P = 0.029. Conclusions Sham acupuncture interventions are often associated with moderately large nonspecific effects which could make it difficult to detect small additional specific effects. Compared to inert placebo interventions, effects associated with sham acupuncture might be larger, which would have considerable implications for the design and interpretation of clinical trials.

  4. Dispersion in rectangular networks: effective diffusivity and large-deviation rate function

    CERN Document Server

    Tzella, Alexandra

    2015-01-01

    We investigate the dispersion of a passive scalar released in a fluid flowing within a rectangular, Manhattan-style network. We use large-deviation theory to approximate the scalar concentration as it evolves under the combined action of advection and diffusion and derive an expression for the rate function that controls the form of the concentration at large times $t$. For moderately large distances $O(t^{1/2})$ from the centre of mass, this form reduces to a Gaussian parameterised by a (tensorial) effective diffusivity given in closed form. Further away, at distances $O(t)$, a more complex form reveals the strong imprint of the network geometry. Our theoretical predictions are verified against Monte Carlo simulations of Brownian particles.

  5. Effects of hydrocarbon pollution in the structure of macrobenthic assemblages from two large estuaries in Brazil.

    Science.gov (United States)

    Camargo, Manuela Zeglin; Sandrini-Neto, Leonardo; Carreira, Renato S; Camargo, Maurício G

    2017-08-05

    Changes in the structure of benthic macrofauna and its relationship with hydrocarbon contamination were determined at different spatial scales in sublittoral sediments of two large estuaries in Brazil. Guanabara Bay (GB) is a heavily polluted estuary due to the presence of a large industrial complex and high demographic density. Laranjeiras Bay (LB) lies in an Environmental Protection Area and can still be considered as preserved from human activities. Despite some spatial differences within each bay, the PAHs concentrations were significantly and consistently higher in GB, with values generally above the threshold effect levels. No signs of hydrocarbon contamination were observed in LB. Macrofauna abundance, diversity and overall assemblage structure were largely different between bays. Canonical analysis of principal coordinates (CAP), used to model the relationship between macrofauna and PAHs levels, indicated that this class of hydrocarbons is the main structuring factor of soft-bottom assemblages in both bays. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Large room-temperature rotating magnetocaloric effect in NdCo4Al polycrystalline alloy

    Science.gov (United States)

    Hu, Y.; Hu, Q. B.; Wang, C. C.; Cao, Q. Q.; Gao, W. L.; Wang, D. H.; Du, Y. W.

    2017-01-01

    The magnetic refrigeration based on rotating magnetocaloric effect (MCE) is promising to build a simplified magnetic cooling system. Until now, most magnetic refrigerants for rotating MCE are single crystal and work at low temperature, which hinder the development of this refrigeration technology. In present paper, we report a large room-temperature rotating MCE in a magnetic-field-aligned NdCo4Al polycrystalline alloy. A large rotating magnetic entropy change of 1.3 J kg-1 K-1 under 10 kOe and a broad operating temperature window of 52 K are achieved. The origin of large rotating MCE in NdCo4Al polycrystalline alloy and its advantages for rotating magnetic refrigeration are discussed.

  7. Retrieval of large volcanomagnetic effects observed during the 1981 eruption of Mt.Etna

    Directory of Open Access Journals (Sweden)

    R. Napoli

    1997-06-01

    Full Text Available A large temporal anomaly was retrieved in the total geomagnetic field series recorded in 1981 on Mt. Etna at two continuously recording magnetometers, and associated with the March 17-23 eruption of the volcano. Variations were of such large scale that a 10 nT anomaly was observed at a distance of some 7 km from the eruptive events, calling for a significant extension and depth of the magnetic anomaly source. We discuss here some models which may account for such magnetic changes in relation to the eruption mechanism inferred by other data. The anomaly is thought to be accounted for by the joint effect of piezomagnetism of the country rocks and thermal demagnetisation engendered by a large intrusive dyke.

  8. Imprint of non-linear effects on HI intensity mapping on large scales

    CERN Document Server

    Umeh, Obinna

    2016-01-01

    Intensity mapping of the HI brightness temperature provides a unique way of tracing large-scale structures of the Universe up to the largest possible scales. This is achieved by using a low angular resolution radio telescopes to detect emission line from cosmic neutral Hydrogen in the post-reionization Universe. We consider how non-linear effects associated with the HI bias and redshift space distortions contribute to the clustering of cosmic neutral Hydrogen on large scales. We use general relativistic perturbation theory techniques to derive for the first time the full expression for the HI brightness temperature up to third order in perturbation theory without making any plane-parallel approximation. We use this result to show how mode coupling at nonlinear order due to nonlinear bias parameters and redshift space distortions leads to about 10\\% modulation of the HI power spectrum on large scales.

  9. Piezoresistive effect of n-type -oriented Si nanowires under large tension/compression

    Science.gov (United States)

    Gao, Di; Yang, Zhenyu; Zheng, Lingli; Zheng, Kun

    2017-03-01

    Small-scale samples enable us to understand changes in physical properties under larger strain due to their higher tolerance to deformation. In this study, the piezoresistive character of n-type -oriented Si nanowires under large strain was measured during tensile and compressive deformations. The Si nanowires were directly cut from the wafer using top-down technology and deformed while capturing their electrical properties inside a transmission electron microscope. The experimental results show that both tensile and compressive deformation enhanced their electrical transport properties. The piezoresistance coefficient is of the same order of magnitude as its bulk counterpart, but half as large, which may be attributed to a larger strain magnitude. We also studied the circulatory characteristics and influence of electron beam radiation. This study provided new physical insights into piezoresistive effects under large strain.

  10. The effect of large deformation and material nonlinearity on gel indentation

    Institute of Scientific and Technical Information of China (English)

    Zheng Duan; Yonghao An; Jiaping Zhang; Hanqing Jiang

    2012-01-01

    A gel,an aggregate of polymers with solvents,has dual attributes of solid and liquid as solvent migrates in and out of the polymer network.Indentation has recently been used to characterize the mechanical properties of gels.This paper evaluates the effects of large deformation and material nonlinearity on gel indentation through theoretical modeling and finite element analysis.It is found that large deformation significantly affects the interpretation of the experimental observations and the classical relation between indentation force and depth has limitations for large deformation.The material nonlinearity does not play a very important role on indentation experiment so that the poroelasticity is a good approximation.Based on these observations,this paper proposes an alternative approach to measure the mechanical properties of gels,namely,uniaxial compression experiment.

  11. The effect of manufacturing tolerances on the load carrying capacity of large diameter bearings

    Indian Academy of Sciences (India)

    Starvin M S; Manisekar K

    2015-09-01

    This paper deals with simplified 3D finite element (FE) analysis on the effect of manufacturing tolerances on the load carrying capacity of large diameter bearings based on Hertz theory. The nonlinear connector elements are used to model the rolling elements. This model enables us to evaluate the contact load on the rolling elements with relatively reduced calculation time. FE study has been carried out by allocating tolerance on balls and raceways using Monte Carlo simulation technique. The variation in dimension on balls is taken as per IS 2898-1976. A coding has been developed and employed for Monte Carlo simulation. Using the results of Monte Carlo simulation, tolerance has been assigned to the elements of large diameter bearing. From the results of finite element analysis, it is identified that analysis of large diameter bearing with tolerance on ball and raceway will lead to safe design.

  12. Performance of informative priors skeptical of large treatment effects in clinical trials: A simulation study.

    Science.gov (United States)

    Pedroza, Claudia; Han, Weilu; Truong, Van Thi Thanh; Green, Charles; Tyson, Jon E

    2015-12-13

    One of the main advantages of Bayesian analyses of clinical trials is their ability to formally incorporate skepticism about large treatment effects through the use of informative priors. We conducted a simulation study to assess the performance of informative normal, Student-t, and beta distributions in estimating relative risk (RR) or odds ratio (OR) for binary outcomes. Simulation scenarios varied the prior standard deviation (SD; level of skepticism of large treatment effects), outcome rate in the control group, true treatment effect, and sample size. We compared the priors with regards to bias, mean squared error (MSE), and coverage of 95% credible intervals. Simulation results show that the prior SD influenced the posterior to a greater degree than the particular distributional form of the prior. For RR, priors with a 95% interval of 0.50-2.0 performed well in terms of bias, MSE, and coverage under most scenarios. For OR, priors with a wider 95% interval of 0.23-4.35 had good performance. We recommend the use of informative priors that exclude implausibly large treatment effects in analyses of clinical trials, particularly for major outcomes such as mortality.

  13. Potential effects of large linear pipeline construction on soil and vegetation in ecologically fragile regions.

    Science.gov (United States)

    Xiao, Jun; Wang, Ya-Feng; Shi, Peng; Yang, Lei; Chen, Li-Ding

    2014-11-01

    Long-distance pipeline construction results in marked human disturbance of the regional ecosystem and brings into question the safety of pipeline construction with respect to the environment. Thus, the direct environmental impact and proper handling of such large projects have received much attention. The potential environmental effects, however, have not been fully addressed, particularly for large linear pipeline projects, and the threshold of such effects is unclear. In this study, two typical eco-fragile areas in western China, where large linear construction projects have been conducted, were chosen as the case study areas. Soil quality indices (SQI) and vegetation indices (VI), representing the most important potential effects, were used to analyze the scope of the effect of large pipeline construction on the surrounding environment. These two indices in different buffer zones along the pipeline were compared against the background values. The analysis resulted in three main findings. First, pipeline construction continues to influence the nearby eco-environment even after a 4-year recovery period. During this period, the effect on vegetation due to pipeline construction reaches 300 m beyond the working area, and is much larger in distance than the effect on soil, which is mainly confined to within 30 m either side of the pipeline, indicating that vegetation is more sensitive than soil to this type of human disturbance. However, the effect may not reach beyond 500 m from the pipeline. Second, the scope of the effect in terms of distance on vegetation may also be determined by the frequency of disturbance and the intensity of the pipeline construction. The greater the number of pipelines in an area, the higher the construction intensity and the more frequent the disturbance. Frequent disturbance may expand the effect on vegetation on both sides of the pipeline, but not on soil quality. Third, the construction may eliminate the stable, resident plant

  14. Characterizing Android apps’ behavior for effective detection of malapps at large scale

    KAUST Repository

    Wang, Xing

    2017-05-06

    Android malicious applications (malapps) have surged and been sophisticated, posing a great threat to users. How to characterize, understand and detect Android malapps at a large scale is thus a big challenge. In this work, we are motivated to discover the discriminatory and persistent features extracted from Android APK files for automated malapp detection at a large scale. To achieve this goal, firstly we extract a very large number of features from each app and categorize the features into two groups, namely, app-specific features as well as platform-defined features. These feature sets will then be fed into four classifiers (i.e., Logistic Regression, linear SVM, Decision Tree and Random Forest) for the detection of malapps. Secondly, we evaluate the persistence of app-specific and platform-defined features on classification performance with two data sets collected in different time periods. Thirdly, we comprehensively analyze the relevant features selected by Logistic Regression classifier to identify the contributions of each feature set. We conduct extensive experiments on large real-world app sets consisting of 213,256 benign apps collected from six app markets, 4,363 benign apps from Google Play market, and 18,363 malapps. The experimental results and our analysis give insights regarding what discriminatory features are most effective to characterize malapps for building an effective and efficient malapp detection system. With the selected discriminatory features, the Logistic Regression classifier yields the best true positive rate as 96% with a false positive rate as 0.06%.

  15. Influence of the large-small split effect on strategy choice in complex subtraction.

    Science.gov (United States)

    Xiang, Yan Hui; Wu, Hao; Shang, Rui Hong; Chao, Xiaomei; Ren, Ting Ting; Zheng, Li Ling; Mo, Lei

    2016-03-31

    Two main theories have been used to explain the arithmetic split effect: decision-making process theory and strategy choice theory. Using the inequality paradigm, previous studies have confirmed that individuals tend to adopt a plausibility-checking strategy and a whole-calculation strategy to solve large and small split problems in complex addition arithmetic, respectively. This supports strategy choice theory, but it is unknown whether this theory also explains performance in solving different split problems in complex subtraction arithmetic. This study used small, intermediate and large split sizes, with each split condition being further divided into problems requiring and not requiring borrowing. The reaction times (RTs) for large and intermediate splits were significantly shorter than those for small splits, while accuracy was significantly higher for large and middle splits than for small splits, reflecting no speed-accuracy trade-off. Further, RTs and accuracy differed significantly between the borrow and no-borrow conditions only for small splits. This study indicates that strategy choice theory is suitable to explain the split effect in complex subtraction arithmetic. That is, individuals tend to choose the plausibility-checking strategy or the whole-calculation strategy according to the split size. © 2016 International Union of Psychological Science.

  16. Effective Boolean dynamics analysis to identify functionally important genes in large-scale signaling networks.

    Science.gov (United States)

    Trinh, Hung-Cuong; Kwon, Yung-Keun

    2015-11-01

    Efficiently identifying functionally important genes in order to understand the minimal requirements of normal cellular development is challenging. To this end, a variety of structural measures have been proposed and their effectiveness has been investigated in recent literature; however, few studies have shown the effectiveness of dynamics-based measures. This led us to investigate a dynamic measure to identify functionally important genes, and the effectiveness of which was verified through application on two large-scale human signaling networks. We specifically consider Boolean sensitivity-based dynamics against an update-rule perturbation (BSU) as a dynamic measure. Through investigations on two large-scale human signaling networks, we found that genes with relatively high BSU values show slower evolutionary rate and higher proportions of essential genes and drug targets than other genes. Gene-ontology analysis showed clear differences between the former and latter groups of genes. Furthermore, we compare the identification accuracies of essential genes and drug targets via BSU and five well-known structural measures. Although BSU did not always show the best performance, it effectively identified the putative set of genes, which is significantly different from the results obtained via the structural measures. Most interestingly, BSU showed the highest synergy effect in identifying the functionally important genes in conjunction with other measures. Our results imply that Boolean-sensitive dynamics can be used as a measure to effectively identify functionally important genes in signaling networks.

  17. Solar-terrestrial effect controls seismic activity to a large extent (Invited)

    Science.gov (United States)

    Duma, G.

    2010-12-01

    , too, and the number of events during Kp maxima is about twice that observed for N-America. For the whole of Eurasia the same becomes evident. In all three regions, the strongest earthquakes with magnitude 7 and even 8 occur during the Kp maxima. In the recent decade, several geophysical models have been tested to interpret the coupling between the solar induced geomagnetic variations and disturbances and its mechanic implications in the Earth’s lithosphere, i.e. in rupture zones. The main questions in that regard are, of course, how mechanic forces are generated by the magnetic variations and whether they are strong enough to influence the tectonic process, that is, to act as a powerful trigger mechanism, as observed. Two such models are demonstrated, which fit well the observations, and which both indicate a surprisingly high energy and mechanic stress involved in the process. They build on Lorentz forces and on the effect of magnetostriction, respectively. The effect applies in particular to strong earthquake activity as outlined above. Moreover, it is a general geodynamic process which acts in nearly all main seismic regions on the globe. Thus, the results add very novel and important aspects to the research on seismic performance, temporal trends of strong earthquake occurrence and hazard assessment.

  18. Estimating the effective Reynolds number in implicit large-eddy simulation.

    Science.gov (United States)

    Zhou, Ye; Grinstein, Fernando F; Wachtor, Adam J; Haines, Brian M

    2014-01-01

    In implicit large-eddy simulation (ILES), energy-containing large scales are resolved, and physics capturing numerics are used to spatially filter out unresolved scales and to implicitly model subgrid scale effects. From an applied perspective, it is highly desirable to estimate a characteristic Reynolds number (Re)-and therefore a relevant effective viscosity-so that the impact of resolution on predicted flow quantities and their macroscopic convergence can usefully be characterized. We argue in favor of obtaining robust Re estimates away from the smallest scales of the simulated flow-where numerically controlled dissipation takes place and propose a theoretical basis and framework to determine such measures. ILES examples include forced turbulence as a steady flow case, the Taylor-Green vortex to address transition and decaying turbulence, and simulations of a laser-driven reshock experiment illustrating a fairly complex turbulence problem of current practical interest.

  19. Mutualist-mediated effects on species' range limits across large geographic scales.

    Science.gov (United States)

    Afkhami, Michelle E; McIntyre, Patrick J; Strauss, Sharon Y

    2014-10-01

    Understanding the processes determining species range limits is central to predicting species distributions under climate change. Projected future ranges are extrapolated from distribution models based on climate layers, and few models incorporate the effects of biotic interactions on species' distributions. Here, we show that a positive species interaction ameliorates abiotic stress, and has a profound effect on a species' range limits. Combining field surveys of 92 populations, 10 common garden experiments throughout the range, species distribution models and greenhouse experiments, we show that mutualistic fungal endophytes ameliorate drought stress and broaden the geographic range of their native grass host Bromus laevipes by thousands of square kilometres (~ 20% larger) into drier habitats. Range differentiation between fungal-associated and fungal-free grasses was comparable to species-level range divergence of congeners, indicating large impacts on range limits. Positive biotic interactions may be underappreciated in determining species' ranges and species' responses to future climates across large geographic scales.

  20. Signatures of collective and matter effects on supernova neutrinos at large detectors

    CERN Document Server

    Choubey, Sandhya; Dighe, Amol; Mirizzi, Alessandro

    2010-01-01

    We calculate the expected galactic supernova neutrino signal at large next-generation underground detectors. At different epochs after the explosion, the primary fluxes can be quite different. For these primary neutrino fluxes, spectral splits induced by collective neutrino flavor transformations can arise for either mass hierarchy in both neutrino and antineutrino channels. We classify flux models according to the nature and number of these splits, and calculate the observable electron-neutrino and electron-antineutrino spectra at Earth, taking into account subsequent matter effects. We find that some of the spectral splits could occur sufficiently close to the peak energies to produce significant distortions in the observable SN neutrino signal. The most striking signature of this effect would be presence of peculiar energy dependent modulations associated with Earth matter crossing, present only in portions of the SN neutrino energy spectra demarcated by spectral splits. These signatures at proposed large ...

  1. Effects of ischemic preconditioning in a pig model of large-for-size liver transplantation

    Science.gov (United States)

    Leal, Antonio José Gonçalves; Tannuri, Ana Cristina Aoun; Belon, Alessandro Rodrigo; Guimarães, Raimundo Renato Nunes; Coelho, Maria Cecília Mendonça; de Oliveira Gonçalves, Josiane; Serafini, Suellen; de Melo, Evandro Sobroza; Tannuri, Uenis

    2015-01-01

    OBJECTIVE: In most cases of pediatric liver transplantation, the clinical scenario of large-for-size transplants can lead to hepatic dysfunction and a decreased blood supply to the liver graft. The objective of the present experimental investigation was to evaluate the effects of ischemic preconditioning on this clinical entity. METHODS: Eighteen pigs were divided into three groups and underwent liver transplantation: a control group, in which the weights of the donors were similar to those of the recipients, a large-for-size group, and a large-for-size + ischemic preconditioning group. Blood samples were collected from the recipients to evaluate the pH and the sodium, potassium, aspartate aminotransferase and alanine aminotransferase levels. In addition, hepatic tissue was sampled from the recipients for histological evaluation, immunohistochemical analyses to detect hepatocyte apoptosis and proliferation and molecular analyses to evaluate the gene expression of Bax (pro-apoptotic), Bcl-XL (anti-apoptotic), c-Fos and c-Jun (immediate-early genes), ischemia-reperfusion-related inflammatory cytokines (IL-1, TNF-alpha and IL-6, which is also a stimulator of hepatocyte regeneration), intracellular adhesion molecule, endothelial nitric oxide synthase (a mediator of the protective effect of ischemic preconditioning) and TGF-beta (a pro-fibrogenic cytokine). RESULTS: All animals developed acidosis. At 1 hour and 3 hours after reperfusion, the animals in the large-for-size and large-for-size + ischemic preconditioning groups had decreased serum levels of Na and increased serum levels of K and aspartate aminotransferase compared with the control group. The molecular analysis revealed higher expression of the Bax, TNF-alpha, I-CAM and TGF-beta genes in the large-for-size group compared with the control and large-for-size + ischemic preconditioning groups. Ischemic preconditioning was responsible for an increase in c-Fos, IL-1, IL-6 and e-NOS gene expression. CONCLUSION

  2. Effects of ischemic preconditioning in a pig model of large-for-size liver transplantation

    Directory of Open Access Journals (Sweden)

    Antonio José Gonçalves Leal

    2015-02-01

    Full Text Available OBJECTIVE: In most cases of pediatric liver transplantation, the clinical scenario of large-for-size transplants can lead to hepatic dysfunction and a decreased blood supply to the liver graft. The objective of the present experimental investigation was to evaluate the effects of ischemic preconditioning on this clinical entity. METHODS: Eighteen pigs were divided into three groups and underwent liver transplantation: a control group, in which the weights of the donors were similar to those of the recipients, a large-for-size group, and a large-for-size + ischemic preconditioning group. Blood samples were collected from the recipients to evaluate the pH and the sodium, potassium, aspartate aminotransferase and alanine aminotransferase levels. In addition, hepatic tissue was sampled from the recipients for histological evaluation, immunohistochemical analyses to detect hepatocyte apoptosis and proliferation and molecular analyses to evaluate the gene expression of Bax (pro-apoptotic, Bcl-XL (anti-apoptotic, c-Fos and c-Jun (immediate-early genes, ischemia-reperfusion-related inflammatory cytokines (IL-1, TNF-alpha and IL-6, which is also a stimulator of hepatocyte regeneration, intracellular adhesion molecule, endothelial nitric oxide synthase (a mediator of the protective effect of ischemic preconditioning and TGF-beta (a pro-fibrogenic cytokine. RESULTS: All animals developed acidosis. At 1 hour and 3 hours after reperfusion, the animals in the large-for-size and large-for-size + ischemic preconditioning groups had decreased serum levels of Na and increased serum levels of K and aspartate aminotransferase compared with the control group. The molecular analysis revealed higher expression of the Bax, TNF-alpha, I-CAM and TGF-beta genes in the large-for-size group compared with the control and large-for-size + ischemic preconditioning groups. Ischemic preconditioning was responsible for an increase in c-Fos, IL-1, IL-6 and e-NOS gene expression

  3. Prokinetic effects of large-dose lubiprostone on gastrointestinal transit in dogs and its mechanisms

    OpenAIRE

    Song, Jun; Yin, Jieyun; Xu, Xiaohong; Chen, Jiande

    2015-01-01

    Objective: To systemically explore effects of large dose of lubiprostone on gastrointestinal (GI) transit and contractions and its safety in dogs. Methods: 12 healthy dogs were studied. 6 dogs were operated to receive duodenal cannula and colon cannula and the other 6 dogs received gastric cannula. Lubiprostone was orally administrated at a dose of 24 µg or 48 µg 1 hr prior to the experiments. Gastric emptying (GE) of solids and small bowel transit were evaluated by collecting the effluents f...

  4. Induced wormholes due to quantum effects of spherically reduced matter in large N approximation

    CERN Document Server

    Nojiri, S; Odintsov, S D; Osetrin, K E

    1999-01-01

    Using one-loop effective action in large N and s-wave approximation we discuss the possibility to induce primordial wormholes at the early Universe. An analytical solution is found for self-consistent primordial wormhole with constant radius. Numerical study gives the wormhole solution with increasing throat radius and red-shift function which first increases and then decreases. This may indicate the possibility of a topological phase transition.

  5. Analysing the effects of rigid and flexible aircraft dynamics on the ejection of a large store

    CSIR Research Space (South Africa)

    Jamison, Kevin

    2011-09-01

    Full Text Available Aeronautical Systems Competency Defence, Peace, Safety and Security (DPSS) ANALYSING THE EFFECTS OF RIGID AND FLEXIBLE AIRCRAFT DYNAMICS ON THE EJECTION OF A LARGE STORE International Aerospace Symposium of South Africa 26 ? 28... & rigid aircraft dynamics on store release ? Closing the loop ? comparison with flight tests ? Conclusions ? CSIR 2011 Slide 3 Background to Hawk / Katleho project ? CSIR 2011 Slide 4 ? Katleho is a PGM under development by Denel Dynamics...

  6. Combined climate and carbon-cycle effects of large-scale deforestation

    OpenAIRE

    G. Bala; Caldeira, K; Wickett, M.; Phillips, T. J.; Lobell, D.B.; Delire, C; Mirin, A.

    2007-01-01

    The prevention of deforestation and promotion of afforestation have often been cited as strategies to slow global warming. Deforestation releases CO2 to the atmosphere, which exerts a warming influence on Earth's climate. However, biophysical effects of deforestation, which include changes in land surface albedo, evapotranspiration, and cloud cover also affect climate. Here we present results from several large-scale deforestation experiments performed with a three-dimensional coupled global ...

  7. Do Newtonian large-scale structure simulations fail to include relativistic effects?

    CERN Document Server

    Faraoni, Valerio; Prain, Angus

    2015-01-01

    The Newtonian simulations describing the formation of large-scale structures do not include relativistic effects. A new approach to this problem is proposed, which consists of splitting the Hawking-Hayward quasi-local energy of a closed spacelike 2-surface into a "Newtonian" part due to local perturbations and a "relativistic" part due to the cosmology. It is found that the Newtonian part dominates over the relativistic one as time evolves, lending support to the validity of Newtonian simulations.

  8. Acute effects of a large bolide impact simulated by a global atmospheric circulation model

    Science.gov (United States)

    Thompson, Starley L.; Crutzen, P. J.

    1988-01-01

    The goal is to use a global three-dimensional atmospheric circulation model developed for studies of atmospheric effects of nuclear war to examine the time evolution of atmospheric effects from a large bolide impact. The model allows for dust and NOx injection, atmospheric transport by winds, removal by precipitation, radiative transfer effects, stratospheric ozone chemistry, and nitric acid formation and deposition on a simulated Earth having realistic geography. Researchers assume a modest 2 km-diameter impactor of the type that could have formed the 32 km-diameter impact structure found near Manson, Iowa and dated at roughly 66 Ma. Such an impact would have created on the order of 5 x 10 to the 10th power metric tons of atmospheric dust (about 0.01 g cm(-2) if spread globally) and 1 x 10 to the 37th power molecules of NO, or two orders of magnitude more stratospheric NO than might be produced in a large nuclear war. Researchers ignore potential injections of CO2 and wildfire smoke, and assume the direct heating of the atmosphere by impact ejecta on a regional scale is not large compared to absorption of solar energy by dust. Researchers assume an impact site at 45 N in the interior of present day North America.

  9. Effect of drop size on the impact thermodynamics for supercooled large droplet in aircraft icing

    Science.gov (United States)

    Zhang, Chen; Liu, Hong

    2016-06-01

    Supercooled large droplet (SLD), which can cause abnormal icing, is a well-known issue in aerospace engineering. Although efforts have been exerted to understand large droplet impact dynamics and the supercooled feature in the film/substrate interface, respectively, the thermodynamic effect during the SLD impact process has not received sufficient attention. This work conducts experimental studies to determine the effects of drop size on the thermodynamics for supercooled large droplet impingement. Through phenomenological reproduction, the rapid-freezing characteristics are observed in diameters of 400, 800, and 1300 μm. The experimental analysis provides information on the maximum spreading rate and the shrinkage rate of the drop, the supercooled diffusive rate, and the freezing time. A physical explanation of this unsteady heat transfer process is proposed theoretically, which indicates that the drop size is a critical factor influencing the supercooled heat exchange and effective heat transfer duration between the film/substrate interface. On the basis of the present experimental data and theoretical analysis, an impinging heating model is developed and applied to typical SLD cases. The model behaves as anticipated, which underlines the wide applicability to SLD icing problems in related fields.

  10. Effectiveness of Acupuncture Therapy on Stress in a Large Urban College Population.

    Science.gov (United States)

    Schroeder, Stefanie; Burnis, James; Denton, Antony; Krasnow, Aaron; Raghu, T S; Mathis, Kimberly

    2017-06-01

    This study is a randomized controlled clinical trial to study the effectiveness of acupuncture on the perception of stress in patients who study or work on a large, urban college campus. The hypothesis was that verum acupuncture would demonstrate a significant positive impact on perceived stress as compared to sham acupuncture. This study included 111 participants with high self-reported stress levels who either studied or worked at a large, urban public university in the southwestern United States. However, only 62 participants completed the study. The participants were randomized into a verum acupuncture or sham acupuncture group. Both the groups received treatment once a week for 12 weeks. The Cohen's global measure of perceived stress scale (PSS-14) was completed by each participant prior to treatment, at 6 weeks, at 12 weeks, and 6 weeks and 12 weeks post-treatment completion. While participants of both the groups showed a substantial initial decrease in perceived stress scores, at 12 weeks post treatment, the verum acupuncture group showed a significantly greater treatment effect than the sham acupuncture group. This study indicates that acupuncture may be successful in decreasing the perception of stress in students and staff at a large urban university, and this effect persists for at least 3 months after the completion of treatment. Copyright © 2017. Published by Elsevier B.V.

  11. Effect of local and large-scale environments on nuclear activity and star formation

    CERN Document Server

    Argudo-Fernández, M; Sabater, J; Puertas, S Duarte; Verley, S; Yang, X

    2016-01-01

    Active galactic nuclei (AGN) is one of the main drivers for transition from star-forming disk to passive spheroidal galaxies. However, the role of large-scale environment versus one-on-one interactions in triggering different types of AGN is still uncertain. We present a statistical study of the prevalence of the nuclear activity in isolated galaxies and physically bound isolated pairs. For the purpose of this study we considered optically and radio selected nuclear activity types. We aim to assess the effect of one-on-one interaction on the fraction of AGN and the role of their large-scale environment. To study the effect of one-on-one interaction on the fraction of AGN in isolated galaxy pairs, we compare with a sample of isolated galaxies homogeneously selected under the same isolation criterion. We examine the effect of the large-scale environment by comparing with control samples of single galaxies and galaxy pairs. In general we found no difference in the prevalence of optical AGN for the considered sam...

  12. Potential Effects on Large Mara Construction Projects Due To Construction Delay

    Directory of Open Access Journals (Sweden)

    M.R. Abdullah

    2009-12-01

    Full Text Available The construction industry continues to be the driving force in the growth of the nation’s socio economic development. One of the major issues in large construction industry is its frequent delay where this delay decelerates the multiplier effects to the economy. This paper presents the study of a survey on significant cause of delay and its effects in large MARA (Majlis Amanah Rakyat construction project in the views of project management consultants (PMC. Respondents of this survey were personnel that work as PMC ranging from the executives, managerial and supporting groups. The result revealed that the five most significant delay causes as seen by PMC were cash flow and financial difficulties faced by contractors, contractor’s poor site management, inadequate contractor experience, shortage of site workers and ineffective planning and scheduling by contractors and its three most significant effects were time overrun, cost overrun and arbitration. Hopefully, the findings of this study will at least shade some lights to the problems faced by Malaysia construction industry particularly MARA large construction project and effort can be taken to improve it.

  13. Effects of rotor location, coning, and tilt on critical loads in large wind turbines

    Science.gov (United States)

    Spera, D. A.; Janetzke, D. C.

    1978-01-01

    Several large (1500 kW) horizontal rotor configurations were analyzed to determine the effects on dynamic loads of upwind downwind rotor locations, coned and radial blade positions, and tilted and horizontal rotor axis positions. Loads were calculated for a range of wind velocities at three locations in the structure: (1) the blade shank; (2) the hub shaft; and (3) the yaw drive. Blade axis coning and rotor axis tilt were found to have minor effects on loads. However, locating the rotor upwind of the tower significantly reduced loads at all locations analyzed.

  14. A large-scale deforestation experiment: effects of patch area and isolation on Amazon birds.

    Science.gov (United States)

    Ferraz, Gonçalo; Nichols, James D; Hines, James E; Stouffer, Philip C; Bierregaard, Richard O; Lovejoy, Thomas E

    2007-01-12

    As compared with extensive contiguous areas, small isolated habitat patches lack many species. Some species disappear after isolation; others are rarely found in any small patch, regardless of isolation. We used a 13-year data set of bird captures from a large landscape-manipulation experiment in a Brazilian Amazon forest to model the extinction-colonization dynamics of 55 species and tested basic predictions of island biogeography and metapopulation theory. From our models, we derived two metrics of species vulnerability to changes in isolation and patch area. We found a strong effect of area and a variable effect of isolation on the predicted patch occupancy by birds.

  15. Effect of corrosion on the ship hull of a double hull very large crude oil carrier

    Science.gov (United States)

    Vu Van, Tuyen; Yang, Ping

    2017-09-01

    This study aims to examine and analyze the effect of corrosion wastage on the ship hull of a double hull very large crude oil carrier. To calculate the ultimate bending moment capacity, along with the neutral axis position at the limit state, section modulus, and moment of inertia, the incremental-iterative method is employed. This paper also considered the residual strength checking criteria of ship hull and the ultimate stress behaviors of the representative structural elements. Then, Paik's probabilistic corrosion, which employs two levels of corrosion rate and three different assumptions of coating life time, is applied to assess the corrosion effects. The calculation results obtained through relevant analyses are also presented.

  16. A large-scale deforestation experiment: Effects of patch area and isolation on Amazon birds

    Science.gov (United States)

    Ferraz, G.; Nichols, J.D.; Hines, J.E.; Stouffer, P.C.; Bierregaard, R.O.; Lovejoy, T.E.

    2007-01-01

    As compared with extensive contiguous areas, small isolated habitat patches lack many species. Some species disappear after isolation; others are rarely found in any small patch, regardless of isolation. We used a 13-year data set of bird captures from a large landscape-manipulation experiment in a Brazilian Amazon forest to model the extinction-colonization dynamics of 55 species and tested basic predictions of island biogeography and metapopulation theory. From our models, we derived two metrics of species vulnerability to changes in isolation and patch area. We found a strong effect of area and a variable effect of isolation on the predicted patch occupancy by birds.

  17. The biological effect of large single doses: a possible role for non-targeted effects in cell inactivation.

    Directory of Open Access Journals (Sweden)

    Marlon R Veldwijk

    Full Text Available BACKGROUND AND PURPOSE: Novel radiotherapy techniques increasingly use very large dose fractions. It has been argued that the biological effect of large dose fractions may differ from that of conventional fraction sizes. The purpose was to study the biological effect of large single doses. MATERIAL AND METHODS: Clonogenic cell survival of MCF7 and MDA-MB-231 cells was determined after direct X-ray irradiation, irradiation of feeder cells, or transfer of conditioned medium (CM. Cell-cycle distributions and the apoptotic sub-G1 fraction were measured by flow cytometry. Cytokines in CM were quantified by a cytokine antibody array. γH2AX foci were detected by immunofluorescence microscopy. RESULTS: The surviving fraction of MCF7 cells irradiated in vitro with 12 Gy showed an 8.5-fold decrease (95% c.i.: 4.4-16.3; P<0.0001 when the density of irradiated cells was increased from 10 to 50×10(3 cells per flask. Part of this effect was due to a dose-dependent transferrable factor as shown in CM experiments in the dose range 5-15 Gy. While no effect on apoptosis and cell cycle distribution was observed, and no differentially expressed cytokine could be identified, the transferable factor induced prolonged expression of γH2AX DNA repair foci at 1-12 h. CONCLUSIONS: A dose-dependent non-targeted effect on clonogenic cell survival was found in the dose range 5-15 Gy. The dependence of SF on cell numbers at high doses would represent a "cohort effect" in vivo. These results support the hypothesis that non-targeted effects may contribute to the efficacy of very large dose fractions in radiotherapy.

  18. Effects of large deep-seated landslides on hillslope morphology, western Southern Alps, New Zealand

    Science.gov (United States)

    Korup, Oliver

    2006-03-01

    Morphometric analysis and air photo interpretation highlight geomorphic imprints of large landslides (i.e., affecting ≥1 km2) on hillslopes in the western Southern Alps (WSA), New Zealand. Large landslides attain kilometer-scale runout, affect >50% of total basin relief, and in 70% are slope clearing, and thus relief limiting. Landslide terrain shows lower mean local relief, relief variability, slope angles, steepness, and concavity than surrounding terrain. Measuring mean slope angle smoothes out local landslide morphology, masking any relationship between large landslides and possible threshold hillslopes. Large failures also occurred on low-gradient slopes, indicating persistent low-frequency/high-magnitude hillslope adjustment independent of fluvial bedrock incision. At the basin and hillslope scale, slope-area plots partly constrain the effects of landslides on geomorphic process regimes. Landslide imprints gradually blend with relief characteristics at orogen scale (102 km), while being sensitive to length scales of slope failure, topography, sampling, and digital elevation model resolution. This limits means of automated detection, and underlines the importance of local morphologic contrasts for detecting large landslides in the WSA. Landslide controls on low-order drainage include divide lowering and shifting, formation of headwater basins and hanging valleys, and stream piracy. Volumes typically mobilized, yet still stored in numerous deposits despite high denudation rates, are >107 m3, and theoretically equal to 102 years of basin-wide debris production from historic shallow landslides; lack of absolute ages precludes further estimates. Deposit size and mature forest cover indicate residence times of 101-104 years. On these timescales, large landslides require further attention in landscape evolution models of tectonically active orogens.

  19. Large local Hall effect in pin-hole dominated multigraphene spin-valves.

    Science.gov (United States)

    Muduli, P K; Barzola-Quiquia, J; Dusari, S; Ballestar, A; Bern, F; Böhlmann, W; Esquinazi, P

    2013-01-11

    We report local and non-local measurements in pin-hole dominated mesoscopic multigraphene spin-valves. Local spin-valve measurements show spurious switching behavior in resistance during magnetic field sweeping similar to the signal observed due to spin injection into multigraphene. The switching behavior has been explained in terms of a local Hall effect due to a thickness irregularity of the tunnel barrier. The local Hall effect appears due to a large local magnetostatic field produced near the roughness in the AlO(x) tunnel barrier. In our samples the resistance change due to the local Hall effect remains negligibly small above 75 K. A strong local Hall effect might hinder spin injection into multigraphene, resulting in no spin signal in non-local measurements.

  20. Surprise and sense making: what newcomers experience in entering unfamiliar organizational settings.

    Science.gov (United States)

    Louis, M R

    1980-06-01

    Growing disillusionment among new members of organizations has been traced to inadequacies in approaches to organizational entry. Current directions of research on organizational entry and their limitations are described, and a new perspective is proposed. The new perspective identifies key features of newcomers' entry experiences, including surprise, contrast, and change, and describes the sense-making processes by which individuals cope with their entry experiences. Implications for research and practice on organizational entry are drawn.

  1. Each individual is a surprise: a conversation with Marianne Horney Eckardt.

    Science.gov (United States)

    Rubin, Jeffrey B

    2014-06-01

    "Each Individual is a Surprise" is a brief account of a dialogue between Marianne Horney Eckardt and myself about the state of psychoanalysis and the psychoanalytic process, the danger of idolatry, the damaging impact of psychoanalytic schools when they create a standardized and pathologizing approach to people, the value of curiosity and humility and retaining one's clinical creativity. The role of Rank, Horney, Sullivan, and Fromm in Dr. Eckardt's long life and rich work is touched upon.

  2. Effective Conformal Descriptions of Black Hole Entropy

    Directory of Open Access Journals (Sweden)

    Steven Carlip

    2011-07-01

    Full Text Available It is no longer considered surprising that black holes have temperatures and entropies. What remains surprising, though, is the universality of these thermodynamic properties: their exceptionally simple and general form, and the fact that they can be derived from many very different descriptions of the underlying microscopic degrees of freedom. I review the proposal that this universality arises from an approximate conformal symmetry, which permits an effective “conformal dual” description that is largely independent of the microscopic details.

  3. Surprise and Opportunity for Learning in Grand Canyon: the Glen Canyon Dam Adaptive Management Program

    Directory of Open Access Journals (Sweden)

    Theodore S. Melis

    2015-09-01

    Full Text Available With a focus on resources of the Colorado River ecosystem below Glen Canyon Dam, the Glen Canyon Dam Adaptive Management Program has included a variety of experimental policy tests, ranging from manipulation of water releases from the dam to removal of non-native fish within Grand Canyon National Park. None of these field-scale experiments has yet produced unambiguous results in terms of management prescriptions. But there has been adaptive learning, mostly from unanticipated or surprising resource responses relative to predictions from ecosystem modeling. Surprise learning opportunities may often be viewed with dismay by some stakeholders who might not be clear about the purpose of science and modeling in adaptive management. However, the experimental results from the Glen Canyon Dam program actually represent scientific successes in terms of revealing new opportunities for developing better river management policies. A new long-term experimental management planning process for Glen Canyon Dam operations, started in 2011 by the U.S. Department of the Interior, provides an opportunity to refocus management objectives, identify and evaluate key uncertainties about the influence of dam releases, and refine monitoring for learning over the next several decades. Adaptive learning since 1995 is critical input to this long-term planning effort. Embracing uncertainty and surprise outcomes revealed by monitoring and ecosystem modeling will likely continue the advancement of resource objectives below the dam, and may also promote efficient learning in other complex programs.

  4. Large reversible magnetocaloric effect induced by metamagnetic transition in antiferromagnetic HoNiGa compound

    Science.gov (United States)

    Wang, Yi-Xu; Zhang, Hu; Wu, Mei-Ling; Tao, Kun; Li, Ya-Wei; Yan, Tim; Long, Ke-Wen; Long, Teng; Pang, Zheng; Long, Yi

    2016-12-01

    The magnetic properties and magnetocaloric effects (MCE) of HoNiGa compound are investigated systematically. The HoNiGa exhibits a weak antiferromagnetic (AFM) ground state below the Ńeel temperature TN of 10 K, and the AFM ordering could be converted into ferromagnetic (FM) ordering by external magnetic field. Moreover, the field-induced FM phase exhibits a high saturation magnetic moment and a large change of magnetization around the transition temperature, which then result in a large MCE. A large -ΔSM of 22.0 J/kg K and a high RC value of 279 J/kg without magnetic hysteresis are obtained for a magnetic field change of 5 T, which are comparable to or even larger than those of some other magnetic refrigerant materials in the same temperature range. Besides, the μ0H2/3 dependence of well follows the linear fitting according to the mean-field approximation, suggesting the nature of second-order FM-PM magnetic transition under high magnetic fields. The large reversible MCE induced by metamagnetic transition suggests that HoNiGa compound could be a promising material for magnetic refrigeration in low temperature range. Project supported by the National Natural Science Foundation of China (Grant Nos. 51671022 and 51427806), the Beijing Natural Science Foundation, China (Grant No. 2162022), and the Fundamental Research Funds for the Central Universities, China (Grant No. FRF-TP-15-002A3).

  5. The comparative effects of large carnivores on the acquisition of carrion by scavengers.

    Science.gov (United States)

    Allen, Maximilian L; Elbroch, L Mark; Wilmers, Christopher C; Wittmer, Heiko U

    2015-06-01

    Pumas (Puma concolor) and black bears (Ursus americanus) are large carnivores that may influence scavenger population dynamics. We used motion-triggered video cameras deployed at deer carcasses to determine how pumas and black bears affected three aspects of carrion acquisition by scavengers: presence, total feeding time, and mean feeding-bout duration. We found that pumas were unable to limit acquisition of carrion by large carnivores but did limit aspects of carrion acquisition by both birds and mesocarnivores. Through their suppression of mesocarnivores and birds, pumas apparently initiated a cascading pattern and increased carrion acquisition by small carnivores. In contrast, black bears monopolized carrion resources and generally had larger limiting effects on carrion acquisition by all scavengers. Black bears also limited puma feeding behaviors at puma kills, which may require pumas to compensate for energetic losses through increasing their kill rates of ungulates. Our results suggest that pumas provide carrion and selectively influence species acquiring carrion, while black bears limit carrion availability to all other scavengers. These results suggest that the effects of large carnivores on scavengers depend on attributes of both carnivores and scavengers (including size) and that competition for carcasses may result in intraguild predation as well as mesocarnivore release.

  6. The ISW effect and the lack of large-angle CMB temperature correlations

    CERN Document Server

    Copi, Craig J; Starkman, Glenn D

    2016-01-01

    It is by now well established that the magnitude of the two-point angular-correlation function of the cosmic microwave background temperature anisotropies is anomalously low for angular separations greater than about 60 degrees. Physics explanations of this anomaly typically focus on the properties of the Universe at the surface of last scattering, relying on the fact that large-angle temperature fluctuations are dominated by the Sachs-Wolfe effect (SW). However, these fluctuations also receive important contributions from the integrated Sachs-Wolfe effect (ISW) at both early (eISW) and late ($\\ell$ISW) times. Here we study the correlations in those large-angle temperature fluctuations and their relative contributions to $S_{1/2}$ -- the standard measure of the correlations on large angular scales. We find that in the best-fitting $\\Lambda$CDM cosmology, while the auto-correlation of the early contributions (SW plus eISW) dominates $S_{1/2}$, there are also significant contributions originating from cross-ter...

  7. Effectively-truncated large-scale shell-model calculations and nuclei around 100Sn

    Science.gov (United States)

    Gargano, A.; Coraggio, L.; Itaco, N.

    2017-09-01

    This paper presents a short overview of a procedure we have recently introduced, dubbed the double-step truncation method, which is aimed to reduce the computational complexity of large-scale shell-model calculations. Within this procedure, one starts with a realistic shell-model Hamiltonian defined in a large model space, and then, by analyzing the effective single particle energies of this Hamiltonian as a function of the number of valence protons and/or neutrons, reduced model spaces are identified containing only the single-particle orbitals relevant to the description of the spectroscopic properties of a certain class of nuclei. As a final step, new effective shell-model Hamiltonians defined within the reduced model spaces are derived by way of a unitary transformation of the original large-scale Hamiltonian. A detailed account of this transformation is given and the merit of the double-step truncation method is illustrated by discussing few selected results for 96Mo, described as four protons and four neutrons outside 88Sr. Some new preliminary results for light odd-tin isotopes from A = 101 to 107 are also reported.

  8. The combined effect of radiofrequency and ethanol ablation in the management of large hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Sakr, Ayman A. [Department of Radiation Sciences, Radiology Unit, Medical Research Institute, University of Alexandria, 165 Horreya Avenue, El Hadara, Alexandria (Egypt)]. E-mail: aymansakr12345@hotmail.com; Saleh, Alaa Ahmed [Department of Radiation Sciences, Radiology Unit, Medical Research Institute, University of Alexandria, 165 Horreya Avenue, El Hadara, Alexandria (Egypt); Moeaty, Amr Ali Abdel [Department of Internal Medicine, Faculty of Medicine, University of Alexandria, Alexandria (Egypt); Moeaty, Ali Abdel [Department of Internal Medicine, Faculty of Medicine, University of Alexandria, Alexandria (Egypt)

    2005-06-01

    Only a small percentage of patients with large hepatocellular carcinoma (HCC) may benefit out of surgical resection. Thus, most of these patients are in need of a form of local control, such as ethanol ablation, transarterial chemoembolization (TACE), radiofrequency thermal ablation (RF), or laser induced thermotherapy (LITT). The purpose of this study was to assess the short-term effect of sequential RF and ethanol ablation in the management of large HCC (>5 cm). Our series included 40 patients with large HCC tumors (>5 cm in diameter). We adopted a protocol of overlapping RF applications, followed by repeated ethanol ablation sessions. Our results showed that the volume of tumor coagulative necrosis initially induced by RF has significantly risen after adjuvant ethanol ablation sessions (P < 0.001). Patients who achieved complete tumor necrosis after RF ablation were 52.5% of the series. This percent has jumped to 80% of the series at the end of the protocol. This indicates that such combined protocol is more effective than RF alone. Besides, it is valuable in reducing the number of RF sessions.

  9. Vertical vibration of a large diameter pipe pile considering transverse inertia effect of pile

    Institute of Scientific and Technical Information of China (English)

    郑长杰; 刘汉龙; 丁选明; 周航

    2016-01-01

    Considering the transverse inertia effect of pile, the vertical dynamic response of a large diameter pipe pile in viscoelastic soil layer is studied. The wave propagations in the outer and inner soil are simulated by three-dimensional elastodynamic theory and those in the pile are simulated by Rayleigh-Love rod theory. The vertical and radial displacements of the outer and inner soil are obtained by utilizing Laplace transform technique and differentiation on the governing equations of soils. Then, based on the continuous conditions between the pile and soils, the displacements of the pile are derived. The frequency domain velocity admittance and time domain velocity response of the pile top are also presented. The solution is compared to a classical rod model solution to verify the validity. The influences of the radii and Poisson ratio of pile on the transverse inertia effect of pile are analyzed. The parametric study shows that Poisson ratio and outer radius of pile have significant influence on the transverse inertia effect of large diameter pipe piles, while the inner radius has little effect.

  10. Reionization on Large Scales IV: Predictions for the 21 cm signal incorporating the light cone effect

    CERN Document Server

    La Plante, Paul; Natarajan, Aravind; Peterson, Jeffrey B; Trac, Hy; Cen, Renyue; Loeb, Abraham

    2013-01-01

    We present predictions for the 21 cm brightness temperature power spectrum during the Epoch of Reionization (EoR). We discuss the implications of the "light cone" effect, which incorporates evolution of the 21 cm brightness temperature along the line of sight. Using a novel method calibrated against radiation-hydrodynamic simulations, we model the neutral hydrogen density field and 21 cm signal in large volumes (L = 2 Gpc/h). The inclusion of the light cone effect leads to a relative increase of 2-3 orders of magnitude in the 21 cm signal power spectrum on large scales (k < 0.1 h/Mpc). When we modify the power spectrum to more closely reflect real-world measurement capabilities, we find that the light cone effect leads to a relative decrease of order unity at all scales. The light cone effect also introduces an anisotropy parallel to the line of sight. By decomposing the 3D power spectrum into components perpendicular and parallel to the line of sight, we find that parallel modes contribute about an order ...

  11. Surprise and Uncertainty—Framing Regional Geohazards in the Theory of Complexity

    Directory of Open Access Journals (Sweden)

    Beate M. W. Ratter

    2013-01-01

    Full Text Available The paper analyzes the concepts of uncertainty and surprise as key variables of a socio-ecological system’s behavior in the context of the theory of complexity. Experiences from the past have shown that living with uncertainty is part of our daily life and surprises are only surprising because our perspective of system trajectories is basically linear and non-dynamic. The future of humanity is dependent on the understanding of the system’s behavior and needs a change in perspective of linearity to non-linearity and from the planning imperative to a management hedging uncertainty and surprise. In the context of humanity’s future, the theory of complexity offers a new perspective on system trajectories and their understanding of surprises and uncertainty. There is a need for a Gestaltwechsel—a change in perception—which helps to see things differently and fosters the search for new answers to emerging questions at the human-nature interface. Drawing on the case study of hazard management the paper will explain the necessity of analysis system’s behavior and the taking into account of multi-agent behavior on the micro level which led to emergent behavior on the macro-level of the system. Regional geohazards are explained as the regional impact of an uncontrolled risk based on a state of a natural feature that has a direct impact on a regional population being affected by the appearance of a hazard and its development into damage. By acting in space, time and connectivity, people construct hazardscapes and change risk into regional geohazards. This concept shows relevance for future mitigation and adaptation measures. The theory of complexity can help in engendering the necessary shift in perspective. What is non-linear dynamic thinking as suggested by the theory of complexity? Why is the consideration of the system’s behavior crucial and not just the number of system’s elements? What is the role of agents in these systems? In

  12. Influence of flow control devices on metallurgical effects in a large-capacity tundish

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The influence of flow control devices on metallurgical effects in a large-capacity tundish has been studied carefully with elements tracing, sampling and theoretical prospecting. The results from the studies are (1) in the continuous casting of clean steel, bad control of tundish operation may deteriorate the cleanliness of steel; (2) the cleanliness of steel is deteriorated mainly at the unsteady state; (3) large amount of macro inclusions come from the top slag and the refractory of tundish; (4) installing dam and weir can improve the cleanliness of steel and lighten the influence of steel fluctuation; and (5) the result of theoretical calculation suggests that the inclusions larger than the critical size of 92.6 μm can be floated out from the tundish bath completely.

  13. Large lateral photovoltaic effect with ultrafast relaxation time in SnSe/Si junction

    Science.gov (United States)

    Wang, Xianjie; Zhao, Xiaofeng; Hu, Chang; Zhang, Yang; Song, Bingqian; Zhang, Lingli; Liu, Weilong; Lv, Zhe; Zhang, Yu; Tang, Jinke; Sui, Yu; Song, Bo

    2016-07-01

    In this paper, we report a large lateral photovoltaic effect (LPE) with ultrafast relaxation time in SnSe/p-Si junctions. The LPE shows a linear dependence on the position of the laser spot, and the position sensitivity is as high as 250 mV mm-1. The optical response time and the relaxation time of the LPE are about 100 ns and 2 μs, respectively. The current-voltage curve on the surface of the SnSe film indicates the formation of an inversion layer at the SnSe/p-Si interface. Our results clearly suggest that most of the excited-electrons diffuse laterally in the inversion layer at the SnSe/p-Si interface, which results in a large LPE with ultrafast relaxation time. The high positional sensitivity and ultrafast relaxation time of the LPE make the SnSe/p-Si junction a promising candidate for a wide range of optoelectronic applications.

  14. Large photon drag effect of intrinsic graphene induced by plasmonic evanescent field

    Science.gov (United States)

    Luo, Ma; Li, Zhibing

    2016-12-01

    A large photon drag effect of the massless Dirac fermions in intrinsic graphene is predicted for a graphene-on-plasmonic-layer system. The surface plasmons in the plasmonic layer enlarge the wave number of the photon hundreds times more than in vacuum. The evanescent field of the surface plasmons generates a directional motion of carriers in the intrinsic graphene because of the large momentum transfer from the surface plasmon to the excited carriers. A model Hamiltonian is developed on the assumption that the in-plane wavelength of the surface plasmons is much smaller than the mean free path of the carriers. The time evolution of the density matrix is solved by perturbation method as well as numerical integration. The nondiagonal density matrix elements with momentum transfer lead to a gauge current, which is an optically driven macroscopic direct current. The dependence of the macroscopic direct current on the incident direction and intensity of the laser field is studied.

  15. Particle Acceleration at a Flare Termination Shock: Effect of Large-scale Magnetic Turbulence

    CERN Document Server

    Guo, Fan

    2012-01-01

    We investigate the acceleration of charged particles (both electrons and protons) at collisionless shocks predicted to exist in the vicinity of solar flares. The existence of standing termination shocks has been examined by flare models and numerical simulations e.g., Shibata,Forbes. We study electron energization by numerically integrating the equations of motion of a large number of test-particle electrons in the time-dependent two-dimensional electric and magnetic fields generated from hybrid simulations (kinetic ions and fluid electron) using parameters typical of the solar flare plasma environment. The shock is produced by injecting plasma flow toward a rigid piston. Large-scale magnetic fluctuations -- known to exist in plasmas and known to have important effects on the nonthermal electron acceleration at shocks -- are also included in our simulations. For the parameters characteristic of the flaring region, our calculations suggest that the termination shock formed in the reconnection outflow region (a...

  16. Hall effect in the extremely large magnetoresistance semimetal WTe{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Yongkang, E-mail: ykluo@lanl.gov; Dai, Y. M.; Taylor, A. J.; Yarotski, D. A.; Prasankumar, R. P.; Thompson, J. D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Li, H.; Miao, H.; Shi, Y. G. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190 (China); Ding, H. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100084 (China)

    2015-11-02

    We systematically measured the Hall effect in the extremely large magnetoresistance semimetal WTe{sub 2}. By carefully fitting the Hall resistivity to a two-band model, the temperature dependencies of the carrier density and mobility for both electron- and hole-type carriers were determined. We observed a sudden increase in the hole density below ∼160 K, which is likely associated with the temperature-induced Lifshitz transition reported by a previous photoemission study. In addition, a more pronounced reduction in electron density occurs below 50 K, giving rise to comparable electron and hole densities at low temperature. Our observations indicate a possible electronic structure change below 50 K, which might be the direct driving force of the electron-hole “compensation” and the extremely large magnetoresistance as well. Numerical simulations imply that this material is unlikely to be a perfectly compensated system.

  17. Hydrologic effects of large southwestern USA wildfires significantly increase regional water supply: fact or fiction?

    Science.gov (United States)

    Wine, M. L.; Cadol, D.

    2016-08-01

    In recent years climate change and historic fire suppression have increased the frequency of large wildfires in the southwestern USA, motivating study of the hydrological consequences of these wildfires at point and watershed scales, typically over short periods of time. These studies have revealed that reduced soil infiltration capacity and reduced transpiration due to tree canopy combustion increase streamflow at the watershed scale. However, the degree to which these local increases in runoff propagate to larger scales—relevant to urban and agricultural water supply—remains largely unknown, particularly in semi-arid mountainous watersheds co-dominated by winter snowmelt and the North American monsoon. To address this question, we selected three New Mexico watersheds—the Jemez (1223 km2), Mogollon (191 km2), and Gila (4807 km2)—that together have been affected by over 100 wildfires since 1982. We then applied climate-driven linear models to test for effects of fire on streamflow metrics after controlling for climatic variability. Here we show that, after controlling for climatic and snowpack variability, significantly more streamflow discharged from the Gila watershed for three to five years following wildfires, consistent with increased regional water yield due to enhanced infiltration-excess overland flow and groundwater recharge at the large watershed scale. In contrast, we observed no such increase in discharge from the Jemez watershed following wildfires. Fire regimes represent a key difference between the contrasting responses of the Jemez and Gila watersheds with the latter experiencing more frequent wildfires, many caused by lightning strikes. While hydrologic dynamics at the scale of large watersheds were previously thought to be climatically dominated, these results suggest that if one fifth or more of a large watershed has been burned in the previous three to five years, significant increases in water yield can be expected.

  18. Temperature effect on the small-to-large crossover lengthscale of hydrophobic hydration.

    Science.gov (United States)

    Djikaev, Y S; Ruckenstein, E

    2013-11-14

    The thermodynamics of hydration is expected to change gradually from entropic for small solutes to enthalpic for large ones. The small-to-large crossover lengthscale of hydrophobic hydration depends on the thermodynamic conditions of the solvent such as temperature, pressure, presence of additives, etc. We attempt to shed some light on the temperature dependence of the crossover lengthscale by using a probabilistic approach to water hydrogen bonding that allows one to obtain an analytic expression for the number of bonds per water molecule as a function of both its distance to a solute and solute radius. Incorporating that approach into the density functional theory, one can examine the solute size effects on its hydration over the entire small-to-large lengthscale range at a series of different temperatures. Knowing the dependence of the hydration free energy on the temperature and solute size, one can also obtain its enthalpic and entropic contributions as functions of both temperature and solute size. These functions can provide some interesting insight into the temperature dependence of the crossover lengthscale of hydrophobic hydration. The model was applied to the hydration of spherical particles of various radii in water in the temperature range from T = 293.15 K to T = 333.15 K. The model predictions for the temperature dependence of the hydration free energy of small hydrophobes are consistent with the experimental and simulational data on the hydration of simple molecular solutes. Three alternative definitions for the small-to-large crossover length-scale of hydrophobic hydration are proposed, and their temperature dependence is obtained. Depending on the definition and temperature, the small-to-large crossover in the hydration mechanism is predicted to occur for hydrophobes of radii from one to several nanometers. Independent of its definition, the crossover length-scale is predicted to decrease with increasing temperature.

  19. Seasonal effects of Pacific-based climate on recruitment in a predator-limited large herbivore.

    Science.gov (United States)

    Hegel, Troy M; Mysterud, Atle; Ergon, Torbjørn; Loe, Leif Egil; Huettmann, Falk; Stenseth, Nils Chr

    2010-03-01

    1. Climate is an important factor influencing the population dynamics of large herbivores operating directly on individuals or through its effect on forage characteristics. However, the seasonal effect of climate may differ between forage- and predator-limited populations because of a climatic influence on predation rates. The influence of climate on predator-limited large herbivores is less well known than on forage-limited populations. Further, the effect of Pacific-based climate on large herbivore populations has been rarely assessed. 2. We investigated the effect of the Pacific Decadal Oscillation (PDO), across different seasons, on recruitment in 10 populations (herds) of mountain-dwelling caribou Rangifer tarandus caribou L. in the Yukon Territory, Canada. These low-density populations occur in highly seasonal environments and are considered predator-limited with high neonatal calf mortality. Hence, in most years females do not spend resources through lactational support during the summer and resource intake is devoted to self-maintenance. We predicted that climate affecting environmental conditions at calving would have a strong effect on recruitment via its influence on predation rates. We also predicted that climatic conditions prior to conception could have an effect on recruitment through its influence on female fecundity. We modelled recruitment (n = 165) by seasonal PDO values using generalized linear mixed-effects models with herd-varying coefficients. 3. We found that recruitment variability was best explained by variation in winter climate (beta = 0.110, SE = 0.007) prior to birth (in utero) and May climate (beta = 0.013, SE = 0.006) at calving. There was little support for a pre-conception climate effect influencing female body condition and hence fecundity. These results confirm that recruitment in these populations is limited by predation and that forage-limitation is not a significant factor in their population dynamics. There was considerable

  20. Large polarization-dependent exciton optical Stark effect in lead iodide perovskites

    Science.gov (United States)

    Yang, Ye; Yang, Mengjin; Zhu, Kai; Johnson, Justin C.; Berry, Joseph J.; van de Lagemaat, Jao; Beard, Matthew C.

    2016-08-01

    A strong interaction of a semiconductor with a below-bandgap laser pulse causes a blue-shift of the bandgap transition energy, known as the optical Stark effect. The energy shift persists only during the pulse duration with an instantaneous response time. The optical Stark effect has practical relevance for applications, including quantum information processing and communication, and passively mode-locked femtosecond lasers. Here we demonstrate that solution-processable lead-halide perovskites exhibit a large optical Stark effect that is easily resolved at room temperature resulting from the sharp excitonic feature near the bandedge. We also demonstrate that a polarized pump pulse selectively shifts one spin state producing a spin splitting of the degenerate excitonic states. Such selective spin manipulation is an important prerequisite for spintronic applications. Our result implies that such hybrid semiconductors may have great potential for optoelectronic applications beyond photovoltaics.

  1. Large Fizeau's light-dragging effect in a moving electromagnetically induced transparent medium

    CERN Document Server

    Kuan, Pei-Chen; Chan, Wei Sheng; Kosen, Sandoko; Lan, Shau-Yu

    2016-01-01

    As one of the most influential experiments on the development of modern macroscopic theory from Newtonian mechanics to Einstein's special theory of relativity, the phenomenon of light dragging in a moving medium has been discussed and observed extensively in different types of systems. To have a significant dragging effect, the long duration of light travelling in the medium is preferred. Here we demonstrate a light-dragging experiment in an electromagnetically induced transparent cold atomic ensemble and enhance the dragging effect by at least three orders of magnitude compared with the previous experiments. With a large enhancement of the dragging effect, we realize an atom-based velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. Such a demonstration could pave the way for motional sensing using the collective state of atoms in a room temperature vapour cell or solid state material.

  2. Large Fizeau's light-dragging effect in a moving electromagnetically induced transparent medium

    Science.gov (United States)

    Kuan, Pei-Chen; Huang, Chang; Chan, Wei Sheng; Kosen, Sandoko; Lan, Shau-Yu

    2016-10-01

    As one of the most influential experiments on the development of modern macroscopic theory from Newtonian mechanics to Einstein's special theory of relativity, the phenomenon of light dragging in a moving medium has been discussed and observed extensively in different types of systems. To have a significant dragging effect, the long duration of light travelling in the medium is preferred. Here we demonstrate a light-dragging experiment in an electromagnetically induced transparent cold atomic ensemble and enhance the dragging effect by at least three orders of magnitude compared with the previous experiments. With a large enhancement of the dragging effect, we realize an atom-based velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. Such a demonstration could pave the way for motional sensing using the collective state of atoms in a room temperature vapour cell or solid state material.

  3. Large Fizeau's light-dragging effect in a moving electromagnetically induced transparent medium.

    Science.gov (United States)

    Kuan, Pei-Chen; Huang, Chang; Chan, Wei Sheng; Kosen, Sandoko; Lan, Shau-Yu

    2016-10-03

    As one of the most influential experiments on the development of modern macroscopic theory from Newtonian mechanics to Einstein's special theory of relativity, the phenomenon of light dragging in a moving medium has been discussed and observed extensively in different types of systems. To have a significant dragging effect, the long duration of light travelling in the medium is preferred. Here we demonstrate a light-dragging experiment in an electromagnetically induced transparent cold atomic ensemble and enhance the dragging effect by at least three orders of magnitude compared with the previous experiments. With a large enhancement of the dragging effect, we realize an atom-based velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. Such a demonstration could pave the way for motional sensing using the collective state of atoms in a room temperature vapour cell or solid state material.

  4. Effects of large conductance Ca(2+)-activated K(+) channels on nitroglycerin-mediated vasorelaxation in humans

    DEFF Research Database (Denmark)

    Gruhn, Nicolai; Boesgaard, Søren; Eiberg, Jonas

    2002-01-01

    Nitric oxide (NO)-induced vasorelaxation and the regulation of endothelial superoxide anion levels is partly mediated by vascular large conductance Ca(2+)-activated K(+) (BK(Ca)) channels. Nitroglycerin acts through the release of NO and its effect is modulated by changes in endothelial superoxide...... levels. This study examines the effect of BK(Ca) channel blockade on nitroglycerin-induced vasorelaxation in human arterial and venous vascular segments and whether responses to BK(Ca) channel blockade are influenced by the development of venous nitroglycerin tolerance. Dose-relaxation curves...... suggest that primarily arterial effects of nitroglycerin are significantly inhibited by changes in the activity of the endothelial BK(Ca) channels. Although endothelial BK(Ca) are likely regulators of mechanisms underlying arterial tolerance development to nitroglycerin, they do not appear to play a role...

  5. Cost-effective Sampling Design Applied to Large-scale Monitoring of Boreal Birds

    Directory of Open Access Journals (Sweden)

    Matthew Carlson

    2002-12-01

    Full Text Available Despite their important roles in biodiversity conservation, large-scale ecological monitoring programs are scarce, in large part due to the difficulty of achieving an effective design under fiscal constraints. Using long-term avian monitoring in the boreal forest of Alberta, Canada as an example, we present a methodology that uses power analysis, statistical modeling, and partial derivatives to identify cost-effective sampling strategies for ecological monitoring programs. Empirical parameter estimates were used in simulations that estimated the power of sampling designs to detect trend in a variety of species' populations and community metrics. The ability to detect trend with increased sample effort depended on the monitoring target's variability and how effort was allocated to sampling parameters. Power estimates were used to develop nonlinear models of the relationship between sample effort and power. A cost model was also developed, and partial derivatives of the power and cost models were evaluated to identify two cost-effective avian sampling strategies. For decreasing sample error, sampling multiple plots at a site is preferable to multiple within-year visits to the site, and many sites should be sampled relatively infrequently rather than sampling few sites frequently, although the importance of frequent sampling increases for variable targets. We end by stressing the need for long-term, spatially extensive data for additional taxa, and by introducing optimal design as an alternative to power analysis for the evaluation of ecological monitoring program designs.

  6. Be skeptical about unexpected large apparent treatment effects: the case of an MRC AML12 randomization.

    Science.gov (United States)

    Wheatley, Keith; Clayton, David

    2003-02-01

    The preliminary results of the twelfth Medical Research Council acute myeloid leukemia trial show no evidence of a survival advantage for five courses of therapy compared to four courses in a randomized comparison involving 1078 patients (hazard ratio 1.09, 95% confidence interval [CI] 0.87-1.37, p=0.4). However, the data presented to the independent data monitoring and ethics committee (DMEC) at both its reviews in 1998 suggested large benefits for the additional course with hazard ratios of 0.47 and 0.55 (95% CIs 0.29-0.77 and 0.38-0.80, p=0.003 and p=0.002, respectively). Despite these highly significant findings, the DMEC did not recommend closure of the randomization, a decision vindicated by the subsequent reversion to a null result. The main reason for not closing the randomization was that the treatment effects observed in 1998 (53% and 45% reductions in the odds of death) were considered too large to be clinically plausible, despite the p-values associated with them. Investigations have not identified any clinical explanations, such as different types of patients in the early and later parts of the trial, to explain the loss of benefit as the trial progressed. Thus, the most likely current explanation for the large benefit observed early on is the play of chance. Lessons to be learned from this example are that: fixed stopping rules based on some predetermined p-value should not be used and the decision to close a randomization or not should take account of other factors such as the medical plausibility of the magnitude of the treatment effect; chance effects do occur and happen more frequently than many clinicians realize; it is important that DMEC members are experienced in the interpretation of clinical trial evidence and aware of the dangers of early stopping without wholly convincing evidence.

  7. Large elastic strain and elastocaloric effect caused by lattice softening in an iron-palladium alloy.

    Science.gov (United States)

    Kakeshita, Tomoyuki; Xiao, Fei; Fukuda, Takashi

    2016-08-13

    A Fe-31.2Pd (at.%) alloy exhibits a weak first-order martensitic transformation from a cubic structure to a tetragonal structure near 230 K. This transformation is associated with significant softening of elastic constant C'. Because of the softening, the alloy shows a large elastic strain of more than 6% in the [001] direction. In addition, the alloy has a critical point and shows a high elastocaloric effect in a wide temperature range for both the parent and the martensite phases.This article is part of the themed issue 'Taking the temperature of phase transitions in cool materials'.

  8. Effects of large herbivores on biodiversity of vegetation and soil microarthropods in low Arctic Greenland

    DEFF Research Database (Denmark)

    Aastrup, Peter; Raundrup, Katrine; Feilberg, Jon;

    This report summarizes the results of a project that aims at documenting long term effects of grazing by comparing baseline data inside and outside exclosures. We collected data on vascular plants, mosses, lichens, microarthropod abundance and food-web structure, soil nutrients, decomposition......, and soil temperature. Data provide a significant basis for understanding the interaction between large herbivores and vegetation in Greenland. The report contains documentation of data collected in 2009 and 2012 as well as documentation of data from 1984-2004 made available by Jon Feilberg....

  9. THERAPEUTIC EFFECT OF SOLASODINE RHAMNOSYL GLYCOSIDES FOR LARGE SKIN CANCERS: TWO CLINICAL CASES

    Directory of Open Access Journals (Sweden)

    Bill E. Cham

    2012-01-01

    Full Text Available Solasodine rhamnosyl glycosides (BEC are a new class of antineoplastics, the efficiency of which administered via intravenous, intraperitoneal, and intratumoral routes is higher than that of many other antitumor agents. Early investigations have established the efficiency of topical BEC applications as a treatment option for non-melanoma skin cancers. There have recently been two clinical cases that count in favor of the fact that the cream formulation Curaderm containing BEC has a very high efficacy in the treatment of large non-melanoma skin cancers that are incurable by other existing methods. Also, Curaderm treatment shows a splendid cosmetic effect

  10. Renormalization-group flow of the effective action of cosmological large-scale structures

    Science.gov (United States)

    Floerchinger, Stefan; Garny, Mathias; Tetradis, Nikolaos; Wiedemann, Urs Achim

    2017-01-01

    Following an approach of Matarrese and Pietroni, we derive the functional renormalization group (RG) flow of the effective action of cosmological large-scale structures. Perturbative solutions of this RG flow equation are shown to be consistent with standard cosmological perturbation theory. Non-perturbative approximate solutions can be obtained by truncating the a priori infinite set of possible effective actions to a finite subspace. Using for the truncated effective action a form dictated by dissipative fluid dynamics, we derive RG flow equations for the scale dependence of the effective viscosity and sound velocity of non-interacting dark matter, and we solve them numerically. Physically, the effective viscosity and sound velocity account for the interactions of long-wavelength fluctuations with the spectrum of smaller-scale perturbations. We find that the RG flow exhibits an attractor behaviour in the IR that significantly reduces the dependence of the effective viscosity and sound velocity on the input values at the UV scale. This allows for a self-contained computation of matter and velocity power spectra for which the sensitivity to UV modes is under control.

  11. Large eddy simulation of a buoyancy-aided flow in a non-uniform channel – Buoyancy effects on large flow structures

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Y. [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom); School of Mechanical, Aerospace and Civil Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); He, S., E-mail: s.he@sheffield.ac.uk [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2017-02-15

    Highlights: • Buoyancy may greatly redistribute the flow in a non-uniform channel. • Flow structures in the narrow gap are greatly changed when buoyancy is strong. • Large flow structures exist in wider gap, which is enhanced when heat is strong. • Buoyancy reduces mixing factor caused by large flow structures in narrow gap. - Abstract: It has been a long time since the ‘abnormal’ turbulent intensity distribution and high inter-sub-channel mixing rates were observed in the vicinity of the narrow gaps formed by the fuel rods in nuclear reactors. The extraordinary flow behaviour was first described as periodic flow structures by Hooper and Rehme (1984). Since then, the existences of large flow structures were demonstrated by many researchers in various non-uniform flow channels. It has been proved by many authors that the Strouhal number of the flow structure in the isothermal flow is dependent on the size of the narrow gap, not the Reynolds number once it is sufficiently large. This paper reports a numerical investigation on the effect of buoyancy on the large flow structures. A buoyancy-aided flow in a tightly-packed rod-bundle-like channel is modelled using large eddy simulation (LES) together with the Boussinesq approximation. The behaviour of the large flow structures in the gaps of the flow passage are studied using instantaneous flow fields, spectrum analysis and correlation analysis. It is found that the non-uniform buoyancy force in the cross section of the flow channel may greatly redistribute the velocity field once the overall buoyancy force is sufficiently strong, and consequently modify the large flow structures. The temporal and axial spatial scales of the large flow structures are influenced by buoyancy in a way similar to that turbulence is influenced. These scales reduce when the flow is laminarised, but start increasing in the turbulence regeneration region. The spanwise scale of the flow structures in the narrow gap remains more or

  12. Effect of sediment on vertical dynamic impedance of rock-socketed pile with large diameter

    Institute of Scientific and Technical Information of China (English)

    俞缙; 蔡燕燕; 吴文兵

    2013-01-01

    Based on the fictitious soil pile model, the effect of sediment on the vertical dynamic impedance of rock-socketed pile with large diameter was theoretically studied by means of Laplace transform technique and impedance function transfer method. Firstly, the sediment under rock-socketed pile was assumed to be fictitious soil pile with the same sectional area. The Rayleigh-Love rode model was used to simulate the rock-socketed pile and the fictitious soil pile with the consideration of the lateral inertial effect of large-diameter pile. The layered surrounding soils and bedrock were modeled by the plane strain model. Then, by virtue of the initial conditions and boundary conditions of the soil pile system, the analytical solution of the vertical dynamic impedance at the head of rock-socketed pile was derived for the arbitrary excitation acting on the pile head. Lastly, based on the presented analytical solution, the effect of sediment properties, bedrock property and lateral inertial effect on the vertical dynamic impedance at rock-socketed pile head were investigated in detail. It is shown that the sediment properties have significant effect on the vertical dynamic impedance at the rock-socketed pile head. The ability of soil-pile system to resist dynamic vertical deformation is weakened with the increase of sediment thickness, but amplified with the increase of shear wave velocity of sediment. The ability of soil pile system to resist dynamic vertical deformation is amplified with the bedrock property improving, but the ability of soil-pile system to resist vertical vibration is weakened with the improvement of bedrock property.

  13. Effect of hypoxia on the blood of large yellow croaker ( Pseudosciaena crocea)

    Science.gov (United States)

    Gu, Xiaolian; Xu, Zhaoli

    2011-05-01

    Large areas of hypoxic water have recently been reported in the East China Sea. It is hypothesized that hypoxia may be partially responsible for the decline of some fish stocks. We evaluated the effect of hypoxia on large yellow croaker ( Pseudosciaena crocea). The fish were exposed to three concentrations of dissolved oxygen (DO; 1.5 mg/L and 2.0 mg/L, and 6.5 mg/L control). We collected blood after 6, 12, 24, 48, and 96 h exposure. There was a significant increase in red blood count, hematocrit, hemoglobin concentration, and mean corpuscular hemoglobin in the group exposed to 1.5 mg/L DO after 6 h or 12 h, and a delayed increase (only elevated after 48 h and 96 h) in these indices in the group exposed to 2.0 mg/L DO. Plasma glucose concentrations increased significantly in both hypoxic groups after 24 h. Furthermore, plasma lactate and lactate dehydrogenase activity increased significantly after the first 6 h exposure in both hypoxic groups. Our results suggest that large yellow croakers could not maintain the aerobic pathway and instead use anaerobic metabolism for survival when DO levels fall below 2.0 mg/L. We conclude that the occurrence of hypoxia (population decline of this species.

  14. Large Electrocaloric Effect in Relaxor Ferroelectric and Antiferroelectric Lanthanum Doped Lead Zirconate Titanate Ceramics

    Science.gov (United States)

    Lu, Biao; Li, Peilian; Tang, Zhenhua; Yao, Yingbang; Gao, Xingsen; Kleemann, Wolfgang; Lu, Sheng-Guo

    2017-01-01

    Both relaxor ferroelectric and antiferroelectric materials can individually demonstrate large electrocaloric effects (ECE). However, in order to further enhance the ECE it is crucial to find a material system, which can exhibit simultaneously both relaxor ferroelectric and antiferroelectric properties, or easily convert from one into another in terms of the compositional tailoring. Here we report on a system, in which the structure can readily change from antiferroelectric into relaxor ferroelectric and vice versa. To this end relaxor ferroelectric Pb0.89La0.11(Zr0.7Ti0.3)0.9725O3 and antiferroelectric Pb0.93La0.07(Zr0.82Ti0.18)0.9825O3 ceramics were designed near the antiferroelectric-ferroelectric phase boundary line in the La2O3-PbZrO3-PbTiO3 phase diagram. Conventional solid state reaction processing was used to prepare the two compositions. The ECE properties were deduced from Maxwell relations and Landau-Ginzburg-Devonshire (LGD) phenomenological theory, respectively, and also directly controlled by a computer and measured by thermometry. Large electrocaloric efficiencies were obtained and comparable with the results calculated via the phenomenological theory. Results show great potential in achieving large cooling power as refrigerants. PMID:28345655

  15. Possible future effects of large-scale algae cultivation for biofuels on coastal eutrophication in Europe.

    Science.gov (United States)

    Blaas, Harry; Kroeze, Carolien

    2014-10-15

    Biodiesel is increasingly considered as an alternative for fossil diesel. Biodiesel can be produced from rapeseed, palm, sunflower, soybean and algae. In this study, the consequences of large-scale production of biodiesel from micro-algae for eutrophication in four large European seas are analysed. To this end, scenarios for the year 2050 are analysed, assuming that in the 27 countries of the European Union fossil diesel will be replaced by biodiesel from algae. Estimates are made for the required fertiliser inputs to algae parks, and how this may increase concentrations of nitrogen and phosphorus in coastal waters, potentially leading to eutrophication. The Global NEWS (Nutrient Export from WaterSheds) model has been used to estimate the transport of nitrogen and phosphorus to the European coastal waters. The results indicate that the amount of nitrogen and phosphorus in the coastal waters may increase considerably in the future as a result of large-scale production of algae for the production of biodiesel, even in scenarios assuming effective waste water treatment and recycling of waste water in algae production. To ensure sustainable production of biodiesel from micro-algae, it is important to develop cultivation systems with low nutrient losses to the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. AN EFFECTIVE CONTINUOUS ALGORITHM FOR APPROXIMATE SOLUTIONS OF LARGE SCALE MAX-CUT PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Cheng-xian Xu; Xiao-liang He; Feng-min Xu

    2006-01-01

    An effective continuous algorithm is proposed to find approximate solutions of NP-hard max-cut problems. The algorithm relaxes the max-cut problem into a continuous nonlinear programming problem by replacing n discrete constraints in the original problem with one single continuous constraint. A feasible direction method is designed to solve the resulting nonlinear programming problem. The method employs only the gradient evaluations of the objective function, and no any matrix calculations and no line searches are required.This greatly reduces the calculation cost of the method, and is suitable for the solution of large size max-cut problems. The convergence properties of the proposed method to KKT points of the nonlinear programming are analyzed. If the solution obtained by the proposed method is a global solution of the nonlinear programming problem, the solution will provide an upper bound on the max-cut value. Then an approximate solution to the max-cut problem is generated from the solution of the nonlinear programming and provides a lower bound on the max-cut value. Numerical experiments and comparisons on some max-cut test problems (small and large size) show that the proposed algorithm is efficient to get the exact solutions for all small test problems and well satisfied solutions for most of the large size test problems with less calculation costs.

  17. Effect of large pore size of multifunctional mesoporous microsphere on removal of heavy metal ions.

    Science.gov (United States)

    Yuan, Qing; Li, Nan; Chi, Yue; Geng, Wangchang; Yan, Wenfu; Zhao, Ying; Li, Xiaotian; Dong, Bin

    2013-06-15

    Pore size of mesoporous materials is crucial for their surface grafting. This article develops a novel multifunctional microsphere with a large pore size mesoporous silica shell (ca. 10.3 nm) and a magnetic core (Fe₃O₄), which is fabricated using cetyltrimethylammonium bromide (CTAB) as pore-forming agents, tetraethyl orthosilicate (TEOS) as silicon source through a sol-gel process. Compared with small pore size mesoporous silica magnetic microspheres (ca. 2-4 nm), the large pore size one can graft 447 mg/g amino groups in order to adsorb more heavy metal ions (Pb(2+): 880.6 mg/g, Cu(2+): 628.3mg/g, Cd(2+): 492.4 mg/g). The metal-loaded multifunctional microspheres could be easily removed from aqueous solution by magnetic separation and regenerated easily by acid treatment. The results suggest that the large pore size multifunctional microspheres are potentially useful materials for high effectively adsorbing and removing different heavy metal ions in aqueous solution. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. The effects of the European Regional Development Fund on the large Romanian enterprises

    Directory of Open Access Journals (Sweden)

    Cristina Elena Ciocoiu

    2015-06-01

    Full Text Available The regional development of Romania in 2014-2020 should rely on the lessons learned from the 2007-2013 period. In this wider context, the paper analyses the effects of the European Regional Development Fund (ERDF provided within the 2007-2013 programme focusing on the development of the economic competitiveness, on the large enterprises from the North-East region of Romania. Three hypotheses are tested within this empirical research. First, that the EU financial assistance granted to a large enterprise implies an increase in its net turnover, gross profit and number of staff. Second, we aim to see whether the increase in the net turnover, gross profit and number of staff is directly linked to the increase of the ERDF grant. Finally, we analyse if the increase of the three indicators is higher for the large enterprises that implemented more projects than for the enterprises that implemented a single project. The analysis also puts under discussion the quality and the availability of the information concerning the projects funded by the European Union in Romania, taking also into consideration the 2014-2020 e-cohesion requirement.

  19. Benford's law predicted digit distribution of aggregated income taxes: the surprising conformity of Italian cities and regions

    Science.gov (United States)

    Mir, Tariq Ahmad; Ausloos, Marcel; Cerqueti, Roy

    2014-11-01

    The yearly aggregated tax income data of all, more than 8000, Italian municipalities are analyzed for a period of five years, from 2007 to 2011, to search for conformity or not with Benford's law, a counter-intuitive phenomenon observed in large tabulated data where the occurrence of numbers having smaller initial digits is more favored than those with larger digits. This is done in anticipation that large deviations from Benford's law will be found in view of tax evasion supposedly being widespread across Italy. Contrary to expectations, we show that the overall tax income data for all these years is in excellent agreement with Benford's law. Furthermore, we also analyze the data of Calabria, Campania and Sicily, the three Italian regions known for strong presence of mafia, to see if there are any marked deviations from Benford's law. Again, we find that all yearly data sets for Calabria and Sicily agree with Benford's law whereas only the 2007 and 2008 yearly data show departures from the law for Campania. These results are again surprising in view of underground and illegal nature of economic activities of mafia which significantly contribute to tax evasion. Some hypothesis for the found conformity is presented.

  20. Surprising results from a search for effective disinfectants for Tobacco mosaic virus-contaminated tools

    Science.gov (United States)

    Tobacco mosaic virus (TMV) and four other tobamoviruses infected multiple petunia cultivars without producing obvious viral symptoms. A single cutting event on a TMV-infected plant was sufficient for transmission to many plants subsequently cut with the same clippers. A number of 'old standbys' an...

  1. Contrasted effects of climate change on temperate large lakes oxygen-depletion (Lakes Geneva, Bourget, Annecy)

    Science.gov (United States)

    Jenny, Jean-Philippe; Arnaud, Fabien; Dorioz, Jean-Marcel; Alric, Benjamin; Sabatier, Pierre; Perga, Marie-Elodie

    2013-04-01

    Among manifestations of the entry in a new geological era -The Anthropocene- marked by the fingerprinting of human activities in global ecology, the development of persistent zones of oxygen-depletion particularly threatens aquatic ecosystems. This results in a loss of fisheries, a loss of biodiversity, an alteration of food-webs and even, in extreme cases, mass mortality of fauna1. Whereas hypoxia -defined as dissolved oxygen ≤2 mg/l- has long been considered as a consequence of the sole eutrophication, recent studies showed it also depends on climate change. Despite basic processes of oxygen-depletion are well-known, till now no study evaluated the contrasted effects of climate changes on a long-term perspective. Here we show that climate change paced fluctuation of hypoxia in 3 large lakes (Lake Geneva, Lake Bourget and Lake Annecy) that were previously disturbed by unprecedented nutrient input. Our approach couples century-scale paleo-reconstruction of 1) hypoxia, 2) flood regime and 3) nutrient level, thanks to an exceptional 80 sediment core data collection taken in three large lakes (Geneva, Bourget, Annecy), and monitoring data. Our results show that volume of hypoxia can be annually estimated according to varve records through large lakes. Quantitative additive models were then used to identify and hierarchy environmental forcings on hypoxia. Flood regime and air temperatures hence appeared as significant forcing factors of hypolimnetic hypoxia. Noticeably, their effects are highly contrasted between lakes, depending on specific lake morphology and local hydrological regime. We hence show that greater is the lake specific river discharge the more is the control of winter mixing and the lower is the control of thermal stratification on oxygen depletion. Our study confirms that the perturbation of food web due to nutrient input led to a higher vulnerability of aquatic ecosystems to climate change. We further show specific hydrological regime play a crucial

  2. Observation of large magnetocaloric effect in equiatomic binary compound ErZn

    Science.gov (United States)

    Li, Lingwei; Yuan, Ye; Xu, Chi; Qi, Yang; Zhou, Shengqiang

    2017-05-01

    The magnetism, magnetocaloric effect and universal behaviour in rare earth Zinc binary compound of ErZn have been studied. The ErZn compound undergoes a second order paramagnetic (PM) to ferromagnetic (FM) transition at Curie temperature of TC ˜ 20 K. The ErZn compound exhibits a large reversible magnetocaloric effect (MCE) around its own TC. The rescaled magnetic entropy change curves overlap with each other under various magnetic field changes, further confirming the ErZn with the second order phase transition. For the magnetic field change of 0-7 T, the maximum values of the magnetic entropy change (-Δ SMmax ) , relative cooling power (RCP) and refrigerant capacity (RC) for ErZn are 23.3 J/kg K, 581 J/kg and 437 J/kg, respectively.

  3. Observation of large magnetocaloric effect in equiatomic binary compound ErZn

    Directory of Open Access Journals (Sweden)

    Lingwei Li

    2017-05-01

    Full Text Available The magnetism, magnetocaloric effect and universal behaviour in rare earth Zinc binary compound of ErZn have been studied. The ErZn compound undergoes a second order paramagnetic (PM to ferromagnetic (FM transition at Curie temperature of TC ∼ 20 K. The ErZn compound exhibits a large reversible magnetocaloric effect (MCE around its own TC. The rescaled magnetic entropy change curves overlap with each other under various magnetic field changes, further confirming the ErZn with the second order phase transition. For the magnetic field change of 0-7 T, the maximum values of the magnetic entropy change (−ΔSMmax, relative cooling power (RCP and refrigerant capacity (RC for ErZn are 23.3 J/kg K, 581 J/kg and 437 J/kg, respectively.

  4. Large Eddy Simulation studies of the effects of alignment and wind farm length

    CERN Document Server

    Stevens, Richard J A M; Meneveau, Charles

    2014-01-01

    Large eddy simulations of wind farms are performed to study the effects of wind turbine row alignment with respect to the incoming flow direction. Various wind farms with fixed stream-wise spacing (7.85 rotor diameters) and varying lateral displacements and span-wise turbine spacings are considered, for a fixed inflow direction. Simulations show that, contrary to common belief, a perfectly staggered (checker-board) configuration does not necessarily give the highest average power output. Instead, the highest mean wind farm power output is found to depend on several factors, the most important one being the alignment that leads to minimization of wake effects from turbines in several upstream rows. This alignment typically occurs at significantly smaller angles than those corresponding to perfect staggering. The observed trends have implications for wind farm designs, especially in sites with a well-defined prevailing wind direction.

  5. Large Eddy Simulation Of Gravitational Effects In Transitional And Turbulent Gas-Jet Diffusion Flames

    Science.gov (United States)

    Jaberi, Farhad A.; Givi, Peyman

    2003-01-01

    The influence of gravity on the spatial and the compositional structures of transitional and turbulent hydrocarbon diffusion flames are studies via large eddy simulation (LES) and direct numerical simulation (DNS) of round and planar jets. The subgrid-scale (SGS) closures in LES are based on the filtered mass density function (FMDF) methodology. The FMDF represents the joint probability density function (PDF) of the SGS scalars, and is obtained by solving its transport equation. The fundamental advantage of LES/FMDF is that it accounts for the effects of chemical reaction and buoyancy exactly. The methodology is employed for capturing some of the fundamental influences of gravity in equilibrium flames via realistic chemical kinetic schemes. Some preliminary investigation of the gravity effects in non-equilibrium flames is also conducted, but with idealized chemical kinetics models.

  6. Effect of the RF wall conditioning on the high performance plasmas in the Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, H., E-mail: takahashi.hiromi@LHD.nifs.ac.jp [National Institute for Fusion Science, Toki 509-5292 (Japan); Osakabe, M.; Nagaoka, K.; Nakano, H.; Tokitani, M. [National Institute for Fusion Science, Toki 509-5292 (Japan); Fujii, K. [Department of Mechanical Engineering and Science, Kyoto University, Kyoto 615-8540 (Japan); Murakami, S. [Department of Nuclear Engineering, Kyoto University, Kyoto 606-8501 (Japan); Takeiri, Y.; Seki, T.; Saito, K.; Kasahara, H.; Seki, R.; Kamio, S.; Masuzaki, S.; Mutoh, T. [National Institute for Fusion Science, Toki 509-5292 (Japan)

    2015-08-15

    The wall conditioning using radio frequency (RF) plasma was carried out using Ion Cyclotron Range of Frequency (ICRF) heating and/or Electron Cyclotron Resonance Heating (ECRH) with the working gas of helium under the established confinement magnetic field. After sufficient numbers of repetitive wall discharge conditioning (DC, ICDC for ICRF and ECDC for ECRH), the formation of the parabolic electron density profile and the increase of the central ion temperature T{sub i} were observed. There was no difference in the attained central T{sub i} of the NBI discharge just after the conditioning using a similar value of input energy regardless of the applied RF source. Thus, it is concluded that both ICDC and the ECDC are effective for the higher T{sub i} plasma production under the established magnetic field in the Large Helical Device. The effective RF wall conditioning scenarios are also investigated for high T{sub i} plasma production.

  7. Effects of the anomalous Higgs couplings on the Higgs boson production at the Large Hadron Collider

    CERN Document Server

    Kanemura, Shinya

    2008-01-01

    We study the impact of dimension-six operators on single- and double-Higgs production via gluon fusion at the Large Hadron Collider (LHC). If the top-Yukawa coupling is modified by some new physics whose scale is of the TeV scale, its effect changes the cross sections of single-Higgs production $gg\\to H$ and double-Higgs production $gg\\to HH$ through the top-loop diagram. In particular, double-Higgs production can receive significant enhancement from the effective top-Yukawa coupling and the new dimension-five coupling $t{\\bar t}HH$ which are induced by the dimension-six operator. Comparing these results to the forthcoming data at the LHC, one can extract information of the dimension-six operators relevant to the top quark and the Higgs boson.

  8. Variability in mutational fitness effects prevents full lethal transitions in large quasispecies populations

    Science.gov (United States)

    Sardanyés, Josep; Simó, Carles; Martínez, Regina; Solé, Ricard V.; Elena, Santiago F.

    2014-04-01

    The distribution of mutational fitness effects (DMFE) is crucial to the evolutionary fate of quasispecies. In this article we analyze the effect of the DMFE on the dynamics of a large quasispecies by means of a phenotypic version of the classic Eigen's model that incorporates beneficial, neutral, deleterious, and lethal mutations. By parameterizing the model with available experimental data on the DMFE of Vesicular stomatitis virus (VSV) and Tobacco etch virus (TEV), we found that increasing mutation does not totally push the entire viral quasispecies towards deleterious or lethal regions of the phenotypic sequence space. The probability of finding regions in the parameter space of the general model that results in a quasispecies only composed by lethal phenotypes is extremely small at equilibrium and in transient times. The implications of our findings can be extended to other scenarios, such as lethal mutagenesis or genomically unstable cancer, where increased mutagenesis has been suggested as a potential therapy.

  9. A Study on the Effect of Welding Sequence in Fabrication of Large Stiffened Plate Panels

    Institute of Scientific and Technical Information of China (English)

    Pankaj Biswas; D.Anil Kumar; N.R.Mandal; M.M.Mahapatra

    2011-01-01

    Welding sequence has a significant effect on distortion pattern of large orthogonally stiffened panels normally used in ships and offshore structures.These deformations adversely affect the subsequent fitup and alignment of the adjacent panels.It may also result in loss of structural integrity.These panels primarily suffer from angular and buckling distortions.The extent of distortion depends on several parameters such as welding speed,plate thickness,welding current,voltage,restraints applied to the job while welding,thermal history as well as sequence of welding.Numerical modeling of welding and experimental validation of the FE model has been carried out for estimation of thermal history and resulting distortions.In the present work an FE model has been developed for studying the effect of welding sequence on the distortion pattern and its magnitude in fabrication of orthogonally stiffened plate panels.

  10. Effects of woody vegetation on overbank sand transport during a large flood, Rio Puerco, New Mexico

    Science.gov (United States)

    Griffin, Eleanor R.; Perignon, Mariela C.; Friedman, Jonathan M.; Tucker, Gregory E.

    2014-01-01

    Distributions of woody vegetation on floodplain surfaces affect flood-flow erosion and deposition processes. A large flood along the lower Rio Puerco, New Mexico, in August 2006 caused extensive erosion in a reach that had been sprayed with herbicide in September 2003 for the purpose of saltcedar (Tamarix spp.) control. Large volumes of sediment, including a substantial fraction of sand, were delivered to the reach downstream, which had not been treated with herbicide. We applied physically based, one-dimensional models of flow and suspended-sediment transport to compute volume concentrations of sand in suspension in floodplain flow at a site within the sprayed reach and at a site downstream from the sprayed reach. We computed the effects of drag on woody stems in reducing the skin friction shear stress, velocity of flow, and suspended-sand transport from open paths into patches of dense stems. Total flow and suspended-sand fluxes were computed for each site using well-constrained flood-flow depths, water-surface slopes, and measured shrub characteristics. Results show that flow in open paths carried high concentrations of sand in suspension with nearly uniform vertical distributions. Drag on woody floodplain stems reduced skin friction shear stresses by two orders of magnitude, yet sufficient velocities were maintained to transport sand more than 50 m into fields of dense, free-surface-penetrating stems. An increase in shrub canopy extent from 31% in the sprayed reach site to 49% in the downstream site was found to account for 69% of the computed decrease in discharge between the two sites. The results demonstrate the need to compute the spatial distribution of skin friction shear stress in order to effectively compute suspended-sand transport and to predict the fate of sediment and contaminants carried in suspension during large floods.

  11. Fitting parametric random effects models in very large data sets with application to VHA national data.

    Science.gov (United States)

    Gebregziabher, Mulugeta; Egede, Leonard; Gilbert, Gregory E; Hunt, Kelly; Nietert, Paul J; Mauldin, Patrick

    2012-10-24

    With the current focus on personalized medicine, patient/subject level inference is often of key interest in translational research. As a result, random effects models (REM) are becoming popular for patient level inference. However, for very large data sets that are characterized by large sample size, it can be difficult to fit REM using commonly available statistical software such as SAS since they require inordinate amounts of computer time and memory allocations beyond what are available preventing model convergence. For example, in a retrospective cohort study of over 800,000 Veterans with type 2 diabetes with longitudinal data over 5 years, fitting REM via generalized linear mixed modeling using currently available standard procedures in SAS (e.g. PROC GLIMMIX) was very difficult and same problems exist in Stata's gllamm or R's lme packages. Thus, this study proposes and assesses the performance of a meta regression approach and makes comparison with methods based on sampling of the full data. We use both simulated and real data from a national cohort of Veterans with type 2 diabetes (n=890,394) which was created by linking multiple patient and administrative files resulting in a cohort with longitudinal data collected over 5 years. The outcome of interest was mean annual HbA1c measured over a 5 years period. Using this outcome, we compared parameter estimates from the proposed random effects meta regression (REMR) with estimates based on simple random sampling and VISN (Veterans Integrated Service Networks) based stratified sampling of the full data. Our results indicate that REMR provides parameter estimates that are less likely to be biased with tighter confidence intervals when the VISN level estimates are homogenous. When the interest is to fit REM in repeated measures data with very large sample size, REMR can be used as a good alternative. It leads to reasonable inference for both Gaussian and non-Gaussian responses if parameter estimates are

  12. Bivariate Mixed Effects Analysis of Clustered Data with Large Cluster Sizes.

    Science.gov (United States)

    Zhang, Daowen; Sun, Jie Lena; Pieper, Karen

    2016-10-01

    Linear mixed effects models are widely used to analyze a clustered response variable. Motivated by a recent study to examine and compare the hospital length of stay (LOS) between patients undertaking percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) from several international clinical trials, we proposed a bivariate linear mixed effects model for the joint modeling of clustered PCI and CABG LOS's where each clinical trial is considered a cluster. Due to the large number of patients in some trials, commonly used commercial statistical software for fitting (bivariate) linear mixed models failed to run since it could not allocate enough memory to invert large dimensional matrices during the optimization process. We consider ways to circumvent the computational problem in the maximum likelihood (ML) inference and restricted maximum likelihood (REML) inference. Particularly, we developed an expected and maximization (EM) algorithm for the REML inference and presented an ML implementation using existing software. The new REML EM algorithm is easy to implement and computationally stable and efficient. With this REML EM algorithm, we could analyze the LOS data and obtained meaningful results.

  13. Effects of stress conditions on rheological properties of granular soil in large triaxial rheology laboratory tests

    Institute of Scientific and Technical Information of China (English)

    陈晓斌; 张家生; 刘宝琛; 唐孟雄

    2008-01-01

    In order to study the rheological properties of red stone granular soil,a series of rheological experiments were executed on large tri-axial rheological apparatus.Under 100,200 and 300 kPa confining stress conditions,the rheological tests were carried out.These experiment results showed that the stress conditions,especially the stress level were the critical influencing factors of the rheological deformation properties.Under the low stress level(S=0.1),the granular soil showed the elastic properties,and there was no obvious rheological deformation.Under the middle stress level(0.20.8) creep curves showed the non-linear viscous plastic rheological properties.Especially,under the stress level of S=1.0,the accelerated rheological phase of creep curves occurred at early time with a trend of failure.The stress level had obvious effects on the final rheological deformation of the soil sample,and the final rheological deformation increments nonlinearly increased with stress level.The final rheological deformation increment and step was little under low stress level,while it became large under high stress level,which showed the nonlinearly rheological properties of the granular soil.The confining pressure also had direct effects on final rheological deformation,and the final rheological deformation linearly increased with confining pressure increments.

  14. The effect of mannanoligosaccharides, bambermycins, and virginiamycin on performance of large white male market turkeys.

    Science.gov (United States)

    Parks, C W; Grimes, J L; Ferket, P R; Fairchild, A S

    2001-06-01

    A study was conducted to evaluate the effects of mannanoligosaccharides (MOS), bambermycins (BAM), and virginiamycin (VIR) on the growth performance of male turkeys. Hybrid Large White male poults were assigned to six dietary treatments: control, MOS, BAM, VIR, MOS+BAM (MB), and MOS+VIR (MV). All diets were formulated to meet NRC (1994) nutrient requirements. There were eight replicate floor pens per treatment with 20 birds per pen reared from 1 to 140 d. Body weight and feed conversion (FC) were collected at 3-wk intervals and at 20 wk of age. Mortality and culled birds were recorded daily. All treatments except MV significantly (P < 0.05) increased 20 wk BW. Body weight was increased at 12 wk by BAM, whereas VIR increased BW at Weeks 12 and 15. All treatments improved FC for Weeks 0 to 3, whereas VIR, MB, and MV improved FC for Weeks 0 to 12 and 0 to 18. There were no treatment effects on cumulative mortality or cull rate. Dietary supplemental MOS, BAM, and VIR resulted in improved growth performance of Large White turkeys. These results indicate that MOS may be utilized as an alternative to antibiotic growth promotants to improve turkey performance.

  15. A Cost-Effective Planning Graph Approach for Large-Scale Web Service Composition

    Directory of Open Access Journals (Sweden)

    Szu-Yin Lin

    2012-01-01

    Full Text Available Web Service Composition (WSC problems can be considered as a service matching problem, which means that the output parameters of a Web service can be used as inputs of another one. However, when a very large number of Web services are deployed in the environment, the service composition has become sophisticated and complicated process. In this study, we proposed a novel cost-effective Web service composition mechanism. It utilizes planning graph based on backward search algorithm to find multiple feasible solutions and recommends a best composition solution according to the lowest service cost. In other words, the proposed approach is a goal-driven mechanism, which can recommend the approximate solutions, but it consumes fewer amounts of Web services and less nested levels of composite service. Finally, we implement a simulation platform to validate the proposed cost-effective planning graph mechanism in large-scale Web services environment. The simulation results show that our proposed algorithm based on the backward planning graph has reduced by 94% service cost in three different environments of service composition that is compared with other existing service composition approaches which are based on a forward planning graph.

  16. Large-scale experimental landscapes reveal distinctive effects of patch shape and connectivity on arthropod communities.

    Energy Technology Data Exchange (ETDEWEB)

    Orrock, John, L.; Curler, Gregory, R.; Danielson, Brent, J.; Coyle, David. R.

    2011-09-14

    The size, shape, and isolation of habitat patches can affect organism behavior and population dynamics, but little is known about the relative role of shape and connectivity in affecting ecological communities at large spatial scales. Using six sampling sessions from July 2001 until August 2002, we collected 33,685 arthropods throughout seven 12-ha experimental landscapes consisting of clear-cut patches surrounded by a matrix of mature pine forest. Patches were explicitly designed to manipulate connectivity (via habitat corridors) independently of area and edge effects. We found that patch shape, rather than connectivity, affected ground-dwelling arthropod richness and beta diversity (i.e. turnover of genera among patches). Arthropod communities contained fewer genera and exhibited less turnover in high-edge connected and high-edge unconnected patches relative to low-edge unconnected patches of similar area. Connectivity, rather than patch shape, affected the evenness of ground-dwelling arthropod communities; regardless of patch shape, high-edge connected patches had lower evenness than low- or high-edge unconnected patches. Among the most abundant arthropod orders, increased richness in low-edge unconnected patches was largely due to increased richness of Coleoptera, whereas Hymenoptera played an important role in the lower evenness in connected patches and patterns of turnover. These findings suggest that anthropogenic habitat alteration can have distinct effects on ground-dwelling arthropod communities that arise due to changes in shape and connectivity. Moreover, this work suggests that corridors, which are common conservation tools that change both patch shape and connectivity, can have multiple effects on arthropod communities via different mechanisms, and each effect may alter components of community structure.

  17. EFFECTS OF LARGE-SCALE NON-AXISYMMETRIC PERTURBATIONS IN THE MEAN-FIELD SOLAR DYNAMO

    Energy Technology Data Exchange (ETDEWEB)

    Pipin, V. V. [Institute of Solar-Terrestrial Physics, Russian Academy of Sciences (Russian Federation); Kosovichev, A. G. [W.W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2015-11-10

    We explore the response of a nonlinear non-axisymmetric mean-field solar dynamo model to shallow non-axisymmetric perturbations. After a relaxation period, the amplitude of the non-axisymmetric field depends on the initial condition, helicity conservation, and the depth of perturbation. It is found that a perturbation that is anchored at 0.9 R{sub ⊙} has a profound effect on the dynamo process, producing a transient magnetic cycle of the axisymmetric magnetic field, if it is initiated at the growing phase of the cycle. The non-symmetric, with respect to the equator, perturbation results in a hemispheric asymmetry of the magnetic activity. The evolution of the axisymmetric and non-axisymmetric fields depends on the turbulent magnetic Reynolds number R{sub m}. In the range of R{sub m} = 10{sup 4}–10{sup 6} the evolution returns to the normal course in the next cycle, in which the non-axisymmetric field is generated due to a nonlinear α-effect and magnetic buoyancy. In the stationary state, the large-scale magnetic field demonstrates a phenomenon of “active longitudes” with cyclic 180° “flip-flop” changes of the large-scale magnetic field orientation. The flip-flop effect is known from observations of solar and stellar magnetic cycles. However, this effect disappears in the model, which includes the meridional circulation pattern determined by helioseismology. The rotation rate of the non-axisymmetric field components varies during the relaxation period and carries important information about the dynamo process.

  18. A strange and surprising debate: mountains, original sin and 'science' in seventeenth-century England.

    Science.gov (United States)

    Wragge-Morley, Alexander

    2009-06-01

    It could come as a shock to learn that some seventeenth-century men of science and learning thought that mountains were bad. Even more alarmingly, some thought that God had imposed them on the earth to punish man for his sins. By the end of the seventeenth century, surprisingly many English natural philosophers and theologians were engaged in a debate about whether mountains were 'good' or 'bad', useful or useless. At stake in this debate were not just the careers of its participants, but arguments about the best ways of looking at and reckoning with 'nature' itself.

  19. Effect of Gd polarization on the large magnetocaloric effect of GdCrO4 in a broad temperature range

    Science.gov (United States)

    Palacios, E.; Tomasi, C.; Sáez-Puche, R.; Dos santos-García, A. J.; Fernández-Martínez, F.; Burriel, R.

    2016-02-01

    The ferromagnetic zircon-type phase of GdCrO4 presents high values for the magnetocaloric (MC) parameters. This compound has large isothermal entropy changes Δ ST under the magnetic field action in a wide temperature range, from 5 to 35 K, reaching a maximum |Δ ST|=29.0 ±0.1 J /kg K at 22 K, for a field increment Δ B =9 T. It orders ferromagnetically at TC=21.3 K via the Cr-Cr exchange interaction and shows a second transition at 4.8 K due to the ordering of the Gd sublattice. The large MC effect is enhanced by the polarization of the Gd3 + ions by the Cr5 + ones via a weaker Gd-Cr interaction. This effect is an interesting feature to be considered in the search for new compounds with a high MC effect in the range of liquid hydrogen or natural gas, regarding the liquefaction of gases by magnetization-demagnetization cycles. This paper contains experimental measurements of magnetization, heat capacity, and direct determinations of the MC effect. The magnetic contribution to the heat capacity Cm has been obtained after subtracting the lattice component. Approximate values for the exchange constants J1 (Cr-Cr) and J3 (Gd-Cr) have been deduced from Cm.

  20. The Lagrangian-space Effective Field Theory of Large Scale Structures

    CERN Document Server

    Porto, Rafael A.; Zaldarriaga, Matias

    2014-01-01

    We introduce a Lagrangian-space Effective Field Theory (LEFT) formalism for the study of cosmological large scale structures. Unlike the previous Eulerian-space construction, it is naturally formulated as an effective field theory of extended objects in Lagrangian space. In LEFT the resulting finite size effects are described using a multipole expansion parameterized by a set of time dependent coefficients and organized in an expansion in powers of the ratio of the wavenumber of interest $k$ over the non-linear scale $k_{\\rm NL}$. The multipoles encode the effects of the short distance modes on the long-wavelength Universe and absorb UV divergences when present. There are no IR divergences in LEFT. Some of the parameters that control the perturbative approach are not assumed to be small and can be automatically resummed. We present an illustrative one-loop calculation for a power law Universe. We describe the dynamics both at the level of the equations of motion and through an action formalism.

  1. A Methodology of Health Effects Estimation from Air Pollution in Large Asian Cities

    Directory of Open Access Journals (Sweden)

    Keiko Hirota

    2017-09-01

    Full Text Available The increase of health effects caused by air pollution seems to be a growing concern in Asian cities with increasing motorization. This paper discusses methods of estimating the health effects of air pollution in large Asian cities. Due to the absence of statistical data in Asia, this paper carefully chooses the methodology using data of the Japanese compensation system. A basic idea of health effects will be captured from simple indicators, such as population and air quality, in a correlation model. This correlation model enables more estimation results of respiratory mortality caused by air pollution to be yielded than by using the relative model. The correlation model could be an alternative method to estimate mortality besides the relative risk model since the results of the correlation model are comparable with those of the relative model by city and by time series. The classification of respiratory diseases is not known from the statistical yearbooks in many countries. Estimation results could support policy decision-making with respect to public health in a cost-effective way.

  2. Effect of Large Negative Phase of Blast Loading on Structural Response of RC Elements

    Directory of Open Access Journals (Sweden)

    Syed Zubair Iman

    2016-01-01

    Full Text Available Structural response of reinforced concrete (RC elements for analysis and design are often obtained using the positive phase of the blast pressure curve disregarding the negative phase assuming insignificant contribution from the negative phase of the loading. Although, some insight on the effect of negative phase of blast pressure based on elastic single-degree-of-freedom (SDOF analysis was presented before, the influence of negative phase on different types of resistance functions of SDOF models and on realistic finite element analysis has not been explored. In this study, the effects of inclusion of pulse negative phase on structural response of RC elements from SDOF analysis and from more detailed finite element analysis have been investigated. Investigation of SDOF part has been conducted using MATLAB code that utilizes non-linear resistance functions of SDOF model. Detailed numerical investigation using finite element code DIANA was conducted on the significance of the negative phase on structural response. In the FE model, different support stiffness was used to explore the effect of support stiffness on the structural response due to blast negative phase. Results from SDOF and FE analyses present specific situations where the effect of large negative phase was found to be significant on the structural response of RC elements.

  3. Effect of nutritive status on Mytilus galloprovincialis pollution biomarkers: Implications for large-scale monitoring programs.

    Science.gov (United States)

    González-Fernández, Carmen; Albentosa, Marina; Campillo, Juan A; Viñas, Lucía; Romero, Diego; Franco, Angeles; Bellas, Juan

    2015-10-01

    Biomarkers have been extensively used in monitoring programs with the aim of assessing the biological effects of pollutants on marine organisms and determining environmental status. Data obtained from these programs are sometimes difficult to interpret due to the large amount of natural variables affecting biological processes, which could act as confounding factors on biomarker responses. The main aim of this work was to identify the effect of one of these variables, the food availability, and consequently, the mussel nutritive status, on biomarker responses. For that purpose, mussels (Mytilus galloprovincialis) were conditioned to three different food rations for 2 months in order to create three mussel nutritive statuses and afterwards, each status was exposed to three nominal concentrations of fluoranthene (FLU) for 3 weeks. A battery of biomarkers was considered in this study to cover a wide range of organism responses, both physiological (scope for growth - SFG) and biochemical (superoxide dismutase - SOD, catalase - CAT, glutathione reductase - GR, glutathione peroxidase - GPx, glutathione-S-transferase - GST and phenoloxidase - PO activities, and lipid membrane peroxidation - LPO). The results obtained, evidenced that most of the studied biomarkers (SFG, SOD, CAT, GPx, and PO) were strongly affected by mussel nutritive status, showing higher values at lower status, whereas the effect of toxicant was not always evident, masked by the nutritive status effect. This paper demonstrates that toxicants are not the only source of variability modulating pollution biomarkers, and confirms nutritive status as a major factor altering biochemical and physiological biomarkers.

  4. Large topological Hall effect in the non-collinear phase of an antiferromagnet.

    Science.gov (United States)

    Sürgers, Christoph; Fischer, Gerda; Winkel, Patrick; Löhneysen, Hilbert V

    2014-03-05

    Non-trivial spin arrangements in magnetic materials give rise to the topological Hall effect observed in compounds with a non-centrosymmetric cubic structure hosting a skyrmion lattice, in double-exchange ferromagnets and magnetically frustrated systems. The topological Hall effect has been proposed to appear also in presence of non-coplanar spin configurations and thus might occur in an antiferromagnetic material with a highly non-collinear and non-coplanar spin structure. Particularly interesting is a material where the non-collinearity develops not immediately at the onset of antiferromagnetic order but deep in the antiferromagnetic phase. This unusual situation arises in non-cubic antiferromagnetic Mn5Si3. Here we show that a large topological Hall effect develops well below the Néel temperature as soon as the spin arrangement changes from collinear to non-collinear with decreasing temperature. We further demonstrate that the effect is not observed when the material is turned ferromagnetic by carbon doping without changing its crystal structure.

  5. Large magnetic field effects in electrochemically doped organic light-emitting diodes

    Science.gov (United States)

    van Reenen, S.; Kersten, S. P.; Wouters, S. H. W.; Cox, M.; Janssen, P.; Koopmans, B.; Bobbert, P. A.; Kemerink, M.

    2013-09-01

    Large negative magnetoconductance (MC) of ˜12% is observed in electrochemically doped polymer light-emitting diodes at sub-band-gap bias voltages (Vbias). Simultaneously, a positive magnetoefficiency (Mη) of 9% is observed at Vbias = 2 V. At higher bias voltages, both the MC and Mη diminish while a negative magnetoelectroluminescence (MEL) appears. The negative MEL effect is rationalized by triplet-triplet annihilation that leads to delayed fluorescence, whereas the positive Mη effect is related to competition between spin mixing and exciton formation leading to an enhanced singlet:triplet ratio at nonzero magnetic field. The resultant reduction in triplet exciton density is argued to reduce detrapping of polarons in the recombination zone at low-bias voltages, explaining the observed negative MC. Regarding organic magnetoresistance, this study provides experimental data to verify existing models describing magnetic field effects in organic semiconductors, which contribute to better understanding hereof. Furthermore, we present indications of strong magnetic field effects related to interactions between trapped carriers and excitons, which specifically can be studied in electrochemically doped organic light-emitting diodes (OLEDs). Regarding light-emitting electrochemical cells (LECs), this work shows that delayed fluorescence from triplet-triplet annihilation substantially contributes to the electroluminescence and the device efficiency.

  6. Direct simulation of phase delay effects on induced-charge electro-osmosis under large ac electric fields

    Science.gov (United States)

    Sugioka, Hideyuki

    2016-08-01

    The standard theory of induced-charge electro-osmosis (ICEO) often overpredicts experimental values of ICEO velocities. Using a nonsteady direct multiphysics simulation technique based on the coupled Poisson-Nernst-Planck and Stokes equations for an electrolyte around a conductive cylinder subject to an ac electric field, we find that a phase delay effect concerning an ion response provides a fundamental mechanism for electrokinetic suppression. A surprising aspect of our findings is that the phase delay effect occurs even at much lower frequencies (e.g., 50 Hz) than the generally believed charging frequency of an electric double layer (typically, 1 kHz) and it can decrease the electrokinetic velocities in one to several orders. In addition, we find that the phase delay effect may also cause a change in the electrokinetic flow directions (i.e., flow reversal) depending on the geometrical conditions. We believe that our findings move toward a more complete understanding of complex experimental nonlinear electrokinetic phenomena.

  7. Infants’ Looking to Surprising Events: When Eye-Tracking Reveals More than Looking Time

    Science.gov (United States)

    Yeung, H. Henny; Denison, Stephanie; Johnson, Scott P.

    2016-01-01

    Research on infants’ reasoning abilities often rely on looking times, which are longer to surprising and unexpected visual scenes compared to unsurprising and expected ones. Few researchers have examined more precise visual scanning patterns in these scenes, and so, here, we recorded 8- to 11-month-olds’ gaze with an eye tracker as we presented a sampling event whose outcome was either surprising, neutral, or unsurprising: A red (or yellow) ball was drawn from one of three visible containers populated 0%, 50%, or 100% with identically colored balls. When measuring looking time to the whole scene, infants were insensitive to the likelihood of the sampling event, replicating failures in similar paradigms. Nevertheless, a new analysis of visual scanning showed that infants did spend more time fixating specific areas-of-interest as a function of the event likelihood. The drawn ball and its associated container attracted more looking than the other containers in the 0% condition, but this pattern was weaker in the 50% condition, and even less strong in the 100% condition. Results suggest that measuring where infants look may be more sensitive than simply how much looking there is to the whole scene. The advantages of eye tracking measures over traditional looking measures are discussed. PMID:27926920

  8. A Large Scale Test of the Effect of Social Class on Prosocial Behavior.

    Directory of Open Access Journals (Sweden)

    Martin Korndörfer

    Full Text Available Does being from a higher social class lead a person to engage in more or less prosocial behavior? Psychological research has recently provided support for a negative effect of social class on prosocial behavior. However, research outside the field of psychology has mainly found evidence for positive or u-shaped relations. In the present research, we therefore thoroughly examined the effect of social class on prosocial behavior. Moreover, we analyzed whether this effect was moderated by the kind of observed prosocial behavior, the observed country, and the measure of social class. Across eight studies with large and representative international samples, we predominantly found positive effects of social class on prosociality: Higher class individuals were more likely to make a charitable donation and contribute a higher percentage of their family income to charity (32,090 ≥ N ≥ 3,957; Studies 1-3, were more likely to volunteer (37,136 ≥N ≥ 3,964; Studies 4-6, were more helpful (N = 3,902; Study 7, and were more trusting and trustworthy in an economic game when interacting with a stranger (N = 1,421; Study 8 than lower social class individuals. Although the effects of social class varied somewhat across the kinds of prosocial behavior, countries, and measures of social class, under no condition did we find the negative effect that would have been expected on the basis of previous results reported in the psychological literature. Possible explanations for this divergence and implications are discussed.

  9. Thermal motion in proteins: Large effects on the time-averaged interaction energies

    Directory of Open Access Journals (Sweden)

    Martin Goethe

    2016-03-01

    Full Text Available As a consequence of thermal motion, inter-atomic distances in proteins fluctuate strongly around their average values, and hence, also interaction energies (i.e. the pair-potentials evaluated at the fluctuating distances are not constant in time but exhibit pronounced fluctuations. These fluctuations cause that time-averaged interaction energies do generally not coincide with the energy values obtained by evaluating the pair-potentials at the average distances. More precisely, time-averaged interaction energies behave typically smoother in terms of the average distance than the corresponding pair-potentials. This averaging effect is referred to as the thermal smoothing effect. Here, we estimate the strength of the thermal smoothing effect on the Lennard-Jones pair-potential for globular proteins at ambient conditions using x-ray diffraction and simulation data of a representative set of proteins. For specific atom species, we find a significant smoothing effect where the time-averaged interaction energy of a single atom pair can differ by various tens of cal/mol from the Lennard-Jones potential at the average distance. Importantly, we observe a dependency of the effect on the local environment of the involved atoms. The effect is typically weaker for bulky backbone atoms in beta sheets than for side-chain atoms belonging to other secondary structure on the surface of the protein. The results of this work have important practical implications for protein software relying on free energy expressions. We show that the accuracy of free energy expressions can largely be increased by introducing environment specific Lennard-Jones parameters accounting for the fact that the typical thermal motion of protein atoms depends strongly on their local environment.

  10. Thermal motion in proteins: Large effects on the time-averaged interaction energies

    Science.gov (United States)

    Goethe, Martin; Fita, Ignacio; Rubi, J. Miguel

    2016-03-01

    As a consequence of thermal motion, inter-atomic distances in proteins fluctuate strongly around their average values, and hence, also interaction energies (i.e. the pair-potentials evaluated at the fluctuating distances) are not constant in time but exhibit pronounced fluctuations. These fluctuations cause that time-averaged interaction energies do generally not coincide with the energy values obtained by evaluating the pair-potentials at the average distances. More precisely, time-averaged interaction energies behave typically smoother in terms of the average distance than the corresponding pair-potentials. This averaging effect is referred to as the thermal smoothing effect. Here, we estimate the strength of the thermal smoothing effect on the Lennard-Jones pair-potential for globular proteins at ambient conditions using x-ray diffraction and simulation data of a representative set of proteins. For specific atom species, we find a significant smoothing effect where the time-averaged interaction energy of a single atom pair can differ by various tens of cal/mol from the Lennard-Jones potential at the average distance. Importantly, we observe a dependency of the effect on the local environment of the involved atoms. The effect is typically weaker for bulky backbone atoms in beta sheets than for side-chain atoms belonging to other secondary structure on the surface of the protein. The results of this work have important practical implications for protein software relying on free energy expressions. We show that the accuracy of free energy expressions can largely be increased by introducing environment specific Lennard-Jones parameters accounting for the fact that the typical thermal motion of protein atoms depends strongly on their local environment.

  11. Thermal motion in proteins: Large effects on the time-averaged interaction energies

    Energy Technology Data Exchange (ETDEWEB)

    Goethe, Martin, E-mail: martingoethe@ub.edu; Rubi, J. Miguel [Departament de Física Fonamental, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Fita, Ignacio [Institut de Biologia Molecular de Barcelona, Baldiri Reixac 10, 08028 Barcelona (Spain)

    2016-03-15

    As a consequence of thermal motion, inter-atomic distances in proteins fluctuate strongly around their average values, and hence, also interaction energies (i.e. the pair-potentials evaluated at the fluctuating distances) are not constant in time but exhibit pronounced fluctuations. These fluctuations cause that time-averaged interaction energies do generally not coincide with the energy values obtained by evaluating the pair-potentials at the average distances. More precisely, time-averaged interaction energies behave typically smoother in terms of the average distance than the corresponding pair-potentials. This averaging effect is referred to as the thermal smoothing effect. Here, we estimate the strength of the thermal smoothing effect on the Lennard-Jones pair-potential for globular proteins at ambient conditions using x-ray diffraction and simulation data of a representative set of proteins. For specific atom species, we find a significant smoothing effect where the time-averaged interaction energy of a single atom pair can differ by various tens of cal/mol from the Lennard-Jones potential at the average distance. Importantly, we observe a dependency of the effect on the local environment of the involved atoms. The effect is typically weaker for bulky backbone atoms in beta sheets than for side-chain atoms belonging to other secondary structure on the surface of the protein. The results of this work have important practical implications for protein software relying on free energy expressions. We show that the accuracy of free energy expressions can largely be increased by introducing environment specific Lennard-Jones parameters accounting for the fact that the typical thermal motion of protein atoms depends strongly on their local environment.

  12. The Effective Field Theory of Large Scale Structures at two loops

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco, John Joseph M.; Foreman, Simon; Green, Daniel; Senatore, Leonardo, E-mail: jjmc@stanford.edu, E-mail: sfore@stanford.edu, E-mail: drgreen@stanford.edu, E-mail: senatore@stanford.edu [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA 94306 (United States)

    2014-07-01

    Large scale structure surveys promise to be the next leading probe of cosmological information. It is therefore crucial to reliably predict their observables. The Effective Field Theory of Large Scale Structures (EFTofLSS) provides a manifestly convergent perturbation theory for the weakly non-linear regime of dark matter, where correlation functions are computed in an expansion of the wavenumber k of a mode over the wavenumber associated with the non-linear scale k{sub NL}. Since most of the information is contained at high wavenumbers, it is necessary to compute higher order corrections to correlation functions. After the one-loop correction to the matter power spectrum, we estimate that the next leading one is the two-loop contribution, which we compute here. At this order in k/k{sub NL}, there is only one counterterm in the EFTofLSS that must be included, though this term contributes both at tree-level and in several one-loop diagrams. We also discuss correlation functions involving the velocity and momentum fields. We find that the EFTofLSS prediction at two loops matches to percent accuracy the non-linear matter power spectrum at redshift zero up to k∼ 0.6 h Mpc{sup −1}, requiring just one unknown coefficient that needs to be fit to observations. Given that Standard Perturbation Theory stops converging at redshift zero at k∼ 0.1 h Mpc{sup −1}, our results demonstrate the possibility of accessing a factor of order 200 more dark matter quasi-linear modes than naively expected. If the remaining observational challenges to accessing these modes can be addressed with similar success, our results show that there is tremendous potential for large scale structure surveys to explore the primordial universe.

  13. Effect of large cold deformation on characteristics of age-strengthening of 2024 aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    NING Ai-lin; LIU Zhi-yi; ZENG Su-min

    2006-01-01

    Effect of large cold deformation on the age-hardening characteristics of 2024 aluminum alloys was investigated. The results reveal: 1) the aging response is accelerated after large cold deformation, and the peak strength is attained after aging for 40 min; 2) double aging peaks can be found in the age-hardening curves, and the first peak appears when aged for 40 min. The corresponding peak tensile strength (σb) and elongation are up to 580 MPa and 9.2% respectively, the second peak appears when aged for 120 min, but the peak tensile strength (520 MPa) is lower than the first one; 3) in early stage of aging (<40 min), elongation slightly increases from 8% with prolonging aging time of the alloy. Elongation markedly decreases to 2% after aging for 60 min, and shows a plateau with the prolonging of aging time on the age-elongation curve. It is indicated that the high density of dislocation introduced by large deformation accelerates the precipitation of GP zones and the aging response of the alloy. The first aging peak is due to the formation of GP zones and the deformation strengthening caused by the high density of dislocation. And the second peak present in the aging curve is attributed to the nucleation and growth of S' phase. The offset between dislocation density decreases and precipitation S'-phase finally results in the phenomenon of double aging peaks when aged at 190 ℃. Moreover, it is suggested that the formation of PFZ and coarse equilibrium phase accompanied by the precipitation of S' phase decrease the elongation.

  14. Climatic variation modulates the indirect effects of large herbivores on small-mammal habitat use.

    Science.gov (United States)

    Long, Ryan A; Wambua, Alois; Goheen, Jacob R; Palmer, Todd M; Pringle, Robert M

    2017-07-01

    Large mammalian herbivores (LMH) strongly shape the composition and architecture of plant communities. A growing literature shows that negative direct effects of LMH on vegetation frequently propagate to suppress the abundance of smaller consumers. Indirect effects of LMH on the behaviour of these consumers, however, have received comparatively little attention despite their potential ecological significance. We sought to understand (i) how LMH indirectly shape small-mammal habitat use by altering the density and distribution of understorey plants; (ii) how these effects vary with climatic context (here, seasonality in rainfall); and (iii) the extent to which behavioural responses of small mammals are contingent upon small-mammal density. We tested the effects of a diverse LMH community on small-mammal habitat use using 4 years of spatially explicit small-mammal trapping and vegetation data from the UHURU Experiment, a replicated set of LMH exclosures in semi-arid Kenyan savanna. Small-mammal habitat use was positively associated with tree density and negatively associated with bare (unvegetated) patches in all plots and seasons. In the presence of LMH, and especially during the dry season, small mammals consistently selected tree cover and avoided bare patches. In contrast, when LMH were excluded, small mammals were weakly associated with tree cover and did not avoid bare patches as strongly. These behavioural responses of small mammals were largely unaffected by changes in small-mammal density associated with LMH exclusion. Our results show that LMH indirectly affect small-mammal behaviour, and that these effects are influenced by climate and can arise via density-independent mechanisms. This raises the possibility that anthropogenic LMH declines might interact with changing patterns of rainfall to alter small-mammal distribution and behaviour, independent of numerical responses by small mammals to these perturbations. For example, increased rainfall in East

  15. Large magnetocaloric effect and adiabatic demagnetization refrigeration with YbPt2Sn.

    Science.gov (United States)

    Jang, Dongjin; Gruner, Thomas; Steppke, Alexander; Mitsumoto, Keisuke; Geibel, Christoph; Brando, Manuel

    2015-10-23

    Adiabatic demagnetization is currently gaining strong interest in searching for alternatives to (3)He-based refrigeration techniques for achieving temperatures below 2 K. The main reasons for that are the recent shortage and high price of the rare helium isotope (3)He. Here we report the discovery of a large magnetocaloric effect in the intermetallic compound YbPt2Sn, which allows adiabatic demagnetization cooling from 2 K down to 0.2 K. We demonstrate this with a home-made refrigerator. Other materials, for example, paramagnetic salts, are commonly used for the same purpose but none of them is metallic, a severe limitation for low-temperature applications. YbPt2Sn is a good metal with an extremely rare weak magnetic coupling between the Yb atoms, which prevents them from ordering above 0.25 K, leaving enough entropy free for use in adiabatic demagnetization cooling. The large volumetric entropy capacity of YbPt2Sn guarantees also a good cooling power.

  16. Evidence for large-scale effects of competition: niche displacement in Canada lynx and bobcat.

    Science.gov (United States)

    Peers, Michael J L; Thornton, Daniel H; Murray, Dennis L

    2013-12-22

    Determining the patterns, causes and consequences of character displacement is central to our understanding of competition in ecological communities. However, the majority of competition research has occurred over small spatial extents or focused on fine-scale differences in morphology or behaviour. The effects of competition on broad-scale distribution and niche characteristics of species remain poorly understood but critically important. Using range-wide species distribution models, we evaluated whether Canada lynx (Lynx canadensis) or bobcat (Lynx rufus) were displaced in regions of sympatry. Consistent with our prediction, we found that lynx niches were less similar to those of bobcat in areas of sympatry versus allopatry, with a stronger reliance on snow cover driving lynx niche divergence in the sympatric zone. By contrast, bobcat increased niche breadth in zones of sympatry, and bobcat niches were equally similar to those of lynx in zones of sympatry and allopatry. These findings suggest that competitively disadvantaged species avoid competition at large scales by restricting their niche to highly suitable conditions, while superior competitors expand the diversity of environments used. Our results indicate that competition can manifest within climatic niche space across species' ranges, highlighting the importance of biotic interactions occurring at large spatial scales on niche dynamics.

  17. Effects of the galactic magnetic field upon large scale anisotropies of extragalactic cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Harari, D.; Mollerach, S.; Roulet, E., E-mail: harari@cab.cnea.gov.ar, E-mail: mollerach@cab.cnea.gov.ar, E-mail: roulet@cab.cnea.gov.ar [CONICET, Centro Atómico Bariloche, Bustillo 9500, 8400 Bariloche (Argentina)

    2010-11-01

    The large scale pattern in the arrival directions of extragalactic cosmic rays that reach the Earth is different from that of the flux arriving to the halo of the Galaxy as a result of the propagation through the galactic magnetic field. Two different effects are relevant in this process: deflections of trajectories and (de)acceleration by the electric field component due to the galactic rotation. The deflection of the cosmic ray trajectories makes the flux intensity arriving to the halo from some direction to appear reaching the Earth from another direction. This applies to any intrinsic anisotropy in the extragalactic distribution or, even in the absence of intrinsic anisotropies, to the dipolar Compton-Getting anisotropy induced when the observer is moving with respect to the cosmic rays rest frame. For an observer moving with the solar system, cosmic rays traveling through far away regions of the Galaxy also experience an electric force coming from the relative motion (due to the rotation of the Galaxy) of the local system in which the field can be considered as being purely magnetic. This produces small changes in the particles momentum that can originate large scale anisotropies even for an isotropic extragalactic flux.

  18. Large Eddy Simulation of the Effects of Plasma Actuation Strength on Film Cooling Efficiency

    Science.gov (United States)

    Li, Guozhan; Chen, Fu; Li, Linxi; Song, Yanping

    2016-11-01

    In this article, numerical investigation of the effects of different plasma actuation strengths on the film cooling flow characteristics has been conducted using large eddy simulation (LES). For this numerical research, the plasma actuator is placed downstream of the trailing edge of the film cooling hole and a phenomenological model is employed to provide the electric field generated by it, resulting in the body forces. Our results show that as the plasma actuation strength grows larger, under the downward effect of the plasma actuation, the jet trajectory near the cooling hole stays closer to the wall and the recirculation region observably reduces in size. Meanwhile, the momentum injection effect of the plasma actuation also actively alters the distributions of the velocity components downstream of the cooling hole. Consequently, the influence of the plasma actuation strength on the Reynolds stress downstream of the cooling hole is remarkable. Furthermore, the plasma actuation weakens the strength of the kidney shaped vortex and prevents the jet from lifting off the wall. Therefore, with the increase of the strength of the plasma actuation, the coolant core stays closer to the wall and tends to split into two distinct regions. So the centerline film cooling efficiency is enhanced, and it is increased by 55% at most when the plasma actuation strength is 10.

  19. Divalent Metal Ion Transport across Large Biological Ion Channels and Their Effect on Conductance and Selectivity

    Directory of Open Access Journals (Sweden)

    Elena García-Giménez

    2012-01-01

    Full Text Available Electrophysiological characterization of large protein channels, usually displaying multi-ionic transport and weak ion selectivity, is commonly performed at physiological conditions (moderate gradients of KCl solutions at decimolar concentrations buffered at neutral pH. We extend here the characterization of the OmpF porin, a wide channel of the outer membrane of E. coli, by studying the effect of salts of divalent cations on the transport properties of the channel. The regulation of divalent cations concentration is essential in cell metabolism and understanding their effects is of key importance, not only in the channels specifically designed to control their passage but also in other multiionic channels. In particular, in porin channels like OmpF, divalent cations modulate the efficiency of molecules having antimicrobial activity. Taking advantage of the fact that the OmpF channel atomic structure has been resolved both in water and in MgCl2 aqueous solutions, we analyze the single channel conductance and the channel selectivity inversion aiming to separate the role of the electrolyte itself, and the counterion accumulation induced by the protein channel charges and other factors (binding, steric effects, etc. that being of minor importance in salts of monovalent cations become crucial in the case of divalent cations.

  20. Effects of large-scale wildfire on ground foraging ants (Hymenoptera: Formicidae) in southern California

    Science.gov (United States)

    Matsuda, Tritia; Turschak, Greta; Brehme, Cheryl; Rochester, Carlton; Mitrovich, Milan; Fisher, Robert

    2011-01-01

    We investigated the effect of broad-scale wildfire on ground foraging ants within southern California. In October and November of 2003, two wildfires burned large portions of the wildlands within San Diego County. Between January 2005 and September 2006, we surveyed 63 plots across four sites to measure the effect of the fires on the ant assemblages present in four vegetation types: 1) coastal sage scrub, 2) chaparral, 3) grassland, and 4) woodland riparian. Thirty-six of the 63 plots were sampled before the fires between March 2001 and June 2003. Mixed model regression analyses, accounting for the burn history of each plot and our pre- and postfire sampling efforts, revealed that fire had a negative effect on ant species diversity. Multivariate analyses showed that ant community structure varied significantly among the four vegetation types, and only the ant assemblage associated with coastal sage scrub exhibited a significant difference between burned and unburned samples. The most notable change detected at the individual species level involved Messor andrei (Mayr), which increased from ant samples to 32.1% in burned plots postfire. We theorize that M. andrei responded to the increase of bare ground and postfire seed production, leading to an increase in the detection rate for this species. Collectively, our results suggest that wildfires can have short-term impacts on the diversity and community structure of ground foraging ants in coastal sage scrub. We discuss these findings in relation to management implications and directions for future research.

  1. Large-strain response of isotropic-hardening elastoplasticity with logarithmic rate: Swift effect in torsion

    Energy Technology Data Exchange (ETDEWEB)

    Bruhns, O.T.; Xiao, H.; Meyers, A. [Bochum Univ. (Germany). Inst. fuer Mechanik

    2001-07-01

    Recently, a new Eulerian rate-type isotropic-hardening elastoplasticity model has been established by utilizing the newly discovered logarithmic rate. It has been proved that this model is unique among all isotropic hardening elastoplastic models with all possible objective corotational stress rates and other known objective stress rates by virtue of the self-consistency criterion: the hypoelastic formulation intended for elastic behaviour must be exactly integrable to deliver a hyperelastic relation. The simple shear response of this model has been studied and shown to be reasonable for both the shear and normal stress components. The objective of this work is to further study the large deformation response of this model, in particular, the second-order effects, including the well-known Swift effect, in torsion of thin-walled cylindrical tubes with free ends. An analytical perturbation solution is derived, and numerical results are presented by means of the Runge-Kutta method. It is shown that the prediction of this model for the shear stress is in good accord with experimental data, but the predicted axial length change is negligibly small and much less than experimental data. This suggests that the strain-induced anisotropy may be the main cause of the Swift effect. (orig.)

  2. Effect of large aspect ratio of biomass particles on carbon burnout in a utility boiler

    Energy Technology Data Exchange (ETDEWEB)

    D. Gera; M.P. Mathur; M.C. Freeman; Allen Robinson [Fluent, Inc./NETL, Morgantown, WV (United States)

    2002-12-01

    This paper reports on the development and validation of comprehensive combustion sub models that include the effect of large aspect ratio of biomass (switchgrass) particles on carbon burnout and temperature distribution inside the particles. Temperature and carbon burnout data are compared from two different models that are formulated by assuming (i) the particles are cylindrical and conduct heat internally, and (ii) the particles are spherical without internal heat conduction, i.e., no temperature gradient exists inside the particle. It was inferred that the latter model significantly underpredicted the temperature of the particle and, consequently, the burnout. Additionally, some results from cofiring biomass (10% heat input) with pulverized coal (90% heat input) are compared with the pulverized coal (100% heat input) simulations and coal experiments in a tangentially fired 150 MW{sub e} utility boiler. 26 refs., 7 figs., 4 tabs.

  3. The Effects of Topology on Throughput Capacity of Large Scale Wireless Networks

    Directory of Open Access Journals (Sweden)

    Qiuming Liu

    2017-03-01

    Full Text Available In this paper, we jointly consider the inhomogeneity and spatial dimension in large scale wireless networks. We study the effects of topology on the throughput capacity. This problem is inherently difficult since it is complex to handle the interference caused by simultaneous transmission. To solve this problem, we, according to the inhomogeneity of topology, divide the transmission into intra-cluster transmission and inter-cluster transmission. For the intra-cluster transmission, a spheroidal percolation model is constructed. The spheroidal percolation model guarantees a constant rate when a power control strategy is adopted. We also propose a cube percolation mode for the inter-cluster transmission. Different from the spheroidal percolation model, a constant transmission rate can be achieved without power control. For both transmissions, we propose a routing scheme with five phases. By comparing the achievable rate of each phase, we get the rate bottleneck, which is the throughput capacity of the network.

  4. Large Scale FEM of the effective elastic properties of particle reinforced composites

    DEFF Research Database (Denmark)

    Rauhe, Jens Christian; Pyrz, Ryszard; Lund, Erik

    2004-01-01

    Over the years several methods have been proposed for the determination of the effective elastic properties of particle reinforced composites. The material microstructures used in the present analysis is a real microstructure and a numerically generated microstructure. X-ray microtomography is used...... to determine the material microstructure and with this method the interior microstructure is determined in a non-destructive way. Using the commercially available equipment, SkyScan 1072, the maximum resolution is approximately 5 microns. The data obtained from the tomographic examination is used to generate...... three-dimensional finite element models of the microstructure. The models contain a large number of elements, up to 1 million, and are solved iteratively using an element-by-element formalism. Models containing 100 particles have been statistically generated and the material properties of each particle...

  5. Large magneto (thermo) dielectric effect in multiferroic orthorhombic LuMnO3

    Science.gov (United States)

    Wang, L. J.; Chai, Y. S.; Feng, S. M.; Zhu, J. L.; Manivannan, N.; Jin, C. Q.; Gong, Z. Z.; Wang, X. H.; Li, L. T.

    2012-06-01

    We have investigated the relation between ferroelectric and magnetic orders of orthorhombic (o-) LuMnO3 ceramics. The increase of dielectric constant ɛ exceeds 82% near incommensurate to commensurate E-type antiferromagnetic (AFM) spin ordering transition temperature TL, reflecting a large magneto (thermo) dielectric response. Meanwhile, distinct anomalies and thermal hysteresis behavior are observed near this temperature in both temperature dependence of ɛ and specific heat Cp, indicating a strong coupling between FE and magnetic orders in o-LuMnO3. Comparing to o-HoMnO3, TmMnO3, and YbMnO3 with similar E-type AFM ground state, o-LuMnO3 has the largest magneto (thermo) dielectric effect

  6. Large reversible magnetocaloric effect in HoMn2O5

    Institute of Scientific and Technical Information of China (English)

    Ge Heng; Zhang Xiang-Qun; Ke Ya-Jiao; Jin Jin-Ling; Liao Zhi-Xin; Cheng Zhao-Hua

    2013-01-01

    Magnetocaloric effect (MCE) in polycrystalline HoMn2O5 was investigated by isothermal magnetization curves from 2 K to 50 K.A relatively large magnetic entropy change,ASM =7.8 J/(kg.K),was achieved with the magnetic field up to 70 kOe (1 Oe =79.5775 A·m-1).The magnetic entropy change is reversible in the whole range of temperature.The contributions of elastic and magnetoelastic energy to the changing of the magnetic entropy are discussed in terms of the Landau theory.The reversibility of MCE with maximal refrigerant capacity Rc =216.7 J/kg makes polycrystalline HoMn2O5 promising as a magnetic refrigerant.

  7. Large magnetocaloric effects in magnetic intermetallics: First-principles and Monte Carlo studies

    Directory of Open Access Journals (Sweden)

    Entel Peter

    2015-01-01

    Full Text Available We have performed ab initio electronic structure calculations and Monte Carlo simulations of frustrated ferroic materials where complex magnetic configurations and chemical disorder lead to rich phase diagrams. With lowering of temperature, we find a ferromagnetic phase which transforms to an antiferromagnetic phase at the magnetostructural (martensitic phase transition and to a cluster spin glass at still lower temperatures. The Heusler alloys Ni-(Co-Mn-(Cr-(Ga, Al, In, Sn, Sb are of particular interest because of their large inverse magnetocaloric effect associated with the magnetostructural transition and the influence of Co/Cr doping. Besides spin glass features, strain glass behavior has been observed in Ni-Co-Mn-In. The numerical simulations allow a complete characterization of the frustrated ferroic materials including the Fe-Rh-Pd alloys.

  8. Large lateral photovoltaic effect observed in nano Al-doped ZnO films.

    Science.gov (United States)

    Lu, Jing; Wang, Hui

    2011-07-18

    Zinc oxide (ZnO), including a variety of metal-doped ZnO, as one kind of most important photoelectric materials, has been widely investigated and received enormous attention for a series of applications. In this work, we report a new finding which we call as lateral photovoltaic effect (LPE) in a nano Al-doped ZnO (ZAO) film based on ZAO/SiO2/Si homo-heterostructure. This large and stable LPE observed in ZAO is an important supplement to the existing ZnO properties. In addition, all data and analyses demonstrate ZAO film can also be a good candidate for new type position-sensitive detector (PSD) devices.

  9. The Trispectrum in the Effective Field Theory of Large Scale Structure

    CERN Document Server

    Bertolini, Daniele; Solon, Mikhail P; Zurek, Kathryn M

    2016-01-01

    We compute the connected four point correlation function (the trispectrum in Fourier space) of cosmological density perturbations at one-loop order in Standard Perturbation Theory (SPT) and the Effective Field Theory of Large Scale Structure (EFT of LSS). This paper is a companion to our earlier work on the non-Gaussian covariance of the matter power spectrum, which corresponds to a particular wavenumber configuration of the trispectrum. In the present calculation, we highlight and clarify some of the subtle aspects of the EFT framework that arise at third order in perturbation theory for general wavenumber configurations of the trispectrum. We consistently incorporate vorticity and non-locality in time into the EFT counterterms and lay out a complete basis of building blocks for the stress tensor. We show predictions for the one-loop SPT trispectrum and the EFT contributions, focusing on configurations which have particular relevance for using LSS to constrain primordial non-Gaussianity.

  10. The trispectrum in the Effective Field Theory of Large Scale Structure

    Science.gov (United States)

    Bertolini, Daniele; Schutz, Katelin; Solon, Mikhail P.; Zurek, Kathryn M.

    2016-06-01

    We compute the connected four point correlation function (the trispectrum in Fourier space) of cosmological density perturbations at one-loop order in Standard Perturbation Theory (SPT) and the Effective Field Theory of Large Scale Structure (EFT of LSS). This paper is a companion to our earlier work on the non-Gaussian covariance of the matter power spectrum, which corresponds to a particular wavenumber configuration of the trispectrum. In the present calculation, we highlight and clarify some of the subtle aspects of the EFT framework that arise at third order in perturbation theory for general wavenumber configurations of the trispectrum. We consistently incorporate vorticity and non-locality in time into the EFT counterterms and lay out a complete basis of building blocks for the stress tensor. We show predictions for the one-loop SPT trispectrum and the EFT contributions, focusing on configurations which have particular relevance for using LSS to constrain primordial non-Gaussianity.

  11. Enabling Effective E-Learning Creation on a Large Scale: Special-Purpose Authoring Tools

    Directory of Open Access Journals (Sweden)

    David Guralnick

    2009-11-01

    Full Text Available E-learning design and development today relies more on technological tools than ever before. In today’s world, for budget and efficiency reasons, e-learning is often created by people without a technical background, using the authoring tools that are available to them. While this process is in some ways unavoidable, the result is that e-learning design is often dictated as much by the capabilities of existing authoring tools as by educational and design principles. In order to support the creation of more sophisticated, effective, educationally-sound e-learning on a large scale, I suggest an approach based on “special-purpose” authoring tools, designed around pedagogical models in a way that encourages good design and speeds up development. In this paper, I describe that approach and provide a brief example of the approach in use.

  12. Planck scale effects and the suppression of power on the large scales in the primordial spectrum

    CERN Document Server

    Shankaranarayanan, S

    2005-01-01

    The enormous red-shifting of the modes during the inflationary epoch suggests that physics at the very high energy scales may modify the primordial perturbation spectrum. Therefore, the measurements of the anisotropies in the Cosmic Microwave Background (CMB) could provide us with clues to understanding physics beyond the Planck scale. In this proceeding, we study the Planck scale effects on the primordial spectrum in the power-law inflation using a model which preserves local Lorentz invariance. While our model reproduces the standard spectrum on small scales, it naturally predicts a suppression of power on the large scales -- a feature that seems to be necessary to explain deficit of power in the lower multipoles of the CMB.

  13. Principal Shapes and Squeezed Limits in the Effective Field Theory of Large Scale Structure

    CERN Document Server

    Bertolini, Daniele

    2016-01-01

    We apply an orthogonalization procedure on the effective field theory of large scale structure (EFT of LSS) shapes, relevant for the angle-averaged bispectrum and non-Gaussian covariance of the matter power spectrum at one loop. Assuming natural-sized EFT parameters, this identifies a linear combination of EFT shapes - referred to as the principal shape - that gives the dominant contribution for the whole kinematic plane, with subdominant combinations suppressed by a few orders of magnitude. For the covariance, our orthogonal transformation is in excellent agreement with a principal component analysis applied to available data. Additionally we find that, for both observables, the coefficients of the principal shapes are well approximated by the EFT coefficients appearing in the squeezed limit, and are thus measurable from power spectrum response functions. Employing data from N-body simulations for the growth-only response, we measure the single EFT coefficient describing the angle-averaged bispectrum with $\\...

  14. Theory of Multifarious Quantum Phases and Large Anomalous Hall Effect in Pyrochlore Iridate Thin Films.

    Science.gov (United States)

    Hwang, Kyusung; Kim, Yong Baek

    2016-07-15

    We theoretically investigate emergent quantum phases in the thin film geometries of the pyrochore iridates, where a number of exotic quantum ground states are proposed to occur in bulk materials as a result of the interplay between electron correlation and strong spin-orbit coupling. The fate of these bulk phases as well as novel quantum states that may arise only in the thin film platforms, are studied via a theoretical model that allows layer-dependent magnetic structures. It is found that the magnetic order develop in inhomogeneous fashions in the thin film geometries. This leads to a variety of magnetic metal phases with modulated magnetic ordering patterns across different layers. Both the bulk and boundary electronic states in these phases conspire to promote unusual electronic properties. In particular, such phases are akin to the Weyl semimetal phase in the bulk system and they would exhibit an unusually large anomalous Hall effect.

  15. Effect of interfacial friction during forging of solid powder discs of large slenderness ratio

    Indian Academy of Sciences (India)

    R K Ranjan; S Kumar

    2004-10-01

    The paper reports an investigation into the effect of interfacial friction law during the forging of a powder circular disc with large slenderness ratio (L/D) between two flat dies. The deformation pattern during the operation is influenced by many factors, which interact with each other in a complex manner. The relative velocity between the work piece material and the die surface, together with high interfacial pressure and/or deformation modes, creates the conditions essential for adhesion in addition to sliding. The decisive factors are the interfacial conditions, initial relative density of the preform and geometry of the preform. An attempt has been made to determine the most realistic interfacial friction law and die pressures developed during such forging using an upper bound approach. The results so obtained are presented graphically and discussed critically to illustrate the interaction of various interfacial friction laws involved.

  16. Demonstration of large field effect in topological insulator films via a high-κ back gate

    Science.gov (United States)

    Wang, C. Y.; Lin, H. Y.; Yang, S. R.; Chen, K. H. M.; Lin, Y. H.; Chen, K. H.; Young, L. B.; Cheng, C. K.; Fanchiang, Y. T.; Tseng, S. C.; Hong, M.; Kwo, J.

    2016-05-01

    The spintronics applications long anticipated for topological insulators (TIs) has been hampered due to the presence of high density intrinsic defects in the bulk states. In this work we demonstrate the back-gating effect on TIs by integrating Bi2Se3 films 6-10 quintuple layer (QL) thick with amorphous high-κ oxides of Al2O3 and Y2O3. Large gating effect of tuning the Fermi level EF to very close to the band gap was observed, with an applied bias of an order of magnitude smaller than those of the SiO2 back gate, and the modulation of film resistance can reach as high as 1200%. The dependence of the gating effect on the TI film thickness was investigated, and ΔN2D/ΔVg varies with TI film thickness as ˜t-0.75. To enhance the gating effect, a Y2O3 layer thickness 4 nm was inserted into Al2O3 gate stack to increase the total κ value to 13.2. A 1.4 times stronger gating effect is observed, and the increment of induced carrier numbers is in good agreement with additional charges accumulated in the higher κ oxides. Moreover, we have reduced the intrinsic carrier concentration in the TI film by doping Te to Bi2Se3 to form Bi2TexSe1-x. The observation of a mixed state of ambipolar field that both electrons and holes are present indicates that we have tuned the EF very close to the Dirac Point. These results have demonstrated that our capability of gating TIs with high-κ back gate to pave the way to spin devices of tunable EF for dissipationless spintronics based on well-established semiconductor technology.

  17. Effect of large-scale parameters for two-phase flow in heterogeneous porous media

    Energy Technology Data Exchange (ETDEWEB)

    Girgrah, B.

    1994-01-01

    Important problems in environmental protection and resource management require quantification of parameters at field (large) scale. A numerical model is utilized to construct large-scale capillary pressure (CP) and relative permeability (RP) curves for two-phase flow in heterogeneous porous media. Two-phase flow simulations were performed over a two-dimensional, numerically generated, heterogeneous permeability field. CP and RP curves were constructed for each simulation. The fields ranged in size from 1.25x1.25 m to 5x10 m and had a mean overall log-hydraulic conductivity of [minus]4.6. Flow was vertically downward with the left and right boundaries of the domain remaining impermeable. Following the simulations on heterogeneous fields, homogeneous equivalents were determined and run for sample simulations. The heterogeneous simulations included investigations into the representative elementary volume (REV) for two permeability fields, the effects of fluid properties on CP and RP, and the effects of correlation structure. The equivalent homogeneous simulations explored the feasibility of homogeneous solutions to predict heterogeneous behavior. Results showed that the REVs for fields one and two were a domain size of 50x50 nodes. Fluid property investigations showed that CP decreased when interfacial tension decreased. Structural explorations showed vertical bedding caused an increase in both CP and RP results. A decrease in log-hydraulic conductivity variance caused slight increases in RP and CP. No direct correlation was obtained between homogeneous and heterogeneous flow behavior. A modification could be made to the homogeneous model to allow it to accurately predict heterogeneous flow. 49 refs., 28 figs., 10 tabs.

  18. Short- and medium-term atmospheric effects of very large solar proton events

    Directory of Open Access Journals (Sweden)

    C. H. Jackman

    2007-07-01

    Full Text Available Solar eruptions sometimes produce protons, which impact the Earth's atmosphere. These solar proton events (SPEs generally last a few days and produce high energy particles that precipitate into the Earth's atmosphere. The protons cause ionization and dissociation processes that ultimately lead to an enhancement of odd-hydrogen and odd-nitrogen in the polar cap regions (>60° geomagnetic latitude. We have used the Whole Atmosphere Community Climate Model (WACCM3 to study the atmospheric impact of SPEs over the period 1963–2005. The very largest SPEs were found to be the most important and caused atmospheric effects that lasted several months to years after the events. We present the short- and medium-term (days to a few months atmospheric influence of the four largest SPEs in the past 45 years (August 1972; October 1989; July 2000; and October–November 2003 as computed by WACCM3 and observed by satellite instruments. The polar effects can be summarized as follows: 1 Mesospheric NOx (NO+NO2 increased by over 50 ppbv and mesospheric ozone decreased by over 30% during these very large SPEs; 2 upper stratospheric and lower mesospheric NOx increased by over 10 ppbv and was transported during polar night down to the middle stratosphere in a few weeks; 3 mid- to upper stratospheric ozone decreased over 20%; and 4 enhancements of HNO3, HOCl, ClO, ClONO2, and N2O5 were indirectly caused by the very large SPEs, although the model results suggest impacts at higher altitudes than indicated by the measurements for the October–November 2003 SPE period.

  19. Fitting parametric random effects models in very large data sets with application to VHA national data

    Directory of Open Access Journals (Sweden)

    Gebregziabher Mulugeta

    2012-10-01

    Full Text Available Abstract Background With the current focus on personalized medicine, patient/subject level inference is often of key interest in translational research. As a result, random effects models (REM are becoming popular for patient level inference. However, for very large data sets that are characterized by large sample size, it can be difficult to fit REM using commonly available statistical software such as SAS since they require inordinate amounts of computer time and memory allocations beyond what are available preventing model convergence. For example, in a retrospective cohort study of over 800,000 Veterans with type 2 diabetes with longitudinal data over 5 years, fitting REM via generalized linear mixed modeling using currently available standard procedures in SAS (e.g. PROC GLIMMIX was very difficult and same problems exist in Stata’s gllamm or R’s lme packages. Thus, this study proposes and assesses the performance of a meta regression approach and makes comparison with methods based on sampling of the full data. Data We use both simulated and real data from a national cohort of Veterans with type 2 diabetes (n=890,394 which was created by linking multiple patient and administrative files resulting in a cohort with longitudinal data collected over 5 years. Methods and results The outcome of interest was mean annual HbA1c measured over a 5 years period. Using this outcome, we compared parameter estimates from the proposed random effects meta regression (REMR with estimates based on simple random sampling and VISN (Veterans Integrated Service Networks based stratified sampling of the full data. Our results indicate that REMR provides parameter estimates that are less likely to be biased with tighter confidence intervals when the VISN level estimates are homogenous. Conclusion When the interest is to fit REM in repeated measures data with very large sample size, REMR can be used as a good alternative. It leads to reasonable inference for

  20. Effects of bryophyte and lichen cover on permafrost soil temperature at large scale

    Science.gov (United States)

    Porada, Philipp; Ekici, Altug; Beer, Christian

    2017-04-01

    Bryophytes and lichens covering the soil surface at high latitudes act as an insulating layer, which has a net cooling effect on the soil and thereby protects permafrost. Climate change, however, may lead to changes in the average surface coverage of bryophytes and lichens. This can result in thawing of permafrost and an associated release of soil carbon to the atmosphere, which may cause a positive feedback on atmospheric CO2 concentration. Hence, it is crucial to predict the future large-scale response of bryophyte and lichen cover to climatic change at high latitudes. Current global land surface models, however, contain mostly empirical approaches to represent the surface cover of bryophytes and lichens, which makes it difficult to quantify its future extent and dynamics. Therefore, we integrate a process-based model of bryophyte and lichen growth into the global land surface model JSBACH (Jena Scheme for Biosphere-Atmosphere Coupling in Hamburg). Thereby, we explicitly simulate dynamic thermal properties of the bryophyte and lichen cover and their relation to environmental factors. To quantify the insulating effect of the cover on the soil, we compare simulations with and without simulated bryophyte and lichen cover. We estimate that the bryophyte and lichen cover exerts an average cooling effect of 2.7 K on temperature in the topsoil for the region north of 50o N under current climatic conditions. Locally, a cooling of up to 5.7 K may be reached. Furthermore, we show that using a simple, empirical representation of the bryophyte and lichen cover instead of a dynamic one results only in an average cooling of around 0.5 K. We conclude that bryophytes and lichens have a significant impact on soil temperature in high-latitude ecosystems and that dynamic thermal properties are necessary for a realistic representation of the cooling effect.

  1. Large Eddy Simulations of Volume Restriction Effects on Canopy-Induced Increased-Uplift Regions

    Science.gov (United States)

    Chatziefstratiou, E.; Bohrer, G.; Velissariou, V.

    2012-12-01

    ABSTRACT Previous modeling and empirical work have shown the development of important areas of increased uplift past forward-facing steps, and recirculation zones past backward-facing steps. Forests edges represent a special kind of step - a semi-porous one. Current models of the effects of forest edges on the flow represent the forest with a prescribed drag term and does not account for the effects of the solid volume in the forest that restrict the airflow. The RAMS-based Forest Large Eddy Simulation (RAFLES) resolves flows inside and above forested canopies. RAFLES is spatially explicit, and uses the finite volume method to solve a descretized set of Navier-Stokes equations. It accounts for vegetation drag effects on the flow and on the flux exchange between the canopy and the canopy air, proportional to the local leaf density. For a better representation of the vegetation structure in the numerical grid within the canopy sub-domain, the model uses a modified version of the cut cell coordinate system. The hard volume of vegetation elements, in forests, or buildings, in urban environments, within each numerical grid cell is represented via a sub-grid-scale process that shrinks the open apertures between grid cells and reduces the open cell volume. We used RAFLES to simulate the effects of a canopy of varying foliage and stem densities on flow over virtual qube-shaped barriers under neutrally buoyant conditions. We explicitly tested the effects of the numerical representation of volume restriction, independent of the effects of the leaf drag by comparing drag-only simulations, where we prescribed no volume or aperture restriction to the flow, restriction-only simulations, where we prescribed no drag, and control simulations, where both drag and volume plus aperture restriction were included. Our simulations show that representation of the effects of the volume and aperture restriction due to obstacles to flow is important (figure 1) and leads to differences in the

  2. Large grazers modify effects of aboveground–belowground interactions on small-scale plant community composition

    NARCIS (Netherlands)

    Veen, G.F.; Geuverink, E.; Olff, H.

    2012-01-01

    Aboveground and belowground organisms influence plant community composition by local interactions, and their scale of impact may vary from millimeters belowground to kilometers aboveground. However, it still poorly understood how large grazers that select their forage on large spatial scales

  3. Large grazers modify effects of aboveground-belowground interactions on small-scale plant community composition

    NARCIS (Netherlands)

    Veen, G. F. (Ciska); Geuverink, Elzemiek; Olff, Han; Schmid, Bernhard

    Aboveground and belowground organisms influence plant community composition by local interactions, and their scale of impact may vary from millimeters belowground to kilometers aboveground. However, it still poorly understood how large grazers that select their forage on large spatial scales

  4. Side effects and accounting aspects of hypothetical large-scale Southern Ocean iron fertilization

    Directory of Open Access Journals (Sweden)

    A. Oschlies

    2010-12-01

    Full Text Available Recent suggestions to slow down the increase in atmospheric carbon dioxide have included ocean fertilization by addition of the micronutrient iron to Southern Ocean surface waters, where a number of natural and artificial iron fertilization experiments have shown that low ambient iron concentrations limit phytoplankton growth. Using a coupled carbon-climate model with the marine biology's response to iron addition calibrated against data from natural iron fertilization experiments, we examine biogeochemical side effects of a hypothetical large-scale Southern Ocean Iron Fertilization (OIF that need to be considered when attempting to account for possible OIF-induced carbon offsets. In agreement with earlier studies our model simulates an OIF-induced increase in local air-sea CO2 fluxes by about 73 GtC over a 100-year period, which amounts to about 48% of the OIF-induced increase in organic carbon export out of the fertilized area. Offsetting CO2 return fluxes outside the region and after stopping the fertilization at 1, 7, 10, 50, and 100 years are quantified for a typical accounting period of 100 years. For continuous Southern Ocean iron fertilization, the CO2 return flux outside the fertilized area cancels about 20% of the fertilization-induced CO2 air-sea flux within the fertilized area on a 100-yr timescale. This "leakage" effect has a radiative impact more than twice as large as the simulated enhancement of marine N2O emissions. Other side effects not yet discussed in terms of accounting schemes include a decrease in Southern Ocean oxygen levels and a simultaneous shrinking of tropical suboxic areas, and accelerated ocean acidification in the entire water column in the Southern Ocean at the expense of reduced globally-averaged surface-water acidification. A prudent approach to account for the OIF-induced carbon sequestration would account for global air-sea CO2 fluxes rather

  5. Large Eddy Simulation Study on Arctic Marine Clouds: the Effect of Aerosol-Cloud Interactions

    Science.gov (United States)

    Raatikainen, T.; Ahola, J.; Tonttila, J.; Romakkaniemi, S.; Laaksonen, A.; Korhonen, H.

    2016-12-01

    Dynamics of marine stratocumulus clouds depend on radiative cooling from cloud tops, turbulent transport of moisture and heat from the sea surface, and the availability of atmospheric aerosols to act as cloud condensation nuclei (CCN). These processes and especially aerosol-cloud interactions can be examined with a recently developed Large Eddy Simulation (LES) model UCLALES-SALSA (Tonttila et al., Geosci. Model Dev. Discuss., 2016). Unlike most other LES models, UCLALES-SALSA has fully interactive sectional description for aerosols and liquid and frozen cloud species. UCLALES-SALSA simulations are initialized using atmospheric observations from the Arctic Summer Cloud Ocean Study (ASCOS). First, the model is used to examine the effects of initial total aerosol number concentration on cloud properties. In agreement with several observations, lowering aerosol number concentration decreases cloud lifetime by increasing drizzle and precipitation rates, which further decreases aerosol number concentration. The second test includes comparison between model versions with different microphysics. The new sectional approach seems to produce thicker and more persistent clouds than a two moment model version (Stevens et al., J. Atmos. Sci., 1999) even when the models are tuned to have equal cloud droplet number concentrations. The third part of the study is focused on the effect of ice on cloud properties. Preliminary results indicate that the current cloud case is so warm that the liquid phase dominates, but further studies are ongoing. In general, the results show that cloud evolution depends on aerosol-cloud interactions.

  6. Effects of Erythropoietin Administration on Adrenal Glands of Landrace/Large White Pigs after Ventricular Fibrillation.

    Science.gov (United States)

    Faa, Armando; Faa, Gavino; Papalois, Apostolos; Obinu, Eleonora; Locci, Giorgia; Pais, Maria Elena; Lelovas, Pavlos; Barouxis, Dimitrios; Pantazopoulos, Charalampos; Vasileiou, Panagiotis V; Iacovidou, Nicoletta; Xanthos, Theodoros

    2016-01-01

    Aim. To evaluate the effects of erythropoietin administration on the adrenal glands in a swine model of ventricular fibrillation and resuscitation. Methods. Ventricular fibrillation was induced via pacing wire forwarded into the right ventricle in 20 female Landrace/Large White pigs, allocated into 2 groups: experimental group treated with bolus dose of erythropoietin (EPO) and control group which received normal saline. Cardiopulmonary resuscitation (CPR) was performed immediately after drug administration as per the 2010 European Resuscitation Council (ERC) guidelines for Advanced Life Support (ALS) until return of spontaneous circulation (ROSC) or death. Animals who achieved ROSC were monitored, mechanically ventilated, extubated, observed, and euthanized. At necroscopy, adrenal glands samples were formalin-fixed, paraffin-embedded, and routinely processed. Sections were stained with hematoxylin-eosin. Results. Oedema and apoptosis were the most frequent histological changes and were detected in all animals in the adrenal cortex and in the medulla. Mild and focal endothelial lesions were also detected. A marked interindividual variability in the degree of the intensity of apoptosis and oedema at cortical and medullary level was observed within groups. Comparing the two groups, higher levels of pathological changes were detected in the control group. No significant difference between the two groups was observed regarding the endothelial changes. Conclusions. In animals exposed to ventricular fibrillation, EPO treatment has protective effects on the adrenal gland.

  7. Effects of Erythropoietin Administration on Adrenal Glands of Landrace/Large White Pigs after Ventricular Fibrillation

    Directory of Open Access Journals (Sweden)

    Armando Faa

    2016-01-01

    Full Text Available Aim. To evaluate the effects of erythropoietin administration on the adrenal glands in a swine model of ventricular fibrillation and resuscitation. Methods. Ventricular fibrillation was induced via pacing wire forwarded into the right ventricle in 20 female Landrace/Large White pigs, allocated into 2 groups: experimental group treated with bolus dose of erythropoietin (EPO and control group which received normal saline. Cardiopulmonary resuscitation (CPR was performed immediately after drug administration as per the 2010 European Resuscitation Council (ERC guidelines for Advanced Life Support (ALS until return of spontaneous circulation (ROSC or death. Animals who achieved ROSC were monitored, mechanically ventilated, extubated, observed, and euthanized. At necroscopy, adrenal glands samples were formalin-fixed, paraffin-embedded, and routinely processed. Sections were stained with hematoxylin-eosin. Results. Oedema and apoptosis were the most frequent histological changes and were detected in all animals in the adrenal cortex and in the medulla. Mild and focal endothelial lesions were also detected. A marked interindividual variability in the degree of the intensity of apoptosis and oedema at cortical and medullary level was observed within groups. Comparing the two groups, higher levels of pathological changes were detected in the control group. No significant difference between the two groups was observed regarding the endothelial changes. Conclusions. In animals exposed to ventricular fibrillation, EPO treatment has protective effects on the adrenal gland.

  8. Primordial Magnetic Field Effects on the CMB and Large-Scale Structure

    Directory of Open Access Journals (Sweden)

    Dai G. Yamazaki

    2010-01-01

    Full Text Available Magnetic fields are everywhere in nature, and they play an important role in every astronomical environment which involves the formation of plasma and currents. It is natural therefore to suppose that magnetic fields could be present in the turbulent high-temperature environment of the big bang. Such a primordial magnetic field (PMF would be expected to manifest itself in the cosmic microwave background (CMB temperature and polarization anisotropies, and also in the formation of large-scale structure. In this paper, we summarize the theoretical framework which we have developed to calculate the PMF power spectrum to high precision. Using this formulation, we summarize calculations of the effects of a PMF which take accurate quantitative account of the time evolution of the cutoff scale. We review the constructed numerical program, which is without approximation, and an improvement over the approach used in a number of previous works for studying the effect of the PMF on the cosmological perturbations. We demonstrate how the PMF is an important cosmological physical process on small scales. We also summarize the current constraints on the PMF amplitude Bλ and the power spectral index nB which have been deduced from the available CMB observational data by using our computational framework.

  9. Combined climate and carbon-cycle effects of large-scale deforestation.

    Science.gov (United States)

    Bala, G; Caldeira, K; Wickett, M; Phillips, T J; Lobell, D B; Delire, C; Mirin, A

    2007-04-17

    The prevention of deforestation and promotion of afforestation have often been cited as strategies to slow global warming. Deforestation releases CO(2) to the atmosphere, which exerts a warming influence on Earth's climate. However, biophysical effects of deforestation, which include changes in land surface albedo, evapotranspiration, and cloud cover also affect climate. Here we present results from several large-scale deforestation experiments performed with a three-dimensional coupled global carbon-cycle and climate model. These simulations were performed by using a fully three-dimensional model representing physical and biogeochemical interactions among land, atmosphere, and ocean. We find that global-scale deforestation has a net cooling influence on Earth's climate, because the warming carbon-cycle effects of deforestation are overwhelmed by the net cooling associated with changes in albedo and evapotranspiration. Latitude-specific deforestation experiments indicate that afforestation projects in the tropics would be clearly beneficial in mitigating global-scale warming, but would be counterproductive if implemented at high latitudes and would offer only marginal benefits in temperate regions. Although these results question the efficacy of mid- and high-latitude afforestation projects for climate mitigation, forests remain environmentally valuable resources for many reasons unrelated to climate.

  10. Combined Climate and Carbon-Cycle Effects of Large-Scale Deforestation

    Energy Technology Data Exchange (ETDEWEB)

    Bala, G; Caldeira, K; Wickett, M; Phillips, T J; Lobell, D B; Delire, C; Mirin, A

    2006-10-17

    The prevention of deforestation and promotion of afforestation have often been cited as strategies to slow global warming. Deforestation releases CO{sub 2} to the atmosphere, which exerts a warming influence on Earth's climate. However, biophysical effects of deforestation, which include changes in land surface albedo, evapotranspiration, and cloud cover also affect climate. Here we present results from several large-scale deforestation experiments performed with a three-dimensional coupled global carbon-cycle and climate model. These are the first such simulations performed using a fully three-dimensional model representing physical and biogeochemical interactions among land, atmosphere, and ocean. We find that global-scale deforestation has a net cooling influence on Earth's climate, since the warming carbon-cycle effects of deforestation are overwhelmed by the net cooling associated with changes in albedo and evapotranspiration. Latitude-specific deforestation experiments indicate that afforestation projects in the tropics would be clearly beneficial in mitigating global-scale warming, but would be counterproductive if implemented at high latitudes and would offer only marginal benefits in temperate regions. While these results question the efficacy of mid- and high-latitude afforestation projects for climate mitigation, forests remain environmentally valuable resources for many reasons unrelated to climate.

  11. Therapeutic Effect of Polysaccharide of Large Yellow Croaker Swim Bladder on Lupus Nephritis of Mice

    Directory of Open Access Journals (Sweden)

    Xianhong Jiang

    2014-03-01

    Full Text Available The therapeutic effect of polysaccharide of large yellow croaker swim bladder (PLYCSB on lupus nephritis has been studied in vivo. A high concentration (50 mg/kg dose of PLYCSB reduced the levels of serum inflammatory cytokine levels of IL-6, IL-12, TNF-α and IFN-γ compared to a low concentration (25 mg/kg dose and control mice. SCr, BUN, TC and TG serum levels of PLYCSB treated mice were lower than those of control mice, and TP and ALB serum levels were higher than control mice. Control mice tested ds-DNA positive at the 6th week, and 50 mg/kg treated mice tested at the 10th week after the experiment began. The output of urine protein of 50 mg/kg PLYCSB treated mice was most closely comparable to the normal mice. The glomerular number of 50 mg/kg PLYCSB treated mice was more than the 25 mg/kg dose and control groups, and the 50 mg/kg dose group showed the lowest glomerular sclerosis index in lupus nephritis mice. By RT-PCR and western blot assay, PLYCSB significantly induced inflammation in kidney tissues of mice by downregulating NF-κB-p65, TGF-β1, Fas, FasL and upregulating IκB-α. These results suggest that PLYCSB showed a potential curative effect on lupus nephritis as a drug or functional food.

  12. Large magneto-optical effect in low-temperature-grown GaDyN

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y.K.; Emura, S.; Hasegawa, S.; Asahi, H. [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

    2011-07-15

    GaDyN layers were grown at temperatures at 300 C by radio-frequency plasma-assisted molecular-beam epitaxy on sapphire substrates. X-ray diffraction results showed no obvious secondary phase in the GaDyN samples. A sharp line was found at 582.4 nm in the photoluminescence spectra from the low-temperature-grown samples, which was assigned intra-4f orbital transition: {sup 4}F{sub 9/2} - {sup 6}H{sub 13/2} of Dy{sup 3+} ion. It was shown that Dy atoms were incorporated into the Ga sites in these GaDyN layers. Magnetic circular dichroism (MCD) measurement was performed for these samples at 10 K to investigate magneto-optical effect. It was found that the large magneto-optical effect in the GaDyN depend on the Dy concentration. It is the evidence of ferromagnetic s -f exchange coupling in the GaDyN, which enhance the Zeeman splitting. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Effect of polymorphism in the leukemia inhibitory factor gene on litter size in Large White pigs.

    Science.gov (United States)

    Lin, H C; Liu, G F; Wang, A G; Kong, L J; Wang, X F; Fu, J L

    2009-09-01

    DNA polymorphism of the porcine leukemia inhibitory factory (LIF) was investigated and used to study the effects on litter size in Large White pigs. A total of 2,167 litter records from 420 sows genotyped at two SNP loci (LIF1 and LIF2) within LIF gene were analyzed to determine whether LIF influenced total number born (TNB) and number born alive (NBA). The results indicated that B allele at LIF1 locus and A allele at LIF2 locus seem to have advantageous effects on litter size. However, the combined analyzed results demonstrated that genotype AAAA, ABBB, and BBBB are better than genotype AAAB, AABB, and ABAB for TNB and NBA in either third to eighth parity or all parities. In all parities, the sows with AAAA genotype had an advantage of 1.76 piglets (P NBA per litter over the AAAB sows, respectively. The results in this study demonstrated that LIF gene was significantly associated with litter size in pigs.

  14. Effect of large density ratios on turbulence budgets in buoyant jets with coflow

    Science.gov (United States)

    Charonko, John; Prestridge, Kathy

    2016-11-01

    Turbulence statistics and energy transport budgets have been measured in two fully turbulent jets with coflow at density ratios of s = 1 . 2 & 4.2 to improve our understanding of variable-density mixing in turbulent flows. The exit Reynolds number was matched for both flows at 20,000 and simultaneous planar PIV and acetone PLIF measurements were acquired so the coupled evolution of the velocity and density statistics could be examined in terms of density-weighted average quantities. Measurements were taken over 10,000 snapshots of the flow at three locations to assure statistical convergence, and the spatial resolution (288 μm) is well below the Taylor microscale. Variable-density effects caused changes in both the magnitude and distribution of the evolving turbulence, with differences most pronounced within the jet half-width. As the jet tends toward pseudo self-similarity, a new scaling based on effective diameter and density successfully scales the energy budgets of the two jets, but significant differences were still seen in the core. For the high density ratio jet, the turbulent kinetic energy production is negative on the centerline, as opposed to slightly positive, leading to large changes in advection and diffusion. A mechanism for these differences is proposed.

  15. Effects of large-scale free stream turbulence on a turbulent boundary layer

    Science.gov (United States)

    Sharp, N. S.; Neuscamman, S.; Warhaft, Z.

    2009-09-01

    Results of a wind tunnel experiment in which there are systematic variations of free stream turbulence above a flat-plate boundary layer are presented. Upstream of the plate, an active grid generates free stream turbulence varying in intensity from 0.25% to 10.5%. The momentum thickness Reynolds number of the boundary layer varies from 550 to nearly 3000. In all cases, the ratio of the free stream turbulence length scale to the boundary layer depth is greater than unity. Hotwire measurements show that, at high turbulence intensities, the effects of the free stream turbulence extend deep into the boundary layer, affecting the wall stress as well as the small-scale (derivative) statistics. Premultiplied energy spectra show a double peak. At very low free stream turbulence intensities these peaks are associated with the inner and outer scales of the turbulent boundary layer, but at high turbulence intensities the free stream energy peak dominates over the boundary layer's outer scale. The implications of the effect of the large free stream turbulence scales on the small, near-wall scales is discussed with reference to recent high Reynolds number experiments in a turbulent boundary layer without free stream turbulence [Hutchins and Marusic, Philos. Trans. R. Soc. London, Ser. A 365, 647 (2007)].

  16. Large tunable image-charge effects in single-molecule junctions.

    Science.gov (United States)

    Perrin, Mickael L; Verzijl, Christopher J O; Martin, Christian A; Shaikh, Ahson J; Eelkema, Rienk; van Esch, Jan H; van Ruitenbeek, Jan M; Thijssen, Joseph M; van der Zant, Herre S J; Dulić, Diana

    2013-04-01

    Metal/organic interfaces critically determine the characteristics of molecular electronic devices, because they influence the arrangement of the orbital levels that participate in charge transport. Studies on self-assembled monolayers show molecule-dependent energy-level shifts as well as transport-gap renormalization, two effects that suggest that electric-field polarization in the metal substrate induced by the formation of image charges plays a key role in the alignment of the molecular energy levels with respect to the metal's Fermi energy. Here, we provide direct experimental evidence for an electrode-induced gap renormalization in single-molecule junctions. We study charge transport through single porphyrin-type molecules using electrically gateable break junctions. In this set-up, the position of the occupied and unoccupied molecular energy levels can be followed in situ under simultaneous mechanical control. When increasing the electrode separation by just a few ångströms, we observe a substantial increase in the transport gap and level shifts as high as several hundreds of meV. Analysis of this large and tunable gap renormalization based on atomic charges obtained from density functional theory confirms and clarifies the dominant role of image-charge effects in single-molecule junctions.

  17. Switching of a large anomalous Hall effect between metamagnetic phases of a non-collinear antiferromagnet

    Science.gov (United States)

    Sürgers, Christoph; Wolf, Thomas; Adelmann, Peter; Kittler, Wolfram; Fischer, Gerda; Löhneysen, Hilbert v.

    2017-01-01

    The anomalous Hall effect (AHE), which in long-range ordered ferromagnets appears as a voltage transverse to the current and usually is proportional to the magnetization, often is believed to be of negligible size in antiferromagnets due to their low uniform magnetization. However, recent experiments and theory have demonstrated that certain antiferromagnets with a non-collinear arrangement of magnetic moments exhibit a sizeable spontaneous AHE at zero field due to a non-vanishing Berry curvature arising from the quantum mechanical phase of the electron’s wave functions. Here we show that antiferromagnetic Mn5Si3 single crystals exibit a large AHE which is strongly anisotropic and shows multiple transitions with sign changes at different magnetic fields due to field-induced rearrangements of the magnetic structure despite only tiny variations of the total magnetization. The presence of multiple non-collinear magnetic phases offers the unique possiblity to explore the details of the AHE and the sensitivity of the Hall effect on the details of the magnetic texture. PMID:28218287

  18. Switching of a large anomalous Hall effect between metamagnetic phases of a non-collinear antiferromagnet.

    Science.gov (United States)

    Sürgers, Christoph; Wolf, Thomas; Adelmann, Peter; Kittler, Wolfram; Fischer, Gerda; Löhneysen, Hilbert V

    2017-02-20

    The anomalous Hall effect (AHE), which in long-range ordered ferromagnets appears as a voltage transverse to the current and usually is proportional to the magnetization, often is believed to be of negligible size in antiferromagnets due to their low uniform magnetization. However, recent experiments and theory have demonstrated that certain antiferromagnets with a non-collinear arrangement of magnetic moments exhibit a sizeable spontaneous AHE at zero field due to a non-vanishing Berry curvature arising from the quantum mechanical phase of the electron's wave functions. Here we show that antiferromagnetic Mn5Si3 single crystals exibit a large AHE which is strongly anisotropic and shows multiple transitions with sign changes at different magnetic fields due to field-induced rearrangements of the magnetic structure despite only tiny variations of the total magnetization. The presence of multiple non-collinear magnetic phases offers the unique possiblity to explore the details of the AHE and the sensitivity of the Hall effect on the details of the magnetic texture.

  19. Effect of stable stratification on dispersion within urban street canyons: A large-eddy simulation

    Science.gov (United States)

    Li, Xian-Xiang; Britter, Rex; Norford, Leslie K.

    2016-11-01

    This study employs a validated large-eddy simulation (LES) code with high tempo-spatial resolution to investigate the effect of a stably stratified roughness sublayer (RSL) on scalar transport within an urban street canyon. The major effect of stable stratification on the flow and turbulence inside the street canyon is that the flow slows down in both streamwise and vertical directions, a stagnant area near the street level emerges, and the vertical transport of momentum is weakened. Consequently, the transfer of heat between the street canyon and overlying atmosphere also gets weaker. The pollutant emitted from the street level 'pools' within the lower street canyon, and more pollutant accumulates within the street canyon with increasing stability. Under stable stratification, the dominant mechanism for pollutant transport within the street canyon has changed from ejections (flow carries high-concentration pollutant upward) to unorganized motions (flow carries high-concentration pollutant downward), which is responsible for the much lower dispersion efficiency under stable stratifications.

  20. Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe 2

    KAUST Repository

    Zhang, Chendong

    2015-09-21

    By using a comprehensive form of scanning tunneling spectroscopy, we have revealed detailed quasi-particle electronic structures in transition metal dichalcogenides, including the quasi-particle gaps, critical point energy locations, and their origins in the Brillouin zones. We show that single layer WSe surprisingly has an indirect quasi-particle gap with the conduction band minimum located at the Q-point (instead of K), albeit the two states are nearly degenerate. We have further observed rich quasi-particle electronic structures of transition metal dichalcogenides as a function of atomic structures and spin-orbit couplings. Such a local probe for detailed electronic structures in conduction and valence bands will be ideal to investigate how electronic structures of transition metal dichalcogenides are influenced by variations of local environment.

  1. OCEAN CIRCULATION. Observing the Atlantic Meridional Overturning Circulation yields a decade of inevitable surprises.

    Science.gov (United States)

    Srokosz, M A; Bryden, H L

    2015-06-19

    The importance of the Atlantic Meridional Overturning Circulation (AMOC) heat transport for climate is well acknowledged. Climate models predict that the AMOC will slow down under global warming, with substantial impacts, but measurements of ocean circulation have been inadequate to evaluate these predictions. Observations over the past decade have changed that situation, providing a detailed picture of variations in the AMOC. These observations reveal a surprising degree of AMOC variability in terms of the intraannual range, the amplitude and phase of the seasonal cycle, the interannual changes in strength affecting the ocean heat content, and the decline of the AMOC over the decade, both of the latter two exceeding the variations seen in climate models. Copyright © 2015, American Association for the Advancement of Science.

  2. Paroxysmal atrial fibrillation occurs often in cryptogenic ischaemic stroke. Final results from the SURPRISE study

    DEFF Research Database (Denmark)

    Christensen, Louisa; Krieger, D W; Højberg, S;

    2014-01-01

    BACKGROUND AND PURPOSE: Atrial fibrillation (AF) increases the risk of stroke fourfold and is associated with a poor clinical outcome. Despite work-up in compliance with guidelines, up to one-third of patients have cryptogenic stroke (CS). The prevalence of asymptomatic paroxysmal atrial...... fibrillation (PAF) in CS remains unknown. The SURPRISE project aimed at determining this rate using long-term cardiac monitoring. METHODS: Patients with CS after protocolled work-up including electrocardiography (ECG) and telemetry were included after informed consent. An implantable loop recorder (ILR...... patients (16.1%). In three patients PAF was detected by other methods before or after monitoring and was undiscovered due to device sensitivity in one case. The first event of PAF was documented at a mean of 109 days (SD ±48) after stroke onset. PAF was asymptomatic in all cases and occurred in episodes...

  3. Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe2.

    Science.gov (United States)

    Zhang, Chendong; Chen, Yuxuan; Johnson, Amber; Li, Ming-Yang; Li, Lain-Jong; Mende, Patrick C; Feenstra, Randall M; Shih, Chih-Kang

    2015-10-14

    By using a comprehensive form of scanning tunneling spectroscopy, we have revealed detailed quasi-particle electronic structures in transition metal dichalcogenides, including the quasi-particle gaps, critical point energy locations, and their origins in the Brillouin zones. We show that single layer WSe2 surprisingly has an indirect quasi-particle gap with the conduction band minimum located at the Q-point (instead of K), albeit the two states are nearly degenerate. We have further observed rich quasi-particle electronic structures of transition metal dichalcogenides as a function of atomic structures and spin-orbit couplings. Such a local probe for detailed electronic structures in conduction and valence bands will be ideal to investigate how electronic structures of transition metal dichalcogenides are influenced by variations of local environment.

  4. Beyond surprise: the puzzle of infants' expressive reactions to expectancy violation.

    Science.gov (United States)

    Scherer, Klaus R; Zentner, Marcel R; Stern, Daniel

    2004-12-01

    The reactions of 58 infants to expectancy violation by digitally filtering the experimenter's voice were studied in a cross-sectional design for ages 5, 7, 9, 11-12, and 14 months. The results show that behavioral freezing and changes in gaze direction, but not facial or vocal expression, are reliable responses to expectancy violation. The pattern suggests that a transition in the infant's capacity for cognitive evaluation of novel and discrepant events may occur around age 9 months. These findings confirm the consistent failure to find prototypical facial surprise reactions in research on novel or impossible situations. Componential theories of emotion, which predict adaptive behavior patterns from appraisal processes, may provide clues for underlying mechanisms and generate hypotheses on age-related changes in emotional expression. copyright (c) 2004 APA, all rights reserved.

  5. Surprising judgments about robot drivers: Experiments on rising expectations and blaming humans

    Directory of Open Access Journals (Sweden)

    Peter Danielson

    2015-05-01

    Full Text Available N-Reasons is an experimental Internet survey platform designed to enhance public participation in applied ethics and policy. N-Reasons encourages individuals to generate reasons to support their judgments, and groups to converge on a common set of reasons pro and con various issues.  In the Robot Ethics Survey some of the reasons contributed surprising judgments about autonomous machines. Presented with a version of the trolley problem with an autonomous train as the agent, participants gave unexpected answers, revealing high expectations for the autonomous machine and shifting blame from the automated device to the humans in the scenario. Further experiments with a standard pair of human-only trolley problems refine these results. While showing the high expectations even when no autonomous machine is involved, human bystanders are only blamed in the machine case. A third experiment explicitly aimed at responsibility for driverless cars confirms our findings about shifting blame in the case of autonomous machine agents. We conclude methodologically that both results point to the power of an experimental survey based approach to public participation to explore surprising assumptions and judgments in applied ethics. However, both results also support using caution when interpreting survey results in ethics, demonstrating the importance of qualitative data to provide further context for evaluating judgments revealed by surveys. On the ethics side, the result about shifting blame to humans interacting with autonomous machines suggests caution about the unintended consequences of intuitive principles requiring human responsibility.http://dx.doi.org/10.5324/eip.v9i1.1727

  6. Resummation of large logarithms in the heavy quark effects on the parton distributions inside the virtual photon

    CERN Document Server

    Kitadono, Yoshio; Uematsu, Tsuneo; Ueda, Takahiro

    2010-01-01

    We discuss the resummation of the large logarithmic terms appearing in the heavy quark effects on parton distribution functions inside the virtual photon. We incorporate heavy quark mass effects by changing the initial condition of the leading-order DGLAP evolution equation. In a certain kinematical limit, we recover the logarithmic terms of the next-to-leading order heavy quark effects obtained in the previous work. This method enables us to resum the large logarithmic terms due to heavy quark mass effects on the parton distributions in the virtual photon. We numerically calculate parton distributions using the formulae derived in this work, and discuss the property of the resummed heavy quark effects.

  7. Trophic cascades result in large-scale coralline algae loss through differential grazer effects.

    Science.gov (United States)

    O'Leary, Jennifer K; McClanahan, Timothy R

    2010-12-01

    Removal of predators can have strong indirect effects on primary producers through trophic cascades. Crustose coralline algae (CCA) are major primary producers worldwide that may be influenced by predator removal through changes in grazer composition and biomass. CCA have been most widely studied in Caribbean and temperate reefs, where cover increases with increasing grazer biomass due to removal of competitive fleshy algae. However, each of these systems has one dominant grazer type, herbivorous fishes or sea urchins, which may not be functionally equivalent. Where fishes and sea urchins co-occur, fishing can result in a phase shift in the grazing community with subsequent effects on CCA and other substrata. Kenyan reefs have herbivorous fishes and sea urchins, providing an opportunity to determine the relative impacts of each grazer type and evaluate potential human-induced trophic cascades. We hypothesized that fish benefit CCA, abundant sea urchins erode CCA, and that fishing indirectly reduces CCA cover by removing sea urchin predators. We used closures and fished reefs as a large-scale, long-term natural experiment to assess how fishing and resultant changes in communities affect CCA abundance. We used a short-term caging experiment to directly test the effects of grazing on CCA. CCA cover declined with increasing fish and sea urchin abundance, but the negative impact of sea urchin grazing was much stronger than that of fishes. Abundant sea urchins reduced the CCA growth rate to almost zero and prevented CCA accumulation. A warming event (El Niño Southern Oscillation, ENSO) occurred during the 18-year study and had a strong but short-term positive effect on CCA cover. However, the effect of the ENSO on CCA was lower in magnitude than the effect of sea urchin grazing. We compare our results with worldwide literature on bioerosion by fishes and sea urchins. Grazer influence depends on whether benefits of fleshy algae removal outweigh costs of grazer

  8. The effects of physiologically plausible connectivity structure on local and global dynamics in large scale brain models.

    NARCIS (Netherlands)

    Knock, S.A.; McIntosh, A.R.; Sporns, O.; Kotter, R.; Hagmann, P.; Jirsa, V.K.

    2009-01-01

    Functionally relevant large scale brain dynamics operates within the framework imposed by anatomical connectivity and time delays due to finite transmission speeds. To gain insight on the reliability and comparability of large scale brain network simulations, we investigate the effects of variations

  9. Aerodynamic Investigation of Incidence Angle Effects in a Large Scale Transonic Turbine Cascade. Revision 1

    Science.gov (United States)

    McVetta, Ashlie B.; Giel, Paul W.; Welch, Gerard E.

    2014-01-01

    Aerodynamic measurements showing the effects of large incidence angle variations on an HPT turbine blade set are presented. Measurements were made in NASA's Transonic Turbine Blade Cascade Facility which has been used in previous studies to acquire detailed aerodynamic and heat transfer measurements for CFD code validation. The current study supports the development of variable-speed power turbine (VSPT) speed-change technology for the NASA Large Civil Tilt Rotor (LCTR) vehicle. In order to maintain acceptable main rotor propulsive efficiency, the VSPT operates over a nearly 50 percent speed range from takeoff to altitude cruise. This results in 50 deg or more variations in VSPT blade incidence angles. The cascade facility has the ability to operate over a wide range of Reynolds numbers and Mach numbers, but had to be modified in order to accommodate the negative incidence angle variation required by the LCTR VSPT operation. Using existing blade geometry with previously acquired aerodynamic data, the tunnel was re-baselined and the new incidence angle range was exercised. Midspan exit total pressure and flow angle measurements were obtained at seven inlet flow angles. For each inlet angle, data were obtained at five flow conditions with inlet Reynolds numbers varying from 6.83×10 (exp 5) to 0.85×10(exp 5) and two isentropic exit Mach numbers of 0.74 and 0.34. The midspan flowfield measurements were acquired using a three-hole pneumatic probe located in a survey plane 8.6 percent axial chord downstream of the blade trailing edge plane and covering three blade passages. Blade and endwall static pressure distributions were also acquired for each flow condition.

  10. Aerodynamic Investigation of Incidence Angle Effects in a Large Scale Transonic Turbine Cascade

    Science.gov (United States)

    McVetta, Ashlie B.; Giel, Paul W.; Welch, Gerard E.

    2013-01-01

    Aerodynamic measurements showing the effects of large incidence angle variations on an HPT turbine blade set are presented. Measurements were made in NASA's Transonic Turbine Blade Cascade Facility which has been used in previous studies to acquire detailed aerodynamic and heat transfer measurements for CFD code validation. The current study supports the development of variable-speed power turbine (VSPT) speed-change technology for the NASA Large Civil Tilt Rotor (LCTR) vehicle. In order to maintain acceptable main rotor propulsive efficiency, the VSPT operates over a nearly 50 percent speed range from takeoff to altitude cruise. This results in 50deg or more variations in VSPT blade incidence angles. The cascade facility has the ability to operate over a wide range of Reynolds numbers and Mach numbers, but had to be modified in order to accommodate the negative incidence angle variation required by the LCTR VSPT operation. Using existing blade geometry with previously acquired aerodynamic data, the tunnel was re-baselined and the new incidence angle range was exercised. Midspan exit total pressure and flow angle measurements were obtained at seven inlet flow angles. For each inlet angle, data were obtained at five flow conditions with inlet Reynolds numbers varying from 6.83×10(exp 5) to 0.85×10(exp 5) and two isentropic exit Mach numbers of 0.74 and 0.34. The midspan flowfield measurements were acquired using a three-hole pneumatic probe located in a survey plane 8.6 percent axial chord downstream of the blade trailing edge plane and covering three blade passages. Blade and endwall static pressure distributions were also acquired for each flow condition.

  11. Clinical Effectiveness and Cognitive Impact of Electroconvulsive Therapy for Schizophrenia: A Large Retrospective Study.

    Science.gov (United States)

    Kaster, Tyler S; Daskalakis, Zafiris J; Blumberger, Daniel M

    2017-04-01

    To determine the clinical effectiveness and cognitive impact of electroconvulsive therapy (ECT) in a large clinical sample of patients with schizophrenia and explore factors associated with treatment response and transient cognitive impairment. We examined the clinical records of 144 patients with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder who were treated at an academic mental health hospital from October 2009 to August 2014. These patients received 171 acute courses of ECT; we attempted to determine their treatment response and transient cognitive impairment from ECT. We explored the impact of various factors including ECT indication, clinical characteristics, medication during ECT, and technical parameters on treatment response and transient cognitive impairment. Treatment with ECT resulted in a 76.7% response rate. Factors associated with a better response to ECT were absence of treatment with antiepileptic medication (17.9% vs 3.9%, P = .007), a previous good response to ECT (36.4% vs 15.4%, P = .017), and primary indication for ECT referral other than failed pharmacotherapy (89.7% vs 69.8%, P = .012). Factors not associated with treatment response included age, clozapine treatment, and benzodiazepine treatment (P > .05). Treatment with ECT caused transient cognitive impairment in 9% of treatment courses; no demographic or clinical factors were associated with cognitive impairment. This work demonstrates the effectiveness of ECT for schizophrenia treatment and several factors associated with treatment response. The rate of transient cognitive impairment is lower than expected based on the rate of cognitive impairment seen in ECT for depression. ECT appears to be an effective treatment option for schizophrenia that is tolerated by the majority of patients.

  12. Up-Regulatory Effects of Curcumin on Large Conductance Ca2+-Activated K+ Channels.

    Directory of Open Access Journals (Sweden)

    Qijing Chen

    Full Text Available Large conductance Ca2+-activated potassium channels (BK are targets for research that explores therapeutic means to various diseases, owing to the roles of the channels in mediating multiple physiological processes in various cells and tissues. We investigated the pharmacological effects of curcumin, a compound isolated from the herb Curcuma longa, on BK channels. As recorded by whole-cell patch-clamp, curcumin increased BK (α and BK (α+β1 currents in transfected HEK293 cells as well as the current density of BK in A7r5 smooth muscle cells in a dose-dependent manner. By incubating with curcumin for 24 hours, the current density of exogenous BK (α in HEK293 cells and the endogenous BK in A7r5 cells were both enhanced notably, though the steady-state activation of the channels did not shift significantly, except for BK (α+β1. Curcumin up-regulated the BK protein expression without changing its mRNA level in A7r5 cells. The surface expression and the half-life of BK channels were also increased by curcumin in HEK293 cells. These effects of curcumin were abolished by MG-132, a proteasome inhibitor. Curcumin also increased ERK 1/2 phosphorylation, while inhibiting ERK by U0126 attenuated the curcumin-induced up-regulation of BK protein expression. We also observed that the curcumin-induced relaxation in the isolated rat aortic rings was significantly attenuated by paxilline, a BK channel specific blocker. These results show that curcumin enhances the activity of the BK channels by interacting with BK directly as well as enhancing BK protein expression through inhibiting proteasomal degradation and activating ERK signaling pathway. The findings suggest that curcumin is a potential BK channel activator and provide novel insight into its complicated pharmacological effects and the underlying mechanisms.

  13. Reheating in tachyonic inflationary models: Effects on the large scale curvature perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Rajeev Kumar, E-mail: rajeev.jain@unige.ch [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India); Chingangbam, Pravabati, E-mail: prava@iiap.res.in [Korea Institute for Advanced Study, 207-43 Cheongnyangni 2-dong, Dongdaemun-gu, Seoul 130-722 (Korea, Republic of); Sriramkumar, L., E-mail: sriram@physics.iitm.ac.in [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211 019 (India)

    2011-11-11

    We investigate the problem of perturbative reheating and its effects on the evolution of the curvature perturbations in tachyonic inflationary models. We derive the equations governing the evolution of the scalar perturbations for a system consisting of a tachyon and a perfect fluid. Assuming the perfect fluid to be radiation, we solve the coupled equations for the system numerically and study the evolution of the perturbations from the sub-Hubble to the super-Hubble scales. In particular, we analyze the effects of the transition from tachyon driven inflation to the radiation dominated epoch on the evolution of the large scale curvature and non-adiabatic pressure perturbations. We consider two different potentials to describe the tachyon and study the effects of two possible types of decay of the tachyon into radiation. We plot the spectrum of curvature perturbations at the end of inflation as well as at the early stages of the radiation dominated epoch. We find that reheating does not affect the amplitude of the curvature perturbations in any of these cases. These results corroborate similar conclusions that have been arrived at earlier based on the study of the evolution of the perturbations in the super-Hubble limit. We illustrate that, before the transition to the radiation dominated epoch, the relative non-adiabatic pressure perturbation between the tachyon and radiation decays in a fashion very similar to that of the intrinsic entropy perturbation associated with the tachyon. Moreover, we show that, after the transition, the relative non-adiabatic pressure perturbation dies down extremely rapidly during the early stages of the radiation dominated epoch. It is these behavior which ensure that the amplitude of the curvature perturbations remain unaffected during reheating. We also discuss the corresponding results for the popular chaotic inflation model in the case of the canonical scalar field.

  14. Surprising robustness of particle-hole symmetry for composite-fermion liquids

    Science.gov (United States)

    Sreejith, G. J.; Zhang, Yuhe; Jain, J. K.

    2017-09-01

    We report on fixed phase diffusion Monte Carlo calculations that show that, even for a large amount of Landau level mixing, the energies of the Pfaffian and anti-Pfaffian phases remain very nearly the same, as also do the excitation gaps at 1 /3 and 2 /3 . These results, combined with previous theoretical and experimental investigations, indicate that particle hole (PH) symmetry for fully spin polarized composite fermion states is much more robust than a priori expected, emerging even in models that explicitly break PH symmetry. We provide insight into this fact by showing that the low energy physics of a generic repulsive 3-body interaction is captured, to a large extent and over a range of filling factors, by a mean field approximation that maps it into a PH symmetric 2-body interaction. This explains why Landau level mixing, which effectively generates such a generic 3-body interaction, is inefficient in breaking PH symmetry. As a byproduct, our results provide a systematic construction of a 2-body interaction which produces, to a good approximation, the Pfaffian wave function as its ground state.

  15. Cost-effective river rehabilitation planning: optimizing for morphological benefits at large spatial scales.

    Science.gov (United States)

    Langhans, Simone D; Hermoso, Virgilio; Linke, Simon; Bunn, Stuart E; Possingham, Hugh P

    2014-01-01

    River rehabilitation aims to protect biodiversity or restore key ecosystem services but the success rate is often low. This is seldom because of insufficient funding for rehabilitation works but because trade-offs between costs and ecological benefits of management actions are rarely incorporated in the planning, and because monitoring is often inadequate for managers to learn by doing. In this study, we demonstrate a new approach to plan cost-effective river rehabilitation at large scales. The framework is based on the use of cost functions (relationship between costs of rehabilitation and the expected ecological benefit) to optimize the spatial allocation of rehabilitation actions needed to achieve given rehabilitation goals (in our case established by the Swiss water act). To demonstrate the approach with a simple example, we link costs of the three types of management actions that are most commonly used in Switzerland (culvert removal, widening of one riverside buffer and widening of both riversides) to the improvement in riparian zone quality. We then use Marxan, a widely applied conservation planning software, to identify priority areas to implement these rehabilitation measures in two neighbouring Swiss cantons (Aargau, AG and Zürich, ZH). The best rehabilitation plans identified for the two cantons met all the targets (i.e. restoring different types of morphological deficits with different actions) rehabilitating 80,786 m (AG) and 106,036 m (ZH) of the river network at a total cost of 106.1 Million CHF (AG) and 129.3 Million CH (ZH). The best rehabilitation plan for the canton of AG consisted of more and better connected sub-catchments that were generally less expensive, compared to its neighbouring canton. The framework developed in this study can be used to inform river managers how and where best to spend their rehabilitation budget for a given set of actions, ensures the cost-effective achievement of desired rehabilitation outcomes, and helps

  16. Large mass movements related to deglaciation effects in southern Peru (Cusco)

    Science.gov (United States)

    Giráldez, Claudia; Choquevilca, Walter; Fernández, Felipe; Frey, Holger; García, Javier; Haeberli, Wilfried; Huggel, Christian; Ludena, Sebastián; Rohrer, Mario; Suarez, Wilson

    2013-04-01

    The Andes of Peru are among the regions most severely affected by glacier and high-mountain hazards over the past 100 years. Large-scale disasters with thousands of people killed are on record, including ice/rock avalanches, debris flows, and glacier lake outburst floods (GLOF's). Effects of climate change such as glacier retreat and formation of glacier lakes have been one of the drivers of hazards in the past. Now, there is an increasing concern about the destabilizing effect that recent and further warming has a on perennially frozen bedrock and on steep glaciers in the steep flanks of high-mountain peaks, with potentially severe consequences to ice/rock avalanches, which may impact existing and new lakes, producing far-reaching outburst floods. Risks are also changing due to the socio-economic development in the Andean region and need to be considered using integrative approaches. Most research so far has concentrated on the Cordillera Blanca region where the most devastating disasters occurred during the 20th century. Very little is known about glacier and high-mountain hazards in the southern Peruvian Cordilleras of Cusco although some of the largest debris flows worldwide affected this region in recent years. In fact, very little is known about the nature, origin and exact dimensions of mass movements in this area, and long-term climatic records are neither available. Here we analyze these recent events in the Santa Teresa region based on field work, satellite images, available meteorological data, and numerical modeling of mass movements. These studies are part of a larger effort towards an integrative risk management. Most of the mass movements that caused disasters have their origin in glaciated catchments draining towards Santa Teresa with catchment sizes between about 100 and 300 km2, and glacier areas of 6 to 16 km2 per catchment. It is known that the enormous 1998 debris flow (ca. 25 million m3) that destroyed the Machu Picchu hydropower plant

  17. Specific effects of large asteroids on the orbits of terrestrial planets and the ASETEP database

    Science.gov (United States)

    Aljbaae, S.; Souchay, J.

    2012-04-01

    The necessity to take into account the perturbations caused by a large number of asteroids on the terrestrial planets is fundamental in the construction of modern numerical ephemeris on the solar system. Therefore about 300 of the largest asteroids were taken into account in recent ephemeris. Yet, the uncertainty on the mass values of the great majority of these asteroids constitutes a crucial and the main limit of accuracy of this ephemeris. Consequently, it is important to conduct a specific and detailed study of their individual effects especially on the terrestrial planets, which are far more affected than the giant planets. This was already done explicitly, but only for Mars and for only two orbital elements (a and λ). We aim both to confirm these previous results and to extend the study to all orbital elements and to the other three terrestrial planets (Mercury, Venus and the Earth), which are priori less affected by asteroid perturbations. Our methodology consists in several steps: we carried out precise computations of the orbital motions of the planets at short (100 y) and longer (1000 y) time scales with numerical integration. For that purpose we included the eight planets and also considered 43 of the most powerful asteroids. These were added to the numerical integrations once separately and once combined to determine their specific effects on the orbital elements of the Earth and the three other terrestrial planets. This procedure also allowed us to assess the spatial geocentric coordinates of the three terrestrial planets. We determined the signal that represents the effects by simple subtraction. Then we systematically analyzed this signal by FFT (fast Fourier transform), and finally we adjusted the signal with a set of sinusoidal components. We analyzed in detail the variations of the six orbital elements a, e, i, Ω, ˜ ω and λ of Mercury, Venus, the Earth-Moon barycenter (EMB) and Mars that are caused by the individual influences of the set of

  18. Assessing cost-effectiveness of specific LID practice designs in response to large storm events

    Science.gov (United States)

    Chui, Ting Fong May; Liu, Xin; Zhan, Wenting

    2016-02-01

    Low impact development (LID) practices have become more important in urban stormwater management worldwide. However, most research on design optimization focuses on relatively large scale, and there is very limited information or guideline regarding individual LID practice designs (i.e., optimal depth, width and length). The objective of this study is to identify the optimal design by assessing the hydrological performance and the cost-effectiveness of different designs of LID practices at a household or business scale, and to analyze the sensitivity of the hydrological performance and the cost of the optimal design to different model and design parameters. First, EPA SWMM, automatically controlled by MATLAB, is used to obtain the peak runoff of different designs of three specific LID practices (i.e., green roof, bioretention and porous pavement) under different design storms (i.e., 2 yr and 50 yr design storms of Hong Kong, China and Seattle, U.S.). Then, life cycle cost is estimated for the different designs, and the optimal design, defined as the design with the lowest cost and at least 20% peak runoff reduction, is identified. Finally, sensitivity of the optimal design to the different design parameters is examined. The optimal design of green roof tends to be larger in area but thinner, while the optimal designs of bioretention and porous pavement tend to be smaller in area. To handle larger storms, however, it is more effective to increase the green roof depth, and to increase the area of the bioretention and porous pavement. Porous pavement is the most cost-effective for peak flow reduction, followed by bioretention and then green roof. The cost-effectiveness, measured as the peak runoff reduction/thousand Dollars of LID practices in Hong Kong (e.g., 0.02 L/103 US s, 0.15 L/103 US s and 0.93 L/103 US s for green roof, bioretention and porous pavement for 2 yr storm) is lower than that in Seattle (e.g., 0.03 L/103 US s, 0.29 L/103 US s and 1.58 L/103 US s for

  19. Including Quantum Effects in the Dynamics of Complex (i.e., Large)Molecular Systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William H.

    2006-04-27

    The development in the 1950's and 60's of crossed molecular beam methods for studying chemical reactions at the single-collision molecular level stimulated the need and desire for theoretical methods to describe these and other dynamical processes in molecular systems. Chemical dynamics theory has made great strides in the ensuing decades, so that methods are now available for treating the quantum dynamics of small molecular systems essentially completely. For the large molecular systems that are of so much interest nowadays (e.g. chemical reactions in solution, in clusters, in nano-structures, in biological systems, etc.), however, the only generally available theoretical approach is classical molecular dynamics (MD) simulations. Much effort is currently being devoted to the development of approaches for describing the quantum dynamics of these complex systems. This paper reviews some of these approaches, especially the use of semiclassical approximations for adding quantum effects to classical MD simulations, also showing some new versions that should make these semiclassical approaches even more practical and accurate.

  20. NonAbelian Vortices, Large Winding Limits and Aharonov-Bohm Effects

    CERN Document Server

    Bolognesi, Stefano; Konishi, Kenichi

    2015-01-01

    Remarkable simplification arises from considering vortex equations in the large winding limit. This was recently used in [1] to display all sorts of vortex zeromodes, the orientational, translational, fermionic as well as semi-local, and to relate them to the apparently distinct phenomena of the Nielsen-Olesen-Ambjorn magnetic instabilities. Here we extend these analyses to more general types of BPS nonAbelian vortices, taking as a prototype a system with gauged U(1) x SU(N) x SU(N) symmetry where the VEV of charged scalar fields in the bifundamental representation breaks the symmetry to SU(N)_{l+r} . The presence of the massless SU(N)_{l+r} gauge fields in 4D bulk introduces all sorts of non-local, topological phenomena such as the nonAbelian Aharonov-Bohm effects, which in the theory with global SU(N)_r group (g_r=0) are washed away by the strongly fluctuating orientational zeromodes in the worldsheet. Physics changes qualitatively at the moment the right gauge coupling constant g_r is turned on.

  1. Tricarboxylate-based Gd(III) coordination polymers exhibiting large magnetocaloric effects.

    Science.gov (United States)

    Liu, Sui-Jun; Cao, Chen; Xie, Chen-Chao; Zheng, Teng-Fei; Tong, Xiao-Lan; Liao, Jin-Sheng; Chen, Jing-Lin; Wen, He-Rui; Chang, Ze; Bu, Xian-He

    2016-05-31

    Two Gd(III) coordination polymers with the formula [Gd(cit)(H2O)]∞ () and [Gd(nta)(H2O)2]∞ () (H4cit = citric acid, H3nta = nitrilotriacetic acid) have been successfully prepared under hydrothermal conditions. Complex exhibits a three-dimensional (3D) structure based on carboxylate-bridged layers, while complex is a double-layer structure containing eight-coordinated Gd(III). Magnetic investigations reveal that weak antiferromagnetic couplings between adjacent Gd(III) ions in both and with different Weiss values result in large cryogenic magnetocaloric effects. It is notable that the maximum entropy changes (-ΔS) of and reach 31.3 J kg(-1) K(-1) and 32.2 J kg(-1) K(-1) at 2 K for a moderate field change (ΔH = 3 T), and a remarkable -ΔS (41.5 J kg(-1) K(-1) for and 42.0 J kg(-1) K(-1) for ) could be obtained for ΔH = 7 T.

  2. Effects of Unstable Dark Matter on Large-Scale Structure and Constraints from Future Surveys

    CERN Document Server

    Wang, Mei-Yu

    2012-01-01

    In this paper we explore the effect of decaying dark matter (DDM) on large-scale structure and possible constraints from galaxy imaging surveys. DDM models have been studied, in part, as a way to address apparent discrepancies between the predictions of standard cold dark matter models and observations of galactic structure. Our study is aimed at developing independent constraints on these models. In such models, DDM decays into a less massive, stable dark matter (SDM) particle and a significantly lighter particle. The small mass splitting between the parent DDM and the daughter SDM provides the SDM with a recoil or "kick" velocity vk, inducing a free-streaming suppression of matter fluctuations. This suppression may be probed via weak lensing power spectra measured by a number of forthcoming imaging surveys that aim primarily to constrain dark energy. Using scales on which linear perturbation theory alone is valid (multipoles 90 km/s for lifetimes ~ 1-5 Gyr. To estimate more aggressive constraints, we model...

  3. Analytical approximation of the neutrino oscillation matter effects at large θ{sub 13}

    Energy Technology Data Exchange (ETDEWEB)

    Agarwalla, Sanjib Kumar [Institute of Physics, Sachivalaya Marg, Sainik School Post,Bhubaneswar 751005, Orissa (India); Kao, Yee [Department of Chemistry and Physics, Western Carolina University,Cullowhee, NC 28723 (United States); Takeuchi, Tatsu [Center for Neutrino Physics, Physics Department, Virginia Tech,Blacksburg, VA 24061 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo,Kashiwa-shi, Chiba-ken 277-8583 (Japan)

    2014-04-07

    We argue that the neutrino oscillation probabilities in matter are best understood by allowing the mixing angles and mass-squared differences in the standard parametrization to ‘run’ with the matter effect parameter a=2√2G{sub F}N{sub e}E, where N{sub e} is the electron density in matter and E is the neutrino energy. We present simple analytical approximations to these ‘running’ parameters. We show that for the moderately large value of θ{sub 13}, as discovered by the reactor experiments, the running of the mixing angle θ{sub 23} and the CP violating phase δ can be neglected. It simplifies the analysis of the resulting expressions for the oscillation probabilities considerably. Approaches which attempt to directly provide approximate analytical expressions for the oscillation probabilities in matter suffer in accuracy due to their reliance on expansion in θ{sub 13}, or in simplicity when higher order terms in θ{sub 13} are included. We demonstrate the accuracy of our method by comparing it to the exact numerical result, as well as the direct approximations of Cervera et al., Akhmedov et al., Asano and Minakata, and Freund. We also discuss the utility of our approach in figuring out the required baseline lengths and neutrino energies for the oscillation probabilities to exhibit certain desirable features.

  4. Analytical approximation of the neutrino oscillation matter effects at large θ 13

    Science.gov (United States)

    Agarwalla, Sanjib Kumar; Kao, Yee; Takeuchi, Tatsu

    2014-04-01

    We argue that the neutrino oscillation probabilities in matter are best understood by allowing the mixing angles and mass-squared differences in the standard parametrization to `run' with the matter effect parameter a = , where N e is the electron density in matter and E is the neutrino energy. We present simple analytical approximations to these `running' parameters. We show that for the moderately large value of θ 13, as discovered by the reactor experiments, the running of the mixing angle θ 23 and the CP violating phase δ can be neglected. It simplifies the analysis of the resulting expressions for the oscillation probabilities considerably. Approaches which attempt to directly provide approximate analytical expressions for the oscillation probabilities in matter suffer in accuracy due to their reliance on expansion in θ 13, or in simplicity when higher order terms in θ 13 are included. We demonstrate the accuracy of our method by comparing it to the exact numerical result, as well as the direct approximations of Cervera et al., Akhmedov et al., Asano and Minakata, and Freund. We also discuss the utility of our approach in figuring out the required baseline lengths and neutrino energies for the oscillation probabilities to exhibit certain desirable features.

  5. Principal shapes and squeezed limits in the effective field theory of large scale structure

    Science.gov (United States)

    Bertolini, Daniele; Solon, Mikhail P.

    2016-11-01

    We apply an orthogonalization procedure on the effective field theory of large scale structure (EFT of LSS) shapes, relevant for the angle-averaged bispectrum and non-Gaussian covariance of the matter power spectrum at one loop. Assuming natural-sized EFT parameters, this identifies a linear combination of EFT shapes—referred to as the principal shape—that gives the dominant contribution for the whole kinematic plane, with subdominant combinations suppressed by a few orders of magnitude. For the covariance, our orthogonal transformation is in excellent agreement with a principal component analysis applied to available data. Additionally we find that, for both observables, the coefficients of the principal shapes are well approximated by the EFT coefficients appearing in the squeezed limit, and are thus measurable from power spectrum response functions. Employing data from N-body simulations for the growth-only response, we measure the single EFT coefficient describing the angle-averaged bispectrum with 𝒪(10%) precision. These methods of shape orthogonalization and measurement of coefficients from response functions are valuable tools for developing the EFT of LSS framework, and can be applied to more general observables.

  6. Large magnetocaloric effect of GdNiAl{sub 2} compound

    Energy Technology Data Exchange (ETDEWEB)

    Dembele, S.N.; Ma, Z.; Shang, Y.F. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Fu, H., E-mail: fuhao@uestc.edu.cn [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Balfour, E.A. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Hadimani, R.L.; Jiles, D.C. [Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011 (United States); Ames Laboratory, US Department of Energy, Ames, IA 50011 (United States); Teng, B.H.; Luo, Y. [School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2015-10-01

    This paper presents the structure, magnetic properties, and magnetocaloric effect of the polycrystalline compound GdNiAl{sub 2}. Powder X-ray diffraction (XRD) measurement and Rietveld refinement revealed that GdNiAl{sub 2} alloy is CuMgAl{sub 2}-type phase structure with about 1 wt% GdNi{sub 2}Al{sub 3} secondary phase. Magnetic measurements suggest that the compound is ferromagnetic and undergoes a second-order phase transition near 28 K. The maximum value of magnetic entropy change reaches 16.0 J/kg K for an applied magnetic field change of 0–50 kOe and the relative cooling power was 6.4×10{sup 2} J/kg. It is a promising candidate as a magnetocaloric material working near liquid hydrogen temperature (~20 K) exhibiting large relative cooling power. - Highlights: • Preferred orientation with axis of [010] was found in the GdNiAl{sub 2} compound. • The ΔS{sub Mmax} and the RCP are 16.0 J/kg K and 640 J/kg, respectively, for ΔH=50 kOe. • Relative low rare earth content in GdNiAl{sub 2} comparing with other candidates.

  7. Effect of Age on the Hemostatic Function in Patients with Degenerative Diseases of the Large Joints

    Directory of Open Access Journals (Sweden)

    Igor L. Shlykov, PhD¹, ScD¹

    2013-06-01

    Full Text Available Background: Aging is associated with an increased hypercoagulable state. Degenerative diseases of the large joints are also accompanied by increased coagulation activity. We investigated the effect of age on the hemostatic function in patients with osteoarthritis. Material and Methods: The study included 192 patients with osteoarthritis admitted to the clinic for primary hip or knee arthroplasty. The patients were categorized into 5 age groups: the age group under 40 years, the 41–to-50 -year age group, the 51–to-60-year age group, the 61-to-70- year age group, and the age group over 70 years. The general blood clotting tests, platelet number, fibrinogen, antithrombin, protein C, TAT, D-dimer, vonWillebrand factor (vWF, PAI-1, ß-thromboglobulin were determined. Results: Among patients with osteoarthritis, the antithrombin III level significantly decreased by the age of 50; however, above the age of 60 there was a distinct decrease in platelet count, and over the age of 70 the activity of the extrinsic coagulation pathway and the plasminogen level dropped significantly. TAT and D-dimer levels were elevated in most of the patients. Conclusion: The decrease in platelet count coupled with the activity of the extrinsic coagulation pathway in elderly osteoarthritic patients may increase blood loss during total arthroplasty; also, the drop in the anticoagulant and fibrinolytic potential may play a negative role in strengthening the prothrombotic state during the postoperative period.

  8. The effects of regulation and litigation on a large for-profit nursing home chain.

    Science.gov (United States)

    Harrington, Charlene; Stockton, Julie; Hooper, Sarah

    2014-08-01

    This article examines the effects of state regulation and civil class action litigation on corporate compliance with nurse staffing and quality standards, corporate strategies to manage staffing and quality, and corporate financial status of a large for-profit nursing home chain. A historical case study was used to examine multiple public data sources, focusing on facilities in California from 2003 to 2011 during and after regulatory actions and litigation. The results showed that the state issued numerous deficiencies for violations of the nurse staffing and quality standards with minimal impact on quality compliance with state law. A class action jury trial found that the chain violated the state's minimum staffing standard on one-third of the total days during a six-year period and awarded a $677 million verdict. A court settlement and supervised injunction resulted in compliance with minimum staffing and some improvement in quality measures, but quality levels remained below the average California facilities. The litigation also had some negative financial impact on Skilled Healthcare Group's California facilities and parent company. Civil litigation had more impact on the chain than the regulatory oversight. Copyright © 2014 by Duke University Press.

  9. [Effects of large-area planting water hyacinth on macro-benthos community structure and biomass].

    Science.gov (United States)

    Liu, Guo-Feng; Liu, Hai-Qin; Zhang, Zhi-Yong; Zhang, Ying-Ying; Yan, Shao-Hua; Zhong, Ji-Cheng; Fan, Cheng-Xin

    2010-12-01

    The effects on macro-benthos and benthos environment of planting 200 hm2 water hyacinth (E. crassipens) in Zhushan Bay, Lake Taihu, were studied during 8-10 months consecutive surveys. Results indicated that average densities of mollusca (the main species were Bellamya aeruginosa) in far-planting, near-planting and planting area were 276.67, 371.11 and 440.00 ind/m2, respectively, and biomass were 373.15, 486.57 and 672.54 g/m2, respectively, showed that average density and biomass of planting area's were higher than those of others. However, the average density and biomass of Oligochaeta (the main species was Limodrilus hoffmeisteri) and Chironomidae in planting area were lower than that of outside planting area. The density and biomass of three dominant species of benthic animal increased quickly during 8-9 months, decreased quickly in October inside and outside water hyacinth planting area. The reason of this phenomenon could be possible that lots of cyanobacteria cells died and consumed dissolve oxygen in proceed decomposing. Algae cells released lots of phosphorus and nitrogen simultaneously, so macro-benthos died in this environment. The indexes of Shannon-Weaver and Simpson indicated that water environment was in moderate polluted state. On the basis of the survey results, the large-area and high-density planting water hyacinth haven't demonstrated a great impact on macrobenthos and benthos environment in short planting time (about 6 months planting time).

  10. Short- and medium-term atmospheric constituent effects of very large solar proton events

    Directory of Open Access Journals (Sweden)

    C. H. Jackman

    2008-02-01

    Full Text Available Solar eruptions sometimes produce protons, which impact the Earth's atmosphere. These solar proton events (SPEs generally last a few days and produce high energy particles that precipitate into the Earth's atmosphere. The protons cause ionization and dissociation processes that ultimately lead to an enhancement of odd-hydrogen and odd-nitrogen in the polar cap regions (>60° geomagnetic latitude. We have used the Whole Atmosphere Community Climate Model (WACCM3 to study the atmospheric impact of SPEs over the period 1963–2005. The very largest SPEs were found to be the most important and caused atmospheric effects that lasted several months after the events. We present the short- and medium-term (days to a few months atmospheric influence of the four largest SPEs in the past 45 years (August 1972; October 1989; July 2000; and October–November 2003 as computed by WACCM3 and observed by satellite instruments. Polar mesospheric NOx (NO+NO2 increased by over 50 ppbv and mesospheric ozone decreased by over 30% during these very large SPEs. Changes in HNO3, N2O5, ClONO2, HOCl, and ClO were indirectly caused by the very large SPEs in October–November 2003, were simulated by WACCM3, and previously measured by Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS. WACCM3 output was also represented by sampling with the MIPAS averaging kernel for a more valid comparison. Although qualitatively similar, there are discrepancies between the model and measurement with WACCM3 predicted HNO3 and ClONO2 enhancements being smaller than measured and N2O5 enhancements being larger than measured. The HOCl enhancements were fairly similar in amounts and temporal variation in WACCM3 and MIPAS. WACCM3 simulated ClO decreases below 50 km, whereas MIPAS mainly observed increases, a very perplexing difference. Upper stratospheric

  11. Backwater rise due to large wood accumulations: Effect of organic fine material

    Science.gov (United States)

    Schalko, Isabella; Schmocker, Lukas; Weitbrecht, Volker; Boes, Robert M.

    2017-04-01

    Large wood (logs with a diameter ≥ 0.1 m and a length ≥ 1.0 m) in rivers improves the diversity of morphological structures and flow conditions. It may be transported as single logs or in a bulk, forming a log jam or an accumulation at an obstruction. In a natural river, large wood (LW) accumulations create heterogeneous hydraulic gradients and increase the flow resistance. Besides various ecological benefits, LW accumulations may intensify flood hazard. During flood events, transported LW may accumulate at river infrastructures or is retained intentionally at LW retention structures. In both cases, the accumulation results in an upstream backwater rise and may lead to flooding of the nearby area. Consequently, engineering measures are necessary to mitigate LW accumulation risk. The number of investigations on the role of LW during flood events has substantially increased within the last decades. At the Laboratory of Hydraulics, Hydrology, and Glaciology (VAW) of ETH Zurich, several studies were conducted on LW accumulation probability and rate. Formulae for backwater rise calculation already exist, but the governing parameters are still contradictory. In addition, the effect of organic fine material (e.g. branches or leaves in a LW accumulation) was neglected in all previous studies. In this present study, a series of small-scale and close-to-prototype model tests were conducted to identify the governing parameters on backwater rise due to LW accumulations. During the experiments, the approach flow conditions (inflow flow depth and Froude number) and LW accumulation characteristics (accumulation length, compactness of LW accumulations, LW characteristics, and organic fine material) were varied systematically. The experimental results show that the backwater rise depends mainly on the compactness of LW accumulations, approach flow Froude number, and organic fine material. The study confirms the hypothesis that organic fine material changes the accumulation

  12. The effect of large milk meals on digestive physiology and behaviour in dairy calves.

    Science.gov (United States)

    Ellingsen, Kristian; Mejdell, Cecilie M; Ottesen, Nina; Larsen, Stig; Grøndahl, Ann Margaret

    2016-02-01

    It is commonly believed that young calves should not be fed more than about 2l of milk per meal. If calves are fed beyond this volume, it is said that the capacity of the abomasum may be exceeded and that milk could enter the rumen. This can disturb the microbial flora/fauna of the rumen and increase the risk of indigestion, diarrhoea and reduced growth. The aim of this study was to examine the effect of large milk meals on digestive physiology and behaviour in dairy calves. Six calves (19-23days of age at the beginning of the experiment) were fed 2l of warm whole milk by teat bottle three times per day, which was the recommended Norwegian feeding regime at the time. The calves were given free access to hay, concentrates and water. During three morning feeding sessions, each separated by 48h, all calves were offered larger meals. The offered amounts were calculated according to the within patient 3-level Response Surface Pathway (RSP) design. The milk given on the three test days contained a contrast medium (barium sulphate), and the animals were radiographed before, during and immediately after intake to reveal whether milk entered the rumen. Four out of the six calves drank more than 5l in one meal and the highest voluntary intake was 6.8l in one meal (13.2% of BW). Abdominal radiographs showed that the abomasum has a large ability for distension. Milk in the rumen was not observed in any of the calves, regardless of intake. The behaviour of the calves was observed for 2h after each test session. No behaviour indicating abdominal pain or discomfort was observed regardless of intake. The results indicate that when warm whole milk is administered from a teat bottle, farmers can increase the amount of milk they offer their calves beyond the traditionally recommended portion size without risk of milk entering the rumen. Hence, farmers who want to feed their calves more milk can do so by increasing meal sizes, and not necessarily by introducing an additional meal.

  13. Large-n approach to thermodynamic Casimir effects in slabs with free surfaces.

    Science.gov (United States)

    Diehl, H W; Grüneberg, Daniel; Hasenbusch, Martin; Hucht, Alfred; Rutkevich, Sergei B; Schmidt, Felix M

    2014-06-01

    The classical n-vector ϕ{4} model with O(n) symmetrical Hamiltonian H is considered in a ∞{2}×L slab geometry bounded by a pair of parallel free surface planes at separation L. Standard quadratic boundary terms implying Robin boundary conditions are included in H. The temperature-dependent scaling functions of the excess free energy and the thermodynamic Casimir force are computed in the large-n limit for temperatures T at, above, and below the bulk critical temperature T_{c}. Their n=∞ limits can be expressed exactly in terms of the spectrum and eigenfunctions of a self-consistent one-dimensional Schrödinger equation. This equation is solved by numerical means for two distinct discretized versions of the model: in the first ("model A"), only the coordinate z across the slab is discretized and the integrations over momenta conjugate to the lateral coordinates are regularized dimensionally; in the second ("model B"), a simple cubic lattice with periodic boundary conditions along the lateral directions is used. Renormalization-group ideas are invoked to show that, in addition to corrections to scaling ∝L{-1}, anomalous ones ∝L{-1}lnL should occur. They can be considerably decreased by taking an appropriate g→∞ (T_{c}→∞) limit of the ϕ{4} interaction constant g. Depending on the model A or B, they can be absorbed completely or to a large extent in an effective thickness L_{eff}=L+δL. Excellent data collapses and consistent high-precision results for both models are obtained. The approach to the low-temperature Goldstone values of the scaling functions is shown to involve logarithmic anomalies. The scaling functions exhibit all qualitative features seen in experiments on the thinning of wetting layers of {4}He and Monte Carlo simulations of XY models, including a pronounced minimum of the Casimir force below T_{c}. The results are in conformity with various analytically known exact properties of the scaling functions.

  14. Dynamic Response and Ground-Motion Effects of Building Clusters During Large Earthquakes

    Science.gov (United States)

    Isbiliroglu, Y. D.; Taborda, R.; Bielak, J.

    2012-12-01

    The objective of this study is to analyze the response of building clusters during earthquakes, the effect that they have on the ground motion, and how individual buildings interact with the surrounding soil and with each other. We conduct a series of large-scale, physics-based simulations that synthesize the earthquake source and the response of entire building inventories. The configuration of the clusters, defined by the total number of buildings, their number of stories, dynamic properties, and spatial distribution and separation, is varied for each simulation. In order to perform these simulations efficiently while recurrently modifying these characteristics without redoing the entire "source to building structure" simulation every time, we use the Domain Reduction Method (DRM). The DRM is a modular two-step finite-element methodology for modeling wave propagation problems in regions with localized features. It allows one to store and reuse the background motion excitation of subdomains without loss of information. Buildings are included in the second step of the DRM. Each building is represented by a block model composed of additional finite-elements in full contact with the ground. These models are adjusted to emulate the general geometric and dynamic properties of real buildings. We conduct our study in the greater Los Angeles basin, using the main shock of the 1994 Northridge earthquake for frequencies up to 5Hz. In the first step of the DRM we use a domain of 82 km x 82 km x 41 km. Then, for the second step, we use a smaller sub-domain of 5.12 km x 5.12 km x 1.28 km, with the buildings. The results suggest that site-city interaction effects are more prominent for building clusters in soft-soil areas. These effects consist in changes in the amplitude of the ground motion and dynamic response of the buildings. The simulations are done using Hercules, the parallel octree-based finite-element earthquake simulator developed by the Quake Group at Carnegie

  15. Investigation of the heat source(s) of the Surprise Valley Geothermal System, Northern California

    Science.gov (United States)

    Tanner, N.; Holt, C. D.; Hawkes, S.; McClain, J. S.; Safford, L.; Mink, L. L.; Rose, C.; Zierenberg, R. A.

    2016-12-01

    Concerns about environmental impacts and energy security have led to an increased interest in sustainable and renewable energy resources, including geothermal systems. It is essential to know the permeability structure and possible heat source(s) of a geothermal area in order to assess the capacity and extent of the potential resource. We have undertaken geophysical surveys at the Surprise Valley Hot Springs in Cedarville, California to characterize essential parameters related to a fault-controlled geothermal system. At present, the heat source(s) for the system are unknown. Igneous bodies in the area are likely too old to have retained enough heat to supply the system, so it is probable that fracture networks provide heat from some deeper or more distributed heat sources. However, the fracture system and permeability structure remain enigmatic. The goal of our research is to identify the pathways for fluid transport within the Surprise Valley geothermal system using a combination of geophysical methods including active seismic surveys and short- and long-period magnetotelluric (MT) surveys. We have collected 14 spreads, consisting of 24 geophones each, of active-source seismic data. We used a "Betsy Gun" source at 8 to 12 locations along each spread and have collected and analyzed about 2800 shot-receiver pairs. Seismic velocities reveal shallow lake sediments, as well as velocities consistent with porous basalts. The latter, with velocities of greater than 3.0 km/s, lie along strike with known hot springs and faulted and tilted basalt outcrops outside our field area. This suggests that basalts may provide a permeable pathway through impermeable lake deposits. We conducted short-period (10Hz-60kHz) MT measurements at 33 stations. Our short-period MT models indicate shallow resistive blocks (>100Ωm) with a thin cover of more conductive sediments ( 10Ωm) at the surface. Hot springs are located in gaps between resistive blocks and are connected to deeper low

  16. Effect of plumes on measuring the large scale circulation in turbulent Rayleigh-Bénard convection

    NARCIS (Netherlands)

    Stevens, Richard Johannes Antonius Maria; Clercx, H.J.H.; Lohse, Detlef

    2011-01-01

    We studied the properties of the large-scale circulation (LSC) in turbulent Rayleigh-Bénard (RB) convection by using results from direct numerical simulations in which we placed a large number of numerical probes close to the sidewall. The LSC orientation is determined by either a cosine or a

  17. Possible future effects of large-scale algae cultivation for biofuels on coastal eutrophication in Europe

    NARCIS (Netherlands)

    Blaas, H.; Kroeze, C.

    2014-01-01

    Biodiesel is increasingly considered as an alternative for fossil diesel. Biodiesel can be produced from rapeseed, palm, sunflower, soybean and algae. In this study, the consequences of large-scale production of biodiesel from micro-algae for eutrophication in four large European seas are analysed.

  18. Possible future effects of large-scale algae cultivation for biofuels on coastal eutrophication in Europe

    NARCIS (Netherlands)

    Blaas, H.; Kroeze, C.

    2014-01-01

    Biodiesel is increasingly considered as an alternative for fossil diesel. Biodiesel can be produced from rapeseed, palm, sunflower, soybean and algae. In this study, the consequences of large-scale production of biodiesel from micro-algae for eutrophication in four large European seas are analysed.

  19. Effectiveness of buffered propionic-acid preservatives for large hay packages

    Science.gov (United States)

    Most hay producers realize that hays packaged in large-round or large-square bales are particularly sensitive to spontaneous heating, dry matter losses, and negative changes in forage quality. During the last two decades, this has become an important dilemma for hay producers because the cost and av...

  20. Unscheduled load flow effect due to large variation in the distributed generation in a subtransmission network

    Science.gov (United States)

    Islam, Mujahidul

    A sustainable energy delivery infrastructure implies the safe and reliable accommodation of large scale penetration of renewable sources in the power grid. In this dissertation it is assumed there will be no significant change in the power transmission and distribution structure currently in place; except in the operating strategy and regulatory policy. That is to say, with the same old structure, the path towards unveiling a high penetration of switching power converters in the power system will be challenging. Some of the dimensions of this challenge are power quality degradation, frequent false trips due to power system imbalance, and losses due to a large neutral current. The ultimate result is the reduced life of many power distribution components - transformers, switches and sophisticated loads. Numerous ancillary services are being developed and offered by the utility operators to mitigate these problems. These services will likely raise the system's operational cost, not only from the utility operators' end, but also reflected on the Independent System Operators and by the Regional Transmission Operators (RTO) due to an unforeseen backlash of frequent variation in the load-side generation or distributed generation. The North American transmission grid is an interconnected system similar to a large electrical circuit. This circuit was not planned but designed over 100 years. The natural laws of physics govern the power flow among loads and generators except where control mechanisms are installed. The control mechanism has not matured enough to withstand the high penetration of variable generators at uncontrolled distribution ends. Unlike a radial distribution system, mesh or loop networks can alleviate complex channels for real and reactive power flow. Significant variation in real power injection and absorption on the distribution side can emerge as a bias signal on the routing reactive power in some physical links or channels that are not distinguishable

  1. The plant host can affect the encapsidation of brome mosaic virus (BMV) RNA: BMV virions are surprisingly heterogeneous.

    Science.gov (United States)

    Ni, Peng; Vaughan, Robert C; Tragesser, Brady; Hoover, Haley; Kao, C Cheng

    2014-03-01

    Brome mosaic virus (BMV) packages its genomic and subgenomic RNAs into three separate viral particles. BMV purified from barley, wheat, and tobacco have distinct relative abundances of the encapsidated RNAs. We seek to identify the basis for the host-dependent differences in viral RNA encapsidation. Sequencing of the viral RNAs revealed recombination events in the 3' untranslated region of RNA1 of BMV purified from barley and wheat, but not from tobacco. However, the relative amounts of the BMV RNAs that accumulated in barley and wheat are similar and RNA accumulation is not sufficient to account for the difference in RNA encapsidation. Virions purified from barley and wheat were found to differ in their isoelectric points, resistance to proteolysis, and contacts between the capsid residues and the RNA. Mass spectrometric analyses revealed that virions from the three hosts had different post-translational modifications that should impact the physiochemical properties of the virions. Another major source of variation in RNA encapsidation was due to the purification of BMV particles to homogeneity. Highly enriched BMV present in lysates had a surprising range of sizes, buoyant densities, and distinct relative amounts of encapsidated RNAs. These results show that the encapsidated BMV RNAs reflect a combination of host effects on the physiochemical properties of the viral capsids and the enrichment of a subset of virions. The previously unexpected heterogeneity in BMV should influence the timing of the infection and also the host innate immune responses.

  2. A computational study of ethylene–air sooting flames: Effects of large polycyclic aromatic hydrocarbons

    KAUST Repository

    Selvaraj, Prabhu

    2015-11-05

    An updated reduced gas-phase kinetic mechanism was developed and integrated with aerosol models to predict soot formation characteristics in ethylene nonpremixed and premixed flames. A primary objective is to investigate the sensitivity of the soot formation to various chemical pathways for large polycyclic aromatic hydrocarbons (PAH). The gas-phase chemical mechanism adopted the KAUST-Aramco PAH Mech 1.0, which utilized the AramcoMech 1.3 for gas-phase reactions validated for up to C2 fuels. In addition, PAH species up to coronene (C24H12 or A7) were included to describe the detailed formation pathways of soot precursors. In this study, the detailed chemical mechanism was reduced from 397 to 99 species using directed relation graph with expert knowledge (DRG-X) and sensitivity analysis. The method of moments with interpolative closure (MOMIC) was employed for the soot aerosol model. Counterflow nonpremixed flames at low strain rate sooting conditions were considered, for which the sensitivity of soot formation characteristics to different nucleation pathways were investigated. Premixed flame experiment data at different equivalence ratios were also used for validation. The findings show that higher PAH concentrations result in a higher soot nucleation rate, and that the total soot volume and average size of the particles are predicted in good agreement with experimental results. Subsequently, the effects of different pathways, with respect to pyrene- or coronene-based nucleation models, on the net soot formation rate were analyzed. It was found that the nucleation processes (i.e., soot inception) are sensitive to the choice of PAH precursors, and consideration of higher PAH species beyond pyrene is critical for accurate prediction of the overall soot formation.

  3. Effects of cold front passage on turbulent fluxes over a large inland water

    Science.gov (United States)

    Zhang, Q.; Liu, H.

    2011-12-01

    Turbulent fluxes of sensible and latent heat over a large inland water in southern USA were measured using the eddy covariance method through the year of 2008. In addition, net radiation, air temperatures and relative humidity, and water temperature in different depths were also measured. The specific objective of this study is to examine effects of a cold front passage on the surface energy fluxes. For the typical cold front event selected from April 11 to 14, air temperature decreased by 16°C, while surface temperature only dropped 6°C. Atmospheric vapor pressure decreased by 1.6 kPa, while that in the water-air interface dropped 0.7 kPa. The behavior difference in the water-air interface was caused by the passage of cold, dry air masses immediately behind the cold front. During the cold front event, sensible heat and latent heat flux increased by 171 W m-2 and 284 W m-2, respectively. Linear aggression analysis showed that the sensible heat flux was proportional to the product of wind speed and the temperature gradient of water-air interface, with a correlation coefficient of 0.95. Latent heat flux was proportional to the product of wind speed and vapor pressure difference between the water surface and overlaying atmosphere, with a correlation coefficient of 0.81. Also, the correlations between both fluxes and the wind speed were weak. This result indicated that the strong wind associated with the cold front event contributed to the turbulent mixing, which indirectly enhanced surface energy exchange between the water surface and the atmosphere. The relationship between the water heat storage energy and turbulent fluxes was also examined.

  4. Large-scale segmentation errors in optical gratings and their unique effect onto optical scattering spectra

    Science.gov (United States)

    Heusinger, Martin; Flügel-Paul, Thomas; Zeitner, Uwe-Detlef

    2016-08-01

    In this paper, we analyze the influence of large-scale segmentation errors in the morphology of high-performance optical gratings. It is thus assumed that the optical grating under consideration (typical lateral extends S are 10-1000 mm) can be spatially decomposed into a great many but unique sub-segments (≪ S; typical extends are 10-100 μm). Any violation of the perfect periodicity will result in the generation of stray light, especially Rowland ghosts, which radiate into a small angular region around the grating's diffraction orders. In this paper, we focus on three different kinds of segmentation errors. On the one hand, there are statistic as well as deterministic alignment errors between otherwise perfect sub-segments. On the other hand, we analyze the effect of chirping of geometrical parameters, i.e., the groove width, within every sub-segment. Most importantly, we find that the particular type of imperfection results in a unique characteristic of the according stray light spectrum which thus acts as a fingerprint. We come to this conclusion on three different ways. First, we rely on a simple theoretical model that is based on scalar diffraction theory. Second, we have performed rigorous numerical simulations for a high aspect ratio purely dielectric spectrometer grating (period = {667} nm). Third, the very same grating was then fabricated by e-beam lithography and its stray light spectrum was measured with a purposely designed optical setup. Eventually, all different routes to analyze the problem turn out to be in very good agreement, and we are confident that stray light measurements can be used as an important tool in the detection of fabrication imperfections.

  5. The composite regulatory basis of the large X-effect in mouse speciation.

    Science.gov (United States)

    Larson, Erica L; Keeble, Sara; Vanderpool, Dan; Dean, Matthew D; Good, Jeffrey M

    2016-12-20

    The disruption of meiotic sex chromosome inactivation (MSCI) has been proposed to be a major developmental mechanism underlying the rapid evolution of hybrid male sterility. We tested this idea by analyzing cell-specific gene expression across spermatogenesis in two lineages of house mice and their sterile and fertile reciprocal hybrids. We found pervasive disruption of sex chromosome gene expression in sterile hybrids at every stage of spermatogenesis. Failure of MSCI was developmentally preceded by increased silencing of autosomal genes, supporting the hypothesis that divergence at the hybrid incompatibility gene, Prdm9, results in increased rates of autosomal asynapsis which in turn triggers widespread silencing of unsynapsed chromatin. We also detected opposite patterns of postmeiotic overexpression or hyper-repression of the sex chromosomes in reciprocal hybrids, supporting the hypothesis that genomic conflict has driven functional divergence that leads to deleterious X-Y dosage imbalances in hybrids. Our developmental timeline also exposed more subtle patterns of mitotic misregulation on the X chromosome, a previously undocumented stage of spermatogenic disruption in this cross. These results indicate that multiple hybrid incompatibilities have converged on a common regulatory phenotype, the disrupted expression of the sex chromosomes during spermatogenesis. Collectively, these data reveal a composite regulatory basis to hybrid male sterility in mice that helps resolve the mechanistic underpinnings of the well-documented large X-effect in mice speciation. We propose that the inherent sensitivity of spermatogenesis to X-linked regulatory disruption has the potential to be a major driver of reproductive isolation in species with chromosomal sex determination.

  6. Surprising results on phylogenetic tree building methods based on molecular sequences

    Directory of Open Access Journals (Sweden)

    Gonnet Gaston H

    2012-06-01

    Full Text Available Abstract Background We analyze phylogenetic tree building methods from molecular sequences (PTMS. These are methods which base their construction solely on sequences, coding DNA or amino acids. Results Our first result is a statistically significant evaluation of 176 PTMSs done by comparing trees derived from 193138 orthologous groups of proteins using a new measure of quality between trees. This new measure, called the Intra measure, is very consistent between different groups of species and strong in the sense that it separates the methods with high confidence. The second result is the comparison of the trees against trees derived from accepted taxonomies, the Taxon measure. We consider the NCBI taxonomic classification and their derived topologies as the most accepted biological consensus on phylogenies, which are also available in electronic form. The correlation between the two measures is remarkably high, which supports both measures simultaneously. Conclusions The big surprise of the evaluation is that the maximum likelihood methods do not score well, minimal evolution distance methods over MSA-induced alignments score consistently better. This comparison also allows us to rank different components of the tree building methods, like MSAs, substitution matrices, ML tree builders, distance methods, etc. It is also clear that there is a difference between Metazoa and the rest, which points out to evolution leaving different molecular traces. We also think that these measures of quality of trees will motivate the design of new PTMSs as it is now easier to evaluate them with certainty.

  7. IP Eri: A surprising long-period binary system hosting a He white dwarf

    CERN Document Server

    Merle, T; Masseron, T; Van Eck, S; Siess, L; Van Winckel, H

    2014-01-01

    We determine the orbital elements for the K0 IV + white dwarf (WD) system IP Eri, which appears to have a surprisingly long period of 1071 d and a significant eccentricity of 0.25. Previous spectroscopic analyses of the WD, based on a distance of 101 pc inferred from its Hipparcos parallax, yielded a mass of only 0.43 M$_\\odot$, implying it to be a helium-core WD. The orbital properties of IP Eri are similar to those of the newly discovered long-period subdwarf B star (sdB) binaries, which involve stars with He-burning cores surrounded by extremely thin H envelopes, and are therefore close relatives to He WDs. We performed a spectroscopic analysis of high-resolution spectra from the HERMES/Mercator spectrograph and concluded that the atmospheric parameters of the K0 component are $T_{\\rm eff} = 4960$ K, $\\log{g} = 3.3$, [Fe/H] = 0.09 and $\\xi = 1.5$ km/s. The detailed abundance analysis focuses on C, N, O abundances, carbon isotopic ratio, light (Na, Mg, Al, Si, Ca, Ti) and s-process (Sr, Y, Zr, Ba, La, Ce, N...

  8. Surprising dissimilarities in a newly formed pair of 'identical twin' stars.

    Science.gov (United States)

    Stassun, Keivan G; Mathieu, Robert D; Cargile, Phillip A; Aarnio, Alicia N; Stempels, Eric; Geller, Aaron

    2008-06-19

    The mass and chemical composition of a star are the primary determinants of its basic physical properties-radius, temperature and luminosity-and how those properties evolve with time. Accordingly, two stars born at the same time, from the same natal material and with the same mass, are 'identical twins,' and as such might be expected to possess identical physical attributes. We have discovered in the Orion nebula a pair of stellar twins in a newborn binary star system. Each star in the binary has a mass of 0.41 +/- 0.01 solar masses, identical to within 2 per cent. Here we report that these twin stars have surface temperatures differing by approximately 300 K ( approximately 10 per cent) and luminosities differing by approximately 50 per cent, both at high confidence level. Preliminary results indicate that the stars' radii also differ, by 5-10 per cent. These surprising dissimilarities suggest that one of the twins may have been delayed by several hundred thousand years in its formation relative to its sibling. Such a delay could only have been detected in a very young, definitively equal-mass binary system. Our findings reveal cosmic limits on the age synchronization of young binary stars, often used as tests for the age calibrations of star-formation models.

  9. The Surprising Composition of the Salivary Proteome of Preterm Human Newborn

    Science.gov (United States)

    Castagnola, Massimo; Inzitari, Rosanna; Fanali, Chiara; Iavarone, Federica; Vitali, Alberto; Desiderio, Claudia; Vento, Giovanni; Tirone, Chiara; Romagnoli, Costantino; Cabras, Tiziana; Manconi, Barbara; Teresa Sanna, Maria; Boi, Roberto; Pisano, Elisabetta; Olianas, Alessandra; Pellegrini, Mariagiuseppina; Nemolato, Sonia; Wilhelm Heizmann, Claus; Faa, Gavino; Messana, Irene

    2011-01-01

    Saliva is a body fluid of a unique composition devoted to protect the mouth cavity and the digestive tract. Our high performance liquid chromatography (HPLC)-electrospray ionization-MS analysis of the acidic soluble fraction of saliva from preterm human newborn surprisingly revealed more than 40 protein masses often undetected in adult saliva. We were able to identify the following proteins: stefin A and stefin B, S100A7 (two isoforms), S100A8, S100A9 (four isoforms), S100A11, S100A12, small proline-rich protein 3 (two isoforms), lysozyme C, thymosins β4 and β10, antileukoproteinase, histone H1c, and α and γ globins. The average mass value reported in international data banks was often incongruent with our experimental results mostly because of post-translational modifications of the proteins, e.g. acetylation of the N-terminal residue. A quantitative label-free MS analysis showed protein levels altered in relation to the postconceptional age and suggested coordinate and hierarchical functions for these proteins during development. In summary, this study shows for the first time that analysis of these proteins in saliva of preterm newborns might represent a noninvasive way to obtain precious information of the molecular mechanisms of development of human fetal oral structures. PMID:20943598

  10. Polar F-layer model-observation comparisons: a neutral wind surprise

    Directory of Open Access Journals (Sweden)

    J. J. Sojka

    2005-01-01

    Full Text Available The existence of a month-long continuous database of incoherent scatter radar observations of the ionosphere from the EISCAT Savlbard Radar (ESR at Longyearbyen, Norway, provides an unprecedented opportunity for model/data comparisons. Physics-based ionospheric models, such as the Utah State University Time Dependent Ionospheric Model (TDIM, are usually only compared with observations over restricted one or two day events or against climatological averages. In this study, using the ESR observations, the daily weather, day-to-day variability, and month-long climatology can be simultaneously addressed to identify modeling shortcomings and successes. Since for this study the TDIM is driven by climatological representations of the magnetospheric convection, auroral oval, neutral atmosphere, and neutral winds, whose inputs are solar and geomagnetic indices, it is not surprising that the daily weather cannot be reproduced. What is unexpected is that the horizontal neutral wind has come to the forefront as a decisive model input parameter in matching the diurnal morphology of density structuring seen in the observations.

  11. The effects of large organic debris on sediment processes and stream morphology in Vermont

    Science.gov (United States)

    Thompson, Douglas M.

    1995-02-01

    Research conducted on a small third-order stream in the Green Mountains of Vermont suggests that large organic debris (LOD) has an important influence on areal sorting and storage of sediment, spacing of pool-riffle sequences, and channel geometry. Large organic debris forms local base-levels that trap over 26 cubic meters of sediment and cause over 14 percent of the vertical drop along a 412 meter study reach on Tiger Brook, Vermont. The local base-levels created by large organic debris accumulations are the most important control on sediment storage between large bedrock knickpoints along the study reach, focusing fine-grained sediment deposition in areas stable at low and moderate discharges. The micro-steps created by these LOD local base-levels dominate gradient and sediment storage at short time-scales between the slowly evolving large bedrock macrosteps. The relation that exists among the volumes of standing timber adjacent to the channel, LOD and sediment stored behind LOD seems to indicate that large organic debris causes a negative feedback-type mechanism where channel degradation leads to increased standing timber recruitment and large organic debris sediment-storage sites.

  12. Large-scale assessment of flood risk and the effects of mitigation measures along the Elbe River

    NARCIS (Netherlands)

    Kok, de J.L.; Grossmann, M.

    2010-01-01

    The downstream effects of flood risk mitigation measures and the necessity to develop flood risk management strategies that are effective on a basin scale call for a flood risk assessment methodology that can be applied at the scale of a large river. We present an example of a rapid flood risk asses

  13. Large-scale surface dielectric barrier discharge type reactor : effect of the electric wind on the conversion effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Jolibois, J. [Univ. de Poitiers, Poitiers (France). Centre national de la recherche scientifique, Laboratoire de Catalyse en Chimie Organique; Poitiers Univ., Futuroscope Chasseneuil Cedex (France). Centre national de la recherche scientifique, Inst. Pprime; Zouzou, N.; Moreau, E. [Poitiers Univ., Futuroscope Chasseneuil Cedex (France). Centre national de la recherche scientifique, Inst. Pprime; Tatibouet, J.M. [Univ. de Poitiers, Poitiers (France). Centre national de la recherche scientifique, Laboratoire de Catalyse en Chimie Organique

    2010-07-01

    Non-thermal plasma (NTP) techniques offer an innovative approach for air pollution reduction. Most studies in NTP techniques use volumetric discharge reactors with small dimensions and low flow rates at laboratory scale. The objective of this study was to develop an air pollution control plasma reactor at industrial scale with surface discharge. Propene (C{sub 3}H{sub 6}) was oxidized at high flow rates in a large-scale plasma reactor based on surface dielectric barrier discharge (DBD). Three different configurations of surface discharges were tested with 15 ppm of C{sub 3}H{sub 6} in air at ambient temperature for a flow rate of 50 m{sup 3} per hour. The properties of these different surface discharges were analyzed using chemical measurements and 3 component particle image velocimetry (PIV) measurements. PIV measurements were used characterize the effect of the electric wind on the polluted gas airflow inside the reactor and to explain the differences of effectiveness of the three tested plasma generators. For the three plasma generators, a propene oxidation of up to 45 percent was obtained at one J per liter. The electric wind produced by the surface discharge resulted in the formation of vortices inside the plasma reactor. This electric wind can increase gas mixing inside the plasma reactor and therefore plays a key role in conversion efficiency. It was concluded that the electric wind produced by surface discharges enables the use of this type of discharge for VOC elimination at high flow rate, with the same effectiveness of volumetric discharges. 5 refs., 10 figs.

  14. Large deformation properties of short doughs: Effect of sucrose in relation to mixing time

    NARCIS (Netherlands)

    Baltsavias, A.; Jurgens, A.; Vliet, T. van

    1999-01-01

    Large deformation rheological properties of short doughs of various composition prepared under various mixing times were determined in uniaxial compression. Sucrose-syrup doughs exhibited prominent yielding and flow behaviour. Their apparent biaxial extensional viscosity decreased with increasing su

  15. The large-X effect in plants: increased species divergence and reduced gene flow on the Silene X-chromosome.

    Science.gov (United States)

    Hu, Xin-Sheng; Filatov, Dmitry A

    2016-06-01

    The disproportionately large involvement of the X-chromosome in the isolation of closely related species (the large-X effect) has been reported for many animals, where X-linked genes are mostly hemizygous in the heterogametic sex. The expression of deleterious recessive mutations is thought to drive the frequent involvement of the X-chromosome in hybrid sterility, as well as to reduce interspecific gene flow for X-linked genes. Here, we evaluate the role of the X-chromosome in the speciation of two closely related plant species - the white and red campions (Silene latifolia and S. dioica) - that hybridize widely across Europe. The two species evolved separate sexes and sex chromosomes relatively recently (~10(7)  years), and unlike most animal species, most X-linked genes have intact Y-linked homologs. We demonstrate that the X-linked genes show a very small and insignificant amount of interspecific gene flow, while gene flow involving autosomal loci is significant and sufficient to homogenize the gene pools of the two species. These findings are consistent with the hypothesis of the large-X effect in Silene and comprise the first report of this effect in plants. Nonhemizygosity of many X-linked genes in Silene males indicates that exposure of recessive mutations to selection may not be essential for the occurrence of the large-X effect. Several possible causes of the large-X effect in Silene are discussed.

  16. Mitigating Aviation Communication and Satellite Orbit Operations Surprises from Adverse Space Weather

    Science.gov (United States)

    Tobiska, W. Kent

    2008-01-01

    Adverse space weather affects operational activities in aviation and satellite systems. For example, large solar flares create highly variable enhanced neutral atmosphere and ionosphere electron density regions. These regions impact aviation communication frequencies as well as precision orbit determination. The natural space environment, with its dynamic space weather variability, is additionally changed by human activity. The increase in orbital debris in low Earth orbit (LEO), combined with lower atmosphere CO2 that rises into the lower thermosphere and causes increased cooling that results in increased debris lifetime, adds to the environmental hazards of navigating in near-Earth space. This is at a time when commercial space endeavors are posed to begin more missions to LEO during the rise of the solar activity cycle toward the next maximum (2012). For satellite and aviation operators, adverse space weather results in greater expenses for orbit management, more communication outages or aviation and ground-based high frequency radio used, and an inability to effectively plan missions or service customers with space-based communication, imagery, and data transferal during time-critical activities. Examples of some revenue-impacting conditions and solutions for mitigating adverse space weather are offered.

  17. Large variations in the onset of rippling in concentric nanotubes

    Science.gov (United States)

    Jackman, H.; Krakhmalev, P.; Svensson, K.

    2014-01-01

    We present a detailed experimental study of the onset of rippling in highly crystalline carbon nanotubes. Modeling has shown that there should be a material constant, called the critical length, describing the dependence of the critical strain on the nanotube outer radius. Surprisingly, we have found very large variations, by a factor of three, in the critical length. We attribute this to a supporting effect from the inner walls in multiwalled concentric nanotubes. We provide an analytical expression for the maximum deflection prior to rippling, which is an important design consideration in nanoelectromechanical systems utilizing nanotubes.

  18. Geophysical Investigation of the Lake City Fault Zone, Surprise Valley, California, and Implications for Geothermal Circulation

    Science.gov (United States)

    McPhee, D. K.; Glen, J. M.; Egger, A. E.; Chuchel, B. A.

    2009-12-01

    New audiomagnetotelluric (AMT), gravity, and magnetic data were collected in Surprise Valley, northwestern Basin and Range, in order to investigate the role that the Lake City Fault Zone (LCFZ) may play in controlling geothermal circulation in the area. Surprise Valley hosts an extensional geothermal system currently undergoing exploration for development on several scales. The focus of much of that exploration has been the LCFZ, a set of NW-SE-trending structures that has been suggested on the basis of (1) low-relief scarps in the NW portion of the zone, (2) dissolved mineral-rich groundwater chemistry along its length, and (3) parallelism with a strong regional fabric that includes the Brothers Fault Zone. The LCFZ extends across the valley at a topographic high, intersecting the N-S-trending basin-bounding faults where major hot springs occur. This relationship suggests that the LCFZ may be a zone of permeability for flow of hydrothermal fluids. Previous potential field data indicate that there is no vertical offset along this fault zone, and little signature at all in either the gravity or magnetic data; along with the lack of surface expression along most of its length, the subsurface geometry of the LCFZ and its influence on geothermal fluid circulation remains enigmatic. The LCFZ therefore provides an ideal opportunity to utilize AMT data, which measures subsurface resistivity and therefore - unlike potential field data - is highly sensitive to the presence of saline fluids. AMT data and additional gravity and magnetic data were collected in 2009 along 3 profiles perpendicular to the LCFZ in order to define the subsurface geometry and conductivity of the fault zone down to depths of ~ 500 m. AMT soundings were collected using the Geometrics Stratagem EH4 system, a four channel, natural and controlled-source tensor system recording in the range of 10 to 92,000 Hz. To augment the low signal in the natural field a transmitter of two horizontal-magnetic dipoles

  19. Lymphocytic alveolitis: A surprising index of poor prognosis in patients with primary Sjogren's syndrome.

    Science.gov (United States)

    Dalavanga, Y A; Voulgari, P V; Georgiadis, A N; Leontaridi, C; Katsenos, S; Vassiliou, M; Drosos, A A; Constantopoulos, S H

    2006-07-01

    Twelve years ago we reported that lymphocytic alveolitis [or bronchoalveolar lavage (BAL) lymphocytosis] correlates with clinical pulmonary involvement in primary Sjogren's syndrome (pSS). Our thesis was based on subtle clinical and functional evidence of interstitial lung disease (ILD) in pSS patients with "high lymphocytic alveolitis" (>15% lymphocytes in BAL). This report is a follow-up study of these patients. Basic clinical and functional re-evaluation of the 22 patients with pSS, studied in 1991, emphasized the differences between those with alveolitis and those without alveolitis. There was no significant functional decline. There were, however, two statistically significant differences between the two groups: (1) only patients with BAL lymphocytosis had to be treated with steroids (5/12 vs. 0/10, P < 0.05) and (2) only patients with BAL lymphocytosis had died in the mean time (6/12 vs. 0/10, P < 0.01). The causes of death were various. On only two occasions were they related to respiratory infections while there were no deaths from respiratory failure secondary to ILD. BAL lymphocytosis appears to be a surprisingly serious index of dismal prognosis in patients with pSS. We offer no unifying pathophysiologic mechanism for it and, therefore, all we propose is that BAL is performed early, in as many patients with pSS as possible. These patients should then be followed up systematically, in order to evaluate if BAL lymphocytosis has any pathophysiologic importance in the development of clinically serious pSS, which is serious enough to lead to death.

  20. A post-genomic surprise. The molecular reinscription of race in science, law and medicine.

    Science.gov (United States)

    Duster, Troy

    2015-03-01

    The completion of the first draft of the Human Genome Map in 2000 was widely heralded as the promise and future of genetics-based medicines and therapies - so much so that pundits began referring to the new century as 'The Century of Genetics'. Moreover, definitive assertions about the overwhelming similarities of all humans' DNA (99.9 per cent) by the leaders of the Human Genome Project were trumpeted as the end of racial thinking about racial taxonomies of human genetic differences. But the first decade of the new century brought unwelcomed surprises. First, gene therapies turned out to be far more complicated than any had anticipated - and instead the pharmaceutical industry turned to a focus on drugs that might be 'related' to population differences based upon genetic markers. While the language of 'personalized medicine' dominated this frame, research on racially and ethnically designated populations differential responsiveness to drugs dominated the empirical work in the field. Ancestry testing and 'admixture research' would play an important role in a new kind of molecular reification of racial categories. Moreover, the capacity of the super-computer to map differences reverberated into personal identification that would affect both the criminal justice system and forensic science, and generate new levels of concern about personal privacy. Social scientists in general, and sociologists in particular, have been caught short by these developments - relying mainly on assertions that racial categories are socially constructed, regionally and historically contingent, and politically arbitrary. While these assertions are true, the imprimatur of scientific legitimacy has shifted the burden, since now 'admixture research' can claim that its results get at the 'reality' of human differentiation, not the admittedly flawed social constructions of racial categories. Yet what was missing from this framing of the problem: 'admixture research' is itself based upon socially

  1. Explanatory models of health and disease: surprises from within the former Soviet Union

    Directory of Open Access Journals (Sweden)

    Tatiana I Andreeva

    2013-06-01

    Full Text Available Extract The review of anthropological theories as applied to public health by Jennifer J. Carroll (Carroll, 2013 published in this issue of TCPHEE made me recollect my first and most surprising discoveries of how differently same things can be understood in different parts of the world. Probably less unexpectedly, these impressions concern substance abuse and addiction behaviors, similarly to many examples deployed by Jennifer J. Carroll. The first of these events happened soon after the break-up of the Soviet Union when some of the most active people from the West rushed to discover what was going on behind the opening iron curtain. A director of an addiction clinic, who had just come into contact with a Dutch counterpart, invited me to join the collaboration and the innovation process he planned to launch. Being a participant of the exchange program started within this collaboration, I had an opportunity to discover how addictive behaviors were understood and explained in books (English, 1961; Kooyman, 1992; Viorst, 1986 recommended by the colleagues in the Netherlands and, as I could observe with my own eyes, addressed in everyday practice. This was a jaw-dropping contrast to what I learnt at the soviet medical university and some post-graduate courses, where all the diseases related to alcohol, tobacco, or drug abuse were considered predominantly a result of the substance intake. In the Soviet discourse, the intake itself was understood as 'willful and deliberate' or immoral behavior which, in some cases, was to be rectified in prison-like treatment facilities. In the West, quite oppositely, substance abuse was seen rather as a consequence of a constellation of life-course adversities thoroughly considered by developmental psychology. This approach was obviously deeply ingrained in how practitioners diagnosed and treated their patients.

  2. The genome of Pelobacter carbinolicus reveals surprising metabolic capabilities and physiological features

    Directory of Open Access Journals (Sweden)

    Aklujkar Muktak

    2012-12-01

    Full Text Available Abstract Background The bacterium Pelobacter carbinolicus is able to grow by fermentation, syntrophic hydrogen/formate transfer, or electron transfer to sulfur from short-chain alcohols, hydrogen or formate; it does not oxidize acetate and is not known to ferment any sugars or grow autotrophically. The genome of P. carbinolicus was sequenced in order to understand its metabolic capabilities and physiological features in comparison with its relatives, acetate-oxidizing Geobacter species. Results Pathways were predicted for catabolism of known substrates: 2,3-butanediol, acetoin, glycerol, 1,2-ethanediol, ethanolamine, choline and ethanol. Multiple isozymes of 2,3-butanediol dehydrogenase, ATP synthase and [FeFe]-hydrogenase were differentiated and assigned roles according to their structural properties and genomic contexts. The absence of asparagine synthetase and the presence of a mutant tRNA for asparagine encoded among RNA-active enzymes suggest that P. carbinolicus may make asparaginyl-tRNA in a novel way. Catabolic glutamate dehydrogenases were discovered, implying that the tricarboxylic acid (TCA cycle can function catabolically. A phosphotransferase system for uptake of sugars was discovered, along with enzymes that function in 2,3-butanediol production. Pyruvate:ferredoxin/flavodoxin oxidoreductase was identified as a potential bottleneck in both the supply of oxaloacetate for oxidation of acetate by the TCA cycle and the connection of glycolysis to production of ethanol. The P. carbinolicus genome was found to encode autotransporters and various appendages, including three proteins with similarity to the geopilin of electroconductive nanowires. Conclusions Several surprising metabolic capabilities and physiological features were predicted from the genome of P. carbinolicus, suggesting that it is more versatile than anticipated.

  3. Surprising results from abiotic enzyme digestion of dissolved organic matter at the molecular scale

    Science.gov (United States)

    Hess, N. J.; Tfaily, M. M.; Heredia-Langnar, A.; Rodriguez, L.; Purvine, E.; Todd-Brown, K. E.

    2016-12-01

    Sometimes even the simplest of experiments leads to unexpected results and new understanding. We extract dissolved organic matter using water from peat soil obtained from the S1 bog at the Marcell Experimental Forest in northern Minnesota. We characterized the dissolved organic matter in the water extract before and after adding glucosidase, peroxidase and β-N-Acetylglucosaminidase enzymes using electrospray Fourier transform ion cyclotron resonance mass spectrometry in negative ion mode. Based on mass measurement accuracy of less than 1 ppm for singly charged ions, we assigned putative chemical formula to greater than 80% of the measured mass spectrometry features. For each enzyme tested we are able to easily distinguish between the types and composition of dissolved organic molecules that are susceptible to enzyme degradation - and those that are not - based on the presence new compounds in reacted extracts and loss of compounds from the initial water extract. Next, we created a consensus molecular network analysis based on the neutral mass loss between the measured compounds for each enzyme. The connectivity within these networks suggested a unique, distinctive chemistry for each enzyme. Some results were expected, like the nondiscriminatory oxidation of organic molecules by peroxidase and preferential loss of lignin and tannin-like molecules by glucosidase. However, surprising results include the apparent reactivity of glucosidase enzymatic products to reassemble, forming larger mass organic molecules. While these experiments were conducted abiotically, these molecular-resolved results suggest that biotic enzymatic processes may result in product compounds with unexpected chemistry and reactivity, implying that our current conceptual model of microbial enzymatic activity may be overly simplistic.

  4. The magnetic shear-current effect: generation of large-scale magnetic fields by the small-scale dynamo

    Science.gov (United States)

    Squire, J.; Bhattacharjee, A.

    2016-04-01

    > A novel large-scale dynamo mechanism, the magnetic shear-current effect, is discussed and explored. The effect relies on the interaction of magnetic fluctuations with a mean shear flow, meaning the saturated state of the small-scale dynamo can drive a large-scale dynamo - in some sense the inverse of dynamo quenching. The dynamo is non-helical, with the mean field coefficient zero, and is caused by the interaction between an off-diagonal component of the turbulent resistivity and the stretching of the large-scale field by shear flow. Following up on previous numerical and analytic work, this paper presents further details of the numerical evidence for the effect, as well as an heuristic description of how magnetic fluctuations can interact with shear flow to produce the required electromotive force. The pressure response of the fluid is fundamental to this mechanism, which helps explain why the magnetic effect is stronger than its kinematic cousin, and the basic idea is related to the well-known lack of turbulent resistivity quenching by magnetic fluctuations. As well as being interesting for its applications to general high Reynolds number astrophysical turbulence, where strong small-scale magnetic fluctuations are expected to be prevalent, the magnetic shear-current effect is a likely candidate for large-scale dynamo in the unstratified regions of ionized accretion disks. Evidence for this is discussed, as well as future research directions and the challenges involved with understanding details of the effect in astrophysically relevant regimes.

  5. Channel Narrowing and Channel Reset: Effects of a Large Flood on the Vegetated, Narrowing Rio Grande

    Science.gov (United States)

    Dean, D. J.; Schmidt, J. C.

    2009-12-01

    In September 2008, heavy precipitation from a tropical storm in the Sierra Madre Occidental, MX, produced large amounts of stream flow to the Rio Conchos and lower Rio Grande. This flood was well publicized in the media due to the widespread flooding in Ojinaga, Chih., and Presidio, TX. Gage records indicate that this flood had an approximate recurrence of 15 years as measured on the Rio Grande near Presidio. Nevertheless, flood stages were the highest ever recorded and resulted from a significant loss of channel capacity due to channel narrowing that had occurred during the previous 18 years. Measurements from aerial photographs indicate that channel width had decreased between 35 and 50% between 1990 and 2008 during regional drought. During this period of low stream flow, invasion by non-native riparian vegetation (Tamarix spp., Arundo donax) helped trap sediment and promote floodplain accretion. Our resurveys of the channel indicate that the 2008 flood was a reset event and that the channel was re-widened by 32 to 48%. Repeated, oblique photographs showed significant channel migration and large scale floodplain stripping during this flood. These results show that although riparian vegetation may actively promote channel narrowing and floodplain accretion, moderately large floods may cause large scale bank erosion, floodplain stripping, and vegetation removal in alluvial valleys subject to large-scale invasion by nonnative plants.

  6. A conceptual review of the psychosocial genomics of expectancy and surprise: neuroscience perspectives about the deep psychobiology of therapeutic hypnosis.

    Science.gov (United States)

    Rossi, Ernest L

    2002-10-01

    This conceptual review explores some speculative associations between the neuroscience of expectancy and surprise during stress and therapeutic hypnosis. Current neuroscience is exploring how novel interactions between the organism and the environment initiate cascades of gene expression, protein synthesis, neurogenesis, and healing that operate via Darwinian principles of natural variation and selection on all levels from the molecular-genomic to the subjective states of consciousness. From a neuroscience perspective, the novel and surprising experiences of consciousness appear to have as important a role as expectancy in memory, learning and behavior change in the psychobiology of therapeutic hypnosis. This paper explores how we may integrate the psychosocial genomics of expectancy and surprise in therapeutic hypnosis as a complex system of creative adaptation on all levels of human experience from mind to gene expression.

  7. Effects of running the Bostom Marathon on plasma concentrations of large neutral amino acids

    Science.gov (United States)

    Conlay, L. A.; Wurtman, R. J.; Lopez G-Coviella, I.; Blusztajn, J. K.; Vacanti, C. A.; Logue, M.; During, M.; Caballero, B.; Maher, T. J.; Evoniuk, G.

    1989-01-01

    Plasma large neutral amino acid concentrations were measured in thirty-seven subjects before and after completing the Boston Marathon. Concentrations of tyrosine, phenylalanine, and methionine increased, as did their 'plasma ratios' (i.e., the ratio of each amino acid's concentration to the summed plasma concentrations of the other large neutral amino acids which compete with it for brain uptake). No changes were noted in the plasma concentrations of tryptophan, leucine, isoleucine, nor valine; however, the 'plasma ratios' of valine, leucine, and isoleucine all decreased. These changes in plasma amino acid patterns may influence neurotransmitter synthesis.

  8. Effect of change in large and fast solar wind dynamic pressure on geosynchronous magnetic field

    Institute of Scientific and Technical Information of China (English)

    Borodkova N L; Liu Jing-Bo; Huang Zhao-Hui; Zastenker G N; Wang Chi; Eiges P E

    2006-01-01

    We present a comparison of changes in large and sharp solar wind dynamic pressure, observed by several spacecraft,with fast disturbances in the magnetospheric magnetic field, measured by the geosynchronous satellites. More than 260 changes in solar wind pressure during the period 1996-2003 are selected for this study. Large statistics show that an increase (a decrease) in dynamic pressure always results in an increase (a decrease) in the magnitude of geosynchronous magnetic field. The amplitude of response to the geomagnetic field strongly depends on the location of observer relative to the noon meridian, the value of pressure before disturbance, and the change in amplitude of pressure.

  9. [Elimination of large pyroninophilic cells due to the effect of phytohemagglutinin].

    Science.gov (United States)

    Bykovskaia, S N; Bykovskiĭ, A F; Shepelenko, A M

    1975-09-01

    Large pyroninophilic lymphocytes adsorbed on the surface of target-cells disappeared after phytohemagglutinin (PHA) addition. Incubation during 45 minutes in the presence of PHA did not reveal cisternas of the granular endoplasmatic reticulum and the number of mitochondrias decreased. The H3-thymidine-labeled cells were almost eliminated. There appeared population of small lymphocytes with even outline and clear cytoplasm, poor in organellas, with ribosomas freely scattered in it. After 24--48 hours of incubation they transformed into blasts, large cells with clear nucleus and clear cytoplasm in which no cisternas of granular endoplasmatic reticulum were revealed.

  10. Large anomalous Hall effect driven by a nonvanishing Berry curvature in the noncolinear antiferromagnet Mn3Ge.

    Science.gov (United States)

    Nayak, Ajaya K; Fischer, Julia Erika; Sun, Yan; Yan, Binghai; Karel, Julie; Komarek, Alexander C; Shekhar, Chandra; Kumar, Nitesh; Schnelle, Walter; Kübler, Jürgen; Felser, Claudia; Parkin, Stuart S P

    2016-04-01

    It is well established that the anomalous Hall effect displayed by a ferromagnet scales with its magnetization. Therefore, an antiferromagnet that has no net magnetization should exhibit no anomalous Hall effect. We show that the noncolinear triangular antiferromagnet Mn3Ge exhibits a large anomalous Hall effect comparable to that of ferromagnetic metals; the magnitude of the anomalous conductivity is ~500 (ohm·cm)(-1) at 2 K and ~50 (ohm·cm)(-1) at room temperature. The angular dependence of the anomalous Hall effect measurements confirms that the small residual in-plane magnetic moment has no role in the observed effect except to control the chirality of the spin triangular structure. Our theoretical calculations demonstrate that the large anomalous Hall effect in Mn3Ge originates from a nonvanishing Berry curvature that arises from the chiral spin structure, and that also results in a large spin Hall effect of 1100 (ħ/e) (ohm·cm)(-1), comparable to that of platinum. The present results pave the way toward the realization of room temperature antiferromagnetic spintronics and spin Hall effect-based data storage devices.

  11. Context-dependent effects of large-wildlife declines on small-mammal communities in central Kenya.

    Science.gov (United States)

    Young, Hillary S; McCauley, Douglas J; Dirzo, Rodolfo; Goheen, Jacob R; Agwanda, Bernard; Brook, Cara; Otarola-Castillo, Erik; Ferguson, Adam W; Kinyua, Stephen N; McDonough, Molly M; Palmer, Todd M; Pringle, Robert M; Young, Truman P; Helgen, Kristofer M

    2015-03-01

    Many species of large wildlife have declined drastically worldwide. These reductions often lead to profound shifts in the ecology of entire communities and ecosystems. However, the effects of these large-wildlife declines on other taxa likely hinge upon both underlying abiotic properties of these systems and on the types of secondary anthropogenic changes associated with wildlife loss, making impacts difficult to predict. To better understand how these important contextual factors determine the consequences of large-wildlife declines on other animals in a community, we examined the effects of three common forms of large-wildlife loss (removal without replacement [using fences], removal followed by replacement with domestic stock, and removal accompanied by crop agricultural use) on small-mammal abundance, diversity, and community composition, in landscapes that varied in several abiotic attributes (rainfall, soil fertility, land-use intensity) in central Kenya. We found that small-mammal communities were indeed heavily impacted by all forms of large-wildlife decline, showing, on average: (1) higher densities, (2) lower species richness per site, and (3) different species assemblages in sites from which large wildlife were removed. However, the nature and magnitude of these effects were strongly context dependent. Rainfall, type of land-use change, and the interaction of these two factors were key predictors of both the magnitude and type of responses of small mammals. The strongest effects, particularly abundance responses, tended to be observed in low-rainfall areas. Whereas isolated wildlife removal primarily led to increased small-mammal abundance, wildlife removal associated with secondary uses (agriculture, domestic stock) had much more variable effects on abundance and stronger impacts on diversity and composition. Collectively, these results (1) highlight the importance of context in determining the impacts of large-wildlife decline on small

  12. How to Produce a Surprise Ending for Readers---Writing Strategies in O. Henry’s The Last Leaf

    Institute of Scientific and Technical Information of China (English)

    姚雪莹

    2014-01-01

    “Twist ending”is well used by writers in a novel in order to leave readers a strong impression. In this essay, the author will focus on the narrative strategies that produce such a surprise ending in a short story, using as the example O. Henry’s The Last Leaf (1907). The author gives each of strategies O. Henry used in the novel a name and explains how it is used to produce a surprise ending, standing at the readers’perspective.

  13. Effective Hierarchical Routing Algorithm for Large-scale Wireless Mobile Networks

    Directory of Open Access Journals (Sweden)

    Guofeng Yan

    2014-02-01

    Full Text Available The growing interest in wireless mobile network techniques has resulted in many routing protocol proposals. The unpredictable motion and the unreliable behavior of mobile nodes is one of the key issues in wireless mobile network. Virtual mobile node (VMN consists of robust virtual nodes that are both predictable and reliable. Based on VMN, in this paper, we present a hierarchical routing algorithm, i.e., EHRA-WAVE, for large-scale wireless mobile networks. By using mobile WAVE technology, a routing path can be found rapidly between VMNs without accurate topology information. We introduce the routing algorithm and the implementation issues of the proposed EHRA-WAVE routing algorithm. Finally, we evaluate the performance of EHRA-WAVE through experiments, and compare the performance on VMN failure and message delivery ratio using hierarchical and non-hierarchical routing methods. However, due to the large amounts WAVE flooding, EHRAWAVE results in too large load which would impede the application of the EHRA-WAVE algorithm. Therefore, the further routing protocol focuses on minimizing the number of WAVE using hierarchical structures in large-scale wireless mobile networks. 

  14. The cognitive dynamics of computer science cost-effective large scale software development

    CERN Document Server

    De Gyurky, Szabolcs Michael; John Wiley & Sons

    2006-01-01

    This book has three major objectives: To propose an ontology for computer software; To provide a methodology for development of large software systems to cost and schedule that is based on the ontology; To offer an alternative vision regarding the development of truly autonomous systems.

  15. A Cost Effectiveness Analysis of Large and Small Classes in the University.

    Science.gov (United States)

    Maxwell, Nan L.; Lopus, Jane S.

    1995-01-01

    Using university cost data and student data from 176 members of university economics classes, this study finds that substantial monetary savings are realized by offering large classes, although their students have a 38% decreased probability of enrolling in future economics classes. Money savings may translate into enrollment losses. (SLD)

  16. The Effects of Large Disturbances on On-Line Reinforcement Learning for aWalking Robot

    NARCIS (Netherlands)

    Schuitema, E.; Caarls, W.; Wisse, M.; Jonker, P.P.; Babuska, R.

    2010-01-01

    Reinforcement Learning is a promising paradigm for adding learning capabilities to humanoid robots. One of the difficulties of the real world is the presence of disturbances. In Reinforcement Learning, disturbances are typically dealt with stochastically. However, large and infrequent disturbances d

  17. External human factors in incident management team decisionmaking and their effect on large fire suppression expenditures

    Science.gov (United States)

    Janie Canton-Tompson; Krista M. Gebert; Brooke Thompson; Greg Jones; David Calkin; Geoff. Donovan

    2008-01-01

    Large wildland fires are complex, costly events influenced by a vast array of physical, climatic, and social factors. Changing climate, fuel buildup due to past suppression, and increasing populations in the wildland-urban interface have all been blamed for the extreme fire seasons and rising suppression expenditures of recent years. With each high-cost year comes a...

  18. Distributed measurement system for long term monitoring of clouding effects on large PV plants

    DEFF Research Database (Denmark)

    Paasch, K. M.; Nymand, M.; Haase, F.

    2013-01-01

    A recording system for the generation of current-voltage characteristics of solar panels is presented. The system is intended for large area PV power plants. The recorded curves are used to optimize the energy output of PV power plants, which are likely to be influenced by passing clouds...

  19. Large-scale horizontal flows in the solar photosphere. III. Effects on filament destabilization

    Science.gov (United States)

    Roudier, T.; Švanda, M.; Meunier, N.; Keil, S.; Rieutord, M.; Malherbe, J. M.; Rondi, S.; Molodij, G.; Bommier, V.; Schmieder, B.

    2008-03-01

    Aims:We study the influence of large-scale photospheric motions on the destabilization of an eruptive filament, observed on October 6, 7, and 8, 2004, as part of an international observing campaign (JOP 178). Methods: Large-scale horizontal flows were investigated from a series of MDI full-disc Dopplergrams and magnetograms. From the Dopplergrams, we tracked supergranular flow patterns using the local correlation tracking (LCT) technique. We used both LCT and manual tracking of isolated magnetic elements to obtain horizontal velocities from magnetograms. Results: We find that the measured flow fields obtained by the different methods are well-correlated on large scales. The topology of the flow field changed significantly during the filament eruptive phase, suggesting a possible coupling between the surface flow field and the coronal magnetic field. We measured an increase in the shear below the point where the eruption starts and a decrease in shear after the eruption. We find a pattern in the large-scale horizontal flows at the solar surface that interact with differential rotation. Conclusions: We conclude that there is probably a link between changes in surface flow and the disappearance of the eruptive filament.

  20. The Effects of Large Disturbances on On-Line Reinforcement Learning for aWalking Robot

    NARCIS (Netherlands)

    Schuitema, E.; Caarls, W.; Wisse, M.; Jonker, P.P.; Babuska, R.

    2010-01-01

    Reinforcement Learning is a promising paradigm for adding learning capabilities to humanoid robots. One of the difficulties of the real world is the presence of disturbances. In Reinforcement Learning, disturbances are typically dealt with stochastically. However, large and infrequent disturbances d