WorldWideScience

Sample records for additional experimental evidence

  1. Experimental Evidence on Transfer Pricing

    Directory of Open Access Journals (Sweden)

    Tran Quoc H.

    2016-06-01

    Full Text Available We use incentivized economics experiments to test both the point predictions and comparative static predictions of optimal transfer pricing models, comparing behavior under varying conditions, including wholly versus partially-owned subsidiaries and different tariff and tax rates. As predicted, we find that transfer prices are responsive to relative tax and tariff rates as well as ownership proportions. Additionally, we examine convergence and learning in this setting. While individuals do not choose optimal transfer prices, their choices converge to optimal levels with experience. This paper thus makes two important contributions. First, by comparing behavior with theoretical predictions it provides evidence of whether (and when individuals set transfer prices optimally. Second, by comparing behavior under conditions of full and partial ownership it provides evidence on the impact of policy interventions (like regulating ownership proportions by MNEs on tax revenues.

  2. Experimental evidence for stress enhanced swelling

    International Nuclear Information System (INIS)

    Bates, J.F.; Gilbert, E.R.

    1976-01-01

    Experimental evidence is presented which shows that the application of a biaxial stress during irradiation can increase the magnitude of irradiation-induced swelling observed in tubular specimens. It is shown that this increase in swelling is linear below the proportional elastic limit of the material and decreases above this value of stress. In the linear region a relationship is found between total swelling and stress free swelling. The phenomenon of reduced swelling is evaluated on the basis of increased cold work due to pre-irradiation straining. This analysis yields a relationship of dislocation density proportional to stress to the 3.82 power. Additional analyses using dislocation density proportional to sigma 2 (sigma = hoop stress) yield a similar but sharper decrease in swelling after the proportional elastic limit is reached. (Auth.)

  3. Income Aspirations and Cooperation : Experimental Evidence

    NARCIS (Netherlands)

    Dalton, P.S.

    2010-01-01

    This article is the first attempt to study the empirical link between income aspirations and cooperation in a one shot public good game. By combining experimental with survey data, we find evidence that the more frustrated people are with their income, the lower is their propensity to cooperate with

  4. Experimental evidence for Abraham pressure of light

    Science.gov (United States)

    Zhang, Li; She, Weilong; Peng, Nan; Leonhardt, Ulf

    2015-05-01

    The question of how much momentum light carries in media has been debated for over a century. Two rivalling theories, one from 1908 by Hermann Minkowski and the other from 1909 by Max Abraham, predict the exact opposite when light enters an optical material: a pulling force in Minkowski's case and a pushing force in Abraham's. Most experimental tests have agreed with Minkowski's theory, but here we report the first quantitative experimental evidence for Abraham's pushing pressure of light. Our results matter in optofluidics and optomechanics, and wherever light exerts mechanical pressure.

  5. Economic incentives for additional critical experimentation applicable to fuel dissolution

    International Nuclear Information System (INIS)

    Mincey, J.F.; Primm, R.T. III; Waltz, W.R.

    1981-01-01

    Fuel dissolution operations involving soluble absorbers for criticality control are among the most difficult to establish economical subcritical limits. The paucity of applicable experimental data can significantly hinder a precise determination of a bias in the method chosen for calculation of the required soluble absorber concentration. Resorting to overly conservative bias estimates can result in excessive concentrations of soluble absorbers. Such conservatism can be costly, especially if soluble absorbers are used in a throw-away fashion. An economic scoping study is presented which demonstrates that additional critical experimentation will likely lead to reductions in the soluble absorber (i.e., gadolinium) purchase costs for dissolution operations. The results indicate that anticipated savings maybe more than enough to pay for the experimental costs

  6. Is there evidence for additional neutrino species from cosmology?

    CERN Document Server

    Feeney, Stephen M.; Verde, Licia

    2013-01-01

    It has been suggested that recent cosmological and flavor-oscillation data favor the existence of additional neutrino species beyond the three predicted by the Standard Model of particle physics. We apply Bayesian model selection to determine whether there is indeed any evidence from current cosmological datasets for the standard cosmological model to be extended to include additional neutrino flavors. The datasets employed include cosmic microwave background temperature, polarization and lensing power spectra, and measurements of the baryon acoustic oscillation scale and the Hubble constant. We also consider other extensions to the standard neutrino model, such as massive neutrinos, and possible degeneracies with other cosmological parameters. The Bayesian evidence indicates that current cosmological data do not require any non-standard neutrino properties.

  7. A Simple Experimental Setup for Teaching Additive Colors with Arduino

    Science.gov (United States)

    Carvalho, Paulo Simeão; Hahn, Marcelo

    2016-04-01

    The result of additive colors is always fascinating to young students. When we teach this topic to 14- to 16-year-old students, they do not usually notice we use maximum light quantities of red (R), green (G), and blue (B) to obtain yellow, magenta, and cyan colors in order to build the well-known additive color diagram of Fig. 1. But how about using different light intensities for R, G, and B? What colors do we get? This problem of color mixing has been intensively discussed for decades by several authors, as pointed out by Ruiz's "Color Addition and Subtraction Apps" work and the references included therein. An early LED demonstrator for additive color mixing dates back to 1985, and apps to illustrate color mixing are available online. In this work, we describe an experimental setup making use of a microcontroller device: the Arduino Uno. This setup is designed as a game in order to improve students' understanding of color mixing.

  8. Experimental validation of additively manufactured optimized shapes for passive cooling

    DEFF Research Database (Denmark)

    Lazarov, Boyan S.; Sigmund, Ole; Meyer, Knud E.

    2018-01-01

    This article confirms the superior performance of topology optimized heat sinks compared to lattice designs and suggests simpler manufacturable pin-fin design interpretations. The development is driven by the wide adoption of light-emitting-diode (LED) lamps for industrial and residential lighting....... The presented heat sink solutions are generated by topology optimization, a computational morphogenesis approach with ultimate design freedom, relying on high-performance computing and simulation. Optimized devices exhibit complex and organic-looking topologies which are realized with the help of additive...... manufacturing. To reduce manufacturing cost, a simplified interpretation of the optimized design is produced and validated as well. Numerical and experimental results agree well and indicate that the obtained designs outperform lattice geometries by more than 21%, resulting in a doubling of life expectancy and...

  9. Experimental evidence for herbivore limitation of the treeline.

    Science.gov (United States)

    Speed, James D M; Austrheim, Gunnar; Hester, Alison J; Mysterud, Atle

    2010-11-01

    The treeline ecotone divides forest from open alpine or arctic vegetation states. Treelines are generally perceived to be temperature limited. The role of herbivores in limiting the treeline is more controversial, as experimental evidence from relevant large scales is lacking. Here we quantify the impact of different experimentally controlled herbivore densities on the recruitment and survival of birch Betula pubescens tortuosa along an altitudinal gradient in the mountains of southern Norway. After eight years of summer grazing in large-scale enclosures at densities of 0, 25, and 80 sheep/km2, birch recruited within the whole altitudinal range of ungrazed enclosures, but recruitment was rarer in enclosures with low-density sheep and was largely limited to within the treeline in enclosures with high-density sheep. In contrast, the distribution of saplings (birch older than the experiment) did not differ between grazing treatments, suggesting that grazing sheep primarily limit the establishment of new tree recruits rather than decrease the survival of existing individuals. This study provides direct experimental evidence that herbivores can limit the treeline below its potential at the landscape scale and even at low herbivore densities in this climatic zone. Land use changes should thus be considered in addition to climatic changes as potential drivers of ecotone shifts.

  10. Output commitment through product bundling : Experimental evidence

    NARCIS (Netherlands)

    Hinloopen, Jeroen; Mueller, Wieland; Normann, Hans-Theo

    We analyze the impact of product bundling in experimental markets. One firm has monopoly power in a first market but competes with another firm la Cournot in a second market. We compare treatments where the multi-product firm (i) always bundles, (ii) never bundles, and (iii) chooses whether to

  11. Output commitment through product bundling: experimental evidence

    NARCIS (Netherlands)

    Hinloopen, J.; Mueller, W.; Normann, H.T.

    2011-01-01

    We analyze the impact of product bundling in experimental markets. A firm has monopoly power in one market but faces competition by a second firm in another market. We compare treatments where the monopolist can bundle its two products to treatments where it cannot, and we contrast simultaneous and

  12. Experimental evidence of infrared scintillation in crystals

    CERN Document Server

    Belogurov, S; Carugno, Giovanni; Conti, E; Iannuzzi, D; Meneguzzo, Anna Teresa

    2000-01-01

    We present experimental results on infrared emission induced by protons in some solid-state samples. Infrared scintillation occurs in many crystals, with different yield values and time-response behaviours. A rough measurement of the emission wavelength of CsI(Tl) is also reported.

  13. Experimental Evidence for Quantum Tunneling Time

    Science.gov (United States)

    Camus, Nicolas; Yakaboylu, Enderalp; Fechner, Lutz; Klaiber, Michael; Laux, Martin; Mi, Yonghao; Hatsagortsyan, Karen Z.; Pfeifer, Thomas; Keitel, Christoph H.; Moshammer, Robert

    2017-07-01

    The first hundred attoseconds of the electron dynamics during strong field tunneling ionization are investigated. We quantify theoretically how the electron's classical trajectories in the continuum emerge from the tunneling process and test the results with those achieved in parallel from attoclock measurements. An especially high sensitivity on the tunneling barrier is accomplished here by comparing the momentum distributions of two atomic species of slightly deviating atomic potentials (argon and krypton) being ionized under absolutely identical conditions with near-infrared laser pulses (1300 nm). The agreement between experiment and theory provides clear evidence for a nonzero tunneling time delay and a nonvanishing longitudinal momentum of the electron at the "tunnel exit."

  14. Experimental evidence for πK-atoms

    International Nuclear Information System (INIS)

    Amsler, C.

    2009-01-01

    We present evidence for the first observation of electromagnetically bound pion-kaon pairs (πK- atoms) with the DIRAC-II experiment at the CERN-PS. The mean life of πK-atoms is related to the s-wave πK-scattering lengths, a measurement of which is relevant to low energy QCD, in particular chiral perturbation theories including the s-quarks. The atoms are produced by a 24 GeV/c proton beam in a thin Pt-target and the dissociated pions and kaons analyzed in a two-arm magnetic spectrometer. The observed enhancement at low relative momentum corresponds to the production of 173± 54 πK-atoms. From these first data we derive a lower limit for the mean life of 0.8 fs at the 90 % confidence level. (author)

  15. Experimental evidence against the paradigm of mortality risk aversion.

    Science.gov (United States)

    Rheinberger, Christoph M

    2010-04-01

    This article deals with the question of how societal impacts of fatal accidents can be integrated into the management of natural or man-made hazards. Today, many governmental agencies give additional weight to the number of potential fatalities in their risk assessments to reflect society's aversion to large accidents. Although mortality risk aversion has been proposed in numerous risk management guidelines, there has been no evidence that lay people want public decisionmakers to overweight infrequent accidents of large societal consequences against more frequent ones of smaller societal consequences. Furthermore, it is not known whether public decisionmakers actually do such overweighting when they decide upon the mitigation of natural or technical hazards. In this article, we report on two experimental tasks that required participants to evaluate negative prospects involving 1-100 potential fatalities. Our results show that neither lay people nor hazard experts exhibit risk-averse behavior in decisions on mortality risks.

  16. Time discounting and pain anticipation. Experimental evidence

    Directory of Open Access Journals (Sweden)

    Brañas Garza, Pablo

    2012-03-01

    Full Text Available This paper deals with pain anticipation experienced before medical procedures. our experimental results show that individuals with lower time discount factors are more prone to suffer pain in advance. We provide a framework to rationalize the connection between pain anticipation and impatience. in this set up, more impatient subjects, who only value very near events, mainly take into account the present negative effects of medical procedures (the costs, whereas more patient individuals have a net positive valuation of medical events, given that they are able to value both the cost incurred now and all the benefits to be accrued in the future.

    Este artículo trata de la anticipación del dolor experimentada antes de los procedimientos médicos. nuestros resultados experimentales muestran que los individuos con factor de descuento temporal más bajo son más proclives a sufrir dolor por adelantado. el artículo proporciona un marco en el que racionalizar la relación existente entre impaciencia y anticipación del dolor. en este marco, los sujetos más impacientes, que evalúan sólo los eventos muy próximos en el tiempo, focalizan su atención principalmente en los efectos negativos de los procedimientos médicos (sólo los costes, mientras que los individuos más pacientes tienen una valoración neta positiva de los actos médicos puesto que valoran tanto el coste en el que se incurre en el presente como los beneficios que se obtendrán en el futuro.

  17. A Simple Experimental Setup for Teaching Additive Colors with Arduino

    Science.gov (United States)

    Carvalho, Paulo Simeão; Hahn, Marcelo

    2016-01-01

    The result of additive colors is always fascinating to young students. When we teach this topic to 14- to 16-year-old students, they do not usually notice we use maximum light quantities of red (R), green (G), and blue (B) to obtain yellow, magenta, and cyan colors in order to build the well-known additive color diagram of Fig. 1. But how about…

  18. A review of experimental evidence for octupole deformation

    International Nuclear Information System (INIS)

    Zylicz, J.

    1986-08-01

    Experimental evidence for octupole correlations, which lead to octupole instability and octupole deformation of some nuclei, is illustrated through typical examples. Data are considered for both the 220< A<230 region and for a few medium mass nuclei. (orig.)

  19. Is there a cosmological evidence for additional particles

    International Nuclear Information System (INIS)

    Kirilova, D.P.; Chizhov, M.V.

    1998-05-01

    An extended cosmological model of the early Universe with additional antisymmetric tensor particles is described. The cosmological effects of the additional particles, namely additional interactions of the early Universe plasma with the tensor particles, a shift of the early Universe temperature-time dependence and the total energy density increase are discussed. The efficiency of the tensor particles interactions with the early Universe plasma components and their corresponding cosmological time and temperature are determined. (author)

  20. Experimental Tests of Cooling: Expectations and Additional Needs

    International Nuclear Information System (INIS)

    Zisman, Michael S

    2008-01-01

    Cooling is a critical aspect for a high-performance Neutrino Factory or a Muon Collider. For this reason, considerable effort is being put toward the experimental verification of this technique. The international Muon Ionization Cooling Experiment, MICE, was approved to operate at Rutherford Appleton Laboratory (RAL) in the UK and beam line commissioning commenced in March, 2008. The MICE collaboration comprises about 130 scientists and engineers from Asia, Europe, and the U.S. In this paper we present the motivation and goals for this experiment and describe its present status. MICE is scheduled for completion in 2011. We will also indicate the prospects for a future 6D muon cooling experiment and discuss its possible time schedule

  1. Experimentation on bio-kerosene stove using organic additive

    Science.gov (United States)

    Varshini, M.; Shetty, Divakar

    2017-07-01

    One of the basic worthy item used in most of the villages even now a day's also is the kerosene stove. But in the current scenario, the petroleum products are been replenished. So an alternate fuel should be found in order delve. This work is to check the contingency of blending pongamia oil and kerosene in which is used as an additive. Pongamia is one of the forest based fast growing evergreen tree which is capable of yielding 9 - 90 kg seeds from which 25% of oil can be extracted. Distilled cow urine is to be used so that the fuel can be stored for longer time and is odorless. Blends of 10% to 70% neat pongamia oil - kerosene(KEP) and pongamia oil - kerosene with additive(KEPWA) are prepared. The properties such as flash point, fire point and viscosity are determined. The blends are been compared by doing emission test. The blends with additive showed better properties and reducing in emission characteristics compared to neat blends. It is also observed that emission of CO is decreasing with increasing blends.

  2. The addition of nanostructured hydroxyapatite to an experimental adhesive resin.

    Science.gov (United States)

    Leitune, Vicente Castelo Branco; Collares, Fabrício Mezzomo; Trommer, Rafael Mello; Andrioli, Daniela Guerra; Bergmann, Carlos Pérez; Samuel, Susana Maria Werner

    2013-04-01

    Was produced nanostructured hydroxyapatite (HAnano) and evaluated the influence of its incorporation in an adhesive resin. HAnano was produced by a flame-based process and was characterized by scanning electron microscopy. The surface area, particle size, micro-Raman and cytotoxicity were evaluated. The organic phase was formulated by mixing 50 wt.% Bis-GMA, 25 wt.% TEGDMA, and 25 wt.% HEMA. HAnano was added at seven different concentrations: 0; 0.5; 1; 2; 5; 10 and 20 wt.%. Adhesive resins with hydroxyapatite incorporation were evaluated for their radiopacity, degree of conversion, flexural strength, softening in solvent and microshear bond strength. The data were analyzed by one-way ANOVA and Tukey's post hoc test (α=0.05), except for softening in solvent (paired t-test) and cytotoxicity (two-way ANOVA and Bonferroni). HAnano presented 15.096 m(2)/g of specific surface area and a mean size of 26.7 nm. The radiopacity values were not different from those of 1-mm aluminium. The degree of conversion ranged from 52.2 to 63.8%. The incorporation of HAnano did not influence the flexural strength, which ranged from 123.3 to 143.4MPa. The percentage of reduction of the microhardness after immersion in the solvent became lower as the HAnano concentration increased. The addition of 2% nanostructured hydroxyapatite resulted in a higher value of microshear bond strength than the control group (phydroxyapatite into an adhesive resin presented the best results. The incorporation of nanostructured hydroxyapatite increases the adhesive properties and may be a promising filler for adhesive resin. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. First experimental evidence of corals feeding on seagrass matter

    NARCIS (Netherlands)

    Lai, S.; Gillis, L.G.; Mueller, C.; Bouma, T.J.; Guest, J.R.; Last, K.S.; Ziegler, A.D.; Todd, P.A.

    2013-01-01

    We present the first experimental evidence of a coral (Oulastrea crispata) ingesting and assimilating seagrass material. Tropical seagrass meadows export a substantial portion of their productivity and can provide an important source of nutrients to neighbouring systems such as coral reefs; however,

  4. Experimental evidence for shape changes at high spin

    International Nuclear Information System (INIS)

    Twin, P.J.

    1985-01-01

    Recent experimental evidence obtained with TESSA for shape changes at high spin is presented. Continuum γ-ray spectroscopy data indicates the co-existence of both prolate and oblate shapes in N = 90 nuclei and lifetime data in 152 Dy shows that the super deformed decays are very enhanced. (orig.)

  5. Experimental Evidence for LENR in a Polarized Pd/D Lattice

    Science.gov (United States)

    Szpak, S.

    2005-03-01

    Experimental evidence in support of claims that excess enthalpy production in a polarized Pd/D lattice is of a nuclear origin is questioned on various grounds, eg marginal intensity and difficulty in reproducing. Here, evidence is presented that is 100% reproducible and of sufficient intensity to be well outside of experimental errors. In addition to the thermal behavior, the nuclear manifestations include: X-ray emission; tritium production; and, when an operating cell is placed in an external electric field, fusion to create heavier metals such as Ca, Al, Mg, and Zn.

  6. Fatigue crack propagation: Probabilistic models and experimental evidence

    International Nuclear Information System (INIS)

    Lucia, A.C.; Jovanovic, A.

    1987-01-01

    The central aim of the LWR Primary Circuit Component Life Prediction Project, going on at JRC-Ispra, is to develop and check a 'procedure' (encompassing monitoring and inspection, data collection and analysis, prediction) allowing the quantitatives estimation of the accumulation of structural damage and of the residual lifetime. The ongoing activity matches theoretical development and experimentation, the latter being at present essentially based on a test-rig for room-temperature fatigue cycling of 1:5 scaled models of pressure vessels. During Phase I of fatigue testing of vessel R2, different pieces of information coming from material characterization, non-destructive inspection, continuous monitoring, stress analysis, have been merged and used to infere the future behaviour of the structure. The prediction of residual lifetime (cycles to failure), based on the outcomes of the ultrasonic continuous monitoring and made by means of the COVASTOL code, was in quite good agreement with experimental evidence. (orig./HP)

  7. Lignin biodegradation: experimental evidence, molecular, biochemical and physiological mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Monties, B

    1985-01-01

    A critical review is presented of English, French and some German language literature, mainly from 1983 onwards. It examines experimental evidence on the behaviour as barriers to biodegradation of lignins and phenolic polymers such as tannins and suberins. The different molecular mechanisms of lignolysis by fungi (mainly), actinomycetes and bacteria are examined. A new biochemical approach to the physiological mechanism of regulation of lignolytic activities is suggested based on the discoveries of ligniolytic enzymes: effects of nitrogen, oxygen and substrate are discussed. It is concluded that a better knowledge of the structure and reactivity of phenolic barriers is needed in order to control the process of lignolysis.

  8. Experimental evidence of body centered cubic iron in Earth's core

    Science.gov (United States)

    Hrubiak, R.; Meng, Y.; Shen, G.

    2017-12-01

    The Earth's core is mainly composed of iron. While seismic evidence has shown a liquid outer core and a solid inner core, the crystalline nature of the solid iron at the core condition remains debated, largely due to the difficulties in experimental determination of exact polymorphs at corresponding pressure-temperature conditions. We have examined crystal structures of iron up to 220 GPa and 6000 K with x-ray diffraction using a double-sided laser heating system at HPCAT, Advanced Photon Source. The iron sample is confined in a small chamber surrounded by single crystal MgO. The laser power can be modulated together with temperature measurements. The modulated heating of iron in an MgO single crystal matrix allows for microstructure analysis during heating and after the sample is quenched. We present experimental evidence of a body-centered-cubic (BCC) iron from about 100 GPa and 3000 K to at least 220 GPa and 4000 K. The observed BCC phase may be consistent with a theoretically predicted BCC phase that is dynamically stable in similar pressure-temperature conditions [1]. We will discuss the stability region of the BCC phase and the melting curve of iron and their implications in the nature of the Earth's inner core. References: A. B. Belonoshko et al., Nat. Geosci., 1-6 (2017).

  9. Experimental evidence for the cardioprotective effects of red wine.

    Science.gov (United States)

    Das, Samarjit; Santani, Dev D; Dhalla, Naranjan S

    2007-01-01

    Both epidemiological and experimental studies have revealed that intake of wine, particularly red wine, in moderation protects cardiovascular health; however, the experimental basis for such an action is not fully understood. Because all types of red wine contain varying amounts of alcohol and antioxidants, it is likely that the cardioprotective effect of red wine is due to both these constituents. In view of its direct action on the vascular smooth muscle cells, alcohol may produce coronary vasodilation in addition to attenuating oxidative stress by its action on the central nervous system. The antioxidant components of red wine may provide cardioprotection by their ability to reduce oxidative stress in the heart under different pathological conditions. Mild-to-moderate red wine consumption improves cardiac function in the ischemic myocardium through the protection of endothelial function, the expression of several cardioprotective oxidative stress-inducible proteins, as well as the activation of adenosine receptors and nitrous oxide synthase mechanisms.

  10. Experimental evidence for the cardioprotective effects of red wine

    Science.gov (United States)

    Das, Samarjit; Santani, Dev D; Dhalla, Naranjan S

    2007-01-01

    Both epidemiological and experimental studies have revealed that intake of wine, particularly red wine, in moderation protects cardiovascular health; however, the experimental basis for such an action is not fully understood. Because all types of red wine contain varying amounts of alcohol and antioxidants, it is likely that the cardioprotective effect of red wine is due to both these constituents. In view of its direct action on the vascular smooth muscle cells, alcohol may produce coronary vasodilation in addition to attenuating oxidative stress by its action on the central nervous system. The antioxidant components of red wine may provide cardioprotection by their ability to reduce oxidative stress in the heart under different pathological conditions. Mild-to-moderate red wine consumption improves cardiac function in the ischemic myocardium through the protection of endothelial function, the expression of several cardioprotective oxidative stress-inducible proteins, as well as the activation of adenosine receptors and nitrous oxide synthase mechanisms. PMID:18650973

  11. Why Nudges Coerce: Experimental Evidence on the Architecture of Regulation.

    Science.gov (United States)

    Hill, Adam

    2017-07-04

    Critics frequently argue that nudges are more covert, less transparent, and more difficult to monitor than traditional regulatory tools. Edward Glaeser, for example, argues that "[p]ublic monitoring of soft paternalism is much more difficult than public monitoring of hard paternalism". As one of the leading proponents of soft paternalism, Cass Sunstein, acknowledges, while "[m]andates and commands are highly visible", soft paternalism, "and some nudges in particular[,] may be invisible". In response to this challenge, proponents of nudging argue that invisibility for any given individual in a particular choice environment is compatible with "careful public scrutiny" of the nudge. This paper offers the first of its kind experimental evidence that tests whether nudges are, in fact, compatible with "careful public scrutiny". Using three sets of experiments, the paper argues that, even when entirely visible, nudges attract less scrutiny than their "hard law" counterparts.

  12. Experimental evidence of planar channeling in a periodically bent crystal

    Energy Technology Data Exchange (ETDEWEB)

    Bagli, E.; Bandiera, L.; Bellucci, V.; Camattari, R.; Germogli, G.; Guidi, V.; Mazzolari, A. [Univ. di Ferrara, Dipartimento di Fisica, Ferrara (Italy); INFN, Sezione di Ferrara (Italy); Berra, A.; Lietti, D.; Prest, M. [Univ. dell' Insubria, Como (Italy); INFN Sezione di Milano Bicocca, Milan (Italy); De Salvador, D. [INFN Laboratori Nazionali di Legnaro, Legnaro (Italy); Univ. di Padova, Dipartimento di Fisica, Padua (Italy); Lanzoni, L. [San Marino Univ. (San Marino). Dept. of Engineering; Tikhomirov, V.V. [Belarusian State University, Research Institute for Nuclear Problems, Minsk (Belarus); Vallazza, E. [INFN, Sezione di Trieste (Italy)

    2014-10-15

    The usage of a crystalline undulator (CU) has been identified as a promising solution for generating powerful and monochromatic γ-rays. A CU was fabricated at Sensors and Semiconductors Lab (SSL) through the grooving method, i.e., by the manufacturing of a series of periodical grooves on the major surfaces of a crystal. The CU was extensively characterized both morphologically via optical interferometry at SSL and structurally via X-ray diffraction at ESRF. Then, it was finally tested for channeling with a 400 GeV/c proton beam at CERN. The experimental results were compared to Monte Carlo simulations. Evidence of planar channeling in the CU was firmly observed. Finally, the emission spectrum of the positron beam interacting with the CU was simulated for possible usage in currently existing facilities. (orig.)

  13. New experimental evidence of the diffusionless transformation nature of bainite

    International Nuclear Information System (INIS)

    Caballero, F.G.; Miller, M.K.; Garcia-Mateo, C.; Cornide, J.

    2013-01-01

    Highlights: ► A new generation of steels has been designed, which on transformation at low temperature (200–350 °C), lead to a nano-scale microstructure, known as NanoBain. The microstructure consists of slender crystals of ferrite, whose controlling scale compares well with that of carbon nanotubes (20–40 nm). ► NanoBain present the highest strength/toughness combinations ever recorded in bainitic steels (∼2.5 GPa/40 MPa m 1/2 ). This structure can be produced without any severe heat treatment, without deformation, simply by phase changes occurring slowly at low temperatures. ► The characterization of NanoBain at the atomic scale has led to revealed extremely important detail on the atomic mechanisms of phase transformations which have been controversial for the last seventy years. ► The results reported in this work have proven beyond doubt that the bainite phase change is essentially displacive in nature. -- Abstract: Since the discovery of bainite, research over many decades has revealed a substantial amount of information about the mechanism of the bainite transformation in steels. Elements of the theory are now routinely being used in many parts of the world in the design of novel alloys and in the interpretation of a variety of experimental data. However, current experimental and theoretical understanding is limiting technological progress. The purpose of this atom probe tomography study was to track atom distributions during the bainite reaction in a nanocrystalline steel. The results are providing new experimental evidence on subjects critically relevant to the understanding of the atomic mechanisms controlling bainitic ferrite formation, such as the incomplete transformation phenomenon, the carbon supersaturation of ferrite, and the plastic accommodation of the surrounding austenite

  14. New experimental evidence of the diffusionless transformation nature of bainite

    Energy Technology Data Exchange (ETDEWEB)

    Caballero, F.G., E-mail: fgc@cenim.csic.es [Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avda Gregorio del Amo, 8, Madrid, E-28040 (Spain); Miller, M.K. [Oak Ridge National Laboratory (ORNL), Materials Science and Technology Division, Oak Ridge, TN 37831-6136 (United States); Garcia-Mateo, C.; Cornide, J. [Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avda Gregorio del Amo, 8, Madrid, E-28040 (Spain)

    2013-11-15

    Highlights: ► A new generation of steels has been designed, which on transformation at low temperature (200–350 °C), lead to a nano-scale microstructure, known as NanoBain. The microstructure consists of slender crystals of ferrite, whose controlling scale compares well with that of carbon nanotubes (20–40 nm). ► NanoBain present the highest strength/toughness combinations ever recorded in bainitic steels (∼2.5 GPa/40 MPa m{sup 1/2}). This structure can be produced without any severe heat treatment, without deformation, simply by phase changes occurring slowly at low temperatures. ► The characterization of NanoBain at the atomic scale has led to revealed extremely important detail on the atomic mechanisms of phase transformations which have been controversial for the last seventy years. ► The results reported in this work have proven beyond doubt that the bainite phase change is essentially displacive in nature. -- Abstract: Since the discovery of bainite, research over many decades has revealed a substantial amount of information about the mechanism of the bainite transformation in steels. Elements of the theory are now routinely being used in many parts of the world in the design of novel alloys and in the interpretation of a variety of experimental data. However, current experimental and theoretical understanding is limiting technological progress. The purpose of this atom probe tomography study was to track atom distributions during the bainite reaction in a nanocrystalline steel. The results are providing new experimental evidence on subjects critically relevant to the understanding of the atomic mechanisms controlling bainitic ferrite formation, such as the incomplete transformation phenomenon, the carbon supersaturation of ferrite, and the plastic accommodation of the surrounding austenite.

  15. Experimental Analysis of DI Diesel Engine Performance with Blend Fuels of Oxygenated Additive and COME Biodiesel

    OpenAIRE

    P. Venkateswara Rao; B.V. Appa Rao; D. Radhakrishna

    2012-01-01

    An experimental investigation was carried out to evaluate the effect of using Triacetin (T) as an additive with biodiesel on direct injection diesel engine for performance and combustion characteristics. Normally in the usage of diesel fuel and neat biodiesel, knocking can be detected to some extent. By adding triacetin [C9H14O6] additive to biodiesel, this problem can be alleviated to some extent and the tail pipe emissions are reduced. Comparative study was conducted using petro-diesel, bio...

  16. Additional Interventions to Enhance the Effectiveness of Individual Placement and Support: A Rapid Evidence Assessment

    Directory of Open Access Journals (Sweden)

    Naomi Boycott

    2012-01-01

    Full Text Available Topic. Additional interventions used to enhance the effectiveness of individual placement and support (IPS. Aim. To establish whether additional interventions improve the vocational outcomes of IPS alone for people with severe mental illness. Method. A rapid evidence assessment of the literature was conducted for studies where behavioural or psychological interventions have been used to supplement standard IPS. Published and unpublished empirical studies of IPS with additional interventions were considered for inclusion. Conclusions. Six published studies were found which compared IPS alone to IPS plus a supplementary intervention. Of these, three used skills training and three used cognitive remediation. The contribution of each discrete intervention is difficult to establish. Some evidence suggests that work-related social skills and cognitive training are effective adjuncts, but this is an area where large RCTs are required to yield conclusive evidence.

  17. Elevation dependent sensitivity of northern hardwoods to Ca addition at Hubbard Brook Experimental Forest, NH USA

    Science.gov (United States)

    Rakesh Minocha; Stephanie Long; Palaniswamy Thangavel; Subhash C. Minocha; Christopher Eagar; Charles T. Driscoll

    2010-01-01

    Acidic deposition has caused a depletion of calcium (Ca) in the northeastern forest soils. Wollastonite (Ca silicate) was added to watershed 1 (WS1) at the Hubbard Brook Experimental Forest (HBEF) in 1999 to evaluate its effects on various functions of the HBEF ecosystem. The effects of Ca addition on foliar soluble (extractable in 5% HClO4) ions...

  18. Decompression to altitude: assumptions, experimental evidence, and future directions.

    Science.gov (United States)

    Foster, Philip P; Butler, Bruce D

    2009-02-01

    Although differences exist, hypobaric and hyperbaric exposures share common physiological, biochemical, and clinical features, and their comparison may provide further insight into the mechanisms of decompression stress. Although altitude decompression illness (DCI) has been experienced by high-altitude Air Force pilots and is common in ground-based experiments simulating decompression profiles of extravehicular activities (EVAs) or astronauts' space walks, no case has been reported during actual EVAs in the non-weight-bearing microgravity environment of orbital space missions. We are uncertain whether gravity influences decompression outcomes via nitrogen tissue washout or via alterations related to skeletal muscle activity. However, robust experimental evidence demonstrated the role of skeletal muscle exercise, activities, and/or movement in bubble formation and DCI occurrence. Dualism of effects of exercise, positive or negative, on bubble formation and DCI is a striking feature in hypobaric exposure. Therefore, the discussion and the structure of this review are centered on those highlighted unresolved topics about the relationship between muscle activity, decompression, and microgravity. This article also provides, in the context of altitude decompression, an overview of the role of denitrogenation, metabolic gases, gas micronuclei, stabilization of bubbles, biochemical pathways activated by bubbles, nitric oxide, oxygen, anthropometric or physiological variables, Doppler-detectable bubbles, and potential arterialization of bubbles. These findings and uncertainties will produce further physiological challenges to solve in order to line up for the programmed human return to the Moon, the preparation for human exploration of Mars, and the EVAs implementation in a non-zero gravity environment.

  19. Models of Investor Forecasting Behavior — Experimental Evidence

    Directory of Open Access Journals (Sweden)

    Federico Bonetto

    2017-12-01

    Full Text Available Different forecasting behaviors affect investors’ trading decisions and lead to qualitatively different asset price trajectories. It has been shown in the literature that the weights that investors place on observed asset price changes when forecasting future price changes, and the nature of their confidence when price changes are forecast, determine whether price bubbles, price crashes, and unpredictable price cycles occur. In this paper, we report the results of behavioral experiments involving multiple investors who participated in a market for a virtual asset. Our goal is to study investors’ forecast formation. We conducted three experimental sessions with different participants in each session. We fit different models of forecast formation to the observed data. There is strong evidence that the investors forecast future prices by extrapolating past price changes, even when they know the fundamental value of the asset exactly and the extrapolated forecasts differ significantly from the fundamental value. The rational expectations hypothesis seems inconsistent with the observed forecasts. The forecasting models of all participants that best fit the observed forecasting data were of the type that cause price bubbles and cycles in dynamical systems models, and price bubbles and cycles ended up occurring in all three sessions.

  20. Experimental Evidence for Wigner’s Tunneling Time

    Science.gov (United States)

    Camus, N.; Yakaboylu, E.; Fechner, L.; Klaiber, M.; Laux, M.; Mi, Y.; Hatsagortsyan, K. Z.; Pfeifer, T.; Keitel, C. H.; Moshammer, R.

    2018-04-01

    Tunneling of a particle through a barrier is one of the counter-intuitive properties of quantum mechanical motion. Thanks to advances in the generation of strong laser fields, new opportunities to dynamically investigate this process have been developed. In the so-called attoclock measurements the electron’s properties after tunneling are mapped on its emission direction. We investigate the tunneling dynamics and achieve a high sensitivity thanks to two refinements of the attoclock principle. Using near-IR wavelength we place firmly the ionization process in the tunneling regime. Furthermore, we compare the electron momentum distributions of two atomic species of slightly different atomic potentials (argon and krypton) being ionized under absolutely identical conditions. Experimentally, using a reaction microscope, we succeed in measuring the 3D electron momentum distributions for both targets simultaneously. Theoretically, the time resolved description of tunneling in strong-field ionization is studied using the leading quantum-mechanical Wigner treatment. A detailed analysis of the most probable photoelectron emission for Ar and Kr allows testing the theoretical models and a sensitive check of the electron initial conditions at the tunnel exit. The agreement between experiment and theory provides a clear evidence for a non-zero tunneling time delay and a non-vanishing longitudinal momentum at this point.

  1. Early-Life Nutritional Programming of Type 2 Diabetes: Experimental and Quasi-Experimental Evidence.

    Science.gov (United States)

    Vaiserman, Alexander M

    2017-03-05

    Consistent evidence from both experimental and human studies suggest that inadequate nutrition in early life can contribute to risk of developing metabolic disorders including type 2 diabetes (T2D) in adult life. In human populations, most findings supporting a causative relationship between early-life malnutrition and subsequent risk of T2D were obtained from quasi-experimental studies ('natural experiments'). Prenatal and/or early postnatal exposures to famine were demonstrated to be associated with higher risk of T2D in many cohorts around the world. Recent studies have highlighted the importance of epigenetic regulation of gene expression as a possible major contributor to the link between the early-life famine exposure and T2D in adulthood. Findings from these studies suggest that prenatal exposure to the famine may result in induction of persistent epigenetic changes that have adaptive significance in postnatal development but can predispose to metabolic disorders including T2D at the late stages of life. In this review, quasi-experimental data on the developmental programming of T2D are summarized and recent research findings on changes in DNA methylation that mediate these effects are discussed.

  2. 20 CFR 10.116 - What additional evidence is needed in cases based on occupational disease?

    Science.gov (United States)

    2010-04-01

    ... based on occupational disease? 10.116 Section 10.116 Employees' Benefits OFFICE OF WORKERS' COMPENSATION... of Proof § 10.116 What additional evidence is needed in cases based on occupational disease? (a) The... occupational diseases. The medical report should also include the information specified on the checklist for...

  3. "Compacted" procedures for adults' simple addition: A review and critique of the evidence.

    Science.gov (United States)

    Chen, Yalin; Campbell, Jamie I D

    2018-04-01

    We review recent empirical findings and arguments proffered as evidence that educated adults solve elementary addition problems (3 + 2, 4 + 1) using so-called compacted procedures (e.g., unconscious, automatic counting); a conclusion that could have significant pedagogical implications. We begin with the large-sample experiment reported by Uittenhove, Thevenot and Barrouillet (2016, Cognition, 146, 289-303), which tested 90 adults on the 81 single-digit addition problems from 1 + 1 to 9 + 9. They identified the 12 very-small addition problems with different operands both ≤ 4 (e.g., 4 + 3) as a distinct subgroup of problems solved by unconscious, automatic counting: These items yielded a near-perfectly linear increase in answer response time (RT) yoked to the sum of the operands. Using the data reported in the article, however, we show that there are clear violations of the sum-counting model's predictions among the very-small addition problems, and that there is no real RT boundary associated with addends ≤4. Furthermore, we show that a well-known associative retrieval model of addition facts-the network interference theory (Campbell, 1995)-predicts the results observed for these problems with high precision. We also review the other types of evidence adduced for the compacted procedure theory of simple addition and conclude that these findings are unconvincing in their own right and only distantly consistent with automatic counting. We conclude that the cumulative evidence for fast compacted procedures for adults' simple addition does not justify revision of the long-standing assumption that direct memory retrieval is ultimately the most efficient process of simple addition for nonzero problems, let alone sufficient to recommend significant changes to basic addition pedagogy.

  4. Experimental evidence that wildflower strips increase pollinator visits to crops.

    Science.gov (United States)

    Feltham, Hannah; Park, Kirsty; Minderman, Jeroen; Goulson, Dave

    2015-08-01

    Wild bees provide a free and potentially diverse ecosystem service to farmers growing pollination-dependent crops. While many crops benefit from insect pollination, soft fruit crops, including strawberries are highly dependent on this ecosystem service to produce viable fruit. However, as a result of intensive farming practices and declining pollinator populations, farmers are increasingly turning to commercially reared bees to ensure that crops are adequately pollinated throughout the season. Wildflower strips are a commonly used measure aimed at the conservation of wild pollinators. It has been suggested that commercial crops may also benefit from the presence of noncrop flowers; however, the efficacy and economic benefits of sowing flower strips for crops remain relatively unstudied. In a study system that utilizes both wild and commercial pollinators, we test whether wildflower strips increase the number of visits to adjacent commercial strawberry crops by pollinating insects. We quantified this by experimentally sowing wildflower strips approximately 20 meters away from the crop and recording the number of pollinator visits to crops with, and without, flower strips. Between June and August 2013, we walked 292 crop transects at six farms in Scotland, recording a total of 2826 pollinators. On average, the frequency of pollinator visits was 25% higher for crops with adjacent flower strips compared to those without, with a combination of wild and commercial bumblebees (Bombus spp.) accounting for 67% of all pollinators observed. This effect was independent of other confounding effects, such as the number of flowers on the crop, date, and temperature. Synthesis and applications. This study provides evidence that soft fruit farmers can increase the number of pollinators that visit their crops by sowing inexpensive flower seed mixes nearby. By investing in this management option, farmers have the potential to increase and sustain pollinator populations over time.

  5. Experimental investigations of the hydrogen addition effects on diesel engine performance

    Science.gov (United States)

    Mirica, I.; Pana, C.; Negurescu, N.; Cernat, A.; Nutu, C.

    2016-08-01

    In the global content regarding the impact on the environmental of the gases emissions resulted from the fossil fuels combustion, an interest aspect discussed on the 21st Session of the Conference of the Parties from the 2015 Paris Climate Conference and the gradual diminution of the worldwide oil reserves contribute to the necessity of searching of alternative energy from durable and renewable resources. At the use of hydrogen as addition in air to diesel engine, the level of CO, HC and smoke from the exhaust gases will decrease due to the improvement of the combustion process. At low and medium partial loads and low hydrogen energetic ratios used the NOX emission level can decrease comparative to classic diesel engine. The hydrogen use as fuel for diesel engine leads to the improving of the energetic and emissions performance of the engine due to combustion improvement and reduction of carbon content. The paper presents, in a comparative way, results of the experimental researches carried on a truck compression ignition engine fuelled with diesel fuel and with hydrogen diesel fuel and hydrogen as addition in air at different engine operation regimes. The results obtained during experimental investigations show better energetic and pollution performance of the engine fuelled with hydrogen as addition in air comparative to classic engine. The influences of hydrogen addition on engine operation are shown.

  6. Essays in the Economics of Corruption: Experimental and empirical evidence

    OpenAIRE

    Leszczynska, Nastassia

    2018-01-01

    The advent of experimental methodologies have led to decisive progress in the study of corrupt behaviour in the last two decades. Since they can complement survey data and perception indexes with controlled experimental data, scholars and policy makers have reached a better understanding of decision-making in bribery situations and are able to design innovative anticorruption policies.In this thesis, I use experimental and empirical data to contribute to the field of the economics of corrupti...

  7. Food additives and children's behaviour: evidence based policy at the margins of certainty

    OpenAIRE

    Stevenson, Jim

    2009-01-01

    The possible effects of food additives (specifically artificial colours) have been debated for over 30 years. The evidence accumulated suggests that for some children with attention deficit hyperactivity disorder (ADHD) food colours exacerbate their condition. Two studies undertaken by a research group at the University of Southampton have extended these findings to the effects on hyperactivity in children from the general population who do not show ADHD. This article reviews the response ...

  8. Experimental Investigations on the effect of Additive on the Tensile Properties of Fiber Glass Fabric Lamina

    Science.gov (United States)

    Nava Sai Divya, A.; Raghu Kumar, B., Dr; Lakshmi Narayana, G., Dr

    2017-09-01

    The main objective of this work is to investigate the effect of additives on tensile behaviour of fiber glass fabric at lamina level to explore an alternative skin material for the outer body of aerospace applications and machines. This experimental work investigates the effect of silica concentration in epoxy resin lapox L-12 on the tensile properties of glass fabric lamina of 4H-satin weave having 3.6 mm thickness. The lamina was prepared by using hand lay-up method and tests were conducted on it. Various tensile properties values obtained from experimentation were compared for four glass fiber lamina composites fabricated by adding the silica powder to resin bath. The effect of variations in silica concentration (0% SiO2, 5% SiO2, 10% SiO2 and 15% SiO2) on the tensile properties of prepared material revealed that maximum stiffness was obtained at 15% and yield strength at 10% SiO2 concentration in glass fiber lamina. Increasing the silica concentration beyond 10% had led to deterioration in the material properties. The experimentation that was carried out on test specimen was reasonably successful as the effect of silica powder as an additive in glass fiber lamina enhanced the mechanical properties up to certain limit. The underpinning microscopic behaviour at the source of these observations will be investigated in a follow up work.

  9. Experimental and Numerical Study of Water Entry Supercavity Influenced by Turbulent Drag-Reducing Additives

    Directory of Open Access Journals (Sweden)

    Chen-Xing Jiang

    2014-04-01

    Full Text Available The configurational and dynamic characteristics of water entry supercavities influenced by turbulent drag-reducing additives were studied through supercavitating projectile approach, experimentally and numerically. The projectile was projected vertically into water and aqueous solution of CTAC with weight concentrations of 100, 500, and 1000 ppm, respectively, using a pneumatic nail gun. The trajectories of the projectile and the supercavity configuration were recorded by a high-speed CCD camera. Besides, water entry supercavities in water and CTAC solution were numerically simulated based on unsteady RANS scheme, together with application of VOF multiphase model. The Cross viscosity model was adopted to represent the fluid property of CTAC solution. It was obtained that the numerical simulation results are in consistence with experimental data. Numerical and experimental results all show that the length and diameter of supercavity in drag-reducing solution are larger than those in water, and the drag coefficient is smaller than that in water; the maintaining time of supercavity is longer in solution as well. The surface tension plays an important role in maintaining the cavity. Turbulent drag-reducing additives have the potential in enhancement of supercavitation and drag reduction.

  10. Mutations in RIT1 cause Noonan syndrome - additional functional evidence and expanding the clinical phenotype.

    Science.gov (United States)

    Koenighofer, M; Hung, C Y; McCauley, J L; Dallman, J; Back, E J; Mihalek, I; Gripp, K W; Sol-Church, K; Rusconi, P; Zhang, Z; Shi, G-X; Andres, D A; Bodamer, O A

    2016-03-01

    RASopathies are a clinically heterogeneous group of conditions caused by mutations in 1 of 16 proteins in the RAS-mitogen activated protein kinase (RAS-MAPK) pathway. Recently, mutations in RIT1 were identified as a novel cause for Noonan syndrome. Here we provide additional functional evidence for a causal role of RIT1 mutations and expand the associated phenotypic spectrum. We identified two de novo missense variants p.Met90Ile and p.Ala57Gly. Both variants resulted in increased MEK-ERK signaling compared to wild-type, underscoring gain-of-function as the primary functional mechanism. Introduction of p.Met90Ile and p.Ala57Gly into zebrafish embryos reproduced not only aspects of the human phenotype but also revealed abnormalities of eye development, emphasizing the importance of RIT1 for spatial and temporal organization of the growing organism. In addition, we observed severe lymphedema of the lower extremity and genitalia in one patient. We provide additional evidence for a causal relationship between pathogenic mutations in RIT1, increased RAS-MAPK/MEK-ERK signaling and the clinical phenotype. The mutant RIT1 protein may possess reduced GTPase activity or a diminished ability to interact with cellular GTPase activating proteins; however the precise mechanism remains unknown. The phenotypic spectrum is likely to expand and includes lymphedema of the lower extremities in addition to nuchal hygroma. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Experimental Study of Hydrogen Addition Effects on a Swirl-Stabilized Methane-Air Flame

    Directory of Open Access Journals (Sweden)

    Mao Li

    2017-11-01

    Full Text Available The effects of H2 addition on a premixed methane-air flame was studied experimentally with a swirl-stabilized gas turbine model combustor. Experiments with 0%, 25%, and 50% H2 molar fraction in the fuel mixture were conducted under atmospheric pressure. The primary objectives are to study the impacts of H2 addition on flame lean blowout (LBO limits, flame shapes and anchored locations, flow field characteristics, precessing vortex core (PVC instability, as well as the CO emission performance. The flame LBO limits were identified by gradually reducing the equivalence ratio until the condition where the flame physically disappeared. The time-averaged CH chemiluminescence was used to reveal the characteristics of flame stabilization, e.g., flame structure and stabilized locations. In addition, the inverse Abel transform was applied to the time-averaged CH results so that the distribution of CH signal on the symmetric plane of the flame was obtained. The particle image velocimetry (PIV was used to detect the characteristics of the flow field with a frequency of 2 kHz. The snapshot method of POD (proper orthogonal decomposition and fast Fourier transform (FFT were adopted to capture the most prominent coherent structures in the turbulent flow field. CO emission was monitored with an exhaust probe that was installed close to the combustor exit. The experimental results indicated that the H2 addition extended the flame LBO limits and the operation range of low CO emission. The influence of H2 addition on the flame shape, location, and flow field was observed. With the assistance of POD and FFT, the combustion suppression impacts on PVC was found.

  12. D-OPTIMAL EXPERIMENTAL DESIGNS TO TEST FOR DEPARTURE FROM ADDITIVITY IN A FIXED-RATIO MIXTURE RAY.

    Science.gov (United States)

    Humans are exposed to mixtures of environmental compounds. A regulatory assumption is that the mixtures of chemicals act in an additive manner. However, this assumption requires experimental validation. Traditional experimental designs (full factorial) require a large number of e...

  13. Experimental evidence for the cardioprotective effects of red wine

    OpenAIRE

    Das, Samarjit; Santani, Dev D; Dhalla, Naranjan S

    2007-01-01

    Both epidemiological and experimental studies have revealed that intake of wine, particularly red wine, in moderation protects cardiovascular health; however, the experimental basis for such an action is not fully understood. Because all types of red wine contain varying amounts of alcohol and antioxidants, it is likely that the cardioprotective effect of red wine is due to both these constituents. In view of its direct action on the vascular smooth muscle cells, alcohol may produce coronary ...

  14. Experimental evidence of enhancement in the anticipation time by cascading

    International Nuclear Information System (INIS)

    Baraik, Abhijit; Singh, Harpartap; Parmananda, P.

    2014-01-01

    We have studied and verified experimentally the enhancement in the anticipation time by cascading Chua's circuits. The experiments have been carried out in a one dimensional array of Chua's circuits (2 to 8) coupled unidirectionally, such that each one acts as a master for the next one. By doing so, it has been observed that the anticipation time increases with an increase in the array size. Moreover, the numerical simulations of an array of eighty Chua's circuits verify the experimental observations.

  15. Experimental evidence of enhancement in the anticipation time by cascading

    Energy Technology Data Exchange (ETDEWEB)

    Baraik, Abhijit; Singh, Harpartap; Parmananda, P.

    2014-04-01

    We have studied and verified experimentally the enhancement in the anticipation time by cascading Chua's circuits. The experiments have been carried out in a one dimensional array of Chua's circuits (2 to 8) coupled unidirectionally, such that each one acts as a master for the next one. By doing so, it has been observed that the anticipation time increases with an increase in the array size. Moreover, the numerical simulations of an array of eighty Chua's circuits verify the experimental observations.

  16. Experimental evidence for self-sealing of fractures in argillites

    International Nuclear Information System (INIS)

    Zhang, Chun-Liang

    2010-01-01

    Document available in extended abstract form only. In argillaceous rocks, self-sealing of fractures generated by the excavation of underground repositories can be expected due to combined impact of rock compression, backfill resistance, and clay swelling during the post-closure phase. The sealing process is determined by the deformability and swelling capacity of the host rock and the backfill as well as by the boundary conditions. As a crucial factor for the long-term safety of repositories, the sealing behaviour of fractures in argillites has been experimentally investigated by GRS on the Callovo-Oxfordian argillite (COX) and the Opalinus clay (OPA) under relevant repository conditions. Comprehensive laboratory tests were carried out on artificially-fractured samples of different sizes (diameter/length = 50/50 - 280/600 mm) and shapes (cylinder and hollow cylinder) under various confining stresses, fluid pressures, and temperatures. The sealing of fractures was detected by measurement of deformation, permeability and wave velocity variations. Following previous studies in which the sealing of fractured samples was determined by gas flow at ambient temperature, additional tests were performed by flowing synthetic pore water through fractures under different confining stresses and at elevated temperatures. Typical results of the tests are presented in this paper. Current results of the ongoing long-term permeability measurements on fractured COX and OPA samples (D/L = 50/50 mm) are summarized, some of which were pre-heated up to high temperatures of 50, 100 and 150 deg. C. In those tests, synthetic pore water was flowed through at injection pressure of 1 MPa, confining stresses of 2 to 3 MPa, and elevated temperatures from 20 to 90 deg. C. All fractured samples showed the same high initial gas permeability of 3.10 -12 m 2 . As the water was injected, the permeability dropped down by three to five orders of magnitude to 10 -15 to 10 -18 m 2 , depending on the

  17. Experimental evidence for a phylogenetic Janzen-Connell effect in a subtropical forest

    NARCIS (Netherlands)

    Liu, Xubing; Liang, Minxia; Etienne, Rampal S.; Wang, Yongfan; Staehelin, Christian; Yu, Shixiao

    Observational evidence increasingly suggests that the JanzenConnell effect extends beyond the species boundary. However, this has not been confirmed experimentally. Herein, we present both observational and experimental evidence for a phylogenetic JanzenConnell effect. In a subtropical forest in

  18. Experimental evidence for partial spatial coherence in imaging Mueller polarimetry.

    Science.gov (United States)

    Ossikovski, Razvigor; Arteaga, Oriol; Yoo, Sang Hyuk; Garcia-Caurel, Enric; Hingerl, Kurt

    2017-11-15

    We demonstrate experimentally the validity of the partial spatial coherence formalism in Mueller polarimetry and show that, in a finite spatial resolution experiment, the measured response is obtained through convolving the theoretical one with the instrument function. The reported results are of primary importance for Mueller imaging systems.

  19. Magnetic order in graphite: Experimental evidence, intrinsic and extrinsic difficulties

    International Nuclear Information System (INIS)

    Esquinazi, P.; Barzola-Quiquia, J.; Spemann, D.; Rothermel, M.; Ohldag, H.; Garcia, N.; Setzer, A.; Butz, T.

    2010-01-01

    We discuss recently obtained data using different experimental methods including magnetoresistance measurements that indicate the existence of metal-free high-temperature magnetic order in graphite. Intrinsic as well as extrinsic difficulties to trigger magnetic order by irradiation of graphite are discussed in view of recently published theoretical work.

  20. Experimental evidence for density dependence of reproduction in great tits

    NARCIS (Netherlands)

    Both, Christiaan

    1998-01-01

    1.  Density dependence of avian reproduction has often been analysed using correlations between annual mean reproductive output and population density. Experiments are necessary to prove that density is the cause of the observed patterns, but so far, three out of four experimental studies do not

  1. Experimental evidence for density dependence of reproduction in great tits

    NARCIS (Netherlands)

    Both, C.

    1998-01-01

    1. Density dependence of avian reproduction has often been analysed using correlations between annual mean reproductive output and population density. Experiments are necessary to prove that density is the cause of the observed patterns, but so far, three out of four experimental studies do not

  2. Experimental evidence for suspence as determinant of video game enjoyment

    NARCIS (Netherlands)

    Klimmt, C.; Rizzo, A.; Vorderer, P.A.; Koch, J.; Fischer, T.

    2009-01-01

    Based on theoretical assumptions from film psychology and their application to video games, the hypothesis is tested that suspense is a major factor in video game enjoyment. A first-person shooter game was experimentally manipulated to create either a low level or a high level of suspense.

  3. Experimental Evidence on the Effects of Early Meetings and Activation

    DEFF Research Database (Denmark)

    Pedersen, Jonas Maibom; Rosholm, Michael; Svarer, Michael

    and case workers increase employment rates over the next two years by 10%. For men, we find evidence of a threat effect of having to participate in early activation programmes. In general, we find large differences between men and women, especially in the dynamics of the effects. A cost-benefit analysis...

  4. Physics of human cooperation: experimental evidence and theoretical models

    Science.gov (United States)

    Sánchez, Angel

    2018-02-01

    In recent years, many physicists have used evolutionary game theory combined with a complex systems perspective in an attempt to understand social phenomena and challenges. Prominent among such phenomena is the issue of the emergence and sustainability of cooperation in a networked world of selfish or self-focused individuals. The vast majority of research done by physicists on these questions is theoretical, and is almost always posed in terms of agent-based models. Unfortunately, more often than not such models ignore a number of facts that are well established experimentally, and are thus rendered irrelevant to actual social applications. I here summarize some of the facts that any realistic model should incorporate and take into account, discuss important aspects underlying the relation between theory and experiments, and discuss future directions for research based on the available experimental knowledge.

  5. Experimental evidence for improved confinement with quasisymmetry in HSX

    International Nuclear Information System (INIS)

    Gerhardt, S.P.; Abdou, A.; Almagri, A.

    2003-01-01

    Plasmas produced by second harmonic electron cyclotron heating (ECH) in the HSX stellarator provide the first evidence of transport improvement due to quasisymmetry in a stellarator. Comparisons are made between plasmas in the base quasi helically symmetric (QHS) configuration and two neo classically degraded configurations which lack quasisymmetry (Mirror configurations). It is found that the plasma breakdown occurs more easily in the QHS configuration, indicating improved confinement of the breakdown electrons. The stored energy in the QHS configuration is up to six times larger than discharges in the Mirror configurations, and evidence is shown for enhanced prompt loss of trapped particles when the Mirror field is applied. The momentum damping rate is measured to be factors of three to four less in the QHS configuration than the Mirror configuration. (author)

  6. Ethnic and gender discrimination in recruitment: experimental evidence from Finland

    OpenAIRE

    Liebkind, Karmela; Larja, Lisa; Brylka, Asteria Anna

    2016-01-01

    We ask (1) how the position of an ethnic (majority or minority) group in the local ethnic hierarchy affects the amount of recruitment discrimination faced by applicants from that group, and (2) whether gender discrimination is dependent on occupational gender stereotypes in the same way among ethnic majority and minority applicants. We use the situation testing method for the first time in Finland: In an experimental study (Study 1), 103 dentistry students made recruitment decisions based on ...

  7. What Behaviors are Disapproved? Experimental Evidence from Five Dictator Games

    Directory of Open Access Journals (Sweden)

    Marc Vorsatz

    2012-04-01

    Full Text Available The literature on social norms has often stressed that social disapproval is crucial to foster compliance with norms and promote fair and cooperative behavior. With this in mind, we explore the disapproval of allocation decisions using experimental data from five dictator games with a feedback stage. Our data suggests that subjects are heterogeneous in their disapproval patterns, distinguishing two main groups: (1 Subjects who only disapprove choices that harm them, and (2 subjects who disapprove socially inefficient choices.

  8. Gender discrimination and social identity: experimental evidence from urban Pakistan

    OpenAIRE

    Delavande, Adeline; Zafar, Basit

    2013-01-01

    Gender discrimination in South Asia is a well-documented fact. However, gender is only one of an individual's many identities. This paper investigates how gender discrimination depends on the social identities of interacting parties. We use an experimental approach to identify gender discrimination by randomly matching 2,836 male and female students pursuing bachelor's-equivalent degrees in three different types of institutions - Madrassas (religious seminaries), Islamic universities, and lib...

  9. Risk, Credit, and Insurance in Peru: Field Experimental Evidence

    OpenAIRE

    Galarza, Francisco

    2009-01-01

    This paper reports the results of behavioral economic experiments conducted in Peru to examine the relationship amongst risk preferences, loan take-up, and insurance purchase decisions. This area-based yield insurance can help reduce people's vulnerability to large scale covariate shocks, and can also lower the loan default probability under extreme negative covariate shocks. In a context of collateralized formal credit markets, we provide suggestive evidence that insurance may help reduce th...

  10. Experimental Investigation on Zonal Structure in Drag-Reducing Channel Flow with Surfactant Additives

    Directory of Open Access Journals (Sweden)

    Masaaki Motozawa

    2011-01-01

    Full Text Available The spatial structure of a drag-reducing channel flow with surfactant additives in a two-dimensional channel was investigated experimentally. We carried out detailed measurements of the instantaneous velocity in the streamwise wall-normal plane and streamwise spanwise plane by using particle image velocimetry (PIV. The surfactant used in this experiment is a kind of cationic surfactant CTAC. The weight concentrations of the CTAC solution were 25 and 40 ppm on the flow. We considered the effects of Reynolds number ranging from 10000 to 25000 and the weight concentration of CTAC. The results of this paper showed that in the drag-reducing flow, there appeared an area where the root mean square of streamwise velocity fluctuation and the vorticity fluctuation sharply decreased. This indicated that two layers with different turbulent structure coexisted on the boundary of this area. Moreover, these layers had characteristic flow structures, as confirmed by observation of the instantaneous vorticity fluctuation map.

  11. Experimental study on SI engine fuelled with butanol–gasoline blend and H2O addition

    International Nuclear Information System (INIS)

    Feng, Renhua; Yang, Jing; Zhang, Daming; Deng, Banglin; Fu, Jianqin; Liu, Jingping; Liu, Xiaoqiang

    2013-01-01

    Highlights: • Ignition timing has been optimized. • 1% H 2 O has been added. • Positive results have been achieved in engine torque, BSEC, CO emissions and HC emissions. • NOx and CO 2 emissions go up. - Abstract: An experimental study was conducted on a single cylinder motorcycle engine for two operating modes of full load and partial load at 6500 rpm and 8500 rpm with pure gasoline and 35% volume butanol–gasoline blend. The engine ignition timing for 35% volume butanol–gasoline blend has been optimized, and 1% volume H 2 O has also been added to the butanol–gasoline blend fuel. Engine performance parameters, fuel economy and emissions have been measured and analyzed. The experimental results showed that engine torque, BSEC, CO emissions and HC emissions are better than that of pure gasoline at both full load and partial load with 35% volume butanol and 1% H 2 O addition, combined with the modified ignition timing. But NOx and CO 2 emissions are worse than that of the original level of pure gasoline

  12. Experimental evidence of a chaotic region in a neural pacemaker

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Hua-Guang, E-mail: guhuaguang@tongji.edu.cn [School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092 (China); Department of Electronic Engineering, City University of Hong Kong, Hong Kong SAR (China); Jia, Bing [School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092 (China); Chen, Guan-Rong [Department of Electronic Engineering, City University of Hong Kong, Hong Kong SAR (China)

    2013-03-15

    In this Letter, we report the finding of period-adding scenarios with chaos in firing patterns, observed in biological experiments on a neural pacemaker, with fixed extra-cellular potassium concentration at different levels and taken extra-cellular calcium concentration as the bifurcation parameter. The experimental bifurcations in the two-dimensional parameter space demonstrate the existence of a chaotic region interwoven with the periodic region thereby forming a period-adding sequence with chaos. The behavior of the pacemaker in this region is qualitatively similar to that of the Hindmarsh–Rose neuron model in a well-known comb-shaped chaotic region in two-dimensional parameter spaces.

  13. Strategic sophistication of individuals and teams. Experimental evidence

    Science.gov (United States)

    Sutter, Matthias; Czermak, Simon; Feri, Francesco

    2013-01-01

    Many important decisions require strategic sophistication. We examine experimentally whether teams act more strategically than individuals. We let individuals and teams make choices in simple games, and also elicit first- and second-order beliefs. We find that teams play the Nash equilibrium strategy significantly more often, and their choices are more often a best response to stated first order beliefs. Distributional preferences make equilibrium play less likely. Using a mixture model, the estimated probability to play strategically is 62% for teams, but only 40% for individuals. A model of noisy introspection reveals that teams differ from individuals in higher order beliefs. PMID:24926100

  14. The evidence for clinically significant bias in plasma glucose between liquid and lyophilized citrate buffer additive.

    Science.gov (United States)

    Juricic, Gordana; Saracevic, Andrea; Kopcinovic, Lara Milevoj; Bakliza, Ana; Simundic, Ana-Maria

    2016-12-01

    Citrate buffer additive has been suggested to be of supreme performance in inhibiting glycolysis. However, there is little evidence in the literature regarding the comparability of glucose concentrations in liquid and lyophilized citrate buffer containing tubes. The aim of this study was to compare glucose concentrations in tubes containing liquid (Glucomedics) and lyophilized citrate buffer (Terumo VENOSAFE™ Glycemia) additive, measured immediately after centrifugation. Blood was collected from forty volunteers into both Glucomedics and Venosafe Glycemia tubes. Blood was centrifuged within 15min from venipuncture and glucose concentration was measured immediately after centrifugation, on the Abbott Architect analyzer. Differences between glucose concentrations in Glucomedics and Terumo tubes were tested using the paired t-test. Mean bias was calculated and compared to recommended quality specification for glucose (i.e. 2.2%). Glucose concentration in Terumo tubes was 3.4% lower than in Glucomedics tubes (Pglucose concentrations in liquid and lyophilized citrate buffer additive tubes (Glucomedics vs. Terumo tubes) measured immediately after centrifugation. This difference may affect the patient outcome due to the misclassification of diabetes. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  15. Experimental evidence for adaptive personalities in a wild passerine bird

    Science.gov (United States)

    Nicolaus, Marion; Tinbergen, Joost M.; Bouwman, Karen M.; Michler, Stephanie P. M.; Ubels, Richard; Both, Christiaan; Kempenaers, Bart; Dingemanse, Niels J.

    2012-01-01

    Individuals of the same species differ consistently in risky actions. Such ‘animal personality’ variation is intriguing because behavioural flexibility is often assumed to be the norm. Recent theory predicts that between-individual differences in propensity to take risks should evolve if individuals differ in future fitness expectations: individuals with high long-term fitness expectations (i.e. that have much to lose) should behave consistently more cautious than individuals with lower expectations. Consequently, any manipulation of future fitness expectations should result in within-individual changes in risky behaviour in the direction predicted by this adaptive theory. We tested this prediction and confirmed experimentally that individuals indeed adjust their ‘exploration behaviour’, a proxy for risk-taking behaviour, to their future fitness expectations. We show for wild great tits (Parus major) that individuals with experimentally decreased survival probability become faster explorers (i.e. increase risk-taking behaviour) compared to individuals with increased survival probability. We also show, using quantitative genetics approaches, that non-genetic effects (i.e. permanent environment effects) underpin adaptive personality variation in this species. This study thereby confirms a key prediction of adaptive personality theory based on life-history trade-offs, and implies that selection may indeed favour the evolution of personalities in situations where individuals differ in future fitness expectations. PMID:23097506

  16. The fungal colonisation of rock-art caves: experimental evidence.

    Science.gov (United States)

    Jurado, Valme; Fernandez-Cortes, Angel; Cuezva, Soledad; Laiz, Leonila; Cañaveras, Juan Carlos; Sanchez-Moral, Sergio; Saiz-Jimenez, Cesareo

    2009-09-01

    The conservation of rock-art paintings in European caves is a matter of increasing interest. This derives from the bacterial colonisation of Altamira Cave, Spain and the recent fungal outbreak of Lascaux Cave, France-both included in the UNESCO World Heritage List. Here, we show direct evidence of a fungal colonisation of rock tablets in a testing system exposed in Altamira Cave. After 2 months, the tablets, previously sterilised, were heavily colonised by fungi and bacteria. Most fungi isolated were labelled as entomopathogens, while the bacteria were those regularly identified in the cave. Rock colonisation was probably promoted by the dissolved organic carbon supplied with the dripping and condensation waters and favoured by the displacement of aerosols towards the interior of the cave, which contributed to the dissemination of microorganisms. The role of arthropods in the dispersal of spores may also help in understanding fungal colonisation. This study evidences the fragility of rock-art caves and demonstrates that microorganisms can easily colonise bare rocks and materials introduced into the cavity.

  17. Sensitivity to food additives, vaso-active amines and salicylates: a review of the evidence.

    Science.gov (United States)

    Skypala, Isabel J; Williams, M; Reeves, L; Meyer, R; Venter, C

    2015-01-01

    Although there is considerable literature pertaining to IgE and non IgE-mediated food allergy, there is a paucity of information on non-immune mediated reactions to foods, other than metabolic disorders such as lactose intolerance. Food additives and naturally occurring 'food chemicals' have long been reported as having the potential to provoke symptoms in those who are more sensitive to their effects. Diets low in 'food chemicals' gained prominence in the 1970s and 1980s, and their popularity remains, although the evidence of their efficacy is very limited. This review focuses on the available evidence for the role and likely adverse effects of both added and natural 'food chemicals' including benzoate, sulphite, monosodium glutamate, vaso-active or biogenic amines and salicylate. Studies assessing the efficacy of the restriction of these substances in the diet have mainly been undertaken in adults, but the paper will also touch on the use of such diets in children. The difficulty of reviewing the available evidence is that few of the studies have been controlled and, for many, considerable time has elapsed since their publication. Meanwhile dietary patterns and habits have changed hugely in the interim, so the conclusions may not be relevant for our current dietary norms. The conclusion of the review is that there may be some benefit in the removal of an additive or a group of foods high in natural food chemicals from the diet for a limited period for certain individuals, providing the diagnostic pathway is followed and the foods are reintroduced back into the diet to assess for the efficacy of removal. However diets involving the removal of multiple additives and food chemicals have the very great potential to lead to nutritional deficiency especially in the paediatric population. Any dietary intervention, whether for the purposes of diagnosis or management of food allergy or food intolerance, should be adapted to the individual's dietary habits and a suitably

  18. An Experimental Study on Effect of Palm – Shell Waste Additive to Cement Strenght Enhancement

    Directory of Open Access Journals (Sweden)

    Adi Novriansyah

    2017-03-01

    Full Text Available Enhancing the cement strength through attaching chemical additive has been popular to meet the required condition for a particular well-cementing job. However, due to a low oil-price phenomenon, pouring and additive should be reconsidered because it can raise the cost and make the project become uneconomic. Another additive material in nanocomposite form will be introduced through this experimental study. The nanocomposite material consist of silica nanoparticle, known as “Nanosilica” and a palm-shell-waste, which is abundant in Indonesia. Before making a nanocomposite, the palm-shell should be burned to obtain a charcoal form, ground and sieved to attain a uniform size.   The study focuses on the two parameters, compressive strength and shear bond strength, which can reflect the strength of the cement. These values are obtained by performing a biaxial loading test to the cement sample. Various samples with different concentration of nanocomposite should be prepared and following the mixing, drying, and hardening process before the loading test is carried out. The result from the test shows a positive indication for compressive strength and shear bond strength values, according to the representative well cementing standards. Increasing the nanocomposite concentration on the cement will increase these values. Furthermore, an investigation on the temperature effect confirms that the sample with 700oC burning temperature have highest compressive-strength and shear-bond-strength values. This is a potential opportunity utilizing a waste-based material to produce another product with higher economic value.

  19. A Tax Evasion - Bribery Game: Experimental Evidence from Ukraine

    Directory of Open Access Journals (Sweden)

    Volodymyr Bilotkach

    2006-06-01

    Full Text Available This paper examines the issue of tax evasion by enterprises through underreporting activity. We develop a view of this phenomenon as an equilibrium of the game between a businessman and an imperfectly monitored supervising official, in which a businessman can hide part of his profit and offer bribe to official. We determine conditions under which such tax evasion and bribery become wide-spread in the society, resulting in shadow economy. The game is put into an experimental setting in Kiev, Ukraine, with the emphasis of spreading of the tax evasion and bribery activity in the laboratory setting. We find that once it becomes known that substantial share of subjects playing the role of supervising officials agree to accept bribes from subjects playing the role of businessmen, the latter offer bribes more aggressively. Yet, this in turn does not affect the behavior of subjects playing the role of supervising officials.

  20. GEOMORPHOLOGY. Experimental evidence for hillslope control of landscape scale.

    Science.gov (United States)

    Sweeney, K E; Roering, J J; Ellis, C

    2015-07-03

    Landscape evolution theory suggests that climate sets the scale of landscape dissection by modulating the competition between diffusive processes that sculpt convex hillslopes and advective processes that carve concave valleys. However, the link between the relative dominance of hillslope and valley transport processes and landscape scale is difficult to demonstrate in natural landscapes due to the episodic nature of erosion. Here, we report results from laboratory experiments combining diffusive and advective processes in an eroding landscape. We demonstrate that rainsplash-driven disturbances in our experiments are a robust proxy for hillslope transport, such that increasing hillslope transport efficiency decreases drainage density. Our experimental results demonstrate how the coupling of climate-driven hillslope- and valley-forming processes, such as bioturbation and runoff, dictates the scale of eroding landscapes. Copyright © 2015, American Association for the Advancement of Science.

  1. Climate warming drives local extinction: Evidence from observation and experimentation

    Science.gov (United States)

    Panetta, Anne Marie; Stanton, Maureen L.; Harte, John

    2018-01-01

    Despite increasing concern about elevated extinction risk as global temperatures rise, it is difficult to confirm causal links between climate change and extinction. By coupling 25 years of in situ climate manipulation with experimental seed introductions and both historical and current plant surveys, we identify causal, mechanistic links between climate change and the local extinction of a widespread mountain plant (Androsace septentrionalis). Climate warming causes precipitous declines in population size by reducing fecundity and survival across multiple life stages. Climate warming also purges belowground seed banks, limiting the potential for the future recovery of at-risk populations under ameliorated conditions. Bolstered by previous reports of plant community shifts in this experiment and in other habitats, our findings not only support the hypothesis that climate change can drive local extinction but also foreshadow potentially widespread species losses in subalpine meadows as climate warming continues. PMID:29507884

  2. Climate warming drives local extinction: Evidence from observation and experimentation.

    Science.gov (United States)

    Panetta, Anne Marie; Stanton, Maureen L; Harte, John

    2018-02-01

    Despite increasing concern about elevated extinction risk as global temperatures rise, it is difficult to confirm causal links between climate change and extinction. By coupling 25 years of in situ climate manipulation with experimental seed introductions and both historical and current plant surveys, we identify causal, mechanistic links between climate change and the local extinction of a widespread mountain plant ( Androsace septentrionalis ). Climate warming causes precipitous declines in population size by reducing fecundity and survival across multiple life stages. Climate warming also purges belowground seed banks, limiting the potential for the future recovery of at-risk populations under ameliorated conditions. Bolstered by previous reports of plant community shifts in this experiment and in other habitats, our findings not only support the hypothesis that climate change can drive local extinction but also foreshadow potentially widespread species losses in subalpine meadows as climate warming continues.

  3. Experimental evidence of energetic neutrals production in an ion diode

    Energy Technology Data Exchange (ETDEWEB)

    Pushkarev, A.I., E-mail: aipush@mail.ru; Isakova, Y.I.; Khaylov, I.P.

    2015-01-15

    The paper presents several experimental proofs of the formation of energetic charge-exchange neutrals in a self-magnetically insulated ion diode with a graphite cathode. The energetic neutrals are thought to be produced as a result of charge exchange process between accelerated ions and stationary neutral molecules. The experiments have been carried out using both a diode with externally applied magnetic insulation (single-pulse mode: 100 ns, 250–300 kV) and a diode with self-magnetic insulation (double-pulse mode: 300–500 ns, 100–150 kV (negative pulse); 120 ns, 250–300 kV (positive pulse)). The motivation for looking at the neutral component of the ion beam came when we compared two independent methods to measure the energy density of the beam. A quantitative comparison of infrared measurements with signals from Faraday cups and diode voltage was made to assess the presence of neutral atoms in the ion beam. As another proof of charge-exchange effects in ion diode we present the results of statistical analysis of diode performance. It was found that the shot-to shot variation of the energy density in a set of 50–100 shots does not exceed 11%, whilst the same variation for ion current density was 20–30%; suggesting the presence of neutrals in the beam. Moreover, the pressure in the zone of ion beam energy dissipation exceeds the results stated in cited references. The difference between our experimental data and results stated by other authors we attribute to the presence of a low-energy charge-exchange neutral component in the ion beam.

  4. Predicting the Unpredictable: 75 Years of Experimental Evidence

    Science.gov (United States)

    Radin, Dean I.

    2011-11-01

    From time immemorial, people have reported foreknowledge of future events. To determine whether such experiences are best understood via conventional explanations, or whether a retrocausal phenomenon might be involved in some instances, researchers have conducted hundreds of controlled laboratory experiments over the past 75 years. These studies fall into four general classes, and each class has generated repeatable evidence consistent with retrocausation. The statistical results for a class of forced-choice studies is associated with odds against chance of about 1024; for a class of free-response studies, odds about 1020; for psychophysiological-based studies, odds about 1017; and for implicit decision studies, odds about 1010. Effect sizes observed in the latter three classes are nearly identical, indicating replication of similar underlying effects. These effects are also in close agreement with the average effect size across 25,000 conventional social psychology experiments conducted over the last century, suggesting that retrocausal phenomena may not be especially unique, at least not in terms of the magnitude of effect. Bayesian analyses of the most recent classes of experiments confirm that the evidence is strongly in favor of a genuine effect, with Bayes Factors ranging from 13,669 to 1 for implicit decision experiments, to 2.9×1013 to 1 for psychophysiological designs. For the two most recent classes of studies examining retrocausal effects via unconscious physiological or behavioral measures, 85 of 101 studies (84%) reported by 25 different laboratories from the United States, Italy, Spain, Holland, Austria, Sweden, England, Scotland, Iran, Japan, and Australia, have produced results in the direction predicted by a retrocausal effect (odds against chance = 1.3×1012, via a sign test). Assessment of the methodologies used in these studies has not identified plausible conventional alternatives for the observed outcomes, suggesting the existence of a

  5. Continuous track paths reveal additive evidence integration in multistep decision making.

    Science.gov (United States)

    Buc Calderon, Cristian; Dewulf, Myrtille; Gevers, Wim; Verguts, Tom

    2017-10-03

    Multistep decision making pervades daily life, but its underlying mechanisms remain obscure. We distinguish four prominent models of multistep decision making, namely serial stage, hierarchical evidence integration, hierarchical leaky competing accumulation (HLCA), and probabilistic evidence integration (PEI). To empirically disentangle these models, we design a two-step reward-based decision paradigm and implement it in a reaching task experiment. In a first step, participants choose between two potential upcoming choices, each associated with two rewards. In a second step, participants choose between the two rewards selected in the first step. Strikingly, as predicted by the HLCA and PEI models, the first-step decision dynamics were initially biased toward the choice representing the highest sum/mean before being redirected toward the choice representing the maximal reward (i.e., initial dip). Only HLCA and PEI predicted this initial dip, suggesting that first-step decision dynamics depend on additive integration of competing second-step choices. Our data suggest that potential future outcomes are progressively unraveled during multistep decision making.

  6. Experimental study of combustion characteristics of nanoscale metal and metal oxide additives in biofuel (ethanol

    Directory of Open Access Journals (Sweden)

    Peterson GP

    2011-01-01

    Full Text Available Abstract An experimental investigation of the combustion behavior of nano-aluminum (n-Al and nano-aluminum oxide (n-Al2O3 particles stably suspended in biofuel (ethanol as a secondary energy carrier was conducted. The heat of combustion (HoC was studied using a modified static bomb calorimeter system. Combustion element composition and surface morphology were evaluated using a SEM/EDS system. N-Al and n-Al2O3 particles of 50- and 36-nm diameters, respectively, were utilized in this investigation. Combustion experiments were performed with volume fractions of 1, 3, 5, 7, and 10% for n-Al, and 0.5, 1, 3, and 5% for n-Al2O3. The results indicate that the amount of heat released from ethanol combustion increases almost linearly with n-Al concentration. N-Al volume fractions of 1 and 3% did not show enhancement in the average volumetric HoC, but higher volume fractions of 5, 7, and 10% increased the volumetric HoC by 5.82, 8.65, and 15.31%, respectively. N-Al2O3 and heavily passivated n-Al additives did not participate in combustion reactively, and there was no contribution from Al2O3 to the HoC in the tests. A combustion model that utilized Chemical Equilibrium with Applications was conducted as well and was shown to be in good agreement with the experimental results.

  7. Experimental evidence for the influence of cognitions on compulsive buying.

    Science.gov (United States)

    McQueen, Paul; Moulding, Richard; Kyrios, Michael

    2014-12-01

    Compulsive buying is a disabling condition, where individuals are unable to resist or control their buying behavior, leading to substantial social and financial problems. Cognitive models implicate the role of beliefs as one factor in buying behavior, for example, "this item is unique and will help me improve my life". This study experimentally examined the contribution of such beliefs to the disorder, in individuals who compulsively buy (N = 18) and in non-clinical controls (N = 17). Participants were presented with photographs of idiosyncratically appealing and unappealing items, in the context of imagined scenarios that either minimized or maximized aspects relevant to hypothesized "compulsive buying beliefs" (i.e., beliefs that acquisition can compensate for negative feelings, beliefs regarding uniqueness and lost opportunities, and emotional reasons for buying). It was found that individuals who compulsively buy demonstrated stronger urges to purchase than control participants, regardless of context, but the overall strength of these urges was responsive to manipulations of beliefs about consumer items said to be associated with compulsive buying. The main limitation of the study was a small sample size, potentially reducing power. Nonetheless, these findings provide insights into the processes underlying compulsive phenomena, in particular supporting the role of cognitions in compulsive buying. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Fostering Early Math Comprehension: Experimental Evidence from Paraguay

    Directory of Open Access Journals (Sweden)

    Emma Naslund-Hadley

    2014-11-01

    Full Text Available Research indicates that preschool children need to learn pre-math skills to build a foundation for primary- and secondary-level mathematics. This paper presents the results from the early stages of a pilot mathematics program implemented in Cordillera, Paraguay. In a context of significant gaps in teacher preparation and pedagogy, the program uses interactive audio segments that cover the entire preschool math curriculum. Since Paraguayan classrooms tend to be bilingual, the audio and written materials use a combination of Spanish and Guaraní. Based on an experimental evaluation since the program’s implementation, we document positive and significant improvements of 0.16 standard deviations in standardized test scores. The program helped narrow learning gaps between low- and high-performing students, and between students with trained teachers and those whose teachers lack formal training in early childhood education. Moreover, the program improved learning equally among both Guaraní- and Spanish-speaking students. But not all learning gaps narrowed as a result of the program. Although girls improved significantly, boys improved much more, ultimately increasing the gender gap. To close this gender gap, the program has been modified to encourage girls’ increased participation in the classroom and general interest in math

  9. Experimental Evidence for Abiotic Sulfurization of Marine Dissolved Organic Matter

    Directory of Open Access Journals (Sweden)

    Anika M. Pohlabeln

    2017-11-01

    Full Text Available Dissolved organic sulfur (DOS is the largest pool of organic sulfur in the oceans, and as such it is an important component of the global sulfur cycle. DOS in the ocean is resistant against microbial degradation and turns over on a millennium time scale. However, sources and mechanisms behind its stability are largely unknown. Here, we hypothesize that in sulfate-reducing sediments sulfur is abiotically incorporated into dissolved organic matter (DOM and released to the ocean. We exposed natural seawater and the filtrate of a plankton culture to sulfidic conditions. Already after 1-h at 20°C, DOS concentrations had increased 4-fold in these experiments, and 14-fold after 4 weeks at 50°C, indicating that organic matter does not need long residence times in natural sulfidic environments to be affected by sulfurization. Molecular analysis via ultrahigh-resolution mass spectrometry showed that sulfur was covalently and unselectively bound to DOM. Experimentally produced and natural DOS from sediments were highly similar on a molecular and structural level. By combining our data with published benthic DOC fluxes we estimate that 30–200 Tg DOS are annually transported from anaerobic and sulfate reducing sediments to the oceans. Uncertainties in this first speculative assessment are large. However, this first attempt illustrates that benthic DOS flux is potentially one order of magnitude larger than that via rivers indicating that this could balance the estimated global net removal of refractory DOS.

  10. Experimental and computational evidence of halogen bonds involving astatine

    Science.gov (United States)

    Guo, Ning; Maurice, Rémi; Teze, David; Graton, Jérôme; Champion, Julie; Montavon, Gilles; Galland, Nicolas

    2018-03-01

    The importance of halogen bonds—highly directional interactions between an electron-deficient σ-hole moiety in a halogenated compound and an acceptor such as a Lewis base—is being increasingly recognized in a wide variety of fields from biomedicinal chemistry to materials science. The heaviest halogens are known to form stronger halogen bonds, implying that if this trend continues down the periodic table, astatine should exhibit the highest halogen-bond donating ability. This may be mitigated, however, by the relativistic effects undergone by heavy elements, as illustrated by the metallic character of astatine. Here, the occurrence of halogen-bonding interactions involving astatine is experimentally evidenced. The complexation constants of astatine monoiodide with a series of organic ligands in cyclohexane solution were derived from distribution coefficient measurements and supported by relativistic quantum mechanical calculations. Taken together, the results show that astatine indeed behaves as a halogen-bond donor—a stronger one than iodine—owing to its much more electrophilic σ-hole.

  11. Mathematical modeling and experimental validation of Phaeodactylum tricornutum microalgae growth rate with glycerol addition

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Keli Cristiane Correia; Ribeiro, Robert Luis Lara; Santos, Kassiana Ribeiro dos; Mariano, Andre Bellin [Mariano Center for Research and Development of Sustainable Energy (NPDEAS), Curitiba, PR (Brazil); Vargas, Jose Viriato Coelho [Departament of Mechanical Engineering, Federal University of Parana (UFPR) Curitiba, PR (Brazil)

    2010-07-01

    The Brazilian National Program for Bio fuel Production has been encouraging diversification of feedstock for biofuel production. One of the most promising alternatives is the use of microalgae biomass for biofuel production. The cultivation of microalgae is conducted in aquatic systems, therefore microalgae oil production does not compete with agricultural land. Microalgae have greater photosynthetic efficiency than higher plants and are efficient fixing CO{sub 2}. The challenge is to reduce production costs, which can be minimized by increasing productivity and oil biomass. Aiming to increase the production of microalgae biomass, mixotrophic cultivation, with the addition of glycerol has been shown to be very promising. During the production of biodiesel from microalgae there is availability of glycerol as a side product of the transesterification reaction, which could be used as organic carbon source for microalgae mixotrophic growth, resulting in increased biomass productivity. In this paper, to study the effect of glycerol in experimental conditions, the batch culture of the diatom Phaeodactylum tricornutum was performed in a 2-liter flask in a temperature and light intensity controlled room. During 16 days of cultivation, the number of cells per ml was counted periodically in a Neubauer chamber. The calculation of dry biomass in the control experiment (without glycerol) was performed every two days by vacuum filtration. In the dry biomass mixotrophic experiment with glycerol concentration of 1.5 M, the number of cells was assessed similarly in the 10{sup th} and 14{sup th} days of cultivation. Through a volume element methodology, a mathematical model was written to calculate the microalgae growth rate. It was used an equation that describes the influence of irradiation and concentration of nutrients in the growth of microalgae. A simulation time of 16 days was used in the computations, with initial concentration of 0.1 g l{sup -1}. In order to compare

  12. Evidence for single metal two electron oxidative addition and reductive elimination at uranium.

    Science.gov (United States)

    Gardner, Benedict M; Kefalidis, Christos E; Lu, Erli; Patel, Dipti; McInnes, Eric J L; Tuna, Floriana; Wooles, Ashley J; Maron, Laurent; Liddle, Stephen T

    2017-12-01

    Reversible single-metal two-electron oxidative addition and reductive elimination are common fundamental reactions for transition metals that underpin major catalytic transformations. However, these reactions have never been observed together in the f-block because these metals exhibit irreversible one- or multi-electron oxidation or reduction reactions. Here we report that azobenzene oxidises sterically and electronically unsaturated uranium(III) complexes to afford a uranium(V)-imido complex in a reaction that satisfies all criteria of a single-metal two-electron oxidative addition. Thermolysis of this complex promotes extrusion of azobenzene, where H-/D-isotopic labelling finds no isotopomer cross-over and the non-reactivity of a nitrene-trap suggests that nitrenes are not generated and thus a reductive elimination has occurred. Though not optimally balanced in this case, this work presents evidence that classical d-block redox chemistry can be performed reversibly by f-block metals, and that uranium can thus mimic elementary transition metal reactivity, which may lead to the discovery of new f-block catalysis.

  13. Experimental evidence for rhombohedral phase of C70 after irradiation

    International Nuclear Information System (INIS)

    Misof, K.; Fratzl, P.; Vogl, G.

    1993-01-01

    Purely f.c.c. C 70 was irradiated with high-energy heavy ions at low temperature. This led to the appearance of additional Bragg peaks attributed to an irradiation-induced f.c.c.-to-rhombohedral phase transition. On heating to about 570 K the retrasition to the pure f.c.c. phase occurred. Since no irradiation-induced phase transition was obsered in C 60 , the rhombohedral phase appears to be connected with the ''rugby-ball shape'' of C 70 which favours the alignment of the molecules. We propose that irradiation provides the agitation enabling the C 70 molecules to overcome the small energy barriers which otherwise prevent the alignment of the rugby balls over larger regions. (orig.)

  14. Experimental evidence for the involvement of dinuclear alkynylcopper(I) complexes in alkyne-azide chemistry.

    Science.gov (United States)

    Buckley, Benjamin R; Dann, Sandra E; Heaney, Harry

    2010-06-01

    Dinuclear alkynylcopper(I) ladderane complexes are prepared by a robust and simple protocol involving the reduction of Cu(2)(OH)(3)OAc or Cu(OAc)(2) by easily oxidised alcohols in the presence of terminal alkynes; they function as efficient catalysts in copper-catalysed alkyne-azide cycloaddition reactions as predicted by the Ahlquist-Fokin calculations. The same copper(I) catalysts are formed during reactions by using the Sharpless-Fokin protocol. The experimental results also provide evidence that sodium ascorbate functions as a base to deprotonate terminal alkynes and additionally give a convincing alternative explanation for the fact that the Cu(I)-catalysed reactions of certain 1,3-diazides with phenylacetylene give bis(triazoles) as the major products. The same dinuclear alkynylcopper(I) complexes also function as catalysts in cycloaddition reactions of azides with 1-iodoalkynes.

  15. Gender differences in cooperation: experimental evidence on high school students.

    Directory of Open Access Journals (Sweden)

    J Alberto Molina

    Full Text Available The emergence of cooperation among unrelated human subjects is a long-standing conundrum that has been amply studied both theoretically and experimentally. Within the question, a less explored issue relates to the gender dependence of cooperation, which can be traced back to Darwin, who stated that "women are less selfish but men are more competitive". Indeed, gender has been shown to be relevant in several game theoretical paradigms of social cooperativeness, including prisoner's dilemma, snowdrift and ultimatum/dictator games, but there is no consensus as to which gender is more cooperative. We here contribute to this literature by analyzing the role of gender in a repeated Prisoners' Dilemma played by Spanish high-school students in both a square lattice and a heterogeneous network. While the experiment was conducted to shed light on the influence of networks on the emergence of cooperation, we benefit from the availability of a large dataset of more 1200 participants. We applied different standard econometric techniques to this dataset, including Ordinary Least Squares and Linear Probability models including random effects. All our analyses indicate that being male is negatively associated with the level of cooperation, this association being statistically significant at standard levels. We also obtain a gender difference in the level of cooperation when we control for the unobserved heterogeneity of individuals, which indicates that the gender gap in cooperation favoring female students is present after netting out this effect from other socio-demographics factors not controlled for in the experiment, and from gender differences in risk, social and competitive preferences.

  16. Ethnic and Gender Discrimination in Recruitment: Experimental Evidence From Finland

    Directory of Open Access Journals (Sweden)

    Karmela Liebkind

    2016-06-01

    Full Text Available We ask (1 how the position of an ethnic (majority or minority group in the local ethnic hierarchy affects the amount of recruitment discrimination faced by applicants from that group, and (2 whether gender discrimination is dependent on occupational gender stereotypes in the same way among ethnic majority and minority applicants. We use the situation testing method for the first time in Finland: In an experimental study (Study 1, 103 dentistry students made recruitment decisions based on the CVs of three bogus applicants from different ethnic groups (Finnish, Austrian and Polish and in a field experiment (Study 2, four test applicants (male and female Finns and Russians with equivalent CVs applied for 1,258 vacant jobs, addressing gender discrimination in relation to occupational gender stereotypes as well as ethnic discrimination. Together these studies cover both skilled (Study 1 and semi-skilled jobs (Study 2 and applicants from ethnic minority groups originating from within as well as outside the EU. Results show that majority group members are more likely to be hired compared to minority members (both Studies and that minority members from a higher status group are more likely to be hired than those from a lower status group (Study 1. Results also show that male applicants from the majority group were discriminated compared to women in occupations characterised as feminine, while Russian men faced recruitment discrimination compared to Russian women independently of the job’s gender stereotype (Study 2. Implications of recruitment discrimination based on ethnicity and gender are discussed.

  17. [Is it possible a bioethics based on the experimental evidence?].

    Science.gov (United States)

    Pastor, Luis Miguel

    2013-01-01

    For years there are different types of criticism about principialist bioethics. One alternative that has been proposed is to introduce empirical evidence within the bioethical discourse to make it less formal, less theoretical and closer to reality. In this paper we analyze first in synthetic form diverse alternative proposals to make an empirical bioethics. Some of them are strongly naturalistic while others aim to provide empirical data only for correct or improve bioethical work. Most of them are not shown in favor of maintaining a complete separation between facts and values, between what is and what ought to be. With different nuances these proposals of moderate naturalism make ethical judgments depend normative social opinion resulting into a certain social naturalism. Against these proposals we think to make a bioethics in that relates the empirical facts with ethical duties, we must rediscover empirical reality of human action. Only from it and, in particular, from the activity of discernment that makes practical reason, when judged on the object of his action, it is possible to integrate the mere descriptive facts with ethical judgments of character prescriptive. In conclusion we think that it is not possible to perform bioethics a mode of empirical science, as this would be contrary to natural reason, leading to a sort of scientific reductionism. At the same time we believe that empirical data are important in the development of bioethics and to enhance and improve the innate ability of human reason to discern good. From this discernment could develop a bioethics from the perspective of ethical agents themselves, avoiding the extremes of an excessive normative rationalism, accepting empirical data and not falling into a simple pragmatism.

  18. Additive-manufactured sandwich lattice structures: A numerical and experimental investigation

    Science.gov (United States)

    Fergani, Omar; Tronvoll, Sigmund; Brøtan, Vegard; Welo, Torgeir; Sørby, Knut

    2017-10-01

    The utilization of additive-manufactured lattice structures in engineered products is becoming more and more common as the competitiveness of AM as a production technology has increased during the past several years. Lattice structures may enable important weight reductions as well as open opportunities to build products with customized functional properties, thanks to the flexibility of AM for producing complex geometrical configurations. One of the most critical aspects related to taking AM into new application areas—such as safety critical products—is currently the limited understanding of the mechanical behavior of sandwich-based lattice structure mechanical under static and dynamic loading. In this study, we evaluate manufacturability of lattice structures and the impact of AM processing parameters on the structural behavior of this type of sandwich structures. For this purpose, we conducted static compression testing for a variety of geometry and manufacturing parameters. Further, the study discusses a numerical model capable of predicting the behavior of different lattice structure. A reasonably good correlation between the experimental and numerical results was observed.

  19. Experimental analysis of damages in a motor piston to gasoline operating with addition of hydroxy gas

    Energy Technology Data Exchange (ETDEWEB)

    Sanabio, Robdon Guimaraes, E-mail: robson.sanabio@alu.ufc.br [Universidade Estadual do Ceara (UFC), Fortaleza, CE(Brazil); Nascimento, Rubens Maribondo; Chellapa, Thiago; Dantas, Valter Bezerra; Medeiros, Isaac Pericles Maia [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2016-07-01

    Full text: The addition of hydrogen gas as an alternative fuel source has been widely used, as well reported in scientific literature. Today, several experiments are underway for the use of hydrogen generators (electrolyser) demand for motor vehicles. In all these products their ads manufacturers claim that this provides a reduction of fuel consumption, reduces the emission levels of toxic gas by the discharge and improves engine life. This research analyzes the physical structure of engine components using electrolysis on demand. To this end, a stationary system was fitted with a power generator of electricity, drum roller and adapted two electrolyzers: a dry cell and wet cell other. In steps observation were consumption analyzes in four work load ranges and observing the piston engine, which has been cut and analyzed by Optical Microscopy (OM), Scanning Electron Microscopy and Dispersive Energy (SEM-EDS), X – Ray Diffraction (XRD) and Confocal Microscopy, the stationary system in each step. The results showed a considerable reduction in fuel consumption and a high corrosion in the original factory piston constituted of aluminum-silicon alloy. As corrosion barrier was made a plasma nitriding in the piston head, which proved resistant to attack by hydrogen, although it has presented evidence also, of having been attacked. It is concluded that the automotive electrolysers can be a good choice in terms of consumption and reducing toxic gas emissions, but the material of the combustion chambers of vehicles must be prepared for this purpose. (author)

  20. Polyphenol nanoformulations for cancer therapy: experimental evidence and clinical perspective

    Directory of Open Access Journals (Sweden)

    Davatgaran-Taghipour Y

    2017-04-01

    Full Text Available Yasamin Davatgaran-Taghipour,1,2 Salar Masoomzadeh,3 Mohammad Hosein Farzaei,4,5 Roodabeh Bahramsoltani,6 Zahra Karimi-Soureh,7 Roja Rahimi,6,8 Mohammad Abdollahi9,10 1Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran; 2PhytoPharmacology Interest Group (PPIG, Universal Scientific Education and Research Network (USERN, Tehran, Iran; 3Zanjan Pharmaceutical Nanotechnology Research Center, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran; 4Pharmaceutical Sciences Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran; 5Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran; 6Department of Traditional Pharmacy, School of Traditional Medicine, Tehran University of Medical Sciences, Tehran, Iran; 7School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 8Evidence-Based Medicine Group, Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran; 9Toxicology and Diseases Group, Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran; 10Department of Toxicology and Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran Abstract: Cancer is defined as the abnormal cell growth that can cause life-threatening malignancies with high financial costs for patients as well as the health care system. Natural polyphenols have long been used for the prevention and treatment of several disorders due to their antioxidant, anti-inflammatory, cytotoxic, antineoplastic, and immunomodulatory effects discussed in the literature; thus, these phytochemicals are potentially able to act as chemopreventive and chemotherapeutic agents in different types of cancer. One of the problems regarding the use of polyphenolic compounds is their low

  1. Implicit attentional bias for facial emotion in dissociative seizures: Additional evidence.

    Science.gov (United States)

    Pick, Susannah; Mellers, John D C; Goldstein, Laura H

    2018-03-01

    This study sought to extend knowledge about the previously reported preconscious attentional bias (AB) for facial emotion in patients with dissociative seizures (DS) by exploring whether the finding could be replicated, while controlling for concurrent anxiety, depression, and potentially relevant cognitive impairments. Patients diagnosed with DS (n=38) were compared with healthy controls (n=43) on a pictorial emotional Stroop test, in which backwardly masked emotional faces (angry, happy, neutral) were processed implicitly. The group with DS displayed a significantly greater AB to facial emotion relative to controls; however, the bias was not specific to negative or positive emotions. The group effect could not be explained by performance on standardized cognitive tests or self-reported depression/anxiety. The study provides additional evidence of a disproportionate and automatic allocation of attention to facial affect in patients with DS, including both positive and negative facial expressions. Such a tendency could act as a predisposing factor for developing DS initially, or may contribute to triggering individuals' seizures on an ongoing basis. Psychological interventions such as Cognitive Behavioral Therapy (CBT) or AB modification might be suitable approaches to target this bias in clinical practice. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Modeling, Simulation, Additive Manufacturing, and Experimental Evaluation of Solid and Porous NiTi

    Science.gov (United States)

    Taheri Andani, Mohsen

    In recent years, shape memory alloys (SMAs) have entered a wide range of engineering applications in fields such as aerospace and medical applications. Nickel-titanium (NiTi) is the most commonly used SMAs due to its excellent functional characteristics (shape memory effect and superelasticity behavior). These properties are based on a solid-solid phase transformation between martensite and austenite. Beside these two characteristics, low stiffness, biocompatibility and corrosion properties of NiTi make it an attractive candidate for biomedical applications (e.g., bone plates, bone screws, and vascular stents). It is well know that manufacturing and processing of NiTi is very challenging. The functional properties of NiTi are significantly affected by the impurity level and due to the high titanium content, NiTi are highly reactive. Therefore, high temperature processed parts through methods such as melting and casting which result in increased impurity levels have inadequate structural and functional properties. Furthermore, high ductility and elasticity of NiTi, adhesion, work hardening and spring back effects make machining quite challenging. These unfavorable effects for machining cause significant tool wear along with decreasing the quality of work piece. Recently, additive manufacturing (AM) has gained significant attention for manufacturing NiTi. Since AM can create a part directly from CAD data, it is predicted that AM can overcome most of the manufacturing difficulties. This technique provides the possibility of fabricating highly complex parts, which cannot be processed by any other methods. Curved holes, designed porosity, and lattice like structures are some examples of mentioned complex parts. This work investigates manufacturing superelastic NiTi by selective laser melting (SLM) technique (using PXM by Phenix/3D Systems). An extended experimental study is conducted on the effect of subsequent heat treatments with different aging conditions on phase

  3. Methods to place a value on additional evidence are illustrated using a case study of corticosteroids after traumatic brain injury

    NARCIS (Netherlands)

    McKenna, Claire; Griffin, Susan; Koffijberg, Hendrik; Claxton, Karl

    2016-01-01

    OBJECTIVES: To establish whether evidence about the effectiveness of a health care intervention is sufficient to justify the use of the intervention in practice and show how value of information (VOI) analysis can be used to place a value on the need for additional evidence and inform research

  4. Experimental study of hydrogen as a fuel additive in internal combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Saanum, Inge

    2008-07-01

    Combustion of hydrocarbons in internal combustion engines results in emissions that can be harmful both to human health and to the environment. Although the engine technology is improving, the emissions of NO{sub x}, PM and UHC are still challenging. Besides, the overall consumption of fossil fuel and hence the emissions of CO{sub 2} are increasing because of the increasing number of vehicles. This has lead to a focus on finding alternative fuels and alternative technologies that may result in lower emissions of harmful gases and lower CO{sub 2} emissions. This thesis treats various topics that are relevant when using blends of fuels in different internal combustion engine technologies, with a particular focus on using hydrogen as a fuel additive. The topics addressed are especially the ones that impact the environment, such as emissions of harmful gases and thermal efficiency (fuel consumption). The thesis is based on experimental work performed at four different test rigs: 1. A dynamic combustion rig with optical access to the combustion chamber where spark ignited premixed combustion could be studied by means of a Schlieren optical setup and a high speed video camera. 2. A spark ignition natural gas engine rig with an optional exhaust gas recycling system. 3. A 1-cylinder diesel engine prepared for homogeneous charge compression ignition combustion. 4. A 6-cylinder standard diesel engine The engine rigs were equipped with cylinder pressure sensors, engine dynamometers, exhaust gas analyzers etc. to enable analyses of the effects of different fuels. The effect of hydrogen blended with methane and natural gas in spark ignited premixed combustion was investigated in the dynamic combustion rig and in a natural gas engine. In the dynamic combustion rig, the effect of hydrogen added to methane on the flame speed and the flame structure was investigated at elevated pressure and temperature. A considerable increase in the flame speed was observed when adding 30 vol

  5. An analytical and experimental study of pool boiling with particular reference to additives

    International Nuclear Information System (INIS)

    Owens, W.L. Jr.

    1963-05-01

    An experimental investigation of nucleate boiling heat transfer and critical heat flux is presented for water and various aqueous solutions boiling from horizontal stainless steel tubes and flat strips at atmospheric pressure. An integral method solution for film boiling is given and compared with existing experimental data. Analytical solutions are also obtained for the temperature profiles with periodic internal heating of a flat plate and a cylinder. (author)

  6. Photorespiratory Bypasses Lead to Increased Growth in Arabidopsis thaliana: Are Predictions Consistent with Experimental Evidence?

    Science.gov (United States)

    Basler, Georg; Küken, Anika; Fernie, Alisdair R.; Nikoloski, Zoran

    2016-01-01

    Arguably, the biggest challenge of modern plant systems biology lies in predicting the performance of plant species, and crops in particular, upon different intracellular and external perturbations. Recently, an increased growth of Arabidopsis thaliana plants was achieved by introducing two different photorespiratory bypasses via metabolic engineering. Here, we investigate the extent to which these findings match the predictions from constraint-based modeling. To determine the effect of the employed metabolic network model on the predictions, we perform a comparative analysis involving three state-of-the-art metabolic reconstructions of A. thaliana. In addition, we investigate three scenarios with respect to experimental findings on the ratios of the carboxylation and oxygenation reactions of Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). We demonstrate that the condition-dependent growth phenotypes of one of the engineered bypasses can be qualitatively reproduced by each reconstruction, particularly upon considering the additional constraints with respect to the ratio of fluxes for the RuBisCO reactions. Moreover, our results lend support for the hypothesis of a reduced photorespiration in the engineered plants, and indicate that specific changes in CO2 exchange as well as in the proxies for co-factor turnover are associated with the predicted growth increase in the engineered plants. We discuss our findings with respect to the structure of the used models, the modeling approaches taken, and the available experimental evidence. Our study sets the ground for investigating other strategies for increase of plant biomass by insertion of synthetic reactions. PMID:27092301

  7. Educational evidence based interventions for adults with autism spectrum disorders: experimental evidence

    Directory of Open Access Journals (Sweden)

    Saverio Fontani

    2017-01-01

    Full Text Available The educational interventions for adults with autism spectrum disorders are a relatively unexplored topic, in the face of numerous studies on the educational intervention models for the child population. In this paper the results of major studies and meta-analysis on the topic are presented and their implications for educational intervention are discussed.Interventi educativi evidence based per adulti con disturbi dello spettro autistico: evidenze sperimentaliGli interventi educativi per adulti con Disturbi dello Spettro Autistico rappresentano un’area relativamente poco esplorata, a fronte di numerosi studi dedicati ai modelli di intervento educativo rivolti alla popolazione infantile. In questo articolo sono presentati i risultati dei principali studi e delle meta-analisi sul tema e vengono discusse le loro implicazioni per l’intervento educativo.

  8. Experimental investigation of the effect of HBr additions on the lasing characteristics of a CuBr laser

    International Nuclear Information System (INIS)

    Shiyanov, D V; Sukhanov, V B; Andrienko, Oleg S; Evtushenko, Gennadii S

    2004-01-01

    It was experimentally determined that introducing small additions of HBr into the active elements of a CuBr laser is similar to the addition of hydrogen and significantly improves the output laser parameters. The effect of additions to small-volume active elements is most pronounced (up to a five-fold increase in output power) and is less pronounced in large-volume active elements (up to a twofold increase). A special-purpose HBr generator was elaborated, making it possible to promptly provide the requisite concentration of the active addition in a sealed-off active element. (lasers, active media)

  9. Bisphenol A and Reproductive Health: Update of Experimental and Human Evidence, 2007–2013

    Science.gov (United States)

    Peretz, Jackye; Vrooman, Lisa; Ricke, William A.; Hunt, Patricia A.; Ehrlich, Shelley; Hauser, Russ; Padmanabhan, Vasantha; Taylor, Hugh S.; Swan, Shanna H.; VandeVoort, Catherine A.

    2014-01-01

    Background: In 2007, an expert panel reviewed associations between bisphenol A (BPA) exposure and reproductive health outcomes. Since then, new studies have been conducted on the impact of BPA on reproduction. Objective: In this review, we summarize data obtained since 2007, focusing on a) findings from human and animal studies, b) the effects of BPA on a variety of reproductive end points, and c) mechanisms of BPA action. Methods: We reviewed the literature published from 2007 to 2013 using a PubMed search based on keywords related to BPA and male and female reproduction. Discussion: Because BPA has been reported to affect the onset of meiosis in both animal and in vitro models, interfere with germ cell nest breakdown in animal models, accelerate follicle transition in several animal species, alter steroidogenesis in multiple animal models and women, and reduce oocyte quality in animal models and women undergoing in vitro fertilization (IVF), we consider it an ovarian toxicant. In addition, strong evidence suggests that BPA is a uterine toxicant because it impaired uterine endometrial proliferation, decreased uterine receptivity, and increased implantation failure in animal models. BPA exposure may be associated with adverse birth outcomes, hyperandrogenism, sexual dysfunction, and impaired implantation in humans, but additional studies are required to confirm these associations. Studies also suggest that BPA may be a testicular toxicant in animal models, but the data in humans are equivocal. Finally, insufficient evidence exists regarding effects of BPA on the oviduct, the placenta, and pubertal development. Conclusion: Based on reports that BPA impacts female reproduction and has the potential to affect male reproductive systems in humans and animals, we conclude that BPA is a reproductive toxicant. Citation: Peretz J, Vrooman L, Ricke WA, Hunt PA, Ehrlich S, Hauser R, Padmanabhan V, Taylor HS, Swan SH, VandeVoort CA, Flaws JA. 2014. Bisphenol A and reproductive

  10. Cardiovascular autonomic dysfunction in primary ovarian insufficiency: clinical and experimental evidence

    Science.gov (United States)

    Goldmeier, Silvia; De Angelis, Kátia; Rabello Casali, Karina; Vilodre, César; Consolim-Colombo, Fernanda; Belló Klein, Adriane; Plentz, Rodrigo; Spritzer, PoliMara; Irigoyen, Maria-Cláudia

    2014-01-01

    Objective: Women with primary ovarian insufficiency (POI) present an increased risk for cardiovascular disease. In this study we tested the hypothesis that POI in women under hormone therapy (HT) are associated with vascular vasodilatation attenuation and cardiovascular autonomic dysfunction and these impairments are related to changes in systemic antioxidant enzymes. Furthermore, the possibility that ovarian hormone deprivation can induce such changes and that HT cannot reverse all of those impairments was examined in an experimental model of POI. Methods: Fifteen control and 17 patients with primary ovarian insufficiency receiving HT were included in the study. To test the systemic and cardiac consequences of ovarian hormone deprivation, ovariectomy was induced in young female rats that were submitted or not to HT. Spectral analysis of RR interval and blood pressure signals were performed and oxidative stress parameters were determined. Results: POI women under HT have increased mean arterial pressure (94±10 vs. 86±5 mmHg) despite normal endothelial and autonomic modulation of vasculature. Additionally, they presented impaired baroreflex sensitivity (3.9±1.38 vs. 7.15±3.62 ms/mmHg) and reduced heart rate variability (2310±1173 vs. 3754±1921 ms2). Similar results obtained in ovariectomized female rats were accompanied by an increased lipoperoxidation (7433±1010 vs. 6180±289 cps/mg protein) and decreased antioxidant enzymes in cardiac tissue. As it was observed in women, the HT in animals did not restore hemodynamic and autonomic dysfunctions. Conclusion: These data provide clinical and experimental evidence that long term HT may not restore all cardiovascular risk factors associated with ovarian hormone deprivation. PMID:24349626

  11. Isomer depletion as experimental evidence of nuclear excitation by electron capture

    Science.gov (United States)

    Chiara, C. J.; Carroll, J. J.; Carpenter, M. P.; Greene, J. P.; Hartley, D. J.; Janssens, R. V. F.; Lane, G. J.; Marsh, J. C.; Matters, D. A.; Polasik, M.; Rzadkiewicz, J.; Seweryniak, D.; Zhu, S.; Bottoni, S.; Hayes, A. B.; Karamian, S. A.

    2018-02-01

    The atomic nucleus and its electrons are often thought of as independent systems that are held together in the atom by their mutual attraction. Their interaction, however, leads to other important effects, such as providing an additional decay mode for excited nuclear states, whereby the nucleus releases energy by ejecting an atomic electron instead of by emitting a γ-ray. This ‘internal conversion’ has been known for about a hundred years and can be used to study nuclei and their interaction with their electrons. In the inverse process—nuclear excitation by electron capture (NEEC)—a free electron is captured into an atomic vacancy and can excite the nucleus to a higher-energy state, provided that the kinetic energy of the free electron plus the magnitude of its binding energy once captured matches the nuclear energy difference between the two states. NEEC was predicted in 1976 and has not hitherto been observed. Here we report evidence of NEEC in molybdenum-93 and determine the probability and cross-section for the process in a beam-based experimental scenario. Our results provide a standard for the assessment of theoretical models relevant to NEEC, which predict cross-sections that span many orders of magnitude. The greatest practical effect of the NEEC process may be on the survival of nuclei in stellar environments, in which it could excite isomers (that is, long-lived nuclear states) to shorter-lived states. Such excitations may reduce the abundance of the isotope after its production. This is an example of ‘isomer depletion’, which has been investigated previously through other reactions, but is used here to obtain evidence for NEEC.

  12. The fishermen were right: experimental evidence for tributary refuge hypothesis during floods.

    Science.gov (United States)

    Koizumi, Itsuro; Kanazawa, Yukiyo; Tanaka, Yuuki

    2013-05-01

    Fishermen often anecdotally report an unexpected increase of fish caught in small tributary streams during floods, presumably due to refuge-seeking behavior from the main stem. From a population perspective, this implies the significance of refuge habitats and connectivity for population viability against natural disturbances. Despite the plausibility, however, surprisingly few studies have examined the tributary refuge hypothesis, mainly due to the difficulty in field survey during floods. Here, we made use of a large-scale controlled flood to assess whether fishes move into tributaries during flooding in the main stem. A planned water release from the Satsunai River Dam located on Hokkaido Island in Japan rapidly increased the main stem discharge by more than 20-fold. Before, during, and after flooding censuses in four tributaries provided evidence of the refuge-seeking behavior of fishes from the main stem. For example, more than 10 Dolly Varden char, a salmonid fish, were caught in a tributary during the flood, even though almost no individuals were captured before or after the flood. The fish responded immediately to the flooding, suggesting the need for studies during disturbances. In addition, the likelihood of refuge movements varied among tributaries, suggesting the importance of local environmental differences between tributary and the main stem habitats. This is the first study to experimentally confirm the tributary refuge hypothesis, and underscores the roles of habitat diversity and connectivity during disturbances, even though some habitats are not used during normal conditions.

  13. Effect of Nanofiller Addition to an Experimental Dentin Adhesive on Microtensile Bond Strength to Human Dentin

    Directory of Open Access Journals (Sweden)

    SH. Kasraei

    2009-06-01

    Full Text Available Objective: The purpose of the study was to evaluate the influence of adding nanofiller particles to a dentin bonding agent on resin-dentin bond strength.Materials and Methods: Fifty-four human intact premolar teeth were divided in to 6 groups of nine. The teeth were ground on occlusal surfaces and polished with 320 and then 600 grit silicon carbide papers. An experimental bonding system based on acetone/alcoholsolvent was provided with filler contents of 0.0, 0.5, 1.0, 2.5, 5.0, and 10.0 weight percent fumed silica nanofiller. After dentin surface etching, rinsing and blot drying, the experimentalbonding agents were applied to dentin surface. A composite resin was, then,bonded to the dentin on the bonding agent. The specimens were thermocycled for 500 cycles and sectioned in stick form. After two week of storage in distilled water, resin-dentin microtensile bond strength of the specimens was measured. Data were analyzed by one way ANOVA and DunnettT3 tests.Results: Bond strength to dentin was significantly affected by the filler level. Minimum and maximum resin-microtensile bond strength was in the experimental bonding agent with no filler (5.88 MPa and with filler level of 1.0 weight percent (15.15 MPa, respectively,and decreased with the increase of filler content down to 8.95 MPa for the filler level of 10.0 weight percent.Conclusion: Filler content seems to be one of the important factors influencing the bond strength of dental adhesives. Maximum dentin bond strength was obtained with 1% silanized nanofiller silica added to experimental adhesive system.

  14. An Experimental Evaluation of Hyperactivity and Food Additives. 1977-Phase I.

    Science.gov (United States)

    Harley, J. Preston

    Reported are findings of a study involving 46 families in which the effect of the Feingold (additive free) diet on hyperactivity in preschool and elementary age children was investigated. Eleven sections cover the following project components: introduction (definition of hyperactivity and the B. Feingold hypothesis), methodology, demographic…

  15. Study types and reliability of Real World Evidence compared with experimental evidence used in Polish reimbursement decision-making processes.

    Science.gov (United States)

    Wilk, N; Wierzbicka, N; Skrzekowska-Baran, I; Moćko, P; Tomassy, J; Kloc, K

    2017-04-01

    The aim of this study was to identify the relationship and impact between Real World Evidence (RWE) and experimental evidence (EE) in Polish decision-making processes for the drugs from selected Anatomical Therapeutic Chemical (ATC) groups. Descriptive study. A detailed analysis was performed for 58 processes from five ATC code groups in which RWE for effectiveness, or effectiveness and safety were cited in Agency for Health Technology Assessment and Tariff System's (AOTMiT) documents published between January 2012 and September 2015: Verification Analysis of AOTMiT, Statement of the Transparency Council of AOTMiT, and Recommendation of the President of AOTMiT. In 62% of the cases, RWE supported the EE and confirmed its main conclusions. The majority of studies in the EE group showed to be RCTs (97%), and the RWE group included mainly cohort studies (89%). There were more studies without a control group within RWE compared with the EE group (10% vs 1%). Our results showed that EE are more often assessed using Jadad, NICE or NOS scale by AOTMiT compared with RWE (93% vs 48%). When the best evidence within a given decision-making process is analysed, half of RWE and two-thirds of EE are considered high quality evidence. RWE plays an important role in the decision-making processes on public funding of drugs in Poland, contributing to nearly half (45%) of all the evidence considered. There exist such processes in which the proportion of RWE is dominant, with one process showing RWE as the only evidence presented. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  16. Experimental evidence of lateral flow in unsaturated homogeneous isotropic sloping soil due to rainfall

    NARCIS (Netherlands)

    Sinai, G.; Dirksen, C.

    2006-01-01

    This paper describes laboratory experimental evidence for lateral flow in the top layer of unsaturated sloping soil due to rainfall. Water was applied uniformly on horizontal and V-shaped surfaces of fine sand, at rates about 100 times smaller than the saturated hydraulic conductivity. Flow regimes

  17. Transparency about past, present and future conduct : Experimental evidence on the impact of competitiveness

    NARCIS (Netherlands)

    Potters, J.J.M.; Hinloopen, J.; Normann, H-T

    2009-01-01

    Transparency relates to communication and information about the conduct of firms. Transparency can relate to the past, the present and the future and it can vary in format, content and reliability. In this chapter I review experimental evidence which relates to the impact of transparency on the

  18. Latent interface-trap building in power VDMOSFETs: new experimental evidence and numerical simulation

    International Nuclear Information System (INIS)

    Ristic, G.F.; Jaksic, A.B.; Pejovic, M.M.

    1999-01-01

    The paper presents new experimental evidence of the latent interface-trap buildup during annealing of gamma-ray irradiated power VDMOSFETs. We try to reveal the nature of this still ill-understood phenomenon by isothermal annealing, switching temperature annealing and switching bias annealing experiments. The results of numerical simulation of interface-trap kinetics during annealing are also shown. (authors)

  19. Memory for musical tempo: Additional evidence that auditory memory is absolute

    OpenAIRE

    Levitin, Daniel J.; Cook, Perry R.

    1996-01-01

    We report evidence that long term memory retains absolute (accurate) features of perceptual events. Specifically, we show that memory for music seems to preserve the absolute tempo of the musical performance. In Experiment 1, 46 subjects sang popular songs from memory, and their tempos were compared to recorded versions of the songs. Seventy-two of the subjects came within 8% of the actual tempo on two consecutive trials (using different songs), demonstrating accuracy near the perceptual thre...

  20. Cycle frequency in standard Rock-Paper-Scissors games: Evidence from experimental economics

    Science.gov (United States)

    Xu, Bin; Zhou, Hai-Jun; Wang, Zhijian

    2013-10-01

    The Rock-Paper-Scissors (RPS) game is a widely used model system in game theory. Evolutionary game theory predicts the existence of persistent cycles in the evolutionary trajectories of the RPS game, but experimental evidence has remained to be rather weak. In this work, we performed laboratory experiments on the RPS game and analyzed the social-state evolutionary trajectories of twelve populations of N=6 players. We found strong evidence supporting the existence of persistent cycles. The mean cycling frequency was measured to be 0.029±0.009 period per experimental round. Our experimental observations can be quantitatively explained by a simple non-equilibrium model, namely the discrete-time logit dynamical process with a noise parameter. Our work therefore favors the evolutionary game theory over the classical game theory for describing the dynamical behavior of the RPS game.

  1. Experimental Evaluation of Oxide Nanoparticles as Friction and Wear Improvement Additives in Motor Oil

    Directory of Open Access Journals (Sweden)

    Nicholaos G. Demas

    2017-01-01

    Full Text Available The effect of two nanoparticle oxides on friction and wear was studied under laboratory test conditions using a reciprocating test machine and two test configurations. The addition of these nanoparticles in base stock oil under certain conditions reduced the coefficient of friction and improved wear, but that depended on the test configuration. Examination of the rubbed surfaces showed the pronounced formation of a tribofilm in some cases, while polishing on the surface was also observed in other cases. Contact configuration is important when oxide nanoparticles are being evaluated and the conclusions about their efficacy can be vastly different.

  2. Fragile X-associated primary ovarian insufficiency: evidence for additional genetic contributions to severity.

    Science.gov (United States)

    Hunter, Jessica Ezzell; Epstein, Michael P; Tinker, Stuart W; Charen, Krista H; Sherman, Stephanie L

    2008-09-01

    The fragile X mental retardation gene (FMR1) contains a CGG repeat sequence in its 5' untranslated region that can become unstable and expand in length from generation to generation. Alleles with expanded repeats in the range of approximately 55-199, termed premutation alleles, are associated with an increased risk for fragile-X-associated primary ovarian insufficiency (FXPOI). However, not all women who carry the premutation develop FXPOI. To determine if additional genes could explain variability in onset and severity, we used a random-effects Cox proportional hazards model to analyze age at menopause on 680 women from 225 families who have a history of fragile X syndrome and 321 women from 219 families from the general population. We tested for the presence of a residual additive genetic effect after adjustment for FMR1 repeat length, race, smoking, body mass index, and method of ascertainment. Results showed significant familial aggregation of age at menopause with an estimated additive genetic variance of 0.55-0.96 depending on the parameterization of FMR1 repeat size and definition of age at menopause (P-values ranging between 0.0002 and 0.0027). This is the first study to analyze familial aggregation of FXPOI. This result is important for proper counseling of women who carry FMR1 premutation alleles and for guidance of future studies to identify additional genes that influence ovarian insufficiency. (c) 2008 Wiley-Liss, Inc.

  3. Biogas Production Experimental Research by Using Sewage Sludge Loading with Biochar Additive

    Directory of Open Access Journals (Sweden)

    Vitalij Kolodynskij

    2017-09-01

    Full Text Available Biogas – ecological fuel, which is assigned to alternative energy sources. It should be noted, that biogas – renewable energy source, which does not require any specific climatic conditions or geographical position of a country. This power source is available and can be successfully produced and used in all countries of the world. The main components of biogas – methane CH4 and carbon monoxide CO2. This gas is formed under anaerobic conditions, when microorganisms decompose biodegradable biomass. In biological sciences biomass means a living matter content, expressed in grams per unit area. Meanwhile, in the energy sector, the definition of biomass is limited and biomass is characterized as fuel source, produced from plant materials and organic waste (food waste, wood, sludge, manure, vegetables, etc.. Currently, to produce biogas from biomass, bioreactors are used worldwide. However, in order to increase the quality and yield of biogas, in the world practice various bioload additives are used: vegetable waste, clay minerals, and a large amount of the protein-containing waste. The goal – to evaluate the impact of biochar on biogas quality and yield using sewage sludge load. It was found, that 10% biochar additive increased average CH4 concentration of 7.9%, reduced the CO2 concentration of 3–4% and totally removed H2S from biogas.

  4. Rheological and filtration characteristics of drilling fluids enhanced by nanoparticles with selected additives: an experimental study

    Directory of Open Access Journals (Sweden)

    Nima Mohamadian

    2018-05-01

    Full Text Available The suspension properties of drilling fluids containing pure and polymer-treated (partially-hydrolyzed polyacrylamide (PHPA or Xanthan gum clay nanoparticles are compared withthose of a conventional water-and-bentonite-based drilling fluid, used as the referencesample. Additionally, the mud weight, plastic viscosity, apparent viscosity, yield point, primary and secondary gelatinization properties, pH, and filtration properties of the various drilling fluids studied are also measured and compared. The performance of each drilling fluid type is evaluated with respect in terms of its ability to reduce mud cake thickness and fluid loss thereby inhibiting differential-pipe-sticking. For that scenario, the mud-cake thickness is varied, and the filtration properties of the drilling fluids are measured as an indicator of potential well-diameter reduction, caused by mud cake, adjacent to permeable formations. The novel results show that nanoparticles do significantly enhance the rheological and filtration characteristics of drilling fluids. A pure-clay-nanoparticle suspension, without any additives, reduced fluid loss to about 42% and reduced mud cake thickness to 30% compared to the reference sample. The xanthan-gum-treated-clay-nanoparticle drilling fluid showed good fluid loss control and reduced fluid loss by 61% compared to the reference sample. The presence of nanofluids also leads to reduced mud-cake thicknesses, directly mitigating the risks of differential pipe sticking.

  5. Modernization at the Y-12 National Security Complex: A Case for Additional Experimental Benchmarks

    Energy Technology Data Exchange (ETDEWEB)

    Thornbury, M. L. [Y-12 National Security Complex, Oak Ridge, TN (United States); Juarez, C. [Y-12 National Security Complex, Oak Ridge, TN (United States); Krass, A. W. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2017-08-14

    Efforts are underway at the Y-12 National Security Complex (Y-12) to modernize the recovery, purification, and consolidation of un-irradiated, highly enriched uranium metal. Successful integration of advanced technology such as Electrorefining (ER) eliminates many of the intermediate chemistry systems and processes that are the current and historical basis of the nuclear fuel cycle at Y-12. The cost of operations, the inventory of hazardous chemicals, and the volume of waste are significantly reduced by ER. It also introduces unique material forms and compositions related to the chemistry of chloride salts for further consideration in safety analysis and engineering. The work herein briefly describes recent investigations of nuclear criticality for 235UO2Cl2 (uranyl chloride) and 6LiCl (lithium chloride) in aqueous solution. Of particular interest is the minimum critical mass of highly enriched uranium as a function of the molar ratio of 6Li to 235U. The work herein also briefly describes recent investigations of nuclear criticality for 235U metal reflected by salt mixtures of 6LiCl or 7LiCl (lithium chloride), KCl (potassium chloride), and 235UCl3 or 238UCl3 (uranium tri-chloride). Computational methods for analysis of nuclear criticality safety and published nuclear data are employed in the absence of directly relevant experimental criticality benchmarks.

  6. Additive effects of repetition and predictability during comprehension: evidence from event-related potentials.

    Directory of Open Access Journals (Sweden)

    Wing-Yee Chow

    Full Text Available Previous research has shown that neural responses to words during sentence comprehension are sensitive to both lexical repetition and a word's predictability in context. While previous research has often contrasted the effects of these variables (e.g. by looking at cases in which word repetition violates sentence-level constraints, little is known about how they work in tandem. In the current study we examine how recent exposure to a word and its predictability in context combine to impact lexical semantic processing. We devise a novel paradigm that combines reading comprehension with a recognition memory task, allowing for an orthogonal manipulation of a word's predictability and its repetition status. Using event-related brain potentials (ERPs, we show that word repetition and predictability have qualitatively similar and additive effects on the N400 amplitude. We propose that prior exposure to a word and predictability impact lexical semantic processing in an additive and independent fashion.

  7. Evidence for Single Metal Two Electron Oxidative Addition and Reductive Elimination at Uranium

    OpenAIRE

    Gardner, Benedict M; Kefalidis, Christos E; Lu, Erli; Patel, Dipti; Mcinnes, Eric; Tuna, Floriana; Wooles, Ashley; Maron, Laurent; Liddle, Stephen

    2017-01-01

    Reversible single-metal two-electron oxidative addition and reductive elimination are common fundamental reactions for transition metals that underpin major catalytic transformations. However, these reactions have never been observed together in the f-block because these metals exhibit irreversible one- or multi-electron oxidation or reduction reactions. Here, we report that azobenzene oxidises sterically and electronically unsaturated uranium(III) complexes to afford a uranium(V)-imido compl...

  8. A comparative experimental study of steel fibre-additive reinforced concrete beams

    Directory of Open Access Journals (Sweden)

    Altun, F.

    2004-12-01

    Full Text Available Five different batches of class C20 concrete, containing Dramix-RC-80/60-BN steel fibers (SFs as additives at doses of 0, 30, 40, 50 and 60 kg/m3, and six Ø 15x30 cm prisms were poured from each batch. Standard crushing tests were run on all the specimens and the respective load-displacement and stress-strain curves were plotted. Toughness, ultimate compressive strength and the modulus of elasticity were determined for all specimens. The compressive strength and modulus of elasticity declined in 30 kg/m3 steel-fiber-additive concrete (SFAC by 9% and 7% compared to the reference C20 concrete without SFs, and the area under the load-deflection curve grew more than twofold. In concrete with a higher SF dosage, the differences in strength and elasticity were around I0% whilst toughness was about the same. Because toughness values were similar in 30, 40, 50 and 60 kg/m3 plain SF-additive concrete and the strength and modulus of elasticity were slightly better in the mixes with the smallest proportion of SF for reasons of economy, 30 kg/m3 was taken as the optimum dose of steel fiber to be added to the reinforced concrete used in a second phase of the study. Hence, of the six reinforced concrete (RC beams made, all of equal size and with the same under-reinforced tensile reinforcement design, three were made with concrete containing the above-mentioned dose of SF. In addition to compressive strength, these beams were tested for flexural strength, which was found to be 18% greater for the SFARC beams than the ordinary RC beams, and the upper arms of the load versus mid-span deflection curves prior to ultimate failure of the SFARC beams were considerably longer than the same arms on the curves for ordinary RC beams.

    Se han utilizado cinco lotes diferentes de hormigón clase C20 cuatro de ellos con fibras de acero (FA, identificadas como Dramix-CR-80/60-BN, en cuatro proporciones diferentes: 30, 40, 50 y 60 kg/m3 y el quinto exento de

  9. Additive impacts of experimental climate change increase risk to an ectotherm at the Arctic's edge

    Science.gov (United States)

    Davenport, Jon M.; Hossack, Blake R.; Fishback, LeeAnn

    2017-01-01

    Globally, Arctic and Subarctic regions have experienced the greatest temperature increases during the last 30 years. These extreme changes have amplified threats to the freshwater ecosystems that dominate the landscape in many areas by altering water budgets. Several studies in temperate environments have examined the adaptive capacity of organisms to enhance our understanding of the potential repercussions of warming and associated accelerated drying for freshwater ecosystems. However, few experiments have examined these impacts in Arctic or Subarctic freshwater ecosystems, where the climate is changing most rapidly. To evaluate the capacity of a widespread ectotherm to anticipated environmental changes, we conducted a mesocosm experiment with wood frogs (Rana sylvatica) in the Canadian Subarctic. Three warming treatments were fully crossed with three drying treatments to simulate a range of predicted changes in wetland environments. We predicted wetland warming and drying would act synergistically, with water temperature partially compensating for some of the negative effects of accelerated drying. Across all drying regimes, a 1 °C increase in water temperature increased the odds of survival by 1.79, and tadpoles in 52-day and 64-day hydroperiod mesocosms were 4.1–4.3 times more likely to survive to metamorphosis than tadpoles in 45-day mesocosms. For individuals who survived to metamorphosis, there was only a weak negative effect of temperature on size. As expected, increased temperatures accelerated tadpole growth through day 30 of the experiment. Our results reveal that one of the dominant herbivores in Subarctic wetlands, wood frog tadpoles, are capable of increasing their developmental rates in response to increased temperature and accelerated drying, but only in an additive manner. The strong negative effects of drying on survival, combined with lack of compensation between these two environmental drivers, suggest changes in the aquatic environment

  10. Additive impacts of experimental climate change increase risk to an ectotherm at the Arctic's edge.

    Science.gov (United States)

    Davenport, Jon M; Hossack, Blake R; Fishback, LeeAnn

    2017-06-01

    Globally, Arctic and Subarctic regions have experienced the greatest temperature increases during the last 30 years. These extreme changes have amplified threats to the freshwater ecosystems that dominate the landscape in many areas by altering water budgets. Several studies in temperate environments have examined the adaptive capacity of organisms to enhance our understanding of the potential repercussions of warming and associated accelerated drying for freshwater ecosystems. However, few experiments have examined these impacts in Arctic or Subarctic freshwater ecosystems, where the climate is changing most rapidly. To evaluate the capacity of a widespread ectotherm to anticipated environmental changes, we conducted a mesocosm experiment with wood frogs (Rana sylvatica) in the Canadian Subarctic. Three warming treatments were fully crossed with three drying treatments to simulate a range of predicted changes in wetland environments. We predicted wetland warming and drying would act synergistically, with water temperature partially compensating for some of the negative effects of accelerated drying. Across all drying regimes, a 1 °C increase in water temperature increased the odds of survival by 1.79, and tadpoles in 52-day and 64-day hydroperiod mesocosms were 4.1-4.3 times more likely to survive to metamorphosis than tadpoles in 45-day mesocosms. For individuals who survived to metamorphosis, there was only a weak negative effect of temperature on size. As expected, increased temperatures accelerated tadpole growth through day 30 of the experiment. Our results reveal that one of the dominant herbivores in Subarctic wetlands, wood frog tadpoles, are capable of increasing their developmental rates in response to increased temperature and accelerated drying, but only in an additive manner. The strong negative effects of drying on survival, combined with lack of compensation between these two environmental drivers, suggest changes in the aquatic environment that

  11. PROCESSING OF MULTI-DIGIT ADDITIONS IN HIGH MATH-ANXIOUS INDIVIDUALS: PSYCHOPHYSIOLOGICAL EVIDENCE

    Directory of Open Access Journals (Sweden)

    MARIA ISABEL eNÚÑEZ-PEÑA

    2015-08-01

    Full Text Available We investigated the time course of neural processing of multi-digit additions in high- (HMA and low-math anxious (LMA individuals. Seventeen HMA and 17 LMA individuals were presented with two-digit additions and were asked to perform a verification task. Behavioral data showed that HMA were slower and more error prone than their LMA peers, and that incorrect solutions were solved more slowly and less accurately than correct ones. Moreover, HMA individuals tended to need more time and commit more errors when having to verify incorrect solutions than correct ones. They also took longer and made more errors than their LMA peers. ERPs time-locked to the presentation of the addends (calculation phase and to the presentation of the proposed solution (verification phase were also analyzed. In both phases, a P2 component of larger amplitude was found for HMA individuals than for their LMA peers. Moreover, in the verification phase, LMA individuals showed a larger late positive component (LPC for incorrect solutions at parietal electrodes than their HMA counterparts. Because the P2 component is considered to be a biomarker of the mobilization of attentional resources towards emotionally negative stimuli, these results suggest that HMA individuals may invest more attentional resources during the arithmetical

  12. Finite element simulation and experimental verification of ultrasonic non-destructive inspection of defects in additively manufactured materials

    Science.gov (United States)

    Taheri, H.; Koester, L.; Bigelow, T.; Bond, L. J.

    2018-04-01

    Industrial applications of additively manufactured components are increasing quickly. Adequate quality control of the parts is necessary in ensuring safety when using these materials. Base material properties, surface conditions, as well as location and size of defects are some of the main targets for nondestructive evaluation of additively manufactured parts, and the problem of adequate characterization is compounded given the challenges of complex part geometry. Numerical modeling can allow the interplay of the various factors to be studied, which can lead to improved measurement design. This paper presents a finite element simulation verified by experimental results of ultrasonic waves scattering from flat bottom holes (FBH) in additive manufacturing materials. A focused beam immersion ultrasound transducer was used for both the modeling and simulations in the additive manufactured samples. The samples were SS17 4 PH steel samples made by laser sintering in a powder bed.

  13. The paradox of natural products as pharmaceuticals. Experimental evidences of a mango stem bark extract.

    Science.gov (United States)

    Núñez-Sellés, Alberto J; Delgado-Hernández, René; Garrido-Garrido, Gabino; García-Rivera, Dagmar; Guevara-García, Mariela; Pardo-Andreu, Gilberto L

    2007-05-01

    Recent findings regarding basic, pre-clinical and clinical studies on a mango stem bark extract (MSBE) developed in Cuba (Vimang) on an industrial scale are summarized. Ethnomedical studies, extract reproducibility, biological effects and clinical evaluations in terms of patient quality of life are described as experimental evidences to support the statement that natural products, even being a mixture of compounds, could be as effective as "monoceuticals" for medical uses. Discussion about the use of "monoceuticals" versus "natureceuticals" in health care and medicine is based on effectiveness and availability, taking Vimang as an example of a natural product with supported scientific evidence to be used as antioxidant, analgesic, anti-inflammatory and immunomodulator.

  14. Effects of experimental nitrogen additions on plant diversity in tropical forests of contrasting disturbance regimes in southern China

    International Nuclear Information System (INIS)

    Lu Xiankai; Mo Jiangming; Gilliam, Frank S.; Yu Guirui; Zhang Wei; Fang Yunting; Huang Juan

    2011-01-01

    Responses of understory plant diversity to nitrogen (N) additions were investigated in reforested forests of contrasting disturbance regimes in southern China from 2003 to 2008: disturbed forest (with harvesting of understory vegetation and litter) and rehabilitated forest (without harvesting). Experimental additions of N were administered as the following treatments: Control, 50 kg N ha -1 yr -1 , and 100 kg N ha -1 yr -1 . Nitrogen additions did not significantly affect understory plant richness, density, and cover in the disturbed forest. Similarly, no significant response was found for canopy closure in this forest. In the rehabilitated forest, species richness and density showed no significant response to N additions; however, understory cover decreased significantly in the N-treated plots, largely a function of a significant increase in canopy closure. Our results suggest that responses of plant diversity to N deposition may vary with different land-use history, and rehabilitated forests may be more sensitive to N deposition. - Highlights: → Nitrogen addition had no significant effect on understory plant diversity in the disturbed forest. → Nitrogen addition significantly decreased understory plant cover. → Nitrogen addition had no effect on richness and density in the rehabilitated forest. → The decrease is largely a function of a significant increase in canopy closure. → Land-use practices may dominate the responses of plant diversity to N addition. - Research in disturbed forests of southeastern China demonstrates that land-use history can substantially alter effects of excess nitrogen deposition on plant diversity of tropical forest ecosystems.

  15. Experimental researches about the influence of the additives for engine oils upon the work of the engine

    International Nuclear Information System (INIS)

    Dimitrovski, Mile; Mucevski, Kiril

    2003-01-01

    In this paper an attempt to get some cognitions about the influence of the additives for engine oils upon the working parameters of the internal combustion engines is made. During the experimental researches the changes of the basic parameters which determine the work of the engine, such as: the pressure of compression, the noise, the vibrations, the friction of the engine mechanism, the internal cleanliness of the engine and similar, were observed. It was conclude that the use of additives into the engine oil resulted with smoother work of the engine and cleaner exhausted as well. (Author)

  16. Numerical and experimental study of Ti6Al4V components manufactured using powder bed fusion additive manufacturing

    OpenAIRE

    Zielinski, J.; Mindt, H.-W.; Düchting, J.; Schleifenbaum, J.H.; Megahed, M.

    2017-01-01

    Powder bed fusion additive manufacturing of titanium alloys is an interesting manufacturing route for many applications requiring high material strength combined with geometric complexity. Managing powder bed fusion challenges, including porosity, surface finish, distortions and residual stresses of as-built material, is the key to bringing the advantages of this process to production main stream. This paper discusses the application of experimental and numerical analysis towards optimizing t...

  17. Increase in transmission loss of single panels by addition of mass inclusions to a poro-elastic layer: Experimental investigation

    Science.gov (United States)

    Kidner, M. R. F.; Fuller, C. R.; Gardner, B.

    2006-06-01

    The insertion loss of standard acoustic blankets can be significantly improved at low frequencies by the addition of randomly placed mass inclusions to the poro-elastic layers. The improvement is much greater than that due to the mass effect alone. The mass inclusions act as resonant systems and so increase the structure impedance. This paper reports the results of experimental investigations into this phenomenon. Increases in insertion loss of 15 dB in the 100 Hz third octave band are reported.

  18. Geochemical evidence for airborne dust additions to soils in Channel Islands National Park, California

    Science.gov (United States)

    Muhs, D.R.; Budahn, J.R.; Johnson, D.L.; Reheis, M.; Beann, J.; Skipp, G.; Fisher, E.; Jones, J.A.

    2008-01-01

    There is an increasing awareness that dust plays important roles in climate change, biogeochemical cycles, nutrient supply to ecosystems, and soil formation. In Channel Islands National Park, California, soils are clay-rich Vertisols or Alfisols and Mollisols with vertic properties. The soils are overlain by silt-rich mantles that contrast sharply with the underlying clay-rich horizons. Silt mantles contain minerals that are rare or absent in the volcanic rocks that dominate these islands. Immobile trace elements (Sc-Th-La and Ta-Nd-Cr) and rare-earth elements show that the basalt and andesite on the islands have a composition intermediate between upper-continental crust and oceanic crust. In contrast, the silt fractions and, to a lesser extent, clay fractions of the silt mantle have compositions closer to average upper-continental crust and very similar to Mojave Desert dust. Island shelves, exposed during the last glacial period, could have provided a source of eolian sediment for the silt mantles, but this is not supported by mineralogical data. We hypothesize that a more likely source for the silt-rich mantles is airborne dust from mainland California and Baja California, either from the Mojave Desert or from the continental shelf during glacial low stands of sea. Although average winds are from the northwest in coastal California, easterly winds occur numerous times of the year when "Santa Ana" conditions prevail, caused by a high-pressure cell centered over the Great Basin. The eolian silt mantles constitute an important medium of plant growth and provide evidence that abundant eolian silt and clay may be delivered to the eastern Pacific Ocean from inland desert sources. ?? 2007 Geological Society of America.

  19. No serological evidence that harbour porpoises are additional hosts of influenza B viruses.

    Directory of Open Access Journals (Sweden)

    Rogier Bodewes

    Full Text Available Influenza A and B viruses circulate among humans causing epidemics almost annually. While various hosts for influenza A viruses exist, influenza B viruses have been detected only in humans and seals. However, recurrent infections of seals in Dutch coastal waters with influenza B viruses that are antigenetically distinct from influenza B viruses circulating among humans suggest that influenza B viruses have been introduced into this seal population by another, non-human, host. Harbour porpoises (Phocoena phocoena are sympatric with seals in these waters and are also occasionally in close contact with humans after stranding and subsequent rehabilitation. In addition, virus attachment studies demonstrated that influenza B viruses can bind to cells of the respiratory tract of these animals. Therefore, we hypothesized that harbour porpoises might be a reservoir of influenza B viruses. In the present study, an unique set of serum samples from 79 harbour porpoises, stranded alive on the Dutch coast between 2003 and 2013, was tested for the presence of antibodies against influenza B viruses by use of the hemagglutination inhibition test and for antibodies against influenza A viruses by use of a competitive influenza A nucleoprotein ELISA. No antibodies were detected against either virus, suggesting that influenza A and B virus infections of harbour porpoises in Dutch coastal waters are not common, which was supported by statistical analysis of the dataset.

  20. The Development of Experimentation and Evidence Evaluation Skills at Preschool Age

    Science.gov (United States)

    Piekny, Jeanette; Grube, Dietmar; Maehler, Claudia

    2014-01-01

    Researchers taking a domain-general approach to the development of scientific reasoning long thought that the ability to engage in scientific reasoning did not develop until adolescence. However, more recent studies have shown that preschool children already have a basic ability to evaluate evidence and a basic understanding of experimentation. Data providing insights into when exactly in the preschool years significant gains in these abilities occur are scarce. Drawing on a sample of 138 preschool children, this longitudinal study therefore examined how children's ability to evaluate evidence and their understanding of experimentation develop between the ages of four and six. Findings showed that the ability to evaluate evidence was already well developed at age four and increased steadily and significantly over time as long as the pattern of covariation was perfect. In the case of imperfect covariation, the proportion of correct answers was low over the period of observation, but showed a significant increase between the ages of four and five. If the data did not allow relationship between variables to be inferred, the proportion of correct answers was low, with a significant increase between the ages of five and six. The children's understanding of experimentation increased significantly between the ages of five and six. The implications of these findings for age-appropriate science programs in preschool are discussed.

  1. Blood harmane, blood lead, and severity of hand tremor: evidence of additive effects.

    Science.gov (United States)

    Louis, Elan D; Factor-Litvak, Pam; Gerbin, Marina; Slavkovich, Vesna; Graziano, Joseph H; Jiang, Wendy; Zheng, Wei

    2011-03-01

    Tremor is a widespread phenomenon in human populations. Environmental factors are likely to play an etiological role. Harmane (1-methyl-9H-pyrido[3,4-β]indole) is a potent tremor-producing β-carboline alkaloid. Lead is another tremor-producing neurotoxicant. The effects of harmane and lead with respect to tremor have been studied in isolation. We tested the hypothesis that tremor would be particularly severe among individuals who had high blood concentrations of both of these toxicants. Blood concentrations of harmane and lead were each quantified in 257 individuals (106 essential tremor cases and 151 controls) enrolled in an environmental epidemiological study. Total tremor score (range = 0-36) was a clinical measure of tremor severity. The total tremor score ranged from 0 to 36, indicating that a full spectrum of tremor severities was captured in our sample. Blood harmane concentration correlated with total tremor score (p = 0.007), as did blood lead concentration (p = 0.045). The total tremor score was lowest in participants with both low blood harmane and lead concentrations (8.4 ± 8.2), intermediate in participants with high concentrations of either toxicant (10.5 ± 9.8), and highest in participants with high concentrations of both toxicants (13.7 ± 10.4) (p=0.01). Blood harmane and lead concentrations separately correlated with total tremor scores. Participants with high blood concentrations of both toxicants had the highest tremor scores, suggesting an additive effect of these toxicants on tremor severity. Given the very high population prevalence of tremor disorders, identifying environmental determinants is important for primary disease prevention. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Additive manufacturing of a functionally graded material from Ti-6Al-4V to Invar: Experimental characterization and thermodynamic calculations

    International Nuclear Information System (INIS)

    Bobbio, Lourdes D.; Otis, Richard A.; Borgonia, John Paul; Dillon, R. Peter; Shapiro, Andrew A.; Liu, Zi-Kui; Beese, Allison M.

    2017-01-01

    In functionally graded materials (FGMs), the elemental composition, or structure, within a component varies gradually as a function of position, allowing for the gradual transition from one alloy to another, and the local tailoring of properties. One method for fabricating FGMs with varying elemental composition is through layer-by-layer directed energy deposition additive manufacturing. This work combines experimental characterization and computational analysis to investigate a material graded from Ti-6Al-4V to Invar 36 (64 wt% Fe, 36 wt% Ni). The microstructure, composition, phases, and microhardness were determined as a function of position within the FGM. During the fabrication process, detrimental phases associated with the compositional blending of the Ti-6Al-4V and Invar formed, leading to cracking in the final deposited part. Intermetallic phases (FeTi, Fe_2Ti, Ni_3Ti, and NiTi_2) were experimentally identified to occur throughout the gradient region, and were considered as the reason that the FGM cracked during fabrication. CALPHAD (CALculation of PHase Diagrams) thermodynamic calculations were used concurrently to predict phases that would form during the manufacturing process and were compared to the experimental results. The experimental-computational approach described herein for characterizing FGMs can be used to improve the understanding and design of other FGMs.

  3. Characterization of the Kootenai River Aquatic Macroinvertebrate Community before and after Experimental Nutrient Addition, 2003-2006. [Chapter 3

    Energy Technology Data Exchange (ETDEWEB)

    Holderman, Charlie [Kootenai Tribe of Idaho Bonners

    2009-02-19

    The Kootenai River ecosystem has experienced numerous ecological changes since the early 1900s. Some of the largest impacts to habitat, biological communities, and ecological function resulted from levee construction along the 120 km of river upstream from Kootenay Lake, completed by the 1950s, and the construction and operation of Libby Dam, completed in 1972 on the river near Libby Montana. Levee construction isolated tens of thousands of hectares of historic functioning floodplain habitat from the river channel, eliminating nutrient production and habitat diversity crucial to the functioning of a large river-floodplain ecosystem. Libby Dam continues to create large changes in the timing, duration, and magnitude of river flows, and greatly reduces sediment and nutrient transport to downstream river reaches. These changes have contributed to the ecological collapse of the post-development Kootenai River ecosystem and its native biological communities. In response to this artificial loss of nutrients, experimental nutrient addition was initiated in the Kootenay Lake's North Arm in 1992, the South Arm in 2004, and in the Kootenai River at the Idaho-Montana border during 2005. This report characterizes the macroinvertebrate community in the Kootenai River and its response to experimental nutrient addition during 2005 and 2006. This report also provides an initial evaluation of cascading trophic interactions in response to nutrient addition. Macroinvertebrates were sampled at 12 sites along a 325 km section of the Kootenai River, representing an upriver unimpounded reference reach, treatment and control canyon reach sites, and braided and meandering reach sites, all downstream from Libby Dam. Principle component analysis revealed that richness explained the greatest amount of variability in response to nutrient addition as did taxa from Acari, Coleoptera, Ephemeroptera, Plecoptera, and Trichoptera. Analysis of variance revealed that nutrient addition had a

  4. Experimental Investigation of the Use of Waste Mineral Oils as a Fuel with Organic-Based Mn Additive

    Directory of Open Access Journals (Sweden)

    Bülent Özdalyan

    2018-06-01

    Full Text Available The heat values of waste mineral oils are equal to the heat value of the fuel oil. However, heat value alone is not sufficient for the use of waste minerals oils as fuel. However, the critical physical properties of fuels such as density and viscosity need to be adapted to the system in order to be used. In this study, the engine oils used in the first 10,000 km of the vehicles were used as waste mineral oil. An organic-based Mn additive was synthesized to improve the properties of the waste mineral oil. It was observed that mixing the Mn additive with the waste mineral oil at different doses (4, 8, 12, and 16 ppm improves the viscosity of the waste oil and the flash point. The resulting fuel was evaluated for emission using different loads in a 5 kW capacity generator to compare the fuel with standard diesel fuel and to determine the effect of Mn addition. In the experimental study, it was observed that the emission characteristics of the fuel obtained from waste mineral oil were worse than diesel fuel, but some improvement was observed with Mn addition. As a result, we found that the use of waste mineral oils in engines in fuel standards was not appropriate, but may be improved with additives.

  5. Theory and experimental evidence of phonon domains and their roles in pre-martensitic phenomena

    Science.gov (United States)

    Jin, Yongmei M.; Wang, Yu U.; Ren, Yang

    2015-12-01

    Pre-martensitic phenomena, also called martensite precursor effects, have been known for decades while yet remain outstanding issues. This paper addresses pre-martensitic phenomena from new theoretical and experimental perspectives. A statistical mechanics-based Grüneisen-type phonon theory is developed. On the basis of deformation-dependent incompletely softened low-energy phonons, the theory predicts a lattice instability and pre-martensitic transition into elastic-phonon domains via 'phonon spinodal decomposition.' The phase transition lifts phonon degeneracy in cubic crystal and has a nature of phonon pseudo-Jahn-Teller lattice instability. The theory and notion of phonon domains consistently explain the ubiquitous pre-martensitic anomalies as natural consequences of incomplete phonon softening. The phonon domains are characterised by broken dynamic symmetry of lattice vibrations and deform through internal phonon relaxation in response to stress (a particular case of Le Chatelier's principle), leading to previously unexplored new domain phenomenon. Experimental evidence of phonon domains is obtained by in situ three-dimensional phonon diffuse scattering and Bragg reflection using high-energy synchrotron X-ray single-crystal diffraction, which observes exotic domain phenomenon fundamentally different from usual ferroelastic domain switching phenomenon. In light of the theory and experimental evidence of phonon domains and their roles in pre-martensitic phenomena, currently existing alternative opinions on martensitic precursor phenomena are revisited.

  6. The impact of free trial acceptance on demand for alternative nicotine products: evidence from experimental auctions.

    Science.gov (United States)

    Rousu, Matthew C; O'Connor, Richard J; Bansal-Travers, Maansi; Pitcavage, James M; Thrasher, James F

    2015-06-11

    This study explored the relationship between product trials and consumer demand for alternative nicotine products (ANP). An experimental auction was conducted with 258 adult smokers, wherein participants were randomly assigned to one of four experimental conditions. The participants received the opportunity to try, but did not have to accept, one of three relatively novel ST products (i.e., snus, dissolvable tobacco, or medicinal nicotine), or they were placed into a control group (i.e., no trial). All the participants then bid on all three of these products, as well as on cigarettes. We assessed interest in using ANP based on both trial of the product and bids placed for the products in the experimental auction. Fewer smokers were willing to try snus (44%) than dissolvable tobacco (64%) or medicine nicotine (68%). For snus, we find modest evidence suggesting that willingness to try is associated with greater demand for the product. For dissolvable tobacco or medicinal nicotine, we find no evidence that those who accept the product trial have higher demand for the product. Free trials of a novel ANP were not strongly associated with product demand, as assessed by willingness to pay. Given the debate over the potential for ANP to reduce the harm from smoking, these results are important in understanding the impact of free trial offers on adoption of ST product as a strategy to reduce harm from tobacco use.

  7. Apology in the criminal justice setting: evidence for including apology as an additional component in the legal system.

    Science.gov (United States)

    Petrucci, Carrie J

    2002-01-01

    The criminal justice system has reached unprecedented scope in the United States, with over 6.4 million people under some type of supervision. Remedies that have the potential to reduce this number are continually being sought. This article analyzes an innovative strategy currently being reconsidered in criminal justice: the apology. Despite a legal system that only sporadically acknowledges it, evidence for the use of apology is supported by social science research, current criminal justice theories, case law, and empirical studies. Social psychological, sociological and socio-legal studies pinpoint the elements and function of apology, what makes apologies effective, and concerns about apology if it were implemented in the criminal justice system. Theoretical evidence is examined (including restorative justice, therapeutic jurisprudence, crime, shame, and reintegration) to explore the process of apology in the criminal justice context. Attribution theory and social conduct theory are used to explain the apology process specifically for victims and offenders. A brief examination of case law reveals that though apology has no formal place in criminal law, it has surfaced recently under the federal sentencing guidelines. Finally, empirical evidence in criminal justice settings reveals that offenders want to apologize and victims desire an apology. Moreover, by directly addressing the harmful act, apology may be the link to reduced recidivism for offenders, as well as empowerment for victims. This evidence combined suggests that apology is worthy of further study as a potentially valuable addition to the criminal justice process. Copyright 2002 John Wiley & Sons, Ltd.

  8. Experimental additions of aluminum sulfate and ammonium nitrate to in situ mesocosms to reduce cyanobacterial biovolume and microcystin concentration

    Science.gov (United States)

    Harris, Ted D.; Wilhelm, Frank M.; Graham, Jennifer L.; Loftin, Keith A.

    2014-01-01

    Recent studies suggest that nitrogen additions to increase the total nitrogen:total phosphorus (TN:TP) ratio may reduce cyanobacterial biovolume and microcystin concentration in reservoirs. In systems where TP is >100 μg/L, however, nitrogen additions to increase the TN:TP ratio could cause ammonia, nitrate, or nitrite toxicity to terrestrial and aquatic organisms. Reducing phosphorus via aluminum sulfate (alum) may be needed prior to nitrogen additions aimed at increasing the TN:TP ratio. We experimentally tested this sequential management approach in large in situ mesocosms (70.7 m3) to examine effects on cyanobacteria and microcystin concentration. Because alum removes nutrients and most seston from the water column, alum treatment reduced both TN and TP, leaving post-treatment TN:TP ratios similar to pre-treatment ratios. Cyanobacterial biovolume was reduced after alum addition, but the percent composition (i.e., relative) cyanobacterial abundance remained unchanged. A single ammonium nitrate (nitrogen) addition increased the TN:TP ratio 7-fold. After the TN:TP ratio was >50 (by weight), cyanobacterial biovolume and abundance were reduced, and chrysophyte and cryptophyte biovolume and abundance increased compared to the alum treatment. Microcystin was not detectable until the TN:TP ratio was <50. Although both treatments reduced cyanobacteria, only the nitrogen treatment seemed to stimulate energy flow from primary producers to zooplankton, which suggests that combining alum and nitrogen treatments may be a viable in-lake management strategy to reduce cyanobacteria and possibly microcystin concentrations in high-phosphorus systems. Additional studies are needed to define best management practices before combined alum and nitrogen additions are implemented as a reservoir management strategy.

  9. Experimental evidence of an effective medium seen by diffuse light in turbid colloids

    International Nuclear Information System (INIS)

    Contreras-Tello, H; Garcia-Valenzuela, A

    2011-01-01

    The propagation of diffuse light in turbid media is usually modeled with radiative transfer theory. When diffuse light travelling in a turbid colloid is reflected and transmitted at a flat interface where there is a refractive index mismatch, it is not clear whether one should assume the incident diffuse-light is travelling in a medium with a refractive index equal to that of the background medium (usually referred to as the matrix) or if one should assume it travels in an effective medium. Most authors simply avoid this issue and most often use the refractive index of the matrix. While this might be a good approximation for dilute turbid media one may suspect that for highly scattering materials it may not be the case. In this work we investigate experimentally this issue. Our experimental results provide clear evidence that diffuse light inside the turbid colloid travels in an effective medium and not in the matrix.

  10. Experimental evidence of a symbiosis between red-cockaded woodpeckers and fungi.

    Science.gov (United States)

    Jusino, Michelle A; Lindner, Daniel L; Banik, Mark T; Rose, Kevin R; Walters, Jeffrey R

    2016-03-30

    Primary cavity excavators, such as woodpeckers, are ecosystem engineers in many systems. Associations between cavity excavators and fungi have long been hypothesized to facilitate cavity excavation, but these relationships have not been experimentally verified. Fungi may help excavators by softening wood, while excavators may facilitate fungal dispersal. Here we demonstrate that excavators facilitate fungal dispersal and thus we report the first experimental evidence of a symbiosis between fungi and a cavity excavator, the red-cockaded woodpecker (RCW,Picoides borealis). Swab samples of birds showed that RCWs carry fungal communities similar to those found in their completed excavations. A 26-month field experiment using human-made aseptically drilled excavations in live trees, half of which were inaccessible to RCWs, demonstrated that RCWs directly alter fungal colonization and community composition. Experimental excavations that were accessible to RCWs contained fungal communities similar to natural RCW excavations, whereas inaccessible experimental excavations contained significantly different fungal communities. Our work demonstrates a complex symbiosis between cavity excavators and communities of fungi, with implications for forest ecology, wildlife management, and conservation. © 2016 The Author(s).

  11. Experimental and theoretical evidence for fluctuation driven activations in an excitable chemical system

    Science.gov (United States)

    Hastings, Harold; Sobel, Sabrina; Field, Richard; Minchenberg, Scott; Spinelli, Nicole; Zauderer, Keith

    2011-03-01

    An excitable medium is a system in which small perturbations die out, but sufficiently large perturbations generate large ``excitations.'' Biological examples include neurons and the heart; the latter supports waves of excitation normally generated by the sinus node, but occasionally generated by other mechanisms. The ferroin-catalyzed Belousov-Zhabotinsky reaction is the prototype chemical excitable medium. We present experimental and theoretical evidence for that random fluctuations can generate excitations in the Belousov-Zhabothinsky reaction. Although the heart is significantly different, there are some scaling analogies. This material is based upon work supported by the Department of Energy under Award Number DE-FG02-08ER64623.

  12. Delayed school start times and adolescent sleep: A systematic review of the experimental evidence.

    Science.gov (United States)

    Minges, Karl E; Redeker, Nancy S

    2016-08-01

    Many schools have instituted later morning start times to improve sleep, academic, and other outcomes in response to the mismatch between youth circadian rhythms and early morning start times. However, there has been no systematic synthesis of the evidence on the effects of this practice. To examine the impact of delayed school start time on students' sleep, health, and academic outcomes, electronic databases were systematically searched and data were extracted using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Six studies satisfied selection criteria and used pre-post, no control (n = 3), randomized controlled trial (n = 2), and quasi-experimental (n = 1) designs. School start times were delayed 25-60 min, and correspondingly, total sleep time increased from 25 to 77 min per weeknight. Some studies revealed reduced daytime sleepiness, depression, caffeine use, tardiness to class, and trouble staying awake. Overall, the evidence supports recent non-experimental study findings and calls for policy that advocates for delayed school start time to improve sleep. This presents a potential long-term solution to chronic sleep restriction during adolescence. However, there is a need for rigorous randomized study designs and reporting of consistent outcomes, including objective sleep measures and consistent measures of health and academic performance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The fetal programming of food preferences: current clinical and experimental evidence.

    Science.gov (United States)

    Dalle Molle, R; Bischoff, A R; Portella, A K; Silveira, P P

    2015-09-28

    Increased energy consumption is one of the major factors implicated in the epidemic of obesity. There is compelling evidence, both clinical and experimental, that fetal paucity of nutrients may have programming effects on feeding preferences and behaviors that can contribute to the development of diseases. Clinical studies in different age groups show that individuals born small for their gestational age (SGA) have preferences towards highly caloric foods such as carbohydrates and fats. Some studies have also shown altered eating behaviors in SGA children. Despite an apparent discrepancy in different age groups, all studies seem to converge to an increased intake of palatable foods in SGA individuals. Small nutrient imbalances across lifespan increase the risk of noncommunicable diseases in adult life. Homeostatic factors such as altered responses to leptin and insulin and alterations in neuropeptides associated with appetite and satiety are likely involved. Imbalances between homeostatic and hedonic signaling are another proposed mechanism, with the mesocorticolimbic dopaminergic pathway having differential reward and pleasure responses when facing palatable foods. Early exposure to undernutrition also programs hypothalamic-pituitary-adrenal axis, with SGA having higher levels of cortisol in different ages, leading to chronic hyperactivity of this neuroendocrine axis. This review summarizes the clinical and experimental evidence related to fetal programming of feeding preferences by SGA.

  14. Stimulus modality and working memory performance in Greek children with reading disabilities: additional evidence for the pictorial superiority hypothesis.

    Science.gov (United States)

    Constantinidou, Fofi; Evripidou, Christiana

    2012-01-01

    This study investigated the effects of stimulus presentation modality on working memory performance in children with reading disabilities (RD) and in typically developing children (TDC), all native speakers of Greek. It was hypothesized that the visual presentation of common objects would result in improved learning and recall performance as compared to the auditory presentation of stimuli. Twenty children, ages 10-12, diagnosed with RD were matched to 20 TDC age peers. The experimental tasks implemented a multitrial verbal learning paradigm incorporating three modalities: auditory, visual, and auditory plus visual. Significant group differences were noted on language, verbal and nonverbal memory, and measures of executive abilities. A mixed-model MANOVA indicated that children with RD had a slower learning curve and recalled fewer words than TDC across experimental modalities. Both groups of participants benefited from the visual presentation of objects; however, children with RD showed the greatest gains during this condition. In conclusion, working memory for common verbal items is impaired in children with RD; however, performance can be facilitated, and learning efficiency maximized, when information is presented visually. The results provide further evidence for the pictorial superiority hypothesis and the theory that pictorial presentation of verbal stimuli is adequate for dual coding.

  15. Experimental and numerical investigation of ion signals in boosted HCCI combustion using cesium and potassium acetate additives

    International Nuclear Information System (INIS)

    Mack, J. Hunter; Butt, Ryan H.; Chen, Yulin; Chen, Jyh-Yuan; Dibble, Robert W.

    2016-01-01

    Highlights: • HCCI engine experiments show that CsOAc and KOAc additives increased the ion SNR. • The ion signal is more apparent at higher equivalence ratios. • An increase in intake pressure produces a decrease in the ion signal. • Use of metal acetates as additives yielded reductions in IMEP g and maximum ROHR. • A numerical model predicted peak ion signal, CA50, and p intake dependence. - Abstract: A sparkplug ion sensor can be used to measure the ion current in a homogeneous charge compression ignition (HCCI) engine, providing insight into the ion chemistry inside the cylinders during combustion. HCCI engines typically operate at lean equivalence ratios (ϕ) at which the ion current becomes increasingly indistinguishable from background noise. This paper investigates the effect of fuel additives on the ion signal at low equivalence ratios, determines side effects of metal acetate addition, and validates numerical model for ionization chemistry. Cesium acetate (CsOAc) and potassium acetate (KOAc) were used as additives to ethanol as the primary fuel. Concentration levels of 100, 200, and 400 mg/L of metal acetate-in-ethanol are investigated at equivalence ratios of 0.08, 0.20, and 0.30. The engine experiments were conducted at a boosted intake pressure of 1.8 bar absolute and compared to naturally aspirated results. Combustion timing was maintained at 2.5° after top-dead-center (ATDC), as defined by the crank angle degree (CAD) where 50% of the cumulative heat release occurs (CA50). CsOAc consistently produced the strongest ion signals at all conditions when compared to KOAc. The ion signal was found to decrease with increased intake pressure; an increase in the additive concentration increased the ion signal for all cases. However, the addition of the metal acetates decreased the gross indicated mean effective pressure (IMEP g ), maximum rate of heat release (ROHR), and peak cylinder pressure. Experimental results were used to validate ion chemistry

  16. Experimental evidence for inherent Lévy search behaviour in foraging animals.

    Science.gov (United States)

    Kölzsch, Andrea; Alzate, Adriana; Bartumeus, Frederic; de Jager, Monique; Weerman, Ellen J; Hengeveld, Geerten M; Naguib, Marc; Nolet, Bart A; van de Koppel, Johan

    2015-05-22

    Recently, Lévy walks have been put forward as a new paradigm for animal search and many cases have been made for its presence in nature. However, it remains debated whether Lévy walks are an inherent behavioural strategy or emerge from the animal reacting to its habitat. Here, we demonstrate signatures of Lévy behaviour in the search movement of mud snails (Hydrobia ulvae) based on a novel, direct assessment of movement properties in an experimental set-up using different food distributions. Our experimental data uncovered clusters of small movement steps alternating with long moves independent of food encounter and landscape complexity. Moreover, size distributions of these clusters followed truncated power laws. These two findings are characteristic signatures of mechanisms underlying inherent Lévy-like movement. Thus, our study provides clear experimental evidence that such multi-scale movement is an inherent behaviour rather than resulting from the animal interacting with its environment. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  17. Experimental and CFD evidence of multiple solutions in a naturally ventilated building.

    Science.gov (United States)

    Heiselberg, P; Li, Y; Andersen, A; Bjerre, M; Chen, Z

    2004-02-01

    This paper considers the existence of multiple solutions to natural ventilation of a simple one-zone building, driven by combined thermal and opposing wind forces. The present analysis is an extension of an earlier analytical study of natural ventilation in a fully mixed building, and includes the effect of thermal stratification. Both computational and experimental investigations were carried out in parallel with an analytical investigation. When flow is dominated by thermal buoyancy, it was found experimentally that there is thermal stratification. When the flow is wind-dominated, the room is fully mixed. Results from all three methods have shown that the hysteresis phenomena exist. Under certain conditions, two different stable steady-state solutions are found to exist by all three methods for the same set of parameters. As shown by both the computational fluid dynamics (CFD) and experimental results, one of the solutions can shift to another when there is a sufficient perturbation. These results have probably provided the strongest evidence so far for the conclusion that multiple states exist in natural ventilation of simple buildings. Different initial conditions in the CFD simulations led to different solutions, suggesting that caution must be taken when adopting the commonly used 'zero initialization'.

  18. Evolution and maintenance of sexual size dimorphism: Aligning phylogenetic and experimental evidence

    Directory of Open Access Journals (Sweden)

    Matjaz eKuntner

    2014-06-01

    Full Text Available Integrating the insights derived from both phylogenetic and experimental approaches offers a more complete understanding of evolutionary patterns and processes, yet it is rarely a feature of investigations of the evolutionary significance of trait variation. We combine these approaches to reinterpret the patterns and processes in the evolution of female biased sexual size dimorphism in Nephilidae, a spider lineage characterized by the most extreme sexual size dimorphism among terrestrial animals. We use a molecular phylogeny to reconstruct the size evolution for each sex and reveal a case of sexually dimorphic gigantism: both sexes steadily outgrow their ancestral sizes, but the female and male slopes differ, and hence sexual size dimorphism steadily increases. A review of the experimental evidence reveals a predominant net selection for large size in both sexes, consistent with the phylogenetic pattern for females but not for males. Thus, while sexual size dimorphism in spiders most likely originates and is maintained by fecundity selection on females, it is unclear what selection pressures prevent males from becoming as large as females. This integrated approach highlights the dangers of inferring evolutionary significance from experimental studies that isolate the effects of single selection pressures.

  19. Live Fast, Die Young: Experimental Evidence of Population Extinction Risk due to Climate Change

    Science.gov (United States)

    Bestion, Elvire; Teyssier, Aimeric; Richard, Murielle; Clobert, Jean; Cote, Julien

    2015-01-01

    Evidence has accumulated in recent decades on the drastic impact of climate change on biodiversity. Warming temperatures have induced changes in species physiology, phenology, and have decreased body size. Such modifications can impact population dynamics and could lead to changes in life cycle and demography. More specifically, conceptual frameworks predict that global warming will severely threaten tropical ectotherms while temperate ectotherms should resist or even benefit from higher temperatures. However, experimental studies measuring the impacts of future warming trends on temperate ectotherms' life cycle and population persistence are lacking. Here we investigate the impacts of future climates on a model vertebrate ectotherm species using a large-scale warming experiment. We manipulated climatic conditions in 18 seminatural populations over two years to obtain a present climate treatment and a warm climate treatment matching IPCC predictions for future climate. Warmer temperatures caused a faster body growth, an earlier reproductive onset, and an increased voltinism, leading to a highly accelerated life cycle but also to a decrease in adult survival. A matrix population model predicts that warm climate populations in our experiment should go extinct in around 20 y. Comparing our experimental climatic conditions to conditions encountered by populations across Europe, we suggest that warming climates should threaten a significant number of populations at the southern range of the distribution. Our findings stress the importance of experimental approaches on the entire life cycle to more accurately predict population and species persistence in future climates. PMID:26501958

  20. Numerical and Experimental Study of Ti6Al4V Components Manufactured Using Powder Bed Fusion Additive Manufacturing

    Science.gov (United States)

    Zielinski, Jonas; Mindt, Hans-Wilfried; Düchting, Jan; Schleifenbaum, Johannes Henrich; Megahed, Mustafa

    2017-12-01

    Powder bed fusion additive manufacturing of titanium alloys is an interesting manufacturing route for many applications requiring high material strength combined with geometric complexity. Managing powder bed fusion challenges, including porosity, surface finish, distortions and residual stresses of as-built material, is the key to bringing the advantages of this process to production main stream. This paper discusses the application of experimental and numerical analysis towards optimizing the manufacturing process of a demonstration component. Powder characterization including assessment of the reusability, assessment of material consolidation and process window optimization is pursued prior to applying the identified optima to study the distortion and residual stresses of the demonstrator. Comparisons of numerical predictions with measurements show good correlations along the complete numerical chain.

  1. Composting system for waste treatment coca leaf with the addition of three biological activators in the Experimental Center Kallutaca

    Directory of Open Access Journals (Sweden)

    Apaza-Condori Emma Eva

    2015-11-01

    Full Text Available The objective of this study was to evaluate the composting process waste coca leaf with the addition of three biological activators (yogurt, whey and yeast. This work was carried out Kallutaca Experimental Center, Biofertilizers module Career Agricultural Engineering at the Public University of El Alto, La Paz municipality of Laja. Posed treatments were: T1 (+ Yogurt Coca wastes; T2 (Coca wastes + whey; T3 (Coca wastes + yeast and T4 (Control. The design was completely randomized with 4 treatments and 3 repetitions. The values in N are classified medium and high levels the quantities of P, K are classified as middle levels. The value obtained 7.9 pH, EC 12950 µS/cm and 61% organic matter belong to treatment T1. The decomposition time was a period of 105 days corresponds to treatment T3.

  2. A combined experimental and in silico characterization to highlight additional structural features and properties of a potentially new drug

    Science.gov (United States)

    Bastos, Isadora T. S.; Costa, Fanny N.; Silva, Tiago F.; Barreiro, Eliezer J.; Lima, Lídia M.; Braz, Delson; Lombardo, Giuseppe M.; Punzo, Francesco; Ferreira, Fabio F.; Barroso, Regina C.

    2017-10-01

    LASSBio-1755 is a new cycloalkyl-N-acylhydrazone parent compound designed for the development of derivatives with antinociceptive and anti-inflammatory activities. Although single crystal X-ray diffraction has been considered as the golden standard in structure determination, we successfully used X-ray powder diffraction data in the structural determination of new synthesized compounds, in order to overcome the bottle-neck due to the difficulties experienced in harvesting good quality single crystals of the compounds. We therefore unequivocally assigned the relative configuration (E) to the imine double bond and a s-cis conformation of the amide function of the N-acylhydrazone compound. These features are confirmed by a computational analysis performed on the basis of molecular dynamics calculations, which are extended not only to the structural characteristics but also to the analysis of the anisotropic atomic displacement parameters, a further information - missed in a typical powder diffraction analysis. The so inferred data were used to perform additional cycles of refinement and eventually generate a new cif file with additional physical information. Furthermore, crystal morphology prediction was performed, which is in agreement with the experimental images acquired by scanning electron microscopy, thus providing useful information on possible alternative paths for better crystallization strategies.

  3. Experimental evidence for a vector-like behaviour of Pomeron exchange

    CERN Document Server

    Barberis, D.; Close, F.E.; Danielsen, K.M.; Donskov, S.V.; Earl, B.C.; Evans, D.; French, B.R.; Hino, T.; Inaba, S.; Jacholkowski, A.; Jacobsen, T.; Khaustov, G.V.; Kinson, J.B.; Kirk, A.; Kondashov, A.A.; Lednev, A.A.; Lenti, V.; Minashvili, I.; Peigneux, J.P.; Romanovsky, V.; Russakovich, N.; Semenov, A.; Shagin, P.M.; Shimizu, H.; Singovsky, A.V.; Sobol, A.; Stassinaki, M.; Stroot, J.P.; Takamatsu, K.; Tsuru, T.; Villalobos Baillie, O.; Votruba, M.F.; Yasu, Y.

    1999-01-01

    Evidence is presented that the Pomeron act as a non-conserved vector current. A study has been made of the azimuthal angle phi, which is defined as the angle between the pT vectors of the two outgoing protons, in the reaction pp -> pp(X0) for those resonances (X0) which are compatible with being produced by double Pomeron exchange. These distributions have been compared with a model which describes the Pomeron as a non-conserved vector current and a qualitative agreement is found. In addition, when one of the particles exchanged is known to have spin 0, namely pi-Pomeron exchange, the phi distribution is flat.

  4. Addition of milk to tea infusions: Helpful or harmful? Evidence from in vitro and in vivo studies on antioxidant properties.

    Science.gov (United States)

    Rashidinejad, Ali; Birch, E John; Sun-Waterhouse, Dongxiao; Everett, David W

    2017-10-13

    Tea consumption is practised as a tradition, and has shown potential to improve human health. Maximal uptake of tea antioxidants and milk proteins without a negative impact on tea flavor is highly desired by consumers. There is a conflicting evidence of the effect of milk addition to tea on antioxidant activity. Differences in the type of tea, the composition, type and amount of milk, preparation method of tea-milk infusions, the assays used to measure antioxidant activity, and sampling size likely account for different findings. Interactions between tea polyphenols and milk proteins, especially between catechins and caseins, could account for a decrease in antioxidant activity, although other mechanisms are also possible, given the similar effects between soy and bovine milk. The role of milk fat globules and the milk fat globule membrane surface is also important when considering interactions and loss of polyphenolic antioxidant activity, which has not been addressed in the literature.

  5. Grading Gradients: Evaluating Evidence for Time-dependent Memory Reorganization in Experimental Animals

    Directory of Open Access Journals (Sweden)

    Katherine G. Akers

    2009-01-01

    Full Text Available In humans, hippocampal damage typically produces temporally graded retrograde amnesia, with relative sparing of remote memories compared to recent memories. This observation led to the idea that as memories age, they are reorganized in a time-dependent manner. Here, we evaluate evidence for time-dependent memory reorganization in animal models. We conclude that, although hippocampal lesions may not always produce temporal gradients under all conditions, studies using alternate experimental approaches consistently support the idea that memories reorganize over time—becoming less dependent on the hippocampus and more dependent on a cortical network. We further speculate on the processes that drive memory reorganization such as sleep, memory reactivation, synaptic plasticity, and neurogenesis.

  6. Bacteria are not too small for spatial sensing of chemical gradients: An experimental evidence

    DEFF Research Database (Denmark)

    Thar, Roland; Kühl, Michael

    2003-01-01

    By analyzing the chemotactic behavior of a recently described marine bacterial species, we provide experimental evidence that bacteria are not too small for sensing chemical gradients spatially. The bipolar flagellated vibrioid bacteria (typical size 2 × 6 µm) exhibit a unique motility pattern...... as they translate along as well as rotate around their short axis, i.e., the pathways of the cell poles describe a double helix. The natural habitat of the bacteria is characterized by steep oxygen gradients where they accumulate in a band at their preferred oxygen concentration of ˜2 µM. Single cells leaving...... the band toward the oxic region typically return to the band within 16 s following a U-shaped track. A detailed analysis of the tracks reveals that the cells must be able to sense the oxygen gradient perpendicular to their swimming direction. Thus, they can detect oxygen gradients along a distance of ˜5 µm...

  7. Enjoyment: A Conceptual Exploration and Overview of Experimental Evidence in the Context of Games for Health.

    Science.gov (United States)

    Crutzen, Rik; van 't Riet, Jonathan; Short, Camille E

    2016-02-01

    Enjoyment is consistently noted as important for engaging audiences in games for health. However, as a term, enjoyment is often used interchangeably with a host of other terms, some of which overlap conceptually. This obscures what does and what does not constitute enjoyment, and in turn slows scientific progress by making the study of enjoyment and the synthesis of enjoyment-related research difficult. This article is aimed at improving our understanding of enjoyment by distinguishing enjoyment from other important constructs, such as fun and engagement, and by providing an overview of the experimental evidence on the determinants of enjoyment in videogames. Competence, narrative transportation, and relevance are identified as key factors related to enjoyment, and future studies examining these factors using games for health are recommended.

  8. Experimental evidence of nitrous acid formation in the electron beam treatment of flue gas

    International Nuclear Information System (INIS)

    Maetzing, H.; Namba, H.; Tokunaga, O.

    1994-01-01

    In the Electron Beam Dry Scrubbing (EBDS) process, flue gas from fossil fuel burning power plants is irradiated with accelerated (300-800 keV) electrons. Thereby, nitrogen oxide (NO x ) and sulfur dioxide (SO 2 ) traces are transformed into nitric and sulfuric acids, respectively, which are converted into particulate ammonium nitrate and sulfate upon the addition of ammonia. The powdery product can be filtered from the main gas stream and can be sold as agricultural fertilizer. A lot of experimental investigations have been performed on the EBDS process and computer models have been developed to interpret the experimental results and to predict economic improvements. According to the model calculations, substantial amounts of intermediate nitrous acid (HNO 2 ) are formed in the electron beam treatment of flue gas. The first experimental investigation about the formation of nitrous acid in an irradiated mixture of NO in synthetic air has been undertaken. Under these conditions, aerosol formation is avoided. UV spectra of the irradiated gas were recorded in the wavelength range λ = 345-375 nm. Both NO 2 and HNO 2 have characteristic absorption bands in this wavelength range. Calibration spectra of NO 2 were subtracted from the sample spectra. The remaining absorption bands can clearly be assigned to nitrous acid. The concentration of nitrous acid was determined by differential optical absorption. It was found lower than the model prediction. The importance of nitrous acid formation in the EBDS process needs to be clarified. (author)

  9. Experimental evidence and modelling of drought induced alternative stable soil moisture states

    Science.gov (United States)

    Robinson, David; Jones, Scott; Lebron, Inma; Reinsch, Sabine; Dominguez, Maria; Smith, Andrew; Marshal, Miles; Emmett, Bridget

    2017-04-01

    The theory of alternative stable states in ecosystems is well established in ecology; however, evidence from manipulation experiments supporting the theory is limited. Developing the evidence base is important because it has profound implications for ecosystem management. Here we show evidence of the existence of alternative stable soil moisture states induced by drought in an upland wet heath. We used a long-term (15 yrs) climate change manipulation experiment with moderate sustained drought, which reduced the ability of the soil to retain soil moisture by degrading the soil structure, reducing moisture retention. Moreover, natural intense droughts superimposed themselves on the experiment, causing an unexpected additional alternative soil moisture state to develop, both for the drought manipulation and control plots; this impaired the soil from rewetting in winter. Our results show the coexistence of three stable states. Using modelling with the Hydrus 1D software package we are able to show the circumstances under which shifts in soil moisture states are likely to occur. Given the new understanding it presents a challenge of how to incorporate feedbacks, particularly related to soil structure, into soil flow and transport models?

  10. Evidence for the additions of clustered interacting nodes during the evolution of protein interaction networks from network motifs

    Directory of Open Access Journals (Sweden)

    Guo Hao

    2011-05-01

    Full Text Available Abstract Background High-throughput screens have revealed large-scale protein interaction networks defining most cellular functions. How the proteins were added to the protein interaction network during its growth is a basic and important issue. Network motifs represent the simplest building blocks of cellular machines and are of biological significance. Results Here we study the evolution of protein interaction networks from the perspective of network motifs. We find that in current protein interaction networks, proteins of the same age class tend to form motifs and such co-origins of motif constituents are affected by their topologies and biological functions. Further, we find that the proteins within motifs whose constituents are of the same age class tend to be densely interconnected, co-evolve and share the same biological functions, and these motifs tend to be within protein complexes. Conclusions Our findings provide novel evidence for the hypothesis of the additions of clustered interacting nodes and point out network motifs, especially the motifs with the dense topology and specific function may play important roles during this process. Our results suggest functional constraints may be the underlying driving force for such additions of clustered interacting nodes.

  11. Evidence of low dimensional chaos in renal blood flow control in genetic and experimental hypertension

    Science.gov (United States)

    Yip, K.-P.; Marsh, D. J.; Holstein-Rathlou, N.-H.

    1995-01-01

    We applied a surrogate data technique to test for nonlinear structure in spontaneous fluctuations of hydrostatic pressure in renal tubules of hypertensive rats. Tubular pressure oscillates at 0.03-0.05 Hz in animals with normal blood pressure, but the fluctuations become irregular with chronic hypertension. Using time series from rats with hypertension we produced surrogate data sets to test whether they represent linearly correlated noise or ‘static’ nonlinear transforms of a linear stochastic process. The correlation dimension and the forecasting error were used as discriminating statistics to compare surrogate with experimental data. The results show that the original experimental time series can be distinguished from both linearly and static nonlinearly correlated noise, indicating that the nonlinear behavior is due to the intrinsic dynamics of the system. Together with other evidence this strongly suggests that a low dimensional chaotic attractor governs renal hemodynamics in hypertension. This appears to be the first demonstration of a transition to chaotic dynamics in an integrated physiological control system occurring in association with a pathological condition.

  12. Lecture 1: Experimental evidence for collective and thermal features in heavy ion reactions

    International Nuclear Information System (INIS)

    Moretto, L.G.

    1979-01-01

    The set of degrees of freedom playing a relevant role in deep inelastic processes is discussed. General considerations concerning the dynamic regimes prevailing during the nucleus--nucleus interaction lead to interesting conclusions regarding classical and quantal features as well as to the applicability of transport theories. The damping associated with the relative distance coordinate is considered and the evidence for thermal equilibrium between fragments is presented. The role of the E1 mode and of all the other odd isovector modes on the charge distrbution at fixed mass asymmetry is discussed and the posssible evidence for quantal fluctuations is analyzed. The mass asymmetry degree of freedom is considered in terms of the experimental mass distributions. The origin of the two components, deep inelastic and fusion--fission, is explained in terms of different dynamical regimes leading to greatly different interaction times. The rotational degrees of freedom are discussed in terms of γ-ray multiplicities and sequential fission. The problem of angular momentum fractionation along the mass asymmetry coordinate is considered and the depolarization and misalignment of the fragment spins are discussed. 43 references

  13. How experimental biology and ecology can support evidence-based decision-making in conservation: avoiding pitfalls and enabling application.

    Science.gov (United States)

    Cooke, Steven J; Birnie-Gauvin, Kim; Lennox, Robert J; Taylor, Jessica J; Rytwinski, Trina; Rummer, Jodie L; Franklin, Craig E; Bennett, Joseph R; Haddaway, Neal R

    2017-01-01

    Policy development and management decisions should be based upon the best available evidence. In recent years, approaches to evidence synthesis, originating in the medical realm (such as systematic reviews), have been applied to conservation to promote evidence-based conservation and environmental management. Systematic reviews involve a critical appraisal of evidence, but studies that lack the necessary rigour (e.g. experimental, technical and analytical aspects) to justify their conclusions are typically excluded from systematic reviews or down-weighted in terms of their influence. One of the strengths of conservation physiology is the reliance on experimental approaches that help to more clearly establish cause-and-effect relationships. Indeed, experimental biology and ecology have much to offer in terms of building the evidence base that is needed to inform policy and management options related to pressing issues such as enacting endangered species recovery plans or evaluating the effectiveness of conservation interventions. Here, we identify a number of pitfalls that can prevent experimental findings from being relevant to conservation or would lead to their exclusion or down-weighting during critical appraisal in a systematic review. We conclude that conservation physiology is well positioned to support evidence-based conservation, provided that experimental designs are robust and that conservation physiologists understand the nuances associated with informing decision-making processes so that they can be more relevant.

  14. Selective Cooperation in the Supermarket : Field Experimental Evidence for Indirect Reciprocity.

    Science.gov (United States)

    Lange, Florian; Eggert, Frank

    2015-12-01

    Numerous laboratory experiments suggest that mechanisms of indirect reciprocity might account for human cooperation. However, conclusive field data supporting the predictions of indirect reciprocity in everyday life situations is still scarce. Here, we attempt to compensate for this lack by examining the determinants of cooperative behavior in a German supermarket. Our methods were as follows: Confederates of the experimenter lined up at the checkout, apparently to buy a single item. As an act of cooperation, the waiting person in front (the potential helper) could allow the confederate to go ahead. By this means, the potential helper could take a cost (additional waiting time) by providing the confederate with a benefit (saved waiting time). We recorded the potential helpers' behavior and the number of items they purchased as a quantitative measure proportional to the confederate's benefit. Moreover, in a field experimental design, we varied the confederates' image by manipulating the item they purchased (beer vs. water). As predicted, the more waiting time they could save, the more likely the confederates were to receive cooperation. This relationship was moderated by the confederates' image. Cost-to-benefit ratios were required to be more favorable for beer-purchasing individuals to receive cooperation. Our results demonstrate that everyday human cooperation can be studied unobtrusively in the field and that cooperation among strangers is selective in a way that is consistent with current models of indirect reciprocity.

  15. TRANSIT TIMING VARIATION MEASUREMENTS OF WASP-12b AND QATAR-1b: NO EVIDENCE OF ADDITIONAL PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Karen A.; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Kielkopf, John F. [Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292 (United States)

    2017-02-01

    WASP-12b and Qatar-1b are transiting hot Jupiters for which previous works have suggested the presence of transit timing variations (TTVs) indicative of additional bodies in these systems—an Earth-mass planet in WASP-12 and a brown-dwarf mass object in Qatar-1. Here, we present 23 new WASP-12b and 18 new Qatar-1b complete (or nearly complete) transit observations. We perform global system fits to all of our light curves for each system, as well as RV and stellar spectroscopic parameters from the literature. The global fits provide refined system parameters and uncertainties for each system, including precise transit center times for each transit. The transit model residuals of the combined and five minute binned light curves have an rms of 183 and 255 parts per million (ppm) for WASP-12b and Qatar-1b, respectively. Most of the WASP-12b system parameter values from this work are consistent with values from previous studies, but have ∼40%–50% smaller uncertainties. Most of the Qatar-1b system parameter values and uncertainties from this work are consistent with values recently reported in the literature. We find no convincing evidence for sinusoidal TTVs with a semi-amplitude of more than ∼35 and ∼25 s in the WASP-12b and Qatar-1b systems, respectively.

  16. Transanal total mesorectal excision: a systematic review of the experimental and clinical evidence.

    Science.gov (United States)

    Araujo, S E; Crawshaw, B; Mendes, C R; Delaney, C P

    2015-02-01

    Achieving a clear distal or circumferential resection margins with laparoscopic total mesorectal excision (TME) may be laborious, especially in obese males and when operating on advanced distal rectal tumors with a poor response to neoadjuvant treatment. Transanal (TaTME) is a new natural orifice translumenal endoscopic surgery modality in which the rectum is mobilized transanally using endoscopic techniques with or without laparoscopic assistance. We conducted a comprehensive systematic review of publications on this new technique in PubMed and Embase databases from January, 2008, to July, 2014. Experimental and clinical studies written in English were included. Experimental research with TaTME was done on pigs with and without survival models and on human cadavers. In these studies, laparoscopic or transgastric assistance was frequently used resulting in an easier upper rectal dissection and in a longer rectal specimen. To date, 150 patients in 16 clinical studies have undergone TaTME. In all but 15 cases, transabdominal assistance was used. A rigid transanal endoscopic operations/transanal endoscopic microsurgery (TEO/TEM) platform was used in 37 patients. Rectal adenocarcinoma was the indication in all except for nine cases of benign diseases. Operative times ranged from 90 to 460 min. TME quality was deemed intact, satisfactory, or complete. Involvement in circumferential resection margins was detected in 16 (11.8 %) patients. The mean lymph node harvest was equal or greater than 12 in all studies. Regarding morbidity, pneumoretroperitoneum, damage to the urethra, and air embolism were reported intraoperatively. Mean hospital stay varied from 4 to 14 days. Postoperative complications occurred in 34 (22.7 %) patients. TaTME with TEM is feasible in selected cases. Oncologic safety parameters seem to be adequate although the evidence relies on small retrospective series conducted by highly trained surgeons. Further studies are expected.

  17. Experimental evidence of the thermal effect of lubricating oil sprayed in sliding-vane air compressors

    Directory of Open Access Journals (Sweden)

    Gianluca Valenti

    2014-11-01

    Full Text Available A way to increase the efficiency of positive-displacement air compressor is spraying the lube oil to exploit it not only as lubricating and sealing agent but also as thermal ballast. This work seeks the experimental evidence in sliding-vane compressors by measuring the air standard volume flow rate and the electrical power input of three diverse configurations. The first configuration, taken as the reference, employs a conventional injection system comprising calibrated straight orifices. The other two, referred to as advanced, adopt smaller orifices and pressure-swirl full-cone nozzles designed for the purpose; the third configuration utilizes a pump to boost the oil pressure. The laser imagining technique shows that the nozzles generate sprays that break-up within a short distance into spherical droplets, ligaments, ramifications and undefined structures. Tests on the packaged compressors reveal that the advanced configurations provide almost the same air flow rate while utilizing half of the oil because the sprays generate a good sealing. Moreover, the sprayed oil is acting as a thermal ballast because the electrical input is reduced by 3.5% and 3.0%, respectively, if the pump is present or not , while the specific energy requirement, accounting for the slightly reduced air flow, by 2.4% and 2.9%, respectively.

  18. Experimental evidence of lateral flow in unsaturated homogeneous isotropic sloping soil due to rainfall

    Science.gov (United States)

    Sinai, G.; Dirksen, C.

    2006-12-01

    This paper describes laboratory experimental evidence for lateral flow in the top layer of unsaturated sloping soil due to rainfall. Water was applied uniformly on horizontal and V-shaped surfaces of fine sand, at rates about 100 times smaller than the saturated hydraulic conductivity. Flow regimes near the surface and in the soil bulk were studied by using dyes. Streamlines and streak lines and wetting fronts were visually studied and photographed through a vertical glass wall. Near wetting fronts the flow direction was always perpendicular to the fronts owing to dominant matrix potential gradients. Thus, during early wetting of dry sloping sand, the flow direction is directed upslope. Far above a wetting front the flow was vertical due to the dominance of gravity. Downslope flow was observed during decreasing rainfall and dry periods. The lateral movement was largest near the soil surface and decayed with soil depth. Unstable downslope lateral flow close to the soil surface was attributed to non-Darcian flow due to variable temporal and spatial raindrop distributions. The experiments verify the theory that predicts unsaturated downslope lateral flow in sloping soil due to rainfall dynamics only, without apparent soil texture difference or anisotropy. This phenomenon could have significant implications for hillside hydrology, desert agriculture, irrigation management, etc., as well as for the basic mechanisms of surface runoff and erosion.

  19. Proprioceptive dysfunction in focal dystonia: from experimental evidence to rehabilitation strategies.

    Directory of Open Access Journals (Sweden)

    Laura eAvanzino

    2014-12-01

    Full Text Available Dystonia has historically been considered a disorder of the basal ganglia, mainly affecting planning and execution of voluntary movements. This notion comes from the observation that most lesions responsible for secondary dystonia involve the basal ganglia. However, what emerges from recent research is that dystonia is linked to the dysfunction of a complex neural network that comprises basal ganglia-thalamic-frontal cortex, but also the inferior parietal cortex and the cerebellum. While dystonia is clearly a motor problem, it turned out that sensory aspects are also fundamental, especially those related to proprioception.We outline experimental evidence for proprioceptive dysfunction in focal dystonia from intrinsic sensory abnormalities to impaired sensorimotor integration, that is the process by which sensory information is used to plan and execute volitional movements. Particularly, we will focus on proprioceptive aspects of dystonia, including: i processing of vibratory input, ii temporal discrimination of two passive movements, iii multimodal integration of visual-tactile and proprioceptive inputs and, iv motor control in the absence of visual feedback. We suggest that these investigations contribute not only to a better understanding of dystonia pathophysiology, but also to develop rehabilitation strategies aimed at facilitating the processing of proprioceptive input.

  20. Spray drift of pesticides and stream macroinvertebrates: Experimental evidence of impacts and effectiveness of mitigation measures

    Energy Technology Data Exchange (ETDEWEB)

    Maltby, Lorraine [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom)], E-mail: l.maltby@sheffield.ac.uk; Hills, Louise [Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN (United Kingdom)

    2008-12-15

    Impoverished stream communities in agricultural landscapes have been associated with pesticide contamination, but conclusive evidence of causality is rare. We address this deficiency by adopting an experimental approach to investigate the effects of the insecticides cypermethrin and chlorpyrifos on benthic macroinvertebrates. Three treatments were established and a combination of biomarker, bioassay and biomonitoring approaches was employed to investigate, individual, population and community-level effects. Animals deployed during pesticide application had altered enzyme activity, depressed feeding rate and reduced survival, but these effects were only observed where pesticide was sprayed to the stream edge. There were no clear pesticide-related effects on macroinvertebrate community structure or on the population densities of individual species. Hence, short-term pesticide exposure did cause individual-level effects in stream macroinvertebrates, but these were not translated to effects at the population or community-level and were effectively mitigated by the adoption of a no-spray buffer zone. - Pulsed pesticide exposures via spray drift adversely affected stream invertebrates but did not cause population or community-level effects and were mitigated by no-spray buffer zones.

  1. Spontaneous Time Symmetry Breaking in System with Mixed Strategy Nash Equilibrium: Evidences in Experimental Economics Data

    Science.gov (United States)

    Wang, Zhijian; Xu, Bin; Zhejiang Collaboration

    2011-03-01

    In social science, laboratory experiment with human subjects' interaction is a standard test-bed for studying social processes in micro level. Usually, as in physics, the processes near equilibrium are suggested as stochastic processes with time-reversal symmetry (TRS). To the best of our knowledge, near equilibrium, the breaking time symmetry, as well as the existence of robust time anti-symmetry processes, has not been reported clearly in experimental economics till now. By employing Markov transition method to analysis the data from human subject 2x2 Games with wide parameters and mixed Nash equilibrium, we study the time symmetry of the social interaction process near Nash equilibrium. We find that, the time symmetry is broken, and there exists a robust time anti-symmetry processes. We also report the weight of the time anti-symmetry processes in the total processes of each the games. Evidences in laboratory marketing experiments, at the same time, are provided as one-dimension cases. In these cases, time anti-symmetry cycles can also be captured. The proposition of time anti-symmetry processes is small, but the cycles are distinguishable.

  2. An extended model of electrons: experimental evidence from high-resolution scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Hofer, Werner A

    2012-01-01

    In a recent paper we introduced a model of extended electrons, which is fully compatible with quantum mechanics in the formulation of Schrödinger. However, it contradicts the current interpretation of electrons as point-particles. Here, we show by a statistical analysis of high-resolution scanning tunneling microscopy (STM) experiments, that the interpretation of electrons as point particles and, consequently, the interpretation of the density of electron charge as a statistical quantity will lead to a conflict with the Heisenberg uncertainty principle. Given the precision in these experiments we find that the uncertainty principle would be violated by close to two orders of magnitude, if this interpretation were correct. We are thus forced to conclude that the density of electron charge is a physically real, i.e. in principle precisely measurable quantity, as derived in a recent paper. Experimental evidence to the contrary, in particular high-energy scattering experiments, is briefly discussed. The finding is expected to have wide implications in condensed matter physics, chemistry, and biology, scientific disciplines which are based on the properties and interactions of electrons.

  3. Infectivity of DWV associated to flower pollen: experimental evidence of a horizontal transmission route.

    Directory of Open Access Journals (Sweden)

    Maurizio Mazzei

    Full Text Available Deformed wing virus (DWV is a honeybee pathogen whose presence is generally associated with infestation of the colony by the mite Varroa destructor, leading to the onset of infections responsible for the collapse of the bee colony. DWV contaminates bee products such as royal jelly, bee-bread and honey stored within the infected hive. Outside the hive, DWV has been found in pollen loads collected directly from infected as well as uninfected forager bees. It has been shown that the introduction of virus-contaminated pollen into a DWV-free hive results in the production of virus-contaminated food, whose role in the development of infected bees from virus-free eggs has been experimentally demonstrated. The aim of this study was twofold: (i to ascertain the presence of DWV on pollen collected directly from flowers visited by honeybees and then quantify the viral load and (ii determine whether the virus associated with pollen is infective. The results of our investigation provide evidence that DWV is present on pollen sampled directly from visited flowers and that, following injection in individuals belonging to the pollinator species Apis mellifera, it is able to establish an active infection, as indicated by the presence of replicating virus in the head of the injected bees. We also provide the first indication that the pollinator species Osmia cornuta is susceptible to DWV infection.

  4. Smectite clays in Mars soil - Evidence for their presence and role in Viking biology experimental results

    Science.gov (United States)

    Banin, A.; Rishpon, J.

    1979-01-01

    Evidence for the presence of smectite clays in Martian soils is reviewed and results of experiments with certain active clays simulating the Viking biology experiments are reported. Analyses of Martian soil composition by means of X-ray fluorescence spectrometry and dust storm spectroscopy and Martian geological history strongly suggest the presence of a mixture of weathered ferro-silicate minerals, mainly nontronite and montmorillonite, accompanied by soluble sulphate salts, as major constituents. Samples of montmorillonite and nontronite incubated with (C-14)-formate or the radioactive nutrient medium solution used in the Viking Labeled Release experiment, were found to produce patterns of release of radioactive gas very similar to those observed in the Viking experiments, indicating the iron-catalyzed decomposition of formate as the reaction responsible for the Viking results. The experimental results of Hubbard (1979) simulating the results of the Viking Pyrolytic Release experiment using iron montmorillonites are pointed out, and it is concluded that many of the results of the Viking biology experiments can be explained in terms of the surface activity of smectite clays in catalysis and adsorption.

  5. Experimental evidence concerning the significant information depth of electron backscatter diffraction (EBSD)

    Energy Technology Data Exchange (ETDEWEB)

    Wisniewski, Wolfgang, E-mail: wolfgang.w@uni-jena.de [Otto-Schott-Institut, Jena University, Fraunhoferstr. 6, 07743 Jena (Germany); Saager, Stefan [Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, Winterbergstraße 28, 01277 Dresden (Germany); Böbenroth, Andrea [Fraunhofer Institute for the Microstructure of Materials and Systems IMWS, Walter-Huelse-Straße 1, 06120 Halle (Saale) (Germany); Rüssel, Christian [Otto-Schott-Institut, Jena University, Fraunhoferstr. 6, 07743 Jena (Germany)

    2017-02-15

    Experiments concerning the information depth of electron backscatter diffraction (EBSD) are performed on samples featuring an amorphous wedge on a crystalline substrate and a crystalline wedge on an amorphous substrate. The effects of the acceleration voltage and exemplary software settings on the ability to measure through an amorphous layer are presented. Changes in the EBSD-signal could be detected through a ≈142 nm thick layer of amorphous Si while orientation measurements could be performed through a ≈116 nm thick layer when using a voltage of 30 kV. The complexity of the information depth significant to a given EBSD-pattern and the multiple parameters influencing it are discussed. It is suggested that a “core information depth” is significant to high quality patterns while a larger “maximum information depth” becomes relevant when the pattern quality decreases or the sample is inhomogeneous within the information volume, i.e. in the form of partially crystalline materials or crystal layers in the nm scale. - Highlights: • Experimental evidence of the significant information depth of EBSD is presented. • Effects of the voltage and exemplary software settings are discussed. • Dependence of the significant information depth on the pattern quality is proposed. • The information depth may reach up to 142 nm in Si when using a voltage of 30 kV. • The information depth depends on the available technology.

  6. Experimental evidence of a liquid-liquid transition in interfacial water

    Science.gov (United States)

    Zanotti, J.-M.; Bellissent-Funel, M.-C.; Chen, S.-H.

    2005-07-01

    At ambient pressure, bulk liquid water shows an anomalous increase of thermodynamic quantities and apparent divergences of dynamic properties on approaching a temperature Ts of 228 K. At normal pressure, supercooled water spontaneously freezes below the homogeneous nucleation temperature, TH = 235 K. Upon heating, the two forms of Amorphous Solid Water (ASW), LDA (Low Density Amorphous Ice) and HDA (High Density Amorphous Ice), crystallise above TX = 150 K. As a consequence, up to now no experiment has been able to explore the properties of liquid water in this very interesting temperature range between 150 and 235 K. We present nanosecond-time-scale measurements of local rotational and translational dynamics of interfacial, non-crystalline, water from 77 to 280 K. These experimental dynamic results are combined with calorimetric and diffraction data to show that after exhibiting a glass transition at 165 K, interfacial water experiences a first-order liquid-liquid transition at 240 K from a low-density to a high-density liquid. This is the first direct evidence of the existence of a liquid-liquid transition involving water.

  7. Is the anomalous effect an experimental evidence for the excitation of new exotic states in heavy-ion collisions

    International Nuclear Information System (INIS)

    Ion, D.B.; Ion, R.; Topor Pop, V.

    1984-10-01

    Lower bound on the mean free path of the projectile fragments from the relativistic heavy ion collisions are drived using generalized Rarita-Schwed's theorems. These bounds are compared with the experimental data on the anomalous mean free path observed in recent experiments. The near saturation of these bounds provide a specific interpretation of the anomalous effects as an experimental evidence for the excitation of those extreme nuclear states which saturate the limits of the convetional nuclear physics. (authors)

  8. Spectroscopic Evidence for Covalent Binding of Sulfadiazine to Natural Soils via 1,4-nucleophilic addition (Michael Type Addition) studied by Spin Labeling ESR

    Science.gov (United States)

    Aleksandrova, Olga

    2015-04-01

    with different polarity. As shown by the spin labeling ESR experiment, molecules modeling SDZ were promptly bound to non-hydrolysable network of soil organic matter only via the aromatic amines that was accompanied by a prompt enlargement of humic particles binding aromatic amines, whereas binding of decomposition products of SDZ to humic acids of soil via the aliphatic amines was not observable. The ESR spectra obviously showed a single-phase process of covalent binding of the aromatic amines. Repeated washouts of labeled soil samples using distil water and ultrafiltration through the membrane of 5000 MWCO PES confirmed irreversible binding of the aromatic amines, and showed that via the aliphatic amines, binding of SDZ or decomposition products of SDZ to soil might also occur but reversibly and only to small soil molecules, which don't enter into the composition of non-hydrolysable part of soil organic matter. SL ESR experiments of different soils at the presence of Laccase highlighted that covalent binding of the aromatic amines to humic particles occurred in the specific hydrophobic areas of soil found as depleted in oxygen. All measured data evidenced that first, SDZ might be decomposed that allowed for measuring the same change of a paramagnetic signal of soil organic matter influenced by both aromatic and aliphatic amines as in the experiment of the interaction of soil with SDZ. Second, a decomposition product of SDZ with the aromatic amine might be bound to non-hydrolysable parts of soil organic matter under specific anaerobic conditions only via 1,4 - nucleophilic addition, Michael-type addition. Gulkowska, A., Thalmann, B., D., Hollender, J., & Krauss, M. (2014). Chemosphere, 107, 366 - 372. Müller, T., Rosendahl, I., Focks, A., Siemens, J., Klasmeier, J., & Matthies. (2013). Environmental Pollution, 172,180 - 185. Nowak, K.M., Miltner, A., Gehre, M., Schaeffer, A., & Kaestner, M. (2011). Environmental Science & Technology 45, 999 - 1006. Weber, E.J., Spidle

  9. Is there any evidence that cerebral protection is beneficial? Experimental data.

    Science.gov (United States)

    Macdonald, S

    2006-04-01

    This article presents the available experimental data from the world literature on the use of cerebral protection devices during carotid artery stenting (CAS). Clinical studies relying on surrogate markers of cerebral embolisation in place of neurological event rate as primary outcome measures are evaluated alongside bench-top and animal studies. These surrogate markers include evaluations of outcomes using procedural transcranial Doppler (TCD) and diffusion-weighted magnetic resonance imaging of brain (DWI). Pathological analyses of debris retrieved from in-vivo analyses of protection devices are also included in this review because although the focus of these studies was primarily clinical, the laboratory data will be preferentially presented and it provides interesting insights. It can be shown that each of the three philosophies of cerebral protection, namely flow arrest (proximal or distal), flow reversal and distal filtration is capable of the entrapment of sizeable debris that would logically threaten devastating stroke if it embolized to the brain. Whilst balloon occlusion significantly reduces the procedural microembolic load (particles less than 60 mm) and flow reversal may be the first means to entirely eliminate it, filters may be associated with increased microembolization. This has been described by some workers as controlled embolization. Certainly, particles smaller than the pore size of currently available filters (60-140 mm) will readily evade capture due to filter periflow and through-flow. There is evidence to suggest that tens of thousands of particles of this size may be released during CAS and there is some evidence that this may be associated with more new white lesions on DWI of brain. The clinical consequences of this controlled embolization however, remain unclear and sophisticated neuropsychometric test batteries may need to be applied at later time points to detect subtle injury that may be compounded by a late inflammatory response

  10. Evident?

    DEFF Research Database (Denmark)

    Plant, Peter

    2012-01-01

    Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind......Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind...

  11. Experimental evidence for the physiological role of bacterial luciferase in the protection of cells against oxidative stress.

    Science.gov (United States)

    Szpilewska, Hanna; Czyz, Agata; Wegrzyn, Grzegorz

    2003-11-01

    The origin and function of bioluminescence was considered a problematic question of the Charles Darwin theory. Early evolution of bacterial luminescence and its current physiological importance seem to be especially mysterious. Recently, it was proposed that stimulation of DNA repair may be a physiological role for production of light by bacterial cells. On the other hand, it was also proposed that primary role of luminescent systems could be detoxification of the deleterious oxygen derivatives. Although some previous results might suggest that this hypothesis can be correct, until now experimental evidence for such a mechanism operating in bacterial cells and having physiological importance was generally lacking. Here we demonstrate that in the presence of various oxidants (hydrogen peroxide, cumene hydroperoxide, t-butyl hydroperoxide, and ferrous ions) at certain concentrations in the culture medium, growth of Vibrio harveyi mutants luxA and luxB, but not of the mutant luxD, is severely impaired relative to wild-type bacteria. This deleterious effect of oxidants on the mutants luxA and luxB could be significantly reduced by addition of the antioxidants A-TEMPO or 40H-TEMPO. We conclude that bacterial luciferase may indeed play a physiological role in the protection of cells against oxidative stress.

  12. The Pay-What-You-Want game: What can be learned from the experimental evidence on Dictator and Trust Games?

    Directory of Open Access Journals (Sweden)

    Greiff Matthias

    2017-03-01

    Full Text Available This paper introduces the Pay-What-You-Want game which represents the interaction between a buyer and a seller in a Pay-What-You-Want (PWYW situation. The PWYW game embeds the dictator game and the trust game as subgames. This allows us to use previous experimental studies with the dictator and the trust game to identify three factors that can influence the success of PWYW pricing in business practice: (i social context, (ii social information, and (iii deservingness. Only few cases of PWYW pricing for a longer period of time have been documented. By addressing repeated games, we isolate two additional factors which are likely to contribute to successful implementations of PWYW as a long term pricing strategy. These are (iv communication and (v the reduction of goal conflicts. The central contribution of this study is an attempt to bridge the gap between laboratory experiments and the research on PWYW pricing, which relies largely on evidence from the field. By reviewing the relevant experiments, this study identifies factors crucial for the success of PWYW pricing and provides guidance to developing long-term applications of PWYW pricing.

  13. Experimental evidence that RNA recombination occurs in the Japanese encephalitis virus

    International Nuclear Information System (INIS)

    Chuang, C.-K.; Chen, W.-J.

    2009-01-01

    Due to the lack of a proofreading function and error-repairing ability of genomic RNA, accumulated mutations are known to be a force driving viral evolution in the genus Flavivirus, including the Japanese encephalitis (JE) virus. Based on sequencing data, RNA recombination was recently postulated to be another factor associated with genomic variations in these viruses. We herein provide experimental evidence to demonstrate the occurrence of RNA recombination in the JE virus using two local pure clones (T1P1-S1 and CJN-S1) respectively derived from the local strains, T1P1 and CJN. Based on results from a restriction fragment length polymorphism (RFLP) assay on the C/preM junction comprising a fragment of 868 nucleotides (nt 10-877), the recombinant progeny virus was primarily formed in BHK-21 cells that had been co-infected with the two clones used in this study. Nine of 20 recombinant forms of the JE virus had a crossover in the nt 123-323 region. Sequencing data derived from these recombinants revealed that no nucleotide deletion or insertion occurred in this region favoring crossovers, indicating that precisely, not aberrantly, homologous recombination was involved. With site-directed mutagenesis, three stem-loop secondary structures were destabilized and re-stabilized in sequence, leading to changes in the frequency of recombination. This suggests that the conformation, not the free energy, of the secondary structure is important in modulating RNA recombination of the virus. It was concluded that because RNA recombination generates genetic diversity in the JE virus, this must be considered particularly in studies of viral evolution, epidemiology, and possible vaccine safety.

  14. Nitrate ammonification by Nautilia profundicola AmH: experimental evidence consistent with a free hydroxylamine intermediate.

    Directory of Open Access Journals (Sweden)

    Thomas E Hanson

    2013-07-01

    Full Text Available The process of nitrate reduction via nitrite controls the fate and bioavailability of mineral nitrogen within ecosystems; i.e. whether it is retained as ammonium (ammonification or lost as nitrous oxide or dinitrogen (denitrification. Here, we present experimental evidence for a novel pathway of microbial nitrate reduction, the reverse hydroxylamine:ubiquinone reductase module (reverse-HURM pathway. Instead of a classical ammonia-forming nitrite reductase that performs a 6 electron-transfer process, the pathway is thought to employ two catalytic redox modules operating in sequence: the reverse-HURM reducing nitrite to hydroxylamine followed by a hydroxylamine reductase that converts hydroxylamine to ammonium. Experiments were performed on Nautilia profundicola strain AmH, whose genome sequence led to the reverse-HURM pathway proposal. N. profundicola produced ammonium from nitrate, which was assimilated into biomass. Furthermore, genes encoding the catalysts of the reverse-HURM pathway were preferentially expressed during growth of N. profundicola on nitrate as an electron acceptor relative to cultures grown on polysulfide as an electron acceptor. Finally, nitrate-grown cells of N. profundicola were able to rapidly and stoichiometrically convert high concentrations of hydroxylamine to ammonium in resting cell assays. These experiments are consistent with the reverse-HURM pathway and a free hydroxylamine intermediate, but could not definitively exclude direct nitrite reduction to ammonium by the reverse-HURM with hydroxylamine as an off-pathway product. N. profundicola and related organisms are models for a new pathway of nitrate ammonification that may have global impact due to the wide distribution of these organisms in hypoxic environments and symbiotic or pathogenic associations with animal hosts.

  15. Monitoring healthy and disturbed sleep through smartphone applications: a review of experimental evidence.

    Science.gov (United States)

    Fino, Edita; Mazzetti, Michela

    2018-04-23

    Smartphone applications are considered as the prime candidate for the purposes of large-scale, low-cost and long-term sleep monitoring. How reliable and scientifically grounded is smartphone-based assessment of healthy and disturbed sleep remains a key issue in this direction. Here we offer a review of validation studies of sleep applications to the aim of providing some guidance in terms of their reliability to assess sleep in healthy and clinical populations, and stimulating further examination of their potential for clinical use and improved sleep hygiene. Electronic literature review was conducted on Pubmed. Eleven validation studies published since 2012 were identified, evaluating smartphone applications' performance compared to standard methods of sleep assessment in healthy and clinical samples. Studies with healthy populations show that most sleep applications meet or exceed accuracy levels of wrist-based actigraphy in sleep-wake cycle discrimination, whereas performance levels drop in individuals with low sleep efficiency (SE) and in clinical populations, mirroring actigraphy results. Poor correlation with polysomnography (PSG) sleep sub-stages is reported by most accelerometer-based apps. However, multiple parameter-based applications (i.e., EarlySense, SleepAp) showed good capability in detection of sleep-wake stages and sleep-related breathing disorders (SRBD) like obstructive sleep apnea (OSA) respectively with values similar to PSG. While the reviewed evidence suggests a potential role of smartphone sleep applications in pre-screening of SRBD, more experimental studies are warranted to assess their reliability in sleep-wake detection particularly. Apps' utility in post treatment follow-up at home or as an adjunct to the sleep diary in clinical setting is also stressed.

  16. Recent theoretical and experimental evidence on the cold fusion of elementary particles

    International Nuclear Information System (INIS)

    Santilli, R.M.

    1993-01-01

    Recent experiments have shown the apparent existence of the cold fusion/chemical synthesis of protons and electrons into neutrons (plus neutrinos), much along Rutherford's original conception. These findings have received indirect, yet significant experimental confirmations in Bose-Einstein correlations, superconductivity and other fields to warrant additional studies. In this paper we present a quantitative theoretical study of the apparent tendency of all massive particles to form a bound state at small distances which is enhanced at low energy. The study is centrally dependent on the isominkowskian geometrization of the expected nonlocal interactions due to total mutual penetrations, and their causal description via the isopoincare symmetry. The cold fusion considered is then made possible by isorenormalizations of the 'intrinsic' characteristics of particles originating from the contact-nonhamiltonian character of the internal nonlocal effects. This latter feature illustrates the reasons why the cold fusion considered is simply beyond the descriptive capacities of relativistic quantum mechanics, but it is fully predicted by its isotopic covering. 23 refs

  17. Scientific Reasoning in Early and Middle Childhood: The Development of Domain-General Evidence Evaluation, Experimentation, and Hypothesis Generation Skills

    Science.gov (United States)

    Piekny, Jeanette; Maehler, Claudia

    2013-01-01

    According to Klahr's (2000, 2005; Klahr & Dunbar, 1988) Scientific Discovery as Dual Search model, inquiry processes require three cognitive components: hypothesis generation, experimentation, and evidence evaluation. The aim of the present study was to investigate (a) when the ability to evaluate perfect covariation, imperfect covariation,…

  18. Experimental investigation of the effect of titanium dioxide and barium titanate additives on DC transient currents in low density polyethylene

    DEFF Research Database (Denmark)

    Khalil, M.S; Henk, Peter O; Henriksen, Mogens

    1988-01-01

    The effect of titanium dioxide as a semiconductive additive and barium titanate as a highly polar additive on the DC transient currents in low-density polyethylene is investigated. Experiments were made using thick specimens under a high electric field (>25×106 V/m) and a constant temperature of 40...

  19. Experimental evidence of biological interactions among different isolates of Trypanosoma cruzi from the Chaco Region.

    Directory of Open Access Journals (Sweden)

    Paula G Ragone

    Full Text Available Many infectious diseases arise from co-infections or re-infections with more than one genotype of the same pathogen. These mixed infections could alter host fitness, the severity of symptoms, success in pathogen transmission and the epidemiology of the disease. Trypanosoma cruzi, the etiological agent of Chagas disease, exhibits a high biological variability often correlated with its genetic diversity. Here, we developed an experimental approach in order to evaluate biological interaction between three T. cruzi isolates belonging to different Discrete Typing Units (DTUs TcIII, TcV and TcVI. These isolates were obtained from a restricted geographical area in the Chaco Region. Different mixed infections involving combinations of two isolates (TcIII + TcV, TcIII + TcVI and TcV + TcVI were studied in a mouse model. The parameters evaluated were number of parasites circulating in peripheral blood, histopathology and genetic characterization of each DTU in different tissues by DNA hybridization probes. We found a predominance of TcVI isolate in blood and tissues respect to TcIII and TcV; and a decrease of the inflammatory response in heart when the damage of mice infected with TcVI and TcIII + TcVI mixture were compared. In addition, simultaneous presence of two isolates in the same tissue was not detected. Our results show that biological interactions between isolates with different biological behaviors lead to changes in their biological properties. The occurrence of interactions among different genotypes of T. cruzi observed in our mouse model suggests that these phenomena could also occur in natural cycles in the Chaco Region.

  20. Experimental evidence for enhanced top-down control of freshwater macrophytes with nutrient enrichment.

    Science.gov (United States)

    Bakker, Elisabeth S; Nolet, Bart A

    2014-11-01

    The abundance of primary producers is controlled by bottom-up and top-down forces. Despite the fact that there is consensus that the abundance of freshwater macrophytes is strongly influenced by the availability of resources for plant growth, the importance of top-down control by vertebrate consumers is debated, because field studies yield contrasting results. We hypothesized that these bottom-up and top-down forces may interact, and that consumer impact on macrophyte abundance depends on the nutrient status of the water body. To test this hypothesis, experimental ponds with submerged vegetation containing a mixture of species were subjected to a fertilization treatment and we introduced consumers (mallard ducks, for 8 days) on half of the ponds in a full factorial design. Over the whole 66-day experiment fertilized ponds became dominated by Elodea nuttallii and ponds without extra nutrients by Chara globularis. Nutrient addition significantly increased plant N and P concentrations. There was a strong interactive effect of duck presence and pond nutrient status: macrophyte biomass was reduced (by 50%) after the presence of the ducks on fertilized ponds, but not in the unfertilized ponds. We conclude that nutrient availability interacts with top-down control of submerged vegetation. This may be explained by higher plant palatability at higher nutrient levels, either by a higher plant nutrient concentration or by a shift towards dominance of more palatable plant species, resulting in higher consumer pressure. Including nutrient availability may offer a framework to explain part of the contrasting field observations of consumer control of macrophyte abundance.

  1. Are bilingualism effects on the L1 byproducts of implicit knowledge? Evidence from two experimental tasks

    Directory of Open Access Journals (Sweden)

    Ricardo Augusto de Souza

    2017-06-01

    Full Text Available Estudos experimentais em Linguística apoiam-se em dados oriundos de desempenho de participantes em tarefas linguísticas. Portanto, a compreensão dos construtos abordados por tais tarefas é fundamental para a interpretação dos resultados gerados pelo trabalho experimental. Neste estudo, explora-se questões trazidas por um estudo previamente publicado baseado em uma tarefa de julgamento de gramaticalidade temporizada que não replicou evidências anteriormente relatadas acerca de efeitos de interações translinguísticas no processamento bilíngue de construções de estrutura argumental que não fazem parte do repertório construcional da L1 dos bilíngues. Apesar da tarefa de julgamento de gramaticalidade temporizada ter sido defendida como uma medida válida de conhecimento linguístico implícito, resenha-se estudos psicométricos recentes que põem este pressuposto em dúvida, ao mostrar que tal tarefa ou não captura conhecimento implícito, ou não o captura tão completamente quanto o fazem tarefas psicolinguísticas de processamento online. Neste estudo, conduz-se dois experimentos com a mesma amostra de sujeitos. Um dos experimentos empregou uma tarefa de processamento online, e o outro empregou uma tarefa de julgamento de gramaticalidade temporizada. Nessas tarefas, sentenças em português do Brasil que emulavam o comportamento linguístico da construção resultativa do inglês constituíram os itens alvo. Relata-se resultados que mostram a discrepância de observações geradas pelos dois tipos de tarefa, com somente a tarefa de processamento online revelando os aparentes efeitos da L2 sobre o desempenho linguístico da L1. Interpreta-se os resultados como sugestivos de que o local das interações translinguísticas de bilíngues é majoritariamente nos processos implícitos.

  2. Theoretical Evidence for Low-Ligated Palladium(0): [Pd-L] as the Active Species in Oxidative Addition Reactions

    DEFF Research Database (Denmark)

    Ahlquist, Mårten Sten Gösta; Fristrup, Peter; Tanner, David Ackland

    2006-01-01

    The oxidative addition of PhI to Pd0 has been studied by DFT with a continuum representation of the solvent. It is shown that the preferred number of ligands on palladium is lower than would be expected from “conventional wisdom” and the 18-electron rule. The most favored oxidative addition is ob...

  3. When culture does not matter: Experimental evidence from coalition formation ultimatum games in Austria and Japan

    NARCIS (Netherlands)

    Okada, A.; Riedl, A.M.

    1999-01-01

    This paper reports the results of a cross-country comparison between Austria andJapan for an experimental 3-personcoalition formation ultimatum game. The experimental design allows thecomparison with respect to three decisions. (i)The coalition decision, (ii) proposers' demand behavior in 2- and

  4. Experimental evidence for dual diffractive resonances in nucleon-nucleus scattering

    International Nuclear Information System (INIS)

    Ion, D.B.; Ion-Mihai, R.

    1981-09-01

    Experimental data on nucleon-nucleus scattering for laboratory momenta between 0.9:10 GeV/c are analysed in terms of the dual diffractive resonance (DDR) mechanism. The experimental data for all the nuclei are found to agree well with the predictions of the collective DDR states dominance. (authors)

  5. Empirical evidence of bias in the design of experimental stroke studies - A metaepidemiologic approach

    NARCIS (Netherlands)

    Crossley, Nicolas A.; Sena, Emily; Goehler, Jos; Horn, Jannekke; van der Worp, Bart; Bath, Philip M. W.; Macleod, Malcolm; Dirnagl, Ulrich

    2008-01-01

    Background and Purpose - At least part of the failure in the transition from experimental to clinical studies in stroke has been attributed to the imprecision introduced by problems in the design of experimental stroke studies. Using a metaepidemiologic approach, we addressed the effect of

  6. Quasi-experimental study designs series-paper 12: strengthening global capacity for evidence synthesis of quasi-experimental health systems research.

    Science.gov (United States)

    Rockers, Peter C; Tugwell, Peter; Grimshaw, Jeremy; Oliver, Sandy; Atun, Rifat; Røttingen, John-Arne; Fretheim, Atle; Ranson, M Kent; Daniels, Karen; Luiza, Vera Lucia; Bärnighausen, Till

    2017-09-01

    Evidence from quasi-experimental studies is often excluded from systematic reviews of health systems research despite the fact that such studies can provide strong causal evidence when well conducted. This article discusses global coordination of efforts to institutionalize the inclusion of causal evidence from quasi-experiments in systematic reviews of health systems research. In particular, we are concerned with identifying opportunities for strengthening capacity at the global and local level for implementing protocols necessary to ensure that reviews that include quasi-experiments are consistently of the highest quality. We first describe the current state of the global infrastructure that facilitates the production of systematic reviews of health systems research. We identify five important types of actors operating within this infrastructure: review authors; synthesis collaborations that facilitate the review process; synthesis interest groups that supplement the work of the larger collaborations; review funders; and end users, including policymakers. Then, we examine opportunities for intervening to build the capacity of each type of actors to support the inclusion of quasi-experiments in reviews. Finally, we suggest practical next steps for proceeding with capacity building efforts. Because of the complexity and relative nascence of the field, we recommend a carefully planned and executed approach to strengthening global capacity for the inclusion of quasi-experimental studies in systematic reviews. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Pursuing Quality Evidence: Applying Single-Subject Quality Indicators to Non-Experimental Qualitative Educational Research

    Science.gov (United States)

    Stodden, Robert A.; Yamamoto, Kathryn K.; Folk, Eric; Kong, Eran; Otsuji, Derek N.

    2013-01-01

    The need for quality evidence in support of strategies used while working with persons with autism and intellectual disability (ID) has been long been recognized by researchers and practitioners. The authors reviewed and applied a number of evidence-based indicators, developed through the "What Works Clearinghouse" (WWC), to the conduct…

  8. The parasitic model of L2 and L3 vocabulary acquisition: evidence from naturalistic and experimental studies

    Directory of Open Access Journals (Sweden)

    Peter Ecke

    2014-09-01

    Full Text Available This paper reviews evidence for the Parasitic Model of Vocabulary Acquisition for second and third language learners/developing multilinguals. It first describes the model’s predictions about default processes based on the detection and use of similarity at the three stages involved in the development of individual lexical items: (1 the establishing of a form representation, (2 the building of connections to syntactic frame and concept representations, and (3 the strengthening and automatization of representations and access routes. The paper then summarizes both naturalistic and experimental evidence for processes involved at these three stages. Finally it discusses open issues and potential areas for future investigation.

  9. Experimental and Modeling Investigation of the Effect of H2S Addition to Methane on the Ignition and Oxidation at High Pressures

    NARCIS (Netherlands)

    Gersen, Sander; van Essen, Martijn; Darmeveil, Harry; Hashemi, Hamid; Rasmussen, Christian Tihic; Christensen, Jakob Munkholdt; Glarborg, Peter; Levinsky, Howard

    The autoignition and oxidation behavior of CH4/H2S mixtures has been studied experimentally in a rapid compression machine (RCM) and a high-pressure flow reactor. The RCM measurements show that the addition of 1% H2S to methane reduces the autoignition delay time by a factor of 2 at pressures

  10. Experimental and theoretical evidence for the chaotic dynamics of complex structures

    International Nuclear Information System (INIS)

    Agop, M; Dimitriu, D G; Poll, E; Niculescu, O; Radu, V

    2013-01-01

    This paper presents the experimental results on the formation, dynamics and evolution towards chaos of complex space charge structures that emerge in front of a positively biased electrode immersed in a quiescent plasma. In certain experimental conditions, we managed to obtain the so-called multiple double layers (MDLs) with non-concentric configuration. Our experiments show that the interactions between each MDL's constituent entities are held responsible for the complex dynamics and eventually for its transition to chaos through cascades of spatio-temporal sub-harmonic bifurcations. Further, we build a theoretical model based on the fractal approximation (scale relativity theory) in order to reproduce the experimental results (plasma self-structuring and scenario of evolution to chaos). Comparing the experimental results with the theoretical ones, we observe a good correlation between them. (paper)

  11. EXPERIMENTAL INVESTIGATION OF EMISSION AND PERFORMANCE PARAMETERS OF PONGAMIA BIODIESEL AND HHO GAS ADDITION IN A COMPRESSION IGNITION ENGINE

    OpenAIRE

    Allen Jeffrey.J1, Divya Meena.S2, Balaji.P3, Bharathi.K4, Arvind Raj.R5

    2018-01-01

    Nowadays the environmental pollution has been increased incredibly by using conventional fuels. To control this increase in pollution alternate fuels has to be used as supplement for conventional fuels. While using conventional fuels such as petrol and diesel in IC engine there is a chance of increase in emissions. Alternate fuels can control emissions. This work is based on the investigation of emission parameters of pongamia biodiesel and HHO gas addition in a CI engine. Pongamia biodiesel ...

  12. Effects of phosphorus and nitrogen additions on tropical soil microbial activity in the context of experimental warming

    Science.gov (United States)

    Foley, M.; Nottingham, A.; Turner, B. L.

    2017-12-01

    Soil warming is generally predicted to increase microbial mineralization rates and accelerate soil C losses which could establish a positive feedback to climatic warming. Tropical rain forests account for a third of global soil C, yet the responseto of tropical soil C a warming climate remains poorly understood. Despite predictions of soil C losses, decomposition of soil organic matter (SOM) in tropical soils may be constrained by several factors including microbial nutrient deficiencies. We performed an incubation experiment in conjunction with an in-situ soil warming experiment in a lowland tropical forest on Barro Colorado Island, Panama, to measure microbial response to two key nutrient additions in shallow (0-10cm) and deep (50-100 cm) soils. We compared the response of lowland tropical soils to montane tropical soils, predicting that lowland soils would display the strongest response to phosphorus additions. Soils were treated with either carbon alone (C), nitrogen (CN), phosphorus (CP) or nitrogen and phosphorus combined (CNP). Carbon dioxide (CO2) production was measured by NaOH capture and titrimetric analysis for 10 days. Cumulative CO2 production in montane soils increased significantly with all additions, suggesting these soils are characterized by a general microbial nutrient deficiency. The cumulative amount of C respired in deep soils from the lowland site increased significantly with CP and CNP additions, suggesting that microbial processes in deep lowland tropical soils are phosphorus-limited. These results support the current understanding that lowland tropical forests are growing on highly weathered, phosphorus-deplete soils, and provide novel insight that deep tropical SOM may be stabilized by a lack of biologically-available phosphorus. Further, this data suggests tropical soil C losses under elevated temperature may be limited by a strong microbial phosphorus deficiency.

  13. Experimental and computational approaches to evaluate the environmental mitigation effect in narrow spaces by noble metal chemical addition (NMCA)

    International Nuclear Information System (INIS)

    Shimizu, Ryosuke; Ota, Nobuyuki; Nagase, Makoto; Aizawa, Motohiro; Ishida, Kazushige; Wada, Yoichi

    2014-01-01

    The environmental mitigation effect of NMCA in a narrow space was evaluated by experimental and computational approaches. In the experiment at 8 MPa and 553K, T-tube whose branched line had a narrow space was prepared, and the Zr electrodes were set in the branched line at certain intervals, which were 1, 3, 5, 7, 9, 11, 15 and 29 cm from the opening section of the branched line. Electrochemical corrosion potential (ECP) at the tip of the branched narrow space varied in response to the water chemistry in the main line which was at right angle with the branched line. Computational fluid dynamics (CFD) analysis reproduced the experimental results. It was also confirmed by CFD analysis that the ingress of water from the main line into the narrow space was accelerated by cavity flow and thermal convection. By CFD analysis in a thermal sleeve of actual plant condition, which had a narrow space, the concentration of dissolved oxygen at a tip of the thermal sleeve reached at 250 ppb within 300 sec, which was the same concentration of the main line. Noble metal deposition on the surface of the thermal sleeve was evaluated by mass transfer model. Noble metal deposition was the largest near the opening section of the branched line, and gradually decreased toward the tip section. In light of the consumption of dissolved oxygen in the branched line, noble metal deposition in the thermal sleeve was sufficient to reduce the ECP. It was expected that NMCA could mitigate the corrosion environment in the thermal sleeve. (author)

  14. Towards the evidence of a purely spatial Einstein-Podolsky-Rosen paradox in images: measurement scheme and first experimental results

    Science.gov (United States)

    Devaux, F.; Mougin-Sisini, J.; Moreau, P. A.; Lantz, E.

    2012-07-01

    We propose a scheme to evidence the Einstein-Podolsky-Rosen (EPR) paradox for photons produced by spontaneous down conversion, from measurement of purely spatial correlations of photon positions both in the near- and in the far-field. Experimentally, quantum correlations have been measured in the far-field of parametric fluorescence created in a type II BBO crystal. Imaging is performed in the photon counting regime with an electron-multiplying CCD (EMCCD) camera.

  15. Evidence-Based Communication Practices for Children with Visual Impairments and Additional Disabilities: An Examination of Single-Subject Design Studies

    Science.gov (United States)

    Parker, Amy T.; Grimmett, Eric S.; Summers, Sharon

    2008-01-01

    This review examines practices for building effective communication strategies for children with visual impairments, including those with additional disabilities, that have been tested by single-subject design methodology. The authors found 30 studies that met the search criteria and grouped intervention strategies to align any evidence of the…

  16. Effects of experimental fuel additions on fire intensity and severity: unexpected carbon resilience of a neotropical forest.

    Science.gov (United States)

    Brando, Paulo M; Oliveria-Santos, Claudinei; Rocha, Wanderley; Cury, Roberta; Coe, Michael T

    2016-07-01

    Global changes and associated droughts, heat waves, logging activities, and forest fragmentation may intensify fires in Amazonia by altering forest microclimate and fuel dynamics. To isolate the effects of fuel loads on fire behavior and fire-induced changes in forest carbon cycling, we manipulated fine fuel loads in a fire experiment located in southeast Amazonia. We predicted that a 50% increase in fine fuel loads would disproportionally increase fire intensity and severity (i.e., tree mortality and losses in carbon stocks) due to multiplicative effects of fine fuel loads on the rate of fire spread, fuel consumption, and burned area. The experiment followed a fully replicated randomized block design (N = 6) comprised of unburned control plots and burned plots that were treated with and without fine fuel additions. The fuel addition treatment significantly increased burned area (+22%) and consequently canopy openness (+10%), fine fuel combustion (+5%), and mortality of individuals ≥5 cm in diameter at breast height (dbh; +37%). Surprisingly, we observed nonsignificant effects of the fuel addition treatment on fireline intensity, and no significant differences among the three treatments for (i) mortality of large trees (≥30 cm dbh), (ii) aboveground forest carbon stocks, and (iii) soil respiration. It was also surprising that postfire tree growth and wood increment were higher in the burned plots treated with fuels than in the unburned control. These results suggest that (i) fine fuel load accumulation increases the likelihood of larger understory fires and (ii) single, low-intensity fires weakly influence carbon cycling of this primary neotropical forest, although delayed postfire mortality of large trees may lower carbon stocks over the long term. Overall, our findings indicate that increased fine fuel loads alone are unlikely to create threshold conditions for high-intensity, catastrophic fires during nondrought years. © 2016 John Wiley & Sons Ltd.

  17. Scientific reasoning in early and middle childhood: the development of domain-general evidence evaluation, experimentation, and hypothesis generation skills.

    Science.gov (United States)

    Piekny, Jeanette; Maehler, Claudia

    2013-06-01

    According to Klahr's (2000, 2005; Klahr & Dunbar, 1988) Scientific Discovery as Dual Search model, inquiry processes require three cognitive components: hypothesis generation, experimentation, and evidence evaluation. The aim of the present study was to investigate (a) when the ability to evaluate perfect covariation, imperfect covariation, and non-covariation evidence emerges, (b) when experimentation emerges, (c) when hypothesis generation skills emerge, and (d), whether these abilities develop synchronously during childhood. We administered three scientific reasoning tasks referring to the three components to 223 children of five age groups (from age 4.0 to 13.5 years). Our results show that the three cognitive components of domain-general scientific reasoning emerge asynchronously. The development of domain-general scientific reasoning begins with the ability to handle unambiguous data, progresses to the interpretation of ambiguous data, and leads to a flexible adaptation of hypotheses according to the sufficiency of evidence. When children understand the relation between the level of ambiguity of evidence and the level of confidence in hypotheses, the ability to differentiate conclusive from inconclusive experiments accompanies this development. Implications of these results for designing science education concepts for young children are briefly discussed. © 2012 The British Psychological Society.

  18. The price elasticity of demand for heroin: Matched longitudinal and experimental evidence.

    Science.gov (United States)

    Olmstead, Todd A; Alessi, Sheila M; Kline, Brendan; Pacula, Rosalie Liccardo; Petry, Nancy M

    2015-05-01

    This paper reports estimates of the price elasticity of demand for heroin based on a newly constructed dataset. The dataset has two matched components concerning the same sample of regular heroin users: longitudinal information about real-world heroin demand (actual price and actual quantity at daily intervals for each heroin user in the sample) and experimental information about laboratory heroin demand (elicited by presenting the same heroin users with scenarios in a laboratory setting). Two empirical strategies are used to estimate the price elasticity of demand for heroin. The first strategy exploits the idiosyncratic variation in the price experienced by a heroin user over time that occurs in markets for illegal drugs. The second strategy exploits the experimentally induced variation in price experienced by a heroin user across experimental scenarios. Both empirical strategies result in the estimate that the conditional price elasticity of demand for heroin is approximately -0.80. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. The price elasticity of demand for heroin: matched longitudinal and experimental evidence#

    Science.gov (United States)

    Olmstead, Todd A.; Alessi, Sheila M.; Kline, Brendan; Pacula, Rosalie Liccardo; Petry, Nancy M.

    2015-01-01

    This paper reports estimates of the price elasticity of demand for heroin based on a newly constructed dataset. The dataset has two matched components concerning the same sample of regular heroin users: longitudinal information about real-world heroin demand (actual price and actual quantity at daily intervals for each heroin user in the sample) and experimental information about laboratory heroin demand (elicited by presenting the same heroin users with scenarios in a laboratory setting). Two empirical strategies are used to estimate the price elasticity of demand for heroin. The first strategy exploits the idiosyncratic variation in the price experienced by a heroin user over time that occurs in markets for illegal drugs. The second strategy exploits the experimentally-induced variation in price experienced by a heroin user across experimental scenarios. Both empirical strategies result in the estimate that the conditional price elasticity of demand for heroin is approximately −0.80. PMID:25702687

  20. Evidence for the safety of gum tragacanth (Asiatic Astragalus spp.) and modern criteria for the evaluation of food additives.

    Science.gov (United States)

    Anderson, D M

    1989-01-01

    Gum tragacanth (GT), affirmed as GRAS within the USA since 1961, was evaluated as 'ADI not specified' by JECFA in 1985. Within the EEC, GT has been permitted temporarily as a food additive (E413), without an ADI, since 1974; a decision regarding its permanent status must be reached before the end of 1988. This review collates the dietary, toxicological, immunological and chemical data available and presents the pre-requisite data concerning the 'Need' and low levels of utilization of GT.

  1. Experimental analysis on semi-finishing machining of Ti6Al4V additively manufactured by direct melting laser sintering

    Science.gov (United States)

    Imbrogno, Stano; Bordin, Alberto; Bruschi, Stefania; Umbrello, Domenico

    2016-10-01

    The Additive Manufacturing (AM) techniques are particularly appealing especially for titanium aerospace and biomedical components because they permit to achieve a strong reduction of the buy-to-fly ratio. However, finishing machining operations are often necessary to reduce the uneven surface roughness and geometrics because of local missing accuracy. This work shows the influence of the cutting parameters, cutting speed and feed rate, on the cutting forces as well as on the thermal field observed in the cutting zone, during a turning operation carried out on bars made of Ti6Al4V obtained by the AM process called Direct Metal Laser Sintering (DMLS). Moreover, the sub-surface microstructure alterations due to the process are also showed and commented.

  2. Evidence for additive effects of virus infection and water availability on phythormone induction in a staple crop

    Directory of Open Access Journals (Sweden)

    Thomas Seth Davis

    2015-09-01

    Full Text Available Infection with phytoviruses influences plant responses to environmental stress, but the biochemical mechanisms underlying these interactions are unknown. Infection of wheat (Triticum aestivum with a cereal virus (Barley yellow dwarf virus, BYDV has context-dependent effects on plant productivity and survival conditional to water stress, and we hypothesized this was due to phythormone induction resulting from virus infection. We tested whether BYDV infection and water availability interact to influence hormone profiles in wheat across multiple time periods. Wheat plants were inoculated with BYDV by exposing them to infectious aphids (Rhopalosiphum padi. Concentrations of five hormones (abscisic acid, jasmonic acid, methyl jasmonate, methyl salicylate [MS], and salicylic acid [SA] in leaf tissues were compared to concentrations in plants exposed to noninfectious aphids (sham treatment and nondamaged control plants for five time-since-infection periods (0, 8, 16, 24, and 32 d and two levels of water availability (0.2 and 0.8 g H20/g soil. Three important findings emerged: (1 total hormone concentrations in BYDV-infected plants exceeded concentrations in sham-treated and control plants up to 16 d following infection, after which nondamaged plants exhibited the highest concentrations of hormones; compared with nondamaged and BYDV-infected plants, hormone levels were reduced in sham-treated plants; (2 inoculation treatment affected concentrations of MS and SA: SA concentrations were increased in BYDV-infected plants, but control plants exhibited higher MS concentrations than either BYDV-infected or sham-treated plants irrespective of watering treatments and across all time periods; and (3 correlation analysis revealed no evidence of hormonal cross-inhibition. This study provides the first evidence that BYDV infection elevates both total phytohormone levels and SA in wheat in a time-sensitive manner, suggesting a potential biochemical basis for virus

  3. Benefit of multiple trait selection to increase reproductive traits; experimental evidence from Golden hamsters.

    NARCIS (Netherlands)

    Satoh, M.; Nishida, A.; Arendonk, van J.A.M.; Lende, van der T.

    1997-01-01

    Fifteen generations of selection were conducted to study responses for litter size at birth (LSB), weight at weaning of standardized litter (LWW), and individual body weight at 8 wk of age (BW8) using golden hamsters as an experimental model for pigs. The experiment involved three lines: selection

  4. Experimental evidence of a symbiosis between red-cockaded woodpeckers and fungi

    Science.gov (United States)

    Michelle A. Jusino; Daniel L. Lindner; Mark T. Banik; Kevin R. Rose; Jeffrey R. Walters

    2016-01-01

    Primary cavity excavators, such as woodpeckers, are ecosystem engineers in many systems. Associations between cavity excavators and fungi have long been hypothesized to facilitate cavity excavation, but these relationships have not been experimentally verified. Fungi may help excavators by softening wood, while excavators may facilitate fungal dispersal. Here we...

  5. Testing the theory of emissions trading : Experimental evidence on alternative mechanisms for global carbon trading

    NARCIS (Netherlands)

    Klaassen, Ger; Nentjes, Andries; Smith, Mark

    2005-01-01

    Simulation models and theory prove that emission trading converges to market equilibrium. This paper sets out to test these results using experimental economics. Three experiments are conducted for the six largest carbon emitting industrialized regions. Two experiments use auctions, the first a

  6. Experimental Evidence of the Knowledge Gap: Message Arousal, Motivation, and Time Delay

    Science.gov (United States)

    Grabe, Maria Elizabeth; Yegiyan, Narine; Kamhawi, Rasha

    2008-01-01

    This study experimentally tested the knowledge gap from an information processing perspective. Specifically, knowledge acquisition was investigated under conditions of medium and low news message arousal, with time delay. Results show the persistence of a knowledge gap, particularly for low arousing messages. In fact, at low levels of message…

  7. Do Decentralized Innovation Systems Promote Agricultural Technology Adoption? Experimental Evidence from Africa

    NARCIS (Netherlands)

    Pamuk, Haki; Bulte, Erwin|info:eu-repo/dai/nl/141315245; Adekunle, Adewale A.

    2014-01-01

    We use experimental data collected in 8 African countries to investigate whether a decentralized approach can promote the adoption of agricultural innovations. This participatory model is based on the creation of so-called ‘innovation platforms’ where local stakeholders meet and seek to identify

  8. Experimental evidence of human recreational disturbance effects on bird-territory establishment.

    Science.gov (United States)

    Bötsch, Yves; Tablado, Zulima; Jenni, Lukas

    2017-07-12

    The worldwide increase in human outdoor activities raises concerns for wildlife. Human disturbances, even at low levels, are likely to impact species during sensitive periods of the annual cycle. However, experimental studies during the putative sensitive period of territory establishment of birds which not only investigate low disturbance levels, but which also exclude the effect of habitat modification (e.g. walking trails) are lacking. Here, we experimentally disturbed birds in forest plots by walking through twice a day during territory establishment. Later we compared the breeding bird community of experimentally disturbed plots with that of undisturbed control plots. We discovered that the number of territories (-15.0%) and species richness (-15.2%) in disturbed plots were substantially reduced compared with control plots. Species most affected included those sensitive to human presence (assessed by flight-initiation distances), open-cup nesters and above-ground foragers. Long-distance migrants, however, were unaffected due to their arrival after experimental disturbance took place. These findings highlight how territory establishment is a sensitive period for birds, when even low levels of human recreation may be perceived as threatening, and alter settlement decisions. This can have important implications for the conservation of species, which might go unnoticed when focusing only on already established birds. © 2017 The Author(s).

  9. Probability Judgements in Multi-Stage Problems : Experimental Evidence of Systematic Biases

    NARCIS (Netherlands)

    Gneezy, U.

    1996-01-01

    We report empirical evidence that in problems of random walk with positive drift, bounded rationality leads individuals to under-estimate the probability of success in the long run.In particular, individuals who were given the stage by stage probability distribution failed to aggregate this

  10. Experimental evidence for electron localization on Au upon photo-activation of Au/anatase catalysts

    NARCIS (Netherlands)

    Carneiro, J.T.; Carneiro, Joana T.; Savenije, Tom J.; Mul, Guido

    2009-01-01

    Time resolved microwave conductivity (TRMC) measurements show that the presence of Au on anatase Hombikat UV100 significantly reduces the lifetime of mobile electrons formed by photo-excitation of this photocatalyst at 300 nm, providing evidence for the widely acclaimed electron localization effect

  11. Experimental evidence for a Mott-Wigner glass phase of magnetite above the Verwey temperature

    NARCIS (Netherlands)

    Boekema, C.; Lichti, R.L.; Chan, K.C.B.; Brabers, V.A.M.; Denison, A.B.; Cooke, D.W.; Heffner, R.H.; Hutson, R.L.; Schillaci, M.E.

    1986-01-01

    New muon-spin-relaxation (µSR) results on magnetite are reported and discussed in light of earlier Mössbauer, neutron, and µSR results. Modification of the µSR anomaly (observed at 247 K in zero field), when an external magnetic field is applied, provides evidence that the anomaly results from cross

  12. Graphical augmentations to the funnel plot assess the impact of additional evidence on a meta-analysis.

    Science.gov (United States)

    Langan, Dean; Higgins, Julian P T; Gregory, Walter; Sutton, Alexander J

    2012-05-01

    We aim to illustrate the potential impact of a new study on a meta-analysis, which gives an indication of the robustness of the meta-analysis. A number of augmentations are proposed to one of the most widely used of graphical displays, the funnel plot. Namely, 1) statistical significance contours, which define regions of the funnel plot in which a new study would have to be located to change the statistical significance of the meta-analysis; and 2) heterogeneity contours, which show how a new study would affect the extent of heterogeneity in a given meta-analysis. Several other features are also described, and the use of multiple features simultaneously is considered. The statistical significance contours suggest that one additional study, no matter how large, may have a very limited impact on the statistical significance of a meta-analysis. The heterogeneity contours illustrate that one outlying study can increase the level of heterogeneity dramatically. The additional features of the funnel plot have applications including 1) informing sample size calculations for the design of future studies eligible for inclusion in the meta-analysis; and 2) informing the updating prioritization of a portfolio of meta-analyses such as those prepared by the Cochrane Collaboration. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Oldest skeleton of a plesiadapiform provides additional evidence for an exclusively arboreal radiation of stem primates in the Palaeocene

    Science.gov (United States)

    Chester, Stephen G. B.; Williamson, Thomas E.; Bloch, Jonathan I.; Silcox, Mary T.; Sargis, Eric J.

    2017-05-01

    Palaechthonid plesiadapiforms from the Palaeocene of western North America have long been recognized as among the oldest and most primitive euarchontan mammals, a group that includes extant primates, colugos and treeshrews. Despite their relatively sparse fossil record, palaechthonids have played an important role in discussions surrounding adaptive scenarios for primate origins for nearly a half-century. Likewise, palaechthonids have been considered important for understanding relationships among plesiadapiforms, with members of the group proposed as plausible ancestors of Paromomyidae and Microsyopidae. Here, we describe a dentally associated partial skeleton of Torrejonia wilsoni from the early Palaeocene (approx. 62 Ma) of New Mexico, which is the oldest known plesiadapiform skeleton and the first postcranial elements recovered for a palaechthonid. Results from a cladistic analysis that includes new data from this skeleton suggest that palaechthonids are a paraphyletic group of stem primates, and that T. wilsoni is most closely related to paromomyids. New evidence from the appendicular skeleton of T. wilsoni fails to support an influential hypothesis based on inferences from craniodental morphology that palaechthonids were terrestrial. Instead, the postcranium of T. wilsoni indicates that it was similar to that of all other plesiadapiforms for which skeletons have been recovered in having distinct specializations consistent with arboreality.

  14. Exposure affects the risk of an owl being mobbed - experimental evidence

    DEFF Research Database (Denmark)

    Hendrichsen, Ditte Katrine; Christiansen, Peter; Nielsen, Elsemarie K.

    2006-01-01

    Mobbing is a widespread anti-predator strategy in birds, and predators are generally expected to avoid mobbing. For example, observational studies suggest that the cryptic roosting behaviour of nocturnal predators, such as many owls, may be a strategy to limit mobbing. In this paper, we present...... the results of the first experimental study investigating to what degree roost exposure influences the risk of being mobbed, and the intensity of a mobbing incidence once initiated. To determine these factors, we used an experimental setup with taxidermic mounts of tawny owls Strix aluco in Grib Skov forest......, Denmark. The risk of an owl being mobbed during a 50 min morning survey period increased with the exposure of its roosting position, from 24% when hidden to 85% when openly exposed. The corresponding increase in the afternoon was from 6% to 36%. This suggests that an owl may minimize the mobbing rate...

  15. The significance of secondary organic aerosol formation and growth in buildings: experimental and computational evidence

    DEFF Research Database (Denmark)

    Sarwar, G.; Corsi, R.; Allen, D.

    2003-01-01

    -pinene, and subsequent gas-to-particle partitioning of the products. A new indoor air quality model was used to predict dynamic particle mass concentrations based on detailed homogeneous chemical mechanisms and partitioning of semi-volatile products to particles. Chamber particle mass concentrations were estimated from......Experiments were conducted in an 11 m3 environmental chamber to investigate secondaryparticles resulting from homogeneous reactions between ozone and alpha-pinene. Experimental results indicate that rapid fine particle growth occurs due to homogeneous reactions between ozone and alpha...... measured particle size distributions and were in reasonable agreement with results predicted from the model. Both experimental and model results indicate that secondary particle mass concentrations incfrease substantially with lower air exchange rates. This is an interesting results, given a continuing...

  16. Orthodontic treatment with preadjusted appliances and low-friction ligatures: experimental evidence and clinical observations.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; Fortini, Arturo

    2008-01-01

    To describe the features of low-friction ligatures during the leveling and aligning phase of fixed appliance therapy with preadjusted brackets. Experimental in vitro and in vivo studies were carried out to test the performance of the low-friction system with regard to leveling and aligning of the dental arches, as well as to increasing the transverse dimension of the maxillary arch. The outcomes of experimental testing showed that the combination of the low-friction ligatures with the superelastic nickel-titanium wires produced a significantly smaller amount of binding at the bracket/archwire/ligature unit when compared to conventional elastomeric ligatures. The biomechanical consequences of the use of low-friction ligatures were shorter duration of orthodontic treatment during the leveling and aligning phase, concurrent dentoalveolar expansion of the dental arch, and the possibility of using biologically adequate orthodontic forces.

  17. Student Perceptions of Auditor Responses to Evidence of Suspicious Activities: An Experimental Assessment

    Directory of Open Access Journals (Sweden)

    David S Murphy

    2015-12-01

    Full Text Available This study assessed student perceptions of auditor responses to evidence that a client failed to respond appropriately to suspicious activities that could indicate money laundering. Subjects were presented with a series of randomized cases in which partner type (new vs. experienced, firm type (regional vs. international and audit fee materiality (not material, material to the local office only, material to the firm were manipulated asked to indicate their perceptions of the likelihood that an audit partner would discuss such evidence with the client, and the likelihood that the issue would be disclosed by the auditor. Both partner type and audit fee materiality was found to have significant effects on perceived likelihoods.

  18. Gluconeogenesis in the ruminant fetus: evaluation of conflicting evidence from radiotracer and other experimental techniques

    International Nuclear Information System (INIS)

    Prior, R.L.

    1982-01-01

    Conflicting evidence exists as to whether the gluconeogenetic process is active in the late gestation fetal lamb. In vitro evidence based on measurements of enzyme activity and substrate flux into glucose indicates that the capacity for gluconeogenesis exists in fetal liver. The in vivo conversion of [ 14 C]lactate and [ 14 C]alanine into glucose in the lamb fetus has been demonstrated. Lactate and alanine account for 49 and 2.3% of the fetal glucose pool, respectively. Although gluconeogenesis can occur in the fetal lamb, alterations in net rates of umbilical uptake of glucose or lactate, fetal blood glucose concentrations, fetal or maternal glucose replacement rates, or maternal nutrition may alter the observed rates of fetal gluconeogenesis

  19. A review of the evidence regarding associations between attachment theory and experimentally induced pain.

    Science.gov (United States)

    Meredith, Pamela Joy

    2013-04-01

    Theoretical and empirical evidence suggests that adult attachment and pain-related variables are predictably and consistently linked, and that understanding these links may guide pain intervention and prevention efforts. In general, insecure attachment has been portrayed as a risk factor, and secure attachment as a protective factor, for people with chronic pain conditions. In an effort to better understand the relationships among attachment and pain variables, these links have been investigated in pain-free samples using induced-pain techniques. The present paper reviews the available research linking adult attachment and laboratory-induced pain. While the diverse nature of the studies precludes definitive conclusions, together these papers offer support for associations between insecure attachment and a more negative pain experience. The evidence presented in this review highlights areas for further empirical attention, as well as providing some guidance for clinicians who may wish to employ preventive approaches and other interventions informed by attachment theory.

  20. Experimental evidence for a Mott-Wigner glass phase of magnetite above the Verwey temperature

    International Nuclear Information System (INIS)

    Boekema, C.; Lichti, R.L.; Chan, K.C.B.; Brabers, V.A.M.; Denison, A.B.; Cooke, D.W.; Heffner, R.H.; Hutson, R.L.; Schillaci, M.E.

    1986-01-01

    New muon-spin-relaxation (μSR) results on magnetite are reported and discussed in light of earlier Moessbauer, neutron, and μSR results. Modification of the μSR anomaly (observed at 247 K in zero field), when an external magnetic field is applied, provides evidence that the anomaly results from cross relaxation between the muon Larmor precession and the electron-correlation process in the B sublattice. The combined results strongly indicate that phonon-assisted electron hopping is the principal conduction mechanism above the Verwey transition temperature (T/sub V/). Together with theoretical evidence, these data support Mott's suggestion that above T/sub V/ magnetite is in the Wigner-glass state

  1. Experimental evidence for vortex-glass superconductivity in Y-Ba-Cu-O

    International Nuclear Information System (INIS)

    Koch, R.H.; Foglietti, V.; Gallagher, W.J.; Koren, G.; Gupta, A.; Fisher, M.P.A.

    1989-01-01

    We demonstrate experimentally the existence of a continuous phase transition between a normal and a true superconducting phase (with zero linear resistivity) in epitaxial films of Y-Ba-Cu-O in strong magnetic fields fields, H much-gt H c1 . The nonlinear I-V curves show scaling behavior near the transition and the relevant critical exponents are extracted. These exponents are consistent with values expected for freezing into a superconducting vortex-glass phase

  2. Primordial condensation of meteorite components - experimental evidence of the state of the source medium

    International Nuclear Information System (INIS)

    Arrhenius, G.; McCrumb, J.L.; Friedman, N.

    1979-01-01

    Mineral grains and grain aggregates in meteorites carry potential information on the conditions in the environment where they formed. To avoid model-dependent interpretations it is necessary to develop experimental criteria that uniquely reflect the environmental parameters of interest. These parameters include the various temperatures of the source medium and the temperature of grains at growth all of which are observed to be highly differentiated in the space medium in accordance with the radiation laws. (orig./WL)

  3. Do Ethnic Enclaves Impede Immigrants’ Integration? Evidence from a Quasi-Experimental Social-Interaction Approach

    OpenAIRE

    Danzer, A. M.; Yaman, F.

    2013-01-01

    It is widely debated whether immigrants who live among co-ethnics are less willing to integrate into the host society. Exploiting the quasi-experimental guest worker placement across German regions during the 1960/70s as well as information on immigrants’ inter-ethnic contact networks and social activities, we are able to identify the causal effect of ethnic concentration on social integration. The exogenous placement of immigrants "switches off" observable and unobservable differences in t...

  4. Tax-Rate Biases in Tax-Planning Decisions: Experimental Evidence

    OpenAIRE

    Amberger, Harald; Eberhartinger, Eva; Kasper, Helmut

    2016-01-01

    Contrary to standard economic theory, recent empirical findings suggest that firms do not always engage in economically optimal tax planning. We conduct a laboratory experiment and find robust evidence that decision biases offer a behavioral explanation for suboptimal tax planning. When facing time pressure in an intra-group cross-border financing decision, subjects apply heuristics based on the salience of statutory tax rates. This stirs decision makers to underestimate the effects of tax-ba...

  5. When Does Money Make Money More Important? Survey and Experimental Evidence

    OpenAIRE

    Sanford E. DeVoe; Jeffrey Pfeffer; Byron Y. Lee

    2013-01-01

    The authors investigate how the amount and source of income affects the importance placed on money. Using a longitudinal analysis of the British Household Panel Survey and evidence from two laboratory experiments, they found that larger amounts of money received for labor were associated with individuals placing greater importance on money; but this effect did not hold for money not related to work. The longitudinal survey analysis demonstrated these differential effects of the source of inco...

  6. Gender differences in risk preferences and stereotypes: Experimental evidence from a matrilineal and a patrilineal society

    OpenAIRE

    Pondorfer, Andreas; Omar Mahmoud, Toman; Rehdanz, Katrin; Schmidt, Ulrich

    2014-01-01

    We use a controlled experiment to analyze gender differences in risk preferences and stereotypes about risk preferences of men and women across two distinct island societies in the Pacific: the patrilineal Palawan in the Philippines and the matrilineal Teop in Papua New Guinea. We find no gender differences in actual risk preferences, but evidence for culture-specific stereotypes. Like men in Western societies, Palawan men overestimate women's actual risk aversion. By contrast, Teop men under...

  7. Strain rate sensitivity of the tensile strength of two silicon carbides: experimental evidence and micromechanical modelling.

    Science.gov (United States)

    Zinszner, Jean-Luc; Erzar, Benjamin; Forquin, Pascal

    2017-01-28

    Ceramic materials are commonly used to design multi-layer armour systems thanks to their favourable physical and mechanical properties. However, during an impact event, fragmentation of the ceramic plate inevitably occurs due to its inherent brittleness under tensile loading. Consequently, an accurate model of the fragmentation process is necessary in order to achieve an optimum design for a desired armour configuration. In this work, shockless spalling tests have been performed on two silicon carbide grades at strain rates ranging from 10 3 to 10 4  s -1 using a high-pulsed power generator. These spalling tests characterize the tensile strength strain rate sensitivity of each ceramic grade. The microstructural properties of the ceramics appear to play an important role on the strain rate sensitivity and on the dynamic tensile strength. Moreover, this experimental configuration allows for recovering damaged, but unbroken specimens, giving unique insight on the fragmentation process initiated in the ceramics. All the collected data have been compared with corresponding results of numerical simulations performed using the Denoual-Forquin-Hild anisotropic damage model. Good agreement is observed between numerical simulations and experimental data in terms of free surface velocity, size and location of the damaged zones along with crack density in these damaged zones.This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'. © 2016 The Author(s).

  8. Strain rate sensitivity of the tensile strength of two silicon carbides: experimental evidence and micromechanical modelling

    Science.gov (United States)

    Erzar, Benjamin

    2017-01-01

    Ceramic materials are commonly used to design multi-layer armour systems thanks to their favourable physical and mechanical properties. However, during an impact event, fragmentation of the ceramic plate inevitably occurs due to its inherent brittleness under tensile loading. Consequently, an accurate model of the fragmentation process is necessary in order to achieve an optimum design for a desired armour configuration. In this work, shockless spalling tests have been performed on two silicon carbide grades at strain rates ranging from 103 to 104 s−1 using a high-pulsed power generator. These spalling tests characterize the tensile strength strain rate sensitivity of each ceramic grade. The microstructural properties of the ceramics appear to play an important role on the strain rate sensitivity and on the dynamic tensile strength. Moreover, this experimental configuration allows for recovering damaged, but unbroken specimens, giving unique insight on the fragmentation process initiated in the ceramics. All the collected data have been compared with corresponding results of numerical simulations performed using the Denoual–Forquin–Hild anisotropic damage model. Good agreement is observed between numerical simulations and experimental data in terms of free surface velocity, size and location of the damaged zones along with crack density in these damaged zones. This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’. PMID:27956504

  9. Astragaloside IV for Experimental Focal Cerebral Ischemia: Preclinical Evidence and Possible Mechanisms

    Directory of Open Access Journals (Sweden)

    Hui-Lin Wang

    2017-01-01

    Full Text Available Astragaloside IV (AST-IV is a principal component of Radix Astragali seu Hedysari (Huangqi and exerts potential neuroprotection in experimental ischemic stroke. Here, we systematically assessed the effectiveness and possible mechanisms of AST-IV for experimental acute ischemic stroke. An electronic search in eight databases was conducted from inception to March 2016. The study quality score was evaluated using the CAMARADES. Rev Man 5.0 software was used for data analyses. Thirteen studies with 244 animals were identified. The study quality score of included studies ranged from 3/10 to 8/10. Eleven studies showed significant effects of AST-IV for ameliorating the neurological function score (P<0.05; seven studies for reducing the infarct volume (P<0.05; and three or two studies for reducing the brain water content and Evans blue leakage (P<0.05, respectively, compared with the control. The mechanisms of AST-IV for ischemic stroke are multiple such as antioxidative/nitration stress reaction, anti-inflammatory, and antiapoptosis. In conclusion, the findings of present study indicated that AST-IV could improve neurological deficits and infarct volume and reduce the blood-brain barrier permeability in experimental cerebral ischemia despite some methodological flaws. Thus, AST-IV exerted a possible neuroprotective effect during the cerebral ischemia/reperfusion injury largely through its antioxidant, anti-inflammatory, and antiapoptosis properties.

  10. Strain rate sensitivity of the tensile strength of two silicon carbides: experimental evidence and micromechanical modelling

    Science.gov (United States)

    Zinszner, Jean-Luc; Erzar, Benjamin; Forquin, Pascal

    2017-01-01

    Ceramic materials are commonly used to design multi-layer armour systems thanks to their favourable physical and mechanical properties. However, during an impact event, fragmentation of the ceramic plate inevitably occurs due to its inherent brittleness under tensile loading. Consequently, an accurate model of the fragmentation process is necessary in order to achieve an optimum design for a desired armour configuration. In this work, shockless spalling tests have been performed on two silicon carbide grades at strain rates ranging from 103 to 104 s-1 using a high-pulsed power generator. These spalling tests characterize the tensile strength strain rate sensitivity of each ceramic grade. The microstructural properties of the ceramics appear to play an important role on the strain rate sensitivity and on the dynamic tensile strength. Moreover, this experimental configuration allows for recovering damaged, but unbroken specimens, giving unique insight on the fragmentation process initiated in the ceramics. All the collected data have been compared with corresponding results of numerical simulations performed using the Denoual-Forquin-Hild anisotropic damage model. Good agreement is observed between numerical simulations and experimental data in terms of free surface velocity, size and location of the damaged zones along with crack density in these damaged zones. This article is part of the themed issue 'Experimental testing and modelling of brittle materials at high strain rates'.

  11. Less is often more, but not always: additional evidence that familiarity breeds contempt and a call for future research.

    Science.gov (United States)

    Norton, Michael I; Frost, Jeana H; Ariely, Dan

    2013-12-01

    Ullrich, Krueger, Brod, and Groschupf (2013)-using a replication of the trait paradigm from Norton, Frost, and Ariely (2007)-suggest that less information does not always equal greater liking. We first ground the current debate in a larger historical debate in social psychology regarding the merits of configural versus algebraic models of person perception. We next review (a) related research that has suggested that more information can in some cases lead to more liking and (b) a large body of "real world" data-from friendships, daters, married couples, employment, celebrities, and politics-that suggests that more information often leads to less liking. We then provide an additional replication of our "less is more" effect, using a slight variation of the trait-list paradigm. The existing data suggest a need for further integrative explorations of when familiarity leads to contempt or liking or has no effect. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  12. Randomised controlled feasibility trial of an evidence-informed behavioural intervention for obese adults with additional risk factors.

    Directory of Open Access Journals (Sweden)

    Falko F Sniehotta

    Full Text Available Interventions for dietary and physical activity changes in obese adults may be less effective for participants with additional obesity-related risk factors and co-morbidities than for otherwise healthy individuals. This study aimed to test the feasibility and acceptability of the recruitment, allocation, measurement, retention and intervention procedures of a randomised controlled trial of an intervention to improve physical activity and dietary practices amongst obese adults with additional obesity related risk factors.Pilot single centre open-labelled outcome assessor-blinded randomised controlled trial of obese (Body Mass Index (BMI≥30 kg/m2 adults (age≥18 y with obesity related co-morbidities such as type 2 diabetes, impaired glucose tolerance or hypertension. Participants were randomly allocated to a manual-based group intervention or a leaflet control condition in accordance to a 2∶1 allocation ratio. Primary outcome was acceptability and feasibility of trial procedures, secondary outcomes included measures of body composition, physical activity, food intake and psychological process measures.Out of 806 potentially eligible individuals identified through list searches in two primary care general medical practices N = 81 participants (63% female; mean-age = 56.56(11.44; mean-BMI = 36.73(6.06 with 2.35(1.47 co-morbidities were randomised. Scottish Index of Multiple Deprivation (SIMD was the only significant predictor of providing consent to take part in the study (higher chances of consent for invitees with lower levels of deprivation. Participant flowcharts, qualitative and quantitative feedback suggested good acceptance and feasibility of intervention procedures but 34.6% of randomised participants were lost to follow-up due to overly high measurement burden and sub-optimal retention procedures. Participants in the intervention group showed positive trends for most psychological, behavioural and body composition outcomes

  13. Post-error response inhibition in high math-anxious individuals: Evidence from a multi-digit addition task.

    Science.gov (United States)

    Núñez-Peña, M Isabel; Tubau, Elisabet; Suárez-Pellicioni, Macarena

    2017-06-01

    The aim of the study was to investigate how high math-anxious (HMA) individuals react to errors in an arithmetic task. Twenty HMA and 19 low math-anxious (LMA) individuals were presented with a multi-digit addition verification task and were given response feedback. Post-error adjustment measures (response time and accuracy) were analyzed in order to study differences between groups when faced with errors in an arithmetical task. Results showed that both HMA and LMA individuals were slower to respond following an error than following a correct answer. However, post-error accuracy effects emerged only for the HMA group, showing that they were also less accurate after having committed an error than after giving the right answer. Importantly, these differences were observed only when individuals needed to repeat the same response given in the previous trial. These results suggest that, for HMA individuals, errors caused reactive inhibition of the erroneous response, facilitating performance if the next problem required the alternative response but hampering it if the response was the same. This stronger reaction to errors could be a factor contributing to the difficulties that HMA individuals experience in learning math and doing math tasks. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Experimental evidence of the effect of nutrient enrichment on the zooplankton in a Brazilian coastal lagoon

    Directory of Open Access Journals (Sweden)

    B. KOZLOWSKY-SUZUKI

    Full Text Available Non-treated sewage disposal is one of the main impacts to which Imboassica Lagoon has been subjected. The aim of this study was to evaluate the effect of a potential increase in the artificial enrichment on the environmental conditions and zooplankton of this system. To this end, an experimental study was conducted in mesocosms where nutrients were added daily. Bacterial numbers, chlorophyll-a, and picoplanktonic cyanobacteria densities showed an increase with the availability of nutrients. Bacterio- and phytoplankton seemed to be regulated by the rotifers Brachionus rotundiformis and Hexarthra brandorffi.

  15. Experimental evidence for the role of ions in particle nucleation under atmospheric conditions

    DEFF Research Database (Denmark)

    Svensmark, Henrik; Pedersen, Jens Olaf Pepke; Marsh, N.D.

    2007-01-01

    Experimental studies of aerosol nucleation in air, containing trace amounts of ozone, sulphur dioxide and water vapour at concentrations relevant for the Earth's atmosphere, are reported. The production of new aerosol particles is found to be proportional to the negative ion density and yields...... nucleation rates of the order of 0.1 1 cm(-3) s(-1). This suggests that the ions are active in generating an atmospheric reservoir of small thermodynamically stable clusters, which are important for nucleation processes in the atmosphere and ultimately for cloud formation....

  16. Experimental Evidence for Quantum Interference and Vibrationally Induced Decoherence in Single-Molecule Junctions

    Science.gov (United States)

    Ballmann, Stefan; Härtle, Rainer; Coto, Pedro B.; Elbing, Mark; Mayor, Marcel; Bryce, Martin R.; Thoss, Michael; Weber, Heiko B.

    2012-08-01

    We analyze quantum interference and decoherence effects in single-molecule junctions both experimentally and theoretically by means of the mechanically controlled break junction technique and density-functional theory. We consider the case where interference is provided by overlapping quasidegenerate states. Decoherence mechanisms arising from electronic-vibrational coupling strongly affect the electrical current flowing through a single-molecule contact and can be controlled by temperature variation. Our findings underline the universal relevance of vibrations for understanding charge transport through molecular junctions.

  17. Experimental evidence of adiabatic splitting of charged particle beams using stable islands of transverse phase space

    Directory of Open Access Journals (Sweden)

    S. Gilardoni

    2006-10-01

    Full Text Available Recently, a novel technique to perform multiturn extraction from a circular particle accelerator was proposed. It is based on beam splitting and trapping, induced by a slow crossing of a nonlinear resonance, inside stable islands of transverse phase space. Experiments at the CERN Proton Synchrotron started in 2002 and evidence of beam splitting was obtained by summer 2004. In this paper, the measurement results achieved with both a low- and a high-intensity, single-bunch proton beam are presented.

  18. The Role of Framing, Inequity and History in a Corruption Game: Some Experimental Evidence

    Directory of Open Access Journals (Sweden)

    Ananish Chaudhuri

    2016-06-01

    Full Text Available We investigate the role of framing, inequity in initial endowments and history in shaping behavior in a corrupt transaction by extending the one-shot bribery game introduced by Cameron et al. (2009 to a repeated game setting. We find that the use of loaded language significantly reduces the incidence of bribery and increases the level of punishment. Punishment of bribery leads to reduced bribery in future. The evidence suggests that this game captures essential features of a corrupt transaction, over and above any sentiments of inequity aversion or negative reciprocity However, showing subjects the history of past play has little effect on the level of corruption.

  19. Gender Performance Gaps: Quasi-Experimental Evidence on the Role of Gender Differences in Sleep Cycles

    OpenAIRE

    Lusher, Lester; Yasenov, Vasil

    2016-01-01

    Sleep studies suggest that girls go to sleep earlier, are more active in the morning, and cope with sleep deprivation better than boys. We provide the first causal evidence on how gender differences in sleep cycles can help explain the gender performance gap. We exploit over 240,000 assignment-level grades from a quasi-experiment with a community of middle and high schools where students' schedules alternated between morning and afternoon start times each month. Relative to girls, we find tha...

  20. Do Gender and Business Trainings Affect Business Outcomes? Experimental Evidence from Vietnam

    NARCIS (Netherlands)

    Bulte, Erwin; Lensink, Robert; Nhung Vu, [No Value

    We use a randomized control trial to evaluate the impact of a business training for female clients of a microfinance institution in northern Vietnam, and we consider the impact on (i) business knowledge, (ii) practices, and (ii) outcomes, as well as (iv) firm entry and exit decisions. In addition,

  1. The behaviour of mosquitoes in relation to humans under holed bednets: the evidence from experimental huts

    Directory of Open Access Journals (Sweden)

    Seth R Irish

    2014-11-01

    Full Text Available The physical integrity of bednets is a concern of national malaria control programs, as it is a key factor in determining the rate of replacement of bednets. It is largely assumed that increased numbers of holes will result in a loss of protection of sleepers from potentially infective bites. Experimental hut studies are valuable in understanding mosquito behaviour indoors, particularly as it relates to blood feeding and mortality. This review summarises findings from experimental hut studies, focusing on two issues: (i the effect of different numbers or sizes of holes in bednets and (ii feeding behaviour and mortality with holed nets as compared with unholed nets. As might be expected, increasing numbers and area of holes resulted in increased blood feeding by mosquitoes on sleepers. However, the presence of holes did not generally have a large effect on the mortality of mosquitoes. Successfully entering a holed mosquito net does not necessarily mean that mosquitoes spend less time in contact with the net, which could explain the lack in differences in mortality. Further behavioural studies are necessary to understand mosquito behaviour around nets and the importance of holed nets on malaria transmission.

  2. EXPERIMENTAL EVIDENCE FOR HOMING IN THE RED SWAMP CRAYFISH, PROCAMBARUS CLARKII

    Directory of Open Access Journals (Sweden)

    BARBARESI S.

    2006-01-01

    Full Text Available The red swamp crayfish, Procambarus clarkii, is an efficient burrower, but its burrow fidelity has been recently questioned. In this study, we aimed at investigating whether individuals of this species are capable to learn the position of a goal (a wet burrow hidden to their sight in experimental tanks and to make more efficient with time their oriented movement towards it. We also analyzed crayfish behavior after having closed one of the two accesses to the goal. Indeed, in successive trials we recorded the crayfish tendency to reduce the distance covered to reach the goal and the time taken, except when they were already familiar to the experimental setting. Memory of the spatial configuration lasted for 16 hours at least and crayfish learned and maintained individual trajectories. The interruption of their usual path always caused a drastic increase of distance and time that however decreased in the successive trials. This study provided also some information of the sensory channels used by P. clarkii to orient. This crayfish, which can be active also during daytime, seemed to adopt a combination of tactile and visual information, together with the possible use of cues (i.e. humidity cues emitted by the goal. Future studies should clarify the paradox of a crayfish species whose individuals, although being physiologically capable to home, seem not to return to the previously occupied burrows at the end of their foraging excursions, notwithstanding the time and energy expended to excavate them.

  3. Experimental evidence for stochastic switching of supercooled phases in NdNiO3 nanostructures

    Science.gov (United States)

    Kumar, Devendra; Rajeev, K. P.; Alonso, J. A.

    2018-03-01

    A first-order phase transition is a dynamic phenomenon. In a multi-domain system, the presence of multiple domains of coexisting phases averages out the dynamical effects, making it nearly impossible to predict the exact nature of phase transition dynamics. Here, we report the metal-insulator transition in samples of sub-micrometer size NdNiO3 where the effect of averaging is minimized by restricting the number of domains under study. We observe the presence of supercooled metallic phases with supercooling of 40 K or more. The transformation from the supercooled metallic to the insulating state is a stochastic process that happens at different temperatures and times in different experimental runs. The experimental results are understood without incorporating material specific properties, suggesting that the behavior is of universal nature. The size of the sample needed to observe individual switching of supercooled domains, the degree of supercooling, and the time-temperature window of switching are expected to depend on the parameters such as quenched disorder, strain, and magnetic field.

  4. Glazed clay pottery and lead exposure in Mexico: Current experimental evidence.

    Science.gov (United States)

    Diaz-Ruiz, Araceli; Tristán-López, Luis Antonio; Medrano-Gómez, Karen Itzel; Torres-Domínguez, Juan Alejandro; Ríos, Camilo; Montes, Sergio

    2017-11-01

    Lead exposure remains a significant environmental problem; lead is neurotoxic, especially in developing humans. In Mexico, lead in human blood is still a concern. Historically, much of the lead exposure is attributed to the use of handcrafted clay pottery for cooking, storing and serving food. However, experimental cause-and-effect demonstration is lacking. The present study explores this issue with a prospective experimental approach. We used handcrafted clay containers to prepare and store lemonade, which was supplied as drinking water to pregnant rats throughout the gestational period. We found that clay pots, jars, and mugs leached on average 200 µg/l lead, and exposure to the lemonade resulted in 2.5 µg/dl of lead in the pregnant rats' blood. Neonates also showed increased lead content in the hippocampus and cerebellum. Caspase-3 activity was found to be statistically increased in the hippocampus in prenatally exposed neonates, suggesting increased apoptosis in that brain region. Glazed ceramics are still an important source of lead exposure in Mexico, and our results confirm that pregnancy is a vulnerable period for brain development.

  5. Experimental evidence of independence of nuclear de-channeling length on the particle charge sign

    Energy Technology Data Exchange (ETDEWEB)

    Bagli, E.; Guidi, V.; Mazzolari, A.; Bandiera, L.; Germogli, G.; Sytov, A.I. [Universita di Ferrara, Dipartimento di Fisica e Scienze della Terra (Italy); INFN Sezione di Ferrara (Italy); De Salvador, D. [Universita di Padova, Dipartimento di Fisica e Astronomia, Padua (Italy); INFN Laboratori Nazionali di Legnaro (Italy); Berra, A.; Prest, M. [Universita dell' Insubria, Como (Italy); INFN Sezione di Milano Bicocca, Milan (Italy); Vallazza, E. [INFN Sezione di Trieste (Italy)

    2017-02-15

    Under coherent interactions, particles undergo correlated collisions with the crystal lattice and their motion result in confinement in the fields of atomic planes, i.e. particle channeling. Other than coherently interacting with the lattice, particles also suffer incoherent interactions with individual nuclei and may leave their bounded motion, i.e., they de-channel. The latter is the main limiting factor for applications of coherent interactions in crystal-assisted particle steering. We experimentally investigated the nature of de-channeling of 120 GeV/c e{sup -} and e{sup +} in a bent silicon crystal at H4-SPS external line at CERN. We found that while channeling efficiency differs significantly for e{sup -} (2 ± 2%) and e{sup +} (54 ± 2%), their nuclear de-channeling length is comparable, (0.6 ± 0.1) mm for e{sup -} and (0.7 ± 0.3) mm for e{sup +}. The experimental proof of the equality of the nuclear de-channeling length for positrons and electrons is interpreted in terms of similar dynamics undergone by the channeled particles in the field of nuclei irrespective of their charge. (orig.)

  6. Bias against foreign-born or foreign-trained doctors: experimental evidence.

    Science.gov (United States)

    Louis, Winnifred R; Lalonde, Richard N; Esses, Victoria M

    2010-12-01

    Bias against foreign-born or -trained medical students and doctors is not well understood, despite its documented impact on recruitment, integration and retention. This research experimentally examines the interaction of location of medical education and nationality in evaluations of doctors' competence and trustworthiness. A convenience sample of prospective patients evaluated fictitious candidates for a position as a doctor in community practice at a new local health clinic. All applicants were described as having the same personality profile, legal qualifications to practise, a multi-degree education and relevant work experience. The location of medical education (the candidate's home country or the UK) and national background (Australia or Pakistan) of the applicants were independently experimentally manipulated. Consistent with previous research on skills discounting and bias, foreign-born candidates were evaluated less favourably than native-born candidates, despite their comparable education level, work experience and personality. However, overseas medical education obtained in the First World both boosted evaluations (of competence and trustworthiness) and attenuated bias based on nationality. The present findings demonstrate the selective discounting of foreign-born doctors' credentials. The data show an interaction of location of medical education and birth nationality in bias against foreign doctors. On an applied level, the data document that the benefits of medical education obtained in the First World can extend beyond its direct outcomes (high-quality training and institutional recognition) to the indirect benefit of the attenuation of patient bias based on nationality. © Blackwell Publishing Ltd 2010.

  7. In silico modeling and experimental evidence of coagulant protein interaction with precursors for nanoparticle functionalization.

    Science.gov (United States)

    Okoli, Chuka; Sengottaiyan, Selvaraj; Arul Murugan, N; Pavankumar, Asalapuram R; Agren, Hans; Kuttuva Rajarao, Gunaratna

    2013-10-01

    The design of novel protein-nanoparticle hybrid systems has applications in many fields of science ranging from biomedicine, catalysis, water treatment, etc. The main barrier in devising such tool is lack of adequate information or poor understanding of protein-ligand chemistry. Here, we establish a new strategy based on computational modeling for protein and precursor linkers that can decorate the nanoparticles. Moringa oleifera (MO2.1) seed protein that has coagulation and antimicrobial properties was used. Superparamagnetic nanoparticles (SPION) with precursor ligands were used for the protein-ligand interaction studies. The molecular docking studies reveal that there are two binding sites, one is located at the core binding site; tetraethoxysilane (TEOS) or 3-aminopropyl trimethoxysilane (APTES) binds to this site while the other one is located at the side chain residues where trisodium citrate (TSC) or Si60 binds to this site. The protein-ligand distance profile analysis explains the differences in functional activity of the decorated SPION. Experimentally, TSC-coated nanoparticles showed higher coagulation activity as compared to TEOS- and APTES-coated SPION. To our knowledge, this is the first report on in vitro experimental data, which endorses the computational modeling studies as a powerful tool to design novel precursors for functionalization of nanomaterials; and develop interface hybrid systems for various applications.

  8. Experimental evidence for convergent evolution of maternal care heuristics in industrialized and small-scale populations.

    Science.gov (United States)

    Kushnick, Geoff; Hanowell, Ben; Kim, Jun-Hong; Langstieh, Banrida; Magnano, Vittorio; Oláh, Katalin

    2015-06-01

    Maternal care decision rules should evolve responsiveness to factors impinging on the fitness pay-offs of care. Because the caretaking environments common in industrialized and small-scale societies vary in predictable ways, we hypothesize that heuristics guiding maternal behaviour will also differ between these two types of populations. We used a factorial vignette experiment to elicit third-party judgements about likely caretaking decisions of a hypothetical mother and her child when various fitness-relevant factors (maternal age and access to resources, and offspring age, sex and quality) were varied systematically in seven populations-three industrialized and four small-scale. Despite considerable variation in responses, we found that three of five main effects, and the two severity effects, exhibited statistically significant industrialized/ small-scale population differences. All differences could be explained as adaptive solutions to industrialized versus small-scale caretaking environments. Further, we found gradients in the relationship between the population-specific estimates and national-level socio-economic indicators, further implicating important aspects of the variation in industrialized and small-scale caretaking environments in shaping heuristics. Although there is mounting evidence for a genetic component to human maternal behaviour, there is no current evidence for interpopulation variation in candidate genes. We nonetheless suggest that heuristics guiding maternal behaviour in diverse societies emerge via convergent evolution in response to similar selective pressures.

  9. Understanding Counterfactuality: A Review of Experimental Evidence for the Dual Meaning of Counterfactuals

    Science.gov (United States)

    Nieuwland, Mante S.

    2016-01-01

    Abstract Cognitive and linguistic theories of counterfactual language comprehension assume that counterfactuals convey a dual meaning. Subjunctive‐counterfactual conditionals (e.g., ‘If Tom had studied hard, he would have passed the test’) express a supposition while implying the factual state of affairs (Tom has not studied hard and failed). The question of how counterfactual dual meaning plays out during language processing is currently gaining interest in psycholinguistics. Whereas numerous studies using offline measures of language processing consistently support counterfactual dual meaning, evidence coming from online studies is less conclusive. Here, we review the available studies that examine online counterfactual language comprehension through behavioural measurement (self‐paced reading times, eye‐tracking) and neuroimaging (electroencephalography, functional magnetic resonance imaging). While we argue that these studies do not offer direct evidence for the online computation of counterfactual dual meaning, they provide valuable information about the way counterfactual meaning unfolds in time and influences successive information processing. Further advances in research on counterfactual comprehension require more specific predictions about how counterfactual dual meaning impacts incremental sentence processing. PMID:27512408

  10. The continuum of monocyte phenotypes: Experimental evidence and prognostic utility in assessing cardiovascular risk.

    Science.gov (United States)

    Cignarella, Andrea; Tedesco, Serena; Cappellari, Roberta; Fadini, Gian Paolo

    2018-03-30

    The monocyte-macrophage cell lineage represents a major player in innate immunity, and is involved in many physiologic and pathologic conditions. Particularly, monocyte-macrophages play a very important role in atherosclerosis and cardiovascular disease. Monocyte heterogeneity is well recognized but the biologic and clinical meaning of the various monocyte subtypes is not entirely understood. Traditionally, monocytes can be divided in classical, intermediate, and nonclassical based on expression of the surface antigens CD14 and CD16. While macrophage diversity is now well recognized to organize as a continuum, monocyte subsets have long been considered as separated entities. However, mounting evidence obtained by tracking the ontology of human monocytes help clarifying that monocytes mature from classical to nonclassical ones, through an intermediate phenotype. This concept is therefore best depicted as a continuum, whereas the subdivision into discrete CD14/CD16 subsets appears an oversimplification. In this review, we discuss the evidence supporting the existence of a monocyte continuum along with the technical challenges of monocyte characterization. In particular, we describe the advantage of considering monocytes along a continuous distribution for the evaluation of cardiovascular risk. We make the point that small transition along the monocyte continuum better reflects cardiovascular risk than a simplified analysis of discrete monocyte subsets. Recognizing the monocyte continuum can be helpful to model other pathophysiologic conditions where these cells are involved. ©2018 Society for Leukocyte Biology.

  11. Babesia sp. BQ1 (Lintan): molecular evidence of experimental transmission to sheep by Haemaphysalis qinghaiensis and Haemaphysalis longicornis.

    Science.gov (United States)

    Guan, Guiquan; Moreau, Emmanuelle; Liu, Junlong; Hao, Xuefen; Ma, Miling; Luo, Jianxun; Chauvin, Alain; Yin, Hong

    2010-06-01

    Ovine babesiosis is an economically important disease induced by tick transmitted haemoparasites throughout the world. In China, several ovine Babesia strains have been isolated from field-collected ticks or sheep blood during the last two decades but little is known about the vector ticks and transmission pattern. Babesia sp. BQ1 (Lintan) is a Babesia strain infective for sheep and goats, isolated from blood of sheep experimentally infested with Haemaphysalis qinghaiensis collected in field. In the present study, we explored the experimental transmission of Babesia sp. BQ1 (Lintan) to sheep by H. qinghaiensis and Haemaphysalis longicornis. Based on the evidence from nested PCR, it suggested that H. qinghaiensis and H. longicornis are the potential vector ticks of Babesia sp. BQ1 (Lintan) and that larvae, nymphs and adults of both tick species were able to transmit Babesia sp. BQ1 (Lintan) to sheep. Parasites could be detected in the blood, by specific nested PCR, for one month post-infestation.

  12. Experimental evidence and theoretical analysis of photoionized plasma under x-ray radiation produced by an intense laser

    International Nuclear Information System (INIS)

    Wang Feilu; Fujioka, Shinsuke; Nishimura, Hiroaki; Takabe, Hideaki; Kato, Daiji; Li Yutong; Zhao Gang; Zhang Jie

    2008-01-01

    Photoionized plasma was studied experimentally under laboratory conditions by means of high intensity short pulse lasers. The experiment consists of a gold cavity filled with nitrogen gas. Six laser beams were focused on the inner surface of the gold cavity, thereby generating an almost black-body radiation having temperature of 80 eV inside the cavity. This radiation heats the nitrogen gas mainly by means of photoionization. L-shell emissions from N V to N VII have been observed in the wavelength range between 90 and 200 A. A time-dependent Detailed Configuration Accounting computer program has been developed to analyze the experimental spectra. In contrast to standard analysis of astrophysical observations, the evidence for photoionization is inferred from the spectral lines ratios. Comparison between the experimental and simulated line spectra indicates that the radiation heated nitrogen attains temperature of 20-30 eV, much lower than the source radiation temperature. Paradoxically, it is also shown that similar line emissions can be reproduced computationally also when the radiation and plasma temperatures both equal approximately 60 eV. This misleading result indicates that experimental simulation in laboratory is sometimes necessary to avoid misinterpretation of astrophysical spectra.

  13. Experimental evidence of off-diagonal transport term and the discrepancy between energy/particle balance and perturbation analyses

    International Nuclear Information System (INIS)

    Nagashima, Keisuke; Fukuda, Takeshi

    1991-12-01

    Evidence of temperature gradient driven particle flux was observed from the sawtooth induced density propagation phenomenon in JT-60. This off-diagonal particle flux was confirmed using the numerical calculation of measured chord integrated electron density. It was shown that the discrepancies between thermal and particle diffusivities estimated from the perturbation method and energy/particle balance analysis can be explained by considering the flux equations with off-diagonal transport terms. These flux equations were compared with the E x B convective fluxes in an electro-static drift wave instability and it was found that the E x B fluxes are consistent with several experimental observations. (author)

  14. Are Notions of Fairness Path‐Dependent? Experimental Evidence from an Efficiency‐Wage Environment

    OpenAIRE

    Stan Hu; Stuart Mestelman; William Scarth

    2015-01-01

    We extend the study of efficiency‐wage environments via laboratory experiments in three ways. First, we introduce exogenous shocks that increase the opportunity for rejection of the gift‐exchange outcome. These additional tests emerge since we carefully derive a series of theoretical predictions so that support for efficiency wages requires much more than simply observing that wage and effort levels exceed what would emerge with competition. Second, we focus on how the exogenous shocks can af...

  15. Experimental evidence on formation of imminent and short-term hydrochemical precursors for earthquakes

    International Nuclear Information System (INIS)

    Du Jianguo; Amita, Kazuhiro; Ohsawa, Shinji; Zhang Youlian; Kang Chunli; Yamada, Makoto

    2010-01-01

    The formation of imminent hydrochemical precursors of earthquakes is investigated by the simulation for water-rock reaction in a brittle aquifer. Sixty-one soaking experiments were carried out with granodiorite and trachyandesite grains of different sizes and three chemically-distinct waters for 6 to 168 h. The experimental data demonstrate that water-rock reaction can result in both measurable increases and decreases of ion concentrations in short times and that the extents of hydrochemical variations are controlled by the grain size, dissolution and secondary mineral precipitation, as well as the chemistry of the rock and groundwater. The results indicate that water-rock reactions in brittle aquifers and aquitards may be an important genetic mechanism of hydrochemical seismic precursors when the aquifers and aquitards are fractured in response to tectonic stress.

  16. Experimental evidence of the role of viscosity in the molecular kinetic theory of dynamic wetting.

    Science.gov (United States)

    Duvivier, D; Seveno, D; Rioboo, R; Blake, T D; De Coninck, J

    2011-11-01

    We report an experimental study of the dynamics of spontaneous spreading of aqueous glycerol drops on glass. For a range of glycerol concentrations, we follow the evolution of the radius and contact angle over several decades of time and investigate the influence of solution viscosity. The application of the molecular kinetic theory to the resulting data allows us to extract the coefficient of contact-line friction ζ, the molecular jump frequency κ(0), and the jump length λ for each solution. Our results show that the modified theory, which explicitly accounts for the effect of viscosity, can successfully be applied to droplet spreading. The viscosity affects the jump frequency but not the jump length. In combining these data, we confirm that the contact-line friction of the solution/air interface against the glass is proportional to the viscosity and exponentially dependent on the work of adhesion.

  17. Experimental evidence for multi-pass extraction with a bent crystal

    CERN Document Server

    Dehning, Bernd; Fidecaro, Giuseppe; Gyr, Marcel; Herr, Werner; Klem, J T; Scandale, Walter; Vuagnin, G; Weisse, E; Weisz, S; Møller, S P; Uggerhøj, Erik; Freund, A; Hustache, R; Carboni, G; Bussa, M P; Tosello, F

    1996-01-01

    The feasibility of extracting particles from the halo of a circulating proton beam using a bent silicon crystal has been demonstrated experimentally at the SPS for a beam energy of 120 GeV. Presently studies are conducted to understand the extraction mechanisms and the measured efficiencies. In particular the contribution of multi-pass extraction, where the particles can pass through the crystal many times before being channelled and extracted, is investigated. In a recent experiment, using a crystal especially fabricated with a finite amorphous layer on its surface, it has been proven that multi-pass extraction plays an important role. The experiment is described and the implication for further studies are discussed.

  18. Evidence for a prolonged role of alpha 4 integrin throughout active experimental allergic encephalomyelitis.

    Science.gov (United States)

    Keszthelyi, E; Karlik, S; Hyduk, S; Rice, G P; Gordon, G; Yednock, T; Horner, H

    1996-10-01

    The leukocyte integrin receptor, alpha 4 beta 1, and its endothelial cell ligand, vascular cell adhesion molecule 1, appear to be of critical importance in the leukocyte trafficking that accompanies CNS damage in experimental allergic encephalomyelitis (EAE). In this study, the persistence of the role for alpha 4 beta 1/VCAM-1 in EAE was established by observing antibody-mediated disease reversal up to 1 month following disease onset. Limited treatment with a monoclonal antibody against alpha 4 integrin, GG5/3, resulted in a significant decrease in both clinical and histopathologic signs. This was not observed in isotype control experiments. In the latter phase of progressive disease, widespread demyelination occurred in the animals that did not respond to 6 days of anti-alpha 4 treatment. These results demonstrate an essential role for alpha 4 beta 1 interactions throughout active EAE and illustrate the difference between reversible clinical deficits caused by edema and irreversible deficits associated with demyelination.

  19. Experimental evidence for excess entropy discontinuities in glass-forming solutions.

    Science.gov (United States)

    Lienhard, Daniel M; Zobrist, Bernhard; Zuend, Andreas; Krieger, Ulrich K; Peter, Thomas

    2012-02-21

    Glass transition temperatures T(g) are investigated in aqueous binary and multi-component solutions consisting of citric acid, calcium nitrate (Ca(NO(3))(2)), malonic acid, raffinose, and ammonium bisulfate (NH(4)HSO(4)) using a differential scanning calorimeter. Based on measured glass transition temperatures of binary aqueous mixtures and fitted binary coefficients, the T(g) of multi-component systems can be predicted using mixing rules. However, the experimentally observed T(g) in multi-component solutions show considerable deviations from two theoretical approaches considered. The deviations from these predictions are explained in terms of the molar excess mixing entropy difference between the supercooled liquid and glassy state at T(g). The multi-component mixtures involve contributions to these excess mixing entropies that the mixing rules do not take into account. © 2012 American Institute of Physics

  20. Direct Experimental Evidence of Back-Surface Acceleration from Laser-Irradiated Foils

    International Nuclear Information System (INIS)

    Allen, M; Patel, P; Mackinnon, A; Price, D; Wilks, S; Morse, E

    2004-01-01

    Au foils were irradiated with a 100-TW, 100-fs laser at intensities greater than 10 20 W/cm 2 producing proton beams with a total yield of ∼ 10 11 and maximum proton energy of > 9 MeV. Removing contamination from the back surface of Au foils with an Ar-ion sputter gun reduced the total yield of accelerated protons to less than 1% of the yield observed without removing contamination. Removing contamination the front surface (laser-interaction side) of the target had no observable effect on the proton beam. We present a one-dimensional particle-in-cell simulation that models the experiment. Both experimental and simulation results are consistent with the back-surface acceleration mechanism described in the text

  1. Experimental evidence of EDGE turbulence driven by multiple mechanisms in ATF

    International Nuclear Information System (INIS)

    Hidalgo, C.

    1993-01-01

    The scaling properties of edge fluctuations have been investigated using Langmuir probes in the edge region of the Advance Toroidal Facility (ATF). Fluctuations in the ion saturation current (ls/ls) and transport inferred from the fluctuations increase with increasing density gradient, while keeping unchanged local electron temperature. The modification of the electron temperature in the range (10-50) eV, Keeping constant the density profile, does not have any significant influence on ls/ ls. In regions were Er/B =0, the poloidal phase velocity of the fluctuations is given by vph 2Te/LnB. More then one of any so far proposed mechanisms must be invoked to explain all the experimental observations. (Author) 14 refs

  2. Experimental Evidence of Edge turbulence driven by multiple mechanisms in ATF

    International Nuclear Information System (INIS)

    Hidalgo, C.; Harris, J.M.; Uckran, T.; Manson, G.R.; Bell, J.D.

    1993-01-01

    The scaling properties of edge fluctuations have been investigated using Langmuir probes in the edge region of the Advance Toroidal Facility (ATF). Fluctuations in the ion saturation current (I s /I s ) and transport inferred from the fluctuations increase with increasing density gradient, while keeping unchanged local electron temperature. The modification of the electron temperature in the range (10-50) eV, Keeping constant the density profile, does not have any significant influence on I s /I s . In regions were E r /B∼0, the poloidal phase velocity of the fluctuations is given by V p h∼ 2T e L n B. More then one of any so far proposed mechanisms must be invoked to explain all the experimental observations.(Author)

  3. Theoretical approaches and experimental evidence for liquid-vapor phase transitions in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Moretto, L.G.; Elliott, J.B.; Phair, L.; Wozniak, G.J.; Mader, C.M.; Chappars, A.

    2001-01-01

    The leptodermous approximation is applied to nuclear systems for T > 0. The introduction of surface corrections leads to anomalous caloric curves and to negative heat capacities in the liquid-gas coexistence region. Clusterization in the vapor is described by associating surface energy to clusters according to Fisher's formula. The three-dimensional Ising model, a leptodermous system par excellence, does obey rigorously Fisher's scaling up to the critical point. Multifragmentation data from several experiments including the ISiS and EOS Collaborations, as well as compound nucleus fragment emission at much lower energy follow the same scaling, thus providing the strongest evidence yet of liquid-vapor coexistence.

  4. The emotional and attitudinal consequences of religious hypocrisy: experimental evidence using a cognitive dissonance paradigm.

    Science.gov (United States)

    Yousaf, Omar; Gobet, Fernand

    2013-01-01

    We explored the emotional and attitudinal consequences of personal attitude-behavior discrepancies using a religious version of the hypocrisy paradigm. We induced cognitive dissonance in participants (n = 206) by making them feel hypocritical for advocating certain religious behaviors that they had not recently engaged in to their own satisfaction. In Experiment 1, this resulted in higher levels of self-reported guilt and shame compared to the control condition. Experiment 2 further showed that a religious self-affirmation task eliminated the guilt and shame. In Experiment 3, participants boosted their religious attitudes as a result of dissonance, and both religious and non-religious self-affirmation tasks eliminated this effect. The findings provide evidence that dissonance induced through religious hypocrisy can result in guilt and shame as well as an attitude bolstering effect, as opposed to the attitude reconciliation effect that is prevalent in previous dissonance research.

  5. Experimental evidence showing that no mitotically active female germline progenitors exist in postnatal mouse ovaries.

    Science.gov (United States)

    Zhang, Hua; Zheng, Wenjing; Shen, Yan; Adhikari, Deepak; Ueno, Hiroo; Liu, Kui

    2012-07-31

    It has been generally accepted for more than half a century that, in most mammalian species, oocytes cannot renew themselves in postnatal or adult life, and that the number of oocytes is already fixed in fetal or neonatal ovaries. This assumption, however, has been challenged over the past decade. In this study, we have taken an endogenous genetic approach to this question and generated a multiple fluorescent Rosa26(rbw/+);Ddx4-Cre germline reporter mouse model for in vivo and in vitro tracing of the development of female germline cell lineage. Through live cell imaging and de novo folliculogenesis experiments, we show that the Ddx4-expressing cells from postnatal mouse ovaries did not enter mitosis, nor did they contribute to oocytes during de novo folliculogenesis. Our results provide evidence that supports the traditional view that no postnatal follicular renewal occurs in mammals, and no mitotically active Ddx4-expressing female germline progenitors exist in postnatal mouse ovaries.

  6. The Impact of Smoking Bans on Smoking and Consumer Behavior: Quasi-Experimental Evidence from Switzerland.

    Science.gov (United States)

    Boes, Stefan; Marti, Joachim; Maclean, Johanna Catherine

    2015-11-01

    In this paper, we exploit the progressive implementation of smoking bans in public venues at the state level in Switzerland to evaluate both the direct effects on smoking and the potential unintended consequences of these legislations on consumer behaviors as measured by visiting restaurants/bars and discos ('going out'). Our results indicate that public venue smoking bans in Switzerland reduce smoking rates, but the findings do not emerge until 1 year following the ban. This pattern of results is consistent with delays in ban enforcement on the part of business owners, difficulties in changing addictive behaviors such as smoking, and/or learning on the part of smokers. We find evidence that smoking bans influence going-out behavior and there is substantial heterogeneity across venue and consumer characteristics. Copyright © 2014 John Wiley & Sons, Ltd.

  7. Self-transcendence facilitates meaning-making and flow: Evidence from a pilot experimental study

    Directory of Open Access Journals (Sweden)

    Osin, Evgeny N.

    2016-06-01

    Full Text Available We review the psychological theory of flow and focus on the notion of the autotelic personality, arguing that self-transcendence (understood within the existential tradition of Frankl and Längle as the individual’s ability to establish inner relationships with values can be viewed as a personality disposition conducive to flow experience. The study aimed to investigate the effects of situational task meaning and dispositional self-transcendence on productivity and flow experience. We present a pilot quasi-experimental study conducted in a student sample (N = 82 Students were asked to work in small-group settings on a creative task, which consisted in finding solutions to a social problem. Each group was randomly assigned to an instruction presenting the problem as happening either in a distant country (low-meaning or in their home country (high-meaning condition. The outcome variables were measures of flow, perceived meaning of the task, and satisfaction with time spent working. The solutions generated by the students were rated by three experts. The experimental manipulation had a main effect on the quality of the resulting solutions, but not on the subjective experience of the participants. A number of significant interaction effects were found, indicating that the associations of self-transcendence with experiential outcomes tended to be linear under the low-meaning condition, but curvilinear under the high-meaning condition. The findings suggest that self-transcendence is particularly beneficial to flow in situations with unclear meaning, but very high levels of self-transcendence may hinder flow in highly meaningful situations. Overall, the findings suggest that self-transcendence can be considered as a disposition of the autotelic personality.

  8. Experimental evidence of population differences in reproductive investment conditional on environmental stochasticity

    Energy Technology Data Exchange (ETDEWEB)

    Gauthey, Zoé [INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle (France); Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet (France); Panserat, Stéphane [INRA, UR 107, Nutrition Metabolism Aquaculture, Aquapôle, 64310 Saint Pée sur Nivelle (France); Elosegi, Arturo [Faculty of Science and Technology, University of the Basque Country UPV/EHU, 48080 Bilbao (Spain); Herman, Alexandre [INRA, UR 107, Nutrition Metabolism Aquaculture, Aquapôle, 64310 Saint Pée sur Nivelle (France); Tentelier, Cédric [INRA, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, Aquapôle, quartier Ibarron, 64310 Saint-Pée sur Nivelle (France); Univ Pau & Pays Adour, UMR 1224, Ecologie Comportementale et Biologie des Populations de Poissons, UFR Sciences et Techniques de la Côte Basque, Allée du parc Montaury, 64600 Anglet (France); and others

    2016-01-15

    Environmental stochasticity is expected to shape life histories of species, wherein organisms subjected to strong environmental variation should display adaptive response by being able to tune their reproductive investment. For riverine ecosystems, climate models forecast an increase in the frequency and intensity of extreme events such as floods and droughts. The speed and the mechanisms by which organisms may adapt their reproductive investment are therefore of primary importance to understand how species will cope with such radical environmental changes. In the present study, we sampled spawners from two different populations of wild brown trout, originating from two environments with contrasting levels of flow stochasticity. We placed them in sympatry within an experimental channel during reproductive season. In one modality, water flow was maintained constant, whereas in another modality, water flow was highly variable. Reproductive investment of all individuals was monitored using weight and energetic plasma metabolite variation throughout the reproductive season. Only the populations originating from the most variable environment showed a plastic response to experimental manipulation of water flow, the females being able to reduce their weight variation (from 19.2% to 13.1%) and metabolites variations (from 84.2% to 18.6% for triglycerides for instance) under variable flow conditions. These results imply that mechanisms to cope with environmental stochasticity can differ between populations of the same species, where some populations can be plastic whereas other cannot. - Highlights: • We place two populations of brown trout under contrasting water flow for reproduction. • Energetic metabolite variation is used as a cue of reproductive investment. • In constant flow, both populations show the same reproductive investment. • In variable flow, only one of the populations modifies its reproductive investment. • Divergent evolution of reproductive

  9. Experimental evidence of population differences in reproductive investment conditional on environmental stochasticity

    International Nuclear Information System (INIS)

    Gauthey, Zoé; Panserat, Stéphane; Elosegi, Arturo; Herman, Alexandre; Tentelier, Cédric

    2016-01-01

    Environmental stochasticity is expected to shape life histories of species, wherein organisms subjected to strong environmental variation should display adaptive response by being able to tune their reproductive investment. For riverine ecosystems, climate models forecast an increase in the frequency and intensity of extreme events such as floods and droughts. The speed and the mechanisms by which organisms may adapt their reproductive investment are therefore of primary importance to understand how species will cope with such radical environmental changes. In the present study, we sampled spawners from two different populations of wild brown trout, originating from two environments with contrasting levels of flow stochasticity. We placed them in sympatry within an experimental channel during reproductive season. In one modality, water flow was maintained constant, whereas in another modality, water flow was highly variable. Reproductive investment of all individuals was monitored using weight and energetic plasma metabolite variation throughout the reproductive season. Only the populations originating from the most variable environment showed a plastic response to experimental manipulation of water flow, the females being able to reduce their weight variation (from 19.2% to 13.1%) and metabolites variations (from 84.2% to 18.6% for triglycerides for instance) under variable flow conditions. These results imply that mechanisms to cope with environmental stochasticity can differ between populations of the same species, where some populations can be plastic whereas other cannot. - Highlights: • We place two populations of brown trout under contrasting water flow for reproduction. • Energetic metabolite variation is used as a cue of reproductive investment. • In constant flow, both populations show the same reproductive investment. • In variable flow, only one of the populations modifies its reproductive investment. • Divergent evolution of reproductive

  10. Experimental Evidence that Abrasion of Carbonate Sand is a Significant Source of Carbonate Mud

    Science.gov (United States)

    Trower, L.; Kivrak, L.; Lamb, M. P.; Fischer, W. W.

    2017-12-01

    Carbonate mud is a major sedimentary component of modern and ancient tropical carbonate environments, yet its enigmatic origin remains debated. Early views on the origin of carbonate mud considered the abrasion of carbonate sand during sediment transport as a possible mechanism. In recent decades, however, prevailing thought has generally settled on a binary explanation: 1) precipitation of aragonite needles within the water column, and 2) post-mortem dispersal of biological aragonite, in particular from algae, and perhaps aided by fish. To test these different hypotheses, we designed a model and a set of laboratory experiments to quantify the rates of mud production associated with sediment transport. We adapted a recent model of ooid abrasion rate to predict the rate of mud production by abrasion of carbonate sand as a function of grain size and sediment transport mode. This model predicts large mud production rates, ranging from 103 to 104 g CaCO3/m2/yr for typical grain sizes and transport conditions. These rate estimates are at least one order of magnitude more rapid than the 102 g CaCO3/m2/yr estimates for other mechanisms like algal biomineralization, indicating that abrasion could produce much larger mud fluxes per area as other mechanisms. We tested these estimates using wet abrasion mill experiments; these experiments generated mud through mechanical abrasion of both ooid and skeletal carbonate sand for grain sizes ranging from 250 µm to >1000 µm over a range of sediment transport modes. Experiments were run in artificial seawater, including a series of controls demonstrating that no mud was produced via homogenous nucleation and precipitation in the absence of sand. Our experimental rates match the model predictions well, although we observed small systematic differences in rates between abrasion ooid sand and skeletal carbonate sand that likely stems from innate differences in grain angularity. Electron microscopy of the experimental products revealed

  11. Experimental evidence that honeybees depress wild insect densities in a flowering crop.

    Science.gov (United States)

    Lindström, Sandra A M; Herbertsson, Lina; Rundlöf, Maj; Bommarco, Riccardo; Smith, Henrik G

    2016-11-30

    While addition of managed honeybees (Apis mellifera) improves pollination of many entomophilous crops, it is unknown if it simultaneously suppresses the densities of wild insects through competition. To investigate this, we added 624 honeybee hives to 23 fields of oilseed rape (Brassica napus L.) over 2 years and made sure that the areas around 21 other fields were free from honeybee hives. We demonstrate that honeybee addition depresses the densities of wild insects (bumblebees, solitary bees, hoverflies, marchflies, other flies, and other flying and flower-visiting insects) even in a massive flower resource such as oilseed rape. The effect was independent of the complexity of the surrounding landscape, but increased with the size of the crop field, which suggests that the effect was caused by spatial displacement of wild insects. Our results have potential implications both for the pollination of crops (if displacement of wild pollinators offsets benefits achieved by adding honeybees) and for conservation of wild insects (if displacement results in negative fitness consequences). © 2016 The Author(s).

  12. Effect of land use change on ecosystem function of dung beetles: experimental evidence from Wallacea Region in Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    SHAHABUDDIN

    2011-07-01

    Full Text Available Shahabuddin (2011 Effect of land use change on ecosystem function of dung beetles: experimental evidence from Wallacea Region in Sulawesi, Indonesia. Biodiversitas 12: 177-181. The deforestation of tropical forests and their subsequent conversion to human-dominated land-use systems is one of the most significant causes of biodiversity loss. However clear understanding of the links between ecological functions and biodiversity is needed to evaluate and predict the true environmental consequences of human activities. This study provided experimental evidence comparing ecosystem function of dung beetles across a land use gradient ranging from natural tropical forest and agroforestry systems to open cultivated areas in Central Sulawesi. Therefore, standardized dung pats were exposed at each land-use type to assess dung removal and parasite suppression activity by dung beetles. The results showed that ecosystem function of dung beetles especially dung burial activity were remarkably disrupted by land use changes from natural forest to open agricultural area. Dung beetles presence enhanced about 53% of the total dung removed and reduced about 83% and 63% of fly population and species number respectively, indicating a pronounce contribution of dung beetles in our ecosystem.

  13. Experimental evidence for several spheroid growth mechanisms in the liquid-phase sintered tungsten-base composites

    International Nuclear Information System (INIS)

    Zukas, E.G.; Rogers, P.S.Z.; Rogers, R.S.

    1976-01-01

    The generally accepted mechanism for spheroid growth during sintering of tungsten-base composites in the presence of a liquid phase is the dissolution of the small spheroids with simultaneous precipitation of tungsten from the molten matrix onto the larger spheroids, the process being driven by the difference in surface energy between the larger and smaller spheroids. From theoretical considerations, the slope of the straight line of log diameter versus log time should be 1 / 3 for this process. The experimental evidence for the dissolution and reprecipitation mechanism is meager, being based primarily on the spheroid growth rate during the latter stages of liquid-phase sintering. Experimental evidence is presented that shows spheroid growth taking place in systems where the tungsten and the matrix are mutually insoluble thereby making dissolution and reprecipitation impossible. Furthermore, the results from these studies and others using the usual matrix compositions indicate that spheroid growth takes place predominantly by the combination or coalescence of two or more spheroids. Deposition of tungsten from the molten matrix also occurs, although not necessarily on spheroid surfaces which have the lowest surface energy. Thus, many mechanisms, each depending on temperature and other variables, operate simultaneously. A satisfactory theoretical treatment must include them all

  14. A spotlight on liquefaction: evidence from clinical settings and experimental models in tuberculosis.

    Science.gov (United States)

    Cardona, Pere-Joan

    2011-01-01

    Liquefaction is one of the most intriguing aspects of human tuberculosis. It is a major cause of the transition from the infection to active disease (tuberculosis, TB) as well as the transmission of M. tuberculosis to other persons. This paper reviews the natural history of liquefaction in humans from a pathological and radiological point of view and discusses how the experimental models available can be used to address the topic of liquefaction and cavity formation. Different concepts that have been related to liquefaction, from the influence of immune response to mechanical factors, are reviewed. Synchronic necrosis or apoptosis of infected macrophages in a close area, together with an ineffective fibrosis, appears to be clue in this process, in which macrophages, the immune response, and bacillary load interact usually in a particular scenario: the upper lobes of the lung. The summary would be that even if being a stochastic effect, liquefaction would result if the organization of the intragranulomatous necrosis (by means of fibrosis) would be disturbed.

  15. A Spotlight on Liquefaction: Evidence from Clinical Settings and Experimental Models in Tuberculosis

    Directory of Open Access Journals (Sweden)

    Pere-Joan Cardona

    2011-01-01

    Full Text Available Liquefaction is one of the most intriguing aspects of human tuberculosis. It is a major cause of the transition from the infection to active disease (tuberculosis, TB as well as the transmission of M. tuberculosis to other persons. This paper reviews the natural history of liquefaction in humans from a pathological and radiological point of view and discusses how the experimental models available can be used to address the topic of liquefaction and cavity formation. Different concepts that have been related to liquefaction, from the influence of immune response to mechanical factors, are reviewed. Synchronic necrosis or apoptosis of infected macrophages in a close area, together with an ineffective fibrosis, appears to be clue in this process, in which macrophages, the immune response, and bacillary load interact usually in a particular scenario: the upper lobes of the lung. The summary would be that even if being a stochastic effect, liquefaction would result if the organization of the intragranulomatous necrosis (by means of fibrosis would be disturbed.

  16. Experimental evidence of impacts of an invasive parakeet on foraging behavior of native birds.

    Science.gov (United States)

    Peck, Hannah L; Pringle, Henrietta E; Marshall, Harry H; Owens, Ian P F; Lord, Alexa M

    2014-05-01

    Resource competition is one potential behavioral mechanism by which invasive species can impact native species, but detecting this competition can be difficult due to the interactions that variable environmental conditions can have on species behavior. This is particularly the case in urban habitats where the disturbed environment can alter natural behavior from that in undisturbed habitats. The rose-ringed parakeet ( Psittacula krameri ), is an increasingly common invasive species, predominantly associated with large urban centers. Using an experimental approach, we tested the behavioral responses of native garden birds in response to the presence of a rose-ringed parakeet versus the presence of a similarly sized and dominant native bird, the great spotted woodpecker ( Dendrocopos major ). Parakeet presence significantly reduced feeding rates and increased vigilance among native birds compared with our control treatments. Of visits made by native birds in the presence of a parakeet, feeding was more likely to occur in sites within the parakeet range compared with sites outside, suggesting some habituation of native birds has occurred following prior exposure to parakeets but overall foraging behavior is still disrupted. The results of our study suggest that nonnative species can have complex and subtle impacts on native fauna and show that a nonnative competitor can impact native species simply through their presence near resources.

  17. Experimental Evidence Shows the Importance of Behavioural Plasticity and Body Size under Competition in Waterfowl

    Science.gov (United States)

    Zhang, Yong; Prins, Herbert H. T.; Versluijs, Martijn; Wessels, Rick; Cao, Lei; de Boer, Willem Frederik

    2016-01-01

    When differently sized species feed on the same resources, interference competition may occur, which may negatively affect their food intake rate. It is expected that competition between species also alters behaviour and feeding patch selection. To assess these changes in behaviour and patch selection, we applied an experimental approach using captive birds of three differently sized Anatidae species: wigeon (Anas penelope) (~600 g), swan goose (Anser cygnoides) (~2700 g) and bean goose (Anser fabalis) (~3200 g). We quantified the functional response for each species and then recorded their behaviour and patch selection with and without potential competitors, using different species combinations. Our results showed that all three species acquired the highest nitrogen intake at relatively tall swards (6, 9 cm) when foraging in single species flocks in the functional response experiment. Goose species were offered foraging patches differing in sward height with and without competitors, and we tested for the effect of competition on foraging behaviour. The mean percentage of time spent feeding and being vigilant did not change under competition for all species. However, all species utilized strategies that increased their peck rate on patches across different sward heights, resulting in the same instantaneous and nitrogen intake rate. Our results suggest that variation in peck rate over different swards height permits Anatidae herbivores to compensate for the loss of intake under competition, illustrating the importance of behavioural plasticity in heterogeneous environments when competing with other species for resources. PMID:27727315

  18. Why natural monazite never becomes amorphous: Experimental evidence for alpha self-healing

    Energy Technology Data Exchange (ETDEWEB)

    Seydoux-Guillaume, Anne -Magali [Univ. Clermont Auvergne, Clermont-Ferrand (France); Univ. Lyon, Saint-Etienne (France); Deschanels, Xavier [Univ. Montpellier, Marcoule (France); Baumier, Cedric [Univ. Paris-Sud, Orsay (France); Neumeier, Stefan [Forschungszentrum Julich GmbH, Julich (Germany); Weber, William John [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peuget, Sylvain [CEA, Bagnols-sur-Ceze Cedex (France)

    2018-05-01

    Monazite, a common accessory rare-earth orthophosphate mineral in the continental crust widely used in U-Pb geochronology, holds promise for (U-Th)/He thermochronology and for the immobilization of Pu and minor actinides (MA) coming from spent nuclear fuel reprocessing. Previous results obtained on natural and plutonium-doped monazite have demonstrated the ability of this structure to maintain a crystalline state despite high radiation damage levels. However, the low critical temperature (180 °C), above which amorphization cannot be achieved in natural monazite under ion irradiation, does not explain this old and unsolved paradox: why do natural monazites, independent of their geological history, remain crystalline even when they did not experience any thermal event that could heal the defects? This is what the present study aims to address. Synthetic polycrystals of LaPO4-monazite were irradiated sequentially and simultaneously with α particles (He) and gold (Au) ions. Here, our results demonstrate experimentally for the first time in monazite, the existence of the defect recovery mechanism, called α-healing, acting in this structure due to electronic energy loss of α particles, which explains the absence of amorphization in natural monazite samples. This mechanism is critically important for monazite geo- and thermochronology and to design and predictively model the long-term behavior of ceramic matrices for nuclear waste conditioning.

  19. Social learning solves the problem of narrow-peaked search landscapes: experimental evidence in humans.

    Science.gov (United States)

    Acerbi, Alberto; Tennie, Claudio; Mesoudi, Alex

    2016-09-01

    The extensive use of social learning is considered a major reason for the ecological success of humans. Theoretical considerations, models and experiments have explored the evolutionary basis of social learning, showing the conditions under which learning from others is more adaptive than individual learning. Here we present an extension of a previous experimental set-up, in which individuals go on simulated 'hunts' and their success depends on the features of a 'virtual arrowhead' they design. Individuals can modify their arrowhead either by individual trial and error or by copying others. We study how, in a multimodal adaptive landscape, the smoothness of the peaks influences learning. We compare narrow peaks, in which solutions close to optima do not provide useful feedback to individuals, to wide peaks, where smooth landscapes allow an effective hill-climbing individual learning strategy. We show that individual learning is more difficult in narrow-peaked landscapes, but that social learners perform almost equally well in both narrow- and wide-peaked search spaces. There was a weak trend for more copying in the narrow than wide condition, although as in previous experiments social information was generally underutilized. Our results highlight the importance of tasks' design space when studying the adaptiveness of high-fidelity social learning.

  20. No evidence of complementary water use along a plant species richness gradient in temperate experimental grasslands.

    Directory of Open Access Journals (Sweden)

    Dörte Bachmann

    Full Text Available Niche complementarity in resource use has been proposed as a key mechanism to explain the positive effects of increasing plant species richness on ecosystem processes, in particular on primary productivity. Since hardly any information is available for niche complementarity in water use, we tested the effects of plant diversity on spatial and temporal complementarity in water uptake in experimental grasslands by using stable water isotopes. We hypothesized that water uptake from deeper soil depths increases in more diverse compared to low diverse plant species mixtures. We labeled soil water in 8 cm (with 18O and 28 cm depth (with ²H three times during the 2011 growing season in 40 temperate grassland communities of varying species richness (2, 4, 8 and 16 species and functional group number and composition (legumes, grasses, tall herbs, small herbs. Stable isotope analyses of xylem and soil water allowed identifying the preferential depth of water uptake. Higher enrichment in 18O of xylem water than in ²H suggested that the main water uptake was in the upper soil layer. Furthermore, our results revealed no differences in root water uptake among communities with different species richness, different number of functional groups or with time. Thus, our results do not support the hypothesis of increased complementarity in water use in more diverse than in less diverse communities of temperate grassland species.

  1. Behavioral response to contamination risk information in a spatially explicit groundwater environment: Experimental evidence

    Science.gov (United States)

    Li, Jingyuan; Michael, Holly A.; Duke, Joshua M.; Messer, Kent D.; Suter, Jordan F.

    2014-08-01

    This paper assesses the effectiveness of aquifer monitoring information in achieving more sustainable use of a groundwater resource in the absence of management policy. Groundwater user behavior in the face of an irreversible contamination threat is studied by applying methods of experimental economics to scenarios that combine a physics-based, spatially explicit, numerical groundwater model with different representations of information about an aquifer and its risk of contamination. The results suggest that the threat of catastrophic contamination affects pumping decisions: pumping is significantly reduced in experiments where contamination is possible compared to those where pumping cost is the only factor discouraging groundwater use. The level of information about the state of the aquifer also affects extraction behavior. Pumping rates differ when information that synthesizes data on aquifer conditions (a "risk gauge") is provided, despite invariant underlying economic incentives, and this result does not depend on whether the risk information is location-specific or from a whole aquifer perspective. Interestingly, users increase pumping when the risk gauge signals good aquifer status compared to a no-gauge treatment. When the gauge suggests impending contamination, however, pumping declines significantly, resulting in a lower probability of contamination. The study suggests that providing relatively simple aquifer condition guidance derived from monitoring data can lead to more sustainable use of groundwater resources.

  2. Experimental evidence of beam-foil plasma creation during ion-solid interaction

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Prashant, E-mail: prashant@iuac.res.in; Nandi, Tapan [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2016-08-15

    Charge state evolution of the energetic projectile ions during the passage through thin carbon foils has been revisited using the X-ray spectroscopy technique. Contributions from the bulk and the solid surface in the charge changing processes have been segregated by measuring the charge state distribution of the projectile ions in the bulk of the target during the ion–solid interaction. Interestingly, the charge state distribution measured in the bulk exhibits Lorentzian profile in contrast to the well-known Gaussian structure observed using the electromagnetic methods and the theoretical predictions. The occurrence of such behavior is a direct consequence of the imbalance between charge changing processes, which has been seen in various cases of the laboratory plasma. It suggests that the ion-solid collisions constitute high-density, localized plasma in the bulk of the solid target, called the beam-foil plasma. This condensed beam-foil plasma is similar to the high-density solar and stellar plasma which may have practical implementations in various fields, in particular, plasma physics and nuclear astrophysics. The present work suggests further modification in the theoretical charge state distribution calculations by incorporating the plasma coupling effects during the ion–solid interactions. Moreover, the multi-electron capture from the target exit surface has been confirmed through comparison between experimentally measured and theoretically predicted values of the mean charge state of the projectile ions.

  3. Adolescents' implicit theories predict desire for vengeance after peer conflicts: correlational and experimental evidence.

    Science.gov (United States)

    Yeager, David S; Trzesniewski, Kali H; Tirri, Kirsi; Nokelainen, Petri; Dweck, Carol S

    2011-07-01

    Why do some adolescents respond to interpersonal conflicts vengefully, whereas others seek more positive solutions? Three studies investigated the role of implicit theories of personality in predicting violent or vengeful responses to peer conflicts among adolescents in Grades 9 and 10. They showed that a greater belief that traits are fixed (an entity theory) predicted a stronger desire for revenge after a variety of recalled peer conflicts (Study 1) and after a hypothetical conflict that specifically involved bullying (Study 2). Study 3 experimentally induced a belief in the potential for change (an incremental theory), which resulted in a reduced desire to seek revenge. This effect was mediated by changes in bad-person attributions about the perpetrators, feelings of shame and hatred, and the belief that vengeful ideation is an effective emotion-regulation strategy. Together, the findings illuminate the social-cognitive processes underlying reactions to conflict and suggest potential avenues for reducing violent retaliation in adolescents. PsycINFO Database Record (c) 2011 APA, all rights reserved

  4. User preferences and willingness to pay for safe drinking water: Experimental evidence from rural Tanzania.

    Science.gov (United States)

    Burt, Zachary; Njee, Robert M; Mbatia, Yolanda; Msimbe, Veritas; Brown, Joe; Clasen, Thomas F; Malebo, Hamisi M; Ray, Isha

    2017-01-01

    Almost half of all deaths from drinking microbiologically unsafe water occur in Sub-Saharan Africa. Household water treatment and safe storage (HWTS) systems, when consistently used, can provide safer drinking water and improve health. Social marketing to increase adoption and use of HWTS depends both on the prices of and preferences for these systems. This study included 556 households from rural Tanzania across two low-income districts with low-quality water sources. Over 9 months in 2012 and 2013, we experimentally evaluated consumer preferences for six "low-cost" HWTS options, including boiling, through an ordinal ranking protocol. We estimated consumers' willingness to pay (WTP) for these options, using a modified auction. We allowed respondents to pay for the durable HWTS systems with cash, chickens or mobile money; a significant minority chose chickens as payment. Overall, our participants favored boiling, the ceramic pot filter and, where water was turbid, PuR™ (a combined flocculant-disinfectant). The revealed WTP for all products was far below retail prices, indicating that significant scale-up may need significant subsidies. Our work will inform programs and policies aimed at scaling up HWTS to improve the health of resource-constrained communities that must rely on poor-quality, and sometimes turbid, drinking water sources. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Experimental evidence that density dependence strongly influences plant invasions through fragmented landscapes.

    Science.gov (United States)

    Williams, Jennifer L; Levine, Jonathan M

    2018-04-01

    Populations of range expanding species encounter patches of both favorable and unfavorable habitat as they spread across landscapes. Theory shows that increasing patchiness slows the spread of populations modeled with continuously varying population density when dispersal is not influence by the environment or individual behavior. However, as is found in uniformly favorable landscapes, spread remains driven by fecundity and dispersal from low density individuals at the invasion front. In contrast, when modeled populations are composed of discrete individuals, patchiness causes populations to build up to high density before dispersing past unsuitable habitat, introducing an important influence of density dependence on spread velocity. To test the hypothesized interaction between habitat patchiness and density dependence, we simultaneously manipulated these factors in a greenhouse system of annual plants spreading through replicated experimental landscapes. We found that increasing the size of gaps and amplifying the strength of density dependence both slowed spread velocity, but contrary to predictions, the effect of amplified density dependence was similar across all landscape types. Our results demonstrate that the discrete nature of individuals in spreading populations has a strong influence on how both landscape patchiness and density dependence influence spread through demographic and dispersal stochasticity. Both finiteness and landscape structure should be critical components to theoretical predictions of future spread for range expanding native species or invasive species colonizing new habitat. © 2018 by the Ecological Society of America.

  6. Exploring the costs and benefits of social information use: an appraisal of current experimental evidence.

    Science.gov (United States)

    Rieucau, Guillaume; Giraldeau, Luc-Alain

    2011-04-12

    Research on social learning has focused traditionally on whether animals possess the cognitive ability to learn novel motor patterns from tutors. More recently, social learning has included the use of others as sources of inadvertent social information. This type of social learning seems more taxonomically widespread and its use can more readily be approached as an economic decision. Social sampling information, however, can be tricky to use and calls for a more lucid appraisal of its costs. In this four-part review, we address these costs. Firstly, we address the possibility that only a fraction of group members are actually providing social information at any one time. Secondly, we review experimental research which shows that animals are circumspect about social information use. Thirdly, we consider the cases where social information can lead to incorrect decisions and finally, we review studies investigating the effect of social information quality. We address the possibility that using social information or not is not a binary decision and present results of a study showing that nutmeg mannikins combine both sources of information, a condition that can lead to the establishment of informational cascades. We discuss the importance of empirically investigating the economics of social information use.

  7. Testing the theory of emissions trading. Experimental evidence on alternative mechanisms for global carbon trading

    International Nuclear Information System (INIS)

    Klaassen, Ger; Nentjes, Andries; Smith, Mark

    2005-01-01

    Simulation models and theory prove that emission trading converges to market equilibrium. This paper sets out to test these results using experimental economics. Three experiments are conducted for the six largest carbon emitting industrialized regions. Two experiments use auctions, the first a single bid auction and the second a Walrasian auction. The third relies on bilateral, sequential trading. The paper finds that, in line with the standard theory, both auctions and bilateral, sequential trading capture a significant part (88% to 99%) of the potential cost savings of emission trading. As expected from trade theory, all experiments show that the market price converges (although not fully) to the market equilibrium price. In contrast to the theory, the results also suggest that not every country might gain from trading. In both the bilateral trading experiment and the Walrasian auction, one country actually is worse off with trade. In particular bilateral, sequential trading leads to a distribution of gains significantly different from the competitive market outcome. This is due to speculative behavior, imperfect foresight and market power

  8. Age and recovery from brain injury: legal opinions, clinical beliefs and experimental evidence.

    Science.gov (United States)

    Johnson, David A; Rose, F D; Brooks, B M; Eyers, S

    2003-01-01

    Despite considerable scientific evidence to the contrary, many medical practitioners maintain that children recover from brain injury better than adults. This belief, which is commonly referred to as the "Kennard Principle", has important ramifications for personal injury compensation claims in which the amount of financial damages claimed is partly based on medical experts' prognoses for recovery and long-term outcome. The present study investigated whether legal practitioners' beliefs are consistent with those of medical practitioners. Lawyers were asked to estimate their confidence in consultant neurologists' estimates of recovery in four clinically-based but fictitious case studies which differed only in the reported age of the patient. The lawyers showed more confidence in estimates which coincided with the Kennard Principle than those which did not. These results support previous findings in showing widespread belief that "younger is better" in recovery from brain injury. In consequence, it is likely that financial compensation for children with brain injury is currently being underestimated in litigation, thereby prejudicing the long-term outcome of the child.

  9. Experimental evidence of pharmacological management of anchorage in Orthodontics: A systematic review

    Science.gov (United States)

    Fernández-González, Felipe José; Cañigral, Aránzazu; Balbontín-Ayala, Felipe; Gonzalo-Orden, José Manuel; de Carlos, Felix; Cobo, Teresa; Fernández-Vázquez, Jose Pedro; Sánchez-Lasheras, Fernando; Vega, José Antonio

    2015-01-01

    Introduction: Orthodontic anchorage is one of the most challenging aspects of Orthodontics. Preventing undesired movement of teeth could result in safer and less complicated orthodontic treatment. Recently, several reviews have been published about the effects of different molecules on bone physiology and the clinical side effects in Orthodontics. However, the effects of local application of these substances on the rate of orthodontic tooth movement have not been assessed. Objectives: The aim of this research was to analyze the scientific evidence published in the literature about the effects of different molecules on orthodontic anchorage. Methods: The literature was systematically reviewed using PubMed/Medline, Scopus and Cochrane databases from 2000 up to July 31st, 2014. Articles were independently selected by two different researchers based on previously established inclusion and exclusion criteria, with a concordance Kappa index of 0.86. The methodological quality of the reviewed papers was performed. Results: Search strategy identified 270 articles. Twenty-five of them were selected after application of inclusion/exclusion criteria, and only 11 qualified for final analysis. Molecules involved in orthodontic anchorage were divided into three main groups: osteoprotegerin (OPG), bisphosphonates (BPs) and other molecules (OMs). Conclusions: Different drugs are able to alter the bone remodeling cycle, influencing osteoclast function and, therefore, tooth movement. Thus, they could be used in order to provide maximal anchorage while preventing undesired movements. OPG was found the most effective molecule in blocking the action of osteoclasts, thereby reducing undesired movements. PMID:26560822

  10. The Function of Gas Vesicles in Halophilic Archaeaand Bacteria: Theories and Experimental Evidence

    Science.gov (United States)

    Oren, Aharon

    2012-01-01

    A few extremely halophilic Archaea (Halobacterium salinarum, Haloquadratum walsbyi, Haloferax mediterranei, Halorubrum vacuolatum, Halogeometricum borinquense, Haloplanus spp.) possess gas vesicles that bestow buoyancy on the cells. Gas vesicles are also produced by the anaerobic endospore-forming halophilic Bacteria Sporohalobacter lortetii and Orenia sivashensis. We have extensive information on the properties of gas vesicles in Hbt. salinarum and Hfx. mediterranei and the regulation of their formation. Different functions were suggested for gas vesicle synthesis: buoying cells towards oxygen-rich surface layers in hypersaline water bodies to prevent oxygen limitation, reaching higher light intensities for the light-driven proton pump bacteriorhodopsin, positioning the cells optimally for light absorption, light shielding, reducing the cytoplasmic volume leading to a higher surface-area-to-volume ratio (for the Archaea) and dispersal of endospores (for the anaerobic spore-forming Bacteria). Except for Hqr. walsbyi which abounds in saltern crystallizer brines, gas-vacuolate halophiles are not among the dominant life forms in hypersaline environments. There only has been little research on gas vesicles in natural communities of halophilic microorganisms, and the few existing studies failed to provide clear evidence for their possible function. This paper summarizes the current status of the different theories why gas vesicles may provide a selective advantage to some halophilic microorganisms. PMID:25371329

  11. Does Incidental Disgust Amplify Moral Judgment? A Meta-Analytic Review of Experimental Evidence.

    Science.gov (United States)

    Landy, Justin F; Goodwin, Geoffrey P

    2015-07-01

    The role of emotion in moral judgment is currently a topic of much debate in moral psychology. One specific claim made by many researchers is that irrelevant feelings of disgust can amplify the severity of moral condemnation. Numerous researchers have found this effect, but there have also been several published failures to replicate it. Clarifying this issue would inform important theoretical debates among rival accounts of moral judgment. We meta-analyzed all available studies--published and unpublished--in which incidental disgust was manipulated prior to or concurrent with a moral judgment task (k = 50). We found evidence for a small amplification effect of disgust (d = 0.11), which is strongest for gustatory/olfactory modes of disgust induction. However, there is also some suggestion of publication bias in this literature, and when this is accounted for, the effect disappears entirely (d = -0.01). Moreover, prevalent confounds mean that the effect size that we estimate is best interpreted as an upper bound on the size of the amplification effect. On the basis of the results of this meta-analysis, we argue against strong claims about the causal role of affect in moral judgment and suggest a need for new, more rigorous research on this topic. © The Author(s) 2015.

  12. Eliciting health care priorities in developing countries: experimental evidence from Guatemala.

    Science.gov (United States)

    Font, Joan Costa; Forns, Joan Rovira; Sato, Azusa

    2016-02-01

    Although some methods for eliciting preferences to assist participatory priority setting in health care in developed countries are available, the same is not true for poor communities in developing countries whose preferences are neglected in health policy making. Existing methods grounded on self-interested, monetary valuations that may be inappropriate for developing country settings where community care is provided through 'social allocation' mechanisms. This paper proposes and examines an alternative methodology for eliciting preferences for health care programmes specifically catered for rural and less literate populations but which is still applicable in urban communities. Specifically, the method simulates a realistic collective budget allocation experiment, to be implemented in both rural and urban communities in Guatemala. We report evidence revealing that participatory budget-like experiments are incentive compatible mechanisms suitable for revealing collective preferences, while simultaneously having the advantage of involving communities in health care reform processes. © The Author 2015. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine.

  13. Prediction and Experimental Evidence for Thermodynamically Stable Charged Orbital Domain Walls

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qing’an; Gray, K. E.; Wilkins, S. B.; Garcia Fernandez, M.; Rosenkranz, S.; Zheng, H.; Mitchell, J. F.

    2014-08-01

    The quest for miniaturization is prevalent in many fields of modern science and technology. The ultimate limit for conduction would be a one-dimensional (1D) chain of atoms and, for example, carbon nanotubes are a notable approximation to this ideal. Here we present strong evidence for an unexpected phenomenon—a sliding charge-density wave along pseudo-1D, atomically homogeneous orbital domain walls (ODWs) in insulating bilayer manganite crystals. At a threshold electric field, crystals exhibit abrupt transformations to higher conductance, while x-ray diffraction confirms that these are not due to heating or melting of charge order. The conductance data resemble those of well-known pseudo-1D sliding-charge-density waves, in particular the presence of a depinning voltage. The vital link is our theoretical insight that ODWs must be partially charged due to competition between orbital-induced strain and Coulomb repulsion. The ideas found here embody a new principle for creating ultra-nano conductive paths in other materials and devices.

  14. Experimental evidence of enhanced ferroelectricity in Ca doped BiFeO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Costa, L.V.; Deus, R.C. [Universidade Estadual Paulista, UNESP, Faculdade de Engenharia de Guaratinguetá, Av. Dr. Ariberto Pereira da Cunha, 333, Bairro Portal das Colinas, CEP 12516-410 Guaratinguetá, SP (Brazil); Foschini, C.R.; Longo, E. [Universidade Estadual Paulista, UNESP, Faculdade de Engenharia de Bauru, Dept. de Eng. Mecânica, Av. Eng. Luiz Edmundo C. Coube 14-01, 17033-360 Bauru, SP (Brazil); Cilense, M. [Universidade Estadual Paulista, UNESP, Instituto de Química – Laboratório Interdisciplinar em Cerâmica (LIEC), Rua Professor Francisco Degni s/n, 14800-90 Araraquara, SP (Brazil); Simões, A.Z., E-mail: alezipo@yahoo.com [Universidade Estadual Paulista, UNESP, Faculdade de Engenharia de Guaratinguetá, Av. Dr. Ariberto Pereira da Cunha, 333, Bairro Portal das Colinas, CEP 12516-410 Guaratinguetá, SP (Brazil)

    2014-04-01

    Calcium (Ca)-doped bismuth ferrite (BiFeO{sub 3}) thin films prepared by using the polymeric precursor method (PPM) were characterized by X-ray diffraction (XRD), field emission gun scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM), polarization and piezoelectric measurements. Structural studies by XRD and TEM reveal the co-existence of distorted rhombohedral and tetragonal phases in the highest doped BiFeO{sub 3} where enhanced ferroelectric and piezoelectric properties are produced by internal strain. Resistive switching is observed in BFO and Ca-doped BFO which are affected by the barrier contact and work function of multiferroic materials and Pt electrodes. A high coercive field in the hysteresis loop is observed for the BiFeO{sub 3} film. Piezoelectric properties are improved in the highest Ca-doped sample due to changes in the crystal structure of BFO for a primitive cubic perovskite lattice with four-fold symmetry and a large tetragonal distortion within the crystal domain. This observation introduces magnetoelectronics at room temperature by combining electronic conduction with electric and magnetic degrees of freedom which are already present in the multiferroic BiFeO{sub 3}. - Highlights: • Ca doped BiFeO{sub 3} thin films were obtained by the polymeric precursor method. • Co-existence of distorted rhombohedral and tetragonal phases are evident. • Enhanced ferroelectric and piezoelectric properties are produced by the internal strain in the Ca doped BiFeO{sub 3} film.

  15. Uranium mobility in non-oxidizing brines: field and experimental evidence

    International Nuclear Information System (INIS)

    Giblin, A.M.; Appleyard, E.C.

    1987-01-01

    The present distribution of U in the Wollaston Sediments in Saskatchewan can be related to the movement of brines as revealed in Na-Ca-Mg-Cl-metasomes. Experiments were conducted at 60 and 200 0 C under stringently non-oxidizing conditions using solvents ranging from distilled water to a Ca-Na-K brine formulated to simulate the major element composition of the Salton Sea geothermal brines. The experiments were conducted on natural pitchblende (UOsub(2.67)) and synthetic uraninite (UOsub(2.01)). Natural pitchblende was more strongly dissolved than the synthetic uraninite, and the synthetic Salton Sea brine was a more potent solvent than distilled water, 1:4 diluted Salton Sea brine, or pure NaCl brine. Within analytical limits of detection the dissolved U is present in the uranous (U 4+ ) state. The evidence demonstrates empirically the mechanism of dissolution of naturally occurring U minerals in reduced brines and describes a geological case where this appears to have happened. (author)

  16. Differential responses of short-term soil respiration dynamics to the experimental addition of nitrogen and water in the temperate semi-arid steppe of Inner Mongolia, China.

    Science.gov (United States)

    Qi, Yuchun; Liu, Xinchao; Dong, Yunshe; Peng, Qin; He, Yating; Sun, Liangjie; Jia, Junqiang; Cao, Congcong

    2014-04-01

    We examined the effects of simulated rainfall and increasing N supply of different levels on CO2 pulse emission from typical Inner Mongolian steppe soil using the static opaque chamber technique, respectively in a dry June and a rainy August. The treatments included NH4NO3 additions at rates of 0, 5, 10, and 20 g N/(m(2)·year) with or without water. Immediately after the experimental simulated rainfall events, the CO2 effluxes in the watering plots without N addition (WCK) increased greatly and reached the maximum value at 2 hr. However, the efflux level reverted to the background level within 48 hr. The cumulative CO2 effluxes in the soil rang ed from 5.60 to 6.49 g C/m(2) over 48 hr after a single water application, thus showing an increase of approximately 148.64% and 48.36% in the effluxes during both observation periods. By contrast, the addition of different N levels without water addition did not result in a significant change in soil respiration in the short term. Two-way ANOVA showed that the effects of the interaction between water and N addition were insignificant in short-term soil CO2 effluxes in the soil. The cumulative soil CO2 fluxes of different treatments over 48 hr accounted for approximately 5.34% to 6.91% and 2.36% to 2.93% of annual C emission in both experimental periods. These results stress the need for improving the sampling frequency after rainfall in future studies to ensure more accurate evaluation of the grassland C emission contribution. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  17. Prebiotics, probiotics, synbiotics, and the immune system: experimental data and clinical evidence.

    Science.gov (United States)

    Frei, Remo; Akdis, Mübeccel; O'Mahony, Liam

    2015-03-01

    The intestinal immune system is constantly exposed to foreign antigens, which for the most part should be tolerated. Certain probiotics, prebiotics, and synbiotics are able to influence immune responses. In this review, we highlight the recent publications (within the last 2 years) that have substantially progressed this field. The immunological mechanisms underpinning probiotics, prebiotics, and synbiotics effects continue to be better defined with novel mechanisms being described for dendritic cells, epithelial cells, T regulatory cells, effector lymphocytes, natural killer T cells, and B cells. Many of the mechanisms being described are bacterial strain or metabolite specific, and should not be extrapolated to other probiotics or prebiotics. In addition, the timing of intervention seems to be important, with potentially the greatest effects being observed early in life. In this review, we discuss the recent findings relating to probiotics, prebiotics, and synbiotics, specifically their effects on immunological functions.

  18. Experimental evidence of obesity as a risk factor for severe acute pancreatitis.

    Science.gov (United States)

    Frossard, Jean-Louis; Lescuyer, Pierre; Pastor, Catherine M

    2009-11-14

    The incidence of acute pancreatitis, an inflammation of the pancreas, is increasing worldwide. Pancreatic injury is mild in 80%-90% of patients who recover without complications. The remaining patients may develop a severe disease with local complications such as acinar cell necrosis, abscess and remote organ injury including lung injury. The early prediction of the severity of the disease is an important goal for physicians in management of patients with acute pancreatitis in order to optimize the therapy and to prevent organ dysfunction and local complications. For that purpose, multiple clinical scale scores have been applied to patients with acute pancreatitis. Recently, a new problem has emerged: the increased severity of the disease in obese patients. However, the mechanisms by which obesity increases the severity of acute pancreatitis are unclear. Several hypotheses have been suggested: (1) obese patients have an increased inflammation within the pancreas; (2) obese patients have an increased accumulation of fat within and around the pancreas where necrosis is often located; (3) increase in both peri- and intra-pancreatic fat and inflammatory cells explain the high incidence of pancreatic inflammation and necrosis in obese patients; (4) hepatic dysfunction associated with obesity might enhance the systemic inflammatory response by altering the detoxification of inflammatory mediators; and (5) ventilation/perfusion mismatch leading to hypoxia associated with a low pancreatic flow might reduce the pancreatic oxygenation and further enhance pancreatic injury. Recent experimental investigations also show an increased mortality and morbidity in obese rodents with acute pancreatitis and the implication of the adipokines leptin and adiponectin. Such models are important to investigate whether the inflammatory response of the disease is enhanced by obesity. It is exciting to speculate that manipulation of the adipokine milieu has the potential to influence the

  19. [Cardiac resynchronization therapy for heart failure - from experimental pacing to evidence-based therapy].

    Science.gov (United States)

    Götze, S; Butter, C; Fleck, E

    2006-01-01

    Within the last decade, cardiac resynchronization therapy (CRT) has become an evidence-based cornerstone for a subset of patients with chronic heart failure. For those, who suffer from ischemic or non-ischemic cardiomyopathies at NYHA III or IV, have sinus rhythm, a left bundle branch block and a left ventricular ejection fraction below 35%, CRT has evolved as an important treatment option with promising results. Numerous studies have shown that in these patients pacemaker-mediated correction of intra- and interventicular conduction disturbances can improve not only clinical symptoms, exercise tolerance and the frequency of hospitalizations, but even more important the overall mortality. These clinical results are due to several functional aspects. In the failing heart characteristic intra- and interventricular alterations in electrical conduction result in mechanical asynchrony that leads to an abnormal contraction of the left ventricle with delayed activation of the lateral wall, a paradoxical septal movement, a reduced diastolic filling and a mitral regurgitation due to dyssynchrony of papillary muscle activation. It is conceivable that these functional changes have fatal consequences for the failing heart. AV-optimized left- or biventricular stimulation by modern pacemakers can correct the pathological dyssynchrony, thereby improving cardiac function and clinical outcome in these patients. Although tremendous progress in cardiac resynchronization therapy has been made during the last decade, a couple of questions still need to be resolved. Critical issues are the identification of patients, who will predictably benefit from CRT, the value of CRT-pacemakers versus CRT-ICDs, and the usefullness of CRT in patients with atrial fibrillation.

  20. Experimental and Modeling Investigation of the Effectof H2S Addition to Methane on the Ignition and Oxidation at High Pressures

    DEFF Research Database (Denmark)

    Gersen, Sander; van Essen, Martijn; Darmeveil, Harry

    2017-01-01

    The autoignition and oxidation behavior of CH4/H2S mixtures has been studied experimentally in a rapid compression machine (RCM) and a high-pressure flow reactor. The RCM measurements show that the addition of 1% H2S to methane reduces the autoignition delay time by a factor of 2 at pressures....... A comparison of the flow reactordata to modeling predictions shows satisfactory agreement under stoichiometric conditions, while at very reducing conditions, the model underestimates the consumption of both H2S and CH4. Similar to the RCM experiments, the presence of H2S is predicted to promote oxidation...

  1. Intrapopulation variability shaping isotope discrimination and turnover: experimental evidence in arctic foxes.

    Directory of Open Access Journals (Sweden)

    Nicolas Lecomte

    Full Text Available Tissue-specific stable isotope signatures can provide insights into the trophic ecology of consumers and their roles in food webs. Two parameters are central for making valid inferences based on stable isotopes, isotopic discrimination (difference in isotopic ratio between consumer and its diet and turnover time (renewal process of molecules in a given tissue usually measured when half of the tissue composition has changed. We investigated simultaneously the effects of age, sex, and diet types on the variation of discrimination and half-life in nitrogen and carbon stable isotopes (δ¹⁵N and δ¹³C, respectively in five tissues (blood cells, plasma, muscle, liver, nail, and hair of a top predator, the arctic fox Vulpes lagopus.We fed 40 farmed foxes (equal numbers of adults and yearlings of both sexes with diet capturing the range of resources used by their wild counterparts. We found that, for a single species, six tissues, and three diet types, the range of discrimination values can be almost as large as what is known at the scale of the whole mammalian or avian class. Discrimination varied depending on sex, age, tissue, and diet types, ranging from 0.3‰ to 5.3‰ (mean  = 2.6‰ for δ¹⁵N and from 0.2‰ to 2.9‰ (mean  = 0.9‰ for δ¹³C. We also found an impact of population structure on δ¹⁵N half-life in blood cells. Varying across individuals, δ¹⁵N half-life in plasma (6 to 10 days was also shorter than for δ¹³C (14 to 22 days, though δ¹⁵N and δ¹³C half-lives are usually considered as equal.Overall, our multi-factorial experiment revealed that at least six levels of isotopic variations could co-occur in the same population. Our experimental analysis provides a framework for quantifying multiple sources of variation in isotopic discrimination and half-life that needs to be taken into account when designing and analysing ecological field studies.

  2. Experimental evidence of the statistical intermittency in a cryogenic turbulent jet of normal and superfluid Helium

    International Nuclear Information System (INIS)

    Duri, D.

    2012-01-01

    This experimental work is focused on the statistical study of the high Reynolds number turbulent velocity field in an inertially driven liquid helium axis-symmetric round jet at temperatures above and below the lambda transition (between 2.3 K and 1.78 K) in a cryogenic wind tunnel. The possibility to finely tune the fluid temperature allows us to perform a comparative study of the quantum He II turbulence within the classical framework of the Kolmogorov turbulent cascade in order to have a better understanding of the energy cascade process in a superfluid. In particular we focused our attention on the intermittency phenomena, in both He I and He II phases, by measuring the high order statistics of the longitudinal velocity increments by means of the flatness and the skewness statistical estimators. A first phase consisted in developing the cryogenic facility, a closed loop pressurized and temperature regulated wind tunnel, and adapting the classic hot-wire anemometry technique in order to be able to work in such a challenging low temperature environment. A detailed calibration procedure of the fully developed turbulent flow was the carried out at 2.3 K at Reynolds numbers based on the Taylor length scale up to 2600 in order to qualify our testing set-up and to identify possible facility-related spurious phenomena. This procedure showed that the statistical properties of the longitudinal velocity increments are in good agreement with respect to previous results. By further reducing the temperature of the working fluid (at a constant pressure) below the lambda point down to 1.78 K local velocity measurements were performed at different superfluid density fractions. The results show a classic behaviour of the He II energy cascade at large scales while, at smaller scales, a deviation has been observed. The occurrence of this phenomenon, which requires further investigation and modelling, is highlighted by the observed changing sign of the third order structure

  3. Experimental evidence for millisecond activation timescales using the Fast IN Chamber (FINCH) measurements

    Science.gov (United States)

    Bundke, U.; Jaenicke, R.; Klein, H.; Nillius, B.; Reimann, B.; Wetter, T.; Bingemer, H.

    2009-04-01

    Ice formation in clouds is a subject of great practical and fundamental importance since the occurrence of ice particle initializes dramatic changes in the microphysical structure of the cloud, which finally ends in the formation of precipitation. The initially step of ice formation is largely unknown. Homogenous nucleation of ice occurs only below -40 °C. If an ice nucleus (IN) is present, heterogeneous nucleation may occur at higher temperature. Here deposition freezing, condensation and immersion freezing as well as contact freezing are known. Also growth rates of ice particles are known as function of crystal surface properties, temperature and super saturation. Timescales for homogenous freezing activation in the order of 0.01 seconds and nucleation rates have been measured by Anderson et al. (1980) and Hagen et al., (1981) using their expansion cloud chamber. This contribution of deposition mode freezing measurements by the ice nucleus counter FINCH presents evidence that the activation timescale of this freezing mode is in the order of 1E-3 seconds. FINCH is an Ice Nucleus counter which activates IN in a supersaturated environment at freezing temperatures. The activation conditions are actively controlled by mixing three gas flows (aerosol, particle-free cold-dry and warm-humid flows).See Bundke et al. 2008 for details. In a special operation mode of FINCH we are able to produce a controlled peak super saturation in the order of 1 ms duration. For several test aerosols the results observed in this particular mode are comparable to normal mode operations, where the maximum super saturation remains for more than a second, thus leading to the conclusion that the time for activation is in the order of 1ms or less. References: R.J. Anderson et al, "A Study of Homogeneous Condensation Freezing Nucleation of Small Water Droplets in an Expansion Cloud Chamber, Journal of the Atmospheric Sciences, Vol. 37, 2508-2520, 1980 U.Bundke et al., "The fast Ice Nucleus

  4. Zingiber officinale and Type 2 Diabetes Mellitus: Evidence from Experimental Studies.

    Science.gov (United States)

    Akash, Muhammad Sajid Hamid; Rehman, Kanwal; Tariq, Muhammad; Chen, Shuqing

    2015-01-01

    Zingiber officinale is being used as diet-based therapy because of its wide therapeutic potential in type 2 diabetes mellitus (T2DM) and against diabetic complications by directly interacting with different molecular and cellular pathways that provoke the pathogenesis of T2DM. This article explores the overall beneficial effects of Z. officinale on T2DM and its associated complications. Along with elucidating the beneficial facts of Z. officinale, this article may also aid in understanding the molecular basis of its effects in T2DM. The mechanistic rationale for antidiabetic effects of Z. officinale includes the inhibition of several transcriptional pathways, lipid peroxidation, carbohydrate-metabolizing enzymes, and HMG-CoA reductase and the activation of antioxidant enzyme capacity and low-density lipoprotein receptors. Consequently, by targeting these pathways, Z. officinale shows its antidiabetic therapeutic effects by increasing insulin sensitivity/synthesis, protecting β-cells of pancreatic islets, reducing fat accumulation, decreasing oxidative stress, and increasing glucose uptake by the tissues. In addition to these effects, Z. officinale also exhibits protective effects against several diabetes-linked complications, notably nephropathy and diabetic cataract, by acting as an antioxidant and antiglycating agent. In conclusion, this work suggests that consumption of Z. officinale can help to treat T2DM and diabetic complications; nevertheless, patient counseling also is required as a guiding force for the success of diet-based therapy in T2DM.

  5. Anosognosia for apraxia: experimental evidence for defective awareness of one's own bucco-facial gestures.

    Science.gov (United States)

    Canzano, Loredana; Scandola, Michele; Pernigo, Simone; Aglioti, Salvatore Maria; Moro, Valentina

    2014-12-01

    Anosognosia is a multifaceted, neuro-psychiatric syndrome characterized by defective awareness of a variety of perceptuo-motor, cognitive or emotional deficits. The syndrome is also characterized by modularity, i.e., deficits of awareness in one domain (e.g., spatial perception) co-existing with spared functions in another domain (e.g., memory). Anosognosia has mainly been reported after right hemisphere lesions. It is however somewhat surprising that no studies have thus far specifically explored the possibility that lack of awareness involves apraxia, i.e., a deficit in the ability to perform gestures caused by an impaired higher-order motor control and not by low-level motor deficits, sensory loss, or failure to comprehend simple commands. We explored this issue by testing fifteen patients with vascular lesions who were assigned to one of three groups depending on their neuropsychological profile and brain lesion. The patients were asked to execute various actions involving the upper limb or bucco-facial body parts. In addition they were also asked to judge the accuracy of these actions, either performed by them or by other individuals. The judgment of the patients was compared to that of two external observers. Results show that our bucco-facial apraxic patients manifest a specific deficit in detecting their own gestural errors. Moreover they were less aware of their defective performance in bucco-facial as compared to limb actions. Our results hint at the existence of a new form of anosognosia specifically involving apraxic deficits. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Modeling and experimental studies on intermittent starch feeding and citrate addition in simultaneous saccharification and fermentation of starch to flavor compounds.

    Science.gov (United States)

    Chavan, Abhijit R; Raghunathan, Anuradha; Venkatesh, K V

    2009-04-01

    Simultaneous saccharification and fermentation (SSF) is a combined process of saccharification of a renewable bioresource and fermentation process to produce products, such as lactic acid and ethanol. Recently, SSF has been extensively used to convert various sources of cellulose and starch into fermentative products. Here, we present a study on production of buttery flavors, namely diacetyl and acetoin, by growing Lactobacillus rhamnosus on a starch medium containing the enzyme glucoamylase. We further develop a structured kinetics for the SSF process, which includes enzyme and growth kinetics. The model was used to simulate the effect of pH and temperature on the SSF process so as to obtain optimum operating conditions. The model was experimentally verified by conducting SSF using an initial starch concentration of 100 g/L. The study demonstrated that the developed kinetic was able to suggest strategies for improved productivities. The developed model was able to accurately predict the enhanced productivity of flavors in a three stage process with intermittent addition of starch. Experimental and simulations demonstrated that citrate addition can also lead to enhanced productivity of flavors. The developed optimal model for SSF was able to capture the dynamics of SSF in batch mode as well as in a three stage process. The structured kinetics was also able to quantify the effect of multiple substrates present in the medium. The study demonstrated that structured kinetic models can be used in the future for design and optimization of SSF as a batch or a fed-batch process.

  7. Gas transport in low-permeability formations: a review of experimental evidence and modeling approaches

    International Nuclear Information System (INIS)

    Marschall, Paul; Keller, Lukas; Lanyon, Bill; Senger, Rainer

    2012-01-01

    , fragmentation and coalescence of the non-wetting fluid. The degree of complexity increases, when two-phase flow processes occur in a deformable porous medium. Basic experimental research has been conducted by Johnsen et al. (2008) and Kong (2010) on air injections in water saturated granular material in which grain motion can take place. New insight was gained on the dynamic processes associated with the mobilisation of the solid phase. In this context, Kong distinguishes between three successive dynamic processes of coupled fluid-gas-grain flows: pore-scale tree-like invasion, finger-scale multi-channelized flow and finger-scale single channelized migration. A dimensionless quantity, the so-called grain mobilization number is defined to discriminate the different flow regimes. Modelling Approaches. The modelling concepts reported in the scientific literature for the simulation of two-phase flow processes in porous media are underlined by two different fundamental approaches: (1) discrete pore network models represent the porous medium as a network of connected channels. At a given location, a channel is occupied either by the wetting or by the non-wetting fluid. Flow in the channels occurs by piston-like displacement as a result of the pressure difference between the phases and the fluid displacement is simulated by simplified invasion percolation (IP) algorithms. Frequently, stochastic approaches are adopted to describe the geostatistical properties of the porous medium on the pore scale. Such stochastic discrete network models have been applied successfully for the simulation of two-phase flow processes in the regime of capillary fingering. The main challenge is the realistic geostatistical description of the pore network in a stochastic framework, which requires comprehensive microstructural databases for the model identification and conditioning process. (2) Equivalent porous medium models are based on the classical mixing theory of continuum mechanics of fluids. In this

  8. Saturation of compacted bentonite under repository conditions: long-term experimental evidences

    International Nuclear Information System (INIS)

    Villar, M.V.; Martin, P.L.; Gomez-Espina, R.; Garcia-Sineriz, J.L.; Barcena, I.; Lloret, A.

    2010-01-01

    bentonite columns have been running for 7 years. In one of them hydration is taking place at room isothermal conditions. The water intake is higher for the sample tested at room temperature, because the hot zones of the sample tested under thermal gradient remain desiccated for long time. In fact, both tests seem to have reached a steady state, since the relative humidity inside the bentonite barely changes, what suggests that the process that causes the water intake to be so slow, must not be solely connected to the thermal gradient. Other tests performed in smaller samples under thermal gradient did show a final full saturation for tests durations around 30-40 days and homogenisation of water contents along the blocks for longer testing periods. Some conclusions could be drawn from these experimental observations: - The rate of hydration depends on the buffer and surrounding media permeabilities, waste temperature and buffer thickness. - It is not clear if full saturation can be reached for any combination of barrier thickness, thermal gradient and material permeability. - For predicting the long-term behaviour of the barrier, the numerical models must take into account the effect on bentonite permeability of the change in its microstructure upon hydration. - When the dry density of the barrier is high, the density of the adsorbed water would be higher than 1 g/ cm 3 , and more water than expected would fit in the bentonite pores. (authors)

  9. The impact of feedback valence and communication style on intrinsic motivation in middle childhood: Experimental evidence and generalization across individual differences.

    Science.gov (United States)

    Mabbe, Elien; Soenens, Bart; De Muynck, Gert-Jan; Vansteenkiste, Maarten

    2018-06-01

    Prior research among adolescents and emerging adults has provided evidence for the beneficial effects of positive (relative to negative) feedback and an autonomy-supportive (relative to a controlling) communication style on students' intrinsic motivation. Unfortunately, similar experimental research in middle childhood is lacking. Moreover, little attention has been paid to the question of whether individual differences in personality and perceived parenting play a role in these effects. In the current experimental study (N = 110; M age  = 10.71 years), children completed puzzles at school under one of four experimental conditions, thereby crossing normative feedback valence (i.e., positive vs. negative) with communication style (i.e., autonomy supportive vs. controlling). Prior to the experiment, children filled out questionnaires tapping into the Big Five personality traits and into perceived maternal autonomy support and psychological control. After the experimental induction, children rated several motivational constructs (i.e., intrinsic motivation and need-based experiences). In addition, their voluntary behavioral persistence in a subsequent challenging puzzle task was recorded objectively. Providing positive normative feedback in an autonomy-supportive way yielded the most favorable motivational outcomes. Both feedback valence and communication style yielded an independent impact on children's experiences of competence and autonomy during task engagement, which in turn helped to explain children's elevated intrinsic motivation, as reflected by their perceived interest and behavioral persistence. A few effects were moderated by children's perceived parenting and personality traits, but the number of interactions was limited. The discussion focuses on the motivating role of positive normative feedback and an autonomy-supportive communication style for children. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. First experimental evidence for carbon starvation at warm temperatures in epiphytic orchids of tropical cloud forests

    Science.gov (United States)

    Hoch, Guenter; Roemer, Helena; Fioroni, Tiffany; Olmedo, Inayat; Kahmen, Ansgar

    2017-04-01

    Tropical cloud forests are among the most climate sensitive ecosystems world-wide. The lack of a strong seasonality and the additional dampening of temperature fluctuations by the omnipresence of clouds and fog produce year-round constant climatic conditions. With climate change the presence of clouds and fog is, however, predicted to be reduced. The disappearance of the cooling fog cover will have dramatic consequences for air temperatures, that are predicted to increase locally well over 5 °C by the end of the 21st century. Especially the large number of endemic epiphytic orchids in tropical cloud forests that contribute substantially to the biological diversity of these ecosystems, but are typically adapted to a very narrow climate envelope, are speculated to be very sensitive to the anticipated rise in temperature. In a phytotron experiment we investigated the effect of increasing temperatures on the carbon balance (gas-exchange and the carbon reserve household) of 10 epiphytic orchid species from the genera Dracula, native to tropical, South-American cloud forests. The orchids were exposed to three temperature treatments: i) a constant temperature treatment (23°C/13°C, day/night) simulating natural conditions, ii) a slow temperature ramp of +0.75 K every 10 days, and iii) a fast temperature ramp of +1.5 K every 10 days. CO2 leaf gas-exchanges was determined every 10 days, and concentrations of low molecular weight sugars and starch were analyses from leaf samples throughout the experiment. We found that increasing temperatures had only minor effects on day-time leaf respiration, but led to a moderate increase of respiration during night-time. In contrast to the rather minor effects of higher temperatures on respiration, there was a dramatic decline of net-photosynthesis above day-time temperatures of 29°C, and a complete stop of net-carbon uptake at 33°C in all investigated species. This high sensitivity of photosynthesis to warming was independent of the

  11. What role can information play in improved equity in Pakistan's irrigation system? Evidence from an experimental game in Punjab

    Directory of Open Access Journals (Sweden)

    Andrew Reid. Bell

    2015-03-01

    Full Text Available The Indus Basin Irrigation System suffers significant inequity in access to surface water across its millions of users. Information, i.e., monitoring and reporting of water availability, may be of value in improving conditions across the basin, and we investigated this via an experimental game of water distribution in Punjab, Pakistan. We found evidence that flow information allowed players to take more effective action to target overuse, and that overall activities that might bring social disapproval were reduced with information. However, we did not find any overall improvement in equity across the system, suggesting that information on its own might not be sufficient to lead to better water distribution among irrigators.

  12. Modulation of Antioxidant Enzymatic Activities by Certain Antiepileptic Drugs (Valproic Acid, Oxcarbazepine, and Topiramate): Evidence in Humans and Experimental Models

    Science.gov (United States)

    Cárdenas-Rodríguez, Noemí; Coballase-Urrutia, Elvia; Rivera-Espinosa, Liliana; Romero-Toledo, Arantxa; Sampieri, Aristides III; Ortega-Cuellar, Daniel; Montesinos-Correa, Hortencia; Floriano-Sánchez, Esaú; Carmona-Aparicio, Liliana

    2013-01-01

    It is estimated that at least 100 million people worldwide will suffer from epilepsy at some point in their lives. This neurological disorder induces brain death due to the excessive liberation of glutamate, which activates the postsynaptic N-methyl-D-aspartic acid (NMDA) receptors, which in turn cause the reuptake of intracellular calcium (excitotoxicity). This excitotoxicity elicits a series of events leading to nitric oxide synthase (NOS) activation and the generation of reactive oxygen species (ROS). Several studies in experimental models and in humans have demonstrated that certain antiepileptic drugs (AEDs) exhibit antioxidant effects by modulating the activity of various enzymes associated with this type of stress. Considering the above-mentioned data, we aimed to compile evidence elucidating how AEDs such as valproic acid (VPA), oxcarbazepine (OXC), and topiramate (TPM) modulate oxidative stress. PMID:24454986

  13. Modulation of Antioxidant Enzymatic Activities by Certain Antiepileptic Drugs (Valproic Acid, Oxcarbazepine, and Topiramate: Evidence in Humans and Experimental Models

    Directory of Open Access Journals (Sweden)

    Noemí Cárdenas-Rodríguez

    2013-01-01

    Full Text Available It is estimated that at least 100 million people worldwide will suffer from epilepsy at some point in their lives. This neurological disorder induces brain death due to the excessive liberation of glutamate, which activates the postsynaptic N-methyl-D-aspartic acid (NMDA receptors, which in turn cause the reuptake of intracellular calcium (excitotoxicity. This excitotoxicity elicits a series of events leading to nitric oxide synthase (NOS activation and the generation of reactive oxygen species (ROS. Several studies in experimental models and in humans have demonstrated that certain antiepileptic drugs (AEDs exhibit antioxidant effects by modulating the activity of various enzymes associated with this type of stress. Considering the above-mentioned data, we aimed to compile evidence elucidating how AEDs such as valproic acid (VPA, oxcarbazepine (OXC, and topiramate (TPM modulate oxidative stress.

  14. The effects of prosocial video games on prosocial behaviors: international evidence from correlational, longitudinal, and experimental studies.

    Science.gov (United States)

    Gentile, Douglas A; Anderson, Craig A; Yukawa, Shintaro; Ihori, Nobuko; Saleem, Muniba; Ming, Lim Kam; Shibuya, Akiko; Liau, Albert K; Khoo, Angeline; Bushman, Brad J; Rowell Huesmann, L; Sakamoto, Akira

    2009-06-01

    Although dozens of studies have documented a relationship between violent video games and aggressive behaviors, very little attention has been paid to potential effects of prosocial games. Theoretically, games in which game characters help and support each other in nonviolent ways should increase both short-term and long-term prosocial behaviors. We report three studies conducted in three countries with three age groups to test this hypothesis. In the correlational study, Singaporean middle-school students who played more prosocial games behaved more prosocially. In the two longitudinal samples of Japanese children and adolescents, prosocial game play predicted later increases in prosocial behavior. In the experimental study, U.S. undergraduates randomly assigned to play prosocial games behaved more prosocially toward another student. These similar results across different methodologies, ages, and cultures provide robust evidence of a prosocial game content effect, and they provide support for the General Learning Model.

  15. Experimental Evidence of Momentum Transport Induced by an Up-Down Asymmetric Magnetic Equilibrium in Toroidal Plasmas

    International Nuclear Information System (INIS)

    Camenen, Y.; Peeters, A. G.; Casson, F. J.; Hornsby, W. A.; Snodin, A. P.; Szepesi, G.; Bortolon, A.; Duval, B. P.; Federspiel, L.; Karpushov, A. N.; Piras, F.; Sauter, O.

    2010-01-01

    The first experimental evidence of parallel momentum transport generated by the up-down asymmetry of a toroidal plasma is reported. The experiments, conducted in the Tokamak a Configuration Variable, were motivated by the recent theoretical discovery of ion-scale turbulent momentum transport induced by an up-down asymmetry in the magnetic equilibrium. The toroidal rotation gradient is observed to depend on the asymmetry in the outer part of the plasma leading to a variation of the central rotation by a factor of 1.5-2. The direction of the effect and its magnitude are in agreement with theoretical predictions for the eight possible combinations of plasma asymmetry, current, and magnetic field.

  16. The Effects of Prosocial Video Games on Prosocial Behaviors: International Evidence from Correlational, Longitudinal, and Experimental Studies

    Science.gov (United States)

    Gentile, Douglas A.; Anderson, Craig A.; Yukawa, Shintaro; Ihori, Nobuko; Saleem, Muniba; Ming, Lim Kam; Shibuya, Akiko; Liau, Albert K.; Khoo, Angeline; Bushman, Brad J.; Huesmann, L. Rowell; Sakamoto, Akira

    2009-01-01

    Although dozens of studies have documented a relation between violent video games and aggressive behaviors, very little attention has been paid to potential effects of prosocial games. Theoretically, games in which game characters help and support each other in nonviolent ways should increase both short-term and long-term prosocial behaviors. We report three studies conducted in three countries with three age groups to test this hypothesis. In the correlational study, Singaporean middle-school students who played more prosocial games behaved more prosocially. In the two longitudinal samples of Japanese children and adolescents, prosocial game play predicted later increases in prosocial behavior. In the experimental study, U.S. undergraduates randomly assigned to play prosocial games behaved more prosocially toward another student. These similar results across different methodologies, ages, and cultures provide robust evidence a prosocial game content effect, and provide support for the General Learning Model. PMID:19321812

  17. The Modulation of Pain by Circadian and Sleep-Dependent Processes: A Review of the Experimental Evidence

    DEFF Research Database (Denmark)

    Hagenauer, Megan; Crodelle, Jennifer; Piltz, Sofia Helena

    2017-01-01

    conditions, pain sensitivity varies across the 24 h day, with highest sensitivity occurring during the evening in humans. Pain sensitivity is also modulated by sleep behavior, with pain sensitivity increasing in response to the build-up of homeostatic sleep pressure following sleep deprivation or sleep...... of physiologically meaningful stimulation levels. Following this normalization, we find that the estimated impact of the daily rhythm and of sleep deprivation on experimental pain measurements is surprisingly consistent across different pain modalities. We also review evidence documenting the impact of circadian...... rhythms and sleep deprivation on the neural circuitry in the spinal cord underlying pain sensation. The characterization of sleep-dependent and circadian influences on pain sensitivity in this review paper is used to develop and constrain the mathematical models introduced in the two companion articles....

  18. Experimental evidence of the spatial coherence moiré and the filtering of classes of radiator pairs.

    Science.gov (United States)

    Castaneda, Roman; Usuga-Castaneda, Mario; Herrera-Ramírez, Jorge

    2007-08-01

    Evidence of the physical existence of the spatial coherence moiré is obtained by confronting numerical results with experimental results of spatially partial interference. Although it was performed for two particular cases, the results reveal a general behavior of the optical fields in any state of spatial coherence. Moreover, the study of the spatial coherence moiré deals with a new type of filtering, named filtering of classes of radiator pairs, which allows changing the power spectrum at the observation plane by modulating the complex degree of spatial coherence, without altering the power distribution at the aperture plane or introducing conventional spatial filters. This new procedure can optimize some technological applications of actual interest, as the beam shaping for instance.

  19. Experimental evidence of structural transition at the crystal-amorphous interphase boundary between Al and Al2O3

    International Nuclear Information System (INIS)

    Yang, Z.Q.; He, L.L.; Zhao, S.J.; Ye, H.Q.

    2002-01-01

    High-resolution transmission electron microscopy observations on the structure of the interphase boundary between crystalline Al and amorphous Al 2 O 3 coating reveal that an interfacial melting transition of Al occurs at 833 K, which is distinctly lower than the bulk melting point of Al. The crystalline lattice planes of Al near the interface bend or small segments of crystalline Al deviated from the matrix Al grains are formed. Stand-off dislocations formed at the interphase boundary are also observed. The amorphous Al 2 O 3 coating plays an important role in retaining the evidence for structural transition at high temperature to room temperature, which makes it possible to make experimental observations. (author)

  20. Experimental evidence of high pressure decoupling between charge transport and structural dynamics in a protic ionic glass-former.

    Science.gov (United States)

    Wojnarowska, Z; Rams-Baron, M; Knapik-Kowalczuk, J; Połatyńska, A; Pochylski, M; Gapinski, J; Patkowski, A; Wlodarczyk, P; Paluch, M

    2017-08-01

    In this paper the relaxation dynamics of ionic glass-former acebutolol hydrochloride (ACB-HCl) is studied as a function of temperature and pressure by using dynamic light scattering and broadband dielectric spectroscopy. These unique experimental data provide the first direct evidence that the decoupling between the charge transport and structural relaxation exists in proton conductors over a wide T-P thermodynamic space, with the time scale of structural relaxation being constant at the liquid-glass transition (τ α  = 1000 s). We demonstrate that the enhanced proton transport, being a combination of intermolecular H + hopping between cation and anion as well as tautomerization process within amide moiety of ACB molecule, results in a breakdown of the Stokes-Einstein relation at ambient and elevated pressure with the fractional exponent k being pressure dependent. The dT g /dP coefficient, stretching exponent β KWW and dynamic modulus E a /ΔV # were found to be the same regardless of the relaxation processes studied. This is in contrast to the apparent activation volume parameter that is different when charge transport and structural dynamics are considered. These experimental results together with theoretical considerations create new ideas to design efficient proton conductors for potential electrochemical applications.

  1. Fission track dating of volcanic glass: experimental evidence for the validity of the Size-Correction Method

    International Nuclear Information System (INIS)

    Bernardes, C.; Hadler Neto, J.C.; Lattes, C.M.G.; Araya, A.M.O.; Bigazzi, G.; Cesar, M.F.

    1986-01-01

    Two techniques may be employed for correcting thermally lowered fission track ages on glass material: the so called 'size-correcting method' and 'Plateau method'. Several results from fission track dating on obsidian were analysed in order to compare the model rising size-correction method with experimental evidences. The results from this work can be summarized as follows: 1) The assumption that mean size of spontaneous and induced etched tracks are equal on samples unaffected by partial fading is supported by experimental results. If reactor effects such as an enhancing of the etching rate in the irradiated fraction due to the radiation damage and/or to the fact that induced fission releases a quantity of energy slightly greater than spontaneous one exist, their influence on size-correction method is very small. 2) The above two correction techniques produce concordant results. 3) Several samples from the same obsidian, affected by 'instantaneous' as well as 'continuous' natural fading to different degrees were analysed: the curve showing decreasing of spontaneous track mean-size vs. fraction of spontaneous tracks lost by fading is in close agreement with the correction curve constructed for the same obsidian by imparting artificial thermal treatements on induced tracks. By the above points one can conclude that the assumptions on which size-correction method is based are well supported, at least in first approximation. (Author) [pt

  2. The impact of product information and trials on demand for smokeless tobacco and cigarettes: evidence from experimental auctions.

    Science.gov (United States)

    Rousu, Matthew C; O'Connor, Richard J; Thrasher, James F; June, Kristie M; Bansal-Travers, Maansi; Pitcavage, James

    2014-03-01

    Epidemiological and toxicological evidence suggests lower risk of smokeless tobacco (ST) products compared to cigarettes. Less is known, however, about consumer perceptions and use of novel forms of ST, including snus and dissolvable tobacco. In this study, we conducted in-person experimental auctions in Buffalo, NY, Columbia, SC, and Selinsgrove, PA with 571 smokers to test the impact of information and product trials on smokers' preferences. Auctions were conducted between November 2010-November 2011. We found no evidence of an impact of product trials on demand in our auctions. Anti-ST information increased demand for cigarettes when presented alone, but when presented with pro-ST information it decreased demand for cigarettes. It did not decrease demand for ST products. Anti-smoking information increased demand for ST products, but did not affect cigarette demand. These findings suggest that credible and effective communications about tobacco harm reduction should reinforce the negative effects of smoking. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Cash transfers, maternal depression and emotional well-being: Quasi-experimental evidence from India's Janani Suraksha Yojana programme.

    Science.gov (United States)

    Powell-Jackson, Timothy; Pereira, Shreya K; Dutt, Varun; Tougher, Sarah; Haldar, Kaveri; Kumar, Paresh

    2016-08-01

    Maternal depression is an important public health concern. We investigated whether a national-scale initiative that provides cash transfers to women giving birth in government health facilities, the Janani Suraksha Yojana (JSY), reduced maternal depression in India's largest state, Uttar Pradesh. Using primary data on 1695 women collected in early 2015, our quasi-experimental design exploited the fact that some women did not receive the JSY cash due to administrative problems in its disbursement - reasons that are unlikely to be correlated with determinants of maternal depression. We found that receipt of the cash was associated with an 8.5% reduction in the continuous measure of maternal depression and a 36% reduction in moderate depression. There was no evidence of an association with measures of emotional well-being, namely happiness and worry. The results suggest that the JSY had a clinically meaningful effect in reducing the burden of maternal depression, possibly by lessening the financial strain of delivery care. They contribute to the evidence that financial incentive schemes may have public health benefits beyond improving uptake of targeted health services. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Nanostructured diamine-fullerene derivatives: computational density functional theory study and experimental evidence for their formation via gas-phase functionalization.

    Science.gov (United States)

    Contreras-Torres, Flavio F; Basiuk, Elena V; Basiuk, Vladimir A; Meza-Laguna, Víctor; Gromovoy, Taras Yu

    2012-02-16

    Nanostructure derivatives of fullerene C(60) are used in emerging applications of composite matrices, including protective and decorative coating, superadsorbent material, thin films, and lightweight high-strength fiber-reinforced materials, etc. In this study, quantum chemical calculations and experimental studies were performed to analyze the derivatives of diamine-fullerene prepared by the gas-phase solvent-free functionalization technique. In particular, the aliphatic 1,8-diamino-octane and the aromatic 1,5-diaminonaphthalene, which are diamines volatile in vacuum, were studied. We addressed two alternative mechanisms of the amination reaction via polyaddition and cross-linking of C(60) with diamines, using the pure GGA BLYP, PW91, and PBE functionals; further validation calculations were performed using the semiempirical dispersion GGA B97-D functional which contains parameters that have been specially adjusted by a more realistic view on dispersion contributions. In addition, we looked for experimental evidence for the covalent functionalization by using laser desorption/ionization time-of-flight mass spectrometry, thermogravimetric analysis, and atomic force microscopy.

  5. Enhancing the gene-environment interaction framework through a quasi-experimental research design: evidence from differential responses to September 11.

    Science.gov (United States)

    Fletcher, Jason M

    2014-01-01

    This article uses a gene-environment interaction framework to examine the differential responses to an objective external stressor based on genetic variation in the production of depressive symptoms. This article advances the literature by utilizing a quasi-experimental environmental exposure design, as well as a regression discontinuity design, to control for seasonal trends, which limit the potential for gene-environment correlation and allow stronger causal claims. Replications are attempted for two prominent genes (5-HTT and MAOA), and three additional genes are explored (DRD2, DRD4, and DAT1). This article provides evidence of a main effect of 9/11 on reports of feelings of sadness and fails to replicate a common finding of interaction using 5-HTT but does show support for interaction with MAOA in men. It also provides new evidence that variation in the DRD4 gene modifies an individual's response to the exposure, with individuals with no 7-repeats found to have a muted response.

  6. Hypoxyradiotherapy: lack of experimental evidence for a preferential radioprotective effect on normal versus tumor tissue as shown by direct oxygenation measurements in experimental sarcomas

    International Nuclear Information System (INIS)

    Kelleher, Debra K.; Thews, Oliver; Vaupel, Peter

    1997-01-01

    Aim: In order to investigate possible pathophysiological mechanisms underlying the postulated preferential protective effect of hypoxia on normal tissue during radiotherapy, the impact of acute respiratory hypoxia (8.2% O 2 + 91.8% N 2 ) on tissue oxygenation was assessed. Methods: Tumor and normal tissue oxygenation was directly determined using O 2 -sensitive electrodes in two experimental rat tumors (DS and Yoshida sarcomas) and in the normal subcutis of the hind foot dorsum. Results: During respiratory hypoxia, arterial blood O 2 tension (pO 2 ), oxyhemoglobin saturation and mean arterial blood pressure decreased. Changes in the arterial blood gas status were accompanied by a reflex hyperventilation leading to hypocapnia and respiratory alkalosis. In the subcutis, tissue oxygenation worsened during acute hypoxia, with decreases in the mean and median pO 2 . Significant increases in the hypoxic fractions were, however, not seen. In tumor tissues, oxygenation also worsened upon hypoxic hypoxia with significant decreases in the mean and median pO 2 and increases in the size of the hypoxic fractions for both sarcomas. Conclusion: These results suggest that during respiratory hypoxia, radiobiologically relevant reductions in the oxygenation (and a subsequent selective radioprotection) of normal tissue may not be achieved. In addition, in the tumor models studied, a worsening of tumor oxygenation was seen which could result in an increased radioresistance

  7. The influence of some additives to the highly carbohydrate diet on the distribution of Al, Ca, Mg, Mn and Na in teeth enamel and bones of experimental animals

    International Nuclear Information System (INIS)

    Bakyrdzhiev, P.

    1985-01-01

    An instrument neutron activation analysis had been used for the investigation of diets with different salt and permanent basic composition. The diets with MgCl 2 and methylene blue additives were used. Three groups of animals Wistar, Hamster and S. Dawley with different genetic reactivity had been fed on adlibidum for 45 days. After killing the animals the teeth enamel, mandibula and tibia had been sampled and content of Al, Mg, Mn, Na and Cl 2 was determined by means of INAA. The samples were irradiated for 1 min in the rabbit system of the experimental reactor IRT-2000. Two measurements were carried out - after a cooling time of 1 min for the determination of Al, Ca, Cl 2 , Mg, and after 2 h cooling time - for Na and Mn. The precision of the analysis was between 4 and 12%

  8. Complete reversal of muscle wasting in experimental cancer cachexia: Additive effects of activin type II receptor inhibition and β-2 agonist.

    Science.gov (United States)

    Toledo, Míriam; Busquets, Sílvia; Penna, Fabio; Zhou, Xiaolan; Marmonti, Enrica; Betancourt, Angelica; Massa, David; López-Soriano, Francisco J; Han, H Q; Argilés, Josep M

    2016-04-15

    Formoterol is a highly potent β2-adrenoceptor-selective agonist, which is a muscle growth promoter in many animal species. Myostatin/activin inhibition reverses skeletal muscle loss and prolongs survival of tumor-bearing animals. The aim of this investigation was to evaluate the effects of a combination of the soluble myostatin receptor ActRIIB (sActRIIB) and the β2-agonist formoterol in the cachectic Lewis lung carcinoma model. The combination of formoterol and sActRIIB was extremely effective in reversing muscle wasting associated with experimental cancer cachexia in mice. Muscle weights from tumor-bearing animals were completely recovered following treatment and this was also reflected in the measured grip strength. This combination increased food intake in both control and tumor-bearing animals. The double treatment also prolonged survival significantly without affecting the weight and growth of the primary tumor. In addition, it significantly reduced the number of metastasis. Concerning the mechanisms for the preservation of muscle mass during cachexia, the effects of formoterol and sActRIIB seemed to be additive, since formoterol reduced the rate of protein degradation (as measured in vitro as tyrosine release, using incubated isolated individual muscles) while sActRIIB only affected protein synthesis (as measured in vivo using tritiated phenylalanine). Formoterol also increased the rate of protein synthesis and this seemed to be favored by the presence of sActRIIB. Combining formoterol and sActRIIB seemed to be a very promising treatment for experimental cancer cachexia. Further studies in human patients are necessary and may lead to a highly effective treatment option for muscle wasting associated with cancer. © 2015 UICC.

  9. Experimental evidence of nitrogen control on pCO2 in phosphorus-enriched humic and clear coastal lagoon waters

    Science.gov (United States)

    Peixoto, Roberta B.; Marotta, Humberto; Enrich-Prast, Alex

    2013-01-01

    Natural and human-induced controls on carbon dioxide (CO2) in tropical waters may be very dynamic (over time and among or within ecosystems) considering the potential role of warmer temperatures intensifying metabolic responses and playing a direct role on the balance between photosynthesis and respiration. The high magnitude of biological processes at low latitudes following eutrophication by nitrogen (N) and phosphorus (P) inputs into coastal lagoons waters may be a relevant component of the carbon cycle, showing controls on partial pressure of CO2 (pCO2) that are still poorly understood. Here we assessed the strength of N control on pCO2 in P-enriched humic and clear coastal lagoons waters, using four experimental treatments in microcosms: control (no additional nutrients) and three levels of N additions coupled to P enrichments. In humic coastal lagoons waters, a persistent CO2 supersaturation was reported in controls and all nutrient-enriched treatments, ranging from 24- to 4-fold the atmospheric equilibrium value. However, both humic and clear coastal lagoons waters only showed significant decreases in pCO2 in relation to the controlled microcosms in the two treatments with higher N addition levels. Additionally, clear coastal lagoons water microcosms showed a shift from CO2 sources to CO2 sinks, in relation to the atmosphere. Only in the two more N-enriched treatments did pCO2 substantially decrease, from 650 µatm in controls and less N-enriched treatments to 10 µatm in more N-enriched microcosms. Humic substrates and N inputs can modulate pCO2 even in P-enriched coastal lagoons waters, thereby being important drivers on CO2 outgassing from inland waters. PMID:23390422

  10. Experimental evidence of nitrogen control on pCO2 in phosphorus-enriched humic and clear coastal lagoon waters

    Directory of Open Access Journals (Sweden)

    Roberta Bittencourt Peixoto

    2013-02-01

    Full Text Available Natural and human-induced controls on carbon dioxide (CO2 in tropical waters may be very dynamic (over time and among or within ecosystems considering the potential role of warmer temperatures intensifying metabolic responses and playing a direct role on the balance between photosynthesis and respiration. The high magnitude of biological processes at low latitudes following eutrophication by nitrogen (N and phosphorus (P inputs into inland waters may be a relevant component of the C cycle, showing controls on partial pressure of CO2 (pCO2 that are still poorly understood. Here we assessed the strength of N control on pCO2 in P-enriched humic and clear coastal lagoons waters, using four experimental treatments in microcosms: control (no additional nutrients and three levels of N additions coupled to P enrichments. In humic coastal lagoon waters, a persistent CO2 supersaturation was reported in controls and all nutrient-enriched treatments, ranging from 24-fold to fourfold the atmospheric equilibrium value. However, both humic and clear coastal lagoon waters only showed significant decreases in pCO2 in relation to the controlled microcosms in the two treatments with higher N addition levels. Additionally, clear coastal lagoon water microcosms showed a shift from CO2 sources to CO2 sinks, in relation to the atmosphere. Only in the two more N-enriched treatments did pCO2 substantially decrease, from 650 µatm in controls and less N-enriched treatments to 10 µatm in more N-enriched microcosms. Humic substrates and N inputs can modulate pCO2 even in P-enriched coastal lagoon waters, thereby being important drivers on CO2 outgassing from inland waters.

  11. Experimental investigation of alternative transmission functions: Quantitative evidence for the importance of nonlinear transmission dynamics in host-parasite systems.

    Science.gov (United States)

    Orlofske, Sarah A; Flaxman, Samuel M; Joseph, Maxwell B; Fenton, Andy; Melbourne, Brett A; Johnson, Pieter T J

    2018-05-01

    Understanding pathogen transmission is crucial for predicting and managing disease. Nonetheless, experimental comparisons of alternative functional forms of transmission remain rare, and those experiments that are conducted are often not designed to test the full range of possible forms. To differentiate among 10 candidate transmission functions, we used a novel experimental design in which we independently varied four factors-duration of exposure, numbers of parasites, numbers of hosts and parasite density-in laboratory infection experiments. We used interactions between amphibian hosts and trematode parasites as a model system and all candidate models incorporated parasite depletion. An additional manipulation involving anaesthesia addressed the effects of host behaviour on transmission form. Across all experiments, nonlinear transmission forms involving either a power law or a negative binomial function were the best-fitting models and consistently outperformed the linear density-dependent and density-independent functions. By testing previously published data for two other host-macroparasite systems, we also found support for the same nonlinear transmission forms. Although manipulations of parasite density are common in transmission studies, the comprehensive set of variables tested in our experiments revealed that variation in density alone was least likely to differentiate among competing transmission functions. Across host-pathogen systems, nonlinear functions may often more accurately represent transmission dynamics and thus provide more realistic predictions for infection. © 2017 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  12. Experimental evidence for the ancestry of allotetraploid Trifolium repens and creation of synthetic forms with value for plant breeding

    Directory of Open Access Journals (Sweden)

    Williams Warren M

    2012-04-01

    Full Text Available Abstract Background White clover (Trifolium repens is a ubiquitous weed of the temperate world that through use of improved cultivars has also become the most important legume of grazed pastures world-wide. It has long been suspected to be allotetraploid, but the diploid ancestral species have remained elusive. Putative diploid ancestors were indicated by DNA sequence phylogeny to be T. pallescens and T. occidentale. Here, we use further DNA evidence as well as a combination of molecular cytogenetics (FISH and GISH and experimental hybridization to test the hypothesis that white clover originated as a hybrid between T. pallescens and T. occidentale. Results T. pallescens plants were identified with chloroplast trnL intron DNA sequences identical to those of white clover. Similarly, T. occidentale plants with nuclear ITS sequences identical to white clover were also identified. Reciprocal GISH experiments, alternately using labeled genomic DNA probes from each of the putative ancestral species on the same white clover cells, showed that half of the chromosomes hybridized with each probe. F1 hybrids were generated by embryo rescue and these showed strong interspecific chromosome pairing and produced a significant frequency of unreduced gametes, indicating the likely mode of polyploidization. The F1 hybrids are inter-fertile with white clover and function as synthetic white clovers, a valuable new resource for the re-incorporation of ancestral genomes into modern white clover for future plant breeding. Conclusions Evidence from DNA sequence analyses, molecular cytogenetics, interspecific hybridization and breeding experiments supports the hypothesis that a diploid alpine species (T. pallescens hybridized with a diploid coastal species (T. occidentale to generate tetraploid T. repens. The coming together of these two narrowly adapted species (one alpine and the other maritime, along with allotetraploidy, has led to a transgressive hybrid with a

  13. Experimental evidence for the ancestry of allotetraploid Trifolium repens and creation of synthetic forms with value for plant breeding.

    Science.gov (United States)

    Williams, Warren M; Ellison, Nicholas W; Ansari, Helal A; Verry, Isabelle M; Hussain, S Wajid

    2012-04-24

    White clover (Trifolium repens) is a ubiquitous weed of the temperate world that through use of improved cultivars has also become the most important legume of grazed pastures world-wide. It has long been suspected to be allotetraploid, but the diploid ancestral species have remained elusive. Putative diploid ancestors were indicated by DNA sequence phylogeny to be T. pallescens and T. occidentale. Here, we use further DNA evidence as well as a combination of molecular cytogenetics (FISH and GISH) and experimental hybridization to test the hypothesis that white clover originated as a hybrid between T. pallescens and T. occidentale. T. pallescens plants were identified with chloroplast trnL intron DNA sequences identical to those of white clover. Similarly, T. occidentale plants with nuclear ITS sequences identical to white clover were also identified. Reciprocal GISH experiments, alternately using labeled genomic DNA probes from each of the putative ancestral species on the same white clover cells, showed that half of the chromosomes hybridized with each probe. F1 hybrids were generated by embryo rescue and these showed strong interspecific chromosome pairing and produced a significant frequency of unreduced gametes, indicating the likely mode of polyploidization. The F1 hybrids are inter-fertile with white clover and function as synthetic white clovers, a valuable new resource for the re-incorporation of ancestral genomes into modern white clover for future plant breeding. Evidence from DNA sequence analyses, molecular cytogenetics, interspecific hybridization and breeding experiments supports the hypothesis that a diploid alpine species (T. pallescens) hybridized with a diploid coastal species (T. occidentale) to generate tetraploid T. repens. The coming together of these two narrowly adapted species (one alpine and the other maritime), along with allotetraploidy, has led to a transgressive hybrid with a broad adaptive range.

  14. Reproductive interference and fecundity affect competitive interactions of sibling species with low mating barriers: experimental and theoretical evidence.

    Science.gov (United States)

    Gebiola, M; Kelly, S E; Velten, L; Zug, R; Hammerstein, P; Giorgini, M; Hunter, M S

    2017-12-01

    When allopatric species with incomplete prezygotic isolation come into secondary contact, the outcome of their interaction is not easily predicted. The parasitoid wasp Encarsia suzannae (iES), infected by Cardinium inducing cytoplasmic incompatibility (CI), and its sibling species E. gennaroi (EG), not infected by bacterial endosymbionts, may have diverged because of the complementary action of CI and asymmetric hybrid incompatibilities. Whereas postzygotic isolation is now complete because of sterility of F1 hybrid progeny, prezygotic isolation is still incipient. We set up laboratory population cage experiments to evaluate the outcome of the interaction between ES and EG in two pairwise combinations: iES vs EG and cured ES (cES, where Cardinium was removed with antibiotics) vs EG. We also built a theoretical model aimed at exploring the role of life-history differences and asymmetric mating on competitive outcomes. In three of four cages in each treatment, ES dominated the interaction. We found evidence for reproductive interference, driven by asymmetric mating preferences, that gave a competitive edge to ES, the species that better discriminated against heterospecifics. However, we did not find the fecundity cost previously shown to be associated with Cardinium infection in iES. The model largely supported the experimental results. The finding of only a slight competitive edge of ES over EG in population cages suggests that in a more heterogeneous environment the species could coexist. This is supported by evidence that the two species coexist in sympatry, where preliminary data suggest reproductive character displacement may have reinforced postzygotic isolation.

  15. Traffic jams without bottlenecks-experimental evidence for the physical mechanism of the formation of a jam

    International Nuclear Information System (INIS)

    Sugiyama, Yuki; Fukui, Minoru; Kikuchi, Macoto; Hasebe, Katsuya; Nakayama, Akihiro; Nishinari, Katsuhiro; Tadaki, Shin-ichi; Yukawa, Satoshi

    2008-01-01

    A traffic jam on a highway is a very familiar phenomenon. From the physical viewpoint, the system of vehicular flow is a non-equilibrium system of interacting particles (vehicles). The collective effect of the many-particle system induces the instability of a free flow state caused by the enhancement of fluctuations, and the transition to a jamming state occurs spontaneously if the average vehicle density exceeds a certain critical value. Thus, a bottleneck is only a trigger and not the essential origin of a traffic jam. In this paper, we present the first experimental evidence that the emergence of a traffic jam is a collective phenomenon like 'dynamical' phase transitions and pattern formation in a non-equilibrium system. We have performed an experiment on a circuit to show the emergence of a jam with no bottleneck. In the initial condition, all the vehicles are moving, homogeneously distributed on the circular road, with the same velocity. The average density of the vehicles is prepared for the onset of the instability. Even a tiny fluctuation grows larger and then the homogeneous movement cannot be maintained. Finally, a jam cluster appears and propagates backward like a solitary wave with the same speed as that of a jam cluster on a highway

  16. Traffic jams without bottlenecks-experimental evidence for the physical mechanism of the formation of a jam

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Yuki [Department of Complex Systems Science, Nagoya University, Nagoya 464-8601 (Japan); Fukui, Minoru [Nakanihon Automotive College, Sakahogi 505-0077 (Japan); Kikuchi, Macoto [Cybermedia Center, Osaka University, Toyonaka 560-0043 (Japan); Hasebe, Katsuya [Aichi University, Miyoshi 470-0296 (Japan); Nakayama, Akihiro [Faculty of Science and Technology, Meijo University, Nagoya 468-8502 (Japan); Nishinari, Katsuhiro [Department of Aeronautics and Astronautics, University of Tokyo, Bunkyo 113-8656 (Japan); Tadaki, Shin-ichi [Computer and Network Center, Saga University, Saga 840-8502 (Japan); Yukawa, Satoshi [Department of Earth and Space Science, Osaka University, Toyonaka 560-0043 (Japan)], E-mail: sugiyama@phys.cs.is.nagoya-u.ac.jp

    2008-03-15

    A traffic jam on a highway is a very familiar phenomenon. From the physical viewpoint, the system of vehicular flow is a non-equilibrium system of interacting particles (vehicles). The collective effect of the many-particle system induces the instability of a free flow state caused by the enhancement of fluctuations, and the transition to a jamming state occurs spontaneously if the average vehicle density exceeds a certain critical value. Thus, a bottleneck is only a trigger and not the essential origin of a traffic jam. In this paper, we present the first experimental evidence that the emergence of a traffic jam is a collective phenomenon like 'dynamical' phase transitions and pattern formation in a non-equilibrium system. We have performed an experiment on a circuit to show the emergence of a jam with no bottleneck. In the initial condition, all the vehicles are moving, homogeneously distributed on the circular road, with the same velocity. The average density of the vehicles is prepared for the onset of the instability. Even a tiny fluctuation grows larger and then the homogeneous movement cannot be maintained. Finally, a jam cluster appears and propagates backward like a solitary wave with the same speed as that of a jam cluster on a highway.

  17. In vivo evidence for a functional role of both tumor necrosis factor (TNF) receptors and transmembrane TNF in experimental hepatitis.

    Science.gov (United States)

    Küsters, S; Tiegs, G; Alexopoulou, L; Pasparakis, M; Douni, E; Künstle, G; Bluethmann, H; Wendel, A; Pfizenmaier, K; Kollias, G; Grell, M

    1997-11-01

    The significance of tumor necrosis factor receptor 1 (TNFR1) for TNF function in vivo is well documented, whereas the role of TNFR2 so far remains obscure. In a model of concanavalin A (Con A)-induced, CD4+ T cell-dependent experimental hepatitis in mice, in which TNF is a central mediator of apoptotic and necrotic liver damage, we now provide evidence for an essential in vivo function of TNFR2 in this pathophysiological process. We demonstrate that a cooperation of TNFR1 and TNFR2 is required for hepatotoxicity as mice deficient of either receptor were resistant against Con A. A significant role of TNFR2 for Con A-induced hepatitis is also shown by the enhanced sensitivity of transgenic mice overexpressing the human TNFR2. The ligand for cytotoxic signaling via both TNF receptors is the precursor of soluble TNF, i.e. transmembrane TNF. Indeed, transmembrane TNF is sufficient to mediate hepatic damage, as transgenic mice deficient in wild-type soluble TNF but expressing a mutated nonsecretable form of TNF developed inflammatory liver disease.

  18. Review: fetal programming of polycystic ovary syndrome by androgen excess: evidence from experimental, clinical, and genetic association studies.

    Science.gov (United States)

    Xita, Nectaria; Tsatsoulis, Agathocles

    2006-05-01

    Polycystic ovary syndrome (PCOS) is a common endocrine disorder of premenopausal women, characterized by hyperandrogenism, polycystic ovaries, and chronic anovulation along with insulin resistance and abdominal obesity as frequent metabolic traits. Although PCOS manifests clinically during adolescence, emerging data suggest that the natural history of PCOS may originate in intrauterine life. Evidence from experimental, clinical, and genetic research supporting the hypothesis for the fetal origins of PCOS has been analyzed. Female primates, exposed in utero to androgen excess, exhibit the phenotypic features of PCOS during adult life. Clinical observations also support a potential fetal origin of PCOS. Women with fetal androgen excess disorders, including congenital 21-hydroxylase deficiency and congenital adrenal virilizing tumors, develop features characteristic of PCOS during adulthood despite the normalization of androgen excess after birth. The potential mechanisms of fetal androgen excess leading to a PCOS phenotype in humans are not clearly understood. However, maternal and/or fetal hyperandrogenism can provide a plausible mechanism for fetal programing of PCOS, and this, in part, may be genetically determined. Thus, genetic association studies have indicated that common polymorphic variants of genes determining androgen activity or genes that influence the availability of androgens to target tissues are associated with PCOS and increased androgen levels. These genomic variants may provide the genetic link to prenatal androgenization in human PCOS. Prenatal androgenization of the female fetus induced by genetic and environmental factors, or the interaction of both, may program differentiating target tissues toward the development of PCOS phenotype in adult life.

  19. Effects of cement organic additives on the adsorption of uranyl ions on calcium silicate hydrate phases: experimental determination and computational molecular modelling

    International Nuclear Information System (INIS)

    Androniuk, Iuliia

    2017-01-01

    Cementitious materials are extensively used in the design and construction of radioactive waste repositories. One of the ways to enhance their performance is to introduce organic admixtures into the cement structure. However, the presence of organics in the pore water may affect the radionuclide mobility: organic molecules can form water-soluble complexes and compete for sorption sites. This work was designed to get detailed understanding of the mechanisms of such interactions on the molecular level. The model system has three components. First, pure C-S-H phases with different Ca/Si ratios were chosen as a cement model. Secondly, gluconate (a simple well-described molecule) is selected as a good starting organic additive model to probe the interaction mechanisms on the molecular scale. A more complex system involving poly-carboxylate super-plasticizer (PCE) was also tested. The third, U(VI), is a representative of the actinide radionuclide series. The development of description of the effects of organics for radioactive waste disposal applications was the primary objective of this work. The study of binary systems provides reference data for the investigation of more complex ternary (C-S-H/organic/U(VI)). The interactions are studied by means of both experimental and computational molecular modelling techniques. Data on sorption and desorption kinetics and isotherms for additives and for U(VI) on C-S-H are acquired in this work. In parallel, atomistic models are developed for the interfaces of interest. Structural, energetic, and dynamic aspects of the sorption processes on surface of cement are quantitatively modeled by molecular dynamics technique. (author)

  20. Dynamic {sup 11}C-methionine PET analysis has an additional value for differentiating malignant tumors from granulomas: an experimental study using small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Songji; Zhao, Yan [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo (Japan); Hokkaido University, Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Sapporo (Japan); Kuge, Yuji; Hatano, Toshiyuki [Hokkaido University, Central Institute of Isotope Science, Sapporo (Japan); Yi, Min; Kohanawa, Masashi [Hokkaido University, Department of Advanced Medicine, Graduate School of Medicine, Sapporo (Japan); Magota, Keiichi; Tamaki, Nagara [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo (Japan); Nishijima, Ken-ichi [Hokkaido University, Department of Molecular Imaging, Graduate School of Medicine, Sapporo (Japan)

    2011-10-15

    We evaluated whether the dynamic profile of L-{sup 11}C-methionine ({sup 11}C-MET) may have an additional value in differentiating malignant tumors from granulomas in experimental rat models by small animal positron emission tomography (PET). Rhodococcus aurantiacus and allogenic rat C6 glioma cells were inoculated, respectively, into the right and left calf muscles to generate a rat model bearing both granulomas and tumors (n = 6). Ten days after the inoculations, dynamic {sup 11}C-MET PET was performed by small animal PET up to 120 min after injection of {sup 11}C-MET. The next day, after overnight fasting, the rats were injected with {sup 18}F-2-deoxy-2-fluoro-D-glucose ({sup 18}F-FDG), and dynamic {sup 18}F-FDG PET was performed up to 180 min. The time-activity curves, static images, and mean standardized uptake value (SUV) in the lesions were calculated. {sup 11}C-MET uptake in the granuloma showed a slow exponential clearance after an initial distribution, while the uptake in the tumor gradually increased with time. The dynamic pattern of {sup 11}C-MET uptake in the granuloma was significantly different from that in the tumor (p < 0.001). In the static analysis of {sup 11}C-MET, visual assessment and SUV analysis could not differentiate the tumor from the granuloma in all cases, although the mean SUV in the granuloma (1.48 {+-} 0.09) was significantly lower than that in the tumor (1.72 {+-} 0.18, p < 0.01). The dynamic patterns, static images, and mean SUVs of {sup 18}F-FDG in the granuloma were similar to those in the tumor (p = NS). Dynamic {sup 11}C-MET PET has an additional value for differentiating malignant tumors from granulomatous lesions, which deserves further elucidation in clinical settings. (orig.)

  1. Dynamic 11C-methionine PET analysis has an additional value for differentiating malignant tumors from granulomas: an experimental study using small animal PET

    International Nuclear Information System (INIS)

    Zhao, Songji; Zhao, Yan; Kuge, Yuji; Hatano, Toshiyuki; Yi, Min; Kohanawa, Masashi; Magota, Keiichi; Tamaki, Nagara; Nishijima, Ken-ichi

    2011-01-01

    We evaluated whether the dynamic profile of L- 11 C-methionine ( 11 C-MET) may have an additional value in differentiating malignant tumors from granulomas in experimental rat models by small animal positron emission tomography (PET). Rhodococcus aurantiacus and allogenic rat C6 glioma cells were inoculated, respectively, into the right and left calf muscles to generate a rat model bearing both granulomas and tumors (n = 6). Ten days after the inoculations, dynamic 11 C-MET PET was performed by small animal PET up to 120 min after injection of 11 C-MET. The next day, after overnight fasting, the rats were injected with 18 F-2-deoxy-2-fluoro-D-glucose ( 18 F-FDG), and dynamic 18 F-FDG PET was performed up to 180 min. The time-activity curves, static images, and mean standardized uptake value (SUV) in the lesions were calculated. 11 C-MET uptake in the granuloma showed a slow exponential clearance after an initial distribution, while the uptake in the tumor gradually increased with time. The dynamic pattern of 11 C-MET uptake in the granuloma was significantly different from that in the tumor (p 11 C-MET, visual assessment and SUV analysis could not differentiate the tumor from the granuloma in all cases, although the mean SUV in the granuloma (1.48 ± 0.09) was significantly lower than that in the tumor (1.72 ± 0.18, p 18 F-FDG in the granuloma were similar to those in the tumor (p = NS). Dynamic 11 C-MET PET has an additional value for differentiating malignant tumors from granulomatous lesions, which deserves further elucidation in clinical settings. (orig.)

  2. Comparison of Thermodynamic Predictions and Experimental Observations on B Additions in Powder-Processed Ni-Based Superalloys Containing Elevated Concentrations of Nb

    Science.gov (United States)

    Antonov, Stoichko; Huo, Jiajie; Feng, Qiang; Isheim, Dieter; Seidman, David N.; Sun, Eugene; Tin, Sammy

    2018-03-01

    Boron additions to Ni-based superalloys are considered to be beneficial to the creep properties of the alloy, as boron has often been reported to increase grain boundary cohesion, increase ductility, and promote the formation of stable boride phases. Despite the importance, it is not well understood whether these improvements are associated with the presence of elemental boron or stable borides along the grain boundaries. In this investigation, two experimental powder-processed Ni-based superalloys containing elevated levels of Nb were found to exhibit increased solubility for B in the γ matrix when compared to similar commercial Ni-based superalloys. This resulted in an overall lower B concentration at grain boundaries that suppressed boride formation. As the predictive capability of CALPHAD database models for Ni-based superalloys have improved over the years, some discrepancies may still persist around compositionally heterogeneous features such as grain boundaries. Improved quantification of the characteristic partitioning of B as a function of the bulk alloy composition is required for understanding and predicting the stability of borides.

  3. Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation

    International Nuclear Information System (INIS)

    O’Brien, Daniel B.; Massari, Aaron M.

    2015-01-01

    In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N′-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report

  4. Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation.

    Science.gov (United States)

    O'Brien, Daniel B; Massari, Aaron M

    2015-01-14

    In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N'-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report.

  5. Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation

    Energy Technology Data Exchange (ETDEWEB)

    O’Brien, Daniel B.; Massari, Aaron M., E-mail: massari@umn.edu [Department of Chemistry, University of Minnesota—Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455 (United States)

    2015-01-14

    In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N′-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report.

  6. Electric transport of a single-crystal iron chalcogenide FeSe superconductor: Evidence of symmetry-breakdown nematicity and additional ultrafast Dirac cone-like carriers

    Science.gov (United States)

    Huynh, K. K.; Tanabe, Y.; Urata, T.; Oguro, H.; Heguri, S.; Watanabe, K.; Tanigaki, K.

    2014-10-01

    An SDW antiferromagnetic (SDW-AF) low-temperature phase transition is generally observed and the AF spin fluctuations are considered to play an important role for the superconductivity pairing mechanism in FeAs superconductors. However, a similar magnetic phase transition is not observed in FeSe superconductors, which has caused considerable discussion. We report on the intrinsic electronic states of FeSe as elucidated by electric transport measurements under magnetic fields using a high quality single crystal. A mobility spectrum analysis, an ab initio method that does not make assumptions on the transport parameters in a multicarrier system, provides very important and clear evidence that another hidden order, most likely the symmetry broken from the tetragonal C4 symmetry to the C2 symmetry nematicity associated with the selective d -orbital splitting, exists in the case of superconducting FeSe other than the AF magnetic order spin fluctuations. The intrinsic low-temperature phase in FeSe is in the almost compensated semimetallic states but is additionally accompanied by Dirac cone-like ultrafast electrons ˜104cm2(VS) -1 as minority carriers.

  7. Out of Africa: modern human origins special feature: additional evidence on the use of personal ornaments in the Middle Paleolithic of North Africa.

    Science.gov (United States)

    d'Errico, Francesco; Vanhaeren, Marian; Barton, Nick; Bouzouggar, Abdeljalil; Mienis, Henk; Richter, Daniel; Hublin, Jean-Jacques; McPherron, Shannon P; Lozouet, Pierre

    2009-09-22

    Recent investigations into the origins of symbolism indicate that personal ornaments in the form of perforated marine shell beads were used in the Near East, North Africa, and SubSaharan Africa at least 35 ka earlier than any personal ornaments in Europe. Together with instances of pigment use, engravings, and formal bone tools, personal ornaments are used to support an early emergence of behavioral modernity in Africa, associated with the origin of our species and significantly predating the timing for its dispersal out of Africa. Criticisms have been leveled at the low numbers of recovered shells, the lack of secure dating evidence, and the fact that documented examples were not deliberately shaped. In this paper, we report on 25 additional shell beads from four Moroccan Middle Paleolithic sites. We review their stratigraphic and chronological contexts and address the issue of these shells having been deliberately modified and used. We detail the results of comparative analyses of modern, fossil, and archaeological assemblages and microscopic examinations of the Moroccan material. We conclude that Nassarius shells were consistently used for personal ornamentation in this region at the end of the last interglacial. Absence of ornaments at Middle Paleolithic sites postdating Marine Isotope Stage 5 raises the question of the possible role of climatic changes in the disappearance of this hallmark of symbolic behavior before its reinvention 40 ka ago. Our results suggest that further inquiry is necessary into the mechanisms of cultural transmission within early Homo sapiens populations.

  8. The impact of positive affect on health cognitions and behaviours: a meta-analysis of the experimental evidence.

    Science.gov (United States)

    Cameron, David S; Bertenshaw, Emma J; Sheeran, Paschal

    2015-01-01

    Several reviews suggest that positive affect is associated with improved longevity, fewer physical symptoms, and biological indicators of good health. It is possible that positive affect could influence these outcomes by promoting healthful cognitions and behaviours. The present review identified conceptual pathways from positive affect to health cognitions and behaviour, and used random effects meta-analysis to quantify the impact of positive affect inductions (versus neutral affect conditions) on these outcomes. Literature searches located 54 independent tests that could be included in the review. Across all studies, the findings revealed no reliable effects on intentions (d+ = -.12, 95% CI = -.32 to .08, k = 15) or behaviour (d+ = .15, 95% CI = -.03 to .33, k = 23). There were four reliable effects involving specific cognitions and behaviours, but little clear evidence for generalised benefits or adverse effects of positive emotions on health-related cognitions or actions. Conclusions must be cautious given the paucity of tests available for analysis. The review offers suggestions about research designs that might profitably be deployed in future studies, and calls for additional tests of the impact of discrete positive emotions on health cognitions and behaviour.

  9. Leaching of Plastic Additives to Marine Organisms

    NARCIS (Netherlands)

    Koelmans, A.A.; Besseling, E.; Foekema, E.M.

    2014-01-01

    It is often assumed that ingestion of microplastics by aquatic species leads to increased exposure to plastic additives. However, experimental data or model based evidence is lacking. Here we assess the potential of leaching of nonylphenol (NP) and bisphenol A (BPA) in the intestinal tracts of

  10. EXPERIMENTAL EVIDENCE FOR THE FORMATION OF HIGHLY SUPERHYDROGENATED POLYCYCLIC AROMATIC HYDROCARBONS THROUGH H ATOM ADDITION AND THEIR CATALYTIC ROLE IN H2 FORMATION

    DEFF Research Database (Denmark)

    Thrower, John; Jørgensen, Bjarke; Friis, Emil Enderup

    2012-01-01

    , in agreement with recent IR measurements. Complementary density functional theory calculations confirm the stability of the observed superhydrogenated species toward spontaneous H and H2 loss indicating that abstraction reactions may be the dominant route to H2 formation involving neutral polycyclic aromatic...

  11. Experimental study of mixed additive of Ni(II) and piperazine on ammonia escape in CO2 capture using ammonia solution

    International Nuclear Information System (INIS)

    Ma, Shuangchen; Chen, Gongda; Zhu, Sijie; Wen, Jiaqi; Gao, Ran; Ma, Lan; Chai, Jin

    2016-01-01

    Highlights: • Compound additive was used to obtain high CO 2 absorption efficiency and low NH 3 escape. • Both organic material and metal ion were applied as compound additive. • Influences of additives on CO 2 absorption and NH 3 escape were investigated. • Possible mechanism and products were analyzed by XRD and UV–visible spectrophotometer. - Abstract: In order to obtain high CO 2 absorption efficiency and low ammonia escape rate, mixed additives of piperazine and Ni(II) were used as absorbent in bubbling reactor. The effects of mixed additive on CO 2 absorption efficiency and ammonia escape rate were investigated; the performances of mixed additive in removal process were compared with that of pure ammonia solution. The proposed mechanism was analyzed by XRD and UV–visible spectrophotometer. The mixed additive has well effect on CO 2 absorption efficiency and ammonia escape reduction. The CO 2 absorption efficiency was 72% when 2 wt% ammonia solution mixed with 0.025 mol/L piperazine and 0.05 mol/L Ni(II), higher than that achieved by 3 wt% ammonia solution without additive, and the amount of ammonia loss was nearly 1/3 compared with 3 wt% pure ammonia solution. This paper provided one feasible method which is beneficial to the balance between CO 2 absorption and ammonia escape in CO 2 capture process.

  12. Long-term calcium addition increases growth release, wound closure, and health of sugar maple (Acer saccharum) trees at the Hubbard Brook Experimental Forest

    Science.gov (United States)

    Brett A. Huggett; Paul G. Schaberg; Gary J. Hawley; Christopher Eager

    2007-01-01

    We surveyed and wounded forest-grown sugar maple (Acer saccharum Marsh.) trees in a long-term, replicated Ca manipulation study at the Hubbard Brook Experimental Forest in New Hampshire, USA. Plots received applications of Ca (to boost Ca availability above depleted ambient levels) or A1 (to compete with Ca uptake and further reduce Ca availability...

  13. Density functional theory calculations establish the experimental evidence of the DX center atomic structure in CdTe.

    Science.gov (United States)

    Lany, Stephan; Wolf, Herbert; Wichert, Thomas

    2004-06-04

    The In DX center and the DX-like configuration of the Cd host atom in CdTe are investigated using density functional theory. The simultaneous calculation of the atomic structure and the electric field gradient (EFG) allows one to correlate the theoretically predicted structure of the DX center with an experimental observable, namely, the EFG obtained from radioactive 111In/111Cd probe atoms in In doped CdTe. In this way, the experimental identification of the DX center structure is established.

  14. The Effect of Feedback by SMS-text messages and email on Household Electricity Consumption: Experimental Evidence

    DEFF Research Database (Denmark)

    Larsen, Anders

    2010-01-01

    This paper analyzes the effect of supplying online feedback by SMS-text messages and email about electricity consumption on the level of total household electricity consumption. An experiment was conducted in which 1,452 households were randomly allocated to three experimental groups and two...

  15. Experimental evidence for cobalt(III)-carbene radicals: key intermediates in cobalt(II)-based metalloradical cyclopropanation

    NARCIS (Netherlands)

    Lu, H.; Dzik, W.I.; Xu, X.; Wojtas, L.; de Bruin, B.; Zhang, X.P.

    2011-01-01

    New and conclusive evidence has been obtained for the existence of cobalt(III)-carbene radicals that have been previously proposed as the key intermediates in the underlying mechanism of metalloradical cyclopropanation by cobalt(II) complexes of porphyrins. In the absence of olefin substrates,

  16. Experimental evidence of a diffusion process associated with the mass asymmetry degree of freedom in heavy ion reactions

    International Nuclear Information System (INIS)

    Moretto, L.G.; Babinet, R.P.; Galin, J.; Thompson, S.G.

    1975-01-01

    Dramatic changes of fragment angular distributions over a large range of atomic numbers in the reactions induced by 14 N, 20 Ne, and 40 Ar on natural Ag targets are interpreted as evidence of a diffusion-controlled evolution of an intermediate complex along the mass asymmetry degree of freedom. (Auth.)

  17. Experimental determination of critical data of multi-component mixtures containing potential gasoline additives 2-butanol by a flow-type apparatus

    International Nuclear Information System (INIS)

    He, Maogang; Xin, Nan; Wang, Chengjie; Liu, Yang; Zhang, Ying; Liu, Xiangyang

    2016-01-01

    Graphical abstract: Experimental critical pressures of 2-butanol + hexane + heptane system. - Highlights: • Critical properties of six binary systems and two ternary systems were measured. • Six binary systems containing 2-butanol show non-ideal behavior in their T c –x 1 curves. • Non-ideal behavior of mixtures with 2-butanol relies on azeotropy. • Experimental data for binary systems were fitted well with Redlich–Kister equation. • Critical surfaces of ternary systems were plotted using the Cibulka’s expressions. - Abstract: In this work, we used a flow method for measurement of critical properties of six binary mixtures (2-butanol + cyclohexane, 2-butanol + hexane, 2-butanol + heptane, 2-butanol + octane, 2-butanol + nonane and 2-butanol + decane) and two ternary mixtures (2-butanol + hexane + heptane and 2-butanol + octane + decane). The critical properties were determined by observing the disappearance and reappearance of the gas–liquid phase meniscus in a quartz glass tube. The standard uncertainties of temperatures and pressures for both binary and ternary mixtures were estimated to be less than 0.2 K and 5.2 kPa, respectively. These critical data provide the boundaries of the two-phase regions of the related mixture systems. Six binary systems show non-ideal behaviors in the loci of critical temperatures. We used the Redlich–Kister equations to correlate the critical temperatures and pressures of these systems and listed the binary interaction parameters. The maximum average absolute deviation (AAD) of each binary system between experimental data and calculated results from Redlich–Kister equations is 0.038% for critical temperatures, and 0.244% for critical pressures. Moreover, the two ternary systems were newly reported and correlated by Cibulka’s and Singh’s expressions. The maximum AAD of critical temperatures and critical pressures are 0.103% and 0.433%, respectively.

  18. Increased risk of schizophrenia from additive interaction between infant motor developmental delay and obstetric complications: evidence from a population-based longitudinal study.

    LENUS (Irish Health Repository)

    Clarke, Mary C

    2011-12-01

    Obstetric complications and developmental delay are well-established risk factors for schizophrenia. The authors investigated whether these risk factors interact in an additive manner to further increase risk for schizophrenia.

  19. Test the principle of maximum entropy in constant sum 2×2 game: Evidence in experimental economics

    International Nuclear Information System (INIS)

    Xu, Bin; Zhang, Hongen; Wang, Zhijian; Zhang, Jianbo

    2012-01-01

    By using laboratory experimental data, we test the uncertainty of strategy type in various competing environments with two-person constant sum 2×2 game in the social system. It firstly shows that, in these competing game environments, the outcome of human's decision-making obeys the principle of the maximum entropy. -- Highlights: ► Test the uncertainty in two-person constant sum games with experimental data. ► On game level, the constant sum game fits the principle of maximum entropy. ► On group level, all empirical entropy values are close to theoretical maxima. ► The results can be different for the games that are not constant sum game.

  20. Test the principle of maximum entropy in constant sum 2×2 game: Evidence in experimental economics

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Bin, E-mail: xubin211@zju.edu.cn [Experimental Social Science Laboratory, Zhejiang University, Hangzhou, 310058 (China); Public Administration College, Zhejiang Gongshang University, Hangzhou, 310018 (China); Zhang, Hongen, E-mail: hongen777@163.com [Department of Physics, Zhejiang University, Hangzhou, 310027 (China); Wang, Zhijian, E-mail: wangzj@zju.edu.cn [Experimental Social Science Laboratory, Zhejiang University, Hangzhou, 310058 (China); Zhang, Jianbo, E-mail: jbzhang08@zju.edu.cn [Department of Physics, Zhejiang University, Hangzhou, 310027 (China)

    2012-03-19

    By using laboratory experimental data, we test the uncertainty of strategy type in various competing environments with two-person constant sum 2×2 game in the social system. It firstly shows that, in these competing game environments, the outcome of human's decision-making obeys the principle of the maximum entropy. -- Highlights: ► Test the uncertainty in two-person constant sum games with experimental data. ► On game level, the constant sum game fits the principle of maximum entropy. ► On group level, all empirical entropy values are close to theoretical maxima. ► The results can be different for the games that are not constant sum game.

  1. Experimental article – Reducing effective dose to a paediatric phantom by using different combinations of kVp, mAs and additional filtration whilst maintaining image quality

    NARCIS (Netherlands)

    Huizinga, Elsbeth; Schaake, Wouter; Visser, Ruurd; Bloomfield, Charlotte; Boavida, Filipa; Chabloz, Diane; Crausaz, Emilie; Hustveit, Hanne; Knight, Heidi; Pereira, Anna; Harsaker, Vanja

    2015-01-01

    Purpose: To determine whether using different combinations of kVp and mAs with additional filtration can reduce the effective dose to a paediatric phantom whilst maintaining diagnostic image quality. Methods: 27 images of a paediatric AP pelvis phantom were acquired with different kVp, mAs and

  2. Experimental article – Reducing effective dose to a paediatric phantom by using different combinations of kVp, mAs and additional filtration whilst maintaining image quality

    NARCIS (Netherlands)

    Elsbeth Huizinga; Ana Pereira; Wouter Schaake; Charlotte Bloomfield; Heidi Knight; Emilie Crausaz; Hanne Hustveit; Ruurd Visser; Vanja Harsaker; Diane Chabloz; Filipa Boavida

    2015-01-01

    Purpose: To determine whether using different combinations of kVp and mAs with additional filtration can reduce the effective dose to a paediatric phantom whilst maintaining diagnostic image quality. Methods: 27 images of a paediatric AP pelvis phantom were acquired with different kVp, mAs

  3. Calcium addition at the Hubbard Brook Experimental Forest increases the capacity for stress tolerance and carbon capture in red spruce (Picea rubens) trees during the cold season

    Science.gov (United States)

    Paul G. Schaberg; Rakesh Minocha; Stephanie Long; Joshua M. Halman; Gary J. Hawley; Christopher. Eagar

    2011-01-01

    Red spruce (Picea rubens Sarg.) trees are uniquely vulnerable to foliar freezing injury during the cold season (fall and winter), but are also capable of photosynthetic activity if temperatures moderate. To evaluate the influence of calcium (Ca) addition on the physiology of red spruce during the cold season, we measured concentrations of foliar...

  4. Experimental evidence of the dependence of spin tunnelling on the concentration of dislocations in Mn12 crystals

    OpenAIRE

    Torres, F.; Hernandez, J. M.; Molins, E.; Garcia-Santiago, A.; Tejada, J.

    2001-01-01

    We present experimental results on resonant spin tunnelling in a single crystal of Mn$_{12}$-2Cl benzoate with different concentration of dislocations. The time evolution of the magnetisation follows the stretched exponential over a few time decades. The values of parameters of stretched exponential deduced from experiment have been used to determine the concentration of dislocations before and after the cooling-annealing process, using the algorithm recently suggested by Garanin and Chudnovsky.

  5. Experimental evidence of E × B plasma rotation in a 2.45 GHz hydrogen discharge

    Energy Technology Data Exchange (ETDEWEB)

    Cortázar, O. D., E-mail: daniel.cortazar@uclm.es [Institute for Energy Research-INEI, University of Castilla-La Mancha, C.J. Cela s/n, 13170 Ciudad Real (Spain); Megía-Macías, A. [CERN, BE-ABP-HSL Department, CH1211 Geneva (Switzerland); E.S.S. Bilbao, Polígono Ugaldeguren III, A-7B, 48170 Zamudio (Spain); Tarvainen, O.; Koivisto, H. [Department of Physics, Accelerator Laboratory, University of Jyväskylä, PO Box 35 (YFL), 40500 Jyväskylä (Finland)

    2015-12-15

    An experimental observation of a rotating plasma structure in a 2.45 GHz microwave-driven hydrogen discharge is reported. The rotation is presumably produced by E × B drift. The formation of the rotating plasma structure is sensitive to the strength of the off-resonance static magnetic field. The rotation frequency is on the order of 10 kHz and is affected by the neutral gas pressure and applied microwave power.

  6. Experimental evidence of E × B plasma rotation in a 2.45 GHz hydrogen discharge

    International Nuclear Information System (INIS)

    Cortázar, O. D.; Megía-Macías, A.; Tarvainen, O.; Koivisto, H.

    2015-01-01

    An experimental observation of a rotating plasma structure in a 2.45 GHz microwave-driven hydrogen discharge is reported. The rotation is presumably produced by E × B drift. The formation of the rotating plasma structure is sensitive to the strength of the off-resonance static magnetic field. The rotation frequency is on the order of 10 kHz and is affected by the neutral gas pressure and applied microwave power

  7. Favorable results from the use of herbal and plant products in inflammatory bowel disease: evidence from experimental animal studies

    Science.gov (United States)

    Triantafillidis, John K.; Triantafyllidi, Aikaterini; Vagianos, Constantinos; Papalois, Apostolos

    2016-01-01

    The use of herbal therapy for inflammatory bowel disease is increasing worldwide. The aim of this study was to review the available literature on the efficacy of herbal therapy in experimental colitis. All relevant studies published in Medline and Embase up to June 2015 have been reviewed. The results of bowel histology and serum parameters have been recorded. A satisfactory number of published experimental studies, and a quite large one of both herbal and plant products tested in different studies have been reported. The results showed that in the majority of the studies, herbal therapy reduced the inflammatory activity of experimental colitis and diminished the levels of many inflammatory indices, including serum cytokines and indices of oxidative stress. The most promising plant and herbal products were tormentil extracts, wormwoodherb, Aloe vera, germinated barley foodstuff, curcumin, Boswellia serrata, Panax notoginseng, Ixeris dentata, green tea, Cordia dichotoma, Plantago lanceolata, Iridoidglycosides, and mastic gum. Herbal therapies exert their therapeutic benefit via various mechanisms, including immune regulation, anti-oxidant activity, inhibition of leukotriene B4 and nuclear factor-κB, and antiplatelet activity. Large, double-blind clinical studies assessing these natural substances should be urgently conducted. PMID:27366027

  8. Evidence for side-chain π-delocalization in a planar substituted benzene: an experimental and theoretical charge density study on 2,5-dimethoxybenzaldehyde thiosemicarbazone.

    Science.gov (United States)

    Farrugia, Louis J; Khalaji, Aliakbar Dehno

    2011-11-17

    The charge density in 2,5-dimethoxybenzaldehyde thiosemicarbazone (1) has been studied experimentally using Mo-K(α) X-ray diffraction at 100 K, and by theory using DFT calculations at the B3LYP/6-311++G(2d,2p) level. The quantum theory of atoms in molecules (QTAIM) was used to investigate the extent of π-delocalization in the thioamide side-chain, which is virtually coplanar with the benzene ring. The experimental and theoretical ellipticity profiles along the bond paths were in excellent agreement, and showed that some of the formal single bonds in the side-chain have significant π-bond character. This view was supported by the magnitudes of the topological bond orders and by the delocalization indices δ(Ω(A), Ω(B)). An orbital decomposition of δ(Ω(A), Ω(B)) demonstrated that there was significant π-character in all the interchain non-H chemical bonds. On the other hand, the source function referenced at the interchain bond critical points could not provide any evidence for π-delocalization, showing instead only limited σ-delocalization between nearest neighbors. Overall, the topological evidence and the atomic graphs of the oxygen atoms did not provide convincing evidence for π-delocalization involving the methoxy substituents.

  9. Experimental study on heat transfer with condensation of vapors of pure nitrogen tetroxide with nitrogen oxide additions on a bundle of horizontal tubes

    International Nuclear Information System (INIS)

    Batishcheva, T.M.; Derov, B.T.; Kolykhan, L.I.; Pulyaev, V.F.

    1977-01-01

    The results of an experimental investigation of heat transfer during condensation of pure N 2 O 4 vapours and with NO admixtures on the outside surface of a bundle of horizontal tubes are considered. The tests with pure N 2 O 4 have been performed at pressures between 0.3-1.0 MPa in the range of thermal loads 22-121 kW/m 2 , temperature heads of 5-33 grades with complete condensation and evaporation. The content of admixtures boiling at high temperatures do not exceed 0.8%. A concentration of noncondensing nitrogen oxide in a gas phase have changed in the range of 3-27%. It is shown, that a concentration of noncondensible NO doesn't result in a considerable decrease of the heat transfer intensity as well as in the case of condensation of vapour-liquid mixtures. The generalized criterion relations are presented

  10. Tropical Andean Forests Are Highly Susceptible to Nutrient Inputs—Rapid Effects of Experimental N and P Addition to an Ecuadorian Montane Forest

    Science.gov (United States)

    Homeier, Jürgen; Hertel, Dietrich; Camenzind, Tessa; Cumbicus, Nixon L.; Maraun, Mark; Martinson, Guntars O.; Poma, L. Nohemy; Rillig, Matthias C.; Sandmann, Dorothee; Scheu, Stefan; Veldkamp, Edzo; Wilcke, Wolfgang; Wullaert, Hans; Leuschner, Christoph

    2012-01-01

    Tropical regions are facing increasing atmospheric inputs of nutrients, which will have unknown consequences for the structure and functioning of these systems. Here, we show that Neotropical montane rainforests respond rapidly to moderate additions of N (50 kg ha−1 yr−1) and P (10 kg ha−1 yr−1). Monitoring of nutrient fluxes demonstrated that the majority of added nutrients remained in the system, in either soil or vegetation. N and P additions led to not only an increase in foliar N and P concentrations, but also altered soil microbial biomass, standing fine root biomass, stem growth, and litterfall. The different effects suggest that trees are primarily limited by P, whereas some processes—notably aboveground productivity—are limited by both N and P. Highly variable and partly contrasting responses of different tree species suggest marked changes in species composition and diversity of these forests by nutrient inputs in the long term. The unexpectedly fast response of the ecosystem to moderate nutrient additions suggests high vulnerability of tropical montane forests to the expected increase in nutrient inputs. PMID:23071734

  11. Right-handed and left-handed neutrinos and the two galactic populations of the universe. Additional evidence for the neutrino mass

    International Nuclear Information System (INIS)

    Fargion, D.

    1981-01-01

    There is astrophysical evidence in favour of the right-handed and left-handed nature of the neutrinos: the existence of our recent galactic population could be associated with a recent clustering of cosmological left-handed neutrinos, while a primordial galactic population could be created by a corresponding clustering of a cosmological right-handed neutrinos. This latter galactic population could be associated with an anomalous excess in the radiosource counts at a large red-shift which is consistent with the range of red-shifts predicted by our estimate, based on presently known elementary-particle physics and thermodynamics. (author)

  12. Speed-resolution advantage of turbulent supercritical fluid chromatography in open tubular columns: II - Theoretical and experimental evidences.

    Science.gov (United States)

    Gritti, Fabrice; Fogwill, Michael

    2017-06-09

    The potential advantage of turbulent supercritical fluid chromatography (TSFC) in open tubular columns (OTC) was evaluated on both theoretical and practical viewpoints. First, the dispersion model derived by Golay in 1958 and recently extended from laminar to turbulent flow regime is used for the predictions of the speed-resolution performance in TSFC. The average dispersion coefficient of matter in the turbulent flow regime was taken from the available experimental data over a range of Reynolds number from 2000 to 6000. Kinetic plots are built at constant pressure drop (ΔP=4500psi) and Schmidt number (Sc=15) for four inner diameters (10, 30, 100, and 300μm) of the OTC and for three retention factors (0, 1, and 10). Accordingly, in turbulent flow regime, for a Reynolds number of 4000 and a retention factor of 1 (the stationary film thickness is assumed to be negligible with respect to the OTC diameter), the theory projects that a 300μm i.d. OTC has the same speed-resolution power (200,000 theoretical plates; 2.4min hold-up time) as that of a 10μm i.d. OTC operated in laminar flow regime. Secondly, the experimental plate heights of n-butylbenzene are measured in laminar and turbulent flow regimes for a 180μm×4.8m fused silica capillary column using pure carbon dioxide as the mobile phase. The back pressure regulator was set at 1500psi, the temperature was uniform at 297K, and the flow rate was increased step-wise from 0.50 to 3.60mL/min so that the experimental Reynolds number increases from 700 to 5400. The experiments are in good agreement with the plate heights projected in TSFC at high flow rates and with those expected at low flow rates in a laminar flow regime. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Experimental evidence; satisfying the Einstein-Podolsky-Rosen criterion for physical reality, for Einstein's Einweg point of view

    International Nuclear Information System (INIS)

    Umakantha, N.

    2009-01-01

    A real Young's double-slit experiment which can, without destroying the fringe pattern, establish unequivocally whether a photon passes like a wave along both the paths or passes like a particle along one or the other path only, is presented. The main feature of this experiment is that the point at which the incident wave is to be regarded as being split into two parts to go along the two paths is distinct from the point at which successive incident particles are to be regarded as having random choice to go along one or the other path. Our experimental results support Einstein's Einweg (one-path) point of view.

  14. Are happier people less judgmental of other people's selfish behaviors? Experimental survey evidence from trust and gift exchange games.

    Science.gov (United States)

    Drouvelis, Michalis; Powdthavee, Nattavudh

    2015-10-01

    What determines people's moral judgments of selfish behaviors? Here we study whether people's normative views in trust and gift exchange games, which underlie many situations of economic and social significance, are themselves functions of positive emotions. We use experimental survey methods to investigate the moral judgments of impartial observers empirically, and explore whether we could influence subsequent judgments by deliberately making some individuals happier. We find that moral judgments of selfish behaviors in the economic context depend strongly on the behavior of the interaction partner of the judged person, but their relationships are significantly moderated by an increase in happiness for the person making the judgment.

  15. Accumulation and transport of microbial-size particles in a pressure protected model burn unit: CFD simulations and experimental evidence

    Directory of Open Access Journals (Sweden)

    Mimoun Maurice

    2011-03-01

    Full Text Available Abstract Background Controlling airborne contamination is of major importance in burn units because of the high susceptibility of burned patients to infections and the unique environmental conditions that can accentuate the infection risk. In particular the required elevated temperatures in the patient room can create thermal convection flows which can transport airborne contaminates throughout the unit. In order to estimate this risk and optimize the design of an intensive care room intended to host severely burned patients, we have relied on a computational fluid dynamic methodology (CFD. Methods The study was carried out in 4 steps: i patient room design, ii CFD simulations of patient room design to model air flows throughout the patient room, adjacent anterooms and the corridor, iii construction of a prototype room and subsequent experimental studies to characterize its performance iv qualitative comparison of the tendencies between CFD prediction and experimental results. The Electricité De France (EDF open-source software Code_Saturne® (http://www.code-saturne.org was used and CFD simulations were conducted with an hexahedral mesh containing about 300 000 computational cells. The computational domain included the treatment room and two anterooms including equipment, staff and patient. Experiments with inert aerosol particles followed by time-resolved particle counting were conducted in the prototype room for comparison with the CFD observations. Results We found that thermal convection can create contaminated zones near the ceiling of the room, which can subsequently lead to contaminate transfer in adjacent rooms. Experimental confirmation of these phenomena agreed well with CFD predictions and showed that particles greater than one micron (i.e. bacterial or fungal spore sizes can be influenced by these thermally induced flows. When the temperature difference between rooms was 7°C, a significant contamination transfer was observed to

  16. Experimental evidence for an associated defect model for the neutron generated As/sub Ga/ center in gallium arsenide

    International Nuclear Information System (INIS)

    Golzene, A.; Meyer, B.; Schwab, C.

    1984-01-01

    The thermal dependence of EPR spectra of fast neutron irradiated n-type GaAs over the whole 4.2 to 300 K temperature range has been studied using the decomposition of spectra into a quadruplet of four identical Gaussian lines and a Lorentzian singlet. Quadruplet and singlet spectra as well as their proper parameters (inverse of paramagnetic susceptibility, hyperfine constants) could be determined separately. Experiments give evidence that the neutron generated anionic antisites As/sub Ga/ in GaAs are constituting associated defect centers, most likely of intrinsic nature

  17. Experimental evidence of significant temperature fluctuations in the plasma EDGE region of the TJ-I Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Hidalgo, C; Balbin, R; Pedrosa, M A; Garcia-Cortes, I; Ochando, M A

    1993-07-01

    Density and temperature fluctuations have been measured in the plasma bulk side of the velocity shear location of the TJ-I tokamak using a feast swept Langmuir probe technique. Evidence of substantial temperature fluctuations which are in phase close to opposition with the corresponding density fluctuations has been found. This result suggests the possible role of radiation in determining edge fluctuation levels and call into question the determination of the density and potential fluctuations from the Langmuir current-probe and floating potential fluctuations. (Author) 16 refs.

  18. Experimental evidence of significant temperature fluctuations in the plasma edge region of the TJ-I Tokamak

    International Nuclear Information System (INIS)

    Hidalgo, C.; Balbin, R.; Pedrosa, M.A.; Garcia-Cortes, I.; Ochando, M.A.

    1993-01-01

    Density and temperature fluctuations have been measured in the plasma bulk side of the velocity shear location of the TJ-I tokamak using a foast swept Langmuir probe technique. Evidence of sustantial temperature fluctuations which are in phase close to opposition with the corresponding density fluctuations has been found. This result suggests the possible role of radiation in determining edge fluctuation levels and call into question the determination of the density and potential fluctuations from the Langmuir current-probe and floating potential fluctuations. (Author)

  19. Experimental evidence of significant temperature fluctuations in the plasma EDGE region of the TJ-I Tokamak

    International Nuclear Information System (INIS)

    Hidalgo, C.; Balbin, R.; Pedrosa, M. A.; Garcia-Cortes, I.; Ochando, M. A.

    1993-01-01

    Density and temperature fluctuations have been measured in the plasma bulk side of the velocity shear location of the TJ-I tokamak using a feast swept Langmuir probe technique. Evidence of substantial temperature fluctuations which are in phase close to opposition with the corresponding density fluctuations has been found. This result suggests the possible role of radiation in determining edge fluctuation levels and call into question the determination of the density and potential fluctuations from the Langmuir current-probe and floating potential fluctuations. (Author) 16 refs

  20. Experimental evidence for a light and broad scalar resonance in D+ → π-π+π+ decay

    International Nuclear Information System (INIS)

    Aitala, E.M.; Amato, S.; Anjos, J.C.

    2000-11-01

    From a sample of 1172±61 D + → π -π+ π + decays, we find Γ(D + → π - π + π + )/Γ(D + → K - π + π + ) 0.0311 ± 0.0018 -0.0026 +0.0016 . Using a coherent amplitude analysis to fit the Dalitz plot of these decays, we find strong evidence that a scalar resonance of mass 478 -23 +24 ± 17 MeV/c 2 and width 324 -40 +42 ± 21 MeV/c 2 accounts for approximately half of all decays. (author)

  1. The 12q14 microdeletion syndrome: additional patients and further evidence that HMGA2 is an important genetic determinant for human height.

    NARCIS (Netherlands)

    Buysse, K.; Reardon, W.; Mehta, L.; Costa, T.; Fagerstrom, C.; Kingsbury, D.J.; Anadiotis, G.; McGillivray, B.C.; Hellemans, J.; Leeuw, N. de; Vries, L.B.A. de; Speleman, F.; Menten, B.; Mortier, G.

    2009-01-01

    Characteristic features of the 12q14 microdeletion syndrome include low birth weight, failure to thrive, short stature, learning disabilities and Buschke-Ollendorff lesions in bone and skin. This report on two additional patients with this microdeletion syndrome emphasizes the rather constant and

  2. Single case design studies in music therapy: resurrecting experimental evidence in small group and individual music therapy clinical settings.

    Science.gov (United States)

    Geist, Kamile; Hitchcock, John H

    2014-01-01

    The profession would benefit from greater and routine generation of causal evidence pertaining to the impact of music therapy interventions on client outcomes. One way to meet this goal is to revisit the use of Single Case Designs (SCDs) in clinical practice and research endeavors in music therapy. Given the appropriate setting and goals, this design can be accomplished with small sample sizes and it is often appropriate for studying music therapy interventions. In this article, we promote and discuss implementation of SCD studies in music therapy settings, review the meaning of internal study validity and by extension the notion of causality, and describe two of the most commonly used SCDs to demonstrate how they can help generate causal evidence to inform the field. In closing, we describe the need for replication and future meta-analysis of SCD studies completed in music therapy settings. SCD studies are both feasible and appropriate for use in music therapy clinical practice settings, particularly for testing effectiveness of interventions for individuals or small groups. © the American Music Therapy Association 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Peroxisome Proliferator-Activated Receptors as Mediators of Phthalate-Induced Effects in the Male and Female Reproductive Tract: Epidemiological and Experimental Evidence

    Directory of Open Access Journals (Sweden)

    Giuseppe Latini

    2008-01-01

    Full Text Available There is growing evidence that male as well as female reproductive function has been declining in human and wildlife populations over the last 40 years. Several factors such as lifestyle or environmental xenobiotics other than genetic factors may play a role in determining adverse effects on reproductive health. Among the environmental xenobiotics phthalates, a family of man-made pollutants are suspected to interfere with the function of the endocrine system and therefore to be endocrine disruptors. The definition of endocrine disruption is today extended to broader endocrine regulations, and includes activation of metabolic sensors, such as the peroxisome proliferator-activated receptors (PPARs. Toxicological studies have shown that phthalates can activate a subset of PPARs. Here, we analyze the epidemiological and experimental evidence linking phthalate exposure to both PPAR activation and adverse effects on male and female reproductive health.

  4. Honest sexual signaling in turtles: experimental evidence of a trade-off between immune response and coloration in red-eared sliders Trachemys scripta elegans.

    Science.gov (United States)

    Ibáñez, Alejandro; Polo-Cavia, Nuria; López, Pilar; Martín, José

    2014-10-01

    Sexual signals can be evolutionarily stable if they are honest and condition dependent or costly to the signaler. One possible cost is the existence of a trade-off between maintaining the immune system and the elaboration of ornaments. This hypothesis has been experimentally tested in some groups of animals but not in others such as turtles. We experimentally challenged the immune system of female red-eared sliders Trachemys scripta elegans, with a bacterial antigen (lipopolysaccharide (LPS)) without pathogenic effects to explore whether the immune activation affected visual colorful ornaments of the head. The LPS injection altered the reflectance patterns of color ornaments. In comparison to the control animals, the yellow chin stripes of injected animals exhibited (1) reduced brightness, (2) lower long wavelength (>470 nm) reflectance, and (3) lower values for carotenoid chroma. The postorbital patches of injected individuals also showed reduced very long wavelength (>570 nm) reflectance but did not change in carotenoid chroma. Thus, experimental turtles showed darker and less "yellowish" chin stripes and less "reddish" postorbital patches at the end of the experiment, whereas control turtles did not change their coloration. This is the first experimental evidence supporting the existence of a trade-off between the immune system and the expression of visual ornaments in turtles. We suggest that this trade-off may allow turtles to honestly signal individual quality via characteristics of coloration, which may have an important role in intersexual selection processes.

  5. Honest sexual signaling in turtles: experimental evidence of a trade-off between immune response and coloration in red-eared sliders Trachemys scripta elegans

    Science.gov (United States)

    Ibáñez, Alejandro; Polo-Cavia, Nuria; López, Pilar; Martín, José

    2014-10-01

    Sexual signals can be evolutionarily stable if they are honest and condition dependent or costly to the signaler. One possible cost is the existence of a trade-off between maintaining the immune system and the elaboration of ornaments. This hypothesis has been experimentally tested in some groups of animals but not in others such as turtles. We experimentally challenged the immune system of female red-eared sliders Trachemys scripta elegans, with a bacterial antigen (lipopolysaccharide (LPS)) without pathogenic effects to explore whether the immune activation affected visual colorful ornaments of the head. The LPS injection altered the reflectance patterns of color ornaments. In comparison to the control animals, the yellow chin stripes of injected animals exhibited (1) reduced brightness, (2) lower long wavelength (>470 nm) reflectance, and (3) lower values for carotenoid chroma. The postorbital patches of injected individuals also showed reduced very long wavelength (>570 nm) reflectance but did not change in carotenoid chroma. Thus, experimental turtles showed darker and less "yellowish" chin stripes and less "reddish" postorbital patches at the end of the experiment, whereas control turtles did not change their coloration. This is the first experimental evidence supporting the existence of a trade-off between the immune system and the expression of visual ornaments in turtles. We suggest that this trade-off may allow turtles to honestly signal individual quality via characteristics of coloration, which may have an important role in intersexual selection processes.

  6. Pre- and post-experimental manipulation assessments confirm the increase in number of birds due to the addition of nest boxes

    Directory of Open Access Journals (Sweden)

    Cecilia Cuatianquiz Lima

    2016-03-01

    Full Text Available Secondary cavity nesting (SCN birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of SCNs in two temperate forest types, and evaluated the change in number of SCNs after adding nest boxes. First, we counted all cavities within each of our 25-m radius sampling points in mature and young forest plots during 2009. We then added nest boxes at standardised locations during 2010 and 2011 and conducted fortnightly bird counts (January–October 2009–2011. In 2011 we added two extra plots of each forest type, where we also conducted bird counts. Prior to adding nest boxes, counts revealed more SCNs in mature than in young forest. Following the addition of nest boxes, the number of SCNs increased significantly in the points with nest boxes in both types of forest. Counts in 2011 confirmed the increase in number of birds due to the addition of nest boxes. Given the likely benefits associated with a richer bird community we propose that, as is routinely done in some countries, forest management programs preserve old tree stumps and add nest boxes to forest plantations in order to increase bird numbers and bird community diversity.

  7. Pre- and post-experimental manipulation assessments confirm the increase in number of birds due to the addition of nest boxes.

    Science.gov (United States)

    Cuatianquiz Lima, Cecilia; Macías Garcia, Constantino

    2016-01-01

    Secondary cavity nesting (SCN) birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of SCNs in two temperate forest types, and evaluated the change in number of SCNs after adding nest boxes. First, we counted all cavities within each of our 25-m radius sampling points in mature and young forest plots during 2009. We then added nest boxes at standardised locations during 2010 and 2011 and conducted fortnightly bird counts (January-October 2009-2011). In 2011 we added two extra plots of each forest type, where we also conducted bird counts. Prior to adding nest boxes, counts revealed more SCNs in mature than in young forest. Following the addition of nest boxes, the number of SCNs increased significantly in the points with nest boxes in both types of forest. Counts in 2011 confirmed the increase in number of birds due to the addition of nest boxes. Given the likely benefits associated with a richer bird community we propose that, as is routinely done in some countries, forest management programs preserve old tree stumps and add nest boxes to forest plantations in order to increase bird numbers and bird community diversity.

  8. Pre- and post-experimental manipulation assessments confirm the increase in number of birds due to the addition of nest boxes

    Science.gov (United States)

    Cuatianquiz Lima, Cecilia

    2016-01-01

    Secondary cavity nesting (SCN) birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of SCNs in two temperate forest types, and evaluated the change in number of SCNs after adding nest boxes. First, we counted all cavities within each of our 25-m radius sampling points in mature and young forest plots during 2009. We then added nest boxes at standardised locations during 2010 and 2011 and conducted fortnightly bird counts (January–October 2009–2011). In 2011 we added two extra plots of each forest type, where we also conducted bird counts. Prior to adding nest boxes, counts revealed more SCNs in mature than in young forest. Following the addition of nest boxes, the number of SCNs increased significantly in the points with nest boxes in both types of forest. Counts in 2011 confirmed the increase in number of birds due to the addition of nest boxes. Given the likely benefits associated with a richer bird community we propose that, as is routinely done in some countries, forest management programs preserve old tree stumps and add nest boxes to forest plantations in order to increase bird numbers and bird community diversity. PMID:26998410

  9. Review of information on the radiation chemistry of materials around waste canisters in salt and assessment of the need for additional experimental information

    Energy Technology Data Exchange (ETDEWEB)

    Jenks, G.H.; Baes, C.F. Jr.

    1980-03-01

    The brines, vapors, and salts precipitated from the brines will be exposed to gamma rays and to elevated temperatures in the regions close to a waste package in the salt. Accordingly, they will be subject to changes in composition brought about by reactions induced by the radiations and heat. This report reviews the status of information on the radiation chemistry of brines, gases, and solids which might be present around a waste package in salt and to assess the need for additional laboratory investigations on the radiation chemistry of these materials. The basic aspects of the radiation chemistry of water and aqueous solutions, including concentrated salt solutions, were reviewed briefly and found to be substantially unchanged from those presented in Jenks's 1972 review of radiolysis and hydrolysis in salt-mine brines. Some additional information pertaining to the radiolytic yields and reactions in brine solutions has become available since the previous review, and this information will be useful in the eventual, complete elucidation of the radiation chemistry of the salt-mine brines. 53 references.

  10. Children's education and parental old age survival - Quasi-experimental evidence on the intergenerational effects of human capital investment.

    Science.gov (United States)

    De Neve, Jan-Walter; Fink, Günther

    2018-03-01

    While a large literature has investigated the role of parental human capital on children's well-being, relatively little is known regarding the effects of human capital investment in children on long run outcomes of parents. In this study we explore the human capital variations created by the 1974 Tanzania education reform to estimate the effect of children's primary schooling attainment on parental survival. Using 5,026,315 census records from 1988, 2002, and 2012, we show that the 1974 reform resulted in an additional 1.1 years (31%) of educational attainment among exposed cohorts. Using the reform as instrument for child education we find that each additional year of primary schooling in children resulted in a 3.7 percentage point reduction (p human capital gains generated by reforms are shared with the parental generation. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Experimental evidence for simultaneous relaxation processes in super spin glass γ-Fe2O3 nanoparticle system

    Science.gov (United States)

    Nikolic, V.; Perovic, M.; Kusigerski, V.; Boskovic, M.; Mrakovic, A.; Blanusa, J.; Spasojevic, V.

    2015-03-01

    Spherical γ-Fe2O3 nanoparticles with the narrow size distribution of (5 ± 1) nm were synthesized by the method of thermal decomposition from iron acetyl acetonate precursor. The existence of super spin-glass state at low temperatures and in low applied magnetic fields was confirmed by DC magnetization measurements on a SQUID magnetometer. The comprehensive investigation of magnetic relaxation dynamics in low-temperature region was conducted through the measurements of single-stop and multiple stop ZFC memory effects, ZFC magnetization relaxation, and AC susceptibility measurements. The experimental findings revealed the peculiar change of magnetic relaxation dynamics at T ≈ 10 K, which arose as a consequence of simultaneous existence of different relaxation processes in Fe2O3 nanoparticle system. Complementarity of the applied measurements was utilized in order to single out distinct relaxation processes as well as to elucidate complex relaxation mechanisms in the investigated interacting nanoparticle system.

  12. Giving offspring a head start in life: field and experimental evidence for selection on maternal basking behaviour in lizards.

    Science.gov (United States)

    Wapstra, E; Uller, T; While, G M; Olsson, M; Shine, R

    2010-03-01

    The timing of birth is often correlated with offspring fitness in animals, but experimental studies that disentangle direct effects of parturition date and indirect effects mediated via variation in female traits are rare. In viviparous ectotherms, parturition date is largely driven by female thermal conditions, particularly maternal basking strategies. Our field and laboratory studies of a viviparous lizard (Niveoscincus ocellatus) show that earlier-born offspring are more likely to survive through their first winter and are larger following that winter, than are later-born conspecifics. Thus, the association between parturition date and offspring fitness is causal, rather than reflecting an underlying correlation between parturition date and maternal attributes. Survival selection on offspring confers a significant advantage for increased maternal basking in this species, mediated through fitness advantages of earlier parturition. We discuss the roles of environmentally imposed constraints and parent-offspring conflict in the evolution of maternal effects on parturition date.

  13. First Clear-Cut Experimental Evidence of a Glass Transition in a Polymer with Intrinsic Microporosity: PIM-1.

    Science.gov (United States)

    Yin, Huajie; Chua, Yeong Zen; Yang, Bin; Schick, Christoph; Harrison, Wayne J; Budd, Peter M; Böhning, Martin; Schönhals, Andreas

    2018-04-19

    Polymers with intrinsic microporosity (PIMs) represent a novel, innovative class of materials with great potential in various applications from high-performance gas-separation membranes to electronic devices. Here, for the first time, for PIM-1, as the archetypal PIM, fast scanning calorimetry provides definitive evidence of a glass transition ( T g = 715 K, heating rate 3 × 10 4 K/s) by decoupling the time scales responsible for glass transition and decomposition. Because the rigid molecular structure of PIM-1 prevents any conformational changes, small-scale bend and flex fluctuations must be considered the origin of its glass transition. This result has strong implications for the fundamental understanding of the glass transition and for the physical aging of PIMs and other complex polymers, both topical problems of materials science.

  14. Chemical and nano-mineralogical study for determining potential uses of legal Colombian gold mine sludge: Experimental evidence.

    Science.gov (United States)

    Sánchez-Peña, Nazly E; Narváez-Semanate, José L; Pabón-Patiño, Daniela; Fernández-Mera, Javier E; Oliveira, Marcos L S; da Boit, Kátia; Tutikian, Bernardo F; Crissien, Tito J; Pinto, Diana C; Serrano, Iván D; Ayala, Claudia I; Duarte, Ana L; Ruiz, José D; Silva, Luis F O

    2018-01-01

    The present study is focused on the chemical and nano-mineralogical characterization of sludge from gold mine activities, in order to put forward diverse solution alternatives, where lack of knowledge has been found. The sample was collected from "La Estrella" mine of Suarez, located in Department of Cauca, south-west Colombia. The sludge micro-structure and chemical composition were analyzed using a high resolution transmission electron microscopy (HR-TEM) equipped with a dispersive X-ray detector (EDS). X-ray diffraction technique was employed to identify the mineralogical phases present in the sludge. Additional mineralogical characterization was done by using RAMAN spectroscopy. Main findings points to its potential to be used as a fertilizer, this is why, mine sludge contains macronutrients such as P, Ca and S, together with micronutrients like Cu. However, the presence of goethite could decrease the mobilization of nutrients to soils, thus additional alternatives, for instance, a mixture with humus or another material containing Humic Acids should be done, in order to minimizing its retention effect. Additionally, another possible uses to explore could be as construction and ceramic material or in the wastewater treatment for nutrient retention and organic material removal. Rutile (TiO 2 nanoparticles) particles have been also detected, what could cause health concern due to its nanoparticle toxic character, mainly during gold extraction process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Could Sodium Chloride be an Environmental Trigger for Immune-Mediated Diseases? An Overview of the Experimental and Clinical Evidence.

    Science.gov (United States)

    Toussirot, Eric; Béreau, Matthieu; Vauchy, Charline; Saas, Philippe

    2018-01-01

    Immune mediated diseases (IMDs) are complex chronic inflammatory diseases involving genetic and environmental factors. Salt intake has been proposed as a diet factor that can influence the immune response. Indeed, experimental data report the influence of sodium chloride on the differentiation of naive CD4 + T cells into IL-17 secreting T helper (Th) cells (Th17 cells), by a mechanism involving the serum glucocorticoid kinase-1 (SGK1) that promotes the expression of the IL-23 receptor (IL-23R). The IL-23/IL-23R is critical for pathogenic inflammatory Th17 cell differentiation. Experimental data in murine models of arthritis, colitis and encephalomyelitis corroborate these findings. This manuscript reviews the current knowledge on the effects of sodium chloride on innate and adaptive immunity. We also performed a systematic literature review for clinical studies examining the relationships between salt consumption and the development or the activity/severity of the most common IMDs mediated by the IL-23/Th17 pathway, i.e., rheumatoid arthritis (RA), multiple sclerosis (MS), and Crohn's disease (CD). Nine studies were found, 4 in RA, 4 in MS and 1 in CD. An association was found between developments of anti-citrullinated protein antibody (ACPA) positive RA in smokers and salt intake, but these results were not confirmed in another study. For MS, no association was observed in pediatric subjects while in adult patients, a link was found between salt intake and disease activity. However, this result was not confirmed in another study. These conflicting results highlight the fact that further evaluation in human IMDs is required. Moreover, physicians need to develop clinical trials with diet interventions to evaluate the impact of low salt intake on disease activity/severity of IMDs.

  16. Could Sodium Chloride be an Environmental Trigger for Immune-Mediated Diseases? An Overview of the Experimental and Clinical Evidence

    Directory of Open Access Journals (Sweden)

    Eric Toussirot

    2018-04-01

    Full Text Available Immune mediated diseases (IMDs are complex chronic inflammatory diseases involving genetic and environmental factors. Salt intake has been proposed as a diet factor that can influence the immune response. Indeed, experimental data report the influence of sodium chloride on the differentiation of naive CD4+ T cells into IL-17 secreting T helper (Th cells (Th17 cells, by a mechanism involving the serum glucocorticoid kinase-1 (SGK1 that promotes the expression of the IL-23 receptor (IL-23R. The IL-23/IL-23R is critical for pathogenic inflammatory Th17 cell differentiation. Experimental data in murine models of arthritis, colitis and encephalomyelitis corroborate these findings. This manuscript reviews the current knowledge on the effects of sodium chloride on innate and adaptive immunity. We also performed a systematic literature review for clinical studies examining the relationships between salt consumption and the development or the activity/severity of the most common IMDs mediated by the IL-23/Th17 pathway, i.e., rheumatoid arthritis (RA, multiple sclerosis (MS, and Crohn's disease (CD. Nine studies were found, 4 in RA, 4 in MS and 1 in CD. An association was found between developments of anti-citrullinated protein antibody (ACPA positive RA in smokers and salt intake, but these results were not confirmed in another study. For MS, no association was observed in pediatric subjects while in adult patients, a link was found between salt intake and disease activity. However, this result was not confirmed in another study. These conflicting results highlight the fact that further evaluation in human IMDs is required. Moreover, physicians need to develop clinical trials with diet interventions to evaluate the impact of low salt intake on disease activity/severity of IMDs.

  17. Blood-pressure-independent wall thickening of intramyocardial arterioles in experimental uraemia: evidence for a permissive action of PTH.

    Science.gov (United States)

    Amann, K; Törnig, J; Flechtenmacher, C; Nabokov, A; Mall, G; Ritz, E

    1995-11-01

    Abnormalities in cardiovascular structures, e.g. LV hypertrophy and thickening of vessels (arteries, arterioles, veins) are hallmarks of renal failure. They are in part independent of elevated blood pressure. Parathyroid hormone (PTH) has been shown to affect cardiac function and has also been identified as a permissive factor in the genesis of cardiac fibrosis. The present study in rats with experimental renal failure was designed to examine whether PTH was permissive for wall thickening of intramyocardial arterioles as well. Male SD rats were sham operated or subtotally nephrectomized and maintained for 2 weeks. Subgroups of subtotally nephrectomized (SNX) rats were parathyroidectomized (PTX). Saline or rat 1, 34 PTH was administered by osmotic minipump. Eucalcaemia was maintained in PTX animals by a high-calcium diet (3%). Serum calcium was not statistically different between the groups. After perfusion fixation, intramyocardial arterioles were assessed using stereological techniques (wall thickness; wall/lumen ratio; minimal lumen diameter; length density). In random samples of the left ventricle, wall thickness of arterioles was 2.2 +/- 0.25 microns in sham-op controls and 2.76 +/- 0.41 in SNX (n = at least 8 animals per group). SNX-PTX animals+solvent did not differ significantly from sham-op controls (2.08 +/- 0.42 microns), while SNX-PTX animals+PTH had values not significantly different from SNX (2.59 +/- 0.54 microns). Differences in wall thickness were not paralleled by differences in systolic blood pressure (sham-op 110 +/- 13.3 mmHg; SNX 138 +/- 8.4 mmHg, SNX-PTX+solvent 142 +/- 5.2 mmHg; SNX-PTX+PTH 148 +/- 5.7 mmHg). PTH treated animals showed signs of marked vascular smooth-muscle cell and endothelial-cell activation. The data suggest that wall thickening of intramyocardial arterioles in short-term experimental uraemia is dependent upon the presence of PTH (permissive effect).

  18. Effects of Exercise on Physical and Mental Health, and Cognitive and Brain Functions in Schizophrenia: Clinical and Experimental Evidence.

    Science.gov (United States)

    Rimes, Ridson Rosa; de Souza Moura, Antonio Marcos; Lamego, Murilo Khede; de Sá Filho, Alberto Souza; Manochio, João; Paes, Flávia; Carta, Mauro Giovanni; Mura, Gioia; Wegner, Mirko; Budde, Henning; Ferreira Rocha, Nuno Barbosa; Rocha, Joana; Tavares, João Manuel R S; Arias-Carrión, Oscar; Nardi, Antonio Egidio; Yuan, Ti-Fei; Machado, Sergio

    2015-01-01

    Exercise promotes several health benefits, such as cardiovascular, musculoskeletal and cardiorespiratory improvements. It is believed that the practice of exercise in individuals with psychiatric disorders, e.g. schizophrenia, can cause significant changes. Schizophrenic patients have problematic lifestyle habits compared with general population; this may cause a high mortality rate, mainly caused by cardiovascular and metabolic diseases. Thus, the aim of this study is to investigate changes in physical and mental health, cognitive and brain functioning due to the practice of exercise in patients with schizophrenia. Although still little is known about the benefits of exercise on mental health, cognitive and brain functioning of schizophrenic patients, exercise training has been shown to be a beneficial intervention in the control and reduction of disease severity. Type of training, form of execution, duration and intensity need to be better studied as the effects on physical and mental health, cognition and brain activity depend exclusively of interconnected factors, such as the combination of exercise and medication. However, one should understand that exercise is not only an effective nondrug alternative, but also acts as a supporting linking up interventions to promote improvements in process performance optimization. In general, the positive effects on mental health, cognition and brain activity as a result of an exercise program are quite evident. Few studies have been published correlating effects of exercise in patients with schizophrenia, but there is increasing evidence that positive and negative symptoms can be improved. Therefore, it is important that further studies be undertaken to expand the knowledge of physical exercise on mental health in people with schizophrenia, as well as its dose-response and the most effective type of exercise.

  19. Effects of experimental warming and nitrogen addition on soil respiration and CH4 fluxes from crop rotations of winter wheat–soybean/fallow

    DEFF Research Database (Denmark)

    Liu, L; Hu, C; Yang, P

    2015-01-01

    Soil respiration and CH4 emissions play a significant role in the global carbon balance. However, in situ studies in agricultural soils on responses of soil respiration and CH4 fluxes to climate warming are still sparse, especially from long-term studies with year-round heating. A warming...... by affecting soil NH4 concentration. Across years, CH4 emissions were negatively correlated with soil temperature in N1 treatment. Soil respiration showed clear seasonal fluctuations, with the largest emissions during summer and smallest in winter. Warming and nitrogen fertilization had no significant effects...... on total cumulative soil CO2 fluxes. Soil respiration was positively correlated with microbial biomass C, and microbial biomass C was not affected significantly by warming or nitrogen addition. The lack of significant effects of warming on soil respiration may have resulted from: (1) warming-induced soil...

  20. Influence of 4-tert-butylpyridine/guanidinium thiocyanate co-additives on band edge shift and recombination of dye-sensitized solar cells: experimental and theoretical aspects

    International Nuclear Information System (INIS)

    Wang, Yuqiao; Lu, Jing; Yin, Jie; Lü, Gang; Cui, Yingmin; Wang, Shasha; Deng, Shengyuan; Shan, Dan; Tao, Hailiang; Sun, Yueming

    2015-01-01

    Graphical Abstract: The frontier orbitals between 4-tert-butylpyridine and TiO 2 are sufficiently overlapped to induce the negative shift of Fermi energy, increasing the open-circuit voltage. The guanidinium cations can be tightly absorbed on TiO 2 surface to form a passivated layer, depressing the recombination rate and improving the short-circuit photocurrent. The photovoltaic performance might be as a result of a synergistic effect of co-additives due to the competitive effect between volume and electrostatic effect. - Highlights: • The frontier orbitals between 4-tert-butylpyridine and TiO 2 are sufficiently overlapped to induce the negative shift of Fermi energy, increasing the open-circuit voltage. • The guanidinium cations can be tightly absorbed on TiO 2 surface by electrostatic attraction to form a passivated layer, depressing the recombination rate and improving the short-circuit photocurrent. • The photovoltaic performance might be as a result of a synergistic effect of co-additives due to the competitive effect between volume and electrostatic effect. - ABSTRACT: The co-additives of 4-tert-butylpyridine (TBP) and guanidinium thiocyanate (GuSCN) in electrolytes can prominently affect the photovoltaic behavior of dye-sensitized solar cell (DSSC) due to their advantages fitting with energy levels and charge transfer. Mott-Schottky analysis is used to quantify the TiO 2 band edge movement to clarify the change of open-circuit voltage. The corresponding kinetic investigations are carried out using cyclic voltammetry, electrochemical impedance spectroscopy, intensity modulated photocurrent/photovoltage spectroscopy and charge extraction. Theoretically, the density functional theory (DFT) method is performed to explore the details of the adsorption, including the interacting energy, Fermi energy and frontier orbitals properties. The results show that the frontier orbitals between TBP and TiO 2 are sufficiently overlapped to induce the negative shift of

  1. Effects of Rhenium Addition on the Temporal Evolution of the Nanostructure and Chemistry of a Model Ni-Cr-Al Superalloy. 1; Experimental Observations

    Science.gov (United States)

    Yoon, Kevin E.; Noebe, Ronald D.; Seidman, David N.

    2006-01-01

    The temporal evolution of the nanostructure and chemistry of a model Ni-8.5 at.% Cr-10 at. % Al alloy, with the addition of 2 at.% Re, aged at 1073 K from 0.25 to 264 h, was studied. Transmission electron microscopy and atom-probe tomography were used to measure the number density and mean radius of the gamma prime (L1(sub 2) structure)-precipitates and the chemistry of the gamma prime-precipitates and the gamma (face-centered cubic)-matrix, including the partitioning behavior of all alloying elements between the gamma- and gamma prime-phases and the segregation behavior at gamma/gamma prime interfaces. The precipitates remained spheroidal for an aging time of up to 264 h and, unlike commercial nickel-based superalloys containing Re, there was not confined (nonmonotonic) Re segregation at the gamma/gamma prime interfaces.

  2. Review: geological and experimental evidence for secular variation in seawater Mg/Ca (calcite-aragonite seas and its effects on marine biological calcification

    Directory of Open Access Journals (Sweden)

    J. B. Ries

    2010-09-01

    Full Text Available Synchronized transitions in the polymorph mineralogy of the major reef-building and sediment-producing calcareous marine organisms and abiotic CaCO3 precipitates (ooids, marine cements throughout Phanerozoic time are believed to have been caused by tectonically induced variations in the Mg/Ca ratio of seawater (molar Mg/Ca>2="aragonite seas", <2="calcite seas". Here, I assess the geological evidence in support of secular variation in seawater Mg/Ca and its effects on marine calcifiers, and review a series of recent experiments that investigate the effects of seawater Mg/Ca (1.0–5.2 on extant representatives of calcifying taxa that have experienced variations in this ionic ratio of seawater throughout the geologic past.

    Secular variation in seawater Mg/Ca is supported by synchronized secular variations in (1 the ionic composition of fluid inclusions in primary marine halite, (2 the mineralogies of late stage marine evaporites, abiogenic carbonates, and reef- and sediment-forming marine calcifiers, (3 the Mg/Ca ratios of fossil echinoderms, molluscs, rugose corals, and abiogenic carbonates, (4 global rates of tectonism that drive the exchange of Mg2+ and Ca2+ along zones of ocean crust production, and (5 additional proxies of seawater Mg/Ca including Sr/Mg ratios of abiogenic carbonates, Sr/Ca ratios of biogenic carbonates, and Br concentrations in marine halite.

    Laboratory experiments have revealed that aragonite-secreting bryopsidalean algae and scleractinian corals and calcite-secreting coccolithophores exhibit higher rates of calcification and growth in experimental seawaters formulated with seawater Mg/Ca ratios that favor their skeletal mineral. These results support the assertion that seawater Mg/Ca played an important role in determining which hypercalcifying marine organisms were the major reef-builders and sediment-producers throughout Earth history. The observation that primary

  3. Experimental pulmonary schistosomiasis: lack of morphological evidence of modulation in schistosomal pulmonary granulomas Esquistossomose pulmonar experimental: falta de evidência morfológica de modulação nos granulomas esquistosomóticos pulmonares

    Directory of Open Access Journals (Sweden)

    Maura R. F. Souza Vidal

    1993-10-01

    Full Text Available Numerous pulmonary schistosome egg granulomas were present in mice submitted to partial portal vein ligation (Warren's model. The granulomas were characterized by cellular aggregations formed within alveolar tissue. Main cellular types were macrophages (epithelioid cells, eosinophils, plasma cells and lymphocytes. These cells were supported by scanty fibrous stroma and exhibited close membrane contact points amongst themselves, but without forming specialized adhesion apparatus. When granulomas involved arterial structures, proliferation of cndothelial and smooth muscle cells occurred and fibrosis associated with angiogenesis became more evident. Granulomas formed around mature eggs in the pulmonary alveolar tissue presented approximately the same size and morphology regardless of the time of infection, the latter being 10, 18 and 25 weeks after cercarial exposure. This persistence of morphological appearance suggests that pulmonary granulomas do not undergo immunological modulation, as is the case with the granulomas in the liver and, to a lesser extent, in the intestines. Probably, besides general immunological factors, local (stromal factors play an important role in schistosomal granuloma modulation.Em camundongos submetidos à ligadura parcial da veia porta e infecção pelo Schistosoma mansoni, os granulomas periovulares apareceram em grande número nos pulmões, comprovando a validade do modelo de Warren. Histologicamente os granulomas eram representados por agregados celulares compactos no seio de escasso estroma. Os macrófagos (células epitelióides e eosinófilos eram os elementos celulares predominantes, vindo em seguida os linfóticos e plasmócitos. Ultraestruturalmenle, as células do granuloma exibiam íntimo contacto de suas membranas, com varios pontos de adesão, mas sem formar estruturas juncionais mais específicas. Os granulomas formados em torno a ovos maduros tinham tamanho, forma e composição celular similares ap

  4. An Experimental Investigation on the Effect of Addition of Ternary Blend on the Mix Design Characteristics of High Strength Concrete using Steel Fibre

    Science.gov (United States)

    Sinha, Deepa A., Dr; Verma, A. K., Dr

    2017-08-01

    This paper presents the results of M60 grade of concrete. M60 grade of concrete is achieved by maximum density technique. Concrete is brittle and weak in tension and develops cracks during curing and due to thermal expansion / contraction over a period ot time. Thus the effect of addition of 1% steel fibre is studied. For ages, concrete has been one of the widely used materials for construction. When cement is manufactured, every one ton of cement produces around one ton of carbon dioxide leading to global warming and also as natural resources are finishing, so use of supplementary cementitious material like alccofine and flyash is used as partial replacement of cement is considered. The effect of binary and ternary blend on the strength characteristics is studied. The results indicate that the concrete made with alccofine and flyash generally show excellent fresh and hardened properties. The ternary system that is Portland cement-fly ash-Alccofine concrete was found to increase the strength of concrete when compared to concrete made with Portland cement or even from Portland cement and fly ash.

  5. Experimental evidence of the impact of rare-earth elements on particle growth and mechanical behaviour of silicon nitride

    International Nuclear Information System (INIS)

    Satet, Raphaelle L.; Hoffmann, Michael J.; Cannon, Rowland M.

    2006-01-01

    The impact of various rare-earth and related doping elements (R = Lu, Sc, Yb, Y, Sm, La) on the grain growth anisotropy and the mechanical properties of polycrystalline β-silicon nitride ceramics has been studied. Model experiments, in which Si 3 N 4 particles can grow freely in an R-Si-Mg-oxynitride glass matrix, show that, with increasing ionic radius of the additive, grain anisotropy increases due to non-linear growth kinetics. Toughness and strength are affected by the rare-earth element. Samples of equivalent grain sizes and morphologies yield an increasing toughness with increasing ion size of the R 3+ , reflecting an increasingly intergranular crack path. These samples are also strong and flaw tolerant, but the trends of strength and toughness do not exactly match. The choice of the rare-earth is essential to tailor microstructure, interfacial strength and mechanical properties. However, somewhat different trends for properties from IIIb and lanthanide additives indicate that more than the R 3+ size (i.e., purely ionic bond strength between R 3+ and its neighbours) is important. The electronic structure of the R-element is responsible for the type of dopant adsorption and the properties of the interface

  6. Experimental evidence of the synergistic effects of warming and invasive algae on a temperate reef-builder coral.

    Science.gov (United States)

    Kersting, Diego K; Cebrian, Emma; Casado, Clara; Teixidó, Núria; Garrabou, Joaquim; Linares, Cristina

    2015-12-22

    In the current global climate change scenario, stressors overlap in space and time, and knowledge on the effects of their interaction is highly needed to understand and predict the response and resilience of organisms. Corals, among many other benthic organisms, are affected by an increasing number of global change-related stressors including warming and invasive species. In this study, the cumulative effects between warming and invasive algae were experimentally assessed on the temperate reef-builder coral Cladocora caespitosa. We first investigated the potential local adaptation to thermal stress in two distant populations subjected to contrasting thermal and necrosis histories. No significant differences were found between populations. Colonies from both populations suffered no necrosis after long-term exposure to temperatures up to 29 °C. Second, we tested the effects of the interaction of both warming and the presence of invasive algae. The combined exposure triggered critical synergistic effects on photosynthetic efficiency and tissue necrosis. At the end of the experiment, over 90% of the colonies subjected to warming and invasive algae showed signs of necrosis. The results are of particular concern when considering the predicted increase of extreme climatic events and the spread of invasive species in the Mediterranean and other seas in the future.

  7. What messages can foster safer sex among young women? Experimental evidence concerning the role of emotions and moral norms.

    Science.gov (United States)

    Matera, Camilla; Nerini, Amanda; Baroni, Duccio; Stefanile, Cristina

    2018-07-01

    Through a 2 × 2 × 2 quasi experimental design (N = 254), this research investigated if a social campaign eliciting positive emotions and activating moral norms might enhance condom negotiation skills, intended and estimated condom among young women with or without past sexual experience with casual partners. Emotions had a main effect on one of the six condom negotiation strategies we considered; for most of the other variables an interaction effect with moral norms and/or past behaviour emerged. Concerning estimated condom use, positive emotions worked better than negative ones when moral norms were salient. With respect to negotiations skills, positive rather than negative emotions seemed more effective for women with past causal sexual experience. In women without this kind of experience, positive emotions seemed to work better when moral norms were salient. Moral norms had a main effect on negotiation self-efficacy, but not in the predicted direction: when moral norms were more salient women were found to be less confident about their negotiation ability. These results suggest that a message which makes moral norms salient should at the same time elicit positive emotions in order to be effective; moreover, messages should be carefully tailored according to women's past behaviour.

  8. Experimental analysis of multivariate female choice in gray treefrogs (Hyla versicolor): evidence for directional and stabilizing selection.

    Science.gov (United States)

    Gerhardt, H Carl; Brooks, Robert

    2009-10-01

    Even simple biological signals vary in several measurable dimensions. Understanding their evolution requires, therefore, a multivariate understanding of selection, including how different properties interact to determine the effectiveness of the signal. We combined experimental manipulation with multivariate selection analysis to assess female mate choice on the simple trilled calls of male gray treefrogs. We independently and randomly varied five behaviorally relevant acoustic properties in 154 synthetic calls. We compared response times of each of 154 females to one of these calls with its response to a standard call that had mean values of the five properties. We found directional and quadratic selection on two properties indicative of the amount of signaling, pulse number, and call rate. Canonical rotation of the fitness surface showed that these properties, along with pulse rate, contributed heavily to a major axis of stabilizing selection, a result consistent with univariate studies showing diminishing effects of increasing pulse number well beyond the mean. Spectral properties contributed to a second major axis of stabilizing selection. The single major axis of disruptive selection suggested that a combination of two temporal and two spectral properties with values differing from the mean should be especially attractive.

  9. Experimental evidence for importance of Hund's exchange interaction for incoherence of charge carriers in iron-based superconductors

    Science.gov (United States)

    Fink, J.; Rienks, E. D. L.; Thirupathaiah, S.; Nayak, J.; van Roekeghem, A.; Biermann, S.; Wolf, T.; Adelmann, P.; Jeevan, H. S.; Gegenwart, P.; Wurmehl, S.; Felser, C.; Büchner, B.

    2017-04-01

    Angle-resolved photoemission spectroscopy is used to study the scattering rates of charge carriers from the hole pockets near Γ in the iron-based high-Tc hole-doped superconductors KxBa1 -xFe2As2 , x =0.4 , and KxEu1 -xFe2As2 , x =0.55 , and the electron-doped compound Ba (Fe1-xCox) 2As2 , x =0.075 . The scattering rate for any given band is found to depend linearly on the energy, indicating a non-Fermi-liquid regime. The scattering rates in the hole-doped compound are considerably higher than those in the electron-doped compounds. In the hole-doped systems the scattering rate of the charge carriers of the inner hole pocket is about three times higher than the binding energy, indicating that the spectral weight is heavily incoherent. The strength of the scattering rates and the difference between electron- and hole-doped compounds signals the importance of Hund's exchange coupling for correlation effects in these iron-based high-Tc superconductors. The experimental results are in qualitative agreement with theoretical calculations in the framework of combined density functional dynamical mean-field theory.

  10. Experimental and geochemical evidence for derivation of the El Capitan Granite, California, by partial melting of hydrous gabbroic lower crust

    Science.gov (United States)

    Ratajeski, K.; Sisson, T.W.; Glazner, A.F.

    2005-01-01

    Partial melting of mafic intrusions recently emplaced into the lower crust can produce voluminous silicic magmas with isotopic ratios similar to their mafic sources. Low-temperature (825 and 850??C) partial melts synthesized at 700 MPa in biotite-hornblende gabbros from the central Sierra Nevada batholith (Sisson et al. in Contrib Mineral Petrol 148:635-661, 2005) have major-element and modeled trace-element (REE, Rb, Ba, Sr, Th, U) compositions matching those of the Cretaceous El Capitan Granite, a prominent granite and silicic granodiorite pluton in the central part of the Sierra Nevada batholith (Yosemite, CA, USA) locally mingled with coeval, isotopically similar quartz diorite through gabbro intrusions (Ratajeski et al. in Geol Soc Am Bull 113:1486-1502, 2001). These results are evidence that the El Capitan Granite, and perhaps similar intrusions in the Sierra Nevada batholith with lithospheric-mantle-like isotopic values, were extracted from LILE-enriched, hydrous (hornblende-bearing) gabbroic rocks in the Sierran lower crust. Granitic partial melts derived by this process may also be silicic end members for mixing events leading to large-volume intermediate composition Sierran plutons such as the Cretaceous Lamarck Granodiorite. Voluminous gabbroic residues of partial melting may be lost to the mantle by their conversion to garnet-pyroxene assemblages during batholithic magmatic crustal thickening. ?? Springer-Verlag 2005.

  11. Cross-cultural similarities and differences in person-body reasoning: experimental evidence from the United Kingdom and Brazilian Amazon.

    Science.gov (United States)

    Cohen, Emma; Burdett, Emily; Knight, Nicola; Barrett, Justin

    2011-01-01

    We report the results of a cross-cultural investigation of person-body reasoning in the United Kingdom and northern Brazilian Amazon (Marajó Island). The study provides evidence that directly bears upon divergent theoretical claims in cognitive psychology and anthropology, respectively, on the cognitive origins and cross-cultural incidence of mind-body dualism. In a novel reasoning task, we found that participants across the two sample populations parsed a wide range of capacities similarly in terms of the capacities' perceived anchoring to bodily function. Patterns of reasoning concerning the respective roles of physical and biological properties in sustaining various capacities did vary between sample populations, however. Further, the data challenge prior ad-hoc categorizations in the empirical literature on the developmental origins of and cognitive constraints on psycho-physical reasoning (e.g., in afterlife concepts). We suggest cross-culturally validated categories of "Body Dependent" and "Body Independent" items for future developmental and cross-cultural research in this emerging area. Copyright © 2011 Cognitive Science Society, Inc.

  12. Strong dependence of rain-induced lidar depolarization on the illumination angle: experimental evidence and geometrical-optics interpretation.

    Science.gov (United States)

    Roy, G; Bissonnette, L R

    2001-09-20

    Backscatter and depolarization lidar measurements from clouds and precipitation are reported as functions of the elevation angle of the pointing lidar direction. We recorded the data by scanning the lidar beam (Nd:YAG) at a constant angular speed of ~3.5 degrees /s while operating at a repetition rate of 10 Hz. We show that in rain there is an evident and at times spectacular dependence on the elevation angle. That dependence appears to be sensitive to raindrop size. We have developed a three-dimensional polarization-dependent ray-tracing algorithm to calculate the backscatter and the depolarization ratio by large nonspherical droplets. We have applied it to raindrop shapes derived from existing static and dynamic (oscillating) models. We show that many of the observed complex backscatter and depolarization features can be interpreted to a good extent by geometrical optics. These results suggest that there is a definite need for more extensive calculations of the scattering phase matrix elements for large deformed raindrops as functions of the direction of illumination. Obvious applications are retrieval of information on the liquid-solid phase of precipitation and on the size and the vibration state of raindrops.

  13. Electro-acupuncture reduces the need for additional anesthetics in experimental studies Eletroacupuntura reduz a necessidade de doses adicionais de anestésicos em estudos experimentais

    Directory of Open Access Journals (Sweden)

    Agamenon Honório Silva

    2010-08-01

    Full Text Available PURPOSE: To evaluate the possible beneficial effects of electro-acupuncture in rats subjected to ketamine/xylazine (KX intra-peritoneal (i.p. anesthesia. METHODS: Forty-eight male Wistar rats were distributed in four equal groups. All rats received i.p. injections of ketamine (90 mg/kg +xylazine (10 mg/kg anesthesia. Basal values group (control rats (BV received no additional treatment. The equivalent of the human right ST36 (Zusanli and CV-12(Zhongwan acupoints were chosen for needling and electrical stimulation. AC rats were needled with sterilized disposable stainless steel needles at right ST36 and CV12 acupoints; needles were retained for 30 minutes. EAC10 rats, after needle insertion as described, had electrodes connected to both needles and to an electro stimulator model NKL EL-608; pulsed square waves, 10 Hz, 10 mA, was applied for 30 minutes. EAC100 rats were submitted to EA as described. However, a greater frequency (100 Hz was used. RESULTS: Thirty-seven rats remained under adequate anesthetic level during the experiment. However, maintenance anesthesia was required by 11 rats. Need for additional anesthesia decreased to 9.1% in EAC100 rats compared to BV (36.3%. CONCLUSION: Both the AC and the EAC10/100 prolong the anesthetic effect of the combination Ketamine-xylazine in rats, allowing longer duration of anesthesia with a lower dose of anesthetic, thereby reducing the occurrence of complications.OBJETIVO: Avaliar os possíveis efeitos benéficos da eletroacupuntura em ratos submetidos à anestesia intraperitoneal (i.p. com ketamina / xilazina. MÉTODOS: Quarenta e oito ratos Wistar foram randomizados em quatro grupos iguais. Todos os ratos receberam injeções i.p. de ketamina (90 mg / kg + xilazina (10 mg / kg. Os ratos do grupo Valores Basais (controle - BV não receberam nenhum tratamento adicional. Os acupontos equivalentes aos humanos E-36 (Zusanli e VC-12 (Zhongwan foram escolhidos para inserção de agulhas e estimulação el

  14. Lack of Impact of Posidonia oceanica Leaf Nutrient Enrichment on Sarpa salpa Herbivory: Additional Evidence for the Generalist Consumer Behavior of This Cornerstone Mediterranean Herbivore.

    Science.gov (United States)

    Marco-Méndez, Candela; Wessel, Caitlin; Scheffel, Whitney; Ferrero-Vicente, Luis; Fernández-Torquemada, Yolanda; Cebrián, Just; Heck, Kenneth L; Sánchez-Lizaso, Jose Luis

    2016-01-01

    The fish Sarpa salpa (L.) is one of the main macroherbivores in the western Mediterranean. Through direct and indirect mechanisms, this herbivore can exert significant control on the structure and functional dynamics of seagrass beds and macroalgae. Past research has suggested nutritional quality of their diet influences S. salpa herbivory, with the fish feeding more intensively and exerting greater top down control on macrophytes with higher internal nutrient contents. However recent findings have questioned this notion and shown that herbivores do not preferentially feed on macrophytes with higher nutrient contents, but rather feed on a wide variety of them with no apparent selectivity. To contribute to this debate, we conducted a field fertilization experiment where we enriched leaves of the seagrass Posidonia oceanica, a staple diet for S. salpa, and examined the response by the herbivore. These responses included quantification of leaf consumption in fertilized and non-fertilized/control plots within the bed, and food choice assays where fertilized and non-fertilized/control leaves were simultaneously offered to the herbivore. Despite the duration of leaf exposure to herbivores (30 days) and abundant schools of S. salpa observed around the plots, leaf consumption was generally low in the plots examined. Consumption was not higher on fertilized than on non-fertilized leaves. Food choice experiments did not show strong evidence for selectivity of enriched leaves. These results add to a recent body of work reporting a broad generalist feeding behavior by S. salpa with no clear selectivity for seagrass with higher nutrient content. In concert, this and other studies suggest S. salpa is often generalist consumers not only dictated by diet nutrient content but by complex interactions between other traits of nutritional quality, habitat heterogeneity within their ample foraging area, and responses to predation risk.

  15. Genetic and experimental evidence for a mixed-age, mixed-origin bank of kelp microscopic stages in southern California.

    Science.gov (United States)

    Carney, Laura T; Bohonak, Andrew J; Edwards, Matthew S; Alberto, Filipe

    2013-09-01

    Laboratory studies have demonstrated that the microscopic stages of kelps can rapidly resume development from a delayed state. Like terrestrial seeds or aquatic resting eggs, banks of delayed kelp stages may supplement population recovery after periods of stress, playing an important role for kelp populations that experience adult sporophyte absences due to seasonal or interannual disturbances. We found that removing the microscopic stages from natural rock substratum could prevent the appearance of juvenile kelp sporophytes for three months and the establishment of a diverse kelp assemblage for over four months within a southern California kelp forest. Juveniles were observed within one month in plots where microscopic stages were left intact, which may confer an advantage for the resulting sporophytes as they attain larger sizes before later recruiting neighbors. Microsatellite diversity was high (expected heterozygosity HE approximately 0.9) for juveniles and adults within our sites. Using a microsatellite-based parentage analysis for the dominant kelp, Macrocystis pyrifera, we estimated that a portion of the new M. pyrifera sporophyte recruits had originated from their parents at least seven months after their parents had disappeared. Similar delay durations have been demonstrated in recent laboratory studies. Additionally, our results suggest that zoospore dispersal distances > 50 m may be supported by including additional microsatellite loci in the analysis. We propose a mixed-age and, potentially, a mixed-origin bank of M. pyrifera gametophytes promotes maximal genetic diversity in recovering populations and reduces population genetic subdivision and self-fertilization rates for intact populations by promoting the survival of zoospores dispersed > 10 m and during inhospitable environmental conditions.

  16. Protective Role of Cyclooxygenase (COX)-2 in Experimental Lung Injury: Evidence of a Lipoxin A(4)-Mediated Effect.

    LENUS (Irish Health Repository)

    2012-02-01

    BACKGROUND: Polymorphoneutrophils (PMNs) are activated by inflammatory mediators following splanchnic ischemia\\/reperfusion (I\\/R), potentially injuring organs such as the lung. As a result, some patients develop respiratory failure following abdominal aortic aneurysm repair. Pulmonary cyclooxygenase (COX)-2 protects against acid aspiration and bacterial instillation via lipoxins, a family of potent anti-inflammatory lipid mediators. We explored the role of COX-2 and lipoxin A(4) in experimental I\\/R-mediated lung injury. MATERIALS AND METHODS: Sprague-Dawley rats were assigned to one of the following five groups: (1) controls; (2) aortic cross-clamping for 45 min and reperfusion for 4 h (I\\/R group); (3) I\\/R and SC236, a selective COX-2 inhibitor; (4) I\\/R and aspirin; and (5) I\\/R and iloprost, a prostacyclin (PGI(2)) analogue. Lung injury was assessed by wet\\/dry ratio, myeloperoxidase (MPO) activity, and bronchoalveolar lavage (BAL) neutrophil counts. BAL levels of thromboxane, PGE(2), 6-keto-PGF(1)alpha (a hydrolysis product of prostacyclin), lipoxin A(4), and 15-epi-lipoxin A(4) were analyzed by enzyme immunoassay (EIA). Immunostaining for COX-2 was performed. RESULTS: I\\/R significantly increased tissue MPO, the wet\\/dry lung ratio, and neutrophil counts. These measures were significantly further aggravated by SC236 and improved by iloprost. I\\/R increased COX-2 immunostaining and both PGE(2) and 6-keto-PGF(1alpha) levels in BAL. SC236 markedly reduced these prostanoids and lipoxin A(4) compared with I\\/R alone. Iloprost markedly increased lipoxin A(4) levels. The deleterious effect of SC236 and the beneficial effect of iloprost was associated with a reduction and an increase, respectively, in lipoxin A(4) levels. CONCLUSIONS: Lipoxin A(4) warrants further evaluation as a mediator of COX-2 regulated lung protection.

  17. Effect of brand and advertising medium on demand for e-cigarettes: Evidence from an experimental auction.

    Science.gov (United States)

    Rousu, Matthew C; O'Connor, Richard; Corrigan, Jay

    2017-09-01

    Print and television advertisements for e-cigarettes are currently legal in the United States. Given that e-cigarettes are a lower-risk alternative to cigarettes, these ads could have a positive public health impact if they motivate smokers to switch to e-cigarettes. However, the public health impact of e-cigarette ads could be negative if ads increase demand for both e-cigarettes and cigarettes. We use experimental auctions -in which participants bid in real auctions and winners pay for the items they purchase - to study the effect of print and TV e-cigarettes ads on demand for the brand from the ad, for another e-cigarettes brand, and for cigarettes. We ran experiments with 288 Pennsylvania smokers in November 2014-March 2015 and we found that in cases where an ad affects demand for e-cigarettes, the ad moves demand for cigarettes in the same direction. For example, the Blu print ad increases demand for Blu e-cigarettes and cigarettes among non-white participants. The Vuse TV ad reduces demand for both types of e-cigarettes and for cigarettes. We also find that non-white participants are willing to pay more for e-cigarettes in the absence of advertising, and that smokers who worry most about their health are willing to pay more for e-cigarettes. The results of this study point to the need for greater scrutiny of advertising for e-cigarette products such that they do not also induce demand for tobacco cigarettes.

  18. The contribution of phytoplankton degradation to chromophoric dissolved organic matter (CDOM) in eutrophic shallow lakes: field and experimental evidence.

    Science.gov (United States)

    Zhang, Yunlin; van Dijk, Mark A; Liu, Mingliang; Zhu, Guangwei; Qin, Boqiang

    2009-10-01

    Eight field campaigns in the eutrophic, shallow, Lake Taihu in the summers from 2005 to 2007, and a phytoplankton degradation experiment of 33 days, were carried out to determine the contribution of phytoplankton degradation to CDOM. Significant and positive correlations were found between the CDOM absorption coefficient at 355 nm [a(CDOM)(355)], normalized fluorescence emission (QSU) at 450 nm from excitation at 355 nm [F(n)(355)], and the chlorophyll a (Chla) concentration for all eight field campaigns, which indicates that the decomposition and degradation of phytoplankton is an important source of CDOM. In the degradation experiment, the CDOM absorption coefficient increased as phytoplankton broke down during the first 12 days, showing the production of CDOM from phytoplankton. After 12 days, a(CDOM)(355) had increased from the initial value 0.41+/-0.03 m(-1) to 1.37+/-0.03 m(-1) (a 234% increase), and the Chla concentration decreased from the initial value of 349.1+/-11.2 microg/L to 30.4+/-13.2 microg/L (a 91.3% decrease). The mean daily production rate of CDOM from phytoplankton was 0.08 m(-1) for a(CDOM)(355). Parallel Factor Analysis (PARAFAC) was used to assess CDOM composition from EEM spectra, and four components were identified: a terrestrial-like humic component, two marine-like humic components, and a protein-like component. The rapid increase in marine-like humic fluorophores (C3 and C4) during the degradation experiment suggests that in situ production of CDOM plays an important role in the dynamics of CDOM. The field campaigns and experimental data in the present study show that phytoplankton can be one of the important CDOM producers in eutrophic shallow lakes.

  19. Experimental evidence for the blue-shifted hydrogen-bonded complexes of CHF3 with π-electron donors.

    Science.gov (United States)

    Gopi, R; Ramanathan, N; Sundararajan, K

    2017-06-15

    Blue-shifted hydrogen-bonded complexes of fluoroform (CHF 3 ) with benzene (C 6 H 6 ) and acetylene (C 2 H 2 ) have been investigated using matrix isolation infrared spectroscopy and ab initio computations. For CHF 3 -C 6 H 6 complex, calculations performed at the B3LYP and MP2 levels of theory using 6-311++G (d,p) and aug-cc-pVDZ basis sets discerned two minima corresponding to a 1:1 hydrogen-bonded complex. The global minimum correlated to a structure, where the interaction is between the hydrogen of CHF 3 and the π-electrons of C 6 H 6 and a weak local minimum was stabilized through H…F interaction. For the CHF 3 -C 2 H 2 complex, computation performed at MP2/aug-cc-pVDZ level of theory yielded two minima, corresponding to the cyclic C-H…π complex A (global) and a linear C-H…F (n-σ) complex B (local). Experimentally a blue-shift of 32.3cm -1 and 7.7cm -1 was observed in the ν 1 C-H stretching mode of CHF 3 sub-molecule in Ar matrix for the 1:1 C-H…π complexes of CHF 3 with C 6 H 6 and C 2 H 2 respectively. Natural bond orbital (NBO), Atoms-in-molecule (AIM) and energy decomposition (EDA) analyses were carried out to explain the blue-shifting and the nature of the interaction in these complexes. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Effect of brand and advertising medium on demand for e-cigarettes: Evidence from an experimental auction

    Directory of Open Access Journals (Sweden)

    Matthew C. Rousu

    2017-09-01

    Full Text Available Print and television advertisements for e-cigarettes are currently legal in the United States. Given that e-cigarettes are a lower-risk alternative to cigarettes, these ads could have a positive public health impact if they motivate smokers to switch to e-cigarettes. However, the public health impact of e-cigarette ads could be negative if ads increase demand for both e-cigarettes and cigarettes. We use experimental auctions –in which participants bid in real auctions and winners pay for the items they purchase – to study the effect of print and TV e-cigarettes ads on demand for the brand from the ad, for another e-cigarettes brand, and for cigarettes. We ran experiments with 288 Pennsylvania smokers in November 2014–March 2015 and we found that in cases where an ad affects demand for e-cigarettes, the ad moves demand for cigarettes in the same direction. For example, the Blu print ad increases demand for Blu e-cigarettes and cigarettes among non-white participants. The Vuse TV ad reduces demand for both types of e-cigarettes and for cigarettes. We also find that non-white participants are willing to pay more for e-cigarettes in the absence of advertising, and that smokers who worry most about their health are willing to pay more for e-cigarettes. The results of this study point to the need for greater scrutiny of advertising for e-cigarette products such that they do not also induce demand for tobacco cigarettes.

  1. Experimental evidence for the interplay of exogenous and endogenous factors on the movement ecology of a migrating songbird.

    Directory of Open Access Journals (Sweden)

    Emily B Cohen

    Full Text Available Movement patterns during songbird migration remain poorly understood despite their expected fitness consequences in terms of survival, energetic condition and timing of migration that will carry over to subsequent phases of the annual cycle. We took an experimental approach to test hypotheses regarding the influence of habitat, energetic condition, time of season and sex on the hour-by-hour, local movement decisions of a songbird during spring stopover. To simulate arrival of nocturnal migrants at unfamiliar stopover sites, we translocated and continuously tracked migratory red-eyed vireos (Vireo olivaceus throughout spring stopover with and without energetic reserves that were released in two replicates of three forested habitat types. Migrants moved the most upon release, during which time they selected habitat characterized by greater food abundance and higher foraging attack rates. Presumably under pressure to replenish fuel stores necessary to continue migration in a timely fashion, migrants released in poorer energetic condition moved faster and further than migrants in better condition and the same pattern was true for migrants released late in spring relative to those released earlier. However, a migrant's energetic condition had less influence on their behavior when they were in poor quality habitat. Movement did not differ between sexes. Our study illustrates the importance of quickly finding suitable habitat at each stopover site, especially for energetically constrained migrants later in the season. If an initial period prior to foraging were necessary at each stop along a migrant's journey, non-foraging periods would cumulatively result in a significant energetic and time cost to migration. However, we suggest behavior during stopover is not solely a function of underlying resource distributions but is a complex response to a combination of endogenous and exogenous factors.

  2. Experimental evidence for the interplay of exogenous and endogenous factors on the movement ecology of a migrating songbird.

    Science.gov (United States)

    Cohen, Emily B; Moore, Frank R; Fischer, Richard A

    2012-01-01

    Movement patterns during songbird migration remain poorly understood despite their expected fitness consequences in terms of survival, energetic condition and timing of migration that will carry over to subsequent phases of the annual cycle. We took an experimental approach to test hypotheses regarding the influence of habitat, energetic condition, time of season and sex on the hour-by-hour, local movement decisions of a songbird during spring stopover. To simulate arrival of nocturnal migrants at unfamiliar stopover sites, we translocated and continuously tracked migratory red-eyed vireos (Vireo olivaceus) throughout spring stopover with and without energetic reserves that were released in two replicates of three forested habitat types. Migrants moved the most upon release, during which time they selected habitat characterized by greater food abundance and higher foraging attack rates. Presumably under pressure to replenish fuel stores necessary to continue migration in a timely fashion, migrants released in poorer energetic condition moved faster and further than migrants in better condition and the same pattern was true for migrants released late in spring relative to those released earlier. However, a migrant's energetic condition had less influence on their behavior when they were in poor quality habitat. Movement did not differ between sexes. Our study illustrates the importance of quickly finding suitable habitat at each stopover site, especially for energetically constrained migrants later in the season. If an initial period prior to foraging were necessary at each stop along a migrant's journey, non-foraging periods would cumulatively result in a significant energetic and time cost to migration. However, we suggest behavior during stopover is not solely a function of underlying resource distributions but is a complex response to a combination of endogenous and exogenous factors.

  3. Direct Observation of Cr3+ 3d States in Ruby: Toward Experimental Mechanistic Evidence of Metal Chemistry.

    Science.gov (United States)

    Hunault, Myrtille O J Y; Harada, Yoshihisa; Miyawaki, Jun; Wang, Jian; Meijerink, Andries; de Groot, Frank M F; van Schooneveld, Matti M

    2018-04-26

    The role of transition metals in chemical reactions is often derived from probing the metal 3d states. However, the relation between metal site geometry and 3d electronic states, arising from multielectronic effects, makes the spectral data interpretation and modeling of these optical excited states a challenge. Here we show, using the well-known case of red ruby, that unique insights into the density of transition metal 3d excited states can be gained with 2p3d resonant inelastic X-ray scattering (RIXS). We compare the experimental determination of the 3d excited states of Cr 3+ impurities in Al 2 O 3 with 190 meV resolution 2p3d RIXS to optical absorption spectroscopy and to simulations. Using the crystal field multiplet theory, we calculate jointly for the first time the Cr 3+ multielectronic states, RIXS, and optical spectra based on a unique set of parameters. We demonstrate that (i) anisotropic 3d multielectronic interactions causes different scaling of Slater integrals, and (ii) a previously not observed doublet excited state exists around 3.35 eV. These results allow to discuss the influence of interferences in the RIXS intermediate state, of core-hole lifetime broadenings, and of selection rules on the RIXS intensities. Finally, our results demonstrate that using an intermediate excitation energy between L 3 and L 2 edges allows measurement of the density of 3d excited states as a fingerprint of the metal local structure. This opens up a new direction to pump-before-destroy investigations of transition metal complex structures and reaction mechanisms.

  4. Experimental selective elevation of renal medullary blood flow in hypertensive rats: evidence against short-term hypotensive effect.

    Science.gov (United States)

    Bądzyńska, B; Sadowski, J

    2012-08-01

    Renal medullary blood flow (MBF) can be selectively increased by intrarenal or systemic infusion of bradykinin (Bk) in anaesthetized normotensive rats. We reproduced this effect in a number of rat models of arterial hypertension and examined whether increased perfusion of the renal medulla can cause a short-term decrease in blood pressure (BP) that is not mediated by increased renal excretion and depletion of body fluids. In uninephrectomized Sprague-Dawley rats, BP was elevated to approx. 145 mmHg by acute i.v. infusion of noradrenaline (NA) or angiotensin II (Ang II) (groups 1, 2), 2-week exposure to high-salt diet (3), high-salt diet + chronic low-dose infusion of Ang II using osmotic minipumps (4) or chronic high-dose Ang II infusion on normal diet (5). Uninephrectomized spontaneous hypertensive rats (SHR) were also examined (6,7). To selectively increase medullary perfusion, in anaesthetized rats, bradykinin was infused during 30-75 min into the renal medullary interstitium or intravenously. Bradykinin increased outer- and inner-medullary blood flow (laser-Doppler fluxes) by 10-20% in groups (1, 2), by 30-50% in groups (3, 4, 5) and approx. 20% in SHR (6, 7). The concurrent increase in total renal blood flow (Transonic probe) was < 3%. A minor (<3%) decrease in BP was seen only in rats acutely rendered hypertensive by NA or Ang II infusions; however, the decreases in BP and increases in medullary perfusion were not correlated. Thus, there was no evidence that in hypertensive rats, substantial selective increases in medullary perfusion can cause a short-term decrease in BP. © 2012 The Authors Acta Physiologica © 2012 Scandinavian Physiological Society.

  5. Experimental evidence for the effect of small wind turbine proximity and operation on bird and bat activity.

    Directory of Open Access Journals (Sweden)

    Jeroen Minderman

    Full Text Available The development of renewable energy technologies such as wind turbines forms a vital part of strategies to reduce greenhouse gas emissions worldwide. Although large wind farms generate the majority of wind energy, the small wind turbine (SWT, units generating <50 kW sector is growing rapidly. In spite of evidence of effects of large wind farms on birds and bats, effects of SWTs on wildlife have not been studied and are likely to be different due to their potential siting in a wider range of habitats. We present the first study to quantify the effects of SWTs on birds and bats. Using a field experiment, we show that bird activity is similar in two distance bands surrounding a sample of SWTs (between 6-18 m hub height and is not affected by SWT operation at the fine scale studied. At shorter distances from operating turbines (0-5 m, bat activity (measured as the probability of a bat "pass" per hour decreases from 84% (71-91% to 28% (11-54% as wind speed increases from 0 to 14 m/s. This effect is weaker at greater distances (20-25 m from operating turbines (activity decreases from 80% (65-89% to 59% (32-81%, and absent when they are braked. We conclude that bats avoid operating SWTs but that this effect diminishes within 20 m. Such displacement effects may have important consequences especially in landscapes where suitable habitat is limiting. Planning guidance for SWTs is currently lacking. Based on our results we recommend that they are sited at least 20 m away from potentially valuable bat habitat.

  6. Experimental and observational evidence reveals that predators in natural environments do not regulate their prey: They are passengers, not drivers

    Science.gov (United States)

    White, T. C. R.

    2013-11-01

    Among both ecologists and the wider community there is a tacit assumption that predators regulate populations of their prey. But there is evidence from a wide taxonomic and geographic range of studies that predators that are adapted to co-evolved prey generally do not regulate their prey. This is because predators either cannot reproduce as fast as their prey and/or are inefficient hunters unable to catch enough prey to sustain maximum reproduction. The greater capacity of herbivores to breed successfully is, however, normally restricted by a lack of enough food of sufficient quality to support reproduction. But whenever this shortage is alleviated by a large pulse of food, herbivores increase their numbers to outbreak levels. Their predators are unable to contain this increase, but their numbers, too, surge in response to this increase in food. Eventually both their populations will crash once the food supply runs out, first for the herbivores and then for the predators. Then an “over-run” of predators will further depress the already declining prey population, appearing to be controlling its abundance. This latter phenomenon has led many ecologists to conclude that predators are regulating the numbers of their prey. However, it is the same process that is revealed during outbreaks that limits populations of both predator and prey in “normal” times, although this is usually not readily apparent. Nevertheless, as all the diverse cases discussed here attest, the abundance of predators and their co-evolved prey are both limited by their food: the predators are passengers, not drivers.

  7. Spatio-Temporal Mapping of Matrix Remodeling and Evidence of in-situ Elastogenesis in Experimental Abdominal Aortic Aneurysms

    Science.gov (United States)

    Deb, Partha Pratim; Ramamurthi, Anand

    2014-01-01

    Spatio-temporal changes in the extracellular matrix (ECM) were studied within abdominal aortic aneurysms (AAA) generated in rats via elastase-infusion. At 7, 14, and 21 days post-induction, AAA tissues were divided into proximal, mid and distal regions based on their location relative to the renal arteries and region of maximal aortic diameter. Wall thicknesses differed significantly between the AAA spatial regions, initially increasing due to positive matrix remodeling, and then decreasing due to wall thinning and compaction of matrix as the disease progressed. Histological images analyzed using custom segmentation tools indicated significant differences in ECM composition and structure, versus healthy tissue and in the extent and nature of matrix remodeling, between the AAA spatial regions. Histology and immunofluorescence (IF) labeling provided evidence of neointimal AAA remodeling characterized by presence of elastin-containing fibers. This remodeling was effected by smooth muscle alpha actin-positive neointimal cells that transmission electron microscopy (TEM) showed to morphologically differ from medial SMCs. TEM of the neointima further showed presence of elongated deposits of amorphous elastin and presence of nascent, but not mature elastic fibers. These structures appeared to be deficient in at least one microfibrillar component, fibrillin-1, which is critical to mature elastic fiber assembly. The substantial production of elastin and elastic fiber-like structures that we observed in the AAA neointima, which was not observed elsewhere within AAA tissues, provides us a unique opportunity to capitalize on this auto-regenerative phenomenon and direct it from the standpoint of matrix organization towards restoring healthy aortic matrix structure, mechanics, and function. PMID:24799390

  8. Field and experimental evidence for coseismic ruptures along shallow creeping faults in forearc sediments of the Crotone Basin, South Italy

    Science.gov (United States)

    Balsamo, Fabrizio; Aldega, Luca; De Paola, Nicola; Faoro, Igor; Storti, Fabrizio

    2014-05-01

    Large seismic slip occurring along shallow creeping faults in tectonically active areas represents an unsolved paradox, which is largely due to our poor understanding of the mechanics governing creeping faults, and to the lack of documented geological evidence showing how coseismic rupturing overprints creep in near-surface conditions. In this contribution we integrate field, petrophysical, mineralogical and friction data to characterize the signature of coseismic ruptures propagating along shallow creeping faults affecting unconsolidated forearc sediments of the seismically active Crotone Basin, in South Italy. Field observations of fault zones show widespread foliated cataclasites in fault cores, locally overprinted by sharp slip surfaces decorated by thin (0.5-1.5 cm) black gouge layers. Compared to foliated cataclasites, black gouges have much lower grain size, porosity and permeability, which may have facilitated slip weakening by thermal fluid pressurization. Moreover, black gouges are characterized by distinct mineralogical assemblages compatible with high temperatures (180-200°C) due to frictional heating during seismic slip. Foliated cataclasites and black gouges were also produced by laboratory friction experiments performed on host sediments at sub-seismic (≤ 0.1 m/s) and seismic (1 m/s) slip rates, respectively. Black gouges display low friction coefficients (0.3) and velocity-weakening behaviours, as opposed to high friction coefficients (0.65) and velocity-strengthening behaviours shown by the foliated cataclasites. Our results show that narrow black gouges developed within foliated cataclasites represent a potential diagnostic marker for episodic seismic activity in shallow creeping faults. These findings can help understanding the time-space partitioning between aseismic and seismic slip of faults at shallow crustal levels, impacting on seismic hazard evaluation of subduction zones and forearc regions affected by destructive earthquakes and

  9. An experimental study of the job demand-control model with measures of heart rate variability and salivary alpha-amylase: Evidence of increased stress responses to increased break autonomy.

    Science.gov (United States)

    O'Donnell, Emma; Landolt, Kathleen; Hazi, Agnes; Dragano, Nico; Wright, Bradley J

    2015-01-01

    We assessed in an experimental design whether the stress response towards a work task was moderated by the autonomy to choose a break during the assigned time to complete the task. This setting is defined in accordance with the theoretical framework of the job-demand-control (JDC) model of work related stress. The findings from naturalistic investigations of a stress-buffering effect of autonomy (or 'buffer hypothesis') are equivocal and the experimental evidence is limited, especially with relation to physiological indices of stress. Our objective was to investigate if increased autonomy in a particular domain (break time control) was related with adaptive physiology using objective physiological markers of stress; heart rate variability (HRV) and salivary alpha amylase (sAA). We used a within-subject design and the 60 female participants were randomly assigned to an autonomy (free timing of break) and standard conditions (fixed timing of break) of a word processing task in a simulated office environment in a random order. Participants reported increased perceptions of autonomy, no difference in demand and performed worse in the task in the break-time autonomy versus the standard condition. The results revealed support for the manipulation of increased autonomy, but in the opposing direction. Increased autonomy was related with dysregulated physiological reactivity, synonymous with typical increased stress responses. Potentially, our findings may indicate that autonomy is not necessary a resource but could become an additional stressor when it adds additional complexity while the amount of work (demands) remains unchanged. Further, our findings underscore the need to collect objective physiological evidence of stress to supplement self-reported information. Self-report biases may partially explain the inconsistent findings with the buffer hypothesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Additive manufacturing.

    Science.gov (United States)

    Mumith, A; Thomas, M; Shah, Z; Coathup, M; Blunn, G

    2018-04-01

    Increasing innovation in rapid prototyping (RP) and additive manufacturing (AM), also known as 3D printing, is bringing about major changes in translational surgical research. This review describes the current position in the use of additive manufacturing in orthopaedic surgery. Cite this article: Bone Joint J 2018;100-B:455-60.

  11. Charge Transport in 4 nm Molecular Wires with Interrupted Conjugation: Combined Experimental and Computational Evidence for Thermally Assisted Polaron Tunneling.

    Science.gov (United States)

    Taherinia, Davood; Smith, Christopher E; Ghosh, Soumen; Odoh, Samuel O; Balhorn, Luke; Gagliardi, Laura; Cramer, Christopher J; Frisbie, C Daniel

    2016-04-26

    We report the synthesis, transport measurements, and electronic structure of conjugation-broken oligophenyleneimine (CB-OPI 6) molecular wires with lengths of ∼4 nm. The wires were grown from Au surfaces using stepwise aryl imine condensation reactions between 1,4-diaminobenzene and terephthalaldehyde (1,4-benzenedicarbaldehyde). Saturated spacers (conjugation breakers) were introduced into the molecular backbone by replacing the aromatic diamine with trans-1,4-diaminocyclohexane at specific steps during the growth processes. FT-IR and ellipsometry were used to follow the imination reactions on Au surfaces. Surface coverages (∼4 molecules/nm(2)) and electronic structures of the wires were determined by cyclic voltammetry and UV-vis spectroscopy, respectively. The current-voltage (I-V) characteristics of the wires were acquired using conducting probe atomic force microscopy (CP-AFM) in which an Au-coated AFM probe was brought into contact with the wires to form metal-molecule-metal junctions with contact areas of ∼50 nm(2). The low bias resistance increased with the number of saturated spacers, but was not sensitive to the position of the spacer within the wire. Temperature dependent measurements of resistance were consistent with a localized charge (polaron) hopping mechanism in all of the wires. Activation energies were in the range of 0.18-0.26 eV (4.2-6.0 kcal/mol) with the highest belonging to the fully conjugated OPI 6 wire and the lowest to the CB3,5-OPI 6 wire (the wire with two saturated spacers). For the two other wires with a single conjugation breaker, CB3-OPI 6 and CB5-OPI 6, activation energies of 0.20 eV (4.6 kcal/mol) and 0.21 eV (4.8 kcal/mol) were found, respectively. Computational studies using density functional theory confirmed the polaronic nature of charge carriers but predicted that the semiclassical activation energy of hopping should be higher for CB-OPI molecular wires than for the OPI 6 wire. To reconcile the experimental and

  12. Ionized Gas Kinematics around an Ultra-luminous X-Ray Source in NGC 5252: Additional Evidence for an Off-nuclear AGN

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minjin [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Im, Myungshin [Center for the Exploration of the Origin of the Universe (CEOU), Astronomy Program, Department of Physics and Astronomy, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)

    2017-08-01

    The Seyfert 2 galaxy NGC 5252 contains a recently identified ultra-luminous X-ray (ULX) source that has been suggested to be a possible candidate off-nuclear low-mass active galactic nucleus. We present follow-up optical integral-field unit observations obtained using Gemini Multi-Object Spectrographs on the Gemini-North telescope. In addition to confirming that the ionized gas in the vicinity of the ULX is kinematically associated with NGC 5252, the new observations reveal ordered motions consistent with rotation around the ULX. The close coincidence of the excitation source of the line-emitting gas with the position of the ULX further suggests that ULX itself is directly responsible for the ionization of the gas. The spatially resolved measurements of [N ii] λ 6584/H α surrounding the ULX indicate a low gas-phase metallicity, consistent with those of other known low-mass active galaxies but not that of its more massive host galaxy. These findings strengthen the proposition that the ULX is not a background source but rather that it is the nucleus of a small, low-mass galaxy accreted by NGC 5252.

  13. At the forefront: evidence of the applicability of using environmental DNA to quantify the abundance of fish populations in natural lentic waters with additional sampling considerations

    Science.gov (United States)

    Klobucar, Stephen L.; Rodgers, Torrey W.; Budy, Phaedra

    2017-01-01

    Environmental DNA (eDNA) sampling has proven to be a valuable tool for detecting species in aquatic ecosystems. Within this rapidly evolving field, a promising application is the ability to obtain quantitative estimates of relative species abundance based on eDNA concentration rather than traditionally labor-intensive methods. We investigated the relationship between eDNA concentration and Arctic char (Salvelinus alpinus) abundance in five well-studied natural lakes; additionally, we examined the effects of different temporal (e.g., season) and spatial (e.g., depth) scales on eDNA concentration. Concentrations of eDNA were linearly correlated with char population estimates ( = 0.78) and exponentially correlated with char densities ( = 0.96 by area; 0.82 by volume). Across lakes, eDNA concentrations were greater and more homogeneous in the water column during mixis; however, when stratified, eDNA concentrations were greater in the hypolimnion. Overall, our findings demonstrate that eDNA techniques can produce effective estimates of relative fish abundance in natural lakes. These findings can guide future studies to improve and expand eDNA methods while informing research and management using rapid and minimally invasive sampling.

  14. Evidence of a major locus for lipoprotein lipase (LPL) activity in addition to a pleiotropic locus for both LPL and fasting insulin: results from the HERITAGE Family Study.

    Science.gov (United States)

    Hong, Y; Rice, T; Després, J P; Gagnon, J; Nadeau, A; Bergeron, J; Pérusse, L; Bouchard, C; Leon, A S; Skinner, J S; Wilmore, J H; Rao, D C

    1999-06-01

    A major gene hypothesis for heparin releasable plasma lipoprotein lipase (PH-LPL) activity was assessed using segregation analyses of data on 495 members in 98 normolipidemic sedentary families of Caucasian descent who participated in the HERITAGE Family Study. Segregation analyses were performed on PH-LPL adjusted for age, and on PH-LPL activity adjusted for age and fasting insulin. Prior to adjustment for insulin, neither a major gene effect nor a multifactorial component could be rejected, and support for a major gene was equivocal i.e. neither the Mendelian transmission nor the no transmission (equal tau s) models were rejected. However, after adjusting for the effects of insulin, a major gene effect on PH-LPL activity was unambiguous. The putative locus accounted for 60% of the total phenotypic variance, and the homozygous recessive form affected 10% (q2) of the sample (i.e. gene frequency (q) = 0.31), and led to a low PH-LPL value. The lack of a significant multifactorial effect suggested that the familial etiology of PH-LPL activity adjusted for insulin was likely to be primarily a function of the major locus. In conclusion, the present study is the first to report segregation analyses on PH-LPL activity prior to and after adjusting for insulin, and suggests that there is an indication of a pleiotropic genetic effect on PH-LPL activity and insulin, in addition to a major gene effect on PH-LPL activity alone.

  15. Radial dependence of surface streamer-channel luminosity: experimental evidence of Gaussian radiative profiles in Ar and N2

    International Nuclear Information System (INIS)

    Šimek, M; Ambrico, P F

    2012-01-01

    Radial distributions of electronically excited species produced during surface streamer propagation were obtained by applying the Abel inverse transform to projected luminosities of single streamers. The streamers were generated in an argon and nitrogen surface coplanar dielectric barrier discharge at atmospheric pressure and their magnified microscopic images were registered with high time resolution. Selected regions of the projected luminosities were processed by the Abel inverse transform procedure based on the Hankel–Fourier method assuming cylindrical symmetry of the streamer channel. Projected as well as Abel-inverted profiles were fitted by Gaussian functions. It is shown that the projected profiles, in addition to the Abel-inverted ones, can be well approximated by the sum of two coaxial Gaussians with two different half-widths and weights. The sharper Gaussian component with higher weight characterizes the radial dependence of the primary cathode-directed streamer-channel luminosity. The second (broader) Gaussian component probably originates either from the pre-breakdown Townsend phase or from the second wave propagating towards the anode. (paper)

  16. Experimental evidence for non-redox transformations between magnetite and hematite under H 2-rich hydrothermal conditions

    Science.gov (United States)

    Otake, Tsubasa; Wesolowski, David J.; Anovitz, Lawrence M.; Allard, Lawrence F.; Ohmoto, Hiroshi

    2007-05-01

    Transformations of magnetite (Fe IIFe 2IIIO 4) to hematite (Fe 2IIIO 3) (and vice versa) have been thought by many scientists and engineers to require molecular O 2 and/or H 2. Thus, the presence of magnetite and/or hematite in rocks has been linked to a specific oxidation environment. However, the availability of reductants or oxidants in many geologic and industrial environments appears to have been too low to account for the transformations of iron oxides through redox reactions. Here, we report the results of hydrothermal experiments in mildly acidic and H 2-rich aqueous solutions at 150 °C, which demonstrate that transformations of magnetite to hematite, and hematite to magnetite, occur rapidly without involving molecular O 2 or H 2: Fe3O 4(Mt) + 2H (aq)+ ↔ Fe 2O 3(Hm) + Fe (aq)2+ + H 2O. The transformation products are chemically and structurally homogeneous, and typically occur as euhedral single crystals much larger than the precursor minerals. This suggests that, in addition to the expected release of aqueous ferrous species to solution, the transformations involve release of aqueous ferric species from the precursor oxides to the solution, which reprecipitate without being reduced by H 2. These redox-independent transformations may have been responsible for the formation of some iron oxides in natural systems, such as high-grade hematite ores that developed from Banded Iron Formations (BIFs), hematite-rich deposits formed on Mars, corrosion products in power plants and other industrial systems.

  17. Additive genetic variation in resistance traits of an exotic pine species: little evidence for constraints on evolution of resistance against native herbivores.

    Science.gov (United States)

    Moreira, X; Zas, R; Sampedro, L

    2013-05-01

    The apparent failure of invasions by alien pines in Europe has been explained by the co-occurrence of native pine congeners supporting herbivores that might easily recognize the new plants as hosts. Previous studies have reported that exotic pines show reduced tolerance and capacity to induce resistance to those native herbivores. We hypothesize that limited genetic variation in resistance to native herbivores and the existence of evolutionary trade-offs between growth and resistance could represent additional potential constraints on the evolution of invasiveness of exotic pines outside their natural range. In this paper, we examined genetic variation for constitutive and induced chemical defences (measured as non-volatile resin in the stem and total phenolics in the needles) and resistance to two major native generalist herbivores of pines in cafeteria bioassays (the phloem-feeder Hylobius abietis and the defoliator Thaumetopoea pityocampa) using half-sib families drawn from a sample of the population of Pinus radiata introduced to Spain in the mid-19th century. We found (i) significant genetic variation, with moderate-to-high narrow-sense heritabilities for both the production of constitutive non-volatile resin and induced total phenolics, and for constitutive resistance against T. pityocampa in bioassays, (ii) no evolutionary trade-offs between plant resistance and growth traits or between the production of different quantitative chemical defences and (iii) a positive genetic correlation between constitutive resistance to the two studied herbivores. Overall, results of our study indicate that the exotic pine P. radiata has limited genetic constraints on the evolution of resistance against herbivores in its introduced range, suggesting that, at least in terms of interactions with these enemies, this pine species has potential to become invasive in the future.

  18. Experimental evidence of inter-blade cavitation vortex development in Francis turbines at deep part load condition

    Science.gov (United States)

    Yamamoto, K.; Müller, A.; Favrel, A.; Avellan, F.

    2017-10-01

    Francis turbines are subject to various types of cavitation flow depending on the operating condition. To enable a smooth integration of the renewable energy sources, hydraulic machines are now increasingly required to extend their operating range, especially down to extremely low discharge conditions called deep part load operation. The inter-blade cavitation vortex is a typical cavitation phenomenon observed at deep part load operation. However, its dynamic characteristics are insufficiently understood today. In an objective of revealing its characteristics, the present study introduces a novel visualization technique with instrumented guide vanes embedding the visualization devices, providing unprecedented views on the inter-blade cavitation vortex. The binary image processing technique enables the successful evaluation of the inter-blade cavitation vortex in the images. As a result, it is shown that the probability of the inter-blade cavitation development is significantly high close to the runner hub. Furthermore, the mean vortex line is calculated and the vortex region is estimated in the three-dimensional domain for the comparison with numerical simulation results. In addition, the on-board pressure measurements on a runner blade is conducted, and the influence of the inter-blade vortex on the pressure field is investigated. The analysis suggests that the presence of the inter-blade vortex can magnify the amplitude of pressure fluctuations especially on the blade suction side. Furthermore, the wall pressure difference between pressure and suction sides of the blade features partially low or negative values near the hub at the discharge region where the inter-blade vortex develops. This negative pressure difference on the blade wall suggests the development of a backflow region caused by the flow separation near the hub, which is closely related to the development of the inter-blade vortex. The development of the backflow region is confirmed by the numerical

  19. Vertical linear feeder to elliptical igneous saucer-shaped sills: evidences from structural observations, geochemistry and experimental modeling

    Science.gov (United States)

    Galerne, C. Y.; Galland, O.; Neumann, E. R.; Planke, S.

    2009-12-01

    The structural relationships between sills and their feeders are poorly documented because they are rarely observed in the field and difficult to image on seismic data. For instance, it is unclear whether sills are fed by pipes, dikes or other sills. Nevertheless, the geometrical relationships between sills and their feeders provide first-order constraints on magma emplacement mechanisms. Here, we investigate the structural and geochemical relationships between sills and potential feeder dikes in a remarkably well-preserved and exposed sill complex, the Golden Valley Sill Complex (GVSC), Karoo Basin, South Africa. The GVSC consists of five major saucer-shaped sills and six dikes. The Golden Valley sill itself is an elliptical saucer, with a N-S trend. A one meter thick dike (D4) crops out underneath the southern tip of the Golden Valley sill. The strike of this dike is parallel to the long axis of the Golden Valley sill. Detailed sampling and geochemical analyses of the GVSC show that each sill and dike exhibits a specific geochemical signature. The Golden Valley sill and its underlying dike D4 have identical signatures. Although there is no clear structural evidence, the consistent geometrical and geochemical relationships between the Golden Valley sill and the D4 dike suggest that this vertical linear structure is the feeder of the overlying saucer-shaped sill. In order to investigate the relationships between sills and feeders, we resorted to scaled laboratory experiments. The experiments consisted of a low-viscosity vegetable oil representing magma and a cohesive fine-grained silica flour representing brittle rocks. We placed a horizontal weak layer into the silica flour, just above the top of the inlet, to simulate strata. Such a weak layer controlled the formation of horizontal sill that subsequently turned into a transgressive sheet leading to the formation of a saucer geometry. We ran experiments with varying inlet shapes: 1) a point inlet representing a

  20. Adição de inulina em géis de amido e leite utilizando planejamento experimental de misturas Addition of inulin to starch and milk gels using an experimental mixture design

    Directory of Open Access Journals (Sweden)

    Luciana Pereira Lobato

    2012-06-01

    Full Text Available O objetivo deste estudo foi investigar o efeito combinado de inulina, amido e leite nas características texturais de géis e de propriedades de pastas empregando o planejamento experimental de misturas. Foram avaliados o perfil viscoamilográfico e a firmeza dos géis. Em todos os parâmetros avaliados, os modelos ajustados mostraram-se influenciados pela presença de inulina, amido e leite, assim como de algumas interações desses ingredientes. A viscosidade máxima e a viscosidade final foram influenciadas positivamente pela concentração de amido e negativamente pelas interações deste com leite e com inulina. A firmeza dos géis aumentou com o aumento do teor de amido, mas a interação amido-inulina foi antagônica, contribuindo para diminuir essa característica. O efeito da interação entre amido e inulina pode ser explicado pelo fato de que a inulina possui maior afinidade pela água, em relação ao amido, ou, ainda, por agir como diluente, fazendo com que haja menor contato entre os grânulos e/ou cadeias de amido. A partir dos resultados encontrados neste estudo, verifica-se que a inclusão da inulina em sistemas amido-leite pode influenciar nas características texturais e de viscosidade, possivelmente refletindo-se nas características sensoriais. Com isso, a avaliação das interações com outros ingredientes da formulação torna-se essencial.The objective of this work was to investigate the combined effect of milk, starch and inulin on the textural characteristics of gels and on the pasting properties, using an experimental mixture design. Gel firmness and the amylographic profile were evaluated. For all the parameters evaluated, the fitted models were shown to be influenced by the presence of inulin, starch and milk, as also some of the interactions between the ingredients. The maximum viscosity and final viscosity were positively influenced by the starch concentration and negatively by interactions between the starch and

  1. Food additives

    Science.gov (United States)

    ... GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Food additives URL of this page: //medlineplus.gov/ency/article/ ...

  2. Experimental evidence of a dual endocrine control of biosynthesis in the main nidamental glands of Sepia officinalis L. by factors from the central nervous system and the ovary.

    Science.gov (United States)

    Henry, J; Boucaud-Camou, E

    1993-12-01

    1. A rapid, reliable and quantitative in vitro bioassay was developed to study the endocrine control of the biosynthesis of the egg capsule: incorporation of 14C-labelled D-glucose in polysaccharides and glycoproteins increased in dispersed-cell suspensions of main nidamental glands from maturing females. 2. Brain, optic lobes (OL) and ovary extracts from mature and maturing females stimulated the incorporation of 14C-labelled D-glucose in polysaccharidic and glycoproteic fractions of a nidamental cell suspension, whereas optic gland (OG) had no effect. 3. These results bring the first experimental evidence that one of the spawning events (egg-capsule edification) is controlled by the central nervous system and the ovary in a cephalopod.

  3. Correlation between catalytic activity and bonding and coordination number of atoms and molecules on transition metal surfaces: theory and experimental evidence

    International Nuclear Information System (INIS)

    Falicov, L.M.; Somorjai, G.A.

    1985-01-01

    Correlation between catalytic activity and low-energy local electronic fluctuation in transition metals is proposed. A theory and calculations are presented which indicate that maximum electronic fluctuants take place at high-coordination metal sites. Either (i) atomically rough surfaces that expose to the reactant molecules atoms with large numbers of nonmagnetic or weakly magnetic neighbors in the first or second layer at the surface or (ii) stepped and kinked surfaces are the most active in carrying out structure-sensitive catalytic reactions. The synthesis of ammonia from N 2 and H 2 over iron and rhenium surfaces, 1 H 2 / 2 H 2 exchange over stepped platinum crystal surfaces at low pressures, and the hydrogenolysis (C - C bond breaking) of isobutane at kinked platinum crystal surfaces are presented as experimental evidence in support of the theory

  4. Experimental violation of entropic inequalities

    International Nuclear Information System (INIS)

    Bovino, F.A.; Castagnoli, G.; Ekert, A.; Horodecki, P.; Alves, C.M.; Sergienko, A.V.

    2005-01-01

    Full text: We report the experimental evidence that polarization entangled photons violate the inequality based on Renyi entropy. Our experimental method is based on four-photon coincidences in photon bunching and antibunching effects. We introduce an additional 'phase marking' technique, which allow observing the violation of the inequalities even with non-deterministic sources of entangled photons. Our method can be applied to measure selected non-linear properties of bipartite quantum states, such as purity or entanglement. (author)

  5. Experimental evidence for negative turgor pressure in small leaf cells of Robinia pseudoacacia L versus large cells of Metasequoia glyptostroboides Hu et W.C.Cheng. 1. Evidence from pressure-volume curve analysis of dead tissue.

    Science.gov (United States)

    Yang, Dongmei; Pan, Shaoan; Ding, Yiting; Tyree, Melvin T

    2017-03-01

    This paper provides a mini-review of evidence for negative turgor pressure in leaf cells starting with experimental evidence in the late 1950s and ending with biomechanical models published in 2014. In the present study, biomechanical models were used to predict how negative turgor pressure might be manifested in dead tissue, and experiments were conducted to test the predictions. The main findings were as follows: (i) Tissues killed by heating to 60 or 80 °C or by freezing in liquid nitrogen all became equally leaky to cell sap solutes and all seemed to pass freely through the cell walls. (ii) Once cell sap solutes could freely pass the cell walls, the shape of pressure-volume curves was dramatically altered between living and dead cells. (iii) Pressure-volume curves of dead tissue seem to measure negative turgor defined as negative when inside minus outside pressure is negative. (iv) Robinia pseudoacacia leaves with small palisade cells had more negative turgor than Metasequoia glyptostroboides with large cells. (v) The absolute difference in negative turgor between R. pseudoacacia and M. glyptostroboides approached as much as 1.0 MPa in some cases. The differences in the manifestation of negative turgor in living versus dead tissue are discussed. © 2016 John Wiley & Sons Ltd.

  6. In vivo evidence for CD4+ and CD8+ suppressor T cells in vaccination-induced suppression of murine experimental autoimmune thyroiditis

    International Nuclear Information System (INIS)

    Flynn, J.C.; Kong, Y.C.

    1991-01-01

    In several experimental autoimmune diseases, including experimental autoimmune thyroiditis (EAT), vaccination with attenuated autoantigen-specific T cells has provided protection against subsequent induction of disease. However, the mechanism(s) of vaccination-induced suppression remains to be clarified. Since the authors have previously shown that suppression generated by pretreatment with mouse thyroglobulin (MTg) or thyroid-stimulating hormone in EAT is mediated by CD4+, not CD8+, suppressor T cells, they examined the role of T cell subsets in vaccination-induced suppression of EAT. Mice were vaccinated with irradiated, MTg-primed, and MTg-activated spleen cells and then challenged. Pretreatment with these cells suppressed EAT induced by immunization with MTg and adjuvant, but not by adoptive transfer of thyroiditogenic cells, suggesting a mechanism of afferent suppression. The activation of suppressor mechanisms did not require CD8+ cells, since mice depleted of CD8+ cells before vaccination showed reduced EAT comparable to control vaccinated mice. Furthermore, depletion of either the CD4+ or the CD8+ subset after vaccination did not significantly abrogate suppression. However, suppression was eliminated by the depletion of both CD4+ and CD8+ cells in vaccinated mice. These results provide evidence for the cooperative effects of CD4+ and CD8+ T cells in vaccination-induced suppression of EAT

  7. Experimental evidence and geological implications

    Indian Academy of Sciences (India)

    explained in the framework of the superradiance applied to the solid state, where individual atoms lose ... Neither radioactive wastes, nor gamma emissions were recorded, but only thermal and fast neutron ... The management software was.

  8. Complex regulation of Hsf1-Skn7 activities by the catalytic subunits of PKA in Saccharomyces cerevisiae: experimental and computational evidences.

    Science.gov (United States)

    Pérez-Landero, Sergio; Sandoval-Motta, Santiago; Martínez-Anaya, Claudia; Yang, Runying; Folch-Mallol, Jorge Luis; Martínez, Luz María; Ventura, Larissa; Guillén-Navarro, Karina; Aldana-González, Maximino; Nieto-Sotelo, Jorge

    2015-07-27

    The cAMP-dependent protein kinase regulatory network (PKA-RN) regulates metabolism, memory, learning, development, and response to stress. Previous models of this network considered the catalytic subunits (CS) as a single entity, overlooking their functional individualities. Furthermore, PKA-RN dynamics are often measured through cAMP levels in nutrient-depleted cells shortly after being fed with glucose, dismissing downstream physiological processes. Here we show that temperature stress, along with deletion of PKA-RN genes, significantly affected HSE-dependent gene expression and the dynamics of the PKA-RN in cells growing in exponential phase. Our genetic analysis revealed complex regulatory interactions between the CS that influenced the inhibition of Hsf1/Skn7 transcription factors. Accordingly, we found new roles in growth control and stress response for Hsf1/Skn7 when PKA activity was low (cdc25Δ cells). Experimental results were used to propose an interaction scheme for the PKA-RN and to build an extension of a classic synchronous discrete modeling framework. Our computational model reproduced the experimental data and predicted complex interactions between the CS and the existence of a repressor of Hsf1/Skn7 that is activated by the CS. Additional genetic analysis identified Ssa1 and Ssa2 chaperones as such repressors. Further modeling of the new data foresaw a third repressor of Hsf1/Skn7, active only in the absence of Tpk2. By averaging the network state over all its attractors, a good quantitative agreement between computational and experimental results was obtained, as the averages reflected more accurately the population measurements. The assumption of PKA being one molecular entity has hindered the study of a wide range of behaviors. Additionally, the dynamics of HSE-dependent gene expression cannot be simulated accurately by considering the activity of single PKA-RN components (i.e., cAMP, individual CS, Bcy1, etc.). We show that the differential

  9. Improving implementation of evidence-based practice in mental health service delivery: protocol for a cluster randomised quasi-experimental investigation of staff-focused values interventions.

    Science.gov (United States)

    Williams, Virginia; Oades, Lindsay G; Deane, Frank P; Crowe, Trevor P; Ciarrochi, Joseph; Andresen, Retta

    2013-07-02

    There is growing acceptance that optimal service provision for individuals with severe and recurrent mental illness requires a complementary focus on medical recovery (i.e., symptom management and general functioning) and personal recovery (i.e., having a 'life worth living'). Despite significant research attention and policy-level support, the translation of this vision of healthcare into changed workplace practice continues to elude. Over the past decade, evidence-based training interventions that seek to enhance the knowledge, attitudes, and skills of staff working in the mental health field have been implemented as a primary redress strategy. However, a large body of multi-disciplinary research indicates disappointing rates of training transfer. There is an absence of empirical research that investigates the importance of worker-motivation in the uptake of desired workplace change initiatives. 'Autonomy' is acknowledged as important to human effectiveness and as a correlate of workplace variables like productivity, and wellbeing. To our knowledge, there have been no studies that investigate purposeful and structured use of values-based interventions to facilitate increased autonomy as a means of promoting enhanced implementation of workplace change. This study involves 200 mental health workers across 22 worksites within five community-managed organisations in three Australian states. It involves cluster-randomisation of participants within organisation, by work site, to the experimental (values) condition, or the control (implementation). Both conditions receive two days of training focusing on an evidence-based framework of mental health service delivery. The experimental group receives a third day of values-focused intervention and 12 months of values-focused coaching. Well-validated self-report measures are used to explore variables related to values concordance, autonomy, and self-reported implementation success. Audits of work files and staff work samples

  10. An experimental study on providing a scientific evidence for seven-time alcohol-steaming of Rhei Rhizoma when clinically used.

    Science.gov (United States)

    Sim, Yeomoon; Oh, Hyein; Oh, Dal-Seok; Kim, Namkwon; Gu, Pil Sung; Choi, Jin Gyu; Kim, Hyo Geun; Kang, Tong Ho; Oh, Myung Sook

    2015-10-27

    Rhei Rhizoma (RR) has been widely used as laxative and processed to alter its therapeutic actions or reduce its side effects. In this study, we evaluated experimentally the clinical application guideline that RR should be alcohol-steamed seven times before being used in elderly patients, as described in Dongeuibogam, the most famous book on Korean traditional medicine. Unprocessed RR (RR-U) was soaked in rice wine, steamed and then fully dried (RR-P1). The process was repeated four (RR-P4) or seven times (RR-P7). Reversed-phase high-performance liquid chromatography was used to determine the RR-U, RR-P1, RR-P4 and RR-P7 (RRs) constituents. To evaluate the effect of RRs on liver toxicity, human hepatoma cells (HepG2) were treated with RRs at 100 μg/mL for 4 h and then cell viabilities were measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. To confirm the effects in vivo, 5-week-old male Sprague-Dawley rats were treated with RRs at 3 g/kg/day for 21 days. Body weight and serum biochemical parameters were measured and liver histology was assessed. The levels of sennosides decreased in processed RRs in an iteration-dependent manner, while the emodin level was unaffected. In HepG2 cells, cell viability was reduced with RR-U, while the toxicity decreased according to the number of processing cycles. The changes in body weight, relative liver weight and liver enzymes of RR-U-treated rats were reduced in processed RRs-treated rats. Histopathological analysis indicated swelling and cholestasis improved following seven times alcohol-steaming cycles. These results provide experimental evidence that RR-P7 almost completely reduces RR hepatotoxicity.

  11. Additive versus multiplicative muon conservation

    International Nuclear Information System (INIS)

    Nemethy, P.

    1981-01-01

    Experimental elucidation of the question of muon conservation is reviewed. It is shown that neutral-current experiments have not yet yielded information about muonium-antimuonium conversion at the weak-interaction level and that all the charged-current experiments agree that there is no evidence for a multiplicative law. The best limits, from the muon-decay neutrino experiment at LAMPF and from the inverse muon-decay experiment in the CERN neutrino beam, definitely exclude multiplicative law schemes with a branching ratio R approximately 1/2. It is concluded that unless the dynamics conspire to make a multiplicative law with very small R it would appear that muon conservation obeys conserved additive lepton flavor law. (U.K.)

  12. Experimental study of heterogeneous organic chemistry induced by far ultraviolet light: Implications for growth of organic aerosols by CH3 addition in the atmospheres of Titan and early Earth

    Science.gov (United States)

    Hong, Peng; Sekine, Yasuhito; Sasamori, Tsutoni; Sugita, Seiji

    2018-06-01

    Formation of organic aerosols driven by photochemical reactions has been observed and suggested in CH4-containing atmospheres, including Titan and early Earth. However, the detailed production and growth mechanisms of organic aerosols driven by solar far ultraviolet (FUV) light remain poorly constrained. We conducted laboratory experiments simulating photochemical reactions in a CH4sbnd CO2 atmosphere driven by the FUV radiations dominated by the Lyman-α line. In the experiments, we analyzed time variations in thickness and infrared spectra of solid organic film formed on an optical window in a reaction cell. Gas species formed by FUV irradiation were also analyzed and compared with photochemical model calculations. Our experimental results show that the growth rate of the organic film decreases as the CH4/CO2 ratio of reactant gas mixture decreases, and that the decrease becomes very steep for CH4/CO2 organic film but that the addition reaction of CH3 radicals onto the organic film with the reaction probability around 10-2 can explain the growth rate. At CH4/CO2 organic film. Our results suggest that organic aerosols would grow through CH3 addition onto the surface during the precipitation of aerosol particles in the middle atmosphere of Titan and early Earth. On Titan, effective CH3 addition would reduce C2H6 production in the atmosphere. On early Earth, growth of aerosol particles would be less efficient than those on Titan, possibly resulting in small-sized monomers and influencing UV shielding.

  13. Characterization of the Kootenai River Algae Community and Primary Productivity Before and After Experimental Nutrient Addition, 2004–2007 [Chapter 2, Kootenai River Algal Community Characterization, 2009 KTOI REPORT].

    Energy Technology Data Exchange (ETDEWEB)

    Holderman, Charlie [Kootenai Tribe of Idaho; Bonners Ferry, ID; Anders, Paul [Cramer Fish Sciences; Moscow, ID; Shafii, Bahman [Statistical Consulting Services; Clarkston, WA

    2009-07-01

    The Kootenai River ecosystem (spelled Kootenay in Canada) has experienced numerous ecological changes since the early 1900s. Some of the largest impacts to habitat, biological communities, and ecological function resulted from levee construction along the 120 km of river upstream from Kootenay Lake, completed by the 1950s, and the construction and operation of Libby Dam on the river near Libby Montana, completed in 1972. Levee construction isolated tens of thousands of hectares of historic functioning floodplain habitat from the river channel downstream in Idaho and British Columbia (B.C.) severely reducing natural biological productivity and habitat diversity crucial to large river-floodplain ecosystem function. Libby Dam greatly reduces sediment and nutrient transport to downstream river reaches, and dam operations cause large changes in the timing, duration, and magnitude of river flows. These and other changes have contributed to the ecological collapse of the post-development Kootenai River ecosystem and its native biological communities. In response to large scale loss of nutrients, experimental nutrient addition was initiated in the North Arm of Kootenay Lake in 1992, in the South Arm of Kootenay Lake in 2004, and in the Kootenai River at the Idaho-Montana border during 2005. This report characterizes baseline chlorophyll concentration and accrual (primary productivity) rates and diatom and algal community composition and ecological metrics in the Kootenai River for four years, one (2004) before, and three (2005 through 2007) after nutrient addition. The study area encompassed a 325 km river reach from the upper Kootenay River at Wardner, B.C. (river kilometer (rkm) 445) downstream through Montana and Idaho to Kootenay Lake in B.C. (rkm 120). Sampling reaches included an unimpounded reach furthest upstream and four reaches downstream from Libby Dam affected by impoundment: two in the canyon reach (one with and one without nutrient addition), a braided reach

  14. Effectiveness of an evidence-based practice (EBP) course on the EBP competence of undergraduate nursing students: A quasi-experimental study.

    Science.gov (United States)

    Ruzafa-Martínez, María; López-Iborra, Lidón; Armero Barranco, David; Ramos-Morcillo, Antonio Jesús

    2016-03-01

    International nursing institutions and experts recommend evidence-based practice (EBP) as a core component of the curriculum for nurses. However, the impact of EBP training on the competence of undergraduate nursing students remains unclear. To evaluate the effectiveness of an EBP course on the EBP competence undergraduate nursing students'. Quasi-experimental study carried out in non-randomized intervention and control groups. The study was conducted in a Spanish public university in 2010. Out of 420 second- and third-year nursing students, 75 were enrolled in the EBP course, forming the intervention group, and 73 were not enrolled in this course were recruited as controls. The educational intervention was a 15-week course designed to teach EBP competence. The EBP Competence Questionnaire (EBP-COQ) was administered before and after the intervention. Repeated-measure ANOVA was used to compare intervention and control group scores before and at two months after the 15-week intervention period. At 2months after the EBP course, mean EBP-COQ scores of the intervention group were significantly improved versus baseline in attitude (4.28 vs. 3.33), knowledge (3.92 vs. 2.82) and skills (4.01 vs. 2.75) dimensions, whereas little change was observed in control group scores over the same time period. Repeated-measures ANOVA revealed a significant effect of Time ×Group interaction on global competence and all three EBP-COQ dimensions. Undergraduate nursing students experience positive changes in EBP competence, knowledge, skills, and attitude as the result of a 15-week educational intervention on EBP. This EBP course may provide nursing school educators and policymakers with a useful model for integrating EBP teaching within the nursing curriculum. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Phasons modulate the atomic Debye-Waller factors in incommensurate structures: Experimental evidence in ThBr4 at 55 K

    International Nuclear Information System (INIS)

    Madariaga, G.; Perez-Mato, J.M.; Aramburu, I.

    1993-01-01

    The incommensurate displacive structure of β-ThBr 4 at 55 K has been determined from a neutron diffraction data set including main reflections and first-order satellites. The superspace group is Psub(s anti 1 s1)sup(I4 1 /amd). Final agreement factors are 0.0193, 0.0186 and 0.045 for all, main and satellite reflections, respectively. It is shown that the effect of phasons on the atomic Debye-Waller factors can be quantified by two additional structural parameters: The modulus β 11,2 Br and the phase χ 11,2 Br of a second harmonic that spatially modulates the temperature factors of Br atoms. Results are in good agreement, within the resolution of the experimental data, with the theoretically expected value for χ 11,2 Br . Crystal data for the average structure: M r =551.65, tetragonal, I4 1 /amd, a=8.919(1), c=7.902(1) A, V=628.6(2) A 3 , Z=4, D x =5.82 Mg m -3 , λ=0.84 A, wavevector q=0.32c*. (orig.)

  16. No evidence of horizontal infection in horses kept in close contact with dogs experimentally infected with canine influenza A virus (H3N8

    Directory of Open Access Journals (Sweden)

    Yamanaka Takashi

    2012-04-01

    Full Text Available Abstract Background Since equine influenza A virus (H3N8 was transmitted to dogs in the United States in 2004, the causative virus, which is called canine influenza A virus (CIV, has become widespread in dogs. To date, it has remained unclear whether or not CIV-infected dogs could transmit CIV to horses. To address this, we tested whether or not close contact between horses and dogs experimentally infected with CIV would result in its interspecies transmission. Methods Three pairs of animals consisting of a dog inoculated with CIV (108.3 egg infectious dose50/dog and a healthy horse were kept together in individual stalls for 15 consecutive days. During the study, all the dogs and horses were clinically observed. Virus titres in nasal swab extracts and serological responses were also evaluated. In addition, all the animals were subjected to a gross pathological examination after euthanasia. Results All three dogs inoculated with CIV exhibited clinical signs including, pyrexia, cough, nasal discharge, virus shedding and seroconversion. Gross pathology revealed lung consolidations in all the dogs, and Streptococcus equi subsp. zooepidemicus was isolated from the lesions. Meanwhile, none of the paired horses showed any clinical signs, virus shedding or seroconversion. Moreover, gross pathology revealed no lesions in the respiratory tracts including the lungs of the horses. Conclusions These findings may indicate that a single dog infected with CIV is not sufficient to constitute a source of CIV infection in horses.

  17. Effects of dietary additives (potassium diformate/organic acids) as well as influences of grinding intensity (coarse/fine) of diets for weaned piglets experimentally infected with Salmonella Derby or Escherichia coli.

    Science.gov (United States)

    Taube, V A; Neu, M E; Hassan, Y; Verspohl, J; Beyerbach, M; Kamphues, J

    2009-06-01

    The aim of this study was to examine whether and to what extent the addition of potassium diformate (pdf) or free organic acids (fpa) to the diet and the grinding intensity might affect the course of infection and the passage of orally applied Salmonella and Escherichia coli in pigs. Experiments were carried out using 80 reared piglets allotted to four groups. Pigs were fed pelleted diets ad libitum (except during a 15 h feed-withholding-period before infection). The control diet contained finely ground cereals (2 mm screen). To two test diets (also finely ground) 1.2% pdf, 0.9% organic acids (75% formic and 25% propionic acid, fpa) respectively were added. The fourth diet (without acids) was based on coarsely ground cereals (6-mm screen). After experimental infection alternately with S. Derby or E. coli, the course of infection was examined (rectal swab technique). Pigs were sacrificed 4-5 h after a further oral application of approximately 10(9)-10(10) CFU S. Derby or E. coli to determine the counts of Salmonella or E. coli in chyme (classical culture methods). Adding pdf or fpa to the diet led to reduced Salmonella shedding and resulted in significantly lower counts of Salmonella and E. coli in the stomach content indicating an improved efficacy of the stomach barrier. In the distal parts of the digestive tract, the effect was less obvious concerning counts of E. coli, whereas counts of Salmonella were reduced markedly as well. The diet based on coarsely ground cereals failed to demonstrate positive effects concerning infection and passage of orally applied bacteria as well, but this diet was also pelleted and showed unintentionally, comparable amounts of fine particles. Results obtained in this study allow the recommendation of using pdf or organic acids as additives when dietary measures against Salmonella or E. coli in pigs are required.

  18. Further evidence of the cross-reactivity of the Binax NOW® Filariasis ICT cards to non-Wuchereria bancrofti filariae: experimental studies with Loa loa and Onchocerca ochengi.

    Science.gov (United States)

    Wanji, Samuel; Amvongo-Adjia, Nathalie; Njouendou, Abdel Jelil; Kengne-Ouafo, Jonas Arnaud; Ndongmo, Winston Patrick Chounna; Fombad, Fanny Fri; Koudou, Benjamin; Enyong, Peter A; Bockarie, Moses

    2016-05-05

    The immunochromatographic test (ICT) for lymphatic filariasis is a serological test designed for unequivocal detection of circulating Wuchereria bancrofti antigen. It was validated and promoted by WHO as the primary diagnostic tool for mapping and impact monitoring for disease elimination following interventions. The initial tests for specificity and sensitivity were based on samples collected in areas free of loiasis and the results suggested a near 100% specificity for W. bancrofti. The possibility of cross-reactivity with non-Wuchereria bancrofti antigens was not investigated until recently, when false positive results were observed in three independent studies carried out in Central Africa. Associations were demonstrated between ICT positivity and Loa loa microfilaraemia, but it was not clearly established if these false positive results were due to L. loa or can be extended to other filarial nematodes. This study brought further evidences of the cross-reactivity of ICT card with L. loa and Onchocerca ochengi (related to O. volvulus parasite) using in vivo and in vitro systems. Two filarial/host experimental systems (L. loa-baboon and O. ochengi-cattle) and the in vitro maintenance of different stages (microfilariae, infective larvae and adult worm) of the two filariae were used in three experiments per filarial species. First, whole blood and sera samples were prepared from venous blood of patent baboons and cattle, and applied on ICT cards to detect circulating filarial antigens. Secondly, larval stages of L. loa and O. ochengi as well as O. ochengi adult males were maintained in vitro. Culture supernatants were collected and applied on ICT cards after 6, 12 and 24 h of in vitro maintenance. Finally, total worm extracts (TWE) were prepared using L. loa microfilariae (Mf) and O. ochengi microfilariae, infective larvae and adult male worms. TWE were also tested on ICT cards. For each experiment, control assays (whole blood and sera from uninfected babon

  19. Varying the number of bidders in the first-price sealed-bid auction: experimental evidence for the one-shot game

    NARCIS (Netherlands)

    Füllbrunn, S.C.; Neugebauer, T.

    2013-01-01

    The paper reports experimental data on the behavior in the first-price sealed-bid auction for a varying number of bidders when values and bids are private information. This feedback-free design is proposed for the experimental test of the one-shot game situation. We consider both within-subjects and

  20. Long-term effects of neighbourhood deprivation on diabetes risk: quasi-experimental evidence from a refugee dispersal policy in Sweden.

    Science.gov (United States)

    White, Justin S; Hamad, Rita; Li, Xinjun; Basu, Sanjay; Ohlsson, Henrik; Sundquist, Jan; Sundquist, Kristina

    2016-06-01

    Although studies have shown associations between neighbourhood quality and chronic disease outcomes, such associations are potentially confounded by the selection of different types of people into different neighbourhood environments. We sought to identify the causal effects of neighbourhood deprivation on type 2 diabetes risk, by comparing refugees in Sweden who were actively dispersed by government policy to low-deprivation, moderate-deprivation, or high-deprivation neighbourhoods. In this quasi-experimental study, we analysed national register data for refugees who arrived in Sweden aged 25-50 years, at a time when the government policy involved quasi-random dispersal of refugees to neighbourhoods with different levels of poverty and unemployment, schooling, and social welfare participation. Individuals in our sample were assigned to a neighbourhood categorised as high deprivation (≥1 SD above the mean), moderate deprivation (within 1 SD of the mean), or low deprivation (≥1 SD below the mean). The primary outcome was new diagnosis of type 2 diabetes between Jan 1, 2002, and Dec 31, 2010. We used multivariate logistic and linear regressions to assess the effects of neighbourhood deprivation on diabetes risk, controlling for potential confounders affecting neighbourhood assignment and assessing effects of cumulative exposure to different neighbourhood conditions. We included data for 61 386 refugees who arrived in Sweden during 1987-91 and who were assigned to one of 4833 neighbourhoods. Being assigned to an area deemed high deprivation versus low deprivation was associated with an increased risk of diabetes (odds ratio [OR] 1·22, 95% CI 1·07-1·38; p=0·001). In analyses that included fixed effects for assigned municipality, the increased diabetes risk was estimated to be 0·85 percentage points (95% CI -0·030 to 1·728; p=0·058). Neighbourhood effects grew over time such that 5 years of additional exposure to high-deprivation versus low

  1. The importance of microclimate variation in determining size, growth and survival of avian offspring: experimental evidence from a cavity nesting passerine.

    Science.gov (United States)

    Dawson, Russell D; Lawrie, Cheyenne C; O'Brien, Erin L

    2005-07-01

    Organisms are expected to balance energy allocation in such a way that fitness is maximized. While much research has focussed on allocation strategies of reproducing parents, in particular birds, relatively little attention has been paid to how nestlings allocate energy while in the nest. Nestling birds are faced with a trade-off between devoting energy to growth or to thermoregulation, and in altricial species it is likely that the thermal environment of the nest site influences the nature of this trade-off. Here, we experimentally investigate how altering the microclimate of nests affects the growth, size and survival, as well as cell-mediated immune (CMI) response, of nestling tree swallows (Tachycineta bicolor) in a temperate environment. We place air-activated heating pads in nests of swallows when young were between 4 days and 16 days of age, and compared performance of offspring to control nests. Our manipulation raised temperatures of heated nests by approximately 5 degrees C compared to control nests. Offspring in heated nests had enhanced survival while in the nest, and we also found that they were heavier and had longer ninth primary feathers at 16 days of age. In addition, heating nest boxes resulted in significantly faster growth of primaries, and there was a trend for growth rates of mass to also be higher in heated nests. There were no significant differences between heated and control nests in growth rate or size of tarsus at age 16 days, and we speculate that this lack of response to elevated nest temperatures may be due to growth of skeletal structures being limited by other factors such as calcium availability. We also found no difference between heated and control nests in CMI response. Nonetheless, our results show overall that increasing temperatures of nests has significant benefits that enhance the fitness of offspring. As provisioning rates to offspring did not differ between heated and control nests, we suspect that the beneficial effects

  2. Varying the number of bidders in the first-price sealed-bid auction: experimental evidence for the one-shot game

    OpenAIRE

    Tibor Neugebauer; Sascha F llbrunn

    2013-01-01

    The paper reports experimental data on the behavior in the first-price sealed-bid auction for a varying number of bidders when values and bids are private information. This feedback-free design is proposed for the experimental test of the one-shot game situation. We consider both within-subject and betweensubjects variations. In line with the qualitative risk neutral Nash equilibrium prediction, the data show that bids increase in the number of bidders. However, in auctions involving a small ...

  3. Evidência da ação antiparasitária da azitromicina na infecção experimental de camundongos pelo Plasmodium berghei

    Directory of Open Access Journals (Sweden)

    Gakiya Erika

    2001-01-01

    Full Text Available A azitromicina debelou a infecção experimental de camundongos pelo Plasmodium berghei quando administrada, pela via oral e durante 28 dias, na dose de 100mg/kg, iniciada no mesmo dia em que os animais foram infectados. Mediante uso de 10mg/kg houve insucesso. Os resultados obtidos suscitam investigações complementares sobre a referida atividade antiparasitária desse medicamento.

  4. Experimental evidence for the microscopic mechanism of the unusual spin-induced electric polarization in GdMn2O5

    Science.gov (United States)

    Yahia, G.; Damay, F.; Chattopadhyay, S.; Balédent, V.; Peng, W.; Kim, S. W.; Greenblatt, M.; Lepetit, M.-B.; Foury-Leylekian, P.

    2018-02-01

    We report in this paper the temperature evolution of the magnetic structure of GdMn2O5 , in the range 2-40 K, studied by neutron diffraction on an isotope-enriched powder. We detail a thorough analysis of the microscopic mechanisms needed to release the different magnetic frustrations that are at the origin of the polarization. In addition to the usual exchange-striction term, known to be at the origin of the polarization in this family, an additional exchange-striction effect between the Gd3 + and Mn3 + spins is found to be responsible for the very large polarization in the Gd compound.

  5. Vitamins Associated with Brain Aging, Mild Cognitive Impairment, and Alzheimer Disease: Biomarkers, Epidemiological and Experimental Evidence, Plausible Mechanisms, and Knowledge Gaps.

    Science.gov (United States)

    Fenech, Michael

    2017-11-01

    The key to preventing brain aging, mild cognitive impairment (MCI), and Alzheimer disease (AD) via vitamin intake is first to understand molecular mechanisms, then to deduce relevant biomarkers, and subsequently to test the level of evidence for the impact of vitamins in the relevant pathways and their modulation of dementia risk. This narrative review infers information on mechanisms from gene and metabolic defects associated with MCI and AD, and assesses the role of vitamins using recent results from animal and human studies. Current evidence suggests that all known vitamins and some "quasi-vitamins" are involved as cofactors or influence ≥1 of the 6 key sets of pathways or pathologies associated with MCI or AD, relating to 1 ) 1-carbon metabolism, 2 ) DNA damage and repair, 3 ) mitochondrial function and glucose metabolism, 4 ) lipid and phospholipid metabolism and myelination, 5 ) neurotransmitter synthesis and synaptogenesis, and 6 ) amyloidosis and Tau protein phosphorylation. The contemporary level of evidence for each of the vitamins varies considerably, but it is notable that B vitamins are involved as cofactors in all of the core pathways or pathologies and, together with vitamins C and E, are consistently associated with a protective role against dementia. Outcomes from recent studies indicate that the efficacy and safety of supplementation with vitamins to prevent MCI and the early stages of AD will most likely depend on 1 ) which pathways are defective, 2 ) which vitamins are deficient and could correct the relevant metabolic defects, and 3 ) the modulating impact of nutrient-nutrient and nutrient-genotype interaction. More focus on a precision nutrition approach is required to realize the full potential of vitamin therapy in preventing dementia and to avoid causing harm. © 2017 American Society for Nutrition.

  6. Can colorectal cancer mass-screening organization be evidence-based? Lessons from failures: The experimental and pilot phases of the Lazio program

    Directory of Open Access Journals (Sweden)

    Valle Sabrina

    2008-09-01

    Full Text Available Abstract Background Screening programmes should be organized to translate theoretical efficacy into effectiveness. An evidence-based organizational model of colorectal cancer screening (CRCS should assure feasibility and high compliance. Methods A multidisciplinary Working Group (WG, reviewed literature and guidelines to define evidence-based recommendations. The WG identified the need for further local studies: physicians' CRCS attitudes, the effect of test type and provider on compliance, and individual reasons for non-compliance. A survey of digestive endoscopy services was conducted. A feasibility study on a target population of 300.000 has begun. Results Based on the results of population trials and on literature review the screening strategy adopted was Faecal Occult Blood Test (FOBT every two years for 50–74 year olds and, for positives, colonoscopy. The immunochemical test was chosen because it has 20% higher compliance than the Guaiac. GPs were chosen as the preferred provider also for higher compliance. Since we observed that distance is the major determinant of non-compliance, we choose GPs because they are the closest providers, both geographically and emotionally, to the public. The feasibility study showed several barriers: GP participation was low, there were administrative problems to involve GPs; opportunistic testing by the GPs; difficulties in access to Gastroenterology centres; difficulties in gathering colonoscopy results; little time given to screening activity by the gastroenterology centre. Conclusion The feasibility study highlighted several limits of the model. Most of the barriers that emerged were consequences of organisational choices not supported by evidence. The principal limit was a lack of accountability by the participating centres.

  7. Experimental evidence for fast cluster formation of chain oxygen vacancies in YBa2Cu3O7-d being at the origin of the fishtail anomaly

    OpenAIRE

    Erb, Andreas; Manuel, Alfred A.; Dhalle, Marc; Marti, Frank; Genoud, Jean-Yves; Revaz, Bernard; Junod, Alain; Vasumathi, Dharmavaram; Ishibashi, Shoji; Shukla, Abhay; Walker, Eric; Fischer, Oystein; Fluekiger, Rene; Pozzi, Riccardo; Mali, Mihael

    1998-01-01

    We report on three different and complementary measurements, namely magnetisation measurements, positron annihilation spectroscopy and NMR measurements, which give evidence that the formation of oxygen vacancy clusters is on the origin of the fishtail anomaly in YBa2Cu3O7-d. While in the case of YBa2Cu3O7.0 the anomaly is intrinsically absent, it can be suppressed in the optimally doped state where vacancies are present. We therefore conclude that the single vacancies or point defects can not...

  8. Neuroprotection of Catalpol for Experimental Acute Focal Ischemic Stroke: Preclinical Evidence and Possible Mechanisms of Antioxidation, Anti-Inflammation, and Antiapoptosis

    Directory of Open Access Journals (Sweden)

    Xia-wei Zheng

    2017-01-01

    Full Text Available Neuroprotection is defined as using a therapy that affects the brain tissue in the still-viable ischemic penumbra to salvage or delay the infarction. Catalpol, the main active principle of the root of Radix Rehmanniae, was reported to have pleiotropic neuroprotective effects in neurodegenerative diseases including ischemic stroke. Here, we evaluated the neuroprotective effects of catalpol in experimental acute ischemic stroke. Studies on catalpol in animal models of acute ischemic stroke were identified from 6 databases. Twenty-five studies involving 805 animals were included. Twelve comparisons showed significant effects of catalpol on decreasing infarct size according to 2,3,5-triphenyltetrazolium chloride staining compared with the control (P<0.05. One study reported significant effect of catalpol on reducing infarct size according to magnetic resonance imaging scan compared with the control (P<0.05. Meta-analysis of these studies indicated that catalpol significantly improved the neurological function score according to Zea Longa score, Bederson score, balance beam-walking test, adhesive removal test, bar-grasping score, and corner test compared with the control (P<0.05. In conclusion, catalpol exerted neuroprotective effects for experimental acute focal ischemic stroke, largely through reducing oxidative reactions, inhibiting apoptosis, and repressing inflammatory reactions and autophagy. However, these apparently positive findings should be interpreted with caution because of the methodological flaws.

  9. Evidence for excited-state intramolecular proton transfer in 4-chlorosalicylic acid from combined experimental and computational studies: Quantum chemical treatment of the intramolecular hydrogen bonding interaction

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Bijan Kumar [Department of Chemistry, University of Calcutta, 92 Acharya Prafulla Chandra Road, Calcutta 700009 (India); Guchhait, Nikhil, E-mail: nikhil.guchhait@rediffmail.com [Department of Chemistry, University of Calcutta, 92 Acharya Prafulla Chandra Road, Calcutta 700009 (India)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer Experimental and computational studies on the photophysics of 4-chlorosalicylic acid. Black-Right-Pointing-Pointer Spectroscopically established ESIPT reaction substantiated by theoretical calculation. Black-Right-Pointing-Pointer Quantum chemical treatment of IMHB unveils strength, nature and directional nature. Black-Right-Pointing-Pointer Superiority of quantum chemical treatment of H-bond over geometric criteria. Black-Right-Pointing-Pointer Role of H-bond as a modulator of aromaticity. -- Abstract: The photophysical study of a pharmaceutically important chlorine substituted derivative of salicylic acid viz., 4-chlorosalicylic acid (4ClSA) has been carried out by steady-state absorption, emission and time-resolved emission spectroscopy. A large Stokes shifted emission band with negligible solvent polarity dependence marks the spectroscopic signature of excited-state intramolecular proton transfer (ESIPT) reaction in 4ClSA. Theoretical calculation by ab initio and Density Functional Theory methods yields results consistent with experimental findings. Theoretical potential energy surfaces predict the occurrence of proton transfer in S{sub 1}-state. Geometrical and energetic criteria, Atoms-In-Molecule topological parameters, Natural Bond Orbital population analysis have been exploited to evaluate the intramolecular hydrogen bond (IMHB) interaction and to explore its directional nature. The inter-correlation between aromaticity and resonance assisted H-bond is also discussed in this context. Our results unveil that the quantum chemical treatment is a more accurate tool to assess hydrogen bonding interaction in comparison to geometrical criteria.

  10. Net Loss of CaCO3 from a subtropical calcifying community due to seawater acidification: mesocosm-scale experimental evidence

    Directory of Open Access Journals (Sweden)

    K. S. Rodgers

    2009-08-01

    Full Text Available Acidification of seawater owing to oceanic uptake of atmospheric CO2 originating from human activities such as burning of fossil fuels and land-use changes has raised serious concerns regarding its adverse effects on corals and calcifying communities. Here we demonstrate a net loss of calcium carbonate (CaCO3 material as a result of decreased calcification and increased carbonate dissolution from replicated subtropical coral reef communities (n=3 incubated in continuous-flow mesocosms subject to future seawater conditions. The calcifying community was dominated by the coral Montipora capitata. Daily average community calcification or Net Ecosystem Calcification (NEC=CaCO3 production – dissolution was positive at 3.3 mmol CaCO3 m−2 h−1 under ambient seawater pCO2 conditions as opposed to negative at −0.04 mmol CaCO3 m−2 h−1 under seawater conditions of double the ambient pCO2. These experimental results provide support for the conclusion that some net calcifying communities could become subject to net dissolution in response to anthropogenic ocean acidification within this century. Nevertheless, individual corals remained healthy, actively calcified (albeit slower than at present rates, and deposited significant amounts of CaCO3 under the prevailing experimental seawater conditions of elevated pCO2.

  11. Experimental analysis in formation of anti-pp interactions between 0. and 1.2 GeV/c: evidence for a anti-pp→5π effect near 1950 MeV/c2

    International Nuclear Information System (INIS)

    Defoix, C.; Dobrzynski, L.; Espigat, P.; Laloum, M.; Ladron de Guevara, P.

    1979-07-01

    An experimental analysis of anti-pp interactions between the anti-pp threshold (√s=1878 MeV) and √s=2100 MeV leads to clear evidence for an s-channel effect in the reaction anti-pp→π + π - π + π - π 0 at 1949+-10 MeV/c 2 (GAMMA approximately 80 MeV/c 2 ). Comparison is made with the backward elastic scattering and charge-exchange behaviors. An interpretation in terms of an object strongly coupled to mesonic decay modes, with a sma-1 or middle-sized elasticity (x<=0.135 + 0.13 (or -0.06)) is given. No significant narrow structure is observed in the backward elastic scattering between 1.9 and 2 GeV. The experimental resolution on √s in this case is 2 MeV

  12. Experimental evidences for reducing Mg activation energy in high Al-content AlGaN alloy by MgGa δ doping in (AlN)m/(GaN)n superlattice

    OpenAIRE

    Xiao Wang; Wei Wang; Jingli Wang; Hao Wu; Chang Liu

    2017-01-01

    P-type doping in high Al-content AlGaN alloys is a main challenge for realizing AlGaN-based deep ultraviolet optoelectronics devices. According to the first-principles calculations, Mg activation energy may be reduced so that a high hole concentration can be obtained by introducing nanoscale (AlN)5/(GaN)1 superlattice (SL) in Al0.83Ga0.17N disorder alloy. In this work, experimental evidences were achieved by analyzing Mg doped high Al-content AlGaN alloys and Mg doped AlGaN SLs as well as MgG...

  13. First experimental evidence of hydrodynamic tunneling of ultra-relativistic protons in extended solid copper target at the CERN HiRadMat facility

    Science.gov (United States)

    Schmidt, R.; Blanco Sancho, J.; Burkart, F.; Grenier, D.; Wollmann, D.; Tahir, N. A.; Shutov, A.; Piriz, A. R.

    2014-08-01

    A novel experiment has been performed at the CERN HiRadMat test facility to study the impact of the 440 GeV proton beam generated by the Super Proton Synchrotron on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed that leads to significant lengthening of the projectile range, which confirms our previous theoretical predictions [N. A. Tahir et al., Phys. Rev. Spec. Top.-Accel. Beams 15, 051003 (2012)]. Simulation results show very good agreement with the experimental measurements. These results have very important implications on the machine protection design for powerful machines like the Large Hadron Collider (LHC), the future High Luminosity LHC, and the proposed huge 80 km circumference Future Circular Collider, which is currently being discussed at CERN. Another very interesting outcome of this work is that one may also study the field of High Energy Density Physics at this test facility.

  14. First experimental evidence of hydrodynamic tunneling of ultra–relativistic protons in extended solid copper target at the CERN HiRadMat facility

    CERN Document Server

    Schmidt, R; Sancho, J Blanco; Burkart, F; Grenier, D; Wollmann, D; Tahir, N A; Shutov, A; Piriz, A R

    2014-01-01

    A novel experiment has been performed at the CERN HiRadMat test facility to study the impact of the 440 GeV proton beam generated by the Super Proton Synchrotron on extended solid copper cylindrical targets. Substantial hydrodynamic tunneling of the protons in the target material has been observed that leads to significant lengthening of the projectile range, which confirms our previous theoretical predictions [N. A. Tahir et al., Phys. Rev. Spec. Top.-Accel. Beams 15, 051003 (2012)]. Simulation results show very good agreement with the experimental measurements. These results have very important implications on the machine protection design for powerful machines like the Large Hadron Collider (LHC), the future High Luminosity LHC, and the proposed huge 80 km circumference Future Circular Collider, which is currently being discussed at CERN. Another very interesting outcome of this work is that one may also study the field of High Energy Density Physics at this test facility.

  15. Experimental Evidence of Radiation Reaction in the Collision of a High-Intensity Laser Pulse with a Laser-Wakefield Accelerated Electron Beam

    Science.gov (United States)

    Cole, J. M.; Behm, K. T.; Gerstmayr, E.; Blackburn, T. G.; Wood, J. C.; Baird, C. D.; Duff, M. J.; Harvey, C.; Ilderton, A.; Joglekar, A. S.; Krushelnick, K.; Kuschel, S.; Marklund, M.; McKenna, P.; Murphy, C. D.; Poder, K.; Ridgers, C. P.; Samarin, G. M.; Sarri, G.; Symes, D. R.; Thomas, A. G. R.; Warwick, J.; Zepf, M.; Najmudin, Z.; Mangles, S. P. D.

    2018-02-01

    The dynamics of energetic particles in strong electromagnetic fields can be heavily influenced by the energy loss arising from the emission of radiation during acceleration, known as radiation reaction. When interacting with a high-energy electron beam, today's lasers are sufficiently intense to explore the transition between the classical and quantum radiation reaction regimes. We present evidence of radiation reaction in the collision of an ultrarelativistic electron beam generated by laser-wakefield acceleration (ɛ >500 MeV ) with an intense laser pulse (a0>10 ). We measure an energy loss in the postcollision electron spectrum that is correlated with the detected signal of hard photons (γ rays), consistent with a quantum description of radiation reaction. The generated γ rays have the highest energies yet reported from an all-optical inverse Compton scattering scheme, with critical energy ɛcrit>30 MeV .

  16. Experimental Evidence of Radiation Reaction in the Collision of a High-Intensity Laser Pulse with a Laser-Wakefield Accelerated Electron Beam

    Directory of Open Access Journals (Sweden)

    J. M. Cole

    2018-02-01

    Full Text Available The dynamics of energetic particles in strong electromagnetic fields can be heavily influenced by the energy loss arising from the emission of radiation during acceleration, known as radiation reaction. When interacting with a high-energy electron beam, today’s lasers are sufficiently intense to explore the transition between the classical and quantum radiation reaction regimes. We present evidence of radiation reaction in the collision of an ultrarelativistic electron beam generated by laser-wakefield acceleration (ϵ>500  MeV with an intense laser pulse (a_{0}>10. We measure an energy loss in the postcollision electron spectrum that is correlated with the detected signal of hard photons (γ rays, consistent with a quantum description of radiation reaction. The generated γ rays have the highest energies yet reported from an all-optical inverse Compton scattering scheme, with critical energy ϵ_{crit}>30  MeV.

  17. Experimental evidence supporting the insensitivity of cloud droplet formation to the mass accommodation coefficient for condensation of water vapor to liquid water

    Science.gov (United States)

    Langridge, Justin M.; Richardson, Mathews S.; Lack, Daniel A.; Murphy, Daniel M.

    2016-06-01

    The mass accommodation coefficient for uptake of water vapor to liquid water, αM, has been constrained using photoacoustic measurements of aqueous absorbing aerosol. Measurements performed over a range of relative humidities and pressures were compared to detailed model calculations treating coupled heat and mass transfer occurring during photoacoustic laser heating cycles. The strengths and weaknesses of this technique are very different to those for droplet growth/evaporation experiments that have typically been applied to these measurements, making this a useful complement to existing studies. Our measurements provide robust evidence that αM is greater than 0.1 for all humidities tested and greater than 0.3 for data obtained at relative humidities greater than 88% where the aerosol surface was most like pure water. These values of αM are above the threshold at which kinetic limitations are expected to impact the activation and growth of aerosol particles in warm cloud formation.

  18. Experimental and Human Evidence for Lipocalin-2 (Neutrophil Gelatinase-Associated Lipocalin [NGAL]) in the Development of Cardiac Hypertrophy and heart failure.

    Science.gov (United States)

    Marques, Francine Z; Prestes, Priscilla R; Byars, Sean G; Ritchie, Scott C; Würtz, Peter; Patel, Sheila K; Booth, Scott A; Rana, Indrajeetsinh; Minoda, Yosuke; Berzins, Stuart P; Curl, Claire L; Bell, James R; Wai, Bryan; Srivastava, Piyush M; Kangas, Antti J; Soininen, Pasi; Ruohonen, Saku; Kähönen, Mika; Lehtimäki, Terho; Raitoharju, Emma; Havulinna, Aki; Perola, Markus; Raitakari, Olli; Salomaa, Veikko; Ala-Korpela, Mika; Kettunen, Johannes; McGlynn, Maree; Kelly, Jason; Wlodek, Mary E; Lewandowski, Paul A; Delbridge, Lea M; Burrell, Louise M; Inouye, Michael; Harrap, Stephen B; Charchar, Fadi J

    2017-06-14

    Cardiac hypertrophy increases the risk of developing heart failure and cardiovascular death. The neutrophil inflammatory protein, lipocalin-2 (LCN2/NGAL), is elevated in certain forms of cardiac hypertrophy and acute heart failure. However, a specific role for LCN2 in predisposition and etiology of hypertrophy and the relevant genetic determinants are unclear. Here, we defined the role of LCN2 in concentric cardiac hypertrophy in terms of pathophysiology, inflammatory expression networks, and genomic determinants. We used 3 experimental models: a polygenic model of cardiac hypertrophy and heart failure, a model of intrauterine growth restriction and Lcn2 -knockout mouse; cultured cardiomyocytes; and 2 human cohorts: 114 type 2 diabetes mellitus patients and 2064 healthy subjects of the YFS (Young Finns Study). In hypertrophic heart rats, cardiac and circulating Lcn2 was significantly overexpressed before, during, and after development of cardiac hypertrophy and heart failure. Lcn2 expression was increased in hypertrophic hearts in a model of intrauterine growth restriction, whereas Lcn2 -knockout mice had smaller hearts. In cultured cardiomyocytes, Lcn2 activated molecular hypertrophic pathways and increased cell size, but reduced proliferation and cell numbers. Increased LCN2 was associated with cardiac hypertrophy and diastolic dysfunction in diabetes mellitus. In the YFS, LCN2 expression was associated with body mass index and cardiac mass and with levels of inflammatory markers. The single-nucleotide polymorphism, rs13297295, located near LCN2 defined a significant cis -eQTL for LCN2 expression. Direct effects of LCN2 on cardiomyocyte size and number and the consistent associations in experimental and human analyses reveal a central role for LCN2 in the ontogeny of cardiac hypertrophy and heart failure. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  19. Sarcocystis neurona infections in raccoons (Procyon lotor): evidence for natural infection with sarcocysts, transmission of infection to opossums (Didelphis virginiana), and experimental induction of neurologic disease in raccoons.

    Science.gov (United States)

    Dubey, J P; Saville, W J; Stanek, J F; Lindsay, D S; Rosenthal, B M; Oglesbee, M J; Rosypal, A C; Njoku, C J; Stich, R W; Kwok, O C; Shen, S K; Hamir, A N; Reed, S M

    2001-10-24

    Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses in the Americas and Sarcocystis neurona is the most common etiologic agent. The distribution of S. neurona infections follows the geographical distributions of its definitive hosts, opossums (Didelphis virginiana, Didelphis albiventris). Recently, cats and skunks were reported as experimental and armadillos as natural intermediate hosts of S. neurona. In the present report, raccoons (Procyon lotor) were identified as a natural intermediate host of S. neurona. Two laboratory-raised opossums were found to shed S. neurona-like sporocysts after ingesting tongues of naturally-infected raccoons. Interferon-gamma gene knockout (KO) mice fed raccoon-opossum-derived sporocysts developed neurologic signs. S. neurona was identified immunohistochemically in tissues of KO mice fed sporocysts and the parasite was isolated in cell cultures inoculated with infected KO mouse tissues. The DNA obtained from the tongue of a naturally-infected raccoon, brains of KO mice that had neurological signs, and from the organisms recovered in cell cultures inoculated with brains of neurologic KO mice, corresponded to that of S. neurona. Two raccoons fed mature S. neurona sarcocysts did not shed sporocysts in their feces, indicating raccoons are not likely to be its definitive host. Two raccoons fed sporocysts from opossum feces developed clinical illness and S. neurona-associated encephalomyelitis was found in raccoons killed 14 and 22 days after feeding sporocysts; schizonts and merozoites were seen in encephalitic lesions.

  20. Why all the confusion? Experimental task explains discrepant semantic priming effects in schizophrenia under "automatic" conditions: evidence from Event-Related Potentials.

    Science.gov (United States)

    Kreher, Donna A; Goff, Donald; Kuperberg, Gina R

    2009-06-01

    The schizophrenia research literature contains many differing accounts of semantic memory function in schizophrenia as assessed through the semantic priming paradigm. Most recently, Event-Related Potentials (ERPs) have been used to demonstrate both increased and decreased semantic priming at a neural level in schizophrenia patients, relative to healthy controls. The present study used ERPs to investigate the role of behavioral task in determining neural semantic priming effects in schizophrenia. The same schizophrenia patients and healthy controls completed two experiments in which word stimuli were identical, and the time between the onset of prime and target remained constant at 350 ms: in the first, participants monitored for words within a particular semantic category that appeared only in filler items (implicit task); in the second, participants explicitly rated the relatedness of word-pairs (explicit task). In the explicit task, schizophrenia patients showed reduced direct and indirect semantic priming in comparison with healthy controls. In contrast, in the implicit task, schizophrenia patients showed normal or, in positively thought-disordered patients, increased direct and indirect N400 priming effects compared with healthy controls. These data confirm that, although schizophrenia patients with positive thought disorder may show an abnormally increased automatic spreading activation, the introduction of semantic decision-making can result in abnormally reduced semantic priming in schizophrenia, even when other experimental conditions bias toward automatic processing.