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Sample records for interaction kn dans

  1. Low energy overlineKN interaction in nuclear matter

    NASA Astrophysics Data System (ADS)

    Waas, T.; Kaiser, N.; Weise, W.

    1996-02-01

    We investigate the low-energy overlineKN interaction in nuclear matter including Pauli blocking, Fermi motion and binding effects. We use a coupled-channel approach based on the Chiral SU(3) Effective Lagrangian which describes all available low energy data of the coupled overlineKN, πΣ, πΛ system. Due to the dynamics of the Λ (1405) resonance we find a strong non-linear density dependence of the K -p scattering amplitude in nuclear matter. The real part of the K -p scattering length changes sign already at a small fraction of nuclear matter density, less than 0.2 po. This may explain the striking behaviour of the K - -nuclear optical potential found in the analysis of kaonic atom data.

  2. bar{K}-Nucleus Interaction Probed by the In-Flight (K^-,N) Reactions

    NASA Astrophysics Data System (ADS)

    Kishimoto, T.; Hayakawa, T.; Ajimura, S.; Khanam, F.; Itabashi, T.; Matsuoka, K.; Minami, S.; Mitoma, Y.; Sakaguchi, A.; Shimizu, Y.; Terai, K.; Chrien, R. E.; Pile, P.; Noumi, H.; Sekimoto, M.; Takahashi, H.; Fukuda, T.; Imoto, W.; Mizoi, Y.

    We would like to point out that the (K^-,N) reactions are particularly useful for the study of the bar{K}-nucleus interaction. We have measured the missing mass spectra derived from the momenta of both neutrons and protons from the ^{12}{C}(K^-,N) reactions. It was found that an appreciable amount of strength were below the bar{K}-nucleus threshold which indicates that the bar{K}-nuclear potential is strongly attractive. The missing mass spectra are compared with theoretical calculations. It is found that a potential depth of around -190 MeV reproduces well the spectrum of the ^{12}C(K^-,n) reaction and a less deep potential of around -160 MeV reproduces well that of the ^{12}C(K^-,p) reaction. Our data show that the bar{K}-nucleus potential is very deep to realize kaon condensation in the core of neutron stars.

  3. Kaon-Nucleus Interaction Studied through the In-Flight (K-,N) Reaction

    NASA Astrophysics Data System (ADS)

    Kishimoto, T.; Hayakawa, T.; Ajimura, S.; Khanam, F.; Itabashi, T.; Matsuoka, K.; Minami, S.; Mitoma, Y.; Sakaguchi, A.; Shimizu, Y.; Terai, K.; Chrien, R. E.; Pile, P.; Noumi, H.; Sekimoto, M.; Takahashi, H.; Fukuda, T.; Imoto, W.; Mizoi, Y.

    2007-08-01

    We studied the bar{K}-nucleus interaction by the 12C(K-,N) reaction. Missing mass spectra were derived from the momenta of both neutrons and protons from the reaction. An appreciable strength was observed below the bar{K}-nucleus threshold, which indicates that the bar{K}-nuclear potential is strongly attractive. The missing mass spectra are compared with the results of theoretical calculations. It is found that a potential depth of approximately -190 MeV best reproduces the spectrum of the 12C(K-,n) reaction and approximately -160 MeV best reproduces that of the 12C(K-,p) reaction. Our data show that the bar{K}-nucleus potential is sufficiently deep to realize kaon condensation in the core of neutron stars.

  4. ''KN'' series cracking catalysts

    SciTech Connect

    Klapstov, V.F.; Khlebrikova, M.A.; Maslova, A.A.; Nefedov, B.K.

    1986-09-01

    The basic directions in improving high-activity zeolitic cracking catalysts at the present stage are improvements in the resistance to attrition and increases in the bulk density of the catalysts, along with a changeover to relatively waste-free catalyst manufacturing technology. Catalysts of the ''KN'' series have been synthesized recently with improved quality characteristics. Low-waste technology is used in manufacturing them. Data are presented which show that the KN catalysts are better than the other Soviet catalysts. The starting materials and reagents in preparing the KN catalysts are technical alumina, rare-earth element nitrates, a natural component (such as clay conforming to specification TU-21-25-146-75), sodium hydroxide, and granulated sodium silicate. The preparation of the KN catalysts is described and no silica gel is used in manufacturing the KN series catalyst, in contrast to the RSG-6Ts catalyst. The use of KN series catalysts in place of KMTsR in catalytic cracking units will result in an increase in the naphtha yield by at least 20% by weight, as well as a reduction of the catalyst consumption by a factor of 2-3. A changeover to the commerical production of this catalyst will make it possible to reduce saline waste by a factor of 8-10 and reduce the catalyst cost by a factor of 1.5-2.

  5. Interactions électron-électron dans les fils mésoscopiques

    NASA Astrophysics Data System (ADS)

    Pierre, F.

    Electron-electron interactions in mesoscopic wires In metallic thin films, the screening of Coulomb interactions is less efficient than in bulk metals because of electron elastic scattering from film boundaries, lattice defects, and impurities. As a consequence, at sub-kelvin temperatures, electron-electron interactions are expected to be the dominant inelastic process undergone by electrons, which determines energy exchange and limits the electronic phase coherence. We present in this book three experiments that probe inelastic collisions experienced by electrons at low temperature, in order to find out their mechanism. In the first part, we present a series of measurements of the energy distribution function of electrons in copper, gold and silver wires driven in a steady-state, out of equilibrium situation. These experiments reveal the rate at which electrons exchange energy. These results are compared in the second part with the temperature dependence of the phase coherence time of electrons tau_{φ}, which is deduced from the magnetoresistance of long wires. The phase coherence of electrons is limited by all inelastic collisions, independently of the energy exchanged. Different mechanisms to account for the energy exchange rate and dephasing times are proposed and compared with experiments. In the third part, we present measurements of the conductance of a long tunnel junction between an aluminum wire and a ground plane. The dip in the conductance at zero voltage is expected from the theory of electron-electron interactions. To compare measurements and theoretical predictions, we rephrase the microscopic theory of electron-electron interactions in terms of an electromagnetic impedance, as is done for the phenomenological theory of Coulomb blockade. Dans les couches minces métalliques, l'écrantage des interactions coulombiennes entre électrons est moins efficace que dans les métaux massifs en raison des chocs élastiques que subissent les électrons sur les

  6. Molecular Dynamics Study of Potassium Azide (KN_3)

    NASA Astrophysics Data System (ADS)

    Ossowski, M.; Hardy, J. R.

    1998-03-01

    An ab initio model developed for intermolecular and intramolecular potentials in ionic molecular solids(H. M. Lu and J. R. Hardy, Phys. Rev. B, 42, 8339 (1990)) is employed to study the phase diagram of potassium azide (KN_3). We performed first-principles static structural relaxation, supercell molecular dynamics, lattice- dynamical studies and predict the existence of a high temperature rotationally disordered phase in KN_3. A selected work on other members of the alkali azide family will also be discussed.

  7. Conceptual Engine System Design for NERVA derived 66.7KN and 111.2KN Thrust Nuclear Thermal Rockets

    SciTech Connect

    Fittje, James E.; Buehrle, Robert J.

    2006-01-20

    The Nuclear Thermal Rocket concept is being evaluated as an advanced propulsion concept for missions to the moon and Mars. A tremendous effort was undertaken during the 1960's and 1970's to develop and test NERVA derived Nuclear Thermal Rockets in the 111.2 KN to 1112 KN pound thrust class. NASA GRC is leveraging this past NTR investment in their vehicle concepts and mission analysis studies, and has been evaluating NERVA derived engines in the 66.7 KN to the 111.2 KN thrust range. The liquid hydrogen propellant feed system, including the turbopumps, is an essential component of the overall operation of this system. The NASA GRC team is evaluating numerous propellant feed system designs with both single and twin turbopumps. The Nuclear Engine System Simulation code is being exercised to analyze thermodynamic cycle points for these selected concepts. This paper will present propellant feed system concepts and the corresponding thermodynamic cycle points for 66.7 KN and 111.2 KN thrust NTR engine systems. A pump out condition for a twin turbopump concept will also be evaluated, and the NESS code will be assessed against the Small Nuclear Rocket Engine preliminary thermodynamic data.

  8. Effet de l'interaction coulombienne sur la localisation d'Anderson dans le gaz bidimensionnel d'électrons

    NASA Astrophysics Data System (ADS)

    Fleury, G.

    2010-09-01

    Nous étudions l’effet des interactions coulombiennes sur la localisation d’Anderson dans le gaz bidimensionnel d’électrons désordonné. L’objectif est de statuer sur la question de l’existence de métaux à deux dimensions. En l’absence d’interaction, la théorie d’échelle de la localisation prédit qu’un désordre infinitésimal suffit à localiser la fonction d’onde électronique et donc à rendre le système isolant à température nulle (Abrahams et al., 1979). Dans certaines limites extrêmes, les interactions peuvent être prises en compte et l’on aboutit également à un état isolant. Cependant, aucune théorie analytique ne permet de traiter le régime quantique non-perturbatif où désordre et interaction sont intermédiaires. Expérimentalement, il est possible de l’explorer dans des échantillons de haute mobilité et basse densité. Depuis 1994, des comportements métalliques inexpliqués y ont été observés (Kravchenko et al., 1994). Nous avons mis au point une méthode numérique permettant d’étudier le problème couplé de la localisation d’Anderson en présence d’interaction. Cette méthode mêle Monte Carlo quantique à température nulle et théorie d’échelle pour la conductance de Thouless. Nous trouvons que la théorie d’échelle de la localisation est préservée en présence d’interaction et donc que le gaz bidimensionnel, même corrélé, est isolant à température nulle. Nos résultats montrent de plus que les interactions délocalisent le gaz bidimensionnel et que cet effet de délocalisation est accru en présence de dégénérescence de vallées. Ils nous permettent de proposer un mécanisme simple rendant compte des principales caractéristiques des comportements métalliques observés expérimentalement.

  9. Force key comparison CCM.F-K2.a.1 (50 kN and 100 kN)

    NASA Astrophysics Data System (ADS)

    Savarin, A.; Medina, N.; Knott, A.

    2016-01-01

    This report describes CIPM key comparison CCM.F-K2.a.1, a key comparison between force standard machines at the national measurement institutes of Argentina (INTI), Spain (CEM), and the United Kingdom (NPL), at generated forces of 50 kN and 100 kN, in the period from 2010 to 2012. Two transducers were used and the force-time profile was strictly controlled, to minimise effects of creep. The final results are linked to the KCRV determined in CIPM Key Comparison CCM.F-K2.a through the use of one common deadweight force standard machine (NPL's 120 kN machine) in the two comparison exercises. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  10. First principles study of structural, electronic and mechanical properties of alkali nitride-KN

    SciTech Connect

    Murugan, A.; Rajeswarapalanichamy, R. Santhosh, M.; Iyakutti, K.

    2015-06-24

    The structural, electronic and elastic properties of alkali- metal nitride (KN) is investigated by the first principles calculations based on density functional theory as implemented in Vienna ab-initio simulation package. At ambient pressure KN is stable in the ferromagnetic state with NaCl structure. The calculated lattice parameters are in good agreement with the available results. The electronic structure reveals that the KN is half metallic ferromagnet at normal pressure. A pressure-induced structural phase transition from NaCl to ZB phase is observed in KN. Half metallicity and ferromagnetism is maintained at all pressures.

  11. Virasoro algebra in the KN algebra; Bosonic string with fermionic ghosts on Riemann surfaces

    SciTech Connect

    Koibuchi, H. )

    1991-10-10

    In this paper the bosonic string model with fermionic ghosts is considered in the framework of the KN algebra. The authors' attentions are paid to representations of KN algebra and a Clifford algebra of the ghosts. The authors show that a Virasoro-like algebra is obtained from KN algebra when KN algebra has certain antilinear anti-involution, and that it is isomorphic to the usual Virasoro algebra. The authors show that there is an expected relation between a central charge of this Virasoro-like algebra and an anomaly of the combined system.

  12. 1-[N, O-bis-(5-isoquinolinesulphonyl)-N-methyl-L-tyrosyl]-4- phenylpiperazine (KN-62), an inhibitor of calcium-dependent camodulin protein kinase II, inhibits both insulin- and hypoxia-stimulated glucose transport in skeletal muscle.

    PubMed Central

    Brozinick, J T; Reynolds, T H; Dean, D; Cartee, G; Cushman, S W

    1999-01-01

    Previous studies have indicated a role for calmodulin in hypoxia-and insulin-stimulated glucose transport. However, since calmodulin interacts with multiple protein targets, it is unknown which of these targets is involved in the regulation of glucose transport. In the present study, we have used the calcium-dependent calmodulin protein kinase II (CAMKII) inhibitor 1-[N, O-bis-(5-isoquinolinesulphonyl) -N-methyl-L-tyrosyl]-4-phenylpiperazine (KN-62) to investigate the possible role of this enzyme in the regulation of glucose transport in isolated rat soleus and epitrochlearis muscles. KN-62 did not affect basal 2-deoxyglucose transport, but it did inhibit both insulin- and hypoxia-stimulated glucose transport activity by 46 and 40% respectively. 1-[N,O-Bis-(1, 5-isoquinolinesulphonyl)-N-methyl-l-tyrosyl]-4-phenylpiperazine (KN-04), a structural analogue of KN-62 that does not inhibit CAMKII, had no effect on hypoxia-or insulin-stimulated glucose transport. Accordingly, KN-62 decreased the stimulated cell-surface GLUT4 labelling by a similar extent as the inhibition of glucose transport (insulin, 49% and hypoxia, 54%). Additional experiments showed that KN-62 also inhibited insulin- and hypoxia-stimulated transport by 37 and 40% respectively in isolated rat epitrochlearis (a fast-twitch muscle), indicating that the effect of KN-62 was not limited to the slow-twitch fibres of the soleus. The inhibitory effect of KN-62 on hypoxia-stimulated glucose transport appears to be specific to CAMKII, since KN-62 did not inhibit hypoxia-stimulated 45Ca efflux from muscles pre-loaded with 45Ca, or hypoxia-stimulated glycogen breakdown. Additionally, KN-62 affected neither insulin-stimulated phosphoinositide 3-kinase nor Akt activity, suggesting that the effects of KN-62 are not due to non-specific effects of this inhibitor on these regions of the insulin-signalling cascade. The results of the present study suggest that CAMKII might have a distinct role in insulin- and hypoxia

  13. BmKn-2 scorpion venom peptide for killing oral cancer cells by apoptosis.

    PubMed

    Tong-ngam, Pirut; Roytrakul, Sittiruk; Sritanaudomchai, Hathaitip

    2015-01-01

    Scorpion venom peptides recently have attracted attention as alternative chemotherapeutic agents that may overcome the limitations of current drugs, providing specific cytotoxicity for cancer cells with an ability to bypass multidrug-resistance mechanisms, additive effects in combination therapy and safety. In the present study, BmKn-2 scorpion venom peptide and its derivatives were chosen for assessment of anticancer activities. BmKn-2 was identified as the most effective against human oral squamous cells carcinoma cell line (HSC-4) by screening assays with an IC50 value of 29 μg/ml. The BmKn-2 peptide killed HSC-4 cells through induction of apoptosis, as confirmed by phase contrast microscopy and RT-PCR techniques. Typical morphological features of apoptosis including cell shrinkage and rounding characteristics were observed in treated HSC-4 cells. The results were further confirmed by increased expression of pro-apoptotic genes such as caspase-3, -7, and -9 but decrease mRNA level of anti-apoptotic BCL-2 in BmKn-2 treated cells, as determined by RT-PCR assay. In summary, the BmKn-2 scorpion venom peptide demonstrates specific membrane binding, growth inhibition and apoptogenic activity against human oral cancer cells. PMID:25854366

  14. KN-B removal from water by non-thermal plasma.

    PubMed

    Liu, Ya-nan; Tian, Lu; Li, Rui; Mei, Shu-fang; Xue, Gang; Ognier, Stéphanie

    2013-01-01

    The degradation of Reactive Black 5 (KN-B) in water using double-dielectric barrier discharge (DDBD) was studied. Experimental results showed that the KN-B degradation rate increased as the initial pH decreased. Low concentrations of Fe(2+) enhanced the degradation, whereas high concentrations of Fe(2+) hindered the degradation. The results showed that DDBD did not noticeably reduce total organic carbon but did reduce the pH value and improve the biodegradability of the solution significantly. Furthermore, the UV-Vis spectra of the dye showed that the chromophore group was damaged and that the solution was decolorized after the 10-min degradation process. PMID:24056425

  15. Expression of almond KNOTTED1 homologue (PdKn1) anticipates adventitious shoot initiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background and Aims: The transcription factor encoded by the gene Knotted1 is a nuclear homeodomain protein, regulating meristematic cells at the shoot apical meristem. It has been proven that Knotted1 (KN1) has a role in the switch from an indeterminate to determinate cell fate and as such this gen...

  16. Polarization Observables in {gamma}N {yields} K{bar K}N

    SciTech Connect

    Winston Roberts

    2004-11-16

    We explore some of the rich structure of the polarization observables recently developed for processes like {gamma}N {yields} {pi}{pi}N and {gamma}N {yields} K{bar K}N in the framework of a specific model for the latter process. Emphasis is placed on observables that may be accessible at existing facilities in the near future. The sensitivity of the observables to the details of the model indicate that they will be a very useful tool in differentiating between different models for reactions like these. In the framework of a model for {gamma}N {yields} K{bar K}N, we examine the sensitivity of the observables to coupling constants of the {phi}, to the properties of the {Lambda}(1405), and to the existence of the {Theta}{sup +}.

  17. A spectroscopic and photometric study of the planetary nebulae Kn 61 and Pa 5

    SciTech Connect

    García-Díaz, Ma. T.; González-Buitrago, D.; López, J. A.; Zharikov, S.; Tovmassian, G.; Borisov, N.; Valyavin, G. E-mail: dgonzalez@astro.unam.mx E-mail: zhar@astro.unam.mx E-mail: borisov@sao.ru

    2014-09-01

    We present the first morpho-kinematical analysis of the planetary nebulae Kn 61 and Pa 5 and explore the nature of their central stars. Our analysis is based on high-resolution and medium-resolution spectroscopic observations, deep narrow-band imaging, and integral photometry. This material allows us to identify the morphological components and study their kinematics. The direct images and spectra indicate an absence of the characteristic [N II] and [S II] emission lines in both nebulae. The nebular spectrum of Kn 61 suggests a hydrogen deficient planetary nebula and the stellar spectrum of the central star reveals a hydrogen-deficient PG 1159-type star. The [O III] position velocity diagram reveals that Kn 61 is a closed, empty, spherical shell with a thin border and a filamentary surface expanding at 67.6 km s{sup –1} and the shell is currently not expanding isotropically. We derived a kinematic age of ∼1.6 × 10{sup 4} yr for an assumed distance of 4 kpc. A photometric period of ∼5.7(±0.4) days has been detected for Kn 61, indicating the presence of a possible binary system at its core. A possible link between filamentary spherical shells and PG 1159-type stars is noted. The morphology of Pa 5 is dominated by an equatorial toroid and faint polar extensions. The equatorial region of this planetary nebula is expanding at 45.2 km s{sup –1}. The stellar spectrum corresponds to a very hot star and is dominated by a steep blue rising continuum and He II, Balmer, and Ca II photospheric lines.

  18. Spectroscopic study of Λ(1405) via the in-flight (K-,n) reaction on deuteron

    NASA Astrophysics Data System (ADS)

    Enomoto, S.; Ajimura, S.; Beer, G.; Bhang, H.; Bragadireanu, M.; Buehler, P.; Busso, L.; Cargnelli, M.; Choi, S.; Curceanu, C.; Faso, D.; Fujioka, H.; Fujiwara, Y.; Fukuda, T.; Guaraldo, C.; Hashimoto, T.; Hayano, R.; Hiraiwa, T.; Iio, M.; Inoue, K.; Ishibashi, N.; Ishikawa, T.; Ishimoto, S.; Ishiwatari, T.; Itahashi, K.; Iwai, M.; Iwasaki, M.; Kawasaki, S.; Kienle, P.; Kou, H.; Marton, J.; Matsuda, Y.; Mizoi, Y.; Morra, O.; Nagae, T.; Noumi, H.; Ohnishi, H.; Okada, S.; Outa, H.; Sada, Y.; Sakaguchi, A.; Sakuma, F.; Sato, M.; Sekimoto, M.; Shi, H.; Sirghi, D.; Sirghi, F.; Suzuki, S.; Suzuki, T.; Tatsuno, H.; Tokuda, M.; Tomono, D.; Toyoda, A.; Tsukada, K.; Widmann, E.; Yamazaki, T.; Yim, H.; Yoshida, K.; Zmeskal, J.

    2011-10-01

    We present an experimental study of Λ(1405) via the in-flight (K-,n) reaction on the deuteron target (J-PARC E31). We will measure all Σ+π-, Σ-π+ and Σ0π0 final states so that the isospin structure of the produced hyperon resonance state can be decomposed. In this report, we present an overview of the experiment and preparation status.

  19. Predictive modelling of Lactobacillus casei KN291 survival in fermented soy beverage.

    PubMed

    Zielińska, Dorota; Dorota, Zielińska; Kołożyn-Krajewska, Danuta; Danuta, Kołożyn-Krajewska; Goryl, Antoni; Antoni, Goryl; Motyl, Ilona

    2014-02-01

    The aim of the study was to construct and verify predictive growth and survival models of a potentially probiotic bacteria in fermented soy beverage. The research material included natural soy beverage (Polgrunt, Poland) and the strain of lactic acid bacteria (LAB) - Lactobacillus casei KN291. To construct predictive models for the growth and survival of L. casei KN291 bacteria in the fermented soy beverage we design an experiment which allowed the collection of CFU data. Fermented soy beverage samples were stored at various temperature conditions (5, 10, 15, and 20°C) for 28 days. On the basis of obtained data concerning the survival of L. casei KN291 bacteria in soy beverage at different temperature and time conditions, two non-linear models (r(2)= 0.68-0.93) and two surface models (r(2)=0.76-0.79) were constructed; these models described the behaviour of the bacteria in the product to a satisfactory extent. Verification of the surface models was carried out utilizing the validation data - at 7°C during 28 days. It was found that applied models were well fitted and charged with small systematic errors, which is evidenced by accuracy factor - Af, bias factor - Bf and mean squared error - MSE. The constructed microbiological growth and survival models of L. casei KN291 in fermented soy beverage enable the estimation of products shelf life period, which in this case is defined by the requirement for the level of the bacteria to be above 10(6) CFU/cm(3). The constructed models may be useful as a tool for the manufacture of probiotic foods to estimate of their shelf life period. PMID:24500482

  20. The Interaction of knotted1 and thick tassel dwarf1 in Vegetative and Reproductive Meristems of Maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Arabidopsis, SHOOT MERISTEMLESS (STM) and CLAVATA1 (CLV1) competitively regulate meristem homeostasis. Here, we explore the interaction of their maize homologs knotted1 (kn1) and thick tassel dwarf1 (td1). kn1 mutants form fewer lateral organs and td1 inflorescences are fasciated with additional ...

  1. Using computational methods to explore improvements to Knölker's iron catalyst.

    PubMed

    Lu, Xi; Zhang, Yawei; Turner, Nicholas; Zhang, Mingtao; Li, Tonglei

    2014-07-01

    Knölker's iron catalyst is characterized by low toxicity and relatively low price in comparison with precious metal catalysts. Density functional theory was used to explore improvements to this catalyst. It was found that electron-withdrawing substituents on the CpOH ring are favorable for improving the efficiency of iron catalysts. Increasing the acidity of CpOH is also an available means of improving the catalytic efficiency. However, replacing the hydroxyl of CpOH with the amino group is not a valid choice for improvement. In contrast, substituting phosphine ligands for carbonyls is the most effective method for improving the catalytic activity of the iron catalyst. But the PR3 ligand must have electron-donating groups and its steric effect should be controlled in a suitable range. Replacing carbonyl groups by PH3 and PPhH2 ligands can effectually improve the catalytic activity for hydrogenation of ketones. PMID:24840123

  2. Kaonic atoms and in-medium K-N amplitudes II: Interplay between theory and phenomenology

    NASA Astrophysics Data System (ADS)

    Friedman, E.; Gal, A.

    2013-02-01

    A microscopic kaonic-atom optical potential VK-(1) is constructed, using the Ikeda-Hyodo-Weise NLO chiral K-N subthreshold scattering amplitudes constrained by the kaonic hydrogen SIDDHARTA measurement, and incorporating Pauli correlations within the Waas-Rho-Weise generalization of the Ericson-Ericson multiple-scattering approach. Good fits to kaonic atom data over the entire periodic table require additionally sizable K-NN-motivated absorptive and dispersive phenomenological terms, in agreement with our former analysis based on a post-SIDDHARTA in-medium chirally-inspired NLO separable model by Cieplý and Smejkal. Such terms are included by introducing a phenomenological potential VK-(2) and coupling it self-consistently to VK-(1). Properties of resulting kaonic atom potentials are discussed with special attention paid to the role of K--nuclear absorption and to the extraction of density-dependent amplitudes representing K- multi-nucleon processes.

  3. Effects of Bacillus subtilis KN-42 on Growth Performance, Diarrhea and Faecal Bacterial Flora of Weaned Piglets

    PubMed Central

    Hu, Yuanliang; Dun, Yaohao; Li, Shenao; Zhao, Shumiao; Peng, Nan; Liang, Yunxiang

    2014-01-01

    This research focused on the effects of different doses of Bacillus subtilis KN-42 on the growth performance, diarrhea incidence, faecal bacterial flora, and the relative number of Lactobacillus and Escherichia coli in faeces of weaned piglets to determine whether the strain can serve as a candidate antimicrobial growth promoter. A total of 360 piglets (initial body weight 7.14±0.63 kg) weaned at 26±2 days of age were randomly allotted to 5 treatment groups (4 pens per treatment with 18 pigs per pen) for a 28-day trial. Dietary treatments were basal diet without any antimicrobial (negative control; NC), basal diet supplemented with 120 mg/kg feed of neomycin sulfate (positive control; PC) and basal diet supplemented with 2×109 (L), 4×109 (M) and 20×109 (H) CFU/kg feed of B. subtilis KN-42. During the overall period, average daily gain and feed efficiency of piglets were higher in groups PC, M, and H than those in group NC (p<0.05), and all probiotics and antibiotics groups had a lower diarrhea index than group NC (p<0.05). The 16S rDNA gene-based methods were used to analyze faecal bacterial flora on day 28 of experiment. The result of denaturing gradient gel electrophoresis analysis showed that supplementation of B. subtilis KN-42 to the diet changed the bacterial communities, with a higher bacterial diversity and band number in group M than in the other four groups. Real-time polymerase chain reaction analysis showed that the relative number of Lactobacillus were higher in groups PC and H than in group NC (p<0.05), and the supplemented B. subtilis KN-42 to the diet also reduced the relative number of E. coli (p<0.05). These results suggest that dietary addition of B. subtilis KN-42 can improve the growth performance and gastrointestinal health of piglets. PMID:25083107

  4. Lattice QCD studies of s-wave meson-baryon interactions

    SciTech Connect

    Ikeda, Yoichi

    2011-10-21

    We study the s-wave KN interactions in the isospin I = 0, 1 channels and associated exotic state {Theta}{sup +} from 2+1 flavor full lattice QCD simulation for relatively heavy quark mass corresponding to m{sub {pi}} = 871 MeV. The s-wave KN potentials are obtained from the Bethe-Salpeter amplitudes. Potentials in both channels reveal short range repulsions: Strength of the repulsion is stronger in the I = 1 potential. The I = 0 potential is found to have attractive well at mid range. The KN scattering phase shifts are calculated and compared with the experimental data.

  5. Comparative genomic analysis of Geobacter sulfurreducens KN400, a strain with enhanced capacity for extracellular electron transfer and electricity production

    PubMed Central

    2012-01-01

    Background A new strain of Geobacter sulfurreducens, strain KN400, produces more electrical current in microbial fuel cells and reduces insoluble Fe(III) oxides much faster than the wildtype strain, PCA. The genome of KN400 was compared to wildtype with the goal of discovering how the network for extracellular electron transfer has changed and how these two strains evolved. Results Both genomes were re-annotated, resulting in 14 fewer genes (net) in the PCA genome; 28 fewer (net) in the KN400 genome; and ca. 400 gene start and stop sites moved. 96% of genes in KN400 had clear orthologs with conserved synteny in PCA. Most of the remaining genes were in regions of genomic mobility and were strain-specific or conserved in other Geobacteraceae, indicating that the changes occurred post-divergence. There were 27,270 single nucleotide polymorphisms (SNP) between the genomes. There was significant enrichment for SNP locations in non-coding or synonymous amino acid sites, indicating significant selective pressure since the divergence. 25% of orthologs had sequence differences, and this set was enriched in phosphorylation and ATP-dependent enzymes. Substantial sequence differences (at least 12 non-synonymous SNP/kb) were found in 3.6% of the orthologs, and this set was enriched in cytochromes and integral membrane proteins. Genes known to be involved in electron transport, those used in the metabolic cell model, and those that exhibit changes in expression during growth in microbial fuel cells were examined in detail. Conclusions The improvement in external electron transfer in the KN400 strain does not appear to be due to novel gene acquisition, but rather to changes in the common metabolic network. The increase in electron transfer rate and yield in KN400 may be due to changes in carbon flux towards oxidation pathways and to changes in ATP metabolism, both of which indicate that the overall energy state of the cell may be different. The electrically conductive pili appear

  6. Comparison of Thoracic Injury Risk in Frontal Car Crashes for Occupant Restrained without Belt Load Limiters and Those Restrained with 6 kN and 4 kN Belt Load Limiters.

    PubMed

    Foret-Bruno, J Y; Trosseille, X; Page, Y; Huère, J F; Le Coz, J Y; Bendjellal, F; Diboine, A; Phalempin, T; Villeforceix, D; Baudrit, P; Guillemot, H; Coltat, J C

    2001-11-01

    In France, as in other countries, accident research studies show that a large proportion of restrained occupants who sustain severe or fatal injuries are involved in frontal impacts (65% and 50%, respectively). In severe frontal impacts with restrained occupants and where intrusion is not preponderant, the oldest occupants very often sustain severe thoracic injuries due to the conventional seat belt. As we have been observing over the last years, we will expect in the coming years developments which include more solidly-built cars, as offset crash test procedures are widely used to evaluate the passive safety of production vehicles. The reduction of intrusion for the most severe frontal impacts, through optimization of car deformation, usually translates into an increase in restraint forces and hence thoracic injury risk with a conventional retractor seat belt for a given impact severity. It is, therefore essential to limit the restraint forces exerted by the seat belt on the thorax in order to reduce the number of road casualties. In order to address thoracic injury risk in frontal impact, Renault cars have been equipped with the Programmed Restraint System (PRS) since 1995. The PRS is a restraint system that combines belt load limitation and pyrotechnic belt pretension. In an initial design of the Programmed Restraint System (PRS1), the belt load limiter was a steel component designed to shear at a given shoulder force, namely 6 kN. It was mounted between the retractor and the lower anchorage point of the belt. The design of the PRS was modified in 1998 (PRS2), but the principle of load limitation was maintained. The threshold was decreased to 4 kN and this lower belt belt-force limiter has been combined with a specially designed airbag. This paper reports on 347 real-world frontal accidents where the EES (Equivalent Energy Speed) ranged from 35 to 75 km/h. One hundred and ninety-eight (198) of these accidents involved cars equipped with the 6 kN load limiter

  7. Analyses of the MSLB benchmark V1000CT-2 by the coupled system code ATHLET-BIPR8KN

    SciTech Connect

    Nikonov, S. P.; Langenbuch, S.; Lizorkin, M. P.; Velkov, K.

    2006-07-01

    Within the activities of OECD/NEA is being initiated the second phase of the VVER-1000 Coolant Transient Benchmark (V1000CT-2). It considers the best estimate analyses of a Main Steam Line Break (MSLB) of a VVER-1000 NPP with two exercises. The analyses have been performed with the coupled system code ATHLET-BIPR8KN which enables to perform realistic simulation of three-dimensional neutron kinetics and thermal-hydraulic processes in VVER NPP. Results are presented and analysed for the two proposed scenarios. These results are supplemented by sensitivity studies varying the number of the thermo-hydraulic channels (THC) in the core and by comparisons with point kinetics calculations. This work is of considerable importance for the validation of the coupled system code ATHLET-BIPR8KN in case of asymmetric core inlet conditions. (authors)

  8. Interaction between Ataxin-2 Binding Protein 1 and Cubitus-interruptus during wing development in Drosophila.

    PubMed

    Usha, N; Shashidhara, L S

    2010-05-15

    Animal growth and development is dependent on reiterative use of key signaling pathways such as Hedgehog (Hh) pathway. It is widely believed that Cubitus-interruptus (Ci) mediates all functions of Hh pathway. Here we report that CG32062, the Drosophila homologue of Ataxin-2 Binding Protein 1 (dA2BP1), functions as a cofactor of Ci to specify intervein region between L3 and L4 veins of the adult wing. Specifically, Ci-mediated transactivation of knot/collier (kn) in this region of the developing wing imaginal disc is dependent on dA2BP1 function. Protein interaction studies and chromatin-immunoprecipiation experiments suggest that Ci helps dA2BP1 to bind kn promoter, which in turn may help Ci to activate kn expression. These results suggest a mechanism by which Ci may activate targets such as kn, which do not have classical Ci/Gli-binding sites. PMID:20226779

  9. Potent and rapid antigonococcal activity of the venom peptide BmKn2 and its derivatives against different Maldi biotype of multidrug-resistant Neisseria gonorrhoeae.

    PubMed

    Arpornsuwan, Teerakul; Buasakul, Brisana; Jaresitthikunchai, Janthima; Roytrakul, Sittiruk

    2014-03-01

    The emergence of multidrug-resistant strains of Neisseria gonorrhoeae constitutes a serious threat to public health and necessitates the discovery of new types of antimicrobial agents. Among the 18 clinical isolates of N. gonorrhoeae with susceptible to spectinomycin, ceftriaxone and cefixime, 14 isolates were resistance to penicillin, tetracycline and ciprofloxacin, while 2 isolates were susceptible to tetracycline and another was penicillin intermediate isolate. Significant differences between laboratory strain and multidrug resistant strains were revealed by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry profiling and bioinformatics examination using the MALDI BioTyper software. However, Maldi Biotyper was not successfully separated ciprofloxacin-penicillin resistance and ciprofloxacin-tetracycline resistance from ciprofloxacin-penicillin-tetracycline resistant N. gonorrhoeae isolates. BmKn2 is a basic, alpha-helical peptide with no disulfide-bridge venom peptides that was first isolated from Buthus martensii Kasch. A panel of BmKn2 scorpion venom peptide and its derivatives of varying length and characteristics were synthesized chemically and evaluated for their ability to inhibit the growth of clinical N. gonorrhoeae isolates. Synthetic BmKn2 displayed potent activity against 18 clinical isolates of N. gonorrhoeae with MIC50 values of 6.9-27.6 μM. BmKn2 exerted its antibacterial activity via a bactericidal mechanism. Cyclic BmKn1 did not show antigonococcal activity. Decreasing the cationicity and helix percentage at the C-terminus of BmKn2 reduced the potency against N. gonorrhoeae. Taken together, the BmKn1 peptide can be developed as a topical therapeutic agent for treating multidrug-resistant strains of N. gonorrhoeae infections. PMID:24184420

  10. Diffusion dans les liquides

    NASA Astrophysics Data System (ADS)

    Dianoux, A. J.

    2003-09-01

    Après une brève introduction qui rappelle les concepts détaillés dans le cours de M. Bée, nous présentons un aperçu de trois de nos travaux sur l'étude de la diffusion. Tout d'abord la dynamique de l'eau, dans son état normal ou surfondu, révèle la complexité apportée par le réseau de liaisons hydrogène. Ensuite l'effet du confinement sur la dynamique de l'eau sera étudié dans le cas de la membrane Nafion. Enfin la diffusion dans les phases nématique et smectique A d'un cristal liquide permet d'obtenir la valeur du potentiel qui maintient les couches dans la phase smectique.

  11. MSL DAN Passive Data and Interpretations

    NASA Astrophysics Data System (ADS)

    Tate, C. G.; Moersch, J.; Jun, I.; Ming, D. W.; Mitrofanov, I. G.; Litvak, M. L.; Behar, A.; Boynton, W. V.; Drake, D.; Lisov, D.; Mischna, M. A.; Hardgrove, C. J.; Milliken, R.; Sanin, A. B.; Starr, R. D.; Martín-Torres, J.; Zorzano, M. P.; Fedosov, F.; Golovin, D.; Harshman, K.; Kozyrev, A.; Malakhov, A. V.; Mokrousov, M.; Nikiforov, S.; Varenikov, A.

    2014-12-01

    In its passive mode of operation, The Mars Science Laboratory Dynamic Albedo of Neutrons experiment (DAN) detects low energy neutrons that are produced by two different sources on Mars. Neutrons are produced by the rover's Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) and by interactions of high energy galactic cosmic rays (GCR) within the atmosphere and regolith. As these neutrons propagate through the subsurface, their energies can be moderated by interactions with hydrogen nuclei. More hydrogen leads to greater moderation (thermalization) of the neutron population energies. The presence of high thermal neutron absorbing elements within the regolith also complicates the spectrum of the returning neutron population, as shown by Hardgrove et al. DAN measures the thermal and epithermal neutron populations leaking from the surface to infer the amount of water equivalent hydrogen (WEH) in the shallow regolith. Extensive modeling is performed using a Monte Carlo approach (MCNPX) to analyze DAN passive measurements at fixed locations and along rover traverse segments. DAN passive WEH estimates along Curiosity's traverse will be presented along with an analysis of trends in the data and a description of correlations between these results and the geologic characteristics of the surfaces traversed.

  12. Dan Johnson the mentor

    NASA Astrophysics Data System (ADS)

    McKinley, Richard

    2003-04-01

    I first met Dan Johnson in early 1975 as I was interviewing for an engineering job with Henning von Gierke's bioengineering and bionics laboratory at Wright-Patterson Air Force Base. From the very beginning Dan was always direct and forthright. Over the ensuing next 27 years my knowledge and respect of Dan constantly grew. This presentation will review Dan's technical and personal contributions while at the laboratory at Wright-Patterson Air Force Base. He was instrumental in the development of a national noise exposure criteria with the equal-energy-rule, an accurate single number hearing protector attenuation measure based on ``C-A,'' an impulse noise exposure criteria, a longitudinal study of hearing loss in children, development of noise dosimeters, and description of hearing damage risk from nonoccupational noise exposures such as disco's, bowling alleys, lawn mowers, and school buses. Dan has had a significant effect on my career. I and the many people who knew him at the laboratory miss him greatly.

  13. A 2 Tesla Full Scale High Performance Periodic Permanent Magnet Model for Attractive (228 KN) and repulsive Maglev

    NASA Technical Reports Server (NTRS)

    Stekly, Z. J. J.; Gardner, C.; Domigan, P.; Baker, J.; Hass, M.; McDonald, C.; Wu, C.; Farrell, R. A.

    1996-01-01

    Two 214.5 cm. long high performance periodic (26 cm period) permanent magnet half-assemblies were designed and constructed for use as a wiggler using Nd-B-Fe and vanadium permendur as hard and soft magnetic materials by Field Effects, a division of Intermagnetics General Corporation. Placing these assemblies in a supporting structure with a 2.1 cm pole to pole separation resulted in a periodic field with a maximum value of 2.04 T. This is believed to be the highest field ever achieved by this type of device. The attractive force between the two 602 kg magnet assemblies is 228 kN, providing enough force for suspension of a 45,500 kg vehicle. If used in an attractive maglev system with an appropriate flat iron rail, one assembly will generate the same force with a gap of 1.05 cm leading to a lift to weight ratio of 38.6, not including the vehicle attachment structure. This permanent magnet compares well with superconducting systems which have lift to weight ratios in the range of 5 to 10. This paper describes the magnet assemblies and their measured magnetic performance. The measured magnetic field and resulting attractive magnetic force have a negative spring characteristic. Appropriate control coils are necessary to provide stable operation. The estimated performance of the assemblies in a stable repulsive mode, with eddy currents in a conducting guideway, is also discussed.

  14. FSP27 and PLIN1 interaction promotes the formation of large lipid droplets in human adipocytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human adipocytes express high levels of two distinct lipid droplet proteins, fat specific protein 27 (FSP27; also called CIDEC), a member of the CIDE family, and perilipin1 (PLIN1), a member of the PAT family. Both proteins play a role in fat metabolism in adipocytes, but how they interact is not kn...

  15. Inhibitory effects of KN-93, an inhibitor of Ca2+ calmodulin-dependent protein kinase II, on light-regulated root gravitropism in maize

    NASA Technical Reports Server (NTRS)

    Feldman, L. J.; Hidaka, H.

    1993-01-01

    Light is essential for root gravitropism in Zea mays L., cultivar Merit. It is hypothesized that calcium mediates this light-regulated response. KN-93, an inhibitor of calcium/calmodulin kinase II (CaMK II), inhibits light-regulated root gravitropism but does not affect light perception. We hypothesize that CaMK II, or a homologue, operates late in the light/gravity signal transduction chain. Here we provide evidence suggesting a possible physiological involvement of CaMK II in root gravitropism in plants.

  16. NPPy With Dan DeVito

    NASA Video Gallery

    The NPP mission mascot NPPy was found by the NPP Ground Project Manager Dan DeVito in a place called Svalbard, located 600 miles from the North Pole. Since then, Dan and other people on the NPP pro...

  17. Site- and bond-percolation thresholds in Kn ,n-based lattices: Vulnerability of quantum annealers to random qubit and coupler failures on chimera topologies

    NASA Astrophysics Data System (ADS)

    Melchert, O.; Katzgraber, Helmut G.; Novotny, M. A.

    2016-04-01

    We estimate the critical thresholds of bond and site percolation on nonplanar, effectively two-dimensional graphs with chimeralike topology. The building blocks of these graphs are complete and symmetric bipartite subgraphs of size 2 n , referred to as Kn ,n graphs. For the numerical simulations we use an efficient union-find-based algorithm and employ a finite-size scaling analysis to obtain the critical properties for both bond and site percolation. We report the respective percolation thresholds for different sizes of the bipartite subgraph and verify that the associated universality class is that of standard two-dimensional percolation. For the canonical chimera graph used in the D-Wave Systems Inc. quantum annealer (n =4 ), we discuss device failure in terms of network vulnerability, i.e., we determine the critical fraction of qubits and couplers that can be absent due to random failures prior to losing large-scale connectivity throughout the device.

  18. Search for the Θ+ pentaquark in the reactions γp→K¯0K+n and γp→K¯0K0p

    NASA Astrophysics Data System (ADS)

    de Vita, R.; Battaglieri, M.; Kubarovsky, V.; Baltzell, N. A.; Bellis, M.; Goett, J.; Guo, L.; Mutchler, G. S.; Stoler, P.; Ungaro, M.; Weygand, D. P.; Amaryan, M. J.; Ambrozewicz, P.; Anghinolfi, M.; Asryan, G.; Avakian, H.; Bagdasaryan, H.; Baillie, N.; Ball, J. P.; Batourine, V.; Bedlinskiy, I.; Benmouna, N.; Berman, B. L.; Biselli, A. S.; Boiarinov, S.; Bouchigny, S.; Bradford, R.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Bültmann, S.; Burkert, V. D.; Butuceanu, C.; Calarco, J. R.; Careccia, S. L.; Carman, D. S.; Chen, S.; Clinton, E.; Cole, P. L.; Collins, P.; Coltharp, P.; Crabb, D.; Crannell, H.; Crede, V.; Cummings, J. P.; Dale, D.; de Masi, R.; de Sanctis, E.; Degtyarenko, P. V.; Deur, A.; Dharmawardane, K. V.; Djalali, C.; Dodge, G. E.; Donnelly, J.; Doughty, D.; Dugger, M.; Dzyubak, O. P.; Egiyan, H.; Egiyan, K. S.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Funsten, H.; Gabrielyan, M. Y.; Gan, L.; Garçon, M.; Gasparian, A.; Gavalian, G.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Glamazdin, O.; Goetz, J. T.; Golovach, E.; Gonenc, A.; Gordon, C. I. O.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guler, N.; Gyurjyan, V.; Hadjidakis, C.; Hafidi, K.; Hakobyan, H.; Hakobyan, R. S.; Hardie, J.; Hersman, F. W.; Hicks, K.; Hleiqawi, I.; Holtrop, M.; Hyde-Wright, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Ito, M. M.; Jenkins, D.; Jo, H. S.; Joo, K.; Juengst, H. G.; Kellie, J. D.; Khandaker, M.; Kim, W.; Klein, A.; Klein, F. J.; Klimenko, A. V.; Kossov, M.; Kramer, L. H.; Kuhn, J.; Kuhn, S. E.; Kuleshov, S. V.; Lachniet, J.; Laget, J. M.; Langheinrich, J.; Lawrence, D.; Lee, T.; Li, Ji; Livingston, K.; Lu, H. Y.; MacCormick, M.; Markov, N.; McKinnon, B.; Mecking, B. A.; Melone, J. J.; Mestayer, M. D.; Meyer, C. A.; Mibe, T.; Mikhailov, K.; Minehart, R.; Mirazita, M.; Miskimen, R.; Mochalov, V.; Mokeev, V.; Morand, L.; Morrow, S. A.; Moteabbed, M.; Nadel-Turonski, P.; Nakagawa, I.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niczyporuk, B. B.; Niroula, M. R.; Niyazov, R. A.; Nozar, M.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Paterson, C.; Pierce, J.; Pivnyuk, N.; Pocanic, D.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Riccardi, G.; Ricco, G.; Ripani, M.; Ritchie, B. G.; Ronchetti, F.; Rosner, G.; Rossi, P.; Sabatié, F.; Salgado, C.; Santoro, J. P.; Sapunenko, V.; Schumacher, R. A.; Serov, V. S.; Sharabian, Y. G.; Shvedunov, N. V.; Smith, E. S.; Smith, L. C.; Sober, D. I.; Stavinsky, A.; Stepanyan, S. S.; Stepanyan, S.; Stokes, B. E.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Tedeschi, D. J.; Teymurazyan, A.; Thoma, U.; Tkabladze, A.; Tkachenko, S.; Todor, L.; Tur, C.; Vineyard, M. F.; Vlassov, A. V.; Watts, D. P.; Weinstein, L. B.; Williams, M.; Wolin, E.; Wood, M. H.; Yegneswaran, A.; Zana, L.; Zhang, J.; Zhao, B.; Zhao, Z.

    2006-08-01

    The exclusive reactions γp→K¯0K+n and γp→K¯0K0p have been studied in the photon energy range 1.6 3.8 GeV, searching for evidence of the exotic baryon Θ+(1540) in the decays Θ+→nK+ and Θ+→pK0. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The integrated luminosity was about 70pb-1. The reactions have been isolated by detecting the K+ and proton directly, the neutral kaon via its decay to KS→π+π- and the neutron or neutral kaon via the missing mass technique. The mass and width of known hyperons such as Σ+, Σ- and Λ(1116) were used as a check of the mass determination accuracy and experimental resolution. Approximately 100 000 Λ*(1520)’s and 150 000 ϕ’s were observed in the K¯0K+n and K¯0K0p final state, respectively. No evidence for the Θ+ pentaquark was found in the nK+ or pKS invariant mass spectra. Upper limits were set on the production cross section of the reaction γp→K¯0Θ+ as functions of center-of-mass angle, nK+ and pKS masses. Combining the results of the two reactions, the 95% C.L. upper limit on the total cross section for a resonance peaked at 1540 MeV was found to be 0.7 nb. Within most of the available theoretical models, this corresponds to an upper limit on the Θ+ width, ΓΘ+, ranging between 0.01 and 7 MeV.

  19. Corner Office: Google's Dan Clancy

    ERIC Educational Resources Information Center

    Albanese, Andrew Richard; Oder, Norman

    2009-01-01

    This article presents an interview with Dan Clancy, engineering director for Google Book Search. In this interview, Clancy talks about the pending Google Book Search settlement, involving millions of volumes digitized from libraries, which drew a lawsuit from the Association of American Publishers and the Authors Guild. He also discusses pricing,…

  20. Versatile device for low temperature in situ generation of forces up to 25 kN: Application to hydrostatic pressure experiments

    NASA Astrophysics Data System (ADS)

    Salce, B.; Thomasson, J.; Demuer, A.; Blanchard, J. J.; Martinod, J. M.; Devoille, L.; Guillaume, A.

    2000-06-01

    We describe a versatile modular device built to generate forces up to 25 kN at cryogenic temperatures in order to achieve very fine in situ hydrostatic pressure tuning in the range 0-21 GPa. This device was designed to save time during measurements and protect the experimental setup by avoiding warming and cooling cycles to vary the pressure. The force is generated by a bellow operated with pressurized 4He and amplified mechanically. Diamond and sapphire anvil cells are used to perform electrical resistivity, magnetic susceptibility, and specific heat measurements under highly hydrostatic conditions by using helium as the transmitting medium. The pressure is determined by the ruby fluorescence technique. The performance of the device is illustrated by measurements of the superconducting transition of Pb and the magnetic transitions of CeRu2Ge2 in the range 0-10 GPa. This device is currently being adapted in a dilution fridge in order to be operated down to 50 mK.

  1. Radiations cosmiques : danger dans l'Espace

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.; Dzitko, H.

    2000-06-01

    Au sol, l'atmosphere nous protege plus ou moins bien. Mais dans l'espace ou a bord des avions de ligne, l'homme est directement expose aux rayonnements cosmiques qui peuvent etre mortels. Un veritable frein a la presence humaine prolongee dans l'espace. Une menace que les agences spatiales prennent tres au serieux.

  2. Étude expérimentale de l'interaction laser-matière dans le cas du soudage d'un acier inoxydable austénitique par laser Nd:YAG continu de 2 kW

    NASA Astrophysics Data System (ADS)

    Dumord, E.; Jouvard, J. M.; Grevey, D.; Druetta, M.; Ottavi, P.

    1997-05-01

    The laser-matter interaction acting during cw 2 kW Nd:YAG laser welding of an austenitic stainless steel is studied and particulary the effects linked to the presence of a keyhole in the liquid bath. This is done in order to define parameters useful to the process modelling. The absorption factor of target has been measured in order to better understand the Nd:YAG laser/stainless steel 304 interaction. Then an experimental approach of the keyhole angle value determination is proposed. Values are presented showing the important keyhole angle at the bottom of the bead. Finally a study relative to the plume above the keyhole shows that it is responsible for the formation of the nail-head part, observed on the experimental melting zone, by laser beam scattering. L'interaction laser-matière se produisant lors du soudage par laser Nd:YAG continu de 2kW d'un acier inoxydable austénitique est étudiée, et notamment les effets liés à la présence du capillaire dans le bain liquide, de façon à définir les paramètres utiles à la modélisation du processus. Le facteur d'absorption des cibles utilisées a été mesuré afin de mieux appréhender l'interaction laser Nd:YAG/acier inoxydable austénitique 304. Puis une approche expérimentale de détermination de l'angle d'inclinaison du capillaire est proposée. Des valeurs sont présentées montrant la forte inclinaison du capillaire en fond de cordon. Finalement une étude relative au panache présent audessus du capillaire met en évidence qu'il est responsable de la formation de la partie en tête de clou observée sur les zones fondues expérimentales par diffusion du faisceau laser

  3. Caracterisation de la cohesion de l'interface AMF/polymere dans une structure deformable adaptative

    NASA Astrophysics Data System (ADS)

    Fischer-Rousseau, Charles

    réponse thermique transitoire du polymère et du fil d’AMF lors d’un chauffage par effet Joule est programmé à l’aide du logiciel ANSYS. Le comportement du modèle est validé avec des résultats expérimentaux où des thermocouples encastrés dans l’échantillon permettent des mesures locales de la température. Les résultats calculés sont en accord avec les résultats expérimentaux d’un point de vue qualitatif, mais accusent des différences significatives d’un point de vue quantitatif. La mesure du champ de déformation à l’interface du fil et du polymère dans une SDA permettrait de développer et valider un modèle numérique prenant en compte l’effet mémoire de forme d’un fil encastré dans une matrice polymère. Dans ce but, une machine de traction miniature permettant l’analyse par microspectrométrie Raman in situ est présentée. Elle a une capacité de 1 kN et un déplacement maximal de 20 mm dans une enveloppe de conception totale de 160 mm de diamètre. La machine est conçue pour que le milieu de l’échantillon soit immobile grâce au fait que le mouvement des deux extrémités soit symétrique. Les résultats montrent que du travail supplémentaire est nécessaire avant de pouvoir encastrer des fils d’AMF dans une structure déformable adaptative. Mots-clés: décohésion, structure active, alliage à mémoire de forme, AMF, tests d’arrachement.

  4. Validation of High Aspect Ratio Cooling in a 89 kN (20,000 lb(sub f)) Thrust Combustion Chamber

    NASA Technical Reports Server (NTRS)

    Wadel, Mary F.; Meyer, Michael L.

    1996-01-01

    In order to validate the benefits of high aspect ratio cooling channels in a large scale rocket combustion chamber, a high pressure, 89 kN (20,000 lbf) thrust, contoured combustion chamber was tested in the NASA Lewis Research Center Rocket Engine Test Facility. The combustion chamber was tested at chamber pressures from 5.5 to 11.0 MPa (800-1600 psia). The propellants were gaseous hydrogen and liquid oxygen at a nominal mixture ratio of six, and liquid hydrogen was used as the coolant. The combustion chamber was extensively instrumented with 30 backside skin thermocouples, 9 coolant channel rib thermocouples, and 10 coolant channel pressure taps. A total of 29 thermal cycles, each with one second of steady state combustion, were completed on the chamber. For 25 thermal cycles, the coolant mass flow rate was equal to the fuel mass flow rate. During the remaining four thermal cycles, the coolant mass flow rate was progressively reduced by 5, 6, 11, and 20 percent. Computer analysis agreed with coolant channel rib thermocouples within an average of 9 percent and with coolant channel pressure drops within an average of 20 percent. Hot-gas-side wall temperatures of the chamber showed up to 25 percent reduction, in the throat region, over that of a conventionally cooled combustion chamber. Reducing coolant mass flow yielded a reduction of up to 27 percent of the coolant pressure drop from that of a full flow case, while still maintaining up to a 13 percent reduction in a hot-gas-side wall temperature from that of a conventionally cooled combustion chamber.

  5. Simultaneous Measurements of Neutron Environment at Mars from Orbit (Mars Odyssey HEND) and from the Surface (MSL DAN)

    NASA Astrophysics Data System (ADS)

    Martinez Sierra, L. M.; Jun, I.; Litvak, M. L.; Sanin, A. B.; Mitrofanov, I. G.

    2015-12-01

    Currently, the high energy neutron detector (HEND) onboard Mars Odyssey and the dynamic albedo of neutrons (DAN) instrument onboard the Mars Science Laboratory rover are simultaneously measuring the neutron environment from orbit and from the surface, respectively. Naturally-occurring neutrons at Mars are produced from the interactions of galactic cosmic rays (GCR) and solar energetic particles (SEP) with the Martian atmosphere and surface material. The neutron data from these simultaneous orbital and surface measurements are a good indicator for the state of general ambient radiation environments at Mars and can be also used as a means to infer how the ambient radiation is transported through the Martian atmosphere. Both HEND and DAN are healthy, and they provide the unique data sources valuable to study these phenomena for the period since the MSL landing in August 2012. Understanding of why there is correlation or no correlation between the two measurements will provide a key clue to understand the processes of GCR/SEP propagation through the Mars atmosphere and the interaction with the Mars surface materials. More detailed comparison between the two data sets and analysis of HEND/DAN data will be presented in the final presentation. Also, the long-term trend of the HEND/DAN data will be also compared with a general space weather condition. We used only publicly available HEND/DAN data in this study, e.g., open literature and/or planetary data system (PDS).

  6. Dan Johnson's impact on hearing research

    NASA Astrophysics Data System (ADS)

    Shotland, Lawrence I.

    2003-04-01

    Daniel L. Johnson is well known for his many technical contributions to noise research. Throughout a long and distinguished career at Wright-Patterson Air Force Base, Dan published the results of several significant experiments, including his landmark experiments on asymptotic threshold shift and exposure to impulse noise. His work in the area of noise exposure laid much of the groundwork for a greater understanding of the physiologic response to hazardous noise, much of which has since been incorporated in national and international standards. Dan is highly regarded for his tireless work on technical and advisory committees in noise, and most recently, ototoxicity. Throughout his career, Dan has adhered to a self-imposed standard of intellectual honesty and discovery. Dan's most recent endeavor, the development of a personal noise dosimeter designed for self-monitoring by the employee, is characteristic of his creativity and energy. Perhaps less well known are his contributions over the years to the success of his younger colleagues. He has accomplished this in an unselfish and egalitarian manner, oftentimes challenging and even contradicting his own research. The focus of this talk will elaborate on these facets of Dan's professional contributions.

  7. Dan jiang kou hydropower station turbine refurbishment

    NASA Astrophysics Data System (ADS)

    Zhang, R. Y.; Nie, S. Q.; Bazin, D.; Cheng, J. H.

    2012-11-01

    Dan jiangkou hydropower station refurbished project, isan important project of Chinese refurbishment market. Tianjin Alstom Hydro Co., ltd won this contract by right of good performance and design technology,Its design took into account all the constraints linked to the existing frame. It results in a specific and highly advanced shape.The objective of this paper is to introduce the successful turbine hydraulic design, model test and mechanical design of Dan jiangkou project; and also analyze the cavitation phenomena occurred on runner band surface of Unit 4 after putting into commercial operation. These technology and feedback shall be a good reference and experience for other similar projects

  8. Registration of 'Dan' winter hulless barley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dan’ (Reg. No. CV- , PI 659066) six-rowed winter hulless barley (Hordeum vulgare L.) was developed and released by the Virginia Agricultural Experiment Station in March 2009. Dan was derived from the cross VA96-41-17 / SC872143. It was released for production in the eastern United States, as a poten...

  9. Drosophila CtBP regulates proliferation and differentiation of eye precursors and complexes with Eyeless, Dachshund, Dan and Danr during eye and antennal development

    PubMed Central

    Hoang, Chinh Q.; Burnett, Micheal E.; Curtiss, Jennifer

    2010-01-01

    Specification factors regulate cell fate in part by interacting with transcriptional co-regulators like CtBP to regulate gene expression. Here, we demonstrate that CtBP forms a complex or complexes with the Drosophila melanogaster Pax6 homolog Eyeless (Ey), and with Distal antenna (Dan), Distal antenna related (Danr) and Dachshund to promote eye and antennal specification. Phenotypic analysis together with molecular data indicates that CtBP interacts with Ey to prevent overproliferation of eye precursors. In contrast CtBP,dan,danr triple mutant adult eyes have significantly fewer ommatidia than CtBP single or dan,danr double mutants, suggesting that the CtBP/Dan/Danr complex functions to recruit ommatidia from the eye precursor pool. Further, CtBP single and to a greater extent CtBP,dan,danr triple mutants affect the establishment and maintenance of the R8 precursor, which is the founding ommatidial cells. Thus, CtBP interacts with different eye specification factors to regulate gene expression appropriate for proliferative versus differentiative stages of eye development. PMID:20730908

  10. Dan Marino Helping Those with Autism Spectrum Disorders | NIH MedlinePlus the Magazine

    MedlinePlus

    ... Marino Foundation. Photo: Dan Marino Foundation Former NFL star quarterback Dan Marino and his wife Claire experienced ... to succeed in life,'" says the former NFL star. "That's where the focus for The Dan Marino ...

  11. Manipulation coherente de qubits de spin dans une boite quantique triple

    NASA Astrophysics Data System (ADS)

    Gaudreau, Louis

    Nous presentons dans cette these une etude detaillee du moment magnetique intrinseque de l'electron, i.e. le spin electronique, incluant la manipulation quantique coherente des etats de spin de trois electrons couples. A cette fin, nous utilisons des boites quantiques laterales pour confiner les electrons. Ces nano-structures, d'une grandeur autour de 1 pm, permettent de confiner un nombre precis d'electrons de facon controlee, allant jusqu'a zero electrons. Les developpements technologiques et d'ingeniosite durant la derniere decennie ont permis de coupler trois boites quantiques, ainsi l'interaction entre plusieurs electrons confines peut etre controlee comme par exemple le couplage quantique tunnel et l'interaction d'echange entre les spins de chacun d'entre eux. A l'aide de boites quantiques couplees, il est possible de realiser des experiences dans plusieurs domaines de la physique moderne : les etats up et down du spin des electrons confines peuvent etre utilisees comme etats quantiques binaires (qubits) dans le domaine de l'informatique quantique, la non-localite quantique peut etre testee en separant spatialement deux electrons enchevetres, il est possible de creer des 'courants de spin enchevetres' utiles en spintronique, et bien d'autres. La manipulation coherente des etats de spin du systeme a trois electrons se fait de facon purement electrique grace a des pulses a haute frequence qui permettent d'augmenter le couplage entre les electrons et de faire la mesure de l'etat resultant apres la manipulation. Nous utilisons l'interaction hyperfine entre les spins des electrons et ceux des noyaux du cristal dans lequel ils resident pour creer les rotations quantiques entre les etats, notamment les etats |Q +3/2> et (D+1/2>. Les resultats obtenus indiquent un temps de coherence de l'ordre de 10 ns. Ces experiences demontrent un niveau de controle sans precedant de boites quantiques triples et pavent la voie vers des nano-structures plus sophistiquees dans

  12. Approximation auto-coherente a deux particules, pseudogap et supraconductivite dans le modele de Hubbard attractif

    NASA Astrophysics Data System (ADS)

    Allen, Steve

    2000-10-01

    Dans cette these nous presentons une nouvelle methode non perturbative pour le calcul des proprietes d'un systeme de fermions. Notre methode generalise l'approximation auto-coherente a deux particules proposee par Vilk et Tremblay pour le modele de Hubbard repulsif. Notre methode peut s'appliquer a l'etude du comportement pre-critique lorsque la symetrie du parametre d'ordre est suffisamment elevee. Nous appliquons la methode au probleme du pseudogap dans le modele de Hubbard attractif. Nos resultats montrent un excellent accord avec les donnees Monte Carlo pour de petits systemes. Nous observons que le regime ou apparait le pseudogap dans le poids spectral a une particule est un regime classique renormalise caracterise par une frequence caracteristique des fluctuations supraconductrices inferieure a la temperature. Une autre caracteristique est la faible densite de superfluide de cette phase demontrant que nous ne sommes pas en presence de paires preformees. Les resultats obtenus semblent montrer que la haute symetrie du parametre d'ordre et la bidimensionalite du systeme etudie elargissent le domaine de temperature pour lequel le regime pseudogap est observe. Nous argumentons que ce resultat est transposable aux supraconducteurs a haute temperature critique ou le pseudogap apparait a des' temperatures beaucoup plus grandes que la temperature critique. La forte symetrie dans ces systemes pourraient etre reliee a la theorie SO(5) de Zhang. En annexe, nous demontrons un resultat tout recent qui permettrait d'assurer l'auto-coherence entre les proprietes a une et a deux particules par l'ajout d'une dynamique au vertex irreductible. Cet ajout laisse entrevoir la possibilite d'etendre la methode au cas d'une forte interaction.

  13. 8. Wabash Ave. North. View of Loop and Dan Ryan ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Wabash Ave. North. View of Loop and Dan Ryan Line. Curve at Van Buren St. and Wabash Ave. at center. Dan Ryan line starts at center and runs south (toward bottom of picture). Photo by Jet Lowe. - Union Elevated Railroad, Union Loop, Wells, Van Buren, Lake Streets & Wabash Avenue, Chicago, Cook County, IL

  14. Frequency specific interactions of MEG resting state activity within and across brain networks as revealed by the multivariate interaction measure.

    PubMed

    Marzetti, L; Della Penna, S; Snyder, A Z; Pizzella, V; Nolte, G; de Pasquale, F; Romani, G L; Corbetta, M

    2013-10-01

    Resting state networks (RSNs) are sets of brain regions exhibiting temporally coherent activity fluctuations in the absence of imposed task structure. RSNs have been extensively studied with fMRI in the infra-slow frequency range (nominally <10(-1)Hz). The topography of fMRI RSNs reflects stationary temporal correlation over minutes. However, neuronal communication occurs on a much faster time scale, at frequencies nominally in the range of 10(0)-10(2)Hz. We examined phase-shifted interactions in the delta (2-3.5 Hz), theta (4-7 Hz), alpha (8-12 Hz) and beta (13-30 Hz) frequency bands of resting-state source space MEG signals. These analyses were conducted between nodes of the dorsal attention network (DAN), one of the most robust RSNs, and between the DAN and other networks. Phase shifted interactions were mapped by the multivariate interaction measure (MIM), a measure of true interaction constructed from the maximization of imaginary coherency in the virtual channels comprised of voxel signals in source space. Non-zero-phase interactions occurred between homologous left and right hemisphere regions of the DAN in the delta and alpha frequency bands. Even stronger non-zero-phase interactions were detected between networks. Visual regions bilaterally showed phase-shifted interactions in the alpha band with regions of the DAN. Bilateral somatomotor regions interacted with DAN nodes in the beta band. These results demonstrate the existence of consistent, frequency specific phase-shifted interactions on a millisecond time scale between cortical regions within RSN as well as across RSNs. PMID:23631996

  15. Transport dans l'hélium 3 polarisé par pompage optique

    NASA Astrophysics Data System (ADS)

    Lhuillier, C.; Leduc, M.

    Optical pumping is, in the case of helium 3, a useful method for polarizing the nuclear spins of the gas. Substantial orientation rates can be now achieved using tunable infrared lasers. Large changes in the macroscopic behaviour of the helium 3 fluid occur as a consequence of the polarization of the nuclei, provided the temperature is low enough, in spite of the small nuclear magnetic moment. These effects result both from interactions and statistics and are subtle consequences of the indistinguishability of particles and of the symmetrization principle in quantum mechanics. One explains in this article the expected changes for the viscosity and the heat conduction in the gas below a few kelvins. Furthermore, one shows that the transport of spin magnetization in polarized helium 3 (3He↑) has a propagative character at low temperature, giving rise to collective oscillatory modes : the transverse spin waves. One describes a recent experiment which proved the existence of these waves and allowed measuring their quality factor. Observations and theoretical predictions are in good agreement. Le pompage optique constitue, dans le cas de l'hélium 3, une méthode commode pour polariser les spins nucléaires du gaz. Des taux d'orientation notables peuvent être maintenant réalisés grâce aux lasers accordables dans l'infrarouge. Des changements importants de comportement macroscopique du fluide d'hélium 3 se produisent sous l'effet de la polarisation des noyaux, à condition que la température soit suffisamment basse, et ceci malgré la petitesse du moment magnétique nucléaire ; il s'agit là d'effets conjugués d'interaction et de statistique, manifestations subtiles de l'indiscernabilité des particules et du principe de symétrisation en mécanique quantique. On explique dans cet article les modifications attendues pour la viscosité et la conduction de la chaleur dans le gaz en dessous de quelques kelvins. De plus, on montre que le transport de spin dans l

  16. Long-term Passive Mode Data Measured by the Dynamic Albedo of Neutrons (DAN) Instrument onboard Mars Science Laboratory (MSL) and Comparison to REMS Surface Pressure and Temperature Measurements

    NASA Astrophysics Data System (ADS)

    Jun, I.; Mitrofanov, I. G.; Litvak, M. L.; Sanin, A. B.; Martín-Torres, J.; Zorzano, M. P.; Boynton, W. V.; Fedosov, F.; Golovin, D.; Hardgrove, C. J.; Harshman, K.; Kozyrev, A.; Kuzmin, R.; Malakhov, A. V.; Mischna, M. A.; Moersch, J.; Mokrousov, M.; Nikiforov, S.; Tate, C. G.

    2014-12-01

    Since the landing in August 2012, DAN has provided a wealth of scientific data from the successful surface operation in both Active mode and Passive mode. While the main DAN science investigation so far has focused in estimating the contents of water-equivalent-hydrogen (WEH) and chlorine-equivalent-neutron-absorption in the surface, here we will provide/discuss low energy (less than about 1 keV) background neutron environment at the Martian surface as measured by DAN Passive mode operation. Passive mode measurements have been done on almost every sols with durations ranging from 1 hour to ~9 hour, covering different times of a day. Neutrons from the onboard power source Multi Mission Radioisotope Thermonuclear Generator (MMRTG) and induced by Galactic Cosmic Ray (GCR)/Solar Energetic Particles (SEP) interactions with the Martian atmosphere and the surface material contribute to the DAN passive data. An approach to separate out the respective contributions from the DAN total count rates was developed previously (Jun et al., 2013) using the data collected at Rocknest (where the rover stayed from sol 60 to sol 100). The main goal of this paper is to extend the same analysis to other locations encountered during the rover traverse especially to understand the long-term (through Sol 800, covering more than 1 Martian year) behavior of the neutron environment at the Martian surface as measured by DAN in response to variation of the free space GCR/SEP environment. Extensive Monte Carlo transport simulations using Monte Carlo N-Particle eXtended (MCNPX) have been performed to support the analysis and to aid interpretation of the DAN passive data. In addition, the DAN passive data are compared to the long-term surface temperature and pressure data (both measured and modeled) from Rover Environmental Monitoring Station (REMS) to investigate possible correlation of the DAN data with ambient environmental conditions.

  17. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2014-06-01

    Future lune ? - L'âge de la Lune - Des volcans actifs sur Vénus - Un lac dans le cratère Gusev ? - Météorites et atmosphère martiennes - L’hexagone de Saturne - Pluton - Exo-Terre - Bêta Pictoris b - Cérès et Vesta depuis Mars - Naine froide - Parallaxes par Hubble - L2 Puppis et le sort du Soleil - Supernova et lentille gravitationnelle - Champ magnétique galactique - L’objet de Sakurai - Fermi et la matière noire - Lentille naine

  18. Fluctuations quantiques et instabilites structurales dans les conducteurs a basse dimensionalite

    NASA Astrophysics Data System (ADS)

    Dikande, Alain Moise

    Un engouement particulier s'est manifeste ces dernieres annees pour les systemes electroniques fortement correles, ce en rapport avec l'immense richesse de leurs proprietes physiques. En general, ces proprietes sont induites par la presence d'interactions entre electrons qui, combinees a la structure du reseau moleculaire, donnent parfois lieu a une tres grande variete de phases electroniques et structurales ayant des incidences directes sur les phenomenes de transport dans ces materiaux. Les systemes electroniques couples a un reseau moleculaire et designes systemes electron-phonon font partie de cette classe de materiaux qui ont recemment capte l'attention, en raison notamment de la competition entre plusieurs echelles d'energie dans un environnement caracterise par une forte anisotropie cristalline et une dynamique moleculaire assez importante. En effet, en plus des proprietes electroniques et structurales particulieres la dimensionalite de ces systemes contribue egalement a leur richesse. Ainsi, une tres forte anisotropie structurale peut rehausser de facon considerable l'importance des interactions entre electrons et entre molecules constituant le reseau au point ou la physique du systeme soit regie par de tres fortes fluctuations. Ce dernier contexte est devenu un domaine a part de la physique des systemes fortement correles, a savoir celui des les phenomenes critiques quantiques . Parmi les systemes electron-phonon, on retrouve les composes inorganique KCP et organique TTF-TCNQ decouverts durant les annees 70, et explores en profondeur a cause de leur tendance vers une instabilite du type onde de densite de charge a basse temperature. Ces composes, en general designes systemes de Peierls en reference a l'instabilite de leurs structures electroniques regie par le reseau moleculaire, ont recemment connu un regain d'interet a la lumiere des nouveaux developpements dans les techniques de caracterisation des structures electroniques ainsi que sur le plan de

  19. Pat Thiel talks about Nobel Prize winner Dan Shechtman

    SciTech Connect

    Thiel, Pat

    2012-01-01

    Ames Laboratory senior scientist and Iowa State University Distinguished Professor of Chemistry Pat Thiel talks about her friend and colleague Dan Shechtman who received the 2011 Nobel Prize for Chemistry.

  20. 4. Historic American Buildings Survey Dan Leyrer, Photographer, July 10, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Historic American Buildings Survey Dan Leyrer, Photographer, July 10, 1963 ENTRANCE HALL & STAIRWAY with BRASS NEWEL POST - Herman-Grima House, 820 Saint Louis Street, New Orleans, Orleans Parish, LA

  1. 1. Historic American Buildings Survey Dan Leyrer, Photographer August 1963 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey Dan Leyrer, Photographer August 1963 PATIO AND GARCONNIERE--VIEW FROM EAST - Herman-Grima House, Garconniere & Kitchen, 820 Saint Louis Street, New Orleans, Orleans Parish, LA

  2. 2. Historic American Buildings Survey Dan Leyrer, Photographer August 1963 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Historic American Buildings Survey Dan Leyrer, Photographer August 1963 KITCHEN (SOUTHEAST ELEVATION) ATTACHED TO GARCONNIERE - Herman-Grima House, Garconniere & Kitchen, 820 Saint Louis Street, New Orleans, Orleans Parish, LA

  3. Environmental Scientist/Chemist Dan Gazda Speaks With Students

    NASA Video Gallery

    From NASA's International Space Station Mission Control Center, Environmental Scientist/Chemist Dan Gazda participates in a Digital Learning Network (DLN) event with students at from St. Peter's Pr...

  4. 1. Historic American Buildings Survey Dan Leyrer, Photographer Summer 1964 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey Dan Leyrer, Photographer Summer 1964 FRONT ELEVATION, OVERLOOKING BAYOU ST. JOHN - Michel-Pitot House, 1370 Moss Street (moved to 1440 Moss Street), New Orleans, Orleans Parish, LA

  5. Pat Thiel talks about Nobel Prize winner Dan Shechtman

    ScienceCinema

    Thiel, Pat

    2013-03-01

    Ames Laboratory senior scientist and Iowa State University Distinguished Professor of Chemistry Pat Thiel talks about her friend and colleague Dan Shechtman who received the 2011 Nobel Prize for Chemistry.

  6. STS-108 Crew Interviews: Dan Tani

    NASA Technical Reports Server (NTRS)

    2001-01-01

    STS-108 Mission Specialist Dan Tani is seen during a prelaunch interview. He answers questions about the mission's goals and significance, explaining the meaning of 'utilization flight 1' (UF-1) as opposed to an 'assembly flight'. He gives details on the payload (Starshine Satellite, Avian Development Facility, and Rafaello Multipurpose Logistics Module (MPLM)), his role in the rendezvous, docking, and undocking of the Endeavour Orbiter to the International Space Station (ISS), how he will participate in the unloading and reloading of the MPLM, and the way in which the old and new resident crews of ISS will exchanged. Tani ends with his thoughts on the short-term and long-term future of the International Space Station.

  7. Pair interaction lattice gas simulations: Flow past obstacles in two and three dimensions

    SciTech Connect

    Vogeler, A.; Wolf-Gladrow, D.A. )

    1993-04-01

    Apart from the FCHC (face-centered hypercube), Nasilowski's pair interaction lattice gas (PI) is the only known lattice gas automaton for three-dimensional hydrodynamic simulations. Unfortunately, the viscosity of PI is not isotropic. In order to determine the degree anisotropy, the authors derive fluid dynamic equations for the regime of compressible viscid flow. From relaxation measurements of waves propagating in various directions they compute the physically relevant dissipation coefficients and compare their results with theoretical predictions. Although PI shows a high degree of anisotropy, they define the mean value of the dissipation tensor as effective shear viscosity. Using this value of v[sub eff][sup 2D] = 0.35, two-dimensional simulations of flow past a cylinder yield drag coefficients in quantitative agreement with wind tunnel measurements over a range of Reynolds numbers of 5-50. Three-dimensional simulations of flow past a sphere yield qualitative agreement with various references. A fit of the results to a semi-empirical curve provides an effective value of v[sub eff][sup 2D] = 0.21 for a range of Reynolds numbers from 0.19 to 40. In order to check for finite-size effects, the authors measured the mean free path [lambda] and computed the Knudsen numbers. They obtained [lambda] [approx]1 lattice unit, corresponding to Kn = 0.01 (2D) and Kn = 0.1 (3D). They found no significant finite-size effects. 44 refs., 10 figs.

  8. Etude theorique des fluctuations structurales dans les composes organiques a dimensionnalite reduite

    NASA Astrophysics Data System (ADS)

    Dumoulin, Benoit

    'instabilite spin-Peierls apparait ensuite vers 60K. Notre etude theorique montre qu'un modele d'electrons en interaction de type "g-ologie" avec possibilite de processus umklapp permet de bien rendre compte des proprietes physiques de ce systeme. Finalement, la troisieme partie de cette these porte sur l'etude des premiers composes organiques quasi-unidimensionnels a avoir ete synthetises: les composes de la famille du TTF-TCNQ. Notre etude theorique des instabilites structurales que presentent ces composes n'est evidemment pas la premiere. L'originalite de cette derniere est qu'elle tient compte des fortes interactions entre les electrons, presentent dans ces composes. Pour tenir compte de telles interactions, nous avons choisi la formulation "liquide de Luttinger" qui nous permet de mieux traiter ce regimne dit de couplage fort.

  9. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2007-09-01

    Anions interstellaires; S Orionis; Altaîr; Courants stellaires; Etoiles jeunes; 2MASSW J1207334-393254; Alpha Andromède; Etoiles à neutrons (1); LH54-425; AGNs invisibles; Deux supernovae; Les GRBs seon Swift; Peser les trous noirs; Formation de trous noirs; Trou noir; ondes gravitationnelles : Virgo entre dans sa phase d'exploitation scientifique; Amas de galaxies actifs; Amas de galaxies; Galaxies actives d'amas; L'univers statique: le retour; Macho; Exoplanètes; Exoplanètes habitables?; Exoplanètes habitables? (suite); Une année d'un an; Une année de 31 heures; Valse des Jupiters; Disque de HD 15115; Impact majeur; Planètes isolées; Super-Jupiter; Impact et mini-extinction; L'effet Pioneer; Toungouska; Spéléo martienne; Autres lunes dactives; Encelade; Hypérion; Pluton dépassé; Satellites d'Uranus; Titan

  10. Functional interactions between large-scale networks during memory search.

    PubMed

    Kragel, James E; Polyn, Sean M

    2015-03-01

    Neuroimaging studies have identified two major large-scale brain networks, the default mode network (DMN) and the dorsal attention network (DAN), which are engaged for internally and externally directed cognitive tasks respectively, and which show anticorrelated activity during cognitively demanding tests and at rest. We identified these brain networks using independent component analysis (ICA) of functional magnetic resonance imaging data, and examined their interactions during the free-recall task, a self-initiated memory search task in which retrieval is performed in the absence of external cues. Despite the internally directed nature of the task, the DAN showed transient engagement in the seconds leading up to successful retrieval. ICA revealed a fractionation of the DMN into 3 components. A posteromedial network increased engagement during memory search, while the two others showed suppressed activity during memory search. Cooperative interactions between this posteromedial network, a right-lateralized frontoparietal control network, and a medial prefrontal network were maintained during memory search. The DAN demonstrated heterogeneous task-dependent shifts in functional coupling with various subnetworks within the DMN. This functional reorganization suggests a broader role of the DAN in the absence of externally directed cognition, and highlights the contribution of the posteromedial network to episodic retrieval. PMID:24084128

  11. Place du Lambeau Interosseux Posterieur dans sa Variante Aponevrotique dans le Traitement des Sequelles de Brulure de la Face Dorsale de la Main

    PubMed Central

    Achbouk, A.; Khales, A.; Oufkir, A.; Ihrai, H.

    2010-01-01

    Summary Le lambeau interosseux postérieur dans sa variante aponévrotique est un outil très intéressant dans le traitement des séquelles de brûlures de la face dorsale de la main. Les Auteurs cherchent, à travers un cas clinique et une revue de la littérature, à replacer cette variante dans l'arsenal thérapeutique. PMID:21991207

  12. Kyste hydatique du foie rompu dans la paroi abdominale et dans le muscle psoas : à propos d'une rare observation

    PubMed Central

    En-Nafaa, Issam; Moujahid, Mountassir; Alahyane, Abdelouahabe; Amil, Touria; Hanine, Ahmed; Ziadi, Tarik

    2011-01-01

    Le kyste hydatique du foie est une parasitose qui sévit à l′état endémique au maroc. La rupture dans la paroi abdominale et dans le psoas est une complication exceptionnelle. Nous rapportons un cas de kyste hydatique du foie rompu dans la paroi et dans le muscle psoas. Le diagnostic a été établi sur les données de l′échographie et surtout de la tomodensitométrie. Le patient a été opéré avec des suites simples. PMID:22187585

  13. Dan Poskevich demonstrates experiment for STS student involvement project

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Dan Poskevich, a college student, demonstrates an experiment he developed for the Space Transportation System (STS) student involvement project. In the aluminum box are thousands of honeybees constructing a honeycomb. Poskevich gave a brief demonstration for news media representatives in the Space Shuttle one-G trainer in JSC's mockup and integration lab.

  14. ADFL Award for Distinguished Service in the Profession: Dan Davidson.

    ERIC Educational Resources Information Center

    Dabars, Zita D.

    1999-01-01

    Discusses the influence of Dan Davidson on the Russian language teaching profession, concentrating on the NEH-CORLAC Institutes in Russian Language and Culture and materials development projects and on Davidson's role in programs involving high schools that teach Russian, the high school exchange program, and two national contests to stimulate…

  15. Transport de paires EPR dans des structures mesoscopiques

    NASA Astrophysics Data System (ADS)

    Dupont, Emilie

    Dans cette these, nous nous sommes particulierement interesses a la propagation de paires EPR1 delocalisees et localisees, et a l'influence d'un supraconducteur sur le transport de ces paires. Apres une introduction de cette etude, ainsi que du cadre scientifique qu'est l'informatique quantique dans lequel elle s'inscrit, nous allons dans le chapitre 1 faire un rappel sur le systeme constitue de deux points quantiques normaux entoures de deux fils supraconducteurs. Cela nous permettra d'introduire une methode de calcul qui sera reutilisee par la suite, et de trouver egalement le courant Josephson produit par ce systeme transforme en SQUID-dc par l'ajout d'une jonction auxiliaire. Le SQUID permet de mesurer l'etat de spin (singulet ou triplet), et peut etre forme a partir d'autres systemes que nous etudierons ensuite. Dans le chapitre 2, nous rappellerons l'etude detaillee d'un intricateur d'Andreev faite par un groupe de Bale. La matrice T, permettant d'obtenir le courant dans les cas ou les electrons sont separes spatialement ou non, sera etudiee en detail afin d'en faire usage au chapitre suivant. Le chapitre 3 est consacre a l'etude de l'influence du bruit sur le fonctionnement de l'intricateur d'Andreev. Ce bruit modifie la forme du courant jusqu'a aboutir a d'autres conditions de fonctionnement de l'intricateur. En effet, le bruit present sur les points quantiques peut perturber le transport des paires EPR par l'intermediaire des degres de liberte. Nous montrerons que, du fait de l'"intrication" entre la charge de la paire et le bruit, la paire est detruite pour des temps longs. Cependant, le resultat le plus important sera que le bruit perturbe plus le transport des paires delocalisees, qui implique une resonance de Breit-Wigner a deux particules. Le transport parasite n'implique pour sa part qu'une resonance de Breit-Wigner a une particule. Dans le chapitre 4, nous reviendrons au systeme constitue de deux points quantiques entoures de deux fils

  16. Powerful Interactions

    ERIC Educational Resources Information Center

    Dombro, Amy Laura; Jablon, Judy R.; Stetson, Charlotte

    2011-01-01

    Interactions are the daily exchanges in words and gestures one has with others. As a teacher, the interactions he/she has with young children can make a positive difference in their lives. A teacher's powerful interactions with children play an important role in their emotional well-being and learning. Powerful interactions are not the same as…

  17. Transport de particules massives dans un fluide turbulent: Application a l'erosion due au sable sur les parois d'une turbine hydraulique

    NASA Astrophysics Data System (ADS)

    Bergeron, Stephen

    Le transport de particules massives par un champ turbulent est un vaste domaine de la mécanique des fluides. Il possède de nombreuses applications comme par exemple le transport de sable dans une turbine hydraulique. En raison de la dureté des grains de quartz et des grandes vitesses de collision avec les parois métalliques, un phénomène d'érosion intensif se produit. Les dommages résultants peuvent diminuer le rendement de la turbine au cours des quelques mois suivant la mise en opération. L'objectif de cette thèse est de mettre au point un outil permettant de prédire ces zones d'érosion. Ce projet de recherche en contexte industriel a été réalisé en collaboration avec la compagnie General Electric Hydro du Canada. Dans un régime hautement turbulent, il est possible d'obtenir une expression suffisamment générale en utilisant une formulation partiellement empirique: l'équation de Basset- Boussinesq-Oseen modifiée. Ce choix de modèle tient compte du niveau de précision recherché et de la méthode numérique employée afin de résoudre la phase fluide. Il permet aussi d'éliminer plusieurs ambiguïtés fréquemment rencontrées dans la littérature et implementées dans certains codes commerciaux courants. La formulation mathématique du problème est effectuée dans un espace mixte Euler-Lagrange. Les paramètres dynamiques sont relies au type de particules et à l'intensité de la turbulence. Le code numérique résultant est le plus performant développé à ce jour (août 1998). Les trajectoires de plusieurs centaines de milliers de particules peuvent être simulées et visualisées de manière interactive sur une station de travail (SGI R4K, R8K et R10K). L'utilisateur du logiciel est libre de se déplacer dans l'espace à l'aide d'un environnement similaire a un ``simulateur de vol''. Il peut ainsi analyser les détails du processus d'érosion de même que l'écoulement du fluide dans la turbine. Les zones d'érosion obtenues à l

  18. Apport de l'imagerie dans le diagnostic des sacroiliites infectieuses : à propos de 19 cas

    PubMed Central

    Abid, Hanen; Chaabouni, Salim; Frikha, Faten; Toumi, Nozha; Souissi, Basma; Lahiani, Dorra; Bahloul, Zouhir; Ben Mahfoudh, Khaireddine

    2014-01-01

    Les sacro-iliites infectieuses méritent d’être mieux connues. Leur diagnostic est souvent retardé en raison d'une symptomatologie trompeuse et des diffcultés d'exploration de l'articulation sacro-iliaque. Notre travail est basé sur une étude rétrospective portant sur les cas de SII, recueillis sur une période comprise entre 1997 et 2008 dans notre centre universitaire Sfax-Tunisie. Le diagnostic de sacro-iliite était retenu en présence d'arguments cliniques et radiologiques d'atteinte sacroiliaque. Nous rapportons dix neuf cas de sacroiliites infectieuses (10 hommes et 9 femmes), avec un âge moyen de 32 ans. L'atteinte était unilatérale dans tous les cas. Les radiographies standard faites dans tous les cas ont été suggestives dans 14 cas et normales dans les autres cas. La TDM faite dans 13 cas a montré, un abcès des parties molles dans 8 cas et un séquestre osseux dans 2 cas. L'IRM réalisée dans 8 cas, a objectivé une infiltration des parties molles dans tous les cas et un abcès dans 3 cas. Le germe a été identifié dans 9 cas (3 cas de tuberculose, 3 cas de brucellose, 2 sacro-iliites à pyogène et un cas de candidose). Cette identification était faite par biopsie dans 3 cas, hémocultures dans 2 cas, prélèvement au niveau de la porte d'entrée dans 1 cas et sérodiagnostic dans 3 cas. Pour les autres cas, l'origine pyogène a été retenue sur des arguments cliniques et biologiques. L'imagerie joue un rôle primordial dans le diagnostic précoce et l'orientation étiologique d'une sacroiliite infectieuse. PMID:25120884

  19. Transport et bruit quantique dans les fils mésoscopiques

    NASA Astrophysics Data System (ADS)

    Torrès, J.

    2002-01-01

    Un conducteur quantique est bien caractérisé par sa conductance donnée par la formule de Landauer. Mais le bruit contient davantage d'informations que la conductance : il mesure les fluctuations temporelles du courant autour de sa valeur moyenne. De plus, le signe des corrélations de bruit est lié à la statistique des porteurs de charge. Dans une jonction entre un métal normal et un supraconducteur, le bruit présente une singularité à la fréquence Josephson, signature de la charge 2e des paires de Cooper impliquées dans le transport. Lorsque la tension appliquée est supérieure au gap du supraconducteur, la courbe du bruit exhibe des singularités à plusieurs fréquences auxquelles on peut associer un processus de réflexion ou de transmission. L'analogue fermionique de l'expérience d'Hanbury-Brown et Twiss avec un supraconducteur permet d'observer à la fois des corrélations positives et négatives dans un même système. Maintenir une différence de potentiel entre les deux extrémités d'un fil crée une situation relevant de la thermodynamique hors de l'équilibre. Formellement, on peut se ramener à un calcul à l'équilibre et écrire une théorie des perturbations grâce à la méthode de Keldysh. La théorie des liquides de Luttinger décrit les systèmes unidimensionnels d'électrons en interaction. Le hamiltonien peut se mettre sous forme quadratique grâce à la bosonisation. D'autre part, un liquide de Luttinger chiral constitue un bon modèle des états de bord de l'effet Hall quantique fractionnaire. Grâce au formalisme de Keldysh, on peut retrouver une formule de type Schottky et identifier la charge des quasiparticules de Laughlin.

  20. Spin-dependent parameters P/sub n/000, D/sub n/0n0, K/sub n/00n, D/sub s/0s0, D/sub s/0k0, M/sub s/0sn, and M/sub s/0kn in pp elastic scattering at 579 MeV

    SciTech Connect

    Aprile, E.; Hausammann, R.; Heer, E.; Hess, R.; Lechanoine-Leluc, C.; Leo, W.R.; Morenzoni, S.; Onel, Y.; Rapin, D.; Mango, S.

    1983-06-01

    The polarization parameter P/sub n/000, the two-spin parameters D/sub n/0n0, K/sub n/00n, D/sub s/0s0, and D/sub s/0k0, and the three-spin parameters M/sub s/0sn and M/sub s/0kn have been measured for pp elastic scattering at 579 MeV between 34/sup 0/ and 118/sup 0/ center-of-mass scattering angle. The experiment was performed at SIN using a polarized proton beam, a polarized butanol target, and a polarimeter for the measurement of the polarization of the scattered proton. These data form the basis for a complete experimental determination of the scattering amplitudes.

  1. Surface Wave Dispersion Analysis Using Time-Frequency Filtering and an Interactive Normal Move Out (NMO) Tool with Uncorrelated Garner Valley Vibroseis Data

    NASA Astrophysics Data System (ADS)

    Lord, N. E.; Wang, H. F.; Fratta, D.; Lancelle, C.; Baldwin, J. A.; Nigbor, R. L.; Chalari, A.; Castongia, E.

    2014-12-01

    Frequency swept seismic sources (vibroseis) recorded by seismic arrays can be used to directly measure the surface wave apparent velocity as a function of frequency. Time-frequency filtering (TFF) passes only a narrow frequency band centered on the time varying frequency of the seismic source. This greatly improves the quality of the uncorrelated seismic data by removing noise outside of the narrow band filter. Sources of noise include traffic, harmonics generated by the seismic source and the propagating seismic waves. TFF also allows the separate analysis of the source fundamental frequency and each harmonic. The filtered data is used with an interactive normal move out (NMO) tool to adjust the time and apparent velocity parameters to extract a surface wave dispersion curve. This technique was used on the vibroseis data collected in the September 2013 seismic experiment conducted at the NEES@UCSB Garner Valley field site. Three vibroseis sources were used: a 45 KN shear shaker, a 450 N portable mass shaker, and a 26 KN vibroseis truck. They were recorded by two lines of 1 and 3 component accelerometers and geophones, and a Distributed Acoustic Sensor (Silixa-iDAS™) system connected to 762 m of trenched fiber optical cable in a larger rectangular area.

  2. NASA Administrator Dan Goldin talks with STS-78 crew

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA Administrator Dan Goldin (left) chats with STS-78 Mission Commander Terence 'Tom' Henricks (center) and KSC Director Jay Honeycutt underneath the orbiter Columbia. Columbia and her seven-member crew touched down on Runway 33 of KSC's Shuttle Landing Facility at 8:36 a.m. EDT, July 7, bringing to a close the longest Shuttle flight to date. STS-78, which also was the 78th Shuttle flight, lasted 16 days, 21 minutes and 47 seconds.

  3. Dissolution de la matiere lignocellulosique dans les liquides ioniques

    NASA Astrophysics Data System (ADS)

    Rebiere, Jeremy

    De nos jours, avec la raréfaction des ressources fossiles, le développement de procédés entrant dans le cadre de la chimie verte s'accentue. De plus, ces procédés utilisent comme ressources, des matériaux d'origine végétale, abondants et biodégradables. Au cours de ces 20 dernières années, la littérature utilisant les liquides ioniques (LI) connait une importante croissance. Ces solvants sont de plus en plus employés dans des réactions chimiques classiques. Cependant le coût de leur synthèse en fait un solvant réactionnel cher dont l'application en tant que tel dans l'industrie ne peut être raisonnablement envisagée. Ces liquides ioniques permettent la dissolution des matériaux lignocellulosiques (lignine ou cellulose) et possèdent des propriétés physico-chimiques intéressantes. Nous savons également que la dissolution de la cellulose par des procédés d'hydrolyse classique s'effectue dans des conditions dures, dues à la structure cristalline de la cellulose, (fortes concentrations en acide) qui paraissent limitées pour une utilisation à grande échelle. Il est donc nécessaire de rechercher des méthodes moins onéreuses et plus efficaces écologiquement. S'appuyant sur des recherches démontrant que la dissolution de la cellulose dans les LI, diminue la cristallinité de la cellulose, nous allons chercher à démontrer au cours de ces travaux, la possibilité d'utiliser les LI comme moyen de prétraitement pour la dissolution de la cellulose. Nous allons nous attacher à dissoudre la cellulose, et à étudier les proportions pouvant être dissoutes. Puis nous chercherons à récupérer puis à réutiliser ces LI. Enfin nous cherchons à caractériser les modifications apportées à notre cellulose. Mots Clés liquide ionique, cellulose, cristallinité, réactivité, dissolution, régénération, non-solvant, purification, prétraitement, zone amorphe.

  4. 77 FR 75628 - STS Hydropower, Ltd., Dan River, Inc., and City of Danville, VA; Notice of Application for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-21

    ... Energy Regulatory Commission STS Hydropower, Ltd., Dan River, Inc., and City of Danville, VA; Notice of..., 2012, Jeoffrey L. Burtch, as Chapter 7 Bankruptcy Trustee for Dan River, Inc. and STS Hydropower, Ltd... the license for the Schoolfield Hydroelectric Project from Dan River, Inc. and STS Hydropower, Ltd....

  5. Drug Interactions

    PubMed Central

    Tong Logan, Angela; Silverman, Andrew

    2012-01-01

    One of the most clinically significant complications related to the use of pharmacotherapy is the potential for drug-drug or drug-disease interactions. The gastrointestinal system plays a large role in the pharmacokinetic profile of most medications, and many medications utilized in gastroenterology have clinically significant drug interactions. This review will discuss the impact of alterations of intestinal pH, interactions mediated by phase I hepatic metabolism enzymes and P-glycoprotein, the impact of liver disease on drug metabolism, and interactions seen with commonly utilized gastrointestinal medications. PMID:22933873

  6. Dan Olweus: Award for Distinguished Contributions to Research in Public Policy

    ERIC Educational Resources Information Center

    American Psychologist, 2012

    2012-01-01

    Presents a short biography of the winner of the American Psychological Association's Award for Distinguished Contributions to Research in Public Policy. The 2012 winner is Dan Olweus for his rigorous scientific research on bullying among children and youth and his early and tireless attention to its public policy implications. Dan Olweus's…

  7. MALDI-MS analysis and imaging of small molecule metabolites with 1,5-diaminonaphthalene (DAN)

    SciTech Connect

    Korte, Andrew R; Lee, Young Jin

    2014-07-08

    1,5-diaminonaphthalene (DAN) has previously been reported as an effective matrix for matrix-assisted laser desorption ionization-mass spectrometry of phospholipids. In the current work, we investigate the use of DAN as a matrix for small metabolite analysis in negative ion mode. DAN was found to provide superior ionization to the compared matrices for MW < ~400 Da; however, 9-aminoacridine (9-AA) was found to be superior for a uridine diphosphate standard (MW 566 Da). DAN was also found to provide a more representative profile of a natural phospholipid mixture than 9-AA. Finally, DAN and 9-AA were applied for imaging of metabolites directly from corn leaf sections. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  8. Imagined Interactions

    ERIC Educational Resources Information Center

    Honeycutt, James M.

    2010-01-01

    Social scientists have been studying imagined interactions since the mid-1980s and have measured numerous physiological correlates (Honeycutt, 2010). In this commentary I assess the research reported in Crisp and Turner (May-June 2009) and highlight the underlying mechanisms of imagined interactions that have empirically been laid out across…

  9. Neuronal oscillations and functional interactions between resting state networks.

    PubMed

    Lei, Xu; Wang, Yulin; Yuan, Hong; Mantini, Dante

    2014-07-01

    Functional magnetic imaging (fMRI) studies showed that resting state activity in the healthy brain is organized into multiple large-scale networks encompassing distant regions. A key finding of resting state fMRI studies is the anti-correlation typically observed between the dorsal attention network (DAN) and the default mode network (DMN), which - during task performance - are activated and deactivated, respectively. Previous studies have suggested that alcohol administration modulates the balance of activation/deactivation in brain networks, as well as it induces significant changes in oscillatory activity measured by electroencephalography (EEG). However, our knowledge of alcohol-induced changes in band-limited EEG power and their potential link with the functional interactions between DAN and DMN is still very limited. Here we address this issue, examining the neuronal effects of alcohol administration during resting state by using simultaneous EEG-fMRI. Our findings show increased EEG power in the theta frequency band (4-8 Hz) after administration of alcohol compared to placebo, which was prominent over the frontal cortex. More interestingly, increased frontal tonic EEG activity in this band was associated with greater anti-correlation between the DAN and the frontal component of the DMN. Furthermore, EEG theta power and DAN-DMN anti-correlation were relatively greater in subjects who reported a feeling of euphoria after alcohol administration, which may result from a diminished inhibition exerted by the prefrontal cortex. Overall, our findings suggest that slow brain rhythms are responsible for dynamic functional interactions between brain networks. They also confirm the applicability and potential usefulness of EEG-fMRI for central nervous system drug research. PMID:25050432

  10. Blocage de Coulomb dans une boite quantique laterale contenant un faible nombre d'electrons

    NASA Astrophysics Data System (ADS)

    Gould, Charles

    Dans ce travail on utilise une nouvelle geometrie pour augmenter le controle sur le nombre d'electrons contenus dans une boite quantique laterale, et ainsi atteindre un regime de petit nombre d'electrons. Ces echantillons permettent une etude du blocage de Coulomb quand les electrons sont injectes a partir d'un gaz electronique a deux dimensions (2DEG). Les mesures a faible champ magnetique demontrent la grande flexibilite des echantillons et montrent que l'on peut faire varier le nombre d'electrons dans une boite quantique a partir de plus de 40 electrons jusqu'a un seul electron, ce qui est assez courant dans les boites quantiques verticales, mais ce qui n'avait jamais ete reussi dans une boite quantique laterale. Nos resultats montrent egalement que dans les boites quantiques laterales il est possible de determiner le spin du niveau qui participe au transport a l'aide du phenomene de blocage de spin. De plus, dans certaines circonstances il est meme possible de determiner le spin total de la boite quantique, ce qui peut avoir des applications pratiques dans des domaines tels l'informatique quantique. Les mesures dans le regime de renversement de spin a un champ magnetique plus eleve montrent l'importance des correlations electrons---electrons dans ces boites quantiques, qui menent a des depolarisations et a des structures de spins qui ont un effet sur le transport. En particulier, ces correlations menent a l'existence de niveaux excites de basse energie qui causent une dependance anormale de l'amplitude des pics de blocage de Coulomb en fonction de la temperature. Nos experiences demontrent egalement la possibilite d'utiliser ces boites quantiques comme sondes pour etudier les proprietes du bord d'un 2DEG. Une voie de recherche a etre exploree.

  11. NASA Administrator Dan Goldin greets 10-year-old VIP.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    NASA Administrator Dan Goldin (left) shares a light moment during his meeting with 10-year-old Jonathan Pierce (right), who is garbed in a protective cooling suit designed by NASA. Behind Goldin is astronaut Doug Wheelock; behind Jonathan is his mother, Penny. Jonathan suffers from erythropoietic protoporphyria, a rare condition that makes his body unable to withstand ultraviolet rays. The suit allows him to be outside during the day, which would otherwise be impossible. Jonathan's trip was funded by the Make-A-Wish Foundation and included a visit to Disney World. He and his family were among a dozen VIPs at KSC to view the launch of STS-99.

  12. Interacting parasites

    USGS Publications Warehouse

    Lafferty, Kevin D.

    2010-01-01

    Parasitism is the most popular life-style on Earth, and many vertebrates host more than one kind of parasite at a time. A common assumption is that parasite species rarely interact, because they often exploit different tissues in a host, and this use of discrete resources limits competition (1). On page 243 of this issue, however, Telfer et al. (2) provide a convincing case of a highly interactive parasite community in voles, and show how infection with one parasite can affect susceptibility to others. If some human parasites are equally interactive, our current, disease-by-disease approach to modeling and treating infectious diseases is inadequate (3).

  13. Antiproton-nucleus interaction

    NASA Astrophysics Data System (ADS)

    Cugnon, J.; Vandermeulen, J.

    The antiproton-nucleus physics is reviewed. On the experimental side, the recent results obtained at the LEAR, BNL and KEK facilities are analyzed. A brief summary of the main pp and pn experimental data is also given. The antiproton-nucleus interaction can lead to elasic, inelastic and charge exchange scattering and to annihilation. The latter is very dominant. The scattering cross-sections are usually analyzed in terms of complex potential models. The relationship between potentials, charge conjugation and Dirac phenomenology is discussed. Much emphasis is put on the dynamics of the antiproton annihilation on nuclei. The energy transfer, pion absorption and target response are analyzed within the intranuclear cascade model. Special interest is devoted to strangeness production, hypernucleus formation and possible annihilation on two nucleons. Signatures for this new process are searched in experimental data. Finally, the highly debated question of quark-gluon formation is analyzed. Cet article constitue une revue de la physique antiproton-noyau. Du point de vue expérimental, cette revue porte particulièrement sur les récents résultats obtenus à LEAR, BNL et KEK. On y a aussi inclus une mise à jour des faits expérimentaux principaux pour pp et pn. L'interaction antiproton-noyau conduit à la diffusion élastique, inélastique et d'xA9change de charge et à des processus d'annihilation. Habituellement, les expériences de diffusion sont analysées en termes de potentiels complexes. La relation entre ces potentiels, la conjugaison de charge et la phénoménologie de Dirac est discutée. On s'est particulièrement intéressé à la dynamique de l'annihilation d'antiprotons sur des noyaux. Le transfert d'énergie, l'absorption de pions et la réponse de la cible sont analysés dans le cadre du modèle de cascade intranucléaire. Certains autres points sont discutés plus en détail: la production d'étrangeté, la formation d'hypernoyaux et l'annihilation sur

  14. Drug Interactions

    MedlinePlus

    ... not be taken at the same time as antacids. WHAT CAUSES THE MOST INTERACTIONS WITH HIV MEDICATIONS? ... azole” Some antibiotics (names end in “mycin”) The antacid cimetidine (Tagamet) Some drugs that prevent convulsions, including ...

  15. Sur la nature des absorbeurs dans l'interpretation transactionnelle de la mecanique quantique

    NASA Astrophysics Data System (ADS)

    Boisvert, Jean-Sebastien

    L'interpretation transactionnelle de la mecanique quantique est l'une des plus recentes propositions de description des phenomenes du microcosme. En accord avec les predictions de la mecanique quantique standard, l'interpretation transactionnelle propose une alternative a celle de Copenhague. Son principal avantage est qu'elle permet de visualiser les mecanismes sous-jacents a l'echange d'energie, de quantite de mouvement ou d'autres quantites quantiques entre un emetteur et un absorbeur. Ces echanges sont le resultat, a l'instar de la theorie de l'absorbeur de Wheeler et Feynman, de l'utilisation autant d'ondes avancees que retardees. Bien que l'interpretation transactionnelle n'ait pas attire la plus grande attention scientifique, plusieurs critiques lui ont ete adressees. Dans les annees 1990, differentes experiences a mesure sans interaction ont ete concues. Depuis, il a ete avance que la version originale de l'interpretation transactionnelle pouvait difficilement rendre compte de ce type d'experience et meme qu'elle n'est pas compatible avec le concept d'univers quadridimensionnel. La recherche de ce memoire par article consiste a montrer que lorsque l'on utilise systematiquement l'interpretation transactionnelle en considerant la configuration totale des absorbeurs (incluant l'absorbeur universel), il n'est pas necessaire de faire appel a une hierarchie de transactions comme certains l'ont propose.

  16. Identification and expression analysis of BMP signaling inhibitors genes of the DAN family in amphioxus.

    PubMed

    Le Petillon, Yann; Oulion, Silvan; Escande, Marie-Line; Escriva, Hector; Bertrand, Stephanie

    2013-12-01

    Bone morphogenetic proteins (BMPs) are members of the Transforming Growth Factor-β (TGF-β) family implicated in many developmental processes in metazoans such as embryo axes specification. Their wide variety of actions is in part controlled by inhibitors that impede the interaction of BMPs with their specific receptors. Here, we focused our attention on the Differential screening-selected gene Aberrative in Neuroblastoma (DAN) family of inhibitors. Although they are well-characterized in vertebrates, few data are available for this family in other metazoan species. In order to understand the evolution of potential developmental roles of these inhibitors in chordates, we identified the members of this family in the cephalochordate amphioxus, and characterized their expression patterns during embryonic development. Our data suggest that the function of Cerberus/Dand5 subfamily genes is conserved among chordates, whereas Gremlin1/2 and NBL1 subfamily genes seem to have acquired divergent expression patterns in each chordate lineage. On the other hand, the expression of Gremlin in the amphioxus neural plate border during early neurulation strengthens the hypothesis of a conserved neural plate border gene network in chordates. PMID:23872339

  17. Talin-KANK1 interaction controls the recruitment of cortical microtubule stabilizing complexes to focal adhesions

    PubMed Central

    Bouchet, Benjamin P; Gough, Rosemarie E; Ammon, York-Christoph; van de Willige, Dieudonnée; Post, Harm; Jacquemet, Guillaume; Altelaar, AF Maarten; Heck, Albert JR; Goult, Benjamin T; Akhmanova, Anna

    2016-01-01

    The cross-talk between dynamic microtubules and integrin-based adhesions to the extracellular matrix plays a crucial role in cell polarity and migration. Microtubules regulate the turnover of adhesion sites, and, in turn, focal adhesions promote the cortical microtubule capture and stabilization in their vicinity, but the underlying mechanism is unknown. Here, we show that cortical microtubule stabilization sites containing CLASPs, KIF21A, LL5β and liprins are recruited to focal adhesions by the adaptor protein KANK1, which directly interacts with the major adhesion component, talin. Structural studies showed that the conserved KN domain in KANK1 binds to the talin rod domain R7. Perturbation of this interaction, including a single point mutation in talin, which disrupts KANK1 binding but not the talin function in adhesion, abrogates the association of microtubule-stabilizing complexes with focal adhesions. We propose that the talin-KANK1 interaction links the two macromolecular assemblies that control cortical attachment of actin fibers and microtubules. DOI: http://dx.doi.org/10.7554/eLife.18124.001 PMID:27410476

  18. Strong Interaction

    SciTech Connect

    Karsch, F.; Vogelsang, V.

    2009-09-29

    We will give here an overview of our theory of the strong interactions, Quantum Chromo Dynamics (QCD) and its properties. We will also briefly review the history of the study of the strong interactions, and the discoveries that ultimately led to the formulation of QCD. The strong force is one of the four known fundamental forces in nature, the others being the electromagnetic, the weak and the gravitational force. The strong force, usually referred to by scientists as the 'strong interaction', is relevant at the subatomic level, where it is responsible for the binding of protons and neutrons to atomic nuclei. To do this, it must overcome the electric repulsion between the protons in an atomic nucleus and be the most powerful force over distances of a few fm (1fm=1 femtometer=1 fermi=10{sup -15}m), the typical size of a nucleus. This property gave the strong force its name.

  19. Weak Interactions

    DOE R&D Accomplishments Database

    Lee, T. D.

    1957-06-01

    Experimental results on the non-conservation of parity and charge conservation in weak interactions are reviewed. The two-component theory of the neutrino is discussed. Lepton reactions are examined under the assumption of the law of conservation of leptons and that the neutrino is described by a two- component theory. From the results of this examination, the universal Fermi interactions are analyzed. Although reactions involving the neutrino can be described, the same is not true of reactions which do not involve the lepton, as the discussion of the decay of K mesons and hyperons shows. The question of the invariance of time reversal is next examined. (J.S.R.)

  20. Transition de phase quantique de type verrouillage-deverrouillage dans les canaux lineaires coherents des phases en rayures dans les doubles puits quantiques sous champ magnetique perpendiculaire

    NASA Astrophysics Data System (ADS)

    Faribault, Alexandre

    On peut creer un gaz electronique bidimensionnel en utilisant le potentiel de confinement d'une couche mince d'un semiconducteur dans un substrat fait d'une autre semiconducteur de gap plus eleve. L'ajout d'un champ magnetique perpendiculaire au plan de confinement modifie de facon drastique les proprietes du gaz electronique. Pour des densites et des valeurs du champ magnetique adequatement choisies, on obtient un etat fondamental en onde de densite de charge. Dans un systeme compose de deux de ces gaz bidimensionnels suffisamment rapproches l'un de l'autre, on prevoit theoriquement l'existence d'un etat fondamental compose d'une onde de densite de charge dans chacun des puits et d'une serie de regions lineaires ou l'on a une delocalisation coherente des electrons entre les deux puits. Dans cette these, on etudie le comportement a temperature nulle de cet etat fondamental en rayures coherentes. L'etude numerique des modes collectifs de ces phases laisse croire qu'un deverrouillage des canaux coherents est envisageable dans ce systeme. Afin d'etudier cette possibilite, nous construisons d'abord un modele effectif de canaux quasi-unidimensionnels couples qui permettent de reproduire correctement les excitations collectives a basse energie de la phase en rayures coherentes du double puits quantique. Dans un systeme de coordonnees adequatement choisi, ces excitations peuvent etre decrites par des ondes de pseudospin. Les parametres de ce modele effectif simple peuvent etre extraits des calculs des fonctions de reponse realises dans l'approximation Hartree-Fock dependante du temps (appelee aussi Generalized Random Phase Approximation). On constate l'efficacite de ce modele a decrire la dynamique basse energie du systeme pour une certaine plage de distances inter-puits. En retirant de ce modele les contributions a l'hamiltonien provenant des couplages de type Josephson entre les canaux, on obtient alors un systeme ou les canaux sont deverrouilles. Un traitement en

  1. Interactive Video.

    ERIC Educational Resources Information Center

    Boyce, Carol

    1992-01-01

    A workshop on interactive video was designed for fourth and fifth grade students, with the goals of familiarizing students with laser disc technology, developing a cadre of trained students to train other students and staff, and challenging able learners to utilize higher level thinking skills while conducting a research project. (JDD)

  2. Interacting Compasses

    ERIC Educational Resources Information Center

    Riveros, Hector G.; Betancourt, Julian

    2009-01-01

    The use of multiple compasses to map and visualize magnetic fields is well-known. The magnetic field exerts a torque on the compasses aligning them along the lines of force. Some science museums show the field of a magnet using a table with many compasses in a closely packed arrangement. However, the very interesting interactions that occur…

  3. Interactive Astronomy.

    ERIC Educational Resources Information Center

    Martin, Jean K.

    1997-01-01

    Presents guiding principles for developing interactive lessons for the World Wide Web. Describes "Amazing Space: Education Online from the Hubble Space Telescope", a program where students study spectacular Hubble Space Telescope images of stars and star-forming regions to learn about the life cycle of stars and the creation of atoms. (JRH)

  4. Structure of Protein Related to DAN and Cerberus (PRDC): Insights into the Mechanism of BMP Antagonism

    PubMed Central

    Nolan, Kristof; Kattamuri, Chandramohan; Luedeke, David M.; Deng, Andy; Jagpal, Amrita; Zhang, Fuming; Linhardt, Robert; Kenny, Alan P.; Zorn, Aaron M.; Thompson, Thomas B.

    2013-01-01

    Summary The Bone Morphogenetic Proteins (BMP) are secreted ligands largely known for their functional roles in embryogenesis and tissue development. A number of structurally diverse extracellular antagonists inhibit BMP ligands to regulate signaling. The DAN family of antagonists represents the largest group of BMP inhibitors, however, little is known for how they mechanistically inhibit BMP ligands. Here, we present the structure of the DAN family member Protein Related to Dan and Cerberus (PRDC) solved by X-ray crystallography. The structure reveals an unexpected growth factor-like appearance with a novel dimerization mechanism that is formed through extensive β-strand contacts. Using site-directed mutagenesis coupled with in vitro and in vivo activity assays, we identified a BMP binding epitope on PRDC. We also determined that PRDC binds heparin with high affinity and that heparin binding to PRDC interferes with BMP antagonism. These results offer insight for how DAN family antagonists functionally inhibit BMP ligands. PMID:23850456

  5. Dynamique et interférence de paquets d'ondes dans les atomes et dimères d'alcalins

    NASA Astrophysics Data System (ADS)

    Bouchene, M. A.

    2002-11-01

    (saturation regime, chirped pulse, ...) that allow us to determine the advantages and limits of this technique. In the case of molecules, the interaction of the two-pulse sequence leads to the interference of vibrational wave packets. We analyse and discuss in this case the effects of a thermal distribution of initial states on the temporal coherent control signal. Ce travail porte sur l'étude expérimentale résolue en temps de la dynamique atomique et moléculaire prenant place sur une échelle de temps femtoseconde. Il présente deux orientations distinctes et complémentaires. La première concerne l'étude de la dynamique de paquets d'ondes dans des atomes et dimères d'alcalins (K, K2) par des méthodes pompe-sonde. Dans le cas du potassium atomique le paquet d'ondes est une superposition des états de structure fine de l'état 4p et représente un paquet de spin électronique. Nous observons la dynamique de ce paquet d'ondes au cours du temps et montrons que celle-ci correspond à une inversion du sens d'orientation du spin. Le formalisme théorique des états brillants et noirs est particulièrement adapté à la description de ce type de dynamique. Nous présentons alors une méthode originale qui, tirant avantage du mouvement d'inversion du spin, permet de produire des électrons polarisés en spin à l'échelle femtoseconde. Dans le cas des molécules, le paquet d'ondes créé est une superposition d'états vibrationnels. Nous présentons les résultats d'une étude systématique de la dynamique de paquet d'ondes vibrationnel dans les états électroniques A^1Σ^+_u et 2^1Pi_g. Le signal pompe-sonde dépend alors de la compétition entre les dynamiques associées aux paquets d'ondes créés dans les deux états électroniques. La deuxième partie traite d'expériences d'interférences de paquets d'ondes dans des systèmes similaires (K, Cs, Cs2). Cette technique, complémentaire de la première, consiste à faire interagir une séquence de deux impulsions

  6. Tuberculome de Bouchut dans la tuberculose multi focale: à propos de quatre cas

    PubMed Central

    Janah, Hicham; Alami, Ahmed; Souhi, Hicham; Zegmout, Adil; Naji-Amrani, Hicham; Raoufi, Mohamed; Elouazzani, Hanane; Rhorfi, Ismail Abderrahmani; Abid, Ahmed

    2014-01-01

    La tuberculose multifocale a connu un regain de fréquence avec la pandémie du SIDA, elle s'observe encore chez des sujets non infectés par le VIH surtout dans les pays en voie de développement notamment au Maroc. Nous rapportons quatre observations de tuberculose multifocale chez trois patients immunocompétents et un patient immunodéprimé. Quatre patients ont bénéficié d'un bilan phtisiologique, biologique, sérologique(HIV), radiologique et d'angiographie à la fluorescéine pour suspicion de tuberculose multifocale. Il s'agit de trois hommes et une femme, d’âge moyen de 44 ans, trois patients sont immunocompétents et un patient séropositif. La tuberculose intéressait trois localisations chez les quatre patients: pulmonaire dans quatre cas, ophtalmique dans quatre cas, digestive dans un cas, urinaire dans un cas, cérébrale dans un cas et un cas d'atteinte de la moelle osseuse. L'atteinte ophtalmologique est représentée par des nodules choroïdiens de Bouchut dans quatre cas et un nodule papillaire de Bouchut dans un cas; aucun des ces patients ne présentait une uvéite granulomateuse. Nos malades ont reçu un traitement anti-tuberculeux d'une durée de neuf mois avec une bonne évolution clinique, biologique, radiologique et angiographique. Au Maroc, la tuberculose continue à surprendre aussi bien par son extension touchant le sujet débilité et le sujet immunocompétent, que par ses présentations diverses y compris l'atteinte oculaire qu'elle faut rechercher par un examen ophtalmologique soigneux et systématique. PMID:25478047

  7. The Dynamic Albedo of Neutrons (DAN) experiment for NASA's 2009 Mars Science Laboratory.

    PubMed

    Litvak, M L; Mitrofanov, I G; Barmakov, Yu N; Behar, A; Bitulev, A; Bobrovnitsky, Yu; Bogolubov, E P; Boynton, W V; Bragin, S I; Churin, S; Grebennikov, A S; Konovalov, A; Kozyrev, A S; Kurdumov, I G; Krylov, A; Kuznetsov, Yu P; Malakhov, A V; Mokrousov, M I; Ryzhkov, V I; Sanin, A B; Shvetsov, V N; Smirnov, G A; Sholeninov, S; Timoshenko, G N; Tomilina, T M; Tuvakin, D V; Tretyakov, V I; Troshin, V S; Uvarov, V N; Varenikov, A; Vostrukhin, A

    2008-06-01

    We present a summary of the physical principles and design of the Dynamic Albedo of Neutrons (DAN) instrument onboard NASA's 2009 Mars Science Laboratory (MSL) mission. The DAN instrument will use the method of neutron-neutron activation analysis in a space application to study the abundance and depth distribution of water in the martian subsurface along the path of the MSL rover. PMID:18598140

  8. Putting Interaction into Interactive Television.

    ERIC Educational Resources Information Center

    Wolfe, Thomas E.

    Current technology provides many new ideas and alternatives to traditional education and training practices. From the experience of the U.S. Air Force (USAF) Academic Instructor School (AIS) and current research in the field, teaching via interactive television (teleseminar/video teletraining) requires new teaching skills and new ways of thinking…

  9. Argentophilic interactions.

    PubMed

    Schmidbaur, Hubert; Schier, Annette

    2015-01-12

    The decade 1990-2000 saw a growing interest in aurophilic interactions in gold chemistry. These interactions were found to influence significantly a variety of structural and other physical characteristics of gold(I) compounds. The attention paid to this unusual and counterintuitive type of intra- and intermolecular bonding between seemingly closed-shell metal centers has rapidly been extended to also include silver chemistry. Hundreds of experimental and computational studies have since been dedicated to the argentophilicity phenomenon. The results of this development are reviewed herein focusing on molecular systems where two or more silver(I) centers are in close contact leading to specific structural characteristics and a variety of novel physical properties. These include strongly modified ligand-to-metal charge-transfer processes observed in absorption and emission spectroscopy, but also colossal positive and negative thermal expansion on the one hand and unprecedented negative linear compressibility of crystal parameters on the other. PMID:25393553

  10. Electroweak interactions

    SciTech Connect

    Renton, P.

    1990-01-01

    The central part of the book consists of a comprehensive discussion of many scattering and decay processes involving electromagnetic, weak and strong interactions. A list of topics includes electron-proton scattering, Compton scattering, muon decay, electron-positron annihilation, photon and hadron structure functions, neutrino-nucleus scattering, Cabibbo theory, tau-lepton decays, W and Z boson decays, mixing phenomena and many others. For most processes, the author presents the appropriate Feynman diagrams, first-order matrix elements and the resulting cross sections or decay rates. The last section of Electroweak Interactions discusses some of the open or unanswered questions in the standard model, including the undiscovered top quark, the Higgs mechanism of electroweak symmetry breaking and detailed tests involving radiative effects. The book concludes with a brief account of ideas that extend beyond the standard model, such as left-right symmetric models, grand unified theories, compositeness, supersymmetry and string theory.

  11. Fair Use Education for the Twenty-First Century: A Comparative Study of Students' Use of an Interactive Tool to Guide Decision Making

    ERIC Educational Resources Information Center

    Greenhow, Christine; Walker, J. D.; Donnelly, Dan; Cohen, Brad

    2008-01-01

    Christine Greenhow, J. D. Walker, Dan Donnelly, and Brad Cohen describe the implementation and evaluation of the University of Minnesota's Fair Use Analysis (FUA) tool, an interactive online application intended to educate users and foster defensible fair use practice in accordance with copyright law by guiding users through a robust,…

  12. Three dimensional, non-linear, finite element analysis of compactable soil interaction with a hyperelastic wheel

    NASA Astrophysics Data System (ADS)

    Chiroux, Robert Charles

    The objective of this research was to produce a three dimensional, non-linear, dynamic simulation of the interaction between a hyperelastic wheel rolling over compactable soil. The finite element models developed to produce the simulation utilized the ABAQUS/Explicit computer code. Within the simulation two separate bodies were modeled, the hyperelastic wheel and a compactable soil-bed. Interaction between the bodies was achieved by allowing them to come in contact but not to penetrate the contact surface. The simulation included dynamic loading of a hyperelastic, rubber tire in contact with compactable soil with an applied constant angular velocity or torque, including a tow load, applied to the wheel hub. The constraints on the wheel model produced a straight and curved path. In addition the simulation included a shear limit between the tire and soil allowing for the introduction of slip. Soil properties were simulated using the Drucker-Prager, Cap Plasticity model available within the ABAQUS/Explicit program. Numerical results obtained from the three dimensional model were compared with related experimental data and showed good correlation for similar conditions. Numerical and experimental data compared well for both stress and wheel rut formation depth under a weight of 5.8 kN and a constant angular velocity applied to the wheel hub. The simulation results provided a demonstration of the benefit of three-dimensional simulation in comparison to previous two-dimensional, plane strain simulations.

  13. New precision era of experiments on strong interaction with strangeness at DAFNE/LNF-INFN

    NASA Astrophysics Data System (ADS)

    Ishiwatari, T.; Bazzi, M.; Beer, G.; Berucci, C.; Bombelli, L.; Bragadireanu, A. M.; Cargnelli, M.; Curceanu, C.; d'Uffizi, A.; Fiorini, C.; Ghio, F.; Guaraldo, C.; Hayano, R. S.; Iliescu, M.; Iwasaki, M.; Kienle, P.; Levi Sandri, P.; Longoni, A.; Marton, J.; Okada, S.; Pietreanu, D.; Ponta, T.; Quaglia, R.; Romero Vidal, A.; Sbardella, E.; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Tudorache, A.; Tudorache, V.; Vazquez Doce, O.; Wünschek, B.; Widmann, E.; Zmeskal, J.

    2014-03-01

    The strong-interaction shifts and widths of kaonic hydrogen, deuterium, 3He, and 4He were measured in the SIDDHARTA experiment. The most precise values of the shift and width of the kaonic hydrogen 1s state were determined to be ɛ1s = -283 ± 36(stat)±6(syst) eV and Γ1s = 541±89(stat)±22(syst) eV. The upper limit of the kaonic deuterium Kα yield was found to be ≤ 0.39%. In addition, the shifts and widths of the kaonic 3He and 4He 2p states were determined to be ɛ2p(3He) = -2 ± 2(stat) ± 4(syst) eV and Γ2p(3He) = 6 ± 6(stat) ± 7(syst) eV; ɛ2p(4He) = +5 ± 3(stat) ± 4(syst) eV and Γ2p(4He) = 14 ± 8(stat) ± 5(syst) eV. These values are important for the constraints of the low-energy bar KN interaction in theoretical approaches.

  14. Iron/Brønsted Acid Catalyzed Asymmetric Hydrogenation: Mechanism and Selectivity-Determining Interactions.

    PubMed

    Hopmann, Kathrin H

    2015-07-01

    Hydrogenation catalysts involving abundant base metals such as cobalt or iron are promising alternatives to precious metal systems. Despite rapid progress in this field, base metal catalysts do not yet achieve the activity and selectivity levels of their precious metal counterparts. Rational improvement of base metal complexes is facilitated by detailed knowledge about their mechanisms and selectivity-determining factors. The mechanism for asymmetric imine hydrogenation with Knölker's iron complex in the presence of chiral phosphoric acids is here investigated computationally at the DFT-D level of theory, with models of up to 160 atoms. The resting state of the system is found to be an adduct between the iron complex and the deprotonated acid. Rate-limiting H2 splitting is followed by a stepwise hydrogenation mechanism, in which the phosphoric acid acts as the proton donor. C-H⋅⋅⋅O interactions between the phosphoric acid and the substrate are involved in the stereocontrol at the final hydride transfer step. Computed enantiomeric ratios show excellent agreement with experimental values, indicating that DFT-D is able to correctly capture the selectivity-determining interactions of this system. PMID:26039958

  15. Mesure de la Polarisation des Lambda Produits dans les Collisions Positron-Electron AU Lep a L'aide du Detecteur Opal

    NASA Astrophysics Data System (ADS)

    Vandenplas, Denis

    Le Modele Standard est le cadre theorique general qui, jusqu'a present, a permis l'interpretation de tous les resultats experimentaux en physique des hautes energies. Cette theorie decrit, entre autres, la production d'une paire de particules elementaires, formee d'un quark et d'un antiquark, a partir de la desintegration de l'un des bosons mediateurs de l'interaction faible, le Z^0. Cependant, dans ce cas precis, la transformation subsequente des quarks primaires en particules reelles, un processus appele hadronisation, n'est decrite qu'a l'aide de modeles phenomenologiques. Afin de sonder les mecanismes de l'hadronisation, cette these presente la mesure du transfert du spin d'un quark etrange primaire a une particule appelee Lambda lors des desintegrations hadroniques du Z^0. L'etude a ete realisee dans le cadre de la collaboration OPAL, une des quatre experiences menees au collisionneur LEP, la ou des electrons et des positrons sont acceleres jusqu'a une energie commune, sqrt{s} = {rm E_ {cm}}, voisine de l'energie de production du rm Z^0, M_{Z ^0} egale a 91.3 GeV. La theorie electrofaible precise la direction du spin, c'est-a-dire la polarisation, d'un quark etrange primaire provenant de la desintegration d'un Z ^0. Quant a lui, le modele des quarks etablit que l'orientation du spin d'un Lambda est directement reliee a la polarisation du quark etrange dont il provient. La question est de determiner dans quelle mesure la polarisation du quark primaire est transmise au Lambda a la suite du processus de l'hadronisation, decrit dans le cadre de la ChromoDynamique Quantique. Une estimation, qui tient compte de tous ces differents aspects theoriques, evalue a 30% la polarisation des Lambda dont l'impulsion est superieure a 15 GeV/c. La mesure experimentale de la polarisation repose sur l'identification des Lambda a partir de la reconstitution de la desintegration Lambdato ppi^-. Ce processus, qui se deroule par le biais de l'interaction faible, viole la parite car

  16. Les fluctuations supraconductrices dans le compose praseodyme-cerium-oxyde de cuivre

    NASA Astrophysics Data System (ADS)

    Renaud, Jacques

    Ce travail etudie les fluctuations supraconductrices dans le compose supraconducteur a haute temperature critique dope aux electrons Pr2-xCe xCuO4+delta. La technique utilisee pour sonder ces fluctuations est le transport electrique DC dans le plan ab. Il s'agit, a notre connaissance, de la premiere etude de ce type dans la classe generale des supraconducteurs a haute temperature critique dopes aux electrons et, plus particulierement, dans Pr2-xCe xCuO4+delta. De plus, l'etude est effectuee pour trois regimes de dopage, soit sous-dope x = 0.135, dopage optimal x = 0.15 et surdope x = 0.17. Les echantillons etudies sont des couches minces d'epaisseur plus grande que 100 nm crues par ablation laser. Les mesures electriques DC effectuees dans ce travail sont la resistance en reponse lineaire et les courbes IV en reponse non lineaire en fonction de la temperature. La mise en oeuvre experimentale de ces mesures a necessite une grande attention au filtrage et aux effets de chauffage a haut courant. Nous montrons que, sans cette attention, les donnees experimentales sont toujours erronees dans le regime pertinent pour nos echantillons. Les resultats pour le dopage optimal x = 0.15 sont expliques de facon tres convaincante dans le cadre de fluctuations purement 2D. D'abord, le regime des fluctuations gaussiennes est tres bien decrit par le modele d'Aslamazov-Larkin en deux dimensions. Ensuite, le regime de fluctuations critiques, se trouvant a plus basse temperature que le regime gaussien, est tres bien decrit par la physique 2D de Kosterlitz-Thouless. Dans cette analyse, les deux regimes ont des temperatures critiques coherentes entre elles, ce qui semble confirmer ce scenario 2D. Une analyse des donnees dans le cadre de fluctuations 3D est exploree mais donne des conclusions incoherentes. Les resultats pour les autres dopages sont qualitativement equivalents avec le dopage optimal et permettent donc une explication purement 2D. Par contre, contrairement au dopage optimal

  17. Neutron Background Measurements by the the MSL Dynamic Albedo of Neutrons (DAN) Instrument during the First 360 sols of the Surface Operation at Mars

    NASA Astrophysics Data System (ADS)

    Jun, I.; Mitrofanov, I. G.; litvak, M. L.; Sanin, A.; Behar, A.; Boynton, W. V.; DeFlores, L.; Golovin, D.; Hardgrove, C. J.; Harshman, K.; Kozyrev, A.; Kuzmin, R.; Malakhov, A.; Mischna, M. A.; Moersch, J.; Mokrousov, M.; Nikiforov, S.; Shvetsov, V.; Tate, C.; Vostrukhin, A.; Team, M.

    2013-12-01

    Since first commissioned on sol 3 after landing in August 2012, DAN has been operating successfully and provided a wealth of surface measurement data both in Active mode and in Passive mode operations. Active mode measurements provide a means to determine the characteristics of subsurface in terms of layering structure, content of water equivalent hydrogen (WEH), and/or content of chlorine. Passive mode measurements provide a general background level of low energy (< ~1 keV) neutrons induced by Galactic Cosmic Ray (GCR) interactions with the Martian atmosphere and the surface material and from Multi Mission Radioisotope Thermonuclear Generator (MMRTG). Passive mode measurements have been done on almost every sols with durations ranging from 1 hour to ~9 hour, covering different times of a day. Extensive numerical simulations have been carried out to aid in interpreting the DAN passive data. Both surface operation and numerical simulations show that the passive data correlate very well with the active data. It was also found that the passive data alone could provide a general trend of WEH content variation along the rover traverse. A methodology to estimate the respective contribution from each source (i.e., MMRTG neutrons and GCR-induced neutrons) for the passive data has been developed and was used to understand the neutron background environment at the Rocknest site, where the rover stayed over an extended period of time (from sol 59 to sol 100). The result shows that the MMRTG contribution to the DAN passive counts was about 60% of the total, and the GCR-induced counts were estimated to be about 40%. Details of all these observations, modeling effort, and analysis and interpretation processes will be presented in the final paper by using the passive data collected through sol 360.

  18. Transitions de phase dans le oxyde de yttrium vanadium

    NASA Astrophysics Data System (ADS)

    Roberge, Benoit

    Dans le mémoire qui suit, les ordres structural, magnétiques et orbital dans le YVO3 sont étudiés avec l'aide de la diffraction des rayons X,de la spectroscopie Raman et de la technique de la cavité résonnante hyperfréquence. L'objectif premier consiste à observer l'évolution de ces ordres en fonction de la température. Le mémoire met ensuite en évidence le couplage entre les différents ordres cohabitants dans le YVO3 . Les mesures effectuées par la diffraction des rayons X permettent de mesurer le caractère polycrystallin des échantillons du YVO 3. Une comparaison de nos mesures avec des mesures de diffraction des rayons X faites sur la poudre de YVO3 indique la faible présence de maclage. Les mesures effectuées avec la technique de résonnance hyperfréquence permettent de suivre l'évolution de la constante diélectrique en fonction de la température. Les changements impliquant l'ordre orbital se manifestent de manière évidente dans la constante diélectrique à 200 K et à 77 K. La transition diélectrique détectée à 77 K est une transition de premier ordre. Un couplage entre les propriétés diélectriques et magnétiques est observable à la température de Néel à 114 K. L'effet d'un champ magnétique fixe sur la température de transition de l'ordre orbital survenant à 77 K est également remarquable. Cela indique un couplage magnétodiélectrique démontrant ainsi le caractère multiferroïque du YVO 3. Finalement, l'observation d'un mécanisme de relaxation pouvant être modélisé par le modèle d'Havriliak-Negami est observé en dessous de 77 K. En utilisant le modèle d'Arrhénius et le modèle d'Havriliak-Negami, on peut caractériser le mécanisme avec son énergie d'activation et son temps de relaxation. Les mesures effectuées en spectroscopie Raman permettent de suivre l'évolution de la structure du YVO3 en fonction de la température. Les deux changements structuraux survenant à 200 K et 77 K sont observés. Le

  19. Réactions chimiques et courant de transport dans la phase Bi2223

    NASA Astrophysics Data System (ADS)

    Duperray, G.; Legat, D.; Savary, H.

    1994-11-01

    To get high transport capacities in magnetic field with Ag sheathed conductors, the Bi2223 phase must be free of residual phases, well-crystallized, the lamellas being parallel with the current lines and very dense. In a research context on multifilamentary conductor, a preliminary study has been done on bulk material (1 × 4 × 40 mm^3 bars) to optimize the frabrication parameters of the multifilamentary tapes. A lot of samples, corresponding to the different operating conditions have been electrically characterized and analyzed by EDS so as to get some correlations between microstructure and superconducting performances : determination, concentration and repartition of residual phases, crystallinity, orientation and compacity of the Bi2223 phase. We also examined the interactions between the " refractory phases ", (Ca, Sr)2CuO3 ; (Ca, Sr) CuO2, ; CuO and the liquid phase, Bi2212 enriched with Bi and Sr + (Ca, Sr)2PbO4 which promote the recombination into pure and well recristallized Bi2223 phase. Maximum transport current capacities at 77 K-O T were 11 A/mm^2 for a commercial powder and 17 A/mm^2 (47 A) for a laboratory type powder, the values being around 50 A/mm^2 for the corresponding multifilamentary conductors. Pour qu'un fil supraconducteur gainé d'argent présente une capacité de transport de courant élevée ainsi qu'une bonne tenue sous champ, il faut que la phase Bi2223 soit exempte de phases résiduelles, soit bien cristallisée en feuillets orientés dans le sens de passage du courant et soit compacte. Dans le contexte d'une recherche sur les conducteurs multifilamentaires, nous avons mené une étude préliminaire sur matériau massif (barrettes de 1 × 4 × 40 mm^3) afin de déterminer les conditions physicochimiques optimales de fabrication de brins multifilamentaires. Un grand nombre d'échantillons, correspondant à différentes conditions opératoires et caractérisés électriquement, ont été analysés par EDS de façon à corréler les

  20. Cosmic Interactions

    NASA Astrophysics Data System (ADS)

    2008-01-01

    An image based on data taken with ESO's Very Large Telescope reveals a triplet of galaxies intertwined in a cosmic dance. ESO PR Photo 02/08 ESO PR Photo 02/08 NGC 7173, 7174, and 7176 The three galaxies, catalogued as NGC 7173 (top), 7174 (bottom right) and 7176 (bottom left), are located 106 million light-years away towards the constellation of Piscis Austrinus (the 'Southern Fish'). NGC 7173 and 7176 are elliptical galaxies, while NGC 7174 is a spiral galaxy with quite disturbed dust lanes and a long, twisted tail. This seems to indicate that the two bottom galaxies - whose combined shape bears some resemblance to that of a sleeping baby - are currently interacting, with NGC 7176 providing fresh material to NGC 7174. Matter present in great quantity around the triplet's members also points to the fact that NGC 7176 and NGC 7173 have interacted in the past. Astronomers have suggested that the three galaxies will finally merge into a giant 'island universe', tens to hundreds of times as massive as our own Milky Way. ESO PR Photo 02/08 ESO PR Photo 02b/08 NGC 7173, 7174, and 7176 The triplet is part of a so-called 'Compact Group', as compiled by Canadian astronomer Paul Hickson in the early 1980s. The group, which is the 90th entry in the catalogue and is therefore known as HCG 90, actually contains four major members. One of them - NGC 7192 - lies above the trio, outside of this image, and is another peculiar spiral galaxy. Compact groups are small, relatively isolated, systems of typically four to ten galaxies in close proximity to one another. Another striking example is Robert's Quartet. Compact groups are excellent laboratories for the study of galaxy interactions and their effects, in particular the formation of stars. As the striking image reveals, there are many other galaxies in the field. Some are distant ones, while others seem to be part of the family. Studies made with other telescopes have indeed revealed that the HCG 90 group contains 16 members

  1. Designing "Interaction": How Do Interaction Design Students Address Interaction?

    ERIC Educational Resources Information Center

    Karlgren, Klas; Ramberg, Robert; Artman, Henrik

    2016-01-01

    Interaction design is usually described as being concerned with interactions with and through artifacts but independent of a specific implementation. Design work has been characterized as a conversation between the designer and the situation and this conversation poses a particular challenge for interaction design as interactions can be elusive…

  2. DAN Active Parameters and Mastcam Hydration Survey Imaging: Comparisons Across Yellowknife Bay, Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

    Hardgrove, C. J.; Rice, M. S.; Moersch, J.; Mitrofanov, I. G.; Litvak, M.; Wellington, D. F.; Behar, A.; Bell, J. F.; Boynton, W. V.; DeFlores, L.; Drake, D.; Fedosov, F.; Golovin, D.; Jun, I.; Harshman, K.; Kozyrev, A.; Malakhov, A.; Milliken, R.; Kuzmin, R.; Mischna, M. A.; Mokrousov, M.; Nikiforov, S.; Sanin, A.; Tate, C.; Team, M.

    2013-12-01

    The Dynamic Albedo of Neutrons (DAN) instrument on the Mars Science Laboratory (MSL) rover Curiosity has recorded variability in neutron counts along traverses in and around Yellowknife Bay that suggest variable amounts of hydrogen (H) are present. At the locations of several DAN observations, Mastcam 'hydration survey' mosaics have been acquired with the R0 (493 nm, 551 nm and 638 nm), R5 (937 nm) and R6 (1013 nm) science filters to characterize RGB color and look for potential hydration as indicated by an absorption near 1000 nm. Whereas DAN is sensitive to H abundance down to 60cm depth, the Mastcam hydration index is sensitive to the presence of certain hydrated minerals (bound-OH and/or H2O) exposed in the upper hundreds of micrometers of the surface. Furthermore, many light-toned, Ca-sulfate-bearing features (i.e. veins and nodules within the outcrop) exposed at the surface in Yellowknife Bay have a high hydration index, consistent with a hydrated mineral such as gypsum. Other light-toned features do not have a high hydration index, suggesting they are composed of anhydrous or lower hydration state phases such as anhydrite or bassanite. The distribution of light-toned features within the outcrop at Yellowknife Bay is also highly variable within a DAN footprint. Given that there is variability in both the DAN signal and Mastcam hydration index throughout Yellowknife Bay, this work investigates whether or not increases or decreases in H seen by DAN correlate to areas of high hydration index as derived from Mastcam observations. Positive correlations of the DAN H signal and Mastcam hydration index may indicate that the observed densities of light-toned features (hydrated or dehydrated) extend to at least 60cm depth. Conversely, negative correlations could indicate that either the veins/nodules are only present at very shallow depths (a few cm), that the hydration of the phases changes with depth (e.g., gypsum at the surface and anhydrite at depth), or that there

  3. Sacroiliites infectieuses dans le centre tunisien: étude rétrospective de 25 cas

    PubMed Central

    Bellazreg, Foued; Alaya, Zeineb; Hattab, Zouhour; Lasfar, Nadia Ben; Ayeche, Mohamed Laziz Ben; Bouajina, Elyes; Letaief, Amel; Hachfi, Wissem

    2016-01-01

    Les sacroiliites infectieuses sont rares mais peuvent se compliquer de séquelles fonctionnelles invalidantes. Décrire les caractéristiques cliniques et bactériologiques des sacroiliites infectieuses chez les patients suivis à Sousse, Centre Tunisien. Etude rétrospective, descriptive, des cas de sacroiliites infectieuses chez les patients hospitalisés à Sousse entre 2000 et 2015. Le diagnostic a été retenu devant des signes cliniques, d'imagerie, et microbiologiques évocateurs. Vingt-cinq patients, 10 hommes et 15 femmes, d’âge moyen 41 ans (19-78) ont été inclus. Les sacroiliites étaient dues à des bactéries pyogènes dans 14 cas (56%), brucelliennes dans 6 cas (24%), et tuberculeuses dans 5 cas (20%). La durée moyenne d’évolution était de 61, 45 et 402 jours respectivement. Les signes cliniques les plus fréquents étaient les douleurs fessières (92%) et la fièvre (88%). La radiographie standard était anormale dans 75% des cas. La TDM et l'IRM sacro-iliaques dans tous les cas. Le diagnostic a été confirmé bactériologiquement dans 24 cas (96%). La durée moyenne d'antibiothérapie était de 83 jours dans les sacroiliites à pyogènes, et de 102 jours dans les SI brucelliennes. L’évolution était favorable chez 12 patients (48%), 9 patients (36%) ont gardé une douleur sacro-iliaque séquellaire, et 4 patients (16%) sont décédés. Dans notre étude, la durée d’évolution de la sacroiliite infectieuse ne permettait pas de prédire la bactérie responsable, d'où la nécessité d'obtenir une documentation bactériologique afin de prescrire une antibiothérapie appropriée. PMID:27583067

  4. Spectres d'absorption X dans les plasmas femtosecondes

    NASA Astrophysics Data System (ADS)

    Bastiani-Ceccotti, S.; Audebert, P.; Renaudin, P.; Chenais-Popovics, C.; Geindre, J. P.; Tzortzakis, S.; Nagels-Silvert, V.; Shepherd, R.; Matsushima, I.; Gary, S.; Girard, F.; Peyrusse, O.; Gauthier, J. C.

    2005-06-01

    Nous avons mesuré le spectre d'absorption en couche K de plasmas d'aluminium à haute densité. Deux faisceaux de la chaîne laser femtoseconde 100 TW du LULI (de durée 300 fs) ont été utilisés pour produire le plasma absorbant sur une feuille mince d'Al (830 Å ou 500 Å), et la source de radiographie sur du samarium massif. Les spectres X étaient résolus spatialement dans une direction perpendiculaire à la direction de la dispersion spectrale. Les spectres ont été mesurés pour différents retards entre la source deradiographie et le plasma d'Al. Des simulations des spectres et de l'ionisation en fonction du temps et de l'intensité, obtenues au moyen de codes hydrodynamiques et de structure atomique, montrent un bon accord avec les résultats expérimentaux.

  5. Cloud Interactions

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 1 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth.

    Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms.

    This image was acquired during mid-spring near the North Pole. The linear water-ice clouds are now regional in extent and often interact with neighboring cloud system, as seen in this image. The bottom of the image shows how the interaction can destroy the linear nature. While the surface is still visible through most of the clouds, there is evidence that dust is also starting to enter the atmosphere.

    Image information: VIS instrument. Latitude 68.4, Longitude 258.8 East (101.2 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration

  6. Migration pelvienne de broche guide dans la chirurgie des fractures de hanche: à propos de 3 cas

    PubMed Central

    Guèye, Mohamadou Lamine; Thiam, Ousmane; Touré, Alpha Oumar; Seck, Mamadou; Cissé, Mamadou; Kâ, Ousmane; Dieng, Madieng; Dia, Abderahmane; Touré, Cheikh Tidiane

    2015-01-01

    La migration de matériel d'ostéosynthèse est une complication bien connue du traitement chirurgical des fractures. Toutefois, la migration pelvienne de broche guide dans la chirurgie des fractures de la hanche est un incident rare et potentiellement grave. Nous rapportons 3 observations dans lesquelles on notait une migration de broche guide dans le pelvis lors d'une ostéosynthèse dela hanche de type DHS. L'indication chirurgicale était une fracture per-trochantérienne dans 2 cas et une fracture du col fémoral type 4 de Garden dans 1 cas. Une minilaparotomie permettait d'objectiver une plaie du ligament large gauche et un hématome ligamentaire dans 1 cas, tandis que dans les 2 autres cas, il n'y avait pas de lésion viscérale. L'extraction de la broche a été effectuée dans les 3 cas. Les suites opératoires ont été simples chez tous les patients. PMID:26327949

  7. The local subsurface water and chlorine distributions evaluated by DAN/MSL in Curiosity observational campaigns

    NASA Astrophysics Data System (ADS)

    Litvak, Maxim; Mitrofanov, Igor; Hardgrove, Craig; Sanin, Anton; Lisov, Denis; Golovin, Dmitry; Jun, Insoo; Kozyrev, Alexander; Malakhov, Alexey; Mischna, Michael; Moersch, Jeffrey; Nikiforov, Sergey; Tate, Cristopher; Vostrukhin, Andrey

    2016-04-01

    The measurements with the Dynamic Albedo of Neutrons (DAN) instrument onboard the Mars Science Laboratory (MSL) Curiosity rover are presented and analyzed as a summary of observations acquired during several special observational campaigns at the Yellowknife Bay area (first discovery of habitability environment), at the striated units of Kimberley formation, at outcrops studied in Pahrump Hills (at the base of Mt Sharp) and in high silica area discovered in Marias Pass (Mudstone facies of the Murray formation). DAN data were analyzed to test local and global variability in the distribution of bulk hydrogen and neutron-absorbing elements, characterized as chlorine-equivalent concentration. Using multi instrument approach in the data analysis we have compared DAN estimations of subsurface H and Cl distributions with inhomogeneity of local geological context, top surface measurements of chlorine with APXS and with SAM measurements of absorbed H2O extracted from the drilled samples based on low temperature evolved gas analysis.

  8. Dynamic Albedo of Neutrons (DAN) Experiment Onboard NASA's Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Mitrofanov, I. G.; Litvak, M. L.; Varenikov, A. B.; Barmakov, Y. N.; Behar, A.; Bobrovnitsky, Y. I.; Bogolubov, E. P.; Boynton, W. V.; Harshman, K.; Kan, E.; Kozyrev, A. S.; Kuzmin, R. O.; Malakhov, A. V.; Mokrousov, M. I.; Ponomareva, S. N.; Ryzhkov, V. I.; Sanin, A. B.; Smirnov, G. A.; Shvetsov, V. N.; Timoshenko, G. N.; Tomilina, T. M.; Tret'yakov, V. I.; Vostrukhin, A. A.

    2012-09-01

    The description of Dynamic Albedo of Neutrons (DAN) experiment is presented, as a part of the NASA's Mars Science Laboratory mission onboard the mars rover Curiosity. The instrument DAN includes Pulsing Neutron Generator (PNG) producing pulses of 14.1 MeV neutrons for irradiation of subsurface material below the rover, and Detectors and Electronics (DE) unit, which operates the instrument itself and measures the die-away time profiles of epithermal and thermal neutrons following each neutron pulse. It is shown that the DAN investigation will measure a content of hydrogen along the path of the MSL rover, and it will also provide information about a depth distribution of hydrogen at 10-20 regions selected for the detailed studies and sampling analysis.

  9. Interactions effectives, théories de champ moyen masses et rayons nucléaires

    NASA Astrophysics Data System (ADS)

    Meyer, J.

    2003-05-01

    Effective interactions, mean field theories, masses and nuclear radii A review of effective interactions used in mean field theories for the description of properties of atomic nuclei is presented. Relativistic as well as non relativistic theories are discussed with a special attention to the cases where their results are very different. We will concentrate on the effective forces built up to investigate the nuclear medium in extreme conditions. Masses and r.m.s. radii along long chain of isotopes will be discussed. Large deformations, as observed in the fission of heavy nuclei, and exotic neutron rich nuclei will be taken as examples of these extreme conditions. Le principal propos de cet ouvrage est : (i) de passer en revue les outils théoriques utilisés sous le sigle ”théories microscopiques de champ moyen ”. Sans entrer dans le détail des formalismes (le lecteur sera systématiquement renvoyé ”pour en savoir plus ” à des cours plus complets qui ont déjà été donnés dans le passé à l'École Joliot-Curie) il s'agira surtout de préciser le contexte, les hypothèses et les approximations qui se cachent sous les sigles : Hartree-Fock (HF), Hartree-Fock-Bogoliubov (HFB), Approximation BCS (HFBCS), Champ Moyen Relativiste (RMF), Approximations Hartree (RH), Hartree-Fock (RHF) et Hartree-Bogoliubov (RHB) Relativistes, ... ; (ii) de présenter la procédure générale et les ingrédients qui entrent dans la construction d'une interaction effective, élément de base de ces théories dont l'intérêt majeur est de livrer des résultats comparables à l'expérience sans paramètre ajustable ; (iii) de discuter des effets des différentes approximations ou interactions effectives sur des résultats expérimentaux pris dans diverses zones de noyaux. Ces discussions seront surtout centrées sur les masses et les rayons des noyaux mais aussi sur certaines quantités plus significatives que l'on peut en extraire : énergies de séparation de deux neutrons

  10. DAnTE: a statistical tool for quantitative analysis of –omics data

    SciTech Connect

    Polpitiya, Ashoka D.; Qian, Weijun; Jaitly, Navdeep; Petyuk, Vladislav A.; Adkins, Joshua N.; Camp, David G.; Anderson, Gordon A.; Smith, Richard D.

    2008-05-03

    DAnTE (Data Analysis Tool Extension) is a statistical tool designed to address challenges unique to quantitative bottom-up, shotgun proteomics data. This tool has also been demonstrated for microarray data and can easily be extended to other high-throughput data types. DAnTE features selected normalization methods, missing value imputation algorithms, peptide to protein rollup methods, an extensive array of plotting functions, and a comprehensive ANOVA scheme that can handle unbalanced data and random effects. The Graphical User Interface (GUI) is designed to be very intuitive and user friendly.

  11. Le pompage optique naturel dans le milieu astrophysique

    NASA Astrophysics Data System (ADS)

    Pecker, J.-C.

    The title of this lecture abstracts only a part of it : the importance in astrophysics of the study of non-LTE situations has become considerable, as well in the stellar atmospheres as, still more, in the study of fortuitous coincidences as a mechanism of formation of emission line nebular spectra, or of molecular interstellar « masers ». Another part of this talk underlines the role of Kastler in his time, and describes his warm personality through his public reactions in front of the nuclear armement, of the Viet-Nam and Algerian wars, of the problems of political refugees... Kastler was a great scientist ; he was also a courageous humanist. 1976 : Les accords nucléaires du Brésil : allocution d'ouverture (19 mars). Colloque sur le sujet ci-dessus. 1976 : La promotion de la culture dans le nouvel ordre économique international, allocution à l'occasion d'une table ronde sur ce thème par l'UNESCO (23-27 juin 1976) ; « Sciences et Techniques », octobre 1976. 1979 : La bête immonde (avec J.-C. Pecker), « Le Matin », 20 mars. 1979 : Appel à nos ministres (avec J.-C. Pecker), « Le Monde », 13 décembre. 1979 : Le flou, le ténébreux, l'irrationnel (avec J.-C. Pecker), « Le Monde », 14 septembre. 1980 : Education à la paix, Préface, in : Publ. UNESCO. 1981 : Le vrai danger, « Le Monde », 6 août 1981. 1982 : Nucléaire civil et militaire, « Le Monde », 1er juin 1982. 1982 : Les scientifiques face à la perspective d'holocauste nucléaire (texte inédit). Le titre de cette communication en résume seulement une partie : l'importance prise en astrophysique par l'analyse des situations hors ETL est devenue considérable, qu'il s'agisse des atmosphères stellaires, ou plus encore, des coïncidences fortuites de la formation des spectres d'émission nébulaires, ou des « masers » moléculaires interstellaires. Une autre partie de cet exposé souligne le rôle de Kastler dans son époque, et décrit sa personnalité généreuse à travers ses r

  12. Theorie de la Levitation Radiative a L'equilibre dans les Etoiles Naines Blanches Chaudes

    NASA Astrophysics Data System (ADS)

    Chayer, Pierre

    1995-01-01

    Les resultats de nouveaux calculs detailles de levitation radiative dans des naines blanches chaudes utilisant la base de donnees atomiques TOPBASE sont presentes. Des accelerations radiatives et des abondances d'equilibre ont ete calculees pour C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, et Fe, sur des grilles de modeles d'enveloppes stellaires riches en hydrogene et riches en helium. La grille des modeles de DA a des gravites telles que log g = 7.0, 7.5, 8.0, et 8.5, et couvre les temperatures effectives pour lesquelles 100,000K >= T_ {rm eff} >= 20,000K par sauts de 2,500K. La grille des modeles de DO/DB est similaire mais se prolonge a T_{rm eff } = 130,000K. Les resultats d'abondances d'equilibre de Ni dans des DA utilisant la base de donnees de Kurucz sont aussi presentes. Nous discutons dans les moindres details de la physique incluse dans les calculs afin de fournir une bonne comprehension physique de la levitation radiative sous les conditions rencontrees dans les naines blanches. Nous discutons aussi de la forme et de la dependance en fonction de la profondeur des reservoirs des elements, crees par un equilibre entre l'acceleration radiative et la gravite locale effective dans differentes enveloppes stellaires. Nous soulignons le role important joue dans la morphologie de ces reserviors par les etats d'ionisation dominants se trouvant dans la configuration gaz noble. Nos resultats centraux sont presentes sous forme de figures montrant le comportement de l'abondance photospherique estimee pour chaque element en fonction de la temperature effective et de la gravite de surface. Nous apportons egalement des ameliorations aux calculs de levitation radiative en utilisant une approche de modeles d'atmospheres pour les etoiles riches en hydrogene. Nous mettons l'emphase, en particulier, sur le role des traces d'elements lourds qui peuvent etre presents dans le plasma. Nous utilisons une table d'opacite monochromatique detaillee calculee pour un plasma compose de H

  13. Étude de l'ancrage du niveau de Fermi dans les jonctions de GaAs/électrolyte aqueux et non aqueux

    NASA Astrophysics Data System (ADS)

    Yao, N. A.; Cachet, H.

    1998-05-01

    In this paper, flatband potential measurements are used to study the Fermi Level Pinning (FLP) at the n or p-GaAs/aqueous and non aqueous electrolyte interface. The semiconductor is put in contact with an aqueous solution containing the 18-tungsto-diphosphate P2W{18}O{62}6- heteropolyanion as a redox system and with two non aqueous solutions: acetonitrile (ACN) and propylene carbonate (CP) in the presence of various redox couples. Our results are firstly analyzed according to the classical model proposed for solid-state semiconductor/metal junctions. A more specific model accounting for the coupling between corrosion and redox reactions at the semiconductor/electrolyte interface is developped. The semiconductor surface equilibrates mainly with the redox species in ACN solutions (total FLP), and only weakly in H2O or CP solutions, because of the pre-eminence of the semiconductor/solvent interactions. Dans cet article, l'ancrage du niveau de Fermi dans les jonctions semiconducteur/électrolyte est étudié à partir de la détermination du potentiel de bandes plates. Le semiconducteur est l'arséniure de gallium (n et p) qui est mis en contact respectivement avec un milieu aqueux contenant un hétéropolyanion comme système oxydo-réducteur, le 18-tungsto-diphosphate P2W{18}O{62}6-, et avec deux milieux non aqueux : l'acétonitrile (ACN) et le carbonate de propylène (CP) contenant divers couples redox. Les résultats sont d'abord analysés suivant le modèle proposé classiquement pour les jonctions semiconducteur/métal, puis à l'aide d'un modèle développé spécifiquement dans le cas de l'interface semiconducteur/électrolyte, prenant en compte le couplage entre réaction de corrosion et réaction redox. En milieu ACN, la surface du semiconducteur s'équilibre principalement avec le système redox (FLP total), et seulement partiellement en milieu H2O ou CP, au profit des interactions avec le milieu électrolytique.

  14. Acute response of airway muscle to extreme temperature includes disruption of actin-myosin interaction.

    PubMed

    Dyrda, Peter; Tazzeo, Tracy; DoHarris, Lindsay; Nilius, Berndt; Roman, Horia Nicolae; Lauzon, Anne-Marie; Aziz, Tariq; Lukic, Dusan; Janssen, Luke J

    2011-02-01

    Despite the emerging use of bronchial thermoplasty in asthma therapy, the response of airway smooth muscle (ASM) to extreme temperatures is unknown. We investigated the immediate effects of exposing ASM to supraphysiologic temperatures. Isometric contractions were studied in bovine ASM before and after exposure to various thermal loads and/or pharmacologic interventions. Actin-myosin interactions were investigated using a standard in vitro motility assay. We found steep thermal sensitivity for isometric contractions evoked by acetylcholine, with threshold and complete inhibition at less than 50°C and greater than 55°C, respectively. Contractile responses to serotonin or KCl were similarly affected, whereas isometric relaxations evoked by the nitric oxide donor S-nitrosyl-N-acetylpenicillamine or the β-agonist isoproterenol were unaffected. This thermal sensitivity developed within 15 minutes, but did not evolve further over the course of several days (such a rapid time-course rules out heat shock proteins, apoptosis, autophagy, and necrosis). Although heat-sensitive transient receptor potential (TRPV2) channels and the calmodulin-dependent (Cam) kinase-II-induced inactivation of myosin light chain kinase are both acutely thermally sensitive, with a temperature producing half-maximal effect (T(1/2)) of 52.5°C, the phenomenon we describe was not prevented by blockers of TRPV2 channels (e.g., ruthenium red, gadolinium, zero-Ca(2+) or zero-Na(+)/zero-Ca(2+) media, and cromakalim) or of Cam kinase-II (e.g., W7, trifluoperazine, and KN-93). However, direct measurements of actin-myosin interactions showed the same steep thermal profile. The functional changes preceded any histologic evidence of necrosis or apoptosis. We conclude that extreme temperatures (such as those used in bronchial thermoplasty) directly disrupt actin-myosin interactions, likely through a denaturation of the motor protein, leading to an immediate loss of ASM cell function. PMID:20395634

  15. An Interview with Dan Hallahan: From Clinical Researcher to Consummate Teacher Educator

    ERIC Educational Resources Information Center

    Sayeski, Kristin L.

    2014-01-01

    Kristin L. Sayeski introduces the reader to Dan Hallahan and provides a synopsis of his educational background. She reports Hallahan received his BA in psychology in 1967 and his PhD in education and psychology in 1971 from the University of Michigan, then began his career as an assistant professor in special education at the University of…

  16. Harold Goldstein (R) and Dan Leiser (L) discuss bone implant development in the the Shuttle Tile

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Harold Goldstein (R) and Dan Leiser (L) discuss bone implant development in the the Shuttle Tile Laboratory N-242. A spin-off of Ames research on both bone density in microgravity and on thermal protection foams is the bone-growth implant shown in 1993.

  17. Southwest Research Institute astronomer Dan Durda checks the alignment of the SWUIS-A Xybion digital

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Southwest Research Institute astronomer Dan Durda checks the alignment of the SWUIS-A Xybion digital camera mounted in the rear cockpit of a NASA Dryden F/A-18B before taking off on an astronomy mission to search for small vulcanoids (asteroids) that may be orbiting between the sun and the planet Mercury.

  18. L'atteinte osseuse dans le sarcome de Kaposi classique et agressif: à propos d'un cas

    PubMed Central

    Sbiyaa, Mouhcine; El Alaoui, Adil; El Bardai, Mohammed; Mezzani, Amine; Lahrach, Kamal; Marzouki, Amine; Boutayeb, Fawzi

    2016-01-01

    Le sarcome de Kaposi classique est une tumeur rare multifocale d'origine des cellules endothéliales vasculaires à caractère évolutif progressif et peu maligne. L'atteinte viscérale dans le sarcome de kaposi est parfois observée chez les patients VIH positif par contre la dissémination tumorale dans les ganglions lymphatiques viscérales dans le SK classique reste très rare. On rapporte un cas rare de sarcome de kaposi classique agressif de la main avec une évolution rapide et destructive. PMID:27347285

  19. Simulation numérique d'écoulement compressible dans les joints labyrinthe

    NASA Astrophysics Data System (ADS)

    Sriti, M.; Agouzoul, M.; Ouazar, D.; Micheau, P.

    1997-05-01

    The labyrinth seals are the devices used machines which serve to restrict the leakages crossing a carter (or stator) by a rotating shaft (or rotor) and to avoid the important friction to high rotation speeds. These devices, which in addition behave as shaft bearings, can modify the dynamics characteristics of the line of the shaft in which they are integrated. The present work has been carried out with the purpose of controlling better the flows within the labyrinth seals and to determine their static (leakage-pressure) and dynamic (stiffness and damping coefficients) characteristics. It's based on the development of a global numerical model, and on the integration of the obtained correlations by 3D axisymmetric computation in this model. Les joints labyrinthe sont des dispositifs utilisés dans les machines, ils servent à limiter les fuites à la traversée d'un carter (ou stator) par un arbre tournant (ou rotor) et éviter le frottement important aux vitesses de rotation élevées. Ces dispositifs, qui de plus, se comportent comme des paliers, peuvent modifier les caractéristiques dynamiques de la ligne d'arbre dans laquelle ils sont intégrés. Le travail présenté a été effectué dans le but de mieux maîtriser les écoulements dans les joints labyrinthe et de déterminer leurs caractéristiques statiques (débit-pression) et dynamiques (coefficients de raideur et d'amortissement). Il s'appuie sur le développement d'outils numériques intégrant dans les calculs globaux des résultats de calculs locaux (3D axisymétriques).

  20. In-medium nuclear interactions of low-energy hadrons

    NASA Astrophysics Data System (ADS)

    Friedman, E.; Gal, A.

    2007-11-01

    Exotic atoms provide a unique laboratory for studying strong interactions and nuclear medium effects at zero kinetic energy. Experimental and theoretical developments of the last decade in the study of exotic atoms and some related low-energy reactions are reviewed. The exotic atoms considered are of π-,K-,pbar,Σ-, and also the so far unobserved Ξ- atoms. The analysis of these atomic systems consists of fitting density-dependent optical potentials Vopt=t(ρ)ρ to comprehensive sets of data of strong-interaction level shifts, widths and yields across the periodic table. These provide information on the in-medium hadron-nucleon t matrix t(ρ) over a wide range of densities up to central nuclear densities. For pions, the review focuses on the extraction of the πN in-medium s-wave interaction from pionic atoms, which include also the deeply bound π- atomic states recently observed at GSI in isotopes of Sn and Pb. Also included are recent measurements at PSI of elastic scattering of π± on Si, Ca, Ni and Zr at 21.5 MeV. The experimental results are analyzed in the context of chirally motivated π-nuclear potentials, and the evidence for partial restoration of chiral symmetry in dense nuclear matter is critically discussed. For antikaons, we review the evidence from K- atoms, and also from low-energy K-p scattering and reaction data for and against a deepKbar-nucleus potential of 150-200 MeV attraction at nuclear matter density. The case for relatively narrow deeply bound K-atomic states is made, essentially independent of the potential-depth issue. Recent experimental suggestions from KEK and DA ΦNE (Frascati) for signals of Kbar-nuclear deeply bound states are reviewed, and dynamical models for calculating binding energies and widths of Kbar- nuclear states are discussed. For kaons we review the evidence, from K+ total and reaction cross section measurements at the AGS (BNL) on Li, C, Si and Ca at plab=500-700 MeV/c, for significant absorptivity of tKN

  1. Apport des moyens endoscopiques dans la dilatation des sténoses caustiques de l’œsophage

    PubMed Central

    Seydou, Togo; Abdoulaye, Ouattara Moussa; xing, Li; Zi, Sanogo Zimogo; sekou, Koumaré; Wen, Yang Shang; Ibrahim, Sankare; Sekou, Toure Cheik Ahmed; Boubacar, Maiga Ibrahim; Saye, Jacque; Jerome, Dakouo Dodino; Dantoumé, Toure Ousmane; Sadio, Yena

    2016-01-01

    Introduction Toutes les sténoses symptomatiques de l’œsophage peuvent être dilatées par voie endoscopique. Nous évaluons l'apport des moyens endoscopiques dans la prise en charge de la dilatation œsophagienne pour sténose caustique de l’œsophage (SCO) au Mali. Méthodes IL s'agissait d'une étude descriptive et prospective réalisée dans le service de chirurgie thoracique à l'hôpital du Mali. Au total 46 dossiers cliniques de patients on été enregistrés et subdivisés en 4 groupes en fonction de la topographie des lésions cicatricielles. Le nombre de cas d'assistance endoscopique réalisé a été déterminé afin de comprendre l'apport des moyens endoscopiques dans le succès de la dilatation des SCO. Pour les 2 différentes méthodes de dilatation utilisées, le résultat du traitement et le coût ont comparés. Résultats La FOGD a été utilisée dans 19 cas (41.30%) de dilatation avec la bougie de Savary Guillard et dans 47.82% des cas dans la dilatation de Lerut. La vidéo-laryngoscopie a été utilisé 58.69% des cas de dilatation à la bougie de Lerut. Le passage de guide métallique et / ou de fil-guide a été réalisée dans 39.13% avec la vidéo laryngoscopie et dans 58.68% avec la FOGD. Dans la comparaison des deux méthodes, il existe une différence significative dans la survenue des complications (p=0.04075), l'anesthésie générale (p=0.02287), l'accessibilité à la méthode (p=0.04805) et la mortalité (p=0.00402). Conclusion La SCO est une pathologie grave et sous évaluée au Mali. Les moyens endoscopiques contribuent considérablement au succès de la dilatation œsophagienne pour sténose caustique dans les différentes méthodes utilisées. PMID:27200129

  2. Etude theorique et experimentale des evaporateurs de dioxyde de carbone operant dans des conditions de givrage

    NASA Astrophysics Data System (ADS)

    Bendaoud, Adlane Larbi

    Les evaporateurs de refrigeration sont surtout du type tube a ailettes, appeles serpentins, et fonctionnent dans l'une des conditions suivantes: seche, humide ou avec formation de givre. Il a ete demontre que la formation du givre sur la paroi exterieure de l'echangeur engendre une surconsommation energetique a cause des operations de degivrage puisque 15 a 20% seulement de la chaleur produite sert au degivrage tandis que le reste est dissipee dans l'environnement [1]. Avec l'avenement des nouveaux refrigerants, moins nocifs envers l'environnement, l'industrie du froid se trouve penalisee du fait que peu ou pas de composantes mecaniques (compresseur, pompe, echangeur...etc.) adaptees sont disponibles [3]. Il s'agit pour la communaute des frigoristes de combler ce retard technologique en redeveloppant ces composantes mecaniques afin qu'elles soient adaptees aux nouveaux refrigerants. Dans cette optique, et afin de mieux comprendre le comportement thermique des evaporateurs au CO2 fonctionnant dans des conditions seches, qu'un groupe de chercheurs du CanmetENERGIE avaient lance, en 2000, un programme de R & D. Dans le cadre de programme un outil de simulation des evaporateurs au CO2 a ete developpe et un banc d'essai contenant une boucle secondaire de refrigeration utilisant le CO2 comme refrigerant a ete construit. Comme continuite de ce travail de recherche, en 2006 ce meme groupe de recherche a lance un nouveau projet qui consiste a faire une etude theorique et experimentale des evaporateurs au CO2 operants dans des conditions de givrage. Et, c'est exactement dans le cadre de ce projet que se positionne ce travail de these. Ce travail de recherche a ete entrepris pour mieux comprendre le comportement thermique et hydrodynamique des serpentins fonctionnant dans des conditions de givrage, l'effet des circuits de refrigerant ainsi que celui des parametres geometriques et d'operation. Pour cela, un travail theorique supporte par une etude experimentale a ete effectue

  3. Rôle des hyrates dans la formation de Titan et des satellites réguliers

    NASA Astrophysics Data System (ADS)

    Mousis, O.

    2001-12-01

    Cette these est dediee a l'etude de l'origine de Titan et de son atmosphere. Dans l'hypothese ou la subnebuleuse de Saturne etait geometriquement mince, le modele de disque turbulent utilise, derive des travaux de Dubrulle (1993), est moins dense que le modele de Prinn et Fegley (1981). De ce fait, les conversions de Co en CH4 et de N2 en NH3 ont ete inhibees dans la subnebuleuse, contrairement a ce qui est couramment admis pour interpreter la presence du methane dans l'atmosphere de Titan. C'est pourquoi nous avons developpe un nouveau scenario de la formation de titan, qui tient compte simultanement des contraintes resultant de la chimie de la subnebuleuse et des abondances de CH4, N2 et CH3D mesurees dans l'atmosphere du satellite. Nous faisons l'hypothese que ces gaz proviennent initialement de la vaporisation du nuage presolaire, qui s'effondra et forma le Soleil et son disque environnant. Lors du refroidissement de la nebuleuse, les volatils auraient ete pieges sous formes de clathrates d'hydrates dans les grains, puis dans les planetesimaux qu'ils formerent. Les planetesimaux hydrates a l'origine de la formation de Titan seraient alors des rescapes de l'effondrement hydsrodynamique de la feeding zone de Saturne. Ce scenario a ete applique aux subnebuleuses de Jupiter et d'Uranus, et a apporte un certain nombre de contraintes sur la formation des satellites reguliers de ces planetes. Le temps et la zone de formation des grains cometaires ont egalement ete estimes dans la nebuleuse solaire. Enfin, l'etude experimentale de la temperature de fusion du dihydrate d'ammoniac dans la gamme des hautes pressions a apporte des nouvelles donnees thermodynamiques qui permettront d'ameliorer les modeles de l'interieur de Titan.

  4. Conductivite dans le modele de Hubbard bi-dimensionnel a faible couplage

    NASA Astrophysics Data System (ADS)

    Bergeron, Dominic

    Le modele de Hubbard bi-dimensionnel (2D) est souvent considere comme le modele minimal pour les supraconducteurs a haute temperature critique a base d'oxyde de cuivre (SCHT). Sur un reseau carre, ce modele possede les phases qui sont communes a tous les SCHT, la phase antiferromagnetique, la phase supraconductrice et la phase dite du pseudogap. Il n'a pas de solution exacte, toutefois, plusieurs methodes approximatives permettent d'etudier ses proprietes de facon numerique. Les proprietes optiques et de transport sont bien connues dans les SCHT et sont donc de bonne candidates pour valider un modele theorique et aider a comprendre mieux la physique de ces materiaux. La presente these porte sur le calcul de ces proprietes pour le modele de Hubbard 2D a couplage faible ou intermediaire. La methode de calcul utilisee est l'approche auto-coherente a deux particules (ACDP), qui est non-perturbative et inclue l'effet des fluctuations de spin et de charge a toutes les longueurs d'onde. La derivation complete de l'expression de la conductivite dans l'approche ACDP est presentee. Cette expression contient ce qu'on appelle les corrections de vertex, qui tiennent compte des correlations entre quasi-particules. Pour rendre possible le calcul numerique de ces corrections, des algorithmes utilisant, entre autres, des transformees de Fourier rapides et des splines cubiques sont developpes. Les calculs sont faits pour le reseau carre avec sauts aux plus proches voisins autour du point critique antiferromagnetique. Aux dopages plus faibles que le point critique, la conductivite optique presente une bosse dans l'infrarouge moyen a basse temperature, tel qu'observe dans plusieurs SCHT. Dans la resistivite en fonction de la temperature, on trouve un comportement isolant dans le pseudogap lorsque les corrections de vertex sont negligees et metallique lorsqu'elles sont prises en compte. Pres du point critique, la resistivite est lineaire en T a basse temperature et devient

  5. Geochemistry of dissolved trace elements and heavy metals in the Dan River Drainage (China): distribution, sources, and water quality assessment.

    PubMed

    Meng, Qingpeng; Zhang, Jing; Zhang, Zhaoyu; Wu, Tairan

    2016-04-01

    Dissolved trace elements and heavy metals in the Dan River drainage basin, which is the drinking water source area of South-to-North Water Transfer Project (China), affect large numbers of people and should therefore be carefully monitored. To investigate the distribution, sources, and quality of river water, this study integrating catchment geology and multivariate statistical techniques was carried out in the Dan River drainage from 99 river water samples collected in 2013. The distribution of trace metal concentrations in the Dan River drainage was similar to that in the Danjiangkou Reservoir, indicating that the reservoir was significantly affected by the Dan River drainage. Moreover, our results suggested that As, Sb, Cd, Mn, and Ni were the major pollutants. We revealed extremely high concentrations of As and Sb in the Laoguan River, Cd in the Qingyou River, Mn, Ni, and Cd in the Yinhua River, As and Sb in the Laojun River, and Sb in the Dan River. According to the water quality index, water in the Dan River drainage was suitable for drinking; however, an exposure risk assessment model suggests that As and Sb in the Laojun and Laoguan rivers could pose a high risk to humans in terms of adverse health and potential non-carcinogenic effects. PMID:26782327

  6. PIC: Protein Interactions Calculator.

    PubMed

    Tina, K G; Bhadra, R; Srinivasan, N

    2007-07-01

    Interactions within a protein structure and interactions between proteins in an assembly are essential considerations in understanding molecular basis of stability and functions of proteins and their complexes. There are several weak and strong interactions that render stability to a protein structure or an assembly. Protein Interactions Calculator (PIC) is a server which, given the coordinate set of 3D structure of a protein or an assembly, computes various interactions such as disulphide bonds, interactions between hydrophobic residues, ionic interactions, hydrogen bonds, aromatic-aromatic interactions, aromatic-sulphur interactions and cation-pi interactions within a protein or between proteins in a complex. Interactions are calculated on the basis of standard, published criteria. The identified interactions between residues can be visualized using a RasMol and Jmol interface. The advantage with PIC server is the easy availability of inter-residue interaction calculations in a single site. It also determines the accessible surface area and residue-depth, which is the distance of a residue from the surface of the protein. User can also recognize specific kind of interactions, such as apolar-apolar residue interactions or ionic interactions, that are formed between buried or exposed residues or near the surface or deep inside. PMID:17584791

  7. La prévention des blessures dans les terrains de jeux

    PubMed Central

    Fuselli, Pamela; Yanchar, Natalie L

    2012-01-01

    RÉSUMÉ Dans un climat d’inquiétude croissante à l’égard de l’obésité juvénile et de l’inactivité, les terrains de jeux permettent aux enfants d’être actifs. Ils comportent toutefois aussi des risques, les blessures causées par des chutes étant de loin les plus courants. Les recherches démontrent la possibilité de réduire les blessures dans les terrains de jeux si on abaisse la hauteur des structures de jeu et si on utilise des surfaces molles et profondes pour amortir les chutes. L’Association canadienne de normalisation a publié des normes volontaires qu’elle a mises à jour plusieurs fois pour tenir compte de ces risques. Afin de contribuer à les réduire, les parents peuvent respecter des stratégies simples. Le présent document de principes souligne le fardeau des blessures subies dans les terrains de jeux. Il procure également aux parents et aux dispensateurs de soins des occasions de réduire l’incidence et la gravité des blessures grâce à l’éducation et à la défense d’intérêts, ainsi que de mettre en œuvre des normes de sécurité probantes et des stratégies plus sécuritaires dans les terrains de jeux locaux. Enfin, il remplace le document de principes de la Société canadienne de pédiatrie publié en 2002 sur le sujet.

  8. Franz Xaver von Zach et l'astronomie dans la France méridionale

    NASA Astrophysics Data System (ADS)

    Brosche, Peter; Débarbat, Suzanne

    Le baron Franz Xaver von Zach, né à Pest (Hongrie), a fait ses études notamment en France et en Angleterre. En 1786 le duc de Saxe-Gotha, Ernst II, lui demande de créer son observatoire de Seeberg. La même année ils se rendent dans le sud de la France, à Hyères à cette occasion, une des tours du mur d'enceinte de la ville est transformée en observatoire. En 1809, Zach et la duchesse régnante viennent près de Marseille et, lors de plusieurs voyages dans le sud de la France. Zach exécute des travaux géodésiques et astronomiques. Dans son "Journal", il mentionne les astronomes français, notamment ceux de la France méridonale auxquels il apporte son soutien. Pons devient, sur sa recommandation, astronome royal de la duchesse de Lucca, épouse du "roi d'Etrurie".

  9. Effets Seebeck et Nernst dans les cuprates: Etude de la reconstruction de la surface de Fermi sous champ magnetique intense

    NASA Astrophysics Data System (ADS)

    Laliberte, Francis

    2010-06-01

    Ce memoire presente des mesures de transport thermoelectrique, les effets Seebeck et Nernst, dans une serie d'echantillons de supraconducteurs a haute temperature critique. Des resultats obtenus recemment au Laboratoire National des Champs Magnetiques Intenses a Grenoble sur La1.7Eu0.2Sr0.1 CuO4, La1.675Eu0.2Sr0.125CuO 4, La1.64Eu0.2Sr0.16CuO4, La1.74Eu0.1Sr0.16CuO4 et La 1.4Nd0.4Sr0.2CuO4 sont analyses. Une attention particuliere est accordee aux equations de la theorie semi-classique du transport et leur validite est verifiee. La procedure experimentale et les materiaux utilises pour concevoir les montages de mesures sont expliques en detail. Enfin, un chapitre est dedie a l'explication et l'interpretation des resultats de transport thermoelectrique sur YBa2Cu3O6+delta publies au cours de l'hiver 2010 dans les revues Nature et Physical Review Letters. Les donnees d'effet Seebeck dans les echantillons de La 1.8-x,Eu0.2SrxCuO 4, ou un changement de signe est observe, permettent de conclure a la presence d'une poche d'electrons dans la surface de Fermi qui domine le transport a basse temperature dans la region sous-dopee du diagramme de phase. Cette conclusion est similaire a celle obtenue par des mesures d'effet Hall dans YBa 2Cu3O6+delta et elle cadre bien dans un scenario de reconstruction de la surface de Fermi. Les donnees d'effet Nernst recueillies indiquent que la contribution des fluctuations supraconductrices est limitee a un modeste intervalle de temperature au-dessus de la temperature critique.

  10. A pilot study using the Chinese herbal paste Liu-He-Dan to manage radiodermatitis associated with breast cancer radiotherapy

    PubMed Central

    Zhou, J.; Fang, L.; Xie, H.; Yao, W.X.; Zhou, X.; Xiong, Z.J.

    2015-01-01

    Background During radiotherapy for breast cancer, patients are greatly affected by pain, infection, and delayed healing of wounds caused by radiodermatitis. In the present study, we aimed to determine the efficacy of Liu-He-Dan in treating radiodermatitis. Methods In 26 breast cancer patients who experienced moist decrustation while receiving radiotherapy, 5 g Liu-He-Dan was applied externally once daily after the wound surface had been cleaned and dried. The healing time was recorded, and a Kaplan–Meier survival curve was applied to analyze the treatment course. Meanwhile, a pain assessment using the Numeric Rating Scale (nrs) recorded the pain level experienced by patients after application of the Liu-He-Dan. Results After application of Liu-He-Dan, the average healing time for the surface of the moist decrustation wounds was 14.17 ± 2.03 days (range: 5–22 days). Inflammatory seepage decreased significantly and exudation almost disappeared in 3 days. The pain trend line indicated that the average nrs score declined with treatment in all patients. The average nrs scores at days 1, 4, and 7 were 6.13, 3.62, and 2.58 respectively. After 3 days of treatment, pain was remarkably alleviated in 80.76% of patients. After treatment for 1 week, the pain remission rate was 96.15%, without any obvious adverse reactions. Conclusions Liu-He-Dan was efficacious in treating radiation skin injury with little toxicity and few side effects; the economic efficiency of the treatment was also favourable. The Liu-He-Dan was generally well tolerated by patients. In future, randomized control trials will be established for further observation of the value of Liu-He-Dan in treating radiodermatitis in breast cancer. PMID:26715882

  11. Interacting dark sector with transversal interaction

    SciTech Connect

    Chimento, Luis P.; Richarte, Martín G.

    2015-03-26

    We investigate the interacting dark sector composed of dark matter, dark energy, and dark radiation for a spatially flat Friedmann-Robertson-Walker (FRW) background by introducing a three-dimensional internal space spanned by the interaction vector Q and solve the source equation for a linear transversal interaction. Then, we explore a realistic model with dark matter coupled to a scalar field plus a decoupled radiation term, analyze the amount of dark energy in the radiation era and find that our model is consistent with the recent measurements of cosmic microwave background anisotropy coming from Planck along with the future constraints achievable by CMBPol experiment.

  12. Les bisphosphonates dans le traitement de l’ostéoporose

    PubMed Central

    Brown, Jacques P.; Morin, Suzanne; Leslie, William; Papaioannou, Alexandra; Cheung, Angela M.; Davison, Kenneth S.; Goltzman, David; Hanley, David Arthur; Hodsman, Anthony; Josse, Robert; Jovaisas, Algis; Juby, Angela; Kaiser, Stephanie; Karaplis, Andrew; Kendler, David; Khan, Aliya; Ngui, Daniel; Olszynski, Wojciech; Ste-Marie, Louis-Georges; Adachi, Jonathan

    2014-01-01

    Résumé Objectif Exposer l’efficacité et les risques du traitement par les bisphosphonates dans la prise en charge de l’ostéoporose et décrire les patients qui seraient de bons candidats aux congés thérapeutiques. Qualité des données Une recherche dans MEDLINE (PubMed, jusqu’au 31 décembre 2012) a permis de relever les publications pertinentes pour l’inclusion. La plupart des données probantes citées sont de niveau II (tirées d’essais non randomisés, de cohorte et d’autres essais comparatifs). Message principal L’efficacité des bisphosphonates de premier recours homologués pour la prévention des fractures a été éprouvée dans le cadre d’essais cliniques randomisés et contrôlés. Cependant, l’usage clinique répandu et prolongé des bisphosphonates a donné lieu à des rapports de manifestations indésirables rares, mais graves. L’ostéonécrose maxillaire et les fractures atypiques sous-trochantériennes ou diaphysaires du fémur seraient liées à l’emploi des bisphosphonates dans le traitement de l’ostéoporose, mais ces manifestations sont extrêmement rares et lorsqu’elles surviennent, elles sont accompagnées d’autres comorbidités ou de l’emploi concomitant de médicaments. Les congés thérapeutiques ne peuvent être envisagés que chez les patients à faible risque et dans un groupe restreint de patients dont le risque de fracture est modéré après un traitement de 3 à 5 ans. Conclusion Lorsque les bisphosphonates sont prescrits à des patients dont le risque de fracture est élevé, leur effet de prévention des fractures l’emporte de loin sur leurs torts potentiels. Chez les patients qui prennent des bisphosphonates depuis 3 à 5 ans, il faut réévaluer le besoin de poursuivre le traitement.

  13. Les superpolynomes symetriques dans les problemes a plusieurs corps de la mecanique quantique supersymetrique

    NASA Astrophysics Data System (ADS)

    Desrosiers, Patrick

    S'inspirant de la supersymetrie, on construit dans cette these une nouvelle generalisation de la theorie des fonctions symetriques. Une theorie physique est supersymetrique si: (1) elle contient des bosons (particules de spin entier) et des fermions (particules de spin demi-entier); (2) elle reste inchangee suite a une transformation des bosons en fermions et vice versa. Les fonctions symetriques dans le superespace (superfonctions symetriques) incorporent a la fois des variables commutatives (bosoniques) et anticommutatives (fermioniques). Ces dernieres engendrent une algebre de Grassmann. Une superfonction symetrique est invariante sous l'echange simultane des variables bosoniques et fermioniques (action diagonale du groupe symetrique); elle se caracterise par une superpartition, i.e., une juxtaposition appropriee de partitions usuelles d'entiers non negatifs. On utilise deux approches dans l'elaboration de la theorie des superfonctions symetriques: l'une provient de la combinatoire et l'autre, de la physique. Suivant la premiere approche, on obtient l'extension des elements standards de la theorie des fonctions symetriques fonctions monomiales, fonctions symetriques elementaires, fonctions completement symetriques, series de puissances, fonctions generatrices et formules de Cauchy. On demontre egalement qu'il existe une extension naturelle, a un parametre, du produit scalaire combinatoire defini par l'orthogonalite des series de puissances dans le superespace. La seconde approche consiste a resoudre des problemes a N corps de la mecanique quantique supersymetrique. On etudie les extensions supersymetriques des modeles Calogero-Moser-Sutherland (CMS), lesquels decrivent l'evolution de particules dont le potentiel d'inter action est proportionnel a l'inverse du carre de la distance separant les particules. Deux modeles supersymetriques CMS sont resolus: trigonometrique (sur un cercle) et rationnel (sur une ligne) avec confinement harmonique. Leurs fonctions d

  14. Les reconstructions acétabulaires dans les prothèses totales de hanche

    PubMed Central

    Zejjari, Hassane; Louaste, Jamal; Cherrad, Taoufik; Bousbae, Hicham; Kasmaoui, Housseine; Amhajji, Larbi; Rachid, Khalid

    2015-01-01

    La chirurgie de reconstruction acétabulaire est une technique qui consiste à combler les pertes de substance osseuse siégeant au niveau du cotyle. Il s'agit d'une étude rétrospective de 15 patients (16 cotyles), sur une période de 6 ans (2006- 2012). Dans douze cas il s'agissait de prothèse totales de la hanche de première intention et dans quatre cas il s'agissait de reprise cotyloïdienne de PTH. L’évaluation clinique préopératoire et postopératoire de tous nos patients a été effectuée par le score de Postel et Merle d'Aubigné. L’évaluation des pertes de substances osseuse du cotyle a été classée selon la classification de Paprosky. L’âge moyen de nos patients au moment de l'intervention a été de 57 ans avec des extrêmes allant de 20 ans à 76 ans. La greffe osseuse a été utilisée chez 12 de nos patients. La reconstruction prothétique a été utilisée chez 8 patients (anneau de Kerboul dans six cas et anneau de Burch-Schneider dans deux cas). Recul post opératoire moyen a été de 56 mois. L’évaluation radiologique a été basée sur les clichés radiologiques du bassin de face strict ainsi que des radiographies de la hanche opérée de face prenant la totalité de la prothèse. Nos résultats cliniques et radiologiques ont été jugé bon à très bon dans la majorité des cas. Pour nous, nous optant pour le recentrage-reconstruction car c'est lui qui s'approche le plus de l'anatomie et de la biomécanique normale de la hanche. PMID:26955415

  15. Interactivity: A Forgotten Art?

    ERIC Educational Resources Information Center

    Sims, Rod

    1997-01-01

    This paper promotes further discussion and analysis of interactivity in learning environments and contains a classification of interaction types appropriate for consideration in multimedia settings. Through an examination of related factors associated with navigation and control, a matrix of interactive dimensions is proposed. (Author)

  16. Global Interaction in Design

    ERIC Educational Resources Information Center

    Bennett, Audrey Grace

    2010-01-01

    Based on a virtual conference, Glide'08 (Global Interaction in Design Education), that brought international design scholars together online, this special issue expands on the topics of cross-cultural communication and design and the technological affordances that support such interaction. The author discusses the need for global interaction in…

  17. DanQ: a hybrid convolutional and recurrent deep neural network for quantifying the function of DNA sequences

    PubMed Central

    Quang, Daniel; Xie, Xiaohui

    2016-01-01

    Modeling the properties and functions of DNA sequences is an important, but challenging task in the broad field of genomics. This task is particularly difficult for non-coding DNA, the vast majority of which is still poorly understood in terms of function. A powerful predictive model for the function of non-coding DNA can have enormous benefit for both basic science and translational research because over 98% of the human genome is non-coding and 93% of disease-associated variants lie in these regions. To address this need, we propose DanQ, a novel hybrid convolutional and bi-directional long short-term memory recurrent neural network framework for predicting non-coding function de novo from sequence. In the DanQ model, the convolution layer captures regulatory motifs, while the recurrent layer captures long-term dependencies between the motifs in order to learn a regulatory ‘grammar’ to improve predictions. DanQ improves considerably upon other models across several metrics. For some regulatory markers, DanQ can achieve over a 50% relative improvement in the area under the precision-recall curve metric compared to related models. We have made the source code available at the github repository http://github.com/uci-cbcl/DanQ. PMID:27084946

  18. Design of interpenetrated network MWCNT/poly(1,5-DAN) on interdigital electrode: toward NO2 gas sensing.

    PubMed

    Nguyen, Dzung Tuan; Nguyen, My Thanh; Ho, Giang Truong; Nguyen, Toan Ngoc; Reisberg, S; Piro, B; Pham, M C

    2013-10-15

    In this paper, poly(1,5-diaminonaphthalene) was interpenetrated into the network made of multiwalled carbon nanotubes (MWCNT) on platinum interdigital electrode (IDE) by electro-polymerization of 1,5-diaminonaphthalene (1,5-DAN). The electro-polymerization process of 1,5-DAN on MWCNT was controlled by scanning the cyclic voltage at 50 mV s(-1) scan rate between -0.1 V and +0.95 V vs. saturated calomel electrode (SCE). The results of voltammetric responses and Raman spectroscopy represented that the films MWCNT/poly(1,5-DAN) were successfully created by this polymerization process. The films MWCNT/poly(1,5-DAN) were investigated for gas-sensing to NO2 at low concentration level. The gas-sensing results showed that the response-recovery times were long and strongly affected by thickness of the film MWCNT/poly(1,5-DAN). Nevertheless, these films represented auspicious results for gas sensors operating at room temperature. PMID:24054652

  19. DanQ: a hybrid convolutional and recurrent deep neural network for quantifying the function of DNA sequences.

    PubMed

    Quang, Daniel; Xie, Xiaohui

    2016-06-20

    Modeling the properties and functions of DNA sequences is an important, but challenging task in the broad field of genomics. This task is particularly difficult for non-coding DNA, the vast majority of which is still poorly understood in terms of function. A powerful predictive model for the function of non-coding DNA can have enormous benefit for both basic science and translational research because over 98% of the human genome is non-coding and 93% of disease-associated variants lie in these regions. To address this need, we propose DanQ, a novel hybrid convolutional and bi-directional long short-term memory recurrent neural network framework for predicting non-coding function de novo from sequence. In the DanQ model, the convolution layer captures regulatory motifs, while the recurrent layer captures long-term dependencies between the motifs in order to learn a regulatory 'grammar' to improve predictions. DanQ improves considerably upon other models across several metrics. For some regulatory markers, DanQ can achieve over a 50% relative improvement in the area under the precision-recall curve metric compared to related models. We have made the source code available at the github repository http://github.com/uci-cbcl/DanQ. PMID:27084946

  20. Evolving synergetic interactions

    PubMed Central

    Wu, Bin; Arranz, Jordi; Du, Jinming; Zhou, Da; Traulsen, Arne

    2016-01-01

    Cooperators forgo their own interests to benefit others. This reduces their fitness and thus cooperators are not likely to spread based on natural selection. Nonetheless, cooperation is widespread on every level of biological organization ranging from bacterial communities to human society. Mathematical models can help to explain under which circumstances cooperation evolves. Evolutionary game theory is a powerful mathematical tool to depict the interactions between cooperators and defectors. Classical models typically involve either pairwise interactions between individuals or a linear superposition of these interactions. For interactions within groups, however, synergetic effects may arise: their outcome is not just the sum of its parts. This is because the payoffs via a single group interaction can be different from the sum of any collection of two-player interactions. Assuming that all interactions start from pairs, how can such synergetic multiplayer games emerge from simpler pairwise interactions? Here, we present a mathematical model that captures the transition from pairwise interactions to synergetic multiplayer ones. We assume that different social groups have different breaking rates. We show that non-uniform breaking rates do foster the emergence of synergy, even though individuals always interact in pairs. Our work sheds new light on the mechanisms underlying such synergetic interactions. PMID:27466437

  1. Evolving synergetic interactions.

    PubMed

    Wu, Bin; Arranz, Jordi; Du, Jinming; Zhou, Da; Traulsen, Arne

    2016-07-01

    Cooperators forgo their own interests to benefit others. This reduces their fitness and thus cooperators are not likely to spread based on natural selection. Nonetheless, cooperation is widespread on every level of biological organization ranging from bacterial communities to human society. Mathematical models can help to explain under which circumstances cooperation evolves. Evolutionary game theory is a powerful mathematical tool to depict the interactions between cooperators and defectors. Classical models typically involve either pairwise interactions between individuals or a linear superposition of these interactions. For interactions within groups, however, synergetic effects may arise: their outcome is not just the sum of its parts. This is because the payoffs via a single group interaction can be different from the sum of any collection of two-player interactions. Assuming that all interactions start from pairs, how can such synergetic multiplayer games emerge from simpler pairwise interactions? Here, we present a mathematical model that captures the transition from pairwise interactions to synergetic multiplayer ones. We assume that different social groups have different breaking rates. We show that non-uniform breaking rates do foster the emergence of synergy, even though individuals always interact in pairs. Our work sheds new light on the mechanisms underlying such synergetic interactions. PMID:27466437

  2. Convergence in Multispecies Interactions.

    PubMed

    Bittleston, Leonora S; Pierce, Naomi E; Ellison, Aaron M; Pringle, Anne

    2016-04-01

    The concepts of convergent evolution and community convergence highlight how selective pressures can shape unrelated organisms or communities in similar ways. We propose a related concept, convergent interactions, to describe the independent evolution of multispecies interactions with similar physiological or ecological functions. A focus on convergent interactions clarifies how natural selection repeatedly favors particular kinds of associations among species. Characterizing convergent interactions in a comparative context is likely to facilitate prediction of the ecological roles of organisms (including microbes) in multispecies interactions and selective pressures acting in poorly understood or newly discovered multispecies systems. We illustrate the concept of convergent interactions with examples: vertebrates and their gut bacteria; ectomycorrhizae; insect-fungal-bacterial interactions; pitcher-plant food webs; and ants and ant-plants. PMID:26858111

  3. Processus mis en jeu dans l'evolution morpho-dynamique de Roberts Bank (Delta du Fraser): Observation et modelisation hydrodynamiques et sedimentaires

    NASA Astrophysics Data System (ADS)

    Meule, Samuel

    Roberts Bank couvre le delta intertidal entre le bras principal du fleuve Fraser et la pointe du Cap Roberts en Colombie Britannique, Canada. Sous la pression du developpement urbain et la modification du regime sedimentaire, cette plage de sable fin est soumise a une erosion significative. L'identification des forces hydrodynamiques, leur importance et leur interaction permettent de determiner les zones de transport, et donc la stabilite de Roberts Bank. Deux periodes de mesures associees a des phases de modelisation de la houle et des courants ont ete effectuees lors de ce travail. La premiere periode de mesure, entre le 29 juin et le 8 juillet 2001, a permis l'identification de processus hydrodynamiques et sedimentaires associes aux forts courants de maree presents le long de Roberts Bank. La seconde phase de mesure, entre le 1er mars et le 26 mars 2002, a permis d'etudier les processus de remise en suspension associes a la houle. Des phases de modelisation ont ete menees a partir des connaissances acquises sur le terrain, afin d'affiner la comprehension des processus sedimentaires et notamment les interactions houle - courant - sediment. Les mecanismes, mis en evidence dans cette etude, participent au faconnage de Roberts Bank, contribuent a son erosion et a la mise en place de nouvelles structures sedimentaires. Les courants de flot de maree vont initier la creation de nuages de resuspension de sediment depuis le fond. En eau peu profonde, la composante " onshore" du courant de maree induit un transport a la cote, tandis qu'en eau plus profonde une faible composante " offshore" du courant peut favoriser un transport au large le long de la pente. Les chenaux, les dunes subaquatiques et les surfaces d'erosion affleurantes fournissent une rugosite de fond suffisante a la generation de turbulence et donc de nuages de sediment en suspension. Lors de la maree de jusant, les sediments resuspendus en eau peu profonde, sont transportes vers le large a partir d

  4. Grossesse dans une corne rudimentaire: difficultés diagnostiques et prise en charge thérapeutique

    PubMed Central

    Mamouni, Nisrine; Ghazal, Nabil; Erraghay, Sanaa; Bouchikhi, Chahrazed; Banani, Abdelaziz

    2016-01-01

    La survenue d'une grossesse dans une corne utérine rudimentaire est une situation obstétricale extrêmement rare et potentiellement grave, menaçant le pronostic materno-fœtal. Les auteurs rapportent cinq observations de grossesse dans une corne utérine rudimentaire, à travers lesquelles, ils relatent les difficultés sur le plan diagnostique ainsi que la prise en charge thérapeutique de cette entité pathologique, soulignant l'intérêt de l’échographie endovaginale, de l'IRM pelvienne et de la cœlioscopie dans le diagnostic précoce de ce type de malformation uterine.

  5. The Interactive Learning Toolkit: supporting interactive classrooms

    NASA Astrophysics Data System (ADS)

    Dutta, S.; McCauley, V.; Mazur, E.

    2004-05-01

    Research-based interactive learning techniques have dramatically improved student understanding. We have created the 'Interactive Learning Toolkit' (ILT), a web-based learning management system, to help implement two such pedagogies: Just in Time Teaching and Peer Instruction. Our main goal in developing this toolkit is to save the instructor time and effort and to use technology to facilitate the interaction between the students and the instructor (and between students themselves). After a brief review of both pedagogies, we will demonstrate the many exciting new features of the ILT. We will show how technology can not only implement, but also supplement and improve these pedagogies. We would like acknowdge grants from NSF and DEAS, Harvard University

  6. Structure of Gremlin-1 and analysis of its interaction with BMP-2.

    PubMed

    Kišonaitė, Miglė; Wang, Xuelu; Hyvönen, Marko

    2016-06-01

    Bone morphogenetic protein 2 (BMP-2) is a member of the transforming growth factor-β (TGF-β) signalling family and has a very broad biological role in development. Its signalling is regulated by many effectors: transmembrane proteins, membrane-attached proteins and soluble secreted antagonists such as Gremlin-1. Very little is known about the molecular mechanism by which Gremlin-1 and other DAN (differential screening-selected gene aberrative in neuroblastoma) family proteins inhibit BMP signalling. We analysed the interaction of Gremlin-1 with BMP-2 using a range of biophysical techniques, and used mutagenesis to map the binding site on BMP-2. We have also determined the crystal structure of Gremlin-1, revealing a similar conserved dimeric structure to that seen in other DAN family inhibitors. Measurements using biolayer interferometry (BLI) indicate that Gremlin-1 and BMP-2 can form larger complexes, beyond the expected 1:1 stoichiometry of dimers, forming oligomers that assemble in alternating fashion. These results suggest that inhibition of BMP-2 by Gremlin-1 occurs by a mechanism that is distinct from other known inhibitors such as Noggin and Chordin and we propose a novel model of BMP-2-Gremlin-1 interaction yet not seen among any BMP antagonists, and cannot rule out that several different oligomeric states could be found, depending on the concentration of the two proteins. PMID:27036124

  7. Structure of Gremlin-1 and analysis of its interaction with BMP-2

    PubMed Central

    Kišonaitė, Miglė; Wang, Xuelu; Hyvönen, Marko

    2016-01-01

    Bone morphogenetic protein 2 (BMP-2) is a member of the transforming growth factor-β (TGF-β) signalling family and has a very broad biological role in development. Its signalling is regulated by many effectors: transmembrane proteins, membrane-attached proteins and soluble secreted antagonists such as Gremlin-1. Very little is known about the molecular mechanism by which Gremlin-1 and other DAN (differential screening-selected gene aberrative in neuroblastoma) family proteins inhibit BMP signalling. We analysed the interaction of Gremlin-1 with BMP-2 using a range of biophysical techniques, and used mutagenesis to map the binding site on BMP-2. We have also determined the crystal structure of Gremlin-1, revealing a similar conserved dimeric structure to that seen in other DAN family inhibitors. Measurements using biolayer interferometry (BLI) indicate that Gremlin-1 and BMP-2 can form larger complexes, beyond the expected 1:1 stoichiometry of dimers, forming oligomers that assemble in alternating fashion. These results suggest that inhibition of BMP-2 by Gremlin-1 occurs by a mechanism that is distinct from other known inhibitors such as Noggin and Chordin and we propose a novel model of BMP-2–Gremlin-1 interaction yet not seen among any BMP antagonists, and cannot rule out that several different oligomeric states could be found, depending on the concentration of the two proteins. PMID:27036124

  8. Antisymmetric Exchange in Antiferromagnetic Materials of Some Rhombohedral Structures

    NASA Astrophysics Data System (ADS)

    Bazhan, Alexander

    2010-03-01

    Transferrings of electrons, holes carriers between magnetic-magnetic and magnetic-oxygen-magnetic ions are in discussions for indication of antisymmetric, Dzyloshinskii -Moria, DzSixSjy-SiySjx, exchange interactions of magnetic ions in rhombohedral structures, taking into account carriers Hubbard Hamiltonians, including spin-orbit interactions. Discussing transferrings are determined by two sets of energy levels in energy levels structures of magnetic ions, determined by, surrounding trigonal oxygen crystal fields and their particularities. Taking into account holes energy levels structures and holes spin-orbit, transferrings as perturbations, exchange symmetric and antisymmetric parts are, Hex =∑i,jJi,j.(Si.Sj)+∑i,jDi,j.[SixSj], [1], where vectors Di,j can be presented as, Di,j =-4i. σn (Ci,kn.tkn,jo . Jn.tjo,kn.tkn,io+ tio,kn. Ckn,j. Jn.tjo,kn.tkn,io- tio,kn.tkn,jo. Jn.Cj,kn. tkn,io- tio,kn. tkn,jo. Jn. tjo,kn.Ckn,i ), where Cj,kn = (-λ/2). σm<ψjm/Lj/ψjo>^*/(ɛm) .tjm,kn, with orbital matrix elements between discussing energy levels, n=x,y,z Jn = 1/ɛ'kn^2. 1/U + 1/2ɛ'kn. Depending on particularities of oxygen crystal fields, transferring integrals, ti,j,m,kn and ti,j,o,kn with i and j -wave functions of the same symmetries, determine Dz - vectors, oriented, according to rhombohedral symmetry, along trigonal, C3 -z axis. [1]. W.Koshibae, Y.Ohta, S.Maekawa, Phys.Rev. B 47 (1993) 3391.

  9. Antiplatelet drug interactions.

    PubMed

    Mackenzie, I S; Coughtrie, M W H; MacDonald, T M; Wei, L

    2010-12-01

    Both laboratory studies in healthy volunteers and clinical studies have suggested adverse interactions between antiplatelet drugs and other commonly used medications. Interactions described include those between aspirin and ibuprofen, aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), and the thienopyridine, clopidogrel, and drugs inhibiting CYP2C19, notably the proton pump inhibitors (PPI) omeprazole and esomeprazole. Other interactions between thienopyridines and CYP3A4/5 have also been reported for statins and calcium channel blockers. The ibuprofen/aspirin interaction is thought to be caused by ibuprofen blocking the access of aspirin to platelet cyclo-oxygenase. The thienopyridine interactions are caused by inhibition of microsomal enzymes that metabolize these pro-drugs to their active metabolites. We review the evidence for these interactions, assess their clinical importance and suggest strategies of how to deal with them in clinical practice. We conclude that ibuprofen is likely to interact with aspirin and reduce its anti-platelet action particularly in those patients who take ibuprofen chronically. This interaction is of greater relevance to those patients at high cardiovascular risk. A sensible strategy is to advise users of aspirin to avoid chronic ibuprofen or to ingest aspirin at least 2 h prior to ibuprofen. Clearly the use of NSAIDs that do not interact in this way is preferred. For the clopidogrel CYP2C19 and CYP3A4/5 interactions, there is good evidence that these interactions occur. However, there is less good evidence to support the clinical importance of these interactions. Again, a reasonable strategy is to avoid the chronic use of drugs that inhibit CYP2C19, notably PPIs, in subjects taking clopidogrel and use high dose H2 antagonists instead. Finally, anti-platelet agents probably interact with other drugs that affect platelet function such as selective serotonin reuptake inhibitors, and clinicians should probably judge

  10. The interactive brain hypothesis

    PubMed Central

    Di Paolo, Ezequiel; De Jaegher, Hanne

    2012-01-01

    Enactive approaches foreground the role of interpersonal interaction in explanations of social understanding. This motivates, in combination with a recent interest in neuroscientific studies involving actual interactions, the question of how interactive processes relate to neural mechanisms involved in social understanding. We introduce the Interactive Brain Hypothesis (IBH) in order to help map the spectrum of possible relations between social interaction and neural processes. The hypothesis states that interactive experience and skills play enabling roles in both the development and current function of social brain mechanisms, even in cases where social understanding happens in the absence of immediate interaction. We examine the plausibility of this hypothesis against developmental and neurobiological evidence and contrast it with the widespread assumption that mindreading is crucial to all social cognition. We describe the elements of social interaction that bear most directly on this hypothesis and discuss the empirical possibilities open to social neuroscience. We propose that the link between coordination dynamics and social understanding can be best grasped by studying transitions between states of coordination. These transitions form part of the self-organization of interaction processes that characterize the dynamics of social engagement. The patterns and synergies of this self-organization help explain how individuals understand each other. Various possibilities for role-taking emerge during interaction, determining a spectrum of participation. This view contrasts sharply with the observational stance that has guided research in social neuroscience until recently. We also introduce the concept of readiness to interact to describe the practices and dispositions that are summoned in situations of social significance (even if not interactive). This latter idea links interactive factors to more classical observational scenarios. PMID:22701412

  11. Flight Investigation of the Performance of a Two-stage Solid-propellant Nike-deacon (DAN) Meteorological Sounding Rocket

    NASA Technical Reports Server (NTRS)

    Heitkotter, Robert H

    1956-01-01

    A flight investigation of two Nike-Deacon (DAN) two-stage solid-propellant rocket vehicles indicated satisfactory performance may be expected from the DAN meteorological sounding rocket. Peak altitudes of 356,000 and 350,000 feet, respectively, were recorded for the two flight tests when both vehicles were launched from sea level at an elevation angle of 75 degrees. Performance calculations based on flight-test results show that altitudes between 358,000 feet and 487,000 feet may be attained with payloads varying between 60 pounds and 10 pounds.

  12. Interpretation des donnees de flux de chaleur et de gravite dans le bouclier Canadien

    NASA Astrophysics Data System (ADS)

    Cheng, Li Zhen

    2000-10-01

    Le champ geothermique du Bouclier Canadien est caracterise par un flux moyen de 41 mW·m-2, qui suggere une production de chaleur moyenne dans la croute comprise entre 0.7 et 0.8 muW·m-3. Le flux de chaleur relativement faible favorise la stabilite du bouclier et lui a permis de resister a la deformation tectonique. Les variations du flux de chaleur a la surface sont dominees par la composition de la croute. Un flux eleve implique generalement une composition felsique et il est d'autant plus faible que la croute devient plus mafique. La production de chaleur en surface n'est pas representative de la production moyenne de la croute. Le flux de chaleur dans le Boucher Canadien ne depend donc pas de la production de chaleur en surface, mais depend de la composition principale de la croute. L'interpretation combinee des donnees geophysiques nous permet de determiner les variations de composition d'echelle crustale a partir desquelles il est possible d'etablir la structure de la croute. L'etude detaillee de l'Orogene de Trans-Hudson et de la Sous-province d'Abitibi a montre que le flux de chaleur, la gravite et la sismique lorsqu'elles sont combinees fournissent des contraintes efficaces pour determiner l'architecture crustale. En general, la croute est trop resistante pour se deformer par fluage, excepte tres localement. Le mode de deformation de la lithosphere continentale depend de la composition et du gradient geothermique. Nous montrons que la lithosphere du Bouclier Canadien demeure principalement fragile jusqu'a une profondeur de plus de 150 km. Une deformation ductile pourrait cependant etre possible localement a la base de la, croute, comme dans la ceinture de Thompson par exemple. Si l'on admet que la lithosphere peut resister a des contraintes allant jusqu'a 20 MPa (taux de deformation 3˙ < 10-15 s-1), l'epaisseur de la lithosphere est de l'ordre de 300 km pour la ceinture de Thompson et est superieure a 300 km pour la sous-province d'Abitibi. La resistance

  13. Altération des sulfures des granulats dans les chaussées

    NASA Astrophysics Data System (ADS)

    Jigorel, A.; Jauberthie, R.

    2002-07-01

    Sulfides present in hornsfeld aggregates, used in light pavanent construction in contact with humid air alter rapidly. Crystallisation of sulfates at the interface of bitumastic material and sub-base creates serious problems (intumescence and crazing) that can lead to a total reconstruction of the project (roads, sidewalks, sports areas, etc). The sulfides in the aggregates and the sulfates produced due to alteration are studied by SEM and XRD. The results show that the intensity of this phenomenon is linked to the nature and the crystallinity of the sulfides. The evolution of the sulfates formed during this alteration process is slow and complex. In new pavements (3 years) the sulfates have a pulverised appearance and consist mostly of epsomite, associated with pickeringite and halotrichite. In older pavements (20 years) the sulfates form a fibrous concretion consisting of pickeringite and small quantities of halotrichite. Les sulfures présents dans les granulats élaborés à partir de cornéen nes s'altèrent rapidement dans les chaussées légères en présence d'air humide. La cristallisation des sulfates à l'interface enrobé-couche de fondation crée des désordres si importants (intumescences, faiençage) qu'il est bien souvent nécessaire d'assurer la réfection totale des ouvrages (routes, trottoirs, plateaux sportifs...). Les sulfures des granulats et les sulfates issus du processus d'altération ont été étudiés par diffractométrie X et examen su Microscope Electronique à Balayage équipé de microanalyse X. Les résultats montrent que !intensité des désordres est liée à la nature et à la cristallinité des sulfures. Les sulfates formés évoluent su cours du processus d'altération qui est long et complexe. Dans les chaussées récentes (3 ans) ils ont un aspect pulvérulent et sont constitués d'epsomite dominante associée à de la pickeringite et à de l'halotrichite. Dans les chaussées plus anciennes (20 ans) ils forment des concr

  14. Food-Drug Interactions

    PubMed Central

    Bushra, Rabia; Aslam, Nousheen; Khan, Arshad Yar

    2011-01-01

    The effect of drug on a person may be different than expected because that drug interacts with another drug the person is taking (drug-drug interaction), food, beverages, dietary supplements the person is consuming (drug-nutrient/food interaction) or another disease the person has (drug-disease interaction). A drug interaction is a situation in which a substance affects the activity of a drug, i.e. the effects are increased or decreased, or they produce a new effect that neither produces on its own. These interactions may occur out of accidental misuse or due to lack of knowledge about the active ingredients involved in the relevant substances. Regarding food-drug interactions physicians and pharmacists recognize that some foods and drugs, when taken simultaneously, can alter the body's ability to utilize a particular food or drug, or cause serious side effects. Clinically significant drug interactions, which pose potential harm to the patient, may result from changes in pharmaceutical, pharmacokinetic, or pharmacodynamic properties. Some may be taken advantage of, to the benefit of patients, but more commonly drug interactions result in adverse drug events. Therefore it is advisable for patients to follow the physician and doctors instructions to obtain maximum benefits with least food-drug interactions. The literature survey was conducted by extracting data from different review and original articles on general or specific drug interactions with food. This review gives information about various interactions between different foods and drugs and will help physicians and pharmacists prescribe drugs cautiously with only suitable food supplement to get maximum benefit for the patient. PMID:22043389

  15. Beam-Bem interactions

    SciTech Connect

    Kim, Hyung Jin; /Fermilab

    2011-12-01

    In high energy storage-ring colliders, the nonlinear effect arising from beam-beam interactions is a major source that leads to the emittance growth, the reduction of beam life time, and limits the collider luminosity. In this paper, two models of beam-beam interactions are introduced, which are weak-strong and strong-strong beam-beam interactions. In addition, space-charge model is introduced.

  16. Interactive brains, social minds

    PubMed Central

    Lindenberger, Ulman

    2011-01-01

    To reveal the neural and behavioral dynamics of social interaction, single-person studies are increasingly complemented by research designs that simultaneously assess two or more interacting individuals. In this article, we review studies on neural mechanisms and markers of social interactions that use multi-person functional magnetic resonance imaging and electrophysiological recordings. We propose a terminology for investigating social interaction dynamics, show how forward models of action regulation may serve as a framework for investigating interpersonal action coordination and discuss different methodological approaches to studying functional brain connectivity. PMID:22448303

  17. Nerve-pulse interactions

    SciTech Connect

    Scott, A.C.

    1982-01-01

    Some recent experimental and theoretical results on mechanisms through which individual nerve pulses can interact are reviewed. Three modes of interactions are considered: (1) interaction of pulses as they travel along a single fiber which leads to velocity dispersion; (2) propagation of pairs of pulses through a branching region leading to quantum pulse code transformations; and (3) interaction of pulses on parallel fibers through which they may form a pulse assembly. This notion is analogous to Hebb's concept of a cell assembly, but on a lower level of the neural hierarchy.

  18. Interactive brains, social minds.

    PubMed

    Sänger, Johanna; Lindenberger, Ulman; Müller, Viktor

    2011-11-01

    To reveal the neural and behavioral dynamics of social interaction, single-person studies are increasingly complemented by research designs that simultaneously assess two or more interacting individuals. In this article, we review studies on neural mechanisms and markers of social interactions that use multi-person functional magnetic resonance imaging and electrophysiological recordings. We propose a terminology for investigating social interaction dynamics, show how forward models of action regulation may serve as a framework for investigating interpersonal action coordination and discuss different methodological approaches to studying functional brain connectivity. PMID:22448303

  19. Two interacting Hofstadter butterflies

    SciTech Connect

    Barelli, A.; Bellissard, J.; Jacquod, P.; Shepelyansky, D.L.

    1997-04-01

    The problem of two interacting particles in a quasiperiodic potential is addressed. Using analytical and numerical methods, we explore the spectral properties and eigenstates structure from the weak to the strong interaction case. More precisely, a semiclassical approach based on noncommutative geometry techniques is used to understand the intricate structure of such a spectrum. An interaction induced localization effect is furthermore emphasized. We discuss the application of our results on a two-dimensional model of two particles in a uniform magnetic field with on-site interaction. {copyright} {ital 1997} {ital The American Physical Society}

  20. The Science of Interaction

    SciTech Connect

    Pike, William A.; Stasko, John T.; Chang, Remco; O'Connell, Theresa

    2009-09-23

    There is a growing recognition with the visual analytics community that interaction and inquiry are inextricable. It is through the interactive manipulation of a visual interface – the analytic discourse – that knowledge is constructed, tested, refined, and shared. This paper reflects on the interaction challenges raised in the original visual analytics research and development agenda and further explores the relationship between interaction and cognition. It identifies recent exemplars of visual analytics research that have made substantive progress toward the goals of a true science of interaction, which must include theories and testable premises about the most appropriate mechanisms for human-information interaction. Six areas for further work are highlighted as those among the highest priorities for the next five years of visual analytics research: ubiquitous, embodied interaction; capturing user intentionality; knowledge-based interfaces; principles of design and perception; collaboration; and interoperability. Ultimately, the goal of a science of interaction is to support the visual analytics community through the recognition and implementation of best practices in the representation of and interaction with visual displays.

  1. Reconceptualizing sex, brain and psychopathology: interaction, interaction, interaction

    PubMed Central

    Joel, D; Yankelevitch-Yahav, R

    2014-01-01

    In recent years there has been a growing recognition of the influence of sex on brain structure and function, and in relation, on the susceptibility, prevalence and response to treatment of psychiatric disorders. Most theories and descriptions of the effects of sex on the brain are dominated by an analogy to the current interpretation of the effects of sex on the reproductive system, according to which sex is a divergence system that exerts a unitary, overriding and serial effect on the form of other systems. We shortly summarize different lines of evidence that contradict aspects of this analogy. The new view that emerges from these data is of sex as a complex system whose different components interact with one another and with other systems to affect body and brain. The paradigm shift that this understanding calls for is from thinking of sex in terms of sexual dimorphism and sex differences, to thinking of sex in terms of its interactions with other factors and processes. Our review of data obtained from animal models of psychopathology clearly reveals the need for such a paradigmatic shift, because in the field of animal behaviour whether a sex difference exists and its direction depend on the interaction of many factors including, species, strain, age, specific test employed and a multitude of environmental factors. We conclude by explaining how the new conceptualization can account for sex differences in psychopathology. Linked Articles This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20 PMID:24758640

  2. Analyte interactions with a new ditopic dansylamide-nitrobenzoxadiazole dyad: a combined photophysical, NMR, and theoretical (DFT) study.

    PubMed

    Bhoi, Abhas Kumar; Das, Sudhir Kumar; Majhi, Debashis; Sahu, Prabhat Kumar; Nijamudheen, A; N, Anoop; Rahaman, Abdur; Sarkar, Moloy

    2014-08-21

    We report herein the synthesis and photophysical studies on a new multicomponent chemosensor dyad comprising two fluorescing units, dansylamide (DANS) and nitrobenzoxadiazole (NBD). The system has been developed to investigate receptor-analyte binding interactions in the presence of both cations and anions in a single molecular system. A dimethyl amino (in the DANS unit) group is used as a receptor for cations, and acidic hydrogens of sulfonamide and the NBD group are used as receptors for anions. The system is characterized by conventional analytical techniques. The photophysical properties of this supramolecular system in the absence and presence of various metal ions and nonmetal ions as additives are investigated in an acetonitrile medium. Utility of this system in an aqueous medium has also been demonstrated. The absorption and fluorescence spectrum of the molecular system consists of a broad band typical of an intramolecular charge-transfer (ICT) transition. A low quantum yield and lifetime of the NBD moiety in the present dyad indicates photoinduced electron transfer (PET) between DANS and the NBD moiety. The fluorescence intensity of the system is found to decrease in the presence of fluoride and acetate anions; however, the quenching is found to be much higher for fluoride. This quenching behavior is attributed to the enhanced PET from the anion receptor to the fluorophore moiety. The mechanistic aspect of the fluoride ion signaling behavior has also been studied by infrared (IR) and (1)H NMR experiments. The hydrogen bonding interaction between the acidic NH protons of the DPN moiety and F(-) is found to be primarily responsible for the fluoride selective signaling behavior. While investigating the cation signaling behavior, contrary to anions, significant fluorescence enhancement has been observed only in the presence of transition-metal ions. This behavior is rationalized by considering the disruption of PET communication between DANS and the NBD moiety

  3. Interactive Visualization of Dependencies

    ERIC Educational Resources Information Center

    Moreno, Camilo Arango; Bischof, Walter F.; Hoover, H. James

    2012-01-01

    We present an interactive tool for browsing course requisites as a case study of dependency visualization. This tool uses multiple interactive visualizations to allow the user to explore the dependencies between courses. A usability study revealed that the proposed browser provides significant advantages over traditional methods, in terms of…

  4. University-industry interaction

    NASA Technical Reports Server (NTRS)

    Hastings, Daniel E.

    1990-01-01

    It is posited that university industry interaction is highly desirable from the viewpoint of the long term economic development of the country as well as being desirable for the Space Grant Programs. The present and future possible interactions are reviewed for the three university levels namely, undergraduate, graduate, and faculty research.

  5. Interactive Videodisc Learning Systems.

    ERIC Educational Resources Information Center

    Currier, Richard L.

    1983-01-01

    Interactive videodisc makes possible a powerful educational experience in which computer-based educational systems can display video imagery, real-time action, and stereo sound. Interactivity, teaching with videodisc, electronic tutors, videodisc technologies, and costs are among the topics discussed. Use of videodisc for games and simulating…

  6. Oral contraceptive drug interactions.

    PubMed

    Baciewicz, A M

    1985-01-01

    Approximately 50 million women use oral contraceptives (OC). Studies and case reports demonstrate that OC failure may be caused by rifampin, anticonvulsant drugs, and possibly some antibiotics. Contraceptive steroids may interfere with the metabolism of the benzodiazepines, theophylline, and the glucocorticoids. Future investigation will document the clinical significance of other OC interactions as well as give rise to new interactions. PMID:2859674

  7. What Is Interactivity?

    ERIC Educational Resources Information Center

    Smuts, Aaron

    2009-01-01

    In this article, the author attempts to develop a definition of "interactivity" that meets two sometimes incompatible goals: the definition should be in accord with the best intuitions on how the term should be used, and it should usefully differentiate interactivity from related but incompatible concepts with which it is often confused. The…

  8. Visualizing Dispersion Interactions

    ERIC Educational Resources Information Center

    Gottschalk, Elinor; Venkataraman, Bhawani

    2014-01-01

    An animation and accompanying activity has been developed to help students visualize how dispersion interactions arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion interactions play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…

  9. The Interaction Equivalency Theorem

    ERIC Educational Resources Information Center

    Miyazoe, Terumi; Anderson, Terry

    2010-01-01

    This paper examines the key issues regarding The Interaction Equivalency Theorem posited by Anderson (2003a), which consists of the three interaction elements found in formal education courses among teacher, student, and content. It first examines the core concepts of the theorem and argues that two theses of different dimensions can be…

  10. Interactive TV: The Sequel.

    ERIC Educational Resources Information Center

    Brown, Eric

    1998-01-01

    Examines the future of interactive TV where consumers navigate the Internet on their TVs with WebTV set-top boxes. Focuses on competition between cable companies and computer and consumer electronics companies. Highlights nine companies and partnerships developing interactive hardware and services. (PEN)

  11. Newseum: Open for Interaction.

    ERIC Educational Resources Information Center

    Luck, Brad

    1998-01-01

    Describes a teenage journalist's visit to the Newseum in Washington, DC, the world's only interactive museum dedicated to news. Describes visiting the Interactive Newsroom, the huge News Globe, the News History Gallery, and the Broadcast Studio. Describes also a brief visit to Freedom Park and the Newseum Education Center. Notes the enthusiasm of…

  12. Interactive Presentation of Content

    ERIC Educational Resources Information Center

    Magdin, Martin; Turcáni, Milan; Vrábel, Marek

    2009-01-01

    In the paper we discus about design of universal environment for solution of creating effective multimedia applications with accent on the implementation of interactive elements with the possibility of using the adaptive systems (AS). We also discuss about possibilities of offline presentation of this interactive multimedia adaptive animations…

  13. LIA: LWS Interactive Analysis

    NASA Astrophysics Data System (ADS)

    Infrared Space Observatory (ISO) Development Team

    2014-08-01

    The Long Wavelength Spectrometer (LWS) was one of two complementary spectrometers on the Infrared Space Observatory (ISO). LIA (LWS Interactive Analysis) is used for processing data from the LWS. It provides access to the different processing steps, including visualization of intermediate products and interactive manipulation of the data at each stage.

  14. Media Embedded Interactions.

    ERIC Educational Resources Information Center

    Johnson, J. David

    A review of literature and two surveys, one of college students and one of a random sample of adults, were used to examine four aspects of media embedded interactions (social behavior in front of a TV or radio): their functions, their environment, their effects, and the reactions of the interactants to them. Television is seen as performing a…

  15. Let Social Interaction Flourish

    ERIC Educational Resources Information Center

    Case, Anny Fritzen

    2016-01-01

    The author describes lessons learned--through a high school project that grouped English language learners with native speakers to create a video--about ways to foster respectful, productive interaction among English learners and peers who are native speakers. The potential benefits of students who are just learning English interacting socially…

  16. Spacelab user interaction

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The results of the third and final phase of a study undertaken to define means of optimizing the Spacelab experiment data system by interactively manipulating the flow of data were presented. A number of payload applicable interactive techniques and an integrated interaction system for each of two possible payloads are described. These interaction systems have been functionally defined and are accompanied with block diagrams, hardware specifications, software sizing and speed requirements, operational procedures and cost/benefits analysis data for both onboard and ground based system elements. It is shown that accrued benefits are attributable to a reduction in data processing costs obtained by, generally, a considerable reduction in the quantity of data that might otherwise be generated without interaction. One other additional anticipated benefit includes the increased scientific value obtained by the quicker return of all useful data.

  17. Legacy Systems Interaction Reengineering

    NASA Astrophysics Data System (ADS)

    El-Ramly, Mohammad; Stroulia, Eleni; Samir, Hani

    We present a lightweight approach for reengineering the human computer interaction (HCI) and/or interaction with other software systems. While interaction reengineering can be achieved by changing the source code and design (e.g., library replacement, refactoring, etc.) resulting in a different user interface (UI), we limit the discussion to interaction reengineering methods that do not involve changing the source code or internal design of the system. Instead, we focus on methods and techniques for wrapping and packaging the existing interaction layer to reproduce it in a different format, e.g., on a different platform or to integrate the legacy system services in another application possibly under a different architecture paradigm, e.g., service-oriented architectures (SOA).

  18. Les succédanés du sucre durant la grossesse

    PubMed Central

    Pope, Eliza; Koren, Gideon; Bozzo, Pina

    2014-01-01

    Résumé Question J’ai une patiente enceinte qui consomme souvent des succédanés du sucre et elle m’a demandé si cette pratique continue pouvait nuire à sa grossesse ou à son enfant. Que devrais-je lui répondre et existe-t-il d’autres meilleurs choix durant la grossesse? Réponse Il faudrait faire plus de recherche pour déterminer plus exactement les effets de l’exposition aux succédanés du sucre in utero, mais les données disponibles ne laissent pas présager d’effets indésirables durant la grossesse. Toutefois, il est recommandé de consommer des substituts du sucre en quantités modérées et de se conformer aux doses journalières admissibles établies par les organismes de règlementation.

  19. Une formation à la recherche en médecine transfusionnelle dans le monde francophone

    PubMed Central

    Shiboski, C.; Fontanet, A.; Murphy, E.L.

    2010-01-01

    Un enseignement accéléré et francophone de formation à la recherche en médecine transfusionnelle a été récemment instauré à l’Institut Pasteur de Paris, sous la codirection de membres hospitalo-universitaires de l’université de Californie San Francisco (UCSF), du Blood Systems Research Institute (BSRI) et de l’Institut national de la transfusion sanguine (INTS). Le but est de former des professionnels de la transfusion des pays en voie de développement à mener une activité de recherche dont les résultats peuvent contribuer à un renforcement de la qualité des soins transfusionnels et de la sécurité transfusionnelle dans leur pays. Le cours enseigne les méthodes de recherche clinique et épidémiologique, et leurs applications transfusionnelles potentielles. Chaque étudiant élabore au cours du stage un protocole personnel de recherche, qu’il lui sera loisible de mettre ensuite en pratique dans le centre de transfusion ou l’hôpital où il exerce. PMID:19640755

  20. Being Irrationally Funny as a Cognitive Psychologist: Interview With Dan Ariely.

    PubMed

    Ariely, Dan; Popescu, Beatrice

    2015-11-01

    The idea of interviewing Dan Ariely was somehow latent on my mind since I started being interested in cognitive psychology and cognitive behavior psychotherapy, but actually got more ardent ever since irrationality became a research topic for his team at Duke University. I picked him as an interviewee thinking not only at his exceptional skills as a researcher and as Kahnemann 'disciple', but mainly for his fantastic wit, true modesty and utmost interest in making people's lives easier and more comfortable, by creating awareness on a lot of topics otherwise neglected. Dan Ariely's very agreeable personality and humor would not let you think of him as a burnt casualty who, in his youth struggled to survive a personal drama, so well-documented in his paper "Painful lessons" posted on the MIT website (http://web.mit.edu/ariely/www/MIT/Papers/mypain.pdf). I think reading his paper and also this transcribed interview with him would be also comforting for people who found out about Bucharest fire incident that rocked our society and also for people who are personally related to this tragedy. PMID:27247678

  1. Les Elements Legers: Diffusion dans les Enveloppes Stellaires et Implications Cosmologiques

    NASA Astrophysics Data System (ADS)

    Richer, Jacques

    1992-01-01

    Les observations des abondances des elements legers (Z <= 5) sont utilisees pour estimer la quantitie de lithium qui a ete produite lors du Big -Bang, et obtenir simultanement des contraintes sur la nature des inhomogeneites qui ont pu exister durant la nucleosynthese primordiale. Nous utilisons un modele simple capable de simuler approximativement la diffusion et la retro-diffusion des neutrons a travers la matiere inhomogene durant les premieres minutes de l'expansion de l'Univers. Nous tenons compte de la difference possible entre l'abondance primordiale de Li et les abondances observees dans les plus vieilles etoiles. Cette difference (un facteur 2, environ) est estimee en construisant des modeles evolutifs d'etoiles peu massives de Population II, incluant la sedimentation gravitationnelle du lithium et de l'helium. Ces modeles montrent egalement que les ages des vieux amas stellaires sont grandement surestimes lorsqu'ils sont determines a partir de modeles stellaires n'incluant pas l'effet de la diffusion de He. Nous calculons ensuite comment evoluent les abondances de Li et Be dans des etoiles plus massives et plus jeunes, de la pre-sequence principale ou de la ZAMS, jusqu'a l'epuisement de leur hydrogene central. Les modeles incluent la sedimentation simultanee de l'helium a travers l'enveloppe. Une approche hierarchique (evolution du coeur--evolution de l'enveloppe --tri des elements traces) est utilisee pour simuler efficacement le grand nombre d'etoiles necessaire pour la construction d'isochrones. Une attention particuliere est portee aux consequences de la sedimentation de He sur l'etendue des zones convectives, et sur la diffusion de Li et Be. Les forces radiatives agissant sur ces deux elements sont calculees en detail a partir des donnees atomiques. Les etoiles simulees correspondent approximativement aux types spectraux A, F, et AmFm. Les abondances de Li et Be observees dans les etoiles jeunes de ces types sont comparees a nos predictions dans le

  2. Prediction inverse d'un front de solidification dans un four de transformation a haute temperature

    NASA Astrophysics Data System (ADS)

    Marois, Marc-Andre

    Ce projet de recherche porte sur une methode numerique permettant de predire l'evolution du profil 2D de la couche solide qui recouvre l'interieur des parois de plusieurs fours de transformation a haute temperature. Un modele mathematique base sur la formulation faible de l'energie est d'abord developpe et valide. Une methode de transfert thermique inverse reposant sur ce modele est ensuite developpee afin d'obtenir une mesure rapide et continue de l'evolution du profil de cette couche solide. Vu la grande inertie thermique du systeme a l'etude, differentes strategies sont proposees afin de faciliter la mise en uvre de cette methode numerique. Finalement, cette approche inverse est confrontee aux resultats experimentaux obtenus a l'aide d'un reacteur metallurgique. Une etude preliminaire montre que les fours de transformation presentent une tres grande inertie thermique qui limite grandement l'utilisation des methodes inverses. En effet, la sensibilite de cette methode numerique repose essentiellement sur le delai temporel observe entre la variation du profil du banc et la fluctuation de la temperature a la surface externe de la paroi du four. Les resultats obtenus demontrent qu'une partie de ce delai est proportionnel a la chaleur latente de fusion lorsque le materiau a changement de phase est constitue d'un melange non eutectique. Afin de limiter l'impact de ce delai temporel, deux astuces numeriques sont proposees : reutiliser plus d'une fois les mesures de temperature et modifier le probleme thermique dans les regions pateuse et liquide. D'une part, le concept de chevauchement propose permet de reduire le temps d'acquisition des donnees entre chacune des predictions. D'autre part, l'approche virtuelle developpee permet de reduire l'inertie thermique du systeme et, par le fait meme, le delai temporel associe a la diffusion de la chaleur. Ces deux strategies ont permis de predire efficacement l'evolution 1D de l'epaisseur de la couche de gelee qui se solidifie a

  3. 75 FR 51292 - Before Commissioners: Ruth Y. Goldway, Chairman; Tony L. Hammond, Vice Chairman; Mark Acton; Dan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-19

    ... From the Federal Register Online via the Government Publishing Office POSTAL REGULATORY COMMISSION Before Commissioners: Ruth Y. Goldway, Chairman; Tony L. Hammond, Vice Chairman; Mark Acton; Dan G. Blair; and Nanci E. Langley; Competitive Product Prices; Global Expedited Package Services 3...

  4. Comparison of cardioprotective effects using ramipril and DanShen for the treatment of acute myocardial infarction in rats.

    PubMed

    Ji, XinYan; Tan, Benny K-H; Zhu, Yi Chun; Linz, Wolfgang; Zhu, Yi Zhun

    2003-08-01

    In the present study, we compared cardioprotective effects of DanShen (an extract from Salvia miltiorrhiza) and the angiotensin-converting enzyme inhibitor, ramipril, in rats. With both treatment regimens, DanShen- and ramipril similar effects were observed: (1) a higher survival rate, (2) a significant reduction of infarct size, (3) significantly lower ratios of heart weight to the body weight as well as the left and right ventricular weights to body weight. DanShen showed some unique effects in the following aspects: (1) higher activities of antioxidant defense enzymes such as superoxide dismutase (SOD), catalase (CAT), glutatione perioxidase (GSH-Px) and glutathione S-transferase (GST) in the liver of rats with acute myocardial infarction (AMI), (2) lower myocardial and hepatic TBARS values; (3) augmented VEGF mRNA expressions in the non-ischemic parts of rat hearts with AMI. These results were consistent with the findings of a slight increase in myocardial capillary density and the special distribution pattern of coronary blood vessels in DanShen-treated rats. PMID:12850502

  5. Hémophilie: état des lieux dans un service de pédiatrie dans la région de l'oriental du Maroc

    PubMed Central

    Benajiba, Noufissa; Boussaadni, Yousra EL; Aljabri, Mohammed; Bentata, Yassamine; Amrani, Rim; Rkain, Maria

    2014-01-01

    Pour les pays en voie de développement, l'hémophilie continue d’être une maladie de conséquence médicale et sociale désastreuse. Le but de ce travail est d'analyser le suivi d'une cohorte de patients hémophiles. Patients et méthodes: étude prospective étalée sur deux années et menée au centre référent d'hémophilie dans la région de l'orient du Maroc. Ont été inclus tous les patients présentant une hémophilie confirmée et âgé de moins de 18 ans. Résultats: sur 16 hémophiles, Quinze patients présentait une hémophilie A, l’âge moyen des patients était de 6,18 ans, la forme sévère, représentait 20,7%, la forme modérée: 33,3% et la forme mineure: 40%. Les circonstances de découverte étaient post circoncisionnelle chez 53,3% des patients, 20,7% post traumatique, 20% à l’âge de la marche; la durée d’évolution variait entre 2 mois et 10 ans. L'hémarthrose a été décrite au niveau des genoux, coudes et chevilles, avec une moyenne allant de 2 à 5 fois par an; l'arthropathie a été remarquée dans 33,3%. Le bilan immunologique a révélé des facteurs circulant inhibant chez deux patients. Le traitement était à base d'antalgiques, de plasma frais congelé. L'administration de facteurs VIII recombinés a été instaurée chez 40,6% des patients (plus de 90% des formes modérées et graves), grâce au programme national de prise en charge des hémophiles. Le décès était noté dans un seul cas lié à une hémorragie cérébrale. Conclusion: Nous insistons sur l'intérêt du programme national de prise en charge des hémophiles dernièrement instauré qui pourrait améliorer les conditions de vie de ces enfants. PMID:25404986

  6. Leo space plasma interactions

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.

    1991-01-01

    Photovoltaic arrays interact with the low earth orbit (LEO) space plasma in two fundamentally different ways. One way is the steady collection of current from the plasma onto exposed conductors and semiconductors. The relative currents collected by different parts of the array will then determine the floating potential of the spacecraft. In addition, these steady state collected currents may lead to sputtering or heating of the array by the ions or electrons collected, respectively. The second kind of interaction is the short time scale arc into the space plasma, which may deplete the array and/or spacecraft of stored charge, damage solar cells, and produce EMI. Such arcs only occur at high negative potentials relative to the space plasma potential, and depend on the steady state ion currents being collected. New high voltage solar arrays being incorporated into advanced spacecraft and space platforms may be endangered by these plasma interactions. Recent advances in laboratory testing and current collection modeling promise the capability of controlling, and perhaps even using, these space plasma interactions to enable design of reliable high voltage space power systems. Some of the new results may have an impact on solar cell spacing and/or coverslide design. Planned space flight experiments are necessary to confirm the models of high voltage solar array plasma interactions. Finally, computerized, integrated plasma interactions design tools are being constructed to place plasma interactions models into the hands of the spacecraft designer.

  7. Comparaison de deux scores pronostiques dans les hémorragies digestives hautes non variqueuses dans un centre hospitalier d'Antananarivo

    PubMed Central

    Rakotondrainibe, Aurélia; Randrianambinina, Thierry Pierre; Randriamizao, Harifetra Mamy Richard; Rasoaherinomenjanahary, Fanjandrainy; Randriamiarana, Mialimanana Joël; Samison, Luc Hervé

    2013-01-01

    Il est actuellement recommandé de stratifier les hémorragies digestives hautes, en fonction de leur risque, par des scores pronostiques. L'objectif de cette étude a été d'appliquer ces scores en vue de les comparer, dans un centre hospitalier malgache. Etude prospective sur 419 patients, sur une période entre janvier et décembre 2011, au Centre Hospitalo-Universitaire d'Antananarivo. Les scores de Rockall initial et de Blatchford ont été calculés pour chaque patient présentant une hémorragie digestive haute non variqueuse dont les dossiers été complets, avec notamment la valeur de l'urémie et de l'hémoglobine. Une comparaison de ces deux scores a été faite pour déterminer le pronostic et l’évolution de cette pathologie. 46,3% des dossiers n'avaient pas de valeur d'urémie ni de l'hémoglobine. Les 185 patients retenus, avaient une moyenne d’âge de 48,2 ± 18,2 ans et une prédominance masculine (72,4%). Le risque clinique était élevé dans 62,7% des cas, dont 59,4% ont bénéficié d'une transfusion. Une mortalité de 9,7% a été observée. Le score de Blatchford était plus prédictif du risque clinique par rapport au score de Rockall initial (AUROC = 0,82 vs 0,64; p < 0,0001), mais aussi de la nécessité d'une transfusion (AUROC = 0,79 vs 0,62; p= 0,00013). L'instauration d'un score clinico-biologique est assez limitée par faute de moyens, alors que le score de Blatchford aiderait en matière de pronostic des hémorragies digestives hautes. PMID:24839534

  8. Morbimortalité périnatale dans les grossesses gémellaires dans une maternité marocaine de niveau 3

    PubMed Central

    Boubkraoui, Mohamed El-Mahdi; Aguenaou, Hassan; Mrabet, Mustapha; Barkat, Amina

    2016-01-01

    Introduction Les grossesses gémellaires sont associées à un risque de morbimortalité périnatale plus élevé que les grossesses simples. Le but de cette étude était d’évaluer la morbimortalité périnatale dans les grossesses gémellaires dans une maternité marocaine de niveau 3. Méthodes Il s'agit d'une étude transversale comparative de la morbimortalité périnatale des nouveau-nés issus de grossesses gémellaires versus grossesses simples ayant accouché à la maternité Souissi de Rabat du 1 janvier au 28 février 2014. Résultats Il y a eu 3297 naissances issues de 65 grossesses gémellaires et 3167 grossesses simples. Les grossesses gémellaires étaient associées à des taux plus élevés de prééclampsie et d’éclampsie (P = 0,046), de HELLP syndrome (P= 0,030), de rupture prématurée des membranes (P < 0,001), de présentation dystocique (P < 0,001), de prématurité (P < 0,001), d'hypotrophie chez les nouveau-nés à terme (P < 0,001), de détresse respiratoire néonatale (P < 0,001), de malformations congénitales (P = 0,015), d'hospitalisation en période néonatale (P = 0,001) et de mortalité périnatale (P = 0,001) par rapport aux grossesses simples. Les jumeaux monochoriaux présentaient des taux plus élevés d'hypotrophie en cas de grossesse menée à terme (P = 0,016) et de mortalité périnatale (P = 0,017) par rapport aux jumeaux bichoriaux. Conclusion Les grossesses gémellaires étaient à risque plus élevé de morbimortalité périnatale par rapport aux grossesses simples en exposant notamment à la prématurité. Les grossesses gémellaires monochoriales étaient plus à risque en exposant notamment à l'hypotrophie chez les nouveau-nés à terme. PMID:27217903

  9. The ADAMS interactive interpreter

    SciTech Connect

    Rietscha, E.R.

    1990-12-17

    The ADAMS (Advanced DAta Management System) project is exploring next generation database technology. Database management does not follow the usual programming paradigm. Instead, the database dictionary provides an additional name space environment that should be interactively created and tested before writing application code. This document describes the implementation and operation of the ADAMS Interpreter, an interactive interface to the ADAMS data dictionary and runtime system. The Interpreter executes individual statements of the ADAMS Interface Language, providing a fast, interactive mechanism to define and access persistent databases. 5 refs.

  10. Adverse Drug Interactions

    PubMed Central

    Becker, Daniel E.

    2011-01-01

    The potential for interactions with current medications should always be considered when administering or prescribing any drug. Considering the staggering number of drugs patients may be taking, this task can be daunting. Fortunately, drug classes employed in dental practice are relatively few in number and therapy is generally brief in duration. While this reduces the volume of potential interactions, there are still a significant number to be considered. This article will review basic principles of drug interactions and highlight those of greatest concern in dental practice. PMID:21410363

  11. The effects of dan-shen root on cardiomyogenic differentiation of human placenta-derived mesenchymal stem cells

    SciTech Connect

    Li, Kun; Li, Shi-zheng; Zhang, Yun-li; Wang, Xue-zhe

    2011-11-11

    Highlights: Black-Right-Pointing-Pointer Conditional medium and dan-shen root were used for cardiomyogenic differentiation. Black-Right-Pointing-Pointer They all could induce hPDMSCs to differentiate into cardiomyocytes. Black-Right-Pointing-Pointer The induction effect of the latter was slightly higher compared to that of the former. Black-Right-Pointing-Pointer Dan-shen root could be a good inducer for cardiomyogenic differentiation. -- Abstract: The aim of this study was to search for a good inducer agent using for cardiomyogenic differentiation of stem cells. Human placenta-derived mesenchymal stem cells (hPDMSCs) were isolated and incubated in enriched medium. Fourth passaged cells were treated with 10 mg/L dan-shen root for 20 days. Morphologic characteristics were analyzed by confocal and electron microscopy. Expression of {alpha}-sarcomeric actin was analyzed by immunohistochemistry. Expression of cardiac troponin-I (TnI) was analyzed by immunohistofluorescence. Atrial natriuretic factor (ANF) and beta-myocin heavy chain ({beta}-MHC) were detected by reverse transcriptase polymerase chain reaction (RT-PCR). hPDMSCs treated with dan-shen root gradually formed a stick-like morphology and connected with adjoining cells. On the 20th day, most of the induced cells stained positive with {alpha}-sarcomeric actin and TnI antibody. ANF and {beta}-MHC were also detected in the induced cells. Approximately 80% of the cells were successfully transdifferentiated into cardiomyocytes. In conclusion, dan-shen root is a good inducer agent used for cardiomyogenic differentiation of hPDMSCs.

  12. Assessment of trace element impacts on agricultural use of water from the Dan River following the Eden coal ash release.

    PubMed

    Hesterberg, Dean; Polizzotto, Matthew L; Crozier, Carl; Austin, Robert E

    2016-04-01

    Catastrophic events require rapid, scientifically sound decision making to mitigate impacts on human welfare and the environment. The objective of this study was to analyze potential impacts of coal ash-derived trace elements on agriculture following a 35,000-tonne release of coal ash into the Dan River at the Duke Energy Steam Station in Eden, North Carolina. We performed scenario calculations to assess the potential for excessive trace element loading to soils via irrigation and flooding with Dan River water, uptake of trace elements by crops, and livestock consumption of trace elements via drinking water. Concentrations of 13 trace elements measured in Dan River water samples within 4 km of the release site declined sharply after the release and were equivalent within 5 d to measurements taken upriver. Mass-balance calculations based on estimates of soil trace-element concentrations and the nominal river water concentrations indicated that irrigation or flooding with 25 cm of Dan River water would increase soil concentrations of all trace elements by less than 0.5%. Calculations of potential increases of trace elements in corn grain and silage, fescue, and tobacco leaves suggested that As, Cr, Se, Sr, and V were elements of most concern. Concentrations of trace elements measured in river water following the ash release never exceeded adopted standards for livestock drinking water. Based on our analyses, we present guidelines for safe usage of Dan River water to diminish negative impacts of trace elements on soils and crop production. In general, the approach we describe here may serve as a basis for rapid assessment of environmental and agricultural risks associated with any similar types of releases that arise in the future. PMID:26033746

  13. Atomic & Molecular Interactions

    SciTech Connect

    2002-07-12

    The Gordon Research Conference (GRC) on Atomic & Molecular Interactions was held at Roger Williams University, Bristol, RI. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  14. Interactive Office user's manual

    NASA Technical Reports Server (NTRS)

    Montgomery, Edward E.; Lowers, Benjamin; Nabors, Terri L.

    1990-01-01

    Given here is a user's manual for Interactive Office (IO), an executive office tool for organization and planning, written specifically for Macintosh. IO is a paperless management tool to automate a related group of individuals into one productive system.

  15. Neutrino self-interactions

    NASA Astrophysics Data System (ADS)

    Hasenkamp, Jasper

    2016-03-01

    We propose a theory that equips the active neutrinos with interactions among themselves that are at least 3 orders of magnitude stronger than the weak interaction. We introduce an Abelian gauge group U (1 )X with vacuum expectation value vx≲O (100 MeV ) . An asymmetric mass matrix implements the active neutrinos as massless mass eigenstates carrying "effective" charges. To stabilize vx, supersymmetry breaking is mediated via loops to the additional sector with the only exception of xHiggs terms. No Standard Model interaction eigenstate carries U (1 )X charge. Thus, the dark photon's kinetic mixing is two-loop suppressed. With only simple and generic values of dimensionless parameters, our theory might explain the high-energy neutrino spectrum observed by IceCube including the PeV neutrinos. We comment on the imposing opportunity to incorporate a self-interacting dark matter candidate.

  16. Interactive DIF Generator

    NASA Technical Reports Server (NTRS)

    Preheim, Larry E.; Amy, Laraine; Young, Jimmie D.

    1993-01-01

    Interactive DIF Generator (IDG) computer program serves as utility to generate and manipulate directory interchange format (DIF) files. Creates and updates DIF files, sent to NASA's Master Directory, also referred to as International Global Change Directory at Goddard Space Flight Center. Many government and university data systems use Master Directory to advertise availability of research data. IDG is interactive software tool and requires mouse or trackball to operate. Written in C language.

  17. Flank solar wind interaction

    NASA Technical Reports Server (NTRS)

    Moses, Stewart L.; Greenstadt, Eugene W.; Coroniti, Ferdinand V.

    1994-01-01

    In this report we will summarize the results of the work performed under the 'Flank Solar Wind Interaction' investigation in support of NASA's Space Physics Guest Investigator Program. While this investigation was focused on the interaction of the Earth's magnetosphere with the solar wind as observed by instruments on the International Sun-Earth Explorer (ISEE) 3 spacecraft, it also represents the culmination of decades of research performed by scientists at TRW on the rich phenomenology of collisionless shocks in space.

  18. Consistent interactions and involution

    NASA Astrophysics Data System (ADS)

    Kaparulin, D. S.; Lyakhovich, S. L.; Sharapov, A. A.

    2013-01-01

    Starting from the concept of involution of field equations, a universal method is proposed for constructing consistent interactions between the fields. The method equally well applies to the Lagrangian and non-Lagrangian equations and it is explicitly covariant. No auxiliary fields are introduced. The equations may have (or have no) gauge symmetry and/or second class constraints in Hamiltonian formalism, providing the theory admits a Hamiltonian description. In every case the method identifies all the consistent interactions.

  19. Grapefruit and drug interactions.

    PubMed

    2012-12-01

    Since the late 1980s, grapefruit juice has been known to affect the metabolism of certain drugs. Several serious adverse effects involving drug interactions with grapefruit juice have been published in detail. The components of grapefruit juice vary considerably depending on the variety, maturity and origin of the fruit, local climatic conditions, and the manufacturing process. No single component accounts for all observed interactions. Other grapefruit products are also occasionally implicated, including preserves, lyophylised grapefruit juice, powdered whole grapefruit, grapefruit seed extract, and zest. Clinical reports of drug interactions with grapefruit juice are supported by pharmacokinetic studies, each usually involving about 10 healthy volunteers, in which the probable clinical consequences were extrapolated from the observed plasma concentrations. Grapefruit juice inhibits CYP3A4, the cytochrome P450 isoenzyme most often involved in drug metabolism. This increases plasma concentrations of the drugs concerned, creating a risk of overdose and dose-dependent adverse effects. Grapefruit juice also inhibits several other cytochrome P450 isoenzymes, but they are less frequently implicated in interactions with clinical consequences. Drugs interacting with grapefruit and inducing serious clinical consequences (confirmed or very probable) include: immunosuppressants, some statins, benzodiazepines, most calcium channel blockers, indinavir and carbamazepine. There are large inter-individual differences in enzyme efficiency. Along with the variable composition of grapefruit juice, this makes it difficult to predict the magnitude and clinical consequences of drug interactions with grapefruit juice in a given patient. There is increasing evidence that transporter proteins such as organic anion transporters and P-glycoprotein are involved in interactions between drugs and grapefruit juice. In practice, numerous drugs interact with grapefruit juice. Although only a few

  20. Interaction: Additivity plus Nonlinearity?

    ERIC Educational Resources Information Center

    Hutchinson, T. P.

    2004-01-01

    Whether or not there is an interaction between two factors in their effects on a dependent variable is often a central question. This paper proposes a general mechanism by which an interaction may arise: (a) the two factors are the same thing--or, at least, have a dimension in common--in the sense that it is meaningful to add (or subtract) them;…

  1. Asymptotically Safe Weak Interactions

    NASA Astrophysics Data System (ADS)

    Calmet, Xavier

    We emphasize that the electroweak interactions without a Higgs boson are very similar to quantum general relativity. The Higgs field could just be a dressing field and might not exist as a propagating particle. In that interpretation, the electroweak interactions without a Higgs boson could be renormalizable at the nonperturbative level because of a nontrivial fixed point. Tree-level unitarity in electroweak bosons scattering is restored by the running of the weak scale.

  2. PIA: ISOPHOT Interactive Analysis

    NASA Astrophysics Data System (ADS)

    Gabriel, Carlos; Acosta, Jose; Heinrichsen, Ingolf; Skaley, Detlef; Tai, Wai Ming; Morris, Huw; Merluzzi, Paola

    2014-08-01

    ISOPHOT is one of the instruments on board the Infrared Space Observatory (ISO). ISOPHOT Interactive Analysis (PIA) is a scientific and calibration interactive data analysis tool for ISOPHOT data reduction. Written in IDL under Xwindows, PIA offers a full context sensitive graphical interface for retrieving, accessing and analyzing ISOPHOT data. It is available in two nearly identical versions; a general observers version omits the calibration sequences.

  3. Human-machine interactions

    DOEpatents

    Forsythe, J. Chris; Xavier, Patrick G.; Abbott, Robert G.; Brannon, Nathan G.; Bernard, Michael L.; Speed, Ann E.

    2009-04-28

    Digital technology utilizing a cognitive model based on human naturalistic decision-making processes, including pattern recognition and episodic memory, can reduce the dependency of human-machine interactions on the abilities of a human user and can enable a machine to more closely emulate human-like responses. Such a cognitive model can enable digital technology to use cognitive capacities fundamental to human-like communication and cooperation to interact with humans.

  4. Interaction with Machine Improvisation

    NASA Astrophysics Data System (ADS)

    Assayag, Gerard; Bloch, George; Cont, Arshia; Dubnov, Shlomo

    We describe two multi-agent architectures for an improvisation oriented musician-machine interaction systems that learn in real time from human performers. The improvisation kernel is based on sequence modeling and statistical learning. We present two frameworks of interaction with this kernel. In the first, the stylistic interaction is guided by a human operator in front of an interactive computer environment. In the second framework, the stylistic interaction is delegated to machine intelligence and therefore, knowledge propagation and decision are taken care of by the computer alone. The first framework involves a hybrid architecture using two popular composition/performance environments, Max and OpenMusic, that are put to work and communicate together, each one handling the process at a different time/memory scale. The second framework shares the same representational schemes with the first but uses an Active Learning architecture based on collaborative, competitive and memory-based learning to handle stylistic interactions. Both systems are capable of processing real-time audio/video as well as MIDI. After discussing the general cognitive background of improvisation practices, the statistical modelling tools and the concurrent agent architecture are presented. Then, an Active Learning scheme is described and considered in terms of using different improvisation regimes for improvisation planning. Finally, we provide more details about the different system implementations and describe several performances with the system.

  5. Nonadditivity of nanoparticle interactions.

    PubMed

    Batista, Carlos A Silvera; Larson, Ronald G; Kotov, Nicholas A

    2015-10-01

    Understanding interactions between inorganic nanoparticles (NPs) is central to comprehension of self-organization processes and a wide spectrum of physical, chemical, and biological phenomena. However, quantitative description of the interparticle forces is complicated by many obstacles that are not present, or not as severe, for microsize particles (μPs). Here we analyze the sources of these difficulties and chart a course for future research. Such difficulties can be traced to the increased importance of discreteness and fluctuations around NPs (relative to μPs) and to multiscale collective effects. Although these problems can be partially overcome by modifying classical theories for colloidal interactions, such an approach fails to manage the nonadditivity of electrostatic, van der Waals, hydrophobic, and other interactions at the nanoscale. Several heuristic rules identified here can be helpful for discriminating between additive and nonadditive nanoscale systems. Further work on NP interactions would benefit from embracing NPs as strongly correlated reconfigurable systems with diverse physical elements and multiscale coupling processes, which will require new experimental and theoretical tools. Meanwhile, the similarity between the size of medium constituents and NPs makes atomic simulations of their interactions increasingly practical. Evolving experimental tools can stimulate improvement of existing force fields. New scientific opportunities for a better understanding of the electronic origin of classical interactions are converging at the scale of NPs. PMID:26450215

  6. Adverse antibiotic drug interactions.

    PubMed

    Bint, A J; Burtt, I

    1980-07-01

    There is enormous potential for drug interactions in patients who, today, often receive many drugs. Antibiotics are prominent amongst the groups of drugs commonly prescribed. Many interactions take place at the absorption stage. Antacids and antidiarrhoeal preparations, in particular, can delay and reduce the absorption of antibiotics such as tetracyclines and clindamycin, by combining with them in the gastrointestinal tract to form chelates or complexes. Other drugs can affect gastric motility, which in turn often controls the rate at which antibiotics are absorbed. Some broad spectrum antibiotics can alter the bacterial flora of the gut which may be related to malabsorption states. The potentiation of toxic side effects of one drug by another is a common type of interaction. Antibiotics which are implicated in this type of interaction are those which themselves possess some toxicity such as aminoglycosides, some cephalosporins, tetracyclines and colistin. Some of the most important adverse interactions with antibiotics are those which involve other drugs which have a low toxicity/efficacy ratio. These include anticoagulants such as warfarin, anticonvulsants such as phenytoin and phenobarbitone and oral antidiabetic drugs like tolbutamide. Risk of interaction arises when the metabolism of these drugs is inhibited by liver microsomal enzyme inhibitors such as some sulphonamides and chloramphenicol, or is enhanced by enzyme inducers such as rifampicin. PMID:6995091

  7. First results from the CheMin, DAN and SAM instruments on Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Blake, D. F.; Mahaffy, P. R.; Mitrofanov, I.

    2012-12-01

    One of the principal goals of the Mars Science Laboratory rover Curiosity is to identify and characterize the early habitable environments of Mars, as recorded in the stratified rocks and soil of Gale crater. The suite of instruments aboard Curiosity will make measurements useful for determining the presence and lateral/vertical distribution of hydrated phases, the mineralogy and "preservation potential" of sediments and rocks, and the identity and isotopic composition of organic and other carbon containing molecules, should such be present. Three of Curiosity's instruments, DAN ("Dynamic Albedo of Neutrons," a soil hydrogen detector), CheMin ("Chemistry and Mineralogy," a mineralogy instrument) and SAM ("Surface Analysis at Mars," an organic molecule and isotopic analysis instrument) are uniquely suited to this purpose. DAN consists of a pulsed neutron generator and neutron detector that will measure the hydrogen content (i.e., hydrated phases, water ice) in the upper meter of the soil. Both passive and active measurements will be obtained, resulting in a meter-scale resolution transect map of near-surface hydrogen along the path of the rover. These measurements will provide context for the mineralogical and organic measurements of drilled and scooped samples analyzed by CheMin and SAM. CheMin, a powder X-ray Diffraction (pXRD) instrument, will determine the mineralogy of scooped soils and powders obtained from drilled rocks. Hydrated minerals will be identified, along with whole-rock mineralogy for characterizing the environment of formation and preservation potential for organic molecules. SAM consists of a sample handling system, a gas chromatograph, a mass spectrometer, and a tunable laser spectrometer. SAM will accept the same powdered rock and soil samples as CheMin, and will measure and identify organic carbon in these samples as well as evolved inorganic gases such as CO2, CH4, and H2O. Isotopic composition of noble gases and several light elements are

  8. Profil de l'infection urinaire nosocomiale dans un service de nephrology

    PubMed Central

    Lazrak, Mohamed Amine; El Bardai, Ghita; Jaafour, Soumia; Kabbali, Nadia; Arrayhani, Mohamed; Houssaini, Tarik Sqalli

    2014-01-01

    L'infection urinaire est l'infection nosocomiale la plus fréquente. Elle constitue un véritable problème de santé publique par la surmortalité et le surcoût qu'elle entraîne. L'objectif de notre étude est de déterminer l'incidence et le profil des IU nosocomiales dans un service de Néphrologie. Etude rétrospective sur dossier de tous les patients hospitalisés dans notre service durant l'année 2011, ayant bénéficié d'un examen cytobactériologique des urines. Ont été exclus, tous les patients admis avec une IU connue ou active. 325 dossiers ont été retenus. L'incidence de l'IU nosocomiale était de l'ordre de 16,9%. La durée moyenne d'hospitalisation était de 14,1±10,15 jours. 30% de nos patients ont été transférés du service des urgences. 80% des IU nosocomiales étaient compliquées. Le germe responsable était E.Coli dans 2/3 des cas dont 14,5% était à E.Coli sécrétrice de bétalactamases à spectre étendu. L’évolution après traitement était favorable chez 90,7%. En analyse multivariée, les facteurs de risque pour contracter une IU nosocomiale étaient le sexe féminin; le sondage urinaire et l'antécédent d'IU à répétition. Nos résultats rejoignent ceux de la littérature concernant les facteurs de risque liés à la survenue de l'IU nosocomiale, la fréquence des infections à entérobactéries, et l’émergence de souches résistantes. Une Surveillance microbiologique et une évaluation de la résistance aux antibiotiques constituent une ligne de défense pour faire face à l'accentuation de nouvelles souches bactériennes de plus en plus résistantes aux antibiotiques rendant les options thérapeutiques très limitées. PMID:25667721

  9. Bruit thermique et effets quantiques dans une cavité optique de grande finesse

    NASA Astrophysics Data System (ADS)

    Caniard, T.; Briant, T.; Heidmann, A.; Pinard, M.

    2006-10-01

    Nous nous intéressons aux bruits dans les mesures optiques de très grande sensibilité et aux limites associées. Une des limitations fondamentales des mesures interférométriques, telles que les détections d'ondes gravitationnelles, est liée aux fluctuations de la pression de radiation exercée par la lumière sur les miroirs. Celle-ci induit des corrélations quantiques entre la position des miroirs et les fluctuations de la lumière. L'observation de ces effets quantiques ouvrirait de nombreuses perspectives: étude de la limite quantique standard, production d'états comprimés, réalisation d'une mesure quantique non destructive ldots

  10. [Story life CHENG Dan-an's, works and his achievements on acupuncture and moxibustion science].

    PubMed

    Lu, Xiang; Cai, Yue

    2011-05-01

    Mr. CHENG Dan-an, who devoted himself to the renaissance of the course of modern Chinese acupuncture, the establishment of acupuncture education unit, correspondence education, acupuncture personnel fostering and publication of periodicals on acupuncture, has great contribution to the academic exchanges and popularization of acupuncture. Mr. CHENG has completed over 10 articles and more than 20 works and translations. According to him, mechanism on meridians, collaterals, acupoints and acupuncture techniques were explored with the promotion on application of "Shen" and "qi" in clinic. Pulse and tongue diagnosis as well as acupuncture treatment were supplemented into Shanghanlun (Treatise on Febrile Diseases). And great importance was attached on the scientific validity and practicability. His professional ethics and dedication are worth to be learned by all medical workers nowadays. His acupuncture theories and academic achievements still inspire us today, which are also taken as the origin for the innovation and development of modern acupuncture science. PMID:21692305

  11. Interactions between photodegradation components

    PubMed Central

    2012-01-01

    Background The interactions of p-cresol photocatalytic degradation components were studied by response surface methodology. The study was designed by central composite design using the irradiation time, pH, the amount of photocatalyst and the p-cresol concentration as variables. The design was performed to obtain photodegradation % as actual responses. The actual responses were fitted with linear, two factor interactions, cubic and quadratic model to select an appropriate model. The selected model was validated by analysis of variance which provided evidences such as high F-value (845.09), very low P-value (<.0.0001), non-significant lack of fit, the coefficient of R-squared (R2 = 0.999), adjusted R-squared (Radj2 = 0.998), predicted R-squared (Rpred2 = 0.994) and the adequate precision (95.94). Results From the validated model demonstrated that the component had interaction with irradiation time under 180 min of the time while the interaction with pH was above pH 9. Moreover, photocatalyst and p-cresol had interaction at minimal amount of photocatalyst (< 0.8 g/L) and 100 mg/L p-cresol. Conclusion These variables are interdependent and should be simultaneously considered during the photodegradation process, which is one of the advantages of the response surface methodology over the traditional laboratory method. PMID:22967885

  12. Phonons and their interactions

    SciTech Connect

    Nicklow, R.M.

    1982-08-01

    The phonon energy spectra nu(vector q) of crystalline materials contains key information about the interatomic interactions. However, it is generally not possible to fully understand the phonon spectra without also understanding the influence on phonon energies and lifetimes caused by interactions with defects, electrons and other excitations. The study of several of these types of interactions have grown over the years so as to now constitute subfields of solid state physics and the contributions of neutron scattering research to each has been, if not of paramount importance, at least very significant. In the present review we can merely touch on a few highlights. Perhaps the largest research effort is expended on electron-phonon interactions. These interactions are, of course, fundamental to the properties of metallic solids. They are seen in the phonon nu(vector q) of metals in a wide variety of effects. We shall mention three: the relatively small fine structure produced by Kohn singularities, large anomalies and phonon lifetimes measured in some superconductors and in materials with fluctuating valence.

  13. Curiethérapie dans le traitement palliatif du cancer de l’œsophage

    PubMed Central

    Toulba, Ahmedou; Bakkali, Hanae; Boutayeb, Salwa; Kebdani, Tayeb; Ahid, Samir; Benjaafar, Noureddine

    2015-01-01

    Les patients atteints du cancer de l’œsophage ont souvent une maladie localement avancée, la dysphagie est le symptôme majeur chez la plupart de ces patients, plusieurs modalités thérapeutiques ont été utilisées pour améliorer cette dysphagie. Le but de ce travail est d’étudier l'efficacité et la tolérance de la curiethérapie haut débit de dose (HDR) endo-luminale dans le traitement palliatif des cancers de l’œsophage inopérable. Sur une période de 15 ans, l’étude a inclus les patients atteints de cancer de l’œsophage inopérable et/ou métastatique avec une dysphagie, sans extension à l'hypopharynx ou a la trachée et qui ont bénéficié d'une curiethérapie HDR avec ou sans radiothérapie externe à visée palliative. Au total 46 patients ont été inclus dans l’étude, 58,7% étaient des hommes, 42,2% avaient une dysphagie grade 2 et 37,8% étaient aphagiques, 78,6% des patients étaient performance satus PS 2, l'amaigrissement à été trouvé chez 81,4%, la localisation de la tumeur était surtout au niveau du tiers moyen et inférieur dans 97,8%, la hauteur médiane de la tumeur était de 7 cm (5,5-9), le carcinome épidermoïde était le type histologique le plus fréquent chez 31 patients (70,5%). Après un médiane de suivi de 5 mois, l'amélioration de la dysphagie a été retrouvée chez 76% des malades (p1]. L′incidence la plus élevée est observée dans certains pays notamment en Asie et en Afrique, et l′incidence dans les pays développés occidentaux est en augmentation [2]. Selon le registre du cancer de Rabat 2006-2008, le cancer de l’œsophage est rare et constitue 1,5% de tous les cancers chez l'homme [3]. Le taux de survie globale à 5 ans est de 8%, avec 80% des décès liés à l’évolution locale de la maladie [4]. Pour la minorité des patients avec une maladie localisée, le traitement par radiochimiothérapie concomitante avec ou sans chirurgie permet une amélioration de la survie [5]. Plus de 50

  14. Achromatic Interaction Point Design

    SciTech Connect

    Guimei Wang,, Yaroslav Derbenev, S.Alex Bogacz, P. Chevtsov, Andre Afanaciev, Charles Ankenbrandt, Valentin Ivanov, Rolland P. Johnson

    2009-05-01

    Designers of high-luminosity energy-frontier muon colliders must provide strong beam focusing in the interaction regions. However, the construction of a strong, aberration-free beam focus is difficult and space consuming, and long straight sections generate an off-site radiation problem due to muon decay neutrinos that interact as they leave the surface of the earth. Without some way to mitigate the neutrino radiation problem, the maximum c.m. energy of a muon collider will be limited to about 3.5 TeV. A new concept for achromatic low beta design is being developed, in which the interaction region telescope and optical correction elements, are installed in the bending arcs. The concept, formulated analytically, combines space economy, a preventative approach to compensation for aberrations, and a reduction of neutrino flux concentration. An analytical theory for the aberration-free, low beta, spatially compact insertion is being developed.

  15. Propeller tip vortex interactions

    NASA Technical Reports Server (NTRS)

    Johnston, Robert T.; Sullivan, John P.

    1990-01-01

    Propeller wakes interacting with aircraft aerodynamic surfaces are a source of noise and vibration. For this reason, flow visualization work on the motion of the helical tip vortex over a wing and through the second stage of a counterrotation propeller (CRP) has been pursued. Initially, work was done on the motion of a propeller helix as it passes over the center of a 9.0 aspect ratio wing. The propeller tip vortex experiences significant spanwise displacements when passing across a lifting wing. A stationary propeller blade or stator was installed behind the rotating propeller to model the blade vortex interaction in a CRP. The resulting vortex interaction was found to depend on the relative vortex strengths and vortex sign.

  16. History of Weak Interactions

    DOE R&D Accomplishments Database

    Lee, T. D.

    1970-07-01

    While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.

  17. Dike/Drift Interactions

    SciTech Connect

    E. Gaffiney

    2004-11-23

    This report presents and documents the model components and analyses that represent potential processes associated with propagation of a magma-filled crack (dike) migrating upward toward the surface, intersection of the dike with repository drifts, flow of magma in the drifts, and post-magma emplacement effects on repository performance. The processes that describe upward migration of a dike and magma flow down the drift are referred to as the dike intrusion submodel. The post-magma emplacement processes are referred to as the post-intrusion submodel. Collectively, these submodels are referred to as a conceptual model for dike/drift interaction. The model components and analyses of the dike/drift interaction conceptual model provide the technical basis for assessing the potential impacts of an igneous intrusion on repository performance, including those features, events, and processes (FEPs) related to dike/drift interaction (Section 6.1).

  18. Dynamics of Galaxy Interactions

    NASA Astrophysics Data System (ADS)

    Barnes, Joshua E.

    Preface Theory of Interacting Galaxies The Role of Gravity Holmberg's Work on Tidal Interactions "Galactic Bridges and Tails" Dark Matter Numerical Stellar Dynamics Collisionless Stellar Systems Simulating the Stars Force Calculation Time Integration Errors and Relaxation Effects Initial Conditions Numerical Gas Dynamics A Sketch of the Interstellar Medium Simulating the ISM Gas in B/D/H Models Tidal Interactions Test-Particle Studies: Bridges and Tails Self-Consistent Studies Bars and Spirals Tidal Dwarf Galaxies Self-Consistent "Lookalikes" Getting the Feel of the Antennae Sneaking Up on the Mice What Happened to the Whirlpool? Unresolved Issues Mechanics of Merging Tidal Drag Orbit Decay Violent Relaxation Final Encounters Remnant Structure Phase Mixing Characteristics Scales Radial Profiles Shapes and Kinematics Orbit Structure Gas Dynamics in Mergers Inflows in Perturbed Disks Merging Encounters Remnant Structure Dissipation and Stellar Backlash Galaxy transformation and the Arrow of Time

  19. Carotenoid-Protein Interactions

    NASA Astrophysics Data System (ADS)

    Britton, George; Helliwell, John R.

    Chapter 5 shows that the aggregation of carotenoid molecules can have a profound effect on their properties and hence their functioning in biological systems. Another important influence is the interaction between carotenoids and other molecules. The way that interactions of carotenoids with lipid bilayers influence the structure and properties of membranes and membrane-asociated processes is discussed in Chapter 10, and the aggregation of carotenoid molecules within the bilayers in Chapter 5. Of particular importance, though, are interactions between carotenoids and proteins. These allow the hydrophobic carotenoids to be transported, to exist, and to function in an aqueous environment. In some cases they may modify strongly the light-absorption properties and hence the colour and photochemistry of the carotenoids.

  20. Herb-drug interaction of 50 Chinese herbal medicines on CYP3A4 activity in vitro and in vivo.

    PubMed

    Pao, Li-Heng; Hu, Oliver Yoa-Pu; Fan, Hsien-Yuan; Lin, Chang-Ching; Liu, Liang-Chun; Huang, Pei-Wei

    2012-01-01

    The purpose of this study is to evaluate the effects of Chinese herbal medicines on the enzymatic activity of CYP3A4 and the possible metabolism-based herb-drug interactions in human liver microsomes and in rats. Fifty single-herbal preparations were screened for the activity of CYP3A4 using human liver microsomes for an in vitro probe reaction study. The enzymatic activity of CYP3A4 was estimated by determing the 6β-hydroxytestosterone metabolized from testosterone performed on a liquid chromatography-tandem mass spectrometry (LC-MS/MS). Huang Qin (Scutellaria baicalensis Geprgi), Mu Dan Pi (Paeonia suffruticosa Andr.), Ji Shiee Terng (Spatholobus suberectus Dunn.) and Huang Qi (Astragalus membranaceus [Fisch] Bge) have been demonstrated to have remarkable inhibiting effects on the metabolism of CYP3A4, whereas Xi Yi Hua (Magnolia biondii Pamp.) exhibited a moderate inhibition. These five single herbs were further investigated in an animal study using midazolam. Mu Dan Pi, Ji Shiee Terng and Huang Qi were observed to have greatly increased in the C(max) and AUC of midazolam. This study provides evidence of possible herb-drug interactions involved with certain single herbs. PMID:22298448

  1. Synchronization via Hydrodynamic Interactions

    NASA Astrophysics Data System (ADS)

    Kendelbacher, Franziska; Stark, Holger

    2013-12-01

    An object moving in a viscous fluid creates a flow field that influences the motion of neighboring objects. We review examples from nature in the microscopic world where such hydrodynamic interactions synchronize beating or rotating filaments. Bacteria propel themselves using a bundle of rotating helical filaments called flagella which have to be synchronized in phase. Other micro-organisms are covered with a carpet of smaller filaments called cilia on their surfaces. They beat highly synchronized so that metachronal waves propagate along the cell surfaces. We explore both examples with the help of simple model systems and identify generic properties for observing synchronization by hydrodynamic interactions.

  2. Identifying Gene Interaction Networks

    PubMed Central

    Bebek, Gurkan

    2016-01-01

    In this chapter, we introduce interaction networks by describing how they are generated, where they are stored, and how they are shared. We focus on publicly available interaction networks and describe a simple way of utilizing these resources. As a case study, we used Cytoscape, an open source and easy-to-use network visualization and analysis tool to first gather and visualize a small network. We have analyzed this network’s topological features and have looked at functional enrichment of the network nodes by integrating the gene ontology database. The methods described are applicable to larger networks that can be collected from various resources. PMID:22307715

  3. Interactive holographic display

    NASA Astrophysics Data System (ADS)

    Son, Jung-Young; Lee, Beam-Ryeol; Kim, Jin-Woong; Chernyshov, Oleksii O.; Park, Min-Chul

    2014-06-01

    A holographic display which is capable of displaying floating holographic images is introduced. The display is for user interaction with the image on the display. It consists of two parts; multiplexed holographic image generation and a spherical mirror. The time multiplexed image from 2 X 10 DMD frames appeared on PDLC screen is imaged by the spherical mirror and becomes a floating image. This image is combined spatially with two layered TV images appearing behind. Since the floating holographic image has a real spatial position and depth, it allows a user to interact with the image.

  4. New interactive CESAR

    SciTech Connect

    Fox, P.B.; Yatabe, M.

    1987-01-01

    The Nuclear Criticality Safety Analytical Methods Resource Center announces the availability of a new interactive version of CESAR, a critical experiments storage and retrieval program available on the Nuclear Criticality Information System (NCIS) data base at Lawrence Livermore National Laboratory. The original version of CESAR did not include interactive search capabilities. The CESAR data base was developed to provide a convenient, readily accessible means of storing and retrieving code input data for the SCALE criticality safety analytical sequences and the codes comprising those sequences. The data base includes data for both cross-section preparation and criticality safety calculations.

  5. The new interactive CESAR

    SciTech Connect

    Fox, P.B.; Yatabe, M.

    1987-01-01

    In this report the Nuclear Criticality Safety Analytical Methods Resource Center describes a new interactive version of CESAR, a critical experiments storage and retrieval program available on the Nuclear Criticality Information System (NCIS) database at Lawrence Livermore National Laboratory. The original version of CESAR did not include interactive search capabilities. The CESAR database was developed to provide a convenient, readily accessible means of storing and retrieving code input data for the SCALE Criticality Safety Analytical Sequences and the codes comprising those sequences. The database includes data for both cross section preparation and criticality safety calculations. 3 refs., 1 tab.

  6. Solar-terrestrial interactions

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The effects of solar radiation on man's environment are discussed. It is solar radiation that is the basic energy source driving the circulations of the earth's atmosphere and oceans. Solar radiation is responsible for the ionization of the earth's upper atmosphere to form the ionosphere, which is important to our understanding of the magnetosphere and its interaction with the solar wind. The solar wind, which is the continuous (but not steady) flow of the sun's coronal plasma and magnetic field into interplanetary space, plays both an active and passive role in its interaction with the earth's environment.

  7. Honesty through repeated interactions.

    PubMed

    Rich, Patricia; Zollman, Kevin J S

    2016-04-21

    In the study of signaling, it is well known that the cost of deception is an essential element for stable honest signaling in nature. In this paper, we show how costs for deception can arise endogenously from repeated interactions between individuals. Utilizing the Sir Philip Sidney game as an illustrative case, we show that repeated interactions can sustain honesty with no observable signal costs, even when deception cannot be directly observed. We provide a number of potential experimental tests for this theory which distinguish it from the available alternatives. PMID:26869213

  8. GENIE final state interactions

    NASA Astrophysics Data System (ADS)

    Dytman, Steven

    2015-10-01

    Final state interactions are an important component of any neutrino-nucleus Monte Carlo program. GENIE has 2 FSI programs which serve different purposes. Each has fair-good agreement with a wide range of hadron-nucleus data. Recent improvements and planned advancements are described.

  9. Electron interaction in matter

    NASA Technical Reports Server (NTRS)

    Dance, W. E.; Rainwater, W. J.; Rester, D. H.

    1969-01-01

    Data on the scattering of 1-MeV electrons in aluminum for the case of non-normal incidence, electron-bremsstrahlung cross-sections in thin targets, and the production of bremstrahlung by electron interaction in thick targets, are presented both in tabular and graphic form. These results may interest physicists and radiologists.

  10. Interactive Tabletops in Education

    ERIC Educational Resources Information Center

    Dillenbourg, Pierre; Evans, Michael

    2011-01-01

    Interactive tabletops are gaining increased attention from CSCL researchers. This paper analyses the relation between this technology and teaching and learning processes. At a global level, one could argue that tabletops convey a socio-constructivist flavor: they support small teams that solve problems by exploring multiple solutions. The…