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Sample records for griggs paired comparison

  1. Percutaneous Dilatational Tracheostomy via Griggs Technique.

    Science.gov (United States)

    Karimpour, Hasan Ali; Vafaii, Kamran; Chalechale, Maryam; Mohammadi, Saeed; Kaviannezhad, Rasool

    2017-01-01

    Tracheostomy is considered the airway management of choice for patients who need prolonged mechanical ventilation support. Percutaneous Dilatational Tracheotomy (PDT) is a technique that can be performed easily and rapidly at bedside and is particularly useful in the intensive care setting. The Griggs percutaneous tracheotomy is unique in its utilization of a guide wire dilator forceps. We aimed to describe the early perioperative and late postoperative complications of PDT using the Griggs technique in patients in the intensive care unit (ICU). This cross-sectional study was conducted on all patients who underwent tracheostomy in the ICU of the Imam Reza Hospital of Kermanshah, Iran, from June 2011 to June 2015. PDT was performed in 184 patients with the Griggs technique. Demographic variables, as well as perioperative and late postoperative complications were recorded. The mean age of patients was 57.3 ± 15.37 years. The most common primary causes of tracheostomy were hypoxic brain damage disorders (43.2%) and pneumonia (14.8%). Perioperative and early complications occurred in 16.7 % of procedures, of which 9.3% were bleedings (minor, significant and major). Furthermore, the incidence of late complications was 8.6%, including: stomal infection, difficult replace tracheostomy tube, tracheoesophageal fistula, tracheal stenosis, and tracheomalacia. PDT via Griggs technique is a safe, quick, and effective method. The low incidence of complications indicates that bedside percutaneous tracheostomy can be performed safely as a routine procedure for daily care implemented in the ICU.

  2. 75 FR 49992 - Peter W.S. Grigg, M.D.; Revocation of Registration

    Science.gov (United States)

    2010-08-16

    ... DEPARTMENT OF JUSTICE Drug Enforcement Administration Peter W.S. Grigg, M.D.; Revocation of... Order to Show Cause and Immediate Suspension of Registration to Peter W.S. Grigg, M.D. (Respondent), of... Registration, BG2107856, issued to Peter W.S. Grigg, M.D., be, and it hereby is, revoked. This Order is...

  3. Experimental congruence of interval scale production from paired comparisons and ranking for image evaluation

    Science.gov (United States)

    Handley, John C.; Babcock, Jason S.; Pelz, Jeff B.

    2003-12-01

    Image evaluation tasks are often conducted using paired comparisons or ranking. To elicit interval scales, both methods rely on Thurstone's Law of Comparative Judgment in which objects closer in psychological space are more often confused in preference comparisons by a putative discriminal random process. It is often debated whether paired comparisons and ranking yield the same interval scales. An experiment was conducted to assess scale production using paired comparisons and ranking. For this experiment a Pioneer Plasma Display and Apple Cinema Display were used for stimulus presentation. Observers performed rank order and paired comparisons tasks on both displays. For each of five scenes, six images were created by manipulating attributes such as lightness, chroma, and hue using six different settings. The intention was to simulate the variability from a set of digital cameras or scanners. Nineteen subjects, (5 females, 14 males) ranging from 19-51 years of age participated in this experiment. Using a paired comparison model and a ranking model, scales were estimated for each display and image combination yielding ten scale pairs, ostensibly measuring the same psychological scale. The Bradley-Terry model was used for the paired comparisons data and the Bradley-Terry-Mallows model was used for the ranking data. Each model was fit using maximum likelihood estimation and assessed using likelihood ratio tests. Approximate 95% confidence intervals were also constructed using likelihood ratios. Model fits for paired comparisons were satisfactory for all scales except those from two image/display pairs; the ranking model fit uniformly well on all data sets. Arguing from overlapping confidence intervals, we conclude that paired comparisons and ranking produce no conflicting decisions regarding ultimate ordering of treatment preferences, but paired comparisons yield greater precision at the expense of lack-of-fit.

  4. WTA estimates using the method of paired comparison: tests of robustness

    Science.gov (United States)

    Patricia A. Champ; John B. Loomis

    1998-01-01

    The method of paired comparison is modified to allow choices between two alternative gains so as to estimate willingness to accept (WTA) without loss aversion. The robustness of WTA values for two public goods is tested with respect to sensitivity of theWTA measure to the context of the bundle of goods used in the paired comparison exercise and to the scope (scale) of...

  5. A comparison of gas geochemistry of fumaroles in the 1912 ash-flow sheet and on active stratovolcanoes, Katmai National Park, Alaska

    Science.gov (United States)

    Sheppard, D.S.; Janik, C.J.; Keith, T.E.C.

    1992-01-01

    Fumarolic gas samples collected in 1978 and 1979 from the stratovolcanoes Mount Griggs, Mount Mageik, and the 1953-68 SW Trident cone in Katmai National Park, Alaska, have been analysed and the results presented here. Comparison with recalculated analyses of samples collected from the Valley of Ten Thousand Smokes (VTTS) in 1917 and 1919 demonstrates differences between gases from the short-lived VTTS fumaroles, which were not directly magma related, and the fumaroles on the volcanic peaks. Fumarolic gases of Mount Griggs have an elevated total He content, suggesting a more direct deep crustal or mantle source for these gases than those from the other volcanoes. ?? 1992.

  6. An enquiry into the method of paired comparison: reliability, scaling, and Thurstone's Law of Comparative Judgment

    Science.gov (United States)

    Thomas C. Brown; George L. Peterson

    2009-01-01

    The method of paired comparisons is used to measure individuals' preference orderings of items presented to them as discrete binary choices. This paper reviews the theory and application of the paired comparison method, describes a new computer program available for eliciting the choices, and presents an analysis of methods for scaling paired choice data to...

  7. Estimation of Disability Weights in the General Population of South Korea Using a Paired Comparison.

    Directory of Open Access Journals (Sweden)

    Minsu Ock

    Full Text Available We estimated the disability weights in the South Korean population by using a paired comparison-only model wherein 'full health' and 'being dead' were included as anchor points, without resorting to a cardinal method, such as person trade-off. The study was conducted via 2 types of survey: a household survey involving computer-assisted face-to-face interviews and a web-based survey (similar to that of the GBD 2010 disability weight study. With regard to the valuation methods, paired comparison, visual analogue scale (VAS, and standard gamble (SG were used in the household survey, whereas paired comparison and population health equivalence (PHE were used in the web-based survey. Accordingly, we described a total of 258 health states, with 'full health' and 'being dead' designated as anchor points. In the analysis, 4 models were considered: a paired comparison-only model; hybrid model between paired comparison and PHE; VAS model; and SG model. A total of 2,728 and 3,188 individuals participated in the household and web-based survey, respectively. The Pearson correlation coefficients of the disability weights of health states between the GBD 2010 study and the current models were 0.802 for Model 2, 0.796 for Model 1, 0.681 for Model 3, and 0.574 for Model 4 (all P-values<0.001. The discrimination of values according to health state severity was most suitable in Model 1. Based on these results, the paired comparison-only model was selected as the best model for estimating disability weights in South Korea, and for maintaining simplicity in the analysis. Thus, disability weights can be more easily estimated by using paired comparison alone, with 'full health' and 'being dead' as one of the health states. As noted in our study, we believe that additional evidence regarding the universality of disability weight can be observed by using a simplified methodology of estimating disability weights.

  8. Estimation of Disability Weights in the General Population of South Korea Using a Paired Comparison.

    Science.gov (United States)

    Ock, Minsu; Ahn, Jeonghoon; Yoon, Seok-Jun; Jo, Min-Woo

    2016-01-01

    We estimated the disability weights in the South Korean population by using a paired comparison-only model wherein 'full health' and 'being dead' were included as anchor points, without resorting to a cardinal method, such as person trade-off. The study was conducted via 2 types of survey: a household survey involving computer-assisted face-to-face interviews and a web-based survey (similar to that of the GBD 2010 disability weight study). With regard to the valuation methods, paired comparison, visual analogue scale (VAS), and standard gamble (SG) were used in the household survey, whereas paired comparison and population health equivalence (PHE) were used in the web-based survey. Accordingly, we described a total of 258 health states, with 'full health' and 'being dead' designated as anchor points. In the analysis, 4 models were considered: a paired comparison-only model; hybrid model between paired comparison and PHE; VAS model; and SG model. A total of 2,728 and 3,188 individuals participated in the household and web-based survey, respectively. The Pearson correlation coefficients of the disability weights of health states between the GBD 2010 study and the current models were 0.802 for Model 2, 0.796 for Model 1, 0.681 for Model 3, and 0.574 for Model 4 (all P-valuesdisability weights in South Korea, and for maintaining simplicity in the analysis. Thus, disability weights can be more easily estimated by using paired comparison alone, with 'full health' and 'being dead' as one of the health states. As noted in our study, we believe that additional evidence regarding the universality of disability weight can be observed by using a simplified methodology of estimating disability weights.

  9. Estimation of Disability Weights in the General Population of South Korea Using a Paired Comparison

    Science.gov (United States)

    Ock, Minsu; Ahn, Jeonghoon; Yoon, Seok-Jun; Jo, Min-Woo

    2016-01-01

    We estimated the disability weights in the South Korean population by using a paired comparison-only model wherein ‘full health’ and ‘being dead’ were included as anchor points, without resorting to a cardinal method, such as person trade-off. The study was conducted via 2 types of survey: a household survey involving computer-assisted face-to-face interviews and a web-based survey (similar to that of the GBD 2010 disability weight study). With regard to the valuation methods, paired comparison, visual analogue scale (VAS), and standard gamble (SG) were used in the household survey, whereas paired comparison and population health equivalence (PHE) were used in the web-based survey. Accordingly, we described a total of 258 health states, with ‘full health’ and ‘being dead’ designated as anchor points. In the analysis, 4 models were considered: a paired comparison-only model; hybrid model between paired comparison and PHE; VAS model; and SG model. A total of 2,728 and 3,188 individuals participated in the household and web-based survey, respectively. The Pearson correlation coefficients of the disability weights of health states between the GBD 2010 study and the current models were 0.802 for Model 2, 0.796 for Model 1, 0.681 for Model 3, and 0.574 for Model 4 (all P-valuesdisability weights in South Korea, and for maintaining simplicity in the analysis. Thus, disability weights can be more easily estimated by using paired comparison alone, with ‘full health’ and ‘being dead’ as one of the health states. As noted in our study, we believe that additional evidence regarding the universality of disability weight can be observed by using a simplified methodology of estimating disability weights. PMID:27606626

  10. BAYESIAN ANALYSIS FOR THE PAIRED COMPARISON MODEL WITH ORDER EFFECTS (USING NON-INFORMATIVE PRIORS

    Directory of Open Access Journals (Sweden)

    Ghausia Masood Gilani

    2008-07-01

    Full Text Available Sometimes it may be difficult for a panelist to rank or compare more than two objects or treatments at the same time. For this reason, paired comparison method is used. In this study, the Davidson and Beaver (1977 model for paired comparisons with order effects is analyzed through the Bayesian Approach. For this purpose, the posterior means and the posterior modes are compared using the noninformative priors.

  11. Bayesian modeling to paired comparison data via the Pareto distribution

    Directory of Open Access Journals (Sweden)

    Nasir Abbas

    2017-12-01

    Full Text Available A probabilistic approach to build models for paired comparison experiments based on the comparison of two Pareto variables is considered. Analysis of the proposed model is carried out in classical as well as Bayesian frameworks. Informative and uninformative priors are employed to accommodate the prior information. Simulation study is conducted to assess the suitablily and performance of the model under theoretical conditions. Appropriateness of fit of the is also carried out. Entire inferential procedure is illustrated by comparing certain cricket teams using real dataset.

  12. Reducing the duration of paired-comparison experiments for visual quality assessment

    DEFF Research Database (Denmark)

    Mantel, Claire; Forchhammer, Søren; Korhonen, Jari

    2013-01-01

    The subjective methodology of paired comparison is currently recognized as the most precise methodology. However, it is not widely used because it implies a larger number of assessments than other methodologies and therefore a longer test duration. In this paper we investigate how sorting algorit...

  13. Rheological Properties of Natural Subduction Zone Interface: Insights from "Digital" Griggs Experiments

    Science.gov (United States)

    Ioannidi, P. I.; Le Pourhiet, L.; Moreno, M.; Agard, P.; Oncken, O.; Angiboust, S.

    2017-12-01

    The physical nature of plate locking and its relation to surface deformation patterns at different time scales (e.g. GPS displacements during the seismic cycle) can be better understood by determining the rheological parameters of the subduction interface. However, since direct rheological measurements are not possible, finite element modelling helps to determine the effective rheological parameters of the subduction interface. We used the open source finite element code pTatin to create 2D models, starting with a homogeneous medium representing shearing at the subduction interface. We tested several boundary conditions that mimic simple shear and opted for the one that best describes the Grigg's type simple shear experiments. After examining different parameters, such as shearing velocity, temperature and viscosity, we added complexity to the geometry by including a second phase. This arises from field observations, where shear zone outcrops are often composites of multiple phases: stronger crustal blocks embedded within a sedimentary and/or serpentinized matrix have been reported for several exhumed subduction zones. We implemented a simplified model to simulate simple shearing of a two-phase medium in order to quantify the effect of heterogeneous rheology on stress and strain localization. Preliminary results show different strength in the models depending on the block-to-matrix ratio. We applied our method to outcrop scale block-in-matrix geometries and by sampling at different depths along exhumed former subduction interfaces, we expect to be able to provide effective friction and viscosity of a natural interface. In a next step, these effective parameters will be used as input into seismic cycle deformation models in an attempt to assess the possible signature of field geometries on the slip behaviour of the plate interface.

  14. Determination of subjective similarity for pairs of masses and pairs of clustered microcalcifications on mammograms: Comparison of similarity ranking scores and absolute similarity ratings

    International Nuclear Information System (INIS)

    Muramatsu, Chisako; Li Qiang; Schmidt, Robert A.; Shiraishi, Junji; Suzuki, Kenji; Newstead, Gillian M.; Doi, Kunio

    2007-01-01

    The presentation of images that are similar to that of an unknown lesion seen on a mammogram may be helpful for radiologists to correctly diagnose that lesion. For similar images to be useful, they must be quite similar from the radiologists' point of view. We have been trying to quantify the radiologists' impression of similarity for pairs of lesions and to establish a ''gold standard'' for development and evaluation of a computerized scheme for selecting such similar images. However, it is considered difficult to reliably and accurately determine similarity ratings, because they are subjective. In this study, we compared the subjective similarities obtained by two different methods, an absolute rating method and a 2-alternative forced-choice (2AFC) method, to demonstrate that reliable similarity ratings can be determined by the responses of a group of radiologists. The absolute similarity ratings were previously obtained for pairs of masses and pairs of microcalcifications from five and nine radiologists, respectively. In this study, similarity ranking scores for eight pairs of masses and eight pairs of microcalcifications were determined by use of the 2AFC method. In the first session, the eight pairs of masses and eight pairs of microcalcifications were grouped and compared separately for determining the similarity ranking scores. In the second session, another similarity ranking score was determined by use of mixed pairs, i.e., by comparison of the similarity of a mass pair with that of a calcification pair. Four pairs of masses and four pairs of microcalcifications were grouped together to create two sets of eight pairs. The average absolute similarity ratings and the average similarity ranking scores showed very good correlations in the first study (Pearson's correlation coefficients: 0.94 and 0.98 for masses and microcalcifications, respectively). Moreover, in the second study, the correlations between the absolute ratings and the ranking scores were also

  15. The Visual Analogue Scale for Rating, Ranking and Paired-Comparison (VAS-RRP): A new technique for psychological measurement.

    Science.gov (United States)

    Sung, Yao-Ting; Wu, Jeng-Shin

    2018-04-17

    Traditionally, the visual analogue scale (VAS) has been proposed to overcome the limitations of ordinal measures from Likert-type scales. However, the function of VASs to overcome the limitations of response styles to Likert-type scales has not yet been addressed. Previous research using ranking and paired comparisons to compensate for the response styles of Likert-type scales has suffered from limitations, such as that the total score of ipsative measures is a constant that cannot be analyzed by means of many common statistical techniques. In this study we propose a new scale, called the Visual Analogue Scale for Rating, Ranking, and Paired-Comparison (VAS-RRP), which can be used to collect rating, ranking, and paired-comparison data simultaneously, while avoiding the limitations of each of these data collection methods. The characteristics, use, and analytic method of VAS-RRPs, as well as how they overcome the disadvantages of Likert-type scales, ranking, and VASs, are discussed. On the basis of analyses of simulated and empirical data, this study showed that VAS-RRPs improved reliability, response style bias, and parameter recovery. Finally, we have also designed a VAS-RRP Generator for researchers' construction and administration of their own VAS-RRPs.

  16. 4D Flexible Atom-Pairs: An efficient probabilistic conformational space comparison for ligand-based virtual screening

    Science.gov (United States)

    2011-01-01

    Background The performance of 3D-based virtual screening similarity functions is affected by the applied conformations of compounds. Therefore, the results of 3D approaches are often less robust than 2D approaches. The application of 3D methods on multiple conformer data sets normally reduces this weakness, but entails a significant computational overhead. Therefore, we developed a special conformational space encoding by means of Gaussian mixture models and a similarity function that operates on these models. The application of a model-based encoding allows an efficient comparison of the conformational space of compounds. Results Comparisons of our 4D flexible atom-pair approach with over 15 state-of-the-art 2D- and 3D-based virtual screening similarity functions on the 40 data sets of the Directory of Useful Decoys show a robust performance of our approach. Even 3D-based approaches that operate on multiple conformers yield inferior results. The 4D flexible atom-pair method achieves an averaged AUC value of 0.78 on the filtered Directory of Useful Decoys data sets. The best 2D- and 3D-based approaches of this study yield an AUC value of 0.74 and 0.72, respectively. As a result, the 4D flexible atom-pair approach achieves an average rank of 1.25 with respect to 15 other state-of-the-art similarity functions and four different evaluation metrics. Conclusions Our 4D method yields a robust performance on 40 pharmaceutically relevant targets. The conformational space encoding enables an efficient comparison of the conformational space. Therefore, the weakness of the 3D-based approaches on single conformations is circumvented. With over 100,000 similarity calculations on a single desktop CPU, the utilization of the 4D flexible atom-pair in real-world applications is feasible. PMID:21733172

  17. Strong pairing approximation in comparison with the exact solutions to the pairing Hamiltonian

    Directory of Open Access Journals (Sweden)

    Lunyov A.V.

    2016-01-01

    Full Text Available Results of the Strong Pairing Approximation (SPA as a method with the exact particle number conservation are compared with those of the quasiparticle method (QM. It is shown that SPA comes to the same equations as QM for the gap parameter, chemical potential and one- and two-quasiparticle states. Calculations are performed for 14864Gd84 as an example, and compared with the exact solutions to the pairing Hamiltonian.

  18. A syntactical comparison between pair sentential calculus PSC and Gupta's definitional calculus Cn

    OpenAIRE

    石井,忠夫

    2016-01-01

    In this paper we will compare two logical systems PSC and Cn with a syntactical point of view. Because both notions of the pair-sentence with stage number in PSC and Gupta's sentence-definition with revision stage number in Cn are very similar, and both can deal with paradoxical sentences like a simple Liar sentence. His system was defined as a predicate calculus, but here we will introduce the propositional version of Cn for the comparison, and we had the following results: (1) C0 is a sublo...

  19. A Study on Visibility Estimation of Web-Safe Colors using Paired Comparison and Discriminant Analysis

    Science.gov (United States)

    Saito, Daisuke; Saito, Keiichi; Notomi, Kazuhiro; Saito, Masao

    This paper presents the visibility ordering of several web safe colors. The research of web page visibility is important because of the rapid dissemination of the World Wide Web. The combination of a foreground color and a background color is an important factor in providing sufficient visibility. Therefore, the rating of color combination visibility is necessary when developing accessible web sites. In this study, the visibility of several web-safe color combinations was examined using psychological methodology, i.e., paired comparison. Eighteen chromatic and 3 achromatic web-safe colors were employed for visual stimuli. Twenty-eight subjects ranging from ages 21 to 75 were recruited, and all were with normal color sensation. They looked at two different colored characters simultaneously on the white background and were instructed to identify which one enabled them to see more clearly. In examining the relationship between the psychological rankings of the color combinations and the visual sensations, each color combination was first scored as to the visibility by Thurstone's paired comparison technique. Secondly, the visual sensation was deduced by applying Weber-Fechner's law to the luminance of the foreground colors. As results, the luminance of a foreground color influenced the visibility; however the visibility rating is difficult only using the luminance of web-safe colors. These indicate that the chromaticity and chroma saturation are necessary in rating of chromatic web-safe color visibility.

  20. Comparison of split double and triple twists in pair figure skating.

    Science.gov (United States)

    King, Deborah L; Smith, Sarah L; Brown, Michele R; McCrory, Jean L; Munkasy, Barry A; Scheirman, Gary I

    2008-05-01

    In this study, we compared the kinematic variables of the split triple twist with those of the split double twist to help coaches and scientists understand these landmark pair skating skills. High-speed video was taken during the pair short and free programmes at the 2002 Salt Lake City Winter Olympics and the 2003 International Skating Union Grand Prix Finals. Three-dimensional analyses of 14 split double twists and 15 split triple twists from eleven pairs were completed. In spite of considerable variability in the performance variables among the pairs, the main difference between the split double twists and split triple twists was an increase in rotational rate. While eight of the eleven pairs relied primarily on an increased rotational rate to complete the split triple twist, three pairs employed a combined strategy of increased rotational rate and increased flight time due predominantly to delayed or lower catches. These results were similar to observations of jumps in singles skating for which the extra rotation is typically due to an increase in rotational velocity; increases in flight time come primarily from delayed landings as opposed to additional height during flight. Combining an increase in flight time and rotational rate may be a good strategy for completing the split triple twist in pair skating.

  1. Selection of candidate plus phenotypes of Jatropha curcas L. using method of paired comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, D.K. [Silviculture Division, Arid Forest Research Institute, P.O. Krishi Mandi, New Pali Road, Jodhpur 342005, Rajasthan (India)

    2009-03-15

    Jatropha curcas L. (Euphorbiaceae) is an oil bearing species with multiple uses and considerable potential as a biodiesel crop. The present communication deals with the method of selecting plus phenotypes of J. curcas for exploiting genetic variability for further improvement. Candidate plus tree selection is the first and most important stage in any tree improvement programme. The selection of candidate plus plants (CPPs) is based upon various important attributes associated with the species and their relative ranking. Relative preference between various traits and scoring for each trait has been worked out by using the method of paired comparisons for the selection of CPP in J. curcas L. The most important ones are seed and oil yields. (author)

  2. Comparison of muon-pair production to the quark-antiquark annihilation model

    International Nuclear Information System (INIS)

    Hogan, G.E.; Anderson, K.J.; Coleman, R.N.; Karhi, K.P.; McDonald, K.T.; Newman, C.B.; Pilcher, J.E.; Rosenberg, E.I.; Sanders, G.H.; Smith, A.J.S.; Thaler, J.J.

    1979-01-01

    New data on muon-pair production at 225 GeV/c by π - , π + , and proton beams are analyzed with regard to the production mechanism. The observed spin alignment of the pair and the dependence of the cross section on beam-particle type are strong indications that the production is through electromagnetic quark-antiquark annihilation

  3. Potential of mean force for ion pairs in non-aqueous solvents. Comparison of polarizable and non-polarizable MD simulations

    Science.gov (United States)

    Odinokov, A. V.; Leontyev, I. V.; Basilevsky, M. V.; Petrov, N. Ch.

    2011-01-01

    Potentials of mean force (PMF) are calculated for two model ion pairs in two non-aqueous solvents. Standard non-polarizable molecular dynamics simulation (NPMD) and approximate polarizable simulation (PMD) are implemented and compared as tools for monitoring PMF profiles. For the polar solvent (dimethylsulfoxide, DMSO) the PMF generated in terms of the NPMD reproduces fairly well the refined PMD-PMF profile. For the non-polar solvent (benzene) the conventional NPMD computation proves to be deficient. The validity of the correction found in terms of the approximate PMD approach is verified by its comparison with the result of the explicit PMD computation in benzene. The shapes of the PMF profiles in DMSO and in benzene are quite different. In DMSO, owing to dielectric screening, the PMF presents a flat plot with a shallow minimum positioned in the vicinity of the van der Waals contact of the ion pair. For the benzene case, the observed minimum proves to be unexpectedly deep, which manifests the formation of a tightly-binded contact ion pair. This remarkable effect arises owing to the strong electrostatic interaction that is incompletely screened by a non-polar medium. The PMFs for the binary benzene/DMSO mixtures display intermediate behaviour depending on the DMSO content.

  4. Comparison of self-administration behavior and responsiveness to drug-paired cues in rats running an alley for intravenous heroin and cocaine.

    Science.gov (United States)

    Su, Zu-In; Wenzel, Jennifer; Baird, Rebeccah; Ettenberg, Aaron

    2011-04-01

    Evidence suggests that responsiveness to a drug-paired cue is predicted by the reinforcing magnitude of the drug during prior self-administration. It remains unclear, however, if this principle holds true when comparisons are made across drug reinforcers. The current study was therefore devised to test the hypothesis that differences in the animals' responsiveness to a cocaine- or heroin-paired cue presented during extinction would reflect differences in the patterns of prior cocaine and heroin runway self-administration. Rats ran a straight alley for single intravenous injections of either heroin (0.1 mg/kg/inj) or cocaine (1.0 mg/kg/inj) each paired with a distinct olfactory cue. Animals experienced 15 trials with each drug reinforcer in a counterbalanced manner. Start latencies, run times, and retreat behaviors (a form of approach-avoidance conflict) provided behavioral indices of the subjects' motivation to seek the reinforcer on each trial. Responsiveness to each drug-paired cue was assessed after 7, 14, or 21 days of non-reinforced extinction trials. Other animals underwent conditioned place preference (CPP) testing to ensure that the two drug reinforcers were capable of producing drug-cue associations. While both drugs produced comparable CPPs, heroin served as a stronger incentive stimulus in the runway as evidenced by faster start and run times and fewer retreats. In contrast, cocaine- but not heroin-paired cues produced increases in drug-seeking behavior during subsequent extinction trials. The subjects' responsiveness to drug-paired cues during extinction was not predicted by differences in the motivation to seek heroin versus cocaine during prior drug self-administration.

  5. Treatment of pairing correlations based on the equations of motion for zero-coupled pair operators

    International Nuclear Information System (INIS)

    Andreozzi, F.; Covello, A.; Gargano, A.; Ye, L.J.; Porrino, A.

    1985-01-01

    The pairing problem is treated by means of the equations of motion for zero-coupled pair operators. Exact equations for the seniority-v states of N particles are derived. These equations can be solved by a step-by-step procedure which consists of progressively adding pairs of particles to a core. The theory can be applied at several levels of approximation depending on the number of core states which are taken into account. Some numerical applications to the treatment of v = 0, v = 1, and v = 2 states in the Ni isotopes are performed. The accuracy of various approximations is tested by comparison with exact results. For the seniority-one and seniority-two problems it turns out that the results obtained from the first-order theory are very accurate, while those of higher order calculations are practically exact. Concerning the seniority-zero problem, a fifth-order calculation reproduces quite well the three lowest states

  6. A preliminary inter-centre comparison study for photon, thermal neutron and epithermal neutron responses of two pairs of ionisation chambers used for BNCT

    International Nuclear Information System (INIS)

    Roca, Antoaneta; Liu, Yuan-Hao; Wojnecki, Cecile; Green, Stuart; Nievaart, Sander; Ghani, Zamir; Moss, Ray

    2009-01-01

    The dual ionisation chamber technique is the recommended method for mixed field dosimetry of epithermal neutron beams. This paper presents initial data from an ongoing inter-comparison study involving two identical pairs of ionisation chambers used at the BNCT facilities of Petten, NL and of University of Birmingham, UK. The goal of this study is to evaluate the photon, thermal neutron and epithermal neutron responses of both pairs of TE(TE) (Exradin T2 type) and Mg(Ar) (Exradin M2 type) ionisation chambers in similar experimental conditions. At this stage, the work has been completed for the M2 type chambers and is intended to be completed for the T2 type chambers in the near future.

  7. Alignments of multi-quasiparticle bands and seniority-dependent reduced pairing

    International Nuclear Information System (INIS)

    Dracoulis, G.D.

    1994-09-01

    Pairing correlations in multi-quasiparticle states in deformed nuclei are expected to be reduced because of blocking. New intrinsic states and their associated rotational bands have been identified allowing comparisons to be made as a function of seniority and between nuclei. The possible effects of the reduced pairing on the collective rotation, and its manifestation in terms of alignment, are discussed. 13 refs., 2 figs

  8. Pair truncation for rotational nuclei: j=17/2 model

    International Nuclear Information System (INIS)

    Halse, P.; Jaqua, L.; Barrett, B.R.

    1989-01-01

    The suitability of the pair condensate approach for rotational states is studied in a single j=17/2 shell of identical nucleons interacting through a quadrupole-quadrupole Hamiltonian. The ground band and a K=2 excited band are both studied in detail. A direct comparison of the exact states with those constituting the SD and SDG subspaces is used to identify the important degrees of freedom for these levels. The range of pairs necessary for a good description is found to be highly state dependent; S and D pairs are the major constituents of the low-spin ground-band levels, while G pairs are needed for those in the γ band. Energy spectra are obtained for each truncated subspace. SDG pairs allow accurate reproduction of the binding energy and K=2 excitation energy, but still give a moment of inertia which is about 30% too small even for the lowest levels

  9. Paired-eye comparison of medical therapies for glaucoma

    Directory of Open Access Journals (Sweden)

    Alfred M Solish

    2010-09-01

    Full Text Available Alfred M Solish1,2, Friedericke James1, John G Walt3, Tina H Chiang31Southern California Glaucoma Consultants, Pasadena CA, USA; 2Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, 3Allergan Inc., Irvine, CA, USA Objective: To evaluate efficacy and patient preference retrospectively among intraocular pressure (IOP-lowering prostamide and prostaglandin medications in a real-world clinical setting.Methods: Chart review of patients with uncontrolled glaucoma or ocular hypertension seen at a private practice clinic (n = 55 who received bimatoprost 0.03% once daily in one eye and either travoprost 0.004% or latanoprost 0.005% once daily in the fellow eye. IOP was evaluated at the initial visit and at a follow-up visit scheduled 4–6 weeks later. At the follow-up visit, each patient discussed the clinical results with their physician, chose which medication they preferred to continue using, and were queried regarding the reason for their choice. This paired-eye comparison method is used routinely in clinical practice to assess clinical response and involve patients in decisions regarding treatment. Change in mean IOP from baseline and patient medication choice were the outcome measures.Results: Bimatoprost-treated eyes (n = 52 had a mean IOP reduction of 2.7 mmHg and travoprost-treated eyes (n = 47 had an average decrease of 1.7 mmHg (P = 0.230. Bimatoprost significantly reduced mean IOP (from 19.8 mmHg at baseline to 17.1 mmHg at follow-up, P < 0.0001, as did travoprost (from 19.4 mmHg at baseline to 17.7 mmHg at follow-up, P = 0.009. Latanoprost-treated eyes were excluded from the efficacy analysis due to small sample size (n = 5. For continued therapy, patients chose bimatoprost over travoprost by a factor of 2.4 to 1. Of the 15 patients who gave a reason for their choice, 80% said their decision was based primarily on IOP change.Conclusions: Bimatoprost and travoprost were efficacious in reducing IOP among patients with

  10. Butterflyfishes as a System for Investigating Pair Bonding

    KAUST Repository

    Nowicki, Jessica

    2017-11-14

    For many animals, affiliative relationships such as pair bonds form the foundation of society, and are highly adaptive. Animal systems amenable for comparatively studying pair bonding are important for identifying underlying biological mechanisms, but mostly exist in mammals. Better establishing fish systems will enable comparison of pair bonding mechanisms across taxonomically distant lineages that may reveal general underlying principles. We examined the utility of wild butterflyfishes (f: Chaetodontidae; g: Chaetodon) for comparatively studying pair bonding. Stochastic character mapping inferred that within the family, pairing is ancestral, with at least seven independent transitions to group formation and seven transition to solitary behavior from the late Miocene to recent. In six sympatric and wide-spread species representing a clade with one ancestrally reconstructed transition from paired to solitary grouping, we then verified social systems at Lizard Island, Australia. In situ observations confirmed that Chaetodon baronessa, C. lunulatus, and C. vagabundus are predominantly pair bonding, whereas C. rainfordi, C. plebeius, and C. trifascialis are predominantly solitary. Even in the predominantly pair bonding species, C. lunulatus, a proportion of adults (15 %) are solitary. Importantly, inter- and intra-specific differences in social systems do not co-vary with other previously established attributes (geographic occurrence, parental care, diet, or territoriality). Hence, the proposed butterflyfish populations are promising for comparative analyses of pair bonding and its mechanistic underpinnings. Avenues for further developing the system are proposed, including determining whether the utility of these species applies across their geographic disruptions.

  11. Sensitivity of Electron Transfer Mediated Decay to Ion Pairing.

    Science.gov (United States)

    Pohl, Marvin N; Richter, Clemens; Lugovoy, Evgeny; Seidel, Robert; Slavíček, Petr; Aziz, Emad F; Abel, Bernd; Winter, Bernd; Hergenhahn, Uwe

    2017-08-17

    Ion pairing in electrolyte solutions remains a topic of discussion despite a long history of research. Very recently, nearest-neighbor mediated electronic de-excitation processes of core hole vacancies (electron transfer mediated decay, ETMD) were proposed to carry a spectral fingerprint of local solvation structure and in particular of contact ion pairs. Here, for the first time, we apply electron-electron coincidence detection to a liquid microjet, and record ETMD spectra of Li 1s vacancies in aqueous solutions of lithium chloride (LiCl) in direct comparison to lithium acetate (LiOAc). A change in the ETMD spectrum dependent on the electrolyte anion identity is observed for 4.5 M salt concentration. We discuss these findings within the framework of the formation and presence of contact ion pairs and the unique sensitivity of ETMD spectroscopy to ion pairing.

  12. PCTFPeval: a web tool for benchmarking newly developed algorithms for predicting cooperative transcription factor pairs in yeast.

    Science.gov (United States)

    Lai, Fu-Jou; Chang, Hong-Tsun; Wu, Wei-Sheng

    2015-01-01

    Computational identification of cooperative transcription factor (TF) pairs helps understand the combinatorial regulation of gene expression in eukaryotic cells. Many advanced algorithms have been proposed to predict cooperative TF pairs in yeast. However, it is still difficult to conduct a comprehensive and objective performance comparison of different algorithms because of lacking sufficient performance indices and adequate overall performance scores. To solve this problem, in our previous study (published in BMC Systems Biology 2014), we adopted/proposed eight performance indices and designed two overall performance scores to compare the performance of 14 existing algorithms for predicting cooperative TF pairs in yeast. Most importantly, our performance comparison framework can be applied to comprehensively and objectively evaluate the performance of a newly developed algorithm. However, to use our framework, researchers have to put a lot of effort to construct it first. To save researchers time and effort, here we develop a web tool to implement our performance comparison framework, featuring fast data processing, a comprehensive performance comparison and an easy-to-use web interface. The developed tool is called PCTFPeval (Predicted Cooperative TF Pair evaluator), written in PHP and Python programming languages. The friendly web interface allows users to input a list of predicted cooperative TF pairs from their algorithm and select (i) the compared algorithms among the 15 existing algorithms, (ii) the performance indices among the eight existing indices, and (iii) the overall performance scores from two possible choices. The comprehensive performance comparison results are then generated in tens of seconds and shown as both bar charts and tables. The original comparison results of each compared algorithm and each selected performance index can be downloaded as text files for further analyses. Allowing users to select eight existing performance indices and 15

  13. Multi-pair states in electron–positron pair creation

    Directory of Open Access Journals (Sweden)

    Anton Wöllert

    2016-09-01

    Full Text Available Ultra strong electromagnetic fields can lead to spontaneous creation of single or multiple electron–positron pairs. A quantum field theoretical treatment of the pair creation process combined with numerical methods provides a description of the fermionic quantum field state, from which all observables of the multiple electron–positron pairs can be inferred. This allows to study the complex multi-particle dynamics of electron–positron pair creation in-depth, including multi-pair statistics as well as momentum distributions and spin. To illustrate the potential benefit of this approach, it is applied to the intermediate regime of pair creation between nonperturbative Schwinger pair creation and perturbative multiphoton pair creation where the creation of multi-pair states becomes nonnegligible but cascades do not yet set in. Furthermore, it is demonstrated how spin and helicity of the created electrons and positrons are affected by the polarization of the counterpropagating laser fields, which induce the creation of electron–positron pairs.

  14. Multi-pair states in electron–positron pair creation

    Energy Technology Data Exchange (ETDEWEB)

    Wöllert, Anton, E-mail: woellert@mpi-hd.mpg.de; Bauke, Heiko, E-mail: heiko.bauke@mpi-hd.mpg.de; Keitel, Christoph H.

    2016-09-10

    Ultra strong electromagnetic fields can lead to spontaneous creation of single or multiple electron–positron pairs. A quantum field theoretical treatment of the pair creation process combined with numerical methods provides a description of the fermionic quantum field state, from which all observables of the multiple electron–positron pairs can be inferred. This allows to study the complex multi-particle dynamics of electron–positron pair creation in-depth, including multi-pair statistics as well as momentum distributions and spin. To illustrate the potential benefit of this approach, it is applied to the intermediate regime of pair creation between nonperturbative Schwinger pair creation and perturbative multiphoton pair creation where the creation of multi-pair states becomes nonnegligible but cascades do not yet set in. Furthermore, it is demonstrated how spin and helicity of the created electrons and positrons are affected by the polarization of the counterpropagating laser fields, which induce the creation of electron–positron pairs.

  15. Multi-pair states in electron–positron pair creation

    International Nuclear Information System (INIS)

    Wöllert, Anton; Bauke, Heiko; Keitel, Christoph H.

    2016-01-01

    Ultra strong electromagnetic fields can lead to spontaneous creation of single or multiple electron–positron pairs. A quantum field theoretical treatment of the pair creation process combined with numerical methods provides a description of the fermionic quantum field state, from which all observables of the multiple electron–positron pairs can be inferred. This allows to study the complex multi-particle dynamics of electron–positron pair creation in-depth, including multi-pair statistics as well as momentum distributions and spin. To illustrate the potential benefit of this approach, it is applied to the intermediate regime of pair creation between nonperturbative Schwinger pair creation and perturbative multiphoton pair creation where the creation of multi-pair states becomes nonnegligible but cascades do not yet set in. Furthermore, it is demonstrated how spin and helicity of the created electrons and positrons are affected by the polarization of the counterpropagating laser fields, which induce the creation of electron–positron pairs.

  16. Eliciting hyperparameters of prior distributions for the parameters of paired comparison models

    Directory of Open Access Journals (Sweden)

    Nasir Abbas

    2013-02-01

    Full Text Available Normal 0 false false false EN-US X-NONE AR-SA In the study of paired comparisons (PC, items may be ranked or issues may be prioritized through subjective assessment of certain judges. PC models are developed and then used to serve the purpose of ranking. The PC models may be studied through classical or Bayesian approach. Bayesian inference is a modern statistical technique used to draw conclusions about the population parameters. Its beauty lies in incorporating prior information about the parameters into the analysis in addition to current information (i.e. data. The prior and current information are formally combined to yield a posterior distribution about the population parameters, which is the work bench of the Bayesian statisticians. However, the problems the Bayesians face correspond to the selection and formal utilization of prior distribution. Once the type of prior distribution is decided to be used, the problem of estimating the parameters of the prior distribution (i.e. elicitation still persists. Different methods are devised to serve the purpose. In this study an attempt is made to use Minimum Chi-square (hence forth MCS for the elicitation purpose. Though it is a classical estimation technique, but is used here for the election purpose. The entire elicitation procedure is illustrated through a numerical data set.

  17. Quantifying the FIR interaction enhancement in paired galaxies

    International Nuclear Information System (INIS)

    Xu Cong; Sulentic, J.W.

    1990-01-01

    We studied the ''Catalogue of Isolated Pairs of Galaxies in the Northern Hemisphere'' by Karachentsev (1972) and a well matched comparison sample taken from the ''Catalogue of Isolated Galaxies'' by Karachentseva (1973) in order to quantify the enhanced FIR emission properties of interacting galaxies. 8 refs, 6 figs

  18. Vocabulary Learning in Collaborative Tasks: A Comparison of Pair and Small Group Work

    Science.gov (United States)

    Dobao, Ana Fernández

    2014-01-01

    This study examined the opportunities that pair and small group interaction offer for collaborative dialogue and second language (L2) vocabulary learning. It compared the performance of the same collaborative writing task by learners working in groups of four (n = 60) and in pairs (n = 50), focusing on the occurrence of lexical language-related…

  19. Scaling Professional Problems of Teachers in Turkey with Paired Comparison Method

    Directory of Open Access Journals (Sweden)

    Yasemin Duygu ESEN

    2017-03-01

    Full Text Available In this study, teachers’ professional problems was investigated and the significance level of them was measured with the paired comparison method. The study was carried out in survey model. The study group consisted of 484 teachers working in public schools which are accredited by Ministry of National Education (MEB in Turkey. “The Teacher Professional Problems Survey” developed by the researchers was used as a data collection tool. In data analysis , the scaling method with the third conditional equation of Thurstone’s law of comparative judgement was used. According to the results of study, the teachers’ professional problems include teacher training and the quality of teacher, employee rights and financial problems, decrease of professional reputation, the problems with MEB policies, the problems with union activities, workload, the problems with administration in school, physical conditions and the lack of infrastructure, the problems with parents, the problems with students. According to teachers, the most significant problem is MEB educational policies. This is followed by decrease of professional reputation, physical conditions and the lack of infrastructure, the problems with students, employee rights and financial problems, the problems with administration in school, teacher training and the quality of teacher, the problems with parents, workload, and the problems with union activities. When teachers’ professional problems were analyzed seniority variable, there was little difference in scale values. While the teachers with 0-10 years experience consider decrease of professional reputation as the most important problem, the teachers with 11-45 years experience put the problems with MEB policies at the first place.

  20. A COMPARISON OF PAIRS FIGURE SKATERS IN REPEATED JUMPS

    Directory of Open Access Journals (Sweden)

    William A. Sands

    2012-03-01

    Full Text Available Trends in pairs figure skating have shown that increasingly difficult jumps have become an essential aspect of high-level performance, especially in the latter part of a competitive program. We compared a repeated jump power index in a 60 s repeated jump test to determine the relationship of repeated jump test to competitive rank and to measure 2D hip, knee, and ankle angles and angular velocities at 0, 20, 40, and 60 s. Eighteen National Team Pairs Figure Skaters performed a 60 s repeated jump test on a large switch-mat with timing of flight and ground durations and digital video recording. Each 60-s period was divided into 6, 10-s intervals, with power indexes (W/kg calculated for each 10-s interval. Power index by 10-s interval repeated measures ANOVAs (RMANOVA showed that males exceeded females at all intervals, and the highest power index interval was during 10 to 20 s for both sexes. RMANOVAs of angles and angular velocities showed main effects for time only. Power index and jumping techniques among figure skaters showed rapid and steady declines over the test duration. Power index can predict approximately 50% of competitive rank variance, and sex differences in jumping technique were rare

  1. Exergetic and energetic comparison of LiCl-H_2O and LiBr-H_2O working pairs in a solar absorption cooling system

    International Nuclear Information System (INIS)

    Bellos, Evangelos; Tzivanidis, Christos; Antonopoulos, Kimon A.

    2016-01-01

    Highlights: • Two working pairs (LiCl-H_2O and LiBr-H_2O) are examined in a solar absorption chiller. • The examined single effect absorption chiller is driven by flat plate collectors. • The system is analyzed energetically and energetically for 3 ambient temperatures. • LiCl-H_2O performs better than LiBr-H_2O in all the examined cases. • The optimum operating temperature is lower for the case of pair LiCl-H_2O. - Abstract: The objective of this study is to investigate the use of an alternative working pair in a solar absorption cooling system. LiCl-H_2O is the new examined pair and it is compared energetically and exegetically with the conventional pair LiBr-H_2O, which is the most usual in air-conditioning applications. The simplest solar cooling system is analyzed in order to focus in the comparison between these working fluids. Specifically, flat plate collectors, coupled with a storage tank, feed the single effect absorption chiller which produces 250 kW cooling at 10 °C. The two pairs are examined parametrically for various heat source temperature levels and for three ambient temperature levels (25 °C, 30 °C and 35 °C). The minimization of the collecting area, which means maximum exergetic efficiency, is the optimization goal in every case. The final results show that LiCl-H_2O pair performs better in all cases by giving greater exergetic efficiency. More specifically, about 8% lower collecting area is required to cover the demanded cooling load with this working pair. Another interesting result is that the optimum heat source temperature for the LiCl-H_2O is roughly lower than the respective for the LiBr-H_2O. The system is analyzed in steady state with the commercial software Engineering Equator Solver (EES).

  2. How Many Alternatives Can Be Ranked? A Comparison of the Paired Comparison and Ranking Methods.

    Science.gov (United States)

    Ock, Minsu; Yi, Nari; Ahn, Jeonghoon; Jo, Min-Woo

    2016-01-01

    To determine the feasibility of converting ranking data into paired comparison (PC) data and suggest the number of alternatives that can be ranked by comparing a PC and a ranking method. Using a total of 222 health states, a household survey was conducted in a sample of 300 individuals from the general population. Each respondent performed a PC 15 times and a ranking method 6 times (two attempts of ranking three, four, and five health states, respectively). The health states of the PC and the ranking method were constructed to overlap each other. We converted the ranked data into PC data and examined the consistency of the response rate. Applying probit regression, we obtained the predicted probability of each method. Pearson correlation coefficients were determined between the predicted probabilities of those methods. The mean absolute error was also assessed between the observed and the predicted values. The overall consistency of the response rate was 82.8%. The Pearson correlation coefficients were 0.789, 0.852, and 0.893 for ranking three, four, and five health states, respectively. The lowest mean absolute error was 0.082 (95% confidence interval [CI] 0.074-0.090) in ranking five health states, followed by 0.123 (95% CI 0.111-0.135) in ranking four health states and 0.126 (95% CI 0.113-0.138) in ranking three health states. After empirically examining the consistency of the response rate between a PC and a ranking method, we suggest that using five alternatives in the ranking method may be superior to using three or four alternatives. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  3. Preliminary evidence suggests extra-pair mating in the endangered ...

    African Journals Online (AJOL)

    This study utilized four microsatellite genetic markers, originally developed for the African grey parrot. Parentage testing was undertaken using genotype comparisons with the dominant pair within the breeding group as well as auxiliary males where available. Although four markers were insufficient to provide conclusive ...

  4. A pair spectrometer for measuring multipolarities of energetic nuclear transitions

    CERN Document Server

    Gulyás, J.; Krasznahorkay, A.J.; Csatlós, M.; Csige, L.; Gácsi, Z.; Hunyadi, M.; Krasznahorkay, A.; Vitéz, A.; Tornyi, T.G.

    2016-02-01

    A multi-detector array has been designed and constructed for the simultaneous measurement of energy- and angular correlations of electron-positron pairs. Experimental results are obtained over a wide angular range for high-energy transitions in 16O, 12C and 8Be. A comparison with GEANT simulations demonstrates that angular correlations between 50 and 180 degrees of the electron-positron pairs in the energy range between 6 and 18 MeV can be determined with sufficient resolution and efficiency.

  5. The role of familiarity in associative recognition of unitized compound word pairs.

    Science.gov (United States)

    Ahmad, Fahad N; Hockley, William E

    2014-01-01

    This study examined the effect of unitization and contribution of familiarity in the recognition of word pairs. Compound words were presented as word pairs and were contrasted with noncompound word pairs in an associative recognition task. In Experiments 1 and 2, yes-no recognition hit and false-alarm rates were significantly higher for compound than for noncompound word pairs, with no difference in discrimination in both within- and between-subject comparisons. Experiment 2 also showed that item recognition was reduced for words from compound compared to noncompound word pairs, providing evidence of the unitization of the compound pairs. A two-alternative forced-choice test used in Experiments 3A and 3B provided evidence that the concordant effect for compound word pairs was largely due to familiarity. A discrimination advantage for compound word pairs was also seen in these experiments. Experiment 4A showed that a different pattern of results is seen when repeated noncompound word pairs are compared to compound word pairs. Experiment 4B showed that memory for the individual items of compound word pairs was impaired relative to items in repeated and nonrepeated noncompound word pairs, and Experiment 5 demonstrated that this effect is eliminated when the elements of compound word pairs are not unitized. The concordant pattern seen in yes-no recognition and the discrimination advantage in forced-choice recognition for compound relative to noncompound word pairs is due to greater reliance on familiarity at test when pairs are unitized.

  6. Effective pair potentials for spherical nanoparticles

    International Nuclear Information System (INIS)

    Van Zon, Ramses

    2009-01-01

    An effective description for rigid spherical nanoparticles in a fluid of point particles is presented. The points inside the nanoparticles and the point particles are assumed to interact via spherically symmetric additive pair potentials, while the distribution of points inside the nanoparticles is taken to be spherically symmetric and smooth. The resulting effective pair interactions between a nanoparticle and a point particle, as well as between two nanoparticles, are then given by spherically symmetric potentials. If overlap between particles is allowed, as can occur for some forms of the pair potentials, the effective potential generally has non-analytic points. It is shown that for each effective potential the expressions for different overlapping cases can be written in terms of one analytic auxiliary potential. Even when only non-overlapping situations are possible, the auxiliary potentials facilitate the formulation of the effective potentials. Effective potentials for hollow nanoparticles (appropriate e.g. for buckyballs) are also considered and shown to be related to those for solid nanoparticles. For hollow nanoparticles overlap is more physical, since this covers the case of a smaller particle embedded in a larger, hollow nanoparticle. Finally, explicit expressions are given for the effective potentials derived from basic pair potentials of power law and exponential form, as well as from the commonly used London–van der Waals, Morse, Buckingham, and Lennard-Jones potentials. The applicability of the latter is demonstrated by comparison with an atomic description of nanoparticles with an internal face centered cubic structure

  7. Evaluation of users' satisfaction on pedestrian facilities using pair-wise comparison approach

    Science.gov (United States)

    Zainol, R.; Ahmad, F.; Nordin, N. A.; Aripin, A. W. M.

    2014-02-01

    Global climate change issues demand people of the world to change the way they live today. Thus, current cities need to be redeveloped towards less use of carbon in their day to day operations. Pedestrianized environment is one of the approaches used in reducing carbon foot print in cities. Heritage cities are the first to be looked into since they were built in the era in which motorized vehicles were minimal. Therefore, the research explores users' satisfaction on assessment of physical attributes of pedestrianization in Melaka Historical City, a UNESCO World Heritage Site. It aims to examine users' satisfaction on pedestrian facilities provided within the study area using pair wise questionnaire comparison approach. A survey of 200 respondents using random sampling was conducted in six different sites namely Jonker Street, Church Street, Kota Street, Goldsmith Street, Merdeka Street to Taming Sari Tower and Merdeka Street to River Cruise terminal. The survey consists of an assessment tool based on a nine-point scale of users' satisfaction level of pathway properties, zebra pedestrian crossing, street furniture, personal safety, adjacent to traffic flow, aesthetic and amenities. Analytical hierarchical process (AHP) was used to avoid any biasness in analyzing the data collected. Findings show that Merdeka Street to Taming Sari Tower as the street that scores the highest satisfaction level that fulfils all the required needs of a pedestrianized environment. Similar assessment elements can be used to evaluate existing streets in other cities and these criteria should also be used in planning for future cities.

  8. Parietal lesion effects on cued recall following pair associate learning.

    Science.gov (United States)

    Ben-Zvi, Shir; Soroker, Nachum; Levy, Daniel A

    2015-07-01

    We investigated the involvement of the posterior parietal cortex in episodic memory in a lesion-effects study of cued recall following pair-associate learning. Groups of patients who had experienced first-incident stroke, generally in middle cerebral artery territory, and exhibited damage that included lateral posterior parietal regions, were tested within an early post-stroke time window. In three experiments, patients and matched healthy comparison groups executed repeated study and cued recall test blocks of pairs of words (Experiment 1), pairs of object pictures (Experiment 2), or pairs of object pictures and environmental sounds (Experiment 3). Patients' brain CT scans were subjected to quantitative analysis of lesion volumes. Behavioral and lesion data were used to compute correlations between area lesion extent and memory deficits, and to conduct voxel-based lesion-symptom mapping. These analyses implicated lateral ventral parietal cortex, especially the angular gyrus, in cued recall deficits, most pronouncedly in the cross-modal picture-sound pairs task, though significant parietal lesion effects were also found in the unimodal word pairs and picture pairs tasks. In contrast to an earlier study in which comparable parietal lesions did not cause deficits in item recognition, these results indicate that lateral posterior parietal areas make a substantive contribution to demanding forms of recollective retrieval as represented by cued recall, especially for complex associative representations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Interactions in ion pairs of protic ionic liquids: Comparison with aprotic ionic liquids

    International Nuclear Information System (INIS)

    Tsuzuki, Seiji; Shinoda, Wataru; Miran, Md. Shah; Kinoshita, Hiroshi; Yasuda, Tomohiro; Watanabe, Masayoshi

    2013-01-01

    The stabilization energies for the formation (E form ) of 11 ion pairs of protic and aprotic ionic liquids were studied by MP2/6-311G ** level ab initio calculations to elucidate the difference between the interactions of ions in protic ionic liquids and those in aprotic ionic liquids. The interactions in the ion pairs of protic ionic liquids (diethylmethylammonium [dema] and dimethylpropylammonium [dmpa] based ionic liquids) are stronger than those of aprotic ionic liquids (ethyltrimethylammonium [etma] based ionic liquids). The E form for the [dema][CF 3 SO 3 ] and [dmpa][CF 3 SO 3 ] complexes (−95.6 and −96.4 kcal/mol, respectively) are significantly larger (more negative) than that for the [etma][CF 3 SO 3 ] complex (−81.0 kcal/mol). The same trend was observed for the calculations of ion pairs of the three cations with the Cl − , BF 4 − , TFSA − anions. The anion has contact with the N–H bond of the dema + or dmpa + cations in the most stable geometries of the dema + and dmpa + complexes. The optimized geometries, in which the anions locate on the counter side of the cations, are 11.0–18.0 kcal/mol less stable, which shows that the interactions in the ions pairs of protic ionic liquids have strong directionality. The E form for the less stable geometries for the dema + and dmpa + complexes are close to those for the most stable etma + complexes. The electrostatic interaction, which is the major source of the attraction in the ion pairs, is responsible for the directionality of the interactions and determining the magnitude of the interaction energy. Molecular dynamic simulations of the [dema][TFSA] and [dmpa][TFSA] ionic liquids show that the N–H bonds of the cations have contact with the negatively charged (oxygen and nitrogen) atoms of TFSA − anion, while the strong directionality of the interactions was not suggested from the simulation of the [etma][CF 3 SO 3 ] ionic liquid

  10. Pairing correlations. II. Microscopic analysis of odd-even mass staggering in nuclei

    International Nuclear Information System (INIS)

    Duguet, T.; Bonche, P.; Heenen, P.-H.; Meyer, J.

    2002-01-01

    The odd-even mass staggering in nuclei is analyzed in the context of self-consistent mean-field calculations, for spherical as well as for deformed nuclei. For these nuclei, the respective merits of the energy differences Δ (3) and Δ (5) to extract both the pairing gap and the time-reversal symmetry breaking effect at the same time are extensively discussed. The usual mass formula Δ (3) is shown to contain additional mean-field contributions when realistic pairing is used in the calculation. A simple tool is proposed in order to remove the time-reversal symmetry breaking effects from Δ (5) . Extended comparisons with the odd-even mass staggering obtained in the zero-pairing limit (schematic model and self-consistent calculations) show the nonperturbative contribution of pairing correlations on this observable

  11. Young children’s learning of relational categories:multiple comparisons and their cognitive constraints

    Directory of Open Access Journals (Sweden)

    Jean-Pierre eThibaut

    2015-05-01

    Full Text Available Relational categories are notoriously difficult to learn because they are not defined by intrinsic stable properties. We studied the impact of comparisons on relational concept learning with a novel word learning task in 42-month-old children. Capitalizing on Gentner et al. (2011, two, three or four pairs of stimuli were introduced with a novel relational word. In a given trial, the set of pairs was composed of either close or far pairs (e.g., close pair: knife1-watermelon, knife2-orange, knife3-slice of bread and knife4-meat; far pair: ax-evergreen tree, saw-log, cutter-cardboard and knife-slice of bread, for the cutter for relation. Close pairs (2 vs. 3 vs. 4 pairs led to random generalizations whereas comparisons with far pairs gave the expected relational generalization. The 3 pair case gave the best results. It is argued that far pairs promote deeper comparisons than close pairs. As shown by a control experiment, this was the case only when far pairs display well known associations.

  12. Full NLO massive gauge boson pair production at the LHC

    CERN Document Server

    Baglio, Julien; Weber, Marcus M

    2013-01-01

    Electroweak gauge boson pair production is a very important process at the LHC as it probes the non-abelian structure of electroweak interactions and is a background process for many searches. We present full next-to-leading order predictions for the production cross sections and distributions of on-shell massive gauge boson pair production in the Standard Model, including both QCD and electroweak corrections. The hierarchy between the ZZ, WW and WZ channels, observed in the transverse momentum distributions, will be analyzed. We will also present a comparison with experimental data for the total cross sections including a study of the theoretical uncertainties.

  13. Classical-quantum correspondence in electron-positron pair creation

    International Nuclear Information System (INIS)

    Chott, N. I.; Su, Q.; Grobe, R.

    2007-01-01

    We examine the creation of electron-positron pairs in a very strong force field. Using numerical solutions to quantum field theory we calculate the spatial and momentum probability distributions for the created particles. A comparison with classical mechanical phase space calculations suggests that despite the fully relativistic and quantum mechanical nature of the matter creation process, most aspects can be reproduced accurately in terms of classical mechanics

  14. Shell-model calculations with a basis that contains correlated pairs

    International Nuclear Information System (INIS)

    Boisson, J.P.; Silvestre-Brac, B.A.; Liotta, R.J.

    1979-01-01

    A method to solve the shell-model equations within a basis that contains correlated pairs of particles is presented. The method is illustrated for the three-identical-particle system. Applications in nuclei around 208 Pb are given and comparisons with both experimental data and other calculations are carried out. (Auth.)

  15. Time- and Space-Order Effects in Timed Discrimination of Brightness and Size of Paired Visual Stimuli

    Science.gov (United States)

    Patching, Geoffrey R.; Englund, Mats P.; Hellstrom, Ake

    2012-01-01

    Despite the importance of both response probability and response time for testing models of choice, there is a dearth of chronometric studies examining systematic asymmetries that occur over time- and space-orders in the method of paired comparisons. In this study, systematic asymmetries in discriminating the magnitude of paired visual stimuli are…

  16. Nonlinear electrostatic structures in homogeneous and inhomogeneous pair-ion plasmas

    International Nuclear Information System (INIS)

    Mahmood, S.; Ur-Rehman, H.; Shah, A.; Haque, Q.

    2012-01-01

    The nonlinear electrostatic structures such as solitons, shocks were studied in homogeneous, unmagnetized pair-ion plasma. The dissipation in the system was taken through kinematic viscosities of both pair-ion species. The one dimensional (Korteweg-de Vries-Burgers) KdVB equation was derived using reductive perturbation method. The analytical solution of KdVB equation was obtained using tanh method. It was found that solitons and monotonic shocks structures were formed in such type of plasmas depending on the value of dissipation in the system. Both compressive and refractive structures of solitons and monotonic shocks were obtained depending on the temperatures of negative and positive ions. The oscillatory shock structures in pair-ion plasmas were also obtained and its necessary conditions of formation were discussed. The acoustic solitons were also investigated in inhomogeneous unmagnetized pair-ion plasmas. The Korteweg-de Vries (KdV) like equation with an additional term due to density gradients was obtained by employing the reductive perturbation technique. It was found that amplitude of both compressive and refractive solitons was found to be enhanced as the density gradient parameter was increased. The Landau damping rates of electrostatic ion waves were studied for non-Maxwellian or Lorentzian pair-ion plasmas. The Val sov equation was solved analytically for weak damping effects in pair-ion plasma. It was found that Landau damping rate of ion plasma wave was increased in Lorentzian case in comparison with Maxwellian pair-ion plasmas. The numerical results were obtained by taking into account the parameters of pair-ion plasmas produced in laboratory experiments in Japan. (orig./A.B.)

  17. Innovation of Methods for Measurement and Modelling of Twisted Pair Parameters

    Directory of Open Access Journals (Sweden)

    Lukas Cepa

    2011-01-01

    Full Text Available The goal of this paper is to optimize a measurement methodology for the most accurate broadband modelling of characteristic impedance and other parameters for twisted pairs. Measured values and theirs comparison is presented in this article. Automated measurement facility was implemented at the Department of telecommunication of Faculty of electrical engineering of Czech technical university in Prague. Measurement facility contains RF switches allowing measurements up to 300 MHz or 1GHz. Measured twisted pair’s parameters can be obtained by measurement but for purposes of fundamental characteristics modelling is useful to define functions that model the properties of the twisted pair. Its primary and secondary parameters depend mostly on the frequency. For twisted pair deployment, we are interested in a frequency band range from 1 MHz to 100 MHz.

  18. Experimental investigation of quantum key distribution with position and momentum of photon pairs

    International Nuclear Information System (INIS)

    Almeida, M.P.; Walborn, S.P.; Souto Ribeiro, P.H.

    2005-01-01

    We investigate the utility of Einstein-Podolsky-Rosen correlations of the position and momentum of photon pairs from parametric down-conversion in the implementation of a secure quantum key distribution protocol. We show that security is guaranteed by the entanglement between down-converted pairs, and can be checked by either direct comparison of Alice and Bob's measurement results or evaluation of an inequality of the sort proposed by Mancini et al. [Phys. Rev. Lett. 88, 120401 (2002)

  19. Evaluation of users' satisfaction on pedestrian facilities using pair-wise comparison approach

    International Nuclear Information System (INIS)

    Zainol, R; Ahmad, F; Nordin, N A; Aripin, A W M

    2014-01-01

    Global climate change issues demand people of the world to change the way they live today. Thus, current cities need to be redeveloped towards less use of carbon in their day to day operations. Pedestrianized environment is one of the approaches used in reducing carbon foot print in cities. Heritage cities are the first to be looked into since they were built in the era in which motorized vehicles were minimal. Therefore, the research explores users' satisfaction on assessment of physical attributes of pedestrianization in Melaka Historical City, a UNESCO World Heritage Site. It aims to examine users' satisfaction on pedestrian facilities provided within the study area using pair wise questionnaire comparison approach. A survey of 200 respondents using random sampling was conducted in six different sites namely Jonker Street, Church Street, Kota Street, Goldsmith Street, Merdeka Street to Taming Sari Tower and Merdeka Street to River Cruise terminal. The survey consists of an assessment tool based on a nine-point scale of users' satisfaction level of pathway properties, zebra pedestrian crossing, street furniture, personal safety, adjacent to traffic flow, aesthetic and amenities. Analytical hierarchical process (AHP) was used to avoid any biasness in analyzing the data collected. Findings show that Merdeka Street to Taming Sari Tower as the street that scores the highest satisfaction level that fulfils all the required needs of a pedestrianized environment. Similar assessment elements can be used to evaluate existing streets in other cities and these criteria should also be used in planning for future cities

  20. On the production of low-mass lepton pairs at large transverse momentum

    International Nuclear Information System (INIS)

    Aurenche, P.; Baier, R.; Fontannaz, M.

    1988-03-01

    We relate the cross section for the production of low-mass lepton (Drell-Yan) pairs at large transverse momentum to the inclusive prompt (real) photon spectrum. The later one is then evaluated at second order in the QCD coupling constant α s ; predictions are obtained using next-to-leading order quark/gluon densities. Finally, a quantitative comparison with the recent pair data of the UA1 Collaboration is successfully performed. Therefore the considered process is conjectured as an extremely useful probe of the proton structure at small values of x

  1. Generalized pairing strategies-a bridge from pairing strategies to colorings

    Directory of Open Access Journals (Sweden)

    Győrffy Lajos

    2016-12-01

    Full Text Available In this paper we define a bridge between pairings and colorings of the hypergraphs by introducing a generalization of pairs called t-cakes for t ∈ ℕ, t ≥ 2. For t = 2 the 2-cakes are the same as the well-known pairs of system of distinct representatives, that can be turned to pairing strategies in Maker-Breaker hypergraph games, see Hales and Jewett [12]. The two-colorings are the other extremity of t-cakes, in which the whole ground set of the hypergraph is one big cake that we divide into two parts (color classes. Starting from the pairings (2-cake placement and two-colorings we define the generalized t-cake placements where we pair p elements by q elements (p, q ∈ ℕ, 1 ≤ p, q < t, p + q = t.

  2. Complementary Cohort Strategy for Multimodal Face Pair Matching

    DEFF Research Database (Denmark)

    Sun, Yunlian; Nasrollahi, Kamal; Sun, Zhenan

    2016-01-01

    Face pair matching is the task of determining whether two face images represent the same person. Due to the limited expressive information embedded in the two face images as well as various sources of facial variations, it becomes a quite difficult problem. Towards the issue of few available images...... provided to represent each face, we propose to exploit an extra cohort set (identities in the cohort set are different from those being compared) by a series of cohort list comparisons. Useful cohort coefficients are then extracted from both sorted cohort identities and sorted cohort images...... for complementary information. To augment its robustness to complicated facial variations, we further employ multiple face modalities owing to their complementary value to each other for the face pair matching task. The final decision is made by fusing the extracted cohort coefficients with the direct matching...

  3. Electron-positron pair production by two identical photons in the nuclear field

    International Nuclear Information System (INIS)

    Smirnov, A.I.

    1977-01-01

    In the Born approximation of the perturbation theory considered is a nonlinear effect of the electron-positron pair production by two identical photons in the Coulomb field of an atomic nucleus. The kinematic version of identical photons is studied. All the particles are considered to be nonpolarized. The calculation of the differential probability of the effect has been carried out earlier by the Feynman method. The total probability of the effect in limiting energy ranges is determined by integrating the formulas of the pair component distribution over energies. The probabilities of the electron-positron pair production and fusion of two photons into one in the nucleus field have been compared for the case of identical quanta. From the comparison of the results of analyzing both the nonlinear effects it follows that in the high-energy range the electron-positron pair production by two identical photons in the nucleus field extremely predominates over the fusion of two photons into one photon in the same field

  4. Comparison versus reminding.

    Science.gov (United States)

    Tullis, Jonathan G; Goldstone, Robert L

    2016-01-01

    Comparison and reminding have both been shown to support learning and transfer. Comparison is thought to support transfer because it allows learners to disregard non-matching features of superficially different episodes in order to abstract the essential structure of concepts. Remindings promote memory for the individual episodes and generalization because they prompt learners to retrieve earlier episodes during the encoding of later related episodes and to compare across episodes. Across three experiments, we compared the consequences of comparison and reminding on memory and transfer. Participants studied a sequence of related, but superficially different, proverb pairs. In the comparison condition, participants saw proverb pairs presented together and compared their meaning. In the reminding condition, participants viewed proverbs one at a time and retrieved any prior studied proverb that shared the same deep meaning as the current proverb. Experiment 1 revealed that participants in the reminding condition recalled more proverbs than those in the comparison condition. Experiment 2 showed that the mnemonic benefits of reminding persisted over a one-week retention interval. Finally, in Experiment 3, we examined the ability of participants to generalize their remembered information to new items in a task that required participants to identify unstudied proverbs that shared the same meaning as studied proverbs. Comparison led to worse discrimination between proverbs related to studied proverbs and proverbs unrelated to studied proverbs than reminding. Reminding supported better memory for individual instances and transfer to new situations than comparison.

  5. Matched-Pair Comparison of Radioembolization Plus Best Supportive Care Versus Best Supportive Care Alone for Chemotherapy Refractory Liver-Dominant Colorectal Metastases

    Energy Technology Data Exchange (ETDEWEB)

    Seidensticker, Ricarda, E-mail: ricarda.seidensticker@med.ovgu.de [Universitaetsklinikum Magdeburg, Klinik fuer Radiologie and Nuklearmedizin (Germany); Denecke, Timm [Universitaetsmedizin Berlin (Germany); Kraus, Patrick; Seidensticker, Max; Mohnike, Konrad [Universitaetsklinikum Magdeburg, Klinik fuer Radiologie and Nuklearmedizin (Germany); Fahlke, Joerg [Universitaetsklinikum Magdeburg, Klinik fuer Allgemein-, Viszeral- und Gefaesschirurgie (Germany); Kettner, Erika [Klinik fuer Haematologie/Onkologie, Klinikum Magdeburg (Germany); Hildebrandt, Bert [Universitaetsmedizin Berlin (Germany); Dudeck, Oliver; Pech, Maciej; Amthauer, Holger; Ricke, Jens [Universitaetsklinikum Magdeburg, Klinik fuer Radiologie and Nuklearmedizin (Germany)

    2012-10-15

    Purpose: This study was designed to evaluate overall survival after radioembolization or best supportive care (BSC) in patients with chemotherapy-refractory liver-dominant metastatic colorectal cancer (mCRC). Methods: This was a matched-pair comparison of patients who received radioembolization plus BSC or BSC alone for extensive liver disease. Twenty-nine patients who received radioembolization were retrospectively matched with a contemporary cohort of >500 patients who received BSC from 3 centers in Germany. Using clinical databases, patients were initially matched for prior treatments and tumor burden and then 29 patients were consecutively identified with two or more of four matching criteria: synchronous/metachronous metastases, tumor burden, increased ALP, and/or CEA >200 U/ml. Survival was calculated from date of progression before radioembolization or BSC by using Kaplan-Meier analysis. Results: Of 29 patients in each study arm, 16 pairs (55.2%) matched for all four criteria, and 11 pairs (37.9%) matched three criteria. Patients in both groups had a similar performance status (Karnofsky index, median 80% [range, 60-100%]). Compared with BSC alone, radioembolization prolonged survival (median, 8.3 vs. 3.5 months; P < 0.001) with a hazard ratio of 0.3 (95% confidence interval, 0.16-0.55; P < 0.001) in a multivariate Cox proportional hazard model. Treatment-related adverse events following radioembolization included: grade 1-2 fatigue (n = 20, 69%), grade 1 abdominal pain/nausea (n = 14, 48.3%), and grade 2 gastrointestinal ulceration (n = 3, 10.3%). Three cases of grade 3 radiation-induced liver disease were symptomatically managed. Conclusions: Radioembolization offers a promising addition to BSC in treatment-refractory patients for whom there are limited options. Survival was prolonged and adverse events were generally mild-to-moderate in nature and manageable.

  6. Matched-Pair Comparison of Radioembolization Plus Best Supportive Care Versus Best Supportive Care Alone for Chemotherapy Refractory Liver-Dominant Colorectal Metastases

    International Nuclear Information System (INIS)

    Seidensticker, Ricarda; Denecke, Timm; Kraus, Patrick; Seidensticker, Max; Mohnike, Konrad; Fahlke, Jörg; Kettner, Erika; Hildebrandt, Bert; Dudeck, Oliver; Pech, Maciej; Amthauer, Holger; Ricke, Jens

    2012-01-01

    Purpose: This study was designed to evaluate overall survival after radioembolization or best supportive care (BSC) in patients with chemotherapy-refractory liver-dominant metastatic colorectal cancer (mCRC). Methods: This was a matched-pair comparison of patients who received radioembolization plus BSC or BSC alone for extensive liver disease. Twenty-nine patients who received radioembolization were retrospectively matched with a contemporary cohort of >500 patients who received BSC from 3 centers in Germany. Using clinical databases, patients were initially matched for prior treatments and tumor burden and then 29 patients were consecutively identified with two or more of four matching criteria: synchronous/metachronous metastases, tumor burden, increased ALP, and/or CEA >200 U/ml. Survival was calculated from date of progression before radioembolization or BSC by using Kaplan–Meier analysis. Results: Of 29 patients in each study arm, 16 pairs (55.2%) matched for all four criteria, and 11 pairs (37.9%) matched three criteria. Patients in both groups had a similar performance status (Karnofsky index, median 80% [range, 60–100%]). Compared with BSC alone, radioembolization prolonged survival (median, 8.3 vs. 3.5 months; P < 0.001) with a hazard ratio of 0.3 (95% confidence interval, 0.16–0.55; P < 0.001) in a multivariate Cox proportional hazard model. Treatment-related adverse events following radioembolization included: grade 1–2 fatigue (n = 20, 69%), grade 1 abdominal pain/nausea (n = 14, 48.3%), and grade 2 gastrointestinal ulceration (n = 3, 10.3%). Three cases of grade 3 radiation-induced liver disease were symptomatically managed. Conclusions: Radioembolization offers a promising addition to BSC in treatment-refractory patients for whom there are limited options. Survival was prolonged and adverse events were generally mild-to-moderate in nature and manageable.

  7. English for au pairs the au pair's guide to learning English

    CERN Document Server

    Curtis, Lucy

    2014-01-01

    English for Au Pairs has interlinked stories about a group of au pairs new to England. Marta, an 18-year-old from Poland arrives in the UK to work as an au pair. Throughout her year-long stay she has many different experiences - some bad, some good - but with the support of her host family she finds new friends and improves her English. English for Au Pairs offers insight into the joys and difficulties of being an au pair while at the same time reinforcing English language learning through grammar explanations and exercises.

  8. Nuclear level densities with pairing and self-consistent ground-state shell effects

    CERN Document Server

    Arnould, M

    1981-01-01

    Nuclear level density calculations are performed using a model of fermions interacting via the pairing force, and a realistic single particle potential. The pairing interaction is treated within the BCS approximation with different pairing strength values. The single particle potentials are derived in the framework of an energy-density formalism which describes self-consistently the ground states of spherical nuclei. These calculations are extended to statistically deformed nuclei, whose estimated level densities include rotational band contributions. The theoretical results are compared with various experimental data. In addition, the level densities for several nuclei far from stability are compared with the predictions of a back-shifted Fermi gas model. Such a comparison emphasizes the possible danger of extrapolating to unknown nuclei classical level density formulae whose parameter values are tailored for known nuclei. (41 refs).

  9. Therapeutic plasma exchange: a paired comparison of Fresenius AS104 vs. COBE Spectra.

    Science.gov (United States)

    Burgstaler, E A; Pineda, A A

    2001-01-01

    For therapeutic plasma exchange (TPE), continuous flow separators are known to be efficient as exemplified by Fresenius AS104 and COBE Spectra. The AS104 uses an interface monitoring system in the centrifuge during TPE, whereas Spectra uses computer algorithms to establish the plasma-cell interface. To determine the plasma collection efficiency (PLCE), anticoagulant (AC) volumes used, and platelets (PLT) lost of the AS104 and the Spectra, we performed a prospective paired comparison of 20 TPE (each machine). The study included 17 patients, 1.3 plasma volume exchanges (without AC), equal inlet rates, and AC ratio of 13:1. Processing times did not include reinfuse mode. Platelet loss was determined by sampling the collection bags. Inlet rates were between 60-110 ml/min. Diagnosis included peripheral neuropathies, TTP and cryoglobulinemia. The AS104 had significantly (P<0.0001) lower average whole blood processed (F:6,601 vs. S:8,584 ml), AC volume (F:532 vs. S:719 ml), and processing time (F:80 vs. S:102 minutes) than Spectra. The AS104 had significantly (P<0.0001) higher average plasma flow rates (F:53 vs. S:44 ml/minute), plasma collection efficiency (F:90 vs. S:69%), and platelet loss (F:2.0 vs. S:0.14 x 10(11) plt) than Spectra. Platelet loss correlated with inlet flow rate with the AS104 but not with the Spectra. The AS104 has a significantly higher collection efficiency than Spectra allowing it to remove the same amount of plasma in significantly less time, by processing significantly less blood, using significantly less AC, but removing significantly more platelets than Spectra. Copyright 2001 Wiley-Liss, Inc.

  10. Comparison of different "along the track" high resolution satellite stereo-pair for DSM extraction

    Science.gov (United States)

    Nikolakopoulos, Konstantinos G.

    2013-10-01

    The possibility to create DEM from stereo pairs is based on the Pythagoras theorem and on the principles of photogrammetry that are applied to aerial photographs stereo pairs for the last seventy years. The application of these principles to digital satellite stereo data was inherent in the first satellite missions. During the last decades the satellite stereo-pairs were acquired across the track in different days (SPOT, ERS etc.). More recently the same-date along the track stereo-data acquisition seems to prevail (Terra ASTER, SPOT5 HRS, Cartosat, ALOS Prism) as it reduces the radiometric image variations (refractive effects, sun illumination, temporal changes) and thus increases the correlation success rate in any image matching.Two of the newest satellite sensors with stereo collection capability is Cartosat and ALOS Prism. Both of them acquire stereopairs along the track with a 2,5m spatial resolution covering areas of 30X30km. In this study we compare two different satellite stereo-pair collected along the track for DSM creation. The first one is created from a Cartosat stereopair and the second one from an ALOS PRISM triplet. The area of study is situated in Chalkidiki Peninsula, Greece. Both DEMs were created using the same ground control points collected with a Differential GPS. After a first control for random or systematic errors a statistical analysis was done. Points of certified elevation have been used to estimate the accuracy of these two DSMs. The elevation difference between the different DEMs was calculated. 2D RMSE, correlation and the percentile value were also computed and the results are presented.

  11. Electron-positron pair production and bremsstrahlung at intermediate energies in the field of heavy atoms

    International Nuclear Information System (INIS)

    Lee, R.N.; Milstein, A.I.; Strakhovenko, V.M.; Schwartz, O.Ya.

    2006-01-01

    The Coulomb corrections (CC) to the processes of bremsstrahlung and pair production are investigated. The next-to-leading term in the high-energy asymptotics is found. This term becomes very essential in the region of intermediate energies. The influence of screening for CC is small for differential cross section, spectrum, and the total cross section of pair production. The same is true for the spectrum of bremsstrahlung, but not for the differential cross section, where the influence of screening can be very large. The corresponding screening corrections as well as the modification of the differential cross section of bremsstrahlung are found. A comparison of our results for the total cross section of pair production with the experimental data available is performed. This comparison has justified our analytical results and allowed to elaborate a simple ansatz for the next-to-leading correction. The influence of the electron beam shape on CC for bremsstrahlung is investigated. It turns out that the differential cross section is very sensitive to this shape

  12. Recent progress in ATLAS top pair cross-sections: from precision measurements to rare processes

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    High-precision top quark pair production cross-section measurements in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV reach a precision of better than 4%, similar to that of recently achieved state-of-art NNLO+NNLL QCD calculations. These benchmark results can be used to extract physical parameters such as the top quark mass or constraints on new physics processes from the comparison between measurement and prediction. Inclusive, differential and fiducial cross section measurements for top pair production are also precision probes of QCD allowing to test latest Monte-Carlo generators. The large Run-1 data sample delivered by the LHC also allows the experiments to explore the production of top pair production in association with bosons.The seminar presents recent ATLAS results on cross-section measurements involving top quark pairs.

  13. Mahonian pairs

    OpenAIRE

    Sagan, Bruce E.; Savage, Carla D.

    2012-01-01

    We introduce the notion of a Mahonian pair. Consider the set, P^*, of all words having the positive integers as alphabet. Given finite subsets S,T of P^*, we say that (S,T) is a Mahonian pair if the distribution of the major index, maj, over S is the same as the distribution of the inversion number, inv, over T. So the well-known fact that maj and inv are equidistributed over the symmetric group, S_n, can be expressed by saying that (S_n,S_n) is a Mahonian pair. We investigate various Mahonia...

  14. Pairing Behavior of the Monogamous King Quail, Coturnix chinensis.

    Directory of Open Access Journals (Sweden)

    Elizabeth Adkins-Regan

    Full Text Available Animals with socially monogamous mating systems are valuable for discovering proximate mechanisms of prosocial behavior and close social relationships. Especially powerful are comparisons between related species that differ in monogamous tendency. Birds are the most socially monogamous vertebrates. Thus far most research on mechanisms of pairing has used zebra finches, which do not have a relative with a different mating system, however. The goal of the experiments reported here was to develop a new comparative avian system by studying the pairing behavior of a reportedly strongly monogamous quail, the king quail (Coturnix chinensis, a species in the same clade as the less monogamous Japanese quail (Coturnix japonica, the subject of much prior research. In Experiment 1 male-female pairs of king quail housed together were initially avoidant or aggressive but most rapidly progressed to allopreening and huddling. A separation-reunion paradigm reliably elicited both of these behaviors in males that had cohabited for one week. In Experiment 2 the allopreening and huddling behavior of males in cohabiting pairs was highly selective, and a majority of the males were aggressive toward a familiar female that was not the cohabitation partner. In Experiment 3 males were separated from their female cohabitation partners for 9-10 weeks and then given two-choice tests. All but one male spent more time near an unfamiliar female, which may have reflected aggression and shows recognition of and memory for the past pairing experience. Thus king quail show robust, selective and easy to measure pairing behavior that can be reliably elicited with simple separation-reunion testing procedures. Copulation is rarely seen during tests. The behavior of king quail is a striking contrast to that of Japanese quail, providing a new comparative system for discovering mechanisms of behavior related to close social relationships and monogamy.

  15. Pairing Behavior of the Monogamous King Quail, Coturnix chinensis.

    Science.gov (United States)

    Adkins-Regan, Elizabeth

    2016-01-01

    Animals with socially monogamous mating systems are valuable for discovering proximate mechanisms of prosocial behavior and close social relationships. Especially powerful are comparisons between related species that differ in monogamous tendency. Birds are the most socially monogamous vertebrates. Thus far most research on mechanisms of pairing has used zebra finches, which do not have a relative with a different mating system, however. The goal of the experiments reported here was to develop a new comparative avian system by studying the pairing behavior of a reportedly strongly monogamous quail, the king quail (Coturnix chinensis), a species in the same clade as the less monogamous Japanese quail (Coturnix japonica), the subject of much prior research. In Experiment 1 male-female pairs of king quail housed together were initially avoidant or aggressive but most rapidly progressed to allopreening and huddling. A separation-reunion paradigm reliably elicited both of these behaviors in males that had cohabited for one week. In Experiment 2 the allopreening and huddling behavior of males in cohabiting pairs was highly selective, and a majority of the males were aggressive toward a familiar female that was not the cohabitation partner. In Experiment 3 males were separated from their female cohabitation partners for 9-10 weeks and then given two-choice tests. All but one male spent more time near an unfamiliar female, which may have reflected aggression and shows recognition of and memory for the past pairing experience. Thus king quail show robust, selective and easy to measure pairing behavior that can be reliably elicited with simple separation-reunion testing procedures. Copulation is rarely seen during tests. The behavior of king quail is a striking contrast to that of Japanese quail, providing a new comparative system for discovering mechanisms of behavior related to close social relationships and monogamy.

  16. Separation of amaranthine-type betacyanins by ion-pair high-speed countercurrent chromatography.

    Science.gov (United States)

    Jerz, Gerold; Gebers, Nadine; Szot, Dominika; Szaleniec, Maciej; Winterhalter, Peter; Wybraniec, Slawomir

    2014-05-30

    Betacyanins, red-violet plant pigments, were fractionated by ion-pair high-speed countercurrent chromatography (IP-HSCCC) from leaves extract of Iresine lindenii Van Houtte, an ornamental plant of the family Amaranthaceae. An HSCCC solvent system consisting of TBME-1-BuOH-ACN-H2O (1:3:1:5, v/v/v/v) was applied using ion-pair forming heptafluorobutyric acid (HFBA). Significantly different elution profiles of betacyanin diastereomeric pairs (derivatives based on betanidin and isobetanidin) observed in the HSCCC in comparison to HPLC systems indicate a complementarity of both techniques' fractionation capabilities. The numerous diastereomeric pairs can be selectively separated from each other using the HSCCC system simplifying the pigment purification process. Apart from the three well known highly abundant pigments (amaranthine, betanin and iresinin I) together with their isoforms, three new acylated (feruloylated and sinapoylated) betacyanins as well as known pigment hylocerenin (previously isolated from cacti fruits) were characterized in the plant for the first time and they are new for the whole Amaranthaceae family. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. How do colonial Eurasian Griffon Vultures prevent extra-pair mating?

    Directory of Open Access Journals (Sweden)

    Joan Bertran

    2016-02-01

    Full Text Available In colonial breeding species, preventive measures to reduce the risks of extra-pair copulations (EPCs should reflect the actual risk perceived by males (e.g., proximity of neighbors, intrusions into the nest mainly during the fertile period. In colonial vultures, specific studies examining the preventive measures that minimize the risks of EPCs occurring within the competitive context of colonial breeding have not been conducted. Here we tested at Eurasian Griffon Vulture (Gyps fulvus nesting sites the intensity of paternity assurance behavior, shown as frequency and duration of within-pair copulations (WPCs, potential mate vigilance or nest attendance, and levels of aggressivity. This was measured according to the frequency of territorial intrusions and comparison of the fertile vs. the non-fertile period. Our findings suggest that the frequency of WPCs and their duration increased significantly during the presumed fertile period, regarded as the period when Griffon pairs spent significantly more time together at their nests. In addition, low levels of territorial intrusions were observed, an aggressive response of pairs towards intruders, and a relatively high presence of pairs at the nests during the fertile period. Thus, although nesting sites are subject to low exposure to EPC attempts, the increased frequency and duration of copulations during the fertile period suggests that, under pressure from the colonial breeding system, a higher rate of copulations is the most effective preventive mechanism against relative uncertainty of paternity.

  18. Pair correlations in nuclei

    International Nuclear Information System (INIS)

    Shimizu, Yoshifumi

    2009-01-01

    Except for the closed shell nuclei, almost all nuclei are in the superconducting state at their ground states. This well-known pair correlation in nuclei causes various interesting phenomena. It is especially to be noted that the pair correlation becomes weak in the excited states of nuclei with high angular momentum, which leads to the pair phase transition to the normal state in the high spin limit. On the other hand, the pair correlation becomes stronger in the nuclei with lower nucleon density than in those with normal density. In the region of neutron halo or skin state of unstable nuclei, this phenomenon is expected to be further enhanced to be observed compared to the ground state of stable nuclei. An overview of those interesting aspects caused via the pair correlation is presented here in the sections titled 'pair correlations in ground states', pair correlations in high spin states' and 'pair correlations in unstable nuclei' focusing on the high spin state. (S. Funahashi)

  19. Variation in social systems within Chaetodon butterflyfishes, with special reference to pair bonding

    KAUST Repository

    Nowicki, Jessica P.

    2018-04-11

    For many animals, affiliative relationships such as pair bonds form the foundation of society and are highly adaptive. Animal systems amenable for comparatively studying pair bonding are important for identifying underlying biological mechanisms, but mostly exist in mammals. Better establishing fish systems will enable comparison of pair bonding mechanisms across taxonomically distant lineages that may reveal general underlying mechanistic principles. We examined the utility of wild butterflyfishes (f: Chaetodontidae; g: Chaetodon) for comparatively studying pair bonding. Using stochastic character mapping, we provide the first analysis of the evolutionary history of butterflyfish sociality, revealing that pairing is ancestral, with at least seven independent transitions to gregarious grouping and solitary behavior since the late Miocene. We then formally verified social systems in six sympatric and widespread species representing a clade with one ancestrally reconstructed transition from paired to solitary grouping at Lizard Island, Australia. In situ observations of the size, selective affiliation and aggression, fidelity, and sex composition of social groups confirmed that Chaetodon baronessa, C. lunulatus, and C. vagabundus are predominantly pair bonding, whereas C. rainfordi, C. plebeius, and C. trifascialis are predominantly solitary. Even in the predominantly pair bonding species, C. lunulatus, a proportion of adults (15%) are solitary. Importantly, inter- and intra-specific differences in social systems do not co-vary with other previously established attributes, including parental care. Hence, the proposed butterflyfish populations are promising for inter- and intra-species comparative analyses of pair bonding and its mechanistic underpinnings. Avenues for further developing the system are proposed, including determining whether the aforementioned utility of these species applies across their geographic disruptions.

  20. Experimental many-pairs nonlocality

    Science.gov (United States)

    Poh, Hou Shun; Cerè, Alessandro; Bancal, Jean-Daniel; Cai, Yu; Sangouard, Nicolas; Scarani, Valerio; Kurtsiefer, Christian

    2017-08-01

    Collective measurements on large quantum systems together with a majority voting strategy can lead to a violation of the Clauser-Horne-Shimony-Holt Bell inequality. In the presence of many entangled pairs, this violation decreases quickly with the number of pairs and vanishes for some critical pair number that is a function of the noise present in the system. Here we show that a different binning strategy can lead to a more substantial Bell violation when the noise is sufficiently small. Given the relation between the critical pair number and the source noise, we then present an experiment where the critical pair number is used to quantify the quality of a high visibility photon pair source. Our results demonstrate nonlocal correlations using collective measurements operating on clusters of more than 40 photon pairs.

  1. Using Pair Wise Rankings in the Assessment of Adaptive Aiding

    Science.gov (United States)

    2017-02-22

    Christina Gruenwald 2 Matthew Middendorf 3 Chelsey Credlebaugh 4 Jonathan Mead 5 Scott Galster 5e. TASK NUMBER 5f. WORK UNIT NUMBER H0DC...operator’s cognitive state. When a model detects the onset of cognitive overload, assistance could then be provided to the operator to help mitigate...in future research. 15. SUBJECT TERMS Man Machine State, Pair-wise Comparisons, Augmentation Evaluation, Task Analysis, Automation , Mental

  2. Au pair trajectories

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2015-01-01

    pair-sending families in the Philippines, this dissertation examines the long-term trajectories of these young Filipinas. It shows how the au pairs’ local and transnational family relations develop over time and greatly influence their life trajectories. A focal point of the study is how au pairs...... that Filipina au pairs see their stay abroad as an avenue of personal development and social recognition, I examine how the au pairs re-position themselves within their families at home through migration, and how they navigate between the often conflicting expectations of participation in the sociality......Since 2000, thousands of young Filipino migrants have come to Denmark as au pairs. Officially, they are there to “broaden their cultural horizons” by living temporarily with a Danish host family, but they also conduct domestic labor in exchange for food and money, which allows them to send...

  3. Multiscale synchrony behaviors of paired financial time series by 3D multi-continuum percolation

    Science.gov (United States)

    Wang, M.; Wang, J.; Wang, B. T.

    2018-02-01

    Multiscale synchrony behaviors and nonlinear dynamics of paired financial time series are investigated, in an attempt to study the cross correlation relationships between two stock markets. A random stock price model is developed by a new system called three-dimensional (3D) multi-continuum percolation system, which is utilized to imitate the formation mechanism of price dynamics and explain the nonlinear behaviors found in financial time series. We assume that the price fluctuations are caused by the spread of investment information. The cluster of 3D multi-continuum percolation represents the cluster of investors who share the same investment attitude. In this paper, we focus on the paired return series, the paired volatility series, and the paired intrinsic mode functions which are decomposed by empirical mode decomposition. A new cross recurrence quantification analysis is put forward, combining with multiscale cross-sample entropy, to investigate the multiscale synchrony of these paired series from the proposed model. The corresponding research is also carried out for two China stock markets as comparison.

  4. Dislocation processes in quasicrystals-Kink-pair formation control or jog-pair formation control

    International Nuclear Information System (INIS)

    Takeuchi, Shin

    2005-01-01

    A computer simulation of dislocation in a model quasiperiodic lattice indicates that the dislocation feels a large Peierls potential when oriented in particular directions. For a dislocation with a high Peierls potential, the glide velocity and the climb velocity of the dislocation can be described almost in parallel in terms of the kink-pair formation followed by kink motion and the jog-pair formation followed by jog motion, respectively. The activation enthalpy of the kink-pair formation is the sum of the kink-pair formation enthalpy and the atomic jump activation enthalpy, while the activation enthalpy of the jog-pair formation involves the jog-pair enthalpy and the self-diffusion enthalpy. Since the kink-pair energy can be considerably larger than the jog-pair energy, the climb velocity can be faster than the glide velocity, so that the plastic deformation of quasicrystals can be brought not by dislocation glide but by dislocation climb at high temperatures

  5. Molecular dynamics study of some non-hydrogen-bonding base pair DNA strands

    Science.gov (United States)

    Tiwari, Rakesh K.; Ojha, Rajendra P.; Tiwari, Gargi; Pandey, Vishnudatt; Mall, Vijaysree

    2018-05-01

    In order to elucidate the structural activity of hydrophobic modified DNA, the DMMO2-D5SICS, base pair is introduced as a constituent in different set of 12-mer and 14-mer DNA sequences for the molecular dynamics (MD) simulation in explicit water solvent. AMBER 14 force field was employed for each set of duplex during the 200ns production-dynamics simulation in orthogonal-box-water solvent by the Particle-Mesh-Ewald (PME) method in infinite periodic boundary conditions (PBC) to determine conformational parameters of the complex. The force-field parameters of modified base-pair were calculated by Gaussian-code using Hartree-Fock /ab-initio methodology. RMSD Results reveal that the conformation of the duplex is sequence dependent and the binding energy of the complex depends on the position of the modified base-pair in the nucleic acid strand. We found that non-bonding energy had a significant contribution to stabilising such type of duplex in comparison to electrostatic energy. The distortion produced within strands by such type of base-pair was local and destabilised the duplex integrity near to substitution, moreover the binding energy of duplex depends on the position of substitution of hydrophobic base-pair and the DNA sequence and strongly supports the corresponding experimental study.

  6. Chest compression quality management and return of spontaneous circulation: a matched-pair registry study.

    Science.gov (United States)

    Lukas, Roman-Patrik; Gräsner, Jan Thorsten; Seewald, Stephan; Lefering, Rolf; Weber, Thomas Peter; Van Aken, Hugo; Fischer, Matthias; Bohn, Andreas

    2012-10-01

    Investigating the effects of any intervention during cardiac arrest remains difficult. The ROSC after cardiac arrest score was introduced to facilitate comparison of rates of return of spontaneous circulation (ROSC) between different ambulance services. To study the influence of chest compression quality management (including training, real-time feedback devices, and debriefing) in comparison with conventional cardiopulmonary resuscitation (CPR), a matched-pair analysis was conducted using data from the German Resuscitation Registry, with the calculated ROSC after cardiac arrest score as the baseline. Matching for independent ROSC after cardiac arrest score variables yielded 319 matched cases from the study period (January 2007-March 2011). The score predicted a 45% ROSC rate for the matched pairs. The observed ROSC increased significantly with chest compression quality management, to 52% (P=0.013; 95% CI, 46-57%). No significant differences were seen in the conventional CPR group (47%; 95% CI, 42-53%). The difference between the observed ROSC rates was not statistically significant. Chest compression quality management leads to significantly higher ROSC rates than those predicted by the prognostic score (ROSC after cardiac arrest score). Matched-pair analysis shows that with conventional CPR, the observed ROSC rate was not significantly different from the predicted rate. Analysis shows a trend toward a higher ROSC rate for chest compression quality management in comparison with conventional CPR. It is unclear whether a single aspect of chest compression quality management or the combination of training, real-time feedback, and debriefing contributed to this result. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  7. Prediction of the return of Comet P/Grigg-Skjellerup in 1987

    International Nuclear Information System (INIS)

    Sitarski, G.

    1986-01-01

    Using 82 observations made in the period 1966-1982 during the last four apparitions of the comet, the corrections of orbital elements were determined together with nongravitational parameters A 1 , A 2 and with a parameter D of a displacement of the photometric center from the center of mass of the comet. It was found that a value of the secular acceleration diminished in comparison with such a value before the close approach of the comet Jupiter in 1964; the nongravitational parameters of Style 2 in Marsden's notation now are: A 1 = +0.0371, A 2 = +0.008. To make the best prediction of the comet's return in 1987, the orbit was improved using 67 observations from the last two apparitions of the comet in 1977 and 1982, and taking the constant values of A 1 , A 2 as determined earlier; basing on the latter orbit the ephemeris of the comet for 1987 was computed. 3 refs., 2 tabs. (author)

  8. Regional pressure and temperature variations across the injured human brain: comparisons between paired intraparenchymal and ventricular measurements.

    Science.gov (United States)

    Childs, Charmaine; Shen, Liang

    2015-06-23

    Intraparenchymal, multimodality sensors are commonly used in the management of patients with severe traumatic brain injury (TBI). The 'gold standard', based on accuracy, reliability and cost for intracranial pressure (ICP) monitoring is within the cerebral ventricle (external strain gauge). There are no standards yet for intracerebral temperature monitoring and little is known of temperature differences between brain tissue and ventricle. The aim of the study therefore was to determine pressure and temperature differences at intraparenchymal and ventricular sites during five days of continuous neuromonitoring. Patients with severe TBI requiring emergency surgery. patients who required ICP monitoring were eligible for recruitment. Two intracerebral probe types were used: a) intraventricular, dual parameter sensor (measuring pressure, temperature) with inbuilt catheter for CSF drainage: b) multiparameter intraparenchymal sensor measuring pressure, temperature and oxygen partial pressure. All sensors were inserted during surgery and under aseptic conditions. Seventeen patients, 12 undergoing neurosurgery (decompressive craniectomy n = 8, craniotomy n = 4) aged 21-78 years were studied. Agreement of measures for 9540 brain tissue-ventricular temperature 'pairs' and 10,291 brain tissue-ventricular pressure 'pairs' were determined using mixed model to compare mean temperature and pressure for longitudinal data. There was no significant overall difference for mean temperature (p = 0.92) or mean pressure readings (p = 0.379) between tissue and ventricular sites. With 95.8 % of paired temperature readings within 2SD (-0.4 to 0.4 °C) differences in temperature between brain tissue and ventricle were clinically insignificant. For pressure, 93.5 % of readings pairs fell within the 2SD range (-9.4756 to 7.8112 mmHg). However, for individual patients, agreement for mean tissue-ventricular pressure differences was poor on occasions. There is good overall agreement between paired

  9. Clock synchronization by remote detection of correlated photon pairs

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Caleb; Lamas-Linares, AntIa; Kurtsiefer, Christian [Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 (Singapore)], E-mail: christian.kurtsiefer@gmail.com

    2009-04-15

    In this study, we present an algorithm to detect the time and frequency differences of independent clocks based on observation of time-correlated photon pairs. This enables remote coincidence identification in entanglement-based quantum key distribution schemes without dedicated coincidence hardware, pulsed sources with a timing structure or very stable reference clocks. We discuss the method for typical operating conditions and show that the requirement for reference clock accuracy can be relaxed by about five orders of magnitude in comparison with previous schemes.

  10. AudioPairBank: Towards A Large-Scale Tag-Pair-Based Audio Content Analysis

    OpenAIRE

    Sager, Sebastian; Elizalde, Benjamin; Borth, Damian; Schulze, Christian; Raj, Bhiksha; Lane, Ian

    2016-01-01

    Recently, sound recognition has been used to identify sounds, such as car and river. However, sounds have nuances that may be better described by adjective-noun pairs such as slow car, and verb-noun pairs such as flying insects, which are under explored. Therefore, in this work we investigate the relation between audio content and both adjective-noun pairs and verb-noun pairs. Due to the lack of datasets with these kinds of annotations, we collected and processed the AudioPairBank corpus cons...

  11. The paired-domination and the upper paired-domination numbers of graphs

    Directory of Open Access Journals (Sweden)

    Włodzimierz Ulatowski

    2015-01-01

    Full Text Available In this paper we continue the study of paired-domination in graphs. A paired-dominating set, abbreviated PDS, of a graph \\(G\\ with no isolated vertex is a dominating set of vertices whose induced subgraph has a perfect matching. The paired-domination number of \\(G\\, denoted by \\(\\gamma_{p}(G\\, is the minimum cardinality of a PDS of \\(G\\. The upper paired-domination number of \\(G\\, denoted by \\(\\Gamma_{p}(G\\, is the maximum cardinality of a minimal PDS of \\(G\\. Let \\(G\\ be a connected graph of order \\(n\\geq 3\\. Haynes and Slater in [Paired-domination in graphs, Networks 32 (1998, 199-206], showed that \\(\\gamma_{p}(G\\leq n-1\\ and they determine the extremal graphs \\(G\\ achieving this bound. In this paper we obtain analogous results for \\(\\Gamma_{p}(G\\. Dorbec, Henning and McCoy in [Upper total domination versus upper paired-domination, Questiones Mathematicae 30 (2007, 1-12] determine \\(\\Gamma_{p}(P_n\\, instead in this paper we determine \\(\\Gamma_{p}(C_n\\. Moreover, we describe some families of graphs \\(G\\ for which the equality \\(\\gamma_{p}(G=\\Gamma_{p}(G\\ holds.

  12. Base pair probability estimates improve the prediction accuracy of RNA non-canonical base pairs.

    Directory of Open Access Journals (Sweden)

    Michael F Sloma

    2017-11-01

    Full Text Available Prediction of RNA tertiary structure from sequence is an important problem, but generating accurate structure models for even short sequences remains difficult. Predictions of RNA tertiary structure tend to be least accurate in loop regions, where non-canonical pairs are important for determining the details of structure. Non-canonical pairs can be predicted using a knowledge-based model of structure that scores nucleotide cyclic motifs, or NCMs. In this work, a partition function algorithm is introduced that allows the estimation of base pairing probabilities for both canonical and non-canonical interactions. Pairs that are predicted to be probable are more likely to be found in the true structure than pairs of lower probability. Pair probability estimates can be further improved by predicting the structure conserved across multiple homologous sequences using the TurboFold algorithm. These pairing probabilities, used in concert with prior knowledge of the canonical secondary structure, allow accurate inference of non-canonical pairs, an important step towards accurate prediction of the full tertiary structure. Software to predict non-canonical base pairs and pairing probabilities is now provided as part of the RNAstructure software package.

  13. Base pair probability estimates improve the prediction accuracy of RNA non-canonical base pairs.

    Science.gov (United States)

    Sloma, Michael F; Mathews, David H

    2017-11-01

    Prediction of RNA tertiary structure from sequence is an important problem, but generating accurate structure models for even short sequences remains difficult. Predictions of RNA tertiary structure tend to be least accurate in loop regions, where non-canonical pairs are important for determining the details of structure. Non-canonical pairs can be predicted using a knowledge-based model of structure that scores nucleotide cyclic motifs, or NCMs. In this work, a partition function algorithm is introduced that allows the estimation of base pairing probabilities for both canonical and non-canonical interactions. Pairs that are predicted to be probable are more likely to be found in the true structure than pairs of lower probability. Pair probability estimates can be further improved by predicting the structure conserved across multiple homologous sequences using the TurboFold algorithm. These pairing probabilities, used in concert with prior knowledge of the canonical secondary structure, allow accurate inference of non-canonical pairs, an important step towards accurate prediction of the full tertiary structure. Software to predict non-canonical base pairs and pairing probabilities is now provided as part of the RNAstructure software package.

  14. Homeostasis of Complementary Pair Theory: Ecological Comparisons in Diverse Universal Design for Learning Environments

    Science.gov (United States)

    Ianneo, Brittany

    2014-01-01

    Accommodation~assimilation relations were theorized by Kelso and Engstrom (2006) as independent and dependent complementary pairs. This study defined relationships between organisms that experienced complementary interactions of accommodation~assimilation in diverse ecologies designed with universal design for learning environments (UDLE) compared…

  15. Pair- ${v}$ -SVR: A Novel and Efficient Pairing nu-Support Vector Regression Algorithm.

    Science.gov (United States)

    Hao, Pei-Yi

    This paper proposes a novel and efficient pairing nu-support vector regression (pair--SVR) algorithm that combines successfully the superior advantages of twin support vector regression (TSVR) and classical -SVR algorithms. In spirit of TSVR, the proposed pair--SVR solves two quadratic programming problems (QPPs) of smaller size rather than a single larger QPP, and thus has faster learning speed than classical -SVR. The significant advantage of our pair--SVR over TSVR is the improvement in the prediction speed and generalization ability by introducing the concepts of the insensitive zone and the regularization term that embodies the essence of statistical learning theory. Moreover, pair--SVR has additional advantage of using parameter for controlling the bounds on fractions of SVs and errors. Furthermore, the upper bound and lower bound functions of the regression model estimated by pair--SVR capture well the characteristics of data distributions, thus facilitating automatic estimation of the conditional mean and predictive variance simultaneously. This may be useful in many cases, especially when the noise is heteroscedastic and depends strongly on the input values. The experimental results validate the superiority of our pair--SVR in both training/prediction speed and generalization ability.This paper proposes a novel and efficient pairing nu-support vector regression (pair--SVR) algorithm that combines successfully the superior advantages of twin support vector regression (TSVR) and classical -SVR algorithms. In spirit of TSVR, the proposed pair--SVR solves two quadratic programming problems (QPPs) of smaller size rather than a single larger QPP, and thus has faster learning speed than classical -SVR. The significant advantage of our pair--SVR over TSVR is the improvement in the prediction speed and generalization ability by introducing the concepts of the insensitive zone and the regularization term that embodies the essence of statistical learning theory

  16. Report on Pairing-based Cryptography.

    Science.gov (United States)

    Moody, Dustin; Peralta, Rene; Perlner, Ray; Regenscheid, Andrew; Roginsky, Allen; Chen, Lily

    2015-01-01

    This report summarizes study results on pairing-based cryptography. The main purpose of the study is to form NIST's position on standardizing and recommending pairing-based cryptography schemes currently published in research literature and standardized in other standard bodies. The report reviews the mathematical background of pairings. This includes topics such as pairing-friendly elliptic curves and how to compute various pairings. It includes a brief introduction to existing identity-based encryption (IBE) schemes and other cryptographic schemes using pairing technology. The report provides a complete study of the current status of standard activities on pairing-based cryptographic schemes. It explores different application scenarios for pairing-based cryptography schemes. As an important aspect of adopting pairing-based schemes, the report also considers the challenges inherent in validation testing of cryptographic algorithms and modules. Based on the study, the report suggests an approach for including pairing-based cryptography schemes in the NIST cryptographic toolkit. The report also outlines several questions that will require further study if this approach is followed.

  17. Possibilities of paired comparison of receptor binding parameters obtained in a single experiment

    International Nuclear Information System (INIS)

    Mashilova, K.V.; Kiriakov, G.V.; Malin, K.M.; Rozhanets, V.V.

    1987-01-01

    The authors explore the use of comparing control and experimental groups on the basis of extrapolation parameters obtained from a single pair of experiments. One of the experiments study the parameters of specific binding of 3 H-D-ala-2-enkephelin-5-D-leucine in the striatum of different groups of rats. The analysis was done by the Cornish-Bowden method

  18. Metal-mediated DNA base pairing: alternatives to hydrogen-bonded Watson-Crick base pairs.

    Science.gov (United States)

    Takezawa, Yusuke; Shionoya, Mitsuhiko

    2012-12-18

    With its capacity to store and transfer the genetic information within a sequence of monomers, DNA forms its central role in chemical evolution through replication and amplification. This elegant behavior is largely based on highly specific molecular recognition between nucleobases through the specific hydrogen bonds in the Watson-Crick base pairing system. While the native base pairs have been amazingly sophisticated through the long history of evolution, synthetic chemists have devoted considerable efforts to create alternative base pairing systems in recent decades. Most of these new systems were designed based on the shape complementarity of the pairs or the rearrangement of hydrogen-bonding patterns. We wondered whether metal coordination could serve as an alternative driving force for DNA base pairing and why hydrogen bonding was selected on Earth in the course of molecular evolution. Therefore, we envisioned an alternative design strategy: we replaced hydrogen bonding with another important scheme in biological systems, metal-coordination bonding. In this Account, we provide an overview of the chemistry of metal-mediated base pairing including basic concepts, molecular design, characteristic structures and properties, and possible applications of DNA-based molecular systems. We describe several examples of artificial metal-mediated base pairs, such as Cu(2+)-mediated hydroxypyridone base pair, H-Cu(2+)-H (where H denotes a hydroxypyridone-bearing nucleoside), developed by us and other researchers. To design the metallo-base pairs we carefully chose appropriate combinations of ligand-bearing nucleosides and metal ions. As expected from their stronger bonding through metal coordination, DNA duplexes possessing metallo-base pairs exhibited higher thermal stability than natural hydrogen-bonded DNAs. Furthermore, we could also use metal-mediated base pairs to construct or induce other high-order structures. These features could lead to metal-responsive functional

  19. Cooper Pairs in Insulators?

    International Nuclear Information System (INIS)

    Valles, James

    2008-01-01

    Nearly 50 years elapsed between the discovery of superconductivity and the emergence of the microscopic theory describing this zero resistance state. The explanation required a novel phase of matter in which conduction electrons joined in weakly bound pairs and condensed with other pairs into a single quantum state. Surprisingly, this Cooper pair formation has also been invoked to account for recently uncovered high-resistance or insulating phases of matter. To address this possibility, we have used nanotechnology to create an insulating system that we can probe directly for Cooper pairs. I will present the evidence that Cooper pairs exist and dominate the electrical transport in these insulators and I will discuss how these findings provide new insight into superconductor to insulator quantum phase transitions.

  20. A new purely growing instability in a strongly magnetized nonuniform pair plasma

    International Nuclear Information System (INIS)

    Shukla, Nitin; Shukla, P.K.

    2007-01-01

    It is shown that a strongly magnetized nonuniform electron-positron (hereafter referred to as e-p or pair) plasma is unstable against low-frequency (in comparison with the electron gyrofrequency) electrostatic oscillations. For this purpose, a dispersion relation is derived by using the Poisson equation as well as the electron and positron continuity equations with the guiding center drifts for the electron and positron fluids. The dispersion relation admits a purely growing instability in the presence of the equilibrium density and magnetic field inhomogeneities. Physically, instability arises because of the inhomogeneous magnetic field induced differential electron and positron density fluctuations, which do not keep in phase with the electrostatic potential arising from the charge separation in our nonuniform pair plasmas

  1. Charge Aspects of Composite Pair Superconductivity

    Science.gov (United States)

    Flint, Rebecca

    2014-03-01

    Conventional Cooper pairs form from well-defined electronic quasiparticles, making the internal structure of the pair irrelevant. However, in the 115 family of superconductors, the heavy electrons are forming as they pair and the internal pair structure becomes as important as the pairing mechanism. Conventional spin fluctuation mediated pairing cannot capture the direct transition from incoherent local moments to heavy fermion superconductivity, but the formation of composite pairs favored by the two channel Kondo effect can. These composite pairs are local d-wave pairs formed by two conduction electrons in orthogonal Kondo channels screening the same local moment. Composite pairing shares the same symmetries as magnetically mediated pairing, however, only composite pairing necessarily involves a redistribution of charge within the unit cell originating from the internal pair structure, both as a monopole (valence change) and a quadrupole effect. This redistribution will onset sharply at the superconducting transition temperature. A smoking gun test for composite pairing is therefore a sharp signature at Tc - for example, a cusp in the Mossbauer isomer shift in NpPd5Al2 or in the NQR shift in (Ce,Pu)CoIn5.

  2. Changes in latent fingerprint examiners' markup between analysis and comparison.

    Science.gov (United States)

    Ulery, Bradford T; Hicklin, R Austin; Roberts, Maria Antonia; Buscaglia, JoAnn

    2015-02-01

    After the initial analysis of a latent print, an examiner will sometimes revise the assessment during comparison with an exemplar. Changes between analysis and comparison may indicate that the initial analysis of the latent was inadequate, or that confirmation bias may have affected the comparison. 170 volunteer latent print examiners, each randomly assigned 22 pairs of prints from a pool of 320 total pairs, provided detailed markup documenting their interpretations of the prints and the bases for their comparison conclusions. We describe changes in value assessments and markup of features and clarity. When examiners individualized, they almost always added or deleted minutiae (90.3% of individualizations); every examiner revised at least some markups. For inconclusive and exclusion determinations, changes were less common, and features were added more frequently when the image pair was mated (same source). Even when individualizations were based on eight or fewer corresponding minutiae, in most cases some of those minutiae had been added during comparison. One erroneous individualization was observed: the markup changes were notably extreme, and almost all of the corresponding minutiae had been added during comparison. Latents assessed to be of value for exclusion only (VEO) during analysis were often individualized when compared to a mated exemplar (26%); in our previous work, where examiners were not required to provide markup of features, VEO individualizations were much less common (1.8%). Published by Elsevier Ireland Ltd.

  3. Linear and nonlinear low-frequency electrostatic waves in a nonuniform pair-ion-dust magnetoplasma

    International Nuclear Information System (INIS)

    Saleem, H; Shukla, P K; Eliasson, B

    2008-01-01

    Linear and nonlinear properties of the low-frequency (in comparison with the ion gyrofrequency) electrostatic oscillations in pair-ion-dust magnetoplasma are presented. In the linear limit, the Shukla-Varma mode is coupled with the ion oscillations while the nonlinearly coupled modes appear in the form of a dipolar or a monopolar vortex

  4. On the theory of electroproduction of small relative momentum nucleon pairs on atomic nuclei

    International Nuclear Information System (INIS)

    Nagornyj, S.I.; Inopin, E.V.

    1979-01-01

    Problems concerning knocking-out of nucleon pairs from atomic nuclei by high-energy electrons are studied. Dependences of cross sections of different processes of the knocking-out on the nucleon relative momentum in a pair are considered. Probabilities of different processes of the knocking-out are compared. A comparison of probabilities of total and three-particle splittings of a 4 He nucleus is performed. On total splitting in the formation of the cross section energy dependence the levels of observable and non-observable subsystems shown to take place. It has been stated that the cross section cannot be increased at the expense of levels of both subsystems simultaneously

  5. Virtual particle-antiparticle pair formation by a scalar particle bound in an external Coulomb field

    International Nuclear Information System (INIS)

    Darewych, J.W.; Horbatsch, M.; Lev, B.I.; Shapoval, D.V.

    1995-01-01

    A Hamiltonian variational Fock-space method is used to describe scalar massive particles in an external Coulomb field with strength f=Zα. The use of an ansatz that includes a three-particle state in addition to a single-particle state built on the field-free vacuum enables one to highlight the role played by particle-antiparticle pair formation. Comparison is made with the Klein-Gordon equation in the Feshbach-Villars representation and it is shown explicitly how the virtual pair contribution corrects an O(f 5 ) deficiency present in the energy spectrum of the naive Schroedinger-type single-particle equation. ((orig.))

  6. Emergency percutaneous tracheostomy in a severely burned patient with upper airway obstruction and circulatory arrest.

    Science.gov (United States)

    Schlossmacher, Pascal; Martinet, Olivier; Testud, Richard; Agesilas, Fabrice; Benhamou, Léon; Gauzëre, Bernard Alex

    2006-02-01

    We report the life-saving use of Griggs percutaneous tracheostomy in an arrested patient with complex upper airway obstruction, as a result of burns, smoke injuries and iterative tracheal intubation attempts. The technique was performed blindly at bedside to treat an acute episode of failed ventilation and intubation and cardiac arrest in a patient with altered neck anatomy. The intervention salvaged the situation, leaving a definitive airway. The feasibility of using an emergency Griggs percutaneous tracheostomy versus cricothyroidotomy is suggested in selected cases.

  7. Opera: reconstructing optimal genomic scaffolds with high-throughput paired-end sequences.

    Science.gov (United States)

    Gao, Song; Sung, Wing-Kin; Nagarajan, Niranjan

    2011-11-01

    Scaffolding, the problem of ordering and orienting contigs, typically using paired-end reads, is a crucial step in the assembly of high-quality draft genomes. Even as sequencing technologies and mate-pair protocols have improved significantly, scaffolding programs still rely on heuristics, with no guarantees on the quality of the solution. In this work, we explored the feasibility of an exact solution for scaffolding and present a first tractable solution for this problem (Opera). We also describe a graph contraction procedure that allows the solution to scale to large scaffolding problems and demonstrate this by scaffolding several large real and synthetic datasets. In comparisons with existing scaffolders, Opera simultaneously produced longer and more accurate scaffolds demonstrating the utility of an exact approach. Opera also incorporates an exact quadratic programming formulation to precisely compute gap sizes (Availability: http://sourceforge.net/projects/operasf/ ).

  8. Watson-Crick base pairing controls excited-state decay in natural DNA.

    Science.gov (United States)

    Bucher, Dominik B; Schlueter, Alexander; Carell, Thomas; Zinth, Wolfgang

    2014-10-13

    Excited-state dynamics are essential to understanding the formation of DNA lesions induced by UV light. By using femtosecond IR spectroscopy, it was possible to determine the lifetimes of the excited states of all four bases in the double-stranded environment of natural DNA. After UV excitation of the DNA duplex, we detected a concerted decay of base pairs connected by Watson-Crick hydrogen bonds. A comparison of single- and double-stranded DNA showed that the reactive charge-transfer states formed in the single strands are suppressed by base pairing in the duplex. The strong influence of the Watson-Crick hydrogen bonds indicates that proton transfer opens an efficient decay path in the duplex that prohibits the formation or reduces the lifetime of reactive charge-transfer states. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Pair potentials in liquid metals

    International Nuclear Information System (INIS)

    Faber, T.E.

    1980-01-01

    The argument which justifies the use of a pair potential to describe the structure-dependent term in the energy of liquid metals is briefly reviewed. Because there is an additional term in the energy which depends upon volume rather than structure, and because the pair potential itself is volume-dependent, the relationship between pair potential and observable properties such as pressure, bulk modulus and pair distribution function is more complicated for liquid metals than it is for molecular liquids. Perhaps for this reason, the agreement between pair potentials inferred from observable properties and pair potentials calculated by means of pseudo-potential theory is still far from complete. The pair potential concept is applicable only to simple liquid metals, in which the electron-ion interaction is weak. No attempt is made to discuss liquid transition and rare-earth metals, which are not simple in this sense. (author)

  10. Pairing correlations in nuclei

    International Nuclear Information System (INIS)

    Baba, C.V.K.

    1988-01-01

    There are many similarities between the properties of nucleons in nuclei and electrons in metals. In addition to the properties explainable in terms of independent particle motion, there are many important co-operative effects suggesting correlated motion. Pairing correlation which leads to superconductivity in metals and several important properties in nuclei , is an exmple of such correlations. An attempt has been made to review the effects of pairing correlations in nuclei. Recent indications of reduction in pairing correlations at high angular momenta is discussed. A comparision between pairing correlations in the cases of nuclei and electrons in metals is attempted. (author). 20 refs., 10 figs

  11. Intermittent pair-housing, pair relationship qualities, and HPA activity in adult female rhesus macaques.

    Science.gov (United States)

    Hannibal, Darcy L; Cassidy, Lauren C; Vandeleest, Jessica; Semple, Stuart; Barnard, Allison; Chun, Katie; Winkler, Sasha; McCowan, Brenda

    2018-05-02

    Laboratory rhesus macaques are often housed in pairs and may be temporarily or permanently separated for research, health, or management reasons. While both long-term social separations and introductions can stimulate a stress response that impacts inflammation and immune function, the effects of short-term overnight separations and whether qualities of the pair relationship mediate these effects are unknown. In this study, we investigated the effects of overnight separations on the urinary cortisol concentration of 20 differentially paired adult female rhesus macaques (Macaca mulatta) at the California National Primate Research Center. These females were initially kept in either continuous (no overnight separation) or intermittent (with overnight separation) pair-housing and then switched to the alternate pair-housing condition part way through the study. Each study subject was observed for 5 weeks, during which we collected measures of affiliative, aggressive, anxious, abnormal, and activity-state behaviors in both pair-housing conditions. Additionally, up to three urine samples were collected from each subject per week and assayed for urinary free cortisol and creatinine. Lastly, the behavioral observer scored each pair on four relationship quality attributes ("Anxious," "Tense," "Well-meshed," and "Friendly") using a seven-point scale. Data were analyzed using a generalized linear model with gamma distribution and an information theoretic approach to determine the best model set. An interaction between the intermittent pairing condition and tense pair adjective rating was in the top three models of the best model set. Dominance and rates of affiliation were also important for explaining urinary cortisol variation. Our results suggest that to prevent significant changes in HPA-axis activation in rhesus macaque females, which could have unintended effects on research outcomes, pairs with "Tense" relationships and overnight separations preventing tactile contact

  12. Quality of Life After Whole Pelvic Versus Prostate-Only External Beam Radiotherapy for Prostate Cancer: A Matched-Pair Comparison

    International Nuclear Information System (INIS)

    Pinkawa, Michael; Piroth, Marc D.; Holy, Richard; Fischedick, Karin; Klotz, Jens; Szekely-Orban, Dalma; Eble, Michael J.

    2011-01-01

    Purpose: Comparison of health-related quality of life after whole pelvic (WPRT) and prostate-only (PORT) external beam radiotherapy for prostate cancer. Methods and Materials: A group of 120 patients (60 in each group) was surveyed prospectively before radiation therapy (RT) (time A), at the last day of RT (time B), at a median time of 2 months (time C) and >1 year after RT (time D) using a validated questionnaire (Expanded Prostate Cancer Index Composite). All patients were treated with 1.8- to 2.0-Gy fractions up to 70.2 to 72.0 Gy with or without WPRT up to 45 to 46 Gy. Pairs were matched according to the following criteria: age ± 5years, planning target volume ± 10 cc (considering planning target volume without pelvic nodes for WPRT patients), urinary/bowel/sexual function score before RT ± 10, and use of antiandrogens. Results: With the exception of prognostic risk factors, both groups were well balanced with respect to baseline characteristics. No significant differences were found with regard to urinary and sexual score changes. Mean bladder function scores reached baseline levels in both patient subgroups after RT. However, bowel function scores decreased significantly more for patients after WPRT than in those receiving PORT at all times (p once a day in 15% vs. 3%; p = 0.03), bloody stools (≥half the time in 7% vs. 0%; p = 0.04) and frequent bowel movements (>two on a typical day in 32% vs. 7%; p < 0.01) more often than did patients after PORT. Conclusion: In comparison to PORT, WPRT (larger bladder and rectum volumes in medium dose levels, but similar volumes in high dose levels) was associated with decreased bowel quality of life in the acute and chronic phases after treatment but remained without adverse long-term urinary effects.

  13. Comparisons of perturbation and integral equation theories for the angular pair correlation function in molecular fluids

    International Nuclear Information System (INIS)

    Murad, S.; Gubbins, K.E.; Gray, C.G.

    1983-01-01

    We compare several recently proposed theories for the angular pair correlation function g(rω 1 ω 2 ), including first- and second-order perturbation theory (the u-expansion), a Pade approximant to this series, first-order f-expansion, the single superchain, generalized mean field, linearized hypernetted chain, and quadratic hypernetted chain approximations. Numerical results from these theories are compared with available computer simulation data for four model fluids whose intermolecular pair potential is of the form u 0 +usub(a), where u 0 is a hard-sphere of Lennard-Jones model, while usub(a) is a dipole-dipole or quadrupole-quadrupole interaction; we refer to these model fluids as HS+μμ, HS+QQ, LJ+μμ, and LJ+QQ. Properties studied include the angular pair correlation function and its spherical harmonic components, the thermodynamic properties, and the angular correlation parameters G 1 and G 2 that are related to the dielectric and Kerr constants. The second-order perturbation theory is superior to the integral equation theories for the thermodynamic harmonics of g(rω 1 ω 2 ) and for the thermodynamic properties themselves at moderate multipole strengths. For other harmonics and properties, the integral equation theories are better, with the quadratic hypernetted chain approximation being the best overall. (orig.)

  14. Schwinger pair creation of Kaluza-Klein particles: Pair creation without tunneling

    International Nuclear Information System (INIS)

    Friedmann, Tamar; Verlinde, Herman

    2005-01-01

    We study Schwinger pair creation of charged Kaluza-Klein (KK) particles from a static KK electric field. We find that the gravitational backreaction of the electric field on the geometry--which is incorporated via the electric KK-Melvin solution--prevents the electrostatic potential from overcoming the rest mass of the KK particles, thus impeding the tunneling mechanism which is often thought of as responsible for the pair creation. However, we find that pair creation still occurs with a finite rate formally similar to the classic Schwinger result, but via an apparently different mechanism, involving a combination of the Unruh effect and vacuum polarization due to the E-field

  15. A comparison of transmission characteristics of Salmonella enterica serovar Enteritidis between pair-housed and group-housed laying hens

    Directory of Open Access Journals (Sweden)

    Thomas Ekelijn

    2011-02-01

    Full Text Available Abstract Human cases of bacterial gastro-enteritis are often caused by the consumption of eggs contaminated with Salmonella species, mainly Salmonella enterica serovar Enteriditis (Salmonella Enteritidis. To reduce human exposure, in several countries worldwide surveillance programmes are implemented to detect colonized layer flocks. The sampling schemes are based on the within-flock prevalence, and, as this changes over time, knowledge of the within-flock dynamics of Salmonella Enteritidis is required. Transmission of Salmonella Enteritidis has been quantified in pairs of layers, but the question is whether the dynamics in pairs is comparable to transmission in large groups, which are more representative for commercial layer flocks. The aim of this study was to compare results of transmission experiments between pairs and groups of laying hens. Experimental groups of either 2 or 200 hens were housed at similar densities, and 1 or 4 hens were inoculated with Salmonella Enteritidis, respectively. Excretion was monitored by regularly testing of fecal samples for the presence of Salmonella Enteritidis. Using mathematical modeling, the group experiments were simulated with transmission parameter estimates from the pairwise experiments. Transmission of the bacteria did not differ significantly between pairs or groups. This finding suggests that the transmission parameter estimates from small-scale experiments might be extrapolated to the field situation.

  16. Pairing and deformation effects in nuclear excitation spectra

    Energy Technology Data Exchange (ETDEWEB)

    Repko, A. [Slovak Academy of Sciences, Institute of Physics, Bratislava (Slovakia); Kvasil, J. [Charles University, Institute of Particle and Nuclear Physics, Prague (Czech Republic); Nesterenko, V.O. [Joint Institute for Nuclear Research, Laboratory of Theoretical Physics, Dubna (Russian Federation); State University ' ' Dubna' ' , Dubna (Russian Federation); Reinhard, P.G. [Universitaet Erlangen, Institut fuer Theoretische Physik II, Erlangen (Germany)

    2017-11-15

    We investigate effects of pairing and of quadrupole deformation on two sorts of nuclear excitations, γ-vibrational K{sup π} = 2{sup +} states and dipole resonances (isovector dipole, pygmy, compression, toroidal). The analysis is performed within the quasiparticle random phase approximation (QRPA) based on the Skyrme energy functional using the Skyrme parametrization SLy6. Particular attention is paid to i) the role of the particle-particle (pp) channel in the residual interaction of QRPA, ii) comparison of volume pairing (VP) and surface pairing (SP), iii) peculiarities of deformation splitting in the various resonances. We find that the impact of the pp-channel on the considered excitations is negligible. This conclusion applies also to any other excitation except for the K{sup π} = 0{sup +} states. Furthermore, the difference between VP and SP is found small (with exception of peak height in the toroidal mode). In the low-energy isovector dipole (pygmy) and isoscalar toroidal modes, the branch K{sup π} = 1{sup -} is shown to dominate over the K{sup π} = 0{sup -} one in the range of excitation energy E < 8-10 MeV. The effect becomes impressive for the toroidal resonance whose low-energy part is concentrated in a high peak of almost pure K{sup π} = 1{sup -} nature. This peculiarity may be used as a fingerprint of the toroidal mode in future experiments. The interplay between pygmy, toroidal and compression resonances is discussed, the interpretation of the observed isoscalar giant dipole resonance is partly revised. (orig.)

  17. Excited cooper pairs

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Arrietea, M. G.; Solis, M. A.; De Llano, M. [Universidad Nacional Autonoma de Mexico, Mexico, D.F (Mexico)

    2001-02-01

    Excited cooper pairs formed in a many-fermion system are those with nonzero total center-of mass momentum (CMM). They are normally neglected in the standard Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity for being too few compared with zero CMM pairs. However, a Bose-Einstein condensation picture requires both zero and nonzero CMM pairs. Assuming a BCS model interaction between fermions we determine the populations for all CMM values of Cooper pairs by actually calculating the number of nonzero-CMM pairs relative to that of zero-CMM ones in both 2D and 3D. Although this ratio decreases rapidly with CMM, the number of Cooper pairs for any specific CMM less than the maximum (or breakup of the pair) momentum turns out to be typically larger than about 95% of those with zero-CMM at zero temperature T. Even at T {approx}100 K this fraction en 2D is still as large as about 70% for typical quasi-2D cuprate superconductor parameters. [Spanish] Los pares de cooper excitados formados en un sistema de muchos electrones, son aquellos con momentos de centro de masa (CMM) diferente de cero. Normalmente estos no son tomados en cuenta en la teoria estandar de la superconductividad de Bardeen-Cooper-Schrieffer (BCS) al suponer que su numero es muy pequeno comparados con los pares de centro de masa igual a cero. Sin embargo, un esquema de condensacion Bose-Einstein requiere de ambos pares, con CMM cero y diferente de cero. Asumiendo una interaccion modelo BCS entre los fermiones, determinamos la poblacion de pares cooper con cada uno de todos los posibles valores del CMM calculando el numero de pares con momentos de centro de masa diferente de cero relativo a los pares de CMM igual a cero, en 2D y 3D. Aunque esta razon decrece rapidamente con el CMM, el numero de pares de cooper para cualquier CMM especifico menor que el momento maximo (o rompimiento de par) es tipicamente mas grande que el 95% de aquellos con CMM cero. Aun a T {approx}100 K esta fraccion en 2D es

  18. Efficient genome editing by FACS enrichment of paired D10A Cas9 nickases coupled with fluorescent proteins.

    Science.gov (United States)

    Gopalappa, Ramu; Song, Myungjae; Chandrasekaran, Arun Pandian; Das, Soumyadip; Haq, Saba; Koh, Hyun Chul; Ramakrishna, Suresh

    2018-05-31

    Targeted genome editing by clustered regularly interspaced short palindromic repeats (CRISPR-Cas9) raised concerns over off-target effects. The use of double-nicking strategy using paired Cas9 nickase has been developed to minimize off-target effects. However, it was reported that the efficiency of paired nickases were comparable or lower than that of either corresponding nuclease alone. Recently, we conducted a systematic comparison of the efficiencies of several paired Cas9 with their corresponding Cas9 nucleases and showed that paired D10A Cas9 nickases are sometimes more efficient than individual nucleases for gene disruption. However, sometimes the designed paired Cas9 nickases exhibited significantly lower mutation frequencies than nucleases, hampering the generation of cells containing paired Cas9 nickase-induced mutations. Here we implemented IRES peptide-conjugation of fluorescent protein to Cas9 nickase and subjected for fluorescence-activated cell sorting. The sorted cell populations are highly enriched with cells containing paired Cas9 nickase-induced mutations, by a factor of up to 40-fold as compared with the unsorted population. Furthermore, gene-disrupted single cell clones using paired nickases followed by FACS sorting strategy were generated highly efficiently, without compromising with its low off-target effects. We envision that our fluorescent protein coupled paired nickase-mediated gene disruption, facilitating efficient and highly specific genome editing in medical research.

  19. Mesoscopic pairing without superconductivity

    Science.gov (United States)

    Hofmann, Johannes

    2017-12-01

    We discuss pairing signatures in mesoscopic nanowires with a variable attractive pairing interaction. Depending on the wire length, density, and interaction strength, these systems realize a simultaneous bulk-to-mesoscopic and BCS-BEC crossover, which we describe in terms of the parity parameter that quantifies the odd-even energy difference and generalizes the bulk Cooper pair binding energy to mesoscopic systems. We show that the parity parameter can be extracted from recent measurements of conductance oscillations in SrTiO3 nanowires by Cheng et al. [Nature (London) 521, 196 (2015), 10.1038/nature14398], where it marks the critical magnetic field that separates pair and single-particle currents. Our results place the experiment in the fluctuation-dominated mesoscopic regime on the BCS side of the crossover.

  20. Top quark pair production at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Baernreuther, Peter

    2012-06-28

    One of the most interesting and manifold processes in the Standard Model of elementary particle physics is the top quark pair production. It enabled the discovery of the top quark at the Tevatron in 1995 and the determination of many of its properties. By means of a precise measurement and calculation of the cross section of top quark pair production it is possible to extract the top quark mass. Improvements in the gluon parton distribution functions (important for the Higgs boson production) or improvements in the prediction of the Higgs mass are also closely linked with the top quark pair production. Furthermore, the production process plays an important role in the discovery of new physics. On the one hand the top quark pair decays form the largest part of the background in many BSM models, on the other hand BSM physics can be detected directly in the decay process by investigating the charge symmetry or the invariant mass spectrum. At the LHC it will be possible for the first time to produce a large amount of top quarks; thereby the statistical errors of the observables will be strongly reduced. The enormous increase in the production rate has two reasons. On the one hand, the acceleration energy of the LHC (14 TeV and 7 TeV) is significantly greater than that of the Tevatron (1.96 Tev). This leads to an increase of the cross section by a factor of 100 ({proportional_to}7.3 pb at the Tevatron to {proportional_to}800 pb at 14 TeV LHC). On the other hand, the luminosity of the LHC outperforms the Tevatron by a factor of 10-100. The reduced experimental errors for the observables demand an improvement of the theoretical error. The experimental accuracy of the LHC and the great relevance of the process led to an intensive activity of different research groups in order to improve the calculation of the cross section of top quark pair production. This work presents for the first time a complete numerical result for the full NNLO correction for the top quark pair

  1. Top quark pair production at the LHC

    International Nuclear Information System (INIS)

    Baernreuther, Peter

    2012-01-01

    One of the most interesting and manifold processes in the Standard Model of elementary particle physics is the top quark pair production. It enabled the discovery of the top quark at the Tevatron in 1995 and the determination of many of its properties. By means of a precise measurement and calculation of the cross section of top quark pair production it is possible to extract the top quark mass. Improvements in the gluon parton distribution functions (important for the Higgs boson production) or improvements in the prediction of the Higgs mass are also closely linked with the top quark pair production. Furthermore, the production process plays an important role in the discovery of new physics. On the one hand the top quark pair decays form the largest part of the background in many BSM models, on the other hand BSM physics can be detected directly in the decay process by investigating the charge symmetry or the invariant mass spectrum. At the LHC it will be possible for the first time to produce a large amount of top quarks; thereby the statistical errors of the observables will be strongly reduced. The enormous increase in the production rate has two reasons. On the one hand, the acceleration energy of the LHC (14 TeV and 7 TeV) is significantly greater than that of the Tevatron (1.96 Tev). This leads to an increase of the cross section by a factor of 100 (∝7.3 pb at the Tevatron to ∝800 pb at 14 TeV LHC). On the other hand, the luminosity of the LHC outperforms the Tevatron by a factor of 10-100. The reduced experimental errors for the observables demand an improvement of the theoretical error. The experimental accuracy of the LHC and the great relevance of the process led to an intensive activity of different research groups in order to improve the calculation of the cross section of top quark pair production. This work presents for the first time a complete numerical result for the full NNLO correction for the top quark pair production in quark anti

  2. PandA : pairings and arithmetic

    NARCIS (Netherlands)

    Chuengsatiansup, C.; Naehrig, M.; Ribarski, P.; Schwabe, P.; Cao, Z.; Zhang, F.

    2014-01-01

    This paper introduces PandA, a software framework for Pairings and Arithmetic. It is designed to bring together advances in the efficient computation of cryptographic pairings and the development and implementation of pairing-based protocols. The intention behind the PandA framework is to give

  3. Filipino au pairs on the move

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2016-01-01

    Most Filipina au pairs in Denmark send remittances back home, and for many, au pairing forms part of longer-term migration trajectories. This article explores how Filipina au pairs try to carve out a future for themselves abroad. It shows that they navigate within tight webs of financial interdep......Most Filipina au pairs in Denmark send remittances back home, and for many, au pairing forms part of longer-term migration trajectories. This article explores how Filipina au pairs try to carve out a future for themselves abroad. It shows that they navigate within tight webs of financial...

  4. Pair production of heavy quarkonium and Bc(*) mesons at hadron colliders

    International Nuclear Information System (INIS)

    Li Rong; Zhang Yujie; Chao Kuangta

    2009-01-01

    We investigate the pair production of S-wave heavy quarkonium at the LHC in the color-singlet mechanism (CSM) and estimate the contribution from the gluon fragmentation process in the color-octet mechanism (COM) for comparison. With the matrix elements extracted previously in the leading-order calculations, the numerical results show that the production rates are quite large for the pair production processes at the LHC. The p t distribution of double J/ψ production in the CSM is dominant over that in the COM when p t is smaller than about 10 GeV. For the production of double Υ, the contribution of the COM is always larger than that in the CSM. The large differences in the theoretical predictions between the CSM and COM for the p t distributions in the large p t region are useful in clarifying the effects of COM on the quarkonium production. We also investigate the pair production of S-wave B c and B c * mesons, and the measurement of these processes is useful to test the CSM and extract the long-distance matrix elements for the B c and B c * mesons. Aside from numerical calculations, analytical expressions for the production differential cross sections of all these processes are also given.

  5. Collective neutrino-pair emission due to Cooper pairing of protons in superconducting neutron stars

    International Nuclear Information System (INIS)

    Leinson, L.B.

    2001-01-01

    The neutrino emission due to formation and breaking of Cooper pairs of protons in superconducting cores of neutron stars is considered with taking into account the electromagnetic coupling of protons to ambient electrons. It is shown that collective response of electrons to the proton quantum transition contributes coherently to the complete interaction with a neutrino field and enhances the neutrino-pair production. Our calculation shows that the contribution of the vector weak current to the ννbar emissivity of protons is much larger than that calculated by different authors without taking into account the plasma effects. Partial contribution of the pairing protons to the total neutrino radiation from the neutron star core is very sensitive to the critical temperatures for the proton and neutron pairing. We show domains of these parameters where the neutrino radiation, caused by a singlet-state pairing of protons is dominating

  6. Effects of Sleep on Word Pair Memory in Children – Separating Item and Source Memory Aspects

    Directory of Open Access Journals (Sweden)

    Jing-Yi Wang

    2017-09-01

    Full Text Available Word paired-associate learning is a well-established task to demonstrate sleep-dependent memory consolidation in adults as well as children. Sleep has also been proposed to benefit episodic features of memory, i.e., a memory for an event (item bound into the spatiotemporal context it has been experienced in (source. We aimed to explore if sleep enhances word pair memory in children by strengthening the episodic features of the memory, in particular. Sixty-one children (8–12 years studied two lists of word pairs with 1 h in between. Retrieval testing comprised cued recall of the target word of each word pair (item memory and recalling in which list the word pair had appeared in (source memory. Retrieval was tested either after 1 h (short retention interval or after 11 h, with this long retention interval covering either nocturnal sleep or daytime wakefulness. Compared with the wake interval, sleep enhanced separate recall of both word pairs and the lists per se, while recall of the combination of the word pair and the list it had appeared in remained unaffected by sleep. An additional comparison with adult controls (n = 37 suggested that item-source bound memory (combined recall of word pair and list is generally diminished in children. Our results argue against the view that the sleep-induced enhancement in paired-associate learning in children is a consequence of sleep specifically enhancing the episodic features of the memory representation. On the contrary, sleep in children might strengthen item and source representations in isolation, while leaving the episodic memory representations (item-source binding unaffected.

  7. QSO Pairs across Active Galaxies

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Several QSO pairs have been reported and their redshifts determined, where the two objects in each pair are located across an active galaxy. The usually accepted explanation of such occurrences is that the pair is ejected from the parent galaxy. Currently interpreted redshifted spectra for both the QSOs ...

  8. Comparison of Paired ROC Curves through a Two-Stage Test.

    Science.gov (United States)

    Yu, Wenbao; Park, Eunsik; Chang, Yuan-Chin Ivan

    2015-01-01

    The area under the receiver operating characteristic (ROC) curve (AUC) is a popularly used index when comparing two ROC curves. Statistical tests based on it for analyzing the difference have been well developed. However, this index is less informative when two ROC curves cross and have similar AUCs. In order to detect differences between ROC curves in such situations, a two-stage nonparametric test that uses a shifted area under the ROC curve (sAUC), along with AUCs, is proposed for paired designs. The new procedure is shown, numerically, to be effective in terms of power under a wide range of scenarios; additionally, it outperforms two conventional ROC-type tests, especially when two ROC curves cross each other and have similar AUCs. Larger sAUC implies larger partial AUC at the range of low false-positive rates in this case. Because high specificity is important in many classification tasks, such as medical diagnosis, this is an appealing characteristic. The test also implicitly analyzes the equality of two commonly used binormal ROC curves at every operating point. We also apply the proposed method to synthesized data and two real examples to illustrate its usefulness in practice.

  9. Isovector pairing in self-conjugate nuclei in a formalism of quartets

    International Nuclear Information System (INIS)

    Sambataro, M; Sandulescu, N

    2014-01-01

    The isovector proton-neutron pairing in self-conjugate nuclei is treated in a formalism of quartets. Quartets are four-body correlated structures built from two neutrons and two protons coupled to total isospin T = 0. The ground state of the isovector pairing Hamiltonian is described as a product of quartets. We review both the case in which the quartets are constrained to be all identical and the case in which they are allowed to be distinct from one another. The quality of the two approaches is tested by making comparisons with exact shell model calculations for N = Z nuclei with valence nucleons outside the 16 O, 40 Ca, and 100 Sn cores. We consider both spherical and axially deformed mean fields. Both approaches are found to be very accurate. In the applications to a deformed mean field, in particular, the formalism with distinct quartets gives rise to results which are basically exact

  10. Base pair mismatches and carcinogen-modified bases in DNA: an NMR study of G x T and G x O4meT pairing in dodecanucleotide duplexes

    International Nuclear Information System (INIS)

    Kalnik, M.W.; Kouchakdjian, M.; Li, B.F.L.; Swann, P.F.; Patel, D.J.

    1988-01-01

    High-resolution two-dimensional NMR studies have been completed on the self-complementary d(C-G-C-G-A-G-C-T-T-G-C-G) duplex (designated G x T 12-mer) and the self-complementary d(C-G-C-G-A-G-C-T-O 4 meT-G-C-G) duplex (designated G x O 4 meT 12-mer) containing G x T and G x O 4 meT pairs at identical positions four base pairs in from either end of the duplex. The exchangeable and nonexchangeable proton resonances have been assigned from an analysis of two-dimensional nuclear Overhauser enhancement (NOESY) spectra for the G x T 12-mer and G x O 4 meT 12-mer duplexes in H 2 O and D 2 O solution. The guanosine and thymidine imino protons in the G x T mismatch resonate at 10.57 and 11.98 ppm, respectively, and exhibit a strong NOE between themselves and to imino protons of flanking base pairs in the G x T 12-mer duplex. The large upfield chemical shift of this proton relative to that of the imino proton resonance of G in the G x T mismatch or in G x C base pairs indicates that hydrogen bonding to O 4 meT is either very weak or absent. This guanosine imino proton has an NOE to the OCH 3 group of O 4 meT across the pair and NOEs to the imino protons of flanking base pairs. Taken together with data from the NMR of nonexchangeable protons, this shows that both G and O 4 meT have anti-glycosidic torsion angles and are stacked into the duplex. Comparison of the intensity of the NOEs between the guanosine imino proton and the OCH 3 of O 4 meT as well as other protons in its vicinity demonstrates that the OCH 3 group of O 4 meT adopts the syn orientation with respect to N3 of the methylated thymidine. The authors propose an alternate base pairing mode stabilized by one short hydrogen bond between the 2-amino group of guanosine and the 2-carbonyl group of O 4 met

  11. Calculations of energy levels and electromagnetic properties for tellurium pair isotopes, by unified method

    International Nuclear Information System (INIS)

    Teixeira, R.R.P.

    1988-01-01

    Calculations with the Unified Model (vibrator coupled to two particles), of the energy levels and the eletromagnetic properties have been performed and compared with the twelve pair isotopes from tellurium with A between 112 and 134. The results were analysed using as particles interaction: pairing and SDI (Surface Delta Interaction). The SDI and 3 fonons collective states were used in the fittings, and a syntematic comparison between the theoretical and experimental results was made. The dependence of the results with the model parameters was determined, through large variation sof them. Calculations using 4 fonons have been made, and the importance of the introduced variations in the results was discussed. Calculations have been made in the VAX Computer of the Pelletron at IFUSP. (author) [pt

  12. Optimal working pairs for solar adsorption cooling applications

    International Nuclear Information System (INIS)

    Allouhi, A.; Kousksou, T.; Jamil, A.; El Rhafiki, T.; Mourad, Y.; Zeraouli, Y.

    2015-01-01

    This article suggests a detailed comparison of 7 working pairs intended for use in solar adsorption cooling systems. The performance analysis was based on two indicators: adsorption capacity and solar coefficient of performance. Based on a reformed form of the Dubinin–Astakhov equation, a 3D graph was constructed to show the adsorbate concentration in the appropriate adsorbent as a first step to determine the adsorption capacity. A MATLAB program was developed to solve the system equation to predict the solar coefficient of performance for a typical summer day in a Moroccan city Fez. It was found that maximal adsorption capacity is obtained by activated carbon fibre/methanol (0.3406 kg kg −1 ) followed by activated carbon/methanol (0.2565 kg kg −1 ) and activated carbon/ethanol (0.2008 kg kg −1 ). At a condenser temperature of 25 °C, with an adsorbent mass of 20 kg, and an integrated collector-reactor configuration, the couple silica gel/water for air conditioning purpose can reach an SCOP of 0.3843. Activated carbon fibre/methanol is the following more efficient couple and can be used in the different cooling applications with an SCOP ranging from 0.1726 to 0.3287. Furthermore, adequate indicators are evaluated addressing the economic, environmental and safe aspects associated with each working pair. - Highlights: • 7 working pairs intended for use in solar adsorption cooling systems are compared. • A MATLAB program is used to predict the solar coefficient of performance. • Maximal adsorption capacity is obtained by activated carbon fibre/methanol

  13. UV-vis, IR and 1H NMR spectroscopic studies and characterization of ionic-pair crystal violet-oxytetracycline

    Science.gov (United States)

    Orellana, Sandra; Soto, César; Toral, M. Inés

    2010-01-01

    The present study shows the formation and characterization of the ionic-pair between the antibiotic oxytetracycline and the dye crystal violet in ammonia solution pH 9.0 ± 0.2 extracted into chloroform. The characterization was demonstrated using UV-vis spectrophotometry, 1H NMR, measurement of relaxation times T1 and IR spectroscopy, using a comparison between the signals of individual pure compounds with the signals with the mixture CV-OTC in different alkaline media. The formation of ionic-pair was also corroborated by new signals and chemical shifts. (2D) NMR spectroscopy experiments show that the interaction is electrostatic.

  14. A configuration space of homologous proteins conserving mutual information and allowing a phylogeny inference based on pair-wise Z-score probabilities

    OpenAIRE

    Maréchal Eric; Ortet Philippe; Roy Sylvaine; Bastien Olivier

    2005-01-01

    Abstract Background Popular methods to reconstruct molecular phylogenies are based on multiple sequence alignments, in which addition or removal of data may change the resulting tree topology. We have sought a representation of homologous proteins that would conserve the information of pair-wise sequence alignments, respect probabilistic properties of Z-scores (Monte Carlo methods applied to pair-wise comparisons) and be the basis for a novel method of consistent and stable phylogenetic recon...

  15. Determination of the pairing-strength constants in the isovector plus isoscalar pairing case

    Science.gov (United States)

    Mokhtari, D.; Fellah, M.; Allal, N. H.

    2016-05-01

    A method for the determination of the pairing-strength constants, in the neutron-proton (n-p) isovector plus isoscalar pairing case, is proposed in the framework of the BCS theory. It is based on the fitting of these constants to reproduce the experimentally known pairing gap parameters as well as the root-mean-squared (r.m.s) charge radii values. The method is applied to some proton-rich even-even nuclei. The single-particle energies used are those of a deformed Woods-Saxon mean field. It is shown that the obtained value of the ratio GnpT=0/G npT=1 is of the same order as the ones, arbitrary chosen, of some previous works. The effect of the inclusion of the isoscalar n-p pairing in the r.m.s matter radii is then numerically studied for the same nuclei.

  16. Analysis of electron pair production in the collision system Ar+KCl at 1.76 AGeV

    International Nuclear Information System (INIS)

    Lang, Simon Martin

    2008-01-01

    The HADES-spectrometer at GSI is used to measure the production of the light vector mesons ρ, ω and φ at SIS energies. Therefore, the medium sized collision system Ar+KCl was measured at 1.76 AGeV kinetic energy of beam particles. In this system the density of particle tracks is much larger as compared to the formerly used collision system C+C, making it necessary to upgrade the data analysis. The previous method of hard-cuts - used for particle identification - was replaced by a newly developed multi-variate analysis based on an artificial neural network. This algorithm has the benefit, that it is more robust against fluctuations in one or more of the used detector observables. This increases the overall efficiency and purity of the analysis procedure. Furthermore, the reconstruction of particle tracks inside the HADES spectrometer is based on a few position information, only. During analysis of raw data, these information are combined to a artificially large manifold of tracks. This leads to the general problem that one has to select the maximum number of true physical tracks out of this set of tracks per event. A new method of track selection is used to filter the data not only to select single tracks, but also to identify electron pairs created during Dalitz-decay of π 0 mesons, which build the bulk of combinatorial background. The result of the analysis is an efficiency corrected invariant mass spectrum of electron pairs, normalized to the mean number of pions per event. The spectrum consists of more than 16,000 pairs with an invariant mass larger than 150 MeV. In total more than 150000 pairs were found. A first comparison with the spectra calculated by using the old analysis approach shows a 30% enhancement in yield of reconstructed electron pairs. A first comparison with a simple thermal model implemented by the Pluto event generator, opens the possibility to compare the measured pair yield of ω and φ mesons via m T -scaling with the yield of η mesons

  17. Affine pairings on ARM

    NARCIS (Netherlands)

    Acar, T.; Lauter, K.; Naehrig, M.; Shumow, D.

    2011-01-01

    Pairings on elliptic curves are being used in an increasing number of cryptographic applications on many different devices and platforms, but few performance numbers for cryptographic pairings have been reported on embedded and mobile devices. In this paper we give performance numbers for affine and

  18. Solutions of nuclear pairing

    International Nuclear Information System (INIS)

    Balantekin, A. B.; Pehlivan, Y.

    2007-01-01

    We give the exact solution of orbit dependent nuclear pairing problem between two nondegenerate energy levels using the Bethe ansatz technique. Our solution reduces to previously solved cases in the appropriate limits including Richardson's treatment of reduced pairing in terms of rational Gaudin algebra operators

  19. Quantifying inbreeding avoidance through extra-pair reproduction.

    Science.gov (United States)

    Reid, Jane M; Arcese, Peter; Keller, Lukas F; Germain, Ryan R; Duthie, A Bradley; Losdat, Sylvain; Wolak, Matthew E; Nietlisbach, Pirmin

    2015-01-01

    Extra-pair reproduction is widely hypothesized to allow females to avoid inbreeding with related socially paired males. Consequently, numerous field studies have tested the key predictions that extra-pair offspring are less inbred than females' alternative within-pair offspring, and that the probability of extra-pair reproduction increases with a female's relatedness to her socially paired male. However, such studies rarely measure inbreeding or relatedness sufficiently precisely to detect subtle effects, or consider biases stemming from failure to observe inbred offspring that die during early development. Analyses of multigenerational song sparrow (Melospiza melodia) pedigree data showed that most females had opportunity to increase or decrease the coefficient of inbreeding of their offspring through extra-pair reproduction with neighboring males. In practice, observed extra-pair offspring had lower inbreeding coefficients than females' within-pair offspring on average, while the probability of extra-pair reproduction increased substantially with the coefficient of kinship between a female and her socially paired male. However, simulations showed that such effects could simply reflect bias stemming from inbreeding depression in early offspring survival. The null hypothesis that extra-pair reproduction is random with respect to kinship therefore cannot be definitively rejected in song sparrows, and existing general evidence that females avoid inbreeding through extra-pair reproduction requires reevaluation given such biases. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  20. Synergy between pair coupled cluster doubles and pair density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Garza, Alejandro J.; Bulik, Ireneusz W. [Department of Chemistry, Rice University, Houston, Texas 77251-1892 (United States); Henderson, Thomas M. [Department of Chemistry and Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892 (United States); Scuseria, Gustavo E. [Department of Chemistry and Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892 (United States); Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2015-01-28

    Pair coupled cluster doubles (pCCD) has been recently studied as a method capable of accounting for static correlation with low polynomial cost. We present three combinations of pCCD with Kohn–Sham functionals of the density and on-top pair density (the probability of finding two electrons on top of each other) to add dynamic correlation to pCCD without double counting. With a negligible increase in computational cost, these pCCD+DFT blends greatly improve upon pCCD in the description of typical problems where static and dynamic correlations are both important. We argue that—as a black-box method with low scaling, size-extensivity, size-consistency, and a simple quasidiagonal two-particle density matrix—pCCD is an excellent match for pair density functionals in this type of fusion of multireference wavefunctions with DFT.

  1. Secure pairing with biometrics

    NARCIS (Netherlands)

    Buhan, I.R.; Boom, B.J.; Doumen, J.M.; Hartel, Pieter H.; Veldhuis, Raymond N.J.

    Secure pairing enables two devices that share no prior context with each other to agree upon a security association, which they can use to protect their subsequent communication. Secure pairing offers guarantees of the association partner identity and it should be resistant to eavesdropping and to a

  2. Property (RD) for Hecke Pairs

    International Nuclear Information System (INIS)

    Shirbisheh, Vahid

    2012-01-01

    As the first step towards developing noncommutative geometry over Hecke C ∗ -algebras, we study property (RD) (Rapid Decay) for Hecke pairs. When the subgroup H in a Hecke pair (G, H) is finite, we show that the Hecke pair (G, H) has (RD) if and only if G has (RD). This provides us with a family of examples of Hecke pairs with property (RD). We also adapt Paul Jolissant’s works in Jolissaint (J K-Theory 2:723–735, 1989; Trans Amer Math Soc 317(1):167–196, 1990) to the setting of Hecke C ∗ -algebras and show that when a Hecke pair (G, H) has property (RD), the algebra of rapidly decreasing functions on the set of double cosets is closed under holomorphic functional calculus of the associated (reduced) Hecke C ∗ -algebra. Hence they have the same K 0 -groups.

  3. Investigations into nuclear pairing

    International Nuclear Information System (INIS)

    Clark, R.M.

    2006-01-01

    This paper is divided in two main sections focusing on different aspects of collective nuclear behavior. In the first section, solutions are considered for the collective pairing Hamiltonian. In particular, an approximate solution at the critical point of the pairing transition from harmonic vibration (normal nuclear behavior) to deformed rotation (superconducting behavior) in gauge space is found by analytic solution of the Hamiltonian. The eigenvalues are expressed in terms of the zeros of Bessel functions of integer order. The results are compared to the pairing bands based on the Pb isotopes. The second section focuses on the experimental search for the Giant Pairing Vibration (GPV) in nuclei. After briefly describing the origin of the GPV, and the reasons that the state has remained unidentified, a novel idea for populating this state is presented. A recent experiment has been performed using the LIBERACE+STARS detector system at the 88-Inch Cyclotron of LBNL to test the idea. (Author)

  4. A natively paired antibody library yields drug leads with higher sensitivity and specificity than a randomly paired antibody library.

    Science.gov (United States)

    Adler, Adam S; Bedinger, Daniel; Adams, Matthew S; Asensio, Michael A; Edgar, Robert C; Leong, Renee; Leong, Jackson; Mizrahi, Rena A; Spindler, Matthew J; Bandi, Srinivasa Rao; Huang, Haichun; Tawde, Pallavi; Brams, Peter; Johnson, David S

    2018-04-01

    Deep sequencing and single-chain variable fragment (scFv) yeast display methods are becoming more popular for discovery of therapeutic antibody candidates in mouse B cell repertoires. In this study, we compare a deep sequencing and scFv display method that retains native heavy and light chain pairing with a related method that randomly pairs heavy and light chain. We performed the studies in a humanized mouse, using interleukin 21 receptor (IL-21R) as a test immunogen. We identified 44 high-affinity binder scFv with the native pairing method and 100 high-affinity binder scFv with the random pairing method. 30% of the natively paired scFv binders were also discovered with the randomly paired method, and 13% of the randomly paired binders were also discovered with the natively paired method. Additionally, 33% of the scFv binders discovered only in the randomly paired library were initially present in the natively paired pre-sort library. Thus, a significant proportion of "randomly paired" scFv were actually natively paired. We synthesized and produced 46 of the candidates as full-length antibodies and subjected them to a panel of binding assays to characterize their therapeutic potential. 87% of the antibodies were verified as binding IL-21R by at least one assay. We found that antibodies with native light chains were more likely to bind IL-21R than antibodies with non-native light chains, suggesting a higher false positive rate for antibodies from the randomly paired library. Additionally, the randomly paired method failed to identify nearly half of the true natively paired binders, suggesting a higher false negative rate. We conclude that natively paired libraries have critical advantages in sensitivity and specificity for antibody discovery programs.

  5. Using dual-process theory and analogical transfer to explain facilitation on a hypothetico-deductive reasoning task.

    Science.gov (United States)

    Koenig, Cynthia S; Platt, Richard D; Griggs, Richard A

    2007-07-01

    Using the analogical transfer paradigm, the present study investigated the competing explanations of Girotto and Legrenzi (Psychological Research 51: 129-135, 1993) and Griggs, Platt, Newstead, and Jackson (Thinking and Reasoning 4: 1-14, 1998) for facilitation on the SARS version of the THOG problem, a hypothetico-deductive reasoning task. Girotto and Legrenzi argue that facilitation is based on logical analysis of the task [System 2 reasoning in Evans's (Trends in Cognitive Sciences 7: 454-459, 2003) dual-process account of reasoning] while Griggs et al. maintain that facilitation is due to an attentional heuristic produced by the wording of the problem (System 1 reasoning). If Girotto and Legrenzi are correct, then System 2 reasoning, which is volitional and responsible for deductive reasoning, should be elicited, and participants should comprehend the solution principle of the THOG task and exhibit analogical transfer. However, if Griggs et al. are correct, then System 1 reasoning, which is responsible for heuristic problem solving strategies such as an attentional heuristic, should occur, and participants should not abstract the solution principle and transfer should not occur. Significant facilitation (68 and 82% correct) was only observed for the two SARS source problems, but significant analogical transfer did not occur. This lack of transfer suggests that System 1 reasoning was responsible for the facilitation observed in the SARS problem, supporting Griggs et al.'s attentional heuristic explanation. The present results also underscore the explanatory value of using analogical transfer rather than facilitation as the criterion for problem understanding.

  6. Instability of vortex pair leapfrogging

    DEFF Research Database (Denmark)

    Tophøj, Laust; Aref, Hassan

    2013-01-01

    Leapfrogging is a periodic solution of the four-vortex problem with two positive and two negative point vortices all of the same absolute circulation arranged as co-axial vortex pairs. The set of co-axial motions can be parameterized by the ratio 0 vortex pair sizes at the time when one...... pair passes through the other. Leapfrogging occurs for α > σ2, where is the silver ratio. The motion is known in full analytical detail since the 1877 thesis of Gröbli and a well known 1894 paper by Love. Acheson ["Instability of vortex leapfrogging," Eur. J. Phys.21, 269-273 (2000...... pairs fly off to infinity, and a "walkabout" mode, where the vortices depart from leapfrogging but still remain within a finite distance of one another. We show numerically that this transition is more gradual, a result that we relate to earlier investigations of chaotic scattering of vortex pairs [L...

  7. Pairing induced superconductivity in holography

    Science.gov (United States)

    Bagrov, Andrey; Meszena, Balazs; Schalm, Koenraad

    2014-09-01

    We study pairing induced superconductivity in large N strongly coupled systems at finite density using holography. In the weakly coupled dual gravitational theory the mechanism is conventional BCS theory. An IR hard wall cut-off is included to ensure that we can controllably address the dynamics of a single confined Fermi surface. We address in detail the interplay between the scalar order parameter field and fermion pairing. Adding an explicitly dynamical scalar operator with the same quantum numbers as the fermion-pair, the theory experiences a BCS/BEC crossover controlled by the relative scaling dimensions. We find the novel result that this BCS/BEC crossover exposes resonances in the canonical expectation value of the scalar operator. This occurs not only when the scaling dimension is degenerate with the Cooper pair, but also with that of higher derivative paired operators. We speculate that a proper definition of the order parameter which takes mixing with these operators into account stays finite nevertheless.

  8. [Paired kidneys in transplant].

    Science.gov (United States)

    Regueiro López, Juan C; Leva Vallejo, Manuel; Prieto Castro, Rafael; Anglada Curado, Francisco; Vela Jiménez, Francisco; Ruiz García, Jesús

    2009-02-01

    Many factors affect the graft and patient survival on the renal transplant outcome. These factors depend so much of the recipient and donor. We accomplished a study trying to circumvent factors that depend on the donor. We checked the paired kidneys originating of a same donor cadaver. We examined the risk factors in the evolution and follow-up in 278 couples of kidney transplant. We describe their differences, significance, the graft and patient survival, their functionality in 3 and 5 years and the risk factors implicated in their function. We study immunogenic and no immunogenic variables, trying to explain the inferior results in the grafts that are established secondly. We regroup the paired kidneys in those that they did not show paired initial function within the same couple. The results yield a discreet deterioration in the graft and patient survival for second group establish, superior creatinina concentration, without obtaining statistical significance. The Cox regression study establishes the early rejection (inferior to three months) and DR incompatibility values like risk factors. This model of paired kidneys would be able to get close to best-suited form for risk factors analysis in kidney transplant from cadaver donors, if more patients examine themselves in the same way. The paired kidneys originating from the same donor do not show the same function in spite of sharing the same conditions of the donor and perioperative management.

  9. Dual origin of pairing in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Idini, A. [University of Jyvaskyla, Department of Physics (Finland); Potel, G. [Michigan State University, National Superconducting Cyclotron Laboratory (United States); Barranco, F. [Escuela Superior de Ingenieros, Universidad de Sevilla, Departamento de Fìsica Aplicada III (Spain); Vigezzi, E., E-mail: enrico.vigezzi@mi.infn.it [INFN Sezione di Milano (Italy); Broglia, R. A. [Università di Milano, Dipartimento di Fisica (Italy)

    2016-11-15

    The pairing correlations of the nucleus {sup 120}Sn are calculated by solving the Nambu–Gor’kov equations, including medium polarization effects resulting from the interweaving of quasiparticles, spin and density vibrations, taking into account, within the framework of nuclear field theory (NFT), processes leading to self-energy and vertex corrections and to the induced pairing interaction. From these results one can not only demonstrate the inevitability of the dual origin of pairing in nuclei, but also extract information which can be used at profit to quantitatively disentangle the contributions to the pairing gap Δ arising from the bare and from the induced pairing interaction. The first is the strong {sup 1}S{sub 0} short-range NN potential resulting from meson exchange between nucleons moving in time reversal states within an energy range of hundreds of MeV from the Fermi energy. The second results from the exchange of vibrational modes between nucleons moving within few MeV from the Fermi energy. Short- (v{sub p}{sup bare}) and long-range (v{sub p}{sup ind}) pairing interactions contribute essentially equally to nuclear Cooper pair stability. That is to the breaking of gauge invariance in open-shell superfluid nuclei and thus to the order parameter, namely to the ground state expectation value of the pair creation operator. In other words, to the emergent property of generalized rigidity in gauge space, and associated rotational bands and Cooper pair tunneling between members of these bands.

  10. Dual origin of pairing in nuclei

    Science.gov (United States)

    Idini, A.; Potel, G.; Barranco, F.; Vigezzi, E.; Broglia, R. A.

    2016-11-01

    The pairing correlations of the nucleus 120Sn are calculated by solving the Nambu-Gor'kov equations, including medium polarization effects resulting from the interweaving of quasiparticles, spin and density vibrations, taking into account, within the framework of nuclear field theory (NFT), processes leading to self-energy and vertex corrections and to the induced pairing interaction. From these results one can not only demonstrate the inevitability of the dual origin of pairing in nuclei, but also extract information which can be used at profit to quantitatively disentangle the contributions to the pairing gap Δ arising from the bare and from the induced pairing interaction. The first is the strong 1 S 0 short-range NN potential resulting from meson exchange between nucleons moving in time reversal states within an energy range of hundreds of MeV from the Fermi energy. The second results from the exchange of vibrational modes between nucleons moving within few MeV from the Fermi energy. Short- ( v p bare) and long-range ( v p ind) pairing interactions contribute essentially equally to nuclear Cooper pair stability. That is to the breaking of gauge invariance in open-shell superfluid nuclei and thus to the order parameter, namely to the ground state expectation value of the pair creation operator. In other words, to the emergent property of generalized rigidity in gauge space, and associated rotational bands and Cooper pair tunneling between members of these bands.

  11. Lewis pair polymerization by classical and frustrated Lewis pairs: Acid, base and monomer scope and polymerization mechanism

    KAUST Repository

    Zhang, Yuetao

    2012-01-01

    Classical and frustrated Lewis pairs (LPs) of the strong Lewis acid (LA) Al(C 6F 5) 3 with several Lewis base (LB) classes have been found to exhibit exceptional activity in the Lewis pair polymerization (LPP) of conjugated polar alkenes such as methyl methacrylate (MMA) as well as renewable α-methylene-γ-butyrolactone (MBL) and γ-methyl- α-methylene-γ-butyrolactone (γ-MMBL), leading to high molecular weight polymers, often with narrow molecular weight distributions. This study has investigated a large number of LPs, consisting of 11 LAs as well as 10 achiral and 4 chiral LBs, for LPP of 12 monomers of several different types. Although some more common LAs can also be utilized for LPP, Al(C 6F 5) 3-based LPs are far more active and effective than other LA-based LPs. On the other hand, several classes of LBs, when paired with Al(C 6F 5) 3, can render highly active and effective LPP of MMA and γ-MMBL; such LBs include phosphines (e.g., P tBu 3), chiral chelating diphosphines, N-heterocyclic carbenes (NHCs), and phosphazene superbases (e.g., P 4- tBu). The P 4- tBu/Al(C 6F 5) 3 pair exhibits the highest activity of the LP series, with a remarkably high turn-over frequency of 9.6 × 10 4 h -1 (0.125 mol% catalyst, 100% MMA conversion in 30 s, M n = 2.12 × 10 5 g mol -1, PDI = 1.34). The polymers produced by LPs at RT are typically atactic (P γMMBL with ∼47% mr) or syndio-rich (PMMA with ∼70-75% rr), but highly syndiotactic PMMA with rr ∼91% can be produced by chiral or achiral LPs at -78 °C. Mechanistic studies have identified and structurally characterized zwitterionic phosphonium and imidazolium enolaluminates as the active species of the current LPP system, which are formed by the reaction of the monomer·Al(C 6F 5) 3 adduct with P tBu 3 and NHC bases, respectively. Kinetic studies have revealed that the MMA polymerization by the tBu 3P/ Al(C 6F 5) 3 pair is zero-order in monomer concentration after an initial induction period, and the polymerization

  12. DFT study on the attacking mechanisms of H and OH radicals to G-C and A-T base pairs in water

    Energy Technology Data Exchange (ETDEWEB)

    Okutsu, N.; Shimamura, K.; Shimizu, E.; Kurita, N., E-mail: kurita@cs.tut.ac.jp [Department of Computer Science and Engineering, Toyohashi University of Technology, Toyohashi, Aichi, 441-8580 (Japan); Shulga, S. [Institute for Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Kyiv (Ukraine); Danilov, V. I. [Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv (Ukraine)

    2016-02-01

    To elucidate the effect of radicals on DNA base pairs, we investigated the attacking mechanism of OH and H radicals to the G-C and A-T base pairs, using the density functional theory (DFT) calculations in water approximated by the continuum solvation model. The DFT calculations revealed that the OH radical abstracts the hydrogen atom of a NH{sub 2} group of G or A base and induces a tautomeric reaction for an A-T base pair more significantly than for a G-C base pair. On the other hand, the H radical prefers to bind to the Cytosine NH{sub 2} group of G-C base pair and induce a tautomeric reaction from G-C to G*-C*, whose activation free energy is considerably small (−0.1 kcal/mol) in comparison with that (42.9 kcal/mol) for the reaction of an A-T base pair. Accordingly, our DFT calculations elucidated that OH and H radicals have a significant effect on A-T and G-C base pairs, respectively. This finding will be useful for predicting the effect of radiation on the genetic information recorded in the base sequences of DNA duplexes.

  13. DFT study on the attacking mechanisms of H and OH radicals to G-C and A-T base pairs in water

    International Nuclear Information System (INIS)

    Okutsu, N.; Shimamura, K.; Shimizu, E.; Kurita, N.; Shulga, S.; Danilov, V. I.

    2016-01-01

    To elucidate the effect of radicals on DNA base pairs, we investigated the attacking mechanism of OH and H radicals to the G-C and A-T base pairs, using the density functional theory (DFT) calculations in water approximated by the continuum solvation model. The DFT calculations revealed that the OH radical abstracts the hydrogen atom of a NH 2 group of G or A base and induces a tautomeric reaction for an A-T base pair more significantly than for a G-C base pair. On the other hand, the H radical prefers to bind to the Cytosine NH 2 group of G-C base pair and induce a tautomeric reaction from G-C to G*-C*, whose activation free energy is considerably small (−0.1 kcal/mol) in comparison with that (42.9 kcal/mol) for the reaction of an A-T base pair. Accordingly, our DFT calculations elucidated that OH and H radicals have a significant effect on A-T and G-C base pairs, respectively. This finding will be useful for predicting the effect of radiation on the genetic information recorded in the base sequences of DNA duplexes

  14. Neutron pair and proton pair transfer reactions between identical cores in the sulfur region

    International Nuclear Information System (INIS)

    Mermaz, M.C.

    1995-12-01

    Optical model and exact finite range distorted-wave Born approximation analyses were performed on neutron pair exchange between identical cores for 32 S and 34 S nuclei and on proton pair exchange between identical cores for 30 Si and 32 S. The extracted spectroscopic factors were compared with theoretical ones deduced from Hartree-Fock calculations on these pair of nuclei. The enhancement of the experimental cross sections with respect to the theoretical ones strongly suggests evidence for a nuclear Josephson effect. (author). 15 refs., 5 figs., 3 tabs

  15. Dynamical pairing correlations in rotating nuclei

    International Nuclear Information System (INIS)

    Szymanski, Z.

    1985-01-01

    When the atomic nucleus rotates fast enough the static pair correlations may be destroyed. In this situation the pair-vibrations become an important manifestation of the short-range attractive pairing force. The influence of this effect on nuclear properties at high spin is discussed. (orig.)

  16. Pair creation at large inherent angles

    International Nuclear Information System (INIS)

    Chen, P.; Tauchi, T.; Schroeder, D.V.

    1992-01-01

    In the next-generation linear colliders, the low-energy e + e - pairs created during the collision of high-energy e + e - beams would cause potential deleterious background problems to the detectors. At low collider energies, the pairs are made essentially by the incoherent process, where the pair is created by the interaction of beamstrahlung photons on the individual particles in the oncoming beam. This problem was first identified by Zolotarev, et al. At energies where the beamstrahlung parameter Υ lies approximately in the range 0.6 approx-lt Υ approx-lt 100, pair creation from the beamstrahlung photons is dominated by a coherent process, first noted by Chen. The seriousness of this pair creation problem lies in the transverse momenta that the pair particles carry when leaving the interaction point (IP) with large angles. Since the central issue is the transverse momentum for particles with large angles, the authors notice that there is another source for it. Namely, when the pair particles are created at low energies, the intrinsic angles of these pairs when produced may already be large. In this paper they reinvestigate the problem, following essentially the same equivalent photon approach, but with changes in specific details including the virtual photon spectrum. In addition, various assumptions are made more explicit. The formulas derived are then applied to the collider parameters designed by Palmer

  17. Radical-pair based avian magnetoreception

    Science.gov (United States)

    Procopio, Maria; Ritz, Thorsten

    2014-03-01

    Behavioural experiments suggest that migratory birds possess a magnetic compass sensor able to detect the direction of the geomagnetic. One hypothesis for the basis of this remarkable sensory ability is that the coherent quantum spin dynamics of photoinduced radical pair reactions transduces directional magnetic information from the geomagnetic field into changes of reaction yields, possibly involving the photoreceptor cryptochrome in the birds retina. The suggested radical-pair based avian magnetoreception has attracted attention in the field of quantum biology as an example of a biological sensor which might exploit quantum coherences for its biological function. Investigations on such a spin-based sensor have focussed on uncovering the design features for the design of a biomimetic magnetic field sensor. We study the effects of slow fluctuations in the nuclear spin environment on the directional signal. We quantitatively evaluate the robustness of signals under fluctuations on a timescale longer than the lifetime of a radical pair, utilizing two models of radical pairs. Our results suggest design principles for building a radical-pair based compass sensor that is both robust and highly directional sensitive.

  18. Power of non-parametric linkage analysis in mapping genes contributing to human longevity in long-lived sib-pairs

    DEFF Research Database (Denmark)

    Tan, Qihua; Zhao, J H; Iachine, I

    2004-01-01

    This report investigates the power issue in applying the non-parametric linkage analysis of affected sib-pairs (ASP) [Kruglyak and Lander, 1995: Am J Hum Genet 57:439-454] to localize genes that contribute to human longevity using long-lived sib-pairs. Data were simulated by introducing a recently...... developed statistical model for measuring marker-longevity associations [Yashin et al., 1999: Am J Hum Genet 65:1178-1193], enabling direct power comparison between linkage and association approaches. The non-parametric linkage (NPL) scores estimated in the region harboring the causal allele are evaluated...... in case of a dominant effect. Although the power issue may depend heavily on the true genetic nature in maintaining survival, our study suggests that results from small-scale sib-pair investigations should be referred with caution, given the complexity of human longevity....

  19. Heteroditopic receptors for ion-pair recognition.

    Science.gov (United States)

    McConnell, Anna J; Beer, Paul D

    2012-05-21

    Ion-pair recognition is a new field of research emerging from cation and anion coordination chemistry. Specific types of heteroditopic receptor designs for ion pairs and the complexity of ion-pair binding are discussed to illustrate key concepts such as cooperativity. The importance of this area of research is reflected by the wide variety of potential applications of ion-pair receptors, including applications as membrane transport and salt solubilization agents and sensors. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Assessing Intimacy: The Pair Inventory.

    Science.gov (United States)

    Schaefer, Mark T.; Olson, David H.

    1981-01-01

    Personal Assessment of Intimacy in Relationships (PAIR) provides systematic information in five types of intimacy: emotional, social, sexual, intellectual and recreational. PAIR can be used with couples in marital therapy and enrichment groups. (Author)

  1. Asymmetries in heavy quark pair and dijet production at an EIC

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Daniël [Van Swinderen Institute for Particle Physics and Gravity, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Mulders, Piet J. [Nikhef and Department of Physics and Astronomy, VU University Amsterdam,De Boelelaan 1081, NL-1081 HV Amsterdam (Netherlands); Pisano, Cristian [Dipartimento di Fisica, Università di Pavia,via Bassi 6, I-27100 Pavia (Italy); INFN Sezione di Pavia,via Bassi 6, I-27100 Pavia (Italy); Zhou, Jian [School of physics, Key Laboratory of Particle Physics and Particle Irradiation (MOE),Shandong University,Jinan, Shandong 250100 (China); Nikhef and Department of Physics and Astronomy, VU University Amsterdam,De Boelelaan 1081, NL-1081 HV Amsterdam (Netherlands)

    2016-08-01

    Asymmetries in heavy quark pair and dijet production in electron-proton collisions allow studies of gluon TMDs in close analogy to studies of quark TMDs in semi-inclusive DIS. Here we present expressions for azimuthal asymmetries for both unpolarized and transversely polarized proton cases and consider the maximal asymmetries allowed. The latter are found to be rather sizeable, except in certain kinematic limits which are pointed out. In addition, we consider the small-x limit and expectations from a McLerran-Venugopalan model for unpolarized and linearly polarized gluons and from a perturbative, large transverse momentum calculation for the T-odd gluon TMDs. Comparison to related observables at RHIC and LHC is expected to provide valuable information about the process dependence of the gluon TMDs. In particular this will offer the possibility of a sign change test of the gluon Sivers TMD and two other T-odd gluon TMDs. This provides additional motivation for studies of azimuthal asymmetries in heavy quark pair and dijet production at a future Electron-Ion Collider.

  2. High spin exotic states and new method for pairing energy

    International Nuclear Information System (INIS)

    Molique, H.

    1996-01-01

    We present a new method called 'PSY-MB', initially developed in the framework of abstract group theory for the solution of the problem of strongly interacting multi-fermionic systems with particular to systems in an external rotating field. The validity of the new method (PSY-MB) is tested on model Hamiltonians. A detailed comparison between the obtained solutions and the exact ones is performed. The new method is used in the study of realistic nuclear Hamiltonians based on the Woods-Saxon potential within the cranking approximation to study the influence of residual monopole pairing interactions in the rare-earth mass region. In parallel with this new technique we present original results obtained with the Woods-Saxon mean-field and the self-consistent Hartree-Fock approximation in order to investigate such exotic effects as octupole deformations and hexadecapole C 4 -polarizing deformations in the framework of high-spin physics. By developing these three approaches in one single work we prepare the ground for the nuclear structure calculations of the new generation - where the residual two-body interactions are taken into account also in the weak pairing limit. (author)

  3. Development of double-pair double difference location algorithm and its application to the regular earthquakes and non-volcanic tremors

    Science.gov (United States)

    Guo, H.; Zhang, H.

    2016-12-01

    Relocating high-precision earthquakes is a central task for monitoring earthquakes and studying the structure of earth's interior. The most popular location method is the event-pair double-difference (DD) relative location method, which uses the catalog and/or more accurate waveform cross-correlation (WCC) differential times from event pairs with small inter-event separations to the common stations to reduce the effect of the velocity uncertainties outside the source region. Similarly, Zhang et al. [2010] developed a station-pair DD location method which uses the differential times from common events to pairs of stations to reduce the effect of the velocity uncertainties near the source region, to relocate the non-volcanic tremors (NVT) beneath the San Andreas Fault (SAF). To utilize advantages of both DD location methods, we have proposed and developed a new double-pair DD location method to use the differential times from pairs of events to pairs of stations. The new method can remove the event origin time and station correction terms from the inversion system and cancel out the effects of the velocity uncertainties near and outside the source region simultaneously. We tested and applied the new method on the northern California regular earthquakes to validate its performance. In comparison, among three DD location methods, the new double-pair DD method can determine more accurate relative locations and the station-pair DD method can better improve the absolute locations. Thus, we further proposed a new location strategy combining station-pair and double-pair differential times to determine accurate absolute and relative locations at the same time. For NVTs, it is difficult to pick the first arrivals and derive the WCC event-pair differential times, thus the general practice is to measure station-pair envelope WCC differential times. However, station-pair tremor locations are scattered due to the low-precision relative locations. The ability that double-pair data

  4. Renormalization-group improved fully differential cross sections for top pair production

    International Nuclear Information System (INIS)

    Broggio, A.; Papanastasiou, A.S.; Signer, A.; Zuerich Univ.

    2014-07-01

    We extend approximate next-to-next-to-leading order results for top-pair production to include the semi-leptonic decays of top quarks in the narrow-width approximation. The new hard-scattering kernels are implemented in a fully differential parton-level Monte Carlo that allows for the study of any IR-safe observable constructed from the momenta of the decay products of the top. Our best predictions are given by approximate NNLO corrections in the production matched to a fixed order calculation with NLO corrections in both the production and decay subprocesses. Being fully differential enables us to make comparisons between approximate results derived via different (PIM and 1PI) kinematics for arbitrary distributions. These comparisons reveal that the renormalization-group framework, from which the approximate results are derived, is rather robust in the sense that applying a realistic error estimate allows us to obtain a reliable prediction with a reduced theoretical error for generic observables and analysis cuts.

  5. Stability of non-Watson-Crick G-A/A-G base pair in synthetic DNA and RNA oligonucleotides.

    Science.gov (United States)

    Ito, Yuko; Sone, Yumiko; Mizutani, Takaharu

    2004-03-01

    A non-Watson-Crick G-A/A-G base pair is found in SECIS (selenocysteine-insertion sequence) element in the 3'-untranslated region of Se-protein mRNAs and in the functional site of the hammerhead ribozyme. We studied the stability of G-A/A-G base pair (bold) in 17mer GT(U)GACGGAAACCGGAAC synthetic DNA and RNA oligonucleotides by thermal melting experiments and gel electrophoresis. The measured Tm value of DNA oligonucleotide having G-A/A-G pair showed an intermediate value (58 degrees C) between that of Watson-Crick G-C/C-G base pair (75 degrees C) and that of G-G/A-A of non-base-pair (40 degrees C). Similar thermal melting patterns were obtained with RNA oligonucleotides. This result indicates that the secondary structure of oligonucleotide having G-A/A-G base pair is looser than that of the G-C type Watson-Crick base pair. In the comparison between RNA and DNA having G-A/A-G base pair, the Tm value of the RNA oligonucleotide was 11 degrees C lower than that of DNA, indicating that DNA has a more rigid structure than RNA. The stained pattern of oligonucleotide on polyacrylamide gel clarified that the mobility of the DNA oligonucleotide G-A/A-G base pair changed according to the urea concentration from the rigid state (near the mobility of G-C/C-G oligonucleotide) in the absence of urea to the random state (near the mobility of G-G/A-A oligonucleotide) in 7 M urea. However, the RNA oligonucleotide with G-A/A-G pair moved at an intermediate mobility between that of oligonucleotide with G-C/C-G and of the oligonucleotide with G-G/A-A, and the mobility pattern did not depend on urea concentration. Thus, DNA and RNA oligonucleotides with the G-A/A-G base pair showed a pattern indicating an intermediate structure between the rigid Watson-Crick base pair and the random structure of non-base pair. RNA with G-A/A-G base pair has the intermediate structure not influenced by urea concentration. Finally, this study indicated that the intermediate rigidity imparted by Non

  6. Pair shell model description of collective motions

    International Nuclear Information System (INIS)

    Chen Hsitseng; Feng Dahsuan

    1996-01-01

    The shell model in the pair basis has been reviewed with a case study of four particles in a spherical single-j shell. By analyzing the wave functions according to their pair components, the novel concept of the optimum pairs was developed which led to the proposal of a generalized pair mean-field method to solve the many-body problem. The salient feature of the method is its ability to handle within the framework of the spherical shell model a rotational system where the usual strong configuration mixing complexity is so simplified that it is now possible to obtain analytically the band head energies and the moments of inertia. We have also examined the effects of pair truncation on rotation and found the slow convergence of adding higher spin pairs. Finally, we found that when the SDI and Q .Q interactions are of equal strengths, the optimum pair approximation is still valid. (orig.)

  7. Some peculiarities of conjoined hadroproduction of standard Higgs boson and heavy quark pair

    International Nuclear Information System (INIS)

    Bagdasaryan, A.S.; Egoryan, R.Sh.; Grigoryan, S.G.; Matinyan, S.G.

    1986-01-01

    A contribution to total cross section of conjoined hadroproduction of the H 0 -boson and the heavy quark pair Q and Q-bar (Q=c, b, t,...) from the H 0 -boson ''gluonic'' production diagrams (the so-called GGH-diagrams) is being discussed. A comparison is carried out between contributions to total cross sections from the GGH-diagrams and the H 0 -boson ''direct'' quark production diagrams (QH-diagrams). It is shown that with increasing M H the enhancement effect of the GGH contribution ''enters the game''

  8. Topological Nodal Cooper Pairing in Doped Weyl Metals

    Science.gov (United States)

    Li, Yi; Haldane, F. D. M.

    2018-02-01

    We generalize the concept of Berry connection of the single-electron band structure to that of a two-particle Cooper pairing state between two Fermi surfaces with opposite Chern numbers. Because of underlying Fermi surface topology, the pairing Berry phase acquires nontrivial monopole structure. Consequently, pairing gap functions have topologically protected nodal structure as vortices in the momentum space with the total vorticity solely determined by the pair monopole charge qp. The nodes of gap function behave as the Weyl-Majorana points of the Bogoliubov-de Gennes pairing Hamiltonian. Their relation with the connection patterns of the surface modes from the Weyl band structure and the Majorana surface modes inside the pairing gap is also discussed. Under the approximation of spherical Fermi surfaces, the pairing symmetry are represented by monopole harmonic functions. The lowest possible pairing channel carries angular momentum number j =|qp|, and the corresponding gap functions are holomorphic or antiholomorphic functions on Fermi surfaces. After projected on the Fermi surfaces with nontrivial topology, all the partial-wave channels of pairing interactions acquire the monopole charge qp independent of concrete pairing mechanism.

  9. Kramers Pairs in configuration interaction

    DEFF Research Database (Denmark)

    Avery, John Scales; Avery, James Emil

    2003-01-01

    The theory of symmetry-preserving Kramers pair creation operators is reviewed and formulas for applying these operators to configuration interaction calculations are derived. A new and more general type of symmetry-preserving pair creation operator is proposed and shown to commute with the total ...

  10. Pairing properties of realistic effective interactions

    Directory of Open Access Journals (Sweden)

    Gargano A.

    2016-01-01

    Full Text Available We investigate the pairing properties of an effective shell-model interaction defined within a model space outside 132Sn and derived by means of perturbation theory from the CD-Bonn free nucleon-nucleon potential. It turns out that the neutron pairing component of the effective interaction is significantly weaker than the proton one, which accounts for the large pairing gap difference observed in the two-valence identical particle nuclei 134Sn and 134Te. The role of the contribution arising from one particle-one hole excitations in determining the pairing force is discussed and its microscopic structure is also analyzed in terms of the multipole decomposition.

  11. Finding Maximal Pairs with Bounded Gap

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Lyngsø, Rune B.; Pedersen, Christian N. S.

    1999-01-01

    . In this paper we present methods for finding all maximal pairs under various constraints on the gap. In a string of length n we can find all maximal pairs with gap in an upper and lower bounded interval in time O(n log n+z) where z is the number of reported pairs. If the upper bound is removed the time reduces...... to O(n+z). Since a tandem repeat is a pair where the gap is zero, our methods can be seen as a generalization of finding tandem repeats. The running time of our methods equals the running time of well known methods for finding tandem repeats....

  12. Effects of Worked Examples, Example-Problem Pairs, and Problem-Example Pairs Compared to Problem Solving

    NARCIS (Netherlands)

    Van Gog, Tamara; Kester, Liesbeth; Paas, Fred

    2010-01-01

    Van Gog, T., Kester, L., & Paas, F. (2010, August). Effects of worked examples, example-problem pairs, and problem-example pairs compared to problem solving. Paper presented at the Biannual EARLI SIG meeting of Instructional design and Learning and instruction with computers, Ulm, Germany.

  13. Study of electron pair production below the Z mass at the CERN anti pp collider

    International Nuclear Information System (INIS)

    Alitti, J.; Ambrosini, G.; Ansari, R.; Autiero, D.; Bareyre, P.; Bertram, I.A.; Blaylock, G.; Bonamy, P.; Borer, K.; Bourliaud, M.; Buskulic, D.; Carboni, G.; Cavalli, D.; Cavasinni, V.; Cenci, P.; Chollet, J.C.; Conta, C.; Costa, G.; Costantini, F.; Cozzi, L.; Cravero, A.; Curatolo, M.; Dell'Acqua, A.; DelPrete, T.; DeWolf, R.S.; DiLella, L.; Ducros, Y.; Egan, G.F.; Einsweiler, K.F.; Esposito, B.; Fayard, L.; Federspiel, A.; Ferrari, R.; Fraternali, M.; Froidevaux, D.; Fumagalli, G.; Gaillard, J.M.; Gianotti, F.; Gildemeister, O.; Goessling, C.; Goggi, V.G.; Gruenendahl, S.; Hara, K.; Hellman, S.; Hrivnac, J.; Hufnagel, H.; Hugentobler, E.; Hultqvist, K.; Iacopini, E.; Incandela, J.; Jakobs, K.; Jenni, P.; Kluge, E.E.; Kurz, N.; Lami, S.; Lariccia, P.; Lefebvre, M.; Linssen, L.; Livan, M.; Lubrano, P.; Magneville, C.; Mandelli, L.; Mapelli, L.; Mazzanti, M.; Meier, K.; Merkel, B.; Meyer, J.P.; Moniez, M.; Moning, R.; Morganti, M.; Mueller, L.; Munday, D.J.; Nessi, M.; Nessi-Tedaldi, F.; Onions, C.; Pal, T.; Parker, M.A.; Parrour, G.; Pastore, F.; Pennacchio, E.; Pentney, J.; Pepe, M.; Perini, L.; Petridou, C.; Petroff, P.; Plothow-Besch, H.; Polesello, G.; Poppleton, A.; Pretzl, K.; Primavera, M.; Punturo, M.; Repellin, J.P.; Rimoldi, A.; Sacchi, M.; Scampoli, P.; Schacher, J.; Schmidt, B.; Simak, V.; Singh, S.L.; Sondermann, V.; Spiwoks, R.; Stapnes, S.; Talamonti, C.; Tondini, F.; Tovey, S.N.; Tsesmelis, E.; Unal, G.; Valdata-Nappi, M.; Vercesi, V.; Weidberg, A.R.; Wells, P.S.; White, T.O.; Wood, D.R.; Wotton, S.A.; Zaccone, H.; Zylberstein, A.

    1992-01-01

    Results on the cross section for the production of electron pairs in anti pp collisions at √s=630 GeV are presented. The measured value is σ=405±51 (syst.)±84(syst.) pb, in the variant mass interval 10 s 2 ) QCD contributions. The comparison of these data with those of lower energy experiments show approximate scaling as a function of the variable √τ=m/√s. (orig.)

  14. Effect of pairing on nuclear dynamics

    International Nuclear Information System (INIS)

    Scamps, Guillaume

    2014-01-01

    Pairing correlations is an essential component for the description of the atomic nuclei. The effects of pairing on static property of nuclei are now well known. In this thesis, the effect of pairing on nuclear dynamics is investigated. Theories that includes pairing are benchmarked in a model case. The TDHF+BCS theory turns out to be a good compromise between the physics taken into account and the numerical cost. This TDHF+BCS theory was retained for realistic calculations. Nevertheless, the application of pairing in the BCS approximation may induce new problems due to (1) the particle number symmetry breaking, (2) the non-conservation of the continuity equation. These difficulties are analysed in detail and solutions are proposed. In this thesis, a 3 dimensional TDHF+BCS code is developed to simulate the nuclear dynamic. Applications to giant resonances show that pairing modify only the low lying peaks. The high lying collective components are only affected by the initial conditions. An exhaustive study of the giant quadrupole resonances with the TDHF+BCS theory is performed on more than 700 spherical or deformed nuclei. Is is shown that the TDHF+BCS theory reproduces well the collective energy of the resonance. After validation on the small amplitude limit problem, the approach was applied to study nucleon transfer in heavy ion reactions. A new method to extract transfer probabilities is introduced. It is demonstrated that pairing significantly increases the two-nucleon transfer probability. (author) [fr

  15. Investigation on the ion pair amphiphiles and their in vitro release of amantadine drug based on PLGA–PEG–PLGA gel

    International Nuclear Information System (INIS)

    Yang, Xiaoxia; Ji, Xiaoqing; Shi, Chunhuan; Liu, Jing; Wang, Haiyang; Luan, Yuxia

    2014-01-01

    The amantadine drug and oleic acid surfactant are used to form amantadine-based ion pair amphiphiles based on proton transfer reaction between the drug and the surfactant molecules. The ion pair amphiphiles are characterized by 1 H-nuclear magnetic resonance, Fourier transform infrared spectroscopy, and X-ray diffraction. Self-assembly properties of amantadine-based ion pair amphiphiles are studied by surface tension determination, transmission electron microscopy, zeta potential, and dynamic light scattering. The aggregation behavior studies indicate that the as-prepared ion pair amphiphiles can self-assemble into vesicles with the size of 200–300 nm in aqueous solution. The drug release results show that the amantadine release rate could be well controlled by incorporating the amantadine-based ion pair vesicles in poly (lactic-co-glycolic acid)-poly (ethylene glycol)-poly (lactic-co-glycolic acid) (PLGA–PEG–PLGA) copolymer hydrogel. The drug release from the AT–OA vesicle-loaded PLGA–PEG–PLGA hydrogel is significantly inhibited in comparison with the AT-loaded PLGA–PEG–PLGA hydrogel. The present work thus demonstrates that the vesicle-loaded hydrogel is a good candidate for the drug delivery system with long-term controlled drug release behavior

  16. Junctionless Cooper pair transistor

    Energy Technology Data Exchange (ETDEWEB)

    Arutyunov, K. Yu., E-mail: konstantin.yu.arutyunov@jyu.fi [National Research University Higher School of Economics , Moscow Institute of Electronics and Mathematics, 101000 Moscow (Russian Federation); P.L. Kapitza Institute for Physical Problems RAS , Moscow 119334 (Russian Federation); Lehtinen, J.S. [VTT Technical Research Centre of Finland Ltd., Centre for Metrology MIKES, P.O. Box 1000, FI-02044 VTT (Finland)

    2017-02-15

    Highlights: • Junctionless Cooper pair box. • Quantum phase slips. • Coulomb blockade and gate modulation of the Coulomb gap. - Abstract: Quantum phase slip (QPS) is the topological singularity of the complex order parameter of a quasi-one-dimensional superconductor: momentary zeroing of the modulus and simultaneous 'slip' of the phase by ±2π. The QPS event(s) are the dynamic equivalent of tunneling through a conventional Josephson junction containing static in space and time weak link(s). Here we demonstrate the operation of a superconducting single electron transistor (Cooper pair transistor) without any tunnel junctions. Instead a pair of thin superconducting titanium wires in QPS regime was used. The current–voltage characteristics demonstrate the clear Coulomb blockade with magnitude of the Coulomb gap modulated by the gate potential. The Coulomb blockade disappears above the critical temperature, and at low temperatures can be suppressed by strong magnetic field.

  17. Agroforestry practices, runoff, and nutrient loss: a paired watershed comparison.

    Science.gov (United States)

    Udawatta, Ranjith P; Krstansky, J John; Henderson, Gray S; Garrett, Harold E

    2002-01-01

    A paired watershed study consisting of agroforestry (trees plus grass buffer strips), contour strips (grass buffer strips), and control treatments with a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation was used to examine treatment effects on runoff, sediment, and nutrient losses. During the (1991-1997) calibration and subsequent three-year treatment periods, runoff was measured in 0.91- and 1.37-m H-flumes with bubbler flow meters. Composite samples were analyzed for sediment, total phosphorus (TP), total nitrogen (TN), nitrate, and ammonium. Calibration equations developed to predict runoff, sediment, and nutrients losses explained 66 to 97% of the variability between treatment watersheds. The contour strip and agroforestry treatments reduced runoff by 10 and 1% during the treatment period. In both treatments, most runoff reductions occurred in the second and third years after treatment establishment. The contour strip treatment reduced erosion by 19% in 1999, while erosion in the agroforestry treatment exceeded the predicted loss. Treatments reduced TP loss by 8 and 17% on contour strip and agroforestry watersheds. Treatments did not result in reductions in TN during the first two years of the treatment period. The contour strip and agroforestry treatments reduced TN loss by 21 and 20%, respectively, during a large precipitation event in the third year. During the third year of treatments, nitrate N loss was reduced 24 and 37% by contour strip and agroforestry treatments. Contour strip and agroforestry management practices effectively reduced nonpoint-source pollution in runoff from a corn-soybean rotation in the clay pan soils of northeastern Missouri.

  18. Web Camera Based Eye Tracking to Assess Visual Memory on a Visual Paired Comparison Task

    Directory of Open Access Journals (Sweden)

    Nicholas T. Bott

    2017-06-01

    Full Text Available Background: Web cameras are increasingly part of the standard hardware of most smart devices. Eye movements can often provide a noninvasive “window on the brain,” and the recording of eye movements using web cameras is a burgeoning area of research.Objective: This study investigated a novel methodology for administering a visual paired comparison (VPC decisional task using a web camera.To further assess this method, we examined the correlation between a standard eye-tracking camera automated scoring procedure [obtaining images at 60 frames per second (FPS] and a manually scored procedure using a built-in laptop web camera (obtaining images at 3 FPS.Methods: This was an observational study of 54 clinically normal older adults.Subjects completed three in-clinic visits with simultaneous recording of eye movements on a VPC decision task by a standard eye tracker camera and a built-in laptop-based web camera. Inter-rater reliability was analyzed using Siegel and Castellan's kappa formula. Pearson correlations were used to investigate the correlation between VPC performance using a standard eye tracker camera and a built-in web camera.Results: Strong associations were observed on VPC mean novelty preference score between the 60 FPS eye tracker and 3 FPS built-in web camera at each of the three visits (r = 0.88–0.92. Inter-rater agreement of web camera scoring at each time point was high (κ = 0.81–0.88. There were strong relationships on VPC mean novelty preference score between 10, 5, and 3 FPS training sets (r = 0.88–0.94. Significantly fewer data quality issues were encountered using the built-in web camera.Conclusions: Human scoring of a VPC decisional task using a built-in laptop web camera correlated strongly with automated scoring of the same task using a standard high frame rate eye tracker camera.While this method is not suitable for eye tracking paradigms requiring the collection and analysis of fine-grained metrics, such as

  19. Full top quark mass dependence in Higgs boson pair production at NLO

    Energy Technology Data Exchange (ETDEWEB)

    Borowka, S.; Greiner, N. [Institute for Physics, Universität Zürich,Winterthurerstr.190, 8057 Zürich (Switzerland); Heinrich, G.; Jones, S.P.; Kerner, M.; Schlenk, J.; Zirke, T. [Max-Planck-Institute for Physics,Föhringer Ring 6, 80805 München (Germany)

    2016-10-20

    We study the effects of the exact top quark mass-dependent two-loop corrections to Higgs boson pair production by gluon fusion at the LHC and at a 100 TeV hadron collider. We perform a detailed comparison of the full next-to-leading order result to various approximations at the level of differential distributions and also analyse non-standard Higgs self-coupling scenarios. We find that the different next-to-leading order approximations differ from the full result by up to 50 percent in relevant differential distributions. This clearly stresses the importance of the full NLO result.

  20. On the comparison of group performance with categorical data.

    Directory of Open Access Journals (Sweden)

    Carmen Herrero

    Full Text Available There are many different evaluation problems that involve several groups (societies, firms or institutions whose members can be classified into ordered categories, pursuant to their characteristics or their achievements. This paper addresses these types of problems and provides an evaluation criterion based on the distribution of the agents across categories. The starting point is that of dominance relations in pair-wise comparisons. We say that group i dominates group j when the expected category of a member of i is higher than the expected category of a member of j. We introduce the notion of relative advantage of a group to extend this principle to multi-group comparisons and show that there is a unique evaluation function that ranks all groups consistently in terms of this criterion. This function associates to each evaluation problem the (unique dominant eigenvector of a matrix whose entries describe the dominance relations between groups in pair-wise comparisons. The working of the model is illustrated by means of three different applications.

  1. PAIR'14 / PAIR'15 STUDENT CONFERENCES ON PLANNING IN ARTIFICIAL INTELLIGENCE AND ROBOTICS

    Directory of Open Access Journals (Sweden)

    Editorial Foreword

    2015-12-01

    Full Text Available Dear Readerthe original idea of the student conference on “Planning in Artificial Intelligence and Robotics” (PAIR is to join young researchers from particular laboratories in Czech Republic, where planning problems are investigated from artificial intelligence (AI or robotics points of view. The first year of PAIR has been organized at the Dept. of Computer Science, Faculty Electrical Engineering, Czech Technical University in 2014.At PAIR 2014, laboratories from Prague and Brno were presented. In particular, students and researchers from Charles University, Czech Technical University in Prague, Brno University of Technology, and Central European Institute of Technology participated at the event. Beside an introduction of the particular research groups and their topics, students presented contributions on their current research results. Ten papers were presented on topics ranging from domain–independent planning, trajectory planning to applications for unmanned aerial and legged robots. This first event provides us an initial experience with the community of young researchers in Czech Republic that are working planning in robotic or AI. Based on the success of PAIR 2014, we decided to continue with our effort to establish a suitable fora for students that are geographically very close, but usually do not meet, because of participation on different Robotics and AI events.The second student conference on Planning in Artificial Intelligence and Robotics (PAIR 2015 successfully continues the tradition of the first year of the conference organized in Prague. This year, the conference was collocated with 10th anniversary of RoboTour contest in Písek. This format enable us to extend the impact of the PAIR conference and improve the visibility of the growing student community. The conference reached a good amount of interesting papers focused on image processing for mobile robots, swarm control, driving simulation, robot control, or domain

  2. Ground Receiving Station Reference Pair Selection Technique for a Minimum Configuration 3D Emitter Position Estimation Multilateration System

    Directory of Open Access Journals (Sweden)

    Abdulmalik Shehu Yaro

    2017-01-01

    Full Text Available Multilateration estimates aircraft position using the Time Difference Of Arrival (TDOA with a lateration algorithm. The Position Estimation (PE accuracy of the lateration algorithm depends on several factors which are the TDOA estimation error, the lateration algorithm approach, the number of deployed GRSs and the selection of the GRS reference used for the PE process. Using the minimum number of GRSs for 3D emitter PE, a technique based on the condition number calculation is proposed to select the suitable GRS reference pair for improving the accuracy of the PE using the lateration algorithm. Validation of the proposed technique was performed with the GRSs in the square and triangular GRS configuration. For the selected emitter positions, the result shows that the proposed technique can be used to select the suitable GRS reference pair for the PE process. A unity condition number is achieved for GRS pair most suitable for the PE process. Monte Carlo simulation result, in comparison with the fixed GRS reference pair lateration algorithm, shows a reduction in PE error of at least 70% for both GRS in the square and triangular configuration.

  3. Pairing gaps from nuclear mean-field models

    International Nuclear Information System (INIS)

    Bender, M.; Rutz, K.; Maruhn, J.A.

    2000-01-01

    We discuss the pairing gap, a measure for nuclear pairing correlations, in chains of spherical, semi-magic nuclei in the framework of self-consistent nuclear mean-field models. The equations for the conventional BCS model and the approximate projection-before-variation Lipkin-Nogami method are formulated in terms of local density functionals for the effective interaction. We calculate the Lipkin-Nogami corrections of both the mean-field energy and the pairing energy. Various definitions of the pairing gap are discussed as three-point, four-point and five-point mass-difference formulae, averaged matrix elements of the pairing potential, and single-quasiparticle energies. Experimental values for the pairing gap are compared with calculations employing both a delta pairing force and a density-dependent delta interaction in the BCS and Lipkin-Nogami model. Odd-mass nuclei are calculated in the spherical blocking approximation which neglects part of the the core polarization in the odd nucleus. We find that the five-point mass difference formula gives a very robust description of the odd-even staggering, other approximations for the gap may differ from that up to 30% for certain nuclei. (orig.)

  4. Exploring Pair Programming Benefits for MIS Majors

    Directory of Open Access Journals (Sweden)

    April H. Reed

    2016-12-01

    Full Text Available Pair programming is a collaborative programming practice that places participants in dyads, working in tandem at one computer to complete programming assignments. Pair programming studies with Computer Science (CS and Software Engineering (SE majors have identified benefits such as technical productivity, program/design quality, academic performance, and increased satisfaction for their participants. In this paper, pair programming is studied with Management Information Systems (MIS majors, who (unlike CS and SE majors taking several programming courses typically take only one programming course and often struggle to develop advanced programming skills within that single course. The researchers conducted two pair programming experiments in an introductory software development course for MIS majors over three semesters to determine if pair programming could enhance learning for MIS students. The program results, researchers’ direct observations, and participants’ responses to a survey questionnaire were analyzed after each experiment. The results indicate that pair programming appears to be beneficial to MIS students’ technical productivity and program design quality, specifically the ability to create programs using high-level concepts. Additionally, results confirmed increased student satisfaction and reduced frustration, as the pairs worked collaboratively to produce a program while actively communicating and enjoying the process.

  5. Differential environmental factors in anorexia nervosa: a sibling pair study.

    Science.gov (United States)

    Murphy, F; Troop, N A; Treasure, J L

    2000-06-01

    Previous studies have explored differences in psychosocial and familial factors between women who develop anorexia nervosa and those who do not. However, these studies have generally used between-group comparisons. This study looks at the environmental factors which may be antecedents of anorexia nervosa looking at sister pairs where one had anorexia nervosa and the other did not. A paired design was used to compare anorexic women with an unaffected sister on a number of background variables, including sibling interaction, parental care, peer group characteristics and other events unique to the individual. The Sibling Inventory of Differential Experience (SIDE) was used to determine non-shared environment. Out of an initial sample of 148 women with past or current anorexia nervosa, 28 were identified who had sisters with no reported history of eating disorders and who also consented to complete the questionnaire. Anorexic sisters perceived more maternal control and reported more antagonism towards and jealousy of their sisters than did unaffected sisters. In addition, anorexic women reported having had fewer friends and boyfriends than their sisters. These results confirm the perceived differences in background environment between women with and women without anorexia nervosa. These issues are discussed in relation to behavioural genetics, family dynamics and psychosexual development.

  6. A configuration space of homologous proteins conserving mutual information and allowing a phylogeny inference based on pair-wise Z-score probabilities.

    Science.gov (United States)

    Bastien, Olivier; Ortet, Philippe; Roy, Sylvaine; Maréchal, Eric

    2005-03-10

    Popular methods to reconstruct molecular phylogenies are based on multiple sequence alignments, in which addition or removal of data may change the resulting tree topology. We have sought a representation of homologous proteins that would conserve the information of pair-wise sequence alignments, respect probabilistic properties of Z-scores (Monte Carlo methods applied to pair-wise comparisons) and be the basis for a novel method of consistent and stable phylogenetic reconstruction. We have built up a spatial representation of protein sequences using concepts from particle physics (configuration space) and respecting a frame of constraints deduced from pair-wise alignment score properties in information theory. The obtained configuration space of homologous proteins (CSHP) allows the representation of real and shuffled sequences, and thereupon an expression of the TULIP theorem for Z-score probabilities. Based on the CSHP, we propose a phylogeny reconstruction using Z-scores. Deduced trees, called TULIP trees, are consistent with multiple-alignment based trees. Furthermore, the TULIP tree reconstruction method provides a solution for some previously reported incongruent results, such as the apicomplexan enolase phylogeny. The CSHP is a unified model that conserves mutual information between proteins in the way physical models conserve energy. Applications include the reconstruction of evolutionary consistent and robust trees, the topology of which is based on a spatial representation that is not reordered after addition or removal of sequences. The CSHP and its assigned phylogenetic topology, provide a powerful and easily updated representation for massive pair-wise genome comparisons based on Z-score computations.

  7. A configuration space of homologous proteins conserving mutual information and allowing a phylogeny inference based on pair-wise Z-score probabilities

    Directory of Open Access Journals (Sweden)

    Maréchal Eric

    2005-03-01

    Full Text Available Abstract Background Popular methods to reconstruct molecular phylogenies are based on multiple sequence alignments, in which addition or removal of data may change the resulting tree topology. We have sought a representation of homologous proteins that would conserve the information of pair-wise sequence alignments, respect probabilistic properties of Z-scores (Monte Carlo methods applied to pair-wise comparisons and be the basis for a novel method of consistent and stable phylogenetic reconstruction. Results We have built up a spatial representation of protein sequences using concepts from particle physics (configuration space and respecting a frame of constraints deduced from pair-wise alignment score properties in information theory. The obtained configuration space of homologous proteins (CSHP allows the representation of real and shuffled sequences, and thereupon an expression of the TULIP theorem for Z-score probabilities. Based on the CSHP, we propose a phylogeny reconstruction using Z-scores. Deduced trees, called TULIP trees, are consistent with multiple-alignment based trees. Furthermore, the TULIP tree reconstruction method provides a solution for some previously reported incongruent results, such as the apicomplexan enolase phylogeny. Conclusion The CSHP is a unified model that conserves mutual information between proteins in the way physical models conserve energy. Applications include the reconstruction of evolutionary consistent and robust trees, the topology of which is based on a spatial representation that is not reordered after addition or removal of sequences. The CSHP and its assigned phylogenetic topology, provide a powerful and easily updated representation for massive pair-wise genome comparisons based on Z-score computations.

  8. Magnetized pair Bose gas: relativistic superconductor

    International Nuclear Information System (INIS)

    Daicic, J.; Frankel, N.E.; Kowalenko, V.

    1993-01-01

    The magnetized Bose gas at temperatures above pair threshold is investigated. New magnetization laws are obtained for a wide range of field strengths, and the gas is shown to exhibit the Meissner effect. Some related results for the Fermi gas, a relativistic paramagnet, are also discussed. It is concluded that the pair gases, through the interplay between pair creation, temperature, field strength, statistics and/in the case of fermions/spin, have remarkable magnetic properties. 14 refs

  9. Nuclear scissors mode with pairing

    International Nuclear Information System (INIS)

    Balbutsev, E. B.; Malov, L. A.; Schuck, P.; Urban, M.; Vinas, X.

    2008-01-01

    The coupled dynamics of the scissors mode and the isovector giant quadrupole resonance are studied using a generalized Wigner function moments method, taking into account pair correlations. Equations of motion for angular momentum, quadrupole moment, and other relevant collective variables are derived on the basis of the time-dependent Hartree-Fock-Bogolyubov equations. Analytical expressions for energy centroids and transition probabilities are found for the harmonic-oscillator model with the quadrupole-quadrupole residual interaction and monopole pairing force. Deformation dependences of energies and B(M1) values are correctly reproduced. The inclusion of pair correlations leads to a drastic improvement in the description of qualitative and quantitative characteristics of the scissors mode.

  10. Pair housing for female longtailed and rhesus macaques in the laboratory: behavior in protected contact versus full contact.

    Science.gov (United States)

    Baker, Kate C; Crockett, Carolyn M; Lee, Grace H; Oettinger, Brooke C; Schoof, Valérie; Thom, Jinhee P

    2012-01-01

    Pair housing for caged macaques in the laboratory generally allows unrestricted tactile contact but, less commonly, may involve limited contact via grooming-contact bars or perforated panels. The purpose of using this protected contact housing, which prevents entry into pair-mates' cages, typically is to accommodate research and management requirements. The study used behavioral data collected on 12 pairs of female longtailed macaques (Macaca fascicularis) at the Washington National Primate Research Center and 7 pairs of female rhesus macaques (Macaca mulatta) housed at the Tulane National Primate Research Center to assess the relative benefits of protected versus full protected contact. The study collected data in stable pairs housed first in protected contact followed by full contact. Species combined, the study found the presence of the panel was associated with lower levels of social grooming and higher levels of self-grooming, abnormal behavior, and tension-related behavior. Within species, only the protected- versus full-contact contrasts for abnormal and tension were statistically significant-and only for rhesus macaques. Results suggest that for female rhesus macaques, potential disadvantages or inconveniences of full contact should be balanced against the improved behavioral profile in comparison to protected contact. The use of protected contact among female longtailed macaques does not appear to require the same cost-benefit analysis. Copyright © Taylor & Francis Group, LLC

  11. An Entropic Approach for Pair Trading

    Directory of Open Access Journals (Sweden)

    Daisuke Yoshikawa

    2017-06-01

    Full Text Available In this paper, we derive the optimal boundary for pair trading. This boundary defines the points of entry into or exit from the market for a given stock pair. However, if the assumed model contains uncertainty, the resulting boundary could result in large losses. To avoid this, we develop a more robust strategy by accounting for the model uncertainty. To incorporate the model uncertainty, we use the relative entropy as a penalty function in the expected profit from pair trading.

  12. Joint sub-carrier pairing and resource allocation for cognitive networks with adaptive relaying

    KAUST Repository

    Soury, Hamza; Bader, F.; Shaat, M.; Alouini, Mohamed-Slim

    2013-01-01

    Relayed transmission in a cognitive radio (CR) environment could be used to increase the coverage and capacity of communication system that benefits already from the efficient management of the spectrum developed by CR. Furthermore, there are many types of cooperative communications, including decode-and-forward (DAF) and amplify-and-forward (AAF). In this paper, these techniques are combined in an adaptive mode to benefit from its forwarding advantages; this mode is called adaptive relaying protocol (ARP). Moreover, this work focuses on the joint power allocation in a cognitive radio system in a cooperative mode that operates ARP in multi-carrier mode. The multi-carrier scenario is used in an orthogonal frequency division multiplexing (OFDM) mode, and the problem is formulated to maximize the end-to-end rate by searching the best power allocation at the transmitters. This work includes, besides the ARP model, a sub-carrier pairing strategy that allows the relays to switch to the best sub-carrier pairs to increase the throughput. The optimization problem is formulated and solved under the interference and power budget constraints using the sub-gradient algorithm. The simulation results confirm the efficiency of the proposed adaptive relaying protocol in comparison to other relaying techniques. The results show also the consequence of the choice of the pairing strategy. 2013 Stolojescu-Crisan and Isar; licensee Springer.

  13. Joint sub-carrier pairing and resource allocation for cognitive networks with adaptive relaying

    KAUST Repository

    Soury, Hamza

    2013-11-09

    Relayed transmission in a cognitive radio (CR) environment could be used to increase the coverage and capacity of communication system that benefits already from the efficient management of the spectrum developed by CR. Furthermore, there are many types of cooperative communications, including decode-and-forward (DAF) and amplify-and-forward (AAF). In this paper, these techniques are combined in an adaptive mode to benefit from its forwarding advantages; this mode is called adaptive relaying protocol (ARP). Moreover, this work focuses on the joint power allocation in a cognitive radio system in a cooperative mode that operates ARP in multi-carrier mode. The multi-carrier scenario is used in an orthogonal frequency division multiplexing (OFDM) mode, and the problem is formulated to maximize the end-to-end rate by searching the best power allocation at the transmitters. This work includes, besides the ARP model, a sub-carrier pairing strategy that allows the relays to switch to the best sub-carrier pairs to increase the throughput. The optimization problem is formulated and solved under the interference and power budget constraints using the sub-gradient algorithm. The simulation results confirm the efficiency of the proposed adaptive relaying protocol in comparison to other relaying techniques. The results show also the consequence of the choice of the pairing strategy. 2013 Stolojescu-Crisan and Isar; licensee Springer.

  14. Alexander-equivalent Zariski pairs of irreducible sextics

    DEFF Research Database (Denmark)

    Eyral, Christophe; Oka, Mutsuo

    2009-01-01

    The existence of Alexander-equivalent Zariski pairs dealing with irreducible curves of degree 6 was proved by Degtyarev. However, no explicit example of such a pair is available (only the existence is known) in the literature. In this paper, we construct the first concrete example.......The existence of Alexander-equivalent Zariski pairs dealing with irreducible curves of degree 6 was proved by Degtyarev. However, no explicit example of such a pair is available (only the existence is known) in the literature. In this paper, we construct the first concrete example....

  15. Proton-neutron correlations in a broken-pair model

    International Nuclear Information System (INIS)

    Akkermans, J.N.L.

    1981-01-01

    In this thesis nuclear-structure calculations are reported which were performed with the broken-pair model. The model which is developed, is an extension of existing broken-pair models in so far that it includes both proton and neutron valence pairs. The relevant formalisms are presented. In contrast to the number-non-conserving model, a proton-neutron broken-pair model is well suited to study the correlations which are produced by the proton-neutron interaction. It is shown that the proton-neutron force has large matrix elements which mix the proton- with neutron broken-pair configurations. This occurs especially for Jsup(PI)=2 + and 3 - pairs. This property of the proton-neutron force is used to improve the spectra of single-closed shell nuclei, where particle-hole excitations of the closed shell are a special case of broken-pair configurations. Using Kr and Te isotopes it is demonstrated that the proton-neutron force gives rise to correlated pair structures, which remain remarkably constant with varying nucleon numbers. (Auth.)

  16. Thermodynamics of pairing phase transition in nuclei

    International Nuclear Information System (INIS)

    Karim, Afaque; Ahmad, Shakeb

    2014-01-01

    The pairing gaps, pairing energy, heat capacity and entropy are calculated within BCS (Bardeen- Cooper-Schrieffer) based quasi particle approach, including thermal fluctuations on pairing field within pairing model for all nuclei (light, medium, heavy and super heavy nuclei). Quasi particles approach in BCS theory was introduced and reformulated to study various properties. For thermodynamic behavior of nuclei at finite temperatures, the anomalous averages of creation and annihilation operators are introduced. It is solved self consistently at finite temperatures to obtain BCS Hamiltonian. After doing unitary transformation, we obtained the Hamiltonian in the diagonal form. Thus, one gets temperature dependence gap parameter and pairing energy for nuclei. Moreover, the energy at finite temperatures is the sum of the condensation energy and the thermal energy of fermionic quasi particles. With the help of BCS Hamiltonian, specific heat, entropy and free energy are calculated for different nuclei. In this paper the gap parameter occupation number and pairing energy as a function of temperature which is important for all the light, medium, heavy and super heavy nuclei is calculated. Moreover, the various thermo dynamical quantities like specific heat, entropy and free energy is also obtained for different nuclei. Thus, the thermodynamics of pairing phase transition in nuclei is studied

  17. Left auditory cortex is involved in pairwise comparisons of the direction of frequency modulated tones

    Directory of Open Access Journals (Sweden)

    Nicole eAngenstein

    2013-07-01

    Full Text Available Evaluating series of complex sounds like those in speech and music requires sequential comparisons to extract task-relevant relations between subsequent sounds. With the present functional magnetic resonance imaging (fMRI study, we investigated whether sequential comparison of a specific acoustic feature within pairs of tones leads to a change in lateralized processing in the auditory cortex of humans. For this we used the active categorization of the direction (up versus down of slow frequency modulated (FM tones. Several studies suggest that this task is mainly processed in the right auditory cortex. These studies, however, tested only the categorization of the FM direction of each individual tone. In the present study we ask the question whether the right lateralized processing changes when, in addition, the FM direction is compared within pairs of successive tones. For this we use an experimental approach involving contralateral noise presentation in order to explore the contributions made by the left and right auditory cortex in the completion of the auditory task. This method has already been applied to confirm the right-lateralized processing of the FM direction of individual tones. In the present study, the subjects were required to perform, in addition, a sequential comparison of the FM-direction in pairs of tones. The results suggest a division of labor between the two hemispheres such that the FM direction of each individual tone is mainly processed in the right auditory cortex whereas the sequential comparison of this feature between tones in a pair is probably performed in the left auditory cortex.

  18. Model for pairing phase transition in atomic nuclei

    International Nuclear Information System (INIS)

    Schiller, A.; Guttormsen, M.; Hjorth-Jensen, M.; Rekstad, J.; Siem, S.

    2002-01-01

    A model is developed which allows the investigation and classification of the pairing phase transition in atomic nuclei. The regions of the parameter space are discussed for which a pairing phase transition can be observed. The model parameters include number of particles, attenuation of pairing correlations with increasing seniority, single-particle level spacing, and pairing gap parameter

  19. Sex-specific differential survival of extra-pair and within-pair offspring in song sparrows, Melospiza melodia.

    Science.gov (United States)

    Sardell, Rebecca J; Arcese, Peter; Keller, Lukas F; Reid, Jane M

    2011-11-07

    It is widely hypothesized that the evolution of female extra-pair reproduction in socially monogamous species reflects indirect genetic benefits to females. However, a critical prediction of this hypothesis, that extra-pair young (EPY) are fitter than within-pair young (WPY), has rarely been rigorously tested. We used 18 years of data from free-living song sparrows, Melospiza melodia, to test whether survival through major life-history stages differed between EPY and WPY maternal half-siblings. On average, survival of hatched chicks to independence from parental care and recruitment, and their total lifespan, did not differ significantly between EPY and WPY. However, EPY consistently tended to be less likely to survive, and recruited EPY survived for significantly fewer years than recruited WPY. Furthermore, the survival difference between EPY and WPY was sex-specific; female EPY were less likely to survive to independence and recruitment and lived fewer years than female WPY, whereas male EPY were similarly or slightly more likely to survive and to live more years than male WPY. These data indicate that extra-pair paternity may impose an indirect cost on females via their female offspring and that sex-specific genetic, environmental or maternal effects may shape extra-pair reproduction.

  20. Demographic mechanisms of inbreeding adjustment through extra-pair reproduction.

    Science.gov (United States)

    Reid, Jane M; Duthie, A Bradley; Wolak, Matthew E; Arcese, Peter

    2015-07-01

    One hypothesis explaining extra-pair reproduction is that socially monogamous females mate with extra-pair males to adjust the coefficient of inbreeding (f) of extra-pair offspring (EPO) relative to that of within-pair offspring (WPO) they would produce with their socially paired male. Such adjustment of offspring f requires non-random extra-pair reproduction with respect to relatedness, which is in turn often assumed to require some mechanism of explicit pre-copulatory or post-copulatory kin discrimination. We propose three demographic processes that could potentially cause mean f to differ between individual females' EPO and WPO given random extra-pair reproduction with available males without necessarily requiring explicit kin discrimination. Specifically, such a difference could arise if social pairings formed non-randomly with respect to relatedness or persisted non-randomly with respect to relatedness, or if the distribution of relatedness between females and their sets of potential mates changed during the period through which social pairings persisted. We used comprehensive pedigree and pairing data from free-living song sparrows (Melospiza melodia) to quantify these three processes and hence investigate how individual females could adjust mean offspring f through instantaneously random extra-pair reproduction. Female song sparrows tended to form social pairings with unrelated or distantly related males slightly less frequently than expected given random pairing within the defined set of available males. Furthermore, social pairings between more closely related mates tended to be more likely to persist across years than social pairings between less closely related mates. However, these effects were small and the mean relatedness between females and their sets of potential extra-pair males did not change substantially across the years through which social pairings persisted. Our framework and analyses illustrate how demographic and social structuring within

  1. Dose-response curve for translocation frequency with single pair of painted chromosome. A comparison with dicentric and micronuclei frequency

    Energy Technology Data Exchange (ETDEWEB)

    Venkatachalam, P.; Paul, S.F.D.; Mohankumar, M.N.; Prabhu, B.K.; Gajendiran, N.; Jeevanram, R.K

    2000-07-01

    A translocation dose-response curve using a single pair of painted chromosomes was constructed. The translocation frequencies observed at different doses were compared to those obtained for dicentrics (DC) and micronuclei (MN). The translocation and DC frequency followed the Poisson distribution and MN showed over-dispersion. The translocation and DC frequencies were nearly the same for each dose point. Micronuclei showed a comparatively lower frequency. The alpha/beta ratio for translocations (0.916) and DC (0.974) were comparable, whereas the value for MN (1.526) was much higher. The equal frequencies of translocations and DC observed for a given dose indicated that genomic translocation frequency estimated using a single pair of painted chromosomes provides a reliable and easy method to measure translocation frequency. (autho000.

  2. Dose-response curve for translocation frequency with single pair of painted chromosome. A comparison with dicentric and micronuclei frequency

    International Nuclear Information System (INIS)

    Venkatachalam, P.; Paul, S.F.D.; Mohankumar, M.N.; Prabhu, B.K.; Gajendiran, N.; Jeevanram, R.K.

    2000-01-01

    A translocation dose-response curve using a single pair of painted chromosomes was constructed. The translocation frequencies observed at different doses were compared to those obtained for dicentrics (DC) and micronuclei (MN). The translocation and DC frequency followed the Poisson distribution and MN showed over-dispersion. The translocation and DC frequencies were nearly the same for each dose point. Micronuclei showed a comparatively lower frequency. The alpha/beta ratio for translocations (0.916) and DC (0.974) were comparable, whereas the value for MN (1.526) was much higher. The equal frequencies of translocations and DC observed for a given dose indicated that genomic translocation frequency estimated using a single pair of painted chromosomes provides a reliable and easy method to measure translocation frequency. (author)

  3. Effects of stimulus pair orientation and hand switching on reaction time estimates of interhemispheric transfer.

    Science.gov (United States)

    Leblanc-Sirois, Yanick; Braun, Claude M J; Elie-Fortier, Jonathan

    2018-03-26

    Two behavioral estimates of interhemispheric transfer time, the crossed-uncrossed difference (CUD) and the unilateral field advantage (UFA), are thought to, respectively, index transfer of premotor and visual information across the corpus callosum in neurotypical participants. However, no attempt to manipulate visual and motor contingencies in a set of tasks while measuring the CUD and the UFA has yet been reported. In two go/no-go comparison experiments, stimulus pair orientations were manipulated. The hand of response changed after each correct response in the second, but not the first experiment. No correlation was found between the CUD and the UFA, supporting the hypothesis that these two measures index different types of information transfer across hemispheres. An effect of manipulation of stimulus pair orientation on UFAs was attributed to the homotopy of callosal fibers transferring visual information, while an effect of hand switching on CUDs was attributed mostly to spatial compatibility.

  4. PAIR PRODUCTION IN LOW-LUMINOSITY GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Moscibrodzka, M.; Gammie, C. F.; Dolence, J. C.; Shiokawa, H.

    2011-01-01

    Electron-positron pairs may be produced near accreting black holes by a variety of physical processes, and the resulting pair plasma may be accelerated and collimated into a relativistic jet. Here, we use a self-consistent dynamical and radiative model to investigate pair production by γγ collisions in weakly radiative accretion flows around a black hole of mass M and accretion rate M-dot . Our flow model is drawn from general relativistic magnetohydrodynamic simulations, and our radiation field is computed by a Monte Carlo transport scheme assuming the electron distribution function is thermal. We argue that the pair production rate scales as r -6 M -1 M-dot 6 . We confirm this numerically and calibrate the scaling relation. This relation is self-consistent in a wedge in M, M-dot parameter space. If M-dot is too low the implied pair density over the poles of the black hole is below the Goldreich-Julian density and γγ pair production is relatively unimportant; if M-dot is too high the models are radiatively efficient. We also argue that for a power-law spectrum the pair production rate should scale with the observables L X ≡ X-ray luminosity and M as L 2 X M -4 . We confirm this numerically and argue that this relation likely holds even for radiatively efficient flows. The pair production rates are sensitive to black hole spin and to the ion-electron temperature ratio which are fixed in this exploratory calculation. We finish with a brief discussion of the implications for Sgr A* and M87.

  5. Constraining scalar resonances with top-quark pair production at the LHC

    Science.gov (United States)

    Franzosi, Diogo Buarque; Fabbri, Federica; Schumann, Steffen

    2018-03-01

    Constraints on models which predict resonant top-quark pair production at the LHC are provided via a reinterpretation of the Standard Model (SM) particle level measurement of the top-anti-top invariant mass distribution, m(t\\overline{t}) . We make use of state-of-the-art Monte Carlo event simulation to perform a direct comparison with measurements of m(t\\overline{t}) in the semi-leptonic channels, considering both the boosted and the resolved regime of the hadronic top decays. A simplified model to describe various scalar resonances decaying into top-quarks is considered, including CP-even and CP-odd, color-singlet and color-octet states, and the excluded regions in the respective parameter spaces are provided.

  6. Pairing fluctuations in trapped Fermi gases

    International Nuclear Information System (INIS)

    Viverit, Luciano; Bruun, Georg M.; Minguzzi, Anna; Fazio, Rosario

    2004-01-01

    We examine the contribution of pairing fluctuations to the superfluid order parameter for harmonically trapped atomic Fermi gases in the BCS regime. In the limit of small systems we consider, both analytically and numerically, their space and temperature dependence. We predict a parity effect, i.e., that pairing fluctuations show a maximum or a minimum at the center of the trap, depending on the value of the last occupied shell being even or odd. We propose to detect pairing fluctuations by measuring the density-density correlation function after a ballistic expansion of the gas

  7. Soliton pair creation at finite temperatures

    International Nuclear Information System (INIS)

    Grigoriev, D.Yu.; Rubakov, V.A.

    1988-01-01

    Creation of soliton-antisoliton pairs at finite temperature is considered within a (1+1)-dimensional model of a real scalar field. It is argued that at certain temperatures, the soliton pair creation in quantum theory can be investigated by studying classical field evolution in real time. The classical field equations are solved numerically, and the pair creation rate and average number of solitons are evaluated. No peculiar suppression of the rate is observed. Some results on the sphaleron transitions in (1+1)-dimensional abelian Higgs model are also presented. (orig.)

  8. Efficient Implementation of the Pairing on Mobilephones Using BREW

    Science.gov (United States)

    Yoshitomi, Motoi; Takagi, Tsuyoshi; Kiyomoto, Shinsaku; Tanaka, Toshiaki

    Pairing based cryptosystems can accomplish novel security applications such as ID-based cryptosystems, which have not been constructed efficiently without the pairing. The processing speed of the pairing based cryptosystems is relatively slow compared with the other conventional public key cryptosystems. However, several efficient algorithms for computing the pairing have been proposed, namely Duursma-Lee algorithm and its variant ηT pairing. In this paper, we present an efficient implementation of the pairing over some mobilephones. Moreover, we compare the processing speed of the pairing with that of the other standard public key cryptosystems, i. e. RSA cryptosystem and elliptic curve cryptosystem. Indeed the processing speed of our implementation in ARM9 processors on BREW achieves under 100 milliseconds using the supersingular curve over F397. In addition, the pairing is more efficient than the other public key cryptosystems, and the pairing can be achieved enough also on BREW mobilephones. It has become efficient enough to implement security applications, such as short signature, ID-based cryptosystems or broadcast encryption, using the pairing on BREW mobilephones.

  9. String pair production in non homogeneous backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Bolognesi, S. [Department of Physics “E. Fermi” University of Pisa, and INFN - Sezione di Pisa,Largo Pontecorvo, 3, Ed. C, 56127 Pisa (Italy); Rabinovici, E. [Racah Institute of Physics, The Hebrew University of Jerusalem,91904 Jerusalem (Israel); Tallarita, G. [Departamento de Ciencias, Facultad de Artes Liberales,Universidad Adolfo Ibáñez, Santiago 7941169 (Chile)

    2016-04-28

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is less suppressed than the rate of particle pair production. We discuss in some detail how the critical field is affected by the non-homogeneity, for both time and space dependent electric field backgrouds. We also comment on what could be an interesting new prediction for the small field limit. The third case we consider is pair production in holographic confining backgrounds with homogeneous and non-homogeneous fields.

  10. String pair production in non homogeneous backgrounds

    International Nuclear Information System (INIS)

    Bolognesi, S.; Rabinovici, E.; Tallarita, G.

    2016-01-01

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is less suppressed than the rate of particle pair production. We discuss in some detail how the critical field is affected by the non-homogeneity, for both time and space dependent electric field backgrouds. We also comment on what could be an interesting new prediction for the small field limit. The third case we consider is pair production in holographic confining backgrounds with homogeneous and non-homogeneous fields.

  11. Nucleon-pair approximation to the nuclear shell model

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y.M., E-mail: ymzhao@sjtu.edu.cn [Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Arima, A. [Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Musashi Gakuen, 1-26-1 Toyotamakami Nerima-ku, Tokyo 176-8533 (Japan)

    2014-12-01

    Atomic nuclei are complex systems of nucleons–protons and neutrons. Nucleons interact with each other via an attractive and short-range force. This feature of the interaction leads to a pattern of dominantly monopole and quadrupole correlations between like particles (i.e., proton–proton and neutron–neutron correlations) in low-lying states of atomic nuclei. As a consequence, among dozens or even hundreds of possible types of nucleon pairs, very few nucleon pairs such as proton and neutron pairs with spin zero, two (in some cases spin four), and occasionally isoscalar spin-aligned proton–neutron pairs, play important roles in low-energy nuclear structure. The nucleon-pair approximation therefore provides us with an efficient truncation scheme of the full shell model configurations which are otherwise too large to handle for medium and heavy nuclei in foreseeable future. Furthermore, the nucleon-pair approximation leads to simple pictures in physics, as the dimension of nucleon-pair subspace is always small. The present paper aims at a sound review of its history, formulation, validity, applications, as well as its link to previous approaches, with the focus on the new developments in the last two decades. The applicability of the nucleon-pair approximation and numerical calculations of low-lying states for realistic atomic nuclei are demonstrated with examples. Applications of pair approximations to other problems are also discussed.

  12. Drift wave in pair-ion plasma

    Indian Academy of Sciences (India)

    ion plasma are discussed. It is shown that the temperature and/or mass difference of both species could produce drift wave in a pair-ion plasma. The results are discussed in the context of the fullerene pair-ion plasma experiment.

  13. Drell-Yan lepton pair photoproduction

    International Nuclear Information System (INIS)

    Badalyan, R.G.; Grabskij, V.O.; Matinyan, S.G.

    1989-01-01

    The study of photon structure functions by spectra of massive lepton pairs (M l + l - ≥ 2 GeV) in photon fragmentation region in γp-interactions at high energies is suggested. In calculations of Drell-Yan lepton pair inclusive spectra in γp-interactions for photon structure functions there are used results obtained within QCD, data on γγ-interactions in e + e - → e + e - X on colliders as well as results from the analysis of vector meson non-diffractive photoproduction at high energies. It is shown that there exists a sufficienly wide kinematic region over variables X l + l - and M l + l - , wherein photon structure functions can be studied by spectra of Grell-Yan lepton pairs in the processes of their photoproduction. 31 refs.; 6 figs.; 1 tab

  14. Pair production in small angle Bhabha scattering

    International Nuclear Information System (INIS)

    Arbuzov, A.B.; Kuraev, Eh.A.; Merenkov, N.P.; Trentadue, L.

    1995-01-01

    The radiative corrections due to a pair production in the small angle high energy e + e - Bhabha scattering are considered. The corrections due to the production of virtual pairs as well as real soft and hard ones are calculated analytically. The collinear and semi-collinear kinematical regions of the hard pair production are taken into account. The results in the leading and next-to-leading logarithmic approximations provide the accuracy of Ο (0.1%). The results of numerical calculations show that the effects of pairs production are to be taken into account in the precise luminosity determination at LEP. 9 refs., 3 figs., 2 tabs

  15. Effects of disorder on the electron pairing

    International Nuclear Information System (INIS)

    Oviedo-Roa, R.; Wang, C.; Navarro, O.

    1996-01-01

    The electron pairing in randomly disordered lattices is studied by using an attractive Hubbard model, and by mapping the many-body problem onto a tight-binding one in a higher dimensional space, where a diagonal disorder is considered within the coherent-potential approximation. The results show an enhancement of the pair-binding energy as the self-energy difference increases in a binary alloy A x B 1-x . This fact suggests that the pairing process is highly sensitive to the one-particle localization condition. A ground-state phase diagram for on-site interaction disorder shows regions where pairing is avoided for ordered diatomic systems but not for disordered case

  16. Variational study of the pair hopping model

    International Nuclear Information System (INIS)

    Fazekas, P.

    1990-01-01

    We study the ground state of a Hamiltonian introduced by Kolb and Penson for modelling situations in which small electron pairs are formed. The Hamiltonian consists of a tight binding band term, and a term describing the nearest neighbour hopping of electron pairs. We give a Gutzwiller-type variational treatment, first with a single-parameter Ansatz treated in the single site Gutzwiller approximation, and then with more complicated trial wave functions, and an improved Gutzwiller approximation. The calculation yields a transition from a partially paired normal state, in which the spin susceptibility has a diminished value, into a fully paired state. (author). 16 refs, 2 figs

  17. Enhanced stability of bound pairs at nonzero lattice momenta

    International Nuclear Information System (INIS)

    Kornilovitch, Pavel

    2004-01-01

    A two-body problem on the square lattice is analyzed. The interaction potential consists of strong on-site repulsion and nearest-neighbor attraction. The exact pairing conditions are derived for s-, p-, and d-symmetric bound states. The pairing conditions are strong functions of the total pair momentum K. It is found that the stability of pairs increases with K. At weak attraction, the pairs do not form at the Γ point but stabilize at lattice momenta close to the Brillouin zone boundary. The phase boundaries in the momentum space, which separate stable and unstable pairs, are calculated. It is found that the pairs are formed easier along the (π,0) direction than along the (π,π) direction. This might lead to the appearance of 'hot pairing spots' on the K x and K y axes

  18. Nonrandom network connectivity comes in pairs

    Directory of Open Access Journals (Sweden)

    Felix Z. Hoffmann

    2017-02-01

    Full Text Available Overrepresentation of bidirectional connections in local cortical networks has been repeatedly reported and is a focus of the ongoing discussion of nonrandom connectivity. Here we show in a brief mathematical analysis that in a network in which connection probabilities are symmetric in pairs, Pij = Pji, the occurrences of bidirectional connections and nonrandom structures are inherently linked; an overabundance of reciprocally connected pairs emerges necessarily when some pairs of neurons are more likely to be connected than others. Our numerical results imply that such overrepresentation can also be sustained when connection probabilities are only approximately symmetric.

  19. Becoming independent through au pair migration

    DEFF Research Database (Denmark)

    Dalgas, Karina Märcher

    2015-01-01

    . This article argues that, despite this critique, au pairing does play an important formative role for young Filipinas because it opens up for experiences abroad that enable them to be recognised as independent adults in Philippine society. Rather than autonomy, however, au pairs define their independence...

  20. Pairing mechanism in oxide superconductors

    International Nuclear Information System (INIS)

    Hirsch, J.E.

    1988-01-01

    A useful way to learn about the pairing mechanism that is responsible for high T c superconductivity is to study properties of model Hamiltonians on small systems. The goal is to find the simplest model that can describe the essential physics of high T c superconductivity. The authors have used Monte Carlo simulation and exact diagonalization techniques to study properties of systems of up to 64 sites. Their results show that spin fluctuations and other spin related mechanisms induced by a Hubbard on-site repulsion U are not likely to give rise to pairing, neither in one nor in multiple band models. In contrast, charge fluctuations in a model with both strong U and V (repulsion between Cu and O) are shown to give rise to pairing and it is suggested that this model provides a plausible mechanism for high T c superconductivity

  1. Southern Monterey Bay Littoral Cell CRSMP Critical Erosion Sites 2008

    Data.gov (United States)

    California Natural Resource Agency — PWA and Griggs (2004) defined three risk categories to Monterey Regional Water Pollution Control Agency (MRWPCA) facilities between Marina and Wharf II. These risk...

  2. Southern Monterey Bay Littoral Cell CRSMP Critical Erosion Sites 2008

    Data.gov (United States)

    California Department of Resources — PWA and Griggs (2004) defined three risk categories to Monterey Regional Water Pollution Control Agency (MRWPCA) facilities between Marina and Wharf II. These risk...

  3. Frequent Pairs in Data Streams: Exploiting Parallelism and Skew

    DEFF Research Database (Denmark)

    Campagna, Andrea; Kutzkow, Konstantin; Pagh, Rasmus

    2011-01-01

    We introduce the Pair Streaming Engine (PairSE) that detects frequent pairs in a data stream of transactions. Our algorithm finds the most frequent pairs with high probability, and gives tight bounds on their frequency. It is particularly space efficient for skewed distribution of pair supports...... items mining in data streams. We show how to efficiently scale these approaches to handle large transactions. We report experimental results showcasing precision and recall of our method. In particular, we find that often our method achieves excellent precision, returning identical upper and lower...... bounds on the supports of the most frequent pairs....

  4. All paired up with no place to go: pairing, synapsis, and DSB formation in a balancer heterozygote.

    Directory of Open Access Journals (Sweden)

    Wei J Gong

    2005-11-01

    Full Text Available The multiply inverted X chromosome balancer FM7 strongly suppresses, or eliminates, the occurrence of crossing over when heterozygous with a normal sequence homolog. We have utilized the LacI-GFP: lacO system to visualize the effects of FM7 on meiotic pairing, synapsis, and double-strand break formation in Drosophila oocytes. Surprisingly, the analysis of meiotic pairing and synapsis for three lacO reporter couplets in FM7/X heterozygotes revealed they are paired and synapsed during zygotene/pachytene in 70%-80% of oocytes. Moreover, the regions defined by these lacO couplets undergo double-strand break formation at normal frequency. Thus, even complex aberration heterozygotes usually allow high frequencies of meiotic pairing, synapsis, and double-strand break formation in Drosophila oocytes. However, the frequencies of failed pairing and synapsis were still 1.5- to 2-fold higher than were observed for corresponding regions in oocytes with two normal sequence X chromosomes, and this effect was greatest near a breakpoint. We propose that heterozygosity for breakpoints creates a local alteration in synaptonemal complex structure that is propagated across long regions of the bivalent in a fashion analogous to chiasma interference, which also acts to suppress crossing over.

  5. Frustrated Lewis Pairs

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 11. Frustrated Lewis Pairs : Enabling via inability. Sanjoy Mukherjee ... Author Affiliations. Sanjoy Mukherjee Pakkirisamy Thilagar1. Department of Inorgainic and Physical Chemistry Indian Institute of Science Bangalore 560 012, India.

  6. Development and implementation of real-time nucleic acid amplification for the detection of enterovirus infections in comparison to rapid culture of various clinical specimens

    NARCIS (Netherlands)

    van Doornum, G J J; Schutten, Martin; Voermans, J; Guldemeester, G J J; Niesters, H G M

    2007-01-01

    Several real-time PCR and nucleic acid sequence-based amplification (NASBA) primer pairs and a modified real-time PCR primer pair for the detection of enteroviruses were compared. The modified real-time PCR primer pair was evaluated on clinical samples in comparison with cell culture using the

  7. Cumulative approaches to track formation under swift heavy ion (SHI) irradiation: Phenomenological correlation with formation energies of Frenkel pairs

    Energy Technology Data Exchange (ETDEWEB)

    Crespillo, M.L., E-mail: mcrespil@utk.edu [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain); Department of Materials Science & Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Agulló-López, F., E-mail: fal@uam.es [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain); Zucchiatti, A. [Centro de Microanálisis de Materiales, CMAM-UAM, Cantoblanco, Madrid 28049 (Spain)

    2017-03-01

    Highlights: • Extensive survey formation energies Frenkel pairs and electronic stopping thresholds. • Correlation: track formation thresholds and the energies for Frenkel pair formation. • Formation energies Frenkel pairs discussed in relation to the cumulative mechanisms. • Amorphous track formation mechanisms: defect accumulation models versus melting. • Advantages cumulative models to deal with new hot topics: nuclear-electronic synergy. - Abstract: An extensive survey for the formation energies of Frenkel pairs, as representative candidates for radiation-induced point defects, is presented and discussed in relation to the cumulative mechanisms (CM) of track formation in dielectric materials under swift heavy ion (SHI) irradiation. These mechanisms rely on the generation and accumulation of point defects during irradiation followed by collapse of the lattice once a threshold defect concentration is reached. The physical basis of those approaches has been discussed by Fecht as a defect-assisted transition to an amorphous phase. Although a first quantitative analysis of the CM model was previously performed for LiNbO{sub 3} crystals, we have, here, adopted a broader phenomenological approach. It explores the correlation between track formation thresholds and the energies for Frenkel pair formation for a broad range of materials. It is concluded that the threshold stopping powers can be roughly scaled with the energies required to generate a critical Frenkel pair concentration in the order of a few percent of the total atomic content. Finally, a comparison with the predictions of the thermal spike model is discussed within the analytical Szenes approximation.

  8. Asymmetric recombination and electron spin relaxation in the semiclassical theory of radical pair reactions

    International Nuclear Information System (INIS)

    Lewis, Alan M.; Manolopoulos, David E.; Hore, P. J.

    2014-01-01

    We describe how the semiclassical theory of radical pair recombination reactions recently introduced by two of us [D. E. Manolopoulos and P. J. Hore, J. Chem. Phys. 139, 124106 (2013)] can be generalised to allow for different singlet and triplet recombination rates. This is a non-trivial generalisation because when the recombination rates are different the recombination process is dynamically coupled to the coherent electron spin dynamics of the radical pair. Furthermore, because the recombination operator is a two-electron operator, it is no longer sufficient simply to consider the two electrons as classical vectors: one has to consider the complete set of 16 two-electron spin operators as independent classical variables. The resulting semiclassical theory is first validated by comparison with exact quantum mechanical results for a model radical pair containing 12 nuclear spins. It is then used to shed light on the spin dynamics of a carotenoid-porphyrin-fullerene triad containing considerably more nuclear spins which has recently been used to establish a “proof of principle” for the operation of a chemical compass [K. Maeda, K. B. Henbest, F. Cintolesi, I. Kuprov, C. T. Rodgers, P. A. Liddell, D. Gust, C. R. Timmel, and P. J. Hore, Nature (London) 453, 387 (2008)]. We find in particular that the intriguing biphasic behaviour that has been observed in the effect of an Earth-strength magnetic field on the time-dependent survival probability of the photo-excited C ·+ PF ·− radical pair arises from a delicate balance between its asymmetric recombination and the relaxation of the electron spin in the carotenoid radical

  9. Paired Expression Analysis of Tumor Cell Surface Antigens

    Directory of Open Access Journals (Sweden)

    Rimas J. Orentas

    2017-08-01

    Full Text Available Adoptive immunotherapy with antibody-based therapy or with T cells transduced to express chimeric antigen receptors (CARs is useful to the extent that the cell surface membrane protein being targeted is not expressed on normal tissues. The most successful CAR-based (anti-CD19 or antibody-based therapy (anti-CD20 in hematologic malignancies has the side effect of eliminating the normal B cell compartment. Targeting solid tumors may not provide a similar expendable marker. Beyond antibody to Her2/NEU and EGFR, very few antibody-based and no CAR-based therapies have seen broad clinical application for solid tumors. To expand the way in which the surfaceome of solid tumors can be analyzed, we created an algorithm that defines the pairwise relative overexpression of surface antigens. This enables the development of specific immunotherapies that require the expression of two discrete antigens on the surface of the tumor target. This dyad analysis was facilitated by employing the Hotelling’s T-squared test (Hotelling–Lawley multivariate analysis of variance for two independent variables in comparison to a third constant entity (i.e., gene expression levels in normal tissues. We also present a unique consensus scoring mechanism for identifying transcripts that encode cell surface proteins. The unique application of our bioinformatics processing pipeline and statistical tools allowed us to compare the expression of two membrane protein targets as a pair, and to propose a new strategy based on implementing immunotherapies that require both antigens to be expressed on the tumor cell surface to trigger therapeutic effector mechanisms. Specifically, we found that, for MYCN amplified neuroblastoma, pairwise expression of ACVR2B or anaplastic lymphoma kinase (ALK with GFRA3, GFRA2, Cadherin 24, or with one another provided the strongest hits. For MYCN, non-amplified stage 4 neuroblastoma, neurotrophic tyrosine kinase 1, or ALK paired with GFRA2, GFRA3, SSK

  10. On pair-absorption in intrinsic vapours

    International Nuclear Information System (INIS)

    Hotop, R.; Niemax, K.; Schlueter, D.

    1982-01-01

    The bound-state pair-absorption bands Cs(6 2 S 1 sub(/) 2 ) + Cs(6 2 S 1 sub(/) 2 ) + hν → Cs(5 2 D 5 sub(/) 2 sub(,) 3 sub(/) 2 ) + Cs(6 2 P 1 sub(/) 2 ) and the K-K continuum-state pair-absorptions in the wavelength region 2.350 <= lambda <= 2.850 Angstroem have been investigated experimentally. In the case of the bound-state pair-absorption bands a theoretical approach for the absorption cross section at the band centre is given which is in good agreement with the experimental observation. Differences between our and the theoretical formulas given by the Stanford group are discussed. (orig.)

  11. Association between patellar cartilage defects and patellofemoral geometry: a matched-pair MRI comparison of patients with and without isolated patellar cartilage defects.

    Science.gov (United States)

    Mehl, Julian; Feucht, Matthias J; Bode, Gerrit; Dovi-Akue, David; Südkamp, Norbert P; Niemeyer, Philipp

    2016-03-01

    To compare the geometry of the patellofemoral joint on magnetic resonance images (MRI) between patients with isolated cartilage defects of the patella and a gender- and age-matched control group of patients without patellar cartilage defects. A total of 43 patients (17 female, 26 male) with arthroscopically verified grade III and IV patellar cartilage defects (defect group) were compared with a matched-pair control group of patients with isolated traumatic rupture of the anterior cruciate ligament without cartilage defects of the patellofemoral joint. Preoperative MRI images were analysed retrospectively with regard to patellar geometry (width, thickness, facet angle), trochlear geometry (dysplasia according to Dejour, sulcus angle, sulcus depth, lateral condyle index, trochlea facet asymmetry, lateral trochlea inclination) and patellofemoral alignment (tibial tuberosity-trochlear groove distance, patella height, lateral patella displacement, lateral patellofemoral angle, patella tilt, congruence angle). In addition to the comparison of group values, the measured values were compared to normal values reported in the literature, and the frequency of patients with pathologic findings was compared between both groups. The defect group demonstrated a significantly higher proximal chondral sulcus angle (p patellofemoral joint. In particular, a flat and shallow trochlea, trochlea dysplasia and patella alta seem to contribute to the development of patellar cartilage defects, which must be taken into consideration when planning to do surgical cartilage repair at the patella. III.

  12. Analyzing survival curves at a fixed point in time for paired and clustered right-censored data

    Science.gov (United States)

    Su, Pei-Fang; Chi, Yunchan; Lee, Chun-Yi; Shyr, Yu; Liao, Yi-De

    2018-01-01

    In clinical trials, information about certain time points may be of interest in making decisions about treatment effectiveness. Rather than comparing entire survival curves, researchers can focus on the comparison at fixed time points that may have a clinical utility for patients. For two independent samples of right-censored data, Klein et al. (2007) compared survival probabilities at a fixed time point by studying a number of tests based on some transformations of the Kaplan-Meier estimators of the survival function. However, to compare the survival probabilities at a fixed time point for paired right-censored data or clustered right-censored data, their approach would need to be modified. In this paper, we extend the statistics to accommodate the possible within-paired correlation and within-clustered correlation, respectively. We use simulation studies to present comparative results. Finally, we illustrate the implementation of these methods using two real data sets. PMID:29456280

  13. Galactic Pairs in the Early Universe

    Science.gov (United States)

    Kohler, Susanna

    2018-02-01

    In the spirit of Valentines Day, today well be exploring apparent pairs of galaxies in the distant, early universe. How can we tell whether these duos are actually paired galaxies, as opposed to disguised singles?Real Pair, or Trick of the Light?In the schematic timeline of the universe, the epoch of reionization is when the first galaxies and quasars began to form and evolve. [NASA]The statistics of merging galaxies throughout the universe reveal not only direct information about how galaxies interact, but also cosmological information about the structure of the universe. While weve observed many merging galaxy pairs at low redshift, however, its much more challenging to identify these duos in the early universe.A merging pair of galaxies at high redshift appears to us as a pair of unresolved blobs that lie close to each other in the sky. But spotting such a set of objects doesnt necessarily mean were looking at a merger! There are three possible scenarios to explain an observed apparent duo:Its a pair of galaxies in a stage of merger.Its a projection coincidence; the two galaxies arent truly near each other.Its a single galaxy being gravitationally lensed by a foreground object. This strong lensing produces the appearance of multiple galaxies.Hubble photometry of one of the three galaxy groups identified at z 8, with the galaxies in the image labeled with their corresponding approximate photometric redshifts. [Adapted from Chaikin et al. 2018]Hunting for Distant DuosIn a recent study led by Evgenii Chaikin (Peter the Great St. Petersburg Polytechnic University, Russia), a team of scientists has explored the Hubble Ultra Deep Field in search ofhigh-redshift galaxies merging during the epoch of reionization, when the first galaxies formed and evolved.Using an approach called the dropout technique, which leverages the visibility of the galaxies in different wavelength filters, Chaikin and collaborators obtain approximate redshifts for an initial sample of 7

  14. QUANTITATIVE ION-PAIR EXTRACTION OF 4(5)-METHYLIMIDAZOLE FROM CARAMEL COLOR AND ITS DETERMINATION BY REVERSED-PHASE ION-PAIR LIQUID-CHROMATOGRAPHY

    DEFF Research Database (Denmark)

    Thomsen, Mohens; Willumsen, Dorthe

    1981-01-01

    A procedure for quantitative ion-pair extraction of 4(5)-methylimidazole from caramel colour using bis(2-ethylhexyl)phosphoric acid as ion-pairing agent has been developed. Furthermore, a reversed-phase ion-pair liquid chromatographic separation method has been established to analyse the content...

  15. Coherent pair creation from beam-beam interaction

    International Nuclear Information System (INIS)

    Chen, Pisin.

    1989-09-01

    It has recently been recognized that in future linear colliders, there is a finite probability that the beamstrahlung photons will turn into e + e - pairs induced by the same beam-beam field, and this would potentially cause background problems. In this paper, we first review the probability of such a coherent pair creation process. It is seen that the constraint on the beamstrahlung parameter, Υ, is tight of these coherent pairs to be totally suppressed. We then point out that there exists a minimum energy for the pair-created particles, which scales as ∼1/5Υ. When combining this condition with the deflection angle for the low-energy particles, the constraint on the allowable Υ value is much relaxed. Finally, we calculate the effective cross section for producing the weak bosons by the low-energy e + e - pairs. It is shown that these cross sections are substantial for Υ > 1. We suggest that this effect can help to autoscan the particle spectrum in the high energy frontier. 10 refs., 2 figs

  16. Seniority zero pair coupled cluster doubles theory

    International Nuclear Information System (INIS)

    Stein, Tamar; Henderson, Thomas M.; Scuseria, Gustavo E.

    2014-01-01

    Coupled cluster theory with single and double excitations accurately describes weak electron correlation but is known to fail in cases of strong static correlation. Fascinatingly, however, pair coupled cluster doubles (p-CCD), a simplified version of the theory limited to pair excitations that preserve the seniority of the reference determinant (i.e., the number of unpaired electrons), has mean field computational cost and is an excellent approximation to the full configuration interaction (FCI) of the paired space provided that the orbital basis defining the pairing scheme is adequately optimized. In previous work, we have shown that optimization of the pairing scheme in the seniority zero FCI leads to a very accurate description of static correlation. The same conclusion extends to p-CCD if the orbitals are optimized to make the p-CCD energy stationary. We here demonstrate these results with numerous examples. We also explore the contributions of different seniority sectors to the coupled cluster doubles (CCD) correlation energy using different orbital bases. We consider both Hartree-Fock and Brueckner orbitals, and the role of orbital localization. We show how one can pair the orbitals so that the role of the Brueckner orbitals at the CCD level is retained at the p-CCD level. Moreover, we explore ways of extending CCD to accurately describe strongly correlated systems

  17. Odd-frequency pairing in superconducting heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Golubov, A A [Faculty of Science and Technology and MESA Institute for Nanotechnology, University of Twente, 7500 AE Enschede (Netherlands); Tanaka, Y [Department of Applied Physics, Nagoya University, Nagoya, 464-8603 (Japan); Asano, Y [Department of Applied Physics, Hokkaido University, Sapporo 060-8628 (Japan); Tanuma, Y [Institute of Physics, Kanagawa University, 3-7-1, Rokkakubashi, Kanagawa-ku, Yokohama 221-8686 (Japan)], E-mail: a.golubov@utwente.nl

    2009-04-22

    We review the theory of odd-frequency pairing in superconducting heterostructures, where an odd-frequency pairing component is induced near interfaces. A general description of the superconducting proximity effect in a normal metal or a ferromagnet attached to an unconventional superconductor (S) is given within quasiclassical kinetic theory for various types of symmetry state in S. Various possible symmetry classes in a superconductor are considered which are consistent with the Pauli principle: even-frequency spin-singlet even-parity (ESE) state, even-frequency spin-triplet odd-parity (ETO) state, odd-frequency spin-triplet even-parity (OTE) state and odd-frequency spin-singlet odd-parity (OSO) state. As an example, we consider a junction between a diffusive normal metal (DN) and a p-wave superconductor (even-frequency spin-triplet odd-parity symmetry), where the pairing amplitude in DN belongs to an odd-frequency spin-triplet even-parity symmetry class. We also discuss the manifestation of odd-frequency pairing in conventional superconductor/normal (S/N) proximity systems and its relation to the classical McMillan-Rowell oscillations.

  18. Pulsational Pair-instability Model for Superluminous Supernova PTF12dam:Interaction and Radioactive Decay

    Energy Technology Data Exchange (ETDEWEB)

    Tolstov, Alexey; Nomoto, Ken’ichi; Blinnikov, Sergei; Quimby, Robert [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Sorokina, Elena [Sternberg Astronomical Institute, M.V.Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Baklanov, Petr, E-mail: alexey.tolstov@ipmu.jp [Institute for Theoretical and Experimental Physics (ITEP), 117218 Moscow (Russian Federation)

    2017-02-01

    Being a superluminous supernova, PTF12dam can be explained by a {sup 56}Ni-powered model, a magnetar-powered model, or an interaction model. We propose that PTF12dam is a pulsational pair-instability supernova, where the outer envelope of a progenitor is ejected during the pulsations. Thus, it is powered by a double energy source: radioactive decay of {sup 56}Ni and a radiative shock in a dense circumstellar medium. To describe multicolor light curves and spectra, we use radiation-hydrodynamics calculations of the STELLA code. We found that light curves are well described in the model with 40 M {sub ⊙} ejecta and 20–40 M {sub ⊙} circumstellar medium. The ejected {sup 56}Ni mass is about 6 M {sub ⊙}, which results from explosive nucleosynthesis with large explosion energy (2–3)×10{sup 52} erg. In comparison with alternative scenarios of pair-instability supernova and magnetar-powered supernova, in the interaction model, all the observed main photometric characteristics are well reproduced: multicolor light curves, color temperatures, and photospheric velocities.

  19. e+e--pair production in Pb-Au collisions at 158 GeV per nucleon

    CERN Document Server

    Agakichiev, G.; Bielcikova, J.; Baur, R.; Braun-Munzinger, P.; Cherlin, A.; Damjanovic, S.; Drees, A.; Esumi, S.; Faschingbauer, U.; Fraenkel, Z.; Fuchs, Ch.; Gatti, E.; Glassel, P.; Hering, G.; de los Heros, C.P.; Holl, P.; Jung, Ch.; Lenkeit, B.; Marin, A.; Messer, F.; Messer, M.; Miskowiec, D.; Nix, O.; Panebrattsev, Yu.; Pfeiffer, A.; Rak, J.; Ravinovich, I.; Razin, S.; Rehak, P.; Richter, M.; Sampietro, M.; Sako, H.; Saveljic, N.; Schmitz, W.; Schukraft, J.; Seipp, W.; Shimanskiy, S.; Socol, E.; Specht, H.J.; Stachel, J.; Tel-Zur, G.; Tserruya, Itzhak; Ullrich, T.; Voigt, C.; Voloshin, S.; Weber, C.; Wessels, J.P.; Wienold, T.; Wurm, J.P.; Yurevich, V.; Fuchs, Ch.; Jung, Ch.; Panebrattsev, Yu.

    2005-01-01

    We present the combined results on electron-pair production in 158 GeV/n {Pb-Au} ($\\sqrt{s}$= 17.2 GeV) collisions taken at the CERN SPS in 1995 and 1996, and give a detailed account of the data analysis. The enhancement over the reference of neutral meson decays amounts to a factor of 2.31$\\pm0.19 (stat.)\\pm0.55 (syst.)\\pm0.69 (decays)$ for semi-central collisions (28% $\\sigma/\\sigma_{geo}$) when yields are integrated over $m>$ 200 MeV/$c^2$ in invariant mass. The measured yield, its stronger-than-linear scaling with $N_{ch}$, and the dominance of low pair $p_t$ strongly suggest an interpretation as {\\it thermal radiation} from pion annihilation in the hadronic fireball. The shape of the excess centring at $m\\approx$ 500 MeV/$c^2$, however, cannot be described without strong medium modifications of the $\\rho$ meson. The results are put into perspective by comparison to predictions from Brown-Rho scaling governed by chiral symmetry restoration, and from the spectral-function many-body treatment in which the a...

  20. Hadronic production of massive lepton pairs

    International Nuclear Information System (INIS)

    Berger, E.L.

    1982-12-01

    A review is presented of recent experimental and theoretical progress in studies of the production of massive lepton pairs in hadronic collisions. I begin with the classical Drell-Yan annihilation model and its predictions. Subsequently, I discuss deviations from scaling, the status of the proofs of factorization in the parton model, higher-order terms in the perturbative QCD expansion, the discrepancy between measured and predicted yields (K factor), high-twist terms, soft gluon effects, transverse-momentum distributions, implications for weak vector boson (W +- and Z 0 ) yields and production properties, nuclear A dependence effects, correlations of the lepton pair with hadrons in the final state, and angular distributions in the lepton-pair rest frame

  1. Learning preferences from paired opposite-based semantics

    DEFF Research Database (Denmark)

    Franco de los Ríos, Camilo; Rodríguez, J. Tinguaro; Montero, Javier

    2017-01-01

    Preference semantics examine the meaning of the preference predicate, according to the way that alternatives can be understood and organized for decision making purposes. Through opposite-based semantics, preference structures can be characterized by their paired decomposition of preference...... on the character of opposition, the compound meaning of preference emerges from the fuzzy reinforcement of paired opposite concepts, searching for significant evidence for affirming dominance among the decision objects. Here we propose a general model for the paired decomposition of preference, examining its...

  2. Observing Pair-Work Task in an English Speaking Class

    Directory of Open Access Journals (Sweden)

    Diana Achmad

    2014-01-01

    Full Text Available This paper reports on students’ pair-work interactions to develop their speaking skills in an ELT classroom which consisted of international learners. A number of 16 learners of intermediate proficiency with IELTS score band 5.5 were observed. The teacher had paired those he considered among them to be the more competent ones (hereafter, stronger with the less competent ones (hereafter, weaker; therefore, eight pairs were observed during the lesson. The task given to the students was to express ‘Agree and Disagree’ in the context of giving opinions related to social life. Based on the observations, the task was successfully implemented by six pairs; thus, the two others faced some problems. From the first pair, it was seen that the stronger student had intimated the weaker one into speaking during the task. The other pair, who was both of the same native, did not converse in English as expected and mostly used their native language to speak with one another presumably due to respect from the stronger student towards the weaker one. In situations like this, when pair-work becomes unproductive, rotating pairs is recommended to strengthen information sharing and assigning roles to avoid a student from taking over the activity from his or her pair. In conclusion, pairing international learners with mixed speaking proficiency by teachers must be conducted as effectively as possible by initially identifying their ability and learning culture to profoundly expand the students’ language resources.

  3. Pair-correlations in swimmer suspensions

    Science.gov (United States)

    Nambiar, Sankalp; Subramanian, Ganesh

    2017-11-01

    Suspensions of rear-actuated swimming microorganisms, such as E.coli, exhibit several interesting phenomena including spontaneous pattern formation above a critical concentration, novel rheological properties, shear-induced concentration banding etc. Explanations based on mean-field theory are only qualitative, since interactions between swimmers are important for typical experimental concentrations. We analytically characterize the hydrodynamic pair-interactions in a quiescent suspension of slender straight swimmers. The pair-correlation, calculated at leading order by integrating the swimmer velocity disturbances along straight trajectories, decays as 1/r2 for r >> L (L being the swimmer size). This allows us to characterize both polar and nematic correlations in an interacting swimmer suspension. In the absence of correlations, the velocity covariance asymptotes from a constant for r > L, the latter being characteristic of a suspension of non-interacting point force-dipoles. On including correlations, the slow decay of the pair-orientation correlation leads to an additional contribution to the velocity covariance that diverges logarithmically with system size.

  4. Binaries and triples among asteroid pairs

    Science.gov (United States)

    Pravec, Petr; Scheirich, Peter; Kušnirák, Peter; Hornoch, Kamil; Galád, Adrián

    2015-08-01

    Despite major achievements obtained during the past two decades, our knowledge of the population and properties of small binary and multiple asteroid systems is still far from advanced. There is a numerous indirect evidence for that most small asteroid systems were formed by rotational fission of cohesionless parent asteroids that were spun up to the critical frequency presumably by YORP, but details of the process are lacking. Furthermore, as we proceed with observations of more and more binary and paired asteroids, we reveal new facts that substantially refine and sometimes change our understanding of the asteroid systems. One significant new finding we have recently obtained is that primaries of many asteroid pairs are actually binary or triple systems. The first such case found is (3749) Balam (Vokrouhlický, ApJL 706, L37, 2009). We have found 9 more binary systems among asteroid pairs within our ongoing NEOSource photometric project since October 2012. They are (6369) 1983 UC, (8306) Shoko, (9783) Tensho-kan, (10123) Fideoja, (21436) Chaoyichi, (43008) 1999 UD31, (44620) 1999 RS43, (46829) 1998 OS14 and (80218) 1999 VO123. We will review their characteristics. These paired binaries as we call them are mostly similar to binaries in the general ("background") population (of unpaired asteroids), but there are a few trends. The paired binaries tend to have larger secondaries with D_2/D_1 = 0.3 to 0.5 and they also tend to be wider systems with 8 of the 10 having orbital periods between 30 and 81 hours, than average among binaries in the general population. There may be also a larger fraction of triples; (3749) Balam is a confirmed triple, having a larger close and a smaller distant satellite, and (8306) Shoko and (10123) Fideoja are suspect triples as they show additional rotational lightcurve components with periods of 61 and 38.8 h that differ from the orbital period of 36.2 and 56.5 h, respectively. The unbound secondaries tend to be of the same size or

  5. Isovectorial pairing in solvable and algebraic models

    International Nuclear Information System (INIS)

    Lerma, Sergio; Vargas, Carlos E; Hirsch, Jorge G

    2011-01-01

    Schematic interactions are useful to gain some insight in the behavior of very complicated systems such as the atomic nuclei. Prototypical examples are, in this context, the pairing interaction and the quadrupole interaction of the Elliot model. In this contribution the interplay between isovectorial pairing, spin-orbit, and quadrupole terms in a harmonic oscillator shell (the so-called pairing-plus-quadrupole model) is studied by algebraic methods. The ability of this model to provide a realistic description of N = Z even-even nuclei in the fp-shell is illustrated with 44 Ti. Our calculations which derive from schematic and simple terms confirm earlier conclusions obtained by using realistic interactions: the SU(3) symmetry of the quadrupole term is broken mainly by the spin-orbit term, but the energies depends strongly on pairing.

  6. Cytoplasmic and Genomic Effects on Meiotic Pairing in Brassica Hybrids and Allotetraploids from Pair Crosses of Three Cultivated Diploids

    Science.gov (United States)

    Cui, Cheng; Ge, Xianhong; Gautam, Mayank; Kang, Lei; Li, Zaiyun

    2012-01-01

    Interspecific hybridization and allopolyploidization contribute to the origin of many important crops. Synthetic Brassica is a widely used model for the study of genetic recombination and “fixed heterosis” in allopolyploids. To investigate the effects of the cytoplasm and genome combinations on meiotic recombination, we produced digenomic diploid and triploid hybrids and trigenomic triploid hybrids from the reciprocal crosses of three Brassica diploids (B. rapa, AA; B. nigra, BB; B. oleracea, CC). The chromosomes in the resultant hybrids were doubled to obtain three allotetraploids (B. juncea, AA.BB; B. napus, AA.CC; B. carinata, BB.CC). Intra- and intergenomic chromosome pairings in these hybrids were quantified using genomic in situ hybridization and BAC-FISH. The level of intra- and intergenomic pairings varied significantly, depending on the genome combinations and the cytoplasmic background and/or their interaction. The extent of intragenomic pairing was less than that of intergenomic pairing within each genome. The extent of pairing variations within the B genome was less than that within the A and C genomes, each of which had a similar extent of pairing. Synthetic allotetraploids exhibited nondiploidized meiotic behavior, and their chromosomal instabilities were correlated with the relationship of the genomes and cytoplasmic background. Our results highlight the specific roles of the cytoplasm and genome to the chromosomal behaviors of hybrids and allopolyploids. PMID:22505621

  7. Pairing of heterochromatin in response to cellular stress

    International Nuclear Information System (INIS)

    Abdel-Halim, H.I.; Mullenders, L.H.F.; Boei, J.J.W.A.

    2006-01-01

    We previously reported that exposure of human cells to DNA-damaging agents (X-rays and mitomycin C (MMC)) induces pairing of the homologous paracentromeric heterochromatin of chromosome 9 (9q12-13). Here, we show that UV irradiation and also heat shock treatment of human cells lead to similar effects. Since the various agents induce very different types and frequencies of damage to cellular constituents, the data suggest a general stress response as the underlying mechanism. Moreover, local UV irradiation experiments revealed that pairing of heterochromatin is an event that can be triggered without induction of DNA damage in the heterochromatic sequences. The repair deficient xeroderma pigmentosum cells (group F) previously shown to fail pairing after MMC displayed elevated pairing after heat shock treatment but not after UV exposure. Taken together, the present results indicate that pairing of heterochromatin following exposure to DNA-damaging agents is initiated by a general stress response and that the sensing of stress or the maintenance of the paired status of the heterochromatin might be dependent on DNA repair

  8. Paired receiver operating characteristic curves and the effect of history on radiographic interpretation: CT of the head as a case study

    International Nuclear Information System (INIS)

    McNeil, B.J.; Hanley, J.A.; Funkenstein, H.H.; Wallman, J.

    1983-01-01

    The use of a statistical technique for paired comparisons using receiver operating characteristic (ROC) curves is illustrated by studying the extent to which clinical history altered the interpretation of computed tomographic (CT) examinations of the head. Eighty-nine CT examinations of the head were presented in random order to four readers, first with minimum history (age and sex) and then several weeks later with complete neutrological history as of the time the CT examination had been obtained. Using a paired ROC analysis, a small but significant (p < .05) improvement was detected for the interpretations in the presence of complete history; for readings without history the average area was 94.4% and for readings with history it was 97.7%

  9. Twin photon pairs in a high-Q silicon microresonator

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Steven; Lu, Xiyuan [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Jiang, Wei C. [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Lin, Qiang, E-mail: qiang.lin@rochester.edu [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York 14627 (United States)

    2015-07-27

    We report the generation of high-purity twin photon pairs through cavity-enhanced non-degenerate four-wave mixing (FWM) in a high-Q silicon microdisk resonator. Twin photon pairs are created within the same cavity mode and are consequently expected to be identical in all degrees of freedom. The device is able to produce twin photons at telecommunication wavelengths with a pair generation rate as large as (3.96 ± 0.03) × 10{sup 5} pairs/s, within a narrow bandwidth of 0.72 GHz. A coincidence-to-accidental ratio of 660 ± 62 was measured, the highest value reported to date for twin photon pairs, at a pair generation rate of (2.47 ± 0.04) × 10{sup 4} pairs/s. Through careful engineering of the dispersion matching window, we have reduced the ratio of photons resulting from degenerate FWM to non-degenerate FWM to less than 0.15.

  10. Separable pairing force for relativistic quasiparticle random-phase approximation

    International Nuclear Information System (INIS)

    Tian Yuan; Ma Zhongyu; Ring, Peter

    2009-01-01

    We have introduced a separable pairing force, which was adjusted to reproduce the pairing properties of the Gogny force in nuclear matter. This separable pairing force is able to describe in relativistic Hartree-Bogoliubov (RHB) calculations the pairing properties in the ground state of finite nuclei on almost the same footing as the original Gogny interaction. In this work we investigate excited states using the Relativistic Quasiparticle Random-Phase Approximation (RQRPA) with the same separable pairing force. For consistency the Goldstone modes and the convergence with various cutoff parameters in this version of RQRPA are studied. The first excited 2 + states for the chain of Sn isotopes with Z=50 and the chain of isotones with N=82 isotones are calculated in RQRPA together with the 3 - states of Sn isotopes. By comparing our results with experimental data and with the results of the original Gogny force we find that this simple separable pairing interaction is very successful in depicting the pairing properties of vibrational excitations.

  11. ΛΛ pairing in NΛ composite matter

    International Nuclear Information System (INIS)

    Tanigawa, Tomonori; Matsuzaki, Masayuki; Chiba, Satoshi

    2003-01-01

    ΛΛ pairing correlation in binary mixed matter of nucleons and lambdas is studied within the relativistic Hartree-Bogoliubov model. Λ hyperons to be paired up are immersed in background nucleons in normal state. A phenomenological ΛΛ interaction, which is derived relativistically from the Lagrangian of the system, is adopted to the gap equation. It is found that increasing the nucleon density makes the ΛΛ pairing gap suppressed. This result suggests a mechanism, specific to relativistic models, of its dependence on the nucleon density. (author)

  12. ΛΛ pairing in NΛ composite matter

    International Nuclear Information System (INIS)

    Tanigawa, Tomonori; Matsuzaki, Masayuki; Chiba, Satoshi

    2002-01-01

    ΛΛ pairing correlation in binary mixed matter of nucleons and lambdas is studied within the relativistic Hartree-Bogoliubov model. Λ hyperons to be paired up are immersed in background nucleons in normal state. A phenomenological ΛΛ interaction, which is derived relativistically from the Lagrangian of the system, is adopted to the gap equation. It is found that increasing the nucleon density makes the ΛΛ pairing gap suppressed. This result suggests a mechanism, specific to relativistic models, of its dependence on the nucleon density. (author)

  13. Recoil effects in multiphoton electron-positron pair creation

    International Nuclear Information System (INIS)

    Krajewska, K.; Kaminski, J. Z.

    2010-01-01

    Triply differential probability rates for electron-positron pair creation in laser-nucleus collisions, calculated within the S-matrix approach, are investigated as functions of the nuclear recoil. Pronounced enhancements of differential probability rates of multiphoton pair production are found for a nonzero momentum transfer from the colliding nucleus. The corresponding rates show a very dramatic dependence on the polarization of the laser field impinging on the nucleus; only for a linearly polarized light are the multiphoton rates for electron-positron pair production considerably large. We focus therefore on this case. Our numerical results for different geometries of the reaction particles demonstrate that, for the linearly polarized laser field of an infinite extent (which is a good approximation for femtosecond laser pulses), the pair creation is far more efficient if the nucleus is detected in the direction of the laser-field propagation. The corresponding angular distributions of the created particles show that the high-energy pairs are predominantly produced in the plane spanned by the polarization vector and the laser-field propagation direction, while the low-energy pairs are rather spread around the latter of the two directions. The enhancement of differential probability rates at each energy sector, defined by the four-momentum conservation relation, is observed with varying the energy of the produced particles. The total probability rates of pair production are also evaluated and compared with the corresponding results for the case when one disregards the recoil effect. A tremendous enhancement of the total probability rates of the electron-positron pair creation is observed if one takes into account the nuclear recoil.

  14. MAJOR-MERGER GALAXY PAIRS IN THE COSMOS FIELD—MASS-DEPENDENT MERGER RATE EVOLUTION SINCE z = 1

    International Nuclear Information System (INIS)

    Xu, C. Kevin; Zhao, Yinghe; Gao, Y.; Scoville, N.; Capak, P.; Drory, N.

    2012-01-01

    We present results of a statistical study of the cosmic evolution of the mass-dependent major-merger rate since z = 1. A stellar mass limited sample of close major-merger pairs (the CPAIR sample) was selected from the archive of the COSMOS survey. Pair fractions at different redshifts derived using the CPAIR sample and a local K-band-selected pair sample show no significant variations with stellar mass. The pair fraction exhibits moderately strong cosmic evolution, with the best-fitting function of f pair = 10 –1.88(±0.03) (1 + z) 2.2(±0.2) . The best-fitting function for the merger rate is R mg (Gyr –1 ) = 0.053 × (M star /10 10.7 M ☉ ) 0.3 (1 + z) 2.2 /(1 + z/8). This rate implies that galaxies of M star ∼ 10 10 -10 11.5 M ☉ have undergone ∼0.5-1.5 major mergers since z = 1. Our results show that, for massive galaxies (M star ≥ 10 10.5 M ☉ ) at z ≤ 1, major mergers involving star-forming galaxies (i.e., wet and mixed mergers) can account for the formation of both ellipticals and red quiescent galaxies (RQGs). On the other hand, major mergers cannot be responsible for the formation of most low mass ellipticals and RQGs of M star ∼ 10.3 M ☉ . Our quantitative estimates indicate that major mergers have significant impact on the stellar mass assembly of the most massive galaxies (M star ≥ 10 11.3 M ☉ ), but for less massive galaxies the stellar mass assembly is dominated by the star formation. Comparison with the mass-dependent (ultra)luminous infrared galaxies ((U)LIRG) rates suggests that the frequency of major-merger events is comparable to or higher than that of (U)LIRGs.

  15. Studies of base pair sequence effects on DNA solvation based on all-atom molecular dynamics simulations.

    Science.gov (United States)

    Dixit, Surjit B; Mezei, Mihaly; Beveridge, David L

    2012-07-01

    Detailed analyses of the sequence-dependent solvation and ion atmosphere of DNA are presented based on molecular dynamics (MD) simulations on all the 136 unique tetranucleotide steps obtained by the ABC consortium using the AMBER suite of programs. Significant sequence effects on solvation and ion localization were observed in these simulations. The results were compared to essentially all known experimental data on the subject. Proximity analysis was employed to highlight the sequence dependent differences in solvation and ion localization properties in the grooves of DNA. Comparison of the MD-calculated DNA structure with canonical A- and B-forms supports the idea that the G/C-rich sequences are closer to canonical A- than B-form structures, while the reverse is true for the poly A sequences, with the exception of the alternating ATAT sequence. Analysis of hydration density maps reveals that the flexibility of solute molecule has a significant effect on the nature of observed hydration. Energetic analysis of solute-solvent interactions based on proximity analysis of solvent reveals that the GC or CG base pairs interact more strongly with water molecules in the minor groove of DNA that the AT or TA base pairs, while the interactions of the AT or TA pairs in the major groove are stronger than those of the GC or CG pairs. Computation of solvent-accessible surface area of the nucleotide units in the simulated trajectories reveals that the similarity with results derived from analysis of a database of crystallographic structures is excellent. The MD trajectories tend to follow Manning's counterion condensation theory, presenting a region of condensed counterions within a radius of about 17 A from the DNA surface independent of sequence. The GC and CG pairs tend to associate with cations in the major groove of the DNA structure to a greater extent than the AT and TA pairs. Cation association is more frequent in the minor groove of AT than the GC pairs. In general, the

  16. STUDI KOMPARATIF MODEL PEMBELAJARAN THINK PAIR SQUARE DAN THINK PAIR SHARE TERHADAP MOTIVASI DAN HASIL BELAJAR SISWA MAPEL TIK KELAS X SMA N 1 SUKASADA

    Directory of Open Access Journals (Sweden)

    Putu Deli Januartini

    2016-10-01

    Abstract The purpose of this study were to determine (1 the significant influence of the application of think pair square and think pair share learning model on student’s learning achievement, (2 better learning achievement between think pair square and think pair share learning model, (3 student’s motivation, (4 the student’s responses. The research was a quasi-experimental design experiment with post test only control group design. The population of study was all the students in grade X. The sample were as X1 class with the application of Think Pair Square learning model, X3 class with the application of Think Pair Share learning model, and X5 class with the application of Direct Instruction learning model. The data was collected by cognitive and psychomotor tests. The student’s learning achievement were analyzed by the prerequisite test with the results of the three groups at normal distribution and homogenous, and the hypothesis tested by One Way Anova which means there is a significant effect on the application of think pair square, think pair share, and direct instruction learning models. Then it was conducted a further test t-Scheffe with the results there are differences in the learning achievement between think pair square, think pair share, and direct instruction learning models. According to the average result we made a conclusion that Think Pair Square was better learning models with higher student’s learning achievement. The questionnaires results shows that Think Pair Square was very high positive response and very high learning motivation, Think Pair Share was high positive response and very high learning motivation.   Keywords :   Think Pair Square, Think Pair Share, Direct Instruction, learning achievement, learning motivation, and student response.

  17. Statistical mechanics of magnetized pair Fermi gas

    International Nuclear Information System (INIS)

    Daicic, J.; Frankel, N.E.; Kowalenko, V.

    1993-01-01

    Following previous work on the magnetized pair Bose gas this contribution presents the statistical mechanics of the charged relativistic Fermi gas with pair creation in d spatial dimensions. Initially, the gas in no external fields is studied. As a result, expansions for the various thermodynamic functions are obtained in both the μ/m→0 (neutrino) limit, and about the point μ/m =1, where μ is the chemical potential. The thermodynamics of a gas of quantum-number conserving massless fermions is also discussed. Then a complete study of the pair Fermi gas in a homogeneous magnetic field, is presented investigating the behavior of the magnetization over a wide range of field strengths. The inclusion of pairs leads to new results for the net magnetization due to the paramagnetic moment of the spins and the diamagnetic Landau orbits. 20 refs

  18. Hot accretion disks with electron-positron pairs

    International Nuclear Information System (INIS)

    White, T.R.; Lightman, A.P.

    1989-01-01

    The hot thermal accretion disks of the 1970s are studied and consideration is given to the effects of electron-positron pairs, which were originally neglected. It is found that disks cooled by internally produced photons have a critical accretion rate above which equilibrium is not possible in a radial annulus centered around r = 10 GM/c-squared, where M is the mass of the central object. This confirms and extends previous work by Kusunose and Takahara. Above the critical rate, pairs are created more rapidly than they can be destroyed. Below the critical rate, there are two solutions to the disk structure, one with a high pair density and one with a low pair density. Depending on the strength of the viscosity, the critical accretion rate corresponds to a critical luminosity of about 3-10 percent of the Eddington limit. 32 refs

  19. Absorbed dose measurement by using tissue equivalent ionization chamber (pair ionization chamber) in the Yayoi reactor

    International Nuclear Information System (INIS)

    Sasuga, N.; Okamura, K.; Terakado, T.; Mabuchi, Y.; Nakagawa, T.; Sukegawa, Toshio; Aizawa, C.; Saito, I.; Oka, Yoshiaki

    1998-01-01

    Each dose rate of neutron and gamma ray in the thermal column of the Yayoi reactor, in which an epithermal neutron field will be used for the boron neutron capture therapy, was measured by using a tissue equivalent ionization chamber and a graphite chamber. The tissue equivalent ionization chamber has some response to both neutron and gamma ray, but the graphite chamber has a few response to the neutron, so called pair ionization chamber method. The epithermal neutron fluxes of the thermal column were calculated by ANISN (one dimensional neutron-gamma transport code). A measured value for gamma dose rate by the pair ionization chamber agrees relevantly with a calculated result. For neutron dose rate, however, the measured value was too much small in comparison with the calculated result. The discrepancy between the measured value and the calculated result for neutron dose rate is discussed in detail in the report. (M. Suetake)

  20. Improving the clinical correlation of multiple sclerosis black hole volume change by paired-scan analysis.

    Science.gov (United States)

    Tam, Roger C; Traboulsee, Anthony; Riddehough, Andrew; Li, David K B

    2012-01-01

    The change in T 1-hypointense lesion ("black hole") volume is an important marker of pathological progression in multiple sclerosis (MS). Black hole boundaries often have low contrast and are difficult to determine accurately and most (semi-)automated segmentation methods first compute the T 2-hyperintense lesions, which are a superset of the black holes and are typically more distinct, to form a search space for the T 1w lesions. Two main potential sources of measurement noise in longitudinal black hole volume computation are partial volume and variability in the T 2w lesion segmentation. A paired analysis approach is proposed herein that uses registration to equalize partial volume and lesion mask processing to combine T 2w lesion segmentations across time. The scans of 247 MS patients are used to compare a selected black hole computation method with an enhanced version incorporating paired analysis, using rank correlation to a clinical variable (MS functional composite) as the primary outcome measure. The comparison is done at nine different levels of intensity as a previous study suggests that darker black holes may yield stronger correlations. The results demonstrate that paired analysis can strongly improve longitudinal correlation (from -0.148 to -0.303 in this sample) and may produce segmentations that are more sensitive to clinically relevant changes.

  1. Adiabatic pair creation in heavy-ion and laser fields

    International Nuclear Information System (INIS)

    Pickl, P.; Durr, D.

    2008-01-01

    The planned generation of lasers and heavy-ion colliders renews the hope to see electron-positron pair creation in strong classical fields. This old prediction is usually referred to as spontaneous pair creation. We observe that both heavy-ion collisions and pair creation in strong laser fields, are instances of the theory of adiabatic pair creation. We shall present the theory, thereby correcting earlier results. We give the momentum distribution of created pairs in overcritical fields. We discuss carefully the proposed experimental verifications and conclude that pure laser-based experiments are highly questionable. We propose a new experiment, joining laser fields and heavy ions, which may be feasible with present-day technology and which may indeed verify the theoretical prediction of adiabatic pair creation. Our presentation relies on recent rigorous works in mathematical physics. (authors)

  2. Hormonal predictors of women's extra-pair vs. in-pair sexual attraction in natural cycles: Implications for extended sexuality.

    Science.gov (United States)

    Grebe, Nicholas M; Emery Thompson, Melissa; Gangestad, Steven W

    2016-02-01

    In naturally cycling women, Roney and Simmons (2013) examined hormonal correlates of their desire for sexual contact. Estradiol was positively associated, and progesterone negatively associated, with self-reported desire. The current study extended these findings by examining, within a sample of 33 naturally cycling women involved in romantic relationships, hormonal correlates of sexual attraction to or interests in specific targets: women's own primary partner or men other than women's primary partner. Women's sexual interests and hormone (estradiol, progesterone, and testosterone) levels were assessed at two different time points. Whereas estradiol levels were associated with relatively greater extra-pair sexual interests than in-pair sexual interests, progesterone levels were associated with relatively greater in-pair sexual interests. Both hormones specifically predicted in-pair sexual desire, estradiol negatively and progesterone positively. These findings have implications for understanding the function of women's extended sexuality - their sexual proceptivity and receptivity outside the fertile phase, especially during the luteal phase. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Exclusive electroproduction of pion pairs

    International Nuclear Information System (INIS)

    Warkentin, N.; Schaefer, A.; Diehl, M.; Ivanov, D. Yu.

    2007-01-01

    We investigate electroproduction of pion pairs on the nucleon in the framework of QCD factorization for hard exclusive processes. We extend previous analyses by taking the hard-scattering coefficients at next-to-leading order in α s . The dynamics of the produced pion pair is described by two-pion distribution amplitudes, for which we perform a detailed theoretical and phenomenological analysis. In particular, we obtain constraints on these quantities by comparing our results with measurements of angular observables that are sensitive to the interference between two-pion production in the isoscalar and isovector channels. (orig.)

  4. Paired fuzzy sets

    DEFF Research Database (Denmark)

    Rodríguez, J. Tinguaro; Franco de los Ríos, Camilo; Gómez, Daniel

    2015-01-01

    In this paper we want to stress the relevance of paired fuzzy sets, as already proposed in previous works of the authors, as a family of fuzzy sets that offers a unifying view for different models based upon the opposition of two fuzzy sets, simply allowing the existence of different types...

  5. Detecting nonlocal Cooper pair entanglement by optical Bell inequality violation

    Energy Technology Data Exchange (ETDEWEB)

    Nigg, Simon E.; Tiwari, Rakesh P.; Walter, Stefan; Schmidt, Thomas L. [Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel (Switzerland)

    2015-07-01

    Based on the Bardeen Cooper Schrieffer (BCS) theory of superconductivity, the coherent splitting of Cooper pairs from a superconductor to two spatially separated quantum dots has been predicted to generate nonlocal pairs of entangled electrons. In order to test this hypothesis, we propose a scheme to transfer the spin state of a split Cooper pair onto the polarization state of a pair of optical photons. We show that the produced photon pairs can be used to violate a Bell inequality, unambiguously demonstrating the entanglement of the split Cooper pairs.

  6. Detecting nonlocal Cooper pair entanglement by optical Bell inequality violation

    Science.gov (United States)

    Nigg, Simon E.; Tiwari, Rakesh P.; Walter, Stefan; Schmidt, Thomas L.

    2015-03-01

    Based on the Bardeen-Cooper-Schrieffer theory of superconductivity, the coherent splitting of Cooper pairs from a superconductor to two spatially separated quantum dots has been predicted to generate nonlocal pairs of entangled electrons. In order to test this hypothesis, we propose a scheme to transfer the spin state of a split Cooper pair onto the polarization state of a pair of optical photons. We show that the photon pairs produced can be used to violate a Bell inequality, unambiguously demonstrating the entanglement of the split Cooper pairs.

  7. Extensions of Bessel sequences to dual pairs of frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Kim, Hong Oh; Kim, Rae Young

    2013-01-01

    Tight frames in Hilbert spaces have been studied intensively for the past years. In this paper we demonstrate that it often is an advantage to use pairs of dual frames rather than tight frames. We show that in any separable Hilbert space, any pairs of Bessel sequences can be extended to a pair of...... be extended to a pair of dual frames. © 2012 Elsevier Inc. All rights reserved....

  8. Hydration of Watson-Crick base pairs and dehydration of Hoogsteen base pairs inducing structural polymorphism under molecular crowding conditions.

    Science.gov (United States)

    Miyoshi, Daisuke; Nakamura, Kaori; Tateishi-Karimata, Hisae; Ohmichi, Tatsuo; Sugimoto, Naoki

    2009-03-18

    It has been revealed recently that molecular crowding, which is one of the largest differences between in vivo and in vitro conditions, is a critical factor determining the structure, stability, and function of nucleic acids. However, the effects of molecular crowding on Watson-Crick and Hoogsteen base pairs remain unclear. In order to investigate directly and quantitatively the molecular crowding effects on base pair types in nucleic acids, we designed intramolecular parallel- and antiparallel-stranded DNA duplexes consisting of Hoogsteen and Watson-Crick base pairs, respectively, as well as an intramolecular parallel-stranded triplex containing both types of base pairs. Thermodynamic analyses demonstrated that the values of free energy change at 25 degrees C for Hoogsteen base-pair formations decreased from +1.45 +/- 0.15 to +1.09 +/- 0.13 kcal mol(-1), and from -1.89 +/- 0.13 to -2.71 +/- 0.11 kcal mol(-1) in the intramolecular duplex and triplex, respectively, when the concentration of PEG 200 (polyethylene glycol with average molecular weight 200) increased from 0 to 20 wt %. However, corresponding values for Watson-Crick formation in the duplex and triplex increased from -10.2 +/- 0.2 to -8.7 +/- 0.1 kcal mol(-1), and from -10.8 +/- 0.2 to -9.2 +/- 0.2 kcal mol(-1), respectively. Furthermore, it was revealed that the opposing effects of molecular crowding on the Hoogsteen and Watson-Crick base pairs were due to different behaviors of water molecules binding to the DNA strands.

  9. Dynamical nuclear safeguard investigations in nuclear materials using Analytic Pair Values

    International Nuclear Information System (INIS)

    Woo, Tae-Ho

    2011-01-01

    Highlights: → The quantification of the safeguard is performed to enhance operation safety. → Newly introduced maximum pair values with multiplications are obtained by the AHP method. → The dynamical simulations are performed based on the energy policy aspect. → The comparisons using NSP are possible. → A better operation skill is developed. - Abstract: The operation of nuclear power plants (NPPs) has been investigated from the view point of safeguard assessment. The risk of terrorist attack on NPPs is one of the critical points in the secure plant operations. The basic event of the related incidents is quantified by the random sampling using a Monte-Carlo method. The Analytic Hierarchy Process (AHP) is developed leading to the maximum pair values with multiplications which are decided by reactor characteristics. The matrix form analysis is compared with five NPP types of interest. Using a life cycle of 60 years, the range of the secure operation is between 0.020628 and 0.0212986, as relative numbers. This means the highest value in the range of secure power operation is about 1.043 times larger than the lowest one in this study. The consistency has the highest consistent values in the 24th and 54th years, as represented by C.I. (Consistency Index) and C.R. (Consistency Ratio). Finally, a nuclear safeguard protocol (NSP) is successfully constructed for the safe operation.

  10. Pulsar Pair Cascades in Magnetic Fields with Offset Polar Caps

    Science.gov (United States)

    Harding, Alice K.; Muslimov, Alex G.

    2012-01-01

    Neutron star magnetic fields may have polar caps (PC) that are offset from the dipole axis, through field-line sweepback near the light cylinder or non-symmetric currents within the star. The effects of such offsets on electron-positron pair cascades are investigated, using simple models of dipole magnetic fields with small distortions that shift the PCs by different amounts or directions. Using a Monte Carlo pair cascade simulation, we explore the changes in the pair spectrum, multiplicity and energy flux across the PC, as well as the trends in pair flux and pair energy flux with spin-down luminosity, L(sub sd). We also give an estimate of the distribution of heating flux from returning positrons on the PC for different offsets. We find that even modest offsets can produce significant increases in pair multiplicity, especially for pulsars that are near or beyond the pair death lines for centered PCs, primarily because of higher accelerating fields. Pair spectra cover several decades in energy, with the spectral range of millisecond pulsars (MSPs) two orders of magnitude higher than for normal pulsars, and PC offsets allow significant extension of all spectra to lower pair energies. We find that the total PC pair luminosity L(sub pair) is proportional to L(sub sd), with L(sub pair) approximates 10(exp -3) L(sub sd) for normal pulsars and L(sub pair) approximates 10(exp -2) L(sub sd) for MSPs. Remarkably, the total PC heating luminosity for even large offsets increases by less than a factor of two, even though the PC area increases by much larger factors, because most of the heating occurs near the magnetic axis.

  11. On the combination of the Cooper pair and the Ogg pair in the high-Tc oxide superconductor

    International Nuclear Information System (INIS)

    Zhang Liyuan.

    1991-08-01

    In this paper it is argued that the superconductivity of the high-T c oxide superconductor (HTOS) can be explained by the combinating mechanism of the Cooper pair and the Ogg pair. The properties of the superconducting state of the HTOS have been calculated under this mechanism, and the theoretical results are overall consistent with the experiment. (author). 37 refs

  12. Matched-pair comparisons of stereotactic body radiotherapy (SBRT) versus surgery for the treatment of early stage non-small cell lung cancer: A systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Zhang, Binglan; Zhu, Fuping; Ma, Xuelei; Tian, Ye; Cao, Dan; Luo, Songe; Xuan, Yu; Liu, Lei; Wei, Yuquan

    2014-01-01

    Purpose: A population-based matched-pair comparison was performed to compare the efficacy of stereotactic body radiotherapy (SBRT) versus surgery for early-stage non-small cell lung cancer (NSCLC). Methods: All the eligible studies were searched by PubMed, Medline, Embase, and the Cochrane Library. The meta-analysis was performed to compare odds ratios (OR) for overall survival (OS), cancer-specific survival (CSS), disease-free survival (DFS), local control (LC), and distant control (DC). Results: Six studies containing 864 matched patients were included in the meta-analysis. The surgery was associated with a better long-term OS in patients with early-stage NSCLC. The pooled OR and 95% confidence interval (CI) for 1-year, 3-year OS were 1.31 [0.90, 1.91] and 1.82 [1.38, 2.40], respectively. However, the difference in 1-year and 3-year CSS, DFS, LC and DC was not significant. Conclusions: This systematic review found a superior 3-year OS after surgery compared with SBRT, which supports the need to compare both treatments in large prospective, randomized, controlled clinical trials

  13. Pair and single neutron transfer with Borromean 8He

    International Nuclear Information System (INIS)

    Lemasson, A.; Navin, A.; Rejmund, M.; Keeley, N.; Zelevinsky, V.; Bhattacharyya, S.; Shrivastava, A.; Bazin, D.; Beaumel, D.; Blumenfeld, Y.; Chatterjee, A.; Gupta, D.; France, G. de; Jacquot, B.; Labiche, M.; Lemmon, R.; Nanal, V.; Nyberg, J.; Pillay, R.G.; Raabe, R.

    2011-01-01

    Direct observation of the survival of 199 Au residues after 2n transfer in the 8 He+ 197 Au system and the absence of the corresponding 67 Cu in the 8 He+ 65 Cu system at various energies are reported. The measurements of the surprisingly large cross sections for 199 Au, coupled with the integral cross sections for the various Au residues, is used to obtain the first model-independent lower limits on the ratio of 2n to 1n transfer cross sections from 8 He to a heavy target. A comparison of the transfer cross sections for 6,8 He on these targets highlights the differences in the interactions of these Borromean nuclei. These measurements for the most neutron-rich nuclei on different targets highlight the need to probe the reaction mechanism with various targets and represent an experimental advance towards understanding specific features of pairing in the dynamics of dilute nuclear systems.

  14. Role of Heparan Sulfate in Cellular Infection of Integrin-Binding Coxsackievirus A9 and Human Parechovirus 1 Isolates.

    Directory of Open Access Journals (Sweden)

    Pirjo Merilahti

    Full Text Available Heparan sulfate/heparin class of proteoglycans (HSPG have been shown to function in cellular attachment and infection of numerous viruses including picornaviruses. Coxsackievirus A9 (CV-A9 and human parechovirus 1 (HPeV-1 are integrin-binding members in the family Picornaviridae. CV-A9 Griggs and HPeV-1 Harris (prototype strains have been reported not to bind to heparin, but it was recently shown that some CV-A9 isolates interact with heparin in vitro via VP1 protein with a specific T132R/K mutation. We found that the infectivity of both CV-A9 Griggs and HPeV-1 Harris was reduced by sodium chlorate and heparinase suggestive of HSPG interactions. We analyzed the T132 site in fifty-four (54 CV-A9 clinical isolates and found that only one of them possessed T132/R mutation while the other nine (9 had T132K. We then treated CV-A9 Griggs and HPeV-1 Harris and eight CV-A9 and six HPeV-1 clinical isolates with heparin and protamine. Although infectivity of Griggs strain was slightly reduced (by 25%, heparin treatment did not affect the infectivity of the CV-A9 isolates that do not possess the T132R/K mutation, which is in line with the previous findings. Some of the HPeV-1 isolates were also affected by heparin treatment, which suggested that there may be a specific heparin binding site in HPeV-1. In contrast, protamine (a specific inhibitor of heparin completely inhibited the infection of both prototypes and clinical CV-A9 and HPeV-1 isolates. We conclude that T132R/K mutation has a role in heparin binding of CV-A9, but we also show data, which suggest that there are other HSPG binding sites in CV-A9. In all, we suggest that HSPGs play a general role in both CV-A9 and HPeV-1 infections.

  15. Variation in adverse drug reactions listed in product information for antidepressants and anticonvulsants, between the USA and Europe: a comparison review of paired regulatory documents.

    Science.gov (United States)

    Cornelius, Victoria R; Liu, Kun; Peacock, Janet; Sauzet, Odile

    2016-03-20

    To compare consistency of adverse drug reaction (ADR) data in publicly available product information documents for brand drugs, between the USA and Europe. To assess the usefulness of information for prescribers and patients. A comparison review of product information documents for antidepressants and anticonvulsants concurrently marketed by the same pharmaceutical company in the USA and Europe. For each drug, data were extracted from the US Product Inserts and the European Summary of Product Characteristics documents between 09/2013 and 01/2015. Individuals contributing ADR information to product information documents. All ADRs reported in product information sections 5 and 6 (USA), and 4·4 and 4·8 (Europe). Twelve brand drugs--24 paired documents--were included. On average, there were 77 more ADRs reported in the USA compared with in the European product information document, with a median number of 201 ADRs (range: 65-425) and 114 (range: 56-265), respectively. More product information documents in the USA reported information on the source of evidence (10 vs 5) and risk (9 vs 5) for greater than 80% of ADRs included in the document. There was negligible information included regarding duration, severity, reversibility or recurrence of ADRs. On average, only 29% of ADR terms were reported in both paired documents. Product information documents contained a large number of ADRs, but lacked contextual data and information important to patients and prescribers, such as duration, severity and reversibility. The ADR profile was found to be inconsistently reported between the USA and Europe, for the same drug. Identifying, selecting, summarising and presenting multidimensional harm data should be underpinned by practical evidence-based guidelines. In order for prescribers to provide considered risk-benefit advice across competing drug therapies to patients, they need access to comprehensible and reliable ADR information. Published by the BMJ Publishing Group Limited

  16. Finding faults: analogical comparison supports spatial concept learning in geoscience.

    Science.gov (United States)

    Jee, Benjamin D; Uttal, David H; Gentner, Dedre; Manduca, Cathy; Shipley, Thomas F; Sageman, Bradley

    2013-05-01

    A central issue in education is how to support the spatial thinking involved in learning science, technology, engineering, and mathematics (STEM). We investigated whether and how the cognitive process of analogical comparison supports learning of a basic spatial concept in geoscience, fault. Because of the high variability in the appearance of faults, it may be difficult for students to learn the category-relevant spatial structure. There is abundant evidence that comparing analogous examples can help students gain insight into important category-defining features (Gentner in Cogn Sci 34(5):752-775, 2010). Further, comparing high-similarity pairs can be especially effective at revealing key differences (Sagi et al. 2012). Across three experiments, we tested whether comparison of visually similar contrasting examples would help students learn the fault concept. Our main findings were that participants performed better at identifying faults when they (1) compared contrasting (fault/no fault) cases versus viewing each case separately (Experiment 1), (2) compared similar as opposed to dissimilar contrasting cases early in learning (Experiment 2), and (3) viewed a contrasting pair of schematic block diagrams as opposed to a single block diagram of a fault as part of an instructional text (Experiment 3). These results suggest that comparison of visually similar contrasting cases helped distinguish category-relevant from category-irrelevant features for participants. When such comparisons occurred early in learning, participants were more likely to form an accurate conceptual representation. Thus, analogical comparison of images may provide one powerful way to enhance spatial learning in geoscience and other STEM disciplines.

  17. Role of pn-pairs in nuclear structure

    International Nuclear Information System (INIS)

    Nie, G.K.

    2003-01-01

    An α-cluster model of nuclear structure based on power of proton + neutron (pn)-pairs to bind themselves to α-clusters is proposed. The α-cluster is taken as the perfect condition of coupling of 2 pn- pairs, reminding complete electron shell in atomic physics. Pn-pairs create 2 other types of coupling of considerably less power between pn-pairs of nearby α-clusters ε α c and between pn-pair not bound into α-cluster with pn-pairs of nearby cluster ε pn c . Last two types of coupling are called covalent because of reminding similar electron coupling in chemistry. According the model nucleus is a liquid drop consisting of molecules, which are α-clusters, tied by covalent coupling with those ones which are in close vicinity. Then in case of even-even nuclei spin of the nucleus has to be zero I=0 + as sum of spinless particles. In case of nucleus has some nucleons (i) in intermolecular space, I=Σj i ; with taking into account that there is coupling of p and n in pn-pair. Therefore for 6 Li (1=0)I=2·1/2=1 + . The values ε α c , ε pn c and binding energy of the pn-pair itself ε pn have been estimated from analysis of binding energy of nuclei 6 Li, 10 B and 12 C. With the values the binding energy of the other nuclei with N=Z up to 58 Cu have been described with difference between experimental values and model ones in average less than 0.4 MeV. The structure reveals some regular forms, in which every cluster has reduced amount of covalent coupling, 3 or 4, and free pn-pair has 6 covalent coupling with 3 nearby clusters pn-pairs. Then the magic numbers are supposed to be the matter of geometry, when total amount of covalent couplings is optimal (minimal for the amount of clusters), α- clusters are placed in the same fixed distant from center of mass. It means that protons of the clusters can be considered as belonging to one shell. In the cluster model single particle effects have to be considered as single particle binding in one of the surface

  18. To pair or not to pair: Sources of social variability with white-faced saki monkeys (Pithecia pithecia) as a case study.

    Science.gov (United States)

    Thompson, Cynthia L

    2016-05-01

    Intraspecific variability in social systems is gaining increased recognition in primatology. Many primate species display variability in pair-living social organizations through incorporating extra adults into the group. While numerous models exist to explain primate pair-living, our tools to assess how and why variation in this trait occurs are currently limited. Here I outline an approach which: (i) utilizes conceptual models to identify the selective forces driving pair-living; (ii) outlines novel possible causes for variability in social organization; and (iii) conducts a holistic species-level analysis of social behavior to determine the factors contributing to variation in pair-living. A case study on white-faced sakis (Pithecia pithecia) is used to exemplify this approach. This species lives in either male-female pairs or groups incorporating "extra" adult males and/or females. Various conceptual models of pair-living suggest that high same-sex aggression toward extra-group individuals is a key component of the white-faced saki social system. Variable pair-living in white-faced sakis likely represents alternative strategies to achieve competency in this competition, in which animals experience conflicting selection pressures between achieving successful group defense and maintaining sole reproductive access to mates. Additionally, independent decisions by individuals may generate social variation by preventing other animals from adopting a social organization that maximizes fitness. White-faced saki inter-individual relationships and demographic patterns also lend conciliatory support to this conclusion. By utilizing both model-level and species-level approaches, with a consideration for potential sources of variation, researchers can gain insight into the factors generating variation in pair-living social organizations. © 2014 The Authors. American Journal of Primatology published by Wiley Periodicals, Inc.

  19. CsI Calorimeter for a Compton-Pair Telescope

    Science.gov (United States)

    Grove, Eric J.

    We propose to build and test a hodoscopic CsI(Tl) scintillating-crystal calorimeter for a medium-energy γ-ray Compton and pair telescope. The design and technical approach for this calorimeter relies deeply on heritage from the Fermi LAT CsI Calorimeter, but it dramatically improves the low-energy performance of that design by reading out the scintillation light with silicon photomultipliers (SiPMs), making the technology developed for Fermi applicable in the Compton regime. While such a hodoscopic calorimeter is useful for an entire class of medium-energy γ-ray telescope designs, we propose to build it explicitly to support beam tests and balloon flight of the Proto-ComPair telescope, the development and construction of which was funded in a four-year APRA program beginning in 2015 ("ComPair: Steps to a Medium Energy γ-ray Mission" with PI J. McEnery of GSFC). That award did not include funding for its CsI calorimeter subsystem, and this proposal is intended to cover that gap. ComPair is a MIDEX-class instrument concept to perform a high-sensitivity survey of the γ-ray sky from 0.5 MeV to 500 MeV. ComPair is designed to provide a dramatic increase in sensitivity relative to previous instruments in this energy range (predominantly INTEGRAL/SPI and Compton COMPTEL), with the same transformative sensitivity increase - and corresponding scientific return- that the Fermi Large Area Telescope provided relative to Compton EGRET. To enable transformative science over a broad range of MeV energies and with a wide field of view, ComPair is a combined Compton telescope and pair telescope employing a silicon-strip tracker (for Compton scattering and pair conversion and tracking) and a solid-state CdZnTe calorimeter (for Compton absorption) and CsI calorimeter (for pair calorimetry), surrounded by a plastic scintillator anti-coincidence detector. Under the current proposal, we will complete the detailed design, assembly, and test of the CsI calorimeter for the risk

  20. Exploring Pair Programming Benefits for MIS Majors

    Science.gov (United States)

    Dongo, Tendai; Reed, April H.; O'Hara, Margaret

    2016-01-01

    Pair programming is a collaborative programming practice that places participants in dyads, working in tandem at one computer to complete programming assignments. Pair programming studies with Computer Science (CS) and Software Engineering (SE) majors have identified benefits such as technical productivity, program/design quality, academic…

  1. Morpholino spin-labeling for base-pair sequencing of a 3'-terminal RNA stem by proton homonuclear Overhauser enhancements: yeast ribosomal 5S RNA

    International Nuclear Information System (INIS)

    Lee, K.M.; Marshall, A.G.

    1987-01-01

    Base-pair sequences for 5S and 5.8S RNAs are not readily extracted from proton homonuclear nuclear Overhauser enhancement (NOE) connectivity experiments alone, due to extensive peak overlap in the downfield (11-15 ppm) proton NMR spectrum. In this paper, we introduce a new method for base-pair proton peak assignment for ribosomal RNAs, based upon the distance-dependent broadening of the resonances of base-pair protons spatially proximal to a paramagnetic group. Introduction of a nitroxide spin-label covalently attached to the 3'-terminal ribose provides an unequivocal starting point for base-pair hydrogen-bond proton NMR assignment. Subsequent NOE connectivities then establish the base-pair sequence for the terminal stem of a 5S RNA. Periodate oxidation of yeast 5S RNA, followed by reaction with 4-amino-2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO-NH2) and sodium borohydride reduction, produces yeast 5S RNA specifically labeled with a paramagnetic nitroxide group at the 3'-terminal ribose. Comparison of the 500-MHz 1H NMR spectra of native and 3'-terminal spin-labeled yeast 5S RNA serves to identify the terminal base pair (G1 . C120) and its adjacent base pair (G2 . U119) on the basis of their proximity to the 3'-terminal spin-label. From that starting point, we have then identified (G . C, A . U, or G . U) and sequenced eight of the nine base pairs in the terminal helix via primary and secondary NOE's

  2. Statistical deprojection of galaxy pairs

    Science.gov (United States)

    Nottale, Laurent; Chamaraux, Pierre

    2018-06-01

    Aims: The purpose of the present paper is to provide methods of statistical analysis of the physical properties of galaxy pairs. We perform this study to apply it later to catalogs of isolated pairs of galaxies, especially two new catalogs we recently constructed that contain ≈1000 and ≈13 000 pairs, respectively. We are particularly interested by the dynamics of those pairs, including the determination of their masses. Methods: We could not compute the dynamical parameters directly since the necessary data are incomplete. Indeed, we only have at our disposal one component of the intervelocity between the members, namely along the line of sight, and two components of their interdistance, i.e., the projection on the sky-plane. Moreover, we know only one point of each galaxy orbit. Hence we need statistical methods to find the probability distribution of 3D interdistances and 3D intervelocities from their projections; we designed those methods under the term deprojection. Results: We proceed in two steps to determine and use the deprojection methods. First we derive the probability distributions expected for the various relevant projected quantities, namely intervelocity vz, interdistance rp, their ratio, and the product rp v_z^2, which is involved in mass determination. In a second step, we propose various methods of deprojection of those parameters based on the previous analysis. We start from a histogram of the projected data and we apply inversion formulae to obtain the deprojected distributions; lastly, we test the methods by numerical simulations, which also allow us to determine the uncertainties involved.

  3. Analysis of Food Pairing in Regional Cuisines of India

    Science.gov (United States)

    Bagler, Ganesh

    2015-01-01

    Any national cuisine is a sum total of its variety of regional cuisines, which are the cultural and historical identifiers of their respective regions. India is home to a number of regional cuisines that showcase its culinary diversity. Here, we study recipes from eight different regional cuisines of India spanning various geographies and climates. We investigate the phenomenon of food pairing which examines compatibility of two ingredients in a recipe in terms of their shared flavor compounds. Food pairing was enumerated at the level of cuisine, recipes as well as ingredient pairs by quantifying flavor sharing between pairs of ingredients. Our results indicate that each regional cuisine follows negative food pairing pattern; more the extent of flavor sharing between two ingredients, lesser their co-occurrence in that cuisine. We find that frequency of ingredient usage is central in rendering the characteristic food pairing in each of these cuisines. Spice and dairy emerged as the most significant ingredient classes responsible for the biased pattern of food pairing. Interestingly while individual spices contribute to negative food pairing, dairy products on the other hand tend to deviate food pairing towards positive side. Our data analytical study highlighting statistical properties of the regional cuisines, brings out their culinary fingerprints that could be used to design algorithms for generating novel recipes and recipe recommender systems. It forms a basis for exploring possible causal connection between diet and health as well as prospection of therapeutic molecules from food ingredients. Our study also provides insights as to how big data can change the way we look at food. PMID:26430895

  4. Analysis of Food Pairing in Regional Cuisines of India.

    Science.gov (United States)

    Jain, Anupam; N K, Rakhi; Bagler, Ganesh

    2015-01-01

    Any national cuisine is a sum total of its variety of regional cuisines, which are the cultural and historical identifiers of their respective regions. India is home to a number of regional cuisines that showcase its culinary diversity. Here, we study recipes from eight different regional cuisines of India spanning various geographies and climates. We investigate the phenomenon of food pairing which examines compatibility of two ingredients in a recipe in terms of their shared flavor compounds. Food pairing was enumerated at the level of cuisine, recipes as well as ingredient pairs by quantifying flavor sharing between pairs of ingredients. Our results indicate that each regional cuisine follows negative food pairing pattern; more the extent of flavor sharing between two ingredients, lesser their co-occurrence in that cuisine. We find that frequency of ingredient usage is central in rendering the characteristic food pairing in each of these cuisines. Spice and dairy emerged as the most significant ingredient classes responsible for the biased pattern of food pairing. Interestingly while individual spices contribute to negative food pairing, dairy products on the other hand tend to deviate food pairing towards positive side. Our data analytical study highlighting statistical properties of the regional cuisines, brings out their culinary fingerprints that could be used to design algorithms for generating novel recipes and recipe recommender systems. It forms a basis for exploring possible causal connection between diet and health as well as prospection of therapeutic molecules from food ingredients. Our study also provides insights as to how big data can change the way we look at food.

  5. Single-flavour and two-flavour pairing in three-flavour quark matter

    International Nuclear Information System (INIS)

    Alford, Mark G; Cowan, Greig A

    2006-01-01

    We study single-flavour quark pairing ('self-pairing') in colour-superconducting phases of quark matter, paying particular attention to the difference between scenarios where all three flavours undergo single-flavour pairing, and scenarios where two flavours pair with each other ('2SC' pairing) and the remaining flavour self-pairs. We perform our calculations in the mean-field approximation using a pointlike four-fermion interaction based on single gluon exchange. We confirm the result from previous weakly-coupled-QCD calculations that when all three flavours self-pair the favoured channel for each is colour-spin-locked (CSL) pseudoisotropic pairing. However, we find that when the up and down quarks undergo 2SC pairing, they induce a colour chemical potential that disfavours the CSL phase. The strange quarks then self-pair in a 'polar' channel that breaks rotational invariance, although the CSL phase may survive in a narrow range of densities

  6. Overdensity of galaxies in the environment of quasar pairs

    Science.gov (United States)

    Sandrinelli, A.; Falomo, R.; Treves, A.; Scarpa, R.; Uslenghi, M.

    2018-03-01

    We report on a study of the galaxy environments of low redshift physical quasars pairs. We selected 20 pairs having projected separation Survey images, we evaluated the galaxy overdensity around these quasars in pairs and then compare it with that of a sample of isolated quasars with same redshift and luminosity. It is found that on average there is a systematic larger overdensity of galaxies around quasars in pairs with respect to that of isolated quasars. This may represent a significant link between nuclear activity and galaxy environment. However, at odds with that, the closest quasar pairs seem to inhabit poorer environments. Implications of present results and perspectives for future work are briefly discussed.

  7. Finding Question-Answer Pairs from Online Forums

    DEFF Research Database (Denmark)

    Cong, Gao; Wang, Long; Lin, Chin-Yew

    2008-01-01

    Online forums contain a huge amount of valuable user generated content. In this paper we address the problem of extracting question-answer pairs from forums. Question-answer pairs extracted from forums can be used to help Question Answering services (e.g. Yahoo! Answers) among other applications...

  8. A New Secure Pairing Protocol using Biometrics

    NARCIS (Netherlands)

    Buhan, I.R.

    2008-01-01

    Secure Pairing enables two devices, which share no prior context with each other, to agree upon a security association that they can use to protect their subsequent communication. Secure pairing offers guarantees of the association partner identity and it should be resistant to eavesdropping or to a

  9. Instantons in lepton pair production

    International Nuclear Information System (INIS)

    Brandenburg, A.; Ringwald, A.; Utermann, A.

    2006-05-01

    We consider QCD instanton-induced contributions to lepton pair production in hadron-hadron collisions. We relate these contributions to those known from deep inelastic scattering and demonstrate that they can be calculated reliably for sufficiently large momentum transfer. We observe that the instanton contribution to the angular distribution of the lepton pairs at finite momentum transfer strongly violates the Lam-Tung relation - a relation between coefficient functions of the angular distribution which is valid within the framework of ordinary perturbation theory. The drastic violation of this relation, as seen in experimental data, might be related to such instanton-induced effects. (Orig.)

  10. Phenomena, dynamics and instabilities of vortex pairs

    International Nuclear Information System (INIS)

    Williamson, C H K; Asselin, D J; Leweke, T; Harris, D M

    2014-01-01

    Our motivation for studying the dynamics of vortex pairs stems initially from an interest in the trailing wake vortices from aircraft and the dynamics of longitudinal vortices close to a vehicle surface. However, our motivation also comes from the fact that vortex–vortex interactions and vortex–wall interactions are fundamental to many turbulent flows. The intent of the paper is to present an overview of some of our recent work concerning the formation and structure of counter-rotating vortex pairs. We are interested in the long-wave and short-wave three-dimensional instabilities that evolve for an isolated vortex pair, but also we would like to know how vortex pairs interact with a wall, including both two-dimensional interactions, and also the influence of the surface on the three-dimensional instabilities. The emphasis of this presentation is on physical mechanisms by which vortices interact with each other and with surfaces, principally from an experimental approach, but also coupled with analytical studies. (paper)

  11. Theoretical study of GC+/GC base pair derivatives

    International Nuclear Information System (INIS)

    Meng Fancui; Wang Huanjie; Xu Weiren; Liu Chengbu

    2005-01-01

    The geometries of R (R=CH 3 , CH 3 O, F, NO 2 ) substituted GC base pair derivatives and their cations have been optimized at B3LYP/6-31G* level and the substituent effects on the neutral and cationic geometric structures and energies have been discussed. The inner reorganization energies of various base pair derivatives and the native GC base pair have been calculated to discuss the substituent effects on the reorganization energy. NBO (natural bond orbital) analysis has been carried out on both the neutral and the cationic systems to investigate the differences of the charge distributions and the electronic structures. The outcomes indicate that 8-CH 3 O-G:C has the greatest reorganization energy and 8-NO 2 -G:C has the least, while the other substituted base pairs have a reorganization energy close to that of G:C. The one charge is mostly localized on guanine part after ionization and as high as 0.95e. The bond distances of N1-N3'andN2-O2' in the cationic base pair derivatives shortened and that of O6-N4' elongated as compared with the corresponding bond distances of the neutral GC base pair derivatives

  12. Two pairs of farnesyl phenolic enantiomers as natural nitric oxide inhibitors from Ganoderma sinense.

    Science.gov (United States)

    Wang, Meng; Wang, Fei; Xu, Feng; Ding, Li-Qin; Zhang, Qian; Li, Hui-Xiang; Zhao, Feng; Wang, Li-Qing; Zhu, Li-Han; Chen, Li-Xia; Qiu, Feng

    2016-07-15

    Four new farnesyl phenolic compounds, ganosinensols A-D (1-4) were isolated from the 95% EtOH extract of the fruiting bodies of Ganoderma sinense. Two pairs of enantiomers, 1/2, and 3/4 were isolated by HPLC using a Daicel Chiralpak IE column. Their structures were elucidated from extensive spectroscopic analyses and comparison with literature data. The absolute configurations of 1-4 were assigned by ECD spectra. All of these isolated compounds showed potent inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages, with IC50 values from 1.15 to 2.26μM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Challenges to the pair bond: neural and hormonal effects of separation and reunion in a monogamous primate

    Directory of Open Access Journals (Sweden)

    Katie Hinde

    2016-11-01

    Full Text Available Social monogamy at its most basic is a group structure in which two adults form a unit and share a territory. However, many socially monogamous pairs display attachment relationships known as pair bonds, in which there is a mutual preference for the partner and distress upon separation. The neural and hormonal basis of this response to separation from the adult pair mate is under-studied. In this project, we examined this response in male titi monkeys (Callicebus cupreus, a socially monogamous New World primate. Males underwent a baseline scan, a short separation (48 hours, a long separation (app. two weeks, a reunion with the female pair mate, and an encounter with a female stranger (with nine males completing all five conditions. Regional cerebral glucose metabolism was measured via positron emission tomography (PET imaging using 18F-fluorodeoxyglucose (FDG co-registered with structural MRI, and region of interest analysis was carried out. In addition, plasma was collected and assayed for cortisol, oxytocin (OT, vasopressin (AVP, glucose, and insulin concentrations. Cerebrospinal fluid (CSF was collected and assayed for OT and AVP. We used generalized estimating equations to examine significant changes from baseline. Short separations were characterized by decreases in FDG uptake, in comparison to baseline, in the lateral septum (LS, ventral pallidum (VP, paraventricular nucleus of the hypothalamus (PVN, periaqueductal gray (PAG, and cerebellum, as well as increases in CSF OT, and plasma cortisol and insulin. Long separations differed from baseline in reduced FDG uptake in the central amygdala (CeA, reduced whole brain FDG uptake, increased CSF OT and increased plasma insulin. The response on encounter with a stranger female depended on whether or not the male had previously reproduced with his pair mate, suggesting that transitions to fatherhood contribute to the neurobiology underlying response to a novel female. Reunion with the partner

  14. Detecting nonlocal Cooper pair entanglement by optical Bell inequality violation

    OpenAIRE

    Nigg, Simon E.; Tiwari, Rakesh P.; Walter, Stefan; Schmidt, Thomas L.

    2014-01-01

    Based on the Bardeen Cooper Schrieffer (BCS) theory of superconductivity, the coherent splitting of Cooper pairs from a superconductor to two spatially separated quantum dots has been predicted to generate nonlocal pairs of entangled electrons. In order to test this hypothesis, we propose a scheme to transfer the spin state of a split Cooper pair onto the polarization state of a pair of optical photons. We show that the produced photon pairs can be used to violate a Bell inequality, unambiguo...

  15. Lax pairs: a novel type of separability

    International Nuclear Information System (INIS)

    Fokas, A S

    2009-01-01

    An attempt is made to place into historical context the fundamental concept of Lax pairs. For economy of presentation, emphasis is placed on the effectiveness of Lax pairs for the analysis of integrable nonlinear evolution PDEs. It is argued that Lax pairs provide a deeper type of separability than the classical separation of variables. Indeed, it is shown that: (a) the solution of the Cauchy problem of evolution equations is based on the derivation of a nonlinear Fourier transform pair, and this is achieved by employing the spectral analysis of one of the two eigenvalue equations forming a Lax pair; thus, although this methodology still follows the reverent philosophy of the classical separation of variables and transform methods, it can be applied to a class of nonlinear PDEs. (b) The solution of initial-boundary-value problems of evolution equations is based on the simultaneous spectral analysis of both equations forming a Lax pair and hence, in a sense, it employs the synthesis instead of the separation of variables; this methodology does not have a direct classical analogue, however, it can be considered as the nonlinearization of a method which combines Green's function classical integral representations with an analogue of the method of images, but which are now formulated in the spectral (Fourier) instead of the physical space. In addition to presenting a general methodology for analysing initial- and initial-boundary-value problems for nonlinear integrable evolution equations in one and two spatial variables, recent progress is reviewed for the derivation and the solution of integrable nonlinear evolution PDEs formulated in higher than two spatial dimensions. (topical review)

  16. Biomolecule Analogues 2-Hydroxypyridine and 2-Pyridone Base Pairing on Ice Nanoparticles.

    Science.gov (United States)

    Rubovič, Peter; Pysanenko, Andriy; Lengyel, Jozef; Nachtigallová, Dana; Fárník, Michal

    2016-07-14

    Ice nanoparticles (H2O)N, N ≈ 450 generated in a molecular beam experiment pick up individual gas phase molecules of 2-hydroxypyridine and 2-pyridone (HP) evaporated in a pickup cell at temperatures between 298 and 343 K. The mass spectra of the doped nanoparticles show evidence for generation of clusters of adsorbed molecules (HP)n up to n = 8. The clusters are ionized either by 70 eV electrons or by two photons at 315 nm (3.94 eV). The two ionization methods yield different spectra, and their comparison provides an insight into the neutral cluster composition, ionization and intracluster ion-molecule reactions, and cluster fragmentation. Quite a few molecules were reported not to coagulate on ice nanoparticles previously. The (HP)n cluster generation on ice nanoparticles represents the first evidence for coagulating of molecules and cluster formation on free ice nanoparticles. For comparison, we investigate the coagulation of HP molecules picked up on large clusters ArN, N ≈ 205, and also (HP)n clusters generated in supersonic expansions with Ar buffer gas. This comparison points to a propensity for the (HP)2 dimer generation on ice nanoparticles. This shows the feasibility of base pairing for model of biological molecules on free ice nanoparticles. This result is important for hypotheses of the biomolecule synthesis on ice grains in the space. We support our findings by theoretical calculations that show, among others, the HP dimer structures on water clusters.

  17. BEC-BCS crossover in a (p+ip)-wave pairing Hamiltonian coupled to bosonic molecular pairs

    International Nuclear Information System (INIS)

    Dunning, Clare; Isaac, Phillip S.; Links, Jon; Zhao, Shao-You

    2011-01-01

    We analyse a (p+ip)-wave pairing BCS Hamiltonian, coupled to a single bosonic degree of freedom representing a molecular condensate, and investigate the nature of the BEC-BCS crossover for this system. For a suitable restriction on the coupling parameters, we show that the model is integrable and we derive the exact solution by the algebraic Bethe ansatz. In this manner we also obtain explicit formulae for correlation functions and compute these for several cases. We find that the crossover between the BEC state and the strong pairing p+ip phase is smooth for this model, with no intermediate quantum phase transition.

  18. Relativistic quasiparticle random phase approximation with a separable pairing force

    International Nuclear Information System (INIS)

    Tian Yuan; Ma Zhongyu; Ring Peter

    2009-01-01

    In our previous work, we introduced a separable pairing force for relativistic Hartree-Bogoliubov calculations. This force was adjusted to reproduce the pairing properties of the Gogny force in nuclear matter. By using the well known techniques of Talmi and Moshinsky it can be expanded in a series of separable terms and converges quickly after a few terms. It was found that the pairing properties can be depicted on almost the same footing as the original pairing interaction, not only in nuclear matter, but also in finite nuclei. In this study, we construct a relativistic quasiparticle random phase approximation (RQRPA) with this separable pairing interaction and calculate the excitation energies of the first excited 2 + states and reduced B(E2; 0 + →2 + ) transition rates for a chain of Sn isotopes in RQRPA. Compared with the results of the full Gogny force, we find that this simple separable pairing interaction can describe the pairing properties of the excited vibrational states as well as the original pairing interaction. (authors)

  19. Pair Housing of Dairy Calves and Age at Pairing: Effects on Weaning Stress, Health, Production and Social Networks.

    Science.gov (United States)

    Bolt, Sarah L; Boyland, Natasha K; Mlynski, David T; James, Richard; Croft, Darren P

    2017-01-01

    The early social environment can influence the health and behaviour of animals, with effects lasting into adulthood. In Europe, around 60% of dairy calves are reared individually during their first eight weeks of life, while others may be housed in pairs or small groups. This study assessed the effects of varying degrees of social contact on weaning stress, health and production during pen rearing, and on the social networks that calves later formed when grouped. Forty female Holstein-Friesian calves were allocated to one of three treatments: individually housed (I, n = 8), pair-housed from day five (P5, n = 8 pairs), and pair-housed from day 28 (P28, n = 8 pairs). From day 48, calves were weaned by gradual reduction of milk over three days, and vocalisations were recorded as a measure of stress for three days before, during and after weaning. Health and production (growth rate and concentrate intakes) were not affected by treatment during the weaning period or over the whole study. Vocalisations were highest post-weaning, and were significantly higher in I calves than pair-reared calves. Furthermore, P28 calves vocalised significantly more than P5 calves. The social network of calves was measured for one month after all calves were grouped in a barn, using association data from spatial proximity loggers. We tested for week-week stability, social differentiation and assortment in the calf network. Additionally, we tested for treatment differences in: coefficient of variation (CV) in association strength, percentage of time spent with ex-penmate (P5 and P28 calves only) and weighted degree centrality (the sum of the strength of an individual's associations). The network was relatively stable from weeks one to four and was significantly differentiated, with individuals assorting based on prior familiarity. P5 calves had significantly higher CV in association strength than I calves in week one (indicating more heterogeneous social associations) but there were no

  20. Analysis of Food Pairing in Regional Cuisines of India.

    Directory of Open Access Journals (Sweden)

    Anupam Jain

    Full Text Available Any national cuisine is a sum total of its variety of regional cuisines, which are the cultural and historical identifiers of their respective regions. India is home to a number of regional cuisines that showcase its culinary diversity. Here, we study recipes from eight different regional cuisines of India spanning various geographies and climates. We investigate the phenomenon of food pairing which examines compatibility of two ingredients in a recipe in terms of their shared flavor compounds. Food pairing was enumerated at the level of cuisine, recipes as well as ingredient pairs by quantifying flavor sharing between pairs of ingredients. Our results indicate that each regional cuisine follows negative food pairing pattern; more the extent of flavor sharing between two ingredients, lesser their co-occurrence in that cuisine. We find that frequency of ingredient usage is central in rendering the characteristic food pairing in each of these cuisines. Spice and dairy emerged as the most significant ingredient classes responsible for the biased pattern of food pairing. Interestingly while individual spices contribute to negative food pairing, dairy products on the other hand tend to deviate food pairing towards positive side. Our data analytical study highlighting statistical properties of the regional cuisines, brings out their culinary fingerprints that could be used to design algorithms for generating novel recipes and recipe recommender systems. It forms a basis for exploring possible causal connection between diet and health as well as prospection of therapeutic molecules from food ingredients. Our study also provides insights as to how big data can change the way we look at food.

  1. Amperean Pairing and the Pseudogap Phase of Cuprate Superconductors

    Science.gov (United States)

    Lee, Patrick A.

    2014-07-01

    The enigmatic pseudogap phase in underdoped cuprate high-Tc superconductors has long been recognized as a central puzzle of the Tc problem. Recent data show that the pseudogap is likely a distinct phase, characterized by a medium range and quasistatic charge ordering. However, the origin of the ordering wave vector and the mechanism of the charge order is unknown. At the same time, earlier data show that precursive superconducting fluctuations are also associated with this phase. We propose that the pseudogap phase is a novel pairing state where electrons on the same side of the Fermi surface are paired, in strong contrast with conventional Bardeen-Cooper-Schrieffer theory which pairs electrons on opposite sides of the Fermi surface. In this state the Cooper pair carries a net momentum and belongs to a general class called pair density wave. The microscopic pairing mechanism comes from a gauge theory formulation of the resonating valence bond (RVB) picture, where spinons traveling in the same direction feel an attractive force in analogy with Ampere's effects in electromagnetism. We call this Amperean pairing. Charge order automatically appears as a subsidiary order parameter even when long-range pair order is destroyed by phase fluctuations. Our theory gives a prediction of the ordering wave vector which is in good agreement with experiment. Furthermore, the quasiparticle spectrum from our model explains many of the unusual features reported in photoemission experiments. The Fermi arc, the unusual way the tip of the arc terminates, and the relation of the spanning vector of the arc tips to the charge ordering wave vector also come out naturally. Finally, we propose an experiment that can directly test the notion of Amperean pairing.

  2. Extending the magnetoelectric efficiency of an MFC/brass/NdFeB energy harvester by coupling a pair of movable magnets

    Science.gov (United States)

    Leung, Chung Ming; Wang, Ya

    2017-10-01

    In this letter, an MFC/brass/NdFeB tip magnet three-phase cantilever beam was coupled with a pair of movable magnets to harness energy from alternating magnetic fields. By coupling with a pair of moveable magnets, both bandwidth and magnetoelectric (ME) voltage coefficient (α\\text{V}) were largely increased by 25% and 87.5%, respectively, in comparison with the same harvester coupled with stationary magnets. Such improvements were attributed to magnetic energy introduced by the moving magnets. Experiments also revealed the boundary positions of external magnets (movable and stationary) where the repulsive magnetic forces jumped to the attractive ones, and the stiffness hardening switched to the softening process. These results provided a wide-band nonlinear approach to efficiently harvest/detect the low-frequency alternating magnetic field energies.

  3. Efficient and accurate local approximations to coupled-electron pair approaches: An attempt to revive the pair natural orbital method.

    Science.gov (United States)

    Neese, Frank; Wennmohs, Frank; Hansen, Andreas

    2009-03-21

    Coupled-electron pair approximations (CEPAs) and coupled-pair functionals (CPFs) have been popular in the 1970s and 1980s and have yielded excellent results for small molecules. Recently, interest in CEPA and CPF methods has been renewed. It has been shown that these methods lead to competitive thermochemical, kinetic, and structural predictions. They greatly surpass second order Moller-Plesset and popular density functional theory based approaches in accuracy and are intermediate in quality between CCSD and CCSD(T) in extended benchmark studies. In this work an efficient production level implementation of the closed shell CEPA and CPF methods is reported that can be applied to medium sized molecules in the range of 50-100 atoms and up to about 2000 basis functions. The internal space is spanned by localized internal orbitals. The external space is greatly compressed through the method of pair natural orbitals (PNOs) that was also introduced by the pioneers of the CEPA approaches. Our implementation also makes extended use of density fitting (or resolution of the identity) techniques in order to speed up the laborious integral transformations. The method is called local pair natural orbital CEPA (LPNO-CEPA) (LPNO-CPF). The implementation is centered around the concepts of electron pairs and matrix operations. Altogether three cutoff parameters are introduced that control the size of the significant pair list, the average number of PNOs per electron pair, and the number of contributing basis functions per PNO. With the conservatively chosen default values of these thresholds, the method recovers about 99.8% of the canonical correlation energy. This translates to absolute deviations from the canonical result of only a few kcal mol(-1). Extended numerical test calculations demonstrate that LPNO-CEPA (LPNO-CPF) has essentially the same accuracy as parent CEPA (CPF) methods for thermochemistry, kinetics, weak interactions, and potential energy surfaces but is up to 500

  4. Electron-positron pair production in Coulomb collisions at ultrarelativistic energies

    International Nuclear Information System (INIS)

    Vane, C.R.; Datz, S.; Dittner, P.F.; Krause, H.F.; Bottcher, C.; Strayer, M.; Schuch, R.; Gao, H.; Hutton, R.

    1993-01-01

    We have measured angular and momentum distributions for electrons and positrons created as pairs in peripheral collisions of 6.4 TeV bare sulfur ions with fixed targets of Al, Pd, and Au. Singly- and doubly-differential cross sections have been determined for 1--17 MeV/c electrons and positrons detected independently and in coincidence as pairs. Integrated yields for pair production are found to vary as the square of the target nuclear charge. Relative angular and momentum differential cross sections are effectively target independent. Probability distributions for the pair total momentum, the positron fraction of the pair momentum, and the pair traverse momentum have been derived from the coincident electron-positron data

  5. Electron Waiting Times of a Cooper Pair Splitter

    Science.gov (United States)

    Walldorf, Nicklas; Padurariu, Ciprian; Jauho, Antti-Pekka; Flindt, Christian

    2018-02-01

    Electron waiting times are an important concept in the analysis of quantum transport in nanoscale conductors. Here we show that the statistics of electron waiting times can be used to characterize Cooper pair splitters that create spatially separated spin-entangled electrons. A short waiting time between electrons tunneling into different leads is associated with the fast emission of a split Cooper pair, while long waiting times are governed by the slow injection of Cooper pairs from a superconductor. Experimentally, the waiting time distributions can be measured using real-time single-electron detectors in the regime of slow tunneling, where conventional current measurements are demanding. Our work is important for understanding the fundamental transport processes in Cooper pair splitters and the predictions may be verified using current technology.

  6. Electron Waiting Times of a Cooper Pair Splitter

    DEFF Research Database (Denmark)

    Walldorf, Nicklas; Padurariu, Ciprian; Jauho, Antti-Pekka

    2018-01-01

    Electron waiting times are an important concept in the analysis of quantum transport in nanoscale conductors. Here we show that the statistics of electron waiting times can be used to characterize Cooper pair splitters that create spatially separated spin-entangled electrons. A short waiting time...... between electrons tunneling into different leads is associated with the fast emission of a split Cooper pair, while long waiting times are governed by the slow injection of Cooper pairs from a superconductor. Experimentally, the waiting time distributions can be measured using real-time single......-electron detectors in the regime of slow tunneling, where conventional current measurements are demanding. Our work is important for understanding the fundamental transport processes in Cooper pair splitters and the predictions may be verified using current technology....

  7. Inhomogeneous ensembles of radical pairs in chemical compasses

    Science.gov (United States)

    Procopio, Maria; Ritz, Thorsten

    2016-11-01

    The biophysical basis for the ability of animals to detect the geomagnetic field and to use it for finding directions remains a mystery of sensory biology. One much debated hypothesis suggests that an ensemble of specialized light-induced radical pair reactions can provide the primary signal for a magnetic compass sensor. The question arises what features of such a radical pair ensemble could be optimized by evolution so as to improve the detection of the direction of weak magnetic fields. Here, we focus on the overlooked aspect of the noise arising from inhomogeneity of copies of biomolecules in a realistic biological environment. Such inhomogeneity leads to variations of the radical pair parameters, thereby deteriorating the signal arising from an ensemble and providing a source of noise. We investigate the effect of variations in hyperfine interactions between different copies of simple radical pairs on the directional response of a compass system. We find that the choice of radical pair parameters greatly influences how strongly the directional response of an ensemble is affected by inhomogeneity.

  8. Electron-positron pair production in inhomogeneous electromagnetic fields

    International Nuclear Information System (INIS)

    Kohlfürst, C.

    2015-01-01

    The process of electron-positron pair production is investigated within the phase-space Wigner formalism. The similarities between atomic ionization and pair production for homogeneous, but time-dependent linearly polarized electric fields are examined mainly in the regime of multiphoton absorption (field-dependent threshold, above-threshold pair production). Characteristic signatures in the particle spectra are identified (effective mass, channel closing). The non-monotonic dependence of the particle yield on the carrier frequency is discussed as well. The investigations are then extended to spatially inhomogeneous electric fields. New effects arising due to the spatial dependence of the effective mass are discussed in terms of a semi-classical interpretation. An increase in the normalized particle yield is found for various field configurations.Pair production in inhomogeneous electric and magnetic fields is also studied. The influence of a time-dependent spatially inhomogeneous magnetic field on the momentum spectrum and the particle yield is investigated. The Lorentz invariants are identified to be crucial in order to understand pair production by strong electric fields in the presence of strong magnetic fields. (author) [de

  9. Comparison of approximate formulas for decision levels and detection limits for paired counting with the exact results

    International Nuclear Information System (INIS)

    Potter, W.E.

    2005-01-01

    The exact probability density function for paired counting can be expressed in terms of modified Bessel functions of integral order when the expected blank count is known. Exact decision levels and detection limits can be computed in a straightforward manner. For many applications perturbing half-integer corrections to Gaussian distributions yields satisfactory results for decision levels. When there is concern about the uncertainty for the expected value of the blank count, a way to bound the errors of both types using confidence intervals for the expected blank count is discussed. (author)

  10. A Golub-Kahan-type reduction method for matrix pairs

    NARCIS (Netherlands)

    Hochstenbach, M.E.; Reichel, L.; Yu, X.

    2015-01-01

    We describe a novel method for reducing a pair of large matrices {A;B} to a pair of small matrices {H;K}. The method is an extension of Golub-Kahan bidiagonalization to matrix pairs, and simplifies to the latter method when B is the identity matrix. Applications to Tikhonov regularization of large

  11. A Golub-Kahan-type reduction method for matrix pairs

    NARCIS (Netherlands)

    Hochstenbach, M.E.; Reichel, L.; Yu, X.

    2015-01-01

    We describe a novel method for reducing a pair of large matrices {A,B} to a pair of small matrices {H,K}. The method is an extension of Golub–Kahan bidiagonalization to matrix pairs, and simplifies to the latter method when B is the identity matrix. Applications to Tikhonov regularization of large

  12. Extra-pair mating and evolution of cooperative neighbourhoods.

    Directory of Open Access Journals (Sweden)

    Sigrunn Eliassen

    Full Text Available A striking but unexplained pattern in biology is the promiscuous mating behaviour in socially monogamous species. Although females commonly solicit extra-pair copulations, the adaptive reason has remained elusive. We use evolutionary modelling of breeding ecology to show that females benefit because extra-pair paternity incentivizes males to shift focus from a single brood towards the entire neighbourhood, as they are likely to have offspring there. Male-male cooperation towards public goods and dear enemy effects of reduced territorial aggression evolve from selfish interests, and lead to safer and more productive neighbourhoods. The mechanism provides adaptive explanations for the common empirical observations that females engage in extra-pair copulations, that neighbours dominate as extra-pair sires, and that extra-pair mating correlates with predation mortality and breeding density. The models predict cooperative behaviours at breeding sites where males cooperate more towards public goods than females. Where maternity certainty makes females care for offspring at home, paternity uncertainty and a potential for offspring in several broods make males invest in communal benefits and public goods. The models further predict that benefits of extra-pair mating affect whole nests or neighbourhoods, and that cuckolding males are often cuckolded themselves. Derived from ecological mechanisms, these new perspectives point towards the evolution of sociality in birds, with relevance also for mammals and primates including humans.

  13. QCD pairing in primordial nuggets

    Science.gov (United States)

    Lugones, G.; Horvath, J. E.

    2003-08-01

    We analyze the problem of boiling and surface evaporation of quark nuggets in the cosmological quark-hadron transition. Recently, it has been shown that QCD pairing modifies the stability properties of strange quark matter. More specifically, strange quark matter in a color-flavor locked state was found to be absolutely stable for a much wider range of the parameters than ordinary unpaired strange quark matter (G. Lugones and J. E. Horvath, Phys. Rev. D, 66, 074017 (2002)). Assuming that primordial quark nuggets are actually formed we analyze the consequences of pairing on the rates of boiling and surface evaporation in order to determine whether they could have survived.

  14. Holographic EPR pairs, wormholes and radiation

    Science.gov (United States)

    Chernicoff, Mariano; Güijosa, Alberto; Pedraza, Juan F.

    2013-10-01

    As evidence for the ER = EPR conjecture, it has recently been observed that the string that is holographically dual to an entangled quark-antiquark pair separating with (asymptotically) uniform acceleration has a wormhole on its worldsheet. We point out that a two-sided horizon and a wormhole actually appear for much more generic quark-antiquark trajectories, which is consistent with the fact that the members of an EPR pair need not be permanently out of causal contact. The feature that determines whether the causal structure of the string worldsheet is trivial or not turns out to be the emission of gluonic radiation by the dual quark and antiquark. In the strongly-coupled gauge theory, it is only when radiation is emitted that one obtains an unambiguous separation of the pair into entangled subsystems, and this is what is reflected on the gravity side by the existence of the worldsheet horizon.

  15. Inflation of the screening length induced by Bjerrum pairs.

    Science.gov (United States)

    Zwanikken, Jos; van Roij, René

    2009-10-21

    Within a modified Poisson-Boltzmann theory we study the effect of Bjerrum pairs on the typical length scale [Formula: see text] over which electric fields are screened in electrolyte solutions, taking into account a simple association-dissociation equilibrium between free ions and Bjerrum pairs. At low densities of Bjerrum pairs, this length scale is well approximated by the Debye length [Formula: see text], with ρ(s) the free-ion density. At high densities of Bjerrum pairs, however, we find [Formula: see text], which is significantly larger than 1/κ due to the enhanced effective permittivity of the electrolyte, caused by the polarization of Bjerrum pairs. We argue that this mechanism may explain the recently observed anomalously large colloid-free zones between an oil-dispersed colloidal crystal and a colloidal monolayer at the oil-water interface.

  16. Imidazopyridine/Pyrrole and hydroxybenzimidazole/pyrrole pairs for DNA minor groove recognition.

    Science.gov (United States)

    Renneberg, Dorte; Dervan, Peter B

    2003-05-14

    The DNA binding properties of fused heterocycles imidazo[4,5-b]pyridine (Ip) and hydroxybenzimidazole (Hz) paired with pyrrole (Py) in eight-ring hairpin polyamides are reported. The recognition profile of Ip/Py and Hz/Py pairs were compared to the five-membered ring pairs Im/Py and Hp/Py on a DNA restriction fragment at four 6-base pair recognition sites which vary at a single position 5'-TGTNTA-3', where N = G, C, T, A. The Ip/Py pair distinguishes G.C from C.G, T.A, and A.T, and the Hz/Py pair distinguishes T.A from A.T, G.C, and C.G, affording a new set of heterocycle pairs to target the four Watson-Crick base pairs in the minor groove of DNA.

  17. Kruskal-Wallis Test in Multiple Comparisons

    OpenAIRE

    Parys, Dariusz

    2009-01-01

    In this paper we show that the Kruskal-Wallis test can be transform to quadratic form among the Mann-Whitney or Kendal τ au concordance measures between pairs of treatments. A multiple comparisons procedure based on patterns of transitive ordering among treatments is implement. We also consider the circularity and non-transitive effects. Statystyka testu Kruskala-Wallisa przedstawiona jest w postaci formy kwadratowej z użyciem statystyki Manna-Whitneya lub miar konkordacji τ au Kendalla. N...

  18. A nucleon-pair and boson coexistent description of nuclei

    Science.gov (United States)

    Dai, Lianrong; Pan, Feng; Draayer, J. P.

    2017-07-01

    We study a mixture of s-bosons and like-nucleon pairs with the standard pairing interaction outside an inert core. Competition between the nucleon-pairs and s-bosons is investigated in this scenario. The robustness of the BCS-BEC coexistence and crossover phenomena are examined through an analysis of pf-shell nuclei with realistic single-particle energies, in which two configurations with Pauli blocking of nucleon-pair orbits due to the formation of the s-bosons is taken into account. When the nucleon-pair orbits are considered to be independent of the s-bosons, the BCS-BEC crossover becomes smooth, with the number of the s-bosons noticeably more than that of the nucleon-pairs near the half-shell point, a feature that is demonstrated in the pf-shell for several values of the standard pairing interaction strength. As a further test of the robustness of the BCS-BEC coexistence and crossover phenomena in nuclei, results are given for values of even-even 102-130Sn with 100Sn taken as a core and valence neutron pairs confined within the 1d 5/2, 0g 7/2, 1d 3/2, 2s 1/2, 1h 11/2 orbits in the nucleon-pair orbit and the s-boson independent approximation. The results indicate that the B(E2) values are reproduced well. Supported by National Natural Science Foundation of China (11375080, 11675071), the U.S. National Science Foundation (OCI-0904874 and ACI-1516338), U. S. Department of Energy (DE-SC0005248), the Southeastern Universities Research Association, the China-U. S. Theory Institute for Physics with Exotic Nuclei (CUSTIPEN) (DE-SC0009971), and the LSU-LNNU joint research program (9961) is acknowledged

  19. Modification of the ρ meson detected by low-mass electron positron pairs in central PbAu collisions at 158A GeV/c

    Science.gov (United States)

    Ceres Collaboration; Adamová, D.; Agakichiev, G.; Antończyk, D.; Appelshäuser, H.; Belaga, V.; Bielcikova, J.; Braun-Munzinger, P.; Busch, O.; Cherlin, A.; Damjanović, S.; Dietel, T.; Dietrich, L.; Drees, A.; Dubitzky, W.; Esumi, S. I.; Filimonov, K.; Fomenko, K.; Fraenkel, Z.; Garabatos, C.; Glässel, P.; Holeczek, J.; Kushpil, V.; Maas, A.; Marín, A.; Milošević, J.; Milov, A.; Miśkowiec, D.; Panebrattsev, Yu.; Petchenova, O.; Petráček, V.; Pfeiffer, A.; Rak, J.; Ravinovich, I.; Rehak, P.; Sako, H.; Schmitz, W.; Sedykh, S.; Shimansky, S.; Stachel, J.; Šumbera, M.; Tilsner, H.; Tserruya, I.; Wessels, J. P.; Wienold, T.; Wurm, J. P.; Xie, W.; Yurevich, S.; Yurevich, V.

    2008-09-01

    We present a measurement of ee pair production in central PbAu collisions at 158A GeV/c. As reported earlier, a significant excess of the ee pair yield over the expectation from hadron decays is observed. The improved mass resolution of the present data set, recorded with the upgraded CERES experiment at the CERN-SPS, allows for a comparison of the data with different theoretical approaches. The data clearly favor a substantial in-medium broadening of the ρ spectral function over a density-dependent shift of the ρ pole mass. The in-medium broadening model implies that baryon induced interactions are the key mechanism to the observed modifications of the ρ meson at SPS energy.

  20. Modification of the ρ meson detected by low-mass electron-positron pairs in central Pbsbnd Au collisions at 158A GeV/c

    Science.gov (United States)

    Adamová, D.; Agakichiev, G.; Antończyk, D.; Appelshäuser, H.; Belaga, V.; Bielcikova, J.; Braun-Munzinger, P.; Busch, O.; Cherlin, A.; Damjanović, S.; Dietel, T.; Dietrich, L.; Drees, A.; Dubitzky, W.; Esumi, S. I.; Filimonov, K.; Fomenko, K.; Fraenkel, Z.; Garabatos, C.; Glässel, P.; Holeczek, J.; Kushpil, V.; Maas, A.; Marín, A.; Milošević, J.; Milov, A.; Miśkowiec, D.; Panebrattsev, Yu.; Petchenova, O.; Petráček, V.; Pfeiffer, A.; Rak, J.; Ravinovich, I.; Rehak, P.; Sako, H.; Schmitz, W.; Sedykh, S.; Shimansky, S.; Stachel, J.; Šumbera, M.; Tilsner, H.; Tserruya, I.; Wessels, J. P.; Wienold, T.; Wurm, J. P.; Xie, W.; Yurevich, S.; Yurevich, V.; Ceres Collaboration

    2008-09-01

    We present a measurement of e+e- pair production in central Pbsbnd Au collisions at 158 A GeV / c. As reported earlier, a significant excess of the e+e- pair yield over the expectation from hadron decays is observed. The improved mass resolution of the present data set, recorded with the upgraded CERES experiment at the CERN-SPS, allows for a comparison of the data with different theoretical approaches. The data clearly favor a substantial in-medium broadening of the ρ spectral function over a density-dependent shift of the ρ pole mass. The in-medium broadening model implies that baryon induced interactions are the key mechanism to the observed modifications of the ρ meson at SPS energy.

  1. Evolution of closely linked gene pairs in vertebrate genomes

    NARCIS (Netherlands)

    Franck, E.; Hulsen, T.; Huynen, M.A.; Jong, de W.W.; Lunsen, N.H.; Madsen, O.

    2008-01-01

    The orientation of closely linked genes in mammalian genomes is not random: there are more head-to-head (h2h) gene pairs than expected. To understand the origin of this enrichment in h2h gene pairs, we have analyzed the phylogenetic distribution of gene pairs separated by less than 600 bp of

  2. Exclusive production of W pairs in CMS

    CERN Document Server

    INSPIRE-00002838

    2014-01-01

    We report the results on the search for exclusive production of $W$ pairs in the LHC with data collected by the Compact Muon Solenoid detector in proton-proton collisions at $\\sqrt{s}$~=~7~TeV. The analysis comprises the two-photon production of a $W$ pairs, ${pp\\to p\\,W^{+}W^{-}\\,p\\to p\\,\

  3. Exclusive production of $W$ pairs in CMS

    OpenAIRE

    Da Silveira, Gustavo Gil; CMS

    2014-01-01

    We report the results on the search for exclusive production of $W$ pairs in the LHC with data collected by the Compact Muon Solenoid detector in proton-proton collisions at $\\sqrt{s}$~=~7~TeV. The analysis comprises the two-photon production of a $W$ pairs, ${pp\\to p\\,W^{+}W^{-}\\,p\\to p\\,\

  4. Phase shifts of the paired wings of butterfly diagrams

    International Nuclear Information System (INIS)

    Li Kejun; Liang Hongfei; Feng Wen

    2010-01-01

    Sunspot groups observed by the Royal Greenwich Observatory/US Air Force/NOAA from 1874 May to 2008 November and the Carte Synoptique solar filaments from 1919 March to 1989 December are used to investigate the relative phase shift of the paired wings of butterfly diagrams of sunspot and filament activities. Latitudinal migration of sunspot groups (or filaments) does asynchronously occur in the northern and southern hemispheres, and there is a relative phase shift between the paired wings of their butterfly diagrams in a cycle, making the paired wings spatially asymmetrical on the solar equator. It is inferred that hemispherical solar activity strength should evolve in a similar way within the paired wings of a butterfly diagram in a cycle, demonstrating the paired wings phenomenon and showing the phase relationship between the northern and southern hemispherical solar activity strengths, as well as a relative phase shift between the paired wings of a butterfly diagram, which should bring about almost the same relative phase shift of hemispheric solar activity strength. (research papers)

  5. Pair formation models for sexually transmitted infections: A primer

    Directory of Open Access Journals (Sweden)

    Mirjam Kretzschmar

    2017-08-01

    Full Text Available For modelling sexually transmitted infections, duration of partnerships can strongly influence the transmission dynamics of the infection. If partnerships are monogamous, pairs of susceptible individuals are protected from becoming infected, while pairs of infected individuals delay onward transmission of the infection as long as they persist. In addition, for curable infections re-infection from an infected partner may occur. Furthermore, interventions based on contact tracing rely on the possibility of identifying and treating partners of infected individuals. To reflect these features in a mathematical model, pair formation models were introduced to mathematical epidemiology in the 1980's. They have since been developed into a widely used tool in modelling sexually transmitted infections and the impact of interventions. Here we give a basic introduction to the concepts of pair formation models for a susceptible-infected-susceptible (SIS epidemic. We review some results and applications of pair formation models mainly in the context of chlamydia infection. Keywords: Pair formation, Mathematical model, Partnership duration, Sexually transmitted infections, Basic reproduction number

  6. Klein tunneling phenomenon with pair creation process

    Science.gov (United States)

    Wu, G. Z.; Zhou, C. T.; Fu, L. B.

    2018-01-01

    In this paper, we study the Klein tunneling phenomenon with electron-positron pair creation process. Pairs can be created from the vacuum by a supercritical single-well potential (for electrons). In the time region, the time-dependent growth pattern of the created pairs can be characterized by four distinct regimes which can be considered as four different statuses of the single well. We find that if positrons penetrate the single well by Klein tunneling in different statuses, the total number of the tunneling positrons will be different. If Klein tunneling begins at the initial stage of the first status i.e. when the sing well is empty, the tunneling process and the total number of tunneling positrons are similar to the traditional Klein tunneling case without considering the pair creation process. As the tunneling begins later, the total tunneling positron number increases. The number will finally settle to an asymptotic value when the tunneling begins later than the settling-down time t s of the single well which has been defined in this paper.

  7. Electromagnetic lepton-pair production in relativistic collisions

    International Nuclear Information System (INIS)

    Albert, C.J.; Ernst, D.J.; Strayer, M.R.; Bottcher, C.

    1991-01-01

    Electromagnetic lepton-pair production in relativistic collisions is studied in an ab initio approach with no free parameters. After a semi-classical approximation to the relative motion of the two incident particles is made, the resulting second-order diagram is calculated using a Monte Carlo technique to evaluate the resulting seven-dimensional integral. We examine the case of electron-positron pair production in π - p collisions at p pi = 17 GeV. We find that a significant fraction of the measured pairs in this reaction are produced via the magnetic spin-flip current of the proton. Approaches, such as the equivalent photon approximation, which neglect this part of the current predict much too small a cross section. This feature is traced to the cuts imposed in taking the experimental data. Lepton-pair production in the scattering of 3 He, 4 He and 4 He, 4 He is proposed as a clean way of experimentally separating the spin-flip and non-flip processes; predictions are made for these systems

  8. Awakened Oscillations in Coupled Consumer-Resource Pairs

    Directory of Open Access Journals (Sweden)

    Almaz Mustafin

    2014-01-01

    Full Text Available The paper concerns two interacting consumer-resource pairs based on chemostat-like equations under the assumption that the dynamics of the resource is considerably slower than that of the consumer. The presence of two different time scales enables to carry out a fairly complete analysis of the problem. This is done by treating consumers and resources in the coupled system as fast-scale and slow-scale variables, respectively, and subsequently considering developments in phase planes of these variables, fast and slow, as if they are independent. When uncoupled, each pair has unique asymptotically stable steady state and no self-sustained oscillatory behavior (although damped oscillations about the equilibrium are admitted. When the consumer-resource pairs are weakly coupled through direct reciprocal inhibition of consumers, the whole system exhibits self-sustained relaxation oscillations with a period that can be significantly longer than intrinsic relaxation time of either pair. It is shown that the model equations adequately describe locally linked consumer-resource systems of quite different nature: living populations under interspecific interference competition and lasers coupled via their cavity losses.

  9. Measurement of the differential cross sections for isolated direct photon pair production in pp¯ collisions at √(s)=1.96 TeV

    International Nuclear Information System (INIS)

    Abazov, V.M.; Abbott, B.; Acharya, B.S.; Adams, M.; Adams, T.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; Anikeev, V.B.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D.V.; Banerjee, S.; Barberis, E.; Baringer, P.

    2013-01-01

    We present measurements of direct photon pair production cross sections using 8.5 fb −1 of data collected with the D0 detector at the Fermilab Tevatron pp ¯ collider. The results are presented as differential distributions of the photon pair invariant mass dσ/dM γγ , pair transverse momentum dσ/dp T γγ , azimuthal angle between the photons dσ/dΔϕ γγ , and polar scattering angle in the Collins–Soper frame dσ/d|cosθ ⁎ |. Measurements are performed for isolated photons with transverse momenta p T γ >18(17) GeV for the leading (next-to-leading) photon in p T , pseudorapidities |η γ | γγ >0.4. We present comparisons with the predictions from Monte Carlo event generators DIPHOX and RESBOS implementing QCD calculations at next-to-leading order, 2γNNLO at next-to-next-to-leading order, and SHERPA using matrix elements with higher-order real emissions matched to parton shower

  10. Magnetic Fluctuations in Pair-Density-Wave Superconductors

    Science.gov (United States)

    Christensen, Morten H.; Jacobsen, Henrik; Maier, Thomas A.; Andersen, Brian M.

    2016-04-01

    Pair-density-wave superconductivity constitutes a novel electronic condensate proposed to be realized in certain unconventional superconductors. Establishing its potential existence is important for our fundamental understanding of superconductivity in correlated materials. Here we compute the dynamical magnetic susceptibility in the presence of a pair-density-wave ordered state and study its fingerprints on the spin-wave spectrum including the neutron resonance. In contrast to the standard case of d -wave superconductivity, we show that the pair-density-wave phase exhibits neither a spin gap nor a magnetic resonance peak, in agreement with a recent neutron scattering experiment on underdoped La1.905 Ba0.095 CuO4 [Z. Xu et al., Phys. Rev. Lett. 113, 177002 (2014)].

  11. Isominkowskian theory of Cooper Pairs in superconductors

    International Nuclear Information System (INIS)

    Animalu, A.O.E.

    1993-01-01

    Via the use of Santilli's isominkowskian space, the author presents a relativistic extension of the author's recent treatment of the Cooper Pair in superconductivity based on the Lie-isotopic lifting of quantum mechanics known as Hadronic Mechanics. The isominkowskian treatment reduces the solution of the eiganvalue problem for the quasiparticle energy spectrum to a geometric problem of specifying the metric of the isominkowskian space inside the pair in various models of ordinary high T c superconductors. The use of an intriguing realization of the metric due to Dirac reduces the dimensionality of the interior space to two yielding a spin mutation from 1/2 to zero inside a Cooper pair in two-band BCS and Hubbard models. 12 refs

  12. e+e--annihilation into baryon-antibaryon pairs

    International Nuclear Information System (INIS)

    Koerner, J.G.; Kuroda, M.

    1976-07-01

    Using GVDM-type form factors we calculate the e + -e - production cross sections for the reactions e + e - → 1 + /2 - anti(1 +- /2), 1 + /2 - anti(3 +- /2), 1 + /2 - anti(5 + /2) and 3 + /2 - anti(3 + /2) including all prominent baryon resonances at energies of present and planned e + -e - storage ring machines. We also evaluate the cross section of charmed baryon pair production. Near their respective thresholds charmed and uncharmed baryon pair production are predicted to constitute comparable fractions of the total hadronic cross section. The calculated cross sections indicate that the interference of direct and 1-photon decay of the PSI-particles into baryon pairs is small. (orig.) [de

  13. Automatic coronary artery calcium scoring in cardiac CT angiography using paired convolutional neural networks.

    Science.gov (United States)

    Wolterink, Jelmer M; Leiner, Tim; de Vos, Bob D; van Hamersvelt, Robbert W; Viergever, Max A; Išgum, Ivana

    2016-12-01

    , were evaluated by a comparison with reference annotations in CCTA and CSCT. In all cases, ensembles of ConvPairs outperformed their individual members. The best performing individual ConvPair detected 72% of lesions in the test set, with on average 0.85 false positive (FP) errors per scan. The best performing ensemble combined all ConvPairs and obtained a sensitivity of 71% at 0.48 FP errors per scan. For this ensemble, agreement with the reference mass score in CSCT was excellent (ICC 0.944 [0.918-0.962]). Aditionally, based on the Agatston score in CCTA, this ensemble assigned 83% of patients to the same cardiovascular risk category as reference CSCT. In conclusion, CAC can be accurately automatically identified and quantified in CCTA using the proposed pattern recognition method. This might obviate the need to acquire a dedicated CSCT scan for CAC scoring, which is regularly acquired prior to a CCTA, and thus reduce the CT radiation dose received by patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Pair production by a superhard photon in a crystal

    International Nuclear Information System (INIS)

    Kalashnikov, N.P.; Kovalev, G.V.; Strikhanov, M.N.

    1980-01-01

    Electron-positron pair production by a hard photon moving almost parallelly to the crystallographic axis or monocrystal plane is considered. Calculation is conducted of the production differential by the energies of pair components and total cross section of pair production in the case when primary photon moved at a small angle THETA 0 m 2 /U [ru

  15. Secondary partitioning isotope effects on solvolytic ion pair intermediates

    International Nuclear Information System (INIS)

    Abbey, K.J.

    1976-01-01

    The thermal decomposition of N-benzhydryl N-nitrosobenzamide (BNB) has been shown to produce an ion pair which either forms ester or reacts with the solvent. In ethanol, the fraction of ester produced, R, was much smaller than R values obtained from solvolysis or from the diphenyldiazomethane (DDM)-benzoic acid reaction, which was suggested to yield the same ion pair as solvolysis. This difference led to the conclusion that the ionic species for the nitrosamide decomposition is a nitrogen-separated ion pair. This study was initiated on the assumption that BNB led to solvolytic ion pairs, but that both the intimate and solvent-separated ion pairs were produced directly from the nitrosamide. The use of α-tritiated BNB for the study of partitioning isotope effects (PIE's) in this system led to activity ratios much lower than expected from other reported work. Results of studies of ''special'' salt effect were not consistent for all situations, but the results do suggest that the assumption that BNB leads to solvolytic ion pairs is probably valid. The investigation of the more stable p-methoxybenzhydryl benzoate system proved to be highly productive. The ester fraction produced, R, responded dramatically to the addition of common-ion as well as ''special'' salts. The functional relationship of R on salt concentration could be explained in terms of Winstein's solvolytic scheme where the intimate ion pair, the solvent-separated ion pair, and the dissociated ion were important. Tritium-labelled compounds were used for PIE studies on 3 different compounds, and three different methods of reaction are proposed

  16. Hole pairing induced by antiferromagnetic spin fluctuations

    International Nuclear Information System (INIS)

    Su, Z.B.; Yu Lu; Dong, J.M.; Tosatti, E.

    1987-08-01

    The effective interaction induced by antiferromagnetic spin fluctuations is considered in the random phase approximation in the context of the recently discovered high T c oxide superconductors. This effective attraction favours a triplet pairing of holes. The implications of such pairing mechanism are discussed in connection with the current experimental observations. (author). 30 refs, 2 figs

  17. Creating a test blueprint for a progress testing program: A paired-comparisons approach.

    Science.gov (United States)

    von Bergmann, HsingChi; Childs, Ruth A

    2018-03-01

    Creating a new testing program requires the development of a test blueprint that will determine how the items on each test form are distributed across possible content areas and practice domains. To achieve validity, categories of a blueprint are typically based on the judgments of content experts. How experts judgments are elicited and combined is important to the quality of resulting test blueprints. Content experts in dentistry participated in a day-long faculty-wide workshop to discuss, refine, and confirm the categories and their relative weights. After reaching agreement on categories and their definitions, experts judged the relative importance between category pairs, registering their judgments anonymously using iClicker, an audience response system. Judgments were combined in two ways: a simple calculation that could be performed during the workshop and a multidimensional scaling of the judgments performed later. Content experts were able to produce a set of relative weights using this approach. The multidimensional scaling yielded a three-dimensional model with the potential to provide deeper insights into the basis of the experts' judgments. The approach developed and demonstrated in this study can be applied across academic disciplines to elicit and combine content experts judgments for the development of test blueprints.

  18. Influence of quadrupole pairing on backbending

    International Nuclear Information System (INIS)

    Faessler, A.; Wakai, M.

    1978-01-01

    The backbending phenomenon is attributed to the Coriolis antipairing and the rotational alignment effects. We can consider both effects simultaneously by applying the cranked Hartree-Fock-Bogoliubov theory to the description of the rotational motion of nuclei. In usual treatments of the backbending, however, only the monopole pairing force is considered and pairing forces of other types are neglected. This may be the main reason for starting of the backbending at too small total angular momentum in theoretical results. (orig.) [de

  19. Top quark pair production in ATLAS

    CERN Document Server

    Moreno Llacer, M; The ATLAS collaboration

    2010-01-01

    Top-quark pairs are expected to be produced at the LHC, even at the lower beam energy and luminosity in the first years of running. Establishing the top-pair signal and measuring the production cross-section are important benchmarks for ATLAS, and will help understand the detector performance for events with high-pT leptons, high jet multiplicity, missing transverse energy. The prospects for early top physics measurements will be shown, with a particular emphasis on the progress achieved with data so far.

  20. Holographic EPR Pairs, Wormholes and Radiation

    OpenAIRE

    Chernicoff, Mariano; Güijosa, Alberto; Pedraza, Juan F.

    2013-01-01

    As evidence for the ER=EPR conjecture, it has recently been observed that the string that is holographically dual to an entangled quark-antiquark pair separating with (asymptotically) uniform acceleration has a wormhole on its worldsheet. We point out that a two-sided horizon and a wormhole actually appear for much more generic quark-antiquark trajectories, which is consistent with the fact that the members of an EPR pair need not be permanently out of causal contact. The feature that determi...

  1. Gluino-pair production at the Tevatron

    International Nuclear Information System (INIS)

    Beenakker, W.; Spira, M.; Zerwas, P.M.

    1995-05-01

    The next-to-leading order QCD corrections to the production of gluino pairs at the Tevatron are presented in this paper. Similar to the production of squark-antisquark pairs, the dependence of the cross section on the renormalization/factorization scale is reduced considerably by including the higher-order corrections. The cross section increases with respect to the lowest-order calculation which, in previous experimental analyses, had been evaluated at the scale of the invariant energy of the partonic subprocesses. (orig.)

  2. Exotic Paired States with Anisotropic Spin-Dependent Fermi Surfaces

    International Nuclear Information System (INIS)

    Feiguin, Adrian E.; Fisher, Matthew P. A.

    2009-01-01

    We propose a model for realizing exotic paired states in cold Fermi gases by using a spin-dependent optical lattice to engineer mismatched Fermi surfaces for each hyperfine species. The BCS phase diagram shows a stable paired superfluid state with coexisting pockets of momentum space with gapless unpaired carriers, similar to the Sarma state in polarized mixtures, but in our case the system is unpolarized. We propose the possible existence of an exotic 'Cooper-pair Bose-metal' phase, which has a gap for single fermion excitations but gapless and uncondensed 'Cooper-pair' excitations residing on a 'Bose surface' in momentum space.

  3. Considerations on Velocities and Accelerations in Higher Pairs Mechanisms

    Directory of Open Access Journals (Sweden)

    Florina-Carmen Ciornei

    2015-12-01

    Full Text Available The paper proposes a method for finding the velocities and accelerations in the pairs from a mechanism with higher pairs in the case when the curvature radii of the curves achieving the higher pair are finite. There are obtained the characteristic equations of the motion in the higher pair for the case that one of the curves has zero curvature radius, condition characteristic to the knife edge follower. The relations are required to justify the difference between the particular cases of knife edge follower and flat face follower. The methodology is exemplified through an actual example.

  4. Pairing from strong repulsion in triangular lattice Hubbard model

    Science.gov (United States)

    Zhang, Shang-Shun; Zhu, Wei; Batista, Cristian D.

    2018-04-01

    We propose a pairing mechanism between holes in the dilute limit of doped frustrated Mott insulators. Hole pairing arises from a hole-hole-magnon three-body bound state. This pairing mechanism has its roots on single-hole kinetic energy frustration, which favors antiferromagnetic (AFM) correlations around the hole. We demonstrate that the AFM polaron (hole-magnon bound state) produced by a single hole propagating on a field-induced polarized background is strong enough to bind a second hole. The effective interaction between these three-body bound states is repulsive, implying that this pairing mechanism is relevant for superconductivity.

  5. {lambda}{lambda} pairing in N{lambda} composite matter

    Energy Technology Data Exchange (ETDEWEB)

    Tanigawa, Tomonori [Japan Society for the Promotion of Science, Tokyo (Japan); Matsuzaki, Masayuki [Japan Atomic Energy Research Inst., Tokyo (Japan); Chiba, Satoshi [Fukuoka Univ. of Education, Dept. of Physics, Munakata, Fukuoka (Japan)

    2002-09-01

    {lambda}{lambda} pairing correlation in binary mixed matter of nucleons and lambdas is studied within the relativistic Hartree-Bogoliubov model. {lambda} hyperons to be paired up are immersed in background nucleons in normal state. A phenomenological {lambda}{lambda} interaction, which is derived relativistically from the Lagrangian of the system, is adopted to the gap equation. It is found that increasing the nucleon density makes the {lambda}{lambda} pairing gap suppressed. This result suggests a mechanism, specific to relativistic models, of its dependence on the nucleon density. (author)

  6. Na Cl ion pair association in water-DMSO mixtures: Effect of ion pair ...

    Indian Academy of Sciences (India)

    The 12-6-1 potential model predicts running coordination numbers closest to experimental data. Keywords. ... value of interaction energy minimum between the Na. + and Cl. − ..... ion pair mostly remains as a CIP, a fair amount of SAIP is also ...

  7. Theoretical analysis of noncanonical base pairing interactions in ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    Noncanonical base pairs in RNA have strong structural and functional implications but are currently not considered ..... Full optimizations of the systems were also carried out using ... of the individual bases in the base pair through the equation.

  8. The coevolution of long-term pair bonds and cooperation.

    Science.gov (United States)

    Song, Z; Feldman, M W

    2013-05-01

    The evolution of social traits may not only depend on but also change the social structure of the population. In particular, the evolution of pairwise cooperation, such as biparental care, depends on the pair-matching distribution of the population, and the latter often emerges as a collective outcome of individual pair-bonding traits, which are also under selection. Here, we develop an analytical model and individual-based simulations to study the coevolution of long-term pair bonds and cooperation in parental care, where partners play a Snowdrift game in each breeding season. We illustrate that long-term pair bonds may coevolve with cooperation when bonding cost is below a threshold. As long-term pair bonds lead to assortative interactions through pair-matching dynamics, they may promote the prevalence of cooperation. In addition to the pay-off matrix of a single game, the evolutionarily stable equilibrium also depends on bonding cost and accidental divorce rate, and it is determined by a form of balancing selection because the benefit from pair-bond maintenance diminishes as the frequency of cooperators increases. Our findings highlight the importance of ecological factors affecting social bonding cost and stability in understanding the coevolution of social behaviour and social structures, which may lead to the diversity of biological social systems. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  9. High Level Rule Modeling Language for Airline Crew Pairing

    Science.gov (United States)

    Mutlu, Erdal; Birbil, Ş. Ilker; Bülbül, Kerem; Yenigün, Hüsnü

    2011-09-01

    The crew pairing problem is an airline optimization problem where a set of least costly pairings (consecutive flights to be flown by a single crew) that covers every flight in a given flight network is sought. A pairing is defined by using a very complex set of feasibility rules imposed by international and national regulatory agencies, and also by the airline itself. The cost of a pairing is also defined by using complicated rules. When an optimization engine generates a sequence of flights from a given flight network, it has to check all these feasibility rules to ensure whether the sequence forms a valid pairing. Likewise, the engine needs to calculate the cost of the pairing by using certain rules. However, the rules used for checking the feasibility and calculating the costs are usually not static. Furthermore, the airline companies carry out what-if-type analyses through testing several alternate scenarios in each planning period. Therefore, embedding the implementation of feasibility checking and cost calculation rules into the source code of the optimization engine is not a practical approach. In this work, a high level language called ARUS is introduced for describing the feasibility and cost calculation rules. A compiler for ARUS is also implemented in this work to generate a dynamic link library to be used by crew pairing optimization engines.

  10. Charged topological black hole pair creation

    International Nuclear Information System (INIS)

    Mann, R.B.

    1998-01-01

    I examine the pair creation of black holes in space-times with a cosmological constant of either sign. I consider cosmological C-metrics and show that the conical singularities in this metric vanish only for three distinct classes of black hole metric, two of which have compact event horizons on each spatial slice. One class is a generalization of the Reissner-Nordstroem (anti-)de Sitter black holes in which the event horizons are the direct product of a null line with a 2-surface with topology of genus g. The other class consists of neutral black holes whose event horizons are the direct product of a null conoid with a circle. In the presence of a domain wall, black hole pairs of all possible types will be pair created for a wide range of mass and charge, including even negative mass black holes. I determine the relevant instantons and Euclidean actions for each case. (orig.)

  11. VLBA Reveals Closest Pair of Supermassive Black Holes

    Science.gov (United States)

    2006-05-01

    Astronomers using the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope have found the closest pair of supermassive black holes ever discovered in the Universe -- a duo of monsters that together are more than 150 million times more massive than the Sun and closer together than the Earth and the bright star Vega. The VLBA The VLBA CREDIT: NRAO/AUI/NSF "These two giant black holes are only about 24 light-years apart, and that's more than 100 times closer than any pair found before," said Cristina Rodriguez, of the University of New Mexico (UNM) and Simon Bolivar University in Venezuela. Black holes are concentrations of mass with gravity so strong that not even light can escape them. The black hole pair is in the center of a galaxy called 0402+379, some 750 million light-years from Earth. Astronomers presume that each of the supermassive black holes was once at the core of a separate galaxy, then the two galaxies collided, leaving the black holes orbiting each other. The black holes orbit each other about once every 150,000 years, the scientists say. "If two black holes like these were to collide, that event would create the type of strong gravitational waves that physicists hope to detect with instruments now under construction," said Gregory Taylor, of UNM. The physicists will need to wait, though: the astronomers calculate that the black holes in 0402+379 won't collide for about a billion billion years. "There are some things that might speed that up a little bit," Taylor remarked. An earlier VLBA study of 0402+379, an elliptical galaxy, showed the pair of radio-wave-emitting objects near its core. Further studies using the VLBA and the Hobby-Eberly Telescope in Texas, revealed that the pair of objects is indeed a pair of supermassive black holes. "We needed the ultra-sharp radio 'vision' of the VLBA, particularly at the high radio frequencies of 22 and 43 GigaHertz, to get the detail needed to show that those objects are a pair of

  12. Quasi spin pairing and the structure of the Lipkin model

    International Nuclear Information System (INIS)

    Cambiaggio, M.C.; Plastino, A.

    1978-01-01

    By introducing the concepts of quasi-spin pairing and quasi-spin seniority, the Lipkin model is extended to a variable number of particles. The properties of quasi-spin pairing are seen to be quite similar to those of ordinary pairing. The quasi-spin seniority allows one to obtain a simple classification of excited multiplets. A 'pairing plus monopole' model is studied in connection with the Hartree-Fock theory. (orig.) [de

  13. Comparisons of mental clocks.

    Science.gov (United States)

    Paivio, A

    1978-02-01

    Subjects in three experiments were presented with pairs of clock times and were required to choose the one in which the hour and minute hand formed the smaller angle. In Experiments 1 and 2, the times were presented digitally, necessitating a transformation into symbolic representations from which the angular size difference could be inferred. The results revealed orderly symbolic distance effects so that comparison reaction time increased as the angular size difference decreased. Moreover, subjects generally reported using imagery to make the judgment, and subjects scoring high on test of imagery ability were faster than those scoring low on such tests. Experiment 3 added a direct perceptual condition in which subjects compared angles between pairs of hands on two drawn (analog) clocks, as well as a mixed condition involving one digital and one analog clock time. The results showed comparable distance effects for all conditions. In addition, reaction time increased from the perceptual, to the mixed, to the pure-digital condition. These results are consistent with predictions from an image-based dual-coding theory.

  14. Monte-Carlo simulations of geminate electron-hole pair dissociation in a molecular heterojunction: a two-step dissociation mechanism

    International Nuclear Information System (INIS)

    Offermans, Ton; Meskers, Stefan C.J.; Janssen, Rene A.J.

    2005-01-01

    The Monte-Carlo simulations are used to investigate the dissociation of a Coulomb correlated charge pair at an idealized interface between an electron accepting and an electron donating molecular material. In the simulations the materials are represented by cubic lattices of sites, with site the energies spread according to Gaussian distributions. The influence of temperature, applied external fields, and the width of the Gaussian densities of states distribution for both the electron and the hole transporting material are investigated. The results show that the dissociation of geminate charge pairs is assisted by disorder and the results can be understood in terms of a two-step model. In the first step, the slow carrier in the most disordered material jumps away from the interface. In the following, second step, the reduced Coulombic attraction allows the faster carrier in the less disordered material to escape from the interface by thermally activated hopping. When the rate for geminate recombination at the interface is very low ( -1 ) the simulations predict a high yield for carrier collection, as observed experimentally. Comparison of the simulated and experimentally observed temperature dependence of the collection efficiency indicates that at low temperature dissociation of the geminate charge pairs may be one of the factors limiting the device performance

  15. Comparison of imagine systems

    International Nuclear Information System (INIS)

    Mitchell, F.

    1997-01-01

    It is of great use to be able to accurately compare different film/screen systems. It allows informed decisions to be made as to the optimal choice of film and screens in regard to technical matters such as speed and resolution. Comparisons of these have not been easy, especially in the face of different terminology and specifications used by different manufacturers. A straight forward method is proposed, which requires only a line pair test tool, and the ability to produce scattergraphs. The relative efficiencies of different film/screen systems, incorporating orthochromatic and monochromatic elements are clearly portrayed. Copyright (1997) Australian Institute of Radiography

  16. Space-Efficient Re-Pair Compression

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Prezza, Nicola

    2017-01-01

    Re-Pair [5] is an effective grammar-based compression scheme achieving strong compression rates in practice. Let n, σ, and d be the text length, alphabet size, and dictionary size of the final grammar, respectively. In their original paper, the authors show how to compute the Re-Pair grammar...... in expected linear time and 5n + 4σ2 + 4d + √n words of working space on top of the text. In this work, we propose two algorithms improving on the space of their original solution. Our model assumes a memory word of [log2 n] bits and a re-writable input text composed by n such words. Our first algorithm runs...

  17. Hybrid TLC-pair meter for the Sphinx Project

    Science.gov (United States)

    Wada, T.; Yamamoto, I.; Takahashi, N.; Misaki, A.

    1985-01-01

    The chief aims in THE SPHINX PROJECT are research of super lepton physics and new detector experiments. At the second phase of THE SPHINX PROJECT, a hybrid TLC-PAIR METER was designed for measuring high energy neutrino sources (E upsilon * TeV), searching high energy muon sources (E mu TeV) and measuring muon group (E mu 1 TeV). The principle of PAIR METER has been already proposed. In this TLC-PAIR METER, electromagnetic shower induced by cosmic ray muons are detected using TL (Thermoluminescence) sheets with position counters.

  18. Hybrid TLC-pair meter for the Sphinx Project

    International Nuclear Information System (INIS)

    Wada, T.; Yamamoto, I.; Takahashi, N.; Misaki, A.

    1985-01-01

    The chief aims in the Sphinx Project are research on super lepton physics and new detector experiments. In the second phase of the Sphinx Project, a hybrid TLC-pair meter was designed for measuring for high energy neutrino sources (E upsilon * TeV), searching high energy muon sources (E mu TeV), and measuring muon groups (E mu 1 TeV). The principle of the pair meter has been already proposed. In this TLC pair meter, electromagnetic showers induced by cosmic ray muons are detected using thermoluminescene sheets with position counters

  19. ON THE POLAR CAP CASCADE PAIR MULTIPLICITY OF YOUNG PULSARS

    Energy Technology Data Exchange (ETDEWEB)

    Timokhin, A. N.; Harding, A. K., E-mail: andrey.timokhin@nasa.gov [Astrophysics Science Division, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2015-09-10

    We study the efficiency of pair production in polar caps of young pulsars under a variety of conditions to estimate the maximum possible multiplicity of pair plasma in pulsar magnetospheres. We develop a semi-analytic model for calculation of cascade multiplicity which allows efficient exploration of the parameter space and corroborate it with direct numerical simulations. Pair creation processes are considered separately from particle acceleration in order to assess different factors affecting cascade efficiency, with acceleration of primary particles described by recent self-consistent non-stationary model of pair cascades. We argue that the most efficient cascades operate in the curvature radiation/synchrotron regime, the maximum multiplicity of pair plasma in pulsar magnetospheres is ∼few × 10{sup 5}. The multiplicity of pair plasma in magnetospheres of young energetic pulsars weakly depends on the strength of the magnetic field and the radius of curvature of magnetic field lines and has a stronger dependence on pulsar inclination angle. This result questions assumptions about very high pair plasma multiplicity in theories of pulsar wind nebulae.

  20. Ponderomotive effects in multiphoton pair production

    Science.gov (United States)

    Kohlfürst, Christian; Alkofer, Reinhard

    2018-02-01

    The Dirac-Heisenberg-Wigner formalism is employed to investigate electron-positron pair production in cylindrically symmetric but otherwise spatially inhomogeneous, oscillating electric fields. The oscillation frequencies are hereby tuned to obtain multiphoton pair production in the nonperturbative threshold regime. An effective mass, as well as a trajectory-based semiclassical analysis, is introduced in order to interpret the numerical results for the distribution functions as well as for the particle yields and spectra. The results, including the asymptotic particle spectra, display clear signatures of ponderomotive forces.

  1. Deformed nuclear state as a quasiparticle-pair

    International Nuclear Information System (INIS)

    Dobaczewski, J.; Skalski, J.

    1988-01-01

    The deformed nuclear states, obtained in terms of the Hartree-Fock plus BCS method with the Skyrme SIII interaction, are approximated by condensates of the low-angular-momentum quasiparticle and particle pairs. The optimal pairs are determined by the variation after truncation method. The influence of the truncation on the deformation energy and the importance of the core-polarization effects are investigated

  2. Dependence of two-proton radioactivity on nuclear pairing models

    Science.gov (United States)

    Oishi, Tomohiro; Kortelainen, Markus; Pastore, Alessandro

    2017-10-01

    Sensitivity of two-proton emitting decay to nuclear pairing correlation is discussed within a time-dependent three-body model. We focus on the 6Be nucleus assuming α +p +p configuration, and its decay process is described as a time evolution of the three-body resonance state. For a proton-proton subsystem, a schematic density-dependent contact (SDDC) pairing model is employed. From the time-dependent calculation, we observed the exponential decay rule of a two-proton emission. It is shown that the density dependence does not play a major role in determining the decay width, which can be controlled only by the asymptotic strength of the pairing interaction. This asymptotic pairing sensitivity can be understood in terms of the dynamics of the wave function driven by the three-body Hamiltonian, by monitoring the time-dependent density distribution. With this simple SDDC pairing model, there remains an impossible trinity problem: it cannot simultaneously reproduce the empirical Q value, decay width, and the nucleon-nucleon scattering length. This problem suggests that a further sophistication of the theoretical pairing model is necessary, utilizing the two-proton radioactivity data as the reference quantities.

  3. Search for Pair Production of Heavy Objects in 4-Jet Events at $\\sqrt{s}=130-136$ GeV

    CERN Document Server

    Adam, W; Agasi, E; Ajinenko, I; Alekseev, G D; Alemany, R; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Apel, W D; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barate, R; Barbi, M S; Barbiellini, Guido; Bardin, Dimitri Yuri; Baroncelli, A; Bärring, O; Barrio, J A; Bartl, Walter; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Belous, K S; Benvenuti, Alberto C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Bricman, C; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Buys, A; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chen, M; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahl-Jensen, Erik; Dahm, J; D'Almagne, B; Dam, M; Damgaard, G; Dauncey, P D; Davenport, Martyn; Da Silva, W; Defoix, C; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Dijkstra, H; Di Ciaccio, Lucia; Di Diodato, A; Djama, F; Dolbeau, J; Dönszelmann, M; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Durand, J D; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fassouliotis, D; Feindt, Michael; Ferrer, A; Fichet, S; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Green, C; Grefrath, A; Gris, P; Grosdidier, G; Grzelak, K; Gumenyuk, S A; Gunnarsson, P; Günther, M; Guy, J; Hahn, F; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Hao, W; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karafasoulis, K; Karlsson, M; Karvelas, E; Katsanevas, S; Katsoufis, E C; Keränen, R; Khokhlov, Yu A; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klapp, O; Klein, H; Klovning, A; Kluit, P M; Köne, B; Kokkinias, P; Koratzinos, M; Korcyl, K; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Lapin, V; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Libby, J; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Maehlum, G; Mahon, J R; Maio, A; Malmgren, T G M; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Masik, J; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Merk, M; Meroni, C; Meyer, S; Meyer, W T; Myagkov, A; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Némécek, S; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Pain, R; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Passeri, A; Pegoraro, M; Peralta, L; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Petrovykh, M; Phillips, H T; Piana, G; Pierre, F; Pimenta, M; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rídky, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Rückstuhl, W; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sahr, O; Sajot, G; Salt, J; Sánchez, J; Sannino, M; Schimmelpfennig, M; Schneider, H; Schwickerath, U; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Serbelloni, L; Shellard, R C; Siccama, I; Siegrist, P; Silvestre, R; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sokolov, A; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stevenson, K; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Chikilev, O G; Thomas, J; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Todorova, S; Toet, D Z; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Weierstall, M; Weilhammer, Peter; Weiser, C; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Woschnagg, K; Yip, K; Yushchenko, O P; Zach, F; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zito, M; Zontar, D; Zucchelli, G C; Zumerle, G

    1996-01-01

    Results are presented of a search for pair production of heavy objects decaying into four hadronic jets, as expected for example from associated or pair production of MSSM Higgs bosons, \\hA ~or \\HH, using a data sample of $5.9\\;$pb$^{-1}$ of $e^+ e^-$ collisions at $\\sqrt{s}=130-136\\;{\\mathrm {GeV}}$ collected with the DELPHI detector at LEP in November 1995. The data and expectations from standard processes agree after four-jet selections. An analysis based on $b$-tagging finds no \\hA ~candidate with high mass. A study optimized to search for \\HH ~events with mass in the $40-50 \\; {\\mathrm{GeV}}/c^2$ range also finds no candidate. Finally a comparison is made with a recent ALEPH analysis which found an excess of four-jet events with high multiplicity and high mass. Such a signal is not observed in the DELPHI data, although a slight excess in the mass region around $105 \\; {\\mathrm{GeV}}/c^2$ is seen.

  4. RNA-PAIRS: RNA probabilistic assignment of imino resonance shifts

    International Nuclear Information System (INIS)

    Bahrami, Arash; Clos, Lawrence J.; Markley, John L.; Butcher, Samuel E.; Eghbalnia, Hamid R.

    2012-01-01

    The significant biological role of RNA has further highlighted the need for improving the accuracy, efficiency and the reach of methods for investigating RNA structure and function. Nuclear magnetic resonance (NMR) spectroscopy is vital to furthering the goals of RNA structural biology because of its distinctive capabilities. However, the dispersion pattern in the NMR spectra of RNA makes automated resonance assignment, a key step in NMR investigation of biomolecules, remarkably challenging. Herein we present RNA Probabilistic Assignment of Imino Resonance Shifts (RNA-PAIRS), a method for the automated assignment of RNA imino resonances with synchronized verification and correction of predicted secondary structure. RNA-PAIRS represents an advance in modeling the assignment paradigm because it seeds the probabilistic network for assignment with experimental NMR data, and predicted RNA secondary structure, simultaneously and from the start. Subsequently, RNA-PAIRS sets in motion a dynamic network that reverberates between predictions and experimental evidence in order to reconcile and rectify resonance assignments and secondary structure information. The procedure is halted when assignments and base-parings are deemed to be most consistent with observed crosspeaks. The current implementation of RNA-PAIRS uses an initial peak list derived from proton-nitrogen heteronuclear multiple quantum correlation ( 1 H– 15 N 2D HMQC) and proton–proton nuclear Overhauser enhancement spectroscopy ( 1 H– 1 H 2D NOESY) experiments. We have evaluated the performance of RNA-PAIRS by using it to analyze NMR datasets from 26 previously studied RNAs, including a 111-nucleotide complex. For moderately sized RNA molecules, and over a range of comparatively complex structural motifs, the average assignment accuracy exceeds 90%, while the average base pair prediction accuracy exceeded 93%. RNA-PAIRS yielded accurate assignments and base pairings consistent with imino resonances for a

  5. RNA-PAIRS: RNA probabilistic assignment of imino resonance shifts

    Energy Technology Data Exchange (ETDEWEB)

    Bahrami, Arash; Clos, Lawrence J.; Markley, John L.; Butcher, Samuel E. [National Magnetic Resonance Facility at Madison (United States); Eghbalnia, Hamid R., E-mail: eghbalhd@uc.edu [University of Cincinnati, Department of Molecular and Cellular Physiology (United States)

    2012-04-15

    The significant biological role of RNA has further highlighted the need for improving the accuracy, efficiency and the reach of methods for investigating RNA structure and function. Nuclear magnetic resonance (NMR) spectroscopy is vital to furthering the goals of RNA structural biology because of its distinctive capabilities. However, the dispersion pattern in the NMR spectra of RNA makes automated resonance assignment, a key step in NMR investigation of biomolecules, remarkably challenging. Herein we present RNA Probabilistic Assignment of Imino Resonance Shifts (RNA-PAIRS), a method for the automated assignment of RNA imino resonances with synchronized verification and correction of predicted secondary structure. RNA-PAIRS represents an advance in modeling the assignment paradigm because it seeds the probabilistic network for assignment with experimental NMR data, and predicted RNA secondary structure, simultaneously and from the start. Subsequently, RNA-PAIRS sets in motion a dynamic network that reverberates between predictions and experimental evidence in order to reconcile and rectify resonance assignments and secondary structure information. The procedure is halted when assignments and base-parings are deemed to be most consistent with observed crosspeaks. The current implementation of RNA-PAIRS uses an initial peak list derived from proton-nitrogen heteronuclear multiple quantum correlation ({sup 1}H-{sup 15}N 2D HMQC) and proton-proton nuclear Overhauser enhancement spectroscopy ({sup 1}H-{sup 1}H 2D NOESY) experiments. We have evaluated the performance of RNA-PAIRS by using it to analyze NMR datasets from 26 previously studied RNAs, including a 111-nucleotide complex. For moderately sized RNA molecules, and over a range of comparatively complex structural motifs, the average assignment accuracy exceeds 90%, while the average base pair prediction accuracy exceeded 93%. RNA-PAIRS yielded accurate assignments and base pairings consistent with imino

  6. Rank error-correcting pairs

    DEFF Research Database (Denmark)

    Martinez Peñas, Umberto; Pellikaan, Ruud

    2017-01-01

    Error-correcting pairs were introduced as a general method of decoding linear codes with respect to the Hamming metric using coordinatewise products of vectors, and are used for many well-known families of codes. In this paper, we define new types of vector products, extending the coordinatewise ...

  7. Quantum private comparison protocol based on the entanglement swapping between χ ^+ state and W-Class state

    Science.gov (United States)

    Xu, Ling; Zhao, Zhiwen

    2017-12-01

    Quantum private comparison (QPC) protocol, including Alice, Bob and the third party Charlie, aims at comparing Alice and Bob's secret inputs correctly without leaking them. Firstly, χ ^+ state and W-Class state are used to conduct the entanglement swapping in this protocol. Either the basis {|φ ^± > ,|ψ ^± >} or the basis {|χ ^± > ,|ω ^± > } is chosen by Alice and Bob based on the predetermined value to measure the particle pairs. And three bits of secret inputs can be compared in this protocol in every comparison time, while most of previous QPC protocols can only compare one or two bits. The qubit efficiency of this protocol is 60% more than others, which are 50% at most. Secondly, if the eavesdropper intends to obtain the secret inputs, it is important and primary to get the measurement results of particle pairs. In this protocol, even if the eavesdropper gets the accurate particle pairs, he cannot get the right measurement results without the right basis. Finally, this protocol is analyzed to be able to defend the secret inputs against various kinds of attack.

  8. Extra-pair parentage and personality in a cooperatively breeding bird

    NARCIS (Netherlands)

    Edwards, Hannah A; Dugdale, Hannah L; Richardson, David S; Komdeur, Jan; Burke, Terry

    Abstract: Why so much variation in extra-pair parentage occurs within and among populations remains unclear. Often the fitness costs and benefits of extra-pair parentage are hypothesised to explain its occurrence; therefore, linking extra-pair parentage with traits such as personality (behavioural

  9. STUDI KOMPARATIF MODEL PEMBELAJARAN THINK PAIR SQUARE DAN THINK PAIR SHARE TERHADAP MOTIVASI DAN HASIL BELAJAR SISWA MAPEL TIK KELAS X SMA N 1 SUKASADA

    OpenAIRE

    Putu Deli Januartini; Ketut Agustini; I Gede Partha Sindu

    2016-01-01

    Abstrak Tujuan penelitian ini untuk mengetahui (1) pengaruh signifikan penggunaan model pembelajaran Think Pair Square dan Think Pair Share terhadap hasil belajar siswa, (2) hasil belajar yang lebih baik antara model pembelajaran Think Pair Square  atau  Think Pair Share, (3) motivasi belajar siswa, (4) respon siswa. Jenis penelitian ini adalah eksperimen semu dengan rancangan Post Test Only Control Group Design. Populasi penelitian ini adalah seluruh siswa kelas X. Sampel dalam penel...

  10. Cooper-pair size and binding energy for unconventional superconducting systems

    Science.gov (United States)

    Dinóla Neto, F.; Neto, Minos A.; Salmon, Octavio D. Rodriguez

    2018-06-01

    The main proposal of this paper is to analyze the size of the Cooper pairs composed by unbalanced mass fermions from different electronic bands along the BCS-BEC crossover and study the binding energy of the pairs. We are considering an interaction between fermions with different masses leading to an inter-band pairing. In addiction to the attractive interaction we have an hybridization term to couple both bands, which in general acts unfavorable for the pairing between the electrons. We get first order phase transitions as the hybridization breaks the Cooper pairs for the s-wave symmetry of the gap amplitude. The results show the dependence of the Cooper-pair size as a function of the hybridization for T = 0 . We also propose the structure of the binding energy of the inter-band system as a function of the two-bands quasi-particle energies.

  11. QCD angular correlations for muon pair production

    International Nuclear Information System (INIS)

    Kajantie, K.; Raitio, R.; Lindfors, J.

    1978-01-01

    Angular distributions of muons are discussed in the framework of a QCD treatment of muon pair production in hadron-hadron collisions. The predicted angular effects are independent of the infrared behavior of QCD. Measuring them will permit one to determine whether the origin of the large transverse momentum of the pair is in the quark transverse momenta or in a constituent-constituent subprocess. (author)

  12. Cellular automaton simulation of counter flow with paired pedestrians

    Directory of Open Access Journals (Sweden)

    Hui Xiong

    2011-12-01

    Full Text Available Knowledge on pedestrian behavior is the basis to build decision support system for crowd evacuation management in emergency. In this paper, the impact of paired walking behavior on pedestrian counter flow in a channel is studied. The pedestrian walking behaviors are simulated by the cellular automaton model and the pedestrians are classified as single right walker, single left walker, paired right walker, and paired left walker. Single walker can move forward, leftward, rightward or stand still. The paired pedestrians are considered as a combined unit similar to the single walker in terms of route choice and they can move to the same direction simultaneously. It is found that flow and velocity decrease with increase of the paired rate in case of stable density. Simulation results reveal the phase transitions in terms of density from free flow to the unstable flow and from the unstable flow to the congestion flow. However, the critical densities of phase transition are unaffected by the channel size.

  13. An Intelligent Model for Pairs Trading Using Genetic Algorithms.

    Science.gov (United States)

    Huang, Chien-Feng; Hsu, Chi-Jen; Chen, Chi-Chung; Chang, Bao Rong; Li, Chen-An

    2015-01-01

    Pairs trading is an important and challenging research area in computational finance, in which pairs of stocks are bought and sold in pair combinations for arbitrage opportunities. Traditional methods that solve this set of problems mostly rely on statistical methods such as regression. In contrast to the statistical approaches, recent advances in computational intelligence (CI) are leading to promising opportunities for solving problems in the financial applications more effectively. In this paper, we present a novel methodology for pairs trading using genetic algorithms (GA). Our results showed that the GA-based models are able to significantly outperform the benchmark and our proposed method is capable of generating robust models to tackle the dynamic characteristics in the financial application studied. Based upon the promising results obtained, we expect this GA-based method to advance the research in computational intelligence for finance and provide an effective solution to pairs trading for investment in practice.

  14. Alpha-transfer reactions and the pairing-vibration model

    International Nuclear Information System (INIS)

    Betts, R.R.

    1977-01-01

    The pairing-vibration model with isospin is extended to include α-transfer reactions. Selection rules and expressions for transition strengths are derived and compared with experimental results for A = 40--66 nuclei. The selection rules are found to be followed quite well in the examples studied. The systematics of ground-state transition strengths are qualitatively quite well reproduced although the quantitative agreement is poor. When the changing nature of the pairing quanta is incorporated using two-particle transfer data the agreement becomes quantitatively good. Evidence is presented for clustering other than that due to pairing in 40 Ca and 44 Ti

  15. QED peripheral mechanism of pair production at colliders

    International Nuclear Information System (INIS)

    Ahmadov, A. I.; Galynskii, M. V.; Bystritskiy, Yu. M.; Kuraev, E. A.; Shatnev, M. G.

    2008-01-01

    Cross sections of the processes of production of neutral pions and pairs of charged fermions and bosons in peripheral interaction of leptons and photons are calculated in the main logarithmic approximation. We investigate the phase volumes and differential cross sections. The differential cross sections of production of a few neutral pions and a few pairs are written down explicitly. Considering the academic problem of summation over a number of pairs for massless particles we reproduce the known results obtained in the 1970s. The possibility of constructing the generator for Monte Carlo modeling of these processes based on these results is discussed.

  16. Importance of interlayer pair tunneling: A variational perspective

    International Nuclear Information System (INIS)

    Medhi, Amal; Basu, Saurabh

    2011-01-01

    We study the effect of interlayer pair tunneling in a bilayer superconductor where each layer is described by a two dimensional t-J model and the two layers are connected by the Josephson pair tunneling term. We study this model using a grand canonical variational Monte Carlo (GVMC) method, for which we develop a new algorithm to perform Monte Carlo simulation of a system with fluctuating particle number. The variational wavefunction is taken to be the product of two Gutzwiller projected d-wave BCS wavefunctions with variable particle densities, one for each layer. We calculate the energy of the above state as a function of the d-wave superconducting gap parameter, Δ. We find that the interlayer pair tunneling energy, E perpendicular shows interesting variation with Δ. E perpendicular tends to enhance the optimal value of Δ, thereby the superconducting pairing. However the magnitude of the tunneling energy is found to be too small to have any appreciable effect on the physical properties. While the result is supported by early experiments and hence may appear known to the community, the current work presents a new approach to the problem and confirms the diminished role of interlayer pair tunneling by directly calculating its contribution to superconducting condensation energy.

  17. Spin-Triplet Pairing Induced by Spin-Singlet Interactions in Noncentrosymmetric Superconductors

    Science.gov (United States)

    Matsuzaki, Tomoaki; Shimahara, Hiroshi

    2017-02-01

    In noncentrosymmetric superconductors, we examine the effect of the difference between the intraband and interband interactions, which becomes more important when the band splitting increases. We define the difference ΔVμ between their coupling constants, i.e., that between the intraband and interband hopping energies of intraband Cooper pairs. Here, the subscript μ of ΔVμ indicates that the interactions scatter the spin-singlet and spin-triplet pairs when μ = 0 and μ = 1,2,3, respectively. It is shown that the strong antisymmetric spin-orbit interaction reverses the target spin parity of the interaction: it converts the spin-singlet and spin-triplet interactions represented by ΔV0 and ΔVμ>0 into effective spin-triplet and spin-singlet pairing interactions, respectively. Hence, for example, triplet pairing can be induced solely by the singlet interaction ΔV0. We name the pairing symmetry of the system after that of the intraband Cooper pair wave function, but with an odd-parity phase factor excluded. The pairing symmetry must then be even, even for the triplet component, and the following results are obtained. When ΔVμ is small, the spin-triplet p-wave interactions induce spin-triplet s-wave and spin-triplet d-wave pairings in the regions where the repulsive singlet s-wave interaction is weak and strong, respectively. When ΔV0 is large, a repulsive interband spin-singlet interaction can stabilize spin-triplet pairing. When the Rashba interaction is adopted for the spin-orbit interaction, the spin-triplet pairing interactions mediated by transverse magnetic fluctuations do not contribute to triplet pairing.

  18. Facial expressions and pair bonds in hylobatids.

    Science.gov (United States)

    Florkiewicz, Brittany; Skollar, Gabriella; Reichard, Ulrich H

    2018-06-06

    Facial expressions are an important component of primate communication that functions to transmit social information and modulate intentions and motivations. Chimpanzees and macaques, for example, produce a variety of facial expressions when communicating with conspecifics. Hylobatids also produce various facial expressions; however, the origin and function of these facial expressions are still largely unclear. It has been suggested that larger facial expression repertoires may have evolved in the context of social complexity, but this link has yet to be tested at a broader empirical basis. The social complexity hypothesis offers a possible explanation for the evolution of complex communicative signals such as facial expressions, because as the complexity of an individual's social environment increases so does the need for communicative signals. We used an intraspecies, pair-focused study design to test the link between facial expressions and sociality within hylobatids, specifically the strength of pair-bonds. The current study compared 206 hr of video and 103 hr of focal animal data for ten hylobatid pairs from three genera (Nomascus, Hoolock, and Hylobates) living at the Gibbon Conservation Center. Using video footage, we explored 5,969 facial expressions along three dimensions: repertoire use, repertoire breadth, and facial expression synchrony [FES]. We then used focal animal data to compare dimensions of facial expressiveness to pair bond strength and behavioral synchrony. Hylobatids in our study overlapped in only half of their facial expressions (50%) with the only other detailed, quantitative study of hylobatid facial expressions, while 27 facial expressions were uniquely observed in our study animals. Taken together, hylobatids have a large facial expression repertoire of at least 80 unique facial expressions. Contrary to our prediction, facial repertoire composition was not significantly correlated with pair bond strength, rates of territorial synchrony

  19. A gp41-based heteroduplex mobility assay provides rapid and accurate assessment of intrasubtype epidemiological linkage in HIV type 1 heterosexual transmission Pairs.

    Science.gov (United States)

    Manigart, Olivier; Boeras, Debrah I; Karita, Etienne; Hawkins, Paulina A; Vwalika, Cheswa; Makombe, Nathan; Mulenga, Joseph; Derdeyn, Cynthia A; Allen, Susan; Hunter, Eric

    2012-12-01

    A critical step in HIV-1 transmission studies is the rapid and accurate identification of epidemiologically linked transmission pairs. To date, this has been accomplished by comparison of polymerase chain reaction (PCR)-amplified nucleotide sequences from potential transmission pairs, which can be cost-prohibitive for use in resource-limited settings. Here we describe a rapid, cost-effective approach to determine transmission linkage based on the heteroduplex mobility assay (HMA), and validate this approach by comparison to nucleotide sequencing. A total of 102 HIV-1-infected Zambian and Rwandan couples, with known linkage, were analyzed by gp41-HMA. A 400-base pair fragment within the envelope gp41 region of the HIV proviral genome was PCR amplified and HMA was applied to both partners' amplicons separately (autologous) and as a mixture (heterologous). If the diversity between gp41 sequences was low (<5%), a homoduplex was observed upon gel electrophoresis and the transmission was characterized as having occurred between partners (linked). If a new heteroduplex formed, within the heterologous migration, the transmission was determined to be unlinked. Initial blind validation of gp-41 HMA demonstrated 90% concordance between HMA and sequencing with 100% concordance in the case of linked transmissions. Following validation, 25 newly infected partners in Kigali and 12 in Lusaka were evaluated prospectively using both HMA and nucleotide sequences. Concordant results were obtained in all but one case (97.3%). The gp41-HMA technique is a reliable and feasible tool to detect linked transmissions in the field. All identified unlinked results should be confirmed by sequence analyses.

  20. Modification of the $\\rho$-meson detected by low-mass electron-positron pairs in central Pb - Au collisions at 158 A GeV/c

    CERN Document Server

    Adamová, D; Appelshäuser, H; Belaga, V; Bielcikova, J; Braun-munziger, P; Busch, O; Cherlin, A; Damjanovic, S; Dietel, T; Dietrich, L; Drees, A; Esumi, S I; Filimonov, K; Fomenko, K; Fraenkel, Zeev; Garabatos, C; Glssel, P; Holeczek, J; Kushpil, V; Ludolphs, a W; Maas, A; Marn, A; Miloevi, J; Milov, A; Mikowiec, D; Panebrattsev, iscs Yu; Petchenova, O; Petrek, V; Pfeiffer, A; Rak, J; Ravinovich, acI; Sako, H; Schmitz, W; Sedykh, S; Shimansky, S; Stachel, J; Sumbera, M; Tilsner, H; Tserruya, Itzhak; Wessels, J P; Wienold, T; Wurm, J P; Xie, W; Yurevich, S; Yurevich, V

    2008-01-01

    We present a measurement of $e^+e^-$ pair production in central Pb-Au collisions at 158$A$ GeV/$c$. As reported earlier, a significant excess of the $e^+e^-$ pair yield over the expectation from hadron decays is observed. The improved mass resolution of the present data set, recorded with the upgraded CERES experiment at the CERN-SPS, allows for a comparison of the data with different theoretical approaches. The data clearly favor a substantial in-medium broadening of the $\\rho$ spectral function over a density-dependent shift of the $\\rho$ pole mass at SPS energy. The in-medium broadening model implies that baryon induced interactions are the key mechanism to in-medium modifications of the $\\rho$-meson in the hot fireball.

  1. Numerical studies of pair creation in counterpropagating laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Ruf, Matthias

    2009-05-27

    Pair creation from vacuum induced by electromagnetic fields is probably one of the most intriguing phenomena in physics. If the fields are sufficiently strong, the QED vacuum become unstable. Due to the remarkable progress in laser technology during recent years an experimental investigation of pair creation by pure laser light is coming into reach. The focus of this thesis is on pair creation in counterpropagating laser beams. The pair creation probability is calculated employing the numerically obtained solutions of the Dirac equation. This numerical ansatz has the capability of calculating the momentum distribution of the created pairs in a single propagation, for pure time dependent field configurations. Furthermore, it allows to take the magnetic component of the laser fields into account, which is usually neglected. The latter strongly affects the creation process at high laser frequency. The involved numerical calculations are rather time consuming, therefore the second project of this thesis was to develop a highly efficient code for solving relativistic quantum mechanical problems. This is accomplished by adopting the split-operator method to the Klein-Gordon equation. Here the possibility arises to use parallel computing. However the corresponding spin-statistics becomes crucial in the case of pair creation, demonstrated in several examples. (orig.)

  2. Numerical studies of pair creation in counterpropagating laser fields

    International Nuclear Information System (INIS)

    Ruf, Matthias

    2009-01-01

    Pair creation from vacuum induced by electromagnetic fields is probably one of the most intriguing phenomena in physics. If the fields are sufficiently strong, the QED vacuum become unstable. Due to the remarkable progress in laser technology during recent years an experimental investigation of pair creation by pure laser light is coming into reach. The focus of this thesis is on pair creation in counterpropagating laser beams. The pair creation probability is calculated employing the numerically obtained solutions of the Dirac equation. This numerical ansatz has the capability of calculating the momentum distribution of the created pairs in a single propagation, for pure time dependent field configurations. Furthermore, it allows to take the magnetic component of the laser fields into account, which is usually neglected. The latter strongly affects the creation process at high laser frequency. The involved numerical calculations are rather time consuming, therefore the second project of this thesis was to develop a highly efficient code for solving relativistic quantum mechanical problems. This is accomplished by adopting the split-operator method to the Klein-Gordon equation. Here the possibility arises to use parallel computing. However the corresponding spin-statistics becomes crucial in the case of pair creation, demonstrated in several examples. (orig.)

  3. Neutrino signal from pair-instability supernovae

    Science.gov (United States)

    Wright, Warren P.; Gilmer, Matthew S.; Fröhlich, Carla; Kneller, James P.

    2017-11-01

    A very massive star with a carbon-oxygen core in the range of 64M ⊙Earth from two, one-dimensional pair-instability supernova simulations which bracket the mass range of stars which explode by this mechanism taking into account the full time and energy dependence of the neutrino emission and the flavor evolution through the outer layers of the star. We calculate the neutrino signals in five different detectors chosen to represent present or near future designs. We find the more massive progenitors explode as pair-instability supernova which can easily be detected in multiple different neutrino detectors at the "standard" supernova distance of 10 kpc producing several events in DUNE, JUNO, and Super-Kamiokande, while the lightest progenitors produce only a handful of events (if any) in the same detectors. The proposed Hyper-Kamiokande detector would detect neutrinos from a large pair-instability supernova as far as ˜50 kpc allowing it to reach the Megallanic Clouds and the several very high mass stars known to exist there.

  4. Nuclear pairing reduction due to rotation and blocking

    International Nuclear Information System (INIS)

    Wu Xi; Zhang Zhenhua; Lei Yi'an; Zeng Jinyan

    2010-01-01

    Nuclear pairing gaps of well-deformed and superdeformed nuclei are investigated using the particle-number conserving (PNC) formalism for the cranked shell model, in which the blocking effects are treated exactly and no spurious states appear. Both the rotational frequency ω-dependence and seniority ν-dependence of the pairing gap Δ-bar are addressed. For the ground-state bands of even-even nuclei, PNC calculations show that in general Δ-bar decreases with increasing ω, but the ω-dependence is much weaker than that calculated by the number-projected Hartree-Fock-Bogolyubov (NHFB) approach. For the multi quasiparticle bands (seniority ν > 2), the pairing gaps keep almost ω-independent. As a function of the seniority ν, the bandhead pairing gaps Δ-bar (ν, ω = 0) decrease slowly with increasing ν. Even for the highest seniority ν bands identified so far, Δ-bar (ν, ω = 0) keep 70% larger than Δ-bar (ν = 0, ω = 0). (authors)

  5. Nuclear pairing reduction due to rotation and blocking

    International Nuclear Information System (INIS)

    Wu, X.; Zhang, Z. H.; Zeng, J. Y.; Lei, Y. A.

    2011-01-01

    Nuclear pairing gaps of normally deformed and superdeformed nuclei are investigated using the particle-number-conserving (PNC) formalism for the cranked shell model, in which the blocking effects are treated exactly. Both rotational frequency ω dependence and seniority (number of unpaired particles) ν dependence of the pairing gap Δ-tilde are investigated. For the ground-state bands of even-even nuclei, PNC calculations show that, in general, Δ-tilde decreases with increasing ω, but the ω dependence is much weaker than that calculated by the number-projected Hartree-Fock-Bogolyubov approach. For the multiquasiparticle bands (seniority ν>2), the pairing gaps stay almost ω independent. As a function of the seniority ν, the bandhead pairing gaps Δ-tilde(ν,ω=0) decrease slowly with increasing ν. Even for the highest seniority ν bands identified so far, Δ-tilde(ν,ω=0) remains greater than 70% of Δ-tilde(ν=0,ω=0).

  6. Strong Neutron Pairing in core+4n Nuclei.

    Science.gov (United States)

    Revel, A; Marqués, F M; Sorlin, O; Aumann, T; Caesar, C; Holl, M; Panin, V; Vandebrouck, M; Wamers, F; Alvarez-Pol, H; Atar, L; Avdeichikov, V; Beceiro-Novo, S; Bemmerer, D; Benlliure, J; Bertulani, C A; Boillos, J M; Boretzky, K; Borge, M J G; Caamaño, M; Casarejos, E; Catford, W N; Cederkäll, J; Chartier, M; Chulkov, L; Cortina-Gil, D; Cravo, E; Crespo, R; Datta Pramanik, U; Díaz Fernández, P; Dillmann, I; Elekes, Z; Enders, J; Ershova, O; Estradé, A; Farinon, F; Fraile, L M; Freer, M; Galaviz, D; Geissel, H; Gernhäuser, R; Golubev, P; Göbel, K; Hagdahl, J; Heftrich, T; Heil, M; Heine, M; Heinz, A; Henriques, A; Ignatov, A; Johansson, H T; Jonson, B; Kahlbow, J; Kalantar-Nayestanaki, N; Kanungo, R; Kelic-Heil, A; Knyazev, A; Kröll, T; Kurz, N; Labiche, M; Langer, C; Le Bleis, T; Lemmon, R; Lindberg, S; Machado, J; Marganiec, J; Movsesyan, A; Nacher, E; Najafi, M; Nilsson, T; Nociforo, C; Paschalis, S; Perea, A; Petri, M; Pietri, S; Plag, R; Reifarth, R; Ribeiro, G; Rigollet, C; Röder, M; Rossi, D; Savran, D; Scheit, H; Simon, H; Syndikus, I; Taylor, J T; Tengblad, O; Thies, R; Togano, Y; Velho, P; Volkov, V; Wagner, A; Weick, H; Wheldon, C; Wilson, G; Winfield, J S; Woods, P; Yakorev, D; Zhukov, M; Zilges, A; Zuber, K

    2018-04-13

    The emission of neutron pairs from the neutron-rich N=12 isotones ^{18}C and ^{20}O has been studied by high-energy nucleon knockout from ^{19}N and ^{21}O secondary beams, populating unbound states of the two isotones up to 15 MeV above their two-neutron emission thresholds. The analysis of triple fragment-n-n correlations shows that the decay ^{19}N(-1p)^{18}C^{*}→^{16}C+n+n is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a ^{14}C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay ^{21}O(-1n)^{20}O^{*}→^{18}O+n+n, attributed to its formation through the knockout of a deeply bound neutron that breaks the ^{16}O core and reduces the number of pairs.

  7. Research of the internal electron-positron pair production

    International Nuclear Information System (INIS)

    Fenyes, Tibor

    1985-01-01

    The phenomenon of internal electron-positron pair production by excited nuclei is briefly reviewed. The advantages of this phenomenon in nuclear structure investigations are pointed. The new Si(Li)-Si(Li) electron spectrometer with superconducting magnetic transporter (SMS) built at ATOMKI, Hungary, was tested for detection of internal electron-positron pair production events. Proton beam of a Van de Graaff accelerator of 5 MV was used to excite the target nuclei of sup(27)Al, sup(42)Ca and sup(19)F. The internal pair production coefficients were measured and compared with the data of literature. The detection efficiency of SMS is calculated to be (37+-7)%. The test proved that the SMS is suitable for nuclear structure investigations producing electron-positron pairs. The SMS of ATOMKI is recently the top instrument all over the world in this field: its detection efficiency, energy resolution and applicability for multipolarity identification are much better than these properties of other detectors. (D.Gy.)

  8. Generating explanations via analogical comparison.

    Science.gov (United States)

    Hoyos, Christian; Gentner, Dedre

    2017-10-01

    Generating explanations can be highly effective in promoting learning in both adults and children. Our interest is in the mechanisms that underlie this effect and in whether and how they operate in early learning. In adult reasoning, explanation may call on many subprocesses-including comparison, counterfactual reasoning, and reasoning by exclusion; but it is unlikely that all these processes are available to young children. We propose that one process that may serve both children and adults is comparison. In this study, we asked whether children would use the results of a comparison experience when asked to explain why a model skyscraper was stable. We focused on a challenging principle-that diagonal cross-bracing lends stability to physical structures (Gentner et al., Cognitive Science, 40, 224-240, 2016). Six-year-olds either received no training or interacted with model skyscrapers in one of three different conditions, designed to vary in their potential to invite and support comparison. In the Single Model condition, children interacted with a single braced model. In the comparison conditions (Low Alignability and High Alignability), children compared braced and unbraced models. Following experience with the models, children were asked to explain why the braced model was stable. They then received two transfer tasks. We found that children who received highly alignable pairs were most likely to (a) produce brace-based explanations and (b) transfer the brace principle to a dissimilar context. This provides evidence that children can benefit from analogical comparison in generating explanations and also suggests limitations on this ability.

  9. Implications of the effective one-component analysis of pair correlations in colloidal fluids with polydispersity

    Science.gov (United States)

    Pond, Mark J.; Errington, Jeffrey R.; Truskett, Thomas M.

    2011-09-01

    Partial pair-correlation functions of colloidal suspensions with continuous polydispersity can be challenging to characterize from optical microscopy or computer simulation data due to inadequate sampling. As a result, it is common to adopt an effective one-component description of the structure that ignores the differences between particle types. Unfortunately, whether this kind of simplified description preserves or averages out information important for understanding the behavior of the fluid depends on the degree of polydispersity and can be difficult to assess, especially when the corresponding multicomponent description of the pair correlations is unavailable for comparison. Here, we present a computer simulation study that examines the implications of adopting an effective one-component structural description of a polydisperse fluid. The square-well model that we investigate mimics key aspects of the experimental behavior of suspended colloids with short-range, polymer-mediated attractions. To characterize the partial pair-correlation functions and thermodynamic excess entropy of this system, we introduce a Monte Carlo sampling strategy appropriate for fluids with a large number of pseudo-components. The data from our simulations at high particle concentrations, as well as exact theoretical results for dilute systems, show how qualitatively different trends between structural order and particle attractions emerge from the multicomponent and effective one-component treatments, even with systems characterized by moderate polydispersity. We examine consequences of these differences for excess-entropy based scalings of shear viscosity, and we discuss how use of the multicomponent treatment reveals similarities between the corresponding dynamic scaling behaviors of attractive colloids and liquid water that the effective one-component analysis does not capture.

  10. Preferred and avoided codon pairs in three domains of life

    Directory of Open Access Journals (Sweden)

    Tenson Tanel

    2008-10-01

    Full Text Available Abstract Background Alternative synonymous codons are not used with equal frequencies. In addition, the contexts of codons – neighboring nucleotides and neighboring codons – can have certain patterns. The codon context can influence both translational accuracy and elongation rates. However, it is not known how strong or conserved the codon context preferences in different organisms are. We analyzed 138 organisms (bacteria, archaea and eukaryotes to find conserved patterns of codon pairs. Results After removing the effects of single codon usage and dipeptide biases we discovered a set of neighboring codons for which avoidances or preferences were conserved in all three domains of life. Such biased codon pairs could be divided into subtypes on the basis of the nucleotide patterns that influence the bias. The most frequently avoided type of codon pair was nnUAnn. We discovered that 95.7% of avoided nnUAnn type patterns contain out-frame UAA or UAG triplets on the sense and/or antisense strand. On average, nnUAnn codon pairs are more frequently avoided in ORFeomes than in genomes. Thus we assume that translational selection plays a major role in the avoidance of these codon pairs. Among the preferred codon pairs, nnGCnn was the major type. Conclusion Translational selection shapes codon pair usage in protein coding sequences by rules that are common to all three domains of life. The most frequently avoided codon pairs contain the patterns nnUAnn, nnGGnn, nnGnnC, nnCGCn, GUCCnn, CUCCnn, nnCnnA or UUCGnn. The most frequently preferred codon pairs contain the patterns nnGCnn, nnCAnn or nnUnCn.

  11. Homologue Pairing in Flies and Mammals: Gene Regulation When Two Are Involved

    Directory of Open Access Journals (Sweden)

    Manasi S. Apte

    2012-01-01

    Full Text Available Chromosome pairing is usually discussed in the context of meiosis. Association of homologues in germ cells enables chromosome segregation and is necessary for fertility. A few organisms, such as flies, also pair their entire genomes in somatic cells. Most others, including mammals, display little homologue pairing outside of the germline. Experimental evidence from both flies and mammals suggests that communication between homologues contributes to normal genome regulation. This paper will contrast the role of pairing in transmitting information between homologues in flies and mammals. In mammals, somatic homologue pairing is tightly regulated, occurring at specific loci and in a developmentally regulated fashion. Inappropriate pairing, or loss of normal pairing, is associated with gene misregulation in some disease states. While homologue pairing in flies is capable of influencing gene expression, the significance of this for normal expression remains unknown. The sex chromosomes pose a particularly interesting situation, as females are able to pair X chromosomes, but males cannot. The contribution of homologue pairing to the biology of the X chromosome will also be discussed.

  12. Silver(I)-Mediated Base Pairs in DNA Sequences Containing 7-Deazaguanine/Cytosine: towards DNA with Entirely Metallated Watson-Crick Base Pairs.

    Science.gov (United States)

    Méndez-Arriaga, José M; Maldonado, Carmen R; Dobado, José A; Galindo, Miguel A

    2018-03-26

    DNA sequences comprising noncanonical 7-deazaguanine ( 7C G) and canonical cytosine (C) are capable of forming Watson-Crick base pairs via hydrogen bonds as well as silver(I)-mediated base pairs by coordination to central silver(I) ions. Duplexes I and II containing 7C G and C have been synthesized and characterized. The incorporation of silver(I) ions into these duplexes has been studied by means of temperature-dependent UV spectroscopy, circular dichroism, and DFT calculations. The results suggest the formation of DNA molecules comprising contiguous metallated 7C G-Ag I -C Watson-Crick base pairs that preserve the original B-type conformation. Furthermore, additional studies performed on duplex III indicated that, in the presence of Ag I ions, 7C G-C and 7C A-T Watson-Crick base pairs ( 7C A, 7-deazadenine; T, thymine) can be converted to metallated 7C G-Ag I -C and 7C A-Ag I -T base pairs inside the same DNA molecule whilst maintaining its initial double helix conformation. These findings are very important for the development of customized silver-DNA nanostructures based on a Watson-Crick complementarity pattern. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. A Comparison of Source Code Plagiarism Detection Engines

    Science.gov (United States)

    Lancaster, Thomas; Culwin, Fintan

    2004-06-01

    Automated techniques for finding plagiarism in student source code submissions have been in use for over 20 years and there are many available engines and services. This paper reviews the literature on the major modern detection engines, providing a comparison of them based upon the metrics and techniques they deploy. Generally the most common and effective techniques are seen to involve tokenising student submissions then searching pairs of submissions for long common substrings, an example of what is defined to be a paired structural metric. Computing academics are recommended to use one of the two Web-based detection engines, MOSS and JPlag. It is shown that whilst detection is well established there are still places where further research would be useful, particularly where visual support of the investigation process is possible.

  14. Modeling top quark pair production in the search of new, heavy resonance that decays into a pair of Higgs bosons

    CERN Document Server

    Liyanage, Kalpanie Madara

    2017-01-01

    The Higgs boson pair production process at the LHC provides an opportunity for performing a study of the trilinear Higgs boson self-coupling. We consider Higgs boson pair production in the bbWW*channel, with subsequent decay of the WW* pair into lνqq. Due to irreducible top quark backgrounds and the associated uncertainties, this is a challenging final state to explore. We apply appropriate selection cuts on suitable kinematic variables in order to obtain a signal-enriched region. Using several different Monte Carlo (MC) samples the top quark background process is then studied in this region of interest. We find that depending on the phase space, different MC samples lead to kinematic differences.

  15. On extensions of wavelet systems to dual pairs of frames

    DEFF Research Database (Denmark)

    Christensen, Ole; Kim, Hong Oh; Kim, Rae Young

    2015-01-01

    It is an open problem whether any pair of Bessel sequences with wavelet structure can be extended to a pair of dual frames by adding a pair of singly generated wavelet systems. We consider the particular case where the given wavelet systems are generated by the multiscale setup with trigonometric...

  16. Shape of Cooper pairs in a norma.-metal/superconductors junction

    NARCIS (Netherlands)

    Tanaka, Yukio; Asano, Yasuhiro; Golubov, Alexandre Avraamovitch

    2008-01-01

    In s-wave superconductors the Cooper pair wave function is isotropic in momentum space. This property may also be expected for Cooper pairs entering a normal metal from a superconductor due to the proximity effect. We show, however, that such a deduction is incorrect and the pairing function in a

  17. Widespread Transient Hoogsteen Base-Pairs in Canonical Duplex DNA with Variable Energetics

    Science.gov (United States)

    Alvey, Heidi S.; Gottardo, Federico L.; Nikolova, Evgenia N.; Al-Hashimi, Hashim M.

    2015-01-01

    Hoogsteen base-pairing involves a 180 degree rotation of the purine base relative to Watson-Crick base-pairing within DNA duplexes, creating alternative DNA conformations that can play roles in recognition, damage induction, and replication. Here, using Nuclear Magnetic Resonance R1ρ relaxation dispersion, we show that transient Hoogsteen base-pairs occur across more diverse sequence and positional contexts than previously anticipated. We observe sequence-specific variations in Hoogsteen base-pair energetic stabilities that are comparable to variations in Watson-Crick base-pair stability, with Hoogsteen base-pairs being more abundant for energetically less favorable Watson-Crick base-pairs. Our results suggest that the variations in Hoogsteen stabilities and rates of formation are dominated by variations in Watson-Crick base pair stability, suggesting a late transition state for the Watson-Crick to Hoogsteen conformational switch. The occurrence of sequence and position-dependent Hoogsteen base-pairs provide a new potential mechanism for achieving sequence-dependent DNA transactions. PMID:25185517

  18. Environmentally benign working pairs for adsorption refrigeration

    International Nuclear Information System (INIS)

    Cui Qun; Tao Gang; Chen Haijun; Guo Xinyue; Yao Huqing

    2005-01-01

    This paper begins from adsorption working pairs: water and ethanol were selected as refrigerants; 13x molecular sieve, silica gel, activated carbon, adsorbent NA and NB, proposed by authors, were selected as adsorbents, and the performance of adsorption working pairs in adsorption refrigeration cycle was studied. The adsorption isotherms of adsorbents (NA and NB) were obtained by high-vacuum gravimetric method. Desorption properties of adsorbents were analyzed and compared by thermal analysis method. The performance of adsorption refrigeration was studied on simulation device of adsorption refrigeration cycle. After presentation of adsorption isotherms, the thermodynamic performance for their use in adsorption refrigeration system was calculated. The results show: (1) the maximum adsorption capacity of water on adsorbent NA reaches 0.7 kg/kg, and the maximum adsorption capacity of ethanol on adsorbent NB is 0.68 kg/kg, which is three times that of ethanol on activated carbon, (2) the refrigeration capacity of NA-water working pair is 922 kJ/kg, the refrigeration capacity of NB-ethanol is 2.4 times that of activated carbon-methanol, (3) as environmental friendly and no public hazard adsorption working pair, NA-H 2 O and NB-ethanol can substitute activated carbon-methanol in adsorption refrigeration system using low-grade heat source

  19. THINK-PAIR-SHARE: A TECNIQUE TO ENHANCE STUDENTS’ WRITING SKILL

    Directory of Open Access Journals (Sweden)

    Okta Ika Rahmawati

    2017-02-01

    Abstrak: artikel ini berisi tentang penelitian tindakan kelas pada pembelajaran menulis dengan menerapkan teknik Think-Pair-Share di SMAN 1 Bojonegoro. Think-Pair-Share adalaha salah satu teknik pembelajaran kooperatif. Teknik ini mendorong siswa untuk aktif berpartisipasi dalam proses belajar karena mereka harus berdiskusi tantang materi yang sedang diajarkan dengan temannya. Subjek penelitian ini adalah siswa kelas sepuluh SMAN 1 Bojonegoro. hasil penelitian menunjukkan bahwa penerapan Think-Pair-Share pada pengajaran menulis narrative text dapat meningkatkan kemampuan menulis siswa kelas sepuluh. Kata Kunci: peningkatan, think-pair-share, kemampuan menulis

  20. The inverse problem for Schwinger pair production

    Directory of Open Access Journals (Sweden)

    F. Hebenstreit

    2016-02-01

    Full Text Available The production of electron–positron pairs in time-dependent electric fields (Schwinger mechanism depends non-linearly on the applied field profile. Accordingly, the resulting momentum spectrum is extremely sensitive to small variations of the field parameters. Owing to this non-linear dependence it is so far unpredictable how to choose a field configuration such that a predetermined momentum distribution is generated. We show that quantum kinetic theory along with optimal control theory can be used to approximately solve this inverse problem for Schwinger pair production. We exemplify this by studying the superposition of a small number of harmonic components resulting in predetermined signatures in the asymptotic momentum spectrum. In the long run, our results could facilitate the observation of this yet unobserved pair production mechanism in quantum electrodynamics by providing suggestions for tailored field configurations.

  1. Theory of antiferromagnetic pairing in cuprate superconductors

    International Nuclear Information System (INIS)

    Plakida, N.M.

    2006-01-01

    A review of the antiferromagnetic exchange and spin-fluctuation pairing theory in the cuprate superconductors is given. We briefly discuss a phenomenological approach and a theory in the limit of weak Coulomb correlations. A microscopic theory in the strong correlation limit is presented in more detail. In particular, results of our recently developed theory for the effective p-d Hubbard model and the reduced t-J model are given. We have proved that retardation effects for the antiferromagnetic exchange interaction are unimportant that results in pairing of all charge carriers in the conduction band and high Tc proportional to the Fermi energy. The spin-fluctuation interaction caused by kinematic interaction gives an additional contribution to the d-wave pairing. Dependence of Tc on the hole concentration and the lattice constant (or pressure) and an oxygen isotope shift are discussed

  2. QSO Pairs across Active Galaxies: Evidence of Blueshifts? D. Basu

    Indian Academy of Sciences (India)

    2006-12-04

    Dec 4, 2006 ... Abstract. Several QSO pairs have been reported and their redshifts determined, where the two objects in each pair are located across an active galaxy. The usually accepted explanation of such occurrences is that the pair is ejected from the parent galaxy. Currently interpreted redshifted spec- tra for both ...

  3. Affine pairings on ARM

    NARCIS (Netherlands)

    Acar, T.; Lauter, K.; Naehrig, M.; Shumow, D.; Abdalla, M.; Lange, T.

    2013-01-01

    We report on relative performance numbers for affine and projective pairings on a dual-core Cortex A9 ARM processor. Using a fast inversion in the base field and doing inversion in extension fields by using the norm map to reduce to inversions in smaller fields, we find a very low ratio of

  4. Tunnel conductance of Watson-Crick nucleoside-base pairs from telegraph noise

    International Nuclear Information System (INIS)

    Chang Shuai; He Jin; Lin Lisha; Zhang Peiming; Liang Feng; Huang Shuo; Lindsay, Stuart; Young, Michael

    2009-01-01

    The use of tunneling signals to sequence DNA is presently hampered by the small tunnel conductance of a junction spanning an entire DNA molecule. The design of a readout system that uses a shorter tunneling path requires knowledge of the absolute conductance across base pairs. We have exploited the stochastic switching of hydrogen-bonded DNA base-nucleoside pairs trapped in a tunnel junction to determine the conductance of individual molecular pairs. This conductance is found to be sensitive to the geometry of the junction, but a subset of the data appears to come from unstrained molecular pairs. The conductances determined from these pairs are within a factor of two of the predictions of density functional calculations. The experimental data reproduces the counterintuitive theoretical prediction that guanine-deoxycytidine pairs (3 H-bonds) have a smaller conductance than adenine-thymine pairs (2 H-bonds). A bimodal distribution of switching lifetimes shows that both H-bonds and molecule-metal contacts break.

  5. A comparison of donor-acceptor pairs for genetically encoded FRET sensors: application to the Epac cAMP sensor as an example.

    Directory of Open Access Journals (Sweden)

    Gerard N M van der Krogt

    Full Text Available We recently reported on CFP-Epac-YFP, an Epac-based single polypeptide FRET reporter to resolve cAMP levels in living cells. In this study, we compared and optimized the fluorescent protein donor/acceptor pairs for use in biosensors such as CFP-Epac-YFP. Our strategy was to prepare a wide range of constructs consisting of different donor and acceptor fluorescent proteins separated by a short linker. Constructs were expressed in HEK293 cells and tested for FRET and other relevant properties. The most promising pairs were subsequently used in an attempt to improve the FRET span of the Epac-based cAMP sensor. The results show significant albeit not perfect correlation between performance in the spacer construct and in the Epac sensor. Finally, this strategy enabled us to identify improved sensors both for detection by sensitized emission and by fluorescent lifetime imaging. The present overview should be helpful in guiding development of future FRET sensors.

  6. Pairing interaction method in crystal field theory

    International Nuclear Information System (INIS)

    Dushin, R.B.

    1989-01-01

    Expressions, permitting to describe matrix elements of secular equation for metal-ligand pairs via parameters of the method of pairing interactions, genealogical coefficients and Clebsch-Gordan coefficients, are given. The expressions are applicable to any level or term of f n and d n configurations matrix elements for the terms of the maximum multiplicity of f n and d n configurations and also for the main levels of f n configurations are tabulated

  7. Transverse Momentum Distributions for Heavy Quark Pairs

    OpenAIRE

    Berger, Edmond L.; Meng, Ruibin

    1993-01-01

    We study the transverse momentum distribution for a $pair$ of heavy quarks produced in hadron-hadron interactions. Predictions for the large transverse momentum region are based on exact order $\\alpha_s^3$ QCD perturbation theory. For the small transverse momentum region, we use techniques for all orders resummation of leading logarithmic contributions associated with initial state soft gluon radiation. The combination provides the transverse momentum distribution of heavy quark pairs for all...

  8. Joint Subcarrier Pairing and Resource Allocation for Cognitive Network and Adaptive Relaying Strategy

    KAUST Repository

    Soury, Hamza

    2012-05-01

    Recent measurements show that the spectrum is under-utilized by licensed users in wireless communication. Cognitive radio (CR) has been proposed as a suitable solution to manage the inefficient usage of the spectrum and increase coverage area of wireless networks. The concept is based on allowing a group of secondary users (SUs) to share the unused radio spectrum originally owned by the primary user (PUs). The operation of CR should not cause harmful interference to the PUs. In the other hand, relayed transmission increases the coverage and achievable capacity of communication systems and in particular in CR systems. In fact there are many types of cooperative communications, however the two main ones are decode-and-forward (DAF) and amplify-and-forward (AAF). Adaptive relaying scheme is a relaying technique by which the benefits of the amplifying or decode and forward techniques can be achieved by switching the forwarding technique according to the quality of the signal. In this dissertation, we investigate the power allocation for an adaptive relaying protocol (ARP) scheme in cognitive system by maximizing the end-to-end rate and searching the best carriers pairing distribution. The optimization problem is under the interference and power budget constraints. The simulation results confirm the efficiency of the proposed adaptive relaying protocol in comparison to other relaying techniques, and the consequence of the choice of the pairing strategy.

  9. Radiation- and pair-loaded shocks

    Science.gov (United States)

    Lyutikov, Maxim

    2018-06-01

    We consider the structure of mildly relativistic shocks in dense media, taking into account the radiation and pair loading, and diffusive radiation energy transfer within the flow. For increasing shock velocity (increasing post-shock temperature), the first important effect is the efficient energy redistribution by radiation within the shock that leads to the appearance of an isothermal jump, whereby the flow reaches the final state through a discontinuous isothermal transition. The isothermal jump, on scales much smaller than the photon diffusion length, consists of a weak shock and a quick relaxation to the isothermal conditions. Highly radiation-dominated shocks do not form isothermal jump. Pair production can mildly increase the overall shock compression ratio to ≈10 (4 for matter-dominated shocks and 7 of the radiation-dominated shocks).

  10. Effects of the R-parity violation in the minimal supersymmetric standard model on dilepton pair production at the CERN LHC

    CERN Document Server

    Jun, Y; Lang-Hui, W; Ren Zhao You; Jun, Yin; Wen-Gan, Ma; Lang-Hui, Wan; Ren-You, Zhang

    2002-01-01

    We investigate in detail the effects of the R-parity lepton number violation in the minimal supersymmetric standard model (MSSM) on the parent process $pp \\to e^+ e^- + X$ at the CERN Large Hadron Collider (LHC). The numerical comparisons between the contributions of the R-parity violating effects to the parent process via the Drell-Yan subprocess and the gluon-gluon fusion are made. We find that the R-violating effects on $e^+ e^-$ pair production at the LHC could be significant. The results show that the cross section of the $ e^+ e^-$ pair productions via gluon-gluon collision at the LHC can be of the order of $10^2$ fb, and this subprocess maybe competitive with the production mechanism via the Drell-Yan subprocess. We give also quantitatively the analysis of the effects from both the mass of sneutrino and coupling strength of the R-parity violating interactions.

  11. Germline progenitors escape the widespread phenomenon of homolog pairing during Drosophila development.

    Directory of Open Access Journals (Sweden)

    Eric F Joyce

    Full Text Available Homolog pairing, which plays a critical role in meiosis, poses a potential risk if it occurs in inappropriate tissues or between nonallelic sites, as it can lead to changes in gene expression, chromosome entanglements, and loss-of-heterozygosity due to mitotic recombination. This is particularly true in Drosophila, which supports organismal-wide pairing throughout development. Discovered over a century ago, such extensive pairing has led to the perception that germline pairing in the adult gonad is an extension of the pairing established during embryogenesis and, therefore, differs from the mechanism utilized in most species to initiate pairing specifically in the germline. Here, we show that, contrary to long-standing assumptions, Drosophila meiotic pairing in the gonad is not an extension of pairing established during embryogenesis. Instead, we find that homologous chromosomes are unpaired in primordial germ cells from the moment the germline can be distinguished from the soma in the embryo and remain unpaired even in the germline stem cells of the adult gonad. We further establish that pairing originates immediately after the stem cell stage. This pairing occurs well before the initiation of meiosis and, strikingly, continues through the several mitotic divisions preceding meiosis. These discoveries indicate that the spatial organization of the Drosophila genome differs between the germline and the soma from the earliest moments of development and thus argue that homolog pairing in the germline is an active process as versus a passive continuation of pairing established during embryogenesis.

  12. Conditions for formation of electron pairs in a metal

    Energy Technology Data Exchange (ETDEWEB)

    Shekhtman, A.Z., E-mail: shekhtmanalexander@gmail.com

    2015-04-15

    Highlights: • A new approach has been developed for consideration of electron pairing in metals. • Binding energy of a single pair induced by electron-phonon interaction is very small. • A new mechanism for electron pairing in metals has been considered. • Conditions for feasibility of the mechanism give conditions for electron pairing. • The mechanism gives wide opportunities to study new conditions for electron pairing. - Abstract: In an isotropic model of the electron system of metal that is presented by the Fröhlich’s initial Hamiltonian, in the approximation of a weak electron–phonon interaction at T = 0, first time, we show that the ground state of the system is the state with pairing correlations of electrons (the pair correlations of occupied electron states). In contrast to the BCS approach, the initial point in our approach is not electron pairing but is the maximum reduction of the energy of the considered system due to virtual processes of the electron–phonon interaction and to the exchange effect for the indirect electron–electron interaction (which is induced by certain phonon modes separately from others). In contrast to the BCS approach, we take into account the portion of the energy of the electron system that is connected with the above exchange effect. In the BCS approach, the corresponding portion is missed, and its role is prescribed to the portion that does not relate to the electron pairing. We show that expectation values of the above Hamiltonian for different wave functions for two interacting electrons above the Fermi sea of the non-interacting system (with interaction between the electrons that is induced by different phonon modes separately from others) are minimum for a certain structure of these functions and simultaneously for phonon modes that can induce the transitions of the interacting electrons between electron states in which they are (without violation of the Pauli exclusion principle and at everything else

  13. On magnon mediated Cooper pair formation in ferromagnetic superconductors

    Directory of Open Access Journals (Sweden)

    Rakesh Kar

    2014-08-01

    Full Text Available Identification of pairing mechanism leading to ferromagnetic superconductivity is one of the most challenging issues in condensed matter physics. Although different models have been proposed to explain this phenomenon, a quantitative understanding about this pairing is yet to be achieved. Using the localized-itinerant model, we find that in ferromagnetic superconducting materials both triplet pairing and singlet pairing of electrons are possible through magnon exchange depending upon whether the Debye cut off frequency of magnons is greater or lesser than the Hund's coupling (J multiplied by average spin (S per site. Taking into account the repulsive interaction due to the existence of paramagnons, we also find an expression for effective interaction potential between a pair of electrons with opposite spins. We apply the developed formalism in case of UGe2 and URhGe. The condition of singlet pairing is found to be fulfilled in these cases, as was previously envisaged by Suhl [Suhl, Phys. Rev. Lett. 87, 167007 (2001]. We compute the critical temperatures of URhGe at ambient pressure and of UGe2 under different pressures for the first time through BCS equation. Thus, this work outlines a very simple way to evaluate critical temperature in case of a superconducting system. A close match with the available experimental results strongly supports our theoretical treatment.

  14. Pair Interaction of Catalytical Sphere Dimers in Chemically Active Media

    Directory of Open Access Journals (Sweden)

    Jing-Min Shi

    2018-01-01

    Full Text Available We study the pair dynamics of two self-propelled sphere dimers in the chemically active medium in which a cubic autocatalytic chemical reaction takes place. Concentration gradient around the dimer, created by reactions occurring on the catalytic sphere surface and responsible for the self-propulsion, is greatly influenced by the chemical activities of the environment. Consequently, the pair dynamics of two dimers mediated by the concentration field are affected. In the particle-based mesoscopic simulation, we combine molecular dynamics (MD for potential interactions and reactive multiparticle collision dynamics (RMPC for solvent flow and bulk reactions. Our results indicate three different configurations between a pair of dimers after the collision, i.e., two possible scenarios of bound dimer pairs and one unbound dimer pair. A phase diagram is sketched as a function of the rate coefficients of the environment reactions. Since the pair interactions are the basic elements of larger scale systems, we believe the results may shed light on the understanding of the collective dynamics.

  15. Olfactory interference during inhibitory backward pairing in honey bees.

    Directory of Open Access Journals (Sweden)

    Matthieu Dacher

    Full Text Available Restrained worker honey bees are a valuable model for studying the behavioral and neural bases of olfactory plasticity. The proboscis extension response (PER; the proboscis is the mouthpart of honey bees is released in response to sucrose stimulation. If sucrose stimulation is preceded one or a few times by an odor (forward pairing, the bee will form a memory for this association, and subsequent presentations of the odor alone are sufficient to elicit the PER. However, backward pairing between the two stimuli (sucrose, then odor has not been studied to any great extent in bees, although the vertebrate literature indicates that it elicits a form of inhibitory plasticity.If hungry bees are fed with sucrose, they will release a long lasting PER; however, this PER can be interrupted if an odor is presented 15 seconds (but not 7 or 30 seconds after the sucrose (backward pairing. We refer to this previously unreported process as olfactory interference. Bees receiving this 15 second backward pairing show reduced performance after a subsequent single forward pairing (excitatory conditioning trial. Analysis of the results supported a relationship between olfactory interference and a form of backward pairing-induced inhibitory learning/memory. Injecting the drug cimetidine into the deutocerebrum impaired olfactory interference.Olfactory interference depends on the associative link between odor and PER, rather than between odor and sucrose. Furthermore, pairing an odor with sucrose can lead either to association of this odor to PER or to the inhibition of PER by this odor. Olfactory interference may provide insight into processes that gate how excitatory and inhibitory memories for odor-PER associations are formed.

  16. Comparison of imagine systems

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, F. [Hong Kong Polytechnic University, Kowloon (Hong Kong). Optometry and Radiography Department

    1997-12-01

    It is of great use to be able to accurately compare different film/screen systems. It allows informed decisions to be made as to the optimal choice of film and screens in regard to technical matters such as speed and resolution. Comparisons of these have not been easy, especially in the face of different terminology and specifications used by different manufacturers. A straight forward method is proposed, which requires only a line pair test tool, and the ability to produce scattergraphs. The relative efficiencies of different film/screen systems, incorporating orthochromatic and monochromatic elements are clearly portrayed. Copyright (1997) Australian Institute of Radiography 12 refs., 1 tab., 4 figs.

  17. Revisiting the picture-superiority effect in symbolic comparisons: do pictures provide privileged access?

    Science.gov (United States)

    Amrhein, Paul C; McDaniel, Mark A; Waddill, Paula

    2002-09-01

    In 4 experiments, symbolic comparisons were investigated to test semantic-memory retrieval accounts espousing processing advantages for picture over word stimuli. In Experiment 1, participants judged pairs of animal names or pictures by responding to questions probing concrete or abstract attributes (texture or size, ferocity or intelligence). Per pair, attributes were salient or nonsalient concerning their prerated relevance to animals being compared. Distance (near or far) between attribute magnitudes was also varied. Pictures did not significantly speed responding relative to words across all other variables. Advantages were found forfar attribute magnitudes (i.e., the distance effect) and salient attributes. The distance effect was much less for salient than nonsalient concrete-attribute comparisons. These results were consistently found in additional experiments with increased statistical power to detect modality effects. Our findings argue against dual-coding and some common-code accounts of conceptual attribute processing, urging reexamination of the assumption that pictures confer privileged access to long-term knowledge.

  18. (RN) pair production by photons in a hot Maxwellian plasma

    International Nuclear Information System (INIS)

    Haug, E.

    2004-01-01

    The production of electron-positron pairs by photons in the Coulomb Field of electrons and positrons (triplet production) in hot thermal plasmas is investigated. The pair production rate for this process is calculated as a function of the photon energy and compared with the rate of photon-nucleus pair production for semi-relativistic and relativistic plasma temperatures. (author)

  19. The Effect of Pair Work on a Word-Building Task

    Science.gov (United States)

    Baleghizadeh, Sasan

    2010-01-01

    This paper reports on a study that was carried out to investigate the effect of pair work on a word-building task in two EFL classes. Forty Iranian adult students participated in this study. The participants in the experimental group completed the word-building task in pairs following the Think-Pair-Share technique, whereas the participants in the…

  20. Paired quasars near NGC 2639: Evidence for quasars in superclusters

    International Nuclear Information System (INIS)

    Ford, H.; Ciardullo, R.; Harms, R.

    1983-01-01

    Arp found 10 quasars near a low-redshift galaxy 27' SSE of NGC 2639. Six of the quasars can be grouped into three redshift pairs which align across the anonymous galaxy. The large number of quasars and pairings could show an association with the low-redshift galaxy, or alternatively, might be due to superclusters seen along the line of sight. We tested the latter hypothesis by using deep, red-sensitive Lick 3 m prime focus plates to search for a supercluster associated with the z = 0.3 quasar pair. The plates show extended nebulosity associated with the quasar U10 (thetaapprox.7'', or 20 kpc at z = 0.3) and a richness class 1, Bautz-Morgan type III cluster 4' NW of U10. A spectrum of one the cluster's brightest galaxies gives z = 0.34, suggesting that the cluster and quasar are unassociated. We obtained spectra of eight of the quasars and find that (i) two of the quasars have very strong absorption shortward of Lyα, and (ii) two of Arp's redshifts (including one which Arp considered uncertain) are incorrect. Our redshifts break two of the redshift pairs, including the pair at z = 0.3. We use the redshift distribution of optically selected quasars to argue that the third pair has no statistical significance, and conclude that there is no basis for associating the quasars with the low-redshift anonymous galaxy. The disappearance of the redshift pairs vitiates the possibility of testing the paired-quasars-in-superclusters hypothesis in the NGC 2639 field

  1. Comparison of Path Length and Ranges of Movement of the Center of Pressure and Reaction Time and Between Paired-Play and Solo-Play of a Virtual Reality Game.

    Science.gov (United States)

    Portnoy, Sigal; Hersch, Ayelet; Sofer, Tal; Tresser, Sarit

    2017-06-01

    To test whether paired-play will induce longer path length and ranges of movement of the center of pressure (COP), which reflects on balance performance and stability, compared to solo-play and to test the difference in the path length and ranges of movement of the COP while playing the virtual reality (VR) game with the dominant hand compared to playing it with the nondominant hand. In this cross-sectional study 20 children (age 6.1 ± 0.7 years old) played an arm movement controlled VR game alone and with a peer while each of them stood on a pressure measuring pad to track the path length and ranges of movement of the COP. The total COP path was significantly higher during the paired-play (median 295.8 cm) compared to the COP path during the solo-play (median 189.2 cm). No significant differences were found in the reaction time and the mediolateral and anterior-posterior COP ranges between solo-play and paired-play. No significant differences were found between the parameters extracted during paired-play with the dominant or nondominant hand. Our findings imply that the paired-play is advantageous compared to solo-play since it induces a greater movement for the child, during which, higher COP velocities are reached that may contribute to improving the balance control of the child. Apart from the positive social benefits of paired-play, this positive effect on the COP path length is a noteworthy added value in the clinical setting when treating children with balance disorder.

  2. Dopamine Modulation of Reunion Behavior in Short and Long Term Marmoset Pairs

    Directory of Open Access Journals (Sweden)

    Sarah B. Carp

    2018-05-01

    Full Text Available One major neurobiological substrate regulating social processes is dopamine (DA. DA is implicated in social behavior in species as diverse as fish and birds, and has an established role in regulating relationships between mates in socially monogamous rodents. Marmoset monkeys display traits associated with social monogamy including high rates of affiliation, biparental care, distress upon separation, and aggression toward strangers; several of these behavioral patterns change throughout the development of relationships. This temporal change may represent changing demands, as pairs are likely to jointly face new experiences (e.g., parenthood throughout pairing. We investigated the role of DA and pairing length on social behavior during reunion after separation from the mate. Marmosets were removed from their home environment and treated with agonists and antagonists for the D1 and D2 receptor subtypes. They were exposed to a novel environment containing an opposite-sex stranger and their pair mate, and then reunited with their mate in the home enclosure. Marmosets in long term pairs exhibited higher levels of food sharing during reunion than marmosets in short term pairs, with females in long term pairs sharing food more than males; no sex difference was observed in short term pairs. Subjects in short term pairs spent more time grooming their mate than receiving grooming during reunion, while marmosets in long term pairs displayed similar amounts of both initiated and received grooming. DA treatment altered pair-level behavior. When females received either a D2 agonist or antagonist, short term pairs spent less time in proximity, compared to when males received the same treatments. In long term pairs, treatment of females with either a D1 agonist or antagonist resulted in pairs spending less time in social proximity than when males were treated. These findings suggest that the function of the DA system in mate behavior may be similar between

  3. Theory of pairing symmetry in the vortex states

    NARCIS (Netherlands)

    Yokoyama, Takehito; Ichioka, Yukio; Yanaka, Yukio; Golubov, Alexandre Avraamovitch

    2010-01-01

    We investigate pairing symmetry in an Abrikosov vortex and vortex lattice. It is shown that the Cooper pair wave function at the center of an Abrikosov vortex with vorticity m has a different parity with respect to frequency from that in the bulk if m is an odd number, while it has the same parity

  4. Teleportation of Quantum States through Mixed Entangled Pairs

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shi-Biao

    2006-01-01

    @@ We describe a protocol for quantum state teleportation via mixed entangled pairs. With the help of an ancilla,near-perfect teleportation might be achieved. For pure entangled pairs, perfect teleportation might be achieved with a certain probability without using an ancilla. The protocol is generalized to teleportation of multiparticle states and quantum secret sharing.

  5. Multi-user distribution of polarization entangled photon pairs

    Energy Technology Data Exchange (ETDEWEB)

    Trapateau, J.; Orieux, A.; Diamanti, E.; Zaquine, I., E-mail: isabelle.zaquine@telecom-paristech.fr [LTCI, CNRS, Télécom ParisTech, Université Paris-Saclay, 75013 Paris (France); Ghalbouni, J. [Applied Physics Laboratory, Faculty of Sciences 2, Lebanese University, Campus Fanar, BP 90656 Jdeidet (Lebanon)

    2015-10-14

    We experimentally demonstrate multi-user distribution of polarization entanglement using commercial telecom wavelength division demultiplexers. The entangled photon pairs are generated from a broadband source based on spontaneous parametric down conversion in a periodically poled lithium niobate crystal using a double path setup employing a Michelson interferometer and active phase stabilisation. We test and compare demultiplexers based on various technologies and analyze the effect of their characteristics, such as losses and polarization dependence, on the quality of the distributed entanglement for three channel pairs of each demultiplexer. In all cases, we obtain a Bell inequality violation, whose value depends on the demultiplexer features. This demonstrates that entanglement can be distributed to at least three user pairs of a network from a single source. Additionally, we verify for the best demultiplexer that the violation is maintained when the pairs are distributed over a total channel attenuation corresponding to 20 km of optical fiber. These techniques are therefore suitable for resource-efficient practical implementations of entanglement-based quantum key distribution and other quantum communication network applications.

  6. Molecular electrostatics for probing lone pair-π interactions.

    Science.gov (United States)

    Mohan, Neetha; Suresh, Cherumuttathu H; Kumar, Anmol; Gadre, Shridhar R

    2013-11-14

    An electrostatics-based approach has been proposed for probing the weak interactions between lone pair containing molecules and π deficient molecular systems. For electron-rich molecules, the negative minima in molecular electrostatic potential (MESP) topography give the location of electron localization and the MESP value at the minimum (Vmin) quantifies the electron-rich character of that region. Interactive behavior of a lone pair bearing molecule with electron deficient π-systems, such as hexafluorobenzene, 1,3,5-trinitrobenzene, 2,4,6-trifluoro-1,3,5-triazine and 1,2,4,5-tetracyanobenzene explored within DFT brings out good correlation of the lone pair-π interaction energy (E(int)) with the Vmin value of the electron-rich system. Such interaction is found to be portrayed well with the Electrostatic Potential for Intermolecular Complexation (EPIC) model. On the basis of the precise location of MESP minimum, a prediction for the orientation of a lone pair bearing molecule with an electron deficient π-system is possible in the majority of the cases studied.

  7. SIMULATION COMPARISON AND STEPS TO DO SIMULATION BY AUTOLISP (AUTOCAD) AND PRO-E FOR GEAR PAIR.

    OpenAIRE

    PRATIK A. SOLANKI; KALPESH P. PATEL; J.R.LIMBACHIYA

    2012-01-01

    This paper gives the basic idea of steps required for doing simulation in AutoCAD with the help of AutoLisp and Pro-Engineering. It includes the comparison between both methods. AutoCAD 2005 and Pro-E wildfireV4.0 used as software to do simulation (Animation).

  8. Phase transitions and pairing signature in strongly attractive Fermi atomic gases

    International Nuclear Information System (INIS)

    Guan, X. W.; Bortz, M.; Batchelor, M. T.; Lee, C.

    2007-01-01

    We investigate pairing and quantum phase transitions in the one-dimensional two-component Fermi atomic gas in an external field. The phase diagram, critical fields, magnetization, and local pairing correlation are obtained analytically via the exact thermodynamic Bethe ansatz solution. At zero temperature, bound pairs of fermions with opposite spin states form a singlet ground state when the external field H c1 . A completely ferromagnetic phase without pairing occurs when the external field H>H c2 . In the region H c1 c2 , we observe a mixed phase of matter in which paired and unpaired atoms coexist. The phase diagram is reminiscent of that of type II superconductors. For temperatures below the degenerate temperature and in the absence of an external field, the bound pairs of fermions form hard-core bosons obeying generalized exclusion statistics

  9. Pair formation models for sexually transmitted infections : A primer

    NARCIS (Netherlands)

    Kretzschmar, MEE; Heijne, Janneke C M

    For modelling sexually transmitted infections, duration of partnerships can strongly influence the transmission dynamics of the infection. If partnerships are monogamous, pairs of susceptible individuals are protected from becoming infected, while pairs of infected individuals delay onward

  10. Quantitative measures of entanglement in pair-coherent states

    International Nuclear Information System (INIS)

    Agarwal, G S; Biswas, Asoka

    2005-01-01

    The pair-coherent states for a two-mode radiation field are known to belong to a family of states with non-Gaussian wavefunction. The nature of quantum entanglement between the two modes and some features of non-classicality are studied for such states. The existing criterion for inseparability are examined in the context of pair-coherent states

  11. Multiple electromagnetic electron-positron pair production in relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    Alscher, A.; Hencken, K.; Trautmann, D.; Baur, G.

    1997-01-01

    We calculate the cross sections for the production of one and more electron-positron pairs due to the strong electromagnetic fields in relativistic heavy-ion collisions. We derive the N-pair amplitude using the generating functional of fermions in an external field and the path-integral formalism. The N-pair production probability is found to be an approximate Poisson distribution. We calculate total cross sections for the production of one pair in lowest order, including corrections from the Poisson distribution up to third order. Furthermore, we calculate cross sections for the production of up to five pairs including corrections from the Poisson distribution. copyright 1997 The American Physical Society

  12. Comparison of the Giemsa C-banded karyotypes of the three subspecies of Psathyrostachys fragilis, subspp. villosus (2x), secaliformis (2x, 4x), and fragilis (2x) (Poaceae), with notes on chromosome pairing

    DEFF Research Database (Denmark)

    Linde-Laursen, I.; Baden, C.

    1994-01-01

    . Only the presence of 12 nucleoli in interphases identified 6 SAT-chromosome pairs. In subsp. villosus one or two extra micronucleoli indicated a chromosome pair with very low nucleolus-forming activity, bringing the number of SAT-chromosome pairs to 4. This number may be a characteristic...... of a common genome, N. NORs had different nucleolus-forming activities. Meiotic analysis demonstrated a high level of bivalent pairing in the three taxa. A chromosomal rearrangement was suggested in subsp. villosus. The low multivalent frequency in subsp. secaliformis indicates the presence of a pairing...

  13. Pair plasma relaxation time scales.

    Science.gov (United States)

    Aksenov, A G; Ruffini, R; Vereshchagin, G V

    2010-04-01

    By numerically solving the relativistic Boltzmann equations, we compute the time scale for relaxation to thermal equilibrium for an optically thick electron-positron plasma with baryon loading. We focus on the time scales of electromagnetic interactions. The collisional integrals are obtained directly from the corresponding QED matrix elements. Thermalization time scales are computed for a wide range of values of both the total-energy density (over 10 orders of magnitude) and of the baryonic loading parameter (over 6 orders of magnitude). This also allows us to study such interesting limiting cases as the almost purely electron-positron plasma or electron-proton plasma as well as intermediate cases. These results appear to be important both for laboratory experiments aimed at generating optically thick pair plasmas as well as for astrophysical models in which electron-positron pair plasmas play a relevant role.

  14. Pairing correlations in N ∝Z pf-shell nuclei

    International Nuclear Information System (INIS)

    Langanke, K.; Dean, D.J.; Koonin, S.E.; Radha, P.B.

    1997-01-01

    We perform shell model Monte Carlo calculations to study pair correlations in the ground states of N=Z nuclei with masses A=48-60. We find that T=1, J π =0 + proton-neutron correlations play an important, and even dominant role, in the ground states of odd-odd N=Z nuclei, in agreement with experiment. By studying pairing in the ground states of 52-58 Fe, we observe that the isovector proton-neutron correlations decrease rapidly with increasing neutron excess. In contrast, both the proton, and trivially the neutron correlations increase as neutrons are added. We also study the thermal properties and the temperature dependence of pair correlations for 50 Mn and 52 Fe as exemplars of odd-odd and even-even N=Z nuclei. While for 52 Fe results are similar to those obtained for other even-even nuclei in this mass range, the properties of 50 Mn at low temperatures are strongly influenced by isovector neutron-proton pairing. In coexistence with these isovector pair correlations, our calculations also indicate an excess of isoscalar proton-neutron pairing over the mean-field values. The isovector neutron-proton correlations rapidly decrease with temperatures and vanish for temperatures above T=700 keV, while the isovector correlations among like-nucleons persist to higher temperatures. Related to the quenching of the isovector proton-neutron correlations, the average isospin decreases from 1, appropriate for the ground state, to 0 as the temperature increases. (orig.)

  15. Isoscalar and isovector pairing in a formalism of quartets

    Energy Technology Data Exchange (ETDEWEB)

    Sambataro, M., E-mail: michelangelo.sambataro@ct.infn.it [Istituto Nazionale di Fisica Nucleare – Sezione di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Sandulescu, N., E-mail: sandulescu@theory.nipne.ro [National Institute of Physics and Nuclear Engineering, P.O. Box MG-6, Magurele, Bucharest (Romania); Johnson, C.W., E-mail: cjohnson@mail.sdsu.edu [Department of Physics, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1233 (United States)

    2015-01-05

    Isoscalar (T=0, J=1) and isovector (T=1, J=0) pairing correlations in the ground state of self-conjugate nuclei are treated in terms of alpha-like quartets built by two protons and two neutrons coupled to total isospin T=0 and total angular momentum J=0. Quartets are constructed dynamically via an iterative variational procedure and the ground state is represented as a product of such quartets. It is shown that the quartet formalism describes accurately the ground state energies of realistic isovector plus isoscalar pairing Hamiltonians in nuclei with valence particles outside the {sup 16}O, {sup 40}Ca and {sup 100}Sn cores. Within the quartet formalism we analyze the competition between isovector and isoscalar pairing correlations and find that for nuclei with the valence nucleons above the cores {sup 40}Ca and {sup 100}Sn the isovector correlations account for the largest fraction of the total pairing correlations. This is not the case for sd-shell nuclei for which isoscalar correlations prevail. Contrary to many mean-field studies, isovector and isoscalar pairing correlations mix significantly in the quartet approach.

  16. Problems of quantum electrodynamics with external field creating pairs

    International Nuclear Information System (INIS)

    Fradkin, E.S.; Gitman, D.M.

    1979-11-01

    This paper is a preliminary version of a review of the results obtained by the authors and their collaborators which mainly concern problems of quantum electrodynamics with the pair-creating external field. In this paper the Furry picture is constructed for quantum electrodynamics with the pair-creating external field. It is shown, that various Green functions in the external field arise in the theory in a natural way. Special features of usage of the unitarity conditions for calculating the total probabilities of transitions are discussed. Perturbation theory for determining the mean electromagnetic field is constructed. Effective Lagrangians for pair-creating fields are built. One of the possible ways to introduce external field in quantum electrodynamics is considered. All the Green functions arising in the theory suggested are calculated for a constant field and a plane wave field. For the case of the electric field the total probability of creation of pairs from the vacuum accompanied by the photon irradiation and the total probability of transition from a single-electron state accompanied by the photon irradiation and creation of pairs are obtained by using the formulated rules for calculating the total probabilities of transitions. (author)

  17. On the pair creation effect in radiative charmonium transitions

    International Nuclear Information System (INIS)

    Lewin, K.

    1985-01-01

    Contribution to radiative charmonium decay amplitudes which come from Feynman diagrams containing creation of internal c anti c quark pair is investigated. The a im of the paper is calulation of this pair creation correction to the wave function overlap integral of the transition amplitude in a quasilocal semirelativistic approximation which works for charmed and heavier quark pairs. The application to the decay width of the spin flip transition psi(3685) → γchi(3415) givesa 12% correction to the nopair term using a meson radius near 0.5 Fm and a scale parameter Λ=400 MeV taken from fits inchar=monium spectroscopy. The error of the approximation is estimated to be smaller than 50%. The investigation indicates that also in the case of electroweak meson decays quatitative results cannot be expected from the no-pair contribution alone

  18. The pairing theory of polarons in real- and impulse spaces

    International Nuclear Information System (INIS)

    Dzhumanov, S.; Abboudy, S.; Baratov, A.A.

    1995-07-01

    A consistent pairing theory of carriers in real- and impulse spaces is developed. The pairing of different free (F), delocalized (D) and self-trapped (S) carriers in real-space, leading to the formation of various bipolaronic states are considered within the continuum model and adiabatic approximation taking into account the combined effect of the short- and long-range components of electron-lattice interaction with and without electron correlation. The formation possibility of D- and S-bipolarons as a function of ε ∞ /ε 0 are shown. The pairing scenarios of carriers in k-space leading to the formation of different bipolarons (including also Cooper pairs dynamic bipolarons) are considered within the generalized BCS-like model taking into account the combined phonon and polaron-bag mediated processes. It is shown that the pure BCS pairing picture is the particular case of the general BCS-like one. The possible relevance of the obtained results to high-T c superconductors is discussed in details in the framework of a novel two-stage Fermi-Bose-liquid scenarios of superconductivity which is caused by single particle and pair condensation of an attracting bipolarons. (author). 51 refs, 6 figs

  19. An exact fermion-pair to boson mapping

    International Nuclear Information System (INIS)

    Johnson, C.W.

    1993-01-01

    I derive in a novel fashion exact formulas for the calculation of general matrix elements, including the overlap (norm) matrix, between states constructed from fermion pairs. Mapping the fermion pairs to bosons, I show how to construct finite and exact (in the sense of preserving matrix elements) boson representations of the norm operator and one- and two-fermion operators. This may lead to a microscopic basis for the Interacting Boson Model, as well as new truncation schemes for the nuclear shell model

  20. Concreteness and relational effects on recall of adjective-noun pairs.

    Science.gov (United States)

    Paivio, A; Khan, M; Begg, I

    2000-09-01

    Extending previous research on the problem, we studied the effects of concreteness and relatedness of adjective-noun pairs on free recall, cued recall, and memory integration. Two experiments varied the attributes in paired associates lists or sentences. Consistent with predictions from dual coding theory and prior results with noun-noun pairs, both experiments showed that the effects of concreteness were strong and independent of relatedness in free recall and cued recall. The generally positive effects of relatedness were absent in the case of free recall of sentences. The two attributes also had independent (additive) effects on integrative memory as measured by conditionalized free recall of pairs. Integration as measured by the increment from free to cued recall occurred consistently only when pairs were high in both concreteness and relatedness. Explanations focused on dual coding and relational-distinctiveness processing theories as well as task variables that affect integration measures.

  1. Pair Formation of Hard Core Bosons in Flat Band Systems

    Science.gov (United States)

    Mielke, Andreas

    2018-05-01

    Hard core bosons in a large class of one or two dimensional flat band systems have an upper critical density, below which the ground states can be described completely. At the critical density, the ground states are Wigner crystals. If one adds a particle to the system at the critical density, the ground state and the low lying multi particle states of the system can be described as a Wigner crystal with an additional pair of particles. The energy band for the pair is separated from the rest of the multi-particle spectrum. The proofs use a Gerschgorin type of argument for block diagonally dominant matrices. In certain one-dimensional or tree-like structures one can show that the pair is localised, for example in the chequerboard chain. For this one-dimensional system with periodic boundary condition the energy band for the pair is flat, the pair is localised.

  2. Red cell storage in E-Sol 5 and Adsol additive solutions: paired comparison using mixed and non-mixed study designs.

    Science.gov (United States)

    Radwanski, K; Thill, M; Min, K

    2014-05-01

    If transfusion of older stored red cells is found to negatively affect clinical outcome, one possible alternative to shortened outdate is the use of new additive solutions (AS) that ameliorate the storage lesion. Erythro-Sol (E-Sol), a previously developed next-generation AS, has been reformulated into E-Sol 5, which is compatible with current anticoagulants and AS volumes. The effect of E-Sol 5 on red cells during storage compared to current AS has not been reported. Paired, ABO-matched whole-blood units were collected into CPD anticoagulant, pooled, split and processed into plasma and red cell units with either 110 ml of Adsol or 105 ml of E-Sol 5 within 8 h of collection. In Study 1, paired units in E-Sol 5 and Adsol were sampled on Day 0 and every 7 days up to Day 42 (n = 10). In Study 2, paired units in E-Sol 5 and Adsol were sampled only on Day 0 and Day 42 (n = 10). In Study 1, 2,3 DPG levels were maintained until Day 28 in E-Sol 5 units and Day 14 in Adsol units. ATP levels were higher in E-Sol 5 units until Day 21, after which they were comparable between the two groups. In both studies, metabolic activity was greater in E-Sol 5 units with respect to glucose consumption and lactate production. Morphology scores were higher, and haemolysis and microparticles generated were lower in E-Sol 5 vs. Adsol units. Weekly mixing of units lowered haemolysis and microparticle levels and increased potassium content on Day 42 in both additive solutions. Regardless of whether units are mixed weekly or are stored non-mixed, E-Sol 5 slows the progression of the red cell storage lesion and improves the overall in vitro quality of RBC throughout storage. © 2013 International Society of Blood Transfusion.

  3. Structure of 2,4-Diaminopyrimidine - Theobromine Alternate Base Pairs

    Science.gov (United States)

    Gengeliczki, Zsolt; Callahan, Michael P.; Kabelac, Martin; Rijs, Anouk M.; deVries, Mattanjah S.

    2011-01-01

    We report the structure of clusters of 2,4-diaminopyrimidine with 3,7-dimethylxanthine (theobromine) in the gas phase determined by IR-UV double resonance spectroscopy in both the near-IR and mid-IR regions in combination with ab initio computations. These clusters represent potential alternate nucleobase pairs, geometrically equivalent to guanine-cytosine. We have found the four lowest energy structures, which include the Watson-Crick base pairing motif. This Watson-Crick structure has not been observed by resonant two-photon ionization (R2PI) in the gas phase for the canonical DNA base pairs.

  4. Enhanced pairing susceptibility in a photodoped two-orbital Hubbard model

    Science.gov (United States)

    Werner, Philipp; Strand, Hugo U. R.; Hoshino, Shintaro; Murakami, Yuta; Eckstein, Martin

    2018-04-01

    Local spin fluctuations provide the glue for orbital-singlet spin-triplet pairing in the doped Mott insulating regime of multiorbital Hubbard models. At large Hubbard repulsion U , the pairing susceptibility is nevertheless tiny because the pairing interaction cannot overcome the suppression of charge fluctuations. Using nonequilibrium dynamical mean field simulations of the two-orbital Hubbard model, we show that out of equilibrium the pairing susceptibility in this large-U regime can be strongly enhanced by creating a photoinduced population of the relevant charge states. This enhancement is supported by the long lifetime of photodoped charge carriers and a built-in cooling mechanism in multiorbital Hubbard systems.

  5. e+e- Pair production from 10 GeV to 10 ZeV

    International Nuclear Information System (INIS)

    Klein, Spencer R.

    2006-01-01

    At very high energies, pair production (γ->e + e - ) exhibits many interesting features. The momentum transfer from the target is very small, so the reaction probes the macroscopic properties of the target, rather than individual nuclei. Interference between interactions with different atoms reduces the pair production cross section considerably below the Bethe-Heitler values. At very high energies, photonuclear interactions may outnumber pair production. In contrast, in crystals, the interaction amplitudes may add coherently, greatly increasing the cross sections. Pair production in matter-free magnetic fields is also possible. The highest energy pair production occurs at high-energy particle colliders. This article will compare pair production in these very different regimes

  6. A family of integrable differential–difference equations, its bi-Hamiltonian structure and binary nonlinearization of the Lax pairs and adjoint Lax pairs

    International Nuclear Information System (INIS)

    Xu Xixiang

    2012-01-01

    Highlights: ► We deduce a family of integrable differential–difference equations. ► We present a discrete Hamiltonian operator involving two arbitrary real parameters. ► We establish the bi-Hamiltonian structure for obtained integrable family. ► Liouvolle integrability of the obtained family is demonstrated. ► Every equation in obtained family is factored through the binary nonlinearization. - Abstract: A family of integrable differential–difference equations is derived by the method of Lax pairs. A discrete Hamiltonian operator involving two arbitrary real parameters is introduced. When the parameters are suitably selected, a pair of discrete Hamiltonian operators is presented. Bi-Hamiltonian structure of obtained family is established by discrete trace identity. Then, Liouville integrability for the obtained family is proved. Ultimately, through the binary nonlinearization of the Lax pairs and adjoint Lax pairs, every differential–difference equation in obtained family is factored by an integrable symplectic map and a finite-dimensional integrable system in Liouville sense.

  7. Pair Cascades and Deathlines in Magnetic Fields with Offset Polar Caps

    Science.gov (United States)

    Harding, Alice K.; Muslimov, Alex G.

    2012-01-01

    We present results of electron-positron pair cascade simulations in a dipole magnetic field whose polar cap is offset from the dipole axis. In such a field geometry, the polar cap is displaced a small fraction of the neutron star radius from the star symmetry axis and the field line radius of curvature is modified. Using the modified parallel electric field near the offset polar cap, we simulate pair cascades to determine the pair deathlines and pair multiplicities as a function of the offset. We find that the pair multiplicity can change dr;unatically with a modest offset, with a significant increase on one side of the polar cap. Lower pair deathlines allow a larger fraction of the pulsar population, that include old and millisecond pulsars, to produce cascades with high multiplicity. The results have some important implications for pulsar particle production, high-energy emission and cosmic-ray contribution.

  8. A novel pseudo-complementary PNA G-C base pair

    DEFF Research Database (Denmark)

    Olsen, Anne G.; Dahl, Otto; Petersen, Asger Bjørn

    2011-01-01

    Pseudo-complementary oligonucleotide analogues and mimics provide novel opportunities for targeting duplex structures in RNA and DNA. Previously, a pseudo-complementary A-T base pair has been introduced. Towards sequence unrestricted targeting, a pseudo-complementary G-C base pair consisting...

  9. Pair production by a deep potential well

    International Nuclear Information System (INIS)

    Nikishov, A.I.

    1987-01-01

    Solutions are obtained for the Dirac and Klein-Gordon equations with a one-dimensional symmetric potential well, having a flat bottom and arbitrary depth, width and field strengths at the walls. Quasi-stationary solutions describing a pair production by the well and the inverse process are obtained. It is shown that if the pair production probability is small, it is expressed in terms of the pair production probability on one wall and the particle oscillation frequency in the well. If the well has a supercritical depth, the lower continuum contains positron resonance scattering states at energies close to the real part of the quasi-stationary level energy (Zeldovich's effect). The qualitative dependence of the positron penetration coefficient through the wall on its energy and the well depth is an evidence that the solution of the so called one-particle Dirac equation describes in fact a many-particle system with a charge of 0 or 1

  10. Kappa statistic for clustered matched-pair data.

    Science.gov (United States)

    Yang, Zhao; Zhou, Ming

    2014-07-10

    Kappa statistic is widely used to assess the agreement between two procedures in the independent matched-pair data. For matched-pair data collected in clusters, on the basis of the delta method and sampling techniques, we propose a nonparametric variance estimator for the kappa statistic without within-cluster correlation structure or distributional assumptions. The results of an extensive Monte Carlo simulation study demonstrate that the proposed kappa statistic provides consistent estimation and the proposed variance estimator behaves reasonably well for at least a moderately large number of clusters (e.g., K ≥50). Compared with the variance estimator ignoring dependence within a cluster, the proposed variance estimator performs better in maintaining the nominal coverage probability when the intra-cluster correlation is fair (ρ ≥0.3), with more pronounced improvement when ρ is further increased. To illustrate the practical application of the proposed estimator, we analyze two real data examples of clustered matched-pair data. Copyright © 2014 John Wiley & Sons, Ltd.

  11. Orthogonal expansions related to compact Gelfand pairs

    DEFF Research Database (Denmark)

    Berg, Christian; Peron, Ana P.; Porcu, Emilio

    2017-01-01

    . The functions of this class are the functions having a uniformly convergent expansion ∑ϕεZB(ϕ)(u)ϕ(x) for xεG,uεL, where the sum is over the space Z of positive definite spherical functions ϕ:G→C for the Gelfand pair, and (B(ϕ))ϕεZ is a family of continuous positive definite functions on L such that ∑ϕε......For a locally compact group G, let P(G) denote the set of continuous positive definite functions f:G→C. Given a compact Gelfand pair (G,K) and a locally compact group L, we characterize the class PK#(G,L) of functions fεP(G×L) which are bi-invariant in the G-variable with respect to K......(d)) and (U(q),U(q-1)) as well as for the product of these Gelfand pairs.The result generalizes recent theorems of Berg-Porcu (2016) and Guella-Menegatto (2016)....

  12. Top-quark pair production at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, Valentin

    2011-12-08

    In this thesis we investigate several phenomenologically important properties of top-quark pair production at hadron colliders. We calculate double differential cross sections in two different kinematical setups, pair invariant-mass (PIM) and single-particle inclusive (1PI) kinematics. In pair invariant-mass kinematics we are able to present results for the double differential cross section with respect to the invariant mass of the top-quark pair and the top-quark scattering angle. Working in the threshold region, where the pair invariant mass M is close to the partonic center-of-mass energy {radical}(s), we are able to factorize the partonic cross section into different energy regions. We use renormalization-group (RG) methods to resum large threshold logarithms to next-to-next-to-leading-logarithmic (NNLL) accuracy. On a technical level this is done using effective field theories, such as heavy-quark effective theory (HQET) and soft-collinear effective theory (SCET). The same techniques are applied when working in 1PI kinematics, leading to a calculation of the double differential cross section with respect to transverse-momentum pT and the rapidity of the top quark. We restrict the phase-space such that only soft emission of gluons is possible, and perform a NNLL resummation of threshold logarithms. The obtained analytical expressions enable us to precisely predict several observables, and a substantial part of this thesis is devoted to their detailed phenomenological analysis. Matching our results in the threshold regions to the exact ones at next-to-leading order (NLO) in fixed-order perturbation theory, allows us to make predictions at NLO+NNLL order in RG-improved, and at approximate next-to-next-to-leading order (NNLO) in fixed order perturbation theory. We give numerical results for the invariant mass distribution of the top-quark pair, and for the top-quark transverse-momentum and rapidity spectrum. We predict the total cross section, separately for both

  13. A multi-parametric particle-pairing algorithm for particle tracking in single and multiphase flows

    International Nuclear Information System (INIS)

    Cardwell, Nicholas D; Vlachos, Pavlos P; Thole, Karen A

    2011-01-01

    Multiphase flows (MPFs) offer a rich area of fundamental study with many practical applications. Examples of such flows range from the ingestion of foreign particulates in gas turbines to transport of particles within the human body. Experimental investigation of MPFs, however, is challenging, and requires techniques that simultaneously resolve both the carrier and discrete phases present in the flowfield. This paper presents a new multi-parametric particle-pairing algorithm for particle tracking velocimetry (MP3-PTV) in MPFs. MP3-PTV improves upon previous particle tracking algorithms by employing a novel variable pair-matching algorithm which utilizes displacement preconditioning in combination with estimated particle size and intensity to more effectively and accurately match particle pairs between successive images. To improve the method's efficiency, a new particle identification and segmentation routine was also developed. Validation of the new method was initially performed on two artificial data sets: a traditional single-phase flow published by the Visualization Society of Japan (VSJ) and an in-house generated MPF data set having a bi-modal distribution of particles diameters. Metrics of the measurement yield, reliability and overall tracking efficiency were used for method comparison. On the VSJ data set, the newly presented segmentation routine delivered a twofold improvement in identifying particles when compared to other published methods. For the simulated MPF data set, measurement efficiency of the carrier phases improved from 9% to 41% for MP3-PTV as compared to a traditional hybrid PTV. When employed on experimental data of a gas–solid flow, the MP3-PTV effectively identified the two particle populations and reported a vector efficiency and velocity measurement error comparable to measurements for the single-phase flow images. Simultaneous measurement of the dispersed particle and the carrier flowfield velocities allowed for the calculation of

  14. Transport de paires EPR dans des structures mesoscopiques

    Science.gov (United States)

    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

  15. rSNPBase 3.0: an updated database of SNP-related regulatory elements, element-gene pairs and SNP-based gene regulatory networks.

    Science.gov (United States)

    Guo, Liyuan; Wang, Jing

    2018-01-04

    Here, we present the updated rSNPBase 3.0 database (http://rsnp3.psych.ac.cn), which provides human SNP-related regulatory elements, element-gene pairs and SNP-based regulatory networks. This database is the updated version of the SNP regulatory annotation database rSNPBase and rVarBase. In comparison to the last two versions, there are both structural and data adjustments in rSNPBase 3.0: (i) The most significant new feature is the expansion of analysis scope from SNP-related regulatory elements to include regulatory element-target gene pairs (E-G pairs), therefore it can provide SNP-based gene regulatory networks. (ii) Web function was modified according to data content and a new network search module is provided in the rSNPBase 3.0 in addition to the previous regulatory SNP (rSNP) search module. The two search modules support data query for detailed information (related-elements, element-gene pairs, and other extended annotations) on specific SNPs and SNP-related graphic networks constructed by interacting transcription factors (TFs), miRNAs and genes. (3) The type of regulatory elements was modified and enriched. To our best knowledge, the updated rSNPBase 3.0 is the first data tool supports SNP functional analysis from a regulatory network prospective, it will provide both a comprehensive understanding and concrete guidance for SNP-related regulatory studies. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  16. Analysis of electron pair production in the collision system Ar+KCl at 1.76 AGeV; Analyse der Elektronpaarproduktion im Stosssystem Ar+KCl bei 1,76 AGeV

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Simon Martin

    2008-06-30

    The HADES-spectrometer at GSI is used to measure the production of the light vector mesons {rho}, {omega} and {phi} at SIS energies. Therefore, the medium sized collision system Ar+KCl was measured at 1.76 AGeV kinetic energy of beam particles. In this system the density of particle tracks is much larger as compared to the formerly used collision system C+C, making it necessary to upgrade the data analysis. The previous method of hard-cuts - used for particle identification - was replaced by a newly developed multi-variate analysis based on an artificial neural network. This algorithm has the benefit, that it is more robust against fluctuations in one or more of the used detector observables. This increases the overall efficiency and purity of the analysis procedure. Furthermore, the reconstruction of particle tracks inside the HADES spectrometer is based on a few position information, only. During analysis of raw data, these information are combined to a artificially large manifold of tracks. This leads to the general problem that one has to select the maximum number of true physical tracks out of this set of tracks per event. A new method of track selection is used to filter the data not only to select single tracks, but also to identify electron pairs created during Dalitz-decay of {pi}{sup 0} mesons, which build the bulk of combinatorial background. The result of the analysis is an efficiency corrected invariant mass spectrum of electron pairs, normalized to the mean number of pions per event. The spectrum consists of more than 16,000 pairs with an invariant mass larger than 150 MeV. In total more than 150000 pairs were found. A first comparison with the spectra calculated by using the old analysis approach shows a 30% enhancement in yield of reconstructed electron pairs. A first comparison with a simple thermal model implemented by the Pluto event generator, opens the possibility to compare the measured pair yield of {omega} and {phi} mesons via m{sub T

  17. Envisaging quantum transport phenomenon in a muddled base pair of DNA

    Science.gov (United States)

    Vohra, Rajan; Sawhney, Ravinder Singh

    2018-05-01

    The effect of muddled base pair on electron transfer through a deoxyribonucleic acid (DNA) molecule connected to the gold electrodes has been elucidated using tight binding model. The effect of hydrogen and nitrogen bonds on the resistance of the base pair has been minutely observed. Using the semiempirical extended Huckel approach within NEGF regime, we have determined the current and conductance vs. bias voltage for disordered base pairs of DNA made of thymine (T) and adenine (A). The asymmetrical behaviour amid five times depreciation in the current characteristics has been observed for deviated Au-AT base pair-Au devices. An interesting revelation is that the conductance of the intrinsic AT base pair configuration attains dramatically high values with the symmetrical zig-zag pattern of current, which clearly indicates the transformation of the bond length within the strands of base pair when compared with other samples. A thorough investigation of the transmission coefficients T( E) and HOMO-LUMO gap reveals the misalignment of the strands in base pairs of DNA. The observed results present an insight to extend this work to build biosensing devices to predict the abnormality with the DNA.

  18. minimal pairs of polytopes and their number of vertices

    African Journals Online (AJOL)

    Preferred Customer

    Using this operation we give a new algorithm to reduce and find a minimal pair of polytopes from the given ... Key words/phrases: Pairs of compact convex sets, Blaschke addition, Minkowski sum, mnimality ... product K(X)×K(X) by K2. (X).

  19. Josephson junction analog and quasiparticle-pair current

    DEFF Research Database (Denmark)

    Bak, Christen Kjeldahl; Pedersen, Niels Falsig

    1973-01-01

    A close analogy exists between a Josephson junction and a phase-locked loop. A new type of electrical analog based on this principle is presented. It is shown that the inclusion in this analog of a low-pass filter gives rise to a current of the same form as the Josephson quasiparticle-pair current....... A simple picture of the quasiparticle-pair current, which gives the right dependences, is obtained by assuming a junction cutoff frequency to be at the energy gap. ©1973 American Institute of Physics...

  20. Arithmetic properties of $\\ell$-regular overpartition pairs

    OpenAIRE

    NAIKA, MEGADAHALLI SIDDA MAHADEVA; SHIVASHANKAR, CHANDRAPPA

    2017-01-01

    In this paper, we investigate the arithmetic properties of $\\ell$-regular overpartition pairs. Let $\\overline{B}_{\\ell}(n)$ denote the number of $\\ell$-regular overpartition pairs of $n$. We will prove the number of Ramanujan-like congruences and infinite families of congruences modulo 3, 8, 16, 36, 48, 96 for $\\overline{B}_3(n)$ and modulo 3, 16, 64, 96 for $\\overline{B}_4(n)$. For example, we find that for all nonnegative integers $\\alpha$ and $n$, $\\overline{B}_{3}(3^{\\alpha}(3n+2))\\equiv ...

  1. Ferromagnetic pairing states on two-coupled chains

    International Nuclear Information System (INIS)

    Tanaka, Akinori

    2008-01-01

    We propose a concrete model which exhibits ferromagnetism and electron-pair condensation simultaneously. The model is defined on two chains and consists of the electron hopping term, the on-site Coulomb repulsion and a ferromagnetic interaction which describes ferromagnetic coupling between two electrons, one on a bond in a chain and the other on a site in the other chain. It is rigorously shown that the model has fully-polarized ferromagnetic pairing ground states. The higher dimensional version of the model is also presented

  2. Study of neutron-proton pairing in N=Z unstable nuclei through transfer reactions

    International Nuclear Information System (INIS)

    Le Crom, B.

    2016-01-01

    A nucleus is described as a set of independent neutrons and protons linked by a mean-field potential. However, in order to have a better description one needs to take into account some residual interactions such as pairing. Neutron-neutron and proton-proton pairings are well-studied but neutron-proton pairing is not well-known. np pairing can be isovector pairing such as nn and pp pairing or isoscalar which is yet unknown. Over-binding of N=Z nuclei could be a manifestation of np pairing. We have studied np pairing through transfer reactions. In this case, the cross-section of np pair transfer is expected to be enhanced in the presence of important np pairing. np pairing is expected to be important in N=Z nuclei with high J orbitals. Since the development of radioactive beam facilities, such beams are only available. The experiment was performed at GANIL with an efficient set-up so as to detect products from the (p, 3 He) transfer reaction. This reaction is affected by isovector and isoscalar np pairing. We used 56 Ni and 52 Fe beams so as to see the effect of the occupancy of 0f 7/2 shell on the np pairing. First, we analysed the data from the 56 Ni(p,d) 55 Ni reaction and we compared the results with the literature to validate analysis procedure. After analysing data from the 56 Ni(p, 3 He) 54 Co reaction and extracting the population of the various states of 54 Co, we obtained information about the relative intensity between isoscalar and isovector np pairing in 56 Ni showing the predominance of isovector np pairing in this nucleus. Moreover, in the framework of developing a new charged particle detector, research on the discrimination of light nuclei using pulse shape analysis was performed and is also presented. (author)

  3. Pair distribution function and structure factor of spherical particles

    International Nuclear Information System (INIS)

    Howell, Rafael C.; Proffen, Thomas; Conradson, Steven D.

    2006-01-01

    The availability of neutron spallation-source instruments that provide total scattering powder diffraction has led to an increased application of real-space structure analysis using the pair distribution function. Currently, the analytical treatment of finite size effects within pair distribution refinement procedures is limited. To that end, an envelope function is derived which transforms the pair distribution function of an infinite solid into that of a spherical particle with the same crystal structure. Distributions of particle sizes are then considered, and the associated envelope function is used to predict the particle size distribution of an experimental sample of gold nanoparticles from its pair distribution function alone. Finally, complementing the wealth of existing diffraction analysis, the peak broadening for the structure factor of spherical particles, expressed as a convolution derived from the envelope functions, is calculated exactly for all particle size distributions considered, and peak maxima, offsets, and asymmetries are discussed

  4. 'Leonard pairs' in classical mechanics

    International Nuclear Information System (INIS)

    Zhedanov, Alexei; Korovnichenko, Alyona

    2002-01-01

    Leonard pairs (LP) are matrices with the property of mutual tri-diagonality. We introduce and study a classical analogue of LP. We show that corresponding classical 'Leonard' dynamical variables satisfy non-linear relations of the AW-type with respect to Poisson brackets. (author)

  5. Damage Mechanism in Counter Pairs Caused by Bionic Non-smoothed Surface

    Directory of Open Access Journals (Sweden)

    ZHANG Zhan-hui

    2016-08-01

    Full Text Available Four biomimetic non-smoothed surface specimens with different shapes were prepared by laser processing. Tests were conducted on MMU-5G wear and abrasion test machine to study the influencing rule of non-smoothed surfaces on counter pairs. The results show that the mass loss of the friction pair matching with the non-smoothed units is much greater than the ones matching with the smooth specimens. The pairs matching with different non-smoothed units suffer differently. The non-smoothed surface protruding zone exerts micro cutting on counter pairs. The striation causes the greatest mass loss of the pairs than the other non-smoothed units, which almost doubles the damage of the grid ones suffering the least. The difference in pairs damage is attributed to the different mechanism of undertaking the load in the process of wear. The damage can be alleviated effectively by changing the shapes of the units without increasing or decreasing the area ratio of the non-smoothed units.

  6. Temperature dependence of pair correlations in nuclei in the iron region

    International Nuclear Information System (INIS)

    Langanke, K.; Dean, D.J.; Oak Ridge National Lab., TN; Radha, P.B.; Koonin, S.E.

    1996-01-01

    We use the shell-model Monte Carlo approach to study thermal properties and pair correlations in 54,56,58 Fe and in 56 Cr. The calculations are performed with the modified Kuo-Brown interaction in the complete 1p0f model space. We find generally that the proton-proton and neutron-neutron J=0 pairing correlations, which dominate the ground-state properties of even-even nuclei, vanish at temperatures around 1 MeV. This pairing phase transition is accompanied by a rapid increase in the moment of inertia and a partial unquenching of the M1 strength. We find that the M1 strength totally unquenches at higher temperatures, related to the vanishing of isoscalar proton-neutron correlations, which persist to higher temperatures than the pairing between like nucleons. The Gamow-Teller strength is also correlated to the isoscalar proton-neutron pairing and hence also unquenches at a temperature larger than that of the pairing phase transition. (orig.)

  7. A Scaffold Analysis Tool Using Mate-Pair Information in Genome Sequencing

    Directory of Open Access Journals (Sweden)

    Pan-Gyu Kim

    2008-01-01

    Full Text Available We have developed a Windows-based program, ConPath, as a scaffold analyzer. ConPath constructs scaffolds by ordering and orienting separate sequence contigs by exploiting the mate-pair information between contig-pairs. Our algorithm builds directed graphs from link information and traverses them to find the longest acyclic graphs. Using end read pairs of fixed-sized mate-pair libraries, ConPath determines relative orientations of all contigs, estimates the gap size of each adjacent contig pair, and reports wrong assembly information by validating orientations and gap sizes. We have utilized ConPath in more than 10 microbial genome projects, including Mannheimia succiniciproducens and Vibro vulnificus, where we verified contig assembly and identified several erroneous contigs using the four types of error defined in ConPath. Also, ConPath supports some convenient features and viewers that permit investigation of each contig in detail; these include contig viewer, scaffold viewer, edge information list, mate-pair list, and the printing of complex scaffold structures.

  8. Pair creation of higher dimensional black holes on a de Sitter background

    International Nuclear Information System (INIS)

    Dias, Oscar J.C.; Lemos, Jose P.S.

    2004-01-01

    We study in detail the quantum process in which a pair of black holes is created in a higher D-dimensional de Sitter (dS) background. The energy to materialize and accelerate the pair comes from the positive cosmological constant. The instantons that describe the process are obtained from the Tangherlini black hole solutions. Our pair creation rates reduce to the pair creation rate for Reissner-Nordstroem-dS solutions when D=4. Pair creation of black holes in the dS background becomes less suppressed when the dimension of the spacetime increases. The dS space is the only background in which we can discuss analytically the pair creation process of higher dimensional black holes, since the C-metric and the Ernst solutions, which describe, respectively, a pair accelerated by a string and by an electromagnetic field, are not known yet in a higher dimensional spacetime

  9. Pairing States of Spin-3/2 Fermions: Symmetry-Enforced Topological Gap Functions

    Science.gov (United States)

    Venderbos, Jörn W. F.; Savary, Lucile; Ruhman, Jonathan; Lee, Patrick A.; Fu, Liang

    2018-01-01

    We study the topological properties of superconductors with paired j =3/2 quasiparticles. Higher spin Fermi surfaces can arise, for instance, in strongly spin-orbit coupled band-inverted semimetals. Examples include the Bi-based half-Heusler materials, which have recently been established as low-temperature and low-carrier density superconductors. Motivated by this experimental observation, we obtain a comprehensive symmetry-based classification of topological pairing states in systems with higher angular momentum Cooper pairing. Our study consists of two main parts. First, we develop the phenomenological theory of multicomponent (i.e., higher angular momentum) pairing by classifying the stationary points of the free energy within a Ginzburg-Landau framework. Based on the symmetry classification of stationary pairing states, we then derive the symmetry-imposed constraints on their gap structures. We find that, depending on the symmetry quantum numbers of the Cooper pairs, different types of topological pairing states can occur: fully gapped topological superconductors in class DIII, Dirac superconductors, and superconductors hosting Majorana fermions. Notably, we find a series of nematic fully gapped topological superconductors, as well as double- and triple-Dirac superconductors, with quadratic and cubic dispersion, respectively. Our approach, applied here to the case of j =3/2 Cooper pairing, is rooted in the symmetry properties of pairing states, and can therefore also be applied to other systems with higher angular momentum and high-spin pairing. We conclude by relating our results to experimentally accessible signatures in thermodynamic and dynamic probes.

  10. Reducing interaction in simultaneous paired stimulation with CI.

    Directory of Open Access Journals (Sweden)

    Dirk Vellinga

    Full Text Available In this study simultaneous paired stimulation of electrodes in cochlear implants is investigated by psychophysical experiments in 8 post-lingually deaf subjects (and one extra subject who only participated in part of the experiments. Simultaneous and sequential monopolar stimulation modes are used as references and are compared to channel interaction compensation, partial tripolar stimulation and a novel sequential stimulation strategy named phased array compensation. Psychophysical experiments are performed to investigate both the loudness integration during paired stimulation at the main electrodes as well as the interaction with the electrode contact located halfway between the stimulating pair. The study shows that simultaneous monopolar stimulation has more loudness integration on the main electrodes and more interaction in between the electrodes than sequential stimulation. Channel interaction compensation works to reduce the loudness integration at the main electrodes, but does not reduce the interaction in between the electrodes caused by paired stimulation. Partial tripolar stimulation uses much more current to reach the needed loudness, but shows the same interaction in between the electrodes as sequential monopolar stimulation. In phased array compensation we have used the individual impedance matrix of each subject to calculate the current needed on each electrode to exactly match the stimulation voltage along the array to that of sequential stimulation. The results show that the interaction in between the electrodes is the same as monopolar stimulation. The strategy uses less current than partial tripolar stimulation, but more than monopolar stimulation. In conclusion, the paper shows that paired stimulation is possible if the interaction is compensated.

  11. The Effects of Reinforcer Pairing and Fading on Preschoolers' Snack Selections

    Science.gov (United States)

    Solberg, Katherine M.; Hanley, Gregory P.; Layer, Stacy A.; Ingvarsson, Einar T.

    2007-01-01

    The effects of reinforcement pairing and fading on preschoolers' snack selections were evaluated in a multiple baseline design. Baseline preferences for snack options were assessed via repeated paired-item preference assessments. Edible, social, and activity-based reinforcers were then exclusively paired with a less preferred snack option. Once…

  12. Free-fall dynamics of a pair of rigidly linked disks

    Science.gov (United States)

    Kim, Taehyun; Chang, Jaehyeock; Kim, Daegyoum

    2018-03-01

    We investigate experimentally the free-fall motion of a pair of identical disks rigidly connected to each other. The three-dimensional coordinates of the pair of falling disks were constructed to quantitatively describe its trajectory, and the flow structure formed by the disk pair was identified by using dye visualization. The rigidly linked disk pair exhibits a novel falling pattern that creates a helical path with a conical configuration in which the lower disk rotates in a wider radius than the upper disk with respect to a vertical axis. The helical motion occurs consistently for the range of disk separation examined in this study. The dye visualization reveals that a strong, noticeable helical vortex core is generated from the outer tip of the lower disk during the helical motion. With an increasing length ratio, which is the ratio of the disk separation to the diameter of the disks, the nutation angle and the rate of change in the precession angle that characterize the combined helical and conical kinematics decrease linearly, whereas the pitch of the helical path increases linearly. Although all disk pairs undergo this helical motion, the horizontal-drift patterns of the disk pair depend on the length ratio.

  13. Micromechanics of base pair unzipping in the DNA duplex

    International Nuclear Information System (INIS)

    Volkov, Sergey N; Paramonova, Ekaterina V; Yakubovich, Alexander V; Solov’yov, Andrey V

    2012-01-01

    All-atom molecular dynamics (MD) simulations of DNA duplex unzipping in a water environment were performed. The investigated DNA double helix consists of a Drew-Dickerson dodecamer sequence and a hairpin (AAG) attached to the end of the double-helix chain. The considered system is used to examine the process of DNA strand separation under the action of an external force. This process occurs in vivo and now is being intensively investigated in experiments with single molecules. The DNA dodecamer duplex is consequently unzipped pair by pair by means of the steered MD. The unzipping trajectories turn out to be similar for the duplex parts with G⋅C content and rather distinct for the parts with A⋅T content. It is shown that during the unzipping each pair experiences two types of motion: relatively quick rotation together with all the duplex and slower motion in the frame of the unzipping fork. In the course of opening, the complementary pair passes through several distinct states: (i) the closed state in the double helix, (ii) the metastable preopened state in the unzipping fork and (iii) the unbound state. The performed simulations show that water molecules participate in the stabilization of the metastable states of the preopened base pairs in the DNA unzipping fork. (paper)

  14. Orbitally limited pair-density-wave phase of multilayer superconductors

    Science.gov (United States)

    Möckli, David; Yanase, Youichi; Sigrist, Manfred

    2018-04-01

    We investigate the magnetic field dependence of an ideal superconducting vortex lattice in the parity-mixed pair-density-wave phase of multilayer superconductors within a circular cell Ginzburg-Landau approach. In multilayer systems, due to local inversion symmetry breaking, a Rashba spin-orbit coupling is induced at the outer layers. This combined with a perpendicular paramagnetic (Pauli) limiting magnetic field stabilizes a staggered layer dependent pair-density-wave phase in the superconducting singlet channel. The high-field pair-density-wave phase is separated from the low-field BCS phase by a first-order phase transition. The motivating guiding question in this paper is: What is the minimal necessary Maki parameter αM for the appearance of the pair-density-wave phase of a superconducting trilayer system? To address this problem we generalize the circular cell method for the regular flux-line lattice of a type-II superconductor to include paramagnetic depairing effects. Then, we apply the model to the trilayer system, where each of the layers are characterized by Ginzburg-Landau parameter κ0 and a Maki parameter αM. We find that when the spin-orbit Rashba interaction compares to the superconducting condensation energy, the orbitally limited pair-density-wave phase stabilizes for Maki parameters αM>10 .

  15. SDSS-IV MaNGA: Galaxy Pair Fraction and Correlated Active Galactic Nuclei

    Science.gov (United States)

    Fu, Hai; Steffen, Joshua L.; Gross, Arran C.; Dai, Y. Sophia; Isbell, Jacob W.; Lin, Lihwai; Wake, David; Xue, Rui; Bizyaev, Dmitry; Pan, Kaike

    2018-04-01

    We have identified 105 galaxy pairs at z ∼ 0.04 with the MaNGA integral-field spectroscopic data. The pairs have projected separations between 1 and 30 kpc, and are selected to have radial velocity offsets less than 600 km s‑1 and stellar mass ratio between 0.1 and 1. The pair fraction increases with both the physical size of the integral-field unit and the stellar mass, consistent with theoretical expectations. We provide the best-fit analytical function of the pair fraction and find that ∼3% of M* galaxies are in close pairs. For both isolated galaxies and paired galaxies, active galactic nuclei (AGNs) are selected using emission-line ratios and Hα equivalent widths measured inside apertures at a fixed physical size. We find AGNs in ∼24% of the paired galaxies and binary AGNs in ∼13% of the pairs. To account for the selection biases in both the pair sample and the MaNGA sample, we compare the AGN comoving volume densities with those expected from the mass- and redshift-dependent AGN fractions. We find a strong (∼5×) excess of binary AGNs over random pairing and a mild (∼20%) deficit of single AGNs. The binary AGN excess increases from ∼2× to ∼6× as the projected separation decreases from 10–30 to 1–10 kpc. Our results indicate that the pairing of galaxies preserves the AGN duty cycle in individual galaxies but increases the population of binary AGNs through correlated activities. We suggest tidally induced galactic-scale shocks and AGN cross-ionization as two plausible channels to produce low-luminosity narrow-line-selected binary AGNs.

  16. Design of a rotary dielectric elastomer actuator using a topology optimization method based on pairs of curves

    Science.gov (United States)

    Wang, Nianfeng; Guo, Hao; Chen, Bicheng; Cui, Chaoyu; Zhang, Xianmin

    2018-05-01

    Dielectric elastomers (DE), known as electromechanical transducers, have been widely used in the field of sensors, generators, actuators and energy harvesting for decades. A large number of DE actuators including bending actuators, linear actuators and rotational actuators have been designed utilizing an experience design method. This paper proposes a new method for the design of DE actuators by using a topology optimization method based on pairs of curves. First, theoretical modeling and optimization design are discussed, after which a rotary dielectric elastomer actuator has been designed using this optimization method. Finally, experiments and comparisons between several DE actuators have been made to verify the optimized result.

  17. Sorting processes with energy-constrained comparisons*

    Science.gov (United States)

    Geissmann, Barbara; Penna, Paolo

    2018-05-01

    We study very simple sorting algorithms based on a probabilistic comparator model. In this model, errors in comparing two elements are due to (1) the energy or effort put in the comparison and (2) the difference between the compared elements. Such algorithms repeatedly compare and swap pairs of randomly chosen elements, and they correspond to natural Markovian processes. The study of these Markov chains reveals an interesting phenomenon. Namely, in several cases, the algorithm that repeatedly compares only adjacent elements is better than the one making arbitrary comparisons: in the long-run, the former algorithm produces sequences that are "better sorted". The analysis of the underlying Markov chain poses interesting questions as the latter algorithm yields a nonreversible chain, and therefore its stationary distribution seems difficult to calculate explicitly. We nevertheless provide bounds on the stationary distributions and on the mixing time of these processes in several restrictions.

  18. Functionally segregated neural substrates for arbitrary audiovisual paired-association learning.

    Science.gov (United States)

    Tanabe, Hiroki C; Honda, Manabu; Sadato, Norihiro

    2005-07-06

    To clarify the neural substrates and their dynamics during crossmodal association learning, we conducted functional magnetic resonance imaging (MRI) during audiovisual paired-association learning of delayed matching-to-sample tasks. Thirty subjects were involved in the study; 15 performed an audiovisual paired-association learning task, and the remainder completed a control visuo-visual task. Each trial consisted of the successive presentation of a pair of stimuli. Subjects were asked to identify predefined audiovisual or visuo-visual pairs by trial and error. Feedback for each trial was given regardless of whether the response was correct or incorrect. During the delay period, several areas showed an increase in the MRI signal as learning proceeded: crossmodal activity increased in unimodal areas corresponding to visual or auditory areas, and polymodal responses increased in the occipitotemporal junction and parahippocampal gyrus. This pattern was not observed in the visuo-visual intramodal paired-association learning task, suggesting that crossmodal associations might be formed by binding unimodal sensory areas via polymodal regions. In both the audiovisual and visuo-visual tasks, the MRI signal in the superior temporal sulcus (STS) in response to the second stimulus and feedback peaked during the early phase of learning and then decreased, indicating that the STS might be key to the creation of paired associations, regardless of stimulus type. In contrast to the activity changes in the regions discussed above, there was constant activity in the frontoparietal circuit during the delay period in both tasks, implying that the neural substrates for the formation and storage of paired associates are distinct from working memory circuits.

  19. Pumping Electron-Positron Pairs from a Well Potential.

    Science.gov (United States)

    Wang, Qiang; Liu, Jie; Fu, Li-Bin

    2016-04-29

    In the presence of very deep well potential, electrons will spontaneously occupy the empty embedded bound states and electron-positron pairs are created by means of a non-perturbative tunneling process. In this work, by slowly oscillating the width or depth, the population transfer channels are opened and closed periodically. We find and clearly show that by the non-synchronous ejections of particles, the saturation of pair number in a static super-critical well can be broken, and electrons and positrons can be pumped inexhaustibly from vacuum with a constant production rate. In the adiabatic limit, final pair number after a single cycle has quantized values as a function of the upper boundary of the oscillating, and the critical upper boundaries indicate the diving points of the bound states.

  20. Inflation of the screening length induced by Bjerrum pairs

    NARCIS (Netherlands)

    Zwanikken, J.W.; van Roij, R.H.H.G.

    2009-01-01

    Within a modified Poisson–Boltzmann theory we study the effect of Bjerrum pairs on the typical length scale 1/¯κ over which electric fields are screened in electrolyte solutions, taking into account a simple association–dissociation equilibrium between free ions and Bjerrum pairs. At low densities

  1. On e(+)e(-) pair production by colliding electromagnetic pulses

    NARCIS (Netherlands)

    Narozhny, NB; Bulanov, SS; Mur, VD; Popov, VS

    2004-01-01

    Electron-positron pair production from vacuum in an electromagnetic field created by two counterpropagating focused laser pulses interacting with each other is analyzed. The dependence of the number of produced pairs on the intensity of a laser pulse and the focusing parameter is studied with a

  2. Solving the Airline Crew Pairing Problem using Subsequence Generation

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Lusby, Richard Martin; Ryan, David M.

    2010-01-01

    Good and fast solutions to the airline crew pairing problem are highly interesting for the airline industry, as crew costs are the biggest expenditure after fuel for an airline. The crew pairing problem is typically modelled as a set partitioning problem and solved by column generation. However, ...

  3. Solving the Airline Crew Pairing Problem using Subsequence Generation

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Ryan, David; Lusby, Richard Martin

    2009-01-01

    Good and fast solutions to the airline crew pairing problem are highly interesting for the airline industry, as crew costs are the biggest expenditure after fuel for an airline. The crew pairing problem is typically modelled as a set partitioning problem and solved by column generation. However, ...

  4. Female bluethroats enhance offspring immunocompetence through extra-pair copulations.

    Science.gov (United States)

    Johnsen, A; Andersen, V; Sunding, C; Lifjeld, J T

    2000-07-20

    Female birds frequently copulate with extra-pair males, but the adaptive value of this behaviour is poorly understood. Some studies have suggested that 'good genes' may be involved, where females seek to have their eggs fertilized by high-quality males without receiving any material benefits from them. Nevertheless, it remains to be shown that a genetic benefit is passed on to offspring. Here we report that nestling bluethroats, Luscinia svecica, sired by extra-pair males had a higher T-cell-mediated immune response than their maternal half-siblings raised in the same nest. The difference could not be attributed to nestling body mass, sex or hatching order, but may be an effect of paternal genotype. Extra-pair young were also more immunocompetent than their paternal half-sibs raised in the genetic father's own nest, which indicates an additional effect of maternal genotype. Our results are consistent with the idea that females engage in extra-pair copulations to obtain compatible viability genes, rather than 'good genes' per se.

  5. Comparison of Spatiotemporal Fusion Models: A Review

    Directory of Open Access Journals (Sweden)

    Bin Chen

    2015-02-01

    Full Text Available Simultaneously capturing spatial and temporal dynamics is always a challenge for the remote sensing community. Spatiotemporal fusion has gained wide interest in various applications for its superiority in integrating both fine spatial resolution and frequent temporal coverage. Though many advances have been made in spatiotemporal fusion model development and applications in the past decade, a unified comparison among existing fusion models is still limited. In this research, we classify the models into three categories: transformation-based, reconstruction-based, and learning-based models. The objective of this study is to (i compare four fusion models (STARFM, ESTARFM, ISTAFM, and SPSTFM under a one Landsat-MODIS (L-M pair prediction mode and two L-M pair prediction mode using time-series datasets from the Coleambally irrigation area and Poyang Lake wetland; (ii quantitatively assess prediction accuracy considering spatiotemporal comparability, landscape heterogeneity, and model parameter selection; and (iii discuss the advantages and disadvantages of the three categories of spatiotemporal fusion models.

  6. Thermodynamic and structural properties of the specific binding between Ag⁺ ion and C:C mismatched base pair in duplex DNA to form C-Ag-C metal-mediated base pair.

    Science.gov (United States)

    Torigoe, Hidetaka; Okamoto, Itaru; Dairaku, Takenori; Tanaka, Yoshiyuki; Ono, Akira; Kozasa, Tetsuo

    2012-11-01

    Metal ion-nucleic acid interactions have attracted considerable interest for their involvement in structure formation and catalytic activity of nucleic acids. Although interactions between metal ion and mismatched base pair duplex are important to understand mechanism of gene mutations related to heavy metal ions, they have not been well-characterized. We recently found that the Ag(+) ion stabilized a C:C mismatched base pair duplex DNA. A C-Ag-C metal-mediated base pair was supposed to be formed by the binding between the Ag(+) ion and the C:C mismatched base pair to stabilize the duplex. Here, we examined specificity, thermodynamics and structure of possible C-Ag-C metal-mediated base pair. UV melting indicated that only the duplex with the C:C mismatched base pair, and not of the duplexes with the perfectly matched and other mismatched base pairs, was specifically stabilized on adding the Ag(+) ion. Isothermal titration calorimetry demonstrated that the Ag(+) ion specifically bound with the C:C base pair at 1:1 molar ratio with a binding constant of 10(6) M(-1), which was significantly larger than those for nonspecific metal ion-DNA interactions. Electrospray ionization mass spectrometry also supported the specific 1:1 binding between the Ag(+) ion and the C:C base pair. Circular dichroism spectroscopy and NMR revealed that the Ag(+) ion may bind with the N3 positions of the C:C base pair without distorting the higher-order structure of the duplex. We conclude that the specific formation of C-Ag-C base pair with large binding affinity would provide a binding mode of metal ion-DNA interactions, similar to that of the previously reported T-Hg-T base pair. The C-Ag-C base pair may be useful not only for understanding of molecular mechanism of gene mutations related to heavy metal ions but also for wide variety of potential applications of metal-mediated base pairs in various fields, such as material, life and environmental sciences. Copyright © 2012 Elsevier

  7. Three mirror pairs of fermion families

    International Nuclear Information System (INIS)

    Montvay, I.

    1988-01-01

    A simple model with three mirror pairs of fermion families is considered which allows for a substantial mixing between the mirror fermion partners without conflicting with known phenomenology. (orig.)

  8. Studying Open versus Traditional Textbook Effects on Students' Course Performance: Confounds Abound

    Science.gov (United States)

    Griggs, Richard A.; Jackson, Sherri L.

    2017-01-01

    To combat the high cost of textbooks, open (digitally free) textbooks have recently entered the textbook market. Griggs and Jackson (2017) reviewed the open introductory psychology textbooks presently available to provide interested teachers with essential information about these texts and how they compare with traditional (commercial)…

  9. Repeatedly pairing vagus nerve stimulation with a movement reorganizes primary motor cortex.

    Science.gov (United States)

    Porter, Benjamin A; Khodaparast, Navid; Fayyaz, Tabbassum; Cheung, Ryan J; Ahmed, Syed S; Vrana, William A; Rennaker, Robert L; Kilgard, Michael P

    2012-10-01

    Although sensory and motor systems support different functions, both systems exhibit experience-dependent cortical plasticity under similar conditions. If mechanisms regulating cortical plasticity are common to sensory and motor cortices, then methods generating plasticity in sensory cortex should be effective in motor cortex. Repeatedly pairing a tone with a brief period of vagus nerve stimulation (VNS) increases the proportion of primary auditory cortex responding to the paired tone (Engineer ND, Riley JR, Seale JD, Vrana WA, Shetake J, Sudanagunta SP, Borland MS, Kilgard MP. 2011. Reversing pathological neural activity using targeted plasticity. Nature. 470:101-104). In this study, we predicted that repeatedly pairing VNS with a specific movement would result in an increased representation of that movement in primary motor cortex. To test this hypothesis, we paired VNS with movements of the distal or proximal forelimb in 2 groups of rats. After 5 days of VNS movement pairing, intracranial microstimulation was used to quantify the organization of primary motor cortex. Larger cortical areas were associated with movements paired with VNS. Rats receiving identical motor training without VNS pairing did not exhibit motor cortex map plasticity. These results suggest that pairing VNS with specific events may act as a general method for increasing cortical representations of those events. VNS movement pairing could provide a new approach for treating disorders associated with abnormal movement representations.

  10. A rolling-gliding wear simulator for the investigation of tribological material pairings for application in total knee arthroplasty

    Science.gov (United States)

    2010-01-01

    Background Material wear testing is an important technique in the development and evaluation of materials for use in implant for total knee arthroplasty. Since a knee joint induces a complex rolling-gliding movement, standardised material wear testing devices such as Pin-on-Disc or Ring-on-Disc testers are suitable to only a limited extent because they generate pure gliding motion only. Methods A rolling-gliding wear simulator was thus designed, constructed and implemented, which simulates and reproduces the rolling-gliding movement and loading of the knee joint on specimens of simplified geometry. The technical concept was to run a base-plate, representing the tibia plateau, against a pivoted cylindrical counter-body, representing one femur condyle under an axial load. A rolling movement occurs as a result of the friction and pure gliding is induced by limiting the rotation of the cylindrical counter-body. The set up also enables simplified specimens handling and removal for gravimetrical wear measurements. Long-term wear tests and gravimetrical wear measurements were carried out on the well known material pairings: cobalt chrome-polyethylene, ceramic-polyethylene and ceramic-ceramic, over three million motion cycles to allow material comparisons to be made. Results The observed differences in wear rates between cobalt-chrome on polyethylene and ceramic on polyethylene pairings were similar to the differences of published data for existing material-pairings. Test results on ceramic-ceramic pairings of different frontal-plane geometry and surface roughness displayed low wear rates and no fracture failures. Conclusions The presented set up is able to simulate the rolling-gliding movement of the knee joint, is easy to use, and requires a minimum of user intervention or monitoring. It is suitable for long-term testing, and therefore a useful tool for the investigation of new and promising materials which are of interest for application in knee joint replacement

  11. A rolling-gliding wear simulator for the investigation of tribological material pairings for application in total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Denkena Berend

    2010-06-01

    Full Text Available Abstract Background Material wear testing is an important technique in the development and evaluation of materials for use in implant for total knee arthroplasty. Since a knee joint induces a complex rolling-gliding movement, standardised material wear testing devices such as Pin-on-Disc or Ring-on-Disc testers are suitable to only a limited extent because they generate pure gliding motion only. Methods A rolling-gliding wear simulator was thus designed, constructed and implemented, which simulates and reproduces the rolling-gliding movement and loading of the knee joint on specimens of simplified geometry. The technical concept was to run a base-plate, representing the tibia plateau, against a pivoted cylindrical counter-body, representing one femur condyle under an axial load. A rolling movement occurs as a result of the friction and pure gliding is induced by limiting the rotation of the cylindrical counter-body. The set up also enables simplified specimens handling and removal for gravimetrical wear measurements. Long-term wear tests and gravimetrical wear measurements were carried out on the well known material pairings: cobalt chrome-polyethylene, ceramic-polyethylene and ceramic-ceramic, over three million motion cycles to allow material comparisons to be made. Results The observed differences in wear rates between cobalt-chrome on polyethylene and ceramic on polyethylene pairings were similar to the differences of published data for existing material-pairings. Test results on ceramic-ceramic pairings of different frontal-plane geometry and surface roughness displayed low wear rates and no fracture failures. Conclusions The presented set up is able to simulate the rolling-gliding movement of the knee joint, is easy to use, and requires a minimum of user intervention or monitoring. It is suitable for long-term testing, and therefore a useful tool for the investigation of new and promising materials which are of interest for application in

  12. A rolling-gliding wear simulator for the investigation of tribological material pairings for application in total knee arthroplasty.

    Science.gov (United States)

    Richter, Berna I; Ostermeier, Sven; Turger, Anke; Denkena, Berend; Hurschler, Christof

    2010-06-15

    Material wear testing is an important technique in the development and evaluation of materials for use in implant for total knee arthroplasty. Since a knee joint induces a complex rolling-gliding movement, standardised material wear testing devices such as Pin-on-Disc or Ring-on-Disc testers are suitable to only a limited extent because they generate pure gliding motion only. A rolling-gliding wear simulator was thus designed, constructed and implemented, which simulates and reproduces the rolling-gliding movement and loading of the knee joint on specimens of simplified geometry. The technical concept was to run a base-plate, representing the tibia plateau, against a pivoted cylindrical counter-body, representing one femur condyle under an axial load. A rolling movement occurs as a result of the friction and pure gliding is induced by limiting the rotation of the cylindrical counter-body. The set up also enables simplified specimens handling and removal for gravimetrical wear measurements. Long-term wear tests and gravimetrical wear measurements were carried out on the well known material pairings: cobalt chrome-polyethylene, ceramic-polyethylene and ceramic-ceramic, over three million motion cycles to allow material comparisons to be made. The observed differences in wear rates between cobalt-chrome on polyethylene and ceramic on polyethylene pairings were similar to the differences of published data for existing material-pairings. Test results on ceramic-ceramic pairings of different frontal-plane geometry and surface roughness displayed low wear rates and no fracture failures. The presented set up is able to simulate the rolling-gliding movement of the knee joint, is easy to use, and requires a minimum of user intervention or monitoring. It is suitable for long-term testing, and therefore a useful tool for the investigation of new and promising materials which are of interest for application in knee joint replacement implants.

  13. Pair correlation of particles in strongly nonideal systems

    International Nuclear Information System (INIS)

    Vaulina, O. S.

    2012-01-01

    A new semiempirical model is proposed for describing the spatial correlation between interacting particles in nonideal systems. The developed model describes the main features in the behavior of the pair correlation function for crystalline structures and can also be used for qualitative and quantitative description of the spatial correlation of particles in strongly nonideal liquid systems. The proposed model is compared with the results of simulation of the pair correlation function.

  14. THINK-PAIR-SHARE: A TECNIQUE TO ENHANCE STUDENTS’ WRITING SKILL

    OpenAIRE

    Okta Ika Rahmawati

    2017-01-01

    Abstract: Think – Pair Share: A Tecnique to Enhance Students’ Writing Skill. This article refers to a classroom action research on teaching writing by implementing Think-Pair-Share at High School in Bojonegoro. Think-Pair-Share Technique is a kind of cooperative learning technique. This technique encourages students to actively involve in the learning process since they have to discuss with their partner about the material being learned. The subject of the study was the tenth-grade students o...

  15. CPM Pairs from LSPM so Far Not WDS Listed – Part IV

    Science.gov (United States)

    Knapp, Wilfried; Nanson, John

    2018-04-01

    The LSPM catalog (Lepine and Shara 2005) is a rich source for CPM pairs we thought already exhausted – but as we found during research for our report "A New Concept for Counter-Checking of Assumed CPM Pairs" (Knapp and Nanson 2017), there are still many potential CPM pairs indicated in LSPM not listed in the WDS catalog. After our first three reports on about 100 such objects (Knapp and Nanson 2017 - CPM pairs from LSPM so far not WDS listed – Part I/II/III), this report with 30 additional potential common proper motion pairs is presented here.

  16. Differential stabilities and sequence-dependent base pair opening dynamics of Watson-Crick base pairs with 5-hydroxymethylcytosine, 5-formylcytosine, or 5-carboxylcytosine.

    Science.gov (United States)

    Szulik, Marta W; Pallan, Pradeep S; Nocek, Boguslaw; Voehler, Markus; Banerjee, Surajit; Brooks, Sonja; Joachimiak, Andrzej; Egli, Martin; Eichman, Brandt F; Stone, Michael P

    2015-02-10

    5-Hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) form during active demethylation of 5-methylcytosine (5mC) and are implicated in epigenetic regulation of the genome. They are differentially processed by thymine DNA glycosylase (TDG), an enzyme involved in active demethylation of 5mC. Three modified Dickerson-Drew dodecamer (DDD) sequences, amenable to crystallographic and spectroscopic analyses and containing the 5'-CG-3' sequence associated with genomic cytosine methylation, containing 5hmC, 5fC, or 5caC placed site-specifically into the 5'-T(8)X(9)G(10)-3' sequence of the DDD, were compared. The presence of 5caC at the X(9) base increased the stability of the DDD, whereas 5hmC or 5fC did not. Both 5hmC and 5fC increased imino proton exchange rates and calculated rate constants for base pair opening at the neighboring base pair A(5):T(8), whereas 5caC did not. At the oxidized base pair G(4):X(9), 5fC exhibited an increase in the imino proton exchange rate and the calculated kop. In all cases, minimal effects to imino proton exchange rates occurred at the neighboring base pair C(3):G(10). No evidence was observed for imino tautomerization, accompanied by wobble base pairing, for 5hmC, 5fC, or 5caC when positioned at base pair G(4):X(9); each favored Watson-Crick base pairing. However, both 5fC and 5caC exhibited intranucleobase hydrogen bonding between their formyl or carboxyl oxygens, respectively, and the adjacent cytosine N(4) exocyclic amines. The lesion-specific differences observed in the DDD may be implicated in recognition of 5hmC, 5fC, or 5caC in DNA by TDG. However, they do not correlate with differential excision of 5hmC, 5fC, or 5caC by TDG, which may be mediated by differences in transition states of the enzyme-bound complexes.

  17. Differential Stabilities and Sequence-Dependent Base Pair Opening Dynamics of Watson–Crick Base Pairs with 5-Hydroxymethylcytosine, 5-Formylcytosine, or 5-Carboxylcytosine

    Science.gov (United States)

    2016-01-01

    5-Hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) form during active demethylation of 5-methylcytosine (5mC) and are implicated in epigenetic regulation of the genome. They are differentially processed by thymine DNA glycosylase (TDG), an enzyme involved in active demethylation of 5mC. Three modified Dickerson–Drew dodecamer (DDD) sequences, amenable to crystallographic and spectroscopic analyses and containing the 5′-CG-3′ sequence associated with genomic cytosine methylation, containing 5hmC, 5fC, or 5caC placed site-specifically into the 5′-T8X9G10-3′ sequence of the DDD, were compared. The presence of 5caC at the X9 base increased the stability of the DDD, whereas 5hmC or 5fC did not. Both 5hmC and 5fC increased imino proton exchange rates and calculated rate constants for base pair opening at the neighboring base pair A5:T8, whereas 5caC did not. At the oxidized base pair G4:X9, 5fC exhibited an increase in the imino proton exchange rate and the calculated kop. In all cases, minimal effects to imino proton exchange rates occurred at the neighboring base pair C3:G10. No evidence was observed for imino tautomerization, accompanied by wobble base pairing, for 5hmC, 5fC, or 5caC when positioned at base pair G4:X9; each favored Watson–Crick base pairing. However, both 5fC and 5caC exhibited intranucleobase hydrogen bonding between their formyl or carboxyl oxygens, respectively, and the adjacent cytosine N4 exocyclic amines. The lesion-specific differences observed in the DDD may be implicated in recognition of 5hmC, 5fC, or 5caC in DNA by TDG. However, they do not correlate with differential excision of 5hmC, 5fC, or 5caC by TDG, which may be mediated by differences in transition states of the enzyme-bound complexes. PMID:25632825

  18. Exclusive production of W pairs in CMS

    Directory of Open Access Journals (Sweden)

    Silveira Da

    2014-04-01

    Full Text Available We report the results on the search for exclusive production of W pairs in the LHC with data collected by the Compact Muon Solenoid detector in proton-proton collisions at √s = 7 TeV. The analysis comprises the two-photon production of a W pairs, pp → pW+ W− p → p νe± νµ∓ p. Two events are observed in data for pT(ℓ > 4 GeV, |η(ℓ| 20 GeV, in agreement with the standard model prediction of 2.2 ± 0.4 signal events with 0.84 ± 0.15 background events. Moreover, a study of the tail of the lepton pair transverse momentum distribution is performed to search for an evidence of anomalous quartic gauge couplings in the γγ → W+ W− vertex. As no events are observed in data, it results in a model-independent upper limits for the anomalous W quartic gauge couplings aW0,C/Λ2, which are of the order of 10−4.

  19. Pair formation by a deep potential well

    International Nuclear Information System (INIS)

    Nikishov, A.I.

    1987-01-01

    We obtain solutions of the Dirac and Klein-Gordon equations for a symmetric one-dimensional potential well with a flat bottom, and arbitrary depth, width, and field strength at the walls. Quasistationary solutions are found describing pair creation by the well, and the inverse process. It is shown that when the probability of pair creation by the well is small, it can be expressed in terms of the probability of pair creation at one of the walls and the oscillation frequency of the particle in the well. Among the states of the lower continuum, there are positron resonance scattering states for supercritical well depths. The energies of these states are close to the real part of the quasistationary energy level (the Zel'dovich effect). The qualitative dependence of the transmission coefficient of the positron through the well on its energy and the well width supports the idea that the solution of the so-called one-particle Dirac equation describes a many-particle system with charge 0 or 1

  20. En route to matter-antimatter pair plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Stenson, Eve V.; Hergenhahn, Uwe; Paschkowski, Norbert; Saitoh, Haruhiko; Stanja, Juliane [Max Planck Institute for Plasma Physics, Greifswald and Garching (Germany); Niemann, Holger; Sunn Pedersen, Thomas [Max Planck Institute for Plasma Physics, Greifswald and Garching (Germany); Ernst Moritz Arndt University of Greifswald, Greifswald (Germany); Schweikhard, Lutz [Ernst Moritz Arndt University of Greifswald, Greifswald (Germany); Hugenschmidt, Christoph [Technische Universitaet Muenchen, Garching (Germany); Danielson, James R.; Surko, Clifford M. [University of California, San Diego, La Jolla (United States)

    2015-05-01

    The APEX and PAX projects have as their overarching goal the laboratory creation and confinement of the world's first positron-electron pair plasma. Plasmas of this type have been the subject of hundreds of theoretical investigations and are also believed to play a role in various astrophysical environments. In order to achieve this goal in an experimentally accessible volume (e.g., 10 liters), a record number (≥ 10{sup 10}) of cold (∝ 1 eV) positrons are to be accumulated and combined with a corresponding population of electrons. Notable requirements include a high-intensity positron beam (such as NEPOMUC), a suitable magnetic confinement device for the pair plasma (such as a levitated dipole), high-efficiency tools for bridging the two (i.e., means by which the positrons can be efficiently cooled, trapped, and injected across flux surfaces), and diagnostics not only for the pair plasma, but also for the positron beam and for intermediary non-neutral plasmas. This talk will summarize the project as a whole and recent work by the APEX/PAX team on its various elements.