1,144 research outputs found
Programmatic and Direct Manipulation, Together at Last
Direct manipulation interfaces and programmatic systems have distinct and
complementary strengths. The former provide intuitive, immediate visual
feedback and enable rapid prototyping, whereas the latter enable complex,
reusable abstractions. Unfortunately, existing systems typically force users
into just one of these two interaction modes.
We present a system called Sketch-n-Sketch that integrates programmatic and
direct manipulation for the particular domain of Scalable Vector Graphics
(SVG). In Sketch-n-Sketch, the user writes a program to generate an output SVG
canvas. Then the user may directly manipulate the canvas while the system
immediately infers a program update in order to match the changes to the
output, a workflow we call live synchronization. To achieve this, we propose
(i) a technique called trace-based program synthesis that takes program
execution history into account in order to constrain the search space and (ii)
heuristics for dealing with ambiguities. Based on our experience with examples
spanning 2,000 lines of code and from the results of a preliminary user study,
we believe that Sketch-n-Sketch provides a novel workflow that can augment
traditional programming systems. Our approach may serve as the basis for live
synchronization in other application domains, as well as a starting point for
yet more ambitious ways of combining programmatic and direct manipulation.Comment: PLDI 2016 Paper + Supplementary Appendice
Higher-order multipole amplitudes in charmonium radiative transitions
Using 24 million decays in CLEO-c, we have searched
for higher multipole admixtures in electric-dipole-dominated radiative
transitions in charmonia. We find good agreement between our data and
theoretical predictions for magnetic quadrupole (M2) amplitudes in the
transitions and ,
in striking contrast to some previous measurements. Let and
denote the normalized M2 amplitudes in the respective aforementioned decays,
where the superscript refers to the angular momentum of the . By
performing unbinned maximum likelihood fits to full five-parameter angular
distributions, we determine the ratios and , where
the theoretical predictions are independent of the charmed quark magnetic
moment and are and .Comment: 32 pages, 7 figures, acceptance updat
Search for rare and forbidden decays of charm and charmed-strange mesons to final states h^+- e^-+ e^+
We have searched for flavor-changing neutral current decays and
lepton-number-violating decays of D^+ and D^+_s mesons to final states of the
form h^+- e^-+ e^+, where h is either \pi or K. We use the complete samples of
CLEO-c open-charm data, corresponding to integrated luminosities of 818 pb^-1
at the center-of-mass energy E_CM = 3.774 GeV containing 2.4 x 10^6 D^+D^-
pairs and 602 pb^-1 at E_CM = 4.170 GeV containing 0.6 x 10^6 D^*+-_s D^-+_s
pairs. No signal is observed in any channel, and we obtain 90% confidence level
upper limits on branching fractions B(D^+ --> \pi^+ e^+ e^-) < 5.9 x 10^-6,
B(D^+ --> \pi^- e^+ e^+) K^+ e^+ e^-) < 3.0 x 10^-6,
B(D^+ --> K^- e^+ e^+) \pi^+ e^+ e^-) < 2.2 x 10^-5,
B(D^+_s --> \pi^- e^+ e^+) K^+ e^+ e^-) < 5.2 x
10^-5, and B(D^+_s --> K^- e^+ e^+) < 1.7 x 10^-5.Comment: 9 pages, available through http://www.lns.cornell.edu/public/CLNS
New Measurement of Parity Violation in Elastic Electron-Proton Scattering and Implications for Strange Form Factors
We have measured the parity-violating electroweak asymmetry in the elastic
scattering of polarized electrons from the proton. The result is A = -15.05 +-
0.98(stat) +- 0.56(syst) ppm at the kinematic point theta_lab = 12.3 degrees
and Q^2 = 0.477 (GeV/c)^2. The measurement implies that the value for the
strange form factor (G_E^s + 0.392 G_M^s) = 0.025 +- 0.020 +- 0.014, where the
first error is experimental and the second arises from the uncertainties in
electromagnetic form factors. This measurement is the first fixed-target parity
violation experiment that used either a `strained' GaAs photocathode to produce
highly polarized electrons or a Compton polarimeter to continuously monitor the
electron beam polarization.Comment: 8 pages, 4 figures, Tex, elsart.cls; revised version as accepted for
Phys. Lett.
Boundary Capabilities in MNCs: Knowledge Transformation for Creative Solution Development
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.The management of knowledge across country units is critical to multinational corporations (MNCs). Building on the argument that boundary spanning leads to the development of creative problem solving outcomes, this study advances the concept of MNC knowledge transformation and examines its relationship with solution creativity. Using questionnaire data on 67 problem solving projects, we find that opportunity formation is an underlying mechanism linking MNC knowledge transformation to the development of creative solutions. These insights contribute to our understanding of boundary spanning in global organizations by substantiating MNC knowledge transformation and elaborating the relationship between boundary spanning and creative solution development. If successful at knowledge transformation, collaborators from across the MNC can construct previously unimagined opportunities for the generation of creative outcomes.This study was funded by the Irish Research Council with co-funding from the European
Commission (Marie-Curie Fellowship). We are very grateful for the insightful comments of
Phillip C. Nell, the three reviewers, editors and participants at the paper development
workshop at Ivey Business School
Measurement of the eta b(1S) mass and the branching fraction for Gamma(3S) -\u3e gamma eta b(1S)
We report evidence for the ground state of bottomonium, eta(b)(1S), in the radiative decay Gamma(3S) -\u3e gamma eta(b) in e(+)e(-) annihilation data taken with the CLEO III detector. Using 6 X 10(6) Gamma(dS) decays, and assuming Gamma(eta(b)) = 10 +/- 5 MeV/c(2), we obtain B(Gamma(3S) -\u3e gamma eta(b)) = (7.1 +/- 1.8 +/- 1.3) X 10(-4), where the first error is statistical and the second is systematic. The statistical significance is -4 sigma. The mass is determined to be M(eta(b)) = 9391.8 +/- 6.6 +/- 2.0 MeV/c(2), which corresponds to the hyperfine splitting Delta M-hf(1S)(b) = 68.5 +/- 6.6 +/- 2.0 MeV/c(2). Using 9 X 10(6) Gamma(2S) decays, we place an upper limit on the corresponding Gamma(2S) decay, B(Gamma(2S) -\u3e gamma eta(b)) \u3c 8.4 X 10(-4) at 90% confidence level
Measurement of absolute branching fractions of inclusive semileptonic decays of charm and charmed-strange mesons
We have measured the inclusive semileptonic branching fractions of D-0, D+, and D-s(+) mesons. For these measurements, we have used the full CLEO-c open-charm data samples, 818 pb(-1) at E-CM = 3.774 GeV, giving D-0(D) over bar (0) and D+D- events, and 602 pb(-1) at E-CM = 4.170 GeV, giving D-s*D-+/-(s)-/+ events. We obtain B(D-0 -\u3e Xe+nu(e)) = (6.46 +/- 0.09 +/- 0.11)%, B(D+ -\u3e Xe+nu(e)) = (16.13 +/- 0.10 +/- 0.29)%, and B(D-s(+) -\u3e Xe+nu(e)) = (6.52 +/- 0.39 +/- 0.15)%, where the first uncertainties are statistical and the second are systematic. From these and lifetimes obtained elsewhere, we obtain the ratios of semileptonic decay widths Gamma(D+ -\u3e Xe+nu(e))/Gamma(D-0 -\u3e Xe+nu(e)) = 0.985 +/- 0.015 +/- 0.024 and Gamma(D-s(+) -\u3e Xe+nu(e))/Gamma(D-0 -\u3e Xe+nu(e)) = 0.828 +/- 0.051 +/- 0.025. The ratio of D+ and D-0 is consistent with the isospin symmetry prediction of unity, and the ratio of D-s(+) and D-0 differs from unity, as expected
Rotavirus group : a genotype circulation patterns across Kenya before and after nationwide vaccine introduction, 2010-2018
Background
Kenya introduced the monovalent G1P [8] Rotarix® vaccine into the infant immunization schedule in July 2014. We examined trends in rotavirus group A (RVA) genotype distribution pre- (January 2010–June 2014) and post- (July 2014–December 2018) RVA vaccine introduction.
Methods
Stool samples were collected from children aged < 13 years from four surveillance sites across Kenya: Kilifi County Hospital, Tabitha Clinic Nairobi, Lwak Mission Hospital, and Siaya County Referral Hospital (children aged < 5 years only). Samples were screened for RVA using enzyme linked immunosorbent assay (ELISA) and VP7 and VP4 genes sequenced to infer genotypes.
Results
We genotyped 614 samples in pre-vaccine and 261 in post-vaccine introduction periods. During the pre-vaccine introduction period, the most frequent RVA genotypes were G1P [8] (45.8%), G8P [4] (15.8%), G9P [8] (13.2%), G2P [4] (7.0%) and G3P [6] (3.1%). In the post-vaccine introduction period, the most frequent genotypes were G1P [8] (52.1%), G2P [4] (20.7%) and G3P [8] (16.1%). Predominant genotypes varied by year and site in both pre and post-vaccine periods. Temporal genotype patterns showed an increase in prevalence of vaccine heterotypic genotypes, such as the commonly DS-1-like G2P [4] (7.0 to 20.7%, P < .001) and G3P [8] (1.3 to 16.1%, P < .001) genotypes in the post-vaccine introduction period. Additionally, we observed a decline in prevalence of genotypes G8P [4] (15.8 to 0.4%, P < .001) and G9P [8] (13.2 to 5.4%, P < .001) in the post-vaccine introduction period. Phylogenetic analysis of genotype G1P [8], revealed circulation of strains of lineages G1-I, G1-II and P [8]-1, P [8]-III and P [8]-IV. Considerable genetic diversity was observed between the pre and post-vaccine strains, evidenced by distinct clusters.
Conclusion
Genotype prevalence varied from before to after vaccine introduction. Such observations emphasize the need for long-term surveillance to monitor vaccine impact. These changes may represent natural secular variation or possible immuno-epidemiological changes arising from the introduction of the vaccine. Full genome sequencing could provide insights into post-vaccine evolutionary pressures and antigenic diversity
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