Simulating Quantum Dynamics On A Quantum Computer

We present efficient quantum algorithms for simulating time-dependent Hamiltonian evolution of general input states using an oracular model of a quantum computer. Our algorithms use either constant or adaptively chosen time steps and are significant because they are the first to have time-complexities that are comparable to the best known methods for simulating time-independent Hamiltonian evolution, given appropriate smoothness criteria on the Hamiltonian are satisfied. We provide a thorough cost analysis of these algorithms that considers discretizion errors in both the time and the representation of the Hamiltonian. In addition, we provide the first upper bounds for the error in Lie-Trotter-Suzuki approximations to unitary evolution operators, that use adaptively chosen time steps.Comment: Paper modified from previous version to enhance clarity. Comments are welcom

The cost of a structure which is to take the place of the Beaver Bridge

The subject of this treatise is the cost of a structure, which is to take the place of the Beaver Bridge. This bridge is located on the St. L and San F. Rwy., four miles southwest of Rolla and it spans a deep valley nearly a 1000 ft. in width in the bottom of which runs a small stream The course of roadway over the bridge is N. 24 1/2 E. The old wooden Howe Truss bridge, being no longer considered perfectly safe, on account of its age, measure was taken to supply its place with some new structure that, with the least expenditure, would carry the road safely over the valley. Now the question before us is this: whether in this case it will cost more to build an Iron Truss bridge, or to construct an embankment, using as the former the peers of the old bridge --page 2

The interpretation of rapidity gaps at HERA

In leading twist deep inelastic ep scattering, the virtual photon interaction is fast compared to the time scale of soft color rearrangement. We compare the Pomeron exchange model, in which a neutral cluster is preformed, with a gluon exchange model, in which color is exchanged after the hard interaction. We find several features of the DIS data and of data on exclusive hard processes that favor a gluon exchange scenario. If correct, the postulate of soft color interactions between the produced (q\bar q) system and the target has important implications for other processes. In particular, this may explain the puzzles of charmonium hadroproduction

The hbar Expansion in Quantum Field Theory

We show how expansions in powers of Planck's constant hbar = h/2\pi can give new insights into perturbative and nonperturbative properties of quantum field theories. Since hbar is a fundamental parameter, exact Lorentz invariance and gauge invariance are maintained at each order of the expansion. The physics of the hbar expansion depends on the scheme; i.e., different expansions are obtained depending on which quantities (momenta, couplings and masses) are assumed to be independent of hbar. We show that if the coupling and mass parameters appearing in the Lagrangian density are taken to be independent of hbar, then each loop in perturbation theory brings a factor of hbar. In the case of quantum electrodynamics, this scheme implies that the classical charge e, as well as the fine structure constant are linear in hbar. The connection between the number of loops and factors of hbar is more subtle for bound states since the binding energies and bound-state momenta themselves scale with hbar. The hbar expansion allows one to identify equal-time relativistic bound states in QED and QCD which are of lowest order in hbar and transform dynamically under Lorentz boosts. The possibility to use retarded propagators at the Born level gives valence-like wave-functions which implicitly describe the sea constituents of the bound states normally present in its Fock state representation.Comment: 8 pages, 1 figure. Version to be published in Phys. Rev.

Homiletics

Homiletics: Preaching and Counselin

Many-Body Dynamics and Exciton Formation Studied by Time-Resolved Photoluminescence

The dynamics of exciton and electron-hole plasma populations is studied via time-resolved photoluminescence after nonresonant excitation. By comparing the peak emission at the exciton resonance with the emission of the continuum, it is possible to experimentally identify regimes where the emission originates predominantly from exciton and/or plasma populations. The results are supported by a microscopic theory which allows one to extract the fraction of bright excitons as a function of time.Comment: 11 pages, 5 figure

SIVdrl detection in captive mandrills: are mandrills infected with a third strain of simian immunodeficiency virus?

A pol-fragment of simian immunodeficiency virus (SIV) that is highly related to SIVdrl-pol from drill monkeys (Mandrillus leucophaeus) was detected in two mandrills (Mandrillus sphinx) from Amsterdam Zoo. These captivity-born mandrills had never been in contact with drill monkeys, and were unlikely to be hybrids. Their mitochondrial haplotype suggested that they descended from founder animals in Cameroon or northern Gabon, close to the habitat of the drill. SIVdrl has once before been found in a wild-caught mandrill from the same region, indicating that mandrills are naturally infected with a SIVdrl-like virus. This suggests that mandrills are the first primate species to be infected with three strains of SIV: SIVmnd1, SIVmnd2, and SIVdrl

Quality of Web Mashups: A Systematic Mapping Study

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-04244-2_8Web mashups are a new generation of applications based on the composition of ready-to-use, heterogeneous components. They are gaining momentum thanks to their lightweight composition approach, which represents a new opportunity for companies to leverage on past investments in SOA, Web services, and public APIs. Although several studies are emerging in order to address mashup development, no systematic mapping studies have been reported on how quality issues are being addressed. This paper reports a systematic mapping study on which and how the quality of Web mashups has been addressed and how the product quality-aware approaches have been defined and validated. The aim of this study is to provide a background in which to appropriately develop future research activities. A total of 38 research papers have been included from an initial set of 187 papers. Our results provided some findings regarding how the most relevant product quality characteristics have been addressed in different artifacts and stages of the development process. They have also been useful to detect some research gaps, such as the need of more controlled experiments and more quality-aware mashup development proposals for other characteristics which being important for the Web domain have been neglected such as Usability and ReliabilityThis work is funded by the MULTIPLE project (TIN2009-13838), the Senescyt program (scholarships 2011), and the Erasmus Mundus Programme of the European Commission under the Transatlantic Partnership for Excellence in Engineering - TEE Project.Cedillo Orellana, IP.; Fernández Martínez, A.; Insfrán Pelozo, CE.; Abrahao Gonzales, SM. (2013). Quality of Web Mashups: A Systematic Mapping Study. En Current Trends in Web Engineering. Springer. 66-78. https://doi.org/10.1007/978-3-319-04244-2_8S6678Alkhalifa, E.: The Future of Enterprise Mashups. Business Insights. E-Strategies for Resource Management Systems (2009)Beemer, B., Gregg, D.: Mashups: A Literature Review and Classification Framework. Future Internet 1, 59–87 (2009)Cappiello, C., Daniel, F., Matera, M.: A Quality Model for Mashup Components. In: Gaedke, M., Grossniklaus, M., Díaz, O. (eds.) ICWE 2009. LNCS, vol. 5648, pp. 236–250. Springer, Heidelberg (2009)Cappiello, C., Daniel, F., Matera, M., Pautasso, C.: Information Quality in Mashups. IEEE Internet Computing 14(4), 32–40 (2010)Cappiello, C., Matera, M., Picozzi, M., Daniel, F., Fernandez, A.: Quality-Aware Mashup Composition: Issues, Techniques and Tools. In: 8th International Conference on the Quality of Information and Communications Technology (QUATIC 2012), pp. 10–19 (2012)Fenton, N.E., Pfleeger, S.L.: Software Metrics: A Rigorous and Practical Approach, 2nd edn. International Thompson 1996, pp. I–XII, 1–638 (1996) ISBN 978-1-85032-275-7Fernandez, A., Insfran, E., Abrahão, S.: Usability evaluation methods for the web: A systematic mapping study. Information and Software Technology 53(8), 789–817 (2011)Garousi, V., Mesbah, A., Betin-Can, A., Mirshokraie, S.: A systematic mapping study of web application testing. Information and Software Technology 55(8), 1374–1396 (2013)Grammel, L., Storey, M.-A.: A survey of mashup development environments. In: Chignell, M., Cordy, J., Ng, J., Yesha, Y. (eds.) The Smart Internet. LNCS, vol. 6400, pp. 137–151. Springer, Heidelberg (2010)Hoyer, V., Fischer, M.: Market Overview of Enterprise Mashup Tools. In: Bouguettaya, A., Krueger, I., Margaria, T. (eds.) ICSOC 2008. LNCS, vol. 5364, pp. 708–721. Springer, Heidelberg (2008)ISO/IEC: ISO/IEC 25010 Systems and software engineering. Systems and software Quality Requirements and Evaluation (SQuaRE). System and software quality models (2011)Kitchenham, B., Charters, S.: Guidelines for performing Systematic Literature Reviews in Software Engineering. Version 2.3, ESBE Technical Report, Keele University, UK (2007)Mendes, E.: A systematic review on the Web engineering research. In: International Symposium on Empirical Software Engineering (ISESE 2005), pp. 498–507 (2005)OrangeLabs: State of the Art in Mashup tools, SocEDA project, pp. 1–59 (2011)Petersen, K., Feldt, R., Mujtaba, S., Mattsson, M.: Systematic mapping studies in software engineering. In: 12th International Conference on Evaluation and Assessment in Software Engineering (EASE), pp. 68–77 (2008)Raza, M., Hussain, F.K., Chang, E.: A methodology for quality-based mashup of data sources. In: 10th International Conference on Information Integration and Web-based Applications & Services (iiWAS 2008), pp. 528–533 (2008)Saeed, A.: A Quality-based Framework for Leveraging the Process of Mashup Component Selection (2009), https://gupea.ub.gu.se/handle/2077/21953Sharma, A., Hellmann, T.D., Maurer, F.: Testing of Web Services - A Systematic Mapping. In: 8th World Congress on Services (SERVICES 2012), pp. 346–352 (2012

Structural characterization of copper(II) binding to α-Synuclein: Insights into the bioinorganic chemistry of Parkinson's disease

The aggregation of α -synuclein (AS) is characteristic of Parkinson’s disease and other neurodegenerative synucleinopathies. We demonstrate here that Cu(II) ions are effective in accelerating AS aggregation at physiologically relevant concentrations without altering the resultant fibrillar structures. By using numerous spectroscopic techniques (absorption, CD, EPR, and NMR), we have located the primary binding for Cu(II) to a specific site in the N terminus, involving His-50 as the anchoring residue and other nitrogen oxygen donor atoms in a square planar or distorted tetragonal geometry. The carboxylate-rich C terminus, originally thought to drive copper binding, is able to coordinate a second Cu(II) equivalent, albeit with a 300-fold reduced affinity. The NMR analysis of AS–Cu(II) complexes reveals the existence of conformational restrictions in the native state of the protein. The metallobiology of Cu(II) in Parkinson’s disease is discussed by a comparative analysis with other Cu(II)-binding proteins involved in neurodegenerative disorders