Quantum walks based on an interferometric analogy

There are presently two models for quantum walks on graphs. The "coined" walk uses discrete time steps, and contains, besides the particle making the walk, a second quantum system, the coin, that determines the direction in which the particle will move. The continuous walk operates with continuous time. Here a third model for a quantum walk is proposed, which is based on an analogy to optical interferometers. It is a discrete-time model, and the unitary operator that advances the walk one step depends only on the local structure of the graph on which the walk is taking place. No quantum coin is introduced. This type of walk allows us to introduce elements, such as phase shifters, that have no counterpart in classical random walks. Walks on the line and cycle are discussed in some detail, and a probability current for these walks is introduced. The relation to the coined quantum walk is also discussed. The paper concludes by showing how to define these walks for a general graph.Comment: Latex,18 pages, 5 figure

Effect of risedronate on joint structure and symptoms of knee osteoarthritis: results of the BRISK randomized, controlled trial [ISRCTN01928173]

To determine the efficacy and safety of risedronate in patients with knee osteoarthritis (OA), the British study of risedronate in structure and symptoms of knee OA (BRISK), a 1-year prospective, double-blind, placebo-controlled study, enrolled patients (40–80 years of age) with mild to moderate OA of the medial compartment of the knee. The primary aims were to detect differences in symptoms and function. Patients were randomized to once-daily risedronate (5 mg or 15 mg) or placebo. Radiographs were taken at baseline and 1 year for assessment of joint-space width using a standardized radiographic method with fluoroscopic positioning of the joint. Pain, function, and stiffness were assessed using the Western Ontario and McMaster Universities (WOMAC) OA index. The patient global assessment and use of walking aids were measured and bone and cartilage markers were assessed. The intention-to-treat population consisted of 284 patients. Those receiving risedronate at 15 mg showed improvement of the WOMAC index, particularly of physical function, significant improvement of the patient global assessment (P < 0.001), and decreased use of walking aids relative to patients receiving the placebo (P = 0.009). A trend towards attenuation of joint-space narrowing was observed in the group receiving 15 mg risedronate. Eight percent (n = 7) of patients receiving placebo and 4% (n = 4) of patients receiving 5 mg risedronate exhibited detectable progression of disease (joint-space width ≥ 25% or ≥ 0.75 mm) versus 1% (n = 1) of patients receiving 15 mg risedronate (P = 0.067). Risedronate (15 mg) significantly reduced markers of cartilage degradation and bone resorption. Both doses of risedronate were well tolerated. In this study, clear trends towards improvement were observed in both joint structure and symptoms in patients with primary knee OA treated with risedronate

Hypomania Checklist-32 - cross-validation of shorter versions screening for bipolar disorders in an epidemiological study.

Self-reports such as Hypomania Checklist (HCL-32) can be used to enhance recognition of bipolar disorders, but they are often too long and only validated in clinical samples. The objectives of this study are therefore to test whether (i) the HCL-32 can be used for screening in the community and (ii) whether two previously suggested shorter versions would do as well. Data stemmed from the CoLaus|PsyColaus, a prospective cohort study which included randomly selected residents aged 35-66 years from an urban area. Participants underwent semistructured interviews to assess DSM-IV disorders and 1712 of them completed the HCL-32. Forty individuals (2.3%) were diagnosed as having BD. Compared to others, participants with BD scored significantly higher on the HCL-32. The HCL-32 had a sensitivity of 0.78 and specificity of 0.68. Very similar figures were found for two previously proposed shorter versions with 16 and 20 items. The results of confirmatory factor analysis and item response theory (IRT) models supported the postulated two-factor structure for the three HCL versions. Despite the low base rate of BD in this sample, the screening properties of the HCL-32 remained almost as good. Importantly, two previously proposed shorter versions performed as well, suggesting that those could be used without losing essential information

Toy Model for Pion Production II: The role of three-particle singularities

The influence of three-particle breakup singularities on s-wave meson production in nucleon-nucleon collisions is studied within the distorted wave Born approximation. This study is based on a simple scalar model for the two-nucleon interaction and the production mechanism. An algorithm for the exact numerical treatment of the inherent three-body cuts, together with its straightforward implementation is presented. It is also shown that two often-used approximations to avoid the calculation of the three-body breakup are not justified. The possible impact on pion production observables is discussed.Comment: 14 pages, 6 figure

Toy Model for Pion Production in Nucleon-Nucleon Collisions

We develop a toy model of pion production in nucleon-nucleon collisions that reproduces some of the features of the chiral Lagrangian calculations. We calculate the production amplitude and examine some common approximations.Comment: 9 pages, 3 figure

Supporting learning with 3D interactive applications in early years

Early years education is an key element for the introduction of children in the education system. In order to improve this process, the aim of this study was to explore how guided interaction with 3D apps can fit into a preschool setting, how it can help children learn through playing and how it can improve their learning outcomes. A study was conducted with six classes of 87 students aged between 3 years to 6 years, over a 12-week period. Children used 10 inch Android tablets with a series of apps developed by our research team, about houses of the world, the skeleton & five senses and, animals. A quasi-experimental design based on a nonequivalent groups pretest and posttest de-sign revealed that an active behavior and better learning outcomes are obtained by children participating in the experimental groupCascales Martínez, A.; Martínez Segura, MJ.; Laguna- Segobia, M.; Pérez Lopez, DC.; Contero, M. (2014). Supporting learning with 3D interactive applications in early years. Lecture Notes in Computer Science. 8524:11-22. doi:10.1007/978-3-319-07485-6_2S11228524Plowman, L., Stephen, C.: Children, Play and Computers in Preschool Education. British Journal of Educational Technology 36(2), 145–157 (2005)Tootell, H., Plumb, M., Hadfield, C., Dawson, L.: Gestural Interface Technology in early childhood education: A framework for fully-engaged communication. In: Proceedings of the Annual Hawaii International Conference on System Sciences, art. no. 6479836, pp. 13–20 (2013)Marco, J., Cerezo, E.: Bringing Tabletop Technologies to Kindergarten Children. In: HCI 2009 International Conference on Human-Computer Interaction–Celebrating People and Technology, pp. 103–111. Springer, Heidelberg (2009)Heft, T.M., Swaminathan, S.: Using Computers in Early Childhood Classrooms: Teachers’ Attitudes, Skills and Practices. Journal of Early Childhood Research 6(4), 169–188 (2006)Wang, X.C., Ching, C.C.: Social Construction of Computer Experience in a First-Grade Classroom: Social Processes and Mediating Artifacts. Early Education and Development 14(3), 335–361 (2003)Couse, L.J., Chen, D.W.: A Tablet Computer for Young Children? Exploring Its Viability for Early Childhood Education. Journal of Research on Technology in Education 43(1), 75–98 (2012)Kearney, J.: Educating Young Children - Learning and Teaching in the Early Childhood Years. Early Childhood Teachers’ Association (ECTA Inc.) 3(18) (2012)Rankothge, W.H., Sendanayake, S.V., Sudarshana, R.G.P., Balasooriya, B.G.G.H., Alahapperuma, D.R., Mallawarachchi, Y.: Technology Assisted Tool for Learning Skills Development in Early Childhood. In: Proc. of 2012 International Conference on Advances in ICT for Emerging Regions (ICTer), pp. 165–168 (2012)Sandvik, M., Smørdal, O., Østerud, S.: Exploring iPads in Practitioners’ Repertoires for Language Learning and Literacy Practices In Kindergarten. Nordic Journal of Digital Literacy 3(7), 204–221 (2012)Priyankara, K.W.T.G.T., Mahawaththa, D.C., Nawinna, D.P., Jayasundara, J.M.A., Tharuka, K.D.N., Rajapaksha, S.K.: Android Based e-Learning Solution for Early Childhood Education in Sri Lanka. In: Proceedings of the 8th International Conference on Computer Science & Education (ICCSE), pp. 715–718 (2013)Zanchi, C., Presser, A.L., Vahey, P.: Next Generation Preschool Math Demo: Tablet Games for Preschool Classrooms. In: Proceedings of the 12th International Conference on Interaction Design and Children, IDC 2013, pp. 527–530 (2013)Meyer, B.: Game-based Language Learning for Pre-School Children: A Design Perspective. Electronic Journal of e-Learning 11(1), 39–48 (2013)Straub, D.W.: Validating Instruments in MIS Research. MIS Quarterly 13(2), 147–169 (1989)Cook, T.D., Campbell, D.T., Day, A.: Quasi-experimentation: Design and Analysis Issues for Field Settings, pp. 19–21. Houghton Mifflin, Boston (1979)Buendía, L., Y Berrocal, E.: La Ética de la Investigación Educativa. Ágora Digital 1 (2011)Tojar, J., Serrano, J.: Ética e Investigación Educativa. RELIEVE 6(2) (2000)Cascales, A., Laguna, I., Pérez-López, D., Perona, P., Contero, M.: 3D Interactive Applications on Tablets for Preschoolers: Exploring the Human Skeleton and the Senses. In: Hernández-Leo, D., Ley, T., Klamma, R., Harrer, A. (eds.) EC-TEL 2013. LNCS, vol. 8095, pp. 71–83. Springer, Heidelberg (2013

Early treatment of posterior crossbite - a randomised clinical trial

Background: The aim of this randomised clinical trial was to assess the effect of early orthodontic treatment in contrast to normal growth effects for functional unilateral posterior crossbite in the late deciduous and early mixed dentition by means of three-dimensional digital model analysis. Methods: This randomised clinical trial was assessed to analyse the orthodontic treatment effects for patients with functional unilateral posterior crossbite in the late deciduous and early mixed dentition using a two-step procedure: initial maxillary expansion followed by a U-bow activator therapy. In the treatment group 31 patients and in the control group 35 patients with a mean age of 7.3 years (SD 2.1) were monitored. The time between the initial assessment (T1) and the follow-up (T2) was one year. The orthodontic analysis was done by a three-dimensional digital model analysis. Using the ‘Digimodel’ software, the orthodontic measurements in the maxilla and mandible and for the midline deviation, the overjet and overbite were recorded. Results: Significant differences between the control and the therapy group at T2 were detected for the anterior, median and posterior transversal dimensions of the maxilla, the palatal depth, the palatal base arch length, the maxillary arch length and inclination, the midline deviation, the overjet and the overbite. Conclusions: Orthodontic treatment of a functional unilateral posterior crossbite with a bonded maxillary expansion device followed by U-bow activator therapy in the late deciduous and early mixed dentition is an effective therapeutic method, as evidenced by the results of this RCT. It leads to three-dimensional therapeutically induced maxillary growth effects. Dental occlusion is significantly improved, and the prognosis for normal craniofacial growth is enhanced

Quantum random walks in optical lattices

We propose an experimental realization of discrete quantum random walks using neutral atoms trapped in optical lattices. The random walk is taking place in position space and experimental implementation with present day technology --even using existing set-ups-- seems feasible. We analyze the influence of possible imperfections in the experiment and investigate the transition from a quantum random walk to the classical random walk for increasing errors and decoherence.Comment: 8 pages, 4 figure

Optimal Hypercontractivity for Fermi Fields and Related Non-Commutative Integration

Optimal hypercontractivity bounds for the fermion oscillator semigroup are obtained. These are the fermion analogs of the optimal hypercontractivity bounds for the boson oscillator semigroup obtained by Nelson. In the process, several results of independent interest in the theory of non-commutative integration are established. {}.Comment: 18 p., princeton/ecel/7-12-9

Modified bibenzimidazole ligands as spectator ligands in photoactive molecular functional Ru-polypyridine units? Implications from spectroscopy

The photophysical properties of Ruthenium-bipyridine complexes bearing a bibenzimidazole ligand were investigated. The nitrogens on the bibenzimidazole-ligand were protected, by adding either a phenylene group or a 1,2-ethandiyl group, to remove the photophysical dependence of the complex on the protonation state of the bibenzimidazole ligand. This protection results in the bibenzimidazole ligand contributing to the MLCT transition, which is experimentally evidenced by (resonance) Raman scattering in concert with DFT calculations for a detailed mode assignment in the (resonance) Raman spectra