A QCD sum rules calculation of the J/ψDs∗DsJ/\psi D_s^* D_s strong coupling constant

In this work, we calculate the form factors and the coupling constant of the strange-charmed vertex $J/\psi D_s^* D_s$ in the framework of the QCD sum rules by studying their three-point correlation functions. All the possible off-shell cases are considered, $D_s$, $D_s^*$ and $J/\psi$, resulting in three different form factors. These form factors are extrapolated to the pole of their respective off-shell mesons, giving the same coupling constant for the process. Our final result for the $J/\psi D_s^* D_s$ coupling constant is $g_{J/\psi D^*_s D_s} = 4.30^{+0.42}_{-0.37}\text{GeV}^{-1}$.Comment: 17 pages, 4 figure

Photonic millimeter-wave frequency multiplication based on cascaded four-wave mixing and polarization pulling

This paper was published in OPTICS LETTERS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.37.005055. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law[EN] A technique for the frequency multiplication of microwave signals based on the combination of two optical nonlinear phenomena in a single nonlinear fiber is investigated. Multiple four-wave mixing is used to generate harmonics on an externally modulated optical carrier while polarization pulling through stimulated Brillouin scattering is used to filter the desired harmonics. Microwave signals in the 60 GHz region are generated showing harmonic frequency multiplication factors of up to 25 with a suppression of undesired harmonics better than 20 dB. © 2012 Optical Society of America.This research was supported in part by the Spanish Ministerio de Economia y Competitividad through TEC2009-08078 and TEC2012-35797 projects.Vidal Rodriguez, B. (2012). Photonic millimeter-wave frequency multiplication based on cascaded four-wave mixing and polarization pulling. Optics Letters. 37(24):25478-25488. https://doi.org/10.1364/OL.37.005055S25478254883724Kawanishi, T., Oikawa, S., Yoshiara, K., Sakamoto, T., Shinada, S., & Izutsu, M. (2005). Low noise photonic Millimeter-wave generation using an integrated reciprocating optical Modulator. IEEE Photonics Technology Letters, 17(3), 669-671. doi:10.1109/lpt.2004.842377Li, W., & Yao, J. (2010). Investigation of Photonically Assisted Microwave Frequency Multiplication Based on External Modulation. IEEE Transactions on Microwave Theory and Techniques, 58(11), 3259-3268. doi:10.1109/tmtt.2010.2075671Vidal, B., Huggard, P. G., Ellison, B. N., & Gomes, N. J. (2010). Optoelectronic generation of W-band millimetre-wave signals using Brillouin amplification. Electronics Letters, 46(21), 1449. doi:10.1049/el.2010.2310Wiberg, A., Perez-Millan, P., Andres, M. V., & Hedekvist, P. O. (2006). Microwave-photonic frequency multiplication utilizing optical four-wave mixing and fiber Bragg gratings. Journal of Lightwave Technology, 24(1), 329-334. doi:10.1109/jlt.2005.860164Wang, Q., Rideout, H., Zeng, F., & Yao, J. (2006). Millimeter-Wave Frequency Tripling Based on Four-Wave Mixing in a Semiconductor Optical Amplifier. IEEE Photonics Technology Letters, 18(23), 2460-2462. doi:10.1109/lpt.2006.886826Li, Y., Naderi, N. A., Kovanis, V., & Lester, L. F. (2010). Enhancing the 3-dB Bandwidth via the Gain-Lever Effect in Quantum-Dot Lasers. IEEE Photonics Journal, 2(3), 321-329. doi:10.1109/jphot.2010.2046481McKinstrie, C. J., & Raymer, M. G. (2006). Four-wave-mixing cascades near the zero-dispersion frequency. Optics Express, 14(21), 9600. doi:10.1364/oe.14.009600Cerqueira Sodre, A., Chavez Boggio, J. M., Rieznik, A. A., Hernandez-Figueroa, H. E., Fragnito, H. L., & Knight, J. C. (2008). Highly efficient generation of broadband cascaded four-wave mixing products. Optics Express, 16(4), 2816. doi:10.1364/oe.16.002816Wise, A., Tur, M., & Zadok, A. (2011). Sharp tunable optical filters based on the polarization attributes of stimulated Brillouin scattering. Optics Express, 19(22), 21945. doi:10.1364/oe.19.021945Hansryd, J., Andrekson, P. A., Westlund, M., Jie Li, & Hedekvist, P.-O. (2002). Fiber-based optical parametric amplifiers and their applications. IEEE Journal of Selected Topics in Quantum Electronics, 8(3), 506-520. doi:10.1109/jstqe.2002.101635

Empiricism and stochastics in cellular automaton modeling of urban land use dynamics

An increasing number of models for predicting land use change in regions of rapidurbanization are being proposed and built using ideas from cellular automata (CA)theory. Calibrating such models to real situations is highly problematic and to date,serious attention has not been focused on the estimation problem. In this paper, wepropose a structure for simulating urban change based on estimating land usetransitions using elementary probabilistic methods which draw their inspiration fromBayes' theory and the related ?weights of evidence? approach. These land use changeprobabilities drive a CA model ? DINAMICA ? conceived at the Center for RemoteSensing of the Federal University of Minas Gerais (CSR-UFMG). This is based on aneight cell Moore neighborhood approach implemented through empirical land useallocation algorithms. The model framework has been applied to a medium-size townin the west of São Paulo State, Bauru. We show how various socio-economic andinfrastructural factors can be combined using the weights of evidence approach whichenables us to predict the probability of changes between land use types in differentcells of the system. Different predictions for the town during the period 1979-1988were generated, and statistical validation was then conducted using a multipleresolution fitting procedure. These modeling experiments support the essential logicof adopting Bayesian empirical methods which synthesize various information aboutspatial infrastructure as the driver of urban land use change. This indicates therelevance of the approach for generating forecasts of growth for Brazilian citiesparticularly and for world-wide cities in general

Levantamento da composição da matovegetação e florística nativa em quintais diversificados.

O solo é componente chave no processo de produção de alimentos e fibras. A produtividade de quintais agroflorestais está diretamente relacionada com a manutenção e/ou construção da fertilidade do solo

On Strong and Weak Sustainability, with an Application to Self-Susp ending Real-Time Tasks

Motivated by an apparent contradiction regarding whether certain scheduling policies are sustainable, we revisit the topic of sustainability in real-time scheduling and argue that the existing definitions of sustainability should be further clarified and generalized. After proposing a formal, generic sustainability theory, we relax the existing notion of (strongly) sustainable scheduling policy to provide a new classification called weak sustainability. Proving weak sustainability properties allows reducing the number of variables that must be considered in the search of a worst-case schedule, and hence enables more efficient schedulability analyses and testing regimes even for policies that are not (strongly) sustainable. As a proof of concept, and to better understand a model for which many mistakes were found in the literature, we study weak sustainability in the context of dynamic self-suspending tasks, where we formalize a generic suspension model using the Coq proof assistant and provide a machine-checked proof that any JLFP scheduling policy is weakly sustainable with respect to job costs and variable suspension times.info:eu-repo/semantics/publishedVersio

Shedding Light on the lifestyle and participation of portuguese adolescents with chronic conditions—Data from the HBSC 2018 Study

Variables associated with lifestyle can constitute either risk or protective factors for the development and progression of chronic conditions (CC). This study intends to explore the differences between adolescents with and without CC and between adolescents whose school participation is affected/not affected by the existing CC with regard to variables related to lifestyle (i.e., sleep, physical activity, BMI, and leisure). In addition, it also intends to analyze the influence of these variables (i.e., CC and lifestyle) regarding the adolescents’ quality of life (QoL). This work is part of the Portuguese HBSC 2018 study. A total of 8215 adolescents participated (52.7% female), with an average age of 14.36 years (SD = 2.28). The results showed that the adolescents with CC and whose school attendance and participation are affected by their CC exhibit more sleep difficulties (i.e., they experience lower sleep quality and have a higher degree of sleepiness), higher BMI levels (i.e., higher values of overweight and obesity), less participation in leisure activities, and a lower perception of QoL. A higher perception of QoL is associated with school participation unaffected by the existing CC, sleeping well, a low level of sleepiness, a more frequent practice of physical activity, a lower BMI, and a greater involvement in leisure activities. Adolescent health and well-being are a prominent issue in terms of public policies, with behavior and lifestyle playing a significant role in this domain. This message needs to be reinforced in regard to families, educators, healthcare professionals, and public sector policies, particularly concerning students with CC.info:eu-repo/semantics/publishedVersio

Magnetic Field Effects on the Head Structure of Protostellar Jets

We present the results of 3-D SPMHD numerical simulations of supermagnetosonic, overdense, radiatively cooling jets. Two initial magnetic configurations are considered: (i) a helical and (ii) a longitudinal field. We find that magnetic fields have important effects on the dynamics and structure of radiative cooling jets, especially at the head. The presence of a helical field suppresses the formation of the clumpy structure which is found to develop at the head of purely hydrodynamical jets. On the other hand, a cooling jet embedded in a longitudinal magnetic field retains clumpy morphology at its head. This fragmented structure resembles the knotty pattern commonly observed in HH objects behind the bow shocks of HH jets. This suggests that a strong (equipartition) helical magnetic field configuration is ruled out at the jet head. Therefore, if strong magnetic fields are present, they are probably predominantly longitudinal in those regions. In both magnetic configurations, we find that the confining pressure of the cocoon is able to excite short-wavelength MHD K-H pinch modes that drive low-amplitude internal shocks along the beam. These shocks are not strong however, and it likely that they could only play a secondary role in the formation of the bright knots observed in HH jets.Comment: 14 pages, 2 Gif figures, uses aasms4.sty. Also available on the web page http://www.iagusp.usp.br/preprints/preprint.html. To appear in The Astrophysical Journal Letter