Physical Fighting and Associated Factors among Adolescents Aged 13-15 Years in Six Western Pacific Countries.

Youth violence is an important public health challenge around the world, yet the literature on this problem in low- and middle-income countries (LMICs) has been limited. The present study aims to examine the prevalence of adolescent physical fighting (defined as having been involved in at least one physical fight during the past 12 months) in selected LMICs, and its relations with potential risk factors. We included 6377 school-going adolescents aged 13-15 years from six Western Pacific (WP) countries that had recently conducted a Global School-based Student Health Survey. Information was gathered through a self-administered anonymous closed-ended questionnaire. The prevalence of adolescent physical fighting varied across countries, ranging from 34.5% in Kiribati to 63.3% in Samoa. The prevalence was higher in boys than in girls, and lower at age 15 than 13-14 years. Physical fighting was significantly associated (pooled odds ratios (ORs), 95% confidence intervals (CIs)) with smoking (1.78, 1.53-2.06), drinking (1.57, 1.33-1.85), drug use (1.72, 1.33-2.23), and missing school (1.72, 1.51-1.95). The association with physical fighting increased with increasing number of joint adverse behaviors (increased from 1.99 (1.73-2.29) for one risk behavior to 4.95 (4.03-6.07) for at least 3 risk behaviors, versus having none of the 4 risk behaviors). The high prevalence of physical fighting and the associations with risk behaviors emphasize the need for comprehensive prevention programs to reduce youth violence and associated risk behaviors

Soil-mechanics based testbed setup for lunar rover wheel and corresponding experimental investigations

This paper introduced a testbed developed from a perspective of soil mechanics which not only focused on wheel design and optimization but also considered the elimination of the boundary effect caused by soil bin. Using this testbed, a series of experimental investigations were performed by changing the wheel rotational velocity, vertical load and towed load. Tracks were generated at a regular spacing as the wheel lugs enter and exit the soil periodically. It has been found that there is a relationship between the track length and wheel slip ratio regardless of different mechanical properties of soil. The wheel rotational velocity has little effect on the driving torque and sinkage. The towed load affects more on the driving torque than on the sinkage. However, the vertical load effects on the driving torque and sinkage are similar. The current models used for parameter estimations may not be appropriate for TJ-1 lunar soil simulant which has a relatively high internal friction angle according to the experimental results. But the internal friction angle and cohesion can still be estimated with proper selection of shear deformation modulus using the model proposed by Li et al(2011)

Topological structure of the many vortices solution in Jackiw-Pi model

We construct an M-solitons solutions in Jackiw-Pi model depends on 5M parameters(two positions, one scale, one phase per solition and one charge of each solution). By using \phi -mapping method, we discuss the topological structure of the self-duality solution in Jackiw-Pi model in terms of gauge potential decomposition. We set up relationship between Chern-Simons vortices solution and topological number which is determined by Hopf indices and and Brouwer degrees. We also give the quantization of flux in this case.Comment: 14 pages, 4 figure

Correlated Photons from Collective Excitations of Three-Level Atomic Ensemble

We systematically study the interaction between two quantized optical fields and a cyclic atomic ensemble driven by a classic optical field. This so-called atomic cyclic ensemble consists of three-level atoms with Delta-type transitions due to the symmetry breaking, which can also be implemented in the superconducting quantum circuit by Yu-xi Liu et al. [Phys. Rev. Lett. 95, 087001 (2005)]. We explore the dynamic mechanisms to creating the quantum entanglements among photon states, and between photons and atomic collective excitations by the coherent manipulation of the atom-photon system. It is shown that the quantum information can be completely transferred from one quantized optical mode to another, and the quantum information carried by the two quantized optical fields can be stored in the collective modes of this atomic ensemble by adiabatically controlling the classic field Rabi frequencies.Comment: 10 pages, 2 figure

A Structural Equation Modeling Approach to Examining Factors Influencing Outcomes with Cochlear Implant in Mandarin-Speaking Children

published_or_final_versio

Hybrid modeling of relativistic underdense plasma photocathode injectors

The dynamics of laser ionization-based electron injection in the recently introduced plasma photocathode concept is analyzed analytically and with particle-in-cell simulations. The influence of the initial few-cycle laser pulse that liberates electrons through background gas ionization in a plasma wakefield accelerator on the final electron phase space is described through the use of Ammosov-Deloine-Krainov theory as well as nonadiabatic Yudin-Ivanov (YI) ionization theory and subsequent downstream dynamics in the combined laser and plasma wave fields. The photoelectrons are tracked by solving their relativistic equations of motion. They experience the analytically described transient laser field and the simulation-derived plasma wakefields. It is shown that the minimum normalized emittance of fs-scale electron bunches released in mulit-GV/m-scale plasma wakefields is of the order of 10-2 mm mrad. Such unprecedented values, combined with the dramatically increased controllability of electron bunch production, pave the way for highly compact yet ultrahigh quality plasma-based electron accelerators and light source applications

Qubit-induced phonon blockade as a signature of quantum behavior in nanomechanical resonators

The observation of quantized nanomechanical oscillations by detecting femtometer-scale displacements is a significant challenge for experimentalists. We propose that phonon blockade can serve as a signature of quantum behavior in nanomechanical resonators. In analogy to photon blockade and Coulomb blockade for electrons, the main idea for phonon blockade is that the second phonon cannot be excited when there is one phonon in the nonlinear oscillator. To realize phonon blockade, a superconducting quantum two-level system is coupled to the nanomechanical resonator and is used to induce the phonon self-interaction. Using Monte Carlo simulations, the dynamics of the induced nonlinear oscillator is studied via the Cahill-Glauber $s$-parametrized quasiprobability distributions. We show how the oscillation of the resonator can occur in the quantum regime and demonstrate how the phonon blockade can be observed with currently accessible experimental parameters