6,514 research outputs found
Induced magnetic moment for a spinless charged particle in the thin-layer approach
We determine the effective dynamics for a spinless charged particle, in the
presence of electromagnetic fields, constrained to a space curve. We employ the
thin-layer procedure and a perturbative expansion for the Schr\"odinger
equation is derived. We find that the first-order term in the perturbative
expansion couples the dynamics of the normal and tangent degrees of freedom.
However, there is always a gauge transformation that allows decouple the
dynamics. We find that the effective Schr\"odinger equation in the curve
contains an induced Zeeman coupling, independent of the curvature and torsion,
which has not been previously reported. This coupling is characteristic of
reducing the dimension by two and allows to identify an induced magnetic
moment.Comment: 7 pages. To be published in Europhysics Letter
Presentación del proyecto
Se describe el Proyecto familia orientado a brindar un cuidado integral al niño menor de 6 años mediante la capacitación de la familia Colombiana como responsable en la formación durante los primeros años con lo que se espera mejorar las condiciones y desarrollo óptimo de los niños. Se rescatan las características, metas, estrategias de formación y metodología del proyecto.It describes the Family Project aimed at providing comprehensive care to the child under 6 years of age by training the Colombian family as responsible for training during the early years, which is expected to improve conditions and optimal development of children. The characteristics, goals, training strategies and methodology of the project are rescued.Generalidades del proyecto familia – Metas y actividades – Bloque modular formación multiplicadores desarrollo integral del niño de 0 a 6 año
Subsystems for future access networks
Current evolution and tendencies of Telecom Networks in general and more specifically optical Metro and Access Networks and their convergence are reported. Based on this evolution, a set of research lines are foreseen regarding subsystems and devices as: high speed optical sources, modulators and receivers, for the next generation of Passive Optical Networks. The ICT project EURO-FOS is achieving European level cooperative research among academia and industry, enabling future telecommunication networks
Malocclusion complexity and orthodontic treatment need in children with autism spectrum disorder.
OBJECTIVES
This study aimed to investigate the malocclusion complexity and orthodontic treatment need among children with and without autism spectrum disorder (ASD) referred for orthodontic treatment by quantifying the Discrepancy Index (DI) and Index of Orthodontic Treatment Need (IOTN).
MATERIALS AND METHODS
Dental records of 48 ASD and 49 non-ASD consecutive patients aged between 9 and 18 years (median age 13.0 years) referred for orthodontic treatment were reviewed and compared. The Discrepancy Index (DI) was quantified to determine the malocclusion complexity, and the Index of Orthodontic Treatment Need (IOTN), including the Dental Health Component (IOTN-DHC) and Aesthetic Component (IOTN-AC), was quantified to determine the orthodontic treatment need. Statistical analysis included descriptive analysis, Pearson chi-square tests, Fisher's exact test, Mann-Whitney U tests, and several univariate and multivariate regression analyses. The statistical analysis used descriptive analysis, Pearson chi-square test, Fisher's exact test, and multivariate logistic regression.
RESULTS
The results show that both malocclusion complexity (DI, p = 0.0010) and orthodontic treatment need (IOTN-DHC, p = 0.0025; IOTN-AC p = 0.0009) were significantly higher in children with ASD. Furthermore, children with ASD had a higher prevalence of increased overjet (p = .0016) and overbite (p = .031).
CONCLUSIONS
Malocclusion complexity and orthodontic treatment need are statistically significantly higher among children with ASD than children without ASD, independent of age and sex.
CLINICAL RELEVANCE
Children with autism may benefit from visits to a dental specialist (orthodontist) to prevent, to some extent, developing malocclusions from an early age
Internal quantum efficiency of III-nitride quantum dot superlattices grown by plasma-assisted molecular-beam epitaxy
We present a study of the optical properties of GaN/AlN and InGaN/GaN quantum dot (QD) superlattices grown via plasma-assisted molecular-beam epitaxy, as compared to their quantum well (QW) counterparts. The three-dimensional/two-dimensional nature of the structures has been verified using atomic force microscopy and transmission electron microscopy. The QD superlattices present higher internal quantum efficiency as compared to the respective QWs as a result of the three-dimensional carrier localization in the islands. In the QW samples, photoluminescence (PL) measurements point out a certain degree of carrier localization due to structural defects or thickness fluctuations, which is more pronounced in InGaN/GaN QWs due to alloy inhomogeneity. In the case of the QD stacks, carrier localization on potential fluctuations with a spatial extension smaller than the QD size is observed only for the InGaN QD-sample with the highest In content (peak emission around 2.76 eV). These results confirm the efficiency of the QD three-dimensional confinement in circumventing the potential fluctuations related to structural defects or alloy inhomogeneity. PL excitation measurements demonstrate efficient carrier transfer from the wetting layer to the QDs in the GaN/AlN system, even for low QD densities (~1010 cm-3). In the case of InGaN/GaN QDs, transport losses in the GaN barriers cannot be discarded, but an upper limit to these losses of 15% is deduced from PL measurements as a function of the excitation wavelength
Real-time 10Gbps Polarization Independent Quasicoherent Receiver for NG-PON2 Access Networks
In this paper, we propose and test experimentally a real-time 10 Gbps polarization independent quasicoherent receiver for NG-PON2 access networks. The proposed 10 Gbps quasicoherent receiver exhibits a sensitivity of -35.2 dBm after 40 km SSMF transmission with a commercial generic EML as transmitter. This sensitivity means a 14.9 dB improvement over a direct detection scheme with a photodiode after 40 km SSMF transmission. Therefore, the use of the proposed 10 Gbps quasicoherent receiver with the tested EML will provide a power budget of 34.76 dB (class E1) and a splitting ratio of 128 after the 40 km SSMF transmission. Finally, the proposed 10 Gbps quasicoherent receiver allows a colorless and optical filterless operation because wavelength selection is done by tuning the local oscillator wavelength and using electrical intermediate frequency filtering. IEE
Niño de 8 a 12 meses
Este documento explica el crecimiento físico, los cuidados y el desarrollo psicosocial en el niño en edad de 8 a 12 años así como los estímulos adecuados para esta edad.This document explains the physical growth, care and psychosocial development in the child at age 8 to 12 years as the appropriate stimuli for this age.Crecimiento físico; características físicas; cuidados – Desarrollo psicosocial; desarrollo de las conductas motoras y su estimulación; desarrollo de las conductas adaptativo – sociales y su estimulación; desarrollo de las conductas del lenguaje y su estimulació
El niño de 1 - 4 meses
Este documento explica las características, cuidados higiénicos, alimentación, prevención de enfermedades y conductas para lograr un desarrollo del bebe de 1 a 4 meses.This document explains the characteristics, hygienic care, food, prevention of diseases and behaviors to achieve a development of the baby from 1 to 4 months.Crecimiento físico ; características físicas ; cuidados – Desarrollo psicosocial ; motor ; adaptativo – social ; lenguaj
Dance Across Cultures: Joint Action Aesthetics in Japan and the UK
Copyright © The Author(s) 2021. Western European and East Asian cultures show marked differences in aesthetic appreciation of the visual arts. East Asian aesthetics are often associated with a holistic focus on balance and harmony, in contrast to Western aesthetics, which often focus on the expression of the individual. In this study, we examined whether cultural differences also exist in relation to the aesthetics of dance. Japanese and British participants completed an online survey in which they evaluated synchronous and asynchronous dance video clips on eight semantic differential scales. We observed that the aesthetics of group dance depend on cultural background. Specifically, British participants preferred asynchronous over synchronous dance whereas Japanese participants equally liked synchronous and asynchronous dance movement. For both cultures, preferences were based on distinct semantic associations with movement synchrony. We argue that cultural differences in aesthetic perception of group dance relate to the culturally specific social signals conveyed by unison movement.ESRC transformative research grant (ES/M000680/2) on “Synchronous movement, cooperation, and the Performing Arts”; Colombian Administrative Department of Science, Technology and Innovation (Colciencias); Universidad del Norte
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