744 research outputs found
Correlación de la Necesidad de Tratamiento Ortodóncico entre la autopercepción de adolescentes Chilenos de 14 a 18 años con la observación del Odontólogo.
Background: To correlate the need for orthodontic treatment between the self-perception of Chilean adolescents from 14 to 18 years old with the observation of a dentist using the same assessment scale, as well as to determine if covariates such as gender, age and type of school influence the self-perception of the adolescent and the examiner. Material and Methods: Cross-sectional descriptive study of adolescents aged 14 to 18 years from public, subsidized and private schools in Temuco, Chile. The probability sample is stratified by course, from first to fourth year, a total of 414 students participated, according to the eligibility criteria. The photographic score of the aesthetic component (AC) of the Index of Orthodontic Treatment Need (IOTN) was used. The statistical analysis of the data was performed with the SPSS Statistics program v.23. Results: 94.9% of the adolescents perceived themselves as having good aesthetics. The examiner considered that 77% presented this condition, p<0.00. Males perceived themselves better than females. At age 15, 1.7% of students considered themselves to have poor aesthetics, p<0.01. From the examiner's perspective, aesthetics are related to type of school, p<0.00. Conclusion: Adolescents perceive themselves better aesthetically than do the evaluators. The school type factor, according to the IOTN-AC examiner, shows a higher proportion of students with no need for orthodontic treatment in private schools, and a threshold need in municipal and subsidized institutions.Objetivo: Correlacionar la necesidad de tratamiento ortodóncico, entre la autopercepción de adolescentes con el diagnóstico de un evaluador odontólogo, utilizando la misma escala de valoración, así también determinar si las variables como el género, la edad y la dependencia educacional influyen en la autopercepción del adolescente y la observación del examinador. Material y Métodos: Estudio descriptivo de corte transversal, en adolescentes de 14 a 18 años de escuelas públicas, subvencionadas y privadas de Temuco-Chile. Muestreo probabilístico estratificado por cursos, de primero a cuarto medio con una muestra de 414 estudiantes, según los criterios de elegibilidad. Se utilizó el score fotográfico del componente estético (AC) del Índice de Necesidad de Tratamiento de Ortodoncia (INTO). El análisis estadístico de los datos fue realizado con el programa SPSS Statistics v.23. Resultados: El 94,9% de los adolescentes se autoperciben con una buena estética, el examinador considera que un 77% presenta esta condición, p<0,00. Los varones se perciben mejor que las damas. Los adolescentes de 15 años un 1,7% considera tener mala estética, p<0,01. Desde la perspectiva del examinador la estética se relaciona con la dependencia educacional, p<0,01. Conclusión: Los adolescentes se autoperciben mejor estéticamente que lo diagnosticado por evaluadores odontólogos. El factor dependencia educacional según INTO-AC examinador, muestra mayor proporción de estudiantes sin necesidad de tratamiento ortodóncico en los establecimientos privados, y necesidad límite en los públicos y subvencionados
Counter-Rotation in Disk Galaxies
Counter-rotating galaxies host two components rotating in opposite directions
with respect to each other. The kinematic and morphological properties of
lenticulars and spirals hosting counter-rotating components are reviewed.
Statistics of the counter-rotating galaxies and analysis of their stellar
populations provide constraints on the formation scenarios which include both
environmental and internal processes.Comment: 10 pages, 2 figures. To appear in ASP Conf. Ser., Multi-Spin
Galaxies, E. Iodice and E. M. Corsini (eds.
GMASS Ultradeep Spectroscopy of Galaxies at redshift z~2. I. The stellar metallicity
Context: Galaxy metallicities have been measured to redshift z~2 by gas-phase
oxygen abundances of the interstellar medium using the R23 and N2 methods.
Galaxy stellar metallicities provide crucial data for chemical evolution models
but have not been assessed reliably much outside the local Universe. Aims: We
determine the iron-abundance, stellar metallicity of star-forming galaxies
(SFGs) at redshift z~2, observed as part of the Galaxy Mass Assembly ultra-deep
Spectroscopic Survey (GMASS). Methods: We compute the equivalent width of a
rest-frame mid-ultraviolet, photospheric absorption-line index, the 1978 index
found to vary monotonically with stellar metallicity by Rix and collaborators.
We normalise and combine 75 SFG spectra from the GMASS survey to produce a
spectrum corresponding to a total integration time 1652.5 hours (and a
signal-to-noise ratio ~100 for our 1.5 angstrom binning) of FORS2 spectroscopic
observations at the Very Large Telescope. Results: We measure an
iron-abundance, stellar metallicity of log (Z/Zsolar) = -0.574+/-0.159 for our
spectrum representative of a galaxy of stellar mass 9.4 x 10^9 Msolar assuming
a Chabrier IMF. We find that the R04 model SFG spectrum for log (Z/Zsolar) =
-0.699 solar metallicity provides the best description of our GMASS coadded
spectrum. For similar galaxy stellar mass, our stellar metallicity is ~0.25 dex
lower than the oxygen-abundance, gas-phase metallicity quantified by Erb and
collaborators for UV-selected star-forming galaxies at z=2. Conclusions: We
conclude that we are witnessing the establishment of a light-element
overabundance in galaxies as they are being formed at redshift z~2. Our
measurements are reminiscent of the alpha-element enhancement seen in
low-redshift, galactic bulges and early-type galaxies. (Abridged)Comment: Accepted for publication in Astronomy and Astrophysics on 18 December
2007, 9 pages, 8 figures, aa.bst and aa.cls A&A style file
Immunosuppression in mice infected with trypanosoma cruzi (chagas, 1909) II - Trypomastigote Crude Extract (TCE) suppress the humoral immune response in mice
Location of chlorogenic acid biosynthesis pathway and polyphenol oxidase genes in a new interspecific anchored linkage map of eggplant
© Gramazio et al.; licensee BioMed Central. 2014. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated
Pilot Evaluation of an Internet-based Natural Family Planning Education and Service Program
Objective: To evaluate the efficacy, knowledge of fertility, and acceptability of a web-based natural family planning (NFP) education and service program.
Design: A 6-month repeated measure longitudinal evaluation pilot study.
Setting: A university based online website.
Participants: The website was piloted with 468 volunteer women seeking NFP services. Of these participants, 222 used the automatic online fertility charting system to avoid pregnancy. The 222 charting participants had a mean age of 29.9 years (SD=5.6), 2.2 children (SD=1.9), 37% were postpartum, and 47% had regular menstrual cycle lengths.
Intervention: Nurse-managed web-based NFP education and service program.
Outcomes: Pregnancies were confirmed by an online self-assessed pregnancy evaluation form. A 10-item fertility quiz and 10-item acceptability survey was administered online.
Results: Among the 222 users avoiding pregnancy, at 6 months of use, there were two correct-use unintended pregnancies that provided a pregnancy rate of 2% and seven total unintended pregnancies providing a typical use pregnancy rate of 7%. Mean knowledge of fertility increased significantly from time of registration (8.96, SD=1.10) to 1 month of use (9.46, SD=.10), t=4.60, pSD=8.98) to 6 months of use (48.4; SD=8.77).
Conclusion: The nurse-managed online NFP system seems to provide adequate knowledge of fertility and help participants meet pregnancy intentions. Acceptability of such a system of NFP is still in question
Near-infrared spectroscopic indices for unresolved stellar populations: I. Template galaxy spectra
Context. A new generation of spectral synthesis models has been developed in recent years, but there is no matching set of template galaxy spectra, in terms of quality and resolution, for testing and refining the new models.
Aims: Our main goal is to find and calibrate new near-infrared spectral indices along the Hubble sequence of galaxies which will be used to obtain additional constraints to the population analysis based on medium-resolution integrated spectra of galaxies.
Methods: Spectra of previously studied and well-understood galaxies with relatively simple stellar populations (e.g., ellipticals or bulge dominated galaxies) are needed to provide a baseline data set for spectral synthesis models.
Results: X-shooter spectra spanning the optical and infrared wavelengths (350-2400 nm) of bright nearby elliptical galaxies with a resolving power of R \u2dc 4000-5400 were obtained. Heliocentric systemic velocity, velocity dispersion, and Mg, Fe, and H\u3b2 line-strength indices are presented.
Conclusions: We present a library of very-high-quality spectra of galaxies covering a large range of age, metallicity, and morphological type. Such a dataset of spectra will be crucial to addressing important questions of the modern investigation concerning galaxy formation and evolution
Unravelling the roles of size, ligands and pressure in the piezochromic properties of CdS nanocrystals
Understanding the effects of pressure-induced deformations on the optoelectronic properties of nanomaterials is important not only from the fundamental point of view, but also for potential applications such as stress sensors and electromechanical devices. Here we describe the novel insights into these piezochromic effects gained from using a linear-scaling density functional theory framework and an electronic enthalpy scheme, which allow us to accurately characterize the electronic structure of CdS nanocrystals with a zincblende-like core of experimentally relevant size. In particular we focus on unravelling the complex interplay of size and surface (phenyl) ligands with pressure. We show that pressure-induced deformations are not simple isotropic scaling of the original structures and that the change in HOMO-LUMO gap with pressure results from two competing factors: (i) a bulk-like linear increase due to compression, which is offset by (ii) distortions/disorder and, to a lesser extent, orbital hybridization induced by ligands affecting the frontier orbitals. Moreover, we observe that the main peak in the optical absorption spectra is systematically red-shifted or blue-shifted, as pressure is increased up to 5 GPa, depending on the presence or absence of phenyl ligands. These heavily hybridize the frontier orbitals, causing a reduction in overlap and oscillator strength, so that at zero pressure the lowest energy transition involves deeper hole orbitals than in the case of hydrogencapped nanocrystals; the application of pressure induces greater delocalisation over the whole nanocrystals bringing the frontier hole orbitals into play and resulting in an unexpected red shift for the phenyl-capped nanocrystals, in part caused by distortions. In response to a growing interest in relatively small nanocrystals that can be difficult to accurately characterize with experimental techniques, this work exemplifies the detailed understanding of structure-property relationships under pressure that can be obtained for realistic nanocrystals with state-of-the-art first principles methods and used for the characterization and design of devices based on these and similar nanomaterials
Surfactant as a drug carrier
Drug delivery using a surfactant vehicle has the potential to prevent systemic side effects by delivering therapeutic agents directly to the respiratory system. The inherent chemical properties of surfactant allows it to readily distribute throughout the respiratory system. Therapeutic agents delivered by surfactant can primarily confer additional benefits but have potential to improve surfactant function. It is critically important that additional agents do not interefere with the innate surface tension lowering function of surfactant. Systemic evaluation through benchtop, translational and human trials are required to translate this potential technique into clinical practice
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