Prevalencia de Caries y Pérdida de Dientes en Población de 65 a 74 Años de Santiago, Chile

AbstractObjectivesTo measure prevalence of caries and tooth loss among low and middle-low socio-economic level elderly from Santiago, Chile.MethodsProportionate stratified probabilistic sampling techniques; sample of 109 people (74 women and 35 men) aged 65 to 74. Data gathered by means of a face-to-face questionnaire. Informed consent was obtained; individuals were examined by a calibrated dentist. The study was carried out from March to December 2008. Data analysis considered chi-square and ANOVA.ResultsDMFT was 24.9 (CI: 23.83; 25.96). All the individuals had caries experience; 45.9% had active caries lesions. The mean of non-treated active caries lesions was 0.9 per individual. Concerning prosthesis, 38.5% of individuals were found to use removable prosthesis and 15 people (13.76%) were edentulous.ConclusionsThe size of the gap and the importance of social environment on damaging oral health should lead to face this problem from a wider perspective of social determinants of health when building public policies

Upscaling A Challenge-Based And Modular Education Concept (CMODE-UP)

In 2019, a course at a Dutch University of Technology was redesigned towards challenge-based and modular education. The course was received positively by students and their learning outcomes (grades and engagement) increased compared to previous years. This redesign was quite intensive, and case-specific. It did not deliver a specific set of design principles that can easily be used to redesign other courses within the university or even other universities. Therefore, a follow-up project was started, that aims to deliver a framework to scale-up the course redesign tested in the previous study (CMODE; Challenge-based Modular On-demand Digital Education). This framework will be designed using practical principles and will be evidence-informed. The project consists of three stages: (1) informal interviews with key actors at our university, experienced in studying and/or designing modular instruction, a systematic literature review on challenge-based education and modular instruction; (2) a test of the design principles that were developed using the interviews and literature review; and (3) a test of the CMODE-up framework that was built on the results from the second stage, using think-out-loud protocols. In the current study we specifically focus on the first stage. A first look at the already existing literature around challenge-based education and modular instruction shows us that both concepts have been around for a long time in higher engineering education. Since education has become more and more digitized (and the development of MOOCs), it appears that the concepts have taken a quick increase in relevance. However, both concepts have only been studied minimally in relation to each other. We deem it thus highly relevant to first build a clear and proper view on both concepts, the strengths and weaknesses, and where both (can) meet. So that anyone who has intentions like ours - to implement both in higher education - can do this in an evidence-informed manner.</p

Determination of the components of the gyration tensor of quartz by oblique incidence transmission two-modulator generalized ellipsometry

The two independent components of the gyration tensor of quartz, g11 and g33, have been spectroscopically measured using a transmission two-modulator generalized ellipsometer. The method is used to determine the optical activity in crystals in directions other than the optic axis, where the linear birefringence is much larger than the optical activity

DIVERSIDAD METABÓLICA FUNCIONAL DE COMUNIDADES MICROBIANAS ASOCIADAS A SUELO RIZOSFÉRICO DE MAÍZ (Zea mays L.) RAZAS AMARILLO-ZAMORANO Y JALA

Information about functional diversity (metabolic potential) is essential to understand the role of microbial communities in different environments. The Biolog System® methodology was introduced into ecological studies to estimate the metabolic potential of microbial communities, which can be determined through the estimation of an index of functional diversity, allowing to establish comparisons between different communities and following the evolution of a specific community when facing the variations of environmental conditions. In this study, samples from the soil of maize (Zea mays L.) rhizosphere cultivars Amarillo-Zamorano and Jala were analyzed, in different cultivation stages. The functional characterizationwas founded on determining the physiological profile of the microbial community, in which its metabolic behavior is determined against a set of substrates and carbon sources with the aim of establishinga characteristic response pattern in vitro and physiological profile at the level of community that offer the advantage of not requiring the isolation of axenic crops. The analyses of functional metabolic diversitythrough estimation of the AWCD and the Shannon-Weaver Index, served as useful indicators that evidenced that there are changes in the functional diversity of microbial communities, both in the different stages of the cultivation and in the different cultivars of maize evaluated.La información sobre la diversidad funcional (potencial metabólico) es esencial para la comprensión del papel de las comunidades microbianas en diferentes entornos. La metodología de Biolog System® se introdujo en los estudios ecológicos para estimar el potencial metabólico de las comunidades microbianas, la cual se pueden determinar mediante la estimación de un índice de diversidad funcional, que permite establecer comparaciones entre comunidades distintas y seguir la evolución de una comunidad en específico frente a las variaciones de las condiciones ambientales. En el presente este estudio, se analizaron muestras de suelo de la rizósfera de maíz (Zea mays L.) razas amarillo-zamorano y Jala, en diferentes etapas de cultivo. La caracterización funcional se fundamentó en la determinación del perfil fisiológico de la comunidad microbiana, en la cual se determina su comportamiento metabólico contra un conjunto de sustratos y fuentes de carbono con el fin de establecer un patrón característico de respuesta in vitro y perfil fisiológico a nivel de comunidad que ofrece la ventaja de que no requiere el aislamiento de cultivos axénicos. Los análisisde la diversidad metabólica funcional mediante la estimación del AWCD y el índice de Shannon-Weaver como indicadores útiles que evidenciaron que existen cambios en la diversidad funcional de las comunidades microbianas tanto en las diferentes etapas del cultivo como en las diferentes razas de maíz evaluadas

Structure vs. excitonic transitions in self-assembled porphyrin nanotubes and their effect on light absorption and scattering

The optical properties of diprotonated meso-tetrakis(4-sulphonatophenyl)porphyrin (TPPS4) J-aggregates of elongated thin particles (nanotubes in solution and ribbons when deposited on solid interfaces) are studied by different polarimetric techniques. The selective light extinction in these structures, which depends on the alignment of the nanoparticle with respect to the polarization of light, is contributed by excitonic absorption bands and by resonance light scattering. The optical response as a function of the polarization of light is complex because, although the quasi-one-dimensional structure confines the local fields along the nanotube axis, there are two orthogonal excitonic bands, of H- and J-character, that can work in favor of or against the field confinement. Results suggest that resonance light scattering is the dominant effect in solid state preparations, i.e. in collective groups (bundles) of ribbons but in diluted solutions, i.e. with isolated nanotubes, the absorption at the excitonic transitions remains dominant and linear dichroism spectra can be a direct probe of the exciton orientations. Therefore, by analyzing scattering and absorption data we can determine the alignment of the excitonic bands within the nanoparticle, i.e. of the orientation of the basic 2D porphyrin architecture in the nanoparticle. This is a necessary first step for understanding the directions of energy transport, charge polarization and non-linear optical properties in these materials

Light scattering by coupled oriented dipoles: decomposition of the scattering matrix

We study the optical response of two coupled oriented dipoles with the dimer axis perpendicular to the wave vector of light by analyzing how their scattering matrix can be decomposed. The scattering matrix can be written as a linear combination of three terms with a clear physical meaning: one for each particle and another that is responsible for the coupling and that vanishes for noninteracting or distant particles. We show that the interaction term may generate optical activity for certain scattering directions and that this effect manifests itself mostly in the near field. This simple and intuitive theory based on matrix and vector states of oriented dipoles also describes hybridization processes and Fano resonances. The decomposition method can be also formulated in terms of a hybrid basis that allows us to quantitatively determine the individual contribution of the in-phase and out-of-phase coupling modes to the overall intensity. Our method can help to understand the optical response of more complex nanostructures that can be decomposed into dipole terms. The results are illustrated in gold nanoantenna dimers which exhibit a strong dipolar resonanc