11,209 research outputs found
Application of a Latent Transition Model to Estimate the Usual Prevalence of Dietary Patterns
Background: This study aims to derive habitual dietary patterns of the Portuguese adult population by applying two methodological approaches: a latent class model and a latent transition model. The novel application of the latent transition model allows us to determine the day-to-day variability of diet and to calculate the usual prevalence of dietary patterns. Methods: Participants are from the National Food, Nutrition and Physical Activity Survey of the Portuguese population, 2015-2016 (2029 women; 1820 men, aged >= 18 years). Diet was collected by two 24 h dietary recalls (8-15 days apart). Dietary patterns were derived by: (1) a latent class model using the arithmetic mean of food weigh intake, with concomitant variables (age and sex); (2) a latent transition model allowing the transition from one pattern to another, with the same concomitant variables. Results: Six dietary patterns were identified by a latent class model. By using a latent transition model, three dietary patterns were identified: "In-transition to Western" (higher red meat and alcohol intake; followed by middle-aged men), "Western" (higher meats/eggs and energy-dense foods intake; followed by younger men), and "Traditional-Healthier" (higher intake of fruit, vegetables and fish, characteristic of older women). Most individuals followed the same pattern on both days, but around 26% transited between "In-transition to Western" and "Western". The prevalence of the dietary patterns using a single recall day (40%, 27%, 33%, respectively) is different from the usual prevalence obtained by the latent transition probabilities (48%, 36%, 16%). Conclusion: Three dietary patterns, largely dependent on age and sex, were identified for the Portuguese adult population: "In-transition to Western" (48%), "Western" (36%), and "Traditional-Healthier" (16%), but 26% were transient between patterns. Dietary patterns are, in general, deviating from traditional habits
Fractal Metrology for biogeosystems analysis
The solid-pore distribution pattern plays an important role in soil functioning being related with the main physical, chemical and biological multiscale and multitemporal processes of this complex system. In the present research, we studied the aggregation process as self-organizing and operating near a critical point. The structural pattern is extracted from the digital images of three soils (<i>Chernozem, Solonetz</i> and <i>"Chocolate" Clay</i>) and compared in terms of roughness of the gray-intensity distribution quantified by several measurement techniques. Special attention was paid to the uncertainty of each of them measured in terms of standard deviation. Some of the applied methods are known as classical in the fractal context (box-counting, rescaling-range and wavelets analyses, etc.) while the others have been recently developed by our Group. The combination of these techniques, coming from Fractal Geometry, Metrology, Informatics, Probability Theory and Statistics is termed in this paper <i>Fractal Metrology</i> (FM). We show the usefulness of FM for complex systems analysis through a case study of the soil's physical and chemical degradation applying the selected toolbox to describe and compare the structural attributes of three porous media with contrasting structure but similar clay mineralogy dominated by montmorillonites
Galaxy-wide radio-induced feedback in a radio-quiet quasar
We report the discovery of a radio-quiet type 2 quasar (SDSS J165315.06+234943.0 nicknamed the ‘Beetle’ at z = 0.103) with unambiguous evidence for active galactic nucleus (AGN) radio-induced feedback acting across a total extension of ∼46 kpc and up to ∼26 kpc from the AGN. To the best of our knowledge, this is the first radio-quiet system where radio-induced feedback has been securely identified at ≫several kpc from the AGN. The morphological, ionization and kinematic properties of the extended ionized gas are correlated with the radio structures. We find along the radio axis (a) enhancement of the optical line emission at the location of the radio hotspots (b) turbulent gas kinematics (FWHM ∼ 380–470 km s−1) across the entire spatial range circumscribed by them (c) ionization minima for the turbulent gas at the location of the hot spots, (d) high temperature Te ≳ 1.9 × 104 K at the NE hotspot. Turbulent gas is also found far from the radio axis, ∼25 kpc in the perpendicular direction. We propose a scenario in which the radio structures have perforated the interstellar medium of the galaxy and escaped into the circumgalactic medium. While advancing, they have interacted with in situ gas modifying its properties. Our results show that jets of modest power can be the dominant feedback mechanism acting across huge volumes in radio-quiet systems, including highly accreting luminous AGNs, where radiative mode feedback may be expected
Dynamically generated resonances
In this talk I report on recent work related to the dynamical generation of
baryonic resonances, some made up from pseudoscalar meson-baryon, others from
vector meson-baryon and a third type from two meson-one baryon systems. We can
establish a correspondence with known baryonic resonances, reinforcing
conclusions previously drawn and bringing new light on the nature of some
baryonic resonances of higher mass.Comment: Talk given at the Workshop on physics of the excited nucleon-NSTAR
2009, Beijing, april 200
Institutional bilateral cooperation for lifelong learning in applied sciences: a multicultural experience integrated in a tempus program
Life Long Learning in Applied Fields (LLAF) é um dos projetos aprovados pelo Programa TEMPUS IV e envolve 16 Instituições de 8 países, incluindo o Instituto Politécnico de Santarém, o ISCTE – Instituto Universitário de Lisboa e a INOVA+. Os parceiros colaboram no sentido de dar resposta ao desafio proposto pelas Instituições de Ensino Superior israelitas para manterem a sua relevância no ensino, através da criação de condições para o desenvolvimento de curricula que possa proporcionar aos estudantes ferramentas e capacidades para novos desenvolvimentos profissionais e inovação, também numa perspetiva de extensão à comunidade. Com uma metodologia ativa, a operacionalização tem acontecido em reuniões periódicas dos parceiros e em trabalho de grupo, numa perspetiva de partilha de conhecimento e experiências, que produziu novos curricula e Educational Units (EDUs), adequados à realidade social e educativa de Israel, mas inovadores nas metodologias e estratégias. Neste momento, as Instituições selecionaram os EDUs ou módulos que lhes parecem ser aplicáveis na sua realidade e deu-se início à fase de pilotagem dos cursos. A disseminação é um dos pontos fundamentais deste processo, pela importância de partilhar resultados, dificuldades de operacionalização e estratégias utilizadas para as ultrapassar. Este artigo surge essencialmente como contributo para esta fase.info:eu-repo/semantics/publishedVersio
Aqueous and Ethanolic Valeriana officinalis Extracts Change the Binding of Ligands to Glutamate Receptors
The effects of two valerian extracts (aqueous and hydroalcoholic) were investigated through [3H]Glutamate ([3H]Glu) and [3H]Fluorowillardine ([3H]FW) receptor binding assays using rat synaptic membranes in presence of different receptor ligands. In addition, the extract stability was monitored spectrophotometrically. Both extracts demonstrated interaction with ionotropic glutamate receptors (iGluRs). However, the extracts displayed considerable differences in receptor selectivity. The hydroalcoholic extract selectively interacted with quisqualic acid (QA), group I metabotropic glutamate receptor (mGluR) ligand, while the aqueous extract did not alter the binding of QA. The stability of the extracts was examined during several weeks. Freshly prepared extract inhibited 38–60% of [3H]FW binding (AMPA). After 10 days, the aqueous extract inhibited 85% of [3H]FW binding while the hydroalcoholic extract markedly potentiated (200%) [3H]FW binding to AMPA receptors. Thus, our results showed that factors such as extraction solvent and extract stability determine the selectivity for glutamate receptor (GluR) interactions
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