941 research outputs found
Valuation and modeling of EQ-5D-5L health states using a hybrid approach
Background: The EQ-5D instrument is the most widely used preference-based health-related quality of life questionnaire in cost-effectiveness analysis of health care technologies. Recently, a version called EQ-5D-5L with 5 levels on each dimension was developed. This manuscript explores the performance of a hybrid approach for the modeling of EQ-5D-5L valuation data. Methods: Two elicitation techniques, the composite time trade-off, and discrete choice experiments, were applied to a sample of the Spanish population (n=1000) using a computer-based questionnaire. The sampling process consisted of 2 stages: stratified sampling of geographic area, followed by systematic sampling in each area. A hybrid regression model combining composite time trade-off and discrete choice data was used to estimate the potential value sets using main effects as starting point. The comparison between the models was performed using the criteria of logical consistency, goodness of fit, and parsimony. Results: Twenty-seven participants from the 1000 were removed following the exclusion criteria. The best-fitted model included 2 significant interaction terms but resulted in marginal improvements in model fit compared to the main effects model. We therefore selected the model results with main effects as a potential value set for this methodological study, based on the parsimony criteria. The results showed that the main effects hybrid model was consistent, with a range of utility values between 1 and -0.224. Conclusion: This paper shows the feasibility of using a hybrid approach to estimate a value set for EQ-5D-5L valuation data.</p
Turbo EP-based Equalization: a Filter-Type Implementation
This manuscript has been submitted to Transactions on Communications on
September 7, 2017; revised on January 10, 2018 and March 27, 2018; and accepted
on April 25, 2018
We propose a novel filter-type equalizer to improve the solution of the
linear minimum-mean squared-error (LMMSE) turbo equalizer, with computational
complexity constrained to be quadratic in the filter length. When high-order
modulations and/or large memory channels are used the optimal BCJR equalizer is
unavailable, due to its computational complexity. In this scenario, the
filter-type LMMSE turbo equalization exhibits a good performance compared to
other approximations. In this paper, we show that this solution can be
significantly improved by using expectation propagation (EP) in the estimation
of the a posteriori probabilities. First, it yields a more accurate estimation
of the extrinsic distribution to be sent to the channel decoder. Second,
compared to other solutions based on EP the computational complexity of the
proposed solution is constrained to be quadratic in the length of the finite
impulse response (FIR). In addition, we review previous EP-based turbo
equalization implementations. Instead of considering default uniform priors we
exploit the outputs of the decoder. Some simulation results are included to
show that this new EP-based filter remarkably outperforms the turbo approach of
previous versions of the EP algorithm and also improves the LMMSE solution,
with and without turbo equalization
Fabrication and deposition of copper and copper oxide nanoparticles by laser ablation in open air
The proximity of the “post-antibiotic era”, where infections and minor injuries could be a cause of death, there are urges to seek an alternative for the cure of infectious diseases. Copper nanoparticles and their huge potential as a bactericidal agent could be a solution. In this work, Cu and Cu oxide nanoparticles were synthesized by laser ablation in open air and in argon atmosphere using 532 and 1064 nm radiation generated by nanosecond and picosecond Nd:YVO4 lasers, respectively, to be directly deposited onto Ti substrates. Size, morphology, composition and the crystalline structure of the produced nanoparticles have been studied by the means of field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), the energy dispersive spectroscopy of X-rays (EDS), selected area electron diffraction (SAED) and X-ray diffraction (XRD). The UV-VIS absorbance of the thin layer of nanoparticles was also measured, and the antibacterial capacity of the obtained deposits tested against Staphylococcus aureus. The obtained deposits consisted of porous coatings composed of copper and copper oxide nanoparticles interconnected to form chain-like aggregates. The use of the argon atmosphere contributed to reduce significantly the formation of Cu oxide species. The synthesized and deposited nanoparticles exhibited an inhibitory effect upon S. aureus.Peer ReviewedPostprint (published version
Molecular Cloning of a GABA Receptor Subunit from Crayfish and Voltage-Clamp Analysis of Homo-Oligomeric Receptor Expressed in Hek Cells
Influence of inflammation in the process of T lymphocyte differentiation: Proliferative, metabolic, and oxidative changes
T lymphocytes, from their first encounter with their specific antigen as naïve cell until the last stages of their differentiation, in a replicative state of senescence, go through a series of phases. In several of these stages, T lymphocytes are subjected to exponential growth in successive encounters with the same antigen. This entire process occurs throughout the life of a human individual and, earlier, in patients with chronic infections/pathologies through inflammatory mediators, first acutely and later in a chronic form. This process plays a fundamental role in amplifying the activating signals on T lymphocytes and directing their clonal proliferation. The mechanisms that control cell growth are high levels of telomerase activity and maintenance of telomeric length that are far superior to other cell types, as well as metabolic adaptation and redox control. Large numbers of highly differentiated memory cells are accumulated in the immunological niches where they will contribute in a significant way to increase the levels of inflammatory mediators that will perpetuate the new state at the systemic level. These levels of inflammation greatly influence the process of T lymphocyte differentiation from naïve T lymphocyte, even before, until the arrival of exhaustion or cell death. The changes observed during lymphocyte differentiation are correlated with changes in cellular metabolism and these in turn are influenced by the inflammatory state of the environment where the cell is located. Reactive oxygen species (ROS) exert a dual action in the population of T lymphocytes. Exposure to high levels of ROS decreases the capacity of activation and T lymphocyte proliferation; however, intermediate levels of oxidation are necessary for the lymphocyte activation, differentiation, and effector functions. In conclusion, we can affirm that the inflammatory levels in the environment greatly influence the differentiation and activity of T lymphocyte populations. However, little is known about the mechanisms involved in these processes. The elucidation of these mechanisms would be of great help in the advance of improvements in pathologies with a large inflammatory base such as rheumatoid arthritis, intestinal inflammatory diseases, several infectious diseases and even, cancerous processes
Multiplexed vortex beam-based optical tweezers
The design and implementation of a multiplexed spiral phase mask in an
experimental optical tweezer setup are presented. This diffractive optical
element allows the generation of multiple concentric vortex beams with
independent topological charges. The generalization of the phase mask for
multiple concentric vortices is also shown. The design for a phase mask of two
multiplexed vortices with different topological charges is developed. We
experimentally show the transfer of angular momentum to the optically trapped
microparticles by enabling orbiting dynamics around the optical axis
independently within each vortex. The angular velocity of the confined
particles versus the optical power in the focal region is also discussed for
different combinations of topological charges
Fusion of Multi-Temporal PAZ and Sentinel-1 Data for Crop Classification
The accurate identification of crops is essential to help environmental sustainability and support agricultural policies. This study presents the use of a Spanish radar mission, PAZ, to classify agricultural areas with a very high spatial resolution. PAZ was recently launched, and it operates at X band, joining the synthetic aperture radar (SAR) constellation along with TerraSAR-X and TanDEM-X satellites. Owing to its novelty and its ability to classify crop areas (both taking individually its time series and blending with the Sentinel-1 series), it has been tested in an agricultural area of the central-western part of Spain during 2020. The random forest algorithm was selected to classify the time series under five alternatives of standalone/fused data. The map accuracy resulting from the PAZ series standalone was acceptable, but it highlighted the need for a denser time-series of data. The overall accuracy provided by eight PAZ images or by eight Sentinel-1 images was below 60%. The fusion of both sets of eight images improved the overall accuracy by more than 10%. In addition, the exploitation of the whole Sentinel-1 series, with many more observations (up to 40 in the same temporal window) improved the results, reaching an overall accuracy around 76%. This overall performance was similar to that obtained by the joint use of all the available images of the two frequency bands (C and X).This work was funded by the Spanish Ministry of Science and Innovation, the State Agency of Research (AEI) and the European Funds for Regional Development (EFRD) under Project TEC2017-85244-C2-1-P
Reporte de análisis cuantitativo de datos: estudio de mercado preferencias de consumo aceite de aguacate hass
This article presents the results of the study that sought to determine the consumption preferences of Hass avocado oil in the cities of Bogotá, Tunja, Bucaramanga and Villavicencio (Colombia), it was carried out through a non-experimental exploratory cross-sectional design taking into account He says that the objective was to obtain a panoramic view of people’s interest in avocado oil products, and identify possible uses and aspects for the development of the product, for which an information collection instrument focused on the supply was designed, demand and price for Hass avocado oil, the population size of this study was 8.465.949, the sample size is 1,872. A very favorable aspect was observed at a general level, such as the great possibility of substituting the different oils that are commonly used with the use of avocado oil, for nutritional purposes (72%), pharmacological use (45%), cosmetic use (57 %) uses as a dressing (75%), in fried foods (63%) and in food cooking (78%). The price that they would be willing to pay for 100mL of avocado oil is in the range of 15.000; 98% of the respondents indicated their interest in the use of avocado oil.En el presente artículo se presenta el resultado del estudio que buscaba determinar las preferencias de consumo de aceite de aguacate Hass en las ciudad de Bogotá, Tunja, Bucaramanga y Villavicencio (Colombia), se llevó a cabo mediante un diseño transversal exploratorio no experimental teniendo en cuenta que el objetivo era obtener una visión panorámica del interés de las personas por los productos de aceite de aguacate, e identificar posibles sus usos y aspecto para el desarrollo del producto, para lo cual se diseñó un instrumento de recolección de información enfocado a la oferta, demanda y precio para el aceite de aguacate hass, el tamaño de la población de este estudio fue de 8.465.949, el tamaño de la muestra es de 1.872. Se observó a nivel general un aspecto muy favorable como lo fue la gran posibilidad de sustituir los diferentes aceites que usan habitualmente con el uso del aceite de aguacate, para fines nutricionales (72%), uso farmacológico (45%), uso cosmético (57%) uso como aderezo (75%), en frituras (63%) y en cocción de alimentos (78%). El precio que estarían dispuestos a pagar por 100mL de aceite de aguacate esta entre un rango de 15.000; el 98% de los encuestados indicaron su interés en el uso del aceite de aguacate.Este artigo apresenta os resultados do estudo que procurou determinar as preferências de consumo do óleo de abacate Hass nas cidades de Bogotá, Tunja, Bucaramanga e Villavicencio (Colômbia), foi realizado através de um desenho transversal exploratório não experimental tendo em conta que o objectivo era obter uma visão panorâmica do interesse das pessoas pelos produtos de óleo de abacate, e para identificar possíveis usos e aspectos para o desenvolvimento do produto, para o qual foi concebido um instrumento para recolher informação centrada na oferta, procura e preço do óleo de abacate, a dimensão da população deste estudo foi 8. 465.949, a dimensão da amostra é de 1.872. Observou-se um aspecto muito favorável a nível geral, como a grande possibilidade de substituir os diferentes óleos que normalmente utilizam pelo óleo de abacate, para fins nutricionais (72%), farmacológicos (45%), cosméticos (57%), como molho (75%), em frituras (63%) e na confecção de alimentos (78%). O preço que estariam dispostos a pagar por 100mL de óleo de abacate varia entre 15.000; 98% dos inquiridos indicaram interesse em utilizar óleo de abacate
Using dates as contextual information for personalised cultural heritage experiences
We present semantics-based mechanisms that aim to promote reflection on cultural heritage by means of dates (historical events or annual commemorations), owing to their connections to a collection of items and to the visitors’ interests. We argue that links to specific dates can trigger curiosity, increase retention and guide visitors around the venue following new appealing narratives in subsequent visits. The proposal has been evaluated in a pilot study on the collection of the Archaeological Museum of Tripoli (Greece), for which a team of humanities experts wrote a set of diverse narratives about the exhibits. A year-round calendar was crafted so that certain narratives would be more or less relevant on any given day. Expanding on this calendar, personalised recommendations can be made by sorting out those relevant narratives according to personal events and interests recorded in the profiles of the target users. Evaluation of the associations by experts and potential museum visitors shows that the proposed approach can discover meaningful connections, while many others that are more incidental can still contribute to the intended cognitive phenomena
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