2,542 research outputs found

    Sentinel-3 MWR Microwave Radiometer – Our contribution to the success of the Copernicus programme

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    Revista oficial de la Asociación Española de Teledetección[EN] The MWR builds, together with the SRAL altimeter, the S3 topography mission. The MWR, developed by EADS CASA Espacio as prime contractor, provides information for tropospheric path correction of SRAL measurements. MWR data can also be used for determining surface emissivity and soil moisture over land, surface energy budget investigations and ice characterization. The MWR instrument is a Noise Injection Radiometer (NIR), working at two frequencies (23.8/36.5 GHz), embarking a dual frequency horn antenna pointing to the cold sky for embedded autonomous calibration.[ES] El radiómetro MWR, desarrollado por EADS CASA Espacio, constituye la misión topográfica de Sentinel-3 (S3) junto al radar altímetro SRAL. Su función es la entrega de información auxiliar para la corrección troposférica de las medidas del SRAL. Sus datos también pueden servir para caracterizar magnitudes físicas del suelo y la criosfera, así como para la evaluación de balances energéticos. El MWR es un radiómetro de inyección de ruido (NIR) que funciona a dos frecuencias (23,8 y 36,5 GHz) e incorpora una bocina para la obtención de la temperatura de brillo del cielo como medio de calibración autónoma.Los autores querrían agradecer el apoyo y la contribución por parte de los clientes del MWR (ESA y TAS-F), así como de los principales subcontratistas, TAS-E, CRISA, TAS-I, CDE, RYMSA, COBHAM, HVS, ABSL, APCO, IABG e ITD.Palacios, M.; Bergadà, M.; González, R.; Gamonal, A.; García-Fernández, J.; Camacho, Y. (2014). El radiómetro de microondas MWR de Sentinel-3: Nuestra contribución al éxito de Copernicus. Revista de Teledetección. (41):79-88. doi:10.4995/raet.2014.2294.SWORD798841Aguirre, M., Berruti, B., Bezy, J.L., Drinkwater, M., Heliere, F., Klein, U., Mavrocordatos, C., Silvestrin, P., Greco, B., Benveniste, J., 2007. Sentinel-3. The Ocean and Medium-Resolution Land Mission for GMES Operational Services. ESA bulletin, 131, 24-29.Guijarro, J., Auriol, A., Costes, M., Jayles, C., Vincent, P., 2000. MWR & DORIS-Supporting Envisat Radar Altimetry Mission, ESA bulletin, 104, 41-46.L'Abbate, M., Bombaci, O., Alberti, G., Femenias, P., 2003. ENVISAT-1 MWR, in flight functional and performance verification. En: Proceedings of Envisat Validation Workshop, Frascati (Italy).Xie, Y., Chen, J., Liu, D., Lv, C., Liu, K., & Miao, J. (2013). DEVELOPMENT AND CALIBRATION OF A K-BAND GROUND-BASED HYPERSPECTRAL MICROWAVE RADIOMETER FOR WATER VAPOR MEASUREMENTS. Progress In Electromagnetics Research, 140, 415-438. doi:10.2528/pier1305070

    Metallosomes for biomedical applications by mixing molybdenum carbonyl metallosurfactants and phospholipids

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    New supramolecular systems have been prepared by mixing molybdenum organometallic metallosurfactants M(CO)5L and M(CO)4L2 {L = Ph2P(CH2)6SO3Na} with the phospholipid phosphatidylcholine. The analysis of the resulting supramolecular structures using dynamic light scattering and cryo-transmission electron microscopy has shown the formation of different aggregates depending on the metallosurfactant/phospholipid ratio, as well as a significantly different behaviour between the two studied metallosurfactants. Mixed vesicles, with properties very similar to liposomes, can be obtained with both compounds, and are called metallosomes. The formation of the mixed aggregates has also been studied by microfluidics using MeOH and EtOH as organic solvents, and it has been observed that the size of the aggregates is strongly dependent on the organic solvent used. In order to analyse the viability of these mixed systems as CO Releasing Molecules (CORMs) for biomedical applications, the CO release was studied by FT-IR spectroscopy, showing that they behave as photo-CORMs with visible and ultraviolet light. Toxicity studies of the different mixed aggregate systems have shown that metallosomes exhibit a very low toxicity, similar to liposomes that do not contain metallosurfactants, which is well below the results observed for pure metallosurfactants. Micro-FTIR microscopy using synchrotron radiation has shown the presence of metallosurfactants in cells. The results of this study show the influence of the length of the hydrocarbon chain on the properties of these mixed systems, compared with previously reported data

    Influence of highway 3D coordination on drivers' perception of horizontal curvature and available sight distance

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    "This paper is a preprint of a paper submitted to [journal] and is subject to Institution of Engineering and Technology Copyright. If accepted, the copy of record will be available at IET Digital Library"Drivers' road perception is an important human factor of comfort and safety on driving. Available sight distance of crest vertical curves superimposed on horizontal curves can be geometrically optimised by applying 3D coordination criteria. However, drivers might not perceive available sight distance improvements. Two approaches were used to investigate the effect of geometrical optimised design on perceived sharpness and visibility of isolated crest vertical curves overlapped with horizontal curves. A survey-based approach was used to evaluate subjective perception of 100 drivers. Three-dimensional renderings were displayed to subjects; who were asked to rank the curves by sharpness and sight distance. Moreover, 50 of those drivers previously participated on a driving simulation experiment involving the same curves, so objective driving data were collected too. Drivers' survey results indicate that driver's curve perception depends on the algebraic difference of grades while coordination of vertical and horizontal curves does not appear to affect this perception. On the other hand, the operating speeds on different curves were not statistically different from each other. Surprisingly, the operating speeds on a flat curve tended to be lower than on the vertical crest curves superimposed on the same horizontal curve. Likely causes are discussed in the paper.Moreno Chou, AT.; García García, A.; Camacho Torregrosa, FJ.; Llorca Garcia, C. (2013). Influence of highway 3D coordination on drivers' perception of horizontal curvature and available sight distance. IET Intelligent Transport Systems. 7(2):244-250. doi:10.1049/iet-its.2012.0146S24425072Hassan, Y., & Easa, S. M. (2000). Modeling of Required Preview Sight Distance. Journal of Transportation Engineering, 126(1), 13-20. doi:10.1061/(asce)0733-947x(2000)126:1(13)García, A. (2004). Discussion of «Optimal Vertical Alignment Analysis for Highway Design» by T. F. Fwa, W. T. Chan, and Y. P. Sim. Journal of Transportation Engineering, 130(1), 138-138. doi:10.1061/(asce)0733-947x(2004)130:1(138)Bidulka, S., Sayed, T., & Hassan, Y. (2002). Influence of Vertical Alignment on Horizontal Curve Perception: Phase I: Examining the Hypothesis. Transportation Research Record: Journal of the Transportation Research Board, 1796(1), 12-23. doi:10.3141/1796-02Hassan, Y., Sayed, T., & Bidulka, S. (2002). Influence of Vertical Alignment on Horizontal Curve Perception: Phase II: Modeling Perceived Radius. Transportation Research Record: Journal of the Transportation Research Board, 1796(1), 24-34. doi:10.3141/1796-03Hasan, M., Sayed, T., & Hassan, Y. (2005). Influence of vertical alignment on horizontal curve perception: effect of spirals and position of vertical curve. Canadian Journal of Civil Engineering, 32(1), 204-212. doi:10.1139/l04-090Wang, F., & Easa, S. M. (2009). Validation of Perspective-View Concept for Estimating Road Horizontal Curvature. Journal of Transportation Engineering, 135(2), 74-80. doi:10.1061/(asce)0733-947x(2009)135:2(74)Bella, F. (2007). Parameters for Evaluation of Speed Differential. Transportation Research Record: Journal of the Transportation Research Board, 2023(1), 37-43. doi:10.3141/2023-05Ben-Bassat, T., & Shinar, D. (2011). Effect of shoulder width, guardrail and roadway geometry on driver perception and behavior. Accident Analysis & Prevention, 43(6), 2142-2152. doi:10.1016/j.aap.2011.06.004Jia, L., Wang, J., & Lu, M. (2011). Using real-world data to calibrate a driving simulator measuring lateral driving behaviour. IET Intelligent Transport Systems, 5(1), 21-31. doi:10.1049/iet-its.2009.0094Antonson, H., Mårdh, S., Wiklund, M., & Blomqvist, G. (2009). Effect of surrounding landscape on driving behaviour: A driving simulator study. Journal of Environmental Psychology, 29(4), 493-502. doi:10.1016/j.jenvp.2009.03.005Land, M. F., & Lee, D. N. (1994). Where we look when we steer. Nature, 369(6483), 742-744. doi:10.1038/369742a0Zuriaga, A. M. P., García, A. G., Torregrosa, F. J. C., & D’Attoma, P. (2010). Modeling Operating Speed and Deceleration on Two-Lane Rural Roads with Global Positioning System Data. Transportation Research Record: Journal of the Transportation Research Board, 2171(1), 11-20. doi:10.3141/2171-02Kweon, B.-S., Ellis, C. D., Lee, S.-W., & Rogers, G. O. (2006). Large-Scale Environmental Knowledge. Environment and Behavior, 38(1), 72-91. doi:10.1177/001391650528009

    Foodways in transition: food plants, diet and local perceptions of change in a Costa Rican Ngäbe community

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    Background Indigenous populations are undergoing rapid ethnobiological, nutritional and socioeconomic transitions while being increasingly integrated into modernizing societies. To better understand the dynamics of these transitions, this article aims to characterize the cultural domain of food plants and analyze its relation with current day diets, and the local perceptions of changes given amongst the Ngäbe people of Southern Conte-Burica, Costa Rica, as production of food plants by its residents is hypothesized to be drastically in recession with an decreased local production in the area and new conservation and development paradigms being implemented. Methods Extensive freelisting, interviews and workshops were used to collect the data from 72 participants on their knowledge of food plants, their current dietary practices and their perceptions of change in local foodways, while cultural domain analysis, descriptive statistical analyses and development of fundamental explanatory themes were employed to analyze the data. Results Results show a food plants domain composed of 140 species, of which 85 % grow in the area, with a medium level of cultural consensus, and some age-based variation. Although many plants still grow in the area, in many key species a decrease on local production–even abandonment–was found, with much reduced cultivation areas. Yet, the domain appears to be largely theoretical, with little evidence of use; and the diet today is predominantly dependent on foods bought from the store (more than 50 % of basic ingredients), many of which were not salient or not even recognized as ‘food plants’ in freelists exercises. While changes in the importance of food plants were largely deemed a result of changes in cultural preferences for store bought processed food stuffs and changing values associated with farming and being food self-sufficient, Ngäbe were also aware of how changing household livelihood activities, and the subsequent loss of knowledge and use of food plants, were in fact being driven by changes in social and political policies, despite increases in forest cover and biodiversity. Conclusions Ngäbe foodways are changing in different and somewhat disconnected ways: knowledge of food plants is varied, reflecting most relevant changes in dietary practices such as lower cultivation areas and greater dependence on food from stores by all families. We attribute dietary shifts to socioeconomic and political changes in recent decades, in particular to a reduction of local production of food, new economic structures and agents related to the State and globalization

    G-arylated hydrogen-bonded cyclic tetramer assemblies with remarkable thermodynamic and kinetic stability

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    The preparation and self-assembly of novel G-C dinucleoside monomers that are equipped with electron-poor aryl groups at the G-N2 amino group have been studied. Such monomers associate via Watson-Crick H-bonding into discrete unstrained tetrameric macrocycles that arise as a thermodynamically and kinetically stabilized product in a wide variety of experimental conditions, including very polar solvent environments and low concentrations. G-arylation produces an increased stability of the cyclic assembly, as a result of a subtle interplay between enthalpic and entropic effects involving the solvent coordination sphereFunding from the European Research Council (ERC-StG 279548) and MINECO (CTQ2011-23659) is gratefully acknowledge

    Thymidylate synthase gene variants as predictors of clinical response and toxicity to fluoropyrimidine-based chemotherapy for colorectal cancer

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    Abstract Background: Fluoropyrimidines form the chemotherapy backbone of advanced and metastatic colorectal cancer (CRC). These drugs are frequently associated with toxicity events that result in dose adjustments and even suspension of the treatment. The thymidylate synthase (TYMS) gene is a potential marker of response and toxicity to fluoropyirimidines as this enzyme is the molecular target of these drugs. Our aim was to assess the association between variants of TYMS with response and toxicity to fluoropyrimidines in patients with CRC in independent retrospective and prospective studies. Methods: Variants namely rs45445694, rs183205964, rs2853542 and rs151264360 of TYMS were genotyped in 105 CRC patients and were evaluated to define their association with clinical response and toxicity to fluoropyrimidines. Additionally, the relationship between genotypes and tumor gene expression was analyzed by quantitative polymerase chain reaction. Results: The 2R/2R (rs45445694) was associated with clinical response (p = 0.05, odds ratio (OR) = 3.45) and severe toxicity (p = 0.0014, OR = 5.21, from pooled data). Expression analysis in tumor tissues suggested a correlation between the 2R/2R genotype and low TYMS expression. Conclusions: The allele 2R (rs45445694) predicts severe toxicity and objective response in advanced CRC patients. In addition, the alleles G(rs2853542) and 6bp-(rs151264360) are independent predictors of response failure to chemotherapy. This is the first study made on a Latin American population that points out TYMS gene variants have predictive values for response and toxicity in patients with CRC treated with fluoropyrimidine-based chemotherapy

    Vejez y envejecimiento. Una aproximación interdisciplinaria

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    Este libro muestra algunos de los hallazgos en el tema de la vejez a partir de ejercicios de investigación y vinculación con población adulta mayor, que pretenden hacer visibles el proceso del envejecimiento en las grandes ciudades y en sectores en pobreza; los desafíos que implica el cuidado de las personas en vejez y la problemática de la salud en esta etapa de la vida. El libro también se concentra en caracterizar el envejecimiento a partir de sus aspectos sociodemográficos y mediante debates desde distintas disciplinas, y en mostrar sus rea­lidades en la salud y la relevancia de generar hábitos saludables para una vejez activa.ITESO, A.C

    Evaluation of the uncertainty in an EBT3 film dosimetry system utilizing net optical density

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    Radiochromic film has become an important tool to verify dose distributions for intensity-modulated radiotherapy (IMRT) and quality assurance (QA) procedures. A new radiochromic film model, EBT3, has recently become available, whose composition and thickness of the sensitive layer are the same as those of previous EBT2 films. However, a matte polyester layer was added to EBT3 to prevent the formation of Newton’s rings. Furthermore, the symmetrical design of EBT3 allows the user to eliminate side-orientation dependence. This film and the flatbed scanner, Epson Perfection V750, form a dosimetry system whose intrinsic characteristics were studied in this work. In addition, uncertainties associated with these intrinsic characteristics and the total uncertainty of the dosimetry system were determined. The analysis of the response of the radiochromic film (net optical density) and the fitting of the experimental data to a potential function yielded an uncertainty of 2.6%, 4.3%, and 4.1% for the red, green, and blue channels, respectively. In this work, the dosimetry system presents an uncertainty in resolving the dose of 1.8% for doses greater than 0.8 Gy and less than 6 Gy for red channel. The films irradiated between 0 and 120 Gy show differences in the response when scanned in portrait or landscape mode; less uncertainty was found when using the portrait mode. The response of the film depended on the position on the bed of the scanner, contributing an uncertainty of 2% for the red, 3% for the green, and 4.5% for the blue when placing the film around the center of the bed of scanner. Furthermore, the uniformity and reproducibility radiochromic film and reproducibility of the response of the scanner contribute less than 1% to the overall uncertainty in dose. Finally, the total dose uncertainty was 3.2%, 4.9%, and 5.2% for red, green, and blue channels, respectively. The above uncertainty values were obtained by minimizing the contribution to the total dose uncertainty of the film orientation and film homogeneity

    Impact of hospitalization on nutritional status in persons aged 65 years and over (NUTRIFRAG Study): Protocol for a prospective observational study

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    Background: Malnutrition is a recurring problem that has become more relevant in recent years. The aim of this study is to assess the risk of malnutrition and nutritional status on admission and its evolution until discharge in patients aged 65 and over admitted to medical and surgical hospitalization units in hospitals of the Spanish National Health System. Methods: Prospective observational study to be carried out in the medical-surgical hospitalization units of 9 public hospitals between 01/09/2022 and 31/12/2024. Using consecutive sampling, a total of 4077 patients will be included (453 in each hospital). Variables included are related to the care process, functionality, cognition and comorbidity, risk profile, nutritional status and dysphagia; as well as frailty, dietary quality and contextual variables. The incidence of risk of malnutrition, undernutrition and dysphagia during the care process and at discharge will be calculated. The association with risk factors will be studied with logistic regression models and multivariate Cox regression models. In addition, an analysis of participants' satisfaction with food services will be carried out. The study was approved by the Ethics and Research Committee on 30/09/2020, approved for funding on 02/12/2021 and with registration number RBR-5jnbyhk in the Brazilian clinical trials database (ReBEC) for observational studies. Discussion: Some studies address nutritional status or dysphagia in older people in various care settings. However, there is a lack of large sample studies including both processes of the impact of hospitalization. The results of the project will provide information on the incidence and prevalence of both pathologies in the study subjects, their associated factors and their relationship with the average length of stay, mortality and early readmission. In addition, early detection of a problem such as malnutrition related to the disease and/or dysphagia during a hospital stay will favor the action of professionals to resolve both pathologies and improve the health status of patients.This study has been funded by Instituto de Salud Carlos III (ISCIII) through the project "PI21/00738" and co-funded by the European Union. The funders did not and will not have a role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S

    Breakup reaction models for two- and three-cluster projectiles

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    Breakup reactions are one of the main tools for the study of exotic nuclei, and in particular of their continuum. In order to get valuable information from measurements, a precise reaction model coupled to a fair description of the projectile is needed. We assume that the projectile initially possesses a cluster structure, which is revealed by the dissociation process. This structure is described by a few-body Hamiltonian involving effective forces between the clusters. Within this assumption, we review various reaction models. In semiclassical models, the projectile-target relative motion is described by a classical trajectory and the reaction properties are deduced by solving a time-dependent Schroedinger equation. We then describe the principle and variants of the eikonal approximation: the dynamical eikonal approximation, the standard eikonal approximation, and a corrected version avoiding Coulomb divergence. Finally, we present the continuum-discretized coupled-channel method (CDCC), in which the Schroedinger equation is solved with the projectile continuum approximated by square-integrable states. These models are first illustrated by applications to two-cluster projectiles for studies of nuclei far from stability and of reactions useful in astrophysics. Recent extensions to three-cluster projectiles, like two-neutron halo nuclei, are then presented and discussed. We end this review with some views of the future in breakup-reaction theory.Comment: Will constitute a chapter of "Clusters in Nuclei - Vol.2." to be published as a volume of "Lecture Notes in Physics" (Springer
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