3,261 research outputs found
Astigmatism of the ex vivo human lens: Surface and gradient refractive index age-dependent contributions
7 págs.; 5 figs.© 2015 The Association for Research in Vision and Ophthalmology, Inc. PURPOSE. We estimated the contribution of the gradient refractive index (GRIN) and lens surfaces to lens astigmatism and lens astigmatic angle as a function of age in human donor lenses. METHODS. Human lenses were imaged, ex vivo, with 3D-spectral optical coherence tomography (OCT) and their back focal length was measured using laser ray tracing. The contribution of lens surfaces and GRIN to lens astigmatism were evaluated by computational ray tracing on the GRIN lens and a homogenous equivalent index lens. Astigmatism magnitude and relative astigmatic angle of and between lens surfaces, GRIN lens, and lens with homogeneous refractive index were evaluated, and all results were correlated with age. RESULTS. The magnitude of astigmatism in the anterior lens surface decreased with age (slope = -0.005 diopters [D]/y; r = 0.397, P =0.018). Posterior surface astigmatism and lens astigmatism were not age-dependent. Presence of GRIN did not alter significantly the magnitude or axis of the lens astigmatism. The astigmatism of GRIN lens and lens with homogeneous refractive index correlated with anterior lens surface astigmatism (GRIN, P = 3.9E - 6, r = 0.693; equivalent refractive index lens, P = 4.1E - 4, r = 0.565). The astigmatic angle of posterior surface, GRIN lens, and homogeneous refractive index lens did not change significantly with age. CONCLUSIONS. The axis of lens astigmatism is close to the astigmatic axis of the anterior lens surface. Age-related changes in lens astigmatism appear to be related to changes in the anterior lens astigmatism. The influence of the GRIN on lens astigmatism and the astigmatic axis is minor.Supported by Spanish Government Grant FIS2011-25637 (SM),
Consejo Superior de Investigaciones Científicas Junta de Ampliacion
de Estudios (CSIC JAE)-Pre Program (JB), CSIC i-LINKþ 2012,
iLINKþ0609 (SM). The research leading to these results has received
funding from the European Research Council under the European
Union’s Seventh Framework Programme (FP7/2007-2013)/ERC
Grant Agreement 294099 (SM).Peer Reviewe
Análisis dinámico de los efectos de la estructura de demanda sobre crecimiento y medio ambiente en Andalucía
En este trabajo se relaciona la especialización productiva de una región española (Andalucía) con el crecimiento económico, el consumo de recursos naturales y la polución atmosférica. Para ello, nos hemos centrado en dos de los recursos naturales básicos, como son el agua y la energía, así como en otros indicadores de calidad atmosférica, tales como las emisiones de CO y SO2. La metodología seguida parte de la aplicación de la dinámica de sistemas, proponiendo un modelo que pone en relación ciertas variables medio ambientales con las de otros subsistemas (laboral y macroeconómico). En el modelo se integran las tablas input-output de Andalucía (Instituto de Estadística de Andalucía) y los resultados recientes, respecto a consumos de agua, energía y emisión de contaminantes, obtenidos en la contabilidad ambiental, elaborada por la Consejería de Medio Ambiente de esta Comunidad Autónoma.environment economics, dymamic systems, input-output analysis, regional analysis
EFECTOS ULTRA FRONTERA Y CONVERGENCIA REGIONAL. UNA REFLEXIÓN A PARTIR DEL MAC 94-99 EN ANDALUCÍA.
En este trabajo se evalúan los efectos ex-post del MAC 1994-1999 en Andalucía (España), los efectos directos e indirectos de las inversiones dentro de la región y los efectos fuga producidos hacia el resto del país (cross-border leakage). Utilizando un modelo multisectorial de dos regiones, la andaluza y el resto de España, se comparan los estímulos inducidos por los fondos estructurales en es resto de la economía nacional con los producidos en la economía andaluza. Los resultados muestran que, al menos a corto y medio plazo, los resultados sobre la convergencia real pueden ser poco o nada relevantes. Podría afirmarse que las regiones más desarrolladas del país han sido grandes beneficiarias indirectas de los fondos destinados a las regiones de objetivo 1.Structural Funds Evaluation; Regional Convergence; Cross- Border Leakages
Towards a service-oriented MDA-based approach to the alignment of business processes with IT systems: From the business model to a web service composition model
In recent years, the automation of business processes has become one of the most prominent and promising uses of Web service technology. Consequently several languages have been created for the execution of business processes, making it possible to define new and more complex services or business processes which are implemented for example by means of Web service composition. Nevertheless, these kinds of languages are not suitable for use in the early stages of the development process of information systems. Special methodologies or techniques are therefore necessary to allow systems analysts to understand services from a business point of view, while facilitating the design and development ofWeb service composition. In this paper, we present a service-oriented approach to information system development that starts by identifying, through business modeling, the services required by the customers of a business, to make it possible to create a Web service composition model. This model will facilitate the transformation to specific languages for business process execution, thereby reducing the development efforts made in service-oriented applications. The method proposed is illustrated by means of a Web application for the management of medical images, which we have taken as a case study
Integrating microbial and host transcriptomics to characterize asthma-associated microbial communities.
BACKGROUND: The relationships between infections in early life and asthma are not completely understood. Likewise, the clinical relevance of microbial communities present in the respiratory tract is only partially known. A number of microbiome studies analyzing respiratory tract samples have found increased proportions of gamma-Proteobacteria including Haemophilus influenzae, Moraxella catarrhalis, and Firmicutes such as Streptococcus pneumoniae. The aim of this study was to present a new approach that combines RNA microbial identification with host gene expression to characterize and validate metagenomic taxonomic profiling in individuals with asthma.
METHODS: Using whole metagenomic shotgun RNA sequencing, we characterized and compared the microbial communities of individuals, children and adolescents, with asthma and controls. The resulting data were analyzed by partitioning human and microbial reads. Microbial reads were then used to characterize the microbial diversity of each patient, and potential differences between asthmatic and healthy groups. Human reads were used to assess the expression of known genes involved in the host immune response to specific pathogens and detect potential differences between those with asthma and controls.
RESULTS: Microbial communities in the nasal cavities of children differed significantly between asthmatics and controls. After read count normalization, some bacterial species were significantly overrepresented in asthma patients (Wald test, p-value \u3c 0.05), including Escherichia coli and Psychrobacter. Among these, Moraxella catarrhalis exhibited ~14-fold over abundance in asthmatics versus controls. Differential host gene expression analysis confirms that the presence of Moraxella catarrhalis is associated to a specific M. catarrhalis core gene signature expressed by the host.
CONCLUSIONS: For the first time, we show the power of combining RNA taxonomic profiling and host gene expression signatures for microbial identification. Our approach not only identifies microbes from metagenomic data, but also adds support to these inferences by determining if the host is mounting a response against specific infectious agents. In particular, we show that M. catarrhalis is abundant in asthma patients but not in controls, and that its presence is associated with a specific host gene expression signature
The biological basis of smoltification in Atlantic salmon
Chile is the second-largest producer of Atlantic salmon in the world, and the Chilean salmon production accounts for 27% of the world’s production. One important step of the productive cycle in freshwater is the smoltification process that prepares the fish for the marine life stage. This review describes the biological basis of smoltification in Atlantic salmon, with particular attention on branchial osmoregulatory adaptations. We also discuss some of the infectious diseases and problems in smoltification (two of the main causes of losses in Chilean aquaculture) that could be related from a physiological point of view
Lead free piezoelectric ceramics based on Bi0.5(Na0.8K0.2)0.5TiO3 y K0.5Na0.5NbO3 systems
Los materiales cerámicos basados en circonato-titanato de plomo, Pb(Zr,Ti)O3(PZT), son muy conocidos por sus excelentes propiedades piezoeléctricas. Si bien, estos materiales se producen generalmente a partir de la técnica de mezcla de óxidos, la cual es relativamente simple y económica, en su formulación se emplea un alto contenido de óxido de plomo (aprox. 70%). Dado que el plomo y sus compuestos son considerados tóxicos y peligrosos, no sólo por la polución directa que genera el proceso de manufactura y maquinado de los compuestos, sino también porque los productos que contienen PZT no pueden ser reciclados, recientemente se han comenzado a investigar diferentes composiciones piezoeléctricas para su reemplazo. En este trabajo, se analizan algunos desarrollos propios en el campo de los materiales piezoeléctricos libres de plomo donde se enfatiza la correlación existente entre las propiedades finales, la microestructura desarrollada y la estructura estabilizada.Ceramics based on lead zirconium titanate Pb(Zr,Ti)O3 (PZT) are well known for their excellent piezoelectric properties. These materials are generally produced by solid reaction technique, which is relatively simple and economical; however their production needs high lead oxide content (approx. 70%). Lead and its compounds are considered toxic and dangerous, due to direct pollution generated by the manufacturing process and machining of the compounds, and the inability to recycle products containing PZT. Therefore, other piezoelectric compositions based on lead free materials have begun investigated. In this paper, some developments in the field of lead-free piezoelectric materials, correlating the structure and microstructure with the properties materials properties are analyzed.Fil: Castro, Miriam Susana. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); ArgentinaFil: Camargo, Javier Eduardo. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); ArgentinaFil: Taub, Jonathan. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); ArgentinaFil: Fernandez, J. F.. Instituto de Ceramica y Vidrio de Madrid; EspañaFil: Rubio-Marcos, F.. Instituto de Ceramica y Vidrio de Madrid; EspañaFil: Ramajo, Leandro Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentin
Changes in monkey crystalline lens spherical aberration during simulated accommodation in a lens stretcher
8 págs.; 7 figs.; 2 apps.© 2015 The Association for Research in Vision and Ophthalmology, Inc. PURPOSE. The purpose of this study was to quantify accommodation-induced changes in the spherical aberration of cynomolgus monkey lenses. METHODS. Twenty-four lenses from 20 cynomolgus monkeys (Macaca fascicularis; 4.4-16.0 years of age; postmortem time 13.5±13.0 hours) were mounted in a lens stretcher. Lens spherical aberration was measured in the unstretched (accommodated) and stretched (relaxed) states with a laser ray tracing system that delivered 51 equally spaced parallel rays along 1 meridian of the lens over the central 6-mm optical zone. A camera mounted below the lens was used to measure the ray height at multiple positions along the optical axis. For each entrance ray, the change in ray height with axial position was fitted with a third-order polynomial. The effective paraxial focal length and Zernike spherical aberration coefficients corresponding to a 6-mm pupil diameter were extracted from the fitted values. RESULTS. The unstretched lens power decreased with age from 59.3±6 4.0 diopters (D) for young lenses to 45.7±6 3.1 D for older lenses. The unstretched lens shifted toward less negative spherical aberration with age, from -6.3±0.7 lm for young lenses to-5.0±0.5 lm for older lenses. The power and spherical aberration of lenses in the stretched state were independent of age, with values of 33.5±6 3.4 D and-2.6±0.5 lm, respectively. CONCLUSIONS. Spherical aberration is negative in cynomolgus monkey lenses and becomes more negative with accommodation. These results are in good agreement with the predicted values using computational ray tracing in a lens model with a reconstructed gradient refractive index. The spherical aberration of the unstretched lens becomes less negative with age.Supported by National Institutes of Health Grants R01EY14225,
R01EY021834, and F31EY021444 Ruth L. Kirschstein National
Research Service Award individual predoctoral fellowship [BM]),
and center Grant P30EY14801; Australian government Cooperative
Research Centre Scheme (Vision CRC); Florida Lions Eye Bank;
Karl R. Olsen and Martha E. Hildebrandt; an unrestricted grant
from Research to Prevent Blindness; Henri and Flore Lesieur
Foundation (JMP); Spanish government Grant FIS2011-25637; and
European Research Council Grants ERC-2011-AdG-294099 and
CSIC i-LINKþ0609Peer Reviewe
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