Terahertz-based system for dehydration analysis of hydrogel contact lenses

The use of terahertz-based techniques has grown very fast since they are capable of performingevaluations at molecular level, being very suitable for the analysis of biological samples and bioma-terials such as those for contact lenses. These biomaterials are continuously evolving to enhancethe lens wearer’s comfort by improving their hydration state and surface wettability. Therefore, thisstudy examines a novel terahertz system for the assessment of the temporary in vitro dehydrationof hydrogel contact lenses, which provides a new index to assess their state of hydration. Severalconventional and silicone hydrogel contact lenses and lens care solutions were analysed. Traditionalmethods such as the gravimetric determination of water content and the measurement of the staticcontact angle were also carried out for the validation of the developed system. The dehydrationrate measurements of contact lenses obtained with the proposed system correlated with the valuesprovided by traditional methods. As a whole, conventional hydrogel contact lenses exhibited thelowest values for dehydration rate. The tests conducted on various solutions showed a correlationbetween the wetting action of the solution and the dehydration rate of the contact lens material.Peer ReviewedPostprint (published version

El teorema de Noether y una aplicación a dualidad electromagnética

Estudiaremos el teorema de Noether mediante el formalismo lagrangiano en sistemas de partículas y en teorías clásicas de campos. Seguidamente, lo aplicaremos al estudio de las simetrías en el electromagnetismo. En particular, expondremos una densidad lagrangiana para el electromagnetismo distinta de la habitual que nos permitirá establecer una conexión clara entre simetrías del sistema y simetrías sobre las ecuaciones de Maxwell. A continuación, presentaremos una transformación, llamada transformación de dualidad, que llevará a la conservación de la helicidad óptica. Seguidamente, mostraremos el enlace que supone esta cantidad entre la descripción clásica y cuántica de la luz, pues mide el entrelazamiento de las líneas de campo electromagnético y es el límite clásico de la diferencia de fotones polarizados a derechas y a izquierdas. Por último, observaremos una familia infinita de transformaciones que llevan a cantidades conservadas que se interpretan como extensiones a mayor orden de la helicidad

La incompletitud de la aritmética mediante métodos de teorías formales

En este trabajo desarrollamos el formalismo y la teoría necesarios para dar una demostración de los teoremas de Gödel. En primer lugar, expondremos el concepto de lenguaje formal y las nociones de modelo y estructura. Seguidamente, enunciaremos las reglas de deducción de los lenguajes de primer orden y daremos una definición de teoría formal y de la consistencia y completitud de las mismas. A continuación, formalizaremos las ideas de decibilidad y computabilidad mediante funciones recursivas parciales. Por último, mostraremos una subteoría aritmética con propiedades que permiten representar proposiciones metamatemáticas dentro de la misma, la aritmética de Robinson, y el teorema del punto fijo, lo que nos permitirá demostrar los teoremas de Gödel, a saber, las extensiones de la aritmética de Robinson son inconsistentes o incompletas y, de ser consistentes, no sería posible probar su consistencia

Spectroscopic and dynamical properties of comet C/2018 F4, likely a true average former member of the Oort cloud

The population of comets hosted by the Oort cloud is heterogeneous. Most studies in this area focused on highly active objects, those with small perihelion distances or examples of objects with peculiar physical properties and/or unusual chemical compositions. This may have produced a biased sample of Oort cloud comets in which the most common objects may be rare, particularly those with perihelia well beyond the orbit of the Earth. Within this context, the known Oort cloud comets may not be representative of the full sample. Here, we study the spectral properties in the visible region and the cometary activity of Comet C/2018 F4 (PANSTARRS). We also explore its orbital evolution with the aim of understanding its origin within the context of known minor bodies moving along nearly parabolic or hyperbolic paths. We present observations obtained with the 10.4 m Gran Telescopio Canarias (GTC), derive the spectral class and visible slope of C/2018 F4 and characterise its level of cometary activity. Direct N-body simulations are carried out to explore its orbital evolution. The absolute magnitude of C/2018 F4 is Hr=13.62+/-0.04. Assuming a pV=0.04 its diameter is D<10.4 km. The object presents a conspicuous coma, with a level of activity comparable to those of other comets observed at similar heliocentric distances. Comet C/2018 F4 has a visible spectrum consistent with that of an X-type asteroid, and has a spectral slope S'=4.0+/-1.0 %/1000\AA and no evidence of hydration. The spectrum matches those of well-studied primitive asteroids and comets. The analysis of its dynamical evolution prior to discovery suggests that C/2018 F4 is not of extrasolar origin. Although the present-day heliocentric orbit of C/2018 F4 is slightly hyperbolic, its observational properties and past orbital evolution are consistent with those of a dynamically old comet with an origin in the Oort cloud.Comment: 6 pages, 5 figures. In pres

ATLAS-TEIDE: The next generations of ATLAS units for the Teide Observatory

In this work we present the design of the ATLAS unit (Asteroid Terrestrial-impact Last Alert System) that will be installed at Teide Observatory in Tenerife island (Spain). ATLAS-Teide will be built by the Instituto de Astrofisica de Canarias (IAC) and will be operated as part of the ATLAS network in the framework of an operation and science exploitation agreement between the IAC and the ATLAS team at University of Hawaii. ATLAS-Teide will be the first ATLAS unit based on commercial on the shelf (COTS) components. Its design is modular, each module (building block) consist of four Celestron RASA 11 telescopes that point to the same sky field, equipped with QHY600PRO CMOS cameras on an equatorial Direct Drive mount. Each module is equivalent to a 56cm effective diameter telescope and provides a 7.3 deg^2 field of view and a 1.26 arcsec/pix plate scale. ATLAS-Teide will consist of four ATLAS modules in a roll-off roof building. This configuration allows to cover the same sky area of the actual ATLAS telescopes. The first ATLAS module was installed in November 2022 in an existing clamshell at the TO. This module (ATLAS-P) is being used as a prototype to test the system capabilities, develop the needed software (control, image processing, etc.) and complete the fully integration of ATLAS-Teide in the ATLAS network. The preliminary results of the tests are presented here, and the benefits of the new ATLAS design are discussed.Comment: 5 pages, 8 figures, Conference pape

Colorimetric analysis of eye fundus structures with multispectral retinography

The analysis of the eye fundus is critical to prevent retinal and choroidal diseases since most of them cause no symptoms at early stages. Treating them when the very first signs appear is crucial to avoid vision losses. To this end, the color of eye fundus structures of healthy and diseased patients was assessed from images acquired with a novel multispectral fundus camera (400 nm – 1300 nm) with high spectral and spatial resolution. Characteristic color traits were found: in healthy eyes, large CIEDE2000 color differences were reported between arteries and veins due to different blood oxygenation; the contrast of nerve fibers/fovea was enhanced, giving rise to relevant color differences; in eyes with age related macular degeneration, lesions such as drusen could be better distinguished than with traditional color retinography; alterations of the optic disk in patients with glaucoma were also assessed, showing remarkable CIEDE2000 values when compared to healthy patientsThis project has received funding from the European Union's Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement No. 801342 (Tecniospring INDUSTRY) and the Government of Catalonia's Agency for Business Competitiveness (ACCIÓ). This research was also supported by the Ministerio de Economía, Industria y Competitividad (MINECO), the Agencia Estatal de Investigación (AEI) and the European Regional Development Fund (FEDER) under the grant DPI2017-89414-R.Peer ReviewedPostprint (published version

Microbial community changes induced by Managed Aquifer Recharge activities: linking hydrogeological and biological processes

Managed Aquifer Recharge (MAR) is a technique used worldwide to increase the availability of water resources. We study how MAR modifies microbial ecosystems and its implications for enhancing biodegradation processes to eventually improve groundwater quality. We compare soil and groundwater samples taken from a MAR facility located in NE Spain during recharge (with the facility operating continuously for several months) and after 4 months of no recharge. The study demonstrates a strong correlation between soil and water microbial prints with respect to sampling location along the mapped infiltration path. In particular, managed recharge practices disrupt groundwater ecosystems by modifying diversity indices and the composition of microbial communities, indicating that infiltration favors the growth of certain populations. Analysis of the genetic profiles showed the presence of nine different bacterial phyla in the facility, revealing high biological diversity at the highest taxonomic range. In fact, the microbial population patterns under recharge conditions agree with the intermediate disturbance hypothesis (IDH). Moreover, DNA sequence analysis of excised denaturing gradient gel electrophoresis (DGGE) band patterns revealed the existence of indicator species linked to MAR, most notably Dehalogenimonas sp., Nitrospira sp. and Vogesella sp.. Our real facility multidisciplinary study (hydrological, geochemical and microbial), involving soil and groundwater samples, indicates that MAR is a naturally based, passive and efficient technique with broad implications for the biodegradation of pollutants dissolved in water.Peer ReviewedPostprint (published version

Diabetes primary prevention program: new insights from data analysis of recruitment period

Primary Prevention of Diabetes Program in Buenos Aires Province evaluates the effectiveness of adopting healthy lifestyle to prevent type 2 diabetes (T2D) in people at high risk of developing it. We aimed to present preliminary data analysis of FINDRISC and laboratory measurements taken during recruitment of people for the Primary Prevention of Diabetes Program in Buenos Aires Province in the cities of La Plata, Berisso, and Ensenada, Argentina.Fil: Gagliardino, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Elgart, Jorge Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Bourgeois, Marcelo Javier. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro Interdisc.universitario Para la Salud; ArgentinaFil: Etchegoyen, Graciela Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Fantuzzi, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Ré, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Ricart, Juan P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: García, Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Giampieri, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Gonzalez, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Suárez Crivaro, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Kronsbein, Peter. Niederrhein University of Applied Sciences Mönchengladbach; AlemaniaFil: Angelini, Julieta M.. Universidad Nacional de La Plata; ArgentinaFil: Martinez, Camilo. Universidad Nacional de La Plata; ArgentinaFil: Martinez, Jorge. Universidad Nacional de La Plata; ArgentinaFil: Ricart, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Humanidades y Ciencias Sociales. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales; ArgentinaFil: Spinedi, Eduardo Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; Argentin

Morphological study of skin cancer lesions through a 3D scanner based on fringe projection and machine learning

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