1,230 research outputs found

    label free fluorescence detection of kinase activity using a gold nanoparticle based indicator displacement assay

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    A straightforward fluorescence indicator-displacement assay (IDA) has been developed for the quantitative analysis of ATP→ADP conversion

    Beyond Jacobian-based tasks: Extended set-based tasks for multi-task execution and prioritization

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    The ability of executing multiple tasks simultaneously is an important feature of redundant robotic systems. As a matter of fact, complex behaviors can often be obtained as a result of the execution of several tasks. Moreover, in safety-critical applications, tasks designed to ensure the safety of the robot and its surroundings have to be executed along with other nominal tasks. In such cases, it is also important to prioritize the former over the latter. In this paper, we formalize the definition of extended set-based tasks, i.e., tasks which can be executed by rendering subsets of the task space asymptotically stable or forward invariant. We propose a mathematical representation of such tasks that allows for the execution of more complex and time-varying prioritized stacks of tasks using kinematic and dynamic robot models alike. We present and analyze an optimization-based framework which is computationally efficient, accounts for input bounds, and allows for the stable execution of time-varying prioritized stacks of extended set-based tasks. The proposed framework is validated using extensive simulations and experiments with robotic manipulators

    Androgenic activation, impairment of the monoaminergic system and altered behavior in zebra!sh larvae exposed to environmental concentrations of fenitrothion

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    Artículo indizadoFenitrothion is an organophosphorus insecticide usually found in aquatic ecosystems at concentrations in the range of low ng/L. In this manuscript we show that 24 h exposure to environmental concentrations of fenitro- thion, from ng/L to low !g/L, altered basal locomotor activity, visual-motor response and acoustic/vibrational es- cape response of zebra!sh larvae. Furthermore, fenitrothion and expression of gap43a, gfap, atp2b1a, and mbp exhibited a signi!cant non-monotonic concentration-response relationship. Once determined that environmen- tal concentrations of fenitrothion were neurotoxic for zebra!sh larvae, a computational analysis identi!ed poten- tial protein targets of this compound. Some of the predictions, including interactions with acetylcholinesterase, monoamine-oxidases and androgen receptor (AR), were experimentally validated. Binding to AR was the most suitable candidate for molecular initiating event, as indicated by both the up-regulation of cyp19a1b and sult2st3 and the non-monotonic relationship found between fenitrothion and the observed responses. Finally, when the integrity of the monoaminergic system was evaluated, altered levels of L-DOPA, DOPAC, HVA and 5-HIAA were found, as well as a signi!cant up-regulation of slc18a2 expression at the lowest concentrations of fenitrothion. These data strongly suggest that concentrations of fenitrothion commonly found in aquatic ecosystems present a signi!cant environmental risk for !sh communities.This work was supported by the Spanish Government with FEDER Funds (CTM2017-83242-R; D.R.) and the net- work of recognized research groups by the Catalan Government (2017 SGR_902)

    Determinación de la edad de transición de madera juvenil a madura y de sus valores elasto-resistentes en Pinus contorta

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    El porcentaje de madera juvenil en coníferas de crecimiento rápido es un factor determinante de las propiedades básicas, ya que su proporción aumenta a medida que disminuye la edad de rotación. Dicha madera se caracteriza por presentar menor longitud y espesor de pared de traqueidas y mayor ángulo micro-fibrilar, lo cual se traduce en menor densidad y propiedades elasto-resistentes más bajas. Para delimitar la edad transición de madera (juvenil-madura) se realiza el análisis radial de algunas de las características mencionadas. La importancia de establecer dicha edad, radica en la estimación de los volúmenes de ambos tipos de madera, su calidad y potencialidad de uso. El objetivo del trabajo fue determinar la edad de transición y comparar sus valores elasto-resistentes en Pinus contorta (lodgepole). Se trabajó con 9 muestras de 35 años, radios norte y sur para estudios anatómicos, y madera juvenil y madura para ensayos físico mecánicos. Las edades de transición resultaron entre los 12 y 16,5 años, dirección norte y sur, respectivamente. Las variables anatómicas, físicas y mecánicas se diferenciaron significativamente, siendo mayores en la madera madura. A fin de generar una base de datos de esta especie para la región, se sugiere continuar con estudios similares en otros sitios

    Papas Chips VIII : tablas de conversión y los parámetros de calidad de tubérculos de papa (Solanum tuberosum L.) materia prima para la industria

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    p.123-131Los valores de peso específico (pe), materia seca (MS) y almidón de los tubérculos de papa son elementos importantes para seleccionar los cultivares (cvs) que se industrializan. Estos tres parámetros se han relacionado por las tablas de conversión, las que a través del dato experimental del pe permiten obtener los de MS y de almidón. Estas tablas son extranjeras, por ello se comparan nuestros valores experimentales de almidón y MS, con lo que se obtendrían de dichas tablas y-o ecuaciones matemáticas. De la confrontación de valores surge la necesidad de disponer de tablas de conversión realizadas en el país, a fin de contar con datos de mayor valor. Se analizaron almidón y materia seca de distintos cvs, de cosecha 1965 a 1980, de diferentes zonas productoras del país, con distinto estado fisiológico y período de almacenamiento. Los valores promedio de materia seca (1.200 determinaciones) y de almidón (600 determinaciones) se correlacionaron. El contenido de MS y de almidón influyen en la calidad de las papas fritas chips. Es importante cuantificar con precisión estos valores para los tubérculos destinados para la industria

    A chemical survey of exoplanets with ARIEL

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    Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

    Reshaping ophthalmology training after COVID-19 pandemic

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    Background The coronavirus disease 2019 (COVID-19) pandemic has had a significant impact on practical activities and didactic teaching of residents and fellows. This survey aimed to propose long-term changes for ophthalmology training based on the changes experienced by trainees and their perception of new training opportunities. Methods An online survey was distributed to ophthalmology trainees in multiple countries. Descriptive statistics were used to analyse the data. Results A total of 504 analyzable responses were collected from 32 different countries. The current impact of COVID-19 pandemic was described as "severe" by most trainees (55.2%); however, the future perspective was more optimistic as demonstrated by the greater number of responses reporting a presumed "moderate" (37.3%), "mild" (14.1%) or "slight" (4.2%) long-term impact. The vast majority of trainees reported a decrease >= 50% of clinical activity (76.4%) and >75% of surgical activity (74.6%). Although an initial gap in didactic teaching has been experienced by many (55.4%), regular web-based teaching was reportedly attended by 67.7% of the respondents. A strong agreement was found regarding the worthwhile role of web-based case-presentations in clinical training (91.7%), web-based discussion of edited surgical videos (85.7%) and simulation-based practice (86.9%) in surgical training. Conclusions This survey, focusing on trainees' perspective, strongly reinforces the need to promptly include new technology-based training tools, such as web-based teaching, virtual surgical simulators, and telementoring, in long-term reorganisation of ophthalmology training to ensure its continuity and effectiveness, which would remain available even in the face of another unpredictable crisis within the health system
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