162 research outputs found

    DescripciĂłn de los procesos de infiltraciĂłn mediante redes neurales artificiales

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    [ES] Se estudia la capacidad de las Redes Neurales Artificiales para modelizar procesos de infiltración de agua en suelos. Se examina, en primer lugar, su utilidad para representar la difusividad hidråulica del suelo en función del contenido de humedad. Se aplican a continuación en el ajuste directo de las curvas de contenido de humedad (Ξ) frente a la distancia o a la variable de transformación de Boltzmann (λ). Estos algoritmos se mostraron como una alternativa vålida para representar la variación de la difusividad hidråulica con el contenido de humedad, y ofrecieron, en el caso del ajuste de las curvas Ξ vs. λ, unos resultados superiores a los obtenidos con otros modelos clåsicos.Álvarez, J.; Bolado, S. (1996). Descripción de los procesos de infiltración mediante redes neurales artificiales. Ingeniería del Agua. 3(2):39-46. https://doi.org/10.4995/ia.1996.2697SWORD394632Alvarez J., R. De Miguel, F. A. Mato, F. Sobrón y J. Atienza. (1993). Reconocimiento de texturas de suelos por redes neurales. EFCE Publication Series. 101:13-18Alessi S., L. Prunty, y W. M. Schuh. (1992). Infiltration simulations among five hydraulic property models. Soil Sci. Soc. Am. J. 56:675-682.Bhagat, P. (1990). An Introduction to Neural Nets. Chemical Engn. Progress (August issue):55-60.Bradbridge, P., y J. White. (1987). Time to ponding comparison of analytical, quasy-analytic, and approximate solutions. Water Resour. Res. 23:2302-2310.Fujita, H. (1952). The exact pattern of concentration-dependent diffusion on a semi-infinite medium. II. Textile Res. J. 22:823-827.Gardner, W.R. (1958). Some Steady state solutions of unsaturated moisture flow equations with application to evaporation from a water table. Soil Sci. 85:228-232.Haverkamp, R., M. Vauclin, J. Touma, P.J. Wierenga, y G. Vachaud. (1977). A comparison of numerical simulation models for one-dimensional infiltration. Soil Sci. Soc. Am. J., 41:285-294.Jansson, P.A., (1991). Neural Networks: An overview. Anal. Chem. 63:357A-362A.Li, Z., Cheng, Z., Xu, L., y Li, T. (1993). Nonlinear fitting by using a Neural Net algorithm. Anal. Chem. 65:393-396.Meyer, J.J., y Warrick, A.W. (1990). Analytical expression for soil diffusivity derived from horizontal infiltration experiments. Soil Sci. Soc. Am. J. 54:1547-1552.Nielsen, D.R., J.W. Biggar, y J.M. Davidson. (1962). Experimental consideration of diffusion analysis in unsaturated flow problems. Soil Sci. Soc. Am. Proc. 26:107-111.Richards, L.A. (1931). Capillary conduction of liquid through porous medida. Physics (New York) 1:318-333.Russo, D. (1988). Determining soil hydraulic properties by parameter estimation: On the selection of a model for the hydraulic properties.Water Resour. Res. 24:453-459.Shu-pui, P.K., (1992). Back Propagation Neural Net Engine v1.32u. Patrick Ko. No.11, 14 ST., Hong Lok Yuen, Tai Po, Hong Kong. (ko053ucs19.cuhk.EDU.hk).Van Genuchten, M. Th. (1980). A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J. 44:892-898.Venkatasubramanian, V., y K. Chan (1989). A Neural Network methodology for process default diagnosis. AIChE Journal. 35:1993-2002.Warrick, A.W. (1994). Soil Water diffusivity estimates from one-dimensional absorption experiments. Soil Sci. Soc. Am. J. 58:72-77

    Improvement of Enzymatic Hydrolysis of Steam-exploded Wheat Straw by Simultaneous Glucose and Xylose Liberation

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    This work aimed at enhancing enzymatic hydrolysis of steam-exploded wheat-straw by investigating factors affecting hydrolysis. A multi-objective optimization of glucose and xylose release was performed using Celluclast 1.5L and Ultraflo-L mixtures with maximal values of 20 for enzyme/substrate ratio, 72 h for reaction time, 50 °C for temperature and 5.0 for pH. The highest sugar yields obtained were 18.9 ± 0.4 g/100gDM for glucose and 4.7 ± 0.2 g/100gDM for xylose. The addition of Ultraflo-L could increase the liberation of xylose, but has no pronounced effect on glucose release. The effect of ÎČ-glucosidase addition to the Ultraflo+Celluclast mixture for improving sugar yield was also studied. The ÎČ-glucosidase supplementation increased the production by approximately 29.9 % for glucose and 5.9 % for xylose, when a ÎČ-glucosidase loading of 10 % gÎČ-glucosidase/gcellulose was used

    Serous cystic neoplasm of the pancreas: A multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)

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    OBJECTIVES: Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality. DESIGN: Retrospective multinational study including SCN diagnosed between 1990 and 2014. RESULTS: 2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58\u2005years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40\u2005mm (2-200)), 9% had resection beyond 1\u2005year of follow-up (3\u2005years (1-20), size at diagnosis: 25\u2005mm (4-140)) and 39% had no surgery (3.6\u2005years (1-23), 25.5\u2005mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1\u2005year (n=1271), size increased in 37% (growth rate: 4\u2005mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1). CONCLUSIONS: After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN

    Field testing, validation and optimization report

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    The COMMON SENSE project has been designed and planned in order to meet the general and specific scientific and technical objectives mentioned in its Description of Work (page 77). As the overall strategy, the 11 work packages (WPs) of the work plan were grouped into 3 key phases: (1) RD basis for cost-effective sensor development , (2) Sensor development, sensor web platform and integration, and (3) Field testing. In the first two phases, partners involved in WP1 and WP2 have provided a general understanding and integrated basis for a cost effective sensors development. Within the following WPs 4 to 8 the new sensors were created and integrated into different identified platforms. During the third phase of field testing (WP9), partners have deployed precompetitive prototypes at chosen platforms (e.g. research vessels, oil platforms, buoys and submerged moorings, ocean racing yachts, drifting buoys). Starting from August 2015 (month 22; task 9.2), these platforms have allowed the partnership to test the adaptability and performance of the in-situ sensors and verify if the transmission of data is properly made, correcting deviations. In task 9.1 all stakeholders identified in WP2 have been contacted in order to agree upon a coordinated agenda for the field testing phase for each of the platforms. Field testing procedures (WP2) and deployment specificities, defined during sensor development in WPs 4 to 8, have been closely studied by all stakeholders involved in field testing activities in order for everyone to know their role, how to proceed and to provide themselves with the necessary material and equipment (e.g. transport of instruments). All this information have provided the basis for designing and coordinating field testing activities. Subsequently, the available new sensors have been tested since August 2015 till mid-October of the current year (2016) as part of task 9.2, following the indications defined in D9.1, such as the intercomparison of the new sensors with commercial ones, when possible. The availability of new sensors was quite different in time starting with the first tests in September and October 2015 on noise, nutrient and heavy metals sensors and closing with pCO2 in late September 2016. Sensors are technically fully described in the deliverables of WPs 3 to 8 and are here just mentioned where necessary. For further details, please consider those reports. Objectives and rationale The protocols prepared in D9.1 have been verified during the field testing activities of the innovative sensors on platforms. These can be summarized into 3 categories: (1) Research vessels (regular cruises); (2) Fixed platforms; (3) Ocean racing yachts. An exhaustive analysis of the different data obtained during field testing activities has been carried on in order to set possible optimization actions for prototypes design and performances. The data from each platform have been analyzed to verify limits and optimal installations or possible improvements. Finally a set of possible optimization actions has been defined. Data and observations collected during the course of field testing have been used to iteratively optimize the design and performance of the precompetitive prototypes

    Reduced Graphene Oxide Electrolyte-Gated Transistor Immunosensor with Highly Selective Multiparametric Detection of Anti-Drug Antibodies

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    The advent of immunotherapies with biological drugs has revolutionized the treatment of cancers and auto-immune diseases. However, in some patients, the production of anti-drug antibodies (ADAs) hampers the drug efficacy. The concentration of ADAs is typically in the range of 1-10 pm; hence their immunodetection is challenging. ADAs toward Infliximab (IFX), a drug used to treat rheumatoid arthritis and other auto-immune diseases, are focussed. An ambipolar electrolyte-gated transistor (EGT) immunosensor is reported based on a reduced graphene oxide (rGO) channel and IFX bound to the gate electrode as the specific probe. The rGO-EGTs are easy to fabricate and exhibit low voltage operations (& LE; 0.3 V), a robust response within 15 min, and ultra-high sensitivity (10 am limit of detection). A multiparametric analysis of the whole rGO-EGT transfer curves based on the type-I generalized extreme value distribution is proposed. It is demonstrated that it allows to selectively quantify ADAs also in the co-presence of its antagonist tumor necrosis factor alpha (TNF-alpha), the natural circulating target of IFX

    Analysis of relevant technical issues and deficiencies of the existing sensors and related initiatives currently set and working in marine environment. New generation technologies for cost-effective sensors

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    The last decade has seen significant growth in the field of sensor networks, which are currently collecting large amounts of environmental data. This data needs to be collected, processed, stored and made available for analysis and interpretation in a manner which is meaningful and accessible to end users and stakeholders with a range of requirements, including government agencies, environmental agencies, the research community, industry users and the public. The COMMONSENSE project aims to develop and provide cost-effective, multi-functional innovative sensors to perform reliable in-situ measurements in the marine environment. The sensors will be easily usable across several platforms, and will focus on key parameters including eutrophication, heavy metal contaminants, marine litter (microplastics) and underwater noise descriptors of the MSFD. The aims of Tasks 2.1 and 2.2 which comprise the work of this deliverable are: ‱ To obtain a comprehensive understanding and an up-to-date state of the art of existing sensors. ‱ To provide a working basis on “new generation” technologies in order to develop cost-effective sensors suitable for large-scale production. This deliverable will consist of an analysis of state-of-the-art solutions for the different sensors and data platforms related with COMMONSENSE project. An analysis of relevant technical issues and deficiencies of existing sensors and related initiatives currently set and working in marine environment will be performed. Existing solutions will be studied to determine the main limitations to be considered during novel sensor developments in further WP’s. Objectives & Rationale The objectives of deliverable 2.1 are: ‱ To create a solid and robust basis for finding cheaper and innovative ways of gathering data. This is preparatory for the activities in other WPs: for WP4 (Transversal Sensor development and Sensor Integration), for WP(5-8) (Novel Sensors) to develop cost-effective sensors suitable for large-scale production, reducing costs of data collection (compared to commercially available sensors), increasing data access availability for WP9 (Field testing) when the deployment of new sensors will be drawn and then realized

    Interaction between Axons and Specific Populations of Surrounding Cells Is Indispensable for Collateral Formation in the Mammillary System

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    An essential phenomenon during brain development is the extension of long collateral branches by axons. How the local cellular environment contributes to the initial sprouting of these branches in specific points of an axonal shaft remains unclear.The principal mammillary tract (pm) is a landmark axonal bundle connecting ventral diencephalon to brainstem (through the mammillotegmental tract, mtg). Late in development, the axons of the principal mammillary tract sprout collateral branches at a very specific point forming a large bundle whose target is the thalamus. Inspection of this model showed a number of distinct, identified cell populations originated in the dorsal and the ventral diencephalon and migrating during development to arrange themselves into several discrete groups around the branching point. Further analysis of this system in several mouse lines carrying mutant alleles of genes expressed in defined subpopulations (including Pax6, Foxb1, Lrp6 and Gbx2) together with the use of an unambiguous genetic marker of mammillary axons revealed: 1) a specific group of Pax6-expressing cells in close apposition with the prospective branching point is indispensable to elicit axonal branching in this system; and 2) cooperation of transcription factors Foxb1 and Pax6 to differentially regulate navigation and fasciculation of distinct branches of the principal mammillary tract.Our results define for the first time a model system where interaction of the axonal shaft with a specific group of surrounding cells is essential to promote branching. Additionally, we provide insight on the cooperative transcriptional regulation necessary to promote and organize an intricate axonal tree

    Harnessing Selectivity and Sensitivity in Ion Sensing via Supramolecular Recognition: A 3D Hybrid Gold Nanoparticle Network Chemiresistor

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    The monitoring of K+ in saliva, blood, urine, or sweat represents a future powerful alternative diagnostic tool to prevent various diseases. However, several K+ sensors are unable to meet the requirements for the development of point‐of‐care (POC) sensors. To tackle this grand‐challenge, the fabrication of chemiresistors (CRs) based on 3D networks of Au nanoparticles covalently bridged by ad‐hoc supramolecular receptors for K+, namely dithiomethylene dibenzo‐18‐crown‐6 ether is reported here. A multi‐technique characterization allows optimizing a new protocol for fabricating high‐performing CRs for real‐time monitoring of K+ in complex aqueous environments. The sensor shows exceptional figures of merit: i) linear sensitivity in the 10^–3 to 10^–6 m concentration range; ii) high selectivity to K+ in presence of interfering cations (Na+, Ca2+, and Mg2+); iii) high shelf‐life stability (>45 days); iv) reversibility of K+ binding and release; v) successful device integration into microfluidic systems for real‐time monitoring; vi) fast response and recovery times (<18 s), and v) K+ detection in artificial saliva. All these characteristics make the supramolecular CRs a potential tool for future applications as POC devices, especially for health monitoring where the determination of K+ in saliva is pivotal for the early diagnosis of diseases
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