2,065 research outputs found

    Developing strategies to reduce spray drift in pneumatic spraying in vineyards: Assessment of the parameters affecting droplet size in pneumatic spraying

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    Pneumatic sprayers are widely used in vineyards due to their very fine droplet size, which makes the drift risk to become an important problem to be considered. The aim of this study was to assess the effect of the spout diameter at the release point on the spray droplet size and uniformity achieved for different liquid flow rates (LFR) and air flow rates (AFR).A test bench was developed to simulate a real pneumatic sprayer under laboratory conditions, and it was empirically adjusted to match the air pressure conditions as closely as possible to real working conditions. Two positions of insertion of the liquid hose, the conventional position (CP) and an alternative position (AP), were tested for three LFRs, 1.00, 1.64, and 2.67Lmin-1, and four AFRs, 0.280, 0.312, 0.345, and 0.376m3 s-1. The air speed decrease between the two insertion points of the liquid hose was measured. A Malvern SprayTec® instrument was used to measure the droplet size, and the D50, D10, and D90 parameter values were obtained. The relative SPAN factor (RSF) was also calculated. A model to predict variations in D50 was fitted using the aforementioned parameters.The results show that variations in the diameter of the spout significantly change the droplet size, producing a mean increase of 59.45% in D50 and similar increases in D10 and D90. The model developed to predict variations in D50 has a very high degree of accuracy (R2 =0.945). The relative decrease in the air speed along the spout did not present significant differences for the different airflow rates tested. The results of the study show that the droplet size produced in pneumatic spraying can be modified easily by varying the air spout dimensions. This should be taken into account by manufacturers from a design point of view.Postprint (author's final draft

    Reducing spray drift by adapting the spraying equipment to the canopy shape in olive orchards with isolated trees

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    The lack of specificity of the spraying equipment commonly used in olive orchards is a remarkable problem, for not allowing farmers to apply adjusted pesticide doses to their trees, making necessary to spray very high liquid volumes that increase the environmental pollution risk. In this context, three prototypes were specially developed to increase the application efficiency in olive orchards with isolated trees, which represent 98% of the olive harvested area in Spain.Postprint (published version

    Chronological constraint of Neanderthal cultural and environmental changes in southwestern Europe: MIS 5-MIS 3 dating of the Axlor site (Biscay, Spain)

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    The cave site of Axlor (Biscay, Spain) preserves one of the most informative Middle Palaeolithic (MP) records for the North Atlantic Iberian region, though its age remains poorly known. Here we use single-grain optically stimulated luminescence (OSL) and single-grain thermally transferred OSL (TT-OSL) dating of sediments to improve the age constraint of Axlor's MP succession (levels N-B). Our new ages are consistent with the previously published terminus ante quem 14C ages for the site (>42.9 cal ka BP), and suggest the sequence accumulated during a period of ~50 kyr. Axlor's levels N-F were deposited ~100-80 ka, probably during marine isotope stage (MIS) 5d-a, while levels D and B were deposited ~70 and ~50 ka, respectively, during MIS 4 and mid-MIS 3. Our results indicate that major faunal and technological turnovers occurred towards the end of MIS 5, potentially coinciding with broader environmental and climatic changes. Axlor's Quina record, dated here to the onset of MIS 4, is one of the oldest in Europe. Comparisons with neighbouring sites point to complex regional chronologies and development for this particular behaviour, though detailed correlations with other MP sequences remain difficult due to their por chronological attributes. The present study highlights the important role that single-grain optical dating can play in elucidating the broader evolution of the MP across southwestern Europe.Research at the Axlor site is funded by the Spanish Ministry of Science and Innovation (Project PID2019‐107260GB‐I00) and Bizkaiko Foru Aldundia. M.D. was supported by Australian Research Council (ARC) Future Fellowship FT200100816 and ARC Discovery Early Career Researcher Award DE160100743. T.L. is a postdoctoral researcher in the María Zambrano Programme for the attraction of international talent. (NextGenerationEU)

    A Carboxylesterase 2 Gene Polymorphism as Predictor of Capecitabine on Response and Time to Progression

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    Este artículo ha sido publicado en la revista Current Drug Metabolism Esta versión tiene Licencia Creative Commons CC-BY-NC-ND Le remito pdf recibido de mi solicitud a la revista del postprint, y que me han enviado por correo electrónico con permiso para su depósito.Capecitabine is a drug that requires the consecutive action of three enzymes: carboxylesterase 2 (CES 2), cytidine deaminase (CDD), and thymidine phosphorylase (TP) for transformation into 5-fluorouracil (5FU). The metabolism of 5FU requires the activity of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) among other enzymes. The present study prospectively examined the possible relationship between the toxicity and efficacy of capecitabine and 14 different polymorphisms in CES 2, CDD, TS and DPD. Between 2003 and 2005, a total of 136 patients with advanced breast or colorectal cancer treated with capecitabine were prospectively enrolled. The presence of two polymorphisms (CDD 943insC and CES 2 Exon3 6046 G/A) were associated with a non-statistically significant higher incidence of grade 3 hand-foot syndrome (HFS) (p=0.07) and grade 3-4 diarrhoea (p=0.09), respectively. Patients heterozygous or homozygous for the polymorphism CES 2 5’UTR 823 C/G exhibited a significantly greater response rate to capecitabine, and time to progression of disease (59%, 8.7 months) than patients with the wild type gene sequence (32%, p=0.015; 5.3 months, p=0.014). For the first time, an association between a polymorphism in the CES2 gene and the efficacy of capecitabine has been described, providing preliminary evidence of its predictive and prognostic value

    Conservation Agriculture and its contribution to the achievement of agri-environmental and economic challenges in Europe

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    Conservation Agriculture is an ecosystem approach to farming capable of providing solutions for numerous of the agri-environmental concerns in Europe. Certainly, most of the challenges addressed in the Common Agriculture Policy (CAP) could be tackled through Conservation Agriculture (CA). Not only the agri-environmental ones, but also those concerning farmer and rural communities’ prosperity. The optimisation of inputs and similar yields than conventional tillage, make Conservation Agriculture a profitable system compared to the tillage based agriculture. Whereas this sustainable agricultural system was conceived for protecting agrarian soils from its degradation, the numerous collateral benefits that emanate from soil conservation, i.e., climate change mitigation and adaptation, have raised Conservation Agriculture as one of the global emerging agrosciences, being adopted by an increasing number of farmers worldwide, including Europe

    Galaxy classification: deep learning on the OTELO and COSMOS databases

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    Context. The accurate classification of hundreds of thousands of galaxies observed in modern deep surveys is imperative if we want to understand the universe and its evolution. Aims. Here, we report the use of machine learning techniques to classify early- and late-type galaxies in the OTELO and COSMOS databases using optical and infrared photometry and available shape parameters: either the Sersic index or the concentration index. Methods. We used three classification methods for the OTELO database: 1) u-r color separation , 2) linear discriminant analysis using u-r and a shape parameter classification, and 3) a deep neural network using the r magnitude, several colors, and a shape parameter. We analyzed the performance of each method by sample bootstrapping and tested the performance of our neural network architecture using COSMOS data. Results. The accuracy achieved by the deep neural network is greater than that of the other classification methods, and it can also operate with missing data. Our neural network architecture is able to classify both OTELO and COSMOS datasets regardless of small differences in the photometric bands used in each catalog. Conclusions. In this study we show that the use of deep neural networks is a robust method to mine the cataloged dataComment: 20 pages, 10 tables, 14 figures, Astronomy and Astrophysics (in press

    A systematic review of serious games in medical education : quality of evidence and pedagogical strategy

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    Q2Q1Introduction: The literature shows an optimistic landscape for the effectiveness of games in medical education. Nevertheless, games are not considered mainstream material in medical teaching. Two research questions that arise are the following: What pedagogical strategies do developers use when creating games for medical education? And what is the quality of the evidence on the effectiveness of games? Methods: A systematic review was made by a multi-disciplinary team of researchers following the Cochrane Collaboration Guidelines. We included peer-reviewed journal articles which described or assessed the use of serious games or gamified apps in medical education. We used the Medical Education Research Study Quality Instrument (MERSQI) to assess the quality of evidence in the use of games. We also evaluated the pedagogical perspectives of such articles. Results: Even though game developers claim that games are useful pedagogical tools, the evidence on their effectiveness is moderate, as assessed by the MERSQI score. Behaviourism and cognitivism continue to be the predominant pedagogical strategies, and games are complementary devices that do not replace traditional medical teaching tools. Medical educators prefer simulations and quizzes focused on knowledge retention and skill development through repetition and do not demand the use of sophisticated games in their classrooms. Moreover, public access to medical games is limited. Discussion: Our aim was to put the pedagogical strategy into dialogue with the evidence on the effectiveness of the use of medical games. This makes sense since the practical use of games depends on the quality of the evidence about their effectiveness. Moreover, recognition of said pedagogical strategy would allow game developers to design more robust games which would greatly contribute to the learning process.https://orcid.org/0000-0002-8980-6590https://orcid.org/0000-0002-1169-9086https://orcid.org/0000-0002-3825-7149https://orcid.org/0000-0002-8060-4140https://orcid.org/0000-0001-5401-0018N/

    The OTELO survey. A case study of [O III]4959,5007 emitters at <z> = 0.83

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    The OTELO survey is a very deep, blind exploration of a selected region of the Extended Groth Strip and is designed for finding emission-line sources (ELSs). The survey design, observations, data reduction, astrometry, and photometry, as well as the correlation with ancillary data used to obtain a final catalogue, including photo-z estimates and a preliminary selection of ELS, were described in a previous contribution. Here, we aim to determine the main properties and luminosity function (LF) of the [O III] ELS sample of OTELO as a scientific demonstration of its capabilities, advantages, and complementarity with respect to other surveys. The selection and analysis procedures of ELS candidates obtained using tunable filter (TF) pseudo-spectra are described. We performed simulations in the parameter space of the survey to obtain emission-line detection probabilities. Relevant characteristics of [O III] emitters and the LF([O III]), including the main selection biases and uncertainties, are presented. A total of 184 sources were confirmed as [O III] emitters at a mean redshift z=0.83. The minimum detectable line flux and equivalent width (EW) in this ELS sample are \sim5 ×\times 1019^{-19} erg s1^{-1} cm2^{2} and \sim6 \AA, respectively. We are able to constrain the faint-end slope (α=1.03±0.08\alpha = -1.03\pm0.08) of the observed LF([O III]) at z=0.83. This LF reaches values that are approximately ten times lower than those from other surveys. The vast majority (84\%) of the morphologically classified [O III] ELSs are disc-like sources, and 87\% of this sample is comprised of galaxies with stellar masses of M_\star << 1010^{10} M_{\odot}.Comment: v1: 16 pages, 6 figures. Accepted in Astronomy \& Astrophysics. v2: Author added in metadat

    Gamificación como instrumento para mejorar los indicadores docentes en asignaturas de ingeniería agroforestal

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    En cursos iniciales de asignaturas de ingeniería aplicada se produce una reducida asistencia y participación del alumnado en clase, minorando el rendimiento de este y promoviendo el absentismo en el examen final. El fomento de la motivación del alumno puede ser un factor determinante en dicho problema, pudiendo presentarse la gamificación como herramienta útil para tal fin. En este trabajo, como respuesta ante esta cuestión, se muestra el uso de una herramienta on-line que ofrece la posibilidad de realizar una prueba tras cada unidad didáctica. Con ello, el alumno puede autoevaluar su proceso de aprendizaje y, al mismo tiempo, el profesorado tiene la posibilidad de conocer la evolución individual de cada estudiante. Para incentivar su uso, se ofrece la opción de superar contenidos de la asignatura para mantener la calificación de parte de la nota, previa a su evaluación en la prueba final de la asignatura. La práctica docente se ha llevado a cabo en una asignatura troncal con 126 alumnos, de los que han participado 87. Los resultados indican que se ha incrementado la asistencia a clase y la retroalimentación y proactividad de los alumnos a través de tutorías, foros y preguntas con relación a los tres cursos académicos anteriores. La práctica propuesta no aumenta sustancialmente la carga de trabajo del profesorado y mejora la compresión y el aprendizaje del alumno, así como la superación de las pruebas escritas de la asignatura
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