850 research outputs found
Diseño de un sistema automático de selección de frutos de café mediante técnicas de visión artificial
En el presente artículo se propone un sistema de visión artificial para la detección del fruto de café apto para producción. Para lograr esta detección se desarrollaron dos algoritmos, uno encargado de clasificar los frutos de café en maduros o no maduros, y otro que detecta la presencia de la plaga de la broca. Para el primero se extrajeron características de color y se usó un clasificador bayesiano. Por otra parte, el algoritmo de detección de brocas busca zonas negras en la imagen, esto debido a que la evidencia dejada por esta plaga son orificios en la superficie del fruto. Además, se diseñó un sistema mecánico para el transporte de los frutos de café durante el proceso, y un mecanismo de extracción para separar los frutos, una vez estos sean clasificados por el algoritmo. Los resultados obtenidos mostraron una efectividad del 87%.In this Article, it is proposed a computer vision system, which can detect whether a coffee fruit is suitable for production
or not. In order to achieve this detection, two algorithms were developed, one to classify the coffee fruit in the ripe orunripe state, and the other to detect the presence of the ‘coffee berry borer’. The first one uses a Bayesian Classifier toidentify the color of the fruit, and the second algorithm searches for the holes made by the coffee berry borer on thesurface of the product. Moreover, a mechanical system was designed for the transportation and separation of the coffeefruits. In the first stage, coffees are transported as pictures of them are taken. At the end of this stage, the separationmechanism alters the path of the fruit based on the result of the classifier. The system proposed obtained aneffectiveness of 87%.
 
Diseño de un sistema automático de selección de frutos de café mediante técnicas de visión artificial
En el presente artículo se propone un sistema de visión artificial para la detección del fruto de café apto para producción. Para lograr esta detección se desarrollaron dos algoritmos, uno encargado de clasificar los frutos de café en maduros o no maduros, y otro que detecta la presencia de la plaga de la broca. Para el primero se extrajeron características de color y se usó un clasificador bayesiano. Por otra parte, el algoritmo de detección de brocas busca zonas negras en la imagen, esto debido a que la evidencia dejada por esta plaga son orificios en la superficie del fruto. Además, se diseñó un sistema mecánico para el transporte de los frutos de café durante el proceso, y un mecanismo de extracción para separar los frutos, una vez estos sean clasificados por el algoritmo. Los resultados obtenidos mostraron una efectividad del 87%.In this Article, it is proposed a computer vision system, which can detect whether a coffee fruit is suitable for production
or not. In order to achieve this detection, two algorithms were developed, one to classify the coffee fruit in the ripe orunripe state, and the other to detect the presence of the ‘coffee berry borer’. The first one uses a Bayesian Classifier toidentify the color of the fruit, and the second algorithm searches for the holes made by the coffee berry borer on thesurface of the product. Moreover, a mechanical system was designed for the transportation and separation of the coffeefruits. In the first stage, coffees are transported as pictures of them are taken. At the end of this stage, the separationmechanism alters the path of the fruit based on the result of the classifier. The system proposed obtained aneffectiveness of 87%.
 
Twelve years of daily weather descriptions in North America in the eighteenth century (Mexico City, 1775-86)
© 2019 American Meteorological Society. The authors are very grateful to Ana Gavilán and César Paradinas for their help with the transcription of the FZO weather diary. Carlos Ordóñez reviewed the language. This work was supported by the research projects IMDROFLOOD financed by the Water Works 2014 cofunded call of the European Commission and INDECIS, which is part of ERA4CS, an ERA-NET initiated by JPI Climate by the European Union (Grant 690462). Marina Peña-Gallardo was granted by the Spanish Ministry of Economy and Competitiveness (MINECO), and Ahmed El Kenawy was supported by a postdoctoral Juan de la Cierva contract by the Spanish Ministry of Economy and Competitiveness (MINECO). F. Domínguez-Castro, M. C. Gallego, J. M. Vaquero, R. García Herrera, M. Peña-Gallardo, A. El Kenawy, and S. M. Vicente-SerranoDepto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEUnión Europea. H2020Ministerio de Economía y Competitividad (MINECO)JPI Climate by the European Unionpu
Tachyonization of the \LaCDM cosmological model
In this work a tachyonization of the CDM model for a spatially flat
Friedmann-Robertson-Walker space-time is proposed. A tachyon field and a
cosmological constant are considered as the sources of the gravitational field.
Starting from a stability analysis and from the exact solutions for a standard
tachyon field driven by a given potential, the search for a large set of
cosmological models which contain the CDM model is investigated. By
the use of internal transformations two new kinds of tachyon fields are derived
from the standard tachyon field, namely, a complementary and a phantom tachyon
fields. Numerical solutions for the three kinds of tachyon fields are
determined and it is shown that the standard and complementary tachyon fields
reproduces the CDM model as a limiting case. The standard tachyon
field can also describe a transition from an accelerated to a decelerated
regime, behaving as an inflaton field at early times and as a matter field at
late times. The complementary tachyon field always behaves as a matter field.
The phantom tachyon field is characterized by a rapid expansion where its
energy density increases with time.Comment: Version accepted for publication in GR
Unwrapping Closed Timelike Curves
Closed timelike curves (CTCs) appear in many solutions of the Einstein
equation, even with reasonable matter sources. These solutions appear to
violate causality and so are considered problematic. Since CTCs reflect the
global properties of a spacetime, one can attempt to change its topology,
without changing its geometry, in such a way that the former CTCs are no longer
closed in the new spacetime. This procedure is informally known as unwrapping.
However, changes in global identifications tend to lead to local effects, and
unwrapping is no exception, as it introduces a special kind of singularity,
called quasi-regular. This "unwrapping" singularity is similar to the string
singularities. We give two examples of unwrapping of essentially 2+1
dimensional spacetimes with CTCs, the Gott spacetime and the Godel universe. We
show that the unwrapped Gott spacetime, while singular, is at least devoid of
CTCs. In contrast, the unwrapped Godel spacetime still contains CTCs through
every point. A "multiple unwrapping" procedure is devised to remove the
remaining circular CTCs. We conclude that, based on the two spacetimes we
investigated, CTCs appearing in the solutions of the Einstein equation are not
simply a mathematical artifact of coordinate identifications, but are indeed a
necessary consequence of General Relativity, provided only that we demand these
solutions do not possess naked quasi-regular singularities.Comment: 29 pages, 9 figure
Long-term precipitation in Southwestern Europe reveals no clear trend attributable to anthropogenic forcing
We present a long-term assessment of precipitation trends in Southwestern Europe (1850-2018) using data from multiple sources, including observations, gridded datasets and global climate model experiments. Contrary to previous investigations based on shorter records, we demonstrate, using new long-term, quality controlled precipitation series, the lack of statistically significant long-term decreasing trends in precipitation for the region. Rather, significant trends were mostly found for shorter periods, highlighting the prevalence of interdecadal and interannual variability at these time-scales. Global climate model outputs from three CMIP experiments are evaluated for periods concurrent with observations. Both the CMIP3 and CMIP5 ensembles show precipitation decline, with only CMIP6 showing agreement with long term trends in observations. However, for both CMIP3 and CMIP5 large interannual and internal variability among ensemble members makes it difficult to identify a trend that is statistically different from observations. Across both observations and models, our results make it difficult to associate any declining trends in precipitation in Southwestern Europe to anthropogenic forcing at this stage
Newtonian and Post Newtonian Expansionfree Fluid Evolution in f(R) Gravity
We consider a collapsing sphere and discuss its evolution under the vanishing
expansion scalar in the framework of gravity. The fluid is assumed to be
locally anisotropic which evolves adiabatically. To study the dynamics of the
collapsing fluid, Newtonian and post Newtonian regimes are taken into account.
The field equations are investigated for a well-known model of the form
admitting Schwarzschild solution. The perturbation scheme is
used on the dynamical equations to explore the instability conditions of
expansionfree fluid evolution. We conclude that instability conditions depend
upon pressure anisotropy, energy density and some constraints arising from this
theory.Comment: 20 pages, accepted for publication in Astrophys. Space Sc
Transcriptomic Profiling of the Adaptive and Innate Immune Responses of Atlantic Salmon to Renibacterium salmoninarum Infection
Indexación: Scopus.Bacterial Kidney Disease (BKD), which is caused by a Gram-positive, intracellular bacterial pathogen (Renibacterium salmoninarum), affects salmonids including Atlantic salmon (Salmo salar). However, the transcriptome response of Atlantic salmon to BKD remained unknown before the current study. We used a 44K salmonid microarray platform to characterise the global gene expression response of Atlantic salmon to BKD. Fish (~54 g) were injected with a dose of R. salmoninarum (H-2 strain, 2 × 108 CFU per fish) or sterile medium (control), and then head kidney samples were collected at 13 days post-infection/injection (dpi). Firstly, infection levels of individuals were determined through quantifying the R. salmoninarum level by RNA-based TaqMan qPCR assays. Thereafter, based on the qPCR results for infection level, fish (n = 5) that showed no (control), higher (H-BKD), or lower (L-BKD) infection level at 13 dpi were subjected to microarray analyses. We identified 6,766 and 7,729 differentially expressed probes in the H-BKD and L-BKD groups, respectively. There were 357 probes responsive to the infection level (H-BKD vs. L-BKD). Several adaptive and innate immune processes were dysregulated in R. salmoninarum-infected Atlantic salmon. Adaptive immune pathways associated with lymphocyte differentiation and activation (e.g., lymphocyte chemotaxis, T-cell activation, and immunoglobulin secretion), as well as antigen-presenting cell functions, were shown to be differentially regulated in response to BKD. The infection level-responsive transcripts were related to several mechanisms such as the JAK-STAT signalling pathway, B-cell differentiation and interleukin-1 responses. Sixty-five microarray-identified transcripts were subjected to qPCR validation, and they showed the same fold-change direction as microarray results. The qPCR-validated transcripts studied herein play putative roles in various immune processes including pathogen recognition (e.g., tlr5), antibacterial activity (e.g., hamp and camp), regulation of immune responses (e.g., tnfrsf11b and socs1), T-/B-cell differentiation (e.g., ccl4, irf1 and ccr5), T-cell functions (e.g., rnf144a, il13ra1b and tnfrsf6b), and antigen-presenting cell functions (e.g., fcgr1). The present study revealed diverse immune mechanisms dysregulated by R. salmoninarum in Atlantic salmon, and enhanced the current understanding of Atlantic salmon response to BKD. The identified biomarker genes can be used for future studies on improving the resistance of Atlantic salmon to BKD. © Copyright © 2020 Eslamloo, Caballero-Solares, Inkpen, Emam, Kumar, Bouniot, Avendaño-Herrera, Jakob and Rise.https://www.frontiersin.org/articles/10.3389/fimmu.2020.567838/ful
Investigating Safety And Preliminary Efficacy Of Afm13 Plus Pembrolizumab In Patients With Relapsed/Refractory Hodgkin Lymphoma After Brentuximab Vedotin Failure
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149522/1/hon134_2629.pd
Search for Rare and Forbidden Dilepton Decays of the D+, Ds, and D0 Charmed Mesons
We report the results of a search for flavor-changing neutral current,
lepton-flavor violating, and lepton-number violating decays of D+, Ds, and D0
mesons (and their antiparticles) into modes containing muons and electrons.
Using data from Fermilab charm hadroproduction experiment E791, we examine the
pi,l,l and K,l,l decay modes of D+ and Ds and the l+l- decay modes of D0. No
evidence for any of these decays is found. Therefore, we present
branching-fraction upper limits at 90% confidence level for the 24 decay modes
examined. Eight of these modes have no previously reported limits, and fourteen
are reported with significant improvements over previously published results.Comment: 12 pages, 3 figures, LaTeX, elsart.cls, epsf.sty, amsmath.sty
Submitted to Physics Letters
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