Contribución al reconocimiento de objetos 2D mediante detección de bordes en imágenes en color

El presente trabajo estudia las características esenciales de las fases de una metodología de reconocimiento de objetos bidimensionales basada en la detección de bordes en imágenes en color y en el análisis de la curvatura de los puntos de los contornos de los objetos. Se ha incluido una revisión del "estado del arte" de cada una de las fases y se han propuesto nuevos algoritmos. Se ha realizado un estudio sobre la influencia, el origen y los métodos de supresión o atenuación del ruido en imágenes digitales. Se han descrito los tipos de bordes y las principales propuestas sobre algoritmos de detección de bordes, tanto en imágenes monocromáticas como en color. Se ha diseñado una metodología para comparar medidas de evaluación de algoritmos de detección de bordes. Las pruebas realizadas han permitido determinar una medida de evaluación adecuada para comparar algoritmos de detección de bordes. La medida seleccionada ha sido utilizada para comparar diferentes algoritmos de detección de bordes en imágenes en color y elegir el más eficiente. Se han estudiado las características del adelgazamiento de bordes, se han descrito algunos de los algoritmos más importantes y se han propuesto dos variantes. Se ha diseñado un método que permite extraer el contorno exterior de un objeto. Para el desarrollo de dicho método, se han propuesto dos algoritmos de identificación de los puntos del contorno exterior y un algoritmo de enlace que permite el cierre de un contorno. Se han revisado los sistemas de representación de contornos y los métodos utilizados para extraer los descriptores de un contorno. Se ha desarrollado un sistema de representación de contornos invariante a rotaciones y traslaciones que ha sido utilizado para obtener los puntos críticos o relevantes de los contornos mediante el análisis de los puntos de curvatura extrema. Se han propuesto dos nuevas funciones de comparación de contornos, basadas en los puntos críticos, que son simétricas y normalizadas. En resumen, se ha desarrollado una metodología de reconocimiento de objetos bidimensionales basada en el uso de un algoritmo de detección de bordes en imágenes en color y en el análisis de la curvatura de los puntos de los contornos

Algunas notas sobre correferencia parcial

El objetivo de este trabajo es estudiar un fenómeno que ha recibido muy poca atención en español, la correferencia parcial entre un pronombre personal y un sintagma nominal u otro pronombre. Vamos a comprobar que el fenómeno es posible en español en determinadas circunstancias sintácticas que detallaremos, contrariamente a lo que se había sostenido previamente. Propondremos que la posibilidad de establecer relaciones de correferencia parcial depende de la naturaleza sintáctica del pronombre en un modo más determinante que de los principios de Ligamiento. La comparación del español con los datos del vasco, del alemán y del francés sostendrá esta hipótesis.The purpose of this work is to study a phenomenon that has not been a central issue of the Spanish grammar: the partial correference between a pronoun and a nominal phrase or another pronoun. We are going to prove that under certain circumstances that we present in detail this becomes possible in Spanish, in opposition to what was previously assumed. We will propose that the possibility of having partial correference depends mainly on the syntactic nature of the pronoun and not on the principles of Binding. A comparison of Spanish with Basque, German and French will prove the validity of our hypothesis

Interpreting sperm DNA damage in a diverse range of mammalian sperm by means of the two-tailed comet assay

Key ConceptsThe two-dimensional Two-Tailed Comet assay (TT-comet) protocol is a valuable technique to differentiate between single-stranded (SSBs) and double-stranded DNA breaks (DSBs) on the same sperm cell.Protein lysis inherent with the TT-comet protocol accounts for differences in sperm protamine composition at a species-specific level to produce reliable visualization of sperm DNA damage.Alkaline treatment may break the sugar-phosphate backbone in abasic sites or at sites with deoxyribose damage, transforming these lesions into DNA breaks that are also converted into ssDNA. These lesions are known as Alkali Labile Sites "ALSs."DBD-FISH permits the in situ visualization of DNA breaks, abasic sites or alkaline-sensitive DNA regions.The alkaline comet single assay reveals that all mammalian species display constitutive ALS related with the requirement of the sperm to undergo transient changes in DNA structure linked with chromatin packing.Sperm DNA damage is associated with fertilization failure, impaired pre-and post- embryo implantation and poor pregnancy outcome.The TT is a valuable tool for identifying SSBs or DSBs in sperm cells with DNA fragmentation and can be therefore used for the purposes of fertility assessment. Sperm DNA damage is associated with fertilization failure, impaired pre-and post- embryo implantation and poor pregnancy outcome. A series of methodologies to assess DNA damage in spermatozoa have been developed but most are unable to differentiate between single-stranded DNA breaks (SSBs) and double-stranded DNA breaks (DSBs) on the same sperm cell. The two-dimensional Two-Tailed Comet assay (TT-comet) protocol highlighted in this review overcomes this limitation and emphasizes the importance in accounting for the difference in sperm protamine composition at a species-specific level for the appropriate preparation of the assay. The TT-comet is a modification of the original comet assay that uses a two dimensional electrophoresis to allow for the simultaneous evaluation of DSBs and SSBs in mammalian spermatozoa. Here we have compiled a retrospective overview of how the TT-comet assay has been used to investigate the structure and function of sperm DNA across a diverse range of mammalian species (eutheria, metatheria, and prototheria). When conducted as part of the TT-comet assay, we illustrate (a) how the alkaline comet single assay has been used to help understand the constitutive and transient changes in DNA structure associated with chromatin packing, (b) the capacity of the TT-comet to differentiate between the presence of SSBs and DSBs (c) and the possible implications of SSBs or DSBs for the assessment of infertility

Communication apprehension and students’ educational choices: An exploratory analysis of Spanish secondary education students

Purpose - The literature evidences the effects of communication apprehension (CA), defined as the level of fear and anxiety associated with either real or anticipated communication, on educational efforts and suggests that (via the perceived desirability of certain professions) it could affect vocational choices. The main objective of this paper is to investigate the link between CA and the vocational choice of secondary education students. Design/methodology/approach - Data were obtained from two sources: a self-administered questionnaire to measure the students’ CA levels and their academic preferences, and the vocational counsellors’ advice for these students. Findings - The results confirm the existence of a link between CA and both students’ vocational choices and counsellors’ advice. In general terms, apprehensive students tend to choose vocational education, whereas students with lower levels of CA prefer university for further education. Focusing on the latter, more apprehensive students tend to choose science degrees, which are perceived as requiring lower levels of communication skills. Research limitations/implications – Apprehensive students could be avoiding a path, with all the implications for their professional future, because it is perceived as frightening due to the apparent communication level required. As the literature notes, the links between CA and communication self-efficacy enables the development of educational interventions, resulting in a reduction of CA. Limitations include the use of a convenience sample in only one country. Originality/value - The scarce early literature has paid attention to occupational and educational choices in higher and further education, but there is no research focusing on the link between CA and preuniversity academic decisions

Heparan sulfate proteoglycans undergo differential expression alterations in left sided colorectal cancer, depending on their metastatic character

Abstract Background Heparan sulfate proteoglycans (HSPGs) are complex molecules which play a role in the invasion and growth and metastatic properties of cancerous cells. In this work we analyze changes in the patterns of expression of HSPGs in left sided colorectal cancer (LSCRC), both metastatic and non-metastatic, and the results are also compared with those previously obtained for right sided tumors (RSCRCs). Methods Eighteen LSCRCs were studied using qPCR to analyze the expression of both the proteoglycan core proteins and the enzymes involved in heparan sulfate chain biosynthesis. Certain HSPGs also carry chondroitin sulfate chains and so we also studied the genes involved in its biosynthesis. The expression of certain genes that showed significant expression differences were also analysed using immunohistochemical techniques. Results Changes in proteoglycan core proteins were dependent on their location, and the main differences between metastatic and non-metastatic tumors affected cell-surface glypicans, while other molecules were quite similar. Glypicans were also responsible for the main differences between RS- and LS- malignances. Regarding the biosynthesis of heparan sulfate chains, differential alterations in transcription depending on the presence or not of metastasis affected genes involved in the modification of uronic acid (epimerization and 2-O sulfation), and some isoforms responsible for sulfation of glucosamine (NDST1, HS6ST1). Moreover, in RSCRCs differences were preferentially found in the expression of genes involved in C6 and C3 sulfation of glucosamine, but not in NDSTs or SULFs. Finally, synthesis of chondroitin sulfate showed some alterations, which affected various steps, including polimerization and the modification of chains, but the main variations dependent on the presence of metastases were epimerization and 6C sulfation; however, when compared with RSCRCs, the essential divergences affected polymerization of the chains and the 6C sulfation of the galactosamine residue. Conclusions We evidenced alterations in the expression of HSPGs, including the expression of cell surface core proteins, many glycosiltransferases and some enzymes that modify the GAG chains in LSCRCs, but this was dependent on the metastatic nature of the tumor. Some of these alterations are shared with RSCRCs, while others, focused on specific gene groups, are dependent on tumor localization

Single-Board-Computer Clusters for Cloudlet Computing in Internet of Things

The number of connected sensors and devices is expected to increase to billions in the near future. However, centralised cloud-computing data centres present various challenges to meet the requirements inherent to Internet of Things (IoT) workloads, such as low latency, high throughput and bandwidth constraints. Edge computing is becoming the standard computing paradigm for latency-sensitive real-time IoT workloads, since it addresses the aforementioned limitations related to centralised cloud-computing models. Such a paradigm relies on bringing computation close to the source of data, which presents serious operational challenges for large-scale cloud-computing providers. In this work, we present an architecture composed of low-cost Single-Board-Computer clusters near to data sources, and centralised cloud-computing data centres. The proposed cost-efficient model may be employed as an alternative to fog computing to meet real-time IoT workload requirements while keeping scalability. We include an extensive empirical analysis to assess the suitability of single-board-computer clusters as cost-effective edge-computing micro data centres. Additionally, we compare the proposed architecture with traditional cloudlet and cloud architectures, and evaluate them through extensive simulation. We finally show that acquisition costs can be drastically reduced while keeping performance levels in data-intensive IoT use cases.Ministerio de Economía y Competitividad TIN2017-82113-C2-1-RMinisterio de Economía y Competitividad RTI2018-098062-A-I00European Union’s Horizon 2020 No. 754489Science Foundation Ireland grant 13/RC/209

Reformas e integración vertical del sector eléctrico en Reino Unido

La industria Eléctrica en Gran Bretaña ha presentado grandes cambios desde 1881 cuando Joseph Chamberlain promovió una ley prohibiendo toda libre competencia y confinándola a unos pocos contratos permitiendo el privilegio de algunos individuos. Desde este entonces el Estado ha procurado maximizar la eficiencia del sector y la prestación del servicio más aún durante los últimos 20 años; además de beneficiarse en el proceso dando total apertura a la participación privada de las compañías relacionadas con todo el sector. Eso sí, controlando y regulando las condiciones de negocio y el mercado con el fin de introducir la libre competencia y garantizar la eficiencia de las compañías prestadoras de este servicio. Esto nos invita a preguntarnos ¿Qué reformas se han realizado en el sector eléctrico del Reino Unido relacionadas con la desintegración vertical? ¿Cuáles son los efectos que han tenido dichas reformas en el sector eléctrico sobre la integración o desintegración vertical? ¿Cuáles han sido los efectos de las reformas sobre la eficiencia asignativa, es decir, el efecto en los precios del servicio? Estos son los interrogantes que se tratarán de responder en el desarrollo de este artículo.The Electrical industry in Great Britain has presented great changes. Back from 1881 when Joseph Chamberlain promoted a law prohibiting all free competition and confining it to few contracts with the purpose of eliminating the privilege of some individuals. Since that time, the State has tried during the last 20 years to maximize the efficiency of the sector and the benefit of the service to benefit in the process. With that being said, giving total opening to the companies related to the sector, but controlling and regulating the conditions of business and the market with the purpose of introducing the free competition and guaranteeing the efficiency of the lending companies of this service. This leads us to ask is this: ¿What reforms have been made in the electrical sector of the United Kingdom related to the vertical disintegration? ¿Which are the effects that have had these reforms in the electrical sector on integration or vertical disintegration? ¿Which have been the effects of the reforms on the asignative efficiency, that is to say, the effect in the prices of the service? These are the questions that will be addressed in the development of this writing

La sucesión del Emsiense más alto-Eifeliense basal (Devónico) en el Dominio Astur-Leonés de la Zona Cantábrica (N de España) y su fauna de braquiópodos

Se analizan las principales características de las Formaciones Moniello-Santa Lucía, de edad Emsiense más alto-Eifeliense basal en el Dominio Astur-Leonés de la Cordillera Cantábrica, en el área de máximo desarrollo arrecifal. Una parte, al menos, de la sucesión de la Fm. Moniello en su localidad-tipo registra repetidas oscilaciones transgresivo-regresivas que podrían reflejar ciclos astronómicos de Milankovitch de oblicuidad o precesión de los equinoccios. Se describe la estratigrafía de los ciclos más completos y se presenta una interpretación paleoecológica simple de los mismos. La parte más alta de las formaciones referidas, en el límite sudoriental entre lasprovincias de Asturias y León e inmediata extensión oriental de la última provincia, se caracteriza por la presencia prematura de rocas terrígenas del tipo de las de las sucesiones suprayacentes, Fms. Naranco-Huergas, alternando con calizas grainstone encriníticas rojas. Se propone singularizar esta facies como unidad litoestratigráfica separada, el Miembro Cebolledo, con estratotipo al ENE del pueblo de La Cueta, en León. El Mb. Cebolledo pertenece al Intervalo Faunístico (IF) 17, de edad Eifeliense inferior y su extensión septentrional en Asturias podría alcanzar la parte inferior de la Fm. Naranco, como parece suceder al este de la ensenada de Moniello. Se actualiza la caracterizaciónde los intervalos faunísticos 14 a 17, propios de las Fms. Moniello-Santa Lucía, incorporando nuevos datos paleontológicos, bioestratigráficos y eventoestratigráficos con vistas a mejorar su utilidad como herramienta en la identificación precisa de dichas formaciones en la Cordillera Cantábricay correlación con otras formaciones españolas y extranjeras. Se describen y figuran nuevos taxones del Orden Orthida de las Fms. Moniello-Santa Lucía. Se proponen Maisorthina (especie-tipo M. saroyani n. sp.) y Castrillonia (especie-tipo C. vivaldiana n. sp.) como nuevos géneros, además de Parmorthina gozonica n. sp., Rhipidomella cervantesi n. sp. y Dalejina telemanni n. sp. La morfología general de Castrillonia y la valoración de los modelos de crenulación marginal interna permiten sugerir una línea filogenética para Rhipidomella diferente de la habitualmente aceptada, enlazando Rhipidomelloides, Discomyorthis y Castrillonia en la ancestralidad directa de Rhipidomella.The main features of the uppermost Emsian to lowermost Eifelian Moniello-Santa Lucía formations in the Asturian-Leonian area of maximum reefal development in the Cantabrian Mountains, are described. At least a portion of the Moniello Fm. in its type locality records several transgressive-regressive oscillations that could be related to obliquity or precessional Milankovith astronomical cycles. A stratigraphical description of the most complete cycles, and a simple paleoecological interpretation of them are given. Along the southwestern limit between the Asturias and León provinces and in the immediate eastern extension of the León province (Somiedo unit) the uppermost part of the Moniello-Santa Lucía Fms. is characterized by the early occurrence of terrigenous rocks like to those of the suprajacent Naranco-Huergas Fms., that alternate with red crinoidal grainstone beds. This characteristic facies is proposed as a new litostratigraphical unit, the Cebolledo Member, with type locality near the Cebolledo river, ENE of La Cueta village (León province). The Cebolledo Mb. belongs to the Lower Eifelian Faunal Interval 17 and its northern extension in Asturias could transcend until the lower part of the Naranco Fm., as could occur east of the Moniello inlet. The Faunal Intervals 14 to 17, where the Moniello-Santa Lucía Fms. develop typically, are updated to include new paleontological, biostratigraphical and event-stratigraphical information, with a view to improve their utility as a tool for the precise Moniello-Santa Lucía Fms. identification and correlation along the Cantabrian Mountains and with other Spanish and foreign formations. Several new Orthida brachiopods of the studied formations are described and figured. Maisorthina (with type-species M. saroyani n. sp.), and Castrillonia (with type-species C. vivaldiana n. sp.) are proposed as new genera, and Parmorthina gozonica n. sp., Rhipidomella cervantesi n. sp. and Dalejina telemanni n. sp. as additional new species. The general morphology of Castrillonia n. gen. and the assessment of the Rhipidomellinae internal marginal crenulations enables the proposal of a phyletic lineage for Rhipidomella, departing of the usually accepted, relating Rhipidomelloides-Discomyorthis-Castrillonia as the ancestral to that genu