1,720,977 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Efecto de los ultrasonidos de potencia en la despolimerización de taninos procedentes de semillas de uva Vitis vinifera
No full textTrabajo Fin de Grado: Grado en Ciencias de la Alimentación presentado por Ana María Muñoz Labrador en la Facultad de Ciencias, Departamento de Química Física Aplicada de la Universidad Autónoma de Madrid.[ES]: Hoy en día el interés de los consumidores por los alimentos saludables está aumentando debido al incremento de determinadas enfermedades relacionadas con una incorrecta alimentación. Por ello, actualmente se requiere que los alimentos no sólo proporcionen constituyentes nutritivos y sensorialmente aceptables, sino también con ciertas propiedades bioactivas que ayuden en la prevención de patologías crónicas y mejoren el estado de salud en general. Por otro lado, existe un renovado interés por el desarrollo de tecnologías emergentes que mantengan en lo posible la calidad y bioactividad de los alimentos. En este contexto se sitúan los ultrasonidos (US) de potencia, tecnología que, sola o en combinación con otras, puede emplearse en la extracción y conservación de alimentos. Se considera una herramienta rápida, económica y sostenible. El objetivo del presente trabajo se centra en el estudio del efecto de los US de potencia sobre la despolimerización de taninos de semillas de uva Vitis vinifera y sobre sus propiedades antioxidantes, con el fin de disponer de potenciales ingredientes con bioactividad mejorada respecto a los compuestos de partida y, así, diversificar sus aplicaciones en la industria agroalimentaria. Se realizaron ensayos con US a 45 y 20 kHz de frecuencia y se observó en general un incremento en la actividad antioxidante que varió en función de la concentración y del sistema empleado. Así mismo, se detectó un aumento en las áreas de los polímeros de procianidinas respecto a los controles sin tratar indicando una posible desagregación de los complejos que forman con otras moléculas lo cual pudo contribuir al incremento en la actividad antioxidante.[EN]: Nowadays, the interest of consumers in healthy food is increasing due to the increase of certain diseases related to bad feeding habits. Therefore, currently it is required that food not just provides nutritious constituents and is sensory acceptable, but also with bioactive properties to help in the prevention of pathologies and improving health. On the other hand, there is a renewed interest about emergent technologies that maintain as far as possible, the quality and bioactivity of food. In this context there is the potential ultrasound (US), a technology that by itself or by combination with others can be employed for extraction and conservation techniques in food. It is considered a fast, economical and sustainable method. The aim of the present work is focused on the study of the effects of US on the depolymerisation of tannins from grape seeds Vitis vinifera, and about their antioxidant properties. With the purpose of obtaining potential ingredients with an improved bioactivity with regard to the initial compound and, thus, diversifying its applications in the food industry.
Assays were performed with US using frequencies of 45 and 20 kHz, and an increase in the antioxidant activity was observed which varied depending on the concentration and the system employed. Furthermore, an increase in polymers of procyanidins was detected in the controls without treatment indicating a possible desegregation of the complexes that form with other molecules which could contribute to the increase of the antioxidant activity.Peer Reviewe
Caracterización de pectinas industriales de cítricos y su aplicación como recubrimientos de fresas
No full textMáster en Química Agrícola y Nuevos Alimentos.[ES]: Una mayor demanda por parte de los consumidores de productos más saludables y la necesidad de minimizar la contaminación del medio ambiente ha incentivado, a los investigadores y a la industria, a explorar nuevas maneras de utilizar los subproductos que se generan en la industria agroalimentaria para la obtención de ingredientes funcionales, de hecho, en los últimos años, esto se ha considerado uno de los retos más importantes. En el sector hortofrutícola español uno de los subproductos más importantes son los obtenidos de las extracción de zumo de cítricos (piel, pulpa y semillas), muy ricos en pectinas. Estos polisacáridos son una de las familias más complejas y abundantes, presentes en las paredes celulares de las plantas y están formadas por unidades de ácido D-galacturónico unidas por enlaces α-(1-4) y cadenas laterales de ramnogalacturonano. Estos biopolímeros presentan propiedades biológicas que los hacen adecuados para su uso en la industria farmacéutica así como en la industria alimentaria, destacando, para este sector, sus propiedades prebióticas y tecno-funcionales por su poder gelificante y estabilizante. Por todo ello, en el presente trabajo se ha realizado una caracterización proximal y estructural de pectinas industriales procedentes de cítricos, así como su evaluación reológica, con el fin de ser empleadas como recubrimientos durante la conservación de fresas frescas. Los resultados indicaron que estas pectinas mostraban un grado de esterificación (DE), determinado por espectroscopía de infrarrojos por transformada de Fourier (FT-IR), superior al 50% y un contenido de ácido galacturónico >65 % en la pectina pura (analizado por GC-FID tras hidrólisis ácida con TFA 2M) pudiendo ser, por tanto, consideradas como aditivo E-440. Según el estudio reológico (análisis de la viscosidad en función de la fuerza de cizalla) estas pectinas presentan distintas viscosidades, lo que las hace idóneas para diferentes usos y, por otra parte, los métodos de preparación posibilitan obtener geles con una más amplia gama de valores de viscosidad, ampliando aún más sus posibilidades de uso. Por último se estudió su utilización como recubrimiento observándose, en la mayoría de los casos, una menor pérdida de humedad, especialmente en las fresas recubiertas con la pectina 4710 preparada con agitador de varilla y de la 4400 preparada en placa, ambas tratadas posteriormente con ultrasonidos (30 min 30% de amplitud), presentando estas fresas mejores características de color (L*, a*, b*, C, h, ΔE), que el control tras 5 días de almacenamiento.[EN]: A growing consumer demand for healthier products and the necessity to minimize the environmental impact, have recently spurred researchers and the industry to develop ways to use the by-products from the food industry to obtain functional ingredients. Indeed, in the last years it has been considered one of the most important issues. In the Spanish fruit and vegetable processing sector, one of the most important by-product is obtained from the citrus extraction (skin, pulp, seeds) rich in pectin. These are one of the most abundant and complex polysaccharides, found in the cell walls, and are chemically constituted by poly α-1-4-D-galacturonic acids and lateral chains of rhamnogalacturonan. These biopolymers present biological properties which make them appropriate to be used in the pharmaceutical and food industry, highlighting the prebiotic and techno functional properties and the gelation and emulsion stabilizing capacity. In this work, a proximal and structural characterization of industrial citrus pectin has been done, together with a rheological evaluation to be used as edible coating in fresh strawberries during storage. The results indicate that the pectin showed a esterification degree (DE), determined through Fourier Transform Infrared Spectroscopy (FT-IR), greater than 50% and galacturonic content >65 % in the pure pectin (analyzed by GC-FID after acid hydrolysis with TFA 2M) which may be considered as additive E-440. Furthermore, in the rheological study (viscosity analysis by the shear stress) these pectin present different viscosity ranges, suitable for many different uses and the preparation methods offering the possibility to obtain gels with different viscosity ranges, further increasing the possibility of uses.
Finally we studied its utilization as edible coating which showed in the majority of cases a lesser humidity loss, especially in strawberries coated with the pectin 4710 prepared by overhead stirrer, and pectin 4400 prepared by heating magnetic stirrer, both treated afterwards with ultrasound (over a period 30 min 30% amplitude), presenting these strawberries improved color characteristics (L*, a*, b**, C, h, ΔE) than the control samples after storage over a period of 5 days.Peer Reviewe
Enzymatic biotransformation of natural intense sweeteners: structural characterization and evaluation of sensorial properties and prebiotic potential
Get PDFTesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Física Aplicada. Fecha de Lectura: 16-07-2021Esta tesis tiene embargado el acceso al texto completo hasta el 16-01-202
- …
