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Three-Dimentional Architecture of the Renal Inner Medulla of the Desert Rodent Dipodomys Merriami: Potential Impact on the Urinary Concentrating Mechanism
No full textThe objective of the following research project was to analyze the methods behind the urinary concentrating mechanism in Dipodomys merriami, Merriam's kangaroo rat. We hypothesize that the inner medulla of Dipodomys merriami contains extreme examples of various architectural features as well as transport properties which enable it to produce concentrated urine at over 6000mOsm/Kg water. The three-dimensional architecture of the vasculature and nephron segments inside the renal inner medulla (IM) was assessed using digital reconstruction from tissue sections. Descending thin limbs (DTLs), ascending thin limbs (ATLs), collecting ducts (CDs), and ascending vasa recta (AVR) were identified with indirect immunofluorescence using antibodies and lectins that recognize segment-specific proteins associated with solute and water transport (AQP1, ClC-K1, and AQP2). Electron microscopy shows close contact between CDs, AVR, and ATLs at adherence areas. The CDs, AVR, and ATLs are sufficiently close together to form discrete interstitial compartments. This architectural arrangement and apparent isolation of these compartments raise questions regarding their function. One possibility is that lateral solute diffusion from ATLs and CDs into AVR could be preferentially restricted to these areas. Interstitial cell architecture, which could increase and define compartmentalization, may further restrict diffusive exchange
Remoción de fósforo en el río Jordán de Tunja utilizando nanopartículas de Fe-Co modificadas con Quitosano
Get PDFSpa: El fósforo es un elemento muy importante para agricultura, aunque su presencia en concentraciones mayores son causas de eutroficación [5]. El desarrollo y progreso de Tunja en los últimos 25 años ha incrementado la cantidad de desechos y aguas residuales generadas. En especial el río Jordán atraviesa la ciudad de Tunja; y recibe las aguas residuales de 27 municipios durante el recorrido que eventualmente se une con el río Chicamocha, que se conecta al río Magdalena y finalmente va a desembocar en el mar Caribe
Removing Phosphate From Aquatic Environments Utilizing Fe-Co/Chitosan Modified Nanoparticles
No full textChitosan modified iron-cobalt nanoparticles (CMNPs) were used for phosphate adsorption in synthetic wastewater and river water from the Jordan river in Tunja, Boyacá, Colombia. Phosphate adsorption by CMNPs reached 52.7% in synthetic wastewater and 58.7% in water taken from the Jordan river. This indicates that the CMNPs ability to adsorb phosphates is independent of other components within river water. Additionally, adsorption measurements were taken using the average pH, temperature, and phosphate concentration of the river water in order to ensure results comparable to those of (Kim 2017). A maximum adsorption rate of 0.138 mg of phosphate per gram of adsorbent was found with the majority of adsorption taking place within the first 15 minutes of contact with the adsorbent. The adsorption of phosphates using CMNPs presents an effective and environmentally friendly solution to reducing phosphates in aquatic ecosystems without altering the characteristics of river water.Se utilizaron nanopartículas de hierro-cobalto modificado con quitosano (CMNP) para la adsorción de fosfato en aguas residuales sintéticas y aguas del río Jordán en Tunja, Boyacá, Colombia. La adsorción de fosfato por los CMNP alcanzó el 52,7% en aguas residuales sintéticas y el 58,7% en agua extraída del río Jordán. Esto indica que la capacidad de CMNP para adsorber fosfatos es independiente de otros componentes dentro del agua del río. Además, las medidas de adsorción se tomaron utilizando el pH, la temperatura y la concentración de fosfato promedio del agua del río para garantizar resultados comparables a los de (Kim 2017). Se encontró una tasa de adsorción máxima de 0.138 mg de fosfato por gramo de adsorbente y la mayoría de la adsorción tuvo lugar dentro de los primeros 15 minutos de contacto con el adsorbente. La adsorción de fosfatos usando CMNPs presenta una solución efectiva y ecológica para reducir los fosfatos en los ecosistemas acuáticos sin alterar las características del agua del río
Removing Phosphate From Aquatic Environments Utilizing Fe-Co/Chitosan Modified Nanoparticles
No full textChitosan modified iron-cobalt nanoparticles (CMNPs) were used for phosphate adsorption in synthetic wastewater and river water from the Jordan river in Tunja, Boyacá, Colombia. Phosphate adsorption by CMNPs reached 52.7% in synthetic wastewater and 58.7% in water taken from the Jordan river. This indicates that the CMNPs ability to adsorb phosphates is independent of other components within river water. Additionally, adsorption measurements were taken using the average pH, temperature, and phosphate concentration of the river water in order to ensure results comparable to those of (Kim 2017). A maximum adsorption rate of 0.138 mg of phosphate per gram of adsorbent was found with the majority of adsorption taking place within the first 15 minutes of contact with the adsorbent. The adsorption of phosphates using CMNPs presents an effective and environmentally friendly solution to reducing phosphates in aquatic ecosystems without altering the characteristics of river water.Se utilizaron nanopartículas de hierro-cobalto modificado con quitosano (CMNP) para la adsorción de fosfato en aguas residuales sintéticas y aguas del río Jordán en Tunja, Boyacá, Colombia. La adsorción de fosfato por los CMNP alcanzó el 52,7% en aguas residuales sintéticas y el 58,7% en agua extraída del río Jordán. Esto indica que la capacidad de CMNP para adsorber fosfatos es independiente de otros componentes dentro del agua del río. Además, las medidas de adsorción se tomaron utilizando el pH, la temperatura y la concentración de fosfato promedio del agua del río para garantizar resultados comparables a los de (Kim 2017). Se encontró una tasa de adsorción máxima de 0.138 mg de fosfato por gramo de adsorbente y la mayoría de la adsorción tuvo lugar dentro de los primeros 15 minutos de contacto con el adsorbente. La adsorción de fosfatos usando CMNPs presenta una solución efectiva y ecológica para reducir los fosfatos en los ecosistemas acuáticos sin alterar las características del agua del río
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
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