1,720,955 research outputs found
Colorantes Diff-Quik y Eosina-Nigrosina en la evaluación morfológica de espermatozoides antes y después de la criopreservación del semen del toro Holstein
No full textEl objetivo del estudio fue Evaluar la morfología espermática utilizando colorantes Diff-Quik (DQ) y Eosina-Nigrosina (EN) antes y después de la criopreservación del semen del toro Holstein. Se formaron 4 grupos de tratamientos (T), T1: Tinción DQ antes de congelación; T2: Tinción EN antes de congelación, T3: Tinción DQ después de congelación; T4: Tinción EN después de congelación del semen. Las muestras de semen se colectaron de un toro Holstein de 2 años de edad, utilizando vagina artificial, dos veces por semana hasta 10 colecciones, se evaluó el semen fresco y criopreservado, en distintos campos escogidos al azar. Se realizó el análisis de varianza mediante el procedimiento GLM del SAS y prueba de Tukey, bajo el diseño completamente al azar. Los defectos de la morfología de la cabeza gigante, pequeña, piriforme, cónica y estrecha, dos cabezas, defecto de acrosoma, normales desprendidas entre la coloración de DQ y EN son similares (P > 0.05), los defectos morfológicos del cuello de los espermatozoides: descentrado, doble, en espiral, granular son similares (P > 0.05) entre las tinciones de DQ y EN durante la pre y post congelación de semen. Hay mayor (P ≤ 0.05) defecto de gota citoplasmática proximal en espermatozoides coloreados con EN versus DQ durante pre y post congelación de semen; las anomalías espermáticas de la cola corta, abaxial, dos colas, gota citoplasmática distal son similares (P > 0.05) con la coloración DQ y EN antes y post congelación de semen. Se identifica mayor porcentaje (P > 0.05) de anomalía de cola doblada con tinción de EN qué DQ antes y después la congelación de semen de toro. Se concluye, que la coloración EN muestra mayores defectos del cuello antes de la congelación, de la cola antes y después de la congelación; siendo EN y DQ similares para identificar defectos de cabeza de espermatozoides de toro.Proyecto financiado por la Universidad Nacional Micaela Bastidas de Apurímac con Resolución N° 357-2018-CU-UNAMB
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
Diff-Quik and Eosin-Nigrosin dyes in the morphological evaluation of sperm before and after cryopreservation of Holstein bull semen
Get PDFEl objetivo del estudio fue evaluar las anormalidades morfológicas espermáticas utilizando colorantes Diff-Quik (DQ) y Eosina-Nigrosina (EN), antes y después de la criopreservación del semen del toro. Se formaron cuatro grupos de tratamientos (T), T1: Tinción DQ antes de congelación; T2: Tinción EN antes de congelación, T3: Tinción DQ después de congelación; T4: Tinción EN después de congelación del semen. Las muestras de semen se colectaron de un toro Holstein de 2 años de edad, utilizando vagina artificial, dos veces por semana hasta 10 colecciones. Se evaluó el semen fresco y post congelado. Se realizó el análisis de varianza. Antes y después de la congelación de semen bovino, las anomalías morfológicas de la cabeza y mayor parte del cuello y la cola del espermatozoide utilizando coloración DQ o EN se observan similarmente (P > 0.05). Se identificó mayor (P ≤ 0.05) defecto de gota citoplasmática proximal y cola doblada en espermatozoides coloreados con EN que DQ en semen fresco y congelado del toro. Se concluye, que se observa mayores anormalidades de gota citoplasmática proximal y cola doblada de espermatozoides con la coloración EN que con DQ, mientras en la identificación de las demás anomalías no hay diferencia, antes y después de la criopreservación de semen del toro Holstein.The objective of this study was to evaluate sperm morphological abnormalities using Diff-Quik (DQ) and Eosin-Nigrosin (EN) dyes before and after cryopreservation of bull semen. Four treatment (T) groups were formed T1: DQ staining before freezing; T2: EN staining before freezing, T3: DQ staining after freeze-thaw; T4: EN staining after semen freeze-thaw. Semen samples were collected from a 2-year-old Holstein bull, using an artificial vagina, twice a week for up to 10 collections. Fresh and after freeze-thaw semen was evaluated. Analysis of variance was calculated. Before and after freezing bovine semen, morphological abnormalities of the head and most of the neck and tail of the sperm using DQ or EN staining are similarly observed (P> 0.05). A greater (P ≤ 0.05) defect of proximal cytoplasmic gout and bent tail was identified in spermatozoa stained with EN than DQ in fresh and frozen bull semen. In conclusion, greater abnormalities of proximal cytoplasmic gout and bent tail of sperm are observed with EN staining than with DQ, while in the identification of the other anomalies there is no difference, before and after cryopreservation of semen from the Holstein bul
Diff-Quik and Eosin-Nigrosin dyes in the morphological evaluation of sperm before and after cryopreservation of Holstein bull semen
Get PDFEl objetivo del estudio fue evaluar las anormalidades morfológicas espermáticas utilizando colorantes Diff-Quik (DQ) y Eosina-Nigrosina (EN), antes y después de la criopreservación del semen del toro. Se formaron cuatro grupos de tratamientos (T), T1: Tinción DQ antes de congelación; T2: Tinción EN antes de congelación, T3: Tinción DQ después de congelación; T4: Tinción EN después de congelación del semen. Las muestras de semen se colectaron de un toro Holstein de 2 años de edad, utilizando vagina artificial, dos veces por semana hasta 10 colecciones. Se evaluó el semen fresco y post congelado. Se realizó el análisis de varianza. Antes y después de la congelación de semen bovino, las anomalías morfológicas de la cabeza y mayor parte del cuello y la cola del espermatozoide utilizando coloración DQ o EN se observan similarmente (P > 0.05). Se identificó mayor (P ≤ 0.05) defecto de gota citoplasmática proximal y cola doblada en espermatozoides coloreados con EN que DQ en semen fresco y congelado del toro. Se concluye, que se observa mayores anormalidades de gota citoplasmática proximal y cola doblada de espermatozoides con la coloración EN que con DQ, mientras en la identificación de las demás anomalías no hay diferencia, antes y después de la criopreservación de semen del toro Holstein.The objective of this study was to evaluate sperm morphological abnormalities using Diff-Quik (DQ) and Eosin-Nigrosin (EN) dyes before and after cryopreservation of bull semen. Four treatment (T) groups were formed T1: DQ staining before freezing; T2: EN staining before freezing, T3: DQ staining after freeze-thaw; T4: EN staining after semen freeze-thaw. Semen samples were collected from a 2-year-old Holstein bull, using an artificial vagina, twice a week for up to 10 collections. Fresh and after freeze-thaw semen was evaluated. Analysis of variance was calculated. Before and after freezing bovine semen, morphological abnormalities of the head and most of the neck and tail of the sperm using DQ or EN staining are similarly observed (P> 0.05). A greater (P ≤ 0.05) defect of proximal cytoplasmic gout and bent tail was identified in spermatozoa stained with EN than DQ in fresh and frozen bull semen. In conclusion, greater abnormalities of proximal cytoplasmic gout and bent tail of sperm are observed with EN staining than with DQ, while in the identification of the other anomalies there is no difference, before and after cryopreservation of semen from the Holstein bul
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
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