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Evaluación de herramientas para el control de la fasciolosis bovina: prueba diagnóstica por amplificación isotérmica mediada por bucle y actividad trematicida del extracto de Allium sativum
Full text linkLa fasciolosis es una de las parasitosis hepáticas más importantes del país. Actualmente, las principales limitaciones del control de esta enfermedad son el correcto diagnóstico y la progresiva resistencia al triclabendazol, que es el fármaco recomendado para su tratamiento. Por tal motivo, el presente trabajo propone i) desarrollar y evaluar la precisión diagnóstica de LAMP (Loop-Mediated isothermal amplification) aplicando una optimización en la extracción de ADN en heces de bovinos y ii) evaluar la eficacia fasciolicida in vitro de los extractos de ajo. Investigación 1: Estudio donde se desarrolla una nueva prueba LAMP optimizando la extracción de ADN evaluando su precisión diagnóstica. Se optimizó la técnica de extracción de ADN para F. hepatica combinando la técnica coprológica de sedimentación (concentración de huevos de F. hepatica) y la técnica de lisis con perlas de Zirconia/Silica en un homogenizador de alta velocidad a 6m/s durante 40 seg; estas dos técnicas se acoplaron a kits de extracción de ADN comerciales. Para el desarrollo de la prueba LAMP se diseñaron primers específicos para la región ITS-1 optimizando las condiciones de la prueba para ejecutarlo a 60°C por 40 min. Para la evaluación de la precisión diagnóstica de LAMP, se utilizó un diseño de casos y controles colectando 139 muestras de heces de bovinos sacrificados en el “Frigorífico camal San Pedro” en Lurín-Perú. Las muestras se clasificaron como positivas y negativas usando la inspección hepática post mortem y la microscopía de huevos en bilis. LAMP optimizado con la técnica de extracción de ADN logró una sensibilidad del 87.8% (IC 95%: 80.4% - 93.2%) y especificidad del 100 % (IC 95%: 85.8% - 100%), con un likelihood ratio negativo de 0.12 (IC95: 0.08 - 0.19). Investigación 2: Estudio experimental donde se evaluó la eficacia trematicida de extractos de ajos in vitro. Estadios adultos de F. hepatica fueron incubados durante 48 h expuestos a 10 μg/ml de aceite esencial de ajo, 10 μg/ml de extracto acuoso de ajo y 15 μg/ml de triclabendazol sulfóxido usando 112 fasciolas por cada tratamiento. La eficacia se evaluó con el porcentaje de fasciolas totalmente paralizadas por cada grupo. Los adultos de F. hepatica incubados con triclabendazol sulfóxido (15 μg/ml) mostraron un mayor porcentaje de fasciolas paralizadas con respecto al extracto acuoso (16.9 vs 0 %; P<0.002) y aceite esencial (16.9 vs 4.5%; P<0.001). Adicionalmente, se hizo una evaluación de dosis-respuesta determinando que la concentración letal 50 (CL50) del aceite esencial de ajo fue de 0.066 mg/ml, mientras que el CL50 del extracto acuoso de ajo fue de 8.37 mg/ml, estas concentraciones no mostraron efectos citotóxicos. Se concluye que la técnica LAMP con la extracción optimizada de ADN es una prueba diagnóstica sensible y altamente específica para el diagnóstico de la fasciolosis bovina y que el extractos acuoso y aceite esencial de ajo a concentración de 10 μg/ml muestra una actividad fasciolicida in vitro inferior al triclabendazol sulfóxido a 15 μg/ml. No obstante, a mayores concentraciones, los extractos de ajos si evidencian actividad fasciolicida sin actividad citotóxica.Fasciolosis is one of the most important liver parasitosis in the country. Currently, the main limitations in the control of this disease are the correct diagnosis and the progressive resistance to triclabendazole, which is the drug recommended for its treatment. For this reason, the present work proposes i) to develop and evaluate the diagnostic accuracy of LAMP (Loop-Mediated isothermal amplification) applying an optimization in the extraction of DNA in bovine feces and ii) to evaluate the in vitro fasciolicide efficacy of the extracts of garlic. Investigation 1: Study where a new LAMP test is developed, optimizing DNA extraction, evaluating its diagnostic accuracy. The DNA extraction technique for F. hepatica was optimized by combining the stool sedimentation technique (F. hepatica eggs concentration) and the lysis technique with Zirconia/Silica beads in a high-speed homogenizer at 6m/s for 40 sec; these two techniques were coupled with commercial DNA extraction kits. For the development of the LAMP test, specific primers were designed for the ITS-1 region, optimizing the test conditions to run it at 60°C for 40 min. For the evaluation of the diagnostic accuracy of LAMP, a case-control design was used, collecting 139 fecal samples from bovines slaughtered in the "Frigorífico camal San Pedro" in Lurín-Perú. Samples were classified as positive and negative using postmortem liver inspection and egg in bile microscopy. LAMP optimized with the DNA extraction technique achieved a sensitivity of 87.8% (95% CI: 80.4% - 93.2%) and a specificity of 100% (95% CI: 85.8% - 100%), with a negative likelihood ratio of 0.12. (CI95: 0.08 - 0.19). Investigation 2: Experimental study where the trematicidal efficacy of garlic extracts was evaluated in vitro. Adult stages of F. hepatica were incubated for 48 h exposed to 10 μg/ml garlic essential oil, 10 μg/ml aqueous garlic extract and 15 μg/ml triclabendazole sulfoxide using 112 flukes for each treatment. Efficacy was evaluated with the percentage of totally paralyzed flukes for each group. Adults of F. hepatica incubated with triclabendazole sulfoxide (15 μg/ml) showed a higher percentage of paralyzed flukes with respect to aqueous extracts (16.9 vs 0%; P<0.002) and essential oils (16.9 vs 4.5%; P< 0.001). Additionally, a dose-response evaluation was made, determining that the lethal concentration 50 (LC50) of the essential oil of garlic was 0.066 mg/ml, while the LC50 of the aqueous extract of garlic was 8.37 mg/ml; these concentrations were not showed cytotoxic effects. In conclusion, LAMP technique with optimized DNA extraction is a sensitive and highly specific diagnostic test for the diagnosis of bovine fasciolosis and that the aqueous extracts and essential oil of garlic at a concentration of 10 μg/ml show fasciolicidal activity in vitro lower than triclabendazole sulfoxide at 15 μg/ml. However, at higher concentrations, garlic extracts do show fasciolicidal activity without cytotoxic activity
Expresión de citoquinas de la respuesta Th2 en mucosa intestinal de crías de alpaca
Full text linkEvalúa la expresión génica de las citoquinas IL-4, IL-5, IL-6, IL-10, TGF- y el factor transcripcional GATA3 en la mucosa intestinal de crías de alpacas clínicamente sanas de 2 a 47 días de edad. Para lo cual se formaron grupos etarios conformados por alpacas de 2 a 8 días (grupo 1), 10 a 21 días (grupo 2) y 26 a 47 días de edad (grupo 3) sin importar sexo, raza y desprovistos de signos clínicos de enfermedad. Se tomó la porción media del yeyuno de cada animal de las cuales se extrajeron el ARN total y se realizó la técnica RT-PCR en tiempo real con cebadores específicos para los genes en estudio. La expresión de genes fue determinado por el método comparativo 2-ΔΔ Ct usando como gen endógeno a Gliceraldehído-3-fosfato deshidrogenasa (GAPDH) y como calibrador fetos de 11 meses. La expresión de los genes de las citoquinas y el factor de transcripción se caracterizó por un temprano incremento de la expresión en todos los genes en evaluación en los animales de 2 a 8 días de edad y una mayor expresión en los animales de 10 a 21 días, asociándose al desarrollo del sistema inmune y a una respuesta estimulada por la colonización de microorganismos del ambiente. En los animales de 26 a 47 días de edad la expresión de los genes de IL-4, IL-5 y GATA3 se vio reducida ligeramente y la expresión de los genes de IL-10 y TGF-β siguió incrementándose; ambas respuestas inmunes estarían asociadas a un proceso de adaptación y regulación frente a los microorganismos saprófitos y antígenos alimenticios. Sin embargo, IL-6 sigue aumentando su expresión en los animales de 26 a 47 días de edad, asociándose a una respuesta inflamatoria contra patógenos del ambiente. El análisis histopatológico mostró un aumento de individuos con presencia de leve enteritis catarral aguda difusa al aumentar la edad, alcanzando un 84% (5/6) en los animales de 26 a 47 días de edad, asociado a la presencia de patógenos como Cryptosporidium spp y Eimeria spp encontrados en este análisis, influyendo en la expresión de los genes de las citoquinas en estudio.Tesi
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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