1,720,995 research outputs found
Combinación de cloxacilina y aceite esencial de Melaleuca armillaris como alternativa contra staphylococcus aureus
Full text linkLa resistencia antimicrobiana representa un grave problema para la salud humana y animal. Los aceites esenciales son un gran recurso para enfrentar esta problemática. Melaleuca armillaris es una planta cuyo aceite esencial (AE) ha sido reportado como antimicrobiano. La cloxacilina (CLOX) es un antibiótico de amplio uso en medicina veterinaria contra Staphylococcus aureus. Nuestro objetivo fue evaluar la interacción farmacodinámica de la combinación del AE con CLOX en busca de un efecto sinérgico que maximiza la actividad antibacteriana contra S. aureus.
Se establecieron las concentraciones inhibitorias mínimas (CIM) frente a S. aureus (3 cepas salvajes aisladas de vacas Holstein y ATCC 29213 como referencia) para CLOX, AE y la combinación de ambos mediante microdilución en caldo a pH 7.4; 6.5 y 5.0. El AE se obtuvo mediante destilación por arrastre de vapor. Se aplicó el método de tablero de damas para evaluar la interacción CLOX/AE, estableciendo el índice de concentración fraccionaria inhibitoria (CFI). Luego evaluamos el índice de actividad antibacteriana E, diferencia entre el Log10 del número de bacterias viables iniciales (nt0) y finales (nt24) de las combinaciones con CFI más bajos. Se construyeron curvas de muerte bacteriana de CLOX y AE/CLOX a 0.5, 1, 2, 4 y 8 veces la CIM en caldo a pH 7.4; 6.5 y 5.0 considerando efecto bacteriostático (E = 0), bactericida (E = -3) y de erradicación virtual (E = -4).
Se observó una clara actividad sinérgica entre el AE y CLOX, permitiendo reducir la CIM del lactamico contra S. aureus. Esta interacción se vio favorecida por la acidificación del medio, donde concentraciones más bajas de CLOX lograron un efecto bactericida cercano a la erradicación virtual en presencia de pequeñas cantidades de AEFil: Buldain, Daniel. Universidad Nacional de La Plata.Fil: Gortari, Lihuel. Universidad Nacional de La Plata
Alternativas Fitoterapéuticas Para el Tratamiento de Infecciones Mamarias
No full textUna de las enfermedades que afecta comúnmente a bovinos productores de leche es la mastitis, la cual produce grandes pérdidas económicas en la industria lechera debido a la disminución del volumen y la calidad de la leche, como así también por los costos de tratamiento y el descarte de animales, entre otras causas. La infección ocurre por la invasión de bacterias patógenas en la glándula mamaria y su multiplicación en los tejidos productores de leche. La infusión intramamaria de antibióticos suele ser el tratamiento más común frente a estas patologías bacterianas, y esta práctica tiene una estrecha relación con la problemática de la resistencia a los antibióticos. Además, el uso irracional de antibióticos conduce a la presencia de residuos en leche, lo cual es un riesgo para el consumidor y, por lo tanto, un serio problema a nivel económico y de salud pública. La búsqueda de productos naturales eficaces y de bajo riesgo en la producción animal ha ganado importancia en la actualidad. La fitoterapia es la utilización de medicamentos de origen vegetal con fines terapéuticos y su aplicación en veterinaria se ha fortalecido en los últimos años. El uso de alternativas fitoterapeuticas está orientado a satisfacer las demandas del mercado, que exigen cada vez más productos saludables que garanticen un menor impacto ambiental y que permitan enfrentar la problemática de la resistencia bacteriana a los antimicrobianos convencionales.Fil: Buldain, Daniel Cornelio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de la Plata. Facultad de Cs.veterinarias. Laboratorio de Estudios Farmacologicos y Toxicologicos.; ArgentinaV Reunión Anual de la Red Latinoamericana de Investigación en MastitisLa PlataArgentinaRed Latinoamericana de Investigación en Mastiti
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
Tissue depletion profile of ivermectin in rabbits
Full text linkAvermectins are largely used in different animal species. Ivermectin, the most popular avermectin, is used against a wide spectrum of endo and ectoparasites. Some mange mites are particularly sensitive to ivermectin. Notoedres cati var. cuniculi, the agent of rabbit mange, is particularly sensitive to ivermectin. Pharmacokinetic and residual studies of ivermectin in rabbits, however, are scarce. The objective of the present paper was to study the tissue residue profile of ivermectin (IVM) after subcutaneous (s.c.) administration of a 1% w/w solution. Sixteen young healthy male rabbits received 200 μg/kg of a 1% w/w ivermectin formulation subcutaneously. Groups of four treated animals were sacrificed at 10, 20, 30 and 40 days after injection. Samples of liver, fat, kidney and muscle tissue were obtained. IVM concentrations were determined by liquid chromatography with fluorescence detection after automatic solid phase extraction with SPE C18 cartridges. Ivermectin was detected after subcutaneous administration until 40 days. Muscle samples showed the lowest IVM concentrations throughout the study. The highest IVM concentrations at all sampling times were measured in liver and fat tissues. Nevertheless, IVM concentrations in all the tissues analyzed were below the accepted maximum residue limits recommended by the European Union at 20 days posttreatment.Fil: Marchetti, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de la Plata. Facultad de Cs.veterinarias. Laboratorio de Estudios Farmacologicos y Toxicologicos.; ArgentinaFil: Buldain, Daniel Cornelio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de la Plata. Facultad de Cs.veterinarias. Laboratorio de Estudios Farmacologicos y Toxicologicos.; ArgentinaFil: Buchamer, Andrea Veronica. Universidad Nacional de la Plata. Facultad de Cs.veterinarias. Laboratorio de Estudios Farmacologicos y Toxicologicos.; ArgentinaFil: Zeinsteger, Pedro Adolfo. Universidad Nacional de la Plata. Facultad de Cs.veterinarias. Laboratorio de Estudios Farmacologicos y Toxicologicos.; ArgentinaFil: Mestorino, Olga Nora. Universidad Nacional de la Plata. Facultad de Cs.veterinarias. Laboratorio de Estudios Farmacologicos y Toxicologicos.; Argentin
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
- …
