1,720,959 research outputs found
Effects of Lactobacillus acidophilus on zinc and calcium bioavailability and protein quality of probiotic beverages
No full textEstudos sobre a qualidade protéica e a biodisponibilidade de minerais têm a sua importância na manipulação dietética, visando a redução da prevalência de desnutrição energético-protéica e de carências nutricionais específicas, uma vez que componentes da dieta podem promover melhor utilização dos nutrientes. Nesse sentido, o presente trabalho visou avaliar os efeitos da adição de Lactobacillus acidophilus, uma bactéria probiótica, na qualidade protéica de uma bebida láctea à base de soro de queijo. Avaliou-se, ainda, o efeito dessa bactéria sobre a biodisponibilidade de cálcio e de zinco. No ensaio para avaliar a qualidade protéica foram utilizados 24 ratos machos recém-desmamados, separados em quatro grupos (n=6): um grupo controle com dieta à base de caseína, um segundo grupo com dieta aprotéica e dois grupos experimentais, sendo um à base da fórmula infantil e o outro à base da bebida láctea probiótica. Foram utilizados os métodos PER (coeficiente de eficiência protéica), NPR (razão protéica líquida), NPU (utilização protéica líquida) e digestibilidade. No estudo com cálcio foram utilizadas 60 ratas fêmeas adultas, sendo 30 intactas e 30 ovariectomizadas, divididas em 6 grupos (n=10), e cada grupo subdividido em três. Dentre as ratas intactas, um grupo recebeu probiótico, outro grupo recebeu leite sem probiótico e um terceiro grupo dose intraperitonial de 45 Ca. Da mesma forma ocorreu com as ratas ovariectomizadas. O cálcio foi avaliado utilizando-se a técnica do traçador bioquímico (45Ca), medindo-se sua absorção fracional no fêmur dos animais. Foi ainda avaliado o efeito do probiótico no íleo das ratas, medindo-se a superfície de absorção intestinal. A biodisponibilidade do zinco foi avaliada em 32 ratos machos recém-desmamados, divididos em quatro grupos: dieta padrão com 15 e 30 μg de zinco/g de dieta e dieta padrão com probiótico, também com 15 e 30 μg de zinco/g de dieta. Foi feita a determinação do teor do mineral no fêmur, nos rins, no fígado, no sangue e no cérebro, por espectrofotometria de absorção atômica. O ganho de peso foi monitorado e determinada a atividade da enzima fosfatase alcalina, indicativa de crescimento ósseo. A bebida láctea elaborada apresentou uma alta qualidade protéica, semelhante a da proteína padrão (caseína), o que pode ser atribuído ao elevado valor biológico das proteínas do soro de queijo, associado à presença de bactérias probióticas e outras culturas lácteas, que ajudam a promover uma melhor utilização da proteína. No experimento com zinco não foi observada diferença nos fêmures dos animais, porém, a presença de Lactobacillus acidophilus proporcionou maior ganho de peso, podendo estar relacionado com a melhor biodisponibilidade desse e de outros nutrientes promotores do crescimento, o que indica efeito benéfico da presença da bactéria. Quanto à retenção de cálcio nos fêmures, os resultados mostraram ser maior nos animais que receberam probiótico e naqueles não submetidos à ovariectomia. Através da análise estatística dos valores observados para os parâmetros ‘espessura’ e ‘superfície de absorção’ dos cortes de íleo, obtidos histologicamente, observou-se que os animais intactos (com ovário) que receberam probiótico apresentaram os valores mais elevados, resultado semelhante ocorrido na retenção no fêmur, sugerindo a interferência do hormônio estrogênio nessas funções. Dessa forma, pode-se concluir que microrganismos probióticos são fatores de promoção da saúde, interferindo positivamente na biodisponibilidade de minerais como o cálcio e o zinco. A elevada qualidade protéica da bebida com probiótico e soro de leite demonstra não só benefícios dos probióticos, como também da utilização do soro de leite na elaboração de produtos lácteos.Studies on protein quality and mineral bioavailability are important on diet manipulation to reduce occurrence of protein-energy malnutrition and specific nutritional deficiencies, since diet components may improve nutrient utilization. The present work aimed at to evaluate the effects of Lactobacillus acidophilus, a probiotic bacteria, on protein quality of a whey-based milky beverage. The effect of this bacteria on calcium and zinc bioavailability was also evaluated. For protein quality assay, twenty-four weaning male rats were divided into four groups (n=6): control group fed a casein-based diet, protein-free group and two experimental groups, one of them fed a commercial probiotic infant formula, and the other fed the probiotic milky beverage. The following methods were utilized: protein efficiency ratio (PER), net protein ratio (NPR), net protein utilization (NPU) and digestibility. Sixty adult females rats, thirty intact and thirty ovariectomized, were utilized in the study on calcium bioavailability. They were divided into six groups (n=10). Among the intact female rats, one group was fed the probiotic, a second one received milk without probiotic, and a third one was fed an intraperitoneal dosis of 45 Ca. The ovariectomized rats were treated in the same manner. The calcium was evaluated by means of the method of biochemical tracer (45Ca), by measuring its fractional absorption in the animal femurs. The effect of the probiotic bacteria on the ileum of the animals was also evaluated, by measuring the intestinal absorption surface. The zinc bioavailability was evaluated in thirty-two weaning male rats divided into four groups, fed a standard diet with 15 or 30 μg zinc/g diet, or a standard diet plus probiotic with 15 or 30 μg zinc/g diet. The zinc content was determined by atomic absorption spectrophotometry in femur, kidneys, liver, blood and brain. The weight gain was monitored and the activity of alkaline fosfatase, used as a bone growth marker, was determined. The formulated milky beverage presented a high protein quality, similar to the standard protein (casein). This may be attributed to the high biological value of the whey proteins combined with the presence of probiotic bacteria and other dairy cultures that help to improve protein utilization. In the experiment with zinc, there was no difference among animal femurs, but the presence of Lactobacillus acidophilus provided an enhanced weight gain, which may be related to the better bioavailability of zinc and other growth-promoting nutrients, indicating a benefic effect of this bacteria. Calcium retention in the femurs was higher in the intact animals fed the probiotic. The statistical analysis of the values reported for the parameters ‘thickness’ and ‘absorption surface’ of the ileum cuts indicated that the intact animals fed the probiotic presented the highest values, similarly to what occurred with calcium retention in the femur, suggesting the influence of estrogen hormone on these functions. It may be concluded that probiotic microorganisms are health-promoting factors, improving calcium and zinc bioavailability. The high protein quality of the beverage indicates the benefits of both probiotics and whey addition to dairy products.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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