1,722,717 research outputs found
O Ferro do sangue e dos alimentos
Full text linkSendo o ferro uma das partes constituintes do sangue, é evidente que deve existir nos alimentos, como os alimentos vegetais, por isso que este metal entra na composição do sangue dos herbívoros e granivoros. Destes fatos resultam duas consequencias: a primeira é que, se fosse possivel formar um regime privado de ferro, o animal que a ele fosse submetido, sucumbiria infalivelmente, em consequencia de não poder ser constituido o sangue; a segunda consequencia é que o ferro parece ser tão indispensável a vida vegetal como a vida animal
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
O ferro e as anemias ferroprivas
No full textO ferro é um composto inorgânico essencial para as diversas funções celulares, tais
como, a síntese de DNA, o metabolismo energético e o transporte de oxigénio.
Adicionalmente funciona como cofator em muitos processos enzimáticos da cadeia
respiratória mitocondrial (Medeiros, 2006).
O ferro utilizado pelo organismo tem duas fontes principais: a dieta e a reciclagem das
hemácias, sendo que o ferro da dieta é encontrado sob duas formas: orgânica e
inorgânica, já o proveniente da reciclagem das hemácias encontra-se na forma orgânica.
O ferro necessário para a eritropoiese é obtido através de um sistema eficiente de
reciclagem no qual os macrófagos fagocitam os eritrócitos, degradando a hemoglobina e
exportando o ferro para a circulação para ser novamente utilizado (Carvalho et al.,
2006).
Apesar da importância do ferro a nível do funcionamento dos organismos, este é um
pode ser tóxico através quando exerce a sua ação catalítica na produção de radicais
livres de oxigénio. Assim sendo, os seres vivos desenvolveram sistemas de regulação do
metabolismo do ferro, quer a nível de regulação do metabolismo intracelular quer ao
nível sistémico, garantindo que os níveis de ferro não sejam deficientes nem em
excesso. As consequências do desequilíbrio do metabolismo do ferro são bem
conhecidas clinicamente, se por um lado a deficiência de ferro se manifesta
clinicamente através da anemia por outro lado o excesso origina, por exemplo, a
hemocromatose hereditária, podendo levar à lesão tecidular em vários órgãos, com
manifestações como a cirrose hepática, diabetes, hipogonadismo, artrite ou cardiopatia
(Cançado e Chiattone, 2002).The iron is an essential inorganic compound for diverse cellular functions such as DNA
synthesis, energy metabolism and transport of oxygen. Additionally it acts as a cofactor
in many enzymatic processes of the mitochondrial respiratory chain (Medeiros, 2006).
The iron used in the body has two main sources: the diet and recycling of red blood
cells, wherein the dietary iron is found in two forms: organic and inorganic, already
from the recycling of erythrocytes is in organic form. The iron required for
erythropoiesis is obtained by an efficient recycling system in which macrophages
phagocytose erythrocytes, hemoglobin and exporting degrading the iron into the
circulation to be used again (Carvalho et al., 2006).
Despite the importance of iron in the operation of the bodies, this is can be toxic when
carrying through their catalytic action on the production of oxygen free radicals. Thus,
living beings developed iron metabolism regulation systems, both in terms of regulation
of intracellular metabolism either at the systemic level, ensuring that iron levels are not
disabled or in excess. The iron metabolism disequilibrium consequences are well known
clinically, is for iron deficiency side clinically manifested by anemia moreover excess
originates, for example, hereditary hemochromatosis, can lead to tissue damage in
several organs, with manifestations such as cirrhosis, diabetes, hypogonadism, arthritis
or disease (Cançado and Chiattone, 2002)
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
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