1,721,021 research outputs found
Contrasting plasma atrial natriuretic factor concentrations during comparable natriuresis with infusions of atrial natriuretic factor and saline in normal man
No full text1. To explore the role of atrial natriuretic factor (ANF) in the response to an acute saline load, we compared plasma hormone and urinary electrolyte interrelationships during administration of ANF and saline. Plasma concentrations of ANF, renin, angiotensin II and aldosterone, together with urine volume and electrolytes, were measured during infusions of placebo, ANF [alpha-human ANF (99-126)] and 0.9% (w/v) NaCl solution in normal subjects under standardized conditions of diet and posture. 2. Saline loading and ANF infusions initially induced similar natriuresis and suppression of renin-angiotensin-aldosterone system activity in association with markedly disparate values of plasma ANF. Plasma ANF levels rose to two- and eight-fold placebo values with saline and ANF, respectively (P less than 0.001). Conversely, in the period after infusion plasma ANF values were similar while natriuresis differed significantly. Peak natriuresis lagged behind peak plasma ANF values with both stimuli. 3. ANF, but not saline, enhanced urinary excretion of calcium and magnesium. Saline, but not ANF, caused increased kaliuresis. 4. The data suggest that ANF makes only a minor contribution to natriuresis induced by saline challenge, although full confirmation of this point requires quantification of end-organ responses to endogenous ANF in the face of changing arterial pressure and circulating volume
Developing Contries and Areas Affected by War Events
No full textThe availability of high resolution satellite images (HRSI) is introducing a new challenge in the mapping
environment. Imagery coming from high resolution satellites such as QuickBird, Ikonos, Eros-Al or the new
Orbview-3, is likely to become in the next years a powerful tool to derive topographic maps as well as a
comprehending medium at large scales. Many researches on this topic have stated the usefulness of HRSI LO
yield cartography in those countries where the production based on traditional methods (aerial photogrammetry)
cannot be afforded, particularly for developing countries and areas recently affected by war events. Obviously,
the cartographic products that might be obtained using satellites data are different with respect to traditional 30-
numerical maps. Moreover, the pixel size of the current sensors seems to allow map production up to 1:10,000 scale. In this paper the authors propose a new cartographic product, called "Fast Mapping" (FM), completely derived
from spaceborne sensors and discuss the accuracy that can be obtained by this technique. The FM is based on
planimetric digital maps, derived from the geometri c correction of HRSI using Digital Terrain Models (OTMs)
and integrated by a set of vector layers acquired by palm GPS receivers. The peculiarity of this kind of maps is
the approach to data collection, which is performed by 10w-cOSI and fasi techniques. In addition, the transfer
process of these technologies from researchers LO local operators is reaJly sustainable. A description of the
technique is gi ven and some case studies are presented
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
Correlates of plasma atrial natriuretic factor in health and hypertension
No full textPlasma concentrations of atrial natriuretic factor (ANF) were compared in normotensive subjects and subjects with untreated, uncomplicated essential hypertension (n = 21 pairs) matched for age, sex, and race. Plasma peptide values were slightly greater (45 +/- 3 vs 36 +/- 3 pg/ml; p less than 0.05) in the hypertensive group. On univariate analysis, age (r = 0.52, n = 47, p less than 0.001) and creatinine clearance (r = -0.30, n = 47, p less than 0.05) were significantly related to plasma ANF concentrations, but arterial pressure was not (r = 0.14, n = 47), in an extended group of normal subjects. In contrast, plasma ANF values were related to arterial pressure in both an extended group of subjects with untreated essential hypertension (r = 0.54, n = 38, p less than 0.001) and in our total heterogeneous pool of hypertensive patients (r = 0.46, n = 79, p less than 0.001), but weak positive associations with age and inverse relationships with creatinine clearance were not statistically significant in either hypertensive group. Similar weak inverse relationships between plasma ANF values and renin-angiotensin-aldosterone system activity were found in both normal and hypertensive subjects.(ABSTRACT TRUNCATED AT 250 WORDS
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
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