1,721,032 research outputs found
Parallelizations on products of spheres and octonionic geometry
No full textA classical theoremof Kervaire states that products of spheres are parallelizable if and only if at least one of the factors has odd dimension. Two explicit parallelizations on Sm × S2h−1 seem to be quite natural, and have been previously studied by the first named author in [32]. The present paper is devoted to the three choices G = G2, Spin(7), Spin(9) of G-structures on Sm × S2h−1, respectively with m + 2h − 1 = 7, 8, 16 and related with octonionic geometry
An even Clifford diamond
No full textWe present a diamond shaped diagram for even Clifford manifolds similar to the quaternion-Kähler diamond studied by Ch. Boyer and K. Galicki. We define two spaces S and U which fiber over an even Clifford manifold which, together with the twistor space Z defined by G. Arizmendi and Ch. Hadfield, form a diamond shaped diagram of fibrations. Moreover, we prove that, under certain natural conditions, Z is Kahler–Einstein, S is Sasaki–Einstein and U is special-Kähler
Rationale of Extracorporeal Removal of Endotoxin in Sepsis: Theory, Timing and Technique
No full textSeveral signs and symptoms in sepsis are due to the presence of endotoxin in the circulation. Both in animal and human models, there is an evident immunological response to the endotoxin insult Furthermore, altered cardiovascular function, lung dysfunction and acute kidney injury are common in sepsis and endotoxemia. In these circumstances it would be extremely important to identify patients with sepsis in the early phases and to characterize the humoral alterations involved with it, including the identification and quantification of circulating endotoxin. Once this is obtained, it seems logical to try to remove as much of the circulating endotoxin as possible in order to mitigate the clinical effects of this condition This can be achieved today with a very specific hemoperfusion process utilizing cartridges with immobilized polymixin B in an extracorporeal circuit. This approach seems to provide a significant removal of endotoxin with a significant reduction of its circulating levels. The clinical consequences of this approach can be summarized in a mitigation of the septic cascade in the early phases, with improvement of outcome Recent clinical results seem to confirm these expectations showing a reduction of mortality in patients with early signs of abdominal sepsis due to recent surgery This opens a new avenue for intervention in sepsis. Copyright (C) 2010 S Karger AG, Base
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
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