1,721,115 research outputs found
Transport of oxidized glutathione into barley vacuoles; evidence for the involvement of the glutathione-S-conjugate ATPase
No full textTommasini R, Martinoia E, Grill E, Dietz K-J, Amrhein N. Transport of oxidized glutathione into barley vacuoles; evidence for the involvement of the glutathione-S-conjugate ATPase. Z. Naturforsch. C. 1993;48:867-871
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
Validation and Testing of an Analytical Formulation to Compute the Reduction Factor in MV Grids
Full text linkGlobal Earthing Systems (GESs) are defined by International Standards IEC 61936-1 and EN 50522 as an equivalent Earthing System (ES) created by the interconnection of local ESs. Thanks to this interconnection, just a percentage of the total fault current is injected to ground in a single ES, reducing the risk of electrocution. However, even if several experiments and models proved this effect, the identification and official certification is still a difficult task. Dangerous scenarios caused by a single-line-to-ground fault can be easily evaluated for a specific MV feeder by measurement or analytic models (quite cumbersome to use), but operative procedures valid for all the scenarios are still not available. In this work, a simplified formula to compute the reduction factor is presented, as well as its rationale. The proposed formula is easy to use and the results provided are sufficiently accurate, taking into account a desired safety margin. For this reason, it could be a valid tool for Distributor System Operators (DSO) and Certification Bodies and a step forward for the GES identification. The proposed formula is finally tested on three study cases
Modulation of pulmonary arterial input impedance during transition from inspiration to expiration
No full textWe investigated whether respiration influences pulmonary arterial input impedance during transition from inspiration to expiration in five anesthetized, spontaneously breathing dogs. Impedance (Z) was separately assessed for heart beats occurring in inspiration, in expiration, and during the transition from inspiration to expiration (transitional beat). Transitional beats were scored by the ratio between the fraction of beat falling in expiration and the total beat duration [expiratory fraction (E-fr)] to quantify their position within the transition. In transitional beats, input resistance linearly increased with Es; Z modulus at the heart-rate frequency (f(HR)) decreased up to -50% for E-fr = 50%. Z phase at f(HR) was greater than in inspiration for E-fr 50%. Unlike blood flow velocity, mean value and first harmonic of pulmonary arterial pressure were correlated to E-fr and paralleled the changes of input resistance and Z at f(HR). This indicates that respiration influences Z through modifications in arterial pressure. The evidence of important respiratory influences on Z function may help the pathophysiological interpretation of dysfunctions of the right heart pumping action, such as the so-called cor pulmonale
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
Does spontaneous respiration alter pulmonary artery input impedance?
No full textThe aim of this study was to determine whether spontaneous respiration influences pulmonary artery input impedance, a question that has received little attention in the literature. Impedance values were assessed during three different phases of the respiratory cycle, namely inspiration, expiration and postexpiration (i.e. the null respiratory flow period between expiration and the next inspiration) in five anaesthetized spontaneously breathing dogs, Firstly, impedance values during postexpiration were taken as the reference baseline, and compared with values obtained during inspiration and expiration, Then, differences between values in inspiration and in expiration were tested, taking impedance during inspiration as the baseline, Differences with respect to postexpiration were found for three parameters of input impedance: input resistance, characteristic impedance, and the frequency at the first zero-crossing of the impedance phase from negative to positive values (fcross), Input resistance was significantly lower in inspiration (85% of the baseline), characteristic impedance was significantly greater in inspiration and in expiration (112 and 119% respectively), and fcross was significantly lower in expiration (89%), By contrast, only input resistance differed significantly when inspiration was compared to expiration. Therefore, spontaneous respiration was shown to influence input impedance significantly, The observed changes in characteristic impedance and fcross might be explained by a stiffening of the pulmonary artery wall, due to neural and/or mechanical factors, during inspiration and expiration
Valori della persone e modelli di tutela contro i rischi ambientali e genotossici. Esperienze a confronto
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