1,721,021 research outputs found
Activity of cardiopulmonary baroreceptors, peripheral resistance and cutaneous microcirculation in patients with peripheral obstructive arterial disease.
Full text linkAbstract. Arosio E, De Marchi S, Prior M, Zannoni M, Lucchese L, Lechi A (Division of Vascular Medicine and Rehabilitation, University of Verona, Italy). Activity of cardiopulmonary baroreceptors, peripheral resistance and cutaneous microcirculation in patients with peripheral obstructive arterial disease. J Intern Med 2000; 247: 471–478. Objectives. To assess the effects of cardiopulmonary baroreceptors on the haemodynamics of the humeral and common carotid arteries in patients suffering from peripheral artery disease (PAD) and to discover whether the stimulation of these receptors modifies the cutaneous microcirculation in the forearm. Design. We studied a group of patients suffering from peripheral artery disease and two groups as controls. Setting. Patients were examined at the ambulatory for Vascular Research, Division of Vascular Medicine and Rehabilitation, University of Verona. Patients. We studied 15 patients with peripheral artery disease of the lower limbs at Fontaine stage II (group C), 10 free of arterial pathologies (group B) and 10 young people (group A). Main outcome measures. We subjected the patients to passive elevation of the legs and the trunk in a horizontal position with pressure monitoring and measurement of the calibre and flow in the brachial and common carotid arteries using a colourDoppler ultrasound. We also studied the cutaneous microcirculation with laserDoppler flowmetry. Results. During the test, arterial pressure and cardiac frequency remained constant in group A, systolic pressure values showed a slight, but statistically significant increase in group B, whilst the increase in systolic pressure values at this stage was marked in group C. Diastolic pressure values and cardiac frequency remained unchanged in all groups. The calibre of the humeral artery increased in the control groups. Carotid resistance was unchanged in the three groups. Humeral resistance during the test decreased in the two control groups whilst it increased in group C. The number of perfusion units felt in the control groups; no variations in group C. Conclusions. Our study demonstrates, in patients with peripheral artery disease, a reduction in the activity of the cardiopulmonary baroreceptors with an increase in the humeral resistance during the test and impairment of the mechanisms of cutaneous microcirculatory vasoregulation in the forearm
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
In contesto. Ceramica a figure rosse nei luoghi di culto
No full textNel quadro delle sempre più numerose conoscenze sulla ceramica figurata italiota da contesti non tombali, si propone un riesame della documentazione dal santuario di Eraclea, Masseria Petrull
Della “verità effettuale della cosa” e del riscontrare le cose. Riflessioni intorno al XV capitolo del Principe
No full textVariations 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
An approach to estimate of 2D-3D motion of surfaces: the frequency domain technique
No full textPhase correlation is one of the robustest methods for estimating planar translations: it is a global approach because it operates in the frequency domain using the whole image information and not just a selected subset of the image as the feature-based methods do. The good characteristics of phase correlation for estimating planar translations were found to be a strong motivation for its extension to the estimation of planar rotations. An original algorithm for estimating planar rotations inspired by phase correlation is presented in this work. Practical experimentation on real imagery confirm the expected robustness of the method. Furthermore, a natural extension of the proposed algorithm will be also presented for 3D shapes motion estimation. Free-form 3-D surfaces registration is a fundamental problem in 3-D imaging, tipi-cally approached by extensions or variations of the ICP algorithm [2,10]. In this paper an alternative procedure for 3-D motion estimation wiil be suggested, based on the Fourier transform of the 3-D intensity function, implicitly described by the registered time-sequences of range data. As the proposed method is very suitable for 2D and 3D modeling of cultural heritages, some examples and results of its application to Madonna of Donatello, located in the Basilica of St. Anthony in Padua, will be also presented
Surrogate finite-element modelling for launch vehicle multidisciplinary optimization
No full textA multi-disciplinary optimization approach is crucial to reduce development time and costs for new launch vehicle configurations, especially in light of the imminent increase in demand for launch services. This paper aims to present a methodology for obtaining a launch vehicle structural model that can be used for multidisciplinary design optimization through the use of genetic algorithms and radial basis functions. Specifically, a finite-element model generator is developed and used to create a solid rocket-based launch vehicle model, whose input parameters (geometry and loads) are affected by the selected payload and mission. To determine the critical load cases needed to size the structural components, the trajectory profile from takeoff to orbit insertion is of paramount importance. The use of surrogate models enhances the process of identifying the optimal design by enabling reductions in the running time of the optimization procedure, making the finite-element analysis suited for conceptual studies
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