1,722,139 research outputs found
Isolated quadriceps training increases maximal exercise capacity in chronic heart failure : the role of skeletal muscle convective and diffusive oxygen transport
No full textObjectives: This study sought to elucidate the mechanisms responsible for the benefits of small muscle mass exercise training in patients with chronic heart failure (CHF). Background: How central cardiorespiratory and/or peripheral skeletal muscle factors are altered with small muscle mass training in CHF is unknown. Methods: We studied muscle structure, and oxygen (O2) transport and metabolism at maximal cycle (whole-body) and knee-extensor exercise (KE) (small muscle mass) in 6 healthy controls and 6 patients with CHF who then performed 8 weeks of KE training (both legs, separately) and repeated these assessments. Results: Pre-training cycling and KE peak leg O2 uptake (Vo2peak) were ∼17% and ∼15% lower, respectively, in the patients compared with controls. Structurally, KE training increased quadriceps muscle capillarity and mitochondrial density by ∼21% and ∼25%, respectively. Functionally, despite not altering maximal cardiac output, KE training increased maximal O2 delivery (∼54%), arterial-venous O2 difference (∼10%), and muscle O2 diffusive conductance (DMO2) (∼39%) (assessed during KE), thereby increasing single-leg Vo2peak by ∼53%, to a level exceeding that of the untrained controls. Post-training, during maximal cycling, O2 delivery (∼40%), arterial-venous O2 difference (∼15%), and DMO2 (∼52%) all increased, yielding an increase in Vo2peak of ∼40%, matching the controls. Conclusions: In the face of continued central limitations, clear improvements in muscle structure, peripheral convective and diffusive O2 transport, and subsequently, O2 utilization support the efficacy of local skeletal muscle training as a powerful approach to combat exercise intolerance in CHF
Effects of fatigue on electromechanical delay in human skeletal muscle : new insights from an electromyographic and mechanomyographic combined approach
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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
The “EVALUATOR” Suite for the Computer-aided Analysis of Advanced Automotive Electrical
No full textIn the last years, the on-board electric power requirement in vehicles is continuously increasing. The increase in power demand is even due to emerging automotive technologies such as variable engine valve, active suspension, x-by-wire (e.g. steering-by-wire, brake-by-wire, etc.) and heated catalytic converter. Since the adaptability of the conventional electrical system to the needs of next future and present electrical loads is very little, alternative architectures of powernet are required, but it isn’t still clear how to detect the best architecture for a fixed automotive application.
The goal of this paper is to introduce a new computer aided technique for the choice of new architectures oriented for advanced automotive applications. The paper presents the software suite EVALUATOR to compare different electrical power systems and to identify which of them has superior performances and is economically competitive
An Optimal Energy Management Strategy for Power-Split Hybrid Electric Vehicles
No full textThe paper deals with a particular application of the optimal control theory in the formulation of an energy management strategy oriented to the minimization of the fuel consumption and pollutant emissions in a well known commercial vehicle; specifically, the Toyota® Prius NHW10 model has been considered as a case study. The results of the suggested strategy show a reduction of 3.6% in fuel use and much more in emissions. The same strategy could be applied for other hybrid architectures (in power-split or parallel configuration), for minimizing both fuel consumption and emissions
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
Pratiche performative metropolitane. Il fenomeno Tribute Band
No full textUrban performance practices: the tribute band phenomenon Interactions between the arts are dramatically increasing, challenging academic views which formerly strictly separated one realm from the other. Beyond the idea of work of art as an object, made and finished by an individual author, we are now experiencing art as an open praxis and an action of collective consumption. Theatre and music growingly blend together under the label of performing arts, involving the execution of something which has been previously prepared and rehearsed. In live popular music, for instance, tribute bands have recently been gaining large favour. But what exactly is a tribute band? Why such a success today and not at the time of the pop-rock explosion? Are there further socio-cultural meanings to this practice? Could it be seen as a form of «ritualized resistance» to market strategies?[...
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