1,721,084 research outputs found
Introduzione
No full textViaggio coinvolgente attraverso le terre d'Emilia e di Romagna, che durante i secoli XV e XVI offrono un formidabile spaccato delle variegate esperienze che animano il Rinascimento
T-wave and heart rate variability changes to assess training in world-class athletes
No full textPurpose: A decrease of electrocardiographic T-wave voltage with increasing training loads has been reported in elite endurance athletes and ascribed to training-related adaptation in sympathetic activity to the ventricles. A switch from vagal to sympathetic predominance in sino-atrial node regulation on going from low to peak training load has been reported in world-class rowers. In this study on world-class endurance athletes, we tested the hypothesis that training-induced variations in T-wave amplitude at higher training loads are paralleled by changes in HR spectral profile. Methods: We studied eight male rowers of the Italian national team in the season culminating with the Rowing World Championship. Athletes were evaluated at 50 and 100% of training load, similar to 20 d before the World Championship, and during the World Championship, when the intensity was markedly reduced. We assessed T-wave maximum amplitude in chest lead V6 and cardiac autonomic regulation by power spectral analysis of R-R interval variability. Results: The increase in training load from 50 to 100% was accompanied by a significant decrease in high frequency and a significant increase in low-frequency R-R variability (in normalized units) with a concomitant significant decrease in T-wave amplitude (muV). Reduction in training load during the World Championship resulted in a return of spectral profile to the level observed at 50% training load and in a partial recovery of T-wave amplitude. HR did not change significantly. Conclusions: In high-performance world-class athletes, training load simultaneously affects both ventricular repolarization and HR variability patterns possibly through variations in cardiac sympathetic modulation to the ventricles and the sino-atrial node. Information on concomitant changes in ventricular repolarization and autonomic cardiac regulation might be employed to tailor training protocols of elite athletes
Preparticipation screening for the detection of cardiovascular abnormalities that may cause sudden death in competitive athletes.
No full textImplementation of Deflection Bowl Measurements for Structural Evaluations at Network Level of Airport Pavement Management System
No full textThe APMS is a useful tool for operators and managers, providing a systematic and objective method for pavement condition evaluation, maintenance planning decisions and budget allocation. The pavement evaluation process also includes the evaluation of structural capacity and, more specifically, the use of deflectometer testing device has become a basic part of the structural evaluation, allowing non-destructive and rapid to execute surveys. The measured deflection bowl is used for the back-analysis process, in order to evaluate the modulus of each layer. This application can be less cost effective, requiring experienced analyst and often providing more detail than necessary, especially for implementation at network-level of Airport PMS. These aspects are amplified for seasonal and regional airports, faced with low budget availability and looking for easy and rapid techniques. The investigation reported in this paper focused on developing a direct method for the assessment of the overall conditions as well single layer strength, based on deflections measured by performing HWD tests. The data collected by deflectometer campaign performed on the runway has been analyzed, focusing the attention on the factors that can affect the measurements.
The survey was performed on five alignments, as required by international regulations, in different seasons and with different loads, then the relative influence was examined, conducting a correlation aimed on comparing deflections. With comparable data, the immediately visual rating of deflection values has been conducted, adopting the relative benchmarking methodology. The application at network level of Airport PMS allows the rapid overview of structural conditions, identifying areas that need further detailed investigations
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
Effect of tadalafil on anaerobic performance indices in healthy athletes
No full textObjective: Given the therapeutic and non-therapeutic use of the tadalafil, (phosphodiesterase-5 inhibitor, PDE-5i), we examined its effects on anaerobic performance indices.
Methods: In total, 12 well-trained subjects reported to the laboratory on two occasions 1 week apart to perform a 30 s Wingate anaerobic power test (WAnT) on a bicycle ergometer. The day before the WAnT, the subjects were double-blinded to receive an oral dose of tadalafil (20 mg) or placebo. Blood lactate value at rest and 1, 3, 6 and 10 minutes of recovery phase, mean power, peak power, time to peak power and fatigue index were assessed for each WAnT.
Results: Blood lactate values at the 3-min recovery WAnT increased significantly in the tadalafil condition (mean (SD) 13.9 (1.7) v 12.8 (1.3) mmol/l; p < 0.05) and time to peak power decreased significantly (6.3 (1.3) v 5.7 (1.5) s; p = 0.05). No differences were observed in any other parameters between the two conditions.
Conclusion: The primary finding of this investigation was that the administration of a single dose of a long-term PDE-5i does not substantially influence anaerobic performance indices. However, results demonstrated both an increase in lactate values at the 3-min point of the recovery phase and a decrease in time to peak power
Analisys of deflectometer campaign on high seasonality airport
No full textThe load-carrying capacity, is one of the indicators used to assess airfield pavement conditions. It could be estimated by evaluating the response of stationary dynamic loads, using a deflectometric device that simulates the stress inducted by an aircraft moving at moderate speed. This device is widely used because tests are non-destructive and rapid to execute and can be conducted for cyclic investigations, providing valuable support to maintenance and rehabilitation (M&R) decision makers through pavement management system (PMS). Pavement response is evaluated as a function of the deflection basin induced by the deflectometric device. It is well known that deflectometric measurements are influenced by external parameters such as weather conditions, especially temperature of upper layers or the percentage of water contained on unbounded layers. In this study the deflections basin response obtained for different load and weather conditions has been analyzed through the application of benchmarking values for immediately structural assessments. Tests were performed using the Heavy Weight Deflectometer (HWD) on 9 points along five longitudinal alignments from the centerline, 0.00 m, ± 3.00 m, and ± 5.20 m. . The benchmarking methodology was used to evaluate and compare runway pavement performance under different weather conditions and testing loads. The applied benchmarking methodology resulted an easy and rapid assessment tool of pavement conditions at network-level
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
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