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1.
Physiological correlates to off-road cycling performance 总被引：1，自引：1，他引：0
Impellizzeri FM Rampinini E Sassi A Mognoni P Marcora S 《Journal of sports sciences》2005,23(1):41-47
The aim of this study was to examine the relationships between maximal and submaximal tests for aerobic fitness and performance in an off-road cross-country circuit race. Thirteen competitive off-road male cyclists participated in the study. Peak oxygen uptake (VO2peak), peak power output, and lactate thresholds corresponding to 1 mmol x l(-1) above baseline (lactate threshold) and to 4 mmol x l(-1) (onset of blood lactate accumulation) were measured during an incremental cycling test. Race time and final ranking within the same group of cyclists were determined during a cross-country off-road competition. All correlations between the measured parameters of aerobic fitness and off-road cycling performance were significant, particularly between race time and physiological parameters scaled to body mass0.79 (r = -0.68 to -0.94; P < 0.05) and between final ranking and physiological parameters expressed relative to body mass0.79 (r = -0.81 to - 0.96; P < 0.001). Moreover, there was a large difference (effect sizes = 1.12-1.70) in all measured parameters of aerobic fitness between the group of six cyclists with a race time above the median and the group of six cyclists with a race time below the median (P < 0.05). In conclusion, the results of this study provide empirical support to the widespread use of these maximal (VO2peak, peak power output) and submaximal (lactate thresholds) parameters of aerobic fitness in the physiological assessments of off-road cyclists. Furthermore, our results suggest body size should be taken into account when evaluating such athletes. 相似文献
2.
Piero Benelli Franca Colasanti Massimiliano Ditroilo Antonio Cuesta-Vargas Giorgio Gatta Francesco Giacomini 《Journal of sports sciences》2013,31(3):268-277
AbstractNon-motorised underwater treadmills are commonly used in fitness activities. However, no studies have examined physiological and biomechanical responses of walking on non-motorised treadmills at different intensities and depths. Fifteen middle-aged healthy women underwent two underwater walking tests at two different depths, immersed either up to the xiphoid process (deep water) or the iliac crest (shallow water), at 100, 110, 120, 130 step-per-minute (spm). Oxygen consumption (VO2), heart rate (HR), blood lactate concentration, perceived exertion and step length were determined. Compared to deep water, walking in shallow water exhibited, at all intensities, significantly higher VO2 (+13.5%, on average) and HR (+8.1%, on average) responses. Water depth did not influence lactate concentration, whereas perceived exertion was higher in shallow compared to deep water, solely at 120 (+40%) and 130 (+39.4%) spm. Average step length was reduced as the intensity increased (from 100 to 130 spm), irrespective of water depth. Expressed as a percentage of maximum, average VO2 and HR were: 64–76% of peak VO2 and 71–90% of maximum HR, respectively at both water depths. Accordingly, this form of exercise can be included in the “vigorous” range of exercise intensity, at any of the step frequencies used in this study. 相似文献
3.
Use of the Internet in Italy is in its early stages. Social representation and public discourse spread by mass media have emphasised the risks for children, at the expense of its opportunities. Such concerns are today largely hypothetical. This paper presents the initial results of an exploratory research project, using both quantitative and qualitative approaches, aimed at investigating the use of the Internet by children in a number of areas, mainly within the family and at school. The study found that children using the Internet as pioneers at home belong to a privileged elite, provided by the family with appropriate instruments and adequate technical and cultural resources. Far from being abandoned to the Internet, such children are supervised and led by parents-indeed often too much, as they are left little room to explore cyberspace independently. The establishment of the Internet in schools is rapid, but faces structural inadequacies while the use made of it is not always in keeping with its particular characteristics. L'emploi d'Internet en Italie se trouve encore dans sa phase initiale. Une analyse menée sur le plan social et le débat public renforcépar les mass media ont révélél'existence de risques pour les enfants au détriment des potentiels offerts par l'Internet. Actuellement nous n'en sommes qu'au stade d'hypothèses. Cet article présente les premiers résultats d'un projet de recherche dont l'objectif est d'étudier l'usage que font les enfants d'Internet, principalement dans les milieux de la famille et de l'école, et ce aussi bien d'un point de vue qualitatif que quantitatif. Cette étude a révéléque les enfants qui naviguent en pionniers sur Internet à la maison, appartiennent à la catégorie des privilégiés dotés, par les familles, d'instruments opportuns mais aussi de ressources techniques et culturelles. En effet ces enfants sont loin d'être abandonnés sur le réseau, mais bien guidés et contrôlés par leurs parents, parfois même d'une façon excessive puisqu'on ne leur laisse guère la possibilitéd'explorer de façon autonome le cyberespace. La diffusion d'Internet dans les écoles est assez rapide malgré le manque de structures, alors que l'usage que l'on en fait ne correspond pas toujours à ses caractéristiques particulières. El uso de Internet en Italia se encuentra actualmente en una fase inicial. El análisis del plano social y el debate público mantenido por los medios de comunicación, han puesto en evidencia posibles riesgos para los niños, en detrimento de las oportunidades que se ofrecen. En la actualidad se trata de preocupaciones hipotéticas. Este artículo presenta los primeros resultados de un proyecto de investigación realizado con el objetivo de estudiar el uso de Internet por parte de los niños principalmente en el ámbito de la familia y de la escuela, utilizando un doble enfoque cualitativo y cuantitativo. El estudio ha puesto en evidencia que los niños que utilizan Internet como pioneros en casa pertenecen a una categoría privilegiada, dotada de instrumentos apropriados asícomo de adecuados recursos técnicos y culturales. A estos niños no sólo no se les deja abandonados en la red, sino que reciben seguimiento y supervisión constante de los padres, a menudo en modo excesivo, en la medida que se les dejan pocas oportunidades para explorar por ellos mismos el ciberespacio. Si bien la difusión de Internet en las escuelas se produce con gran rapidez a pesar de las carencias estructurales, el uso que se hace de Internet no siempre toma en cuenta las posibilidades que éste ofrece. Die Benutzung von Internet in Italien befindet sich in seiner Anfangsphase. Die von den Medien übermittelte soziale Darstellung und öffentliche Auseinandersetzung hat die Risiken für Kinder hervorgehoben, auf Kosten seiner Möglichkeiten. Solche Bedenken sind heutzutage grösstenteils hypothetisch. Diese Studie enthält die ersten Ergebnisse eines untersuchenden Forschungsprojektes, dessen Ziel darin besteht, die Benutzung von Internet durch Kinder auf verschiedenen Gebieten zu untersuchen, hauptsächlich innnerhalb der Familie und in der Schule, mit einem sowie quantitativen als auch qualitativen Ansatz. Diese Untersuchung stellte fest, dass Kinder, die als Pioniere zu Hause Internet benutzt haben, zu einer ausgewählten Elite gehören, die von der Familie durch passende Instrumente und angemessene technische und kulturelle Mitteln unterstützt wurden. Auch wenn sie nicht dem Netz völlig überlassen werden, werden diese Kinder doch zu sehr von ihren Eltern überwacht und geleitet, so dass ihnen wenig Zeit bleibt unabhängig den Cyberspace auf eigene Faust zu erkundigen. Die Verbreitung von Internet in den Schulen geht ziemlich schnell vor sich an, trifft jedoch auf strukturelle Schwierigkeiten wobei sein Gebrauch nicht immer den spezifischen Eigenschaften entspricht. 相似文献
4.
Maura Di Vito Maria Grazia Bellardi Piero Colaizzi Daniele Ruggiero Claudia Mazzuca Laura Micheli 《文物保护研究》2018,63(1):13-23
The gellan hydrogel is used as a cleaning agent for paper artworks. The purposes of this work were to give the gellan hydrogel both a microbial resistance and a cytocidal action against the biodeteriogens using hydrolates. Broth microdilution assays were performed to identify the fungicidal action of 16 hydrolates vs 3 fungal strains. The study concerned the Minimal Fungicidal Concentration and pH, colour, and ultra-structural variations on all paper samples, by placing them in contact with GELYD (GELlan?+?hYDrolat). The in vitro tests showed that eight out of 16 hydrolates strongly inhibited fungal growth, but only two of them (Monarda fistulosa, Citrus aurantium subsp amara) showed in situ fungicidal action. Data indicate a new and interesting eco-innovative use of hydrolates, since GELYD is able not only to clean paper artworks, but also to kill the fungal cells present on paper that are potentially harmful for paper and operators. 相似文献
5.
In the southern part of Italy, along the National Road 163 (the Amalfi Coastal road), and particularly close to Positano, some stone formations are present with a cylindrical shape (pinnacles) due to the erosion of the rock and the presence of sub-vertical cracking planes in the rocky slope. The landscape beauty and the dangerousness of these pinnacles, more than 10 m in height, leaning on the underlying road, requested a vulnerability study. The dynamic behavior of these natural solids is influenced by the notable mechanical inhomogeneity due to the nature of the rock, to the presence of diffused crack patterns and to the position along the slope. Some inspections have been performed to have a detailed survey of the pinnacles, using the Laser Scanner 3D technique and with the collaboration of geologist-mountain climbers; some rock specimens have also been taken to be analyzed and tested. The specific weight, the tensile (for bending) strength and the compressive strength, as well as the Young Modulus, considering various directions with respect to cracking planes, were analyzed during laboratory tests on the specimens sampled on site. Different structural modeling to analyze the seismic vulnerability of the pinnacles have been performed and compared: starting from simplified mechanical models of rigid blocks, passing through elastic analyses and finally to finite element (FEM) analyses. Numerical dynamic and static analyses, particularly, the modal dynamic analyses for the elastic continuum and the non-linear static analyses, considering both cracking and plasticity behavior of the rock have been performed. The analyses concerned the pinnacles both under the actual in-situ conditions and according to some strengthening interventions to evaluate the effectiveness and safety of the design. 相似文献
6.
This article addresses some of the most important legal and ethical issues posed by robot companions. Firstly, we clarify that robots are to be deemed objects and more precisely products. This on the one hand excludes the legitimacy of all such considerations involving robots as bearers of own rights and obligations, and forces a functional approach in the analysis. Secondly, pursuant to these methodological considerations we address the most relevant ethical and legal concerns, ranging from the risk of dehumanization and isolation of the user, to privacy and liability concerns, as well as financing of the diffusion of this—still expensive—technology. Solutions are briefly sketched, in order to provide the reader with sufficient indications on what strategies could and should be implemented, already in the design phase, as well as what kind of intervention ought to be favored and expected by national and European legislators. The recent Report with Recommendations to the Commission on Civil Law Rules on Robotics of January 24, 2017 by the European Parliament is specifically taken into account. 相似文献
7.
Guannan Qian Junyang Wang Hong Li Zi-Feng Ma Piero Pianetta Linsen Li Xiqian Yu Yijin Liu 《国家科学评论(英文版)》2022,(2):104-120
Rechargeable battery technologies have revolutionized electronics,transportation and grid energy storage.Many materials are being researched for battery applica... 相似文献
8.
Emiliano Carretti Marco Milano Luigi Dei Piero Baglioni 《Journal of Cultural Heritage》2009,10(4):501-508
The present work was one of the first attempts to analyze the conservation status of two ferrotypes, ancient photographic plates realized on a support made of iron. The photographic material was constituted of collodion as binder for the photosensitive silver halides grains. The two ferrotypes studied belonged to a private collection of a family from Durham, UK, and were made at the end of the 19th century. The analytical techniques used for the morphological and physicochemical characterization were noninvasive. The surface morphology was studied by means of optical microscopy (OM) and environmental scanning electron microscopy (ESEM) coupled with an energy dispersive X-rays (EDX) system for the elemental analysis. These techniques, together with microreflectance Fourier transform infrared spectroscopy (μ-FTIR) and contact angle, allowed to obtain information on both the chemical – elemental – composition of the materials constituting the ferrotypes, and the conservation status of these photographic plates. The study showed that the physicochemical diagnostics allowed to characterize the two ferrotypes that, despite their similar age and provenance, showed different conservation status, surface properties, and elemental composition. 相似文献
9.
The paper focuses on an interdisciplinary research project concerning the preservation of the XVII century monumental building of Monte di Pietà in Naples, Italy. The building underwent a series of restorations being the structural walls affected by humidity and cracks. The importance of this monumental building in the historical city center of Naples led to design an extensive surveying program to provide the designers of strengthening with a detailed investigation of the geometry of the entire structure, and particularly of the entrance façade, with great details on several materials, thicknesses and restraints. A preliminary investigation was performed on the historical phases of this monumental building to have a clear knowledge of its vicissitudes, and then in situ structural assessment included 3D laser scanner techniques probing radar, in situ stress measures. This surveying phase was crucial especially for the subsequent Finite Elements modeling (F.E.M.) of the façade. The scope of the numerical refined analyses was to evaluate the state of stress in the structural elements of the façade putting in evidence structural ‘weak points’ and finally to design a retrofit intervention having a detailed map of the ‘intervention areas’. The theoretical damage assessment has been compared with on-site assessment and in situ stress measures. The damage primarily concerned the entrance façade and its valuable decorations. Furthermore, the basic principles for the design of the strengthening have been discussed. 相似文献
10.
Fabio Galbusera Davide Zai Tornese Federica Anasetti Simone Bersini Piero Volpi Luigi La Barbera 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(3):293-301
Non-contact injuries in soccer players may be related to the interplay between cleat type and playing surface, and bladed shoes were often blamed for non-contact injuries with no research support. The aim of this study was to compare the rotational resistance (stiffness and peak sustainable torque) among three types of soccer cleats (metal studs, molded rubber studs, and bladed) in a controlled laboratory environment. The shoes were tested on both natural and artificial turfs under a compressive preload of 1000 N and with internal and external rotations. The three shoe models showed comparable performances with a good repeatability for each individual test on both playing surfaces. A less stiff behavior was observed for the natural turf. A tendency toward highest peak torque was observed in the studded model on natural surface. The bladed cleats provided peak torque and rotational stiffness comparable to the other models. Studded and bladed cleats did not significantly differ in their interaction with the playing surface. Therefore, soccer shoes with bladed cleats should not be banned in the context of presumed higher risk for non-contact injuries. 相似文献