Physiological responses at the lactate-minimum-intensity with and without prior high-intensity exercise     

Alessandro Moura Zagatto  Johnny Padulo  Adelino Ramos Sanchez da Silva  Paulo de Tarso Guerrero Müller  Willian Eiji Miyagi  Claudio Alexandre Gobatto 《Journal of sports sciences》2016,34(21):2106-2113

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Teachers’ Emotional Competence and Social Support: Assessing the Mediating Role of Teacher Burnout     

Caterina Fiorilli  Ottavia Albanese  Piera Gabola  Alessandro Pepe 《Scandinavian Journal of Educational Research》2017,61(2):127-138

This study explored the relationships among teachers’ emotional competence, burnout as a mediator, and social support. Teachers’ emotional competence was assessed via measures of emotional intensity and emotional regulation. Social support was evaluated in terms of external versus internal support, and teacher dissatisfaction with support received. Participants were 149 Italian primary school teachers. Data were analysed using structural equation modelling. The findings suggested that teacher burnout partially mediated the relationship between emotional intensity and satisfaction with social support received. Overall, the results showed that teachers were at risk of highly intense unpleasant emotions in relation to their burnout syndrome. Moreover, teachers’ satisfaction/dissatisfaction with social support received was predicted by burnout symptoms. These results extend the findings of earlier studies, and provide indications as to how to help teachers experiencing burnout.  相似文献   

‘Me and maths’: towards a definition of attitude grounded on students’ narratives     

Pietro Di Martino  Rosetta Zan 《Journal of Mathematics Teacher Education》2010,13(1):27-48

The attitude construct is widely used by teachers and researchers in mathematics education. Often, however, teachers’ diagnosis of ‘negative attitude’ is a causal attribution of students’ failure, perceived as global and uncontrollable, rather than an accurate interpretation of students’ behaviour, capable of steering future action. In order to make this diagnosis useful for dealing with students’ difficulties in mathematics, it is necessary to clarify the construct attitude from a theoretical viewpoint, while keeping in touch with the practice that motivates its use. With this aim, we investigated how students tell their own relationship with mathematics, proposing the essay “Me and maths” to more than 1,600 students (1st to 13th grade). A multidimensional characterisation of a student’s attitude towards mathematics emerges from this study. This characterisation and the study of the evolution of attitude have many important consequences for teachers’ practice and education. For example, the study shows how the relationship with mathematics is rarely told as stable, even by older students: this result suggests that it is never too late to change students’ attitude towards mathematics.  相似文献   

Flow biosensing and sampling in indirect electrochemical detection     

Lamberti F  Luni C  Zambon A  Andrea Serra P  Giomo M  Elvassore N 《Biomicrofluidics》2012,6(2):24114-2411413

Miniaturization in biological analyses has several advantages, such as sample volume reduction and fast response time. The integration of miniaturized biosensors within lab-on-a-chip setups under flow conditions is highly desirable, not only because it simplifies process handling but also because measurements become more robust and operator-independent. In this work, we study the integration of flow amperometric biosensors within a microfluidic platform when analyte concentration is indirectly measured. As a case study, we used a platinum miniaturized glucose biosensor, where glucose is enzymatically converted to [Formula: see text] that is oxidized at the electrode. The experimental results produced are strongly coupled to a theoretical analysis of fluid dynamic conditions affecting the electrochemical response of the sensor. We verified that the choice of the inlet flow rate is a critical parameter in flow biosensors, because it affects both glucose and [Formula: see text] transport, to and from the electrode. We identify optimal flow rate conditions for accurate sensing at high time resolution. A dimensionless theoretical analysis allows the extension of the results to other sensing systems according to fluid dynamic similarity principles. Furthermore, we developed a microfluidic design that connects a sampling unit to the biosensor, in order to decouple the sampling flow rate from that of the actual measurement.  相似文献   

Disambiguated query suggestions and personalized content-similarity and novelty ranking of clustered results to optimize web searches     

Gloria Bordogna  Alessandro Campi  Giuseppe Psaila  Stefania Ronchi 《Information processing & management》2012

In this paper, we face the so called “ranked list problem” of Web searches, that occurs when users submit short requests to search engines. Generally, as a consequence of terms’ ambiguity and polysemy, users engage long cycles of query reformulation in an attempt to capture relevant information in the top ranked results.  相似文献   

Mechanical and EMG responses of the vastus lateralis and changes in biochemical variables to isokinetic exercise in endurance and power athletes     

Rainoldi A  Gazzoni M  Merletti R  Minetto MA 《Journal of sports sciences》2008,26(3):321-331

Twelve endurance athletes and six power athletes performed fatiguing isokinetic knee flexions/extensions. Isokinetic torque was recorded during the exercise. Isometric torque, cortisol and lactate responses, electromyographic (EMG) mean power frequency, average rectified value, and conduction velocity were analysed before and after the isokinetic exercise to determine correlations between electrophysiological variables and mechanical performances and/or blood concentrations of biomarkers in the two groups of athletes. The EMG variables were estimated from signals recorded from the vastus lateralis in both voluntary and electrically elicited isometric contractions. Power athletes recorded higher values than endurance athletes for the following variables: pre-exercise isometric maximal voluntary contraction (MVC), isokinetic MVC, rate of mechanical fatigue during isokinetic contractions, pre - post exercise variations and recovery times of conduction velocity and mean power frequency, and lactate concentrations. Moreover, conduction velocity overshooting was observed in endurance athletes during the recovery phase after exercise. The correlation analyses showed that the higher the rate of mechanical fatigue, the higher the lactate production and the reduction in conduction velocity due to the exercise.  相似文献   

The palette of the Macchia Italian artist Giovanni Fattori in the second half of the xixth century     

Monica Favaro  Sara Bianchin  Pietro A. Vigato  Muriel Vervat 《Journal of Cultural Heritage》2010,11(3):265-278

Giovanni Fattori (Livorno 1825–Firenze 1908) is the most representative artist of the Macchiaioli's current, an early group of Italian plein-air artists, whose work anticipates, in the xixth century, that of their younger contemporaries, the French Impressionists. The study, performed by a multidisciplinary team made up of scientists and conservators, presents the results of the scientific characterization carried out on a group of 10 paintings made by Fattori between 1854 and 1893 and shows the way he used complex mixtures of a large variety of traditional and synthetic pigments, ranging from lead white, found pure and also extended with calcium carbonate, natural barite and gypsum to zinc white, from red ochre to cinnabar and vermilion, from yellow ochre and Naples yellow to chrome yellow, cadmium yellow and zinc yellow, combined with many other ones reported in details. This paper highlights the evolution of his painting technique during a time of great technological and social innovations and puts forward some hypothesis on his awareness about manufactured pigments, i.e. tube paints recently introduced into the artists’ circles. The wide range of pigments and their different quality among the same synthetic products suggest that the artist used all the available materials, and that picking out the pigments he retained the early xixth century artists techniques, such as the use of mineral earths and Prussian blue, similarly to his contemporary Italian artists Federico Zandomeneghi and Telemaco Signorini, but he also experimented new and peculiar pigment mixtures in the making of “colored darks” and an innovative use of the grounds in the final composition, that are also distinctive features of the French Impressionists. This work is aimed at contributing to overcome the lack of a comprehensive overview on the widespread historical and scientific data collected up to now on the Italian paintings in the xixth century, which has been severely underestimated with respect to previous art movements.  相似文献   

Energy cost and kinematics of level,uphill and downhill running: fatigue-induced changes after a mountain ultramarathon     

Gianluca Vernillo  Aldo Savoldelli  Andrea Zignoli  Spyros Skafidas  Alessandro Fornasiero  Antonio La Torre 《Journal of sports sciences》2015,33(19):1998-2005

This study aimed to determine whether the fatigue induced by a mountain ultramarathon (MUM) led to changes in energy cost and kinematic during level and graded running. Pre- and post-race, 14 ultratrail runners ran on a level, uphill (5%) and downhill (5%) treadmill at 10 km · h^?1. Kinematic data were acquired using a photocell system. Post-race, the downhill energy cost increased by 13.1% (P < 0.001). No change was noted in level and uphill running. Duty factor and stride frequency were increased, whereas swing time, cycle time and stride length were decreased in all conditions (P < 0.05). Contact time was increased and the rate of force generation was decreased only in the uphill and downhill conditions (P < 0.05). Positive correlations were observed between performance time and the pre- to post-changes in the energy cost of level (r = 0.52, P = 0.04) and uphill running (r = 0.50, P = 0.04). MUM-induced fatigue resulted in physiological and spatiotemporal changes, though the response to fatigue varied considerably between running conditions. These changes resulted in a significant increment only in the downhill energy cost. Incorporating downhill locomotion in the training programmes of ultratrailers may help to improve performance-related physiological and biomechanical parameters.  相似文献   

Intangible assets and firm heterogeneity: Evidence from Italy     

Alessandro Arrighetti  Fabio Landini  Andrea Lasagni 《Research Policy》2014

The positive impact of intangible assets on several measures of economic performance is well documented in the literature. Less clear is what initially leads firms to invest in intangible assets. The latter is particularly important because, at least for the Italian manufacturing sector, firms exhibit strong heterogeneity in their investments in intangible assets. In line with the capability-based theory of the firm, we argue that the firm's propensity to invest in intangible assets can be explained by factors that are internal and specific to the firm. Making use of a rich dataset, we test and provide support for our hypotheses. In particular, we find that the propensity to invest in intangible assets increases with the firm's size, human capital, and historical intangible asset base. This points towards the existence of a cumulative process of intangible asset accumulation, which may account for most of the heterogeneity observed in the data. The paper adds to the previous literature in two ways: first, it highlights the existence of strong intra-industry heterogeneity in intangible asset investments, and second, it offers an explanation for such heterogeneity.  相似文献   

Linguistic kernels for answer re-ranking in question answering systems     

Alessandro Moschitti  Silvia Quarteroni 《Information processing & management》2011

Answer selection is the most complex phase of a question answering (QA) system. To solve this task, typical approaches use unsupervised methods such as computing the similarity between query and answer, optionally exploiting advanced syntactic, semantic or logic representations.  相似文献