Paris West University Nanterre La Défense

About: Paris West University Nanterre La Défense is a education organization based out in Paris, France. It is known for research contribution in the topics: Computer science & Politics. The organization has 895 authors who have published 1430 publications receiving 21712 citations.

Price Drivers and Structural Breaks in European Carbon Prices 2005-2007

Abstract: This article aims at characterizing the daily price fundamentals of European Union Allowances (EUAs) traded since 2005 as part of the Emissions Trading Scheme (ETS). The presence of two structural changes on April 2006 following the disclosure of 2005 verified emissions and on October 2006 following the European Commission announcement of stricter Phase II allocation allows to isolate distinct fundamentals evolving overtime. The results extend previous literature by showing that EUA spot prices react not only to energy prices with forecast errors, but also to unanticipated temperatures changes during colder events. Besides, the sub-period decomposition of the pilot phase gives a better grasp of institutional and market events that drive allowance price changes.

Evidence for a common process in gait initiation and stepping on to a new level to reach gait velocity

Abstract: The aim of this study was to examine the adaptability of the gait initiation process when confronted with stepping on (SO) to a new level. Eight young adults performed gait initiation at two different speed conditions in a level walking (LW) situation and in a SO situation aimed at walking on an elevated (16 cm) level surface. As in a previous study using a single step, we found in SO a contradiction between the characteristics of anticipatory postural adjustments (APA) and gait velocity, i.e. the peak of anteroposterior velocity of the body’s centre of gravity (CG) reached at the end of the first step. In normal and fast gaits, gait velocity was similar in both situations, whereas the duration and amplitude of the APA were smaller in SO than in LW. The reduction of APA in SO allowed the forward velocity of CG at the time of foot contact of the stepping limb to be lower than in LW. This is explained by the fact that the majority of body lift, beginning at this time, required a greater increase in forward velocity than in LW. Thus, with lower APA in SO, the gait velocity could be similar in both situations. From LW to SO, the spatio-temporal patterns in the forward velocity of CG varied within characteristic phases of the movement, but in a predictable way as gait velocity changed. These results gave evidence of an adaptation of the gait initiation process for the new constraints, despite the contradiction between APA and gait velocity. The spatio-temporal parameters of the anticipation phase in SO were pre-set according to the new requirements of the task: reaching gait velocity with a body lift. Furthermore, the time for reaching gait velocity was independent of both the amplitude of this velocity and the situation. This expressed the capacity of the subjects to use in SO the same optimal conditions to reach gait velocity as in LW, i.e. essentially in a ballistic manner.

Analysis of Gambling in the Media Related to Screens: Immersion as a Predictor of Excessive Use?

Abstract: This study investigates the intricacies between the player interface proposed by the screens, (in particular on smartphone applications or in video games) and gambling. Recent research indicates connections between "immersion" and excessive screen practice. We want to understand the causal-effects between online gambling and the "immersion" variable and understand their relationship and its contingencies. This article empirically investigates whether and how it is possible to observe immersion with its sub-dimensions in gambling on different screens. The objective of this study was to analyze: (1) the costs and benefits associated with gambling practice on screens (2) the link between gambling practice and screen practice (video game, Internet, mobile screen); (3) to observe the propensity to immersion for individuals practicing gambling on screens; and (4) to examine the comorbidities and cognitive factors associated with the practice of gambling on screen. A total of 432 adults (212 men, 220 women), recruited from Ile-de-France (France), responded to a battery of questionnaires. Our study suggests that immersion variables make it possible to understand the cognitive participation of individuals towards screens in general, the practice of gambling on screens and the excessive practice of screens.

Gathered fruits and cultivated plants at Bercy (Paris), a Neolithic village in a fluvial context

Abstract: Recent rescue excavations at Bercy (Paris), a site on the alluvial plain of the Seine valley, yielded plant remains which are associated with the recent occupation phase dating from the middle Neolithic II (Chasseen), when a village was established on the former channel of the river Seine. Various contexts (the channel, the flat lower part of the bank, and several archaeological features) have been studied and 84 taxa have been identified. Cultivated plants are represented by Triticum aestivum/durum, T. dicoccum, T. monococcum and Hordeum vulgare. Among the wild plants with potentially edible fruits or seeds, only very few satisfy the various criteria for association with human activities: Corylus avellana, Vitis sylvestris, Cornus sanguinea, Quercus sp. and Prunus spinosa of which carbonized fruits were also present, were found in archaeological features and were very abundant. Though not found in archaeological features, we consider that Crataegus monogyna (carbonized and well represented) and Rubus spp. (especially abundant) were not deposited there naturally and had also been intentionally collected. Finally, it is suggested that the allochthonous (varied) origin of these taxa is the reason why there are no concentrations of their fruits in the channel. The exploitation of wild seeds and fruits appears to have been very selective. All other wild taxa can be attributed to natural deposition.

Exploring the effects of kinesiological awareness and mental imagery on movement intention in the performance of demi-plié.

Abstract: This study was designed to assess the ability of a practitioner intervention using kinesiological explanations and mental imagery techniques to optimize the performance of demi-plie in dancers. Seven professional female ballet dancers were involved in the study. Biomechanical and electromyographical parameters (maximum knee flexion, jump height, maximal vertical acceleration and its duration, ratio of sagittal acceleration variation, and ratio of muscle activity in four muscles of the lower limb) were analyzed before and after the practitioner intervention. Results demonstrated no significant difference in the depth of the demi-plie, nor in the height of the jump that followed, nor in the maximal vertical acceleration and its duration, leading to the suggestion that the technical potential of the dancers was preserved. Significant differences were found in the SEMG of the hamstrings during the demi-plie and the jump, implying that an improvement in the dynamic alignment of the dancers was present. A correlation was also found between the ratio of sagittal acceleration variation and the hamstring activity, suggesting that increased hamstring engagement produces decreased disruption of dynamic alignment. However, the intervention was not assimilated equally by all of the dancers.