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.

Development and validation of the aging stereotypes and exercise scale.

Abstract: This article presents the development and validation of the Aging Stereotypes and Exercise Scale (ASES), which measures different dimensions of aging stereotypes in the exercise domain. Drawing on past research on older adults’ perceived barriers to exercise, these dimensions include stereotypes about positive and negative exercise outcomes for older adults and about older adults’ psychological barriers to exercise (i.e., lack of self-efficacy and motivation). Four studies involving 714 participants examined the factorial structure and invariance, temporal stability, and external validity of the scale. The results supported a 3-factor model that was invariant across age. Age differences in stereotype content appeared, with older adults holding more positive stereotypes than younger adults. Also as predicted, the more older adults endorsed negative stereotypes, the lower their physical self-worth, self-rated health, and subjective age. Last, responses to the ASES appeared to be stable over a 6-wk period.

Versatile metasurface platform for electromagnetic wave tailoring

Abstract: The emergence of metasurfaces provides a novel strategy to tailor the electromagnetic response of electromagnetic waves in a controlled manner by judicious design of the constitutive meta-atom. However, passive metasurfaces tend to perform a specific or limited number of functionalities and suffer from narrow-frequency-band operation. Reported reconfigurable metasurfaces can generally be controlled only in a 1D configuration or use p-i-n diodes to show binary phase states. Here, a 2D reconfigurable reflective metasurface with individually addressable meta-atoms enabling a continuous phase control is proposed in the microwave regime. The response of the meta-atom is flexibly controlled by changing the bias voltage applied to the embedded varactor diode through an elaborated power supply system. By assigning appropriate phase profiles to the metasurface through voltage modulation, complex beam generation, including Bessel beams, vortex beams, and Airy beams, is fulfilled to demonstrate the accurate phase-control capability of the reconfigurable metasurface. Both simulations and measurements are performed as a proof of concept and show good agreement. The proposed design paves the way toward the achievement of real-time and programmable multifunctional meta-devices, with enormous potential for microwave applications such as wireless communication, electromagnetic imaging, and smart antennas.

Can stereotype threat affect motor performance in the absence of explicit monitoring processes? Evidence using a strength task.

Abstract: Previous evidence shows that stereotype threat impairs complex motor skills through increased conscious monitoring of task performance. Given that one-step motor skills may not be susceptible to these processes, we examined whether performance on a simple strength task may be reduced under stereotype threat. Forty females and males performed maximum voluntary contractions under stereotypical or nullified-stereotype conditions. Results showed that the velocity of force production within the first milliseconds of the contraction decreased in females when the negative stereotype was induced, whereas maximal force did not change. In males, the stereotype induction only increased maximal force. These findings suggest that stereotype threat may impair motor skills in the absence of explicit monitoring processes, by influencing the planning stage of force production.

Effects of Polyphenol-Rich Interventions on Cognition and Brain Health in Healthy Young and Middle-Aged Adults: Systematic Review and Meta-Analysis.

Abstract: Context: Affecting older and even some younger adults, neurodegenerative disease represents a global public health concern and has been identified as a research priority. To date, most anti-aging interventions have examined older adults, but little is known about the effects of polyphenol interventions on brain-related aging processes in healthy young and middle-aged adults. Objective: This systematic review and meta-analysis aimed to evaluate the acute and chronic effects of (poly)phenol-rich diet supplementation on cognitive function and brain health in young and middle-aged adults. In July 2019, two electronic databases (PubMed and Web of Science) were used to search for relevant trials examining the effect of acute or chronic (poly)phenol-rich supplementation on cognitive function and neuroprotective measures in young and middle-aged adults (<60 years old). A total of 4303 records were screened by two researchers using the PICOS criteria. Fifteen high quality (mean PEDro score = 8.8 ± 0.58) trials with 401 total participants were included in the final analyses. Information on treatment, study design, characteristics of participants, outcomes and used tools were extracted following PRISMA guidelines. When items were shown to be sufficiently comparable, a random-effects meta-analysis was used to pool estimates across studies. Effect size (ES) and its 95% confidence interval (CI) was calculated. The meta-analysis indicated that (poly)phenol supplementation significantly increased brain-derived neurotrophic factor (ES = 3.259, p = 0.033), which was accompanied by higher performance in serial (7s) subtraction (ES = 1.467, p = 0.001) and decreases in simple reaction time (ES = −0.926, p = 0.015) and mental fatigue (ES = −3.521, p = 0.010). Data related to cognitive function were skewed towards an effect from acute compared to chronic polyphenol intervention; data related to BDNF were skewed toward an effect from higher bioavailability phenolic components. Conclusion: This meta-analysis provides promising findings regarding the usefulness of polyphenol-rich intervention as an inexpensive approach for enhancing circulation of pro-cognitive neurotrophic factors. These beneficial effects appear to depend on the supplementation protocols. An early acute and/or chronic application of low- to high-dose phenolic components with high bioavailability rates (≥30%) at a younger age appear to provide more promising effects.

European carbon prices fundamentals in 2005-2007: the effects of energy markets, temperatures and sectorial production

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). First, the presence of two structural changes on April, 2006 following the disclosure of 2005 veri?ed emissions and on October, 2006 following the European Commission announcement of stricter Phase II allocation allow to isolate distinct fundamentals evolv- ing overtime. The results extend previous literature by showing that spot prices react not only to other energy markets and temperatures, but also to economic activity within the main sectors covered by the EU ETS such as proxied by sectoral production indices. Besides, the sub-period decomposition of the pilot phase gives a better grasp of institutional and market events that drive allowance price changes.