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: Population & Finite element method. The organization has 895 authors who have published 1430 publications receiving 21712 citations.

A weed–crop complex in sorghum: The dynamics of genetic diversity in a traditional farming system

Abstract: Despite the major ecological and economic impacts of gene flow between domesticated plants and their wild relatives, many aspects of the process, particularly the relative roles of natural and human selection in facilitating or constraining gene flow, are still poorly understood. We developed a multidisciplinary approach, involving both biologists and social scientists, to investigate the dynamics of genetic diversity of a sorghum weed-crop complex in a village of Duupa farmers in northern Cameroon. Farmers distinguish a gradient from weedy morphotypes (naa baa see, haariya, and genkiya) to domesticated morphotypes; haariya and genkiya have intermediate morphological traits. We investigated the pattern of diversity in this complex using both morphological and genetic data. Our biological results are interpreted in the light of data on farmers' taxonomy and practices such as spatial pattern of planting and plant selection. Both morphological and genetic data are congruent with farmers' taxonomy and confirm the introgressed status of intermediate weedy morphotypes. Farmers actively select against weedy morphotypes, but several practices unconsciously favor gene flow. Furthermore, haariya and genkiya may facilitate introgression between naa baa see and domesticated morphotypes by virtue of their intermediate flowering period and their mode of management by farmers.

Training During the COVID-19 Lockdown: Knowledge, Beliefs, and Practices of 12,526 Athletes from 142 Countries and Six Continents

Abstract: Our objective was to explore the training-related knowledge, beliefs, and practices of athletes and the influence of lockdowns in response to the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Athletes (n = 12,526, comprising 13% world class, 21% international, 36% national, 24% state, and 6% recreational) completed an online survey that was available from 17 May to 5 July 2020 and explored their training behaviors (training knowledge, beliefs/attitudes, and practices), including specific questions on their training intensity, frequency, and session duration before and during lockdown (March–June 2020). Overall, 85% of athletes wanted to “maintain training,” and 79% disagreed with the statement that it is “okay to not train during lockdown,” with a greater prevalence for both in higher-level athletes. In total, 60% of athletes considered “coaching by correspondence (remote coaching)” to be sufficient (highest amongst world-class athletes). During lockdown, < 40% were able to maintain sport-specific training (e.g., long endurance [39%], interval training [35%], weightlifting [33%], plyometric exercise [30%]) at pre-lockdown levels (higher among world-class, international, and national athletes), with most (83%) training for “general fitness and health maintenance” during lockdown. Athletes trained alone (80%) and focused on bodyweight (65%) and cardiovascular (59%) exercise/training during lockdown. Compared with before lockdown, most athletes reported reduced training frequency (from between five and seven sessions per week to four or fewer), shorter training sessions (from ≥ 60 to < 60 min), and lower sport-specific intensity (~ 38% reduction), irrespective of athlete classification. COVID-19-related lockdowns saw marked reductions in athletic training specificity, intensity, frequency, and duration, with notable within-sample differences (by athlete classification). Higher classification athletes had the strongest desire to “maintain” training and the greatest opposition to “not training” during lockdowns. These higher classification athletes retained training specificity to a greater degree than others, probably because of preferential access to limited training resources. More higher classification athletes considered “coaching by correspondence” as sufficient than did lower classification athletes. These lockdown-mediated changes in training were not conducive to maintenance or progression of athletes’ physical capacities and were also likely detrimental to athletes’ mental health. These data can be used by policy makers, athletes, and their multidisciplinary teams to modulate their practice, with a degree of individualization, in the current and continued pandemic-related scenario. Furthermore, the data may drive training-related educational resources for athletes and their multidisciplinary teams. Such upskilling would provide athletes with evidence to inform their training modifications in response to germane situations (e.g., COVID related, injury, and illness).

An evolving simulation/gaming process to facilitate adaptive watershed management in northern mountainous Thailand

Abstract: The decentralization of natural resource management provides an opportunity for communities to increase their participation in related decision making. Research should propose adapted methodologies enabling the numerous stakeholders of these complex socioecological settings to define their problems and identify agreed-on solutions. This article presents a companion modeling (ComMod) experiment combining role-playing games and multiagent systems conducted in a community in northern Thailand to support collective learning for adaptive land management. Researchers and local stakeholders collectively built a representation of the situation and used it as a platform to explore scenarios. This ComMod process initially addressed a soil erosion problem. The participants identified the expansion of perennial crops as a promising solution but also raised the problem of the unequal ability among villagers to invest in such crops. The researchers flexibly adapted the simulation tools to the emerging matter. The authors assess the learning effects of this experiment and identify two favoring factors: the increasing participation of local stakeholders and a flexible and adaptive modeling process suited to learning, which by nature is an evolving process. But to ensure sustainable impacts for the communities, stronger links with higher institutional levels are needed.

An Omega-K algorithm for SAR bistatic systems

Abstract: Bistatic SAR uses separate flying transmitter and receiver platforms. There are two principal configurations : spatial invariant case, in which velocity vectors are equal; and spatial variant case, in which velocity vectors are not equal. ONERA and DLR performed experimental flights on the spatial invariant case in february 2003 [1]. The experiment was conducted using the X-band front ends that are compatible in terms of frequency (on a 100 MHz-Wide band). Estimation and compensation of the phase drift between the transmitter and the receiver master oscillator was presented in [1]. Until now, data have been processed with a back projection algorithm. This article investigates an Omega-K algorithm - or Range Migration Algorithm - for bistatic SAR systems in spatial invariant cases. First results of this algorithm on real data are included.

Abstraction of Two Forms of Underlying Structure in a Tonal Melody

Abstract: This experiment, based on the work of Lerdahl and Jackendoff (1983), was designed to test the abstraction of two forms of underlying structures: "reduced structure" and "prolongational structure". ...