Search results for " Direct"

Adaptive control of a class of strict-feedback time-varying nonlinear systems with unknown control coefficients

2018

Abstract In this paper, robust adaptive control of a class of strict-feedback nonlinear systems with unknown control directions is investigated. A novel Nussbaum-type function is developed and a key theorem is drawn which involves quantifying the addition of multiple Nussbaum functions with different control directions in a single inequality. Global stability of the closed-loop system and asymptotic stabilization of system output are proved. A simulation example is given to illustrate the effectiveness of the proposed control scheme.

Estimating the non-market benefits of water quality improvement for a case study in Spain: A contingent valuation approach

2012

Abstract This article addresses an important topic related to the application of the European Water Framework Directive (WFD) in Spanish watersheds. Results on a contingent valuation study, aimed to assess the non-market benefits of water quality improvements in the Guadiana river basin (GRB), are shown. Special attention has been paid to the issue of zero willingness-to-pay (WTP) responses, while addressing the possible presence of self-selection caused by protest responses. The results (i) indicate that sample selection bias is not a problem in our application, (ii) allow us to identify some key determinants of voting behaviour, and (iii) through the use of different econometric models al…

Análise semiótico e discursivo dos filmes: "Deus e o diabo na terra do Sol" e "O dragão da maldade contra Santo Guerreiro", de Glauber Rocha

2016

ABSTRACT In 1964, Glauber Rocha directed the film Black God, White Devil year when Brazil suffered a military coup state. Due to strong censorship at the time, the dialogue about political or social issues was forbidden. Despite all that chaos, Glauber Rocha wrote and directed Black God, White Devil and Antonio das Mortes that deal with the dichotomy between good / evil, educated / uneducated, order / disorder, the social, the symbolic constructions of space as semiosphere, borders and their breaks causing chaos. For the director, religion is closely related to politics. The desire for power is enshrined in relations: political and social (interest of the owners on the workers) and religiou…

La conférence du Columa 2013 racontée par des étudiants AgroSup-Dijon

2014

Document accessible depuis la notice de ProdInra : https://prodinra.inra.fr/?locale=en#!ConsultNotice:306111; La 22e conférence du Columa de l’AFPP, tenue à Dijon du 11 au 13 décembre 2013, a été suivie par des étudiants d’AgroSup-Dijon. Ils rendent compte ici de ce qu’ils en ont retenu. Ils analysent particulièrement les sessions : – « Nuisibilité » des adventices (indirecte, ex. : favoriser l’ergot, et directe). – « Cultures méditerranéennes et tropicales » (différences Dom-Tom/autres pays, techniques émergentes). – « Résistance » (extension, mécanismes, facteurs de risque). – « Transfert aux milieux » (facteurs de risque de pollution des eaux, suivis et modélisation pour les prévoir). – …

Effects of low-gamma tACS on primary motor cortex in implicit motor learning

2019

Abstract In the primary motor cortex (M1), rhythmic activity in the gamma frequency band has been found during movement planning, onset and execution. Although the role of high-gamma oscillatory activity in M1 is well established, the contribution of low-gamma activity is still unexplored. In this study, transcranial alternating current stimulation (tACS) was used with the aim to specifically modulate low-gamma frequency band in M1, during an implicit motor learning task. A 40 Hz-tACS was applied over the left M1 while participants performed a serial reaction time task (SRTT) using their right hand. The task required the repetitive execution of sequential movements in response to sequences …

Functional Role of Cerebellar Gamma Frequency in Motor Sequences Learning: a tACS Study

2021

Although the role of the cerebellum in motor sequences learning is widely established, the specific function of its gamma oscillatory activity still remains unclear. In the present study, gamma (50 Hz)—or delta (1 Hz)—transcranial alternating current stimulation (tACS) was applied to the right cerebellar cortex while participants performed an implicit serial reaction time task (SRTT) with their right hand. The task required the execution of motor sequences simultaneously with the presentation of a series of visual stimuli. The same sequence was repeated across multiple task blocks (from blocks 2 to 5 and from blocks 7 to 8), whereas in other blocks, new/pseudorandom sequences were reproduce…

2018

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that allows the modulation of cortical excitability as well as neuroplastic reorganization using a weak constant current applied through the skull on the cerebral cortex. TDCS has been found to improve motor performance in general and motor learning in particular. However, these effects have been reported almost exclusively for unimanual motor tasks such as serial reaction time tasks, adaptation tasks, or visuo-motor tracking. Despite the importance of bimanual actions in most activities of daily living, only few studies have investigated the effects of tDCS on bimanual motor skills. The objectives …

Citrus biotechnology

2020

Agricultural crops that can better withstand the changing climatic and pathogen landscape have been produced through natural selection throughout the millennia and, in recent years, through the process of human-assisted plant breeding and selection. However, a lack of genetic diversity in many commercially cultivated crops (due to monoculture) has made them more vulnerable to biotic and abiotic stresses (Esquinas-Alcazar, 2005; Keneni et al., 2012). Citrus, belonging to the Rutaceae family, is one of the most important commercial woody fruit crops in the tropical and subtropical areas of the world. The origin of citrus is traced back to parts of tropical and subtropical Southeast Asia (Wu e…

I pantani di Anguillara (Calatafimi Segesta, Trapani): dati preliminari sulla biodiversità a supporto della tutela del biotopo

2016

Vengono presentati i risultati preliminari di una indagine multidisciplinare condotta in una zona umida nel territorio di Calatafimi Segesta in provincia di Trapani. L'area è di grande interesse per la presenza di rare specie animali e vegetali, di habitat minacciati tutelati da normative nazionali ed internazionali, ma anche perché è una delle ultime zone umide superstiti dell'entroterra trapanese. L'area ha subito in tempi recenti un pesante disturbo antropico che rischia di portare alla distruzione questo ambiente e il suo biota di pregio. Con questo contributo gli autori intendono supportare la richiesta di adeguata e urgente tutela del sito. Anguillara Ponds (Calatafimi Segesta, Trapan…

Report on medium-term effects of the habitat protection and restoration activities of the LIFE Project “Maintenance of the habitats of the Macalube o…

2013

The Site of Community Importance (SCI) “Macalube di Aragona” is prone to severe desertification risk. In fact, its vegetation is disturbed not only by cyclic soil movements resulting from sedimentary volcanism, but it is strongly influenced by the hostile properties of the clayey substratum (prone to intense linear erosion, badly aired, rich in salts, etc.), the long drought period (ca. 4 months) and by the long-lasting history of human pressure. Both stress and disturbance factors influence progressive succession processes, so that the most “mature” local plant communities are () the chenopod shrublands referred to Salsolo-Peganion (habitat 1430 according to 92/43 EU Directive) and the hal…