Rac-1-mediated O2- secretion requires Ca2+ influx in neutrophil-like HL-60 cells

in Cell Calcium (2001), 29(6), 409-15

Neutrophil-like HL-60 cells reacted to N -formyl- l -Methionyl- l -Leucyl- l -P henylalanine (f MLP) with a rise in the intracellular calcium concentration ([Ca2]i), NADPH oxidase activation, and ... [more ▼]

Neutrophil-like HL-60 cells reacted to N -formyl- l -Methionyl- l -Leucyl- l -P henylalanine (f MLP) with a rise in the intracellular calcium concentration ([Ca2]i), NADPH oxidase activation, and increased superoxide anion (O2-) production. [Ca2+]i mobilization and superoxide production were largely dependent on extracellular calcium (Ca2+]e) and a capacitative calcium entry. The monomeric G-protein, Rac-1, regulates NADPH oxidase activity. We tested the effect of removal of Ca2+]e on Rac-1 plasma membrane sequestration and activation of NADPH oxidase using immunodetection and a double labelling fluorescent method. Results showed that Rac-1 activation is mediated via a pertussis toxin (PTX)-sensitive heteromeric G-protein pathway, and that Rac-1 membrane sequestration was preceded by [Ca2+]i mobilization following entry of Ca2+ e. Therefore, we propose that O2- production is dependent on activation of PTX-sensitive G-proteins and sequestration of Rac-1 in the plasma membrane, following entry of Ca2+ e. [less ▲]

Race and gender homophily in collaborations and citations

Scientific Conference (2022, October 09)

Rachat des parts d'un OPC par un autre OPC et respect des obligations professionnelles des sociétés de gestion de portefeuille note sous Commission des sanctions AMF, 30 oct. 2014

in Bulletin Joly Bourse (2015)

Racial disparities in observers' attention to and estimations of others' pain

in Pain (2021)

Research has demonstrated racial disparities in pain care such that Black patients often receive poorer pain care than White patients. Little is known about mechanisms accounting for the emergence of such ... [more ▼]

Research has demonstrated racial disparities in pain care such that Black patients often receive poorer pain care than White patients. Little is known about mechanisms accounting for the emergence of such disparities. The present study had 2 aims. First, we examined whether White observers' attentional processing of pain (using a visual search task [VST] indexing attentional engagement to and attentional disengagement from pain) and estimation of pain experience differed between White vs Black faces. Second, we examined whether these differences were moderated by (1) racially biased beliefs about pain experience and (2) the level of pain expressed by Black vs White faces. Participants consisted of 102 observers (87 females) who performed a VST assessing pain-related attention to White vs Black avatar pain faces. Participants also reported on racially biased beliefs about White vs Black individuals' pain experience and rated the pain intensities expressed by White and Black avatar faces. Results indicated facilitated attentional engagement towards Black (vs White) pain faces. Furthermore, observers who more strongly endorsed the belief that White individuals experience pain more easily than Black individuals had less difficulty disengaging from Black (vs White) pain faces. Regarding pain estimations, observers gave higher pain ratings to Black (vs White) faces expressing high pain and White (vs Black) faces expressing no pain. The current findings attest to the importance of future research into the role of observer attentional processing of sufferers' pain in understanding racial disparities in pain care. Theoretical and clinical implications are discussed, and future research directions are outlined. [less ▲]

Racism and Racialisation as Structural Elements in Unfree Labour Formation in Brazilian Agriculture

Scientific Conference (2017)

Radial analysis and scaling of urban land use

in Scientific Reports (2021), (22044),

We determine the functional form and scaling law of radial artificial land use profiles in 300 European functional urban areas (FUAs). These profiles, starting from a fully artificial surface in the city ... [more ▼]

We determine the functional form and scaling law of radial artificial land use profiles in 300 European functional urban areas (FUAs). These profiles, starting from a fully artificial surface in the city center, decrease exponentially, the faster the smaller the city. More precisely, the characteristic decrease distance scales like the square root of total population, meaning that the artificial surface of cities is proportional to their population. This also means that the amount of artificial land per capita is independent of city size, and that larger cities are not more or less parsimonious in terms of land use than smaller ones. [less ▲]

Radial processes for sub-Riemannian Brownian motions and applications

in Electronic Journal of Probability (2020), 25(paper no. 97), 1-17

We study the radial part of sub-Riemannian Brownian motion in the context of totally geodesic foliations. Itô's formula is proved for the radial processes associated to Riemannian distances approximating ... [more ▼]

We study the radial part of sub-Riemannian Brownian motion in the context of totally geodesic foliations. Itô's formula is proved for the radial processes associated to Riemannian distances approximating the Riemannian one. We deduce very general stochastic completeness criteria for the sub-Riemannian Brownian motion. In the context of Sasakian foliations and H-type groups, one can push the analysis further, and taking advantage of the recently proved sub-Laplacian comparison theorems one can compare the radial processes for the sub-Riemannian distance to one-dimensional model diffusions. As a geometric application, we prove Cheng's type estimates for the Dirichlet eigenvalues of the sub-Riemannian metric balls, a result which seems to be new even in the Heisenberg group. [less ▲]

Radial Urban Forms: Lessons from Land Profile Scaling Analyses & Spatial-Explicit Models

Scientific Conference (2020, November 25)

We definitely live in an increasingly urban World for half of humanity now lives in cities. Cities provide wealth but also negatively impact the environment and the health of citizens. Arguably the ... [more ▼]

We definitely live in an increasingly urban World for half of humanity now lives in cities. Cities provide wealth but also negatively impact the environment and the health of citizens. Arguably the benefits and costs of cities relate to both their size, in population terms, and their internal structure, in terms of the relative spatial arrangement of built-up and natural land. Much of urban research focusses on very large cities and urban cores. Yet 3 urban human out of 4 live in cities of less than 4 million inhabitants (according to the global GHSL dataset). Similarly, 3 out of 4 in a typical (European) city do not live in its core but beyond (using a 7-8km radius to define core for a city like London or Paris). To address urban sustainability issues and design adaptation policies, these 75% certainly count and, we can argue, also deserve specific attention because of the relative proximity between urban and non-urban (natural) use that smaller cities and suburban (non-core) areas may permit. In this respect, it is key to understand how the internal structure of cities, in particular the form and density of built-up areas and the interwoven green space emerge out of the core up until the fringe. It is also key to understand whether the form of cities, especially density gradients and the share of urbanised/non-urbanised land change with city size. In this talk we draw lessons from 2 research approaches to urban forms: one theoretical that uses spatial micro-economic simulations, and one empirical that uses spatially detailed land use datasets. Our theoretical simulations relate individual behaviour to urban forms while our empirics relate urban forms to city size. Both have in common a radial perspective to cities, i.e. explicitly or implicitly assuming that the accessibility trade-off to a given centre is a key determinant of locations and land uses. In both cases, we look at urbanisation and green space structures and at pollution exposure as an example of impact. [less ▲]

Radical entanglement for elliptic curves

E-print/Working paper (2020)

Let G be a commutative connected algebraic group over a number field K, let A be a finitely generated and torsion-free subgroup of G(K) of rank r>0 and, for n>1, let K(n^{−1}A) be the smallest extension ... [more ▼]

Let G be a commutative connected algebraic group over a number field K, let A be a finitely generated and torsion-free subgroup of G(K) of rank r>0 and, for n>1, let K(n^{−1}A) be the smallest extension of K inside an algebraic closure K¯ over which all the points P∈G(K¯) such that nP∈A are defined. We denote by s the unique non-negative integer such that G(K¯)[n]≅(Z/nZ)s for all n≥1. We prove that, under certain conditions, the ratio between nrs and the degree [K(n^{−1}A):K(G[n])] is bounded independently of n>1 by a constant that depends only on the ℓ-adic Galois representations associated with G and on some arithmetic properties of A as a subgroup of G(K) modulo torsion. In particular we extend the main theorems of [13] about elliptic curves to the case of arbitrary rank [less ▲]

Radical intersubjectivity. Reflections on the "different" foundation of education.

in Studies in Philosophy and Education (1999), 18(4), 203-220