| 1. |
- Airaud, M, et al.
(författare)
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Biologie - Les manuels visuels pour la Licence
- 2018
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- En couleurs et très illustré, ce manuel a été conçu pour vous qui débutez un cursus scientifique universitaire. Il vous permettra d’acquérir les connaissances fondamentales en biologie, mais aussi la démarche et la rigueur scientifiques indispensables aux études supérieures. De multiples rubriques vous garantissent un apprentissage progressif et complet : un cours visuel avec de nombreux exemples concrets pour introduire et illustrer les notions et concepts clés ; des encadrés méthodologiques pour vous guider vers les bonnes pratiques et vous faire découvrir les grandes méthodes expérimentales ; des focus sur des applications, sujets de recherche ou thèmes d’actualité ; des repères historiques ; de nombreux QCM et exercices (tous corrigés) pour tester vos acquis et vous entraîner.
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| 2. |
- Lelièvre, E.C., et al.
(författare)
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Ptf1a/Rbpj complex inhibits ganglion cell fate and drives the specification of all horizontal cell subtypes in the chick retina
- 2011
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Ingår i: Developmental Biology. - : Elsevier BV. - 0012-1606 .- 1095-564X. ; 358:2, s. 296-308
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Tidskriftsartikel (refereegranskat)abstract
- During development, progenitor cells of the retina give rise to six principal classes of neurons and the Müller glial cells found within the adult retina. The pancreas transcription factor 1 subunit a (Ptf1a) encodes a basic-helix–loop–helix transcription factor necessary for the specification of horizontal cells and the majority of amacrine cell subtypes in the mouse retina. The Ptf1a-regulated genes and the regulation of Ptf1a activity by transcription cofactors during retinogenesis have been poorly investigated. Using a retrovirus-mediated gene transfer approach, we reported that Ptf1a was sufficient to promote the fates of amacrine and horizontal cells from retinal progenitors and inhibit retinal ganglion cell and photoreceptor differentiation in the chick retina. Both GABAergic H1 and non-GABAergic H3 horizontal cells were induced following the forced expression of Ptf1a. We describe Ptf1a as a strong, negative regulator of Atoh7 expression. Furthermore, the Rbpj-interacting domains of Ptf1a protein were required for its effects on cell fate specification. Together, these data provide a novel insight into the molecular basis of Ptf1a activity on early cell specification in the chick retina.
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| 3. |
- Aebersold, M. A., et al.
(författare)
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Spin density maps in the triplet ground state of Cu-2(t-Bupy)(4)(N-3)(2) (ClO4)(2) (t-bupy = p-tert-butylpyridine): A polarized neutron diffraction study
- 1998
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Ingår i: Journal of the American Chemical Society. ; 120:21, s. 5238-5245
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Tidskriftsartikel (refereegranskat)abstract
- This paper is devoted to the determination of the spin distribution in the spin triplet ground state of [Cu-2(t-Bupy)(4)(N-3)(2)](ClO4)(2), With t-Bupy = p-tert-butylpyridine. The crystal structure, previously solved at room temperature from X-ray diffraction, has been redetermined at 18 K from unpolarized neutron diffraction. The structure consists of binuclear cations in which Cu2+ ions are doubly bridged by azido groups in the 1,1-fashion, and noncoordinated perchlorate anions. The experimental spin distribution has been determined from polarized neutron diffraction (PND) at 1.6 K under 50 kOe. The spin populations have been found to be strongly positive on the Cu2+ ions, weakly positive on the terminal and bridging nitrogen atoms of the azido groups as well as on the nitrogen atoms of the t-Bupy ligands, and weakly negative on the central nitrogen atoms of the N-3(-) bridges. The PND results have been discussed. The spin distribution in [Cu-2(t-Bupy)(4)(N-3)2](ClO4)(2) has been analyzed as resulting from a spin delocalization from the Cu2+ ions toward the azido bridges, to which a spin polarization effect within the azido pi orbitals is superimposed. The experimental data have been compared to the results of DFT calculations. The spin density map is qualitatively reproduced; however, the DFT calculations overestimate the spin delocalization from the Cu2+ ions toward the peripheral and bridging ligands.
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| 6. |
- DiJulio, Douglas, et al.
(författare)
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Optimization of multi-channel neutron focusing guides for extreme sample environments
- 2014
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Ingår i: International Workshop on Neutron Optics and Detectors (NOP&D 2013) 2–5 July 2013, Munich, Germany. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 528, s. 012006-012006
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Konferensbidrag (refereegranskat)abstract
- In this work, we present and discuss simulation results for the design of multi-channel neutron focusing guides for extreme sample environments. A single focusing guide consists of any number of supermirror-coated curved outer channels surrounding a central channel. Furthermore, a guide is separated into two sections in order to allow for extension into a sample environment. The performance of a guide is evaluated through a Monte-Carlo ray tracing simulation which is further coupled to an optimization algorithm in order to find the best possible guide for a given situation. A number of population-based algorithms have been investigated for this purpose. These include particle-swarm optimization, artificial bee colony, and differential evolution. The performance of each algorithm and preliminary results of the design of a multi-channel neutron focusing guide using these methods are described. We found that a three-channel focusing guide offered the best performance, with a gain factor of 2.4 compared to no focusing guide, for the design scenario investigated in this work.
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