1,985 research outputs found

    Three puzzles about denominal adjectives in- EUX

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    French adjectives in- EUX (e.g., laiteux ‘milky’) usually have all the properties of true intersective adjectives. However, they sometimes behave like ordinary denominal adjectives e.g., presidential (no predication, no gradation, argument-saturating capacity). It is argued that this change is tied to the nature of the relationship between the base N ( lait in laiteux ) and the N which heads the NP the denominal adjective occurs in. Assuming that the denominal adjective’s semantics is equivalent to that of its base noun, three cases have to be distinguished. In the first one, the adjective functions as an argument of a predicate denoting an event and involving causal chaining, e.g., presidential trip . In the second one, the adjective is an argument of an event denoting predicate but the latter involves an internal causation instead of causal chaining, e.g., averse neigeuse ‘snowfall’. In the third, the relationship is based upon an internal link between the two nouns (e.g., pont dangereux ‘dangerous bridge’) and the A is intersective

    Functional analysis of the tomato Ve resistance locus against Verticillium wilt

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    Verticillium dahliae, V. albo-atrum and V. longisporum are soil-borne plant pathogens that are responsible for Verticillium wilt diseases in temperate and subtropical regions. Collectively they can infect over 200 hosts, including many economically important crops. Chapter 1 is a “pathogen profile” which describes the most important aspects of the biology of the Verticillium wilt pathogens. They colonize the xylem vessels of their host plants and cause symptoms such as wilting, chlorosis, stunting, necrosis and vein clearing. Verticillium species are notoriously difficult to control as there are no fungicides available to cure plants once they are infected. Therefore, genetic resistance is the preferred method for disease control. Chapter 2 describes the functional characterization of the tomato (Solanum lycopersicum) Ve locus. This locus is responsible for resistance against race 1 strains of V. dahliae and V. albo-atrum and comprises two closely linked inversely oriented genes, Ve1 and Ve2. Both genes encode cell surface receptor proteins of the extracellular leucine-rich repeat (eLRR) receptor-like protein (RLP) class of disease resistance proteins. In chapter 2, it is demonstrated that Ve1, but not Ve2, provides resistance in tomato against race 1 but not against race 2 strains of V. dahliae and V. albo-atrum. Using virus-induced gene silencing in tomato, the signaling cascade downstream of Ve1 was shown to require both EDS1 (enhanced disease susceptibility1) and NDR1 (non-race-specific disease resistance1). In addition, also NRC1 (NB-LRR protein required for hypersensitive response-associated cell death1), ACIF (Avr9/Cf-9–induced F-box1), MEK2 (MAP/ERK kinase2), and SERK3/BAK1 (somatic embryogenesis receptor kinase 3/brassinosteroid-associated kinase 1) act as positive regulators of Ve1 in tomato. In conclusion, Ve1-mediated resistance signaling only partially overlaps with signaling mediated by Cf proteins, type members of the eLRR-RLP-class of resistance proteins. In chapter 3 an attempt to introduce Nicotiana benthamiana as a model to facilitate the study of Ve1-mediated resistance is described. Challenge of wild type plants with several race 1 and race 2 strains of V. dahliae and V. albo-atrum demonstrated that N. benthamiana is susceptible to both Verticillium species. To obtain Verticillium wilt resistant plants, N. benthamiana was engineered to express the tomato Ve1 coding sequence. However, out of thirteen transgenic lines, six showed clear phenotypic aberrancies that included severe stunting and malformed leaves when compared to wild type plants. The seven Ve1-transgenic lines that did not show any phenotypic alterations were challenged with race 1 and race 2 strains. Although the pathogenicity assays indicated that in few lines Ve1 expression temporarily reduced disease development, most lines were as susceptible as wild type parental line. In conclusion, in chapter 3 it is demonstrated that the Ve1-transgenic N. benthamiana lines could not be used to study Ve1-mediated resistance signaling. In chapter 4, the use of Arabidopsis (Arabidopsis thaliana) as model to facilitate the study of Ve1-mediated resistance is presented. To this end, tomato Ve1 was expressed in susceptible Arabidopsis plants. Upon challenge with race 1 strains of V. dahliae or V. albo-atrum, Ve1-expressing plants were found to be resistant. In contrast, Ve1-expressing plants were susceptible to race 2 strains of both V. dahliae and V. albo-atrum. Furthermore, expression of Ve1 in Arabidopsis plants did not prevent colonization by V. longisporum strains. Through Ve1-expression in Arabidopsis defense signaling mutants, it was demonstrated that signaling downstream of Ve1 is highly conserved between tomato and Arabidopsis. In previous chapters it was shown that the receptor kinase SERK3/BAK1 is required for Ve1-mediated resistance in tomato as well as in Arabidopsis. In Arabidopsis, SERK3/BAK1 belongs to a gene family consisting of five members. In chapter 5, the requirement of the different SERK family members in Ve1-mediated resistance in Arabidopsis is investigated, revealing the requirement of SERK1 and, although to a lesser extent, SERK4 for resistance. Using virus-induced gene silencing, it was subsequently shown that SERK1 is also required for Ve1-mediated resistance in tomato. In conclusion, the results of chapter 5 demonstrate that Arabidopsis can be used as model to unravel the molecular mechanisms of Ve1-mediated resistance. In chapter 6, the recognition specificity of Ve1 was further investigated by performing domain-swaps with Ve2 and expressing the chimeric Ve proteins in Arabidopsis. Various domain swaps in which eLRRs from Ve1 were replaced by those of Ve2 suggest that the region between eLRR22 and eLRR35 is required for full Ve1-mediated resistance. However, plants expressing a Ve chimera in which eLRR1 to eLRR30 of Ve1 was replaced with those of Ve2 were resistant against Verticillium. Overall, these results suggest that Ve2 may still bind the elicitor in the eLRR domain, but its C-terminal domain is not able to activate a successful defense response. Finally in Chapter 7, highlights of this thesis are discussed and placed in a broader perspective. </p

    Maria Schneider’s Voicing Techniques: Annotated Bibliography

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    Since her emergence on the jazz scene, Maria Schneider has made a name for herself all around the world with her unique compositional voice. Despite her ever-increasing prominence and influence as a jazz composer, there is a startling lack of scholarly work on how she writes for her ensemble. It is my aim to begin to fill that gap by examining how she voices chords at critical moments in her pieces and juxtaposing the techniques in her earliest works, latest works, and traditional writing techniques

    GÉNÉTIQUE ET ÉPIGÉNÉTIQUE DU COMPORTEMENT SOCIAL

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    International audienc

    Aging and DNA methylation

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    International audienc

    EXPLORATION DES FONCTIONS IMMUNOSUPPRESSIVES DES ARN NON CODANTS CONTENUS DANS LES EXOSOMES DU MÉLANOME

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    National audienc

    Characterizing anomalous diffusion in crowded polymer solutions and gels over five decades in time with variable-lengthscale fluorescence correlation spectroscopy

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    The diffusion of macromolecules in cells and in complex fluids is often found to deviate from simple Fickian diffusion. One explanation offered for this behavior is that molecular crowding renders diffusion anomalous, where the mean-squared displacement of the particles scales as ⟹r2⟩∝tα\langle r^2 \rangle \propto t^{\alpha} with α<1\alpha < 1. Unfortunately, methods such as fluorescence correlation spectroscopy (FCS) or fluorescence recovery after photobleaching (FRAP) probe diffusion only over a narrow range of lengthscales and cannot directly test the dependence of the mean-squared displacement (MSD) on time. Here we show that variable-lengthscale FCS (VLS-FCS), where the volume of observation is varied over several orders of magnitude, combined with a numerical inversion procedure of the correlation data, allows retrieving the MSD for up to five decades in time, bridging the gap between diffusion experiments performed at different lengthscales. In addition, we show that VLS-FCS provides a way to assess whether the propagator associated with the diffusion is Gaussian or non-Gaussian. We used VLS-FCS to investigate two systems where anomalous diffusion had been previously reported. In the case of dense cross-linked agarose gels, the measured MSD confirmed that the diffusion of small beads was anomalous at short lengthscales, with a cross-over to simple diffusion around ≈1 Ό\approx 1~\mum, consistent with a caged diffusion process. On the other hand, for solutions crowded with marginally entangled dextran molecules, we uncovered an apparent discrepancy between the MSD, found to be linear, and the propagators at short lengthscales, found to be non-Gaussian. These contradicting features call to mind the "anomalous, yet Brownian" diffusion observed in several biological systems, and the recently proposed "diffusing diffusivity" model

    Microscopic measurement of the linear compressibilities of two-dimensional fatty acid mesophases

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    The linear compressibility of two-dimensional fatty acid mesophases has determined by grazing incidence x-ray diffraction. Surface pressure vs molecular area isotherms were reconstructed from these measurements, and the linear compressibility (relative distortion along a given direction for isotropic applied stress) was determined both in the sample plane and in a plane normal to the aliphatic chain director (transverse plane). The linear compressibilities range over two orders of magnitude from 0.1 to 10 m/N and are distributed depending on their magnitude in 4 different sets which we are able to associate with different molecular mechanisms. The largest compressibilities (10m/N) are observed in the tilted phases. They are apparently independent of the chain length and could be related to the reorganization of the headgroup hydrogen-bounded network, whose role should be revalued. Intermediate compressibilities are observed in phases with quasi long-range order (directions normal to the molecular tilt in L_2 or L_2' phases, S phase), and could be related to the ordering of these phases. The lowest compressibilities are observed in the solid untilted CS phase and for 1 direction of the S and L_2'' phases. They are similar to the compressibility of crystalline polymers and correspond to the interactions between methyl groups in the crystal. Finally, negative compressibilities are observed in the transverse plane for L_2' and L_2'' phases and can be traced to subtle reorganizations upon untilting.Comment: 24 pages, 17 figure

    Multiple Quantum Well AlGaAs Nanowires

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    This letter reports on the growth, structure and luminescent properties of individual multiple quantum well (MQW) AlGaAs nanowires (NWs). The composition modulations (MQWs) are obtained by alternating the elemental flux of Al and Ga during the molecular beam epitaxy growth of the AlGaAs wire on GaAs (111)B substrates. Transmission electron microscopy and energy dispersive X-ray spectroscopy performed on individual NWs are consistent with a configuration composed of conical segments stacked along the NW axis. Micro-photoluminescence measurements and confocal microscopy showed enhanced light emission from the MQW NWs as compared to non-segmented NWs due to carrier confinement and sidewall passivation
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