Search results for "Polar"
showing 10 items of 3817 documents
The differentiation of the serotonergic neurons in the Drosophila ventral nerve cord depends on the combined function of the zinc finger proteins Eag…
1997
ABSTRACT The Drosophila ventral nerve cord (vNC) derives from a stereotyped population of neural stem cells, neuroblasts (NBs), each of which gives rise to a characteristic cell lineage. The mechanisms leading to the specification and differentiation of these lineages are largely unknown. Here we analyse mechanisms leading to cell differentiation within the NB 7-3 lineage. Analogous to the grasshopper, NB 7-3 is the progenitor of the Drosophila vNC serotonergic neurons. The zinc finger protein Eagle (Eg) is expressed in NB 7-3 just after delamination and is present in all NB 7-3 progeny until late stage 17. DiI cell lineage tracing and immunocytochemistry reveal that eg is required for norm…
3D digitization of transparent objects by polalization techniques in IR & by triangulation in UV
2011
Two non-conventional methods for the 3D digitization of transparent objects via non-contact measurement are reported in this thesis. 3D digitization is a well acknowledged technique for opaque objects and various commercial solutions based on different measurement approaches are available in the market offering different types of resolution at different prices. Since these techniques require a diffused or lambertian surface, their application to transparent surfaces fails. Indeed, rays reflected by the transparent surface are perturbed by diverse inter-reflections induced by the refractive properties of the object. Therefore, in industrial applications like quality control, the transparent …
Polarographische Untersuchungen an monomeren und polymeren N-Chlorcarbonamiden
1979
The polarographic reduction of low molecular and high molecular N-chlorocarboxamides at the dropping mercury electrode proceeds in two one-electron-transfer steps, which are highly irreversible. In the case of the low molecular models 1 and 2 the reaction is diffusion-controlled, whereas in the case of the poly(N-chloroamide) 3 the reaction is adsorption-controlled. Reduction of several poly(N-chloroamide)s shows always two reduction waves with a distance of 0,5 V. There is, however, no relation between the polyamide-type and the position of the half-wave potentials. The polarographic reduction can be used as an analytical method for quantitative determination of N-chlorocarboxamide groups …
Tinkering and Evolution
2015
Jacob is one of the fathers of modern Biology, and in his monumental work The Logic of Life he recounts the polarity that has always existed in biological science between analytical and synthetic traditions, between reductionism and holism . Interestingly, however, although he is a model example of the reductionist tradition and one of the fathers of Molecular Biology, Jacob does not rule out the possibility of emergent properties.
A new multimodal RGB and polarimetric image dataset for road scenes analysis
2020
International audience; Road scene analysis is a fundamental task for both autonomous vehicles and ADAS systems. Nowadays, one can find autonomous vehicles that are able to properly detect objects present in the scene in good weather conditions but some improvements are left to be done when the visibility is altered. People claim that using some non conventional sensors (infra-red, Lidar, etc.) along with classical vision enhances road scene analysis but still when conditions are optimal. In this work, we present the improvements achieved using polarimetric imaging in the complex situation of adverse weather conditions. This rich modality is known for its ability to describe an object not o…
Mapping of landfills using time-domain spectral induced polarization data: the Eskelund case study
2012
This study uses time-domain induced polarization data for the delineation and characterization of the former landfill site at Eskelund, Denmark. With optimized acquisition parameters combined with a new inversion algorithm, we use the full content of the decay curve and retrieve spectral information from time-domain IP data. Thirteen IP/DC profiles were collected in the area, supplemented by el-log drilling for accurate correlation between the geophysics and the lithology. The data were inverted using a laterally constrained 1D inversion considering the full decay curves to retrieve the four Cole-Cole parameters. For all profiles, the results reveal a highly chargeable unit that shows a ver…
Critical Regulation of Early Th17 Cell Differentiation by Interleukin-1 Signaling
2009
SummaryT helper (Th) 17 cells have been recently discovered in both mouse and human. Here we show that interleukin-1 (IL-1) signaling on T cells is critically required for the early programming of Th17 cell lineage and Th17 cell-mediated autoimmunity. IL-1 receptor1 expression in T cells, which was induced by IL-6, was necessary for the induction of experimental autoimmune encephalomyelitis and for early Th17 cell differentiation in vivo. Moreover, IL-1 signaling in T cells was required in dendritic cell-mediated Th17 cell differentiation from naive or regulatory precursors and IL-1 synergized with IL-6 and IL-23 to regulate Th17 cell differentiation and maintain cytokine expression in effe…