33 research outputs found
Tailoring the ferromagnetic surface potential landscape by a templating two-dimensional metal-organic porous network
Two-dimensional metal-organic porous networks (2D-MOPNs) have been identified
as versatile nanoarchitectures to tailor surface electronic and magnetic
properties on noble metals. In this context, we propose a protocol to
redecorate a ferromagnetic surface potential landscape using a 2D-MOPN.
Ultrathin cobalt (Co) films grown on Au(111) exhibit a well-ordered surface
triangular reconstruction. On the ferromagnetic surface, the adsorbed
2,4,6-tris(4-pyridyl)-1,3,5triazine (T4PT) molecules can coordinate with the
native Co atoms to form a large-scale Co-T4PT porous network. The Co-T4PT
network with periodic nanocavities serves as a templating layer to reshape the
ferromagnetic surface potential. The subsequently deposited C60 molecules are
steered by the network porous potential and the neighboring C60 interactions.
The prototype of the ferromagnetic-supported 2D-MOPN is a promising template
for the tailoring of molecular electronic and spin properties
Prospectus, July 23, 1991
https://spark.parkland.edu/prospectus_1991/1010/thumbnail.jp
Staphylococcal Peptidoglycan Co-Localizes with Nod2 and TLR2 and Activates Innate Immune Response via Both Receptors in Primary Murine Keratinocytes
In mammalian host cells staphylococcal peptidoglycan (PGN) is recognized by Nod2. Whether PGN is also recognized by TLR2 is disputed. Here we carried out PGN co-localization and stimulation studies with TLR2 and Nod2 in wild type and mutant host cells. To exclude contamination with lipoproteins, polymeric staphylococcal PGN (PGNpol) was isolated from Staphylococcus aureus Îlgt (lacking lipidated prelipoproteins). PGNpol was biotinylated (PGN-Bio) for fluorescence monitoring with specific antibodies. Keratinocytes from murine oral epithelium (MK) readily internalized PGN-Bio in an endocytosis-like process. In wt MK, PGNpol induced intracellular accumulation of Nod2 and TLR2 and co-localized with Nod2 and TLR2, but not with TLR4. In TLR2-deficient MK Nod2 and in Nod2-deficient MK TLR2 was induced, indicating that PGNpol recognition by Nod2 is independent of TLR2 and vice versa. In both mutants IL-6 and IL-1B release was decreased by approximately 50% compared to wt MK, suggesting that the immune responses induced by Nod2 and TLR2 are comparable and that the two receptors act additively in MK. In TLR2-tranfected HEK293 cells PGNpol induced NFkB-promoter fused luciferase expression. To support the data, co-localization and signaling studies were carried out with SHL-PGN, a lipase protein covalently tethered to PGN-fragments of varying sizes at its C-terminus. SHL-PGN also co-localized with Nod2 or TLR2 and induced their accumulation, while SHL without PGN did not. The results show that staphylococcal PGN not only co-localizes with Nod2 but also with TLR2. PGN is able to stimulate the immune system via both receptors
Competing signatures of intersite and interlayer spin transfer in the ultrafast magnetization dynamics
Optically driven intersite and interlayer spin transfer are individually
known as the fastest processes for manipulating the spin order of magnetic
materials on the sub 100 fs time scale. However, their competing influence on
the ultrafast magnetization dynamics remains unexplored. In our work, we show
that optically induced intersite spin transfer (also known as OISTR) dominates
the ultrafast magnetization dynamics of ferromagnetic alloys such as Permalloy
(Ni80Fe20) only in the absence of interlayer spin transfer into a substrate.
Once interlayer spin transfer is possible, the influence of OISTR is
significantly reduced and interlayer spin transfer dominates the ultrafast
magnetization dynamics. This provides a new approach to control the
magnetization dynamics of alloys on extremely short time scales by fine-tuning
the interlayer spin transfer
Death and the Societies of Late Antiquity
Ce volume bilingue, comprenant un ensemble de 28 contributions disponibles en français et en anglais (dans leur version longue ou abrĂ©gĂ©e), propose dâĂ©tablir un Ă©tat des lieux des rĂ©flexions, recherches et Ă©tudes conduites sur le fait funĂ©raire Ă lâĂ©poque tardo-antique au sein des provinces de lâEmpire romain et sur leurs rĂ©gions limitrophes, afin dâouvrir de nouvelles perspectives sur ses Ă©volutions possibles. Au cours des trois derniĂšres dĂ©cennies, les transformations considĂ©rables des mĂ©thodologies dĂ©ployĂ©es sur le terrain et en laboratoire ont permis un renouveau des questionnements sur les populations et les pratiques funĂ©raires de lâAntiquitĂ© tardive, pĂ©riode marquĂ©e par de multiples changements politiques, sociaux, dĂ©mographiques et culturels. Lâapparition de ce qui a Ă©tĂ© initialement dĂ©signĂ© comme une « Anthropologie de terrain », qui fut le dĂ©but de la dĂ©marche archĂ©othanatologique, puis le rĂ©cent dĂ©veloppement dâapproches collaboratives entre des domaines scientifiques divers (archĂ©othanatologie, biochimie et gĂ©ochimie, gĂ©nĂ©tique, histoire, Ă©pigraphie par exemple) ont Ă©tĂ© dĂ©cisives pour le renouvellement des problĂ©matiques dâĂ©tude : rĂ©vision dâanciens concepts comme apparition dâaxes dâanalyse inĂ©dits. Les recherches rassemblĂ©es dans cet ouvrage sont articulĂ©es autour de quatre grands thĂšmes : lâĂ©volution des pratiques funĂ©raires dans le temps, lâidentitĂ© sociale dans la mort, les ensembles funĂ©raires en transformation (organisation et topographie) et les territoires de lâempire (du cĆur aux marges). Ces Ă©tudes proposent un rĂ©examen et une rĂ©vision des donnĂ©es, tant anthropologiques quâarchĂ©ologiques ou historiques sur lâAntiquitĂ© tardive, et rĂ©vĂšlent, Ă cet Ă©gard, une mosaĂŻque de paysages politiques, sociaux et culturels singuliĂšrement riches et complexes. Elles accroissent nos connaissances sur le traitement des dĂ©funts, lâemplacement des aires funĂ©raires ou encore la structure des sĂ©pultures, en rĂ©vĂ©lant une diversitĂ© de pratiques, et permettent au final de relancer la rĂ©flexion sur la maniĂšre dont les sociĂ©tĂ©s tardo-antiques envisagent la mort et sur les Ă©lĂ©ments permettant dâidentifier et de dĂ©finir la diversitĂ© des groupes qui les composent. Elles dĂ©montrent ce faisant que nous pouvons vĂ©ritablement apprĂ©hender les structures culturelles et sociales des communautĂ©s anciennes et leurs potentielles transformations, Ă partir de lâĂ©tude des pratiques funĂ©raires.This bilingual volume proposes to draw up an assessment of the recent research conducted on funerary behavior during Late Antiquity in the provinces of the Roman Empire and on their borders, in order to open new perspectives on its possible developments. The considerable transformations of the methodologies have raised the need for a renewal of the questions on the funerary practices during Late Antiquity, a period marked by multiple political, social, demographic and cultural changes. The emergence field anthropology, which was the beginning of archaeothanatology, and then the recent development of collaborative approaches between various scientific fields (archaeothanatology, biochemistry and geochemistry, genetics, history, epigraphy, for example), have been decisive. The research collected in this book is structured around four main themes: Evolution of funerary practices over time; Social identity through death; Changing burial grounds (organisation and topography); Territories of the Empire (from the heart to the margins). These studies propose a review and a revision of the data, both anthropological and archaeological or historical on Late Antiquity, and reveal a mosaic of political, social, and cultural landscapes singularly rich and complex. In doing so, they demonstrate that we can truly understand the cultural and social structures of ancient communities and their potential transformations, based on the study of funerary practices
Global urban environmental change drives adaptation in white clover
Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale
DĂ©velopper la coopĂ©ration au cycle 2 en jouant⊠et en sâĂ©valuant
Professorat des Ă©colesNotre mĂ©moire est avant tout un dĂ©fi ! DĂ©fi, car il a lâambition de dĂ©velopper la coopĂ©ration dans une classe de CP-CE1âŠĂ travers un jeu de balle. LâexpĂ©rience fut passionnante dans la mesure oĂč la sĂ©quence mise en place a permis de voir naĂźtre des stratĂ©gies de coopĂ©ration dâune part, mais Ă©galement parce quâelle a rĂ©ellement permis dâassocier lâĂ©lĂšve au processus dâĂ©valuation, et donc de constater leur enthousiasme pour le jeu proposĂ©, ainsi que leur volontĂ© de progresser. Le dĂ©fi est donc bien relevĂ©, et nous pouvons affirmer quâil est parfaitement possible de dĂ©velopper lâesprit de coopĂ©ration Ă partir du cycle des apprentissages fondamentaux Ă condition toutefois dâĂȘtre Ă lâĂ©coute des enfants