Search results for "TCR"
showing 10 items of 157 documents
Flow and Deformation
1998
A hunter who investigates tracks in muddy ground near a waterhole may be able to reconstruct which animals arrived last, but older tracks will be partly erased or modified. A geologist faces similar problems to reconstruct the changes in shape that a volume of rock underwent in the course of geological time, since the end products, the rocks that are visible in outcrop, are the only direct data source. In many cases it is nevertheless possible to reconstruct at least part of the tectonic history of a rock from this final fabric. This chapter treats the change in shape of rocks and the methods that can be used to investigate and describe this change in shape. This is the field of kinematics,…
The evolutionary history of the Arabidopsis arenosa complex: diverse tetraploids mask the Western Carpathian center of species and genetic diversity.
2012
The Arabidopsis arenosa complex is closely related to the model plant Arabidopsis thaliana. Species and subspecies in the complex are mainly biennial, predominantly outcrossing, herbaceous, and with a distribution range covering most parts of latitudes and the eastern reaches of Europe. In this study we present the first comprehensive evolutionary history of the A. arenosa species complex, covering its natural range, by using chromosome counts, nuclear AFLP data, and a maternally inherited marker from the chloroplast genome [trnL intron (trnL) and trnL/F intergenic spacer (trnL/F-IGS) of tRNA(Leu) and tRNA(Phe), respectively]. We unravel the broad-scale cytogeographic and phylogeographic pa…
Synsedimentary-tectonic, soft-sediment deformation and volcanism in the rifted Tethyan margin from the Upper Triassic–Middle Jurassic deep-water carb…
2014
Abstract The Pizzo Lupo section (Sicanian Mts, central Sicily) is an Upper Triassic–Lower Jurassic condensed deep-water succession, where the relationships among synsedimentary tectonic, soft-sediment deformations, volcanism and lithological changes reflect the evolution of a rift-basin. The morphostructural setting of the studied basin appears as a gently dipping slope where a fault-delimited area (graben to halfgraben) was developed. The instability of the sea floor, related to the seismic shocks, was the cause of the gravity-driven deformational sedimentary structures (slumping, breccia channelized bodies). The partly stratified basaltic rocks, with disorganized and chaotic stratificatio…
T Cells Integrate Local and Global Cues to Discriminate between Structurally Similar Antigens
2015
International audience; T lymphocytes' ability to discriminate between structurally related antigens has been attributed to the unique signaling properties of the T cell receptor. However, recent studies have suggested that the output of this discrimination process is conditioned by environmental cues. Here, we demonstrate how the IL-2 cytokine, collectively generated by strongly activated T cell clones, can induce weaker T cell clones to proliferate. We identify the PI3K pathway as being critical for integrating the antigen and cytokine responses and for controlling cell-cycle entry. We build a hybrid stochastic/deterministic computational model that accounts for such signal synergism and …
Specialized subsets of innate-like T cells and dendritic cells protect from lethal pneumococcal infection in the lung
2021
SummaryInnate-like T cells, including invariant natural killer T (iNKT) cells, mucosal-associated invariant T (MAIT) cells and γδ T cells, are present in various barrier tissues, including the lung. They carry out protective responses during infections, but the mechanisms for protection are not completely understood. Here, we investigated their roles during pulmonary infection with Streptococcus pneumoniae. Following infection, innate-like T cells rapidly increased in lung tissue, in part through recruitment, but TCR activation and cytokine production occurred mostly in IL-17-producing NKT17 and γδ T cells. NKT17 cells were preferentially located outside the vasculature prior to infection, …
Early Cretaceous termites in amber from northern Spain (Isoptera)
2020
Abstract Two virtually complete termites in Lower Cretaceous amber from the Penacerrada I outcrop, Spain, are described and figured, representing the most well-preserved Isoptera yet discovered from the Albian stage. The material is described as Ithytermes montoyai gen. et sp. nov., and is similar in many details to the slightly younger Krishnatermes yoddha Engel, Barden, and Grimaldi from northern Myanmar amber. Given the presence of distinct soldiers in this grade of Cretaceous termites, it is likely that I. montoyai also exhibited such a tripartite caste system. In addition to the type material of I. montoyai, two fragmentary termites are recorded for the first time in Albian amber from …
3D visualization of sheath folds in Ancient Roman marble wall coverings from Ephesos, Turkey
2014
Abstract Archaeological excavations and restoration of a palatial Roman housing complex in Ephesos, Turkey yielded 40 wall-decorating plates of folded mylonitic marble (Cipollino verde), derived from the internal Hellenides near Karystos, Greece. Cipollino verde was commonly used for decoration purposes in Roman buildings. The plates were serial-sectioned from a single quarried block of 1,25 m3 and provided a research opportunity for detailed reconstruction of the 3D geometry of meterscale folds in mylonitized marble. A GOCAD model is used to visualize the internal fold structures of the marble, comprising curtain folds and multilayered sheath folds. The sheath folds are unusual in that the…
Secret versus public reserve price in an “outcry” English procurement auction: Experimental results
2015
Abstract In a set of human experiments, we analyze the impact of the buyer׳s reserve price policy in an online open outcry reverse auction. We measure the impact of revealing or not the reserve price on the buyer׳s expected cost when suppliers may be risk-averse. Results confirm that the optimal public reserve price policy dominates for the buyer when the lowest cost supplier is weakly risk-averse but in contrast with theory, the secret reserve price policy does not dominate when he becomes very risk-averse. Analysis of strategic suppliers׳ bidding behavior shows, in conformity with theory, that they react to the secret reserve price and are more aggressive when they are more risk-averse. T…
Middle to Upper Pleistocene morphostructural evolution of the NW-coast of Sicily: thermoluminescence dating and palaeontological-stratigraphical eval…
1997
Abstract Infralittoral and terrigenous Middle to Upper Pleistocene deposits outcropping at the NW-coast of Sicily (Gulf of Castellammare and peninsula of Capo San Vito) were investigated in order to recognise glacio-eustatically caused sea level highstands and the interference between tectonics, eustasy and local conditions of the coast. The results, originating from a stratigraphically important area, were obtained by palaeontological-stratigraphical analyses, physical age determination with the thermoluminescence method and by detailed morphostructural studies. The marine deposits, situated at 3–40 m a.s.l., mainly provide an oligotypic molluscan fauna referable to modern SGCF-, SFHN- and…
The Phycosiphon record in the Ladrilleros-Juanchaco section (Miocene, Colombian Pacific): palaeoecological implications
2018
Miocene rocks of the Ladrilleros-Juanchaco section, located on the NW margin of South America, contain a high diverse and abundant trace fossil assemblage. The relative abundance of Phycosiphon, together with its morphological variations, provides new insights into the environmental conditions. Detailed outcrop stratigraphic, ichnological, and geochemical analyses carried out in the section focused on the trace fossil assemblages (distribution, relative abundance), ichnofabric index, and, especially, in the general ichnological features of Phycosiphon . In addition, the detailed photographic documentation and the use of the digital image treatment technique facilitate the precise study of …