Jacobian varieties of genus 3 and the inverse Galois problem

Presentation (2015, September 11)

The inverse Galois problem, first addressed by D. Hilbert in 1892, asks which finite groups occur as the Galois group of a finite Galois extension K/Q. This question is encompassed in the general problem ... [more ▼]

The inverse Galois problem, first addressed by D. Hilbert in 1892, asks which finite groups occur as the Galois group of a finite Galois extension K/Q. This question is encompassed in the general problem of understanding the structure of the absolute Galois group G_Q of the rational numbers. A deep fact in arithmetic geometry is that one can attach compatible systems of Galois representations of GQ to certain arithmetic-geometric objects, (e.g. abelian varieties). These representations can be used to realise classical linear groups as Galois groups over Q. In this talk we will discuss the case of Galois representations attached to Jacobian varieties of genus n curves. For n = 3, we provide an explicit construction of curves C defined over Q such that the action of G_Q on the group of l-torsion points of the Jacobian of C provides a Galois realisation of GSp(6, l) for a prefixed prime l. This construction is a joint work with Cécile Armana, Valentijn Karemaker, Marusia Rebolledo, Lara Thomas and Núria Vila, and was initiated as a working group in the Conference Women in Numbers Europe (CIRM, 2013). [less ▲]

Jacobiennes de certaines courbes de genre 2 : torsion et simplicité

in Journal de Théorie des Nombres de Bordeaux (1995), 7

Jacques Derrida's religion with/out religion and the im/possibility of religious education

in Litchfield, R.G. (Ed.) Leading with hope.The Vocation of the Religious Educator. 2002 Proceedings of the Association of Professors and Researchers in Religious Education. (2002)

Jacques Derrida’s religion with/out religion and the im/possibility of religious education.

in Religious Education (2004), 99(1), 23-37

Jacques Fontanille, Soma et Séma, 2004

in RSSI : Recherches Sémiotiques = RSSI: Semiotic Inquiry (2004), 24(1-3), 299-317

Jahn-Teller, Polarity, and Insulator-to-Metal Transition in BiMnO3 at High Pressure

in Physical Review Letters (2014), 112

The interaction of coexisting structural instabilities in multiferroic materials gives rise to intriguing coupling phenomena and extraordinarily rich phase diagrams, both in bulk materials and strained ... [more ▼]

The interaction of coexisting structural instabilities in multiferroic materials gives rise to intriguing coupling phenomena and extraordinarily rich phase diagrams, both in bulk materials and strained thin films. Here we investigate the multiferroic BiMnO3 with its peculiar 6s2 electrons and four interacting mechanisms: electric polarity, octahedra tilts, magnetism, and cooperative Jahn-Teller distortion. We have probed structural transitions under high pressure by synchrotron x-ray diffraction and Raman spectroscopy up to 60 GPa. We show that BiMnO3 displays under pressure a rich sequence of five phases with a great variety of structures and properties, including a metallic phase above 53 GPa and, between 37 and 53 GPa, a strongly elongated monoclinic phase that allows ferroelectricity, which contradicts the traditional expectation that ferroelectricity vanishes under pressure. Between 7 and 37 GPa, the Pnma structure remains remarkably stable but shows a reduction of the Jahn-Teller distortion in a way that differs from the behavior observed in the archetypal orthorhombic Jahn-Teller distorted perovskite LaMnO3. [less ▲]

Jahrmärkte in Europa im 14.-16. Jahrhundert. Regionale Untersuchungen und der Versuch einer Typologie

in Irsigler, Franz; Pauly, Michel (Eds.) Messen, Jahrmärkte und Stadtentwicklung in Europa (2007)

Jak1 has a dominant role over Jak3 in signal transduction through γc-containing cytokine receptors

in Chemistry & Biology (2011), 18(3), 314-323

Genetic deficiency of Jak3 leads to abrogation of signal transduction through the common gamma chain (γc) and thus to immunodeficiency suggesting that specific inhibition of Jak3 kinase may result in ... [more ▼]

Genetic deficiency of Jak3 leads to abrogation of signal transduction through the common gamma chain (γc) and thus to immunodeficiency suggesting that specific inhibition of Jak3 kinase may result in immunosuppression. Jak1 cooperates with Jak3 in signaling through γc-containing receptors. Unexpectedly, a Jak3-selective inhibitor was less efficient in abolishing STAT5 phosphorylation than pan-Jak inhibitors. We therefore explored the roles of Jak1 and Jak3 kinase functionality in signaling using a reconstituted system. The presence of kinase-inactive Jak1 but not kinase-inactive Jak3 resulted in complete abolishment of STAT5 phosphorylation. Specific inhibition of the "analog-sensitive" mutant AS-Jak1 but not AS-Jak3 by the ATP-competitive analog 1NM-PP1 abrogated IL-2 signaling, corroborating the data with the selective Jak3 inhibitor. Jak1 thus plays a dominant role over Jak3 and these data challenge the notion that selective ATP-competitive Jak3 kinase inhibitors will be effective. © 2011 Elsevier Ltd. [less ▲]

JAK2 mutants (e.g., JAK2V617F) and their importance as drug targets in myeloproliferative neoplasms

in JAK-STAT (2013), 2(3), 25025

The Janus kinase 2 (JAK2) mutant V617F and other JAK mutants are found in patients with myeloproliferative neoplasms and leukemias. Due to their involvement in neoplasia and inflammatory disorders, Janus ... [more ▼]

The Janus kinase 2 (JAK2) mutant V617F and other JAK mutants are found in patients with myeloproliferative neoplasms and leukemias. Due to their involvement in neoplasia and inflammatory disorders, Janus kinases are promising targets for kinase inhibitor therapy. Several small-molecule compounds are evaluated in clinical trials for myelofibrosis, and ruxolitinib (INCB018424, Jakafi®) was the first Janus kinase inhibitor to receive clinical approval. In this review we provide an overview of JAK2V617F signaling and its inhibition by small-molecule kinase inhibitors. In addition, myeloproliferative neoplasms are discussed regarding the role of JAK2V617F and other mutant proteins of possible relevance. We further give an overview about treatment options with special emphasis on possible combination therapies. [less ▲]

Jaks and cytokine receptors - an intimate relationship

in Biochemical Pharmacology (2006), 72(11), 1538-46

Most cytokine receptors lack intrinsic kinase activity and many of them signal via Janus kinases (Jaks). These tyrosine kinases are associated with cytokine receptor subunits, they become activated upon ... [more ▼]

Most cytokine receptors lack intrinsic kinase activity and many of them signal via Janus kinases (Jaks). These tyrosine kinases are associated with cytokine receptor subunits, they become activated upon receptor triggering and subsequently activate downstream signalling events, e.g. the phosphorylation of STAT transcription factors. The successful interplay between cytokines, their receptors and the connected Jaks not only determines signalling competence but is also vital for intracellular traffic, stability, and fate of the cognate receptors. Here, we will discuss underlying mechanisms as well as some structural features with a focus on Jak1 and two of the signal transducing receptor subunits of interleukin (IL)-6 type cytokines, gp130 and OSMR. Regions that are critically involved in Jak-binding have been identified for many cytokine receptor subunits. In most cases the membrane-proximal parts comprising the box1 and box2 regions within the receptor are involved in this association while, within Jaks, the N-terminal FERM domain, possibly together with the SH2-like domain, are pivotal for binding to the relevant receptors. The exclusive membrane localisation of Jaks depends on their ability to associate with cytokine receptors. For gp130 and Jak1, it was shown that the cytokine receptor/Jak complex can be regarded as a receptor tyrosine kinase since both molecules have the same diffusion dynamics and are virtually undissociable. Furthermore, Jaks take an active role in the regulation of the surface expression of at least some cytokine receptors, including the OSMR and this may provide a quality control mechanism ensuring that only signalling-competent receptors (i.e. those with an associated Jak) would be enriched at the cell surface. [less ▲]