Linkage of Pfister forms over C(x1,…,xn)\mathbb{C}(x_1,\ldots,x_n)

In this note, we prove the existence of a set of $n$-fold Pfister forms of cardinality $2^n$ over $\mathbb{C}(x_1,\dots,x_n)$ which do not share a common $(n-1)$-fold factor. This gives a negative answer to a question raised by Becher. The main tools are the existence of the dyadic valuation on the complex numbers and recent results on symmetric bilinear over fields of characteristic 2

Une infrastructure logicielle pour instrumenter l'expérimentation des EIAH

International audienceCet article a pour objet de présenter une plate-forme logicielle développée dans le but de faciliter le travail des chercheurs dans la mise en place et la réalisation d'expérimentations dans le domaine des EIAH. Ce travail a été réalisé dans le cadre de l'action « Shared Virtual Lab » (SVL) du réseau d'excellence Kaleidoscope, et les outils ont été exploités pour la réalisation d'une expérimentation complexe mettant en oeuvre simultanément plusieurs EIAH développés au sein de l'équipe MeTAH du LIG. Le scénario décrivant l'activité des élèves et des enseignants impliqués dans l'expérimentation est décrit en langage LDL et interprété par la plate-forme. Les traces d'activité produites par les logiciels expérimentés et par la plate-forme sont centralisées dans une base de données XML. Elles ont été exploitées en temps réel par un outil de suivi destiné aux enseignants

AMGEN DRUM HANDLER: LIFTING & TILTING MECHANISM

Team Pick It Up & Put It Down was challenged to design the lifting and tilting portion of a device that will transport chemical-filled plastic barrels from a pallet located on the dirty” side of Amgen’s facilities airlock to another pallet located across a demarcation on the clean” side of the same airlock. This device must also allow for the required 10-minute cleaning process to occur. The device must be reliable, safe, and work in a timely manner to eliminate the current labor-intensive process of manually manipulating these barrels, which can weigh up to 250 pounds. Operation of this device must comply with the particulate standards for an ISO-8 class clean room environment. To meet the design requirements, the team completed thorough market research and review of the 2016-2017 design, assessing the best approach to solving Amgen’s problem. The team used market research and input from Amgen to identify design specifications necessary to develop an effective, quality product. Using brainstorming activities in tandem with patent and literature searches, 120 unique concepts were generated and judged based on their feasibility and effectiveness in solving the given challenge. After careful consideration with the assistance of engineering and concept analysis, it was determined that use of electronics, by means of an electric linear actuator is the most effective concept in eliminating human labor input and abiding by the cleanliness standards. The team worked closely with the University of Rhode Island’s Mechanical Engineering Capstone Team 8, who was challenged to develop the overall device design. Detailed engineering analysis along with side by side development, integrated the lifting and tilting mechanism into a viable concept that functions with the overall design. The team spent the duration of the spring semester building, testing, and redesigning the prototype. At this point in time, the team has effectively developed a product that reduces the physical human manipulation of cleaning the barrels. The clamping and bottom prong system successfully secures barrels during the tilting process when the barrel is correctly placed in contact with the prongs and upper clamp. The team accomplished building an integrated device that improves the safety of day-to-day drum handling and the efficiency of the physical drum positioning for cleaning

Discussions on "Riemann manifold Langevin and Hamiltonian Monte Carlo methods"

This is a collection of discussions of `Riemann manifold Langevin and Hamiltonian Monte Carlo methods" by Girolami and Calderhead, to appear in the Journal of the Royal Statistical Society, Series B.Comment: 6 pages, one figur

Preterminal host dendritic cells in irradiated mice prime CD8+ T cell–mediated acute graft-versus-host disease

To understand the relationship between host antigen-presenting cells (APCs) and donor T cells in initiating graft-versus-host disease (GVHD), we followed the fate of host dendritic cells (DCs) in irradiated C57BL/6 (B6) recipient mice and the interaction of these cells with minor histocompatibility antigen- (miHA-) mismatched CD8(+) T cells from C3H.SW donors. Host CD11c(+) DCs were rapidly activated and aggregated in the T cell areas of the spleen within 6 hours of lethal irradiation. By 5 days after irradiation, <1% of host DCs were detectable, but the activated donor CD8(+) T cells had already undergone as many as seven divisions. Thus, proliferation of donor CD8(+) T cells preceded the disappearance of host DCs. When C3H.SW donor CD8(+) T cells were primed in vivo in irradiated B6 mice or ex vivo by host CD11c(+) DCs for 24–36 hours, they were able to proliferate and differentiate into IFN-γ–producing cells in β(2)-microglobulin–deficient (β(2)m(–/–)) B6 recipients and to mediate acute GVHD in β(2)m(–/–) → B6 chimeric mice. These results indicate that, although host DCs disappear rapidly after allogeneic bone marrow transplantation, they prime donor T cells before their disappearance and play a critical role in triggering donor CD8(+) T cell–mediated GVHD

POV: Obama's ban on juvenile solitary confinement

Point of view article in BU Toda

Rapport du comité d'évaluation de la qualité de la recherche scientifique du CQRDA

Rapport d'évaluation de la qualité de la recherche scientifique à laquelle le CQRDA est associé, incluant une évaluation de l'exploitation des résultats des projets de recherche. Plus particulièrement, l'évaluation de la recherche scientifique devrait permettre d'illustrer la valeur des projets de recherche sur le plan scientifique ainsi que la valeur des experts et des chercheurs sollicités. Cette évaluation a porté sur les travaux couvant la période du 1er juin 2001 au 31 mai 2006