On the symplectic eightfold associated to a Pfaffian cubic fourfold

We show that the irreducible holomorphic symplectic eightfold Z associated to a cubic fourfold Y not containing a plane is deformation-equivalent to the Hilbert scheme of four points on a K3 surface. We do this by constructing for a generic Pfaffian cubic Y a birational map Z ---> Hilb^4(X), where X is the K3 surface associated to Y by Beauville and Donagi. We interpret Z as a moduli space of complexes on X and observe that at some point of Z, hence on a Zariski open subset, the complex is just the ideal sheaf of four points.Comment: 9 pages. Minor changes; to appear in Crelle as an appendix to 1305.017

Vertex Operators, Grassmannians, and Hilbert Schemes

We describe a well-known collection of vertex operators on the infinite wedge representation as a limit of geometric correspondences on the equivariant cohomology groups of a finite-dimensional approximation of the Sato grassmannian, by cutoffs in high and low degrees. We prove that locality, the boson-fermion correspondence, and intertwining relations with the Virasoro algebra are limits of the localization expression for the composition of these operators. We then show that these operators are, almost by definition, the Hilbert scheme vertex operators defined by Okounkov and the author in \cite{CO} when the surface is $\mathbb{C}^2$ with the torus action $z\cdot (x,y) = (zx,z^{-1}y)$.Comment: 20 pages, 0 figure

Proceedings of the Spacecraft Charging Technology Conference: Executive Summary

Aerospace environments are reviewed in reference to spacecraft charging. Modelling, a theoretical scheme which can be used to describe the structure of the sheath around the spacecraft and to calculate the charging currents within, is discussed. Materials characterization is considered for experimental determination of the behavior of typical spacecraft materials when exposed to simulated geomagnetic substorm conditions. Materials development is also examined for controlling and minimizing spacecraft charging or at least for distributing the charge in an equipotential manner, using electrical conductive surfaces for materials exposed to space environment

Synthesis and transfection properties of a series of lipidic neamine derivatives

International audienceWith the view to develop novel bioinspired nonviral vectors for gene delivery, we synthesized a series of cationiclipids with a neamine headgroup, which incorporates rings I and II of the natural antibiotic aminoglycoside neomycin B. Indeed, we reasoned that neamine might constitute a straightforward and versatile building block for synthesizing a variety of lipophilic aminoglycosides and modulating their characteristics such as size, topology, lipophilicity, number of charges, and charge density. Neamine derivatives bearing long dialkyl chains, one or two neamine headgroups, and four to ten protonatable amine functions were prepared through the selective alkylation of the 4′- or 5-hydroxyl function in ring I and ring II of neamine, respectively. The transfection activity of the twelve derivatives synthesized was investigated in Vitro in gene transfection experiments using several mammalian cell lines. The results allowed us to unveil interesting structure-activity relationships and to identify a formulation incorporating a small neamine derivative as a highly efficient gene delivery system

Blinking statistics of a molecular beacon triggered by end-denaturation of DNA

We use a master equation approach based on the Poland-Scheraga free energy for DNA denaturation to investigate the (un)zipping dynamics of a denaturation wedge in a stretch of DNA, that is clamped at one end. In particular, we quantify the blinking dynamics of a fluorophore-quencher pair mounted within the denaturation wedge. We also study the behavioural changes in the presence of proteins, that selectively bind to single-stranded DNA. We show that such a setup could be well-suited as an easy-to-implement nanodevice for sensing environmental conditions in small volumes.Comment: 14 pages, 5 figures, LaTeX, IOP style. Accepted to J Phys Cond Mat special issue on diffusio

First results of material charging in the space environment

A satellite experiment, designed to measure potential charging of typical thermal control materials at near geosynchronous altitude, was flown as part of the SCATHA program. Direct observations of charging of typical satellite materials in a natural charging event ( 5 keV) are presented. The results show some features which differ significantly from previous laboratory simulations of the environment

a pilot randomized controlled trial

Objectives: Our primary aim of this pilot study was to test feasibility of the planned design, the interventions (education plus telephone coaching), and the outcome measures, and to facilitate a power calculation for a future randomized controlled trial to improve adherence to recovery goals following hip fracture. Design: This is a parallel 1:1 randomized controlled feasibility study. Setting: The study was conducted in a teaching hospital in Vancouver, BC, Canada. Participants: Participants were community-dwelling adults over 60 years of age with a recent hip fracture. They were recruited and assessed in hospital, and then randomized after hospital discharge to the intervention or control group by a web-based randomization service. Treatment allocation was concealed to the investigators, measurement team, and data entry assistants and analysts. Participants and the research physiotherapist were aware of treatment allocation. Intervention: Intervention included usual care for hip fracture plus a 1-hour in-hospital educational session using a patient- centered educational manual and four videos, and up to five postdischarge telephone calls from a physiotherapist to provide recovery coaching. The control group received usual care plus a 1-hour in-hospital educational session using the educational manual and videos. Measurement: Our primary outcome was feasibility, specifically recruitment and retention of participants. We also collected selected health outcomes, including health- related quality of life (EQ5D-5L), gait speed, and psychosocial factors (ICEpop CAPability measure for Older people and the Hospital Anxiety and Depression Scale). Results: Our pilot study results indicate that it is feasible to recruit, retain, and provide follow-up telephone coaching to older adults after hip fracture. We enrolled 30 older adults (mean age 81.5 years; range 61–97 years), representing a 42% recruitment rate. Participants excluded were those who were not community dwelling on admission, were discharged to a residential care facility, had physician-diagnosed dementia, and/or had medical contraindications to participation. There were 27 participants who completed the study: eleven in the intervention group, 15 in the control group, and one participant completed a qualitative interview only. There were no differences between groups for health measures. Conclusion: We highlight the feasibility of telephone coaching for older adults after hip fracture to improve adherence to mobility recovery goals

6,7,9,10-Tetra­hydro-16,22-ethano­oxyethano-5,8,11,19-tetra­oxa-16,22-diaza­dibenzo[h,q]cyclo­octa­decine-17,21-dione: a benzyl­annelated macrobicyclic diamide

The macrobicyclic title compound, C24H28N2O7, has two tertiary diamide bridgehead atoms and is composed of a 12-membered ring (N2O2 donor set) and two 18-membered rings (N2O4 donor sets). The solid-state structure shows that each of the amide groups is not coplanar with the adjacent benzene ring and NMR studies indicate that this conformational relationship persists in solution