Attosecond VUV Coherent Control of Molecular Dynamics

High harmonic light sources make it possible to access attosecond time-scales, thus opening up the prospect of manipulating electronic wave packets for steering molecular dynamics. However, two decades after the birth of attosecond physics, the concept of attosecond chemistry has not yet been realized. This is because excitation and manipulation of molecular orbitals requires precisely controlled attosecond waveforms in the deep ultraviolet, which have not yet been synthesized. Here, we present a novel approach using attosecond vacuum ultraviolet pulse-trains to coherently excite and control the outcome of a simple chemical reaction in a deuterium molecule in a non-Born Oppenheimer regime. By controlling the interfering pathways of electron wave packets in the excited neutral and singly-ionized molecule, we unambiguously show that we can switch the excited electronic state on attosecond timescales, coherently guide the nuclear wave packets to dictate the way a neutral molecule vibrates, and steer and manipulate the ionization and dissociation channels. Furthermore, through advanced theory, we succeed in rigorously modeling multi-scale electron and nuclear quantum control in a molecule for the first time. The observed richness and complexity of the dynamics, even in this very simplest of molecules, is both remarkable and daunting, and presents intriguing new possibilities for bridging the gap between attosecond physics and attochemistry

Misty, Spellbound and the lost Gothic of British girls’ comics.

This article is a case study of the 1970s British girls’ comics Spellbound (DC Thomson, 1976–1977) and Misty (IPC, 1978–1980). These mystery anthology comics followed the more famous American horror comics from publishers like EC Comics - but were aimed at pre-teen girls. The article situates these comics with respect to Gothic critical theory and within the wider landscape of British girls’ comics. Firstly, it closely considers and compares the structure and content of their stories with respect to theories of the terror and horror Gothic. It discovers that both comics offer similar fare, with a subversive streak that undercuts established horror archetypes. The article then looks closely at both titles’ aesthetics and their use of the page to draw comparisons. It uses comics theory and Gothic cinematic theory to demonstrate that the appearance of Misty is more strongly Gothic than the aesthetic of Spellbound. Finally, it considers a selection of stories from both comics and analyses their common themes using Gothic critical theory. It argues that both comics rework Gothic themes into new forms that are relevant to their pre-teen and teenage readers. It concludes by summarising the study’s findings and suggesting that these comics offer a “Gothic for Girls” that is part cautionary tale and part bildungsroman. This article is published as part of a collection on Gothic and horror

Non-Equilibrium Dynamics in Two-Color, Few-Photon Dissociative Excitation and Ionization of D2_2

D$_2$ molecules, excited by linearly cross-polarized femtosecond extreme ultraviolet (XUV) and near-infrared (NIR) light pulses, reveal highly structured D$^+$ ion fragment momenta and angular distributions that originate from two different 4-step dissociative ionization pathways after four photon absorption (1 XUV + 3 NIR). We show that, even for very low dissociation kinetic energy release $\le$~240~meV, specific electronic excitation pathways can be identified and isolated in the final ion momentum distributions. With the aid of {\it ab initio} electronic structure and time-dependent Schr\"odinger equation calculations, angular momentum, energy, and parity conservation are used to identify the excited neutral molecular states and molecular orientations relative to the polarization vectors in these different photoexcitation and dissociation sequences of the neutral D$_2$ molecule and its D$_2^+$ cation. In one sequential photodissociation pathway, molecules aligned along either of the two light polarization vectors are excluded, while another pathway selects molecules aligned parallel to the light propagation direction. The evolution of the nuclear wave packet on the intermediate \Bstate electronic state of the neutral D$_2$ molecule is also probed in real time.Comment: 11 pages including 6 figure

Patterning the geographies of organ transplantation: corporeality, generosity and justice

publication-status: PublishedThis is the author's post-print version of an article published in Transactions of the Institute of British Geographers, 2006, Vol. 31, Issue 3 pp. 257 – 271 Copyright © 2006 Institute of British Geographers / Royal Geographical Society. The definitive version is available at www3.interscience.wiley.comOrgan transplantation is now an established treatment for patients with end-stage organ failure, yet there are spatial inequalities in access to this procedure. This paper explores the uneven geographies of kidney transplantation in London, arguing that inequalities in access to organ transplantation are created through interlocking spatialities of corporeal difference, enacted through global movements of populations, national organ transplantation protocols and the internal immunological spaces of the body. The combination of these processes, operating at different scales, has produced a distinctive configuration in the embodiment of risk in relation to kidney transplants, particularly born by London's Black and Asian communities. Two ethical dimensions to this geography of organ transplantation are explored here: the ethical responsiveness to others shaping the generous practices of organ donation, and the medical practices categorizing difference through techniques of blood typing, tissue matching and the spatial organization of organ transplantation. In concluding, I argue both are critical to understanding the links between ethics and justice in the geographies of organ exchange in London. Further, I suggest geography is central to political debate about the exchange of biological material elsewhere, for it is only through tracing the intersection of ethical, corporeal and technological practices in situ that we can fully reflect on questions of justice within the developing bioeconomy

Organ donation, ethnicity and the negotiation of death: ethnographic insights from the UK

The introduction of end-of-life care criteria in the UK aims at standardising the processes of care at the end of life, including how medical decisions on death are communicated to the families of dying and (brain) dead patients. In the setting of the intensive care unit, these activities are routinely complicated by the imperative to secure donor organs for transplantation: where recent changes to donation services have seen the accommodation of organ donation procedures into end-of-life care routines. This has ramifications for understanding how medical decisions around death and dying are brokered with the families of potential organ donors. Drawing on an ethnographic study in England, this paper will document how communications around death get turned into a particular matter of concern for the practice of requesting organ donation from minority ethnic families. It shows how attempts to resolve differences of opinion between health professionals and families about a diagnosis of brain stem death or dying are mediated by sets of brokering practices: specifically, those termed technological, authoritative and religious brokering. These practices, we argue, not only facilitate a family’s acceptance of their relative’s death, but also serve to make possible a decision on organ donation

Plant-made polio type 3 stabilized VLPs—a candidate synthetic polio vaccine

Poliovirus (PV) is the causative agent of poliomyelitis, a crippling human disease known since antiquity. PV occurs in two distinct antigenic forms, D and C, of which only the D form elicits a robust neutralizing response. Developing a synthetically produced stabilized viruslike particle (sVLP)-based vaccine with D antigenicity, without the drawbacks of current vaccines, will be a major step towards the final eradication of poliovirus. Such a sVLP would retain the native antigenic conformation and the repetitive structure of the original virus particle, but lack infectious genomic material. In this study, we report the production of synthetically stabilized PV VLPs in plants. Mice carrying the gene for the human PV receptor are protected from wild-type PV when immunized with the plant-made PV sVLPs. Structural analysis of the stabilized mutant at 3.6 Å resolution by cryo-electron microscopy and single particle reconstruction reveals a structure almost indistinguishable from wild-type PV3

Recommendations for Nanomedicine Human Subjects Research Oversight: An Evolutionary Approach for an Emerging Field

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96363/1/j.1748-720X.2012.00703.x.pd

The Enterovirus 71 A-particle Forms a Gateway to Allow Genome Release: A CryoEM Study of Picornavirus Uncoating

Since its discovery in 1969, enterovirus 71 (EV71) has emerged as a serious worldwide health threat. This human pathogen of the picornavirus family causes hand, foot, and mouth disease, and also has the capacity to invade the central nervous system to cause severe disease and death. Upon binding to a host receptor on the cell surface, the virus begins a two-step uncoating process, first forming an expanded, altered "A-particle", which is primed for genome release. In a second step after endocytosis, an unknown trigger leads to RNA expulsion, generating an intact, empty capsid. Cryo-electron microscopy reconstructions of these two capsid states provide insight into the mechanics of genome release. The EV71 A-particle capsid interacts with the genome near the icosahedral two-fold axis of symmetry, which opens to the external environment via a channel ~10 Å in diameter that is lined with patches of negatively charged residues. After the EV71 genome has been released, the two-fold channel shrinks, though the overall capsid dimensions are conserved. These structural characteristics identify the two-fold channel as the site where a gateway forms and regulates the process of genome release. © 2013 Shingler et al