Propagation and Ghosts in the Classical Kagome Antiferromagnet

We investigate the classical spin dynamics of the kagome antiferromagnet by combining Monte Carlo and spin dynamics simulations. We show that this model has two distinct low temperature dynamical regimes, both sustaining propagative modes. The expected gauge invariance type of the low energy low temperature out of plane excitations is also evidenced in the non linear regime. A detailed analysis of the excitations allows to identify ghosts in the dynamical structure factor, i.e propagating excitations with a strongly reduced spectral weight. We argue that these dynamical extinction rules are of geometrical origin.Comment: 4+ pages, 4 figures. Accepted for publication in the Physical Review Letter

Conflicting interests in the pathogen-host tug of war : fungal micronutrient scavenging versus mammalian nutritional immunity

Funding: The authors are supported by the European Research Council (STRIFE project funded on grant number ERC-2009-AdG-249793, http://erc.europa.eu). AJPB is also supported by the Wellcome Trust (grant numbers 080088, 097377, www.wellcome.ac.uk) and the UK Biotechnology and Biological Sciences Research Council (grant number BB/F00513X/1, www.bbsrc.ac.uk). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Quantum interference oscillations of the superparamagnetic blocking in an Fe8 molecular nanomagnet

We show that the dynamic magnetic susceptibility and the superparamagnetic blocking temperature of an Fe8 single molecule magnet oscillate as a function of the magnetic field Hx applied along its hard magnetic axis. These oscillations are associated with quantum interferences, tuned by Hx, between different spin tunneling paths linking two excited magnetic states. The oscillation period is determined by the quantum mixing between the ground S=10 and excited multiplets. These experiments enable us to quantify such mixing. We find that the weight of excited multiplets in the magnetic ground state of Fe8 amounts to approximately 11.6%.Comment: Accepted in Phys. Rev. Let

The roles of zinc and copper sensing in fungal pathogenesis

Open Access funded by Wellcome Trust Acknowledgements ERB is funded by the BBSRC (BB/M014525/1). DW is supported by a Sir Henry Dale Fellowship jointly funded by the Wellcome Trust and the Royal Society (Grant Number 102549/Z/13/Z). We additionally acknowledge the MRC and University of Aberdeen for funding (MR/N006364/1) and the Wellcome Trust Strategic Award for Medical Mycology and Fungal Immunology (097377/Z/11/Z). Finally, we acknowledge FungiDB and the Candida Genome Database [ 56 and 57].Peer reviewedPublisher PD

Magnetic excitations in a new anisotropic Kagom\'{e} antiferromagnet

The Nd-langasite compound contains planes of magnetic Nd3+ ions on a lattice topologically equivalent to a kagom\'{e} net. The magnetic susceptibility does not reveal any signature of long-range ordering down to 2 K but rather a correlated paramagnetism with significant antiferromagnetic interactions between the Nd and a single-ion anisotropy due to crystal field effect. Inelastic neutron scattering on Nd-langasite powder and single-crystal allowed to probe its very peculiar low temperature dynamical magnetic correlations. They present unusual dispersive features and are broadly localized in wave-vector Q revealing a structure factor associated to characteristics short range-correlations between the magnetic atoms. From comparison with theoretical calculations, these results are interpreted as a possible experimental observation of a spin liquid state in an anisotropic kagom\'{e} antiferromagnet.Comment: to appear in Physica

The Impact of Students\u27 Perceived Computer Experience on Behavior and Performance in an Introductory Information Systems Course

In this study the impact of perceived computer experience on the behavior and performance of students in an introductory information systems (IS) course with both lab and lecture components was examined. Perceived computer experience was predicted to affect behavior and performance in the course because of its relationship to positive internal attitudes towards computers and because students\u27 perceptions of their computer experience are related to their actual level of knowledge about computers. The results of the study showed that higher levels of perceived computer experience positively affected lecture and lab homework and exam performance. In addition, higher levels of positive class behaviors (attendance and extra-credit participation) positively affected both lecture and lab exam performance. Gender and lab/lecture section were included as control variables and both had an impact on behavior and performance. Women participated more in extra-credit opportunities. Lecture and lab sections varied significantly with regard to attendance, extra-credit participation, lab homework, and lab and lecture exam performance. These results are discussed in the context of previous research on factors affecting introductory information systems course performance and prior research on the effects of prior computer experience on learning

Dispatcher: A Theory-Based Design for Study of Real-Time Decision-Making

Dispatcher is a computer simulation being used in a series of experiments involving the study of real-time dynamic decision making. The design of the simulation is based on current theory of providing decision support for this type of decision making task. This paper provides an overview of the process used in designing and implementing Dispatcher, as well as a description of some of the main features of the simulation as they relate to current research efforts in the study of decision support for RTDDM

New Clox Systems for rapid and efficient gene disruption in Candida albicans

Acknowledgements: We are grateful to Janet Quinn, Lila Kastora, Joanna Potrykus, Michelle Leach, and others for sharing their experiences with the Clox cassettes. We thank Julia Kohler for her kind gift of the NAT1-flipper plasmid pJK863, Claudia Jacob for her advice with In-fusion cloning, and our colleagues in the Aberdeen Fungal Group for numerous stimulating discussions. Data Availability: The authors confirm that all data underlying the findings are fully available without restriction. The sequences of all Clox cassettes are available in GenBank: URA3-Clox (loxP-URA3-MET3p-cre-loxP): GenBank accession number KC999858. NAT1-Clox (loxP-NAT1-MET3p-cre-loxP): GenBank accession number KC999859. LAL (loxP-ARG4-loxP): GenBank accession number DQ015897. LHL (loxP-HIS1-loxP): GenBank accession number DQ015898. LUL (loxP-URA3-loxP): GenBank accession number DQ015899. Funding: This work was supported by the Wellcome Trust (www.wellcome.ac.uk): S.S., F.C.O., N.A.R.G., A.J.P.B. (080088); N.A.R.G., A.J.P.B. (097377). The authors also received support from the European Research Council [http://erc.europa.eu/]: DSC. ERB, AJPB (STRIFE Advanced Grant; C-2009-AdG-249793). The European Commission also provided funding [http://ec.europa.eu/research/fp7]: I.B., A.J.P.B. (FINSysB MC-ITN; PITN-GA-2008-214004). Also the UK Biotechnology and Biological Research Council provided support [www.bbsrc.ac.uk]: N.A.R.G., A.J.P.B. (Research Grant; BB/F00513X/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD