365 research outputs found
Torsional Newton-Cartan Geometry and Lifshitz Holography
We obtain the Lifshitz UV completion in a specific model for z=2 Lifshitz
geometries. We use a vielbein formalism which enables identification of all the
sources as leading components of well-chosen bulk fields. We show that the
geometry induced from the bulk onto the boundary is a novel extension of
Newton-Cartan geometry with a specific torsion tensor. We explicitly compute
all the vevs including the boundary stress-energy tensor and their Ward
identities. After using local symmetries/Ward identities the system exhibits
6+6 sources and vevs. The FG expansion exhibits, however, an additional free
function which is related to an irrelevant operator whose source has been
turned off. We show that this is related to a second UV completion.Comment: v2: 5 pages, matches version published in PR
CREATIVITY IN STRATEGIC PLANNING: THE INFLUENCE OF TEMPORAL PERSPECTIVE
As organizational environments become more turbulent and complex and as
uncertainty about the future increases, reliance on quantitative decision-making
approaches for strategic planning becomes less appropriate. Scenario analysis can
be an effective qualitative technique for enhancing strategic planning. Typically,
scenarios are presented as alternate futures. Some theorists, however, have
suggested that forward and backward thinking are different cognitive processes. In
this study, we investigate the effect of presenting scenarios retrospectively; that is,
as if future events had already happened.
A repeated measures laboratory study compared the performance of
professional planners (n = 64) using prospective and retrospective scenarios in two
simulated business planning tasks. Measures consisted of objective factors
(number of individual planning statements and number of monitoring statements),
subjective factors (quality based on an 18-question rating instrument), and subject
attitudes concerning their experience with the two treatments.
Results suggest that use of retrospective scenarios do increase the number of
planning statements. In addition, plans prepared using retrospective scenarios
were rated higher overall than those prepared with prospective scenarios.
Moreover, evidence emerged that a subset of subjects were better able to make use
of the retrospective technique, suggesting that selection along with training may
improve planning performance.Information Systems Working Papers Serie
Low Voltage Totally Free Flexible RF MEMS Switch With Anti-Stiction System
This paper concerns a new design of RF MEMS switch combined with an
innovative process which enable low actuation voltage (<5V) and avoid stiction.
First, the structure described with principal design issues, the corresponding
anti-stiction system is presented and FEM simulations are done. Then, a short
description of the process flow based on two non polymer sacrificial layers.
Finally, RF measurements are presented and preliminary experimental protocol
and results of anti-stiction validation is detailed. Resulting RF performances
are -30dB of isolation and -0.45dB of insertion loss at 10 GHz.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/handle/2042/16838
CREATIVITY IN STRATEGIC PLANNING: THE INFLUENCE OF TEMPORAL PERSPECTIVE
As organizational environments become more turbulent and complex and as
uncertainty about the future increases, reliance on quantitative decision-making
approaches for strategic planning becomes less appropriate. Scenario analysis can
be an effective qualitative technique for enhancing strategic planning. Typically,
scenarios are presented as alternate futures. Some theorists, however, have
suggested that forward and backward thinking are different cognitive processes. In
this study, we investigate the effect of presenting scenarios retrospectively; that is,
as if future events had already happened.
A repeated measures laboratory study compared the performance of
professional planners (n = 64) using prospective and retrospective scenarios in two
simulated business planning tasks. Measures consisted of objective factors
(number of individual planning statements and number of monitoring statements),
subjective factors (quality based on an 18-question rating instrument), and subject
attitudes concerning their experience with the two treatments.
Results suggest that use of retrospective scenarios do increase the number of
planning statements. In addition, plans prepared using retrospective scenarios
were rated higher overall than those prepared with prospective scenarios.
Moreover, evidence emerged that a subset of subjects were better able to make use
of the retrospective technique, suggesting that selection along with training may
improve planning performance.Information Systems Working Papers Serie
Brown-York Energy and Radial Geodesics
We compare the Brown-York (BY) and the standard Misner-Sharp (MS) quasilocal
energies for round spheres in spherically symmetric space-times from the point
of view of radial geodesics. In particular, we show that the relation between
the BY and MS energies is precisely analogous to that between the
(relativistic) energy E of a geodesic and the effective (Newtonian) energy
E_{eff} appearing in the geodesic equation, thus shedding some light on the
relation between the two. Moreover, for Schwarzschild-like metrics we establish
a general relationship between the BY energy and the geodesic effective
potential which explains and generalises the recently observed connection
between negative BY energy and the repulsive behaviour of geodesics in the
Reissner-Nordstrom metric. We also comment on the extension of this connection
between geodesics and the quasilocal BY energy to regions inside a horizon.Comment: v3: 7 pages, shortened and revised version to appear in CQ
The AMCIS 2003 Panels of IS Education-II: The Chicken and the Egg Debate: Positioning Database Content in the Information Systems Curriculum
This paper summarizes the results of a panel on how database content is covered in current university programs, with reference to the IS2002 model curriculum. Panelists included information systems (IS) faculty members who are actively involved in determining the coverage of database content at their institutions and in establishing academy-wide database content and technology resources. Topics included positioning database content in the overall curriculum, sequencing of content within the database course(s), and summary suggestions for tailoring database coverage at colleges and universities
Holographic Renormalization for z=2 Lifshitz Space-Times from AdS
Lifshitz space-times with critical exponent z=2 can be obtained by
dimensional reduction of Schroedinger space-times with critical exponent z=0.
The latter space-times are asymptotically AdS solutions of AdS gravity coupled
to an axion-dilaton system and can be uplifted to solutions of type IIB
supergravity. This basic observation is used to perform holographic
renormalization for 4-dimensional asymptotically z=2 locally Lifshitz
space-times by Scherk-Schwarz dimensional reduction of the corresponding
problem of holographic renormalization for 5-dimensional asymptotically locally
AdS space-times coupled to an axion-dilaton system. We can thus define and
characterize a 4-dimensional asymptotically locally z=2 Lifshitz space-time in
terms of 5-dimensional AdS boundary data. In this setup the 4-dimensional
structure of the Fefferman-Graham expansion and the structure of the
counterterm action, including the scale anomaly, will be discussed. We find
that for asymptotically locally z=2 Lifshitz space-times obtained in this way
there are two anomalies each with their own associated nonzero central charge.
Both anomalies follow from the Scherk--Schwarz dimensional reduction of the
5-dimensional conformal anomaly of AdS gravity coupled to an axion-dilaton
system. Together they make up an action that is of the Horava-Lifshitz type
with nonzero potential term for z=2 conformal gravity.Comment: 32 pages, v2: modified discussion of the central charge
T- and B-cell responses to multivalent prime-boost DNA and viral vectored vaccine combinations against hepatitis C virus in non-human primates.
Immune responses against multiple epitopes are required for the prevention of hepatitis C virus (HCV) infection, and the progression to phase I trials of candidates may be guided by comparative immunogenicity studies in non-human primates. Four vectors, DNA, SFV, human serotype 5 adenovirus (HuAd5) and Modified Vaccinia Ankara (MVA) poxvirus, all expressing hepatitis C virus Core, E1, E2 and NS3, were combined in three prime-boost regimen, and their ability to elicit immune responses against HCV antigens in rhesus macaques was explored and compared. All combinations induced specific T-cell immune responses, including high IFN-Îł production. The group immunized with the SFV+MVA regimen elicited higher E2-specific responses as compared with the two other modalities, while animals receiving HuAd5 injections elicited lower IL-4 responses as compared with those receiving MVA. The IFN-Îł responses to NS3 were remarkably similar between groups. Only the adenovirus induced envelope-specific antibody responses, but these failed to show neutralizing activity. Therefore, the two novel regimens failed to induce superior responses as compared with already existing HCV vaccine candidates. Differences were found in response to envelope proteins, but the relevance of these remain uncertain given the surprisingly poor correlation with immunogenicity data in chimpanzees, underlining the difficulty to predict efficacy from immunology studies.This work was supported by European Union contract QLK2-CT-1999-
00356, by the Biomedical Primate Research Centre, The Netherlands, and by the Swedish
Research Council. We are grateful to Alexander van den Berg for technical assistance with the
ICS, to our colleagues from Animal Science Department for technical assistance and expert care
of the macaques, to the participants of the European HCVacc Cluster who provided help and
support, and to Thomas Darton (Oxford Vaccine Group, UK) for input and advice on the
manuscript. Christine Rollier is an Oxford Martin fellow and a Jenner Insitute Investigator.This is the author accepted manuscript. The final version is available from Nature Publishing Group at https://doi.org/10.1038/gt.2016.55
Clearance of Genotype 1b Hepatitis C Virus in Chimpanzees in the Presence of Vaccine-Induced E1-Neutralizing Antibodies
Accumulating evidence indicates that neutralizing antibodies play an important role in protection from chronic hepatitis C virus (HCV) infection. Efforts to elicit such responses by immunization with intact heterodimeric E1E2 envelope proteins have met with limited success. To determine whether antigenic sites, which are not exposed by the combined E1E2 heterodimer structure, are capable of eliciting neutralizing antibody responses, we expressed and purified each as separate recombinant proteins E1 and E2, from which the immunodominant hypervariable region (HVR-1) was deleted. Immunization of chimpanzees with either E1 or E2 alone induced antigen-specific T-helper cytokines of similar magnitude. Unexpectedly, the capacity to neutralize HCV was observed in E1 but not in animals immunized with E2 devoid of HVR-1. Furthermore, in vivo only E1-vaccinated animals exposed to the heterologous HCV-1b inoculum cleared HCV infection
- …