592 research outputs found
Creating the Ideal Digital Self: 3G Mobile Phone Content Production and Distribution as Social Communication
Mobile phone ownership presents users with the opportunity to regularly update others of their actions through the digital documentation and circulation of their experiences. There is a sense that an event is not complete until it is shared through text, voice or images. An empirical study of 35 users aged 18-30, conducted for the Smart Internet Technology CRC [3] revealed that when members of a social group cannot be together physically, circulating digitised accounts of an activity becomes an authentic way to share the event. Furthermore, the study indicated that with the convergence of 3G mobile phones, digital cameras and the Internet, users are taking advantage of the best of all three communication channels to create, circulate, distribute and archive content in new and dynamic ways. Through this process users are creating the 'ideal digital self' by which to communicate socially. However, the effectiveness of these new practices is eroded by specific design and technological limitations, thus a distinct set of user problems emerged. This paper illustrates how the Trophy Room scenario, which is a 3G phone and web application, was developed to address the user needs identified in the study
Numerical Simulation of Coronal Waves interacting with Coronal Holes: I. Basic Features
We developed a new numerical code that is able to perform 2.5D simulations of
a magnetohydrodynamic (MHD) wave propagation in the corona, and its interaction
with a low density region, such as a coronal hole (CH). We show that the impact
of the wave on the CH leads to different effects, such as reflection and
transmission of the incoming wave, stationary features at the CH boundary, or
formation of a density depletion. We present a comprehensive analysis of the
morphology and kinematics of primary and secondary waves, that is, we describe
in detail the temporal evolution of density, magnetic field, plasma flow
velocity, phase speed and position of the wave amplitude. Effects like
reflection, refraction and transmission of the wave strongly support the theory
that large scale disturbances in the corona are fast MHD waves and build the
major distinction to the competing pseudo-wave theory. The formation of
stationary bright fronts was one of the main reasons for the development of
pseudo-waves. Here we show that stationary bright fronts can be produced by the
interactions of an MHD wave with a CH. We find secondary waves that are
traversing through the CH and we show that one part of these traversing waves
leaves the CH again, while another part is being reflected at the CH boundary
inside the CH. We observe a density depletion that is moving in the opposite
direction of the primary wave propagation. We show that the primary wave pushes
the CH boundary to the right, caused by the wave front exerting dynamic
pressure on the CH
The translational regulator dFMRP interacts with epidermal growth factor receptor to regulate apoptosis in Drosophila
poster abstractPosttranscriptional gene regulation is required for all aspects of cellular and tissue development and is a major mechanism underlying many diseases ranging from neurological disorders to cancer. The translational repressor fragile x mental retardation protein (FMRP) is ubiquitously expressed throughout development but is silenced in Fragile X Syndrome, an autism spectrum disorder. Interestingly, high levels of FMRP have recently been identified in human metastatic breast cancer. FMRP overexpression in these patients is directly correlated with increased lung metastasis suggesting a direct role for translational regulation both in cell proliferation and in invasive cell migration. Interestingly, however, FMRP can promote both proliferation and apoptosis. To dissect FMRP’s role in cancer development and progression, we are exploiting the powerful genetic system of Drosophila. Drosophila is an excellent model organism for human diseases associated with FMRP due to the strong evolutionary conservation of the fragile x mental retardation gene 1 which encodes this protein. dFMRP was overexpressed in the Drosophila imaginal wing disc, an epithelial tissue model. Contrary to a role in proliferation, overexpression of dFMRP leads to obvious cell loss in the adult wing and an increase in apoptotic markers. Using a combinatorial genetic screen, we have identified genes which are able to suppress this apoptotic phenotype and thus may be important for FMRP-‐dependent tumorigenesis. Our focus is now on the epidermal growth factor receptor (EGFR) signaling pathway since blocking this mechanism is able to completely rescue the dFMRP-‐overexpression wing defects. Clonal analysis reveals that dFMRP overexpressing cells survive their dFMRP-induced apoptotic programming when co-‐expressing a dominant negative form of EGFR. Additional clonal analyses are being used to explore the potential significance of this survival on tumor formation and metastasis
Authentication and authorisation in entrusted unions
This paper reports on the status of a project whose aim is to implement and demonstrate in a real-life environment an integrated eAuthentication and eAuthorisation framework to enable trusted collaborations and delivery of services across different organisational/governmental jurisdictions. This aim will be achieved by designing a framework with assurance of claims, trust indicators, policy enforcement mechanisms and processing under encryption to address the security and confidentiality requirements of large distributed infrastructures. The framework supports collaborative secure distributed storage, secure data processing and management in both the cloud and offline scenarios and is intended to be deployed and tested in two pilot studies in two different domains, viz, Bio-security incident management and Ambient Assisted Living (eHealth). Interim results in terms of security requirements, privacy preserving authentication, and authorisation are reported
Designing a fully compensated half-metallic ferrimagnet
Recent experimental work on Mn2RuxGa demonstrates its potential as a compensated ferrimagnetic
half-metal (CFHM). Here we present a set of high-throughput ab initio density functional
theory calculations and detailed experimental characterisation, that enable us to correctly describe
the nominal Mn2RuxGa thin films, in particular with regard to site-disorder and defects. We then
construct models that accurately capture all the key features of the Mn-Ru-Ga system, including
magnetic compensation and the spin gap at the Fermi level. We find that electronic doping is neccessary,
which is achieved with a Mn/Ga ratio smaller than two. Our study shows how composition
and substrate-induced biaxial strain can be combined to design a ferrimagnetic half-metal with a
compensation point close to room temperature
On the Propagation of a Geoeffective Coronal Mass Ejection during March 15 -- 17, 2015
The largest geomagnetic storm so far in the solar cycle 24 was produced by a
fast coronal mass ejection (CME) originating on 2015 March 15. It was an
initially west-oriented CME and expected to only cause a weak geomagnetic
disturbance. Why did this CME finally cause such a large geomagnetic storm? We
try to find some clues by investigating its propagation from the Sun to 1 AU.
First, we reconstruct the CME's kinematic properties in the corona from the
SOHO and SDO imaging data with the aid of the graduated cylindrical shell (GCS)
model. It is suggested that the CME propagated to the west
away from the Sun-Earth line with a speed of
about 817 km s before leaving the field of view of the SOHO/LASCO C3
camera. A magnetic cloud (MC) corresponding to this CME was measured in-situ by
the Wind spacecraft two days later. By applying two MC reconstruction methods,
we infer the configuration of the MC as well as some kinematic information,
which implies that the CME possibly experienced an eastward deflection on its
way to 1 AU. However, due to the lack of observations from the STEREO
spacecraft, the CME's kinematic evolution in interplanetary space is not clear.
In order to fill this gap, we utilize numerical MHD simulation, drag-based CME
propagation model (DBM) and the model for CME deflection in interplanetary
space (DIPS) to recover the propagation process, especially the trajectory, of
the CME from to 1 AU. It is suggested that the trajectory of the CME
was deflected toward the Earth by about , consistent with the
implication from the MC reconstruction at 1 AU. This eastward deflection
probably contributed to the CME's unexpected geoeffectiveness by pushing the
center of the initially west-oriented CME closer to the Earth.Comment: 10 pages, 5 figures, 1 table, accepted by JGR - Space Physic
Combined Multipoint Remote and In Situ Observations of the Asymmetric Evolution of a Fast Solar Coronal Mass Ejection
We present an analysis of the fast coronal mass ejection (CME) of 2012 March
7, which was imaged by both STEREO spacecraft and observed in situ by
MESSENGER, Venus Express, Wind and Mars Express. Based on detected arrivals at
four different positions in interplanetary space, it was possible to strongly
constrain the kinematics and the shape of the ejection. Using the white-light
heliospheric imagery from STEREO-A and B, we derived two different kinematical
profiles for the CME by applying the novel constrained self-similar expansion
method. In addition, we used a drag-based model to investigate the influence of
the ambient solar wind on the CME's propagation. We found that two preceding
CMEs heading in different directions disturbed the overall shape of the CME and
influenced its propagation behavior. While the Venus-directed segment underwent
a gradual deceleration (from ~2700 km/s at 15 R_sun to ~1500 km/s at 154
R_sun), the Earth-directed part showed an abrupt retardation below 35 R_sun
(from ~1700 to ~900 km/s). After that, it was propagating with a quasi-constant
speed in the wake of a preceding event. Our results highlight the importance of
studies concerning the unequal evolution of CMEs. Forecasting can only be
improved if conditions in the solar wind are properly taken into account and if
attention is also paid to large events preceding the one being studied
Meter- to Millimeter Emission from Cool Stellar Systems : Latest Results, Synergies Across the Spectrum, and Outlook for the Next Decade
Splinter session summary, to appear in the proceedings of the 20th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun (ed. S. J. Wolk)Radio observations of cool stellar systems provide unique information on their magnetic fields, high-energy processes, and chemistry. Buoyed by powerful new instruments (e.g. ALMA, JVLA, LOFAR), advances in related fields (e.g., the Gaia astrometric revolution), and above all a renewed interest in the relevant stellar astrophysics, stellar radio astronomy is experiencing a renaissance. In this splinter session, participants took stock of the present state of stellar radio astronomy to chart a course for the field's future
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