318 research outputs found
Recommended from our members
The Texas Spoofing Test Battery: Toward a Standard for Evaluating GPS Signal Authentication Techniques
A battery of recorded spoofing scenarios has been compiled
for evaluating civil Global Positioning System (GPS) signal
authentication techniques. The battery can be considered
the data component of an evolving standard meant to
define the notion of spoof resistance for commercial GPS
receivers. The setup used to record the scenarios is described.
A detailed description of each scenario reveals
readily detectable anomalies that spoofing detectors could target to improve GPS securityAerospace Engineering and Engineering Mechanic
Recommended from our members
A Testbed for Developing and Evaluating GNSS Signal Authentication Techniques
An experimental testbed has been created for developing
and evaluating Global Navigation Satellite System (GNSS)
signal authentication techniques. The testbed advances the state
of the art in GNSS signal authentication by subjecting candidate
techniques to the strongest publicly-acknowledged GNSS spoofing
attacks. The testbed consists of a real-time phase-coherent GNSS
signal simulator that acts as spoofer, a real-time softwaredefined
GNSS receiver that plays the role of defender, and
post-processing versions of both the spoofer and defender. Two
recently-proposed authentication techniques are analytically and
experimentally evaluated: (1) a defense based on anomalous
received power in a GNSS band, and (2) a cryptographic
defense against estimation-and-replay-type spoofing attacks. The
evaluation reveals weaknesses in both techniques; nonetheless,
both significantly complicate a successful GNSS spoofing attackAerospace Engineering and Engineering Mechanic
Blended e-learning skeleton of conversation: improving formative assessment in undergraduate dissertation supervision
The supervision of undergraduate student dissertations is an area in need of research. Although some studies have already addressed this, these are primarily based on academic staff responses. This study contributes to knowledge by gathering the responses of students and focusing on formative electronic assessment. Data was collected using a student focus group and student questionnaire. The findings suggest that good supervisor-student communication is crucial to the supervision process and a number of students felt unhappy with this aspect. It is suggested that to improve the undergraduate student dissertation experience, a combination of face-to-face and electronic formative assessment is used. In addition, the Blended E-learning Skeleton of Conversation model provides a sound theoretical framework that could guide supervisors and students in the supervision process. This model is advocated for use in dissertation module design and in supervisor development
LâextrĂȘme droite et « Mai 68 ».
Pendant et juste aprĂšs lâexplosion de 1968, lâextrĂȘme droite, au moins dans ses publications, a rĂ©ussi Ă reconvertir son obsession algĂ©rienne â de la « trahison » de lâAlgĂ©rie français Ă la description des hommes AlgĂ©riens comme une menace pour la France dâalors â dans lâĂ©laboration de grilles dâanalyse reposant sur un registre sexuĂ© et sexuel permettant de comprendre « Mai » : câest-Ă -dire Ă la fois les Ă©vĂ©nements eux-mĂȘmes et la crise gĂ©nĂ©rale qui minait la France.The French far right press, responded to May â68 by resituating its ongoing obsession with Algerian themes, which fixated both on the Gaullist « betrayal » of French Algeria and the threat that Algerian male immigrants now posed to France. This redefinition depended on gendered and sexualized certainties to propose an analysis of « May », both the events and the larger problems that produced it, around which right and far-right could find common ground
Isovector Giant Dipole Resonance of Stable Nuclei in a Consistent Relativistic Random Phase Approximation
A fully consistent relativistic random phase approximation is applied to
study the systematic behavior of the isovector giant dipole resonance of nuclei
along the -stability line in order to test the effective Lagrangians
recently developed. The centroid energies of response functions of the
isovector giant dipole resonance for stable nuclei are compared with the
corresponding experimental data and the good agreement is obtained. It is found
that the effective Lagrangian with an appropriate nuclear symmetry energy,
which can well describe the ground state properties of nuclei, could also
reproduce the isovector giant dipole resonance of nuclei along the
-stability line.Comment: 4 pages, 1 Postscript figure, to be submitted to Chin.Phys.Let
Sensing iron availability via the fragile [4Fe-4S] cluster of the bacterial transcriptional repressor RirA
Rhizobial iron regulator A (RirA) is a global regulator of iron homeostasis in many nitrogen-fixing Rhizobia and related species of α-proteobacteria. It belongs to the widespread Rrf2 super-family of transcriptional regulators and features three conserved Cys residues that characterise the binding of an ironâsulfur cluster in other Rrf2 family regulators. Here we report biophysical studies demonstrating that RirA contains a [4Feâ4S] cluster, and that this form of the protein binds RirA-regulated DNA, consistent with its function as a repressor of expression of many genes involved in iron uptake. Under low iron conditions, [4Feâ4S] RirA undergoes a cluster conversion reaction resulting in a [2Feâ2S] form, which exhibits much lower affinity for DNA. Under prolonged low iron conditions, the [2Feâ2S] cluster degrades to apo-RirA, which does not bind DNA and can no longer function as a repressor of the cell's iron-uptake machinery. [4Feâ4S] RirA was also found to be sensitive to O2, suggesting that both iron and O2 are important signals for iron metabolism. Consistent with this, in vivo data showed that expression of RirA-regulated genes is also affected by O2. These data lead us to propose a novel regulatory model for iron homeostasis, in which RirA senses iron via the incorporation of a fragile ironâsulfur cluster that is sensitive to iron and O2 concentrations
UrokinaseĂą deficient and urokinase receptorĂą deficient mice have impaired neutrophil antimicrobial activation in vitro
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141382/1/jlb0648.pd
Antigenic characterization of highly pathogenic avian influenza A(H5N1) viruses with chicken and ferret antisera reveals clade-dependent variation in hemagglutination inhibition profiles.
Highly pathogenic avian influenza (HPAI) A(H5N1) viruses pose a significant economic burden to the poultry industry worldwide and have pandemic potential. Poultry vaccination against HPAI A(H5N1) viruses has been an important component of HPAI control measures and has been performed in Vietnam since 2005. To systematically assess antigenic matching of current vaccines to circulating field variants, we produced a panel of chicken and ferret antisera raised against historical and contemporary Vietnamese reference viruses representing clade variants that were detected between 2001 and 2014. The antisera were used for hemagglutination inhibition (HI) assays to generate data sets for analysis by antigenic cartography, allowing for a direct comparison of results from chicken or ferret antisera. HI antigenic maps, developed with antisera from both hosts, revealed varying patterns of antigenic relationships and clustering of viruses that were dependent on the clade of viruses analyzed. Antigenic relationships between existing poultry vaccines and circulating field viruses were also aligned with in vivo protection profiles determined by previously reported vaccine challenge studies. Our results establish the feasibility and utility of HPAI A(H5N1) antigenic characterization using chicken antisera and support further experimental and modeling studies to investigate quantitative relationships between genetic variation, antigenic drift and correlates of poultry vaccine protection in vivo
Feel it in my bones: Composing multimodal experience through tissue conduction
We outline here the feasibility of coherently utilising tissue conduction for spatial audio and tactile input. Tissue conduction display-specific compositional concerns are discussed; it is hypothesised that the qualia available through this medium substantively differ from those for conventional artificial means of appealing to auditory spatial perception. The implications include that spatial music experienced in this manner constitutes a new kind of experience, and that the ground rules of composition are yet to be established. We refer to results from listening experiences with one hundred listeners in an unstructured attribute elicitation exercise, where prominent themes such as âstrangeâ, âweirdâ, âpositiveâ, âspatialâ and âvibrationsâ emerged. We speculate on future directions aimed at taking maximal advantage of the principle of multimodal perception to broaden the informational bandwidth of the display system. Some implications for composition for hearing-impaired are elucidated.n/
Psychomotor Tremor and Proprioceptive Control Problems in Current and Former Stimulant Drug Users: An Accelerometer Study of Heavy Users of Amphetamine, MDMA, and Other Recreational Stimulants
- âŠ