SAN models of communication scenarios inside the Electrical Power System

This report provides all the details about the models and the quantitative results presented in [1], about the simulation of communication scenarios inside the Electrical Power System. In particular, the scenarios deal with the communication between one area control centre and a set of substations in a distribution grid, exchanging commands and signals by means of a redundant communication network. The communication may be affected by threats such as the communication network failure, or intrusions into the communication, causing the loss of commands or signals. The scenarios have been modeled and simulated in form of Stochastic Activity Networks, with the purpose of evaluating the effects of such threats on the communication reliability

Overlapping-gate architecture for silicon Hall bar MOSFET devices in the low electron density regime

We report the fabrication and study of Hall bar MOSFET devices in which an overlapping-gate architecture allows four-terminal measurements of low-density 2D electron systems, while maintaining a high density at the ohmic contacts. Comparison with devices made using a standard single gate show that measurements can be performed at much lower densities and higher channel resistances, despite a reduced peak mobility. We also observe a voltage threshold shift which we attribute to negative oxide charge, injected during electron-beam lithography processing.Comment: 4 pages, 4 figures, submitted for Applied Physics Letter

Toll-like receptor 3 activation is required for normal skin barrier repair following UV damage.

UV damage to the skin leads to the release of noncoding RNA (ncRNA) from necrotic keratinocytes that activates Toll-like receptor 3 (TLR3). This release of ncRNA triggers inflammation in the skin following UV damage. Recently, TLR3 activation was also shown to aid wound repair and increase the expression of genes associated with permeability barrier repair. Here, we sought to test whether skin barrier repair after UVB damage is dependent on the activation of TLR3. We observed that multiple ncRNAs induced expression of skin barrier repair genes, that the TLR3 ligand Poly (I:C) also induced expression and function of tight junctions, and that the ncRNA U1 acts in a TLR3-dependent manner to induce expression of skin barrier repair genes. These observations were shown to have functional relevance as Tlr3-/- mice displayed a delay in skin barrier repair following UVB damage. Combined, these data further validate the conclusion that recognition of endogenous RNA by TLR3 is an important step in the program of skin barrier repair

Characterisation of Brachycephalic Obstructive Airway Syndrome in French Bulldogs Using Whole-Body Barometric Plethysmography.

Brachycephalic obstructive airway syndrome (BOAS) is an important health and welfare problem in several popular dog breeds. Whole-body barometric plethysmography (WBBP) is a non-invasive method that allows safe and repeated quantitative measurements of respiratory cycles on unsedated dogs. Here respiratory flow traces in French bulldogs from the pet population were characterised using WBBP, and a computational application was developed to recognise affected animals. Eighty-nine French bulldogs and twenty non-brachycephalic controls underwent WBBP testing. A respiratory functional grading system was used on each dog based on respiratory signs (i.e. respiratory noise, effort, etc.) before and after exercise. For development of an objective BOAS classifier, functional Grades 0 and I were considered to have insignificant clinical signs (termed here BOAS-) and Grades II and III to have significant signs (termed here BOAS+). A comparison between owner-perception of BOAS and functional grading revealed that 60 % of owners failed to recognise BOAS in dogs that graded BOAS+ in this study.WBBP flow traces were found to be significantly different between non-brachycephalic controls and Grade 0 French bulldogs; BOAS- and BOAS+ French bulldogs. A classifier was developed using quadratic discriminant analysis of the respiratory parameters to distinguish BOAS- and BOAS + French bulldogs, and a BOAS Index was calculated for each dog. A cut-off value of the BOAS Index was selected based on a receiver operating characteristic (ROC) curve. Sensitivity, specificity, positive predictive value, and negative predictive value of the classifier on the training group (n=69) were 0.97, 0.93, 0.95, and 0.97, respectively. The classifier was validated using a test group of French bulldogs (n=20) with an accuracy of 0.95. WBBP offers objective screening for the diagnosis of BOAS in French Bulldogs. The technique may be applied to other brachycephalic breeds affected by BOAS, and possibly to other respiratory disease in dogs.Funding was provided by (1) The Kennel Club Charitable Trust (KCCT), Grant no.: RG 71960, http://www.thekennelclub.org.uk/our-reso​urces/kennel-club-charitable-trust/, to DRS JFL; and (2) Cambridge Overseas Trust (Taiwan Cambridge Scholarship), https://www.cambridgetrust.org/about/cam​bridge-overseas-trust/, to NCL.This is the final published version. It first appeared at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0130741

Genetically identified suppressed-by-contrast retinal ganglion cells reliably signal self-generated visual stimuli

Spike trains of retinal ganglion cells (RGCs) are the sole source of visual information to the brain; and understanding how the ∼20 RGC types in mammalian retinae respond to diverse visual features and events is fundamental to understanding vision. Suppressed-by-contrast (SbC) RGCs stand apart from all other RGC types in that they reduce rather than increase firing rates in response to light increments (ON) and decrements (OFF). Here, we genetically identify and morphologically characterize SbC-RGCs in mice, and target them for patch-clamp recordings under two-photon guidance. We find that strong ON inhibition (glycine > GABA) outweighs weak ON excitation, and that inhibition (glycine > GABA) coincides with decreases in excitation at light OFF. These input patterns explain the suppressive spike responses of SbC-RGCs, which are observed in dim and bright light conditions. Inhibition to SbC-RGC is driven by rectified receptive field subunits, leading us to hypothesize that SbC-RGCs could signal pattern-independent changes in the retinal image. Indeed, we find that shifts of random textures matching saccade-like eye movements in mice elicit robust inhibitory inputs and suppress spiking of SbC-RGCs over a wide range of texture contrasts and spatial frequencies. Similarly, stimuli based on kinematic analyses of mouse blinking consistently suppress SbC-RGC spiking. Receiver operating characteristics show that SbC-RGCs are reliable indicators of self-generated visual stimuli that may contribute to central processing of blinks and saccades. SIGNIFICANCE STATEMENT This study genetically identifies and morphologically characterizes suppressed-by-contrast retinal ganglion cells (SbC-RGCs) in mice. Targeted patch-clamp recordings from SbC-RGCs under two-photon guidance elucidate the synaptic mechanisms mediating spike suppression to contrast steps, and reveal that SbC-RGCs respond reliably to stimuli mimicking saccade-like eye movements and blinks. The similarity of responses to saccade-like eye movements and blinks suggests that SbC-RGCs may provide a unified signal for self-generated visual stimuli

Effect of hirtisation on the roughness and fatigue performance of porous titanium lattice structures

Additive manufacturing (AM) has enabled the fabrication of extremely complex components such as porous metallic lattices, which have applications in aerospace, automotive, and in particular biomedical devices. The fatigue resistance of these materials is currently an important limitation however, due to manufacturing defects such as semi-fused particles and weld lines. Here Hirtisation$^\circledR$ is used for post-processing of Ti-6Al-4V lattices, reducing the strut surface roughness (Sa) from 12 to 6 $\mu$m, removing all visible semi-fused particles. The evenness of this treatment in lattices with $\rho /\rho_{s}$ up to 18.3% and treatment depth of 6.5 mm was assessed, finding no evidence of reduced effectiveness on internal surfaces. After normalising to quasi-static mechanical properties to account for material losses during hirtisation (34-37% reduction in strut diameter), the fatigue properties show a marked improvement due to the reduction in surface roughness. Normalised high cycle fatigue strength ($\sigma_{f,10^{6}}/\sigma_{y}$) increased from around 0.1 to 0.16-0.21 after hirtisation, an average increase of 80%. For orthopaedic implant devices where matching the stiffness of surrounding bone is crucial, the $\sigma_{f}/E$ ratio is a key metric. After hirtisation the $\sigma_{f}/E$ ratio increased by 90%, enabling design of stiffness matched implant materials with greater fatigue strength. This work demonstrates that hirtisation is an effective method for improving the surface roughness of porous lattice materials, thereby enhancing their fatigue performance.Comment: 10 figure