The Use of Triboemission Imaging and Charge Measurements to Study DLC Coating Failure

We present a study on the simultaneous evolution of the electron emission and surface charge accumulation that occurs during scratching tests in order to monitor coating failure. Steel discs coated with a diamond-like-carbon (DLC) film were scratched in both vacuum (~10−5 Torr) and atmospheric conditions, with electron emission and surface charge being measured by a system of microchannel plates and an electrometer, respectively. The results highlight a positive correlation between emission intensity values, surface charge measurements and surface damage topography, suggesting the effective use of these techniques to monitor coating wear in real time

Harvest-induced disruptive selection increases variance in fitness-related traits

The form of Darwinian selection has important ecological and management implications. Negative effects of harvesting are often ascribed to size truncation (i.e. strictly directional selection against large individuals) and resultant decrease in trait variability, which depresses capacity to buffer environmental change, hinders evolutionary rebound and ultimately impairs population recovery. However, the exact form of harvest-induced selection is generally unknown and the effects of harvest on trait variability remain unexplored. Here we use unique data from the Windermere (UK) long-term ecological experiment to show in a top predator (pike, Esox lucius) that the fishery does not induce size truncation but disruptive (diversifying) selection, and does not decrease but rather increases variability in pike somatic growth rate and size at age. This result is supported by complementary modelling approaches removing the effects of catch selectivity, selection prior to the catch and environmental variation. Therefore, fishing most likely increased genetic variability for somatic growth in pike and presumably favoured an observed rapid evolutionary rebound after fishery relaxation. Inference about the mechanisms through which harvesting negatively affects population numbers and recovery should systematically be based on a measure of the exact form of selection. From a management perspective, disruptive harvesting necessitates combining a preservation of large individuals with moderate exploitation rates, and thus provides a comprehensive tool for sustainable exploitation of natural resources

Simultaneous measurement of Young's modulus and Poisson's ratio at microscale with two-modes scanning microdeformation microscopy

International audienceIn this paper, we present a technique to simultaneously measure Young's modulus E and Poisson's ratio ν of an isotropic material at local scale in a single experiment. Using several flexural modes of vibration of the scanning microdeformation microscope, it is possible to decouple the contributions of E and ν from the first two resonant frequencies, thereby providing access to both the elastic parameters. The proposed approach is applied to SU8 thin films deposited on silicon substrates and provides values consistent with those from the literature

Retinal safety of intravitreal rtPA in healthy rats and under excitotoxic conditions.

Intravitreal recombinant tissue plasminogen activator (rtPA) is used off-label for the surgical management of submacular hemorrhage, a severe complication of neovascular age-related macular degeneration. rtPA is approved for coronary and cerebral thrombolysis. However, in ischemic stroke rtPA is known to increase excitotoxic neural cell death by interacting with the N-methyl-D-aspartate (NMDA) receptor. We therefore investigated the retinal toxicity of rtPA in healthy rats and in a model of NMDA-induced retinal excitotoxicity. First, rtPA at three different doses (2.16 µg/5 µl, 0.54 µg/5 µl, and 0.27 µg/5 µl) or vehicle (NaCl 0.9%) was injected intravitreally in healthy rat eyes. Electroretinograms (ERGs) were performed at 24 h or 7 days. Annexin V-fluorescein isothiocyanate (FITC)-labeled apoptotic retinal ganglion cells (RGCs) were counted on flatmounted retinas at 24 h or 7 days. Next, NMDA + vehicle or NMDA + rtPA (0.27 µg/5 µl) was injected intravitreally to generate excitotoxic conditions. Apoptotic annexin V-FITC-labeled RGCs and surviving Brn3a-labeled RGCs were quantified on flatmounted retinas and radial sections, 18 h after treatment. In healthy rat eyes, the number of apoptotic RGCs was statistically significantly increased 24 h after the administration of rtPA at the highest dose (2.16 µg/5 µl; p = 0.0250) but not at the lower doses of 0.54 and 0.27 µg/5 µl (p = 0.36 and p = 0.20), compared to vehicle. At day 7, there was no difference in the apoptotic RGC count between the rtPA- and vehicle-injected eyes (p = 0.70, p = 0.52, p = 0.11). ERG amplitudes and implicit times were not modified at 24 h or 7 days after injection of any tested rtPA doses, compared to the baseline. Intravitreal administration of NMDA induced RGC death, but under these excitotoxic conditions, coadministration of rtPA did not increase the number of dead RGCs (p = 0.70). Similarly, the number of surviving RGCs on the flatmounted retinas and retinal sections did not differ between the eyes injected with NMDA + vehicle and NMDA + rtPA (p = 0.59 and p = 0.67). At low clinical equivalent doses corresponding to 25 µg/0.1 ml in humans, intravitreal rtPA is not toxic for healthy rat retinas and does not enhance NMDA-induced excitotoxicity. Vitreal equivalent doses ≥200 µg/0.1 ml should be avoided in patients, due to potential RGC toxicity

Adolescents and adults with Fontan circulation:insights from the PREpArE-Fontan registry

The Patient Registry for Adolescents and Adults with Stable Fontan Circulation aims to describe a contemporary cohort of Fontan patients who could be eligible for a clinical trial investigating macitentan, an endothelin receptor antagonist. This international, non-interventional, multicentre, cross-sectional, observational registry enrolled patients with “stable” Fontan circulation ≥10 years following extra-cardiac conduit or lateral tunnel procedure. Main exclusion criteria were NYHA functional class IV, reoperation of Fontan circulation, or signs of disease worsening. Patient characteristics at enrolment are described; available data were collected during a single registration visit. Of the 266 screened patients, 254 were included in this analysis. At enrolment, median (interquartile range) age was 24 (20;30) years, 37%/63% of patients were from the USA/Europe, 54% were male, 54%/47% had undergone extra-cardiac conduit/lateral tunnel procedures, and 95% were in NYHA functional class I or II. History of arrhythmia was more common in older patients and patients with lateral tunnel; overall prevalence was 19%. Most laboratory values were within the normal range but mean creatinine clearance was abnormally low (87.7 ml/min). Angiotensin-converting enzyme inhibitors were used by 48% of patients and their use was associated with creatinine clearance <90 ml/min (p = 0.007), as was Fontan completion at an older age (p = 0.007). 53.4% of patients had clinical characteristics that could potentially meet an endothelin receptor antagonist trial’s eligibility criteria. The PREpArE-Fontan registry describes a cohort of patients who could potentially participate in an endothelin receptor antagonist trial and identified early subtle signs of Fontan failure, even in “stable” patients

Probe-based schemes to guarantee lightpath quality of transmission (QoT) in transparent optical networks

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Enhancing GMPLS signaling protocol for encompassing quality of transmission (QoT) in all-optical networks

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An integrated view on monitoring and compensation for dynamic optical networks: from management to physical layer

A vertical perspective, ranging from management and routing to physical layer options, concerning dynamic network monitoring and compensation of impairments (M&C), is given. Feasibility, reliability, and performance improvements on reconfigurable transparent networks are expected to arise from the consolidated assessment of network management and control specifications, as a more accurate evaluation of available M&C techniques. In the network layer, physical parameters aware algorithms are foreseen to pursue reliable network performance. In the physical layer, some new M&C methods were developed and rating of the state-of-the-art reported in literature is given. Optical monitoring implementation and viability is discussed.Publicad