Automatic Updates of Transition Potential Matrices in Dempster-Shafer Networks Based on Evidence Inputs.

Sensor fusion is a topic central to aerospace engineering and is particularly applicable to unmanned aerial systems (UAS). Evidential Reasoning, also known as Dempster-Shafer theory, is used heavily in sensor fusion for detection classification. High computing requirements typically limit use on small UAS platforms. Valuation networks, the general name given to evidential reasoning networks by Shenoy, provides a means to reduce computing requirements through knowledge structure. However, these networks use conditional probabilities or transition potential matrices to describe the relationships between nodes, which typically require expert information to define and update. This paper proposes and tests a novel method to learn these transition potential matrices based on evidence injected at nodes. Novel refinements to the method are also introduced, demonstrating improvements in capturing the relationships between the node belief distributions. Finally, novel rules are introduced and tested for evidence weighting at nodes during simultaneous evidence injections, correctly balancing the injected evidenced used to learn the transition potential matrices. Together, these methods enable updating a Dempster-Shafer network with significantly less user input, thereby making these networks more useful for scenarios in which sufficient information concerning relationships between nodes is not known a priori.

Design, simulation, and testing of a tunable MEMS multi-threshold inertial switch.

This paper presents a tunable multi-threshold micro-electromechanical inertial switch with adjustable threshold capability. The demonstrated device combines the advantages of accelerometers in providing quantitative acceleration measurements and g-threshold switches in saving power when in the inactive state upon experiencing acceleration below the thresholds. The designed proof-of-concept device with two thresholds consists of a cantilever microbeam and two stationary electrodes placed at different positions in the sensing direction. The adjustable threshold capability and the effect of the shock duration on the threshold acceleration are analytically investigated using a nonlinear beam model. Results are shown for the relationships among the applied bias voltage, the duration of shock impact, and the tunable threshold. The fabricated prototypes are tested using a shock-table system. The analytical results agree with the experimental results. The designed device concept is very promising for the classification of the shock and impact loads in transportation and healthcare applications.

A systematic review of robotic efficacy in coral reef monitoring techniques.

Coral reefs are home to a variety of species, and their preservation is a popular study area; however, monitoring them is a significant challenge, for which the use of robots offers a promising answer. The purpose of this study is to analyze the current techniques and tools employed in coral reef monitoring, with a focus on the role of robotics and its potential in transforming this sector. Using a systematic review methodology examining peer-reviewed literature across engineering and earth sciences from the Scopus database focusing on "robotics" and "coral reef" keywords, the article is divided into three sections: coral reef monitoring, robots in coral reef monitoring, and case studies. The initial findings indicated a variety of monitoring strategies, each with its own advantages and disadvantages. Case studies have also highlighted the global application of robotics in monitoring, emphasizing the challenges and opportunities unique to each context. Robotic interventions driven by artificial intelligence and machine learning have led to a new era in coral reef monitoring. Such developments not only improve monitoring but also support the conservation and restoration of these vulnerable ecosystems. Further research is required, particularly on robotic systems for monitoring coral nurseries and maximizing coral health in both indoor and open-sea settings.

Flight safety during Covid-19: A study of Charles de Gaulle airport atypical energy approaches.

During the COVID-19 period and particularly during lockdown, deviations from nominal operations have shown to become more frequent. To confirm this observation this paper proposes to evaluate the impact of COVID-19, and more generally of crises that lead to a sharp drop in traffic, on the pilot/controller system, especially during the critical approach and landing phases. To study the influence of this type of crisis on flight operations at Charles De Gaulle airport, an existing energy atypicality metric is applied on a reference period before COVID-19 and compared to the COVID-19 period. Whereas the traffic at Charles De Gaulle airport has decreased by around 90% on April 2020, the obtained statistics underlined an increase in the atypical flight ratio of around 50%. This trend can be explained in part by the appearance of glide interceptions from above as a result of trajectory shortenings, and an increase in the proportion of high speed approaches.

The effect of a preoperative subconjuntival injection of dexamethasone on blood-retinal barrier breakdown following scleral buckling retinal detachment surgery: a prospective randomized placebo-controlled double blind clinical trial.

BACKGROUND: Blood-retinal barrier breakdown secondary to retinal detachment and retinal detachment repair is a factor in the pathogenesis of proliferative vitreoretinopathy (PVR). We wished to investigate whether an estimated 700 to 1000 ng/ml subretinal dexamethasone concentration at the time of surgery would decrease the blood-retinal barrier breakdown postoperatively. METHODS: Prospective, placebo-controlled, double blind clinical trial. In 34 patients with rhegmatogenous retinal detachment scheduled for conventional scleral buckling retinal detachment surgery, a subconjunctival injection of 0.5 ml dexamethasone diphosphate (10 mg) or 0.5 ml placebo was given 5-6 hours before surgery. Differences in laser flare photometry (KOWA) measurements taken 1, 3 and 6 weeks after randomisation between dexamethasone and placebo were analysed using mixed model ANOVA, while correcting for the preoperative flare measurement. RESULTS: Six patients did not complete the study, one because of recurrent detachment within 1 week, and five because they missed their postoperative laser flare visits. The use of dexamethasone resulted in a statistically significant decrease in laser flare measurements at the 1-week postoperative visit. CONCLUSION: The use of a preoperative subconjunctival injection of dexamethasone decreased 1-week postoperative blood-retina barrier breakdown in patients undergoing conventional scleral buckling retinal detachment surgery. This steroid priming could be useful as a part of a peri-operative regime that would aim at decreasing the incidence of PVR.

Impact of Covid-19 on passengers and airlines from passenger measurements: Managing customer satisfaction while putting the US Air Transportation System to sleep.

The COVID-19 pandemic has had a significant impact on the air transportation system worldwide. This paper aims at analyzing the effect of the travel restriction measures implemented during the COVID-19 pandemic from a passenger perspective on the US air transportation system. Four metrics based on data generated by passengers and airlines on social media are proposed to measure how the travel restriction measures impacted the relation between passengers and airlines in close to real-time. The proposed metrics indicate that each airline has reacted differently to the COVID-19 travel restriction measures from a passenger perspective, therefore they can be used by airlines and passengers to improve their decision making process. This report comes ahead of official data related to the same sequence of events, thereby showing the value of passenger-borne data in an industry where corporate priorities, institutional prudence, and passenger satisfaction come close together.

Microplasmin intravitreal administration in patients with vitreomacular traction scheduled for vitrectomy: the MIVI I trial.

PURPOSE: To evaluate the safety and preliminary efficacy of 4 doses and several exposure times of intravitreal microplasmin given before pars plana vitrectomy for vitreomacular traction maculopathy. DESIGN: A multicenter, prospective, uncontrolled, dose-escalation, phase I/II clinical trial. PARTICIPANTS: Sixty patients enrolled into 6 successive cohorts. INTERVENTION: A single intravitreal injection of microplasmin at 1 of 4 doses (25, 50, 75, or 125 microg in 100 microl) administered either 1 to 2 hours, 24 hours, or 7 days before planned pars plana vitrectomy. MAIN OUTCOME MEASURES: For safety, a complete ophthalmologic examination, fundus photography, fluorescein angiography, Humphrey visual fields, and electrophysiology; for efficacy, posterior vitreous detachment (PVD) induction as assessed by B-scan ultrasound and ease of PVD induction at the time of vitrectomy. RESULTS: The use of microplasmin led to a progressively higher incidence of PVD induction on ultrasonography with increasing time exposure. A PVD before surgery was observed with 25 microg microplasmin in 0, 2, and 5 patients with increasing exposures (2 hours, 24 hours, 7 days). With increasing dose, a PVD before surgery was observed by ultrasound as follows: 25 microg, 0; 50 microg, 1; 75 microg, 2; 125 microg, 3. However, at surgery, with a 125-microg dose, these patients had a discontinuous layer of vitreous present on the retinal surface resulting from the induction of an anomalous PVD in the form of vitreoschisis. One retinal detachment developed shortly after administration of microplasmin. Two developed after surgery. There were no other safety concerns. CONCLUSIONS: Results from this initial clinical trial evaluating intravitreal microplasmin show the drug to be well tolerated and capable of inducing a pharmacologic PVD in some patients. These results warrant evaluation of microplasmin in larger, controlled trials.

Trypan blue staining of epiretinal membranes in proliferative vitreoretinopathy.

OBJECTIVE: To determine whether trypan blue staining facilitates epiretinal membrane (ERM) removal in proliferative vitreoretinopathy. METHODS: In 10 patients undergoing vitrectomy for proliferative vitreoretinopathy, ERM peeling was performed without staining the tissue, until no additional ERMs were clearly visible. Then, after a fluid-air exchange, 0.06% trypan blue solution was applied onto the retinal surface. After 1 minute, all excess dye was removed and, after an air-fluid exchange, ERM peeling was completed. Excised ERM specimens were analyzed by transmission electron microscopy. MAIN OUTCOME MEASURES: For each patient, the efficacy of trypan blue staining of ERMs during surgery was scored. RESULTS: In all patients, intraoperative staining of ERMs with trypan blue was found to be a useful adjunct, since the dye consistently improved direct visualization and delineation of ERMs and facilitated ERM removal. A clear contrast was created between the stained ERMs and the nonstaining, underlying retina. Electron microscopy showed that only ERM tissue was removed. No adverse reactions related to the use of the dye were observed up to 3 months after surgery. CONCLUSIONS: Trypan blue may be an important new tool in the surgical management of proliferative vitreoretinopathy, since it may allow a more complete and safer ERM removal.

Trypan blue not toxic for retinal pigment epithelium in vitro.

PURPOSE: To investigate whether trypan blue has a toxic effect on cultured retinal pigment epithelial (retinal pigment epithelium) cells. DESIGN: Experimental study with a direct live/dead cell staining technique using fluorescent dyes. METHODS: Cultured human retinal pigment epithelium cells were exposed for 5 minutes to various concentrations of trypan blue (0.06%, 0.15%, 0.30%), and cell viability was confocally measured. RESULTS: No increased cell death was found in cultures incubated in any of the trypan blue concentrations used. CONCLUSION: These findings indicate that a short exposure of trypan blue does not have a toxic effect on cultured retinal pigment epithelium cells.

Toxic effect of indocyanine green on retinal pigment epithelium related to osmotic effects of the solvent.

PURPOSE: To investigate whether the toxic effect on cultured retinal pigment epithelial (RPE) cells after application of indocyanine green is related to the osmolarity of the solvent or to toxic effects of the dye and evaluate whether these changes also occur using infracyanine green. DESIGN: Experimental study with a direct live/dead cell staining technique using fluorescent dyes. METHODS: Cultured human RPE cells were exposed to various solutions and cell viability was confocally measured. RESULTS: Increased cell death was found in cultures incubated in the hypoosmotic solvent that is generally used for indocyanine green (P <.001, n = 12). Addition of indocyanine green did not alter this observation (P <.001, n = 12). In cultures exposed to a 5% glucose solution, no increased cell death was found (P =.94, n = 12), nor when infracyanine green was added (P =.13, n = 12). CONCLUSION: The observed toxicity of indocyanine green on RPE cells is probably related to the hypo-osmolarity of the solvent and may be avoided by using infracyanine green dissolved in glucose 5%.

Intravitreal dexamethasone as adjuvant in the treatment of postoperative endophthalmitis: a prospective randomized trial.

PURPOSE: To study whether intravitreal dexamethasone as adjuvant to intravitreal antibiotics improves the outcome in patients with suspected postoperative bacterial endophthalmitis. DESIGN: Prospective randomized clinical trial. SETTING: Tertiary referral center. PATIENT POPULATION: Twenty-nine consecutive patients with suspected postoperative bacterial endophthalmitis within 6 weeks of cataract surgery. INTERVENTION: Patients underwent a vitreous biopsy followed by intravitreal injection of antibiotics (0.2 mg vancomycin and 0.05 mg gentamicin) and 400 microg dexamethasone or placebo. After 3-4 days the intravitreal injection of antibiotics and dexamethasone or placebo was repeated. PRIMARY OUTCOME MEASURE: Snellen visual acuity at 3 and 12 months after treatment. RESULTS: In 20/29 patients (69%) the vitreous cultures were positive. 13/29 patients received dexamethasone. Seven patients had a functionally lost eye (final vision of hand movements or less), in four due to retinal detachment. Visual acuity tended to be better in the dexamethasone treated patients than in those given placebo, at both 3 months (P=0.055) and 12 months (P=0.080). CONCLUSION: This small prospective, placebo-controlled series showed a trend towards a better visual outcome in patients with suspected bacterial endophthalmitis when treatment with intravitreal antibiotics was combined with intravitreal dexamethasone. Our findings justify a larger multicenter randomized study.

Postoperative laser coagulation as retinopexy in patients with rhegmatogenous retinal detachment treated with scleral buckling surgery: a prospective clinical study.

PURPOSE: To evaluate postoperative laser photocoagulation as retinopexy mode in patients with rhegmatogenous retinal detachment treated with scleral buckling surgery. METHODS: The authors conducted a prospective feasibility study of consecutive patients with rhegmatogenous retinal detachment treated with scleral buckling surgery and postoperative laser during an 18-month period with a minimal follow-up of 6 months. Outcome measures were total retinal reattachment and the occurrence of proliferative vitreoretinopathy (PVR). RESULTS: A total of 123 patients (124 eyes) were included in this study. Seventy-six percent were phakic and 24% were pseudophakic. Fifty percent presented with one horseshoe tear, 15% with multiple tears, 30% with round breaks, and 5% with no identifiable break. Ten percent presented with a vitreous hemorrhage and 25% with three or four quadrants of detached retina. Six patients had PVR C1. Twelve patients required a postoperative gas injection, five patients received an additional buckle, and five patients underwent a vitrectomy, in four because of PVR. In all patients the retina was fully reattached at the end of follow-up. Planned postoperative laser coagulation took place 1 day to 10 weeks (median 3(1/2) weeks) after buckling surgery. Buckling material was removed in three patients without redetachment. CONCLUSION: Postoperative laser coagulation is a feasible alternative retinopexy mode in scleral buckling surgery, with encouraging anatomical results and a low incidence of PVR.

Trypan blue staining in vitreoretinal surgery.

PURPOSE: To evaluate the efficacy of trypan blue for staining the internal limiting membrane (ILM) and epiretinal membranes (ERM) in vitreoretinal surgery. DESIGN: Prospective noncomparative case series. PARTICIPANTS: Fifty eyes of 50 patients with macular pucker (n = 22), macular hole (n = 18), or a combination (n = 2), proliferative vitreoretinopathy (n = 5), or diabetic retinopathy (n = 3). METHODS: Trypan blue 0.2% was used to stain the ILM or ERM during vitreoretinal surgery. MAIN OUTCOME MEASURES: The intraoperative visibility of the membranes was scored as poor, moderate, good, or excellent. RESULTS: The application of trypan blue onto the ILM or the ERM resulted in a useful bluish staining, facilitating the identification, delineation, and removal of the membranes in all surgeries. No residual staining or adverse effects related to the dye were observed. CONCLUSIONS: Trypan blue stains both ILM and ERM and might be an useful tool in vitreoretinal surgery.