The Impact of Cognitive Fatigue on Airline Pilots Performance

Purpose: Air transport is a highly regulated branch of aviation, but it continues to show occurrences where human error is present. Fatigue is now recognized as a hazard which degrades human performance and can put flight safety at risk. In this regard, the general objective of this study is to assess the impact of cognitive fatigue on airline pilots and how it can contribute to the occurrence of accidents and incidents. Design/methodology: Three airline pilots participated in the case study. The participants’ cognitive fatigue was monitored according to four methods, being two of them of a subjective nature – the sleep diary (SD) and the Samn-Perelli 7-Point Fatigue Scale (SPS), and the other two of an objective nature – the Psychomotor Vigilance Task (PVT) and the actigraphy (actiwatch ReadibandTM 5). During their flight duty periods (FDPs), the pilots’ performance was also assessed according to the score delivered by a fatigue management software (FAID®). Findings: The obtained results allowed to understand whether the pilots are aware of their alertness and to identify factors which affect their performance levels. Between the beginning and the end of each FDP, significant changes were observed concerning the assessment on the SPS scale, the reaction time (RT) and the fatigue score generated by the biomathematical models associated to the technique of the actigraphy and the software FAID®. Originality/value: The risk of accident or serious error was classified according to the four methodologies used. Thus, it is possible to verify if there is a correspondence between the different scales or if there are scales more conservative (with a higher associated risk) than others.Peer Reviewe

Audiovisual integration increases the intentional step synchronization of side-by-side walkers

When people walk side-by-side, they often synchronize their steps. To achieve this, individuals might cross-modally match audiovisual signals from the movements of the partner and kinesthetic, cutaneous, visual and auditory signals from their own movements. Because signals from different sensory systems are processed with noise and asynchronously, the challenge of the CNS is to derive the best estimate based on this conflicting information. This is currently thought to be done by a mechanism operating as a Maximum Likelihood Estimator (MLE). The present work investigated whether audiovisual signals from the partner are integrated according to MLE in order to synchronize steps during walking. Three experiments were conducted in which the sensory cues from a walking partner were virtually simulated. In Experiment 1 seven participants were instructed to synchronize with human-sized Point Light Walkers and/or footstep sounds. Results revealed highest synchronization performance with auditory and audiovisual cues. This was quantified by the time to achieve synchronization and by synchronization variability. However, this auditory dominance effect might have been due to artifacts of the setup. Therefore, in Experiment 2 human-sized virtual mannequins were implemented. Also, audiovisual stimuli were rendered in real-time and thus were synchronous and co-localized. All four participants synchronized best with audiovisual cues. For three of the four participants results point toward their optimal integration consistent with the MLE model. Experiment 3 yielded performance decrements for all three participants when the cues were incongruent. Overall, these findings suggest that individuals might optimally integrate audiovisual cues to synchronize steps during side-by-side walking.info:eu-repo/semantics/publishedVersio

Fabrication of a MEMS micromirror based on bulk silicon micromachining combined with grayscale lithography

A 1D MEMS (Micro-Electro-Mechanical Systems) mirror for LiDAR applications, based on vertically asymmetric comb-drive electrostatic actuators, is presented in this work employing a novel fabrication process. This novel micromachining process combines typical SOI-based bulk micromachining and grayscale lithography, enabling the fabrication of combs actuators with asymmetric heights using a single lithography step in the active layer. With this technique, the fabrication process is simplified, and the overall costs are reduced since the number of required lithography steps decrease. The fabricated mirrors present self-aligned electrodes with a 2.8 mu m gap and asymmetric heights of the movable and the fixed electrodes of 20 mu m and 50 mu m, respectively. These asymmetric actuators are an essential feature for the operation mode of this device, enabling both in resonant and static mode operation. A mirror field of view (FOV) of 54 degrees at 838 Hz was achieved under low-pressure, when resonantly operated, and a FOV of 0.8 degrees in the static mode.This work was supported by the European Structural and Investment Funds in the FEDER Component through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) under Project 037902 (POCI-01-0247-FEDER-037902). The work of Carlos Ferreira was supported by the Fundacao para a Ciencia e Tecnologia (FCT) under Grant PD/BDE/135102/2017. Subject Editor M. Rais-Zadeh

Re-use assessment of thermoset composite wastes as aggregate and filler replacement for concrete-polymer composite materials: a case study regarding GFRP pultrusion wastes

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites

Postpartum changes in plasma viral load and CD4 percentage among HIV-infected women from Latin American and Caribbean countries: the NISDI Perinatal Study

The goal of this study was to evaluate changes in plasma human immunodeficiency virus (HIV) RNA concentration [viral load (VL)] and CD4+ percentage (CD4%) during 6-12 weeks postpartum (PP) among HIV-infected women and to assess differences according to the reason for receipt of antiretrovirals (ARVs) during pregnancy [prophylaxis (PR) vs. treatment (TR)]. Data from a prospective cohort of HIV-infected pregnant women (National Institute of Child Health and Human Development International Site Development Initiative Perinatal Study) were analyzed. Women experiencing their first pregnancy who received ARVs for PR (started during pregnancy, stopped PP) or for TR (initiated prior to pregnancy and/or continued PP) were included and were followed PP. Increases in plasma VL (> 0.5 log10) and decreases in CD4% (> 20% relative decrease in CD4%) between hospital discharge (HD) and PP were assessed. Of the 1,229 women enrolled, 1,119 met the inclusion criteria (PR: 601; TR: 518). At enrollment, 87% were asymptomatic. The median CD4% values were: HD [34% (PR); 25% (TR)] and PP [29% (PR); 24% (TR)]. The VL increases were 60% (PR) and 19% (TR) (p < 0.0001). The CD4% decreases were 36% (PR) and 18% (TR) (p < 0.0001). Women receiving PR were more likely to exhibit an increase in VL [adjusted odds ratio (AOR) 7.7 (95% CI: 5.5-10.9) and a CD4% decrease (AOR 2.3; 95% CI: 1.6-3.2). Women receiving PR are more likely to have VL increases and CD4% decreases compared to those receiving TR. The clinical implications of these VL and CD4% changes remain to be explored.Universidade Federal de Minas Gerais Faculdade de MedicinaWestatUniversidad Nacional Mayor de San MarcosHospital FeminaHospital ConceiçãoUniversidade Federal de São Paulo (UNIFESP)Hospital dos Servidores do EstadoNational Institute of Health Human Development Department of Health and Human ServicesUNIFESPSciEL

FASN expression, angiogenesis and lymphangiogenesis in central and peripheral giant cell lesions

Central giant cell lesion (CGCL) and peripheral giant cell lesion (PGCL) are non-neoplastic proliferative processes of the jaws. PGCL is a reactive process induced by irritant local factors and CGCL is an intra-osseous lesion of unknown etiology. Both lesions exhibit similar histologic features showing abundant mononuclear cells, admixed with a large number of multinucleated giant cells and a rich vascularized stroma with extravasated erythrocytes, hemosiderin deposition, and blood-filled pools. Recent studies have linked fatty acid synthase (FASN) with angiogenesis. Objective: To evaluate angiogenesis and lymphangiogenesis and their relationship with FASN expression in CGCL and PGCL. Material and Methods: Thirteen CGCL and 14 PGCL of the jaws were selected for immunoexpression of FASN; CD34 and CD105 (to assess blood microvessel density [MVD] and microvessel area [MVA]); and D2-40 (to assess lymphatic MVD and MVA). Results: Within PGCL and CGCL, MVD-CD34 was signifcantly higher than MVD-CD10S, followed by MVD-D2-40. Moreover, a signifcantly higher number of FASN-positive multinucleated giant cells than mononuclear cells were observed. Between PGCL and CGCL, only MVD-CD34 and all MVA were signifcantly higher in PGCL. Positive correlation between MVA-CD10S with FASNpositive mononuclear cells in both lesions was observed. Conclusions: Our results show both lesions exhibiting similar levels of FASN expression and neoangiogenesis, suggesting constitutive processes that regulate tissue maintenance

Asymmetric data acquisition system for an endoscopic PET-US detector

According to current prognosis studies of pancreatic cancer, survival rate nowadays is still as low as 6% mainly due to late detections. Taking into account the location of the disease within the body and making use of the level of miniaturization in radiation detectors that can be achieved at the present time, EndoTOFPET-US collaboration aims at the development of a multimodal imaging technique for endoscopic pancreas exams that combines the benefits of high resolution metabolic information from time-of- flight (TOF) positron emission tomography (PET) with anatomical information from ultrasound (US). A system with such capabilities calls for an application-specific high-performance data acquisition system (DAQ) able to control and readout data from different detectors. The system is composed of two novel detectors: a PET head extension for a commercial US endoscope placed internally close to the region-of-interest (ROI) and a PET plate placed over the patient's abdomen in coincidence with the PET head. These two detectors will send asymmetric data streams that need to be handled by the DAQ system. The approach chosen to cope with these needs goes through the implementation of a DAQ capable of performing multi-level triggering and which is distributed across two different on-detector electronics and the off-detector electronics placed inside the reconstruction workstation. This manuscript provides an overview on the design of this innovative DAQ system and, based on results obtained by means of final prototypes of the two detectors and DAQ, we conclude that a distributed multi-level triggering DAQ system is suitable for endoscopic PET detectors and it shows potential for its application in different scenarios with asymmetric sources of data