Longitudinal flight control with a variable span morphing wing

The present study focuses on the design of a longitudinal flight controller for an unmanned aircraft equipped with dissymmetric variable-span system (VSMW or Variable-Span Morphing Wing). Its primary role consists in the longitudinal flight stabilization of the aeroplane while in levelled cruise flight, although, it was designed to offer longitudinal flight stabilization for other flight phases as well, such as e.g. take-off and landing. The stabilization algorithm relies on the most up-to-date developments in the state-of-the-art LQR and Batz-Kleinman controller techniques to stabilize the aircraft on its intended longitudinal attitude upon any small atmospheric disturbances inflicted. It was designed for the experimental UAV prototype Olharapo equipped with the VSMW, so it can automatically adjust the VSMW overall wingspan in accordance with the flight speed and stabilize the aircraft in the desired attitude, although, its modular concept allows it to be used for different configurations of the aircraft or even for a different aircraft. The development, simulation and testing of the algorithm were done using the MATLAB® software and the aircraft’s stability and control derivatives previously obtained using the XFLR5® software. Minor adaptations of the flight dynamics equations were performed to allow the compatibilization with the VSMW. The required implementation of imposed flight qualities was also performed to ensure proper scaling the controller weight matrix for optimal values. Finally, the algorithm was tested using three different methods: Classic Disturbances Simulation, Sinusoidal Pitch Variation Test Response and Random Pitch Variation Test Response.O presente trabalho consiste na projeção, programação e teste de um controlador de voo longitudinal destinado a uma aeronave não-tripulada equipada com um sistema de variação dissimétrica da envergadura das asas (conhecido como VSMW, asa dissimétrica ou asa telescópica). Este trabalho tem como principal objetivo desenvolver um controlador capaz de assegurar a estabilidade longitudinal da aeronave em voo nivelado a velocidade de cruzeiro, contudo, este foi também projetado para providenciar essa mesma estabilidade noutras fases de voo tais como a aterragem ou a descolagem. O algoritmo de estabilização baseia-se nas mais sofisticadas técnicas de controlo de voo atualmente disponíveis, mais concretamente LQR e Batz-Kleinman, para estabilizar a aeronave na atitude pretendida aquando da ocorrência de quaisquer pequenas perturbações atmosféricas que afetem a aeronave durante o voo. A aeronave a que se destina trata-se de um protótipo designado de Olharapo equipado com uma asa telescópica que permite ajustar a envergadura total das asas de acordo com a velocidade de voo. No entanto, o conceito modular da estrutura do programa permite que o controlador possa ser utilizado para diferentes configurações da mesma aeronave, ou até mesmo com uma aeronave totalmente diferente. Tanto o desenvolvimento como as simulações e testes do algoritmo foram efetuados com recurso ao software MATLAB® , tendo as necessárias derivadas de estabilidade e controlo iniciais sido providenciadas pelo software XFLR5® . As equações de voo foram devidamente adaptadas para permitirem uma compatibilização com o sistema da asa telescópica e a sua integração nos métodos de controlo LQR e Batz-Kleinman. As qualidades de voo da aeronave foram devidamente definidas e impostas ao controlador para garantir a afinação da matriz de ponderação para valores ótimos. Por fim, o algoritmo foi sujeito a três tipos de testes e simulações: Simulação Clássica por meio de Imposição de Perturbações Atmosféricas, Teste de Resposta a uma Variação Sinusoidal do Ângulo de Arfagem, e Teste de Reposta a uma Variação Aleatória do Ângulo de Arfagem

Optimal Robust Nonlinear LQG/LTR Control with Application to Longitudinal Flight Control

As part of the development of a new 4D Autopilot System for Unmanned Aerial Aircrafts (UAVs), i.e. a time-dependent robust trajectory generation and control algorithm, this work addresses the problem of optimal path finding based on the aircraft’s own sensors data output, that may be unreliable due to noise on data acquisition and/or transmission under certain circumstances. Although several filtering methods, such as the Kalman-Bucy Filter or the LQG/LTR, are available, the utter complexity of the new control system, together with the robustness and reliability required of such a system on an UAV for airworthiness certifiable autonomous flight, required the development of a proper robust filter for a nonlinear system, as a way of further mitigate errors propagation to the control system and improve its performance. As such, a new nonlinear LQG/LTR algorithm, validated through computational simulation testing, is proposed on this paper. This research work was conducted in the Laboratory of Avionics and Control of the Department of Aerospace Sciences (DCA) at the Faculty of Engineering of the University of Beira Interior and supported by the Aeronautics and Astronautics Research Group (AeroG) of the Associated Laboratory for Energy, Transports and Aeronautics (LAETA).info:eu-repo/semantics/publishedVersio

LESÃO MEDULAR POR MERGULHO EM ÁGUAS RASAS

The aim of this study was to evaluate the main motor and functional changes before and after physical therapy of a patient with spinal cord injury caused by diving in shallow water. We analyzed previous records of a patient with spinal cord injury by diving in shallow water, who had rehabilitation at the Rehabilitation Clinical of Oeste Paulista, between 2008 and 2011, attending two one-hour-sessions a week. The patient improved muscle strength as consequence of the rehabilitation program. The treatment also helped the patient improve functionality observing the development while being transferred, in other words, during position changes, between 2008 and 2011. It is understood that patients with spinal cord injury show muscle strength and functional pattern improvement when undergoing physical therapy

Influenza seroprotection correlates with predominant circulating viruses during 2014/15 and 2015/16 seasons in Portugal

Rede Portuguesa de Laboratórios para o Diagnóstico da GripeBACKGROUND: Population immune profile for influenza is highly affected by circulating influenza viruses, thus changing the risk of infection for influenza. This study aims to assess influenza immunity in the Portuguese population by age groups, during 2014 and 2015 and establish a relationship between seroprotection and circulating influenza viruses in 2014/15 and 2015/16 seasons. METHODS: Two cross-sectional studies were developed based on a convenience serum sample collected in June 2014 (n=626) and July 2015 (n=675) in hospitals from mainland and Azores and Madeira.Serums equally represent all age groups. Antibody titers were evaluated by HI assay for strains recommended for seasonal influenza vaccine northern hemisphere,2014/15 and 2015/2016. Seroprevalences were estimated for each strain by age group and the association with seasonal cumulative influenza-like illness (ILI) rates for influenza virus during both seasons was analised. RESULTS: In June 2014 the highest seroprotection was observed for influenza A(H3) (39.0%; 95% CI: 36.2-43.8%) and A(H1)pdm09 (29.7; 95% CI: 26.3-33.4%), with higher levels in children 5-14 years old. In 2014/2015 a dominant circulation of influenza B/Yamagata was observed with high incidence rates in individuals under 65 years old, the ones that had lower seroprotection. Although before the start of the season high protection for A(H3) was observed, the circulation of the new drift A(H3) strains had gained an immunological advantage,in accordance with A(H3) elevated incidence rates observed during 2014/15. In July 2015 the highest seroprotection was observed for influenza B/ Yamagata (55.1%; 95% CI: 51.4-58.9%), 2.4 times the estimated 2014.This increase was even more pronounced in younger (≤ 4 years old), 6.3 times increase in 2015.This fact is in agreement with the predominant influenza B virus detected and the high ILI incidence rate observed in children during 2014/2015 epidemic. Seroprotection levels for influenza A in July 2015 were not significantly different from 2014.During 2015/16 season, influenza A(H1N1)pdm09 was predominant, with high incidence rate in < 65 year old. Influenza B/Victoria lineage,although detected at low levels increased in frequency, in agreement with the lowest level of seroprotection detected in the general population before the start of 2015/2016 season (21.8%; 95% CI: 18.7-24.0%). CONCLUSIONS There was a correlation between virus circulation, incidence rates for each age group and the previous seroprotection for seasonal influenza viruses.Our study highlights the value of measuring the serological profile for influenza to establishe risk groups for infection for which an increase preventive measures, including vaccination, should be fostered.info:eu-repo/semantics/publishedVersio

Cross-protection to new drifted influenza A(H3) viruses and prevalence of protective antibodies to seasonal influenza, during 2014 in Portugal

Em colaboração com a Rede Portuguesa de Laboratóros para o Diagnóstico da GripeIntroduction: Immune profile for influenza viruses is highly changeable over time. Serological studies can assess the prevalence of influenza, estimate the risk of infection, highlight asymptomatic infection rate and can also provide data on vaccine coverage. The aims of the study were to evaluate pre-existing cross-protection against influenza A(H3) drift viruses and to assess influenza immunity in the Portuguese population. Materials and methods: We developed a cross-sectional study based on a convenience sample of 626 sera collected during June 2014, covering all age groups, both gender and all administrative health regions of Portugal. Sera antibody titers for seasonal and new A(H3) drift influenza virus were evaluated by hemagglutination inhibition assay (HI). Seroprevalence to each seasonal influenza vaccine strain virus and to the new A(H3) drift circulating strain was estimated by age group, gender and region and compared with seasonal influenza-like illness (ILI) incidence rates before and after the study period. Results: Our findings suggest that seroprevalences of influenza A(H3) (39.9%; 95% CI: 36.2–43.8) and A(H1)pdm09 (29.7%; 95% CI: 26.3–33.4) antibodies were higher than for influenza B, in line with high ILI incidence rates for A(H3) followed by A(H1)pdm09, during 2013/2014 season. Low pre-existing crossprotection against new A(H3) drift viruses were observed in A(H3) seropositive individuals (46%). Both against influenza A(H1)pdm09 and A(H3) seroprotection was highest in younger than 14-years old. Protective antibodies against influenza B were highest in those older than 65 years old, especially for B/Yamagata lineage, 33.3% (95% CI: 25.7–41.9). Women showed a high seroprevalence to influenza, although without statistical significance, when compared to men. A significant decreasing trend in seroprotection from north to south regions of Portugal mainland was observed. Conclusions: Our results emphasize that low seroprotection increases the risk of influenza infection in the following winter season. Seroepidemiological studies can inform policy makers on the need for vaccination and additional preventive measures.This work was supported by the National Institute of Health Doutor Ricardo Jorge, IP Lisbon, Portugal.info:eu-repo/semantics/acceptedVersio

Neotropical freshwater fisheries : A dataset of occurrence and abundance of freshwater fishes in the Neotropics

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p&lt;0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p&lt;0·0001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status