Satellite selection in the context of an operational GBAS

When incorporating multiple constellations into future ground based augmentation systems (GBAS), a problem with limited VDB (VHF data broadcast) capacity might arise. Furthermore, the number of airborne receiver tracking channels could be insufficient to use all visible satellites. One way to cope with these issues is to perform a satellite selection to limit the number of used satellites with minor impact on performance. This paper investigates different factors that constrain the approach of simply selecting "the best set in every epoch" and shows how to overcome some limitations. These constraints include limitations in satellite visibility, loss of satellites during approach (i.e. in curves), and convergence times in the airborne processing until satellites are usable. Various protection level simulations are performed to show the influence of the named factors on the nominal performance. Taking into account all these contextual influences, results show satellite selection is still applicable in GBAS ground stations

A Secure Broadcast Service for LDACS with Application to Secure GBAS

The VHF Data Broadcast (VDB) data link, responsible for transmitting Ground Based Augmentation System (GBAS) corrections from the GBAS ground station to the aircraft, is one major bottleneck for the evolution and security of GBAS. It provides limited bandwidth, range, only line-of-sight capabilities and no cyber-security protections for the transmitted data. Hence the use of an alternative data link for GBAS, overcoming these constraints, is desirable. The L-band Digital Aeronautical Communications System (LDACS) has been demonstrated to overcome aforementioned issues. The first demonstration of secure GBAS over LDACS used the Timed Efficient Stream loss-Tolerant Authentication (TESLA) for broadcast authentication of GBAS data. In flight trials, the concept and support of TESLA secured GBAS via LDACS for GAST-D services, supporting category II/III precision approach capabilities, was demonstrated. In this work, different ways are investigated to further optimize latency and security data overhead for an optimized transmission of TESLA secure GBAS packets via LDACS. Initial evaluation show how promising the different options are. Further it is shown how the developed concept for secure GBAS can also be applied to generalized secure broadcast over LDACS

Network‐based ionospheric gradient monitoring to support GBAS

Large ionospheric gradients acting between a Ground Based Augmentation System (GBAS) reference station and an aircraft on approach could lead to hazardous position errors if undetected. Current GBAS stations provide solutions against this threat that rely on the use of “worst‐case” conservative threat models, which could limit the availability of the system. This paper presents a methodology capable of detecting ionospheric gradients in real time and estimating the actual threat model parameters based on a network of dual‐frequency and multi‐constellation GNSS monitoring stations. First, we evaluate the performance of our algorithm with synthetic gradients that are simulated over the nominal measurements recorded by a reference network in Alaska. Afterwards, we also assess it with one real ionospheric gradient measured by the same network. Results with both simulated gradients and a real gradient show the potential to support GBAS by detecting and estimating these gradients instead of always using “worst‐case” models

Percepção da enfermagem sobre a qualidade do Acolhimento com Classificação de Risco do serviço de emergência

Aim: to evaluate the quality of triage in an emergency service according to the perception of the nursing professionals. Method: a cross-sectional study carried out at the emergency service triage of the São Paulo Hospital, between March and July 2016. A hundred and thirty-three professionals who worked in the sector for at least three months participated in the study. A questionnaire was used with variables for sociodemographic characterization and, also, an instrument for triage quality evaluation. Results: mean age 36.2 years, the majority of females (77.4%) and graduated for more than 5 years (59.1%). The triage obtained the following scores: structure (23.0), process (22.0) and result (20.9). Conclusion: the triage quality was evaluated as precarious in the perception of the nursing professionals.Objetivo: evaluar la calidad de la Acogida con Evaluación y Clasificación de Riesgo de un servicio de emergencia a partir de la percepción de los profesionales de la enfermería. Método: estudio transversal, realizado en la Acogida con Evaluación y Clasificación de Riesgo, del servicio de emergencia del Hospital São Paulo, entre marzo y julio de 2016. Participaron 133 profesionales que actuaban en ese sector por pelo menos tres meses. Utilización de cuestionario con variables para caracterización sociodemográfica e instrumento para Evaluación de Acogida con Clasificación de Riesgo. Resultados: edad media 36,2 años, mayoría del sexo femenino (77,4%) y con grado académico por más de 5 años (59,1%). La Acogida con Evaluación y Clasificación de Riesgo obtuvo puntuaciones: estructura (23,0), proceso (22,0) y resultado (20,9). Conclusión: la Acogida con Evaluación y Clasificación de Riesgo fue evaluada como precaria en la percepción de los profesionales de enfermería.Objetivo: avaliar a qualidade do Acolhimento com Avaliação e Classificação de Risco de um serviço de emergência segundo percepção dos profissionais de enfermagem. Método: estudo transversal realizado no Acolhimento com Avaliação e Classificação de Risco do serviço de emergência do Hospital São Paulo, entre março e julho de 2016. Participaram 133 profissionais que atuavam no setor no mínimo há três meses. Foi utilizado questionário com variáveis para caracterização sociodemográfica e instrumento para Avaliação do Acolhimento com Classificação de Risco. Resultados: idade média 36,2 anos, maioria do sexo feminino (77,4%) e formado há mais de 5 anos (59,1%). O Acolhimento com Avaliação e Classificação de Risco obteve as seguintes pontuações: estrutura (23,0), processo (22,0) e resultado (20,9). Conclusão: o Acolhimento com Avaliação e Classificação de Risco foi avaliado como precário na percepção dos profissionais de enfermagem

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes

Future GBAS Processing - Do we need an ionosphere-free mode?

The Ground Based Augmentation System (GBAS) is a landing system for aircraft. It consists of carefully sited reference receivers at an airport, generating corrections for the navigation signals from Global Navigation Satellite Systems (GNSS). Along with the corrections, integrity parameters are generated and transmitted to arriving aircraft that allow the aviation users to bound their residual position errors after applying the corrections. Currently, corrections are generated for the GPS constellation and the L1 frequency. However, with the ongoing buildup of the European Galileo, the Chinese BeiDou and the modernized Russian Glonass the number of available GNSS constellations is increasing. This provides the opportunity to design systems more robust against disturbances, such as ionospheric scintillation effects, through a larger number of available ranging sources. Furthermore, all Galileo and the latest generation of GPS satellites feature signals in the L5 band that can be used by aviation. Therefore, it is possible to apply dual frequency techniques for mitigation of the ionospheric gradient threat. This paper discusses the advantages and disadvantages of using an ionosphere free combination of the signals for positioning and if such a mode for a future generation of GBAS should be developed