Dynamic network modelling and simulation for air traffic flow analysis

This dissertation describes the achievement of a set of equations in order to represent a discrete model for air traffic dynamics in terminal areas. Such a mathematical model could be used to investigate the occupation of a TMA‡ at a single instant and has the potential to be used on the prediction of a future occupation. There are safety and legal limits to how many aircraft should be inside a TMA at once. It could also be useful for an Air Traffic Controller to predict a future overoccupation and thus being able to prevent it. That is why there is an interest to know at each instant an estimate of how many aircraft are in a specific TMA. The idea behind it was to make a Control Theory approach so that the same classical tools used in other topics such as flight dynamics could be applied to this subject. In order for that to happen there were needed some Network notions along with navigation formulae. If an aircraft leaves one place we know a priori that he will follow a path and later enter a certain TMA, unless something goes wrong. That information is known even before lift off. It limits our monitoring window and we can now focus on the physical existence of an aircraft in or out a determined TMA. Every aircraft within a radius of several nautical miles, depending on each TMA, does belong to that TMA. A transition between areas is considered a control input. Knowing the initial amount of aircraft on the zero instant at a particular site we can calculate the following instant state by adding the arrivals and subtracting the departures. This system has mass conservation in a sense that aircraft don’t just disappear - instead they move around and the total number of aircraft on the system remains the same. Depending on the complexity of the system other separated states can be monitored and we could separate the grounded aircraft from the airborne aircraft; allow mid-flight decision change to go to a different TMA, etc. Data retrieved from the website www.localizatodo.com together with Octave Software allowed the validation of the model. On this website the captured transponder signals are transformed into several bits of information from which were retrieved the ones useful: Longitude, Latitude and time stamp. The equations performed as they should, making them applicable to a real scenario, since the utilized data are in fact coming themselves from a real scenario and they are not invented. The first two models are slightly different from the third. One concerns the TMA as if they were contiguous and another considers the paths among each other. They are steps towards an objective, rather than a final solution. The inclusion of a sigmoid function to the model was the latest work to be done. It has to do with the prediction and how much would an incoming airship weight on the eyes of the Air Traffic Controller. There is a need to remove abrupt changes inherent to the model in a way that an aircraft would gradually become present on the arriving TMA from the moment he lifted off the departing TMA, instead of just showing up on the arriving TMA and thus giving no anticipation opportunity to the air traffic controllers. In a future work an estimator, such as a Kalman Filter, should be added to this model or even an improved similar model, since it has the flexibility to incorporate new features in a simple way. There is an explanation on how to perform these additions. This work could be used as a foundation for the implementation of a warning to the Air Traffic Controllers of the occupation status. Not only that but it could be a module on a fully automatic Airspace Controller or even other applications yet to be considered. It could even be applied on the traffic of buses (coaches) and it can be extrapolated to many other fields.Esta dissertação descreve o processo pelo qual se encontraram um conjunto de equações representativas de um modelo discreto de dinâmica de tráfego aéreo em zonas terminais. Tal modelo matemático poderá ser utilizado para investigar a ocupação de uma TMA† num instante singular, tendo o potencial de ser utilizado para prever a ocupação futura. Existem limites de segurança e legais acerca de quantas aeronaves deverão estar dentro de uma TMA de uma só vez. Poderia também ser usável por um Controlador de Tráfego Aéreo em prever uma futura sobre-ocupação e portanto ser capaz de a prevenir. É por isso que existe um interesse em saber a cada instante uma estimativa de quantas aeronaves estão numa TMA específica. A idéia por detrás deste assunto foi a de fazer uma abordagem de Teoria de Controlo de forma a que as ferramentas clássicas utilizadas noutros tópicos, tais como dinâmica de voo, pudessem ser aplicadas a este problema. Para que isso fosse possível eram necessárias noções de Network a par de fórmulas de navegação. Se uma aeronave deixa um determinado sítio sabemos a priori que vai seguir um caminho e mais tarde vai entrar numa TMA específica, a menos que algo corra mal. Essa informação é sabida antes sequer de haver descolagem. Isto permite-nos limitar a nossa janela de monitorização e podemos agora focar-nos na existência física de uma aeronave dentro ou fora de uma determinada TMA. Qualquer aeronave num raio de várias milhas náuticas, dependendo de cada TMA, pertence a essa TMA. Uma transição entre áreas é considerado um input de controlo. Sabendo a quantidade inicial de aeronaves no instante inicial num determinado sítio, podemos calcular o instante seguinte adicionando as chegadas e eliminando as partidas. Este sistema tem conservação de massa no sentido em que as aeronaves não desaparecem. Ao invés elas movem-se de um lado para o outro e o número total de aeronaves num sistema continua o mesmo. Dependendo da complexidade do sistema, outros estados separados poderão ser monitorizados e podemos separar as aeronaves no chão das do ar; permitir alteração de decisão a meio de um voo para dirigir-se a uma TMA diferente, etc. Dados obtidos do sítio web www.localizatodo.com em conjunto com o Software Octave, permitiram a validação do modelo. Neste sítio web os sinais de transponder capturados são depois transformados em vários bits de informação dos quais se retiram os úteis: Longitude, Latitude e carimbo de tempo. As equações comportaram-se como deviam, fazendo este modelo aplicável a um cenário real, já que os dados utilizados de facto provêm eles mesmos de de um cenário real e não de um inventado. Os primeiros dois modelos são ligeiramente diferentes do terceiro. Um deles é relativo às TMA como se elas fossem contíguas umas das outras e segundo já considera os caminhos entre elas. São passos no caminho de um objectivo, em vez de serem uma solução final. A inclusão de uma função sigmóide ao modelo foi o último trabalho a ser efectuado. Tem que ver com a previsão e de quanto pesaria uma aeronave a chegar aos olhos do Controlador de Tráfego Aéreo. Existe uma necessidade de remover mudanças abruptas inerentes ao modelo, de forma que uma aeronave fosse ficando presente gradualmente na TMA de chegada a partir do momento que tenha descolado da TMA de partida, ao invés de somente aparecer na TMA de chegada e assim sendo não dar oportunidade de antecipação aos Controladores de Tráfego Aéreo. Num trabalho futuro um estimador, tal como um Filtro de Kalman, deveria ser adicionado a este modelo ou até a um modelo similar melhorado, já que este tem a flexibilidade de incorporar novas características de uma forma expedita. Existe uma explicação em como fazer essa adições. Este trabalho poderia ser utilizado como fundação para a implementação de um sistema de alerta aos Controladores de Tráfego Aéreo do estado de ocupação. Não só isso como também poderia ser um módulo num Controlador Automático de Espaço Aéreo e mesmo noutras aplicações ainda por considerar. Poderia até ser aplicado no tráfego de autocarros ou poderia ser extrapolado para muitos outros campos

Constitutive deficiency of the neurogenic hippocampal modulator AP2γ promotes anxiety-like behavior and cumulative memory deficits in mice from juvenile to adult periods

The transcription factor activating protein two gamma (AP2γ) is an important regulator of neurogenesis both during embryonic development as well as in the postnatal brain, but its role for neurophysiology and behavior at distinct postnatal periods is still unclear. In this work, we explored the neurogenic, behavioral, and functional impact of a constitutive and heterozygous AP2γ deletion in mice from early postnatal development until adulthood. AP2γ deficiency promotes downregulation of hippocampal glutamatergic neurogenesis, altering the ontogeny of emotional and memory behaviors associated with hippocampus formation. The impairments induced by AP2γ constitutive deletion since early development leads to an anxious-like phenotype and memory impairments as early as the juvenile phase. These behavioral impairments either persist from the juvenile phase to adulthood or emerge in adult mice with deficits in behavioral flexibility and object location recognition. Collectively, we observed a progressive and cumulative impact of constitutive AP2γ deficiency on the hippocampal glutamatergic neurogenic process, as well as alterations on limbic-cortical connectivity, together with functional behavioral impairments. The results herein presented demonstrate the modulatory role exerted by the AP2γ transcription factor and the relevance of hippocampal neurogenesis in the development of emotional states and memory processes.H2020 -“la Caixa” Foundation(101003187

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

A prática pedagógica e as tensões enfrentadas por licenciandos em Ciências Biológicas no âmbito da regência do estágio supervisionado

The supervised internship should enable the contact of undergraduate students with real opportunities to develop their potential, combining theory and practice, developing knowledge and analyzing reality. This study aimed to describe, analyze and compare the educational practice of two undergraduate students during the internship in Biology and the educational practice of a high school teacher. Conceptions of these undergraduates about their own educational practice were investigated. The results reveal the numerous problems to be faced by teachers in initial training process, besides the challenge of developing a transition space for innovative activities in biology teaching.Las prácticas supervisadas deben permitir el contacto del estudiante de licenciatura con oportunidades reales para desarrollar su potencialidad, vincular la teoría y práctica, elaborar conocimientos y analizar la realidad. Este estudio tiene como objetivo describir, analizar y comparar la práctica educativa de dos estudiantes de Ciencias Biológicas durante la regencia en las prácticas de Biología y la práctica educativa de una profesora de la Educación Secundaria. Las concepciones de estos estudiantes acerca de la práctica educativa fueron investigadas. Los resultados muestran los numerosos problemas que van a enfrentarse los docentes en el proceso de formación inicial, además del reto de desarrollar un espacio de transición para las actividades innovadoras en la enseñanza de Biología.O estágio supervisionado deve possibilitar o contato do licenciando com oportunidades reais no desenvolvimento de suas potencialidades, articulando teoria e prática, elaborando conhecimentos e analisando a realidade. Este estudo objetivou descrever, analisar e comparar a prática educativa de dois licenciandos durante a regência no estágio em Biologia e a prática educativa de uma professora do Ensino Médio. Foram averiguadas as concepções destes licenciandos sobre a própria prática educativa. Os resultados revelam os inúmeros problemas a serem enfrentados pelos docentes em processo de formação inicial, além do desafio de desenvolver um espaço de transição para atividades inovadoras no ensino de Biologia

Differential Modulation of the Phospholipidome of Proinflammatory Human Macrophages by the Flavonoids Quercetin, Naringin and Naringenin

The immunomodulatory activity of flavonoids is increasingly appreciated. Macrophage phospholipids (PLs) play crucial roles in cell-mediated inflammatory responses. However, little is known on how these PLs are affected upon flavonoid treatment. In this work, we have used mass-spectrometry-based lipidomics to characterize the changes in the phospholipidome of proinflammatory human-macrophage-like cells (THP-1-derived and LPS+IFN-γ-stimulated) incubated with non-cytotoxic concentrations of three flavonoids: quercetin, naringin and naringenin. One hundred forty-seven PL species belonging to various classes were identified, and their relative abundances were determined. Each flavonoid displayed its own unique signature of induced effects. Quercetin produced the strongest impact, acting both on constitutive PLs (phosphatidylcholines, phosphatidylethanolamines and sphingomyelins) and on minor signaling lipids, such as phosphatidylinositol (PI) and phosphatidylserine (PS) species. Conversely, naringin hardly affected structural PLs, producing changes in signaling molecules that were opposite to those seen in quercetin-treated macrophages. In turn, albeit sharing some effects with quercetin, naringenin did not change PI and PS levels and interfered with a set of phosphatidylcholines distinct from those modulated by quercetin. These results demonstrate that flavonoids bioactivity involves profound and specific remodeling of macrophage phospholipidome, paving the way to future studies on the role of cellular phospholipids in flavonoid-mediated immunomodulatory effects