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

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

Ten active electrode linear array for wireless surface

Submitted by Erika Demachki ([email protected]) on 2015-01-16T17:10:19Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Gustavo Souto de Sá e Souza - 2013.pdf: 6684567 bytes, checksum: fefcf131a81d9d993c2ef7f8bf77fa9e (MD5)Approved for entry into archive by Erika Demachki ([email protected]) on 2015-01-16T17:36:13Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Gustavo Souto de Sá e Souza - 2013.pdf: 6684567 bytes, checksum: fefcf131a81d9d993c2ef7f8bf77fa9e (MD5)Made available in DSpace on 2015-01-16T17:36:13Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Gustavo Souto de Sá e Souza - 2013.pdf: 6684567 bytes, checksum: fefcf131a81d9d993c2ef7f8bf77fa9e (MD5) Previous issue date: 2013-12-18This project, in the area of biomedical engineering, belongs to the promising field of research in surface electromyography (s-EMG). This technology can be used for in-depth study of some neuromuscular diseases, such as polyneuropathies and myopathies. Using an array of multichannel electrodes, we can also obtain the decomposition of s-EMG signals, estimation of conduction velocity of muscle fibers, location of innervation zones (set of motor units), among other applications. Although there are wireless electromyographers, there are no wireless electrode arrays in the market. Thinking about this, it was developed a wireless linear array of ten active electrodes for surface electromyography and a set of programs able to receive and process the data captured by this device. The hardware’s features are: low cost compared to similar equipment on the market, 12 bits resolution, 9216 samples per second (1024 samples per second per channel, with 9 channels and 10 electrodes in bipolar configuration), common mode rejection ratio greater than 50 dB; possess an interface for easy interaction with any computers via Bluetooth; enabling research in diverse areas (biomechanics, signal acquisition in athletes, animals, among other possibilities). In addition, it is powered by two lithium-ion batteries and autonomy of approximately 3 hours and 18 minutes. Although there were challenges in various stages of the device construction process, for example, in obtaining a high processing capacity and a high data transmission rate, the tests with prototypes show excellent results, consistent with the literature. After the implementation of the hardware, operational tests were performed as well as practical applications the use of a multi-channel electromyographer.Esse projeto, da área da engenharia biomédica, pertence ao campo promissor de pesquisas em eletromiografia de superfície (EMG-s). Essa tecnologia pode ser usada para o estudo aprofundado de algumas doenças neuromusculares, como por exemplo, polineuropatias, miastenias e miopatias. Utilizando um arranjo de eletrodos multicanal, também podemos obter a decomposição de sinais de EMG-S, estimativa de velocidade de condução das fibras musculares, localização de zonas de inervação (conjunto de pontos motores), entre outras aplicações. Apesar de existirem eletromiógrafos sem fio, não há arranjos de eletrodos sem fio no mercado. Pensando nisso, foi desenvolvido um arranjo linear de dez eletrodos sem fio para eletromiografia de superfície e um conjunto de programas capazes de receber e processar os dados capturados por esse dispositivo. As características alcançadas por esse eletromiógrafo portátil são um baixo custo mesmo quando comparado aos eletromiógrafos de apenas um canal do mercado, 12 bits de resolução, 9216 amostras por segundo (1024 amostras por segundo por canal, com 9 canais e 10 eletrodos utilizando a configuração bipolar), taxa de rejeição de modo comum maior que 50 dB, uma interface que permite interação com computadores via Bluetooth, permitindo pesquisa em diversas áreas (biomecânica, aquisição de sinais em atletas, animais, entre outras possibilidades). Além disso, é alimentado por duas baterias de íon-lítio e possui uma autonomia média de 3 horas e 18 minutos. Apesar de terem surgidos desafios em várias etapas do processo de construção do dispositivo, como por exemplo, a obtenção de uma alta capacidade de processamento e de uma alta taxa de transmissão de dados, os testes com protótipos construídos mostram um resultado excelente e condizente com a literatura. Após a implementação deste hardware, foram realizados testes de funcionamento, assim como aplicações práticas da utilização de um eletromiógrafo de múltiplos canais

Development of instrumentation and methods used to acquire, process and interpret surface eletromiographic signs

Monografia (graduação)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2006.A tese proposta apresenta a realização de estudos relacionados com a eletromiografia de superfície em basicamente duas frentes de estudo. Uma parte do projeto consiste na elaboração e desenvolvimento de uma metodologia para a aquisição, o processamento e a interpretação de sinais eletromiográficos em ambientes subaquáticos. Na outra frente de trabalho tivemos o projeto, implementação e posterior validação de um eletromiógrafo composto por 7 canais de aquisição capaz de captar sinais elétricos dos músculos com precisão bastante satisfatória. A parte experimental do projeto consiste na estimativa de amplitude e de freqüência mediana no eletromiograma de superfície do bíceps braquial e no tríceps braquial em contração isométrica em ambiente aéreo e subaquático. Foi criado todo um protocolo para a coleta desses dados, levando em consideração os padrões recomendados pelo projeto SENIAM; referência européia no estabelecimento de pesquisa envolvendo eletromiografia de superfície. De posse desses dados, desenvolveu-se um software em ambiente MatLab para se realizar todo o processamento dos mesmos. Foi realizado posteriormente um tratamento estatístico dos resultados alcançados com o objetivo de concluir o projeto desenvolvido, comprovando semelhanças e diferenças entre sinais de EMG-S no ambiente aéreo e subaquático. A segunda parte do projeto foi focada no projeto e construção de um eletromiógrafo de superfície capaz de captar 7 canais de EMG simultaneamente. Este hardware consiste de uma sonda seca composta de 8 eletrodos ativos de prata e de um condicionador de sinais que, ligado diretamente à primeira, realiza todo o tratamento do sinal obtido. Este tratamento consiste na filtragem, amplificação e adequação do sinal, minimizando ruídos e isolando o paciente da rede elétrica. Após a implementação deste hardware, foi realizada toda uma extensa gama de testes de funcionamento, assim como aplicações práticas da utilização de um eletromiógrafo de múltiplos canais.The proposed thesis presents a research related to surface electromyography basically in two ways. First, the project is about the elaboration and development of methods to acquire, processing and interpretation of electromyographic signs on sub aquatic environments. And second, we had the project, implementation and later, the validation of a electromyograph composed by 7 acquisition channels, capable of catching electric signs from muscles with quite good results. The project’s experimental part consists in amplitude and median frequency estimatives on surface electromyogram from brach biceps and triceps, in isometric contraction in air and sub aquatic environments. A protocol was created for data gathering, considering all the recommended SENIAM project standards - European reference when dealing with surface electromyography researches. With those data, a software was developed in MatLab environment, so all the signal processing could be done. Later, the data was analyzed in a statistical way, so we could prove the similarities and differences in signals, concluding the experiment on EMG-S in air and sub aquatic environments. On this project’s second part we focused on projecting and building a surface electromyograph able to catch 7 channels of EMG signs at once. This hardware consists on a dry array composed of 8 active electrodes in pure silver, and a signal conditioner connected to the array, that is responsible for further treating of the signals. This treatment consists on filtering and amplification of the signal, minimizing the noise and isolating the patient from the electricity distribution. After this hardware implementation, we made a lot of tests to prove that it works as it should, as well as practical applications of a multiple channel electromyograph

Gait stability, variability and complexity on inclined surfaces

This study evaluated the gait stability, variability, and complexity of healthy young adults on inclined surfaces. A total of 49 individuals walked on a treadmill at their preferred speed for 4min at inclinations of 6%, 8%, and 10% in upward (UP) and downward (DOWN) conditions, and in horizontal (0%) condition. Gait variability was assessed using average standard deviation trunk acceleration between strides (VAR), gait stability was assessed using margin of stability (MoS) and maximum Lyapunov exponent (λs), and gait complexity was assessed using sample entropy (SEn). Trunk variability (VAR) increased in the medial-lateral (ML), anterior-posterior, and vertical directions for all inclined conditions. The SEn values indicated that movement complexity decreased almost linearly from DOWN to UP conditions, reflecting changes in gait pattern with longer and slower steps as inclination increased. The DOWN conditions were associated with the highest variability and lowest stability in the MoS ML, but not in λs. Stability was lower in UP conditions, which exhibited the largest λs values. The overall results support the hypothesis that inclined surfaces decrease gait stability and alter gait variability, particularly in UP conditions

Effects of backpack loads and positions on the variability of gait spatiotemporal parameters in young adults

<div><p>Abstract Introduction: People carry backpacks of different weight in different positions every day. The effects of backpack wearing under different loads and positions were assessed according to the gait’s spatiotemporal parameters and their variability in young adults. Methods Twenty-one subjects performed trials of 4 min in the conditions: control condition with no backpack; bilateral back load consisting of 10% body weight (BW); bilateral back load of 20% BW (B20); unilateral load of 10% BW; unilateral load with 20% BW (U20); bilateral frontal load with 10% BW; bilateral frontal load with 20% BW. Results Step length (SL) and step frequency (SF) show that frontal conditions differed from others as seen in B20. Gait cycle phases showed an increase in the B20 condition for double stance phase and stance phase, swing phase presented reduction in the B20 condition. There were significant main effects in position for SL, SF, and walk ratio, in load only for stride width. The highest variability of spatiotemporal parameters occurred in the U20 condition. All load conditions with 20% BW showed a greater variability when compared to the 10% BW counterpart. Conclusion We concluded that young adults can cope with up to a 15% BW load under a bilateral back position, but in the frontal position not even a 10% BW load was proven to be a safe limit. 20% BW loads should be avoided in any position. These recommendations may assure increased gait stability, decreased trunk forward lean and decreased muscle activation and fatigue reducing back pain occurrence.</p></div